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April 2018

A Competitive Edge Starts at the Spindle

These high torque retention knobs were specially designed to help machining centers achieve optimized toolholder productivity.

Despite some 750,000 CNC mills put into service in the United States over the past 15 years, CNC machining job shops often hover at the bottom of the totem pole where there’s little room for error, as most bids are won by a 1-2 percent price variance. Representing the backbone of the U.S. machinery resurrection, […]
John Stoneback

Choosing a Resharpening Resource

Cutting tool management is a critical aspect of gear manufacturing operations, and expert resharpening services are worth their weight in accumulated chips.

On a per-unit basis, the overall cost of cutting tools in a gear cutting process boils down to only a few percentage points. As a result, this overshadows the cutting tool’s obvious direct impact on the cutting process and cut gear. Consequently, some gear manufacturing operations focus elsewhere to find productivity gains, better quality, or […]
Adam Gimpert

Effects of Asymmetric Cutter Tip Radii on Gear Tooth Root Bending Stress

When fillet geometry is modified and controlled for decreasing bending stress, improved gear service life is the primary result.

By Dr. Abdullah Akpolat, Dr. Nihat Yildirim, Burak Sahin, Omer Yildirim, Bulent Karatas, and Fatih Erdogan Tooth root fillet is the maximum bending stress concentration region during a torque transmission via gear pairs. Increase in gear root fillet radius due to a larger cutter tip radius provides a smoother transition from involute to root via a […]
Abdullah Akpolat

Introducing the New Blue

New segmented collet design meets the industry’s need for reliable, accurate, and universal bore clamping for a wide range of cylindrical gear production applications.

Gear manufacturers today must turn on a dime to meet fast-changing customer demand and marketplace conditions with faster production of smaller lot sizes. More frequent part changeover has fostered the development of workholding systems with quick-change, often tool-less designs to take increasingly valuable non-productive time out of the process. This new gear production paradigm has […]
Timothy Zenoski

March 2018

JM Performance Products

JM Performance Products has established itself as a model shop leader for manufacturing development and quality control of precision-turned parts.

JM Performance Products may be a small company, but the products and services it offers are anything but. “We are a small company that manufactures with the traceability and quality standards gained from years working from a defense manufacturer’s standpoint,” said Plant Manager Craig Fischer. “We buy all U.S. steel. Our products are guaranteed not […]
Kenneth Carter

Induction Gear Hardening: Part 2

The second in a two-part series, this installment addresses induction gear hardening by encircling the whole gear or sprocket with an induction coil,
also known as ‘spin hardening.’

This is the second installment of a two-part article on induction hardening of gears and gear-like components. Part 1 was published in the February 2018 issue of Gear Solutions magazine, covering the following subjects: Materials selection for induction gear hardening, including specifics of electromagnetic induction vs. thermo-chemical diffusion processes (e.g., carburizing). Impact of friendly vs. […]
Valery Rudnev

Root Fillet Optimization of Gears with Asymmetric Teeth

This paper provides an analysis of the benefits of optimizing the tooth root fillet of thin rim planet gears with asymmetric teeth.

By Dr. A.L. Kapelevich and Dr. Y.V. Shekhtman The Direct Gear Design method optimizes various parameters and elements of gear tooth geometry to achieve the required gear drive performance. One such critical element of the tooth profile is the root fillet. Its optimization by means of Direct Gear Design provides the ultimate bending stress minimization. […]
Alexander Kapelevich, Dr. Yuriy Shekhtman

Improving the Friction Power of Gears and Bearings

Proper lubrication can extend the overall fatigue life of gears by a factor of 2.6.

A machine that runs endlessly without any wear and frictional losses — who wouldn’t dream of that? Unfortunately, such a machine does not exist yet. However classic car fans know that through solid technology and ongoing service, cars can even outlast their owners. However, this does not happen with machinery of all industries. In the […]
Stefan Bill

CFD Simulation of Power Losses and Lubricant Flows in Gearboxes

Growing interest in the energy efficiency of gearboxes has led to the use of Computational Fluid Dynamics (CFD) to calculate load-independent power losses as well as lubricant flows.

Printed with permission of the copyright holder, the American Gear Manufacturers Association, 1001 N. Fairfax Street, Suite 500, Alexandria, Virginia 22314. Statements presented in this paper are those of the authors and may not represent the position or opinion of the American Gear Manufacturers Association. (AGMA) This paper was presented October 2017 at the AGMA […]
Franco Concli, Carlo Gorla

February 2018


TRUMPF may have started as a machine tool company, 
but laser manufacturing has made it a shining industrial star.

TRUMPF has been manufacturing for nearly a century but lasers energized the company’s mission, changing it forever. “In the late ’70s, we made one of the most important decisions in our company’s history, which was to develop laser technology,” said Ralf Kimmel, general manager and head of the Laser Technology division at TRUMPF Inc. “Cutting […]
Kenneth Carter

Induction Gear Hardening

Part 1: The practice and science of modern induction heat-treating has 
advanced in many areas over the last decade, including computer modeling, power supplies, failure analysis, quality assurance, and more.

Over the years, gear manufacturers have increased their knowledge of the production of quality gears and gear-like components. This knowledge has led to many improvements including lower noise, lighter weight, and lower cost as well as increased load-carrying capacity to handle higher speeds and torque with a minimum amount of generated heat. Improvement in wear […]
Valery Rudnev

Choosing a Planetary Gearhead

Motion projects featuring planetary gearheads excel in the areas 
of system response, inertia matching, speed matching, system stiffness, 
and system resolution.

From CGI Inc. staff When a motor is being designed into a motion control system, all too often the benefits of a gearhead are realized much too late. Designing in a gearhead at the end of the project will many times cause delay and additional cost, which could have been prevented if it had been […]
Rick Frennea

January 2018

Bevel Gears (India) Pvt. Ltd.

Bevel Gears (India) Pvt. Ltd. has designed and manufactured bevel gears and bevel gearboxes for more than 40 years.

Bevel Gears (India) Pvt. Ltd. considers itself a “niche within a niche” when it comes to making and supplying bevel gears. “Our niche is bevel gears,” said Mushtaq Jamal, vice president of engineering and business development with Bevel Gears (India). “We manufacture straight, spiral, hypoids, and high ratio hypoids.” That niche within a niche comes […]
Kenneth Carter

Closed Loop Machining of Cylindrical Gears

Looking to raise the quality and accuracy of your gearing? Consider Closed Loop design and manufacturing, which has done away with the error-prone data transfer from the measuring sheet.

Leonhard Euler’s 1760 invention of making cylindrical gears with an involute profile was the beginning of a success story. As a tooth profile, the involute has many advantages that are still being used by engineers to design high-performance transmissions that even function under high loads and the consequential deformation of the shaft bearing system. However, […]
Dr. Markus Brumm

Fatigue Performance and Cleanliness of Carburizing Steels for Gears

This investigation shows that steels with a higher cleanliness level reach a higher performance level as well, both in terms of increased loads and longer service life.

The cleanliness of steels used for gears is of great importance when looking to improve their life or increase loads. In this paper, carburizing steels with the same basic chemical composition, but with a varying cleanliness level, are compared in regards to cleanliness and performance. Steel cleanliness can be described as size and frequency of […]
Joakim Fagerlund, MSc, Lily Kamjou, MSc

Extending gear life in demanding applications

Specialized PVD coatings increase the surface hardness and durability of gears, thereby increasing their lifespan under high-load conditions.

Although gears and other precision components are generally made of hardened steel or metal alloys, those used in high load applications still can fail due to excessive wear, surface fatigue, pitting, galling, and corrosion. This is exacerbated in applications with metal-to-metal interaction, repetitive friction at high speeds or where little to no lubrication is present. […]
Jeff Elliot

Advanced Thermal Processing for Enhanced Gear Tribology

TriboNite technology can help improve gear performance by combining the well-known advantages of nitriding with the superior tribological performance profile of solid lubricant coatings.

By Boris Zhmud, Johan Blomkvist, and Mikael Fallström

Abstract Vast empirical knowledge accumulated over centuries, in conjunction with recent advances in the areas of material science, tribology, and big data analysis, have allowed significant progress in gear design. Still, gears sometimes fail. Gear tooth flanks are most vulnerable to damage under tribological stress. Gear material, machining, and finishing methods, lubricant, and end use […]
Boris Zhmud, Ph.D., FRSC, Mikael Fallström, M.Sc.