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Articles About tool steel
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Manufacturers focus on tool design, materials, coating, machine tool options and cutting parameters.
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.
To meet the future goals of higher productivity and lower production costs, the cutting speeds and feeds in modern gear hobbing applications have to increase further. In several cases, coated carbide tools have replaced the commonly used high speed steel (HSS) tools.
The latest technology on display in Columbus, OH. October 24-26.
Hobs, broaches, shaper cutters, shaver cutters, milling cutters, and bevel cutters used in the manufacture of gears are commonly made of high speed steel. These specialized gear cutting tools often require properties, such as toughness or manufacturability, that are difficult to achieve with carbide, despite the developments in carbide cutting tools for end mills, milling cutters, and tool inserts.
The complete Industry News section from the March/April 2019 issue of Gear Technology.
The complete industry news section from the May 2018 issue of Gear Technology.
"Documentation is not a Substitute for an Intuitive Interface." The author explores the development of modern controls for a CNC gear grinding machine.
The complete Industry News section from the November/December 2018 issue of Gear Technology.
The complete Industry News section from the January/February 2019 issue of Gear Technology.
The complete Industry News section from the May 2019 issue of Gear Technology.
Meeting Todayâ€™s Requirements for High-Quality Gears
New Solutions Aim at Reducing Changeover Times and Improving Reliability
How machine tool maintenance has evolved in recent years in gear manufacturing.
Inspection of the cutting blades is an important step in the bevel gear manufacture. The proper blade geometry ensures that the desired gear tooth form can be achieved. The accuracy of the process can be compromised when the blade profile consists of several small sections such as protuberance, main profile, top relief and edge radius. Another common obstacle - are outliers which can be caused by dust particles, surface roughness and also floor vibrations during the data acquisition. This paper proposes the methods to improve the robustness of the inspection process in such cases.
The complete Industry News section from the June 2019 issue of Gear Technology./
The complete Industry News section from the July 2019 issue of Gear Technology.
Mitsubishi Heavy Industries, Ltd. (MHI) conducted a comparison test between the super skiving cutter and the pinion skiving cutter used in the conventional skiving process and the test results are reported here.
As coating technology improves to handle harsher conditions, cutting tool manufacturers are faced with new challenges during the resharpening process.
A calculation method is developed to estimate tool wear on hobs.
Fraunhofer CMI focuses on new U.S. gear and transmission technologies group, plus other news from around the industry.
From standardization to automated, Industry 4.0 capable broachers, here's the latest in what's being developed in the field of broaching.
Gear Technology hosts dinner for technical contributors to the gear industry during this year's AGMA Fall Technical Meeting and Gear Expo in Columbus, OH. Plus other news from around the industry.
The author compares the standard two-face blade technology with the three-face blade technology for manufacturing bevel gears.
Results from the 2017 Powder Metallurgy Design Excellence Awards, plus other news from around the industry.
The latest new products from EMAG, Emuge, Ransohoff, Seco Tools, Solar Atmospheres and more.
Nuttall Gear taps Machine Tool Builders for shop floor upgrades.
The complete Product News section from the June 2017 issue of Gear Technology, featuring the latest from Liebherr, Heller, Sandvik Coromant, Mahr and more.
Educational initiatives, company news, acquisitions and people in the industry are all featured this issue.
News from around the Gear Industry
News about all of the upcoming products int he industry.
News From Around the Gear Industry
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News about the latest products in the industry.
Latest new from the Gear Industry
Motion + Power Technology Expo VIP Exhibitors special advertising section.
Everybody's working with carbide tools these days, but carbide materials are expensive. However, these cutting tool companies think they might have some solutions to extend tool life and reduce costs.
News from the Gear Industry
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 complete Product News section from the August 2019 issue of Gear Technology.
The effects of non-metallic inclusions in steel matrix on tooth root strength based on theoretical approach of Murakami.
As gear manufacturing techniques become more precise and demanding, there is a growing demand for cleaner, higher quality steel.
Will tariffs and quotas affect your ability to operate in the fourth quarter this year?
Three samples of quenched and tempered 4140 steel, with varying levels of oxygen and sulfur, were submitted to a series of bending fatigue tests.
Background on the development of a high-speed, automatic hardness tester for gear steels.
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.
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.
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.
Broaching is a machining technique commonly used to cut gear teeth or cam profiles for the high volume manufacture of power transmission parts used in vehicles (Refs. 1â€“2). This article shows how the right gear blank material can make all the difference if you want to get more parts out of each tool.
The complete Industry News section from the August 2014 issue of Gear Technology.
Much of the existing guidelines for making large, high-performance gears for wind turbine gearboxes exhibit a need for improvement. Consider: the large grinding stock used to compensate for heat treatment distortion can significantly reduce manufacturing productivity; and, materials and manufacturing processes are two other promising avenues to improvement. The work presented here investigates quenchable alloy steels that, combined with specifically developed Case-hardening and heat treatment processes, exhibits reduced distortion and, in turn, requires a smaller grinding stock.
Industry battles it out for World's Largest Gear title.
The selection of the proper steel for a given gear application is dependent on many factors. This paper discusses the many aspects related to material, design, manufacture, and application variables. The results of several studies on the optimization of alloy design for gas- and plasma- carburization processing and reviewed.
Sivyer Steel Corporation, Bettendorf, IA, an ISO-9002-certified casting specialist, is familiar with tackling tough jobs. The company has built an international reputation as a supplier of high-integrity castings, especially those which require engineering and/or full machining. Its not unusual for Sivyer's customers, especially those in the mining, recycling, power generation, valve and nuclear fields, to ask the foundry to produce a one-of-a-kind casting - often something revolutionary - but AnClyde Engineered Products' request was a special challenge, even for Sivyer.
Shop floor inspection and gaging equipment is putting advanced metrology systems right on the factory floor. Hereâ€™s a collection of articles on shop floor inspection and gages from companies like Gleason, Mahr, Comtorgage, United Tool Supply and Frenco.
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.
Plane strain fracture toughness of twelve high-carbon steels has been evaluated to study the influence of alloying elements, carbon content and retained austenite. The steels were especially designed to simulate the carburized case microstructure of commonly used automotive type gear steels. Results show that a small variation in carbon can influence the K IC significantly. The beneficial effect of retained austenite depends both on its amount and distribution. The alloy effect, particularly nickel, becomes significant only after the alloy content exceeds a minimum amount. Small amounts of boron also appear beneficial.
The manufacturing process to produce a gear essentially consist of: material selection, blank preshaping, tooth shaping, heat treatment, and final shaping. Only by carefully integrating of the various operations into a complete manufacturing system can an optimum gear be obtained. The final application of the gear will determine what strength characteristics will be required which subsequently determine the material and heat treatments.
Technology investments lead to product innovation at gear materials suppliers.
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.
This study quantified the performance of a new alloy and has provided guidance for the design and development of next-generation gear steels.
Corus Engineering Steels' formula for its new gear steels: Maintain achievable hardness while using fewer alloys, thereby cutting steel costs for gear manufacturers.
This article summarizes results of research programs on RCF strength of wrought steels and PM steels.
This is part II of a two-part paper that presents the results of extensive test programs on the RCF strength of PM steels.
Natural resourcesâ€”minerals, coal, oil, agricultural products, etc.â€”are the blessings that Mother Earth confers upon the nations of the world. But it takes unnaturally large gears to extract them.
The performance of carburized components can be improved simply by changing the alloy content of the steel.
The complete Industry News section from the September/October 2020 issue of Gear Technology.
The latest gear industry news from Machine Tool Builders, Global Gear, EMAG, Bourn & Koch, Klingelnberg and others.
A Look at Complex, High-Performance Five-Axis Machining Solutions.
Latest news about the Latest Products
Manufacturing involute gears using form grinding or form milling wheels are beneficial to hobs in some special cases, such as small scale production and, the obvious, manufacture of internal gears. To manufacture involute gears correctly the form wheel must be purpose-designed, and in this paper the geometry of the form wheel is determined through inverse calculation. A mathematical model is presented where it is possible to determine the machined gear tooth surface in three dimensions, manufactured by this tool, taking the finite number of cutting edges into account. The model is validated by comparing calculated results with the observed results of a gear manufactured by an indexable insert milling cutter.
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.
Some gear-related highlights from the recent EMO show in Hannover, Germany.
What Is Whisker-Reinforced Ceramic? Whisker-reinforced ceramic as applied to cutting tool inserts comprises a matrix of aluminum oxide into which approximately 50% by volume of high-purity silicon carbide "whiskers" are randomly dispersed. The "whiskers" are, in fact, single crystals having dimensions of approximately 0.6 microns in diameter x 10-80 microns in length. These "whiskers" have a tensile strength on the order of 1,000,000 psi (690 MPa). The composite material that is the best known and most widely applied using this technology is designated WG-300 and manufactured by the Greenleaf Corporation of Saegertown, PA.
Gear Technology's bimonthly aberration - gear trivia, humor, weirdness and oddments for the edification and amusement of our readers. Contributions are welcome.
Question: We are interested in purchasing our first gear hobbing machine. What questions should we ask the manufacturer, and what do we need to know in order to correctly specify the CNC hardware and software system requirements?
Robots, computers and other signs of high technology abounded at IMTS 94, supporting the claim by many that this was one of the best shows ever. Many of the machines on display had so many robotic attachments and computer gizmos that they looked more like they belonged in some science fiction movie than on the floor of a machine shop.
This is Part II of a two-part series on the basics of gear hobbing. Part I discussed selection of the correct type of hobbing operation, the design features of hobs and hob accuracy. This part will cover sharpening errors and finish hob design considerations.
The Hobbing Process The hobbing process involves a hob which is threaded with a lead and is rotated in conjunction with the gear blank at a ratio dependent upon the number of teeth to be cut. A single thread hob cutting a 40-tooth gear will make 40 revolutions for each revolution of the gear. The cutting action in hobbing is continuous, and the teeth are formed in one passage of the hob through the blank. See Fig. 1 for a drawing of a typical hob with some common nomenclature.
Today's high technology hobs are visible different from their predecessors. Gear hobs have taken on a different appearance and function with present day technology and tool and material development. This article shows the newer products being offered today and the reasons for investigating their potential for use in today's modern gear hobbers, where cost reduction and higher productivity are wanted.
Precision gears play a vital role in today's economy. Through their application, automobile transmissions are more compact and efficient, ships sail faster, and diesel locomotives haul more freight. Today great emphasis is being placed upon the reduction of noise in all gear applications and, to be quiet, gears must be accurate.
Question: I have just become involved with the inspection of gears in a production operation and wonder why the procedure specifies that four involute checks must be made on each side of the tooth of the gear being produced, where one tooth is checked and charted in each quadrant of the gear. Why is this done? These particular gears are checked in the pre-shaved, finish-shaved, and the after-heat-treat condition, so a lot of profile checking must be done.
Cutter Sharpening Cutter sharpening is very important both during manufacturing and subsequently in resharpening after dulling. Not only does this process affect cutter "over cutting edge" quality and the quality of the part cut, but it can also affect the manner in which chip flow takes place on the cutter face if the surface finished is too rough or rippled.
Gear shaping is one of the most popular production choices in gear manufacturing. While the gear shaping process is really the most versatile of all the gear manufacturing methods and can cut a wide variety of gears, certain types of gears can only be cut by this process. These are gears closely adjacent to shoulders; gears adjacent to other gears, such as on countershafts; internal gears, either open or blind ended; crown or face gears; herringbone gears of the solid configuration of with a small center groove; rack; parts with filled-in spaces or teeth, such as are used in some clutches.
Universal machines capable of cutting both spur and helical gears were developed in 1910, followed later by machines capable of cutting double helical gears with continuous teeth. Following the initial success, the machines were further developed both in England and France under the name Sunderland, and later in Switzerland under the name Maag.
A brief introduction to the subject of Thin Film Coatings and their application to gear hobs and shaper cutters is followed by a detailed description of the Chemical Vapor Deposition Process and the Physical Vapor Deposition Process. Advantages and disadvantages of each of these processes is discussed. Emphasis is placed upon: application engineering of coated gear tools based on laboratory and field test results. Recommendations are suggested for tool design improvements and optimization of gear cutting operations using coated tools. Productivity improvements potentially available by properly utilizing coated tools are considered in terms of both tool cost and machining cost.
Hainbuch offers workholding solutions for United Gear.
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 today's industrial marketplace, deburring and chamfering are no longer just a matter of cosmetics. The faster speeds at which transmissions run today demand that gear teeth mesh as smoothly and accurately as possible to prevent premature failure. The demand for quieter gears also requires tighter tolerances. New heat treating practices and other secondary gear operations have placed their own set of demands on manufacturers. Companies that can deburr or chamfer to these newer, more stringent specifications - and still keep costs in line - find themselves with a leg up on their competition.
At Andrew Tool, CMMs have been an integral part of their manufacturing processes for years, but they had never faced a project with such intricate measurements, tight tolerances, heat treatments and a very short time frame requirement.
Indexable carbide insert cutting tools for gears are nothing new. But big gears have recently become a very big business. The result is that there's been a renewed interest in carbide insert cutting tools.
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.
Faster, more efficient manufacturing offered with table-top design from American Broach & Machine.
This article presents some of the findings of cutting investigations at WZL in which the correlation of cutting parameters, cutting materials, tool geometry and tool life have been determined.
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.
Machine tool manufacturers supplying machines to the gearing world have been in existence for many years. The machines have changed, and so has the acceptance criteria for the machines.
As we approach the problem of hard gear processing, it is well to take a look at the reason for discussing it at this time. In our present economic atmosphere throughout the world, more and more emphasis is being placed upon efficiency which is dictated by higher energy costs.
The gear hobbing process is a generating type of production operation. For this reason, the form of the hob tooth is always different from the form of the tooth that it produces.
Indexable carbide insert (ICI) cutting tools continue to play a pivotal role in gear manufacturing. By offering higher cutting speeds, reduced cycle times, enhanced coatings, custom configurations and a diverse range of sizes and capabilities, ICI tools have proven invaluable for finishing and pre-grind applications. They continue to expand their unique capabilities and worth in the cutting tool market.
In todayâ€™s manufacturing environment, shorter and more efficient product development has become the norm. It is therefore important to consider every detail of the development process, with a particular emphasis on design. For green machining of gears, the most productive and important process is hobbing. In order to analyze process design for this paper, a manufacturing simulation was developed capable of calculating chip geometries and process forces based on different models. As an important tool for manufacturing technology engineers, an economic feasibility analysis is implemented as well. The aim of this paper is to show how an efficient process designâ€”as well as an efficient processâ€”can be designed.
Hobbing is probably the most popular gear manufacturing process. Its inherent accuracy and productivity makes it a logical choice for a wide range of sizes.
The proper design or selection of gear cutting tools requires thorough and detailed attention from the tool designer. In addition to experience, intuition and practical knowledge, a good understanding of profile calculations is very important.
In today's economy, when purchasing a new state-of-the-art gear shaper means a significant capital investment, common sense alone dictates that you develop strategies to get the most for your money. One of the best ways to do this is to take advantage of the sophistication of the machine to make it more than just a single-purpose tool.
The cutting tool is basic to gear manufacturing. Whether it's a hob, broach, shaper cutter or EDM wire, not much gets done without it. And the mission of the tool remains the same as always; removing material as quickly, accurately and cost-effectively as possible. Progress in the field tends to be evolutionary, coming gradually over time, but recently, a confluence of emerging technologies and new customer demands has caused significant changes in the machines, the materials and the coatings that make cutting tools.
Over many years of being in the machine tool business, it has been interesting to observe the way we suppliers are forced to quote and sell machine tools to many large companies.
Sandvik presents the latest in gear milling technologies.
Product news from the Gear Industry
The complete Product News section from the November/December 2014 issue.
The complete Industry News section from the November/December 2014 issue.
Recently, a new type of hob with carbide inserts has been introduced, providing higher cutting speeds, longer tool life and higher feed rates when compared to re-grindable, high-speed steel hobs. But with this kind of hob, new challenges occur due to positional errors of the cutting edges when mounted on the tool. These errors lead to manufacturing errors on the gear teeth which must be controlled. In this paper, the tooth quality of a gear manufactured by hobs with different quality classes is analyzed using a simulation model in combination with Monte Carlo methods.
The complete Product News section from the July 2014 issue of Gear Technology.
Machine tools boost speed and throughput with automation technology.
The complete Industry News section from the November/December 2013 issue of Gear Technology.
The complete Industry News section from the September 2013 issue of Gear Technology.
Preview of some of the exhibits relevant to gear manufacturing at the upcoming EMO 2013.
The Society of Manufacturing Engineers (SME) has been gathering, validating and sharing manufacturing knowledge for more than 80 years. Traditionally, SME resources were purchased by individuals for their own personal use or by colleges and universities as textbooks. Recently, these same colleges and universities were looking for digital resources to provide to their instructors and students. Companies were requesting SME content digitally for their employees as well.
The complete Industry News section from the June/July 2013 issue of Gear Technology.
Itâ€™s been said that the best ideas are often someone else's. But with rebuilt, retrofitted, re-controlled or remanufactured machine tools, buyer beware and hold onto your wallet. Sourcing re-work vendors and their services can require just as much homework, if not necessarily dollars, as with just-off-the-showroom-floor machines.
Investment in advanced new manufacturing technologies is helping to reinvent production processes for bevel gear cutters and coarse-pitch hobs at Gleason - delivering significant benefits downstream to customers seeking shorter deliveries, longer tool life and better results.
The hob is a perfect example of how a little manufacturing ingenuity can make a reliable, highly productive cutting tool. It's an engineering specimen that creates higher cutting speeds, better wear resistance and increases rigidity. The cutting tool alone, however, can't take all the credit for its resourcefulness. Advanced coating technology from companies like Sulzer, Oerlikon Balzers, Ionbond, Seco Tools and Cemecon helps improve cutting tools by reducing overall costs, increasing tool life and maintaining the highest levels of productivity. The following is a quick recap of new technologies and the latest information in the coating market.
The complete Industry News section from the November/December 2012 issue of Gear Technology.
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.
Previews of manufacturing technology related to gears that will be on display at IMTS 2012.
Booth previews from exhibitors showing products and services for the gear industry.
In the past, the blades of universal face hobbing cutters had to be resharpened on three faces. Those three faces formed the active part of the blade. In face hobbing, the effective cutting direction changes dramatically with respect to the shank of the blade. Depending on the individual ratio, it was found that optimal conditions for the chip removal action (side rake, side relief and hook angle) could just be established by adjusting all major parameters independently. This, in turn, results automatically in the need for the grinding or resharpening of the front face and the two relief surfaces in order to control side rake, hook angle and the relief and the relief angles of the cutting and clearance side.
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.
Users of gear-cutting tools probably do not often consciously consider the raw material from which those hobs, broaches or shavers are made. However, a rudimentary awareness of the various grades and their properties may allow tool users to improve the performance or life of their tools, or to address tool failures. The high-speed steel from which the tool is made certainly is not the only factor affecting tool performance, but as the raw material, the steel may be the first place to start.
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.
The cutting tool industry has undergone some serious changes in the last couple of years in both technology and the way the industry does business. The emerging technology today, as well as for the foreseeable future, is dry cutting, especially in high volume production settings. Wet cutting continues to be as popular as ever with lubrication advances making it more economical and environmentally friendly. There has also developed a process called "near dry cutting." this process offers many of the benefits of fluids while eliminating many of hte associated problems.
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.
Rotary gear honing is a crossed-axis, fine, hard finishing process that uses pressure and abrasive honing tools to remove material along the tooth flanks in order to improve the surface finish (.1-.3 um or 4-12u"Ra), to remove nicks and burrs and to change or correct the tooth geometry. Ultimately, the end results are quieter, stronger and longer lasting gears.
Broaching is a process in which a cutting tool passes over or through a part piece to produce a desired form. A broach removes part material with a series of teeth, each one removing a specified amount of stock.
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.
Physical Vapor Deposited (PVD) coatings such as TiN (Titanium nitride) have been a boon for cutting tool manufacturers. They reduce wear and, therefore, extend tool life, which in turn reduces production costs. But PVD coatings are expensive, and when they fail, they cost both time and money, and they causes of the failure are not always readily apparent.
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.
The International Manufacturing Technology Show provided one of the biggest ever marketplaces for buying and selling gear-making equipment, with 121601 attenders, making it the largest IMTS ever. The show took place September 4-11 at McCormick Place in Chicago, IL.
News from around the Gear Industry