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(SPONSORED CONTENT)Gleason Home Trainer Webinars: The Perfect Antidote to COVID-19
Gleasonâ€™s Home Trainer Webinar is a cost-free customer service to support gear manufacturers during COVID-19 times. The Webinars, moderated by gear technology experts and covering the widest spectrum of the most topical gear-related subjects, have been a welcome alternative to face-to-face training and a great opportunity for customers to maintain their edge during these challenging restrictions. Article Courtesy of Gleason
Solar Atmospheres provides low pressure vacuum carburizing (LPVC) that significantly increases the surface hardness/strength of steel parts for improved friction and wear. Performing LPVC in a vacuum furnace eliminates oxygen and prevents IGO (intergranular oxidation) that is inherent in atmospheric carburizing, resulting in clean parts with less distortion reducing post process finishing operations, and costs. Article Courtesy of Solar Atmospheres
With the surge in Electric Vehicles, gear noise reduction is of paramount importance. Gleason is at the forefront of gear noise analysis, offering a variety of industry-leading metrology tools with its GMSÂ® Analytical Gear Inspection Systems to help minimize noise by optimizing gear design and manufacturing. Download the Gleason Noise Analysis Whitepaper to learn more. Article Courtesy of Gleason Corporation
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Traditionally, profile and lead inspections have been indispensable portions of a standard inspection of an involute gear. This also holds true for the worm of a worm gear drive (Ref. 1). But the inspection of the profile and the lead is rarely performed on a worm wheel. One of the main reasons is our inability to make good definitions of these two elements (profile and lead) for the worm wheel. Several researchers have proposed methods for profile and lead inspections of a worm wheel using CNC machines or regular involute and lead inspections of a worm wheel using CNC machines or regular involute measuring machines. Hu and Pennell measured a worm wheel's profile in an "involute" section and the lead on the "pitch" cylinder (Ref. 2). This method is applicable to a convolute helicoid worm drive with a crossing angle of 90 degrees because the wheel profile in one of the offset axial planes is rectilinear. This straight profile generates an involute on the generated worm wheel. Unfortunately, because of the hob oversize, the crossing angle between the hob and the worm wheel always deviates from 90 degrees by the swivel angle. Thus, this method can be implemented only approximately by ignoring the swivel angle. Another shortcoming of this method is that there is only one profile and one lead on each flank. If the scanned points deviated from this curve, it produced unreal profile deviation. Octrue discussed profile inspection using a profile checking machine (Ref. 3).
Part I of this paper, which appeared in the January/February issue of Gear Technology, described the theory behind double-flank composite inspection. It detailed the apparatus used, the various measurements that can be achieved using it, the calculations involved and their interpretation. The concluding Part II presents a discussion of the practical application of double-flank composite inspection -- especially for large-volume operations. It also addresses statistical techniques that can be used in conjunction with double-flank composite inspection, as well as an in-depth analysis of gage R&R for this technique.
This paper examines the expanding capabilities of induction hardening of gears through methods like spin hardening or tooth-by-tooth techniques.
Question: When evaluating charts from a gear inspection machine, it is sometimes found that the full length of the profile traces vary, and that sometimes they are less than the length of active profile (above start of active profile-SAP) by up to 20%. This condition could be caused by a concentricity error between tooth grinding and shaping, or by unequal stock removal when grinding. (See Fig. 1.) Is it possible that some of the variation is coming from the inspection machine? How can variation from the inspection machine be reduced?
Forest City Gear applies advanced gear shaping and inspection technologies to help solve difficult lead crown correction challenges half a world away. But these solutions can also benefit customers much closer to home, the company says. Here's howâ€¦
Having outlasted the worldwide Great Recession, the Global Wind Energy Council (GWEC) forecasts a constant growth in wind energy, i.e.: "increase in worldwide capacity to 460,000 MW by 2015."
What are the ins-and-outs of quality inspection of girth gears, from both a manufacturer and buyer perspective? Our experts respond.
How well you conduct your inspections can be the difference-maker for securing high-value contracts from your customers. And as with most other segments of the gear industry, inspection continues striving to attain â€śexact scienceâ€ť status. With that thought in mind, following is a look at the state of gear inspection and what rigorous inspection practices deliver—quality.
Gleason's GMS analytical gear inspection systems provide all the right features at Eaton Corp.
Part I of this paper describes the theory behind double-flank composite inspection, detailing the apparatus used, the various measurements that can be achieved using it, the calculations involved and their interpretation. Part II, which will appear in the next issue, includes a discussion of the practical application of double-flank composite inspection, especially for large-volume operations. Part II covers statistical techniques that can be used in conjunction with double-flank composite inspection, as well as an in-depth analysis of gage R&R for this technique.
The load carrying behavior of gears is strongly influenced by local stress concentrations in the tooth root and by Hertzian pressure peaks in the tooth flanks produced by geometric deviations associated with manufacturing, assembly and deformation processes. The dynamic effects within the mesh are essentially determined by the engagement shock, the parametric excitation and also by the deviant tooth geometry.
From time to time, the editors of "Shop Floor" receive correspondence from readers relating to particular articles they have written for past issues. As one of the purposes of this column is to provide a forum for the exchange of ideas, we reproduce here two of these letters and their replies. The subject of the first is the functional measurement of gears. (See Gear Technology, Sept/Oct, 1991, p. 17) Robert E. Smith writes the reply.
Compact, custom and portable solutions are gaining more attention in manufacturing today as companies seek out the tools that offer the greatest productivity gains on the shop floor. Gear inspection seems to be following suit.
A much-used method for checking the tooth thickness of an involute gear tooth is to measure the dimension over two balls placed in most nearly opposite spaces in the case of external gears, and the dimension between the balls in the case of internal gears. This measurement is then checked against a pre-calculated dimension to denote an acceptable part.
It used to be that gear manufacturers wanting to perform analytical gear inspection required at least three machines to do so: The lead measuring instrument, the tooth space comparator and the involute checking instrument. In the beginning, these machines were mechanically driven. Over the years, the manufacturers of analytical gear inspection equipment have combined these functions - and a host of others.
As in nearly all industries, more costeffective solutions are currently called for in the gear manufacturing industry.
The cutting process consists of either a roll only (only generating motion), a plunge only or a combination of plunging and rolling. The material removal and flank forming due to a pure generating motion is demonstrated in the simplified sketch in Figure 1 in four steps. In the start roll position (step 1), the cutter profile has not yet contacted the work. A rotation of the work around its axis (indicated by the rotation arrow) is coupled with a rotation of the cutter around the axis of the generating gear (indicated by the vertical arrow) and initiates a generating motion between the not-yet-existing tooth slot of the work and the cutter head (which symbolizes one tooth of the generating gear).
Until recently, form gear grinding was conducted almost exclusively with dressable, conventional abrasive grinding wheels. In recent years, preformed, plated Cubic Boron Nitride (CBN) wheels have been introduced to this operation and a considerable amount of literature has been published that claim that conventional grinding wheels will be completely replaced in the future. The superior machining properties of the CBN wheel are not disputed in this paper.
Schafer Gear Works greatly reduces gear inspection queue time and adds precious capacity by installing Gleason's new "shop-hardened" 300GMS P gear inspection system.
This paper addresses Austempered Ductile Iron (ADI) as an emerging Itechnology and defines its challenge by describing the state-of-the-art of incumbent materials. The writing is more philosophical in nature than technical and is presented to establish a perspective.
Induction hardening is widely used in both the automotive and aerospace gear industries to minimize heat treat distortion and obtain favorable compressive residual stresses for improved fatigue performance. The heating process during induction hardening has a significant effect on the quality of the heat-treated parts. However, the quenching process often receives less attention even though it is equally important.
The purpose of gear inspection is to: Assure required accuracy and quality, Lower overall cost of manufacture by controlling rejects and scrap, Control machines and machining practices and maintain produced accuracy as machines and tools wear, Determine hear treat distortions to make necessary corrections.
In the past gear manufacturers have had to rely on hob manufacturers' inspection of individual elements of a hob, such as lead, involute, spacing, and runout. These did not always guarantee correct gears, as contained elements may cause a hob to produce gears beyond tolerance limits.
Revolutionary new inspection technologies are helping gear manufacturers develop and produce more complex, higher quality gears in a fraction of the time it used to take.
Powder metallurgy (P/M) is a precision metal forming technology for the manufacture of parts to net or near-net shape, and it is particularly well-suited to the production of gears. Spur, bevel and helical gears all may be made by made by powder metallurgy processing.
This section is dedicated to what's new and what's happening in the world of gear inspection and metrology. Here you will find news about products, companies and organizations, services and events affecting the gear inspection and metrology industry.
The tooth-by-tooth, submerged induction hardening process for gear tooth surface hardening has been successfully performed at David Brown for more than 30 years. That experience - backed up by in-depth research and development - has given David Brown engineers a much greater understanding of, and confidence in, the results obtainable from the process. Also, field experience and refinement of gear design and manufacturing procedures to accommodate the induction hardening process now ensure that gears so treated are of guaranteed quality.
So, you've been assigned the task to buy an induction heating system for heat treating: It's an intimidating, but by no means impossible, assignment. With the help of the information in this article, you could be able to develop common ground with your supplier and have the tools to work with him or her to get the right machine for your jobs.
A programmable algorithm is developed to separate out the effect of eccentricity (radial runout) from elemental gear inspection date, namely, profile and lead data. This algorithm can be coded in gear inspection software to detect the existence, the magnitude and the orientation of the eccentricity without making a separate runout check. A real example shows this algorithm produces good results.
No one (not even you and I) consistently makes parts with perfect form and dimensions, so we must be able to efficiently check size and shape at many stages in the manufacturing and assembly process to eliminate scrap and rework and improve processes and profits. Automated inspection systems, which are widely used in all kinds of manufacturing operations, provide great efficiencies in checking individual features, but may not be as effective when asked to evaluate an entire part. You need to know why this is true and what you can do to improve your part yields.
What is so unique about gear manufacturing and inspection? Machining is mostly associated with making either flat or cylindrical shapes. These shapes can be created by a machine's simple linear or circular movements, but an involute curve is neither a straight line nor a circle. In fact, each point of the involute curve has a different radius and center of curvature. Is it necessary to go beyond simple circular and linear machine movements in order to create an involute curve? One of the unique features of the involute is the fact that it can be generated by linking circular and linear movements. This uniqueness has become fertile soil for many inventions that have simplified gear manufacturing and inspection. As is the case with gear generating machines, the traditional involute inspection machines take advantage of some of the involute properties. Even today, when computers can synchronize axes for creating any curve, taking advantage of involute properties can be very helpful. I t can simplify synchronization of machine movements and reduce the number of variables to monitor.
When hardened steel components are ground, there is always the possibility of damage to the steel in the form of residual stress or microstructural changes. Methods for detecting this sort of damage have always had one or more drawbacks, such as cost, time, complexity, subjectivity, or the use of hazardous chemicals.
Many potential problems are not apparent when using new induction heat treating systems. The operator has been trained properly, and setup parameters are already developed. Everything is fresh in one's mind. But as the equipment ages, personnel changes or new parts are required to be processed on the old equipment ages, personnel changes or new parts are required to b processed on the old equipment, important information can get lost in the shuffle.
The data discussed in this article was taken from an upright vacuum cleaner. This was a prototype cleaner that was self-propelled by a geared transmission. It was the first time that the manufacturer had used a geared transmission in this application.
A road map is presented listing critical considerations and optimal use of materials and methods in the construction of large gears.
Question: We just received permission to purchase our first CNC gear inspection system. With capital approvals so hard to come by, especially for inspection equipment, I want to be sure to purchase a system I can count of for years to come. My past experience with purchasing CNC equipment has shown me that serviceability of the computer and the CNC controller portion of the system can be a problem in just a few years because of the obsolescence factor. What information do I need to look for when selecting a supplier to reduce the risk of obsolescence, as well as to reduce the long-term servicing costs in the computer and controls portion of the system?
There's a reason they call it catastrophic gear failure: For example, if the line goes down at a large aluminum rolling mill because a gear set goes bad, the cost can run up to a whopping $200,000 a week. Even in smaller operations, the numbers alone (not to mention all the other problems) can be a plant manager's worst nightmare.
This section will deal with the use of gear inspection for diagnostic purposes rather than quality determination. The proper evaluation of various characteristics in the data can be useful for the solution of quality problems. It is important to sort out whether the problem is coming from the machine, tooling and/or cutters, blanks, etc. An article by Robert Moderow in the May/June 1985 issue of Gear Technology is very useful for this purpose.
Quality gear inspection means doing the "right" inspections "right." A lot of time and money can be spent doing the wrong types of inspections related to function and doing them incorrectly. As we will discover later, such things as runout can creep into the manufacturing and inspection process and completely ruin any piece of data that is taken. this is one of the most important problems to control for quality inspection.
Mitutoyo offers capable, affordable and flexible gear inspection option via coordinate measuring machines and gear inspection software.
An overview of nondestructive testing and its importance in the manufacture of big gears.
Flute Index Flute index or spacing is defined as the variation from the desired angle between adjacent or nonadjacent tooth faces measured in a plane of rotation. AGMA defines and provides tolerance for adjacent and nonadjacent flute spacing errors. In addition, DIN and ISO standards provide tolerances for individual flute variation (Fig. 1).
Can a gear profile generated by the hobbing method be an ideal involute? In strictly theoretical terms - no, but in practicality - yes. A gear profile generated by the hobbing method is an approximation of the involute curve. Let's review a classic example of an approximation.
In the typical gear production facility, machining of gear teeth is followed by hear treatment to harden them. The hardening process often distorts the gear teeth, resulting in reduced and generally variable quality. Heat treating gears can involve many different types of operations, which all have the common purpose of producing a microstructure with certain optimum properties. Dual frequency induction hardening grew from the need to reduce cost while improving the accuracy (minimizing the distortion) of two selective hardening processes: single tooth induction and selective carburizing.
The latest in big gear machining with DMG/Mori Seiki.
Contact fatigue and bending fatigue are two main failure modes of steel gears, while surface pitting and spalling are two common contact fatigue failures -- caused by alternating subsurface shear stresses from the contact load between two gear mates. And when a gear is in service under cyclic load, concentrated bending stresses exist at the root fillet -- the main driver of bending fatigue failures. Induction hardening is becoming an increasingly popular response to these problems, due to its process consistency, reduced energy consumption, clean environment and improved product quality -- but not without issues of its own (irregular residual stresses and bending fatigue). Thus a new approach is proposed here that flexibly controls the magnitude of residual stress in the regions of root fillet and tooth flank by pre-heating prior to induction hardening. Using an external spur gear made of AISI 4340 as an example, this new concept/process is demonstrated using finite element modeling and DANTE commercial software.
Alternative business strategies from some alternative gear manufacturers.
Minimizing gear losses caused by churning, windage and mesh friction is important if plant operating costs and environmental impact are to be minimized. This paper concentrates on mesh friction losses and associated scuffing risk. It describes the preliminary results from using a validated, 3-D Finite Element Analysis (FEA) and Tooth Contact Analysis (TCA) program to optimize cylindrical gears for low friction losses without compromising transmission error (TE), noise and power density. Some case studies and generic procedures for minimizing losses are presented. Future development and further validation work is discussed.
An Interview with Dr. Valery Rudnev, FASM, IFHTSE Fellow, Director of Science & Technology at Inductoheat, Inc.
PTB's two microgear measurement standards and their analyses using seven measurement methods which are then presented, evaluated and compared with each other.
Most of us would agree that the idea of a perfect world is absurd. Just for starters, who gets to decide what perfect means? "The Perfectionists" by Simon Winchester explores this theme as it relates to engineering.
Klingelnberg measuring centers eliminate trial-and-error with modern analysis tools.
Much information has been written on gear inspection, analytical. functional. semiautomatic and automatic. In most cases, the charts, (if you are lucky enough to have recording equipment) have been explained.
The Past, Present and Future of Vehicle Electrification
Inspection of the cutting blades is an important step in the bevel gear manufacture. The proper blade geometry ensures that the desired gear tooth form can be achieved. The accuracy of the process can be compromised when the blade profile consists of several small sections such as protuberance, main profile, top relief and edge radius. Another common obstacle - are outliers which can be caused by dust particles, surface roughness and also floor vibrations during the data acquisition. This paper proposes the methods to improve the robustness of the inspection process in such cases.
This paper presents the results of research directed at measuring the total stress in a pair of statically loaded and carburized spur gears. Measurements were made to examine the change in total stress as a function of externally applied load and depth below the surface.
Investment in Gleason GMM Series inspection equipment helps drive Milwaukee Gear's expansion into profitable new markets around the worldâ€”all hungry for high-precision custom gears and gear drives.
Gear metrology is a revolving door of software packages and system upgrades. It has to be in order to keep up with the productivity and development processes of the machines on the manufacturing floor. Temperature compensation, faster inspection times and improved software packages are just a few of the advancements currently in play as companies prepare for new opportunities in areas like alternative energy, automotive and aerospace/defense.
Profile corrections on gears are a commonly used method to reduce transmission error, contact shock, and scoring risk. There are different types of profile corrections. It is a known fact that the type of profile correction used will have a strong influence on the resulting transmission error. The degree of this influence may be determined by calculating tooth loading during mesh. The current method for this calculation is very complicated and time consuming; however, a new approach has been developed that could reduce the calculation time.
Delta Research upgrades its Gleason Metrology Workhorses to meet the development requirements of the latest electrical drive vehicles.
Induction hardening is a heat treating technique that can be used to selectively harden portions of a gear, such as the flanks, roots and tips of teeth, providing improved hardness, wear resistance, and contact fatigue strength without affecting the metallurgy of the core and other parts of the component that donâ€™t require change. This article provides an overview of the process and special considerations for heat treating gears. Part I covers gear materials, desired microsctructure, coil design and tooth-by-tooth induction hardening.
This article covers preventive maintenance and modification to machinery to induction harden different types of gear.
Publisher Michael Goldstein discusses the loss of U.S. manufacturing capability and what we should do about it.
Higher productivity, faster setup times and single unattended operations are just a few of the capabilities gear manufacturers seek in the multifunctional machine tool market.
A reader asks about ion-nitride finished shafts and the proper friction coefficient to be used for calculations.
Super-reduction hypoid gears (SRH) are bevel worm gears with certain differences regarding hypoid gears. If two axes are positioned in space and the task is to transmit motion and torque between them using some kind of gears with a ratio above 5 and even higher than 50, the following cases are commonly known. Tribology Aspects in Angular Transmission Systems, Part VIII.
It may not be widely recognized that most of the inspection data supplied by inspection equipment, following the practices of AGMA Standard 2015 and similar standards, are not of elemental accuracy deviations but of some form of composite deviations. This paper demonstrates the validity of this â€ścompositeâ€ť label by first defining the nature of a true elemental deviation and then, by referring to earlier literature, demonstrating how the common inspection practices for involute, lead (on helical gears), pitch, and, in some cases, total accumulated pitch, constitute composite measurements.
REANY is software for the evaluation of gears and splines that have been measured completely on all teeth. It is suited to both quality assessment and analyzing the causes for deviations. REANY is short for Reality Analysis.
As is well known in involute gearing, â€śperfectâ€ť involute gears never work perfectly in the real world. Flank modifications are often made to overcome the influences of errors coming from manufacturing and assembly processes as well as deflections of the system. The same discipline applies to hypoid gears.
Gear noise is among the issues of greatest concern in today's modern gearboxes. Significant research has resulted in the application of enhancements in all phases of gear manufacturing, and the work is ongoing. With the introduction of Electric Vehicles (EV), research and development in this area has surged in recent years. Most importantly, powerful new noise analysis solutions are fast becoming available.
Before the optimum mechanical properties can be selected, the working stress must be determined, based on recommended allowable stresses.
In recent years, there has been significant interest in expanding the use of induction hardening in gear manufacturing operations. Over the past several years, many of the limits to induction hardening have shrunk, thanks to recent advances in technology, materials and processing techniques.
Gear inspection has long been a highly specialized costly investment and an overall challenging part of the gear manufacturing process. Given that complicated gages, testers, and CNC equipment all go into creating high quality gears, companies may want to invest in a CMM to streamline inspection.
This paper discusses the influence of tip relief, root relief, load modification, end relief and their combinations on gear stresses and transmission errors due to shaft deflections.
Part I, which was published in the September/October 2008 issue, covered gear materials, desired microstructure, coil design and tooth-by-tooth induction hardening. Part II covers spin hardening and various heating concepts used with it.
New GRSL technology adds value to high-volume transmission gear inspection by combining non-contact laser inspection with tried-and-true composite roll testing.
CTI Symposium Presents Latest Automotive Transmission Developments and Applications.
Previews of manufacturing technology related to gears that will be on display at IMTS 2012.
Publisher Michael Goldstein is confident that the manufacturing economy will continue to grow throughout next year, no matter who wins the 2012 presidential election.
The two candidates in the upcoming presidential election offer two distinctly different approaches to solving Americaâ€™s economic problems -- neither of which is likely to be successful
Gleason Combines Threaded Wheel Grinding with GRSL Gear Inspection
Optimizing the running behavior of bevel and hypoid gears means improving both noise behavior and load carrying capacity. Since load deflections change the relative position of pinion and ring gear, the position of the contact pattern will depend on the torque. Different contact positions require local 3-D flank form optimizations for improving a gear set.
The selection of the proper steel for a given gear application is dependent on many factors. This paper discusses the many aspects related to material, design, manufacture, and application variables. The results of several studies on the optimization of alloy design for gas- and plasma- carburization processing and reviewed.
During the revision of ISO 1328-1:2013 Cylindrical gears â€” ISO system of flank tolerance classification, ISO Technical Committee TC 60 WG2 delegates discussed proposals that the standard should be modified to ensure that it is compatible with the ISO Geometrical Product Specification (GPS) series of standards (Refs. 1-3). This seems sensible because the gears are geometrical components, but after reviewing the implications, it was rejected because ISO TC 60 WG2 did not think the gear manufacturing industry was ready for such a radical change in measurement strategy. The feasibility of the implementation of gears into the GPS matrix of standards has been carried out and the results conclude that this is practical, provided some key issues related to measurement uncertainty and establishing appropriate KPIs are addressed.
Shop floor inspection and gaging equipment is putting advanced metrology systems right on the factory floor. Hereâ€™s a collection of articles on shop floor inspection and gages from companies like Gleason, Mahr, Comtorgage, United Tool Supply and Frenco.
In this article, equations for finding profile and base pitch errors with a micrometer are derived. Limitations of micrometers with disc anvils are described. The design of a micrometer with suitable anvils is outlined.
Carburized gears have higher strengths and longer lives compared with induction-hardened or quench-tempered gears. But in big module gears, carburizing heat-treatment becomes time-consuming and expensive and sometimes cannot achieve good hardness due to the big mass-effect. Also, it is not easy to reduce distortion of gears during heat treatment.
The traditional way of controlling the quality of hypoid gears' tooth flank form is to check the tooth flank contact patterns. But it is not easy to exactly judge the tooth flank form quality by the contact pattern. In recent years, it has become possible to accurately measure the tooth flank form of hypoid gears by the point-to-point measuring method and the scanning measuring method. But the uses of measured data of the tooth flank form for hypoid gears have not yet been well developed in comparison with cylindrical involute gears. In this paper, the tooth flank form measurement of generated face-milled gears, face-hobbed gears and formulate/generated gears are reported. The authors discuss the advantages and disadvantages of scanning and point-to-point measuring of 3-D tooth flank forms of hypoid gears and introduce some examples of uses of measured data for high-quality production and performance prediction.
The configuration of flank corrections on bevel gears is subject to relatively narrow restrictions. As far as the gear set is concerned, the requirement is for the greatest possible contact zone to minimize flank compression. However, sufficient reserves in tooth depth and longitudinal direction for tooth contact displacement should be present. From the machine - and particularly from the tool - point of view, there are restrictions as to the type and magnitude of crowning that can be realized. Crowning is a circular correction. Different kinds of crowning are distinguished by their direction. Length crowning, for example, is a circular (or 2nd order) material removal, starting at a reference point and extending in tooth length or face width.
Base helix error - the resultant of lead and profile errors is the measured deviation from the theoretical line of contact (Fig. 1). It can be measured in the same way that lead error on a spur gear is measured, namely, by setting a height gage to height H based on the radial distance r to a specified line of contact (Fig. 2), rotating the gear so as to bring a tooth into contact with the indicator on the height gage, and then moving the height gage along two or more normals to the plane of action. The theoretical line of contact on helical gear must be parallel to the surface plate, which is attained by mounting the gear on a sine bar (Fig. 3).
In this article, the focus is put on one technology, X-ray diffraction (XRD), and more specifically, residual stress measurement by way of XRD for both process development and quality control.
Would you like to be able to see the condition of the gears in your transmissions without having to open the box and physically examine them? There is a way, and not too many people know about it. It's called Wear Particle Analysis, or ferrography, and it is just starting to get noticed.
Klingelnberg presents the technical aspects of its roughness measurement system.
In manufacturing, we all know that tracking statistics on your operation is essential for understanding how you're doing, as well as identifying areas for improvement. But what does the efficiency metric actually tell you?
The past several months have been filled with uncertainty. Everyone wanted to wait and see who would be our next president and how the political landscape might change. Now the elections are over, and the polls are all closed, so we should all be getting back to business, right? Publisher Michael Goldstein shares insight from our state-of-the-gear-industry survey.
It's not easy being big. Maybe that's not exactly how the phrase goes, but it's applicable, particularly when discussing the quality requirements of large gears. The size alone promises unique engineering challenges. BONUS Online Exclusive: Big or Small - Inspection is Key to Success.
Which transmission system will come out on top is a hot topic in the automotive community. With multiple transmission-centric conferences on the horizon, there will be plenty of debate, but how much will the answer actually affect gear manufacturers, and when?
This proposed standard would not make any recommendations regarding the required quality for any application. The intent is to establish standard pre-finish quality classes for typical finishing operations, which only include the inspection elements that are important to properly evaluate pre-finish gear quality as it applies to the finishing operation. It would be the responsibility of the manufacturing/process engineer, quality engineer, or other responsible individual to establish the required pre-finish quality class for their application.
Induction hardening is becoming an increasingly popular alternative to thermochemical diffusion processes such as carburizing, and as it does so, manufacturers are on a never-ending quest to expand the scope of what's possible with the technology.
Germany adopts ISO 1328 standard for the measurement of gears, plus other news and announcements from around the industry.
Many years ago, when asked how the five-meter gear was checked, the quality manager responded, â€śWhen theyâ€™re that big, theyâ€™re never bad!â€ť That may have been the attitude and practice in the past, but it no longer serves the manufacturer nor the customer. Requirements have been evolving steadily, requiring gears to perform better and last longer.
More than any other field, IIoT overlaps directly with metrology's mission to analyze and measure as much of the manufacturing process as possible, and it's no surprise that the latter is utilizing the former.
I have heard that X-ray diffraction does not tell the whole story and that I should really run a fatigue test. I understand this may be the best way, but is there another method that gives a high degree of confidence in the residual stress measurement?
Gleason 350GMS helps put higher quality, more reliable gears into its next-generation TC10 automatic transmission.
New technology from Eldec/EMAG helps control the induction hardening process.
In today's production environment, a variety of different measurement devices is used to assess the quality and accuracy of workpieces. These devices include CMMs, gear checkers, form testers, roughness testers, and more. It requires a high machine investment and a high handling effort - especially if a full end-of-line measurement is needed. One approach to reduce quality costs is to include all measurements in one single machine that is suitable and robust enough for use in production.
Video from C&B Machinery; Introducing the Gear Technology Blog, featuring technical editor Charles D. Schultz; plus an online-exclusive article on big gear inspection.
A reader asks: We are currently revising our gear standards and tolerances and a few questions with the new standard AGMA 2002-C16 have risen. Firstly, the way to calculate the tooth thickness tolerance seems to need a "manufacturing profile shift coefficient" that isn't specified in the standard; neither is another standard referred to for this coefficient. This tolerance on tooth thickness is needed later to calculate the span width as well as the pin diameter. Furthermore, there seems to be no tolerancing on the major and minor diameters of a gear.
In todayâ€™s globalized manufacturing, all industrial products having dimensional constraints must undergo conformity specifications assessments on a regular basis. Consequently, (standardization) associated with GD&T (geometrical dimensioning and tolerancing) should be un-ambiguous and based on common, accepted rules. Of course gears - and their mechanical assemblies - are special items, widely present in industrial applications where energy conversion and power transmission are involved.
Although a comprehensive on-site gearbox inspection is desirable in many situations, there may be constraints that limit the extent of the inspection such as cost, time, accessibility and qualified personnel. This article describes the equipment and techniques necessary to perform an on-site gearbox inspection.
Methods of examining large ring gear teeth to detect surface breaking discontinuities have often been time-consuming and limited in terms of data collected. Methods such as visual and magnetic particle inspection can miss critical discontinuities. However, a new ASTM international standard provides a more effective method for gear examination using eddy current array, a technology that has been widely used but, until now, not standardized.
The complete Industry News section from the January/February 2019 issue of Gear Technology.
For two days in Saline, Michigan, Liebherr's clients, customers and friends came together to discuss the latest gear products and technology. Peter Wiedemann, president of Liebherr Gear Technology Inc., along with Dr.-Ing. Alois Mundt, managing director, Dr.-Ing. Oliver Winkel, head of application technology, and Dr.-Ing. Andreas Mehr, technology development shaping and grinding, hosted a variety of informative presentations.
Market needs push in 2013, but will it get one? The construction/off-highway industries have been here before. New equipment, technologies and innovations during an economic standstill that some have been dealing with since 2007.
This paper introduces mandatory improvements in design, manufacturing and inspection - from material elaboration to final machining - with special focus on today's large and powerful gearing.
CMM Inspection vs. GMM Inspection. Speed is the name of the game.
Our experts tackle the topic of measuring involute masters, including both master gears and gear inspection artifacts.
The secret to meeting today's inspection demands is influenced by the technology and those in charge of operating it.
What does it mean to make "better" gears? Better gears more closely resemble the intended design parameters.
Until recently, there was a void in the quality control of gear manufacturing in this country (Ref. 1). Gear measurements were not traceable to the international standard of length through the National Institute of Standards and Technology (NIST). The U.S. military requirement for traceability was clearly specified in the military standard MIL-STD-45662A (Ref. 2). This standard has now been replaced by commercial sector standards including ISO 9001:1994 (Ref. 3), ISO/IEC Guide 25 (Ref, 4), and the U.S. equivalent of ISO/IEC Guide 25 - ANSI/NCSL Z540-2-1997 (Ref. 5). The draft replacement to ISO/IEC Guide 25 - ISO 17025 states that measurements must either be traceable to SI units or reference to a natural constant. The implications of traceability to the U.S. gear industry are significant. In order to meet the standards, gear manufacturers must either have calibrated artifacts or establish their own traceability to SI units.
The status on traceability of gear artifacts in the United States.
A reader clarifies technology presented in the March/April 2011 issue.
In comparison with the traditional gear design approach based on preselected, typically standard generating rack parameters, the Direct Gear Design method provides certain advantages for custom high-performance gear drives that include: increased load capacity, efficiency and lifetime; reduced size, weight, noise, vibrations, cost, etc. However, manufacturing such directly designed gears requires not only custom tooling, but also customization of the gear measurement methodology. This paper presents definitions of main inspection dimensions and parameters for directly designed spur and helical, external and internal gears with symmetric and asymmetric teeth.
With growing markets in aerospace and energy technologies, measuring hob cutters used in gear cutting is becoming an essential requirement for workpieces and machine tools. Zoller, a provider of solutions for tool pre-setters, measuring and inspection machines and tool management software, has developed a new partnership with Ingersoll/Germany for shop floor checking of hob cutters by a combined hardware and software approach.
A new inspection method has several advantages over traditional methods, especially for very large or very small gears.
When parts you manufacture pass through numerous processes such as deep hole drilling, machining, hobbing and grinding, a CMM is essential when your customers require 100 percent in-process and final inspection.
Meeting the many challenges of large gear inspection.
This article provides an overview of the benefits of using psychoacoustic characteristics for describing gear noise. And with that, human hearing and the most important psychoacoustic values are introduced. Finally, results of noise tests with different gear sets aree presented. The tests are the basis for a correlation analysis between psychoacoustic values and gear characteristics.
Gear flank breakage can be observed on edge zone-hardened gears. It occurs, for example, on bevel gears for water turbines, on spur gears for wind energy converters and on single- and double-helical gears for other industrial applications.
Good timing leads to partnership between Process Equipment and Schafer Gear.
Presumably, everyone who would be interested in this subject is already somewhat familiar with testing of gears by traditional means. Three types of gear inspection are in common use: 1) measurement of gear elements and relationships, 2) tooth contact pattern checks and 3) rolling composite checks. Single Flank testing falls into this last category, as does the more familiar Double Flank test.
I received a letter from Mr. G. W. Richmond, Sullivan Machinery Company, N.H., in which in addition to correcting mistyping, he made several suggestions concerning my article "General Equations for Gear Cutting Tool Calculations."
It has previously been demonstrated that one gear of an interchangeable series will rotate with another gear of the same series with proper tooth action. It is, therefore, evident that a tooth curve driven in unison with a mating blank, will "generate" in the latter the proper tooth curve to mesh with itself.
Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.
Gear manufacturing schedules that provide both quality and economy are dependent on efficient quality control techniques with reliable measuring equipment. Given the multitude of possible gear deviations, which can be found only by systematic and detailed measuring of the gear teeth, adequate quality control systems are needed. This is especially true for large gears, on which remachining or rejected workpieces create very high costs. First, observation of the gears allows adjustment of the settings on the equipment right at the beginning of the process and helps to avoid unproductive working cycles. Second, the knowledge of deviations produced on the workpiece helps disclose chance inadequacies on the production side: e.g., faults in the machines and tools used, and provides an opportunity to remedy them.
A pair of spur gears generally has an effective lead error which is caused, not only by manufacturing and assembling errors, but also by the deformations of shafts, bearings and housings due to the transmitted load. The longitudinal load distribution on a contact line of the teeth of the gears is not uniform because of the effective lead error.
Xspect Solutions Provides Wenzel Bridge-Type CMM Equipped with OpenDMIS Software for Basic Gear Measuring Capability with CMM Flexibility.
A trial test of the calibration procedures outlined in ISO 18653â€”Gears: Evaluation of Instruments for the Measurement of Individual Gears, shows that the results are reasonable, but a minor change to the uncertainty formula is recommended. Gear measuring machine calibration methods are reviewed. The benefits of using workpiece-like artifacts are discussed, and a procedure for implementing the standard in the workplace is presented. Problems with applying the standard to large gear measuring machines are considered and some recommendations offered.
The first commandment for gears reads "Gears must have backlash!" When gear teeth are operated without adequate backlash, any of several problems may occur, some of which may lead to disaster. As the teeth try to force their way through mesh, excessive separating forces are created which may cause bearing failures. These same forces also produce a wedging action between the teeth with resulting high loads on the teeth. Such loads often lead to pitting and to other failures related to surface fatigue, and in some cases, bending failures.
This paper initially defines bias errorâ€”the â€śtwisted tooth phenomenon.â€ť Using illustrations, we explain that bias error is a by-product of applying conventional, radial crowning methods to produced crowned leads on helical gears. The methods considered are gears that are finished, shaped, shaved, form and generated ground. The paper explains why bias error occurs in these methods and offers techniques used to limit/eliminate bias error. Sometimes, there may be a possibility to apply two methods to eliminate bias error. In those cases, the pros/cons of these methods will be reviewed.
Much of the information in this article has been extracted from an AGMA Technical Paper, "What Single Flank Testing Can Do For You", presented in 1984 by the author
Your May/June issue contains a letter from Edward Ubert of Rockwell International with some serious questions about specifying and measuring tooth thickness.
This paper presents the results of a study performed to measure the change in residual stress that results from the finish grinding of carburized gears. Residual stresses were measured in five gears using the x-ray diffraction equipment in the Large Specimen Residual Stress Facility at Oak Ridge National Laboratory.
This article was originally published 20 years ago, in Gear Technologyâ€™s first issue. It describes a method of evaluating the smoothness, or lack of smoothness, of gear motion. This lack of smoothness of motion, known as â€śtransmission error,â€ť is responsible for excitation of gear noise and problems of gear accuracy and sometimes has a relationship to gear failure.
"Frenco--Inspecting All Flanks in Minutes."
When gears are case-hardened, it is known that some growth and redistribution of stresses that result in geometric distortion will occur. Aerospace gears require post case-hardening grinding of the gear teeth to achieve necessary accuracy. Tempering of the case-hardened surface, commonly known as grinding burn, occurs in the manufacturing process when control of the heat generation at the surface is lost.
AGMA has started to replace its 2000-A88 standard for gear accuracy with a new series of documents based largely on ISO standards. The first of the replacement AGMA standards have been published with the remainder coming in about a year. After serving as a default accuracy specification for U.S. commerce in gear products for several decades, the material in AGMA 2000-A88 is now considered outdated and in need of comprehensive revision.
Modern gearboxes are characterized by high torque load demands, low running noise and compact design. In order to fulfill these demands, profile and lead modifications are being applied more often than in the past. This paper will focus on how to produce profile and lead modifications by using the two most common grinding processesâ€”threaded wheel and profile grinding. In addition, more difficult modificationsâ€”such as defined flank twist or topological flank correctionsâ€”will also be described in this paper.
Two high-volume gear production cells grace the shop floor at Delta Research Corporation in Livonia, Michigan. Thanks to lean manufacturing, these cells have never shipped a defective part to a customer since they were developed over three years ago.
The two-flank roll test measures kickout (tooth-to-tooth composite error) and tooth thickness. In this article, it will be shown that measured values vary with the number of teeth on the master gear.
The German National Metrology Institute has developed a novel calibration concept that allows for highly accurate calibration of product-like artifacts.
This article reviews mathematical models for individual components associated with power losses, such as windage, churning, sliding and rolling friction losses.
The presence of significant errors in the two-flank roll test (a work gear rolled in tight mesh against a master gear) is well-known, but generally overlooked.
This article offers an overview of the practical design of a naval gear for combined diesel or gas turbine propulsion (CODOG type). The vibration performance of the gear is tested in a back-to-back test. The gear presented is a low noise design for the Royal Dutch Navy's LCF Frigate. The design aspects for low noise operation were incorporated into the overall gear system design. Therefore, special attention was paid to all the parameters that could influence the noise and vibration performance of the gearbox. These design aspects, such as tooth corrections, tooth loading, gear layout, balance, lubrication and resilient mounting, will be discussed.
In this paper, a method is presented for analyzing and documenting the pitting failure of spur and helical gears through digital photography and automatic computerized evaluation of the damaged tooth fl ank surface. The authors have developed an accurate, cost-effective testing procedure that provides an alternative to vibration analysis or oil debris methods commonly used in conjunction with similar test-rig programs.
The modern day requirement for precision finished hobbed gears, coupled with the high accuracy characteristics of modern CNC hobbing machines, demands high tool accuracy.
The objective, according to Dr.- Ing. HansjĂ¶rg Geiser, head of development and design for gear machines at Liebherr, was to develop and design a combined turning and hobbing machine in which turning, drilling and hobbing work could be carried out in the same clamping arrangement as the hobbing of the gearings and the subsequent chamfering and deburring processes.
Among the various types of gearing systems available to the gear application engineer is the versatile and unique worm and worm gear set. In the simpler form of a cylindrical worm meshing at 90 degree axis angle with an enveloping worm gear, it is widely used and has become a traditional form of gearing. (See Fig. 1) This is evidenced by the large number of gear shops specializing in or supplying such gear sets in unassembled form or as complete gear boxes. Special designs as well as standardized ratio sets covering wide ratio ranges and center distanced are available with many as stock catalog products.
Nondestructive examination (NDE) of ferrous and nonferrous materials has long proved an effective maintenance and anomaly characterization tool for many industries. Recent research has expanded its applicability to include the inspection of large, open gear drives. Difficulties inherent in other NDE methods make them time-consuming and labor-intensive. They also present the user with the environmental problem of the disposal of used oil. The eddy current method addresses these problems.
If someone were to tell you that he had a gear material that was stronger per pound than aluminum, as wear-resistant as steel, easier to machine than free-machining steel and capable of producing gears domestically for 20% less than those now cut from foreign made forgings, would you consider that material to be "high tech"? Probably. Well, throw out all the pre-conceived notions that you may have had about "high tech" materials. The high-performance material they didn't teach you about in school is austempered ductile iron (ADI).
There are problems in dimensional measurement that should be simple to solve with standard measuring procedures, but aren't. In such cases, using accepted practices may result in errors of hundreds of microns without any warning that something is wrong.
The purpose of this article is to clarify some terms and methods used in measuring the size of gears. There is also an explanation given of the error induced and how to correct for it in certain cases when the measurement is made using pins instead of balls.
In recent years, gear inspection requirements have changed considerably, but inspection methods have barely kept pace. The gap is especially noticeable in bevel gears, whose geometry has always made testing them a complicated, expensive and time-consuming process. Present roll test methods for determining flank form and quality of gear sets are hardly applicable to bevel gears at all, and the time, expense and sophistication required for coordinate measurement has limited its use to gear development, with only sampling occurring during production.
The American Society of Mechanical Engineers (ASME) announced at Gear Expo '95 that a national service for the calibration of involute artifacts is now available at the Department of Energy's Y-12 Plant in Oak Ridge, TN.
A good many things bother me about election years - the annoying sound bites, the negative commercials, the endless political over-analysis. But what bothers me most about the coming election is this: So far (when I'm writing this, it's admittedly early in the campaign) there's little or no talk about what is one of the most critical national issues of the next thirty years - our growing government debt.
A few years ago, during a presidential election campaign, I saw an editorial cartoon that depicted a man standing outside a voting booth with a bemused expression on his face. Over the door to the booth was a quotation from Dante: "Abandon hope, all ye who enter here." Unfortunately for all of us, the grim jest is just as timely now. Once again, when we make our choice for president this year, the pick seems to be between Mr. Well-He's-Not-Actually-Awful and Mr. At-Least-He's-Not-The-Other-Guy. A candidate who can arouse truly positive and hopeful feelings in the electorate is once again not on the ballot.
In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated, and the individual tooth load is overstated, especially for heavily loaded gears. This article compares the static transmission error and dynamic load of heavily loaded, low-contact-ratio spur gears when the effect of tooth flexibility has been considered and when it has been ignored. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.
Surface roughness measuring of gear teeth can be a very frustrating experience. Measuring results often do not correlate with any functional characteristic, and many users think that they need not bother measuring surface roughness, since the teeth are burnished in operation. They mistakenly believe that the roughness disappears in a short amount of time. This is a myth! The surface indeed is shiny, but it still has considerable roughness. In fact, tests indicate that burnishing only reduces the initial roughness by approximately 25%.
Several articles have appeared in this publication in recent years dealing with the principles and ways in which the inspection of gears can be carried out, but these have dealt chiefly with spur, helical and bevel gearing, whereas worm gearing, while sharing certain common features, also requires an emphasis in certain areas that cause it to stand apart. For example, while worm gears transmit motion between nonparallel shafts, as do bevel and hypoid gears, they usually incorporate much higher ratios and are used in applications for which bevel would not be considered, including drives for rotary and indexing tables in machine tools, where close tolerance of positioning and backlash elimination are critical, and in situations where accuracy of pitch and profile are necessary for uniform transmission at speed, such as elevators, turbine governor drives and speed increasers, where worm gears can operate at up to 24,000 rpm.
The trend toward moving coordinate measuring machines to the shop floor to become an integral part of the manufacturing operations brings real time process control within the reach of many companies. Putting measuring machines on the shop floor, however, subjects them to harsh environmental conditions. Like any measuring system, CMMs are sensitive to any ambient condition that deviates from the "perfect" conditions of the metrology lab.
Computers are everywhere. It's gotten so that it's hard to find an employee who isn't using one in the course of his or her day - whether he be CEO or salesman, engineer or machinist. Everywhere you look, you find the familiar neutral-colored boxes and bright glowing screens. And despite the gear industry's traditional reluctance to embrace new technology, more and moe of what you find on those screens are gears.
In the approximately 15 years that I have been writing editorials for Gear Technology, I've purposely avoided certain topics. Sex, religion and my own used gear machinery business are among the subjects that have always been off limits. But with this issue, I'm going to break one of my long-standing taboos by talking politics.
It is very common for those working in the gear manufacturing industry to have only a limited understanding of the fundamental principals of involute helicoid gear metrology, the tendency being to leave the topic to specialists in the gear lab. It is well known that quiet, reliable gears can only be made using the information gleaned from proper gear metrology.
In the last section, we discussed gear inspection; the types of errors found by single and double flank composite and analytical tests; involute geometry; the involute cam and the causes and symptoms of profile errors. In this section, we go into tooth alignment and line of contact issues including lead, helix angles, pitch, pitchline runout, testing and errors in pitch and alignment.
The purpose of this article is to discuss ISO 4156/ANSI B92.2M-1980 and to compare it with other, older standards still in use. In our experience designing and manufacturing spline gauges and other spline measuring or holding devices for splined component manufacturers throughout the world, we are constantly surprised that so many standards have been produced covering what is quite a small subject. Many of the standards are international standards; others are company standards, which are usually based on international standards. Almost all have similarities; that is, they all deal with splines that have involute flanks of 30 degrees, 37.5 degrees or 45 degrees pressure angle and are for the most part flank-fitting or occasionally major-diameter-fitting.
In 1993, M & M Precision Systems was awarded a three-year, partial grant from the Advanced Technology Program of the Department of Commerce's National Institute of Standards and Technology (NIST). Working with Pennsylvania State University, M&M embarked on a technology development project to advance gear measurement capabilities to levels of accuracy never before achieved.
"God is in the details," says the philosopher. What he meant was that on the scale of the universe, it's not just the galaxies, the planets, the mountain ranges, or the major rivers that are important. So are the subatomic particles and the genes. It's the little things that make all the difference.
Question: I have just become involved with the inspection of gears in a production operation and wonder why the procedure specifies that four involute checks must be made on each side of the tooth of the gear being produced, where one tooth is checked and charted in each quadrant of the gear. Why is this done? These particular gears are checked in the pre-shaved, finish-shaved, and the after-heat-treat condition, so a lot of profile checking must be done.
The working surfaces of gear teeth are often the result of several machining operations. The surface texture imparted by the manufacturing process affects many of the gear's functional characteristics. To ensure proper operation of the final assembly, a gear's surface texture characteristics, such as waviness and roughness, can be evaluated with modern metrology instruments.
The purpose of this article is to describe an analytical method free of the drawbacks mentioned above and providing absolutely reliable results.
The phenomenon of white layers, which arises from high stress, can be observed under a microscope after the white layers have been treated with a weak nitric acid solution. Their occurrences in zones of high shear stress can provide qualitatively valuable indications of the size and direction of the stress, and they can point out possible starting points for flank damage. An investigation of this phenomenon is described.
Taxes may be one of the only two sure things in life, but that doesn't make them popular. Nobody is happy to pay them, and the bigger the amount due, the unhappier the taxpayer. Conversely, politicians know that coming out in favor of a tax cut is the equivalent of voting for apple pie and motherhood. It's a sure-fire success at the ballot box.
Our experts discuss runout and helix accuracy, as well as the maximum number of teeth in a shaper cutter.
Carburized and hardened gears have optimum load-carrying capability. There are many alternative ways to produce a hard case on the gear surface. Also, selective direct hardening has some advantages in its ability to be used in the production line, and it is claimed that performance results equivalent to a carburized gear can be obtained. This article examines the alternative ways of carburizing, nitriding, and selective direct hardening, considering equipment, comparative costs, and other factors. The objective must be to obtain the desired quality at the lowest cost.
Runout is a troublemaker! Good shop practice for the manufacture or inspection of gears requires the control of runout. Runout is a characteristic of gear quality that results in an effective center distance variation. As long as the runout doesn't cause loss of backlash, it won't hurt the function of the gear, which is to transmit smooth motion under load from one shaft to another. However, runout does result in accumulated pitch variation, and this causes non-uniform motion, which does affect the function of the gears. Runout is a radial phenomenon, while accumulated pitch variation is a tangential characteristic that causes transmission error. Gears function tangentially. It is also possible to have a gear with accumulated pitch variation, but little or no runout.
AGMA introduced ANSI/AGMA 2015â€“2â€“A06â€” Accuracy Classification System: Radial System for Cylindrical Gears, in 2006 as the first major rewrite of the double-flank accuracy standard in over 18 years. This document explains concerns related to the use of ANSI/AGMA 2015â€“2â€“A06 as an accuracy classification system and recommends a revised system that can be of more service to the gearing industry.
Question: What is functional measurement and what is the best method for getting truthful answers?
Metrology is a vital component of gear manufacturing. Recent changes in this area, due in large part to the advent of computers, are highlighted in this article by comparison with more traditional methods.
Dear Editor: In Mr. Yefim Kotlyar's article "Reverse Engineering" in the July/August issue, I found an error in the formula used to calculate the ACL = Actual lead from the ASL = Assumed lead.
In a very general sense, increasing the hardness of a steel gear increases the strength of the gear. However, for each process there is a limit to its effectiveness. This article contains background information on each of the processes covered. In each section what is desired and what is achievable is discussed. Typical processes are presented along with comments on variables which affect the result. By reviewing the capabilities and processes, it is possible to determine the limits to each process.
Of timing is crucial in the successful implementation of good ideas, then now is the time to reinstate a good idea that fell into disfavor in the mid-1980s. Now is the time to include the investment tax credit as part of whatever inevitable tax structure tinkering is going to take place during this election year.
Whether gear engineers have to replace an old gear which is worn out, find out what a gear's geometry is after heat treatment distortion, or just find out parameters of gears made by a competitor, sometimes they are challenged with a need to determine the geometry of unknown gears. Depending on the degree of accuracy required, a variety of techniques are available for determining the accuracy of an unknown gear. If a high degree of precision is important, a gear inspection device has to be used to verify the results. Frequently, several trial-and-error attempts are made before the results reach the degree of precision required.
Temperature Induced Dimensional Changes Temperature causes various materials to change size at different rate, known as their Coefficients of Expansion (COE). The effects of this phenomenon on precision dimensional measurements are continuous and costly to industry. Precautions can be taken to allow parts and gages to temperature stabilize before conducting gage R & R studies, but the fact remains that on the shop floor temperatures vary all the time. The slow pace at which industry has accepted this reality probably has to do with the subtlety of these tiny size variations and our inability to sense gradual, but significant temperature changes.
This paper proposes a new method â€” using neural oscillators â€” for filtering out background vibration noise in meshing plastic gear pairs in the detection of signs of gear failure. In this paper these unnecessary frequency components are eliminated with a feed-forward control system in which the neural oscillatorâ€™s synchronization property works. Each neural oscillator is designed to tune the natural frequency to a particular one of the components.
"Going green" and energy efficiency are goals that all industries -- especially in Europe and the United States -- are working on, in such sectors as electric motors, lubrication, gears and on and on. Drumroll here please for magnetic gearing
We are well into an odd-number year, so it must be just about time for another Gear Expo. Indeed, the big show -- Gear Expo 2013 -- kicks off in Indianapolis at 9:00 a.m. Tuesday, September 17, wrapping up Thursday the 19th at 4:00 p.m. And whether you are exhibiting or attending, the bottom line is you are going -- a good thing for you, your company and the tightly knit U.S. gear industry.
Preview of some of the exhibits relevant to gear manufacturing at the upcoming EMO 2013.
One process for hard finishing gears is generating gear grinding. Due to its high process efficiency, generating gear grinding has replaced other grinding processes such as profile grinding in batch production of small- and middle-sized gears. Yet despite the wide industrial application of generating gear grinding, the process design is based on experience along with time- and cost-intensive trials. The science-based analysis of generating gear grinding demands a high amount of time and effort, and only a few published scientific analyses exist. In this report a thermo-mechanical process model that describes influences on the surface zone in generating gear grinding is introduced.
Environmentally friendly, highly efficient and lasting a product's lifetime. With characteristics like this, Pulsed-Plasma Diffusion (PPD) technology from Oerlikon Balzers has established itself as an industry standard for the treatment of large automotive press tooling. Now the technology specialists are targeting new applications with this advanced process, offering an alternative to traditional hard-chrome processes.
This presentation introduces a new procedure that - derived from exact calculations - aids in determining the parameters of the validation testing of spiral bevel and hypoid gears in single-reduction axles.
Introduction The standard profile form in cylindrical gears is an involute. Involutes are generated with a trapezoidal rack â€” the basis for easy and production-stable manufacturing (Fig. 1).
Almost any external tooth form that is uniformly spaced around a center can be hobbed. Hobbing is recognized as an economical means of producing spur and helical gears with involute tooth profiles.
Investment in advanced new manufacturing technologies is helping to reinvent production processes for bevel gear cutters and coarse-pitch hobs at Gleason - delivering significant benefits downstream to customers seeking shorter deliveries, longer tool life and better results.
Editor's Note: The following article details the advantages of synthetic lubricants in certain applications. However, the user should be aware of certain design issues arising from the extract chemistry of the synthetic. For example, some synthetics may have low solvency for additives. Others may not be compatible with mineral oils or nonmetallic components such as seals and paints. Some synthetics may absorb water and may not have the same corrosion resistance as mineral oils. Finally, the user should consider biodegradability or toxicity before switching to any new lubricant. Many of these concerns are present in petroleum-based lubricants as well, so consult a lubrication specialist before specifying a lubricant.
In order to increase the load carrying capacity of hardened gears, the distortion of gear teeth caused by quenching must be removed by precision cutting (skiving) and/or grinding. In the case of large gears with large modules, skiving by a carbide hob is more economical than grinding when the highest accuracy is not required.
The selection of the heat treat process and the congruent material required for high performance gears can become very involved.
The purpose of this paper was to verify, when using an oil debris sensor, that accumulated mass predicts gear pitting damage and to identify a method to set threshold limits for damaged gears.
Using the DANTE software, a finite element simulation was developed and executed to study the response of a carburized 5120 steel helical gear to quenching in molten salt. The computer simulation included heat-up, carburization, transfer and immersion in a molten salt bath, quenching, and air cooling. The results of the simulation included carbon distribution of phases, dimensional change, hardness, and residual stress throughout the process. The predicted results were compared against measured results for hardness, dimensions and residual stress. The excellent agreement between predictions and measured values for this carburized 5120 steel gear provides a basis for assessing the various process parameters and their respective importance in the characteristics of not only these heat-treated parts, but of other compositions and shapes.
There are numerous engineering evaluations required to design gear sets for optimum performance with regard to torque capacity, noise, size and cost. How much cost savings and added gear performance is available through optimization? Cost savings of 10% to 30% and 100% added capacity are not unusual. The contrast is more pronounced if the original design was prone to failure and not fit for function.
Effective gear designs balance strength, durability, reliability, size, weight, and cost. Even effective designs, however, can have the possibility of gear cracks due to fatigue. In addition, truly robust designs consider not only crack initiation, but also crack propagation trajectories. As an example, crack trajectories that propagate through the gear tooth are the preferred mode of failure compared to propagation through the gear rim. Rim failure will lead to catastrophic events and should be avoided. Analysis tools that predict crack propagation paths can be a valuable aid to the designer to prevent such catastrophic failures.
Crown gearings are not a new type of gear system. On the contrary, they have been in use since very early times for various tasks. Their earliest form is that of the driving sprocket, found in ancient Roman watermills or Dutch windmills. The first principles of gear geometry and simple methods of production (shaper cutting) were developed in the 1940s. In the 1950s, however, crown gears' importance declined. Their tasks were, for example, taken over by bevel gears, which were easier to manufacture and could transmit greater power. Current subject literature accordingly contains very little information on crown gears, directed mainly to pointing out their limitations (Ref. 1).
The major focus of the American Gear Manufacturers Association standards activity has been the accurate determination of a gearbox's ability to transmit a specified amount of power for a given amount of time. The need for a "level playing field" in the critical arena was one of the reasons the association was formed in the first place. Over the past 85 years, AGMA committees have spent countless hours "discussing" the best ways to calculate the rating of a gear set, often arguing vigorously over factors that varied the resulting answers by fractions of a percentage point. While all that "science" was being debated in test labs and conference rooms all over the country, out industry's customers were conducting their own experiments through the daily operation of gear-driven equipment of all types.
Plastic gears and transmissions require a different design approach than metal transmissions. Different tools are available to the plastic transmission designer for optimizing his geared product, and different requirements exist for inspection and testing. This paper will present some of the new technology available to the plastic gear user, including design, mold construction, inspection, and testing of plastic gears and transmissions.
Alongside the macro test parameters on tooth flanks for profile and tooth traces, surface properties (roughness) play a decisive role in ensuring proper toothed gear function. This article addresses roughness measurement systems on tooth flanks. In addition to universal test equipment, modified test equipment based on the profile method for use on gears is addressed in particular. The equipment application here refers to cylindrical gear flanks and bevel gear flanks. The most important roughness parameters, as well as the implementation of the precise measurement procedure will also be described under consideration of the applicable DIN EN ISO standards as well as the current VDI/VDE Directive 2612 Sheet 5.
The geometry of the bevel gear is quite complicated to describe mathematically, and much of the overall surface topology of the tooth flank is dependent on the machine settings and cutting method employed. AGMA 929-A06 â€” Calculation of Bevel Gear Top Land and Guidance on Cutter Edge Radius â€” lays out a practical approach for predicting the approximate top-land thicknesses at certain points of interest â€” regardless of the exact machine settings that will generate the tooth form. The points of interest that AGMA 929-A06 address consist of toe, mean, heel, and point of involute lengthwise curvature. The following method expands upon the concepts described in AGMA 929-A06 to allow the user to calculate not only the top-land thickness, but the more general case as well, i.e. â€” normal tooth thickness anywhere along the face and profile of the bevel gear tooth. This method does not rely on any additional machine settings; only basic geometry of the cutter, blank, and teeth are required to calculate fairly accurate tooth thicknesses. The tooth thicknesses are then transformed into a point cloud describing both the convex and concave flanks in a global, Cartesian coordinate system. These points can be utilized in any modern computer-aided design software package to assist in the generation of a 3D solid model; all pertinent tooth macrogeometry can be closely simulated using this technique. A case study will be presented evaluating the accuracy of the point cloud data compared to a physical part.
Increased productivity in roughing operations for gear cutting depends mainly on lower production costs in the hobbing process. In addition, certain gears can be manufactured by shaping, which also needs to be taken into account in the search for a more cost-effective form of production.
Due to increasing requirements regarding the vibrational behavior of automotive transmissions, it is necessary to develop reliable methods for noise evaluation and design optimization. Continuous research led to the development of an elaborate method for gear noise evaluation. The presented methodology enables the gear engineer to optimize the microgeometry with respect to robust manufacturing.
This paper analyzes the different influences of the deviations between nominal and actual geometry for a first-cut bevel gear. In each section, the customary tolerances are quantified and the possibilities to reduce them are discussed.
This paper relates specifically to gears that are finish ground and considered high speed per ANSI/AGMA 6011; meshing elements with PLVs (pitch line velocities) in excess of 35 m/s or rotational speeds greater than 4,500 rpm.
FVA software offers simulation and calculation of transmission systems.
Are there rules to aid in grinding process optimization?
This paper shows a method to calculate the occurring tooth root stress for involute, external gears with any form of fillets very precisely within a few seconds.
This article provides a guideline for the selection of a suitable standard in connection with the kind of spline to be designed and manufactured. Some basic formulae have been explained, together with a strategy on how to find standard tooling by calculating an appropriate profile shift factor for the spline to be designed.
New book from Gleason's Vice President Bevel Gear Technology will be exclusively excerpted in Gear Technology magazine.
The oil-off (also known as loss-of-lubrication or oil-out) performance evaluation of gears is of significant interest to the Department of Defense and various rotorcraft manufacturers, so that the aircraft can safely land in an accidental loss-of-lubricant situation. However, unlike typical gear failure modes such as pitting or bending fatigue where early detection is possible, gear failure in an oil-off situation is very rapid and likely catastrophic. Failures rapidly result in the loss of torque transmission and the inability to control the aircraft.
Gear honing is a highly productive process for the production of small and medium sized gears and is used mainly in the serial production of the automotive industry. The low robustness of the process is a particular challenge in gear honing. The consequences range from an inadequate gear quality to an early breakage of the honing tool. In order to describe the processmachine interaction, the machining forces must be known.
An experimental investigation on spur gears to characterize pitting degradation process using monitoring features.
Designing and sizing a rack-and-pinion system, per AGMA and ISO gear calculation.
Chapter 2, Continued In the previous sections, development of conjugate, face milled as well as face hobbed bevel gearsets - including the application of profile and length crowning - was demonstrated. It was mentioned during that demonstration that in order to optimize the common surface area, where pinion and gear flanks have meshing contact (common flank working area), a profile shift must be introduced. This concluding section of chapter 2 explains the principle of profile shift; i.e. - how it is applied to bevel and hypoid gears and then expands on profile side shift, and the frequently used root angle correction which - from its gear theoretical understanding - is a variable profile shift that changes the shift factor along the face width. The end of this section elaborates on five different possibilities to tilt the face cutter head relative to the generating gear, in order to achieve interesting effects on the bevel gear flank form. This installment concludes chapter 2 of the Bevel Gear Technology book that lays the foundation of the following chapters, some of which also will be covered in this series.
A reader asks: We are currently revising our gear standards and tolerances, and a few problems with the new standard AGMA 2002-C16 have arisen. Firstly, the way to calculate the tooth thickness tolerance seems to need a "manufacturing profile shift coefficient" that isn't specified in the standard; neither is another standard referred to for this coefficient. This tolerance on tooth thickness is needed later to calculate the span width as well as the pin diameter. Furthermore, there seems to be no tolerancing on the major and minor diameters of a gear.
Accurate prediction of gear dynamic factors (also known as Kv factors) is necessary to be able to predict the fatigue life of gears. Standards-based calculations of gear dynamic factors have some limitations. In this paper we use a multibody dynamic model, with all 6 degrees of freedom (DOF) of a high-speed gearbox to calculate gear dynamic factors. The findings from this paper will help engineers to understand numerous factors that influence the prediction of dynamic factors and will help them to design more reliable gears.
This report describes Klingelnberg's vision of Industry 4.0 gear production.
The aim of the study was to apply such a specialized tooth contact analysis method, well-used within the steel gear community, to a polymer gear application to assess what modifications need be made to these models for them to be applicable to polymer gears.
Toyoda's new GS300H5 Gear Skiving Center is the first in the world to equip a skiving function to a general purpose horizontal machining center (HMC), through which mass production of gear parts is achieved. CNC controls and a high speed rotary table were developed specifically to achieve high-speed, multifunctional machining, as a compact and lightweight product, simple in programming functions.
Exciting new machine, cutting tool and software technologies are compelling many manufacturers to take a fresh look at producing their larger gears on machining centers. They're faster than ever, more flexible, easy to operate, highly affordable - and for any type of gear.
Gear Technology interviews Scott Yoders of Liebherr about the latest gear machining technologies of relevance to automotive manufacturers.
In comparison to the visionary Industry 4.0 - or the Fourth Industrial Revolution - the machine tool industry can appear rather down-to-earth.
With the ongoing push towards electric vehicles (EVs), there is likely to be increasing focus on the noise impact of the gearing required for the transmission of power from the (high-speed) electric motor to the road. Understanding automotive noise, vibration and harshness (NVH) and methodologies for total in-vehicle noise presupposes relatively large, internal combustion (IC) contributions, compared to gear noise. Further, it may be advantageous to run the electric motors at significantly higher rotational speed than conventional automotive IC engines, sending geartrains into yet higher speed ranges. Thus the move to EV or hybrid electric vehicles (HEVs) places greater or different demands on geartrain noise. This work combines both a traditional NVH approach (in-vehicle and rig noise, waterfall plots, Campbell diagrams and Fourier analysis) - with highly detailed transmission error measurement and simulation of the complete drivetrain - to fully understand noise sources within an EV hub drive. A detailed methodology is presented, combining both a full series of tests and advanced simulation to troubleshoot and optimize an EV hub drive for noise reduction.
Effective case depth is an important factor and goal in gas carburizing, involving complicated procedures in the furnace and requiring precise control of many thermal parameters. Based upon diffusion theory and years of carburizing experience, this paper calculates the effective case depth governed by carburizing temperature, time, carbon content of steel, and carbon potential of atmosphere. In light of this analysis, carburizing factors at various temperatures and carbon potentials for steels with different carbon content were calculated to determine the necessary carburizing cycle time. This methodology provides simple (without computer simulation) and practical guidance of optimized gas carburizing and has been applied to plant production. It shows that measured, effective case depth of gear parts covering most of the industrial application range (0.020 inch to over 0.250 inch) was in good agreement with the calculation.
The induction hardening and tempering of gears and critical components is traditionally a hot subject in heat treating. In recent years, gear manufacturers have increased their knowledge in this technology for quality gears.
The art of gear hobbing has advanced dramatically since the development and introduction of unique machine and tool features such as no backlash, super rigidity, automatic loading of cutting tools, CNC controls, additional machine power and improved cutter materials and coatings. It is essential to utilize all these features to run the machine economically.
Q&A is your interactive gear forum. Send us your gear design, manufacturing, inspection or other related questions, and we'll put them before our panel of experts.
This article presents some of the findings of cutting investigations at WZL in which the correlation of cutting parameters, cutting materials, tool geometry and tool life have been determined.
The great thing about a trade show the size of IMTS is the amount of options available to attendees. If youâ€™re into cars, fighter jets, machine tools, fighting robots, manufacturing relics or simply the latest technology advancements in a particular industry, youâ€™ll find it at IMTS 2010.
Examples from gears in wind turbine, automotive and industrial applications.
Whatâ€™s that sound? The churning of gear teeth meshing with the creak of film reels. A bit of â€śHolmesian deductionâ€ť leads us to the conclusion that itâ€™s time for the next installment of the Addendumâ€™s Gears in Film Series!
As the automotive industry continues to reinvent itself, new transmission technologies are at the forefront of this effort, and there is a whirlwind of new developments being detailed at the German Car Training Instituteâ€™s Automotive Transmissions and Drive Trains Symposium North America.
Gear manufacturers are moving into an era that will see changes in both engineering practices and industry standards as new end-products evolve. Within the traditional automotive industry, carbon emission reduction legislation will drive the need for higher levels of efficiency and growth in electric and hybrid vehicles. Meanwhile, the fast growing market of wind turbines is already opening up a whole new area of potential for gearbox manufacturers, but this industry is one that will demand reliability, high levels of engineering excellence and precision manufacturing.
The quality of molded plastic gears is typically judged by dimensional feature measurements only. This practice overlooks potential deficiencies in the molding process.
Adaptation key to success for gear software developers.
Hagen Hofmann of Hoefler presents his views on global trade, competition and the future of the gear industry.
The palette of thermoplastic materials for gears has grown rapidly, as have the applications themselves. Designers need to be aware of key properties and attributes in selecting the right material.
For a high-speed gearbox, an important part of power losses is due to the mesh. A global estimation is not possible and an analytical approach is necessary with evaluations of three different origins of power losses: friction in mesh contact, gear windage and pumping effect between teeth.
A series of short reports on global manufacturing growth and the gear industry's role.
Material losses and long production times are two areas of conventional spur and helical gear manufacturing in which improvements can be made. Metalforming processes have been considered for manufacturing spur and helical gears, but these are costly due to the development times necessary for each new part design. Through a project funded by the U.S. Army Tank - Automotive Command, Battelle's Columbus Division has developed a technique for designing spur and helical gear forging and extrusion dies using computer aided techniques.
The effect of various lubricant factors on wormgear efficiency has been evaluated using a variety of gear types and conditions. In particular, the significant efficiency improvements afforded by certain types of synthetic lubricants have been investigated to determine the cause of these improvements. This paper describes broad wormgear testing, both in the laboratory and in service, and describes the extent to which efficiency can be affected by changes in the lubricant; the effects of viscosity, viscosity index improvers and, finally, synthetic lubricants are discussed. The work concludes that lubricant tractional properties can play a significant role in determining gear efficiency characteristics.
The development of a new gear strength computer program based upon the finite element method, provides a better way to calculate stresses in bevel and hypoid gear teeth. The program incorporates tooth surface geometry and axle deflection data to establish a direct relationship between fillet bending stress, subsurface shear stress, and applied gear torque. Using existing software links to other gear analysis programs allows the gear engineer to evaluate the strength performance of existing and new gear designs as a function of tooth contact pattern shape, position and axle deflection characteristics. This approach provides a better understanding of how gears react under load to subtle changes in the appearance of the no load tooth contact pattern.
This article describes a new technique for the size determination of external Involute splines by using a span measuring method. It provides application performance information demonstrating how this method and its measurements correlate with the traditional spline ring gage sizing method.
This special advertising section features some of the premier gear-related exhibitors at IMTS 2004.
The approximate tensile strength of any steel is measured by its hardness, Table 1. Since hardness is determined by both chemical composition and heat treatment, these are the two important metallurgical considerations in selecting gear steels.
Large marine gearboxes. More than a year in production, each weighing 125,000 pounds, the gearboxes were for U.S. Navy amphibious ships, for combining the power of 10,000 hp diesel engines to drive propeller shafts. They were also the last major gear products shipped from Philadelphia Gear Corp.â€™s King of Prussia factory.
The Pentac Plus is the latest generation of Gleasonâ€™s Pentac bevel gear cutting system. It is designed to allow much higher tool life and improved productivity, especially for cutters using multiple face blade geometry.
When a man looks into a mirror, the image reflects who he is today. But it also reveals who he used to be. Although appearances change, many of the underlying characteristics remain the same. The same is true with Gear Technology, as we celebrate our 20th anniversary and reflect on who we are.
An analysis of possibilities for the selection of tool geometry parameters was made in order to reduce tooth profile errors during the grinding of gears by different methods. The selection of parameters was based on the analysis of he grid diagram of a gear and a rack. Some formulas and graphs are presented for the selection of the pressure angle, module and addendum of the rack-tool. The results from the grinding experimental gears confirm the theoretical analysis.
A study was performed to evaluate fault detection effectiveness as applied to gear-tooth pitting-fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study.
I recently attended a briefing, arranged by the White House, regarding the Treasury's tax simplification plan. A Treasury Undersecretary explained that their goal was to come up with a tax code that was "fair" to everyone.
The objective of this study was to investigate the limits concerning possible reduction of lubricant quantity in gears that could be tolerated without detrimental effects on their load carrying capacity.
One of the hot items on the public agenda these days is "The Environment." Suddenly everyone wants to save the whales and the rain forest. Politicians, rock stars, and big business have all discovered that you can't get anything but good press for saying that you're in favor of trees and marine mammals.
ISO 6336 Calculation of Load Capacity of Spur and Helical Gears was published in 1997 after 50 years of effort by an international committee of experts whose work spanned three generations of gear technology development. It was a difficult compromise between the existing national standards to get a single standard published which will be the basis for future work. Many of the compromises added complication to the 1987 edition of DIN 3990, which was the basic document.
As a result of extensive research into the vibration characteristics of gear drives, a systematic approach has evolved, by which damaging resonances can be eliminated. The method combines finite element techniques with experimental signature and modal analyses. Implementation of the bulk of the method can be carried out early in the design stage. A step-by-step description of the approach, as it was applied to an existing accessory drive, is given in the text. It is shown how premature bearing failures were eliminated by detuning the torsional oscillations of a gearshaft. A dramatic reduction in vibration levels was achieved as a result of detuning the problem gear. The proposed approach can be extended to other types of rotating machines.
The present article contains a preliminary description of studies carried out by the authors with a view toward developing asymmetrical gear teeth. Then a comparison between numerous symmetrical and asymmetrical tooth stress fields under the same modular conditions follows. This leads to the formulation of a rule for similar modules governing variations of stress fields, depending on the pressure angle of the nonactive side. Finally a procedure allowing for calculations for percentage reductions of asymmetrical tooth modules with respect to corresponding symmetrical teeth, maximum ideal stress being equal, is proposed. Then the consequent reductions in size and weight of asymmetrical teeth are assessed.
It isn't for everyone, but... Within the installed base of modern CNC gear profile grinding machines (approximately 542 machines worldwide), grinding from the solid isn't frequent, but a growing number of gear profile grinder users are applying it successfully using CBN-plated wheels.
We are all looking for ways to increase production without sacrificing quality. One of the most cost-effective ways is by improving the substrate material of your hob. Solid carbide hobs are widely used in many applications throughout the world. LMT-Fette was the first to demonstrate the use of solid carbide hobs in 1993 on modern high-speed carbide (HSC) hobbing machines. Since then the process of dry hobbing has been continuously improving through research and product testing. Dry hobbing is proving to be successful in the gear cutting industry as sales for dry hobbing machines have steadily been rising along with the dramatic increase in sales of solid carbide hobs.
Today gear drive operations have several options when selecting the proper lubricant for their gearboxes. As in the past, the primary lubricant used for gearbox lubrication is mineral oil. But with the advances in technology, synthetic hydrocarbons (PAOs) and polyglycols show very specific advantages in certain applications. With gear drives becoming more and more precise, it is now also to the benefit of the gear operator to verify that he or she has the proper additive package and viscosity in the lubricant selected. Fig. 1 shoes that a gear oil is a combination of a base oil and specific additives. The base oils can be either mineral oil, a synthetic or even in some cases a combination of the two.
For heat treatment of tool and alloy steels, the end-user has a wide range of basic types of heat treating equipment to choose from. This article reviews them and details the criteria that must be considered in selecting equipment for a specific application. In making this choice, the most important criterion must be the quality of the tool or part after processing.
Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ration under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque and power. Significant parameters in the design are the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near-optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.
The aim of this article is to show a practical procedure for designing optimum helical gears. The optimization procedure is adapted to technical limitations, and it is focused on real-world cases. To emphasize the applicability of the procedure presented here, the most common optimization techniques are described. Afterwards, a description of some of the functions to be optimized is given, limiting parameters and restrictions are defined, and, finally, a graphic method is described.
Worm gears are among the oldest types of gearing, but that does not mean they are obsolete, antiquated technology. The main reasons for the bad experiences some engineers have with worm gearing are misapplication and misuse. No form of gearing works for every application. Strengths and weaknesses versus the application must be weighed to decide which form of gearing to use. For proper application and operation of worm gears, certain areas that may differ from other types of gearing need to be addressed.
Several trends in mechanical engineering are leading to greater surface stress on components and thus to unacceptable wear. These trends include greater stresses due to increased power densities; the need to maintain high precision of components throughout their service life; and the environmental imperative to reduce use of lubricants and additives.
In many gear transmissions, a tooth load on one flank is significantly higher and is applied for longer periods of time than for the opposite one; an asymmetric tooth shape reflects this functional difference. This paper describes an approach that rationalizes the degree of asymmetry (or asymmetry factor K) selection to meet a variety of operating conditions and requirements for custom gear drives.
Noisy gear trains have been a common problem for gear designers for a long time. With the demands for smaller gear boxes transmitting more power at higher rpms and incumbent demands for greater efficiency, gear engineers are always searching for new ways to reduce vibration and limit noise without increasing costs.
For many years chromium has been a popular alloy for heat treatable steels because of its contribution to hardenability more than offsets its costs. As a consequence, it is specified in such high-tonnage steel grades as the 5100, 4100, and 8600 series; and, as a result, about 15% of the annual U.S. consumption of chromium is used in constructional alloy steels.
The manufacturing process to produce a gear essentially consist of: material selection, blank preshaping, tooth shaping, heat treatment, and final shaping. Only by carefully integrating of the various operations into a complete manufacturing system can an optimum gear be obtained. The final application of the gear will determine what strength characteristics will be required which subsequently determine the material and heat treatments.
The following is a general overview of some of the different factors that lead to the specific design. and the selection of the correct tool for a given hobbing application.
The power of high speed gears for use in the petrochemical industry and power stations is always increasing. Today gears with ratings of up to 70,000kW are already in service. For such gears, the failure mode of scoring can become the limiting constraint. The validity of an analytical method to predict scoring resistance is, therefore, becoming increasingly important.
The higher load carrying capacities, compact dimensions and longer life of hardened gears is an accepted fact in industry today. However, the costs involved in case hardening and subsequent finishing operations to achieve these advantages are considerable. For example, in order to achieve desired running properties on larger gears, it has been necessary to grind the tooth flanks. This costly operation can now be replaced, in many cases, by a new Hard Cutting (HC) process which permits the cutting of hardened gears while maintaining extremely low tooling costs.
The last decade has been a period of far-reaching change for the metal working industry. The effect of higher lubricant costs, technical advances in machine design and increasing competition are making it essential that manufacturers of gears pay more attention to testing, selecting and controlling cutting fluid systems. Lubricant costs are not a large percentage of the process cost relative to items such as raw materials, equipment and labor, and this small relative cost has tended to reduce the economic incentive to evaluate and to change cutting fluids.
Experience has proven that the involute provides the most satisfactory profile for spur and helical gear teeth, and fulfills the requirements for transmitting smooth, uniform angular motion.
The south-pointing chariot exhibited at the Smithsonian Institution, Washington, D.C., (circa 2600 BC)is shown in Fig. 1. Although the mechanism is ancient, it is by no means either primitive or simplistic. The pin-tooth gears drive a complex system, wherein the monk on the top of the chariot continues to point in a preset direction, no matter what direction the vehicle in moved, without a slip of the wheels.(1)
The effort described in this paper addresses a desire in the gear industry to increase power densities and reduce costs of geared transmissions. To achieve these objectives, new materials and manufacturing processes, utilized in the fabrication of gears, and being evaluated. In this effort, the first priority is to compare the performance of gears fabricated using current materials and processes. However, once that priority is satisfied, it rapidly transforms to requiring accurate design data to utilize these novel materials and processes. This paper describes the effort to address one aspect of this design data requirement.
This paper reviews the necessity for detailed specification, design and manufacture to achieve required performance in service. The precise definition of duty rating and a thorough understanding of the environmental conditions, whether it is in a marine or industrial application, is required to predict reliable performance of a gearbox through its service life. A case study relating to complex marine gears and other general practice is presented to review the techniques used by Allen Gears to design and develop a gearbox that integrates with the requirements of the whole machinery installation. Allen Gears has considerable experience in the design of a variety of industrial and marine gears(Ref. 1,2).
Computer technology has touched all areas of our lives, impacting how we obtain airline tickets, purchase merchandise and receive medical advice. This transformation has had a vast influence on manufacturing as well, providing process improvements that lead to higher quality and lower costs. However, in the case of the gear industry, the critical process of tooth contact pattern development for spiral bevel gears remains relatively unchanged.
"Ahem. Could everybody please scootch over? We need to make as much room as possible, because we're expecting a full house."
Transmission errors, axial shuttling forces and friction result in bearing forces that serve as the major excitations of gear noise. This paper will use these factors as well as gear stresses and tribological factors to assist in obtaining optimal gear designs.
In the past, the blades of universal face hobbing cutters had to be resharpened on three faces. Those three faces formed the active part of the blade. In face hobbing, the effective cutting direction changes dramatically with respect to the shank of the blade. Depending on the individual ratio, it was found that optimal conditions for the chip removal action (side rake, side relief and hook angle) could just be established by adjusting all major parameters independently. This, in turn, results automatically in the need for the grinding or resharpening of the front face and the two relief surfaces in order to control side rake, hook angle and the relief and the relief angles of the cutting and clearance side.
Darle Dudley, an internationally known gear engineer, of San Diego, CA, died April 11 of hear problems and a serious infection. He was 86 years old.
A special advertising section featuring gear industry exhibitors at IMTS 2012.
Universal tractor transmission oil (UTTO) is multifunctional tractor oil formulated for use in transmissions, final drives, differentials, wet brakes, and hydraulic systems of farm tractors employing a common oil reservoir. In the present work, the gear protection properties of two formulated vegetable-based UTTO oils, one synthetic ester-based UTTO oil, one synthetic ester gear oil, and one mineral based UTTO oil are investigated.
I. Inspect failed components as soon as possible. If an early on-site inspection is not possible, someone at the site must preserve the evidence based on your instructions.
The complete Product News section from the August 2012 issue of Gear Technology.
Except for higher-end gear applications found in automotive and aerospace transmissions, for example, high-performance, sintered-steel gears match wrought-steel gears in strength and geometrical quality. The enhanced P/M performance is due largely to advances in powder metallurgy over last two decades, such as selective surface densification, new materials and lubricants for high density and warm-die pressing. This paper is a review of the results of a decade of research and development of high- performance, sintered-steel gear prototypes.
The complete Industry News section from the August 2012 issue of Gear Technology.
The complete Product News section from the September 2012 issue of Gear Technology.
Special advertising section for IMTS 2012
IMTS exists primarily as a buy-and-sell North American venue for practically every conceivable technology used in manufacturing, and in that regard it has no equal. There youâ€™ll find on display the latest and greatest technology, from hardware to software and everything in between. But anyone who has attended past shows is aware that IMTS is much more than that. Following is a rundown of "extracurricular" activities youâ€™ll find waiting for your edification and enjoyment.
Richard Spens has a hobby that leads him onto the Internet, through magazines, to auctions and into farmers' back yards.
Q&A is an interactive gear forum. Send us your gear design, manufacturing, inspection or other related questions, and we will pass them to our panel of experts.
Modern gear design is generally based on standard tools. This makes gear design quite simple (almost like selecting fasteners), economical, and available for everyone, reducing tooling expenses and inventory. At the same time, it is well known that universal standard tools provide gears with less than optimum performance and - in some cases - do not allow for finding acceptable gear solutions. Application specifies, including low noise and vibration, high density of power transmission (lighter weight, smaller size) and others, require gears with nonstandard parameters. That's why, for example, aviation gear transmissions use tool profiles with custom proportions, such as pressure angle, addendum, and whole depth. The following considerations make application of nonstandard gears suitable and cost-efficient:
The Dictionary of American Biography describes him as "one of the founders of the gear-cutting industry in the United State." He built the first hobbing machine for cutting spur gears. He founded the companies that are now Boston Gear and Philadelphia Gear Corp.
Dear Editor, I am writing this in response to some articles appearing in your journal, but I want to take the opportunity, also, to express my thanks for all the good work your publication is doing. I always look forward to your next issue being in my mail slot. I know I will find timely technical articles relevant to our manufacturing situation here at Amarillo Gear Co., as well as thought provoking commentary on events and trends affecting our business. The Publisher's Page is always worth the reading.
The complete Product News section from the October 2012 issue of Gear Technology.
The implementation of powder metal (PM)components in automotive applications increases continuously, in particular for more highly loaded gear components like synchromesh mechanisms. Porosity and frequently inadequate material properties of PM materials currently rule out PM for automobile gears that are subject to high loads. By increasing the density of the sintered gears, the mechanical properties are improved. New and optimized materials designed to allow the production of high-density PM gears by single sintering may change the situation in the future.
Ever since the first cavemen bartered clamshells and spears, business has been about people interacting. In simpler times, commerce was conducted according to the look in someone's eye or the feel of his handshake. Today we have computers, fax machines, modems, e-mail and cell phones - all powerful tools that have increased our productivity. Those devices have shrunk our world, but, in some ways, they've also distanced us from each other by reducing personal interaction. In the name of efficiency, profitability and progress, we've found ways to place orders, sell products and exchange information without ever coming into contact with another human being.
Recent trends in gear cutting technology have left process engineers searching for direction about which combination of cutting tool material, coating, and process technology will afford the best quality at the lowest total cost. Applying the new technologies can have associated risks that may override the potential cost savings. The many interrelated variables to be considered and evaluated tend to cloud the issue and make hobbing process development more difficult.
Q&A is an interactive gear forum. Send us you gear design, manufacturing, inspection or other related questions, and we will pass them to our panel of experts.
Users of gear-cutting tools probably do not often consciously consider the raw material from which those hobs, broaches or shavers are made. However, a rudimentary awareness of the various grades and their properties may allow tool users to improve the performance or life of their tools, or to address tool failures. The high-speed steel from which the tool is made certainly is not the only factor affecting tool performance, but as the raw material, the steel may be the first place to start.
Besides Gear Expo 2001, Detroit is home to a museum with an 1896 Durya Motor Wagon, America's first production car; home to a casino in a building that use to be Internal Revenue Service offices; and home to the studio where Diana Ross and the Supremes recorded "Stop in the Name of Love."
Nobody's sure what went on in Bolsa Chica, CA, when gear-shaped stones were used there 8,700 years ago, but a popular belief is that at least some activity revolved around manufacturing.
Economic production is one of the main concerns of any manufacturing facility. In recent years, cost increases and tougher statutory requirements have increasingly made cutting fluids a problematic manufacturing and cost factor in metalworking. Depending on the cutting fluid, production process and supply unit, cutting-fluid costs may account for up to 16% of workpiece cost. In some cases, they exceed tool cost by many times (Ref. 1). The response by manufacturers is to demand techniques for dry machining (Ref. 2).
Mineral-oil-base lubricants show a significant decrease of kinematic viscosity with rising temperature, as exemplified in Figure 1 by lubricants for vehicle gears. An important attribute of lubricants is their viscosity index (VI), according to DIN/ISO 2909 (Ref. 4). Viscosity index is a calculated coefficient, which characterizes the change of viscosity of lubricants as a function of temperature. A high viscosity index represents a low variation of viscosity due to temperature and vice versa. A low viscosity-temperature-dependence is required for lubricants that are operated at significantly varying temperature conditions, such as vehicle engine and gear lubricants in summer and winter time. This way, the oils remain flowing and pumpable at low temperatures on the one hand; and on the other hand, sufficiently thick lubricant films can be formed at higher temperatures for a safe separation of the surfaces.
Early in the practice of involute gearing, virtually all gears were made with the teeth in a standard relationship to the reference pitch circle. This has the advantages that any two gears of the same pitch, helix angle and pressure angle can operate together, and that geometry calculations are relatively simple. It was soon realized, though, that there are greater advantages to be gained by modifying the relationship of the teeth to the reference pitch circle. The modifications are called profile shift.
Traditionally, high-quality gears are cut to shape from forged blanks. Great accuracy can be obtained through shaving and grinding of tooth forms, enhancing the power capacity, life and quietness of geared power transmissions. In the 1950s, a process was developed for forging gears with teeth that requires little or no metal to be removed to achieve final geometry. The initial process development was undertaken in Germany for the manufacture of bevel gears for automobile differentials and was stimulated by the lack of available gear cutting equipment at that time. Later attention has turned to the forging of spur and helical gears, which are more difficult to form due to the radial disposition of their teeth compared with bevel gears. The main driver of these developments, in common with most component manufacturing, is cost. Forming gears rather than cutting them results in increased yield from raw material and also can increase productivity. Forging gears is therefore of greater advantage for large batch quantities, such as required by the automotive industry.
Bodine Electric Co. of Chicago, IL., has a 97-year history of fine-and medium-pitch gear manufacturing. Like anywhere else, traditions, old systems, and structures can be beneficial, but they can also become paradigms and obstacles to further improvements. We were producing a high quality product, but our goal was to become more cost effective. Carbide hobbing is seen as a technological innovation capable of enabling a dramatic, rather than an incremental, enhancement to productivity and cost savings.
The gear industry, like any other, is constantly changing. Companies vie for customers, resources, employees and time. They come, go and shuffle for position. Usually, the changes are small, affecting only a few companies. But sometimes, many changes happen at once, and when those changes are large, it can seem as though an earthquake has struck and transformed the landscape of the industry.
Carbon steels have primarily been used to manufacture aerospace gears due to the steels' mechanical characteristics. An alloyed low carbon steel is easily case-hardened to obtain a hard wear surface while maintaining the ductile core characteristics. The microstructure achieved will accept the heavy loading, shocks, and elevated temperatures that gears typically experience in applications. The carbon steel machinability allows for general machining practices to be employed when producing aerospace gears versus the more advanced metal removal processes required by stainless and nickel-based alloys.
Technology creates excitement. Just consider the natural buzz around IMTS, where manufacturers will go to explore ways they can increase productivity, improve quality, decrease costs or provide better service.
The complete Industry News section from the September 2012 issue of Gear Technology.
The essence of designing gears is often by necessity risk-averse, given that many of them are used in applications where loss of life is a distinct possibility. The Gear Research Institute (GRI) at The Pennsylvania State University conducts risk reduction testing with the same goal in mind - whether it be gears in fighter jets, Ferris wheels, tanks, or countless other gear-reliant vehicles and machinery.
Following is a report on the R&D findings regarding remediation of high-value, high-demand spiral bevel gears for the UHâ€“60 helicopter tail rotor drivetrain. As spiral bevel gears for the UHâ€“60 helicopter are in generally High-Demand due to the needs of new aircraft production and the overhaul and repair of aircraft returning from service, acquisition of new spiral bevel gears in support of R&D activities is very challenging. To compensate, an assessment was done of a then-emerging superfinishing method—i.e., the micromachining process (MPP)—as a potential repair technique for spiral bevel gears, as well as a way to enhance their performance and durability. The results are described in this paper.
It's nice to see old friends. It's also advantageous to make new ones. Gear Expo has always been a family reunion of sorts, but it's first and foremost an opportunity to show off the latest and greatest technologies that are impacting the gear industry today. With this in mind, Gear Technology recently spoke with those responsible for putting the Fall Technical Meeting (FTM) and Gear Expo 2013 together in Indianapolis.
It is widely recognized that the reduction of CO2 requires consistent light-weight design of the entire vehicle. Likewise, the trend towards electric cars requires light-weight design to compensate for the additional weight of battery systems. The need for weight reduction is also present regarding vehicle transmissions. Besides the design of the gearbox housing, rotating masses such as gear wheels and shafts have a significant impact on fuel consumption. The current technology shows little potential of gear weight reduction due to the trade-off between mass optimization and the manufacturing process. Gears are usually forged followed or not by teeth cutting operation.
The complete Industry News section from the May 2013 issue of Gear Technology
The complete Product News section from the June/July 2013 issue of Gear Technology.
Although a cell is dedicated to produce a single part family, it must have the requisite equipment capabilities, routing flexibility, cross-trained employees and, to the extent possible, minimal external process dependencies. Cells are often implemented in job shops since they provide the operational benefits of flowline production.
The complete Industry News section from the June/July 2013 issue of Gear Technology.
Following is a report from The Manufacturers Alliance for Productivity and Innovation (MAPI). Founded in 1933, the alliance contributes to the competitiveness of U.S. manufacturing by providing economic research, professional development, and an independent, expert source of manufacturing information.
The complete Product News Section from the August 2013 issue of Gear Technology.
Our special advertising section featuring Gear Expo exhibitors.
The hob is a perfect example of how a little manufacturing ingenuity can make a reliable, highly productive cutting tool. It's an engineering specimen that creates higher cutting speeds, better wear resistance and increases rigidity. The cutting tool alone, however, can't take all the credit for its resourcefulness. Advanced coating technology from companies like Sulzer, Oerlikon Balzers, Ionbond, Seco Tools and Cemecon helps improve cutting tools by reducing overall costs, increasing tool life and maintaining the highest levels of productivity. The following is a quick recap of new technologies and the latest information in the coating market.
The complete Industry News section from the August 2013 issue of Gear Technology.
The complete Product News section from the September 2013 issue of Gear Technology.
Our special advertising section featuring exhibitors from Gear Expo and ASM Heat Treat 2013
The complete Industry News section from the September 2013 issue of Gear Technology.
The complete Product News section from the October 2013 issue of Gear Technology.
Whether you spent time at Gear Expo in Indianapolis or EMO in Hannover, there was certainly new technology attracting attention. Machine tools are faster, more efficient and can integrate numerous functions in a single setup. Grinding technology is turning science upside down and inside out with high-speed removal rates and increased throughput.
When it comes to purchasing gear lubricants, many people on both the sales and purchasing side decide to play the numbers game. The person with the most numbers, or the biggest numbers, or the lowest numbers, must have the best product - right? Wrong; gear oil selection is not a game, and numbers alone cannot determine the right product for an application.
Designers are constantly searching for ways to reduce rotocraft drive system weight. Reduced weight can increase the payload, performance, or power density of current and future systems. One example of helicopter transmission weight reduction was initiated as part of the United States Army Advanced Rotocraft Transmission program. This example used a split-torque, face-gear configuration concept (Ref. 1). compared to a conventional design with spiral-bevel gears, the split-torque, face-gear design showed substantial weight savings benefits. Also, the use of face gears allows a wide-range of possible configurations with technical and economic benefits (Ref. 2).
The complete Product News section from the May 2013 issue of Gear Technology.
The complete Industry News section from the October 2012 issue of Gear Technology.
The complete Product News section from the January/February 2013 issue of Gear Technology.
A large number of technologies aimed primarily at higher productivity were presented by exhibitors at the AMB, International Exhibition for Metal Working at the Stuttgart Trade Fair Centre in September. Following the successful 2010 show, AMB 2012 boasted further developments in energy and resource efficiency, higher productivity, life cycle performance, quality assurance and user-friendliness.
Indiana Technology and Manufacturing Companies (ITAMCO) has released iBlueâ€”the first handheld bluetooth transmitter that gathers crucial production data and sends it to bluetooth-enabled smartphones, tablets and computers.
The complete Product News section from the November/December 2012 issue of Gear Technology.
Before we get into projections and prognostications about the future, letâ€™s take a minute to review 2012. For many in the gear industry, the year was better than expected. Some manufacturers had a very successful year leading up to an even more successful manufacturing trade show (IMTS 2012). Others were searching for more business, hoping that the general state of the economy wouldnâ€™t make things worse. In some cases, it did.
Understanding the morphology of micropitting is critical in determining the root cause of failure. Examples of micropitting in gears and rolling-element bearings are presented to illustrate morphological variations that can occur in practice.
AGMA925â€“A03 scuffing risk predictions for a series of spur and helical gear sets of transmissions used in commercial vehicles ranging from SAE Class 3 through Class 8.
The complete Industry News section from the November/December 2012 issue of Gear Technology.
"Gear Train" is a new Gear Technology section focusing on training and education in the gear industry. For the first installment, we've focused on AGMA's online and video training programs.
This machine concept facilitates highly productive profile grinding for large workpieces. The range for external and internal gears comprises models for manufacturing workpieces up to 2,000 millimeters â€“ for industrial gear units, wind power, and marine propulsion applications
The complete Industry News section from the January/February 2013 issue of Gear Technology.
Trying to figure out whatâ€™s going on in this crazy economy of ours seems a bit like reading tea leavesâ€”one part pseudoscience and three parts wild conjecture. Of course some pundits are telling us that this bull market has legs, while others insist that weâ€™re due for a major correction. Some pump us up with positive news, while others remind us about scary stuff like the budget deficit, the European financial crisis and unemployment.
"Design for manufacturability" (DFM) is a well-established practice, essential to realizing the successful transformation of concepts into mass-produced gears and motion control devices. And yet, all too often issues that could have been avoided are identified very late in the process that impact production costs and schedules. This suggests that key DFM principles are often underutilized in practice and are not applied consistently - or to the degree necessary - to avoid these negative results.
The complete Product News section from the March/April 2013 issue of Gear Technology.
The shipping department is the closest to the customer, and its main objective is to maximize shipped orders every month. Our lean guru shows how to eliminate waste in the shipping department.
The research presented here is part of an ongoing (six years to date) project of the Cluster of Excellence (CoE). CoE is a faculty-wide group of researchers from RWTH Aachen University in Aachen (North Rhine-Westphalia). This presentation is a result of the groupâ€™s examination of "integrative production technology for high-wage countries," in which a shaft for a dual-clutch gearbox is developed.
The complete Industry News section from the March/April 2013 issue of Gear Technology.
Hobbing is one of the most fundamental processes in gear manufacturing. Its productivity and versatility make hobbing the gear manufacturing method of choice for a majority of spur and helical gears.
For eight days every other year, the sponsor of the International Manufacturing Technology Show (IMTS), the Association for Manufacturing Technology (AMT), strives to turn Chicago's McCormick Place into a "productivity marketplace," the largest and most completer display and demonstration of manufacturing technology ever seen in the Americas. If the growth of the show is any indicator, that effort has been very successful indeed. With over 1.4 million square feet of exhibit space taking up all five levels and all three exhibit halls of McCormick Place, each level would rank as one of the nation's 200 largest trade shows. That wasn't always the size or scope of the show. Its inception, while impressive for the time, was humble by today's standards.
"We're taking over," says Art Milano. It's a bold statement from the engineering manager of Seitz Corporation, one of the largest manufacturers of injection molded plastic gears, but Milano has reason for his optimism. Plastic gears are big business-probably bigger than most gear industry "insiders" realize.
Noncircular gearing is not new. There are well-documented articles covering standard and high order elliptical gears, sinusoidal gears, logarithmic spiral gears, and circular gears mounted eccentrically. What these designs have in common is a pitch curve defined by a mathematical function. This article will cover noncircular gearing with free-form pitch curves, which, of course, includes all the aforementioned functions. This article also goes into the generation of teeth on the pitch curve, which is not usually covered in the technical literature. Needless to say, all this is possible only with the help of a computer.
In the process of developing gear trains, it occasionally occurs that the tip of one gear will drag in the fillet of the mating gear. The first reaction may be to assume that the outside diameter of the gear is too large. This article is intended to show that although the gear dimensions follow AGMA guidelines, if the gear is cut with a shaper, the cutting process may not provide sufficient relief in the fillet area and be the cause of the interference.
In the quest for ever more exacting and compact commercial gears, precision abrasives are playing a key production role - a role that can shorten cycle time, reduce machining costs and meet growing market demand for such requirements as light weights, high loads, high speed and quiet operation. Used in conjunction with high-quality grinding machines, abrasives can deliver a level of accuracy unmatched by other manufacturing techniques, cost-effectively meeting AGMA gear quality levels in the 12 to 15 range. Thanks to advances in grinding and abrasive technology, machining has become one of the most viable means to grind fast, strong and quiet gears.
In today's industrial marketplace, deburring and chamfering are no longer just a matter of cosmetics. The faster speeds at which transmissions run today demand that gear teeth mesh as smoothly and accurately as possible to prevent premature failure. The demand for quieter gears also requires tighter tolerances. New heat treating practices and other secondary gear operations have placed their own set of demands on manufacturers. Companies that can deburr or chamfer to these newer, more stringent specifications - and still keep costs in line - find themselves with a leg up on their competition.
The popular perception today is that technological advancement is an engine running almost out of control. New products and processes are developing faster than we can keep up with them, as anyone who has had a new computer system crash into obsolescence practically before it's out of the box can tell you. But that's not the case everywhere. Transmission technology, for example.
221B Baker Street We've always said that gears show up in all the best places, even, it turns out, among the papers of that most famous of detectives, Sherlock Holmes. "The Adventure of the Engineer's Thumb" is, according to Dr. Watson, a case "so strange in its inception and so dramatic in its details," that it merits a mention even in our exalted pages.
Surface-hardened, sintered powder metal gears are increasingly used in power transmissions to reduce the cost of gear production. One important problem is how to design with surface durability, given the porous nature of sintered gears. Many articles have been written about mechanical characteristics, such as tensile and bending strength, of sintered materials, and it is well-known that the pores existing on and below their surfaces affect their characteristics (Refs. 1-3). Power transmission gears are frequently employed under conditions of high speed and high load, and tooth surfaces are in contact with each other under a sliding-rolling contact condition. Therefore it is necessary to consider not only their mechanical, but also their tribological characteristics when designing sintered gears for surface durability.
Introducing backlash into spline couplings has been common practice in order to provide for component eccentric and angular misalignment. The method presented here is believed to be exact for splines with even numbers of teeth and approximate for those with odd numbers of teeth. This method is based on the reduction of the maximum effective tooth thickness to achieve the necessary clearance. Other methods, such as tooth crowning, are also effective.
Gears are manufactured with thin rims for several reasons. Steel gears are manufactured with thin rims and webs where low weight is important. Nonmetallic gears, manufactured by injection molding, are designed with thin rims as part of the general design rule to maintain uniform thickness to ensure even post-mold cooling. When a thin-rimmed gear fails, the fracture is thought the root of the gear, as shown in Fig. 1a, rather than the usual fillet failure shown in Fig. 1b.
Today motion control systems are migrating from analog to digital technology at an ever increasing rate because digital technology at an ever-increasing rate because digital drives provide performance equal to or exceeding that of analog drives, plus information to run your machine more effectively and manage your quality program and your business. Most of this data is simply not available from analog drives.
Business ethics are like apple pie and motherhood. Few people are willing to come out agin'em. But in reablity, apple pie is full of fat and refined sugar, motherhood is not what it was when June Cleaver ran the kitchen, and business ethics? Well, it's always been easier to talk about them than to actually practice them, and things certainly haven't improved in the last few years.
Gears are designed to be manufactured, processed and used without failure throughout the design life of the gear. One of INFAC's objectives (*see p.24) is to help manufacture of gears to optimize performance and life. One way to achieve this is to identify failure mechanisms and then devise strategies to overcome them by modifying the manufacturing parameters.
The word gear, in various forms, has been in use since around A.D. 1200, according to the Oxford English Dictionary. Last issue we brought you Shakespearean gears. Now we'd like to show you some of the uses Americans have given our favorite word (from the Random House Dictionary of American Slang).
The cutting tool is basic to gear manufacturing. Whether it's a hob, broach, shaper cutter or EDM wire, not much gets done without it. And the mission of the tool remains the same as always; removing material as quickly, accurately and cost-effectively as possible. Progress in the field tends to be evolutionary, coming gradually over time, but recently, a confluence of emerging technologies and new customer demands has caused significant changes in the machines, the materials and the coatings that make cutting tools.
The capabilities and limitations of manufacturing gears by conventional means are well-known and thoroughly documented. In the search to enhance or otherwise improve the gear-making process, manufacturing methods have extended beyond chip-cutting - hobbing, broaching, shaping, shaving, grinding, etc. and their inherent limitations based on cutting selection and speed, feed rates, chip thickness per tooth, cutting pressure, cutter deflection, chatter, surface finish, material hardness, machine rigidity, tooling, setup and other items.
Election News, New Faces, Getting Together, And the winners are...
The diagnosis and prevention of gear tooth and bearing wear requires the discovery and understanding of the particular mechanism of wear, which in turn indicates the best method of prevention. Because a gearbox is a tribologically dependent mechanism, some understanding of gear and bearing tribology is essential for this process. Tribology is the general term for the study and practice of lubrication, friction and wear. If tribology is neglected or considered insignificant, poor reliability and short life will result.
A major source of helicopter cabin noise (which has been measured at over 100 decibels sound pressure level) is the gear box. Reduction of this noise is a NASA and U.S. Army goal.
Continuing our series of interviews with industry leaders, Gear Technology spoke recently with Bradley Lawton, executive vice president of Star Cutter Co., about the role and direction of cutting tools in the gear industry today.
"Values" is one of he buzzwords we hear everywhere today. Family values. Traditional values. Alternative values. Along with a balanced budget, less government and more fiber in our diets, "values" - and their practical counterparts, "ethics" - are being promoted as one of the simple, obvious solutions to what ails us as a country and as individuals.
It takes confidence to be the first to invest in new manufacturing technology. But the payback can be significant. That has been the experience at the Ford Motor Company's Transmission & Chassis Division plant at Indianapolis, IN, which boasts the world's first production application of dry hobbing.
A little more than ten years ago this month, the first Gear Technology came off the presses. It was a fledgling effort in every respect. The gear industry had never a magazine of its very own before. Those of us involved in its production were like first-time parents; we were proud and excited, but unsure of what we'd let ourselves in for. None of us knew if this baby could really fly.
Mike Viney's curiosity about the evolving designs of apple parers began after reading the article, "There's a Fascination in Apple Parers" by Marion Levy, which appeared in the second edition of Linda Campbell's 300 Years of Kitchen Collectibles.
In this article we will characterize the nitride layers that are generated by different nitriding processes and compare their respective wear characteristics.
Getting and keeping a work force capable of meeting the demands of the 21st century is one of the key challenges most U.S. manufacturers face today. That's not even news anymore. I - and others - have been talking about it in editorials and speeches for ten years now. It's also not news that the job is a tough one and that industry-wide response often has not been particularly effective.
On of the key questions confronting any company considering ISO 9000 certification is, how much is this going to cost? The up-front fees are only the beginning. Dissect the ISO 9000 certification procedure with an eye for hidden costs, and two segments of the process will leap out - the cost of consultants and the cost of making in-house improvements for the sake of passing certification. Most of these costs can be controlled by careful selection f the right consultant in the first place.
Going to IMTS? Beware. It's easy to make any number of common mistakes that can turn your productive buying trip into an expensive bomb.
With all the heated debate and hoopla surrounding ISO 9000 certification, everyone seems to have an opinion about whether to sign up. Executives in the gear industry are flooded with information and ideas that often seem at odds. Gear Technology asked AGMA executive director Joe T. Franklin, Jr. to give an industry perspective on the pros and cons of ISO 9000 certification.
Prior to the introduction of titanium nitride to the cutting tool industry in the early 1980s, there was very little progress in the general application of hobbing in the gear cutting industry. The productivity gains realized with this new type of coating initiated a very active time of advancement in the gear manufacturing process.
For environmental and economic reasons, the use of coolant in machining processes is increasingly being questioned. Rising coolant prices and disposal costs, as well as strains on workers and the environment, have fueled the debate. The use of coolant has given rise to a highly technical system for handling coolant in the machine (cooling, filtering) and protecting the environment (filter, oil-mist collector). In this area the latest cutting materials - used with or without coolant - have great potential for making the metal-removal process more economical. The natural progression to completely dry machining has decisive advantages for hobbing.
Precise heat treatment plays an essential role in the production of quality carburized gears. Seemingly minor changes in the heat treating process can have significant effects on the quality, expense and production time of a gear, as we will demonstrate using a case study from one of our customer's gears.
Robots, computers and other signs of high technology abounded at IMTS 94, supporting the claim by many that this was one of the best shows ever. Many of the machines on display had so many robotic attachments and computer gizmos that they looked more like they belonged in some science fiction movie than on the floor of a machine shop.
NC and CNC machines are at the heart of manufacturing today. They are the state-of-the-art equipment everybody has (or is soon going to get) that promise to lower costs, increase production and turn manufacturers into competitive powerhouses. Like many other high tech devices (such as microwaves and VCRs), lots of people have and use them - even successfully - without really knowing much about how they operate. But upgrading to CNC costs a lot of money, so it's crucial to separate the hype from the reality.
Gear design has long been a "black art." The gear shop's modern alchemists often have to solve problems with a combination of knowledge, experience and luck. In many cases, trial and error are the only effective way to design gears. While years of experience have produced standard gearsets that work well for most situations, today's requirements for quieter, more accurate and more durable gears often force manufacturers to look for alternative designs.
Arrow Gear Company of Downers Grove, IL, has implemented a computer system that fully integrates exchange between all of its computer applications. The ELIMS (Electronic Linkage of Information Management Systems) project has increased manufacturing productivity and reduced lead times.
A research program, conducted in conjunction with a U.S. Army contract, has resulted in the development of manufacturing technology to produce a multi-metal composite gear/shaft representing a substantial weight savings compared to a solid steel component. Inertia welding is used to join a steel outer ring to a light-weight titanium alloy web and/or shaft through the use of a suitable interlayer material such as aluminum.
What follows is the first of a series of interviews Gear Technology is conducting with leaders in the gear industry. We will be asking them for their insights on where the industry is, where it's been and where they see it going in the future. Our first interview is with Jim Gleason, president and chairman of Gleason Corporation, Rochester, NY.
You're already a veteran of the computer revolution. Only you and your controller know how much money you've spent and only your spouse knows how many sleepless nights you've had in the last ten years trying to carve out a place in the brave new world of computerized gear manufacturing. PC's, CNCs, CAD, CAM, DNC, SPC, CMM: You've got a whole bowl of alphabet soup out there on the shop floor. Overall these machines have lived up to their promises. Production time is down, quality is up. You have fewer scrapped parts and better, more efficient machine usage.
Heat Treating - The evil twin of the gear processing family. Heat treating and post-heat treating corrective processes can run up to 50% or more of the total gear manufacturing cost, so it's easy to see why, in these days when "lean and mean" production is the rage, and every part of the manufacturing process is under intense scrutiny, some of the harshest light falls on heat treating.
The type of lubricant and the method of applying it to the tooth flanks of large open gears is very important from the point of view of lubrication technology and maintenance. When selecting the type of lubricant and the application method, it is important to check whether it is possible to feed the required lubricant quantity to the load-carrying tooth flanks, This is necessary to avoid deficient lubrication, damage to the gear and operational malfunctions. It is important to determine the type of lubricant, which may be fluid or grease-like. The consistency of the lubricant will have a direct impact on the ability of the lubrication system to feed adequately the lubricant to the gear. The interactions between the common types of lubricant and the lubrication application methods for open gear drives are shown in Fig. 1.
Standards are unlike gears themselves: mundane, but complex, ubiquitous and absolutely vital. Standards are a lingua franca, providing a common language with reference points for evaluating product reliability and performance for manufacturers and users. The standards development process provides a scientific forum for discussion of product design, materials and applications, which can lead to product improvement. Standards can also be a powerful marketing tool for either penetrating new markets or protecting established ones.
Q&A is your interactive gear forum.
Q&A is your interactive gear forum. send us your gear design, manufacturing, inspection or other related questions, and we'll put them before our panel of experts.
In his Handbook of Gear Design (Ref.1), Dudley states (or understates): "The best gear people around the world are now coming to realize that metallurgical quality is just as important as geometric quality." Geometric accuracy without metallurgical integrity in any highly stressed gear or shaft would only result in wasted effort for all concerned - the gear designer, the manufacturer, and the customer - as the component's life cycle would be prematurely cut short. A carburized automotive gear or shaft with the wrong surface hardness, case depth or core hardness may not even complete its basic warranty period before failing totally at considerable expense and loss of prestige for the producer and the customer. The unexpected early failure of a large industrial gear or shaft in a coal mine or mill could result in lost production and income while the machine is down since replacement components may not be readily available. Fortunately, this scenario is not common. Most reputable gear and shaft manufacturers around the world would never neglect the metallurgical quality of their products.
New innovations in the management of hear treating parts washers and yielding powerful, unexpected benefits. Simply, cost effective shop floor practices are being combined in new ways to deliver big quality improvements and significant help to the bottom line. Employing these steps early in the process can dramatically cut waste hauling expenses and greatly reduce environmental liabilities while continuously producing cleaner parts.
The efficient and reliable transmission of mechanical power continues, as always, to be a central area of concern and study in mechanical engineering. The transmission of power involves the interaction of forces which are transmitted by specially developed components. These components must, in turn, withstand the complex and powerful stresses developed by the forces involved. Gear teeth transmit loads through a complex process of positive sliding, rolling and negative sliding of the contacting surfaces. This contact is responsible for both the development of bending stresses at the root of the gear teeth and the contact stresses a the contacting flanks.
The cutting tool industry has undergone some serious changes in the last couple of years in both technology and the way the industry does business. The emerging technology today, as well as for the foreseeable future, is dry cutting, especially in high volume production settings. Wet cutting continues to be as popular as ever with lubrication advances making it more economical and environmentally friendly. There has also developed a process called "near dry cutting." this process offers many of the benefits of fluids while eliminating many of hte associated problems.
Friction weighs heavily on loads that the supporting journals of gear trains must withstand. Not only does mesh friction, especially in worm gear drives, affect journal loading, but also the friction within the journal reflects back on the loads required of the mesh itself.
The grinding of gears with dish wheels (Maad type grinding machines) is widely viewed as the most precise method of gear grinding because of the very short and simple kinematic links between the gear and the tool, and also because the cutting edges of the wheels represent planar surfaces. However, in this grinding method, depending on the parameters of the gears and one of the adjustments (such as the number of teeth encompassed by the grinding wheels), so-called overtravel at the tip or at the root of the teeth being ground generally occurs. When this happens, machining with only one wheel takes place. As a result, the profile error and the length of the generating path increases while productivity decreases.
Thousands of gear industry professionals will converge October 24-27 in Nashville, TN, for Gear Expo 99, the industry's biennial collection of the latest in gear manufacturing technology. With nearly 50,000 square feet of exhibit space sold more than two months in advance of the show, this year's Gear Expo will offer visitors more opportunity for supplier comparison than ever before. As of July 20, 166 suppliers of equipment, tooling, services and precision gear products were scheduled to participate, with as many as 20 additional booths yet to be sold, according to AGMA vice president and Gear Expo show manager Kurt Medert. The largest previous Gear Expo was held in 1997 in Detroit, with 43,100 square feet of exhibit space and 161 exhibitors.
Material selection can play an important role in the constant battle to reduce gear noise. Specifying tighter dimensional tolerances or redesigning the gear are the most common approaches design engineers take to minimize noise, but either approach can add cost to the finished part and strain the relationship between the machine shop and the end user. A third, but often overlooked, alternative is to use a material that has high noise damping capabilities. One such material is cast iron.
The primary objective in designing reliable gear drives is to avoid failure. Avoiding failure is just as important for the manufacturer and designer as it is for the end user. Many aspects should be considered in order to maximize the potential reliability and performance of installed gearing.
Many people seem to be counting this year's Gear Expo in Nashville as a resounding success. There were 180 American and international exhibitors occupying over 50,000 square feet of exhibit space in the Nashville Convention Center, with total attendance of 2,700. This figure is dramatically down from past shows but that doesn't seem to be an issue with the show organizers. According to Kurt Medert, vice president of AGMA;s Administrative Division, even though attendance was off from the 1997 show, the exhibitors were pleased with the quality of the people who did come to the show. "This was an excellent show for us," said Marty Woodhouse, vice president of sales for Star Cutter Company and chairman of AGMA's Gear Expo committee. "Our customer base was there and they came to buy. It was very active."
Designing a gear set implies a considerable effort in the determination of the geometry that fulfills the requirements of load capacity, reliability, durability, size, etc. When the objective is to design a new set of gears, there are many alternatives for the design, and the designer has the freedom to choose among them. Reverse engineering implies an even bigger challenge to the designer, because the problem involves already manufactured gears whose geometry is generally unknown. In this case, the designer needs to know the exact geometry of the actual gears in order to have a reference for the design.
Helical gear pairs with narrow face width can be theoretically classified into three categories over the contact ration domain whose abscissa is the transverse contact ration and whose ordinate is the overlap contact ratio. There is a direct relation between vibration magnitude and shaft parallelism deviation. To clarify the effect of the tooth deviation types on the vibration behavior of helical gear pairs, performance diagrams on vibration are introduced. the acceleration levels of gear pairs are shown by contour lines on the contact ratio domain. Finally, the performance of gears with bias-in and bias-out modifications is discussed considering the effect of the shaft parallelism deviation with use of the developed simulator on a helical gear unit. It becomes clear that there is an asymmetrical feature on the relation between the vibration magnitude of a gear pair and the direction of each deviation.
Clocks with wooden gears? In these days of gears made from plastic, steel and exotic materials; it is a little unusual to hear about a practical application for wooden gears. But that is exactly what David Scholl, the owner of Changing Times, a Harlingen, TX, clockmaker is offering us.
Quality gear manufacturing depends on controlled tolerances and geometry. As a result, ferritic nitrocarburizing has become the heat treat process of choice for many gear manufacturers. The primary reasons for this are: 1. The process is performed at low temperatures, i.e. less than critical. 2. the quench methods increase fatigue strength by up to 125% without distorting. Ferritic nitrocarburizing is used in place of carburizing with conventional and induction hardening. 3. It establishes gradient base hardnesses, i.e. eliminates eggshell on TiN, TiAIN, CrC, etc. In addition, the process can also be applied to hobs, broaches, drills, and other cutting tools.
In general, bevel gears and curvic couplings are completely different elements. Bevel gears rotate on nonintersecting axis with a ratio based on the number of teeth. Curvic couplings work like a clutch (Fig. 1).
Oliver E Saari was an engineer with two great professional loves in his life - writing and gear design, and he was devoted to each in their turn. The same original thinking that informed his fiction, giving life to tales of space exploration, the evolution of man, and many other topics, let him to become one of the great pioneers in gear design.
I'm a big believer in the value of IMTS as a marketplace where gear manufacturers can go and look at the latest machine tools and processes; compare hobbing machines, gear grinders and inspection equipment; see turning, milling or grinding machines in action; and ask questions of the various vendors all in one place. This year's IMTS promised to be the biggest ever, and I have no doubt that it will be a valuable experience to those who go there looking for ways to improve the way they manufacture products.
In 1927 the first precursor of IMTS was held in Cleveland. Back then, lasers, robots and computer controls were just science fiction. At IMTS 98 they will fill nearly every last corner of the recently expended McCormick Place.
Planetary gear transmissions are compact, high-power speed reducers that use parallel load paths. The range of possible reduction ratios is bounded from below and above by limits on the relative size of the planet gears. For a single-plane transmission, the planet gear has no size of the sun and ring. Which ratio is best for a planetary reduction can be resolved by studying a series of optimal designs. In this series, each design is obtained by maximizing the service life for a planetary transmission with a fixed size, gear ratio, input speed, power and materials. The planetary gear reduction service life is modeled as a function of the two-parameter Weibull distributed service lives of the bearings and gears in the reduction. Planet bearing life strongly influences the optimal reduction lives, which point to an optimal planetary reduction ratio in the neighborhood of four to five.
Interesting gear factoids discovered wasting time on the Net while pretending to be working...The first four-function mechanical calculator was built by the mathematician Gottfried Leibniz in 1694. While not commercially available for nearly 200 years, the design was the basis of many such calculators until well into this century.
In 1961 I presented a paper, "Calculating Conjugate Helical Forms," at the semi-annual meeting of the American Gear Manufacturers Association (AGMA). Since that time, thousands of hobs, shaper cutters and other meshing parts have been designed on the basis of the equations presented in that paper. This article presents the math of that paper without the formality of its development and goes on to discuss its practical application.
Physical Vapor Deposited (PVD) coatings such as TiN (Titanium nitride) have been a boon for cutting tool manufacturers. They reduce wear and, therefore, extend tool life, which in turn reduces production costs. But PVD coatings are expensive, and when they fail, they cost both time and money, and they causes of the failure are not always readily apparent.
Electroless Nickel (EN) plating, a process dating back to the 1940s, is one of the predominant metal finishing methods today. It is especially suitable for the gear industry, whose end uses span innumerable other industries, providing an endless assortment of requirements, environments, materials and specifications. EN plating has a broad array of functional features, which include:
In July of 1996 we introduced the gear community to the Internet in these pages through the Gear Industry Home Page (GIHP). This electronic buyers guide for gear machine tools, tooling, accessories and services has proven to be more popular than we could have envisioned. In our first month, we had over 3,000 hits, and in our third month, we have over 4,500. By our fourth month, we topped the 7,000 mark, and we are on our way to 11,000 hits in November. As our advertisers develop their own home sites in order to offer layers of information about their companies, their products and services, we expect this activity will increase even more.
Recent advances in spiral bevel gear geometry and finite element technology make it practical to conduct a structural analysis and analytically roll the gear set through mesh. With the advent of user-specific programming linked to 3-D solid modelers and mesh generators, model generation has become greatly automated. Contact algorithms available in general purpose finite element codes eliminate the need for the use and alignment of gap elements. Once the gear set it placed in mesh, user subroutines attached to the FE code easily roll it through mesh. The method is described in detail. Preliminary result for a gear set segment showing the progression of the contact line load is given as the gears roll through mesh.
Joe Garfien came to America in 1928 to play soccer. He also learned to cut gears and build a business. "When I came here [to America] I came in on a Friday, and I had to go work on Monday, so I found a job at Perfection Gear...and that's how I got started in gears."
"A Decade of Performance" is the theme of the American Gear Manufacturers Association Gear Expo 97, to be held October 19-22 at Detroit's Cobo Hall. Products and services related to every aspect of the gear manufacturing process, from turning and grinding the blanks to coating and inspection of the gears,will be represented at the show.
Hoechst Technical Polymers has expanded its interests in plastic gears with the introduction of the new Plastic Gear Evaluation and Research machine P-Gear. The machine is the centerpiece of the company's continuing efforts to promote and develop the use of plastic gears in higher-powered applications.
When traveling about in search of gears and other adventures, wise explorers bring along as much important information as they can. In the interest of keeping our readers as well-informed as possible, we bring you the following collection of Important Facts About Motor City.
the gear industry is awash in manufacturing technologies that promise to eliminate waste by producing gears in near-net shape, cut production and labor costs and permit gear designers greater freedom in materials. These methods can be broken down into the following categories: alternative ways to cut, alternative ways to form and new, exotic alternatives. Some are new, some are old and some are simply amazing.
A common design goal for gears in helicopter or turboprop power transmission is reduced weight. To help meet this goal, some gear designs use thin rims. Rims that are too thin, however, may lead to bending fatigue problems and cracks. The most common methods of gear design and analysis are based on standards published by the American Gear Manufacturers Association. Included in the standards are rating formulas for gear tooth bending to prevent crack initiation (Ref. 1). These standards can include the effect of rim thickness on tooth bending fatigue (Ref 2.). The standards, however, do not indicate the crack propagation path or the remaining life once a crack has started. Fracture mechanics has developed into a useful discipline for predicting strength and life of cracked structures.
A major source of helicopter cabin noise (which has been measured at over 100 decibels sound pressure level) is the gearbox. Reduction of this noise is a NASA and U.S. Army goal. A requirement for the Army/NASA Advanced Rotorcraft Transmission project was a 10 dB noise reduction compared to current designs.
Happy days are here again, says the old song, and given the current economic numbers, one can scarcely argue. Productivity is up; unemployment is down; inflation is practically nonexistent; the budget deficit is shrinking fast.
Every now and then, it strikes us as wise to keep our thoughts to ourselves and let our betters speak for us. Therefore, we present to you a collection of observations on work; science and other items of interest to gear engineers.
The wind turbine industry has been plagued with gearbox failures, which cause repair costs, legal expenses, lost energy production and environmental pollution.
For over 50 years, grinding has been an accepted method of choice for improving the quality of gears and other parts by correcting heat treat distortions. Gears with quality levels better than AGMA 10-11 or DIN 6-7 are hard finished, usually by grinding. Other applications for grinding include, but are not limited to, internal/external and spur/helical gear and spline forms, radius forms, threads and serrations, compressor rotors, gerotors, ball screw tracks, worms, linear ball tracks, rotary pistons, vane pump rotators, vane slots, and pump spindles.
Every once in a while something happens to fundamentally change the nature of your business. Despite the best of intentions and the most careful planning, there's no way we can anticipate every event. What do you do, for example, when your two biggest competitors merge, when the economy collapses in the region that imports your products or when key employees leave your company? Your reactions may make the difference between success and struggling to survive.
High-speed machining using carbide has been used for some decades for milling and turning operations. The intermittent character of the gear cutting process has delayed the use of carbide tools in gear manufacturing. Carbide was found at first to be too brittle for interrupted cutting actions. In the meantime, however, a number of different carbide grades were developed. The first successful studies in carbide hobbing of cylindrical gears were completed during the mid-80s, but still did not lead to a breakthrough in the use of carbide cutting tools for gear production. Since the carbide was quite expensive and the tool life was too short, a TiN-coated, high-speed steel hob was more economical than an uncoated carbide hob.
The complete Industry News section from the October 2013 issue of Gear Technology.
The complete Product News section from the September/October 2019 issue of Gear Technology.
The complete Product News section from the November/December 2013 issue of Gear Technology.
The complete Product News section from the August 2018 issue of Gear Technology.
I would like some instructions for setting the degrees and minutes on a Liebherr or Barber Colman hob. Our machines use a Vernier scale to match the lead angle of the cutter to the part to form straight teeth. There is a dispute on how to do this task, and I wanted insight from another professional.
Back around 2005-2010, the most exciting things that were happening in broaching had little to do with broaching. What was happening - and continues to evolve today - was the emergence of on-the-edge CNC, software and servo drive technology. Together, they practically transformed a metalworking process as old as water into a viable, alternative consideration for producing high-volume part runs.
Gear Industry Steps Up to Automation Challenges in Auto Industry. Automotive parts are always moving. They are zipping across conveyors, smashing into each other in bins and traveling across the production chain before ending up inside an automobile. For gears, this can be a somewhat precarious situation as they tend to run best when they're free from nicks, abrasions, cracks or other damages.
The complete industry news section from the May 2018 issue of Gear Technology.
The complete industry news section from the June 2018 issue of Gear Technology.
The complete Product News section from the July 2018 issue of Gear Technology.
The complete Industry News section from the July 2018 issue of Gear Technology.
Our special advertising section highlights some of the booths that will be of interest to gear manufacturers.
The complete Product News section from the January/February issue of Gear Technology.
Our editors have compiled a comprehensive section featuring the booths you won't want to miss at IMTS 2018.
The complete Industry News section from the August 2018 issue of Gear Technology.
Deburring or chamfering of gear teeth is gaining attention in practical settings. And with a view to make the production sequence as efficient as possible, it is becoming increasingly important to be able to implement the deburring tasks directly on the cutting machine after spiral cutting.
Lubricant experts are doing more than ever to make their products less toxic and harmful to everything from the environment to the people using them â€” which comes with plenty of extra benefits for productivity, too!
The complete Industry News section from the November/December 2018 issue of Gear Technology.
The complete Product News section from the January/February issue of Gear Technology.
For this yearâ€™s exercise in large gears, weâ€™re not going to dwell on size range or length, merely look at the fundamental challenges and latest technologies required to manufacture large parts in the gear industry. This could be a gearbox assembly for the construction, mining or oil and gas industries or simply a large standalone gear pinion set for a custom application. Whatever the industry or application, large gears require more preparation, planning and precision than other areas of gear manufacturing.
As you might imagine, I talk to many gear industry people through the course of my day-to-day activities. And there is one question that I hear over and over again. "Joe, we need an experienced gear process engineer. Do you know anyone who's available?"
The DVS gearing specialist Praewema Antriebstechnik continues to expand its technological expertise in order to keep pace with the growing significance of planetary geartrains for automatic and particularly electric vehicles, with the associated need for even higher-precision production of toothed gear components.
In many gear transmissions, tooth load on one flank is significantly higher and is applied for longer periods of time than on the opposite one; an asymmetric tooth shape should reflect this functional difference. The advantages of these gears allow us to improve the performance of the primary drive tooth flanks at the expense of the opposite coast flanks, which are unloaded or lightly loaded during a relatively short work period by drive flank contact and bending stress reduction. This article is about the microgeometry optimization of the spur asymmetric gearsâ€™ tooth flank profile based on the tooth bending and contact deflections.
The usage of modern thrusters allows combining the functions of the drive and the ship rudder in one unit, which are separated in conventional ship propulsion systems. The horizontally oriented propeller is supported in a vertically rotatable nacelle that is mounted underneath the ship's hull. The propeller can directly or indirectly be driven by an electric motor or combustion engine. Direct drive requires the installation of a low-speed electric motor in the nacelle. This present paper concentrates on indirect drives where the driving torque is transferred by bevel gear stages and shafts from the motor to the propeller.
The complete Product News section from the July 2017 issue.
In several applications like hoisting equipment and cranes, open gears are used to transmit power at rather low speeds (tangential velocity < 1m/s) with lubrication by grease. In consequence those applications have particularities in terms of lubricating conditions and friction involved, pairing of material between pinion and gear wheel, lubricant supply, loading cycles and behavior of materials with significant contact pressure due to lower number of cycles.
Grinding of bevel and hypoid gears creates on the surface a roughness structure with lines that are parallel to the root. Imperfections of those lines often repeat on preceding teeth, leading to a magnification of the amplitudes above the tooth mesh frequency and their higher harmonics. This phenomenon is known in grinding and has led in many cylindrical gear applications to an additional finishing operation (honing). Until now, in bevel and hypoid gear grinding, a short time lapping of pinion and gear after the grinding operation, is the only possibility to change the surface structure from the strongly root line oriented roughness lines to a diffuse structure.
Gear hobbing is one of the most productive manufacturing processes for cylindrical gears. The quality of the gears is a result of the tool quality, the precision of the workpiece, tool clamping and kinematics of the machine. The dry gear hobbing process allows machining of gears with a quality according to the DIN standard up to IT 5. To evaluate which gear quality is possible to machine with a given clamping and hob, it is useful to simulate the process in advance.
Special Advertising Section featuring Gear Expo exhibitors.
RCD Engineering's switch from manual to CNC hobbing operations breaks gear manufacturing lead time records with Bourn & Koch 100H in their gear production pit crew.
Skiving will be front and center when the gear industry comes together in Columbus this October. Attendees will find dedicated skiving equipment, multifunctional machines with skiving options and a slew of new cutting tools, machine designs and modifications to make the process more efficient and robust.
In order to improve load-carrying capacity and noise behavior, gears usually have profile and lead modifications. Furthermore, in gears where a specified tooth-flank load application direction (for drive and coast flanks) is a design enhancement, or even compulsory, the asymmetric tooth profile is a further solution. Nowadays, many gears need to be hard finished. Continuous generating grinding offers a very high process efficiency, but is this process able to grind all modifications, especially asymmetric gears? Yes, it is!
It's probably no surprise to anyone that the majority of the gear industry had a pretty good year in 2017, and that most gear manufacturers are expecting a pretty good 2018 as well. After all, most major economic indicators - including the ones that focus on the manufacturing sector - have been positive for some time.
EMO is arguably the most important trade show when it comes to the introduction of machine tool technology, and this year's show - taking place from September 18-23 in Hannover, Germany - promises not to disappoint. We've talked to a number of gear manufacturing technology providers to give you a sneak peak of what you can expect to see if you attend this year.
Gear Expo 2017 is your best opportunity to expand your knowledge, get answers to your technical questions and solve your toughest manufacturing challenges. The reason is quite simple. Gear Expo provides you with the greatest collection of gear expertise, know-how and experience you can find.
This special advertising section highlights exhibitors from Gear Expo 2017 and ASM Heat Treat 2017.
First, the facts: powder metallurgy is a cost-effective method of forming precision net-shape metal components that allows for more efficiently designed products. It saves valuable raw materials through recycling and the elimination of costly secondary-machining. PM competes with wrought steel gears as the technology continues to advance. You'll find PM components in everything from automobile transmissions to aircraft turbine engines, surgical equipment and power tools.
When manufacturing powder metal (PM) gears lead crowning is not achievable in the compaction process. This has to be accomplished either by shaving, grinding or honing. Each of these processes has their merits and draw backs. When employing rolling using a roll burnishing machine lead crowning can be accomplished but due to errors in profile a hard finishing operation such as grinding is used by the industry. In this paper a helical PM gear that has sufficient tolerance class after rolling has been tested in a test rig for durability and the wear has been studied.
In order to reduce costs for development and production, the objective in gearbox development and design is to predict running and noise behavior of a gearbox without manufacturing a prototype and running expensive experimental investigations. To achieve this objective, powerful simulation models have to be set up in a first step. Afterwards, those models have to be qualified and compared to experimental investigations. During the investigation procedure of gearboxes, there are two possibilities to evaluate the running and noise behavior: quasi-static and dynamic investigations. In times of engine downsizing, e-mobility and lightweight design, the dynamic excitation behavior is becoming increasingly important.
Although gear geometry and the design of asymmetric tooth gears are well known and published, they are not covered by modern national or international gear design and rating standards. This limits their broad implementation for various gear applications, despite substantial performance advantages in comparison to symmetric tooth gears for mostly unidirectional drives. In some industries â€” like aerospace, that are accustomed to using gears with non-standard tooth shapes â€” the rating of these gears is established by comprehensive testing. However, such testing programs are not affordable for many other gear drive applications that could also benefit from asymmetric tooth gears.
The objective of this work is to introduce a method for the calculation of the tooth root load carrying capacity for gears, under consideration of the influence of the defect size on the endurance fatigue strength of the tooth root. The theoretical basis of this method is presented in this paper as well as the validation in running tests of helical and beveloid gears with different material batches, regarding the size distribution of inclusions. The torque level for a 50 percent failure probability of the gears is evaluated on the test rig and then compared to the results of the simulation. The simulative method allows for a performance of the staircase method that is usually performed physically in the back-to-back tests for endurance strength, as the statistical influence of the material properties is considered in the calculation model. The comparison between simulation and tests shows a high level of accordance.
Contrary to what appears to be popular belief, 5-axis CNC gear manufacturing is not limited to milling with end mill, ball mill or CoSIMT (Conical Side Milling Tool â€” it is the generic form of the Sandvik InvoMill and Gleason UpGear tools.) tools, where throughput is too low to prevent production at any significant level. Straight and spiral bevel gear manufacturing on 5-axis CNC machines using face mill cutters provides essentially the same throughput as conventional gear cutting machines â€” with added benefits.
Before Dr. Who, there was Professor Quartermass (a 1950s BBC TV and film creation). And, in the-here-and-now, there is Elon Musk â€” a flesh-and-blood living legend in his own time â€” or mind: take your pick. But the point here is that heâ€™s for real â€” not a fictional sci-fi icon.
A reader wants to know: Are profile ground and hobbed globoidal worm sets better than multi-axis CNC generated globoidal worm gear sets for reduction of noise and vibration?
The complete Product News section from the May 2020 issue of Gear Technology.
The complete Industry News section from the November/December 2019 issue of Gear Technology.
Integrated Production Chains from Kapp Niles, an alternative to press quenching from Seco/Warwick, an expansion of the Profilator line and more.
An economical modernization program gives Designatronics' tried-and-true Gleason No. 102 Coniflex generators a new lease on life for fast, reliable production of smaller precision straight bevel gears.
Spur cylindrical gears are usually cut using a hob and therefore present an essentially straight face to which crowning can be added to prevent edge contact. Rather than using a rack or hob, it is possible to cut cylindrical gears with a face mill cutter. In the following presentation, these gears are termed "spurved," i.e. â€” a contraction of "spur" and "curved."
The complete Industry News section from the March/April issue of Gear Technology.
"Fascinating, fun, and functional." Thatâ€™s how Clayton Boyer describes the gears in the Brew Tipper, his wooden mechanism that pours a bottle of beer into a glass. He adds: "I love creating geared mechanisms and gadgets."
With much of America still under stay-at-home orders, it's very difficult for many of us to stay connected. In our personal lives, we're celebrating birthdays with a drive-by and a wave, we're attending religious service on our laptops and talking with loved ones via video chat. If you're allowed to go to work, you're expected to wear a mask and keep your distance. And if you're working from home, your only connection to co-workers, employers, suppliers and vendors is via virtual meetings and conference calls.
Nowadays, the progress in polymer materials and injection molding processing has enabled a drastic expansion of plastic gear applications. They are used not only for lightly loaded motion transmissions, but also in moderately loaded power drives in automotive, agriculture, medical, robotics, and many other industries.
The complete Industry News section from the September/October 2019 issue of Gear Technology.
The complete Industry News section from the May 2020 issue of Gear Technology.
uncertainty is still an everyday experience. Given the wealth of sometimes confusing and contradictory information we are spoon fed by Washington, we are left to our own devices to decipher announcements, e.g. â€” Do I wear a mask or not wear a mask? Do I still need to practice social distancing (a classic oxymoron: what is sociable about keeping distances between each other)? And so on.
Often in life we're forced to make decisions with too little information. Phone's dead and you don't have access to GPS? Lost the instructions for assembling that new gas grill? Don't have the recipe for your favorite dessert? â€śNo problem," I often tell my wife or my kids, "I'll just use the Force."
The complete Product News section from the June 2020 issue of Gear Technology.
Writing about additive manufacturing (AM) and the 3-D printing of gears is somewhat akin to publishing an updated dictionary. A new edition dictionary is literally already out of date before it hits Amazon's or your local bookseller's shelves. New words are coined and definitions are updated constantly. So it is with AM: The technology is evolving so quickly that technical papers and other sources of AM information require constant revision.
Mathematically precise tooth surface definition and contact analysis help to develop state-of-the-art straight bevel gears for many industrial applications. The new Coniflex-Plus manufacturing process utilizes high-speed dry cutting with production times per slot which are about twice compared to the fast Revacycle process.
Due to production by pressing and sintering, PM gears are porous. Since pores reduce the loaded area and are also probable crack initiators, the porosity determines the strength of the PM component. PM gears can be densified to increase their local density and, therefore, the load-carrying capacity. PM gears are compacted locally since they are mainly loaded directly at the surface. A common process to densify PM gears locally is the cold rolling process. The contact conditions in the cold rolling process determine the density profile and, therefore, the material properties of the PM component. The influence of the contact conditions in cold rolling of PM gears on the resulting density profile is yet to be investigated.
The complete Product News section from the November/December 2019 issue of Gear Technology.
Motion + Power Technology Expo VIP Exhibitors special advertising section.
The complete Product News section from the March/April 2019 issue of Gear Technology.
The complete Industry News section from the June 2019 issue of Gear Technology./
Single Piece Flow Streamlines Production for High-Volume Gear Manufacturers.
PSP Peugeot Improves Production Process with Blaser Swisslube
The complete Industry News section from the March/April 2019 issue of Gear Technology.
The complete Product News section from the May 2019 issue of Gear Technology.
The complete Industry News section from the May 2019 issue of Gear Technology.
The complete Product News section from the June 2019 issue of Gear Technology.
One way to implement the growing performance requirements for transmissions is by optimizing the surface finish of the gearing. In addition to increasing the flank load capacity and the transmittable torque, this also allows for improvements in efficiency. On Oerlikon bevel gear grinding machines from Klingelnberg, fine grinding can be implemented efficiently in bevel gear production - even in an industrial serial process.
The complete Product News section from the July 2019 issue of Gear Technology.
Photography is an essential part of gear failure analysis. It not only provides a fast, convenient way to accurately document the appearance of gear failure, but also is an effective diagnostic tool because the magnification obtained through photographic enlargement and slide projection often discloses evidence that may have been missed if the gears were not photographed.
With this first installment we begin a series of randomly excerpted chapters from Dr. Hermann J. Stadtfeld's new book â€” Practical Gear Engineering.
The complete Industry News section from the July 2019 issue of Gear Technology.
The complete Product News section from the August 2019 issue of Gear Technology.
When you go to MPT Expo, make sure to visit the exhibitors in our special advertising section!
This study emphasizes the importance of a closed-loop approach togear design and manufacturing to assure designed root fillet shapes are attained in production, and gears meet the design intent.
The authors use data analysis to determine which tolerances have the greatest effect on transmission error, enabling them to make adjustments and reduce production costs.
The complete Industry News section from the August 2019 issue of Gear Technology.
You have challenges. We all do. If your challenges are related to any aspect of gear design, manufacturing, inspection, heat treating or use, the solutions can be found at Motion + Power Technology Expo, which takes place October 15â€“17 in Detroit.
The complete Industry News section from the June 2017 issue of Gear Technology.
The complete Product News section from the June 2017 issue of Gear Technology, featuring the latest from Liebherr, Heller, Sandvik Coromant, Mahr and more.
Light-weight construction and consideration of available resources result in gearbox designs with high load capacity and power density. At the same time, expectations for gear reliability are high. Additionally, there is a diversity of planetary gears for different applications.
Multiple CAM initiatives at Snyder Industries are improving safety, quality and productivity for parts ranging from 50 to 5,000 lbs.
Heat treating is one of the most critical operations in the manufacture of quality gears. Everything can be done to perfection, but if the heat treating isnâ€™t right, all of your hard work and efforts are wasted. We know how important it is for gear manufacturers to find the right heat treating service provider. Thatâ€™s why weâ€™ve compiled this Heat Treat Resource Guide -- the only directory of heat treat service providers thatâ€™s specific to the gear industry. The companies listed here are all interested in working with gear manufacturers, and many of them have specialties and capabilities that are uniquely suited to the types of products you manufacture.
The complete Industry News section from the July 2014 issue of Gear Technology.
The complete Product News section from the August 2014 issue of Gear Technology.
Special advertising section featuring IMTS 2014 booths you won't want to miss!
The honing of gears - by definition - facilitates ease of operation, low noise and smoother performance in a transmission. Honing also contributes to reduced friction in the powertrain. Both the intense cutting (roughing process) as well as the functionally fine- finishing of transmission gears can be performed in one setup, on one machine.
The complete Industry News section from the August 2014 issue of Gear Technology.
The complete product news section from the September / October 2014 Issue Gear Technology.
The hobbing and generation grinding production processes are complex due to tool geometry and kinematics. Expert knowledge and extensive testing are required for a clear attribution of cause to work piece deviations. A newly developed software tool now makes it possible to simulate the cutting procedure of the tool and superimpose systematic deviations on it. The performance of the simulation software is illustrated here with practical examples. The new simulation tool allows the user to accurately predict the effect of errors. With this knowledge, the user can design and operate optimal, robust gearing processes.
The complete Industry News section from the May 2014 issue of Gear Technology.
The complete Industry News section from the September / October 2014 issue of Gear Technology.
Most companies spend this time of year crystal ball gazing. Managers want to know the future so they can make projections, plan schedules, determine budgets and make major decisions that will ensure their success.
From a technological perspective, there typically aren't many EUREKA! breakthroughs in the "state of the gear industry" to report, and 2014 was really no different.
This article discusses applications of statistical process capability indices for controlling the quality of tooth geometry characteristics, including profile and lead as defined by current AGMA-2015, ISO-1328, and DIN-3960 standards. It also addresses typical steps to improve manufacturing process capability for each of the tooth geometry characteristics when their respective capability indices point to an incapable process.
The complete Industry News section from the November/December 2014 issue.
The complete Product News section from the November/December 2014 issue.
The name Gleason is practically synonymous with gear manufacturing. Since the company was founded in 1865, the technology of gear manufacturing has been its focus, its core and its competitive advantage.
The complete Product News section from the July 2014 issue of Gear Technology.
The complete Product News Section from the May 2014 issue of Gear Technology.
This issue, GT Extras brings you "Heat Treat and Induction Hardening of Industrial Gears," a treasure trove of heat treating related technical articles and a call for help in preparation for AGMA's 100th anniversary.
The complete Industry News section from the June 2014 issue of Gear Technology.
Historically, wind turbine gearbox failures have plagued the industry. Yet an effective oil analysis program will increase the reliability and availability of your machinery, while minimizing maintenance costs associated with oil change-outs, labor, repairs and downtime. Practical action steps are presented here to improve reliability.
The complete Industry News section from the November/December 2013 issue of Gear Technology.
Gears in nature: The Issus develops working gears in response to selective pressure.
The complete Product News section from the January/February 2014 issue of Gear Technology.
Much of the existing guidelines for making large, high-performance gears for wind turbine gearboxes exhibit a need for improvement. Consider: the large grinding stock used to compensate for heat treatment distortion can significantly reduce manufacturing productivity; and, materials and manufacturing processes are two other promising avenues to improvement. The work presented here investigates quenchable alloy steels that, combined with specifically developed Case-hardening and heat treatment processes, exhibits reduced distortion and, in turn, requires a smaller grinding stock.
The complete Industry News section from the January/February 2014 issue of Gear Technology.
The complete Product News section from the June 2014 issue of Gear Technology.
The Addendum team thought it fitting to celebrate George Orwell's 1984 with the 30th Anniversary of Gear Technology. We do not condone the extreme tactics discussed in this fictional press release unless instructed by the proper authorities.
Vibration and noise from wind turbines can be significantly influenced - and therefore reduced - by selecting suitable gearing modifications. New options provided by manufacturers of machine tools and grinding machines, and especially state-of-the-art machines and controls, provide combined gearing modifications - or topological gearing corrections - that can now be reliably machined. Theoretical investigations of topological modifications are discussed here with the actual machining and their possible use.
GT Videos featuring R&P Metrology, the latest from our Twitter and LinkedIn feeds and an introduction to gearboxfailure.com
The grinding/abrasives market is rapidly changing, thanks to new technology, more flexibility and an attempt to lower customer costs. Productivity is at an all-time high in this market, and itâ€™s only going to improve with further R&D. By the time IMTS 2014 rolls around this September, the gear market will have lots of new toys and gadgets to offer potential customers. If you havenâ€™t upgraded any grinding/abrasives equipment in the last five years, now might be a good time to consider the investment.
The heat treatment processing of powder metal (PM) materials like Astaloy requires four steps -- de-waxing, HT sintering, carburizing and surface hardening -- which are usually achieved in dedicated, atmospheric furnaces for sintering and heat treat, respectively, leading to intermediate handling operations and repeated heating and cooling cycles. This paper presents the concept of the multi-purpose batch vacuum furnace, one that is able to realize all of these steps in one unique cycle. The multiple benefits brought by this technology are summarized here, the main goal being to use this technology to manufacture high-load transmission gears in PM materials.
Dressable vitrified bond CBN grinding tools combine the advantages of other common tool systems in generating gear grinding. Yet despite those technological advantages, there is only a small market distribution of these grinding tools due to high tool costs. Furthermore, scant literature exists regarding generating gear grinding with dressable CBN. This is especially true regarding the influence of the grinding tool system on manufacturing-related component properties. The research objective of this report is to determine the advantages of dressable CBN tools in generating gear grinding.
The complete product news section from the March/April 2014 issue, featuring quick-change spline rolling racks from U.S. Gear Tools.
The complete Industry News section from the March/April 2014 issue of Gear Technology.
Decades ago, technology shifted from HSS to indexable inserts in turning and milling. This movement wasn't immediately realized in gear hobbing because coated PM-HSS hobs and complex gear profiles remained highly effective and productive methods. Only fairly recently have gear manufacturers started to take a serious look at indexable technology to cut gear teeth.
A finite elements-based contact model is developed to predict load distribution along the spline joint interfaces; effects of spline misalignment are investigated along with intentional lead crowning of the contacting surfaces. The effects of manufacturing tooth indexing error on spline load distributions are demonstrated by using the proposed model.
At the dawn of the Industrial Revolution, so-called mechanics were tasked with devising the precise methods that would make mass production possible. The result was the first generation of machine tools, which in turn required improved tooling and production methods.
The complete Product News section from the March/April 2015 issue of Gear Technology.
Reduced component weight and ever-increasing power density require a gear design on the border area of material capacity. In order to exploit the potential offered by modern construction materials, calculation methods for component strength must rely on a deeper understanding of fracture and material mechanics in contrast to empirical-analytical approaches.
It's hard for me to think of a massive Christmas exhibit as being the fifth largest tourist attraction in the entire country. I mean, sure, it's still a tradition to show up at the local Macy's to check out the Christmas decorations, but for my generation, the idea that a Christmas exhibit could draw out 1.5 million visitors, more tourists than either Yellowstone Park or the Statue of Liberty received, is stunning. But at the height of its popularity, that's exactly what the Ford Rotunda was.
THE FINAL CHAPTER This is the last in the series of chapters excerpted from Dr. Hermann J. Stadtfeld's Gleason Bevel Gear Technology - a book written for specialists in planning, engineering, gear design and manufacturing. The work also addresses the technical information needs of researchers, scientists and students who deal with the theory and practice of bevel gears and other angular gear systems. While all of the above groups are of course of invaluable importance to the gear industry, it is surely the students who hold the key to its future. And with that knowledge it is reassuring to hear from Dr. Stadtfeld of the enthusiastic response he has received from younger readers of these chapter installments.
While designing gear and spline teeth, the root fillet area and the corresponding maximum tensile stress are primary design considerations for the gear designer. Root fillet tensile stress may be calculated using macro-geometry values such as module, minor diameter, effective fillet radius, face width, etc.
Our special advertising section featuring some of the premier gear industry suppliers at IMTS 2016.
This paper addresses the lubrication of helical gears - especially those factors influencing lubricant film thickness and pressure. Contact between gear teeth is protected by the elastohydrodynamic lubrication (EHL) mechanism that occurs between nonconforming contact when pressure is high enough to cause large increases in lubricant viscosity due to the pressure-viscosity effect, and changes of component shape due to elastic deflection. Acting together, these effects lead to oil films that are stiff enough to separate the contacting surfaces and thus prevent significant metal-to-metal contact occurring in a well-designed gear pair.
The increasing demands in the automotive industry for weight reduction, fuel efficiency and a reduced carbon footprint need to be addressed urgently. Up until now, widely used conventional steels have lived up to expectations. However, with more stringent emissions standards, demands on materials are increasing. Materials are expected to perform better, resulting in a need for increased fatigue strength. A possibility to increase torque on current generations without design changes can be achieved by selecting suitable materials.
There's no substitute for a good software package in gear manufacturing. It's a critical shop floor tool that provides practical engineering services that customers appreciate. When you're in the business of specifying and procuring high quality gears, the software needs to meet many objectives including the consideration of all tolerances of center distance, tooth thickness and tip diameters, root diameters, fillets, etc. It's also imperative that the software updates include the latest revisions to the gear standards being used in the industry.
While the two have taught a variety of AGMA courses over the years, without question their most popular courses are Gear Failure Analysis (Errichello with longtime colleague Jane Muller) and Gearbox CSI: Forensic Analysis of Gear & Bearing Failures (Drago). Drago currently teaches Manufacturing & Inspection (with AGMA instructor Joseph W. Lenski, Jr.) and Gearbox System Design: The Rest of the Story - Everything but the Gears and Bearings (with AGMA instructor Steve Cymbala) as well.
It's Monday morning, December 15, 2036. An autonomous vehicle drops off two engineers in front of a gear manufacturing facility in Metro Detroit. They punch in for work on their wristwatches and pay Uber for the ride on a smartphone. One of the engineers begins walking the shop floor, monitoring a series of collaborative robots using a tablet the size of a paperback novel. These robots interact right on the floor with the minimal staff scheduled to oversee manufacturing operations. Another engineer wears an interactive headset and begins training a group of new engineers (in real time) from China using some form of augmented reality.
A best practice in gear design is to limit the amount of backlash to a minimum value needed to accommodate manufacturing tolerances, misalignments, and deflections, in order to prevent the non-driving side of the teeth to make contact and rattle. Industry standards, such as ANSI/AGMA 2002 and DIN3967, provide reference values of minimum backlash to be used in the gear design. However, increased customers' expectations in vehicle noise eduction have pushed backlash and allowable manufacturing tolerances to even lower limits. This is especially true in the truck market, where engines are quieter because they run at lower speeds to improve fuel economy, but they quite often run at high torsional vibration levels. Furthermore, gear and shaft arrangements in truck transmissions have become more complex due to increased number of speeds and to improve efficiency. Determining the minimum amount of backlash is quite a challenge. This paper presents an investigation of minimum backlash values of helical gear teeth applied to a light-duty pickup truck transmission. An analytical model was developed to calculate backlash limits of each gear pair when not transmitting load, and thus susceptible to generate rattle noise, through different transmission power paths. A statistical approach (Monte Carlo) was used since a significant number of factors affect backlash, such as tooth thickness variation; center distance variation; lead; runout and pitch variations; bearing clearances; spline clearances; and shaft deflections and misalignments. Analytical results identified the critical gear pair, and power path, which was confirmed experimentally on a transmission. The approach presented in this paper can be useful to design gear pairs with a minimum amount of backlash, to prevent double flank contact and to help reduce rattle noise to lowest levels.
In the design process of transmissions, one major criterion is the resulting noise emission of the powertrain due to gear excitation. Within the past years, much investigation has shown that the noise emission can be attributed to quasi-static transmission error. Therefore, the transmission error can be used for a tooth contact analysis in the design process, as well as a characteristic value for quality assurance by experimental inspections.
At first sight the appearance of 5-axis milling for bevel gears opens new possibilities in flank form design. Since in comparison to existing machining methods applying cutter heads no kinematic restrictions exist for 5-axis milling technology, any flank form can be machined. Nevertheless the basic requirements for bevel gears did not change. Specifications and functional requirements like load carrying capacity and running behavior are still increasing demands for design and manufacturing. This paper describes the demands for gear design and gives an overview about different design principles in the context of the surrounding periphery of the gear set.
Outside of our industry, there's a whole slew of hobbyists working with gears to make clocks, art pieces, watches and all manner of bizarrely shaped gears (you know, all the people that usually end up featured right here in our Addendum section).
It's the New Year, and with it comes the opportunity to take a fresh look at your business objectives. Because business development is such a vital part of running a company, I'd like to present some guidelines I have found beneficial for securing new work and new customers.
Multiple possibilities are available to increase the transmissible power of girth gears. These solutions include: using a larger module, increasing of the gear diameter through the number of teeth, enlarging the face width, and increasing the hardness of the base material. The first three parameters are mostly limited by cutting machine capability. Module, outside diameter, and face width (for a cast gear) can theoretically be increased to infinity, but not the cutting machine dimensions. There are also practical limits with respect to the installation of very large diameter/large face width gears.
The latest in machine tools, cutting tools, inspection equipment, shop floor gages and other products for the gear industry.
This article presents an analysis of asymmetric tooth gears considering the effective contact ratio that is also affected by bending and contact tooth deflections. The goal is to find an optimal solution for high performance gear drives, which would combine high load capacity and efficiency, as well as low transmission error (which affects gear noise and vibration).
A reader wonders about gears where the tops of the teeth are the bearing surface, as used in spur gear differentials. Do they require any special construction or processing?
This paper outlines the comparison of efficiencies for worm gearboxes with a center distance ranging from 28 - 150 mm that have single reduction from 5 to 100:1. Efficiencies are calculated using several standards (AGMA, ISO, DIN, BS) or by methods defined in other bibliographic references. It also deals with the measurement of torque and temperature on a test rig — required for the calibration of an analytical model to predict worm gearbox efficiency and temperature. And finally, there are examples of experimental activity (wear and friction measurements on a blockon- ring tribometer and the measurements of dynamic viscosity) regarding the effort of improving the efficiency for worm gear drivers by adding nanoparticles of fullerene shape to standard PEG lubricant
I'd like to apologize to the dedicated people working on revisions to the AGMA 925 standard and the Technical Report ISO 15144-1, both of which deal with the issue of micropitting. In the March/April issue of Gear Technology, we published an opinion piece in our Voices column that harshly criticized the methods for predicting micropitting outlined in ISO 15144-1.
In this special section, our editors have gathered recent news and information related to the heat treatment of gears. Here youâ€™ll find a comprehensive assortment of news and upcoming events that will help you understand the various heat treatment processes available for gears and choose the best option for your projects, whether you heat treat in-house or send your gears to a commercial heat treating provider.
I have outsourced gear macrogeometry due to lack of resources. Now I received the output from them and one of the gears is with â€”0.8Ă— module correction factor for m = 1.8 mm gear. Since bending root stress and specific slide is at par with specification, but negative correction factor â€”0.8Ă— module â€” is quite high â€” how will it influence NVH behavior/transmission error? SAP and TIF are very close to 0.05 mm; how will that influence the manufacturing/cost?
The complete Industry News section from the March/April 2015 issue of Gear Technology.
Here is some history that bears repeating - or at least re-reading. So take a few minutes to give it up for a long-gone Brit named Henry Maudslay (August 22, 1771 - February 14, 1831) - also known as "A Founding Father of Machine Tool Technology." You might also consider him an early leader in inspection, as he also invented the first bench micrometer capable of measuring to one ten-thousandth of an inch.
Beginning with our June Issue, Gear Technology is pleased to present a series of full-length chapters excerpted from Dr. Hermann J. Stadtfeldâ€™s latest scholarly â€” yet practical â€” contribution to the gear industry â€” Gleason Bevel Gear Technology. Released in March, 2014 the book boasts 365 figures intended to add graphic support of a better understanding and easier recollection of the covered material.
Developed here is a new method to automatically find the optimal topological modification from the predetermined measurement grid points for bevel gears. Employing this method enables the duplication of any flank form of a bevel gear given by the measurement points and the creation of a 3-D model for CAM machining in a very short time. This method not only allows the user to model existing flank forms into 3-D models, but also can be applied for various other purposes, such as compensating for hardening distortions and manufacturing deviations which are very important issues but not yet solved in the practical milling process.
In David Koeppâ€™s 2012 bicycle messenger actionthriller Premium Rush (yes, apparently that is an actual genre), Joseph Gordon-Levittâ€™s beleaguered hero Wilee deadpans...
We are currently experiencing wear on the bull gear on our converter at the steel plant. We want to be able to draw the original gear profile to compare this with the worn tooth before we decide on the next steps. I have attempted this, but there is a correction factor given and I am unsure how to apply this. Could someone give advice on this? Please find attached the PDFâ€™s for the bull gear and the pinion gear. They are old drawings! The wear is on the wheel.
Reshoring offers an opportunity for increased domestic gear production. Reshoring is growing at a steady pace in most industries, and is particularly strong in the gear intensive industries such as automotive, aerospace and construction equipment (Table 1). This article provides background on the overall trend and tools for the gear buyer and the gear producer to make the offshore vs. domestic decision.
This article is the fourth installment in Gear Technology's series of excerpts from Dr. Hermann J. Stadtfeld's book, Gleason Bevel Gear Technology. The first three excerpts can be found in our June, July and August 2015 issues. In the previous chapter, we demonstrated the development of a face-milled spiral bevel gearset. In this section, an analogue face-hobbed bevel gearset is derived.
your life and in your professional career is an inflection point for you to take stock of where you came from and where you are going.
Manufacturing involute gears using form grinding or form milling wheels are beneficial to hobs in some special cases, such as small scale production and, the obvious, manufacture of internal gears. To manufacture involute gears correctly the form wheel must be purpose-designed, and in this paper the geometry of the form wheel is determined through inverse calculation. A mathematical model is presented where it is possible to determine the machined gear tooth surface in three dimensions, manufactured by this tool, taking the finite number of cutting edges into account. The model is validated by comparing calculated results with the observed results of a gear manufactured by an indexable insert milling cutter.
Generating gear grinding is one of the most important finishing processes for small and medium-sized gears, its process design often determined by practical knowledge. Therefore a manufacturing simulation with the capability to calculate key values for the process â€” such as the specific material removal rate â€” is developed here. Indeed, this paper presents first results of a model for a local analysis of the value. Additionally, an empirical formula â€” based on a multiple regression model for a global value describing the process â€” is provided.
In the previous sections, the development of conjugate bevel gearsets via hand calculations was demonstrated. The goal of this exercise was to encourage the reader to gain a basic understanding of the theory of bevel gears. This knowledge will help gear engineers to better judge bevel gear design and their manufacturing methods. In order to make the basis of this learning experience even more realistic, this chapter will convert a conjugate bevel gearset into a gearset that is suitable in a real-world application. Length and profile crowning will be applied to the conjugate flank surfaces. Just as in the previous chapter, all computations are demonstrated as manual hand calculations. This also shows that bevel gear theory is not as complicated as commonly assumed.
Detection of impending gear tooth failure is of interest to every entity that utilizes geared transmissions. However, it is of particular significance at the Gear Research Institute (GRI), where sponsored efforts are conducted to establish gear material endurance limits, utilizing gear fatigue tests. Consequently, knowing when a gear is about to fail in each and every test, in a consistent manner, is essential for producing reliable and useful data for the gear industry.
For us, 2016 is the year of smart ideas. Not our smart ideas, but yours. We've spent a lot of effort collecting information from Gear Expo, our State of the Gear Industry annual survey and market research to find out more about what you want from us. We've also taken your suggestions and used them to make improvements, add new features and build on what we've been doing here for 32 years in our role as the Gear Industry's Information Source.
Let's talk about large gears. Not the size or scope or inspection process, but the forecast and market potential in areas that utilize these massive components. We'll examine key industry segments like energy and mining and tap IHS Economics for a forecast for 2016 and 2017 (spoiler alert: it's not great). Additionally, we'll discuss some of the critical factors influencing global big gear manufacturers Ferry-Capitain and Hofmann Engineering.
The oil industry is (pardon the pun) tanking. That may conjure up horrific images of other industries following suit in a domino effect of collective collapse into the overabundant oil slick the industry is currently drowning in, but not everyone is getting knocked down alongside the oil sector.
Onshore and offshore wind turbines boast some of the most critical assets in order to run effectively.
Most steel gear applications require appreciable loads to be applied that will result in high bending and compressive stresses. For the material (steel) to meet these performance criteria, the gear must be heat treated. Associated with this thermal processing is distortion. To control the distortion and achieve repeatable dimensional tolerances, the gear will be constrained during the quenching cycle of the heat treatment process. This type of fixture quenching is the function of gear quench pressing equipment.
The complete Product News section from the September/October 2010 issue of Gear Technology.
The Shaping Process - A Quick Review of the Working Principle. In the shaping process, cutter and workpiece represent a drive with parallel axes rotating in mesh (generating motion) according to the number of teeth in both cutter and workpiece (Fig. 1), while the cutter reciprocates for the metal removal action (cutting motion).
The complete Events section from January/February 2005, including coverage of a vacuum carburizing conference.
The complete Product News section from September/October 2006.
The complete Events section from September/October 2006, including a profile of gear seminars offered by WZL.
The complete Industry News section from September/October 2006.
In order to grind gears burn-free and as productively as possible, a better understanding of the process is required.
The complete Events section from November/December 2006, including coverage of Gear China.
The complete Industry News section from November/December 2006.
The complete Product News section from January/February 2005
The complete Product News section from March/April 2005
The complete Events section from July/August 2006, including a profile on the UTS gear course.
The complete Events section from March/April 2005, including coverage of Hannover Fair and SAE World Congress.
The complete Industry News section from March/April 2005
The complete Product News section from May/June 2005.
The complete Events section from May/June 2005.
The complete Industry News section from May/June 2005.
Tom Lang of Kapp Technologies shares his views on the trends affecting ground gears.
The complete Events section from July/August 2005, including coverage of EMO 2005.
The complete Industry News section from July/August 2006.
Molded plastic gears have very little in common with machined gears other than the fact that both use the involute for conjugate action.
The complete Product News section from the September/October 2005 issue of Gear Technology.
The complete Industry News section from the January/February 2008 issue.
This article summarizes the use of laboratory fatigue data for bearings and gears coupled with probabilistic life prediction and EHD theories to predict the life and reliability of a commercial turboprop gearbox.
WithÂ reference toÂ the machining of anÂ involute spur or helical gear by the hobbing process,Â this paper suggests a new criterionÂ for selectingÂ the positionÂ of the hob axis relative toÂ the gear axis.
Results of research on trends in employment, outsourcing, machine tool investment and other gear industry business practices.
We love gears. We love talking about gears, writing about gears and examining gears. If youâ€™re reading this cover to cover, itâ€™s a safe bet you feel the same way. We also love collecting information for Gear Technologyâ€™s holiday buyer's guide. Call us sentimental.
Forty years ago, the plastics industry was practically in its embryonic phase...
This paper describes the research and development of the first production gearbox with asymmetric tooth profiles for the TV7-117S turboprop engine. The paper also presents numerical design data related to development of this gearbox.
The complete Events and Technical Calendar section
The complete product news section from March/April 2006
The complete Product News section from the July/August 2006 issue.
LMS International helped a Fiat subsidiary develop a new, dynamic vibro-acoustic prediction method to reduce design time and engineering costs through accurate prediction of gear noise in the design phase.
The complete Industry News section from March/April 2006
The complete events section from March/April 2006, including a feature on the Koepfer Gear School and our technical calendar.
The 130SV shaving machine from Gleason is the newest of the company's Genesis family of gear production equipment.
The complete Industry News section from May/June 2006
The complete Events section from May/June 2006, including profiles of the University of Wisconsin gear seminars and the MPIF international conference on powder metallurgy.
I just finished conducting annual reviews with our employees. They, we--all of us--get our paychecks from our customers.
The GS:TE-LM thread grinder from Drake Manufacturing is fitted with a robot load/unload system that provides maximum throughput for high-volume production of ground threads.
The complete Industry News section from July/August 2005.
The objective of this research is to develop a new lapping process that can efficiently make tooth flanks of hardened steel gears smooth as a mirror.
Above all, a gear is not just a mechanical transmission, but is developed to a system fulfilling multiple demands, such as clutch integration, selectable output speeds, and controls of highest electronic standards. This paper shows the basics for high-speed gear design and a selection of numerous applications in detailed design and operational needs.
The world is full of acronyms. At work, the inbox reveals e-mails from the AWEA, SAE, MPIF and AMT. On the weekends, Saturday mornings are consumed by activities involving the AYSO, PTA, YMCA or DMV. Itâ€™s a struggle to determine what organization does what and why we should care in the first place.
Itâ€™s that even-numbered-year time-of-the-year again. The International Manufacturing Technology Show, IMTS 2008, is right around the corner. This 27th installment of the biennial trade show is focusing on connecting global technology.
This paper acknowledges the wide variety of manufacturing processes--especially in grinding--utlized in the production of bevel gears...
The proper control of distortion after thermal treatment of powertrain components in the automotive industry is an important measure in ensuring high-quality parts and minimizing subsequent hard machining processes in order to reduce overall production costs.
This paper intends to determine the load-carrying capacity of thermally damaged parts under rolling stress. Since inspection using real gears is problematic, rollers are chosen as an acceptable substitute. The examined scope of thermal damage from hard finishing extends from undamaged, best-case parts to a rehardening zone as the worst case. Also, two degrees of a tempered zone have been examined.
The complete Events section from the August 2008 issue of Gear Technology. Includes the Technical Calendar.
The complete Industry News section from the August 2008 issue of Gear Technology.
The complete Product News section from the September/October 2008 issue of Gear Technology.
For more than 10 months, NASA ground engineers and International Space Station (ISS) astronauts have been struggling with a perplexing malfunction of one of the stationâ€™s two solar array rotary joints (SARJ).
The complete Industry News section from the July 2008 issue of Gear Technology.
The complete events section, including Technical Calendar, from the September/October 2008 issue of Gear Technology.
The complete Industry News section from the September/October 2008 issue of Gear Technology.
The complete Industry News section from the November/December 2009 issue of Gear Technology.
The struggles of the manufacturing economy in 2009 are well documented. Even among those of us with long careers, most of us have never seen activity come to a screeching halt the way it did last year. 2009 was tough on all of us. So, what should we expect in 2010?
The complete Product News section from the January/February 2010 issue.
This paper presents a unique approach and methodology to define the limits of selection for gear parameters. The area within those limits is called the â€śarea of existence of involute gearsâ€ť (Ref. 1). This paper presents the definition and construction of areas of existence of both external and internal gears. The isograms of the constant operating pressure angles, contact ratios and the maximum mesh efficiency (minimum sliding) isograms, as well as the interference isograms and other parameters are defined. An area of existence allows the location of gear pairs with certain characteristics. Its practical purpose is to define the gear pair parameters that satisfy specific performance requirements before detailed design and calculations. An area of existence of gears with asymmetric teeth is also considered.
The complete Industry News section from the January/February 2010 issue of Gear Technology.
The complete Product News section from the August 2008 issue of Gear Technology
The complete Events section, including technical calendar, from the July 2008 issue of Gear Technology
The complete Events section from the September/October 2005 issue of Gear Technology, including a profile of the UTS plastic gear course.
The complete Product News section from the May 2008 issue of Gear Technology.
The complete Industry News section from the September/October 2005 issue of Gear Technology.
Review of "Gigacycle Fatigue in Mechanical Practice," by Claude Bathias and Paul C. Paris
Conical involute gears (beveloids) are used in transmissions with intersecting or skewed axes and for backlash-free transmissions with parallel axes.
The complete Events section from November/December 2005, including post-show coverage of Gear Expo 2005, AGMA's Fall Technical Meeting, and our regular technical calendar.
The complete Product News section from the March/April 2008 issue of Gear Technology.
The complete Events section from the March/April 2008 issue of Gear Technology.
The complete Industry News section from the March/April 2008 issue of Gear Technology.
A net-shaped metal forming process has been developed for manufacturing quality, durable, high-yield and cost-efficient gears for high-volume production.
A graphical procedure for selecting optimum combinations of profile and lead modifications.
2008 World Congress on Powder Metallurgy, plus the technical calendar. Complete Events section from May 2008 Gear Technology.
The complete Industry News section from the May 2008 issue of Gear Technology.
The complete Product News section from the June 2008 issue of Gear Technology.
In the past two years DSM has been conducting fatigue tests on actual molded gears in order to provide design data.
The complete Events section from the June 2008 issue of Gear Technology.
The complete industry news section from the June 2008 issue of Gear Technology.
The complete product news section from the July 2008 issue of Gear Technology.
How machine tools R&D helps drive gear manufacturing productivity.
Dontyne Systems, a U.K. company founded by Michael Fish and David Palmer, recently unveiled a new software program for its Gear Production Suite.
[special advertising section]
Several innovations have been introduced to the gear manufacturing industry in recent years. In the case of gear hobbingâ€”the dry cutting technology and the ability to do it with powder-metallurgical HSSâ€”might be two of the most impressive ones. And the technology is still moving forward. The aim of this article is to present recent developments in the field of gear hobbing in conjunction with the latest improvements regarding tool materials, process technology and process integration.
When designing gears, the engineer is often faced with the problem of selecting the number of teeth in each gear, so that the gear train will provide a given speed ratio
The complete Product News section from the May 2009 issue of Gear Technology.
Special advertising section featuring gear industry exhibitors.
The complete Events section from the November/December 2008 issue of Gear Technology
In this study, the combined influence of shaft misalignments and gear lead crown on load distribution and tooth bending stresses is investigated. Upon conclusion, the experimental results are correlated with predictions of a gear load distribution model, and recommendations are provided for optimal lead crown in a given misalignment condition.
Never have so few served so many. That, in essence, describes gear makers and the role they play in our world. Think of itâ€”although the gear cutting industry represents much less than one percent of the global workforceâ€”the gears it produces are what make things run in practically every industry and profession imaginable. From bulldozers to Rolexes, gears are an integral part of the mix.
The complete Industry News section from the March/April 2004 issue of Gear Technology.
The complete Product News section from the March/April 2004 issue of Gear Technology.
One of the current research activities here at California State University at Fullerton is systematization of existing knowledge of design of planetary gear trains.
The complete Product News section from the November/December 2009 issue of Gear Technology.
The proper design or selection of gear cutting tools requires thorough and detailed attention from the tool designer. In addition to experience, intuition and practical knowledge, a good understanding of profile calculations is very important.
While on holiday in England during July, my thoughts for this page were on the proposed changes to our tax law, and how they would adversely affect America's industry. But with the President undergoing cancer surgery, Congress deadlocked on deficit reduction and the budget on the back burner, nothing new was being said or done regarding a new tax law
Hobbing is probably the most popular gear manufacturing process. Its inherent accuracy and productivity makes it a logical choice for a wide range of sizes.
This paper presents two new techniques for aligning and maintaining large ring gears. One technique uses lubricant temperature analysis, and the other uses stop action photography.
The complete industry news section from the June 2009 issue of Gear Technology.
Recent breakthroughs in profile grinding software are helping Anderson Precision Gears and others meet wind powerâ€™s insatiable appetite for faster production of large, high-quality gears.
Once upon a time there was a computer. This computer served as a conduit to waste a great deal of time through social networking and online video games. Still, there was always potential to turn these rather sedentary activities into something more positive and useful to mankind. Siemens may have stumbled upon such a concept.
The complete Industry News section from the January/February 2004 issue.
As I write this editorial, much of America seems frozen solid. It snowed again here in Chicago yesterday, and last night the wind chill was â€“30ÂşF (â€“34ÂşC). Itâ€™s been cold like this for more than a week, and the forecasters are predicting more of the same. After a while, such a deep freeze can be depressing.
After a period of operation, high-speed turbo gears may exhibit a change in longitudinal tooth contact pattern, reducing full face width contact and thereby increasing risk of tooth distress due to the decreased loaded area of the teeth. But this can be trickyâ€”the phenomenon may or may not occur. Or, in some units the shift is more severe than others, with documented cases in which shifting occurred after as little as 16,000 hours of operation. In other cases, there is no evidence of any change for units in operation for more than 170,000 hours. This condition exists primarily in helical gears. All recorded observations here have been with case-carburized and ground gear sets. This presentation describes phenomena observed in a limited sampling of the countless high-speed gear units in field operation. While the authors found no existing literature describing this behavior, further investigation suggests a possible cause. Left unchecked and without corrective action, this occurrence may result in tooth breakage.
The complete Industry News section from the August 2009 issue of Gear Technology.
Tom Every has a collection of gears that would rival many small warehouses.
With the right selection of nonstandard center distance and tool shifting, it may be possible to use standard tools to improve the gear set capacity with a considerable reduction in cost when compared to the use of special tools.
Google â€ślean manufacturingâ€ť and you will find a virtually endless font of information regarding formal lean implementation. Youâ€™ll see definitions for Japanese words such as kaizen, gemba, muda, mura, kanban, and so on. You will also find other variations or iterations of lean, e.g.: Six Sigma, Lean Sigma, TPS (Toyota Production System), TOC (Theory of Constraints), JIT (Just in Time), and others.
On May 20, the city of Pittsburgh celebrated the 130th anniversary of the Duquesne Incline, a funicular railway that allows passengers to travel via cable car to an observation area and catch a panoromic view of the city andâ€”most importantlyâ€”get a birdâ€™s eye glimpse of the gear teeth in action.
The gear companies enjoying the most success in today’s global market are those that firmly believe quality is much more than expert craftsmanship and foolproof inspection methodologies.
This paper will present data from both laboratory and field testing demonstrating that superfinished components exhibit lower friction, operating temperature, wear and/ or higher horsepower, all of which translate directly into increased fuel economy.
The complete Product News section from the September/October 2009 issue of Gear Technology.
The complete Industry News section from the September/October 2009 issue of Gear Technology.
What do glam and avant garde rock star Brian Eno, AGMA and Seattle Gear Works have in common? Admittedly, not much. But there is a connection of sorts.
Often, the required hardness qualities of parts manufactured from steel can only be obtained through suitable heat treatment. In transmission manufacturing, the case hardening process is commonly used to produce parts with a hard and wear-resistant surface and an adequate toughness in the core. A tremendous potential for rationalization, which is only partially used, becomes available if the treatment time of the case hardening process is reduced. Low pressure carburizing (LPC) offers a reduction of treatment time in comparison to conventional gas carburizing because of the high carbon mass flow inherent to the process (Ref. 1).
To meet the future goals of higher productivity and lower production costs, the cutting speeds and feeds in modern gear hobbing applications have to increase further. In several cases, coated carbide tools have replaced the commonly used high speed steel (HSS) tools.
The complete Product News section from the August 2009 issue of Gear Technology.
The complete Industry News section from the November/December 2004 issue of Gear Technology.
The complete Industry News section from the May/June 2004 issue of Gear Technology.
Results of research on trends in employment, outsourcing, machine tool investment and other gear industry business practices.
Forensics isn't just for tough-talking, crime-busting scientists--most commonly found on your television; the tactic also holds the key to successful gearbox design and manufacture.
The complete industry news section from the July 2009 issue of Gear Technology.
The complete Industry News section from the May 2012 issue of Gear Technology.
Thereâ€™s a bustle of activity as exhibitors prepare for Americaâ€™s most significant manufacturing trade show. The red carpets are ready, the lights are being tested, and the crowds are gathering with anticipation. Amid the excitement, Gear Technology has managed to sneak under the usherâ€™s ropes to provide you with this advance look at some of the gear-related products and technologies that will be featured at IMTS 2004.
In this paper, an accurate FEM analysis has been done of the â€śtrueâ€ť stress at tooth root of spur gears in the function of the gear geometry. The obtained results confirm the importance of these differences.
The complete product news section from the January/February 2009 issue of Gear Technology, featuring giant-sized David Brown girth gears, gear inspection up to 4.5 meters and the latest Gleason gear grinder.
The complete Industry News section from the September/October 2004 issue of Gear Technology.
The complete Product News section from the March/April 2009 issue of Gear Technology.
e-Bay shopping, newspaper reading and excessive e-mailing arenâ€™t a problem for most managers in the gear industry, but now thereâ€™s a new employee distraction headed their way.
Powder metallurgy (P/M) techniques have proven successful in displacing many components within the automobile drive train, such as: connecting rods, carriers, main bearing caps, etc. The reason for P/Mâ€™s success is its ability to offer the design engineer the required mechanical properties with reduced component cost.
The complete Events section from the January/February 2009 issue of Gear Technology.
There are great advantages in dry hobbing, not only for friendliness toward the environment, but also for increasing productivity and for decreasing manufacturing cost. Dry hobbing, however, often causes failures in hob cutting edges or problems with the surface quality of gear tooth flanks. These difficulties are not present when hobbing with cutting oil. Pinching and crushing of generated chips between the hob cutting edge and the work gear tooth flank is considered a major cause of those problems.
Much has happened since we last reported on the malfunctioning solar array rotary joint (SARJ) attached to the International Space Station. Space shuttle Endeavour dropped in for a two-week visit in November during which repairs were made and invaluable data collected.
The complete Product News section from the November/December 2004 issue of Gear Technology.
The fundamental purpose of gear grinding is to consistently and economically produce "hard" or "soft" gear tooth elements within the accuracy required by the gear functions. These gear elements include tooth profile, tooth spacing, lead or parallelism, axial profile, pitch line runout, surface finish, root fillet profile, and other gear geometry which contribute to the performance of a gear train.
The complete Product News section from the September/October 2004 issue of Gear Technology.
The complete Industry News section from the November/December 2003 issue of Gear Technology.
The complete Industry News section from the January/February 2009 issue of Gear Technology.
The complete industry news section from the March/April 2009 issue of Gear Technology.
The complete Industry News section from the May 2009 issue of Gear Technology.
The complete Product News section from the November/December 2003 issue of Gear Technology.
A computational fluid dynamics (CFD) method is adapted, validated and applied to spinning gear systems with emphasis on predicting windage losses. Several spur gears and a disc are studied. The CFD simulations return good agreement with measured windage power loss.
Listing of papers to be presented and activities for the 2007 AGMA Fall Technical Meeting.
High demands for cost-effectiveness and improved product quality can be achieved via a new low pressure carburizing process with high pressure gas quenching. Up to 50% of the heat treatment time can be saved. Furthermore, the distortion of the gear parts could be reduced because of gas quenching, and grinding costs could be saved. This article gives an overview of the principles of the process technology and the required furnace technology. Also, some examples of practical applications are presented.
The complete product news section from the November/December 2008 issue.
In todayâ€™s manufacturing environment, shorter and more efficient product development has become the norm. It is therefore important to consider every detail of the development process, with a particular emphasis on design. For green machining of gears, the most productive and important process is hobbing. In order to analyze process design for this paper, a manufacturing simulation was developed capable of calculating chip geometries and process forces based on different models. As an important tool for manufacturing technology engineers, an economic feasibility analysis is implemented as well. The aim of this paper is to show how an efficient process designâ€”as well as an efficient processâ€”can be designed.
The complete Industry News section from the July/August 2004 issue of Gear Technology.
The auction has been held. The warehouse is bare. The computers and furniture are being packed, and Cadillac Machinery, the company started by my father in 1950, and of which I was president for more than 25 years, is close to being no more.
The complete Product News section from the May/June 2004 issue of Gear Technology.
Companies around the world are learning to embrace the environment, and the gear industry is no exception. This special section takes a look at how some gear manufacturers are doing their part to conserve resources, preserve and protect the environment, and give back to the land. What weâ€™ve found is that adopting environmental measures is far more than just good corporate citizenship. For many gear industry companies, good environmental practices also turn out to be good for the bottom line.
The objective of this paper is to demonstrate that transmission gears of rotary-wing aircraft, which are typically scrapped due to minor foreign object damage (FOD) and grey staining, can be repaired and re-used with signifi cant cost avoidance. The isotropic superfinishing (ISF) process is used to repair the gear by removing surface damage. It has been demonstrated in this project that this surface damage can be removed while maintaining OEM specifications on gear size, geometry and metallurgy. Further, scrap CH-46 mix box spur pinions, repaired by the ISF process, were subjected to gear tooth strength and durability testing, and their performance compared with or exceeded that of new spur pinions procured from an approved Navy vendor. This clearly demonstrates the feasibility of the repair and re-use of precision transmission gears.
The complete Product News section from the May 2012 issue of Gear Technology.
The complete product news section from the June 2009 issue of Gear Technology.
The complete Product News section from the July/August 2004 issue of Gear Technology.
On the production floor at Knechtel, food scientists, chemists and engineers take part in Willy Wonka-like experiments in search of the perfect piece of candy.
The complete Product News section from the January/February 2004 issue of Gear Technology.
The complete Product News section from the July 2009 issue of Gear Technology.
The use of plastic gearing is increasing steadily in new products. This is due in part to the availability of recent design data. Fatigue stress of plastic gears as a function of diametral pitch, pressure angle, pitch line velocity, lubrication and life cycles are described based on test information. Design procedures for plastic gears are presented.
Flexibility and productivity are the keywords in todayâ€™s grinding operations. Machines are becoming more flexible as manufacturers look for ways to produce more parts at a lower cost. What used to take two machines or more now takes just one.
The seemingly simple process of placing a uniform chamfer on the face ends of spur and helical gears, at least for the aerospace industry, has never been a satisfactory or cost effective process.
"One of the reasons AGMA has been successful over our 93-year history is that the associationâ€™s agenda, programs and activities reflect the voices of our members," says Joe T. Franklin, Jr., AGMA President.
The gear hobbing process is a generating type of production operation. For this reason, the form of the hob tooth is always different from the form of the tooth that it produces.
The gear tooth fillet is an area of maximum bending stress concentration. However, its profile is typically less specified in the gear drawing and hardly controlled during gear inspection in comparison with the gear tooth flanks. This paper presents a fillet profile optimization technique for gears with symmetric and asymmetric teeth based on FEA and a random search method. It allows achieving substantial bending stress reduction in comparison with traditionally designed gears. This bending stress reduction can be traded for higher load capacity, longer lifetime, lower noise and vibration and cost reduction.
No matter how well gears are designed and manufactured, gear corrosion can occur that may easily result in catastrophic failure. Since corrosion is a sporadic and rare event and often difficult to observe in the root fillet region or in finely pitched gears with normal visual inspection, it may easily go undetected. This paper presents the results of an incident that occurred in a gear manufacturing facility several years ago that resulted in pitting corrosion and intergranular attack (IGA).
The complete Product News section from the March/April 2010 issue of Gear Technology.
This paper shows an experimental study on the fatigue lifetime of high-heat polyamide (Stanyl) gears running in oil at 140Â°C. Based on previous works (Refs. 1â€“2), an analysis is made correcting for tooth bending and calculating actual root stresses. A comparison with tensile bar fatigue data for the same materials at 140Â°C shows that a good correlation exists between gear fatigue data and tensile bar fatigue data. This insight provides a solid basis for gear designers to design plastic gears using actual material data.
Because of the better thermal conductivity of CBN abrasives compared to that of conventional aluminum oxide wheels, CBN grinding process, which induces residual compressive stresses into the component, and possibly improves the subsequent stress behavior. This thesis is the subject of much discussion. In particular, recent Japanese publications claim great advantages for the process with regard to an increased component load capacity, but do not provide further details regarding the technology, test procedures or components investigated. This situation needs clarification, and for the this reason the effect of the CBN grinding material on the wear behavior and tooth face load capacity of continuously generated ground gears was further investigated.
Plastic gears are being used increasingly in applications, such as printers, cameras, small household appliances, small power tools, instruments, timers, counters and various other products. Because of the many variables involved, an engineer who designs gear trains on an occasional basis may find the design process to be somewhat overwhelming. This article outlines a systematic design approach for developing injection molded plastic spur and helical gears. The use of a computer program for designing plastic gears is introduced as an invaluable design tool for solving complex gearing equations.
In 1985 a new tooling concept for high volume gear production was introduced to the gear manufacturing industry. Since then this tool, the wafer shaper cutter, has proven itself in scores of applications as a cost-effective, consistent producer of superior quality parts. This report examines the first high-production installation at the plant of a major automotive supplies, where a line of twenty shapers is producing timing chain sprockets.
How dynamic load affects the pitting fatigue life of external spur gears was predicted by using NASA computer program TELSGE. TELSGE was modified to include an improved gear tooth stiffness model, a stiffness-dynamic load iteration scheme and a pitting-fatigue-life prediction analysis for a gear mesh. The analysis used the NASA gear life model developed by Coy, methods of probability and statistics and gear tooth dynamic loads to predict life. In general, gear life predictions based on dynamic loads differed significantly from those based on static loads, with the predictions being strongly influenced by the maximum dynamic load during contact.
Several methods of oil jet lubrication of gears are practiced by the gear industry. These include the oil jet directed into the mesh, out of the mesh and radially directed into the gear teeth. In most cases an exact analysis is not used to determine the optimum condition such as, jet nozzle location, direction and oil jet velocity, for best cooling. As a result many gear sets are operating without optimum oil jet lubrication and cooling.
Hobbing is a continuous gear generation process widely used in the industry for high or low volume production of external cylindrical gears. Depending on the tooth size, gears and splines are hobbed in a single pass or in a two-pass cycle consisting of a roughing cut followed by a finishing cut. State-of-the-art hobbing machines have the capability to vary cutting parameters between first and second cut so that a different formula is used to calculate cycle times for single-cut and double-cut hobbing.
Assorted thoughts while in a holding pattern over O'Hare... I recently returned from England where I spent time checking out the overseas markets and attending a machinery auction. Buyers came to this auction from all over - Germany, Italy, Switzerland, India, Australia, America - and the prices were astonishing. Often buyers were paying in pounds sterling the same amount or more than they would have paid in U.S. dollars.
Profitable hard machining of tooth flanks in mass production has now become possible thanks to a number of newly developed production methods. As used so far, the advantages of hard machining over green shaving or rolling are the elaborately modified tooth flanks are produced with a scatter of close manufacturing tolerances. Apart from an increase of load capacity, the chief aim is to solve the complex problem of reducing the noise generation by load-conditioned kinematic modifications of the tooth mesh. In Part II, we shall deal with operating sequences and machining results and with gear noise problems.
This article deals with certain item to be taken into consideration for gear grinding, common problems that arise in gear grinding and their solutions. The discussion will be limited to jobbing or low-batch production environments, where experimental setup and testing is not possible for economic and other reasons.
Gear shaping is one of the most popular production choices in gear manufacturing. While the gear shaping process is really the most versatile of all the gear manufacturing methods and can cut a wide variety of gears, certain types of gears can only be cut by this process. These are gears closely adjacent to shoulders; gears adjacent to other gears, such as on countershafts; internal gears, either open or blind ended; crown or face gears; herringbone gears of the solid configuration of with a small center groove; rack; parts with filled-in spaces or teeth, such as are used in some clutches.
This article describes a method of obtaining gear tooth profiles from the geometry of the rack (or hob) that is used to generate the gear. This method works for arbitrary rack geometries, including the case when only a numerical description of the rack is available. Examples of a simple rack, rack with protuberances and a hob with root chamfer are described. The application of this technique to the generation of boundary element meshes for gear tooth strength calculation and the generation of finite element models for the frictional contact analysis of gear pairs is also described.
The complete Product News section from the June/July 2012 issue of Gear Technology.
Micropitting, pitting and wear are typical gear failure modes that can occur on the flanks of slowly operated and highly stressed internal gears. However, the calculation methods for the flank load-carrying capacity have mainly been established on the basis of experimental investigations of external gears. This paper describes the design and functionality of the newly developed test rigs for internal gears and shows basic results of the theoretical studies. It furthermore presents basic examples of experimental test results.
The complete Industry News section from the June/July 2012 issue of Gear Technology.
Cubic boron nitride (CBN) finishing of carburized gearing has been shown to have certain economic and geometric advantages and, as a result, it has been applied to a wide variety of precision gears in many different applications. In critical applications such as aerospace drive systems, however, any new process must be carefully evaluated before it is used in a production application. Because of the advantages associated with this process, a test program was instituted to evaluate the load capacity of aerospace-quality gears finished by the CBN process as compared to geometrically identical gears finished by conventional grinding processes. This article presents a brief description of the CBN process, its advantages in an aerospace application, and the results of an extensive test program conducted by Boeing Helicopters (BH) aimed at an evaluation of the effects of this process on the scoring, surface durability, and bending fatigue properties of spur gears. In addition, the results of an x-ray diffraction study to determine the surface and subsurface residual stress distributions of both shot-peened and nonshot-peened CBN-ground gears as compared to similar conventionally ground gears are also presented.
Solutions to the governing equations of a spur gear transmission model, developed in a previous article are presented. Factors affecting the dynamic load are identified. It is found that the dynamic load increases with operating speed up to a system natural frequency. At operating speeds beyond the natural frequency the dynamic load decreases dramatically. Also, it is found that the transmitted load and shaft inertia have little effect upon the total dynamic load. Damping and friction decrease the dynamic load. Finally, tooth stiffness has a significant effect upon dynamic loadings the higher the stiffness, the lower the dynamic loading. Also, the higher the stiffness, the higher the rotating speed required for peak dynamic response.
This article presents an efficient and direct method for the synthesis of compound planetary differential gear trains for the generation of specified multiple speed ratios. It is a train-value method that utilizes the train values of the integrated train components of the systems to form design equations which are solved for the tooth numbers of the gears, the number of mating gear sets and the number of external contacts in the system. Application examples, including vehicle differential transmission units, rear-end differentials with unit and fractional speed ratios, multi-input functions generators and robot wrist joints are given.
Traditional methods of manufacturing precision gears usually employ either hobbing or shaper cutting. Both of these processes rely upon generating the conjugate tooth form by moving the work-piece in a precise relation to the tool. Recently, attention has been given to forming gear teeth in a single step. Advantages to such a process include reduced production time, material savings, and improved performance characteristics. Drawbacks include complicated tool designs, non-uniformity of gears produced throughout the life of the tooling, and lengthy development times.
In principal, the design of internal helical gear teeth is the same as that for external helical gears. Any of the basic rack forms used for external helical gears may be applied to internal helical gears. The internal gear drive, however, has several limitations; not only all those which apply to external gears, but also several others which are peculiar to internal gears. As with external gears, in order to secure effective tooth action, interferences must be avoided. The possible interferences on an internal gear drive are as follows: 1. Involute interference. To avoid this, all of the working profile of the internal tooth must be of involute form.
Worm gear speed reducers give the design engineer considerable options, but these gear systems present a challenge to the lubrication engineer. Heat energy generated by the high rate of sliding and friction in the contact zone causes worm gears to be relatively inefficient compared to other gear types. Because worm gears operate under a boundary or near-boundary lubrication regime, a satisfactory lubricant should contain a friction modifier to alleviate these conditions.
A universal gear is one generated by a common rack on a cylindrical, conical, or planar surface, and whose teeth can be oriented parallel or skewed, centered, or offset, with respect to its axes. Mating gear axes can be parallel or crossed, non-intersecting or intersecting, skewed or parallel, and can have any angular orientation (See Fig.1) The taper gear is a universal gear. It provides unique geometric properties and a range of applications unmatched by any other motion transmission element. (See Fig.2) The taper gear can be produced by any rack-type tool generator or hobbing machine which has a means of tilting the cutter or work axis and/or coordinating simultaneous traverse and infeed motions.
Throughout the history of civilization attempts have been made to limit the number of the measuring systems in use with the result that today only two systems, English and metric, are practiced in the industrial nations. Globally, the metric system has been gaining ground, and the English system has been losing it. As of 1986, only the United States, Burma and Brunei remain uncommitted to metric conversion in the sense that no government controlled deadlines for the conversion have been established.
Gear noise can be a source of intense annoyance. It is often the primary source of annoyance even when it is not the loudest noise component. This is because of the way it is perceived. Gear noise is a collection of pure tones which the human ear can detect even when they are 10dB lower than the overall noise level. Another reason for our sensitivity to transmission noise is that we associate it with impending mechanical failure.
Crossed helical gear sets are used to transmit power and motion between non-intersecting and non-parallel axes. Both of the gears that mesh with each other are involute helical gears, and a point contact is made between them. They can stand a small change in the center distance and the shaft angle without any impairment in the accuracy of transmitting motion.
Today it is common practice when climb hobbing to keep the direction of the hob thread the same as that of the helical gear. The same generalization holds true for the mass production of gears for automobiles. It is the authors' opinion, however, that conventional hobbing with a reverse-handed hob is more effective for the high-speed manufacture of comparatively small module gears for automobiles. The authors have proven both experimentally and theoretically that reverse-handed conventional hobbing, using a multi-thread hob with a smaller diameter is very effective for lengthening the life of the hob and for increasing cutting efficiency at high speeds.
Rotary gear honing is a hard gear finishing process that was developed to improve the sound characteristics of hardened gears by: Removing nicks and burrs; improving surface finish; and making minor corrections in tooth irregularities caused by heat-treat distortion.
In this discussion of gear roll-finishing particular attention is called to the special tooth nomenclature resulting from the interaction between the rolling die teeth and the gear teeth. To eliminate confusion the side of a gear tooth that is in contact with the "approach" side of a rolling die tooth is also considered to be the approach side. The same holds true for the "trail" side. Thus, the side of the gear tooth that is in contact with the trail side of a rolling die is also considered to be the trail side.
How important is the right choice of coupling in determining successful machine design? Consider the following example. A transmission of appropriate size was needed to transfer the speed of the engine driver to that of the driven generator. The transmission was properly selected and sized to endure the rated power requirements indefinitely, but after only a short time in operation, it failed anyway. What happened? The culprit in the case was a coupling. It provided the necessary power and protection against misalignment but it lacked the ability to isolate the gears from the torque peaks of the diesel engine.
A commitment to boost United States' industrial competitiveness in future years must strike beyond legislative action and economic debates.
How is it that we woke up one day in the early 1980s to find that apparently American industry was suddenly inefficient, our workforce unproductive and our management inept? Almost overnight industry found its sales dropping dramatically, while for many companies foreign competition became excruciatingly intense. This sudden change in the economic climate proved fatal for many companies and has been nearly as hard on our collective morale. In a country used to winning, we began to hear ourselves talked of as losers.
Primitive gears were known and used well over 2,000 years ago, and gears have taken their place as one of the basic machine mechanisms; yet, our knowledge and understanding of gearing principles is by no means complete. We see the development of faster and more reliable gear quality assessment and new, more productive manufacture of gears in higher materials hardness states. We have also seen improvement in gear applications and design, lubricants, coolants, finishes and noise and vibration control. All these advances push development in the direction of smaller, more compact applications, better material utilization and improved quietness, smoothness of operation and gear life. At the same time, we try to improve manufacturing cost-effectiveness, making use of highly repetitive and efficient gear manufacturing methods.
The geometry factor, which is a fundamental part of the AGMA strength rating of gears, is currently computed using the Lewis parabola which allows computation of the Lewis form factor.(1) The geometry factor is obtained from this Lewis factor and load sharing ratio. This method, which originally required graphical construction methods and more recently has been computerized, works reasonably well for external gears with thick rims.(2-6) However, when thin rims are encountered or when evaluating the strength of internal gears, the AGMA method cannot be used.
The following excerpt is from the Revised Manual of Gear Design, Section III, covering helical and spiral gears. This section on helical gear mathematics shows the detailed solutions to many general helical gearing problems. In each case, a definite example has been worked out to illustrate the solution. All equations are arranged in their most effective form for use on a computer or calculating machine.
Although there is plenty of information and data on the determination of geometry factors and bending strength of external gear teeth, the computation methods regarding internal gear design are less accessible. most of today's designs adopt the formulas for external gears and incorporate some kind of correction factors for internal gears. However, this design method is only an approximation because of the differences between internal gears and external gears. Indeed, the tooth shape of internal gears is different from that of external gears. One has a concave curve, while the other has a convex curve.
Service performance and load carrying capacity of bevel gears strongly depend on the size and position of the contact pattern. To provide an optimal contact pattern even under load, the gear design has to consider the relative displacements caused by deflections or thermal expansions expected under service conditions. That means that more or less lengthwise and heightwise crowning has to be applied on the bevel gear teeth.
The following excerpt is from the Revised Manual of Gear Design, Section III, covering helical and spiral gears. This section on helical gear mathematics shows the detailed solutions to many general helical gearing problems. In each case, a definite example has been worked out to illustrate the solution. All equations are arranged in their most effective form for use on a computer or calculating machine.
The newer profile-shifted (long and short addendum) gears are often used as small size reduction gears for automobiles or motorcycles. The authors have investigated the damage to each cutting edge when small size mass-produced gears with shifted profiles are used at high speeds.
Involute spur gears are very sensitive to gear misalignment. Misalignment will cause the shift of the bearing contact toward the edge of the gear tooth surfaces and transmission errors that increase gear noise. Many efforts have been made to improve the bearing contact of misaligned spur gears by crowning the pinion tooth surface. Wildhaber(1) had proposed various methods of crowning that can be achieved in the process of gear generation. Maag engineers have used crowning for making longitudinal corrections (Fig. 1a); modifying involute tooth profile uniformly across the face width (Fig. 1b); combining these two functions in Fig. 1c and performing topological modification (Fig. 1d) that can provide any deviation of the crowned tooth surface from a regular involute surface. (2)
Recent history has taught us that global competition has become tougher and is a major concern of American gear manufacturers from abroad have invaded American markets with products designed in an environment where management of technology has been practiced effectively. If American companies intend to compete in the changing world market, they must acquire the technologies that will allow them to do so.
An accurate and fast calculation method is developed to determine the value of a trigonometric function if the value of another trigonometric function is given. Some examples of conversion procedures for well-known functions in gear geometry are presented, with data for accuracy and computing time. For the development of such procedures the complete text of a computer program is included.
In Part I differences in pitting ratings between AGMA 218, the draft ISO standard 6336, and BS 436:1986 were examined. In this part bending strength ratings are compared. All the standards base the bending strength on the Lewis equation; the ratings differ in the use and number of modification factors. A comprehensive design survey is carried out to examine practical differences between the rating methods presented in the standards, and the results are shown in graphical form.
These are changing times for industry. Trauma and uncertainty are always a part of change, and change is not always for the better. Change is usually forced, most frequently by competition. Our competitive free enterprise system should be able to respond to competition because that's its basis. These are critical years. If we do not respond effectively to change and competition, it could be disasterous.
Most gear cutting shops have shelves full of expensive tooling used in the past for cutting gears which are no longer in production. It is anticipated that these cutters will be used again in the future. While this may take place if the cutters are "standard," and the gears to be cut are "standard," most of the design work done today involves high pressure angle gears for strength, or designs for high contact ratio to reduce noise. The re-use of a cutter under these conditions requires a tedious mathematical analysis, which is no problem if a computer with the right software is available. This article describes a computerized graphical display which provides a quick analysis of the potential for the re-use of shaving cutters stored in a computer file.
An analytical method is presented to predict the shifts of the contact ellipses on spiral bevel gear teeth under load. The contact ellipse shift is the motion of the point to its location under load. The shifts are due to the elastic motions of the gear and pinion supporting shafts and bearings. The calculations include the elastic deflections of the gear shafts and the deflections of the four shaft bearings. The method assumes that the surface curvature of each tooth is constant near the unloaded pitch point. Results from these calculations will help designers reduce transmission weight without seriously reducing transmission performance.
Investigation of Gear Rattle Phenomena The article by Messrs. Rust, Brandl and Thien was very interesting in its description of the problem and of some of the interactions which occur.
The advent of CNC technology as applied to gear shaping machines has, in the last 10 years, led to an astonishing improvement in both productivity and quality. As is usual when developments such as this take place, the technology of the machine tool suddenly jumps ahead of that of the cutting tool, and the machine is then capable of producing faster than the cutting tool can withstand.
Today's high technology hobs are visible different from their predecessors. Gear hobs have taken on a different appearance and function with present day technology and tool and material development. This article shows the newer products being offered today and the reasons for investigating their potential for use in today's modern gear hobbers, where cost reduction and higher productivity are wanted.
Not long ago, many manufacturing managers thought sensitivity to environmental protection standards meant additional expenses, decreased productivity, and a plethora of headaches and hassles.
Exporting. It's one of the hot strategies for helping boost businesses of all kinds, gear manufacturing among them. With domestic markets tight and new markets opening up overseas, exporting seems like a reasonable tactic. But while the pressure is on to sell overseas, there is equal, justifiable concern about whether the move is a good one. Horror stories abound about foreign restrictions, bureaucratic snafus, carloads of paperwork, and the complications and nuances of doing business in other languages and with other cultures.
Durability is the most important criterion used to define the quality of a gear. The freezing of metals has been acknowledged for almost thirty years as an effective method for increasing durability, or "wear life," and decreasing residual stress in tool steels. The recent field of deep cryogenics (below -300 degrees F) has brought us high temperature superconductors, the superconducting super collider, cryo-biology, and magnotehydrodynamic drive systems. It has also brought many additional durability benefits to metals.
Many CAD (Computer Aided Design) systems have been developed and implemented to produce a superior quality design and to increase the design productivity in the gear industry. In general, it is true that a major portion of design tasks can be performed by CAD systems currently available. However, they can only address the computational aspects of gear design that typically require decision-making as well. In most industrial gear design practices, the initial design is the critical task that significantly effects the final results. However, the decisions about estimating or changing gear size parameters must be made by a gear design expert.
To mechanical engineers, the strength of gear teeth is a question of constant recurrence, and although the problem to be solved is quite elementary in character, probably no other question could be raised upon which such a diversity of opinion exists, and in support of which such an array of rules and authorities might be quoted. In 1879, Mr. John H. Cooper, the author of a well-known work on "Belting," made an examination of the subject and found there were then in existence about forty-eight well-established rules for horsepower and working strength, sanctioned by some twenty-four authorities, and differing from each other in extreme causes of 500%. Since then, a number of new rules have been added, but as no rules have been given which take account of the actual tooth forms in common use, and as no attempt has been made to include in any formula the working stress on the material so that the engineer may see at once upon what assumption a given result is based, I trust I may be pardoned for suggesting that a further investigation is necessary or desirable.
In this issue of Gear Technology, we are focusing on using computers to their greatest advantage in gear design and manufacturing. In a sense, that's old news. It's a cliche to suggest that computers make our work life easier and more productive. No company that wishes to remain competitive in today's global manufacturing environment can afford to be without computers in all their manifestations. We need them in the office; we need them next to our desks in place of drafting boards; we need them on the shop floor.
This article discusses briefly some common manufacturing problems relating to coarse pitch gears and their suggested solutions. Most of the discussion will be limited to a low-quality production environment using universal machine tools.
The object of any business transaction, be it foreign or domestic, is making a profit. That's why you go through all the effort of making and selling your product in the first place. Getting paid in a timely manner is crucial to making profit, but when your customer is in another country, this "timely and convenient" payment can become complicated; hence, your need for a banker with expertise in international markets.
New freedom of motion available with CNC generators make possible improving tooth contact on bevel and hypoid gears. Mechanical machines by their nature are inflexible and require a special mechanism for every desired motion. These mechanisms are generally exotic and expensive. As a result, it was not until the introduction of CNC generators that engineers started exploring motion possibilities and their effect on tooth contact.
Surface measurement of any metal gear tooth contact surface will indicate some degree of peaks and valleys. When gears are placed in mesh, irregular contact surfaces are brought together in the typical combination of rolling and sliding motion. The surface peaks, or asperities, of one tooth randomly contact the asperities of the mating tooth. Under the right conditions, the asperities form momentary welds that are broken off as the gear tooth action continues. Increased friction and higher temperatures, plus wear debris introduced into the system are the result of this action.
The Hobbing Process The hobbing process involves a hob which is threaded with a lead and is rotated in conjunction with the gear blank at a ratio dependent upon the number of teeth to be cut. A single thread hob cutting a 40-tooth gear will make 40 revolutions for each revolution of the gear. The cutting action in hobbing is continuous, and the teeth are formed in one passage of the hob through the blank. See Fig. 1 for a drawing of a typical hob with some common nomenclature.
This is Part II of a two-part series on the basics of gear hobbing. Part I discussed selection of the correct type of hobbing operation, the design features of hobs and hob accuracy. This part will cover sharpening errors and finish hob design considerations.
One of our readers in England has asked for our help in locating published technical data and information on the design, manufacture, and inspection of camshaft gears. Although millions of these gears have been made and are in constant use, we are not aware of any formal material having been published. We would be pleased to hear from anyone who had knowledge of such information.
CNC technology offers new opportunities for the manufacture of bevel gears. While traditionally the purchase of a specific machine at the same time determined a particular production system, CNC technology permits the processing of bevel gears using a wide variety of methods. The ideological dispute between "tapered tooth or parallel depth tooth" and "single indexing or continuous indexing" no longer leads to an irreversible fundamental decision. The systems have instead become penetrable, and with existing CNC machines, it is possible to select this or that system according to factual considerations at a later date.
There are different types of spiral bevel gears, based on the methods of generation of gear-tooth surfaces. A few notable ones are the Gleason's gearing, the Klingelnberg's Palloid System, and the Klingelnberg's and Oerlikon's Cyclo Palliod System. The design of each type of spiral bevel gear depends on the method of generation used. It is based on specified and detailed directions which have been worked out by the mentioned companies. However, there are some general aspects, such as the concepts of pitch cones, generating gear, and conditions of force transmissions that are common for all types of spiral bevel gears.
Next year will be the 500th anniversary of Christopher Columbus' famous "discovery" of America. Poor Columbus has fallen on hard times of late, what with revisionist historians smacking their lips over his more notable failures and reminding us that American natives have a vastly different point of view on this Great American Success Story. But before we relegate the Great Navigator to the scrap heap of trashed-over heros, let's take one last look at some of the positive lessons to be learned from the Columbus experience - ones that could be instructive to our current situation in the American gear industry.
Countless research studies confirm this fact: Companies that advertise aggressively during a recession will flourish after the economic tide turns. Regardless of company size, effective advertising generally requires the services of an agency, and under current economic conditions, you may need one now more than ever. The question is, how do you go about getting the right one for your company.
The quality of gearing is a function of many factors ranging from design, manufacturing processes, machine capability, gear steel material, the machine operator, and the quality control methods employed. This article discusses many of the bevel gear manufacturing problems encountered by gear manufacturers and some of the troubleshooting techniques used.
What follows is Part 2 of a three-part article covering the principles of gear lubrication. Part 2 gives an equation for calculating the lubricant film thickness, which determines whether the gears operate in the boundary, elastohydrodynamic, or full-film lubrication regime. An equation for Blok's flash temperature, which is used for predicting the risk of scuffing, is also given.
Pride. Awe. Relief. Admiration. These were some of the emotions with which I, like most Americans, greeted the end of the Persian Gulf War. I was proud of our country for saying it would do a job and then doing it with a minimum of loss and a maximum of effectiveness; I was awed by the terrifying efficiency of our weapons and relieved that our casualties were so light; and I was filled with admiration at the skill with which one of the most complex logistical military operations of the century was carried out.
The following article is a collection of data intended to give the reader a general overview of information related to a relatively new subject within the gear cutting industry. Although carbide hobbing itself is not necessarily new, some of the methods and types of application are. While the subject content of this article may be quite broad, it should not be considered all-inclusive. The actual results obtained and the speeds, feeds, and tool life used in carbide hobbing applications can vary significantly.
This is the final part of a three-part series on the basics of gear lubrication. It covers selection of lubricant types and viscosities, the application of lubricants, and a case history
Shot peening is widely recognized as a prove, cost-effective process to enhance the fatigue characteristics of metal parts and eliminate the problems of stress corrosion cracking. Additional benefits accrue in the areas of forming and texturizing. Though shot peening is widely used today, the means of specifying process parameters and controlling documents for process control are not widely understood. Questions regarding shot size, intensity, and blueprint specification to assure a high quality and repeatable shot peening process are continually asked by many design and materials engineers. This article should answer many of the questions frequently asked by engineering professionals and to further assist companies interested in establishing a general shot peening specification.
The design of any gearing system is a difficult, multifaceted process. When the system includes bevel gearing, the process is further complicated by the complex nature of the bevel gears themselves. In most cases, the design is based on an evaluation of the ratio required for the gear set, the overall envelope geometry, and the calculation of bending and contact stresses for the gear set to determine its load capacity. There are, however, a great many other parameters which must be addressed if the resultant gear system is to be truly optimum. A considerable body of data related to the optimal design of bevel gears has been developed by the aerospace gear design community in general and by the helicopter community in particular. This article provides a summary of just a few design guidelines based on these data in an effort to provide some guidance in the design of bevel gearing so that maximum capacity may be obtained. The following factors, which may not normally be considered in the usual design practice, are presented and discussed in outline form: Integrated gear/shaft/bearing systems Effects of rim thickness on gear tooth stresses Resonant response
The acceptance by discerning customers of passenger cars is dependent upon both the actual noise lever and the subjective noise character. The subjective noise character itself can contain, among other features, undesirable noise phenomena which become apparent at certain points in the vehicle operating range. One such critical phenomenon is gear rattle, which is mainly present under low speed, high load conditions. Due to changes in the angular velocity of the crankshaft, gear rattle under driving conditions occurs at the unloaded gears and splines.
Precision gears play a vital role in today's economy. Through their application, automobile transmissions are more compact and efficient, ships sail faster, and diesel locomotives haul more freight. Today great emphasis is being placed upon the reduction of noise in all gear applications and, to be quiet, gears must be accurate.
At the next meeting of your association's marketing committee, notice what happens. The rate of taking notes increases dramatically when the market analysis and international trade trends reports begin. Even with the handouts to match the overhead projections of numbers, the audience's pace is furious. This is vital, apparently hard-to-come-by information, and no one wants to miss out. Almost all of the information comes from one source, yet the data offered is only one small dip from an enormous treasure chest - the U.S. Government.
The availability of technical software has grown rapidly in the last few years because of the proliferation of personal computers. It is rare to find an organization doing technical work that does not have some type of computer. For gear designers and manufacturers, proper use of the computer can mean the difference between meeting the competition or falling behind in today's business world. The right answers the first time are essential if cost-effective design and fabrication are to be realized. The computer is capable of optimizing a design by methods that are too laborious to undertake using hard calculations. As speeds continue to climb and more power per pound is required from gear systems, it no longer is possible to design "on the safe side" by using larger service factors. At high rotational speeds a larger gear set may well have less capacity because of dynamic effects. The gear engineer of today must consider the entire gear box or even the entire rotating system as his or her domain.
It's a buyer's market these days on solutions for our country's economic problems. Everybody with access to a t.v. camera or a publisher is telling us what we need to do. Usually their solution involves either buying their book or tape or electing them to office.
When I was new to gear engineering, I found the array of gear literature scare, and the information scattered and conflicting. After investigating the materials available, I set the goal of creating an annotated listing of the references. There are many valuable resources, but for this article I have selected ten of the best. These references, in my opinion, are the most useful, and cover the scope while minimizing redundancy.
Grinding is a technique of finish-machining, utilizing an abrasive wheel. The rotating abrasive wheel, which id generally of special shape or form, when made to bear against a cylindrical shaped workpiece, under a set of specific geometrical relationships, will produce a precision spur or helical gear. In most instances the workpiece will already have gear teeth cut on it by a primary process, such as hobbing or shaping. There are essentially two techniques for grinding gears: form and generation. The basic principles of these techniques, with their advantages and disadvantages, are presented in this section.
The whole point of a trade show is to get leads that will turn into sales. No matter how attractive your booth was, no matter how smoothly the setup and the show ran, no matter how many visitors you had at your booth, if your presence at a show didn't net you any sales, then your considerable investment of time, money, and effort has been wasted.
There is one dimension common to both members of a pair of properly mating spur gears - the base pitch (BP). This base pitch is equal to the circular pitch of the gear on the base circle (see Fig. 1). For a helical gear, the base pitch can be described in either the transverse or normal plane, and is called the transverse base pitch (TBP) or normal base pitch (NBP), respectively. For parallel axis helical gears, both the TBP and NBP must be the same on both mating gears. For skew axis helical gears, only the NBP must be common.
Now that the new tax bill has been passed, the time has come to begin evaluating how it will affect investment strategies in the machine tool business. Your first reaction may be to think that any motivation to invest in capital improvements in your company is gone, because both the investment tax credit and the accelerated depreciation on capital investment have been removed from the tax law. After all, if Uncle Sam is not going to help us out through some short term tax gains, why should we bother? Can we afford to bother?
In robot configurations it is desirable to be able to obtain an arbitrary orientation of the output element or end-effector. This implies a minimum of two independent rotations about two (generally perpendicular) intersecting axes. If, in addition, the out element performs a mechanical task such as in manufacturing or assembly (e.g., drilling, turning, boring, etc.) it may be necessary for the end-effector to rotate about its axis. If such a motion is to be realized with gearing, this necessitates a three-degree-of-freedom, three-dimensional gear train, which provides a mechanical drive of gyroscopic complexity; i.e., a drive with independently controlled inputs about three axes corresponding to azimuth, nutation, and spin.
The complete Industry News section from the March/April 2010 issue of Gear Technology.
Chairman Todd Praneis of Cotta Transmission describes the activities of AGMA's Enclosed Drives technical committee.
The complete Product News section from the November/December 2010 issue of Gear Technology.
Results of Gear Technology research on trends in employment, outsourcing, machine tool investment and other gear industry business practices.
The complete Industry News section from the November/December 2010 issue of Gear Technology.
The complete product news section from the January/February 2011 issue of Gear Technology.
Point-surface-origin (PSO) macropitting occurs at sites of geometric stress concentration (GSC) such as discontinuities in the gear tooth profile caused by micropitting, cusps at the intersection of the involute profile and the trochoidal root fillet, and at edges of prior tooth damage, such as tip-to-root interference. When the profile modifications in the form of tip relief, root relief, or both, are inadequate to compensate for deflection of the gear mesh, tip-to-root interference occurs. The interference can occur at either end of the path of contact, but the damage is usually more severe near the start-of-active-profile (SAP) of the driving gear.
The complete technical calendar section from the January/February 2011 issue of Gear Technology.
The complete Industry News section from the January/February 2011 issue of Gear Technology.
The complete Product News section from the March/April 2011 issue of Gear Technology.
The complete Industry News section from the September/October 2010 issue of Gear Technology.
Machine tool companies are expanding capabilities to better accommodate the changing face of manufacturing. Customers want smaller-sized equipment to take up less valuable floor space, multifunctional machines that can handle a variety of operations and easy set-up changes that offer simplified operation and maintenance.
In this paper a new method for the introduction of optimal modifications into gear tooth surfaces - based on the optimal corrections of the profile and diameter of the head cutter, and optimal variation of machine tool settings for pinion and gear finishingâ€”is presented. The goal of these tooth modifications is the achievement of a more favorable load distribution and reduced transmission error. The method is applied to face milled and face hobbed hypoid gears.
The complete Industry News section from the March/April 2011 issue of Gear Technology.
Interactive jewelry designed from micro-precision parts.
The complete Product News section from the May 2011 issue of Gear Technology.
A very direct and effective way of increasing power transmission efficiency is a changeover from mineral-oil-based lubricants to synthetic lubricants.
The complete Industry News section from the May 2011 issue of Gear Technology.
Dutch design and Swiss ingenuity cause transmission breakthrough. Updated examples of Cylkro face gears in action.
When the term, â€śwhat you see is what you getâ€ť is applied in the computer industry, it means that users or customers are able to see their end results without the encumbrances of complicated software code that enables this function. Software works behind the scenes ultimately to produce transparency and the desired effects. In many ways, this concept should be extended to the relationships that exist between suppliers and buyers and even among internal company departments.
In the majority of spiral bevel gears, spherical crowning is used. The contact pattern is set to the center of the active tooth flank and the extent of the crowning is determined by experience. Feedback from service, as well as from full-torque bench tests of complete gear drives, has shown that this conventional design practice leads to loaded contact patterns, which are rarely optimal in location and extent. Oversized reliefs lead to small contact area, increased stresses and noise, whereas undersized reliefs result in an overly sensitive tooth contact.
Bore finishing system from Sunnen helps Cloyes Gear and Products achieve high accuracy, productivity and process capability.
A reflection by Michael Goldstein, Publisher & Editor-in-Chief.
The complete Product News section from the May 2010 issue of Gear Technology.
Easily one of the central issues affecting U.S. manufacturing is what one might call the exports deficitâ€”the inability of American companies to sell products to, for instance, Asian markets, developing countries and other ports of callâ€”due to what they perceive to be unfair trade agreements and or policies.
Itâ€™s happened to most manufacturers at one point or another. A defective product comes back from a customer in need of repair. Perhaps a bearing or a gear drive has failed, and the customer simply needs a replacement. Upon further examination, the company realizes it was never one of its products in the first place, but a fabricated copy that snuck into the market. The manufacturing community has been dealing with counterfeit products for decades, but used machinery dealers and Internet shoppers seem to continuously get hit by scam artists.
The complete Industry News section from the May 2010 issue of Gear Technology.
The complete Product News section from the June 2010 issue of Gear Technology.
In the hypercompetitive race to increase automobile efficiency, Metaldyne has been developing its balance shaft module line with Victrex PEEK polymer in place of metal gears. The collaborative product development resulted in significant reductions in inertia, weight and power consumption, as well as improvement in noise, vibration and harshness (NVH) performance.
The powder metal (P/M) process is making inroads in automotive transmission applications due to substantially lower costs of P/M-steel components for high-volume production, as compared to wrought or forged steel parts. Although P/M gears are increasingly used in powered hand tools, gear pumps and as accessory components in automotive transmissions, P/M-steel gears are currently in limited use in vehicle transmission applications. The primary objective of this project was to develop high-strength P/M-steel gears with bending fatigue, impact resistance and pitting fatigue performance equivalent to current wrought steel gears.
The complete Industry News section from the August 2010 issue of Gear Technology.
The complete Industry News section from the June 2010 issue of Gear Technology.
Publisher Michael Goldstein describes the remarkable accomplishments of Randall Publications LLC over the past year, despite the intense and hectic transformation he and the staff experienced unbelievable strain on their time and concentration.
The complete Product News section from the July 2010 issue of Gear Technology.
The complete Industry News section from the July 2010 issue of Gear Technology.
In co-operation with Voith, a major transmission manufacturer in Germany, Heller has developed a process that significantly enhances the productivity of pre-milling and gear milling operations performed on a single 5-axis machining center.
The complete Product News section from the August 2010 issue of Gear Technology.
One of the most effective methods in solving the edge loading problem due to excess misalignment and deflection in aerospace actuation gearing is to localize tooth-bearing contact by crowning the teeth. Irrespective of the applied load, if the misalignment and/or deflection are large enough to cause the contact area to reduce to zero, the stress becomes large enough to cause failure. The edge loading could cause the teeth to break or pit, but too much crowning may also cause the teeth to pit due to concentrated loading. In this paper, a proposed method to localize the contact bearing area and calculate the contact stress with crowning is presented and demonstrated on some real-life examples in aerospace actuation systems.
In this article, gear buyers have been given an opportunity to discuss quality, value, customer service and how gear manufacturers can improve business practices.
The complete Product News section from the June/July 2011 issue of Gear Technology.
The complete Industry News section from the June/July 2011 issue of Gear Technology.
Curvic Couplings were first introduced in 1942 to meet the need for permanent couplings and releasing couplings (clutches), requiring extreme accuracy and maximum load carrying capacity, together with a fast rate of production. The development of the Curvic Coupling stems directly from the manufacture of Zerol and spiral bevel gears since it is made on basically similar machines and also uses similar production methods. The Curvic Coupling can therefore lay claim to the same production advantages and high precision associated with bevel gears.
A recent U.S. Army Tank-Automotive Command project, conducted by Battelle's Columbus Laboratories. successfully developed the methodology of CAD/CAM procedures for manufacturing dies (via EDM) for forging spiral bevel gears. Further, it demonstrated that precision forging of spiral bevel gears is a practical production technique. Although no detailed economic evaluation was made in this study, it is expected that precision forging offers an attractive alternative to the costly gear cutting operations for producing spiral bevel gears.
The complete Industry News section from the January/February 2012 issue of Gear Technology.
The complete Product News section from the March/April 2012 issue of Gear Technology.
The large gears found in mining, steel, construction, off-road, marine and energy applicationsâ€”massive and robust in natureâ€”need to tackle the greatest production demands. This, in turn, means that a special emphasis must be put on the heat treating methods used to increase the wear resistance and strength properties of gears this size.
The complete Industry News section from the March/April 2012 issue of Gear Technology.
A brief introduction to the subject of Thin Film Coatings and their application to gear hobs and shaper cutters is followed by a detailed description of the Chemical Vapor Deposition Process and the Physical Vapor Deposition Process. Advantages and disadvantages of each of these processes is discussed. Emphasis is placed upon: application engineering of coated gear tools based on laboratory and field test results. Recommendations are suggested for tool design improvements and optimization of gear cutting operations using coated tools. Productivity improvements potentially available by properly utilizing coated tools are considered in terms of both tool cost and machining cost.
Borazon is a superabrasive material originally developed by General Electric in 1969. It is a high performance material for machining of high alloy ferrous and super alloy materials. Borazon CBN - Cubic Born Nitride - is manufactured with a high temperature, high pressure process similar to that utilized with man-made diamond. Borazon is, next to diamond, the hardest abrasive known; it is more than twice as hard as aluminum oxide. It has an extremely high thermal strength compared to diamond. It is also much less chemically reactive with iron, cobalt or nickel alloys.
What was once recognized as the unique genius of America is now slipping away from us and, in many areas, is now seen as a "second rate" capability. Unless action is taken now, this country is in real danger of being unable to regain its supremacy in technological development and economic vigor. First Americans must understand the serious implications of the problem; and second, we must dedicate ourselves to national and local actions that will ensure a greater scientific and technological literacy in America.
One of the major problems of plastic gear design is the knowledge of their running temperature. Of special interest is the bulk temperature of the tooth to predict the fatigue life, and the peak temperature on the surface of the tooth to avert surface failure. This paper presents the results of an experimental method that uses an infrared radiometer to measure the temperature variation along the profile of a plastic gear tooth in operation. Measurements are made on 5.08, 3.17, 2.54, 2.12 mm module hob cut gears made from nylon 6-6, acetal and UHMWPE (Ultra High Molecular Weight Polyethylene). All the tests are made on a four square testing rig with thermoplastic/steel gear pairs where the plastic gear is the driver. Maximum temperature prediction curves obtained through statistical analysis of the results are presented and compared to data available from literature.
The connection between transmission error, noise and vibration during operation has long been established. Calculation methods have been developed to describe the influence so that it is possible to evaluate the relative effect of applying a specific modification at the design stage. These calculations enable the designer to minimize the excitation from the gear pair engagement at a specific load. This paper explains the theory behind transmission error and the reasoning behind the method of applying the modifications through mapping surface profiles and determining load sharing.
Selection of the number of teeth for each gear in a gear train such that the output to input angular velocity ratio is a specified value is a problem considered by relatively few published works on gear design.
History comes around full circle. It is interesting to talk to gear manufacturers who service the defense, aerospace, automotive and computer industries and find that their sales, production and backlogs reflect excellent and, in some cases, record breaking business.
With the publishing of various ISO draft standards relating to gear rating procedures, there has been much discussion in technical papers concerning the various load modification factors. One of the most basic of parameters affecting the rating of gears, namely the endurance limit for either contact or bending stress, has not, however, attracted a great deal of attention.
The Integral Temperature Method for the evaluation of the scoring load capacity of gears is described. All necessary equations for the practical application are presented. The limit scoring temperature for any oil can be obtained from a gear scoring test.
As I thought about what we might expect for 1986, the most important news affecting our industry is the tax revision bill just finished by the House Ways and Means Committee.
Sub: 'Finding Tooth Ratios' article published in Nov/Dec 1985 issue Let us congratulate you and Orthwein, W.C. for publishing this superb article in Gear Technology Journal. We liked the article very much and wish to impliment it in our regular practice.
Since we are a high volume shop, we were particularly interested in Mr. Kotlyar's article describing the effects of hob length on production efficiency which appeared in the Sept/Oct issue of Gear Technology. Unfortunately, some readers many be unnecessarily deterred from applying the analysis to their own situations by the formidabilty of the mathematical calculations. I am making the following small suggestion concerning the evaluation of the constant terms.
Mechanical efficiency is an important index of gearing, especially for epicyclic gearing. Because of its compact size, light weight, the capability of a high speed ratio, and the ability to provide differential action, epicyclic gearing is very versatile, and its use is increasing. However, attention should be paid to efficiency not only to save energy, but sometimes also to make the transmission run smoothly or to avoid a self-locking condition.
At Muncie Power, the objective of noise and vibration testing is to develop effective ways to eliminate power take-off (PTO) gear rattle, with specific emphasis on PTO products. The type of sound of largest concern in this industry is tonal.
In the wide, wide world of moving parts, the gears required for the big jobsâ€”the really big jobsâ€”often experience big problems. Proper lubrication of these gears is paramount in industrial applications such as wind turbines, kilns, sugar mills, crushers, heavy construction, offshore drilling rigs, mining and quarrying.
The complete Product News section from the August 2011 issue of Gear Technology.
The complete Industry News section from the September 2011 issue of Gear Technology.
There are a number of companies working to change the way broaching is perceived, and over the past 10 years, theyâ€™ve incorporated significant technological changes to make the process more flexible, productive and accurate.
The complete Industry News section from the August 2011 issue of Gear Technology.
Klingelnberg's new tool and machine concept allow for precise production.
The complete Product News section from the September 2011 issue of Gear Technology.
Make no mistake -- lean manufacturing is here to stay. And no wonder. As a fiercely competitive global economy continues to alter companiesâ€™ â€śMain Streetâ€ť thinking, that relatively new dynamic is spurring the need for â€śI-need-it-yesterdayâ€ť production output. And for increasingly more industries -- big or small -- that means getting as lean as you can, as fast as you can.
Our special Gear Expo advertising section.
The complete Technical Calendar section from the September 2011 issue of Gear Technology.
The complete Product News section from the October 2011 issue of Gear Technology.
The complete Product News section from the January/February 2012 issue of Gear Technology.
Our special advertising section brings you the highlights of Gear Expo 2011.
The complete Technical Calendar section from the October 2011 issue of Gear Technology.
The complete Industry News section from the October 2011 issue of Gear Technology.
While the cable networks seem to be inundated with collectible television shows, the Addendum staff believes there's room for one more.
If you make hardened gears and have not seen any micropitting, then you havenâ€™t looked closely enough. Micropitting is one of the modes of failure that has more recently become of concern to gear designers and manufacturers. Micropitting in itself is not necessarily a problem, but it can lead to noise and sometimes other more serious forms of failure. Predicting when this will occur is the challenge facing designers.
The complete Product News section from the November/December 2011 issue.
This paper presents an approach that provides optimization of both gearbox kinematic arrangement and gear tooth geometry to achieve a high-density gear transmission. It introduces dimensionless gearbox volume functions that can be minimized by the internal gear ratio optimization. Different gearbox arrangements are analyzed to define a minimum of the volume functions. Application of asymmetric gear tooth profiles for power density maximization is also considered.
The complete Industry News section from the November/December 2011 issue of Gear Technology
The complete Industry News section from the June 2020 issue of Gear Technology.
News Items About CTI
1 CTI Berlin Presents Young Drive Experts Award (December 6, 2018)
Once again, three candidates qualified for the CTI Young Drive Experts Award at the 17th CTI Symposium: "Automotive Drivetrains | In... Read News
2 SMT to Present Paper at CTI Symposium USA (May 5, 2016)
SMT's Baydu Al will be at the CTI Symposium USA in May to present his paper, "FEA of Tooth Flank Fracture (TFF) Using Boundary C... Read News
3 USCTI and AMT Cutting Tool Market Report Finds Cutting Tool Consumption Down 6% in July (September 23, 2015)
July U.S. cutting tool consumption totaled $177.5 million, according to the U.S. Cutting Tool Institute (USCTI) and AMT – the Assoc... Read News
4 Hoganas AB Showcases PM at CTI Symposium (November 27, 2017)
Höganäs AB will showcase its range of sustainable metal powder solutions for future powertrains at CTI Symposium and Transmissi... Read News
5 Sigmasoft Offers Options for Injection Molding Simulation (April 11, 2012)
Sigma Plastic Services, Inc. recently presented Sigmasoft - The Virtual Process and Mold Development software designed for injection mold... Read News
6 Kistler Introduces Injection Molding Software (April 6, 2012)
Kistler North America, a worldwide supplier of precision sensors, systems and instrumentation for the dynamic measurement of pressure, fo... Read News
7 Ipsen Doubles Titan Production (January 26, 2012)
Due to high worldwide demand for Ipsen's Titan Vacuum Furnace, Ipsen announces the doubling of production for H4 and H6 sizes ef... Read News
8 KISSsoft Offers Optimization of Profile Corrections (January 12, 2012)
An important step in terms of noise and strength optimization of a gear pair is the optimal design of the micro-geometry.Thereby a combin... Read News
9 Sandvik and Hofler Team Up in Schaumburg Productivity Center (November 22, 2011)
The collaboration between Sandvik Coromant and Höfler Maschinenbau began in 2009. Since then it has developed into several joint act... Read News
10 LMC Face Drivers Improve Turning Productivity (October 11, 2011)
Gear hobbing is easier and more productive with Neidlein's FDNC face driver from LMC Workholding. With Neidlein's FDNC Face Drive... Read News
11 Seco to Play Interactive Role at imX 2011 (August 23, 2011)
In keeping with the interactive nature of imX, Seco's executive management and technical experts will be on hand to discuss new metal... Read News
12 Ingersoll Announces Construction of New Facility (August 3, 2011)
Ingersoll Cutting Tools is proud to announce the start of construction on a new facility at its Rockford campus. Following months of... Read News
13 Gleason Invests in Coarse Pitch Hob Production Cell (August 2, 2011)
In response to unprecedented global demand for large cylindrical gears, Gleason Cutting Tools Corporation has invested in an advanced coa... Read News
14 Seco Tools Offers IIoT Solutions for HMLV Production (June 9, 2020)
Seco Tools Manufacturing Transformation helps customers address the challenges of high-mix/low-volume (HMLV) production and other modern ... Read News
15 Thread Former Boosts Productivity and Quality (April 18, 2012)
Walter USA, LLC has introduced the Walter Prototyp Protodyn HSC thread former, a solid carbide tool engineered to boost thread forming cu... Read News
16 Gleason Gear Testers Handle Day-to-Day Production Rigors (May 18, 2011)
Now roll testing and single flank testing of bevel, angular bevel and parallel-axis gears with diameters up to 2,500 mm can be completed ... Read News
17 CA614 Enables High-Speed, In-Line Contour Inspection (May 9, 2011)
The new opticline CA614 noncontact shaft measuring system is designed for fast, easy, economical and robust submicron measurement of all ... Read News
18 Techniks Boring Tools Maximize Productivity (April 29, 2011)
Pinzbohr High Precision Modular Boring Tools from Techniks offer accuracy, rigidity and repeatability. All Pinzbohr boring tools are buil... Read News
19 Interactive Manufacturing Experience Charts New Course for U.S. Manufacturing (February 28, 2011)
From some of the United States' largest industrial technology innovators to the heads of small machine shops and providers of workhol... Read News
20 Inductoheat Ships Induction Hardening and Tempering System (December 6, 2010)
Inductoheat, Inc., a leading induction heating equipment manufacturer, recently shipped an induction hardening and tempering system to a ... Read News
21 Gleason Introduces 350GMS Inspection System (November 2, 2010)
Complete inspection of gears as large as 350 mm in diameter now can be performed up to 40 percent faster (gear design dependant... Read News
22 KISSsoft Implements Spline Connections (October 26, 2010)
Due to numerous requests from the industry, the spline connections according to DIN 5481 and DIN 5482 were recently implemented in K... Read News
23 Gleason Offers Upgrade Package for Inspection Systems (October 18, 2010)
Early models of Gleason's GMM SIGMA series of analytical gear inspection systems can now be equipped with an upgrade package that com... Read News
24 Nordex Begins Wind Production in Arkansas (October 5, 2010)
Nordex's newly built wind turbine manufacturing plant in Jonesboro, Arkansas officially opened October 4. "Two years ago, we ann... Read News
25 Non-Coplanar Connecting Rod System Does the Work of Three Machines (July 21, 2011)
C & B Machinery of Livonia, Michigan has improved productivity and flexibility of their double disc non-coplanar connecting rod grind... Read News
26 Microprecision Offers New Gear Production Machines (May 11, 2012)
Hemel Hempstead-based Microprecision, a specialist in the field of precision component manufacturing, is now exclusively distributing a h... Read News
27 Sandvik Opens Productivity Center (April 18, 2012)
Sandvik Coromant officially unveiled its new California productivity center at a VIP event and ribbon cutting ceremony on Monday, April 2... Read News
28 LFG Machine Offers Precision and Productivity (May 1, 2013)
This machine concept facilitates highly productive profile grinding for large workpieces. The range for external and internal gears compr... Read News
29 Gleason Offers Retrofit Package for Inspection Systems (November 25, 2013)
Gleason Corporation’s GMM and GMS Series of Analytical Gear Inspection Systems currently in service can be easily updated with a ne... Read News
30 Gleason Updates 1500GMS Inspection System (November 18, 2013)
Gleason Corporation’s 1500GMS Analytical Gear Inspection System has been updated to deliver improved inspection speeds and offer ma... Read News
31 GWJ Adds Dimensioning Function in Cylindrical Gear Pair Module (November 12, 2013)
GWJ Technology GmbH, headquartered in Braunschweig, Germany, recently added a new function to the web-based eAssistant software module fo... Read News
32 Ipsen Offers Furnace Maintenance Best Practices (October 30, 2013)
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33 Fanuc Offers Control Productivity (October 8, 2013)
The Fanuc CNC Series 30i/31i-L Model B high-speed laser controls offer fabricators streamlined efficiency and increased productivity usin... Read News
34 Excon 2013 Focuses on India Construction Market (August 20, 2013)
India's Premier Industry Association has been playing a role in developing the construction equipment industry in India through organ... Read News
35 Global Distributed Gear Production (August 13, 2013)
Two significant gear producers from different ends of the market in terms of volume have recently invested in additional manufacturing pl... Read News
36 Koepfer Acquires Getrag Timing Gear Production (June 25, 2013)
The company, Koepfer Zahnrad- und Getriebetechnik GmbH, headquartered in Furtwangen, Germany, has acquired the Getrag timing gear product... Read News
37 Ovako Blanks Speed Production While Reducing Waste (May 16, 2013)
Machining quality components from steel bar can generate large amounts of waste material, but with Ovako pre-components this waste can be... Read News
38 Marposs Offers Gaging Station for Gear Inspection (May 14, 2013)
The line of manual systems and machines for functional gear verification includes a wide range of highly precise solutions, to measure al... Read News
39 GMTA Updates Activity in Gear Market (April 5, 2013)
GMTA (German Machine Tools of America) represents various top-quality German metalworking machine builders, including Profilator, Pittler... Read News
40 Mazak Constructing Southwest Tech Center, HQ (August 27, 2010)
Houston is the site of Mazak Corporation's future Southwest Technology Center and Regional Headquarters. The facility will offer supp... Read News
41 Zoller Offers Inspection for Hob Cutters (January 14, 2013)
Gear cutting is a challenging task. Only perfect and re-sharpened tools can guarantee correct workpieces, short setup times and low downt... Read News
42 Maiorino Joins GH Induction (January 4, 2013)
GH Induction Atmospheres (GH IA), part of the worldwide GH Group, has hired a veteran sales professional to penetrate the market for its ... Read News
43 Liebherr's RLS 800 Offers High Efficiency Production (January 3, 2013)
Liebherr's RLS 800 rotary loading system is a welcome complement to the existing PHS linear pallet handling system. The system is sui... Read News
44 Morris Group Names Fonte Productivity Specialist (November 13, 2012)
Morris Group, Inc. has announced the appointment of George J. Fonte to the position of productivity specialist for The Robert E. Morris C... Read News
45 Oelheld Offers Cooling and Corrosion Protection Fluid (November 1, 2012)
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46 Okuma Presents Job Shop Productivity Open House (October 17, 2012)
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47 Junker Offers Lean Selection Speed at IMTS 2012 (July 27, 2012)
Junker's Lean Selection allround offers custom-tailored power and precision and is especially prized for being user-friendly and cost... Read News
48 Renishaw Offers Machine Tool Inspection Probing (July 25, 2012)
Renishaw's new RMI-Q multiple probe radio transmission system uses a single radio receiver for tool setting probe and spindle-mounted... Read News
49 SKF Stroboscope Facilitates Easy Inspection (June 29, 2012)
The portable SKF TKRS 10 Stroboscope facilitates easy inspection of rotating or reciprocating machinery in a "flash" without st... Read News
50 GH IA Develops Induction Hardening Machine (May 21, 2012)
GH Induction Atmospheres (GH IA), part of the worldwide GH Group, has built an induction heating machine that hardens, tempers, and ... Read News
51 KISSsoft Releases New Function for Face Gears (September 9, 2010)
A new functionality to generate a solid model of a face gear with arbitrary shaft angle and offset is implemented in the development vers... Read News
52 U.S. Demand for Synthetic Lubricant, Functional Fluid to Reach $4.8 Billion in 2013 (June 25, 2010)
U.S. demand for synthetic lubricants and functional fluids will expand more than three percent per year to $4.8 billion in 2013, with gro... Read News
53 ECM Process Deburrs Injection System Components (August 9, 2010)
Deburring may not be a core process in machining, but it is still considered a necessary evil. Although other machining operations have b... Read News
54 NexxtDrives Variable Speed Power Take-Off Provides Micro Hybrid-Functionality (April 2, 2006)
The NexxtPTO is a compact, variable speed mechanical power take-off that can be configured to act as an engine starter and alternator, pr... Read News
55 Performance Gear Adds Inspection Capabilities (January 8, 2007)
Performance Gear Systems, Inc. has purchased a Hofler ZAP Analytical Gear Checking Machine. According to the companys press re... Read News
56 alpha gears Right Angle Gear Reducer Designed for High Reduction Ratios (April 22, 2006)
alphas TPK+ dual technology gear reducer is a two-stage right-angle gearhead for servo applications featuring a robot flange accord... Read News
57 Frenco Assumes Control of Hommelwerke Gear Inspection Line (April 22, 2006)
Hommelwerke GmbH announced recently that gear inspection specialist Frenco GmbH has assumed control of the manufacture, sales, calibratio... Read News
58 Chimera Expands Mold Production Capacity (April 14, 2006)
Chimera Co., a precision mold parts designer and manufacturer in Tokyo, Japan, plans to expand its finished mold product plants. Accor... Read News
59 Toyota Raises Transmission Production Capacity in Poland (April 14, 2006)
Toyota Motor Corp. announced that Toyota Motor Manufacturing Poland Sp.zo.o, a producer of transmissions and engines, will increase its ... Read News
60 Alpha Gears Gearmotor Offers Significant Reduction in Inertia (April 11, 2006)
The TPM from alpha gear drives Inc. is a geared motor containing a rotary actuator based on an AC servo motor and high precision planetar... Read News
61 Alpha Gear New Gearhead Follows Trends in High Reduction Torque and Ratios (April 11, 2006)
The new SPK+ right-angle gearhead is designed for applications with high reduction ratios and torques. This product combines features of... Read News
62 Magnetic Gearing and Turbine Corp. Releases New Injection Molded Plastic Gears (April 6, 2006)
Magnetic Gearing & Turbine Corporation of Australia annonced the release of a new generation injection moulded magnetic gear. Accordi... Read News
63 Kinefac Introduces New Automated Production System (April 6, 2006)
Kinefac is introducing a new Robo-Roller, which is a quick changeover, automated production system for rolling threads, knurls, worms and... Read News
64 Induction Heating Companies Combine Sales Efforts (February 7, 2006)
Inductoheat Inc., Radyne Corp., Newelco and HIS combined their sales efforts to serve induction heating and forging customers. Accord... Read News
65 Doshi Returns to Schafer Gear as Production Manager (March 26, 2007)
Robert Doshi returned to Schafer Gear Works as production manager. According to a company press release, Doshi held this position befo... Read News
66 GKS Inspection Systems Expands In-House Measurement Capabilities (January 18, 2006)
GKS Inspection Services, Inc., a division of Laser Design, Inc., has expanded its Detroit-area dimensional inspec... Read News
67 Solar Atmospheres Offers Full Production Vacuum Carburizing Services (January 15, 2006)
Solar Atmospheres’ new Low Torr Vacuum Carburizing furnace and services are now operating at Solar’s Eastern Pennsylvania ... Read News
68 New Scanner from Induction Tooling (February 20, 2005)
The Model No. Scan I.T-LRS36 scanner from Induction Tooling was introducted at Gear Expo 2005. According to the companys literat... Read News
69 Holroyd Expands Production Department (February 18, 2005)
Holroyd has expanded its technical support team and introduced a new product structure to help customers. According to the company'... Read News
70 American Stress Technologies Introduces New Inspection System (February 15, 2005)
For the gear manufacturer plagued with nightmares about the possibility of grinding damage, GearScan 600 from American Stress Technologie... Read News
71 New High-Speed Inspection System from Renishaw (February 9, 2005)
Introduced at EMO, the Renscan5 high-speed inspection system from Renishaw delivers part inspection speeds up to 20 times faster than con... Read News
72 Sigma Pool Merges All Grinding Activities (February 7, 2005)
Sigma Pool partners have merged all activities in the field of cylindrical gear grinding under the roof of Liebherr-Verzahntechnik GmbH i... Read News
73 New Retoolable Manual Bench for Gear Inspection from Marposs (January 15, 2005)
The new M62 OBD (over ball diameter) retoolable manual bench measuring system for checkng gear shafts from Marposs is designed to permit ... Read News
74 New Gear Inspection System from M&M Precision (January 4, 2005)
The new in-line, in-process inspection equipment from M&M Precision is designed around a completely modular concept, allowing for ease of... Read News
75 Surface Combustion Helps Destroy Weapons of Mass Destruction (December 22, 2003)
Surface Combustion of Maumee, OH, has been authorized to proceed in building a highly engineered thermal system for the decontamination o... Read News
76 Honda Begins Powertain Components Production in China (March 8, 2007)
Production began on March 8 at the new Honda Auto Parts Manufacturing Co.Ltd. (CHAM) plant in Nanhai Industrial Park District, Foshan Cit... Read News
77 Maag Sells Marine and Turbo Gear Activities (May 24, 2007)
Maag Gear AG divested its marine and turbo gear business units, effective May 1, 2007. Renk AG bought the business unit and plans to cont... Read News
78 Mazak to Showcase Oil and Gas Production Innovations (December 11, 2013)
Mazak invites oil and gas and other large part manufacturers to its Discover More With Mazak event that’s taking place Jan. 15 and ... Read News
79 Camshaft Inspection Gage Measures Up to 200 Parts-Per-Hour (November 24, 2008)
The Adcole 1310 is a high-speed camshaft inspection gage with sub-micron accuracy measuring camshafts for rise error and chattermark dete... Read News
80 Renishaw Presents Lathe Inspection Probes at IMTS (May 27, 2010)
Renishaw's new RLP40 and OLP40 lathe inspection probes offer a choice of signal transmission technologies - radio or optical - to mak... Read News
81 Induction Hardening and Tempering System for Driveline Components (May 11, 2010)
Inductoheat, Inc., an induction heating equipment manufacturer, recently delivered an induction hardening and tempering system to a leadi... Read News
82 Gleason to Exhibit Large Gear Production Technologies at Windpower 2010 (May 7, 2010)
Wind turbine gears produced by Gleason gear production machines and cutting tools supply over 50 percent of the world's wind energy.&... Read News
83 Wenzel Introduces New Grind Burn Detection Capability (March 15, 2010)
In a continuing effort to enhance the capabilities of its gear measuring equipment, Wenzel has introduced a new feature that detects any ... Read News
84 Bevel Gear Cutter Slashes Production Time (March 8, 2010)
The Phoenix 280C Bevel Gear Cutting Machine from Gleason reduces cycle times by up to 35 percent for bevel gears and pinions up to 280 mm... Read News
85 QuesTek Awards Production Licenses for Gear Alloys (February 11, 2010)
Latrobe Specialty Steel Company was awarded licenses to produce and sell Ferrium C61 and C64 alloys from QuesTek Innovations LLC. Both hi... Read News
86 Illuminated Pocket Scopes Provide Clear, Precise Inspection (December 15, 2009)
Carry-along microscopes for gear manufacturing applications are more sophisticated than their convenient size may suggest. The latest mod... Read News
87 Mobile Induction Heater Treats Metal Parts (December 11, 2009)
Digimac is a compact, transportable induction heating system from GH Induction Group. It is capable of outputs up to 25 kW and 20 kHz. ... Read News
88 Surface Grinder Operates with Maximum Productivity, Minimum Cycle Times (February 4, 2009)
The TechMaster 844, from Jones and Shipman, offers 800 mm x 400 mm grinding capacity with a vertical capacity of 360 mm. The machine is ... Read News
89 Gleason Grinder Cuts Production Times (February 4, 2009)
The Genesis 160TWG threaded wheel grinder from Gleason is capable of hard finish grinding of cylindrical gears with diameters up to 160 m... Read News
90 GKS Expands Availability of On-Site Dimensional Inspection Services to Toledo (September 16, 2008)
GKS Inspection Services, Inc., a division of Laser Design Inc., is expanding its area of on-site services coverage to the Toledo market. ... Read News
91 Marposs Introduces Wireless Bore Gauge with Optional Inductive Battery Charger (July 19, 2007)
Marposs Corp. will present its new M1 Wave wireless bore gauge with an optional inductive battery charger in at South-Tec 2007.Equi... Read News
92 Alpha Gear's Newest Software Simplifies Selecting Gear Reducers (September 3, 2008)
The Cymex calculation software from alpha gear drives Inc. uses a database of company products and 6,000 motors from various manufacturer... Read News
93 GH Gear/Raceway Hardening Machine Handles Large Bearings More Productively (April 24, 2008)
GH Induction Group recently shipped a new design gear/raceway hardening machine capable of hardening gears and bearing raceways up to 3... Read News
94 PcTime! Released for PalmOS and Windows Mobile Devices (January 23, 2008)
InfosystemsPro LLC announces the release of PcTime! for PalmOS and Windows Mobile devices. PcTime! makes it easy to calculate production... Read News
95 Induction Heating Seminar Leads to Big Plans in 2008 (November 21, 2007)
The First Mexican Induction Heating and NDT seminar, held at the Plaza Camelinas Hotel in Queretaro, Mexico, featured several world-recog... Read News
96 Dontyne Debuts GATES Software for its Gear Production Suite (November 9, 2007)
Dontyne Systems, a U.K. company founded by Michael Fish and David Palmer, recently unveiled a new software program for its Gear Productio... Read News
97 Lufkin Announces Election of John F. Glick as president (October 31, 2007)
The board of directors at Lufkin Industries Inc. has elected John (Jay) F. Glick as president of the company. Glick has been a senior off... Read News
98 Moventas Invests in Wind Turbine Gear Production, Hires New Executives (August 30, 2007)
Moventas invested approximately 115 million euros in a new wind turbine gear factory in central Finland. Construction will begin in fall ... Read News
99 Mitsubishi Heavy Industries Completes Gear Cutting Tool Production Plant in India (August 30, 2007)
Mitsubishi Heavy Industries Ltd. completed construction of a new plant at Mitsubishi Heavy Industries India Precision Tools, Ltd., an Ind... Read News
100 StarragHeckert's Machining Centers for Large-Scale Gear Housings Improve Productivity (August 16, 2007)
Flender Guss GmbH & Co. KG manufacturers of large scale gear housings for wind power plants, recently discovered its rate of or... Read News
101 Sensor Development's Latest Model Measures Small Reaction Torque Level (August 6, 2007)
The Model 01165 small flange reaction torque sensor from Sensor Development is designed to measure small reaction torqu levels using flan... Read News
102 NUM Offers CNC Solution for Gear Production (December 10, 2013)
NUM has announced a high performance CNC solution for gear production machines that fully automates threaded wheel grinding. Incorporatin... Read News
103 Birchwood Gives Options for Water Restrictions (January 30, 2014)
Metal finishers facing water restrictions now have a great new option for the black oxide process from Birchwood Tec... Read News
104 R&P Metrology Announces CMM Capabilities for Portable Gear Inspection (January 13, 2014)
R&P Metrology GmbH announced new measurement capabilities for the RPG PM 750/1250 Portable Gear Metrology machines. When the system i... Read News
105 Sandvik Coromant InvoMilling CAD/CAM Software Offers Additional Five-Axis Functionality (January 12, 2018)
Cutting tool and tooling system specialist Sandvik Coromant has extended the functionality of its InvoMilling software. Th... Read News
106 Sandvik Coromant Enables Single-Setup Gear Production with Power Skiving Solution (February 6, 2019)
A new power skiving solution composed of CoroMill 178 and CoroMill 180 cutters from Sandvik Coromant is being released to help automotive... Read News
107 Hexagon Keynote Speaker Discusses Connectivity and the Changing Workforce (October 19, 2018)
Zachary Cobb, director of engineering and R&D in North America, Hexagon Manufacturing Intelligence, was the keynote speaker at the ... Read News
108 Forest City Gear Adds Metal Alloy Analysis to Gear Inspection Capabilities (October 16, 2018)
Forest City Gear can now perform fast, comprehensive analysis and verification of metal alloys for quality assurance and control using ... Read News
109 Dontyne Systems Honored for Best Practices by the UK Parliament (October 4, 2018)
Dontyne Systems applies Industry 4.0 principles to rejuvenate ancient technology. In 2006, Dontyne Systems created the Gear Production Su... Read News
110 Profilator GmbH Moves to New German Production Facility (September 25, 2018)
GMTA recently announced that Profilator has moved to a modern production facility in Wuppertal-Vohwinkel, Germany. With adjoining offic... Read News
111 Norton | Saint-Gobain Increases Grinding Productivity with Winter Vitrified CBN Wheels (September 21, 2018)
Saint-Gobain Abrasives has announced the introduction of its new Norton Winter Vitron7 cBN Grinding Wheels. The wheels feature a high-p... Read News
112 Grinding Machines Increase Quality and Productivity at Nixon Gear (September 18, 2018)
Two new grinding machines were recently added to production at Gear Motions’ Nixon Gear Division in Syracuse, NY.The Studer S121 is... Read News
113 FlexArm GH-18 Tapping Arm Improves Shift Productivity (May 14, 2018)
FlexArm Inc., will feature a mobile tapping package which yields mobility, productivity and efficiency by allowing operators to tap holes... Read News
114 CTI Symposia Germany and China Call for Papers (January 16, 2018)
Worldwide, the automotive industry is undergoing a major technological transformation. A rollout of electric cars and commercial veh... Read News
115 Liebherr PHS Allround Pallet Handling System Offers Flexible Production with 4- and 5-Axis Machining Centers (December 18, 2017)
Liebherr Automation Systems introduced its new PHS Allround pallet handling system, designed to enable a broad range of shops to engage i... Read News
116 C & B Machinery Supplies Specialty Grinder for Large Non-Coplanar Connecting Rods (February 12, 2019)
C & B Machinery of Brighton, Michigan has received an order from a major North American manufacturer of large construction and mining... Read News
117 KISSsoft Adds Plastic Materials Manager Function (December 6, 2017)
It is often the case that plastics manufacturers don't provide any data that is relevant for calculations when they supply their prod... Read News
118 KISSsoft Offers Selection of Predefined Gear Stages (November 16, 2017)
KISSsoft Release 03/2017 has a new function, the "Groups box", which lists a selection of predefined gear stages. These gear st... Read News
119 Mahr Inc. MarOpto MT 100 Fizeau Interferometer Towers Offers In-Production Measurement Solution (November 6, 2017)
Mahr Inc. has introduced the MarOpto MT 100, the first in a new series of Fizeau interferometer towers for measuring optics directly in p... Read News
120 Oerlikon Presents Paper at CTI Symposium USA 2017 (May 23, 2017)
High-performance transmission specialist Oerlikon Graziano, brand of Oerlikon Drive Systems Segment, presented its range of hybrid transm... Read News
121 Seco/Warwick Awarded Production Company of the Year Title (May 2, 2017)
Seco/Warwick has won a Production Company of the Year title in the Leaders of the Manufacturing World Competition. The title given to Se... Read News
122 Sandvik Coromant PrimeTurning Offers All-Directional Turning Capabilities (April 18, 2017)
Sandvik Coromant has unveiled a new turning concept that offers improved machining flexibility and the potential for significant producti... Read News
123 Gleason Inspection System Offers Key Measurements on Single Platform (April 11, 2017)
Gleason Corporation’s new 300GMSL Multi-Sensor Gear Inspection System will have its European première at the Control Show in... Read News
124 Kitagawa NorthTech Productivity Team Designs Custom Engineered Workholding Services (March 15, 2017)
Kitagawa NorthTech, Inc. provides turnkey and custom engineered workholding services. Known for their standard and advanced chucks, the c... Read News
125 Blackstone-NEY Ultrasonics PROHT Ultrasonic Cleaning Tanks Designed for Small Scale Production Cleaning (February 28, 2017)
Blackstone-NEY Ultrasonics, a division of Cleaning Technologies Group LLC, introduces its popular PROHT ultrasonic cleaning tanks with ne... Read News
126 Victrex Invests in Injection and Compression Molding Technology with Surface Generation (February 8, 2019)
An innovative and differentiated tooling design and processing technology called PtFS (Production to Functional Specification), from U.K.... Read News
127 Modern Heat Treat Expands Production Capability with AFC Holcroft Equipment (March 18, 2019)
In support of its continued growth, Modern Heat Treat, a commercial heat treating operation located in Richland Hills, Texas (USA), has a... Read News
128 Seco/Warwick Relocates Operations to Production, Assembly and Test Equipment Facility in India (February 2, 2017)
To better serve its customer base in India, Seco/Warwick has relocated its operations to a new production, assembly and test equipment fa... Read News
129 Gleason Expands Development and Production Center in Munich (July 29, 2019)
Gleason-Hurth Tooling GmbH, Munich, Germany, with its 160 employees, develops and manufactures tools and workholding systems for cylindri... Read News
130 Eaton Collaborates with Thogus on Face Shield Design and Production (May 4, 2020)
The global COVID-19 crisis is placing unprecedented demands on government and healthcare organizations, driving a critical need for front... Read News
131 Gleason Offers Free Gear Inspection Online Events with Control@Home Series (April 28, 2020)
While the Control Show in Stuttgart/Germany was cancelled due to COVID-19, metrology goes on. See how Gleason's latest inspection pro... Read News
132 Blaser Examines Coolant Options During Extended Production Stops (April 20, 2020)
The machines may not be running, but you need to monitor and maintain your metalworking fluid anyway. A production stop, triggered by a v... Read News
133 Dassault Systemes and Xometry Partner on Instant Part Production in Design Environment (February 19, 2020)
Dassault Systèmes and Xometry recently announced their partnership to provide customers with a seamless, integrated way to produce... Read News
134 Continental Invests in LK Metrology Multi-Sensor Inspection System (December 31, 2019)
Continental needed a high capacity system capable of rapid inspection cycles combined with fast surface scanning and accurate feature mea... Read News
135 Frenco Offers Horizontal Slide Option for Spline Inspection (December 20, 2019)
Frenco GmbH is now offering a horizontal slide option for the inspection of internal and external splines with AVM and IVM gauging system... Read News
136 EMAG Machines Rotor Shafts with End-to-End Production Systems (December 17, 2019)
Lightweight construction has been one of the primary challenges in automotive engineering for decades. Each component, from gears to driv... Read News
137 SMT Offers System Deflection Analysis Webinar (December 3, 2019)
System deflection takes misalignment into account and solves Force = Stiffness x Deflection equation for all components and connections. ... Read News
138 Dillon Offers Same Day Shipment on Largest Selection of Standard Jaws (August 27, 2019)
Touting the industry’s largest selection of standard jaws in stock for immediate shipment, Dillon Manufacturing’s hard and so... Read News
139 Sunnen and ANS Collaborate on Friction and Wear Reduction Technology (July 24, 2019)
Sunnen Products Company and Sweden’s Applied Nano Surfaces (ANS) have entered into a joint market development agreement to advance ... Read News
140 LK Metrology Introduces 5-Axis Multi-Sensor CMM for Complex Component Inspection (March 26, 2019)
LK Metrology, Inc. has introduced a new Altera CMM called the Scantek 5, that is coupled with Renishaw’s Revo-2 scanning system and... Read News
141 Index Integrates Automation Cell with Production Turning Centers (July 23, 2019)
Index has announced that the iXcenter automation cell is now available with its C Series of highly productive turning centers. Docked to ... Read News
142 Gleason Releases Latest Practical Gear Engineering Textbook (July 16, 2019)
Gleason has released a new edition of Practical Gear Engineering, a technical publication designed to benefit both gear engineering exper... Read News
143 NUM Helps Automate Production of Involute and Cyclodial Gears for Robotics (July 1, 2019)
NUM is helping the Taiwanese machine tool company Chien Wei Precise Technology to develop innovative CNC grinding machines for manufactur... Read News
144 EMAG Eldec Offers Induction Heating System for Elektror (June 17, 2019)
Air is an indispensable working medium in industrial production: It is used, for example, to extract excess humidity or dust, cool down h... Read News
145 TE Connectivity Promotes Kladder to Sales Director (June 7, 2019)
TE Connectivity (TE), a world leader in connectivity and sensors, has appointed Melissa Kladder to the position of director of sales, Ame... Read News
146 EMAG Production Lines Utilize Industry 4.0 with Modular Solutions (May 28, 2019)
Industry 4.0 is a relatively simple term; however, it contains complex challenges involving questions of unified standards, safety, and t... Read News
147 Ricardo Presents Technical Papers During CTI Symposium (May 22, 2019)
With diverse commercial applications ranging from defence to mining, farming and forestry, as well as innumerable leisure pursuits, the g... Read News
148 Forest City Gear Launches Advanced Turning and Milling Facility for Gear Blank Production (April 30, 2019)
Forest City Gear has expanded its turning and milling operations with a state-of-the-art facility designed to greatly improve lead times ... Read News
149 Gleason Offers Gear Inspection Technologies at Control 2019 (April 19, 2019)
Gleason Corporation will present its 300GMSL Multi-Sensor Gear Inspection System and the GRSL Gear Rolling System with integrated Laser S... Read News
150 Hexagon to Host Second Annual Production Software Users' Group Meeting at HxGN Live (April 9, 2019)
Hexagon’s Manufacturing Intelligence recently announced it will host the second annual Production Software Users’ Group meeti... Read News
151 Marposs Optoquick 3.0 High Precision Gage Delivers Both Tactile and Optical Measurement Technology in One Package (February 23, 2017)
Marposs announces the introduction of Optoquick 3.0, its latest addition to the industrial gauging solutions portfolio. Optoquick is a hi... Read News
152 Mazak VTC-805E Offers Versatility and Productivity for Long and Heavy Parts Manufacturers (February 1, 2017)
The new Mazak VTC-805E Vertical Traveling Column Machining Center brings high versatility and productivity to those shops that need to ta... Read News
153 EMAG Demonstrates Gear Production Advances (January 28, 2014)
Drivers are already used to the sixth gear – and the development continues. There are plans afoot for an automatic gearbox for a ni... Read News
154 Gleason to Introduce 300GMSP Analytical Gear Inspection System (April 6, 2015)
Gleason Corporation will introduce its latest gear metrology innovation at the upcoming Control Show in Stuttgart, Germany, from May 5-8.... Read News
155 Dillon Offers Large Standard Jaws Selection (January 11, 2016)
Dillon Manufacturing, Inc., stocks a large selection of standard jaws for immediate shipment. Suitable for a wide variety of workhol... Read News
156 EMAG Eldec Modular Induction (MIND) Hardening Systems Offer Flexibility and Simplicity (December 16, 2015)
EMAG subsidiary Eldec has developed new modular induction hardening systems designed to simplify the gear hardening process and increase ... Read News
157 Ajax TOCCO Selling 5/10 kW TOCCOtron AC Induction Heating Systems (September 4, 2015)
Ajax TOCCO Magnethermic recently delivered 5/10 kW TOCCOtron AC induction heating systems to an international on-site heat treating firm.... Read News
158 Dillon Full Grip Jaws Reduce Distortion and Provide More Friction (August 4, 2015)
Dillon Manufacturing recently introduced full grip jaws made of 1018 CR steel from 6 inches to 15 inches in diameter, with heights of 2, ... Read News
159 Siemens Sinumerik Blackline Panels Enable Rapid Interaction With the User Interface (July 22, 2015)
The Sinumerik blackline panels OP 015 black and OP 019 black are a new generation of operator panels for the Sinumerik 840D sl CNC system... Read News
160 TDM Global Line Software Tailored to International Manufacturers With Global Production Sites (July 20, 2015)
TDM Systems recently announced it will launch its new software module, TDM Global Line. in early August. TDM Global Line is tailored to i... Read News
161 Dillon 1018 CR Steel Full Grip Jaws Reduce Distortion and Provides More Friction (July 16, 2015)
Dillon Manufacturing recently introduced full grip jaws made of 1018 CR steel from 6" to 15" in diameter, with heights of 2&quo... Read News
162 EFD Induction Awarded Orders for Induction Scanners to Harden Sun Gears and Output Shafts (May 26, 2015)
EFD Induction USA has recently won major orders from two American tier-one automotive suppliers.The orders involve EFD Induction ‘H... Read News
163 Paulo Selects AFC-Holcroft Equipment for Production Expansion (April 16, 2015)
Paulo, a commercial heat treater headquartered in St. Louis, MO, USA, recently purchased two new Universal Batch Quench (UBQ) furnaces fr... Read News
164 Artur Pajak named VP of EFD Induction Group (January 26, 2015)
EFD Induction Group, a maker of induction-based industrial heating solutions, recently announced the appointment of Artur Pająk... Read News
165 EMAG Eldec Induction Hardening Systems Offer Precision Hardening, Lower Power Consumption (January 15, 2016)
EMAG subsidiary Eldec has developed modular induction hardening systems. The technology ensures efficient processes that integrate harden... Read News
166 Gleason Announces 175GMS Analytical Gear Inspection System (December 15, 2014)
Gleason Corporation, a developer and manufacturer of gear production machinery and related equipment, recently announced the introdu... Read News
167 Spectroline Introduces Industrial Leak Detection Kit (December 15, 2014)
The Spectroline OLK-444 Industrial Leak Detection Kit is a kit that pinpoints leaks in any size oil-based fluid system. It locates l... Read News
168 New SKF Machine Tool Connects All sensors for Active Monitoring and Data Logging (December 15, 2014)
The new SKF Machine Tool Observer MTx serves as a single device connecting all operating-parameter sensors to actively monitor, observe, ... Read News
169 Oelheld U.S., Inc. Announces ControXid 1642 Rust Protection Fluid (November 13, 2014)
ControXid 1642 is a ready-to-use rust protection fluid for coolant circuits based on synthetic, water-soluble corrosion inhibitors. It is... Read News
170 Miba Expands U.S. Production (August 5, 2014)
Miba Sinter USA, LLC, recently opened its new production facilities. The company, a subsidiary of the Austrian Miba group, produces high ... Read News
171 KISSsoft Stays Active in Various Committees (June 10, 2014)
For KISSsoft, calculation standards are naturally fundamental. Therefore, the KISSsoft company works actively in the standardization comm... Read News
172 SMS Siemag Chooses R&P Metrology for Gear Inspection (June 10, 2014)
SMS Siemag AG understands that to be competitive in today’s global business requires state of the art equipment and technology. Tha... Read News
173 Solar Atmospheres Receives Inspection Certification (May 27, 2014)
Manufacturers looking for Nadcap certified heat treating and fluorescent penetrant inspection have a solution in western Pennsylvania. Na... Read News
174 FCG Delivers High Volume Production Experience (February 26, 2014)
Forest City Gear Director of Technical Operations Jeff Mains wants to make life easier for you. He will be instrumental in putting in pla... Read News
175 RĂ¶ders GmbH Offers Flexible Gearwheel Production with 5-Axis Machining Centers (May 20, 2020)
The manufacture of gearwheels for machine building applications usually involves machines especially designed for the purpose. Important ... Read News
176 Precision Technologies Group Launches Program with Alliance Business School to Give MSc Students Global Perspective (January 12, 2016)
Precision Technologies Group (PTG) has partnered with The University of Manchester's Alliance Business School to help equip MSc stude... Read News
177 Ajax Tocco Ships Induction Heating Dryer System to China (January 18, 2016)
Ajax Tocco Magnethermic recently shipped a 1,900 kW/100,000 hz induction heating dryer system to a steel strip galvanizing producer in Ch... Read News
178 Oelheld Introduces AirForge Protective Lubricant (January 13, 2017)
AirForge 4028 is a newly developed protective lubricant for hot forging of steel and alloys. It is colorless and does not contain gr... Read News
179 Mitutoyo Quick Vision Active CNC Vision Measurement System Offers Interchangeable Objective Zoom Lenses (July 1, 2016)
Mitutoyo America Corporation has announced the addition of the Quick Vision Active series to the line-up of vision measurement systems. T... Read News
180 Cortec Provides Environmentally Safe Corrosion Protection (December 23, 2016)
Technological innovations have enabled Cortec Corporation to successfully replace hazardous synthetic chemicals with safe "green&quo... Read News
181 GKN Sinter Metals Starts Automotive Series Production with 3D Printing System (December 9, 2016)
GKN Sinter Metals announced that the first additive manufacturing (AM) machine in the automotive industry to enable series production of ... Read News
182 Gleason 300GMSL Provides Several Inspection Capabilities on Single Platform (November 14, 2016)
The Gleason 300GMSL offers a single, compact, reliable and easy-to operate inspection solution to apply the most desirable gear measureme... Read News
183 Mazak Quick Turn-250MSY Turning Center Offers Productivity-Enhancing Features (November 3, 2016)
For those shops looking to boost productivity as well as profitability, Mazak's Quick Turn-250MSY Turning Center sports several new p... Read News
184 Toyoda GS300H5 Gear Skiving Center Offers Skiving Function on a Horizontal Type Machining Center (October 31, 2016)
Toyoda's new GS300H5 Gear Skiving Center is the first in the world to equip a skiving function to a general purpose horizontal type m... Read News
185 Ipsen Shows Off PdMetrics Predictive Software at FNA 2016 (October 28, 2016)
Last week at Furnaces North America (FNA) 2016, Ipsen provided an in-depth look at their latest technologies and advancements. They also ... Read News
186 Ajax TOCCO Magnethermic Bright Annealing Induction Furnace Produces Ready-to-Ship Finish (October 26, 2016)
Ajax TOCCO Magnethermic recently shipped a bright annealing induction furnace to a major stainless steel tube manufacturer in the Northea... Read News
187 Mahr Offers Handheld Inspection Tool (September 22, 2016)
Mahr introduced the MarSurf PS 10 during IMTS in Chicago. The PS 10 brings smartphone operation and laboratory performance to the shop fl... Read News
188 Ever Sharp Tools Begins Construction on New Michigan Facility (July 26, 2016)
In 2016, Ever Sharp Tools made a $4 million investment to open and staff a new facility in Michigan. New machines and tools are being sol... Read News
189 Ajax Tocco Supplies Induction Billet Heating System (June 17, 2016)
Ajax Tocco Magnethermic recently shipped a 1,000 kW PowerZone billet heating system to LC Manufacturing, located in Lake City, MI. The 1,... Read News
190 Bodycote Launches Interactive History of Metallurgy (January 25, 2016)
Bodycote, announces the launch of their Interactive History of Metallurgy after taking a look back at the long history of metal processin... Read News
191 Cortec CorrLube CpCl Lithium EP Grease Provides Corrosion Resistance for Electrical Connections (June 13, 2016)
When it comes time to lubricate bearings, fans, chassis or other metal areas where grease is applied, Cortec's CorrLube VpCI Lithium ... Read News
192 R&P Metrology Installs Large Mobile Inspection Equipment (May 3, 2016)
R&P Metrology GmbH has announced it has recently installed two very large portable measuring machines, one in Asia and one in Europe.... Read News
193 Brevini Gear Systems Focuses on Waste Reduction (May 3, 2016)
Brevini Gear Systems (BGS) has reduced its environmental impact through a waste disposal program that will help it achieve a ‘zero-... Read News
194 Forest City Gear Expands High Volume Gear Production Capabilities (May 2, 2016)
Forest City Gear has expanded its high volume gear production capabilities with the addition of a Reishauer RZ 160 Gear Grinding Machine ... Read News
195 Maynards to Auction Surplus Equipment from Abundant Manufacturing, Inc. (April 14, 2016)
Plans are now gearing up for an auction of surplus assets from Abundant Manufacturing, Inc. and RP Machine Enterprises, Inc. This top qua... Read News
196 Gleason Offers 500CB Cutter Build Inspection Machine (March 21, 2016)
Gleason Corporation has introduced its latest innovation, the 500CB Cutter Build Inspection Machine. The 500CB delivers more accura... Read News
197 Hexagon Releases Portable Laser Scanner for Large Volume Inspection (February 26, 2016)
Hexagon Manufacturing Intelligence has released the new Leica Absolute Scanner LAS-20-8, a portable laser scanner for large volume inspec... Read News
198 MS3D GearInspection Creates 3D Scan of Gears in Under 10 Seconds (February 19, 2016)
In cooperation with various universities, the French manufacturer Mesure-Systems-3D (MS3D) has developed a contactless in line testing sy... Read News
199 IHEA Announces Induction Division (February 12, 2016)
The Industrial Heating Equipment Association (IHEA) is excited to announce the launch of its Induction Division which represents a very i... Read News
200 Pferd Cast Cut Carbide Burs Feature High Stock Removal Rate, Smooth Milling Action (February 5, 2016)
Pferd Inc. has introduced Cast Cut, a new line of high-performance carbide burs specially designed for work on cast iron. They are charac... Read News
201 United Gear Installs New Inspection Equipment (December 16, 2003)
United Gear & Inspection has installed a new M&M Precision gear inspection machine to double its manufacturing capacity. According to ... Read News