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(SPONSORED CONTENT)Low Pressure Vacuum Carburizing of Gears
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
Many techniques have been developed over the years to control heat treatment distortion, including the use of different quenching medias, optimization of heat treatment cycles, altering the material chemical composition and even press quenching. Now, learn about Quenching in the 4th Dimension! SECO/VACUUM's Tom Hart presented a webinar about 4D Quenching technology, a safe and simple hands-off heat treatment process, minus the challenges of press quenching. Article Courtesy of Seco/Vacuum
With the surge in Electric Vehicles (EV), gear noise reduction is critically important. Gleasonâ€™s GMSÂ® inspection systems using powerful GAMAâ„˘ applications software apply multiple analysis tools to help identify the root cause of gear noise. These include Fourier analysis, Tooth Contact Analysis, Surface Finish Analysis, KTEPS and Advanced Waviness Analysis. The GMSL system offers the added benefit of laser technology and ultra-fast inspection speeds. Article Courtesy of Gleason Corporation
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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.
Gear designers face constant pressure to increase power density in their drivetrains. In the automotive industry, for example, typical engine torque has increased significantly over the last several decades. Meanwhile, the demands for greater fuel efficiency mean designers must accommodate these increased loads in a smaller, more lightweight package than ever before. In addition, electric and hybrid vehicles will feature fewer gears, with fewer transmission speeds, running at higher rpms, meaning the gears in those systems will have to endure life cycles far beyond what is typical with internal combustion engines.
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.
The effects of non-metallic inclusions in steel matrix on tooth root strength based on theoretical approach of Murakami.
What's not to like about a more focused, user-friendly Gear Expo? Booth Previews.
Three samples of quenched and tempered 4140 steel, with varying levels of oxygen and sulfur, were submitted to a series of bending fatigue tests.
Photographer/filmmaker Ralph Steiner made poetry out of a simple short film on machine components in the 1930s
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.
Let's take a look at Cincinnati -- Henry Longfellow's "Queen of the West" and Ohio's third-largest city.
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.
These lines, interesting enough, are from the notebooks of an artist whose images are part of the basic iconography of Western culture. Even people who have never set foot in a museum and wouldn't know a painting by Corregio from a sculpture by Calder, recognize the Mona Lisa. But Leonardo da Vinci was much more than an artist. He was also a man of science who worked in anatomy, botany, cartography, geology, mathematics, aeronautics, optics, mechanics, astronomy, hydraulics, sonics, civil engineering, weaponry and city planning. There was little in nature that did not interest Leonardo enough to at least make a sketch of it. Much of it became a matter of lifelong study. The breadth of his interests, knowledge, foresight, innovation and imagination is difficult to grasp.
The ultimate Renaissance man was also a gear man. Addendum pays tribute to Leonardo da Vinci.
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.
This article also appears as Chapter 1 in the Gleason Corporation publication "Advanced Bevel Gear Technology." Gearing Principles in Cylindrical and Straight Bevel Gears The purpose of gears is to transmit motion and torque from one shaft to another. That transmission normally has to occur with a constant ratio, the lowest possible disturbances and the highest possible efficiency. Tooth profile, length and shape are derived from those requirements.
The complete industry news section from the June 2018 issue of Gear Technology.
"If it ain't broke, don't fix it," goes the hoary bromide. But what if the time comes - and it most surely will - that in fact it is broke? Do you fix it or replace it? And when does gearbox maintenance and repair arrive at a point of diminishing returns and buying new is the answer?
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.
As gear manufacturing techniques become more precise and demanding, there is a growing demand for cleaner, higher quality steel.
The complete Industry News section from the July 2019 issue of Gear Technology.
It is said that â€śThe squeaky wheel gets the grease.â€ť Ok, but what about gear noise? We talked to three experts with considerable knowledge and experience in this area.
Gear designers today are continually challenged to provide more power in less space and improve gear performance. The following article looks at some of the most common ways to increase the power density or improve the performance of gear trains. The author also takes an in-depth look at the case of a steel worm mating with a plastic helical gear and explores ways to optimize this increasingly common configuration.
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 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.
News from around the Gear Industry
Good References In the 7th Edition of McGraw Hill Encyclopedia of Science and Technology, 10 pages are devoted to the subjects of Gears, Gear Cutting and Gear Trains.
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Lastest news from around the industry.
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Multiple CAM initiatives at Snyder Industries are improving safety, quality and productivity for parts ranging from 50 to 5,000 lbs.
News about new Products in the Industry
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 August 2014 issue of Gear Technology.
Gearing for Munchkins Gene Kasten, president of Repair Parts, Inc., of Rockford, IL, is the proud owner of a miniature Barber-Colman hobber, the only one of its kind in the world. The machine, a replica of the old B-C "A" machine, was built between 1933 and 1941 by W. W. Dickover, who devoted 2, 640 hours of his spare time to the project.
When a gear set is to be designed for a new application, the minimum size gears with the required capacity are desired. These gears must be capable of meeting the power, speed, ratio, life, and reliability requirements.
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.
Gear engineers have long recognized the importance of considering system factors when analyzing a single pair of gears in mesh. These factors include important considerations such as load sharing in multi-mesh geartrains and bearing clearances, in addition to the effects of flexible components such as housings, gear blanks, shafts and carriers for planetary geartrains. However, in recent years, transmission systems have become increasingly complexâ€”with higher numbers of gears and componentsâ€”while the quality requirements and expectations in terms of durability, gear whine, rattle and efficiency have increased accordingly.
The search for greater gear life involves improvement in cost, weight and increased power output. There are many events that affect gear life, and this paper addresses those relating to fatigue, gear tooth pitting, fatigue strength losses due to the heat treating processes and shot peening technique. The capability of shot peening to increase fatigue strength and surface fatigue life eliminate machine marks which cause stress risers, and to aid in lubrication when properly controlled, suggests increased use and acceptance of the process.
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.
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.
QuesTek Innovations LLC is applying its Materials by Design computational design technology to develop a new class of high-strength, secondary hardening gear steels that are optimized for high-temperature, low-pressure (i.e., vacuum) carburization. The new alloys offer three different levels of case hardness (with the ability to â€śdial-inâ€ť hardness profiles, including exceptionally high case hardness), and their high core strength, toughness and other properties offer the potential to reduce drivetrain weight or increase power density relative to incumbent alloys such as AISI 9310 or Pyrowear Alloy 53.
Gleason Corporation has announced that agreement has been reached on all terms to acquire for approximately $36 million in cash the Hermann Pfauter Group, including, among other operations, Hermann Pfauter GmbH & Co., a privately held leading producer of gear equipment based in Ludwigsburg, Germany; its 76% interest in Pfauter-Maad Cutting Tools, a leading cutting tool manufacturer basked in Loves Park, IL; and Pfauter-Maag management's 24% ownership interest in that company. The acquisition includes all assets and liabilities, including the assumption of approximately $56 million in bank debt.
A fundamental characteristic of the gear industry is that it is capital intensive. In the last decade, the gear manufacturing industry has been undergoing an intense drive toward improving and modernizing its capital equipment base. The Department of Commerce reports that annual sales of gear cutting equipment have increased nearly 60% since 1990. While this effort has paid off in increased competitiveness for the American gear industry, it is important to remember that there is another capital crucial to manufacturing success - "human capital."
This article presents a new spur gear 20-degree design that works interchangeably with the standard 20-degree system and achieves increased tooth bending strength and hence load carrying capacity.
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.
Turnkey Design Services is manufacturing a planetary gear system to increase power density.
The author has written this book primarily from the viewpoint of analyzing vibrations on heavy industrial and mill gearing that may have been in service for a prolonged time. The purpose is to diagnose problems, especially the source or cause of failure. However, the principles and analysis techniques can be used for all types and sizes of gears, as well as for gear noise analysis.
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 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.
Due to its economical efficiency, the gear shaving process is a widely used process for soft finishing of gears. A simulation technique allows optimization of the process.
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.
Since size and efficiency are increasingly important considerations in modern machinery, the trend is gear design is to use planetary gearing instead of worm gearing and multi-stage gear boxes. Internal gearing is an important part of most of planetary gear assemblies. In external gearing, if the gears are standard (of no-modified addenda), interference rarely happens. But in an internal gearing, especially in some new types of planetary gears, such as the KHV planetary, the Y planetary, etc., (1) various types of interference may occur. Therefore, avoiding interference is of significance for the design of internal gearing.
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.
If you've got a gear performance problem, the Gear Research Institute (GRI) is here to help you. Since inception in 1982, GRI has been a primarily industry sponsored, experimentation driven research facility. Whether establishing the fatigue life of gears or evaluating the impact of manufacturing processes on the performance of gears, GRI has pioneered methods and procedures for characterizing such properties that are accepted by the aerospace, vehicle and other industry sectors.
Peter Kozma, executive vice president of Liebherr-America, Inc., talks with us about Liebherr and its partners in the Sigma Pool.
More than 100 years ago, gear manufacturers were facing a significant challenge from industry. The incredible advances in industrialization and transportation that occurred at the turn of the 20th century resulted in incredible growth for gear makers, but there were significant technical issues. "The lack of process and product standardization was a continuing problem in all U.S. industry. The lack of industry-wide gear standards meant there were no standard gear tooth sizes, ratings, quality definition or consistent manufacturing methods" (Celebrating 100 Years of Gearing, pg. 22).
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).
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.
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.
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).
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.
Cracks initiated at the surface of case-hardened gears may lead to typical life-limiting fatigue failure modes such as pitting and tooth root breakage. Furthermore, the contact load on the flank surface induces stresses in greater material depth that may lead to crack initiation below the surface if the local material strength is exceeded. Over time the sub-surface crack propagation may lead to gear failure referred to as â€śtooth flank fractureâ€ť (also referred to as â€śtooth flank breakageâ€ť). This paper explains the mechanism of this subsurface fatigue failure mode and its decisive influence factors, and presents an overview of a newly developed calculation model.
Lines at McCormick Place's Starbucks concession stand will probably be a little longer at IMTS 2006, but the show's organizers won't be complaining.
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.
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.
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.
Mekanizmalar. Ever heard of it? No, itâ€™s not a lost password from 1,001 Arabian Nights. In fact it is a website â€” since 2004 â€” that employs the universally loved art of animation (Adobe Flash) to clearly explain the basic and not-so-basic workings of mechanisms â€” including geared, pneumatic, hydraulic and electronic components.
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.
Observations while traveling through Hungary last November...this is a very ancient country; people have lived and worked here along the Danube River since early times, and change is just another piece of the landscape. Still, the collapse of the old Communist economy is one of the more remarkable phenomena in a land that has seen and lived under different versions of the "new world order" since the first barbarian invasions. The difference is that this time, the people themselves are working the change, and the results are exciting in their variety and effect.
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.
â€śHighway vehicles release about 1.7 billion tons of greenhouse gases (GHGs) into the atmosphere each year â€” mostly in the form of carbon dioxide (CO2) â€” contributing to global climate change. The CO2 emissions of a car are directly proportional to the quantity of fuel consumed by an engine. In 2013, U.S. greenhouse gas emissions from transportation were second only to the electricity sector â€” an increase of about 16% since 1990.â€ť (EPA.GOV).
In our last issue, we covered the basic principles of gear shaving and preparation of parts for shaving. In this issue, we will cover shaving methods, design principles and cutter mounting techniques.
The goal of gear drive design is to transit power and motion with constant angular velocity. Current trends in gear drive design require greater load carrying capacity and increased service life in smaller, quieter, more efficient gearboxes. Generally, these goals are met by specifying more accurate gears. This, combined with the availability of user-friendly CNC gear grinding equipment, has increased the use of ground gears.
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.
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.
Worm gearing is of great antiquity, going back about 2100 years to Archimedes, who is generally acknowledged as its inventor. Archimedes' concept used an Archimedial spiral to rotate a toothed wheel. Development of the worm gearing principle progressed along conventional lines until about 500 years ago when Leonardo DaVinci evolved the double enveloping gear concept.
Fig. 1 shows the effects of positive and negative rake on finished gear teeth. Incorrect positive rake (A) increase the depth and decreases the pressure angle on the hob tooth. The resulting gear tooth is thick at the top and thin at the bottom. Incorrect negative rake (B) decreases the depth and increases the pressure angle. This results in a cutting drag and makes the gear tooth thin at the top and thick at the bottom.
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 common calculation methods according to DIN 3990 and ISO 6336 are based on a comparison of occurring stress and allowable stress. The influence of gear size on the load-carrying capacity is considered with the size factors YX (tooth root bending) and ZX (pitting), but there are further influences, which should be considered. In the following, major influences of gear size on the load factors as well as on the permissible tooth root bending and contact stress will be discussed.
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.
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.
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.
The method of cutting teeth on a cylindrical gear by the hobbing process has been in existence since the late 1800s. Advances have been made over the years in both the machines and the cutting tools used in the process. This paper will examine hob tool life and the many variables that affect it. The paper will cover the state-of-the-art cutting tool materials and coatings, hob tool design characteristics, process speeds and feeds, hob shifting strategies, wear characteristics, etc. The paper will also discuss the use of a common denominator method for evaluating hob tool life in terms of meters (or inches) per hob tooth as an alternative to tool life expressed in parts per sharpening.
This article summarizes the development of an improved titanium nitride (TiN) recoating process, which has, when compared to conventional recoat methods, demonstrated tool life increases of up to three times in performance testing of hobs and shaper cutters. This new coating process, called Super TiN, surpasses the performance of standard TiN recoating for machining gear components. Super TiN incorporates stripping, surface preparation, smooth coating techniques and polishing before and after recoating. The combination of these improvements to the recoating process is the key to its performance.
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.
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.
Okay. You've been convinced. You've gritted your teeth and decided to spend the money to launch a company Web site. Everybody from your teenage propeller-head to the girl in the mail room and the salesman in the flashy suit who gave you "such a deal" on Web site services has promised that your site will be the best thing that's happened to your business since the advent of CNC machines.
To achieve the requested quality, most gears today are ground. The usual grinding process includes treating the gear flank but disengaging before reaching the root rounding area. If the gear is premanufactured with a tool without protuberance, then at the position where the grinding tool retracts from the flank a grinding notch in the tooth root area is produced. Such a notch may increase the bending stresses in the root area, thus reducing the strength rating.
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.
Since the design of involute splines and their manufacture requires considerable knowledge, not only of the basic properties of the involute profile, but also of various other elements which affect the spline fit and the sometimes complex principles underlying manufacturing and checking equipment, the question is frequently raised as to why the involute profile is given preference in designing splines over the seemingly simpler straight sided tooth profile.
There is an increasing significance of screw helical and worm gears that combine use of steel and plastics. This is shown by diverse and continuously rising use in the automotive and household appliance industries. The increasing requirements for such gears can be explained by the advantageous qualities of such a material combination in comparison with that of the traditional steel/bronze pairing.
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.
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.
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.
The lifetime of worm gears is usually delimited by the bronze-cast worm wheels. The following presents some optimized cast bronzes, which lead to a doubling of wear resistance.
It is well known that hobs with straight-sided teeth do not cut true involutes. In this paper, the difference between the straight side of a hob tooth and the axial profile of an involute worm is evaluated. It is shown that the difference increases as the diametral pitch increases, to the extent that for fine-pitch gearing, the difference is insignificant.
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).
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.
James J. Cervinka and Frank E. Pielsticker must've known the future when they named their new business Arrow Gear Co. in 1947. They started out to manufacture gears for hand tools and machine tools, but their business has taken off since then.
Austempered irons and steels offer the design engineer alternatives to conventional material/process combinations. Depending on the material and the application, austempering may provide the producers of gear and shafts with the following benefits: ease of manufacturing, increased bending and/or contact fatigue strength, better wear resistance or enhanced dampening characteristics resulting in lower noise. Austempered materials have been used to improve the performance of gears and shafts in many applications in a wide range of industries.
In recent years, the demands for load capacity and fatigue life of gears constantly increased while weight and volume had to be reduced. To achieve those aims, most of today's gear wheels are heat treated so tooth surfaces will have high wear resistance. As a consequence of heat treatment, distortion unavoidably occurs. With the high geometrical accuracy and quality required for gears, a hard machining process is needed that generates favorable properties on the tooth surfaces and the near-surface material with high reliability.
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.
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.
When you're manufacturing fun, very often you need gears. The Addendum team recently went on a behind-the-scenes gear-finding mission with Jerold S. Kaplan, Principal Engineer, Show/Ride Mechanical Engineering at Walt Disney Imagineering in Lake Buena Vista, FL. We found that at least part of Disney's magic comes from good, old-fashioned mechanical engineering.
In one of my many visits to northern New York state, which included the St. Lawrence River (Thousand Islands Region) and the Adirondack Mountains, I visited Croghan, a village on the Beaver River, which is fed by the Stillwater Resevoir in the Adirondack Mountains. At the base of a dam within the village, I found the remnants of a water turbine and a bevel gear drive system. Having worked for The Gleason Works for many years, I was intrigued by the remains of the bevel gears, which appeared to have had wooden teeth at one time.
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:
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.
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 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.
In a little-known incident, Soviet machinists at Mil Helicopter worked in 1988 and 1989 on a special project to be used against Americans.
In high precision and heavily loaded spur gears, the effect of gear error is negligible, so the periodic variation of tooth stiffness is the principal cause of noise and vibration. High contact ration spur gears can be used to exclude or reduce the variation of tooth stiffness.
Although the cultures and areas of expertise of Solomon and Sun Tzu are worlds apart, the two offer similar opinions on the importance of seizing the moment. Their ancient wisdom may have increasing relevance to modern manufacturers in a global economy, particularly those contemplating whether now is the time to invest in capital equipment.
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.
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.
The chamfering and deburring operations on gear teeth have become more important as the automation of gear manufacturing lines in the automotive industry have steadily increased. Quieter gears require more accurate chamfers. This operation also translates into significant coast savings by avoiding costly rework operations. This article discusses the different types of chamfers on gear teeth and outlines manufacturing methods and guidelines to determine chamfer sizes and angles for the product and process engineer.
Designing and manufacturing gears requires the skills of a mathematician, the knowledge of an engineer and the experience of a precision machinist. For good measure, you might even include the are of a magician, because the formulas and calculations involved in gear manufacturing are so obscure and the processes so little known that only members of an elite cadre of professionals can perform them.
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.
The process of nitriding has been used to case harden gears for years, but the science and technology of the process have not remained stagnant. New approaches have been developed which are definitely of interest to the gear designer. These include both new materials and new processing techniques.
This book is written for those among us, with or without a technical background, who have an occasional need to use, purchase or specify gears. The author assumes an audience that is not made up of experienced gear designers, but of people who do need to have a basic understanding of the criteria used by the designer. The subjects covered include not only the gears themselves, but their manufacturing methods, the systems that contain them and the terms used to describe them.
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.
Recently I had the pleasure of having dinner with Frank Sinatra, Jr. He was here in Chicago for a benefit concert for Roosevelt University (my wife is co-chairperson of the benefit). Our conversation ranged over a wide variety of subjects, including a small gem of an HBO television movie, "Truman" with Gary Sinise in the title role.
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%.
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.
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
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.
Product announcements so often trumpet minor, incremental advances with works like "revolutionary" and "unique" that even the best thesaurus can fail to offer a fresh alternative to alert the reader when something really innovative and important is introduced. In the case of Mitsubishi's new CNC gear shaper, the ST25CNC, both terms apply.
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.
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).
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 Gear Research Laboratory of the University of Illinois at Chicago is home to a unique tribute to gear pioneers from around the world, the Gallery of Fame. The gallery is the brainchild of the laboratory director, Professor Faydor L. Litvin. The Gallery was begun in 1994 an dis a photographic tribute to those gear company founders, inventors and researchers who devoted their careers to the study and development of gears.
When you're 15, you're filled with confidence and exuberance, and you have a future full of potential and room for growth. You're ready to take on the world. Gear Technology began publishing exactly 15 year ago, with the May/June 1984 issue, and the magazine has grown in many ways since then.
Powder metal. To gear makers today, the phrase conjures images of low power applications in non-critical systems. As powder metal technology advances, as the materials increase in density and strength, such opinions are changing. It is an ongoing, evolutionary process and one that will continue for some time. According to Donald G. White, the executive director of the Metal Powder Industries Federation, in his State-of-the-P/M Industry - 1999 report. "The P/M world is changing rapidly and P/M needs to be recognized as a world-class process - national, continental and even human barriers and prejudices must be eliminated - we must join forces as a world process - unified in approach and goals."
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.
The market demand for gear manufacturers to transmit higher torques via smaller-sized gear units inevitably leads to the use of case-hardened gears with high manufacturing and surface quality. In order to generate high part quality, there is an increasing trend towards the elimination of the process-induced distortion that occurs during heat treatment by means of subsequent hard finishing.
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.
Geoffrey Parrish has updated and expanded his previous book: The Influence of Microstructure on the Properties of Case-Carburized Components. It now contains at least twice the material. References and bibliography include 449 citations.
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.
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.
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.
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.
Capstan Atlantic, located in Wrentham, Massachusetts, produces powder metal gears, sprockets and complex structural components. The company has provided unique powder metal products in a variety of industries including automotive, business machines, appliances, lawn and garden equipment and recreational vehicles.
The first part of this publication series covered the general basics of involute gearing and applied the generating principle of cylindrical gears analogous to angular gear axis arrangements the kinematic coupling conditions between the two mating members have been postulated in three rules. Entering the world of bevel gears also required to dwell somewhat on the definition of conjugacy. The second part is devoted to the different generating gears and the chain of kinematic relationships between the gear - gear generator - pinion generator and pinion.
By increasing the number of gears and the transmission-ratio spread, the engine will run with better fuel efficiency and without loss of driving dynamics. Transmission efficiency itself can be improved by: using fuelefficient transmission oil; optimizing the lubrication systems and pumps; improving shifting strategies and optimizing gearings; and optimizing bearings and seals/gaskets.
There are many different gear rating methods in use today, and they can give substantially different results for any given gearset. This paper will make it easy to understand the choices and the impact the choices have on gearbox design. Eight standards are included - AGMA 2001; AGMA 6011; AGMA 6013; ISO 6336; API 613; API 617; API 672; and API 677. (Click HERE for the Appendix to this article).
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.
In a capitalist society, the way things usually work is that government and academia focus on research and development, while industry focuses on commercialization. The result is an increasingly wide disconnect in the applied research sector, which deals primarily with technology development and demonstration.
For many of us, 2016 was a rough year - and the results of our annual State of the Gear Industry Survey show it. 40% of respondents indicated their companies had cut staff, while only 27% indicated an increase in employment. Clearly, there have been widespread cutbacks.
Suppliers are working hard to make sure their heat treating equipment is controllable, repeatable and efficient, and manufacturers continue to incorporate technology that gives heat treaters and their customers more information about what's going on inside the magic box.
It is becoming increasingly apparent that material properties can and will play a greater role than before in addressing the challenges most transmission manufacturers are facing today. Making use of materials' intrinsic fatigue properties provides a new design tool to support the market changes taking place.
Though we think of the computer as a distinctly 20th Century invention, Charles Babbage designed several precursors way back in the early 1800s.
As the science of Scudding has rapidly evolved, the interest in the more advanced process Hard Scudding is increasing.
The deformation of the gear teeth due to load conditions may cause premature tooth meshing. This irregular tooth contact causes increased stress on the tooth flank. These adverse effects can be avoided by using defined flank modifications, designed by means of FE-based tooth contact analysis.
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.
This special edition of Product News includes highlights from Gear Expo 2017 of new products that caught the editors' eyes.
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.
Call it new wine in old bottles, or old wine in new bottles, but gear skiving has certainly aged well over time. Gear skiving's evolution, perhaps gaining momentum most dramatically since around 2004, has ultimately led to rather dramatic technological advancement and cost saving in the manufacture of certain gears.
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.
With increasingly smaller returns from improving the speed of the actual gear grinding process, improving your setup time has become a primary way to keep improving efficiency. Here's the latest on how you can do that today.
The latest technological solutions help keep chamfering and deburring operations in-line -- often without increasing cycle times.
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.
Experiencing a Dickensian dilemma in its essence, a Los Angeles based manufacturing company was faced with the good fortune of ever increasing orders for steel gears from a good customer with a new recreational product in very high demand. Confronting the possibility of an untold number of lonely late nights tending to the whims of a 1950s era manual hobber was an unpalatable prospect no one desired.
In 2021, the AGMA Foundation begins its 27th year. It is a critical year for the AGMA Foundation as our industry is facing incredible challenges and opportunities, and AGMA members are asking a great deal from our industry Foundation.
Agostino Ramelli was a 16th-century Italian military engineer of some note who designed many machines and other contributions used in the go-go Renaissance period, including cranes, grain mills, and water pumps. But his most compelling apparatus was a real mindbender - a revolving wooden wheel with angled shelves that allowed users to read multiple books at one time.
Lately, the use of asymmetric gears in automotive and other applications is an upcoming trend, though few applications are known to have asymmetric teeth. However, an increased interest in asymmetric gears can be seen. Many companies have started to design and test such applications.
Kapp Niles celebrates young inventors, Solar Atmospheres expands, Klingelnberg increases training programs, Liebherr celebrates 50 years in the USA, Timken Expands Southeast regional repair facility and more news for the gear industry.
Reader Survey Results. Gear Technology's annual State-of-the-Gear-Industry survey polls gear manufacturers about the latest trends and opinions relating to the overall health of the gear industry. As in years past, the survey was conducted anonymously, with invitations sent by e-mail to gear industry companies â€“ primarily in North America, but also including some respondents from around the world.
You may have noticed a few changes around here. Most notably, the face on this page isn't the one you're used to seeing here. As you've probably heard by now, Michael Goldstein, founder and Publisher since 1984, has stepped back from his day-to-day duties and transferred the operation of Gear Technology, Power Transmission Engineering and Gear Technology India to the American Gear Manufacturers Association.
Polymer gears find increasing applications in the automotive industry, office machines, food machinery, and home appliances. The main reason for this success is their low cost. Their low weight, quietness of operation, and meshing without lubricant are also interesting. However, they have poor heat resistance and are limited to rotational transmission. In order to improve the gears' behavior, glass fiber is added
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.
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.
This paper outlines the basic principles of involute gear generation by using a milling cutter; the machine and cutting tool requirements; similarities and differences with other gear generative methods; the cutting strategy; and setup adjustments options. It also discusses the applications that would benefit the most: for coarse-pitch gears the generative gear milling technologies offer improved efficiency, expanded machine pitch capacity, decreased cutter cost, and a possibility for reducing the number of machining operations.
Automotive gear manufacturers have implemented significant improvements in external planetary gear manufacturing yielding quieter gears. In addition, process stability has increased due to the post-heat treatment finishing processes employed. This article explains various complete solutions for cutting and finishing internal ring gears.
The latest product news for the gear industry, including new products and services from Gleason, Liebherr, Forest City Gear, GMTA, Starrett and Kennametal.
Technical articles have been the hallmark of Gear Technology since we first started publishing, more than 34 years ago, in 1984. One of the achievements IĂ˘??m most proud of is the development of the GT LIBRARY at geartechnology.com, where you can find every single one of those articles, going all the way back to the beginning.
Electrification has already started to have a noticeable impact on the global automotive industry. As a result, the drivetrains of hybrid (HEV) and full electric vehicles (EV) are facing many challenges, like increased requirements for NVH in high speed e-Drives and the need for performance improvements to deal with recuperation requirements. Motivated by the positive validation results of surface densified manual transmission gears which are also applicable for dedicated hybrid transmissions (DHTs) like e-DCTs, GKN engineers have been looking for a more challenging application for PM gears within those areas.
I make all the double helical gears that go into a gearbox - four different gears in this unit. If the gear module for the bull gear and the intermediate gear are the same (these are the two individual gears that mate), and the gear module for the high-speed pinion and high-speed gears are the same (these are the other two individual gears that mate in the gear box as well), is it then possible to just use two hobs in this setup to make all four gears, since they mate together with each other? We are currently using a different gear hob for each gear.
Chamfering and deburring of cylindrical gears does not get much love from manufacturers. The process is seen as a necessary evil since it is adding cost without adding value. However, there are good reasons for not underrating this important auxiliary process. Chamfering and deburring takes care of several issues which may come up during the manufacture of quality gears.
Romax Technology, the gearbox, bearing and driveline engineering specialist, has launched a new design software package that will increase speed, quality, creativity and innovation when designing gearboxes and drivelines. Called Concept, the new product delivers on the Romax vision of streamlining the end-to-end, planning-to-manufacture process with open, easy to use software solutions. It has been developed in close collaboration with engineers in the largest ground vehicle, wind energy and industrial equipment companies around the globe.
This paper presents an original method for computing the loaded mechanical behavior of fiber reinforced polymer gears. Although thermoplastic gears are unsuitable for application transmitting high torque, adding fibers can significantly increase their performance. The particular case of polyamide 6 + 30% glass fibers is studied in this paper.
Our comprehensive directory of gear industry suppliers, including a breakdown by product or service category, as well as an alphabetical list of gear industry suppliers.
Our experts tackle the topic of measuring involute masters, including both master gears and gear inspection artifacts.
"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.
What's new on the Gear Technology website this month? Videos from DMG Mori-Seiki, the latest e-mail newsletter and updates on upcoming events, including the Kapp-Niles Rocky Mountain Gear School.
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.
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.
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.
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."
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.
The final installment of our Job Shop Lean series includes a wide variety of educational resources to help you continue your own lean journey.
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.
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.
Blogging is BIG and getting bigger all the time. There doesnâ€™t exist, for example, a news, industry, or entertainment entity that does not have at least one resident blogger. And now, since January -- we have ours.
A great deal of attention has been paid to the decline of manufacturing in America, and I've been accused of being a town crier since the 1980s, when I began to see our nation lose its edge to foreign competition. My concerns have proven well-founded.
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.
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.
Since we began publishing in 1984, Gear Technology's mission has been to educate our readers. For 31 years, we've shown you the basics of gear manufacturing as well as the cutting edge. We take our educational mission quite seriously, and we go through steps that most publishers don't have time for or wouldn't consider.
I would appreciate if you could assist with a gear failure (occurring) after just seven weeks in service, post installation. This driving gear wheel has been installed in a medium-speed engine with backlash present at four different positions; with additional backlash checked on the mating surfaces. All backlash was found within (OEM)-recommended values. Please note included photos - it seems that the crack has started at the root fillet. Any comments would be appreciated.
One of the great benefits of Gear Expo for us here at Gear Technology is the opportunity to meet faceto-face with many of the people who, in one way or another, contribute to our success throughout the year. After all, our success is dependent almost entirely on information and the people who provide it. These contributors include researchers at top technical universities, the heads of technology at major gear industry corporations, independent consultants with decades of gear industry experience, members and volunteers at leading industry organizations like the AGMA, our technical editors and others.
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?
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.
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.
Over the past decade, the wire electrical discharge machine (EDM) has become an increasingly important tool for machining non-standard shapes. It has even been used to cut gears and gear cavities for plastic molds. While generally accepted as a quick and versatile method for cutting spur gears, the EDM gear has lacked the precision of a mechanically machined or ground gear. We suspected that many of the errors associated with these gears were caused by inexact setup procedures, poor tool path control and improper cutting parameters. We decided to test the potential for the wire EDM to make the most accurate gear possible.
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.
Here's everything you need to know about IMTS 2014, including an interview with Peter Eelman, AMT's VP of Exhibitions and Communications.
This paper presents the geometric design of hypoid gears with involute gear teeth. An overview of face cutting techniques prevalent in hypoid gear fabrication is presented. Next, the specification of a planar involute rack is reviewed. This rack is used to define a variable diameter cutter based upon a system of cylindroidal coordinates; thus, a cursory presentation of cylindroidal coordinates is included. A mapping transforms the planar involute rack into a variable diameter cutter using the cylindroidal coordinates. Hypoid gears are based on the envelope of this cutter. A hypoid gear set is presented based on an automotive rear axle.
In 1964, a young and tidy Bob Dylan sang away in that infamous voice of his, all nasally and grating yet wonderfully distinct, opining to the fervent masses: â€śThe times, they are a-changin.â€ť
The process of forging metal into shapes possesses a surprisingly long and storied history. For example, the method of hot rolling can trace its protracted existence all the way back to an enigmatic Italian polymath named Leonardo da Vinci (you may have heard of him), who reportedly invented the rolling mill one lazy day in the 1400s.
The recently available capability for the free-form milling of gears of various gear types and sizes â€” all within one manufacturing system â€” is becoming increasingly recognized as a flexible machining process for gears.
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 other day I went to Starbuckâ€™s and ordered my usual four shots of espresso, straight up. I know what youâ€™re thinking: thatâ€™s a lot of caffeine, especially for someone as naturally energetic as I am. But after years and years, I may have built up a tolerance to the caffeine. I picked up the espresso habit as a much younger man, when I worked for Daldi & Matteucci (DEMM) in Italy back in the â€™70s. And Iâ€™ve stuck with it ever since.
A gear shaper cutter is actually a gear with relieved cutting edges and increased addendum for providing clearance in the root of the gear being cut. The maximum outside diameter of such a cutter is limited to the diameter at which the teeth become pointed. The minimum diameter occurs when the outside diameter of the cutter and the base circle are the same. Those theoretical extremes, coupled with the side clearance, which is normally 2 degrees for coarse pitch cutters an d1.5 degrees for cutters approximately 24-pitch and finer, will determine the theoretical face width of a cutter.
A common goal of gear manufacturers is to produce gearing that is competitively priced, that meets all quality requirements with the minimum amount of cost in a timely manner, and that satisfies customers' expectations. In order to optimize this goal, the gear manufacturer must thoroughly understand each manufacturing process specified, the performance capability of that process, and the effect of that particular process as it relates to the quality of the manufactured gear. If the wrong series of processes has been selected or a specific selected process is not capable of producing a quality part, manufacturing costs are greatly increased.
Bevel gears have been the standard for several decades in situations where power transmission has to occur between shafts mounted at a given angle. Now a new approach has been developed that challenges the bevel gear's de facto monopoly in such applications. The concept is based on the principle of the crown gear; i.e., a cylindrical pinion mates with a face gear. Crown Gear B.V. in Enschede, Holland, is the developer of these specialty gear teeth, which are marketed under the trade name Cylkro.
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.
Stringent NVH requirements, higher loads and the trend towards miniaturization to save weight and space are forcing transmission gear designers to increasingly tighten the surface finish, bore size and bore-to-face perpendicularity tolerances on the bores of transmission gears.
An offshore jack-up drilling rig is a barge upon which a drilling platform is placed. The barge has legs that can be lowered to the sea floor to support the rig. Then the barge can be â€śjacked upâ€ť out of the water, providing a stable work platform from which to drill for oil and gas. Jack-up drilling rigs were first introduced in the late 1950s. Rack-and- pinion-type jack-up units were introduced soon after that and have dominated the industry ever since.
In this paper, the potential for geometrical cutting simulations - via penetration calculation to analyze and predict tool wear as well as to prolong tool life - is shown by means of gear finish hobbing. Typical profile angle deviations that occur with increasing tool wear are discussed. Finally, an approach is presented here to attain improved profile accuracy over the whole tool life of the finishing hob.
Before retiring from St. Louis Gear in 2000, Roy Harmon liked to tinker. Since the customer base at the time was seasonal, Harmon was looking for a project to keep himself busy. The engineer decided to challenge himself by designing a â€śSouth Pointing Chariot,â€ť a device he had read about in the book The Evolution of the Gear Art by Darle Dudley.
Is economic relief on the way? This was the general consensus coming out of Indianapolis after Gear Expo 2009 closed its doors in September. Though the numbers were slightly downâ€”2,539 exhibitors and attendees compared to 2,992 in 2007â€”it appeared to be steady as she goes at the gear industryâ€™s biennial main event, good news considering the state of the gear industry since Gear Expo 2007 in Detroit.
The complete events section, including Technical Calendar, from the September/October 2008 issue of Gear Technology.
The complete Events section, including technical calendar, from the July 2008 issue of Gear Technology
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.
How lean manufacturing principles can help transform your gear manufacturing business.
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 Events section from the September/October 2005 issue of Gear Technology, including a profile of the UTS plastic gear course.
The complete Events section from July/August 2005, including coverage of EMO 2005.
The complete Events section from March/April 2005, including coverage of Hannover Fair and SAE World Congress.
The complete Events section from January/February 2005, including coverage of a vacuum carburizing conference.
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.
Who knew what a few hundred bacteria could do with a little cooperation? Andrey Sokolov of Princeton University, Igor Aronson from the Argonne National Laboratory and Bartosz Grzybowski and Mario Apodaca from Northwestern University found out after placing microgears (380 microns long with slanted spokes) in a solution with the common aerobic bacteria Bacillus subtilis. The scientists observed that the bacteria appeared to swim randomly but occasionally collided with the spokes of the gears and turned them.
The complete Events section from November/December 2006, including coverage of Gear China.
Don't miss Gear Technology's booth #1337 at this year's Gear Expo in Cincinnati.
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).
Gear gashing is a gear machining process, very much like gear milling, utilizing the principle of cutting one or more tooth (or tooth space) at a time. The term "GASHING" today applies to the roughing, or roughing and finishing, of coarse diametral pitch gears and sprockets. Manufacturing these large coarse gears by conventional methods of rough and finish hobbing can lead to very long machining cycles and uneconomical machine utilization.
Over the years, we have traveled extensively throughout the industrialized world, and became increasingly aware of the availability of enormous amounts of technical writing concerning research, experiments, and techniques in the gear manufacturing field. New manufacturing methods, materials, and machines were continuously being developed, but the technical information about them was not readily available to those that could best use it. There was no central source for disseminating this knowledge.
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 Forest City Gear booth at Gear Expo featured a wide variety of gears utilized in medical equipment, Indy cars, fishing reels, even the recently launched Mars Rover. Scattered among Forest Cityâ€™s products in Cincinnati were some unique gear sculptures created by an artist that finds more inspiration from the pages of industrial magazines than art galleries.
This paper presents an original method to compute the loaded mechanical behavior of polymer gears. Polymer gears can be used without lubricant, have quieter mesh, are more resistant to corrosion, and are lighter in weight. Therefore their application fields are continually increasing. Nevertheless, the mechanical behavior of polymer materials is very complex because it depends on time, history of displacement and temperature. In addition, for several polymers, humidity is another factor to be taken into account. The particular case of polyamide 6.6 is studied in this paper.
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.
Publisher Michael Goldstein sat down with Dr. Thomas Koepfer, whose family company, Josef Koepfer & SĂ¶hne GmbH, was founded in 1867. Over the years, the Koepfer name has become one of the best-known in the gear industry, with company operations including the manufacture of gear machines, cutting tools and gears.
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.
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.
AGMA president Joe T. Franklin Jr. talks about how the AGMA Gear Expo has grown and changed since its beginnings as a table-top show in 1987.
A very direct and effective way of increasing power transmission efficiency is a changeover from mineral-oil-based lubricants to synthetic lubricants.
This article is part five of an eight-part series on the tribology aspects of angular gear drives. Each article will be presented first and exclusively by Gear Technology, but the entire series will be included in Dr. Stadtfeldâ€™s upcoming book on the subject, which is scheduled for release in 2011.
Gear shaving is a free-cutting gear finishing operation which removes small amounts of metal from the working surfaces of the gear teeth. Its purpose is to correct errors in index, helical angle, tooth profile and eccentricity. The process can also improve tooth surface finish and eliminate, by crowned tooth forms, the danger of tooth end load concentrations in service. Shaving provides for form modifications that reduce gear noise. These modifications can also increase the gear's load carrying capacity, its factor of safety and its service life.
This article is part four of an eight-part series on the tribology aspects of angular gear drives. Each article will be presented first and exclusively by Gear Technology, but the entire series will be included in Dr. Stadtfeldâ€™s upcoming book on the subject, which is scheduled for release in 2011.
More strength, less noise. Those are two major demands on gears, including bevel and hypoid gears.
The complete Events section from September/October 2006, including a profile of gear seminars offered by WZL.
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.
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.
Results from the Technical University of Munich were presented in a previous technical article (see Ref. 4). This paper presents the results of Ruhr University Bochum. Both research groups concluded that superfinishing is one of the most powerful technologies for significantly increasing the load-carrying capacity of gear flanks.
For years, politicians, educators and business leaders have generated various ideas to revitalize U.S. manufacturing and engineering. These include manufacturing initiatives, internal training programs and an emphasis on science, technology, engineering and mathematics (STEM) in the classroom. The declining expertise in these fields, however, continues to be a growing problem in every facet of manufacturing and engineering.
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.
Advancements in machining and assembly techniques of thermoplastic gearing along with new design data has lead to increased useage of polymeric materials. information on state of the art methods in fabrication of plastic gearing is presented and the importance of a proper backlash allowance at installation is discussed. Under controlled conditions, cast nylon gears show 8-14 dBA. lower noise level than three other gear materials tested.
In response to Ed Uberts letter, we have come a long way in gearing since WWII. The Europeans do use long addendum pinions in many cases. This modification does improve load capacity, sliding conditions and the working life of a gearset. When modifying a pinion tooth it is necessary to modify the gear tooth or adjust the center distance accordingly but we will leave that to the designers.
Despite increased overseas competition, there doesn't seem to be an urge among Americans to attend technical conferences.
Up until approximately 1968-69, pinion cutter-type gear shaping machines had changed very little since their conception in the early 1900's.
The aim of our research is to clearly show the influence of defects on the bending fatigue strength of gear teeth. Carburized gears have many types of defects, such as non-martensitic layers, inclusions, tool marks, etc. It is well known that high strength gear teeth break from defects in their materials, so itâ€™s important to know which defect limits the strength of a gear.
As the international business community grows closer together, the need for understanding differences between national and international gear rating standards becomes increasingly important for U.S. gear manufacturers competing in the world market.
Imagine the flexibility of having one machine capable of milling, turning, tapping and gear cutting with deburring included for hard and soft material. No, youâ€™re not in gear fantasy land. The technology to manufacture gears on non gear-dedicated, mult-axis machines has existed for a few years in Europe, but has not yet ventured into mainstream manufacturing. Deckel Maho Pfronten, a member of the Gildemeister Group, took the sales plunge this year, making the technology available on most of its 2009 machines.
Tom Lang liked what he saw in the Gear Generation Pavilion at IMTS 2004. Standing in his booth, Kapp Technologiesâ€™ vice president/general manager talked with many attendees during the show and afterward said: â€śWe had an increase of both quality and quantity of visitors.â€ť
This article shows the newest developments to reduce overall cycle time in grinding wind power gears, including the use of both profile grinding and threaded wheel grinding.
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.
When children are asked what they want to be when they grow up, the answers are undoubtedly diverse. Some immediately respond with doctor, lawyer or firefighter while others take a more creative approach with answers like spy, princess or superhero. The Addendum Staff has yet to come across a youngster that seems committed to a career in gear manufacturing.
Since our founding in 1984, Gear Technologyâ€™s goal has been to educate and inform our readers of the technologies, products, processes, services and news of importance to the gear industry and to provide our advertisers with the most complete and current circulation of gear industry professionals available anywhere!
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.
The complete Events section from July/August 2006, including a profile on the UTS gear course.
This article includes a brief summary of the characteristics of involute asymmetric teeth and the problems connected with the related bending tests.
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.
The complete events section from March/April 2006, including a feature on the Koepfer Gear School and our technical calendar.
Gear Technology was founded 22 years ago on a very simple principle: to provide the best possible educational articles and information for the gear industry.
The complete product news from January/February 2007, including items from SMT, Monnier+Zahner, Mahr Federal, ExxonMobil, KissSoft, Geartech, Midwest Motion, Adcole and Makino.
There are three distinct gear types in angle drives. The most commonly used are bevel and worm drives. Face gear drives are the third alternative.
MASTA 4.5.1 models complete transmissions and includes 3-D stress analysis.
This month's online features include ITAMCO's app for MTConnect and Google Glass.
If anyone should ever need convincing that the state of American manufacturing is in ongoing decline, consider this: the state of Michigan has the highest concentration of engineers in the country, yet also has the highest unemployment rate. But there are ripples of hope out there as grassroots and otherwise organized groups are fighting the good fight in an attempt to reverse that trend.
Today, because of reduced cost of coatings and quicker turnaround times, the idea of all-around coating on three-face-sharpened blades is again economically viable, allowing manufacturers greater freedoms in cutting blade parameters, including three-face-sharpened and even four-face-sharpened blades.
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.
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 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.
Instances of damage to discontinuous form ground and surface-hardened gears, especially of large scale, have recently increased. This may be attributed partly to a faulty grinding process with negative effects on the surface zones and the surface properties.
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 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.
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.
This is the timely and relevant sequel to our Nov/Dec 2018 Addendum article, "Safety Guaranteed." In the original article will looked at some incredible gear applications from the safety of our desktop computers and smartphones. Who knew we would be spending most of 2020 doing the same exact thing?
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.
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.
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.
On many occasions a reasonably approximate, but not exact, representation of an involute tooth profile is required. Applications include making drawings, especially at enlarged scale, and laser or EDM cutting of gears, molds, and dies used to produce gears. When numerical control (NC) techniques are to be used, a simple way to model an involute can make the NC programming task much easier.
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.
This is a three-part article explaining the principles of gear lubrication. It reviews current knowledge of the field of gear tribology and is intended for both gear designers and gear operators. Part 1 classifies gear tooth failures into five modes and explains the factors that a gear designer and operator must consider to avoid gear failures. It defines the nomenclature and gives a list of references for those interested in further research. It also contains an in-depth discussion of the gear tooth failure modes that are influenced by lubrication and gives methods for preventing gear tooth failures.
Gears are currently run at high speed and under high load. It is a significant problem to develop lubricants and gears with high load-carrying capacity against scoring. The particles of molybdenum disulfide have been considered to increase the scoring resistance of the gears. The wear characteristics and the scoring resistance of the gears lubricated with MoS2 paste and MoS2 powder have been investigated. (1) However, there are few investigations on the performance of the gears coated with MoS2 film with respect to scoring.
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 past fall, I had the opportunity to travel to Japan, Korea, Taiwan, and Singapore to witness first-hand the status of the power transmission and machine tool industries in these areas. Points of interest included equipment, material handling, computerization, wage and tax structures, inventory controls, and workforce attitude.
This method of testing large gearboxes or, indeed, any power transmission element, had numerous advantages and offers the possibility of large savings in time, energy, and plant, if the overall situation is conducive to its use. This usually requires that several such units need to be tested, and that they can be conveniently connected to each to each other in such a way as to form a closed-loop drive train. No power sink is required, and the drive input system has only to make up power losses. The level of circulating power is controlled by the torque, which is applied statically during rotation, and the drive speed. Principles, advantage, and limitations are described, together with recent experiences in the only known large-scale usage of this technique in Australia.
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.
The finished gear engineer, the man who is prepared for all emergencies, must first of all know the basic design principles. Next he must be well versed in all sorts of calculations which come under the heading of "involute trigonometry."
A simple, closed-form procedure is presented for designing minimum-weight spur and helical gearsets. The procedure includes methods for optimizing addendum modification for maximum pitting and wear resistance, bending strength, or scuffing resistance.
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
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.
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 paper describes a procedure for the design of internal gear pairs, which is a generalized form of the long and short addendum system. The procedure includes checks for interference, tip interference, undercutting, tip interference during cutting, and rubbing during cutting.
The phenomena of deterioration of surfaces are generally very complex and depend on numerous conditions which include the operating conditions, the type of load applied, the relative speeds of surfaces in contact, the temperature, lubrication, surfaces hardness and roughness, and the compatibility and nature of materials.
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.
Beginning with this issue, one of the last bits of the "old" Gear Technology is gone. From now on we'll be running the new picture of me you see on this page. It was time, my art and editorial staff explained to me, to move ahead with the rest of the updated art and editorial in the magazine. (I emphatically deny that the real motivation for the new picture was putting a stop to the ever-increasing number of jabs from certain friends about my "Dorian Gray" look.)
The first part of this article included abrasive wear with two bodies, streaks and scoring, polishing, and hot and cold scuffing. This part will deal with three-body wear, scratches or grooves, and interference wear. Normal, moderate, and excessive wear will be defined, and a descriptive chart will be presented.
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.
Welcome to the new Gear Technology. With this issue we begin bringing you a new look - a new cover, new graphics, a new, broader and more inclusive editorial focus. Our goal is to be an even better resource for the entire gear industry.
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.
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.
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.
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).
ISO 9000 is the latest hot topic in marketing and manufacturing circles. Everyone seems to be talking about it, but few seem to understand it completely. depending on whom one talks to, it's either the greatest thing to hit industry since the assembly line, another cash cow for slick consultants, a conspiracy on the part of Europeans to dominate global markets, or the next necessary step to compete in the global economy of the twenty-first century. It may be all of the above.
Much about ISO 9000 is the subject of noisy debate. But on one thing almost everyone, true believers and critics alike, agrees: Getting ISO 9000 certification can be expensive. Companies can expect to spend at least $35,000 for basic certification and six-month checkup fees over a three-year period. These figures do not include hidden costs like time and money spent on internal improvements required to meet ISO 9000 certification. But the really big-ticket items in the process are employee time and the cost of bringing in outside consultants. Many ISO 9000 consultants charge upwards of $1,800 a day.
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.
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.
The turbines are still spinning. Theyâ€™re spinning on large wind farms in the Great Plains, offshore in the Atlantic and even underwater where strong tidal currents offer new energy solutions. These turbines spin regularly while politicians and policy makersâ€” tied up in discussions on tax incentives, economic recovery and a lot of finger pointingâ€”sit idle. Much like the auto and aerospace industries of years past, renewable energy is coping with its own set of growing pains. Analysts still feel confident that clean energy will play a significant role in the future of manufacturingâ€”itâ€™s just not going to play the role envisioned four to five years ago.
The first part of this article, which ran in the September/October 1994 issue, explained the fundamentals of gear hobbing and some of the latest techniques, including methods of hob performance analysis and new tool configurations, being used to solve specific application problems. In this issue, the author continues his exploration of hobbing by describing the effects of progress on requirements in accuracy, as well as the latest in materials, coating and dry hobbing.
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.
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.
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.
In the gearing industry, gears are lubricated and cooled by various methods. At low to moderate speeds and loads, gears may be partly submerged in the lubricant which provides lubrication and cooling by splash lubrication. With splash lubrication, power loss increases considerably with speed. This is partially because of churning losses. It is shown that gear scoring and surface pitting can occur when the gear teeth are not adequately lubricated and cooled.
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.
NC and CNC metal cutting machines are among the most popular machine tools in the business today, There is also a strong trend toward using flexible machining centers and flexible manufacturing systems. The same trend is apparent in gear cutting. Currently the trend toward CNC tools has increased, and sophisticated controls and peripheral equipment for gear cutting machines are now available; however, the investment in a CNC gear machine has to be justified on the basis of economic facts as well as technical advantages.
It is with great anticipation that we move closer to AGMA's Fall Technical Conference and Gear Expo '87, which is being held on Oct. 4-6 in Cincinnati, OH. This bold undertaking by both AGMA and the exhibitors in the Expo's 160 booths is an attempt to make a major change in the industry's approach to the exposition of gear manufacturing equipment. By combining the Expo with the Fall Technical Conference, those involved in gear manufacturing will have the opportunity to review the latest equipment, trends, and most innovative ideas, while keeping up with the newest technology in the industry.
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.
The quality of the finished gear is influenced by the very first machining operations of the blank. Since the gear tooth geometry is generated on a continuously rotating blank in hobbing or shaping, it is important that the timed relationship between the cutter and workpiece is correct. If this relationship is disturbed by eccentricities of the blank to its operating centerline, the generated gear teeth will not be of the correct geometry. During the blanking operations, the gear's centerline and locating surfaces are established and must be maintained as the same through the following operations that generate the gear teeth.
Letters to the editor covering a variety of subjects, including computers in gear design, couplings and more.
Traditionally, a worm or a multi-stage gear box has been used when a large speed ratio is required. However, such boxes will become obsolete as size and efficiency become increasingly important considerations for a modern transmission. The single-enveloped worm gear has a maximum speed ratio of only 40 to 60. Its efficiency is only 30 to 60 per cent. The necessity of using bronze for the worm gear and grinding nitoalloy steel for the worm drives up material and manufacturing costs.
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.
AGMA has an excellent Training School for Gear Manufacturing. It's a great product providing a great service to the gear industry. Thus far we've educated 117 employees from 71 companies; students range from new hires with no experience to company presidents. Essentially every class since December, 1992, has been sold out.
Letters to the editor on a variety of subjects, including couplings, gear planers and ausforming.
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)
In our last issue, the labels on the drawings illustrating "Involutometry" by Harlan Van Gerpan and C. Kent Reece were inadvertently omitted. For your convenience we have reproduced the corrected illustrations here. We regret any inconvenience this may have caused our readers.
Recently, there has been increased interest in the dynamic effects in gear systems. This interest is stimulated by demands for stronger, higher speed, improved performance, and longer-lived systems. This in turn had stimulated numerous research efforts directed toward understanding gear dynamic phenomena. However, many aspects of gear dynamics are still not satisfactorily understood.
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.
We need a method to analyze cumulative fatigue damage to specify and to design gear drives which will operate under varying load. Since load is seldom constant, most applications need this analysis.
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.
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.
Mission: Competing to Win Like a lot of people, I grew up seeing the world as fairly flat and believing that everything of importance happened in Texas. As I grew older, my outlook grew to include the United States, Canada, and Mexico. The rest of the world did not seem very important, if it existed at all. Unfortunately, I was not alone in this very narrow view. Many other in the gear business shared this perception.
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.
From tiny beginnings, the AGMA Gear Expo is growing into a fine, strapping show. This year's effort, Gear Expo '89, "The Cutting Edge," will be bigger and better than ever. What started as a few tabletop exhibits in Chicago four years ago has now grown to a full-size, international exhibition at the David Lawrence Convention Center in Pittsburgh. With over 160 exhibitors, including major gear manufacturers and suppliers from around the world, this year's show promises to be a great success as well.
At the time I'm writing this editorial, the new year is barely two weeks old. The air and the papers are still full of those inevitable end-of-the-year estimates of how far we've come in one area or another and how far we have to go. Analyses of the future, both grim and humorous, abound. There are even more of these laundry lists of PROBLEMS TO BE SOLVED IMMEDIATELY than usual, since a new president will be inaugurated in a week or so. Everyone had advice for George Bush on what to do first and how to do it. Some of the advice is sound, and I hope he's listening; however, reading all these position papers can be a depressing exercise.
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.
Knowing the right thing to do isn't hard. Most often, it's very obvious. Actually doing it is something else again. For example, we all know that we probably eat too much refined sugar and fat, but when the double chocolate cheesecake come by, it's easy to convince ourselves that one piece won't hurt.
Why Brushes? In this age of hi-tech, robots, automatic machines, machining cells, etc., is there a niche somewhere for power brushes? Let me answer by asking another question. What tool does the gear manufacturer have in his arsenal that allows him to deburr green gears, hardened gears, hobbed gears, ground gears and shaved gears? What tool allows him to deburr powder metal gears - green and sintered - brass gears, bronze gears, stainless gears made of exotic materials such as inconel, waspaloy, or hastaloy, and fiber and plastic gears? How about spur gears, helical gears, sprockets, both internal and external splines, clutch teeth and pump gears?
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.
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.
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.
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.
Increasingly gear designers and product engineers are capitalizing on the economic advantages of powder metallurgy (P/M) for new and existing gear applications. Powder metal gears are found in automobiles, outdoor power equipment transmissions and office machinery applications as well as power hand tools, appliances and medial components.
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.
Machinery's Handbook 25 by Erik Oberg, Franklin D. Jones, Holbrook L. Horton & Henry H. Ryffel, Reobert E. Green, ed., Industrial Press Inc., New York, NY, 1996 ISBA 0-8311-2424-5, $75.00 (Large Print Version, $95.00).
An Interview with Dr. Valery Rudnev, FASM, IFHTSE Fellow, Director of Science & Technology at Inductoheat, Inc.
Custom Gear and Machine, Inc., of Roscoe, IL, recently purchased a Reishauer RZ400 gear grinder and, on one job, has seen the cycle time drop from 40 minutes to six minutes, according to Tim Rose, vice president of manufacturing, who runs the business with co-owners Dave Patterson and Mike Rasmann.
Two items of interest have crossed my desk in the last couple of weeks. One of them is a copy of a speech by Harry E. Figge, Jr., Chairman and CEO of Figge, International Inc., and the other is an article by Peter Brimelow in the July 19, 1993, issue of Forbes. The two items are directly related to one another, the Brimelow article being a response to the points raised in Figge's speech and in much grater detail in his book, Bankruptcy 1995: The Coming Collapse of America and How to Stop It. Both the speech and the response are well worth our attention.
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.
Business is finally starting to get back to usual in the big gear world, which offers us a chance to look back at the greatest lesson on how to survive an economic downturn. Includes the sidebar: "Brass Tacks with Klingelnberg."
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.
The performance of metal surfaces can be dramatically enhanced by the thermal process of rapid surface melting and re-solidification (RMRS). When the surface of a metal part (for instance, a gear) is melted and re-solidified in less than one thousandth of a second, the resulting changes in the material can lead to: Increased wear and corrosion resistance, Improved surface finish and appearance, Enhanced surface uniformity and purity, and Sealing of surface cracks and pores.
The complete Events section from the August 2008 issue of Gear Technology. Includes the Technical Calendar.
Questions to Ask Your Heat Treater Provided by Justin Lefevre (Joyworks LLC, Ann Arbor, MI), Kathy Hayrynen (Applied Process, Inc., Livonia, MI) and Vasko Popovski (Applied Process, Inc.)
"If it's broken, bring it on in." That's the advice offered by Roy Parker, president and owner of Jones Welding Company Inc.
Look beyond the obvious, and you may well find a better way to machine a part, and serve your customer better. Thatâ€™s the lesson illustrated in a gear machining application at Allied Specialty Precision Inc. (ASPI), located in Mishawaka, Indiana.
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25 IMTS Cancelled for the First Time Since WWII (June 9, 2020)
Because of health and safety requirements imposed by the state of Illinois for holding conventions, which include the availability of a v... Read News
26 AMT Reports Manufacturing Technology Orders Increase in June (August 11, 2020)
U.S. manufacturing technology orders soared to $346.7 million in June, a 56% increase over May 2020 according to the latest U.S. Manufact... Read News
27 Cincinnati Machine Introduces CNC Tape Layer Technology (February 6, 2007)
Cincinnati Machine's new CHARGER Series of machines were designed to improve upon the technology and productivity of CNC composite ta... Read News
28 Kadia Installs Deburring Automation Cells to Increase ZSO Production (October 8, 2020)
Besides honing, mechanical deburring is the second business area of Kadia. The company's portfolio includes a wide variety of deburri... Read News
29 Winco and Star Cutter Consolidate Sales (April 1, 2005)
Michael E. Winbald, president of Winco Industries, Brad Lawton, president of Star Cutter Co. and David W. Goodfellow, president of Star S... Read News
30 Whittemore Expands Midwest Territory to Include Kansas and Missouri (February 7, 2018)
The Whittemore Co. (Chicago, IL) recently announced they have expanded their territory coverage to include the states of Kansas and Misso... Read News
31 AMT Reports Manufacturing Technology Consumption on Best Pace Since 2000 (January 14, 2006)
September U.S. manufacturing technology consumption totaled $407.21 million, according to AMTDA, the American Machine Tool Distributors... Read News
32 IMTS Preview: Hardinge Inc. (June 15, 2012)
Hardinge Inc. (Elmira, NY) manufactures workholding products to grip parts to be turned, milled, ground, welded, assembled or positioned ... Read News
33 Waterjet Service Inc. Changes Name to WSI Waterjet Systems International (November 1, 2012)
WSI Waterjet Systems International (formerly named Waterjet Service Inc.) , the globally established, recommended and trusted designer, m... Read News
34 AMT Reports Manufacturing Technology Consumption on Best Pace Since 2000 (January 14, 2006)
September U.S. manufacturing technology consumption totaled $407.21 million, according to the American Machine Tool Distributors' ... Read News
35 ABB Joins Partners in THINC (November 7, 2012)
Okuma America Corporation recently announced that ABB has joined Partners in THINC. ABB, headquartered in Zurich, Switzerland, operates i... Read News
36 Smith Increases Role at Kapp and Niles (February 11, 2013)
Kapp Technologies is pleased to announce that Dwight Smith, has been named sales manager for Kapp and Niles products and services for the... Read News
37 Manufacturing Technology Orders Off to Best Start Since 1998 (April 17, 2012)
February U.S. manufacturing technology orders totaled $444.06 million according to the Association for Manufacturing Technology (AMT).&nb... Read News
38 5ME Named Partner in THINC (April 2, 2014)
5ME has been named a Partner in THINC by Okuma America, joining more than 40 technology leaders focused on developing specialized manufacturing systems... Read News
39 USMTO Reports Increase in Manufacturing Technology Orders (March 12, 2012)
January U.S. manufacturing technology orders totaled $401.69 million according to the Association for Manufacturing Technology (AMT). Thi... Read News
40 Small Wind Sees Increase in Sales Revenue in 2010 (October 24, 2011)
America's small wind turbine industry saw substantial growth in 2010, the American Wind Energy Association (AWEA) reported recently, ... Read News
41 PHL Gripper Increases Module Efficiency (October 14, 2011)
With the PHL, Schunk launches a new generation of long stroke grippers. The PHL from Schunk alternatively disposes of a multi-tooth guida... Read News
42 Inductoheat, Inc. Announces Executive Changes (February 18, 2008)
John H. Hooper, senior vice president and general manager of Inductoheat Inc. has retired after 35 years of service at the Inductotherm G... Read News
43 Manufacturing Technology Consumption Increased From 2007 (August 19, 2008)
U.S. manufacturing technology consumption totaled $341 million in May, reports the American Machine Tool Distributors’ Association... Read News
44 Mahr Federals New Portable Finish Gage Includes USB Interface (February 20, 2007)
Mahr Federal will feature its new Pocket Surf PS1 portable surface finish gage at the EASTEC 2007 Exposition. Based on Mahr Federal... Read News
45 Tyrolit Inc. Appoints New President and Sales Managers (December 17, 2008)
Tyrolit Inc., a manufacturer of grinding, cut-off, sawing and drilling tools, recently announced the appointment of Chip Storie (pictured... Read News
46 Oven Industries, Inc. Receives Aerospace Certification (March 24, 2010)
Oven Industries, Inc. recently announced it has been awarded official accreditation to the AS9100 international aerospace quality standar... Read News
47 alpha & Wittenstein Increase Measurement Accuracy (February 18, 2008)
New sensor technology from alpha & Wittenstein integrates torque and force sensors into the housing of servo gear reducers, enabling ... Read News
48 Helix Wiper Geometries Reduce Vibrations and Increase Tool Life (February 13, 2008)
Seco Tools Inc. recently unveiled Helix wiper geometries for operations in high-feed machining of case hardened steels where standard wip... Read News
49 Solar Manufacturing, Inc. Adds Sales Support in Pacific Northwest (April 5, 2010)
Solar Manufacturing, Inc. recently formed an agreement with Kelly LeBard, owner of Hartley Sales Corporation, to provide sales representa... Read News
50 Marposs Acquires Control Gaging Incorporated (December 19, 2007)
Marposs S.p.A. of Bologna, Italy recently announced the acquisition of Control Gaging Incorporated of Ann Arbor, Michigan. According to t... Read News
51 IMTS Preview: Felsomat USA, Inc. (July 18, 2014)
Felsomat Corporation will feature the latest gear honing technology at Booth N-7040. With the introduction of the Felsomat Power Speed Ho... Read News
52 St-Pierre Joins Nordex USA, Inc. (May 6, 2011)
Nordex USA, Inc. recently announced the appointment of Dany St-Pierre to vice president sales. A respected leader in the wind indust... Read News
53 Quebec-Area Manufacturing Increases (May 10, 2010)
In the midst of the recent recession, recovery for the manufacturing sector in Quebec was expected to be long and slow, but the momentum ... Read News
54 High-Speed Inserts Incorporate Through Coolant (June 11, 2010)
The Power-Feed+Mini high feed cutter from Ingersoll Cutting Tools features high-speed geometry with a double-sided, four-edge insert engi... Read News
55 Software Update Includes Calculation Method for Scuffing (June 18, 2010)
In the release 04/2010, the calculation of flash and integral temperature according to ISO/TR 13989-1 and 13989-2 is available. With... Read News
56 Solar Carburizes 60 Inch Diameter Gear (June 18, 2010)
Solar Atmospheres, Souderton, Pa, recently announced it has successfully vacuum carburized a large gear required for a defense appli... Read News
57 VAST Increases Measurement Performance (November 22, 2010)
Carl Zeiss recently introduced VAST Performance scanning. The new VAST Performance Kit is optionally available for the PRISMO, CenterMax ... Read News
58 Groschopp Inc. Expands Iowa Facility (April 26, 2006)
Groschopp, Inc. announced recently a 10% expansion of its Sioux Center, IA manufacturing plant. The company attributed the growth to i... Read News
59 Turbo Chamfer Mills Increase Versatility (April 22, 2011)
Seco Tools has announced a new line of Super Turbo chamfer mills designed to provide high metal removal rates while reducing production c... Read News
60 CMSC Includes 24 Comprehensive Technical Presentations (April 30, 2014)
The Coordinate Metrology Society (CMS) announced that it has selected a comprehensive slate of 24 technical presentations for the 2014 Coordinate Metrology Systems Conference... Read News
61 True Gear & Spline Increases Grinding Capacity With New Niles ZP 12 (June 26, 2015)
True Gear& Spline Ltd. recently added CNC gear profile grinding to their machining capabilities with their newly installed Niles ZP 1... Read News
62 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
63 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
64 J.L. Becker IQ Furnace Line Includes Three Furnaces, Washer and More (April 21, 2017)
J.L. Becker, a Gasbarre Furnace Group Company, recently manufactured, shipped and commissioned a complete IQ Furnace line at the East Car... Read News
65 Mahr Federal Changes Name to Mahr Inc. (June 6, 2017)
Mahr Federal has changed its name to Mahr Inc. and will immediately begin transitioning to the new company name in all legal, product and... Read News
66 Third Wave Systems AdvantEdge Software Expanded to Include Gear Machining (July 11, 2017)
Third Wave Systems has successfully developed and simulated the complex processes involved in spiral bevel gear machining. With this Adva... Read News
67 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
68 Mahr Inc. Hires Karen Gardner as Director of Human Resources (December 28, 2017)
Mahr Inc. has announced that Karen Gardner has joined the company as Director of Human Resources. Gardner has over 26 years of human res... Read News
69 Marposs Electrical Gauge Actuators Provides Increased Control and Reduced Maintenance time for E-Fenar and BlĂş Systems (January 4, 2018)
Marposs has enhanced its gauging solutions for grinding machines with new electrical gauge actuators. As compared to former hydraulic and... Read News
70 Pferd Inc. Appoints John Hibbard as Regional Sales Manager (January 29, 2018)
Pferd Inc., a global manufacturer of abrasives, brushes and power tools, has announced the appointment of John Hibbard as the new Regiona... Read News
71 Mahr Inc. Promotes Don Foisy to Director of Operations (April 2, 2018)
Mahr Inc. announced that Don Foisy has been promoted to Director of Operations to support continued company growth. In his new position, ... Read News
72 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
73 Precision Gear Inc. Acquires Arrow Gear to Establish Precision Arrow Gear Group (November 19, 2018)
Precision Gear Inc. of College Point, NY is pleased to announce the acquisition of Arrow Gear Company of Downers Grove, Illinois. The Pur... Read News
74 Methods 3D Inc. Introduces ProX SLS 500 (February 2, 2017)
Methods 3D Inc. has introduced the 3D Systems' ProX SLS 500 Selective Laser Sintering production 3D printer featuring fast speeds, hi... Read News
75 Heimatec Inc. Combines With Other Tooling Lines Under Platinum Tooling Technologies (December 13, 2018)
Heimatec Inc., recently announced that it will become part of a new corporation, Platinum Tooling Technologies, Inc. The announcement was... Read News
76 Southtec Preview: EXSYS Tool, Inc. (July 25, 2019)
EXSYS Tool, Inc. will offer attendees at Southtec the chance to experience its comprehensive range of tooling technology for turning mach... Read News
77 Mike McKernin Joins United Stars, Inc. as Gear Group Sales and Marketing Director (September 16, 2019)
United Stars, Inc. recently announced the appointment of Michael McKernin as the gear group sales and marketing director. With 35 years i... Read News
78 Siemens Acquires MultiMechanics, Inc. (December 2, 2019)
Siemens recently announced that it has signed an agreement to acquire MultiMechanics, Inc., developer of MultiMech finite element softwar... Read News
79 A3 Reports a Slight Increase in 2019 North American Robotic Orders (February 14, 2020)
The Robotic Industries Association (RIA), part of the Association for Advancing Automation (A3), recently announced 2019 North American r... Read News
80 Paul Carlson Named CEO of Tolomatic, Inc. (February 25, 2020)
Paul Carlson has been named president and chief executive officer of Tolomatic, Inc. Carlson has more than 30 years of manufacturin... Read News
81 IMTS Digital Technology Showcase: Platinum Tooling Technologies, Inc. (September 15, 2020)
Platinum Tooling Technologies, Inc., the exclusive North American importer of Heimatec Live Tools and Angle Heads, Tecnicrafts Swiss Coll... Read News
82 Norton Winter AEON Electroplated Wheels Offer Increased Productivity (October 13, 2020)
Saint-Gobain Abrasives has announced the introduction of its new Norton Winter AEON Electroplated Grinding Wheels for high precision appl... Read News
83 AGMA Releases Publication for Splines - Design and Application (Inch Edition) (October 14, 2020)
AGMA Technical Division has released AGMA 945-2-B20, Splines - Design and application (Inch Edition). AbstractThis information... Read News
84 Emuge EF-Series Drill Line Expanded to Include Micro and Sub-Micro Grain Drills (March 20, 2017)
Emuge Corp. announced that it has expanded its EF-Series of high penetration rate drills with a new line of sub-micro grain carbide coola... Read News
85 Hubbard-Hall Increases Heat Treat Salts Capacity (January 19, 2017)
Hubbard-Hall has announced additional capacity for heat treat salts and corresponding services, effective immediately. "As a result ... Read News
86 Dillon Manufacturing, Inc. Will Feature its Hard Jaws at Houstex (November 18, 2014)
Dillon Manufacturing, Inc. announced that it's hard jaws will be featured in Houstex booth #127. Hard jaws from Dillon Manufactu... Read News
87 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
88 Steinmeyer, Inc. Offers 'World's Smallest Ball Screw' (November 21, 2014)
The ultra-minature ball screws are available in diameters as small as 3 millimeter with a choice of two pitches – 1 millimeter... Read News
89 OSG USA, Inc. Promotes Jones to Vice President- Sales (April 13, 2015)
OSG USA, Inc. recently announced the promotion of Rick Jones to Vice President- Sales. Jones joined the OSG sales team as a District Mana... Read News
90 Gleason's Gear Solutions Forum to Include Over 40 Demonstrations on Products and Technologies (June 16, 2015)
Gleason Corporation will host the Gear Solutions Forum (GSF) at its worldwide headquarters in Rochester, NY on Sept. 23-24. This year als... Read News
91 Emuge EF Series Drills Incorporate Special Geometry for Faster Penetration and Longer Tool Life (June 17, 2015)
Emuge Corp. recently announced the North American debut of its line of high-performance solid carbide drills. The new Emuge EF series dri... Read News
92 Pittler SkiveLine Increases Quality While Reducing Costs (December 9, 2020)
The future of automation lies above all in the intelligent combination of the respective strengths of man and machine. In order to achiev... Read News
93 Cimcool Cimperial 861 Metalworking Fluid Increases Tool Life and Provides Superior Lubricity (July 13, 2015)
Cimcool recently announced the release of Cimperial 861 with InSol technology, a hybrid lubricity, semi-synthetic metalworking fluid, whi... Read News
94 Mahr Acquires Engineering Synthesis Design Inc. (August 27, 2015)
The Mahr Group recently acquired Engineering Synthesis Design Inc. (ESDI), headquartered (Tucson, AZ). Over the past two years, Mahr... Read News
95 German Machine Tools of America Incorporate Hard Scudding Process (January 12, 2016)
The scudding industry took another step forward recently with a new process known as Hard Scudding. The conventional Scudding process wor... Read News
96 Rollomatic Inc. Appoints Daniel Franklin as Team Leader of Applications and Service (March 23, 2016)
Rollomatic Inc., a subsidiary of Rollomatic Holding Switzerland, has announced the appointment of Daniel Franklin as the new Service/Appl... Read News
97 Ricardo Software Ignite Vehicle System Simulator Incorporates Modelon's Optimica Compiler Toolkit (May 3, 2016)
Ricardo Software recently announced a key partnership that will deliver immediate benefits to users of its Ignite complete vehicle system... Read News
98 Index G200 Turn-Mill Center Redesigned to Include XPanel i4.0 Technology (December 22, 2016)
Index has developed a new generation of its turn-mill center G200, a compact machine offering significantly higher performance - potentia... Read News
99 Methods Machine Tools, Inc. Announces Jerry Rex as New COO (June 8, 2016)
Methods Machine Tools, Inc. announced the appointment of Jerry Rex as Chief Operating Officer of all Methods Machine Tools operations. Th... Read News
100 Walter M4000 Family Helical Milling Cutters Expanded to Include Three New Models (July 15, 2016)
Walter has announced the addition of the M4256, M4257 and M4258 high-performance helical milling cutters to its M4000 family. The M4000 p... Read News
101 IMTS 2016: Liebherr Gear Technology, Inc. (N-6930) (August 30, 2016)
LGG 280 Gear Grinding MachineWith a one-table design and a new-design grinding head, the new Liebherr LGG 280 gear grinding machine great... Read News
102 IMTS 2016: Hardinge Inc. (S-8738) (September 6, 2016)
Hardinge Talent 51 MSY CNC Turning CenterThe all-new Hardinge Talent 51 MSY CNC Turning Center will make its debut at IMTS. This machine ... Read News
103 IMTS 2016: Mahr Federal Inc. (E-5614) (September 7, 2016)
Mahr Federal will feature the MarShaft Scope 250 Plus, the new MarShaft Scope 600 Plus 3D, and the MarGear GMX 400 at IMTS 2016. Also on ... Read News
104 IMTS 2016: Renishaw Inc. (E-5509) (September 8, 2016)
RVP Vision Measurement ProbeRVP, Renishaw's new vision measurement probe for use with the REVO 5-axis measurement system on coordinat... Read News
105 IMTS 2016: Oelheld U.S. Inc. (N-7475) (September 9, 2016)
SintoGrind IG 540Oelheld's SintoGrind IG 540 grinding oil is designed for flute grinding, profile grinding and outside and inside dia... Read News
106 IMTS 2016: Zoller Inc. (W-2022) (September 9, 2016)
»hobCheck« Gear Hob Measuring MachineThe Zoller »hobCheck« brings an expanded range of possibilities and solution... Read News
107 Hardinge Inc. Announces Retirement of Board of Directors Chairman, John J. Perrotti (November 9, 2016)
The board of directors of Hardinge Inc. announced that John J. Perrotti, chairman, has chosen to retire from the board effective October ... Read News
108 Hardinge Inc. Appoints Ryan Levenson to Board of Directors (November 15, 2016)
The board of directors of Hardinge Inc. announced that it has appointed Ryan Levenson of Privet Fund Management LLC, to serve as a direct... Read News
109 Matlab Increases Heat Treating Capaciy for Gears (January 4, 2005)
Metlab has completed the upgrade of one of its large pit carburizing furnaces, which doubles its capabilities for carburizng, nitriding, ... Read News