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Materials

TECHNICAL ARTICLES | 2025-02-27

Very High Cycle Fatigue Testing of AMS 6308 Steel

In this paper, ultrasonic fatigue testing results for “core hardened” AMS 6308 gear steel are presented. AMS 6308 is a gear and bearing steel with high tempering resistance and high hot hardness case targeted to high temperature applications

TECHNICAL ARTICLES | 2024-12-12

An Experimental Study on the NVH Performance of Plastic Gears

The following study presents an experimental methodology, employed to characterize the NVH behavior of plastic gears NVH in application-like operating conditions, presenting guidelines for material selection in terms of optimal gear NVH. 

EVENT | 2024-09-18

Formnext 2024

Formnext (Frankfurt, Germany) is more than an exhibition and conference. It’s an entire platform for companies from the world of additive manufacturing. Here, a veritable who’s who from the realms of design and product development, industrial tooling, production solutions, quality management, and measurement technology comes together with leading providers in basic materials and component construction.

TECHNICAL ARTICLES | 2024-05-10

Plastic Gear Testing Methods—Characterization of Crucial Material Data Required for Reliable Design of Plastic Gears

An extremely wide selection of different plastic materials is currently available on the market. A major limitation, however, is a huge gap in gear-specific material data on these materials, which is a problem that has been persisting for decades now. Providing a step towards a solution is the German guideline VDI 2736, which proposes design rating methods (Ref. 2) along with testing procedures (Ref. 3) to be followed to generate reliable data required in the gear rating process. This paper delves into the current state of the art in plastic gear testing, providing a comprehensive overview of employed testing methods, supplemented with case studies.

EVENT | 2024-04-03

Rapid + TCT 2024

For more than 30 years, RAPID + TCT has defined the crucial role of additive manufacturing and industrial 3D printing by empowering the establishment of an industry that continues to conceive, test, improve and manufacture new products at a faster, more cost-efficient pace. SME and Rapid News Publications team up to produce the annual RAPID + TCT event. which will take place June 25-27 in Los Angeles, CA.

EVENT | 2024-03-13

AISTech 2024

With 100+ technical sessions and more than 300+ individual presentations, AISTech attendees can plan their day around the conference schedule and learn about the latest products and processes happening in every aspect of the steelmaking process. Sessions include safety/health, environmental technology, cokemaking, ironmaking, sheet rolling, metallurgy, MRO, lubrication, material handling and more. Join this steel industry event in Columbus, OH from May 6-9, 2024, at the Greater Columbus Convention Center.

INDUSTRY NEWS | 2024-01-08

Frenco Offers Material Upgrade on INO-System Spline Gages

Euro-Tech Corporation in cooperation with Frenco, the precision specialist in gear & spline metrology, is offering a Free Material Upgrade for quotes between now and March 31, 2024.

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EVENT | 2023-09-15

Advanced Engineering 2024

Advanced Engineering (Birmingham) has rebranded to celebrate the evolution and new developments in the industrial manufacturing. Sectors include aerospace, automotive, defense, composites, marine, rail, energy, medical and more. To ensure that visitors and exhibitors can still easily find relevant contacts, Advanced Engineering exhibitors will now be categorized by the services, products and solutions offered. They will have the opportunity to highlight all of the sectors they work in, removing any limitations created by the specific show zones. Advanced Engineering will welcome back a full speaker program with representatives from some of the leading companies in UK manufacturing including GE, Shell, ZF, Bosch, Siemens, 3M, IBM, Airbus and more. 

EVENT | 2023-05-12

Formnext Forum Austin

Formnext Forum: Austin is the first in a series of events to drive industrial 3D printing innovation and growth in the Americas. Hosted in one of the world's most tech-forward manufacturing communities, Formnext Forum: Austin, will connect leaders from across the industrial additive manufacturing supply chain. 

EVENT | 2023-04-11

PowderMet 2024

The leading technical conference on powder metallurgy and particulate materials in the Americas, PowderMet 2024 is a hub for technology transfer for professionals from every part of the industry, including buyers and specifiers of metal powders, tooling and more!

EVENT | 2023-03-23

Automate 2023

Between intimate workshops, news making keynotes, networking events, innovation competitions and live demonstrations, Automate offers comprehensive automation education and cutting-edge robotics, vision, AI, motion control and other technologies. Automate delivers the latest innovations in manufacturing automation technology from more than 600 leading exhibitors. 

EVENT | 2023-02-16

2023 STLE Tribology Frontiers Conference and Tribology and Lubrication for E-Mobility Conference

The 2023 STLE Tribology Frontiers Conference (TFC) will be held November 12-14. The event will allow attendees to engage with world-renowned industry, academic and government researchers to learn more about the technical, environmental and social issues impacting tribology research in the 21st Century. The deadline for TFC abstract submissions is April 15, 2023, but the website will remain open after this date for wait-listed submissions and posters.

EVENT | 2023-01-18

Nextlub 2023

Lubricants and tribological systems are undergoing rapid change. The challenges and uncertainties are enormous. Ecological challenges such as the de-carbonization of industry, mobility and society on the one hand, economic challenges such as the resilience of global supply chains on the other, are changing the way lubricants and tribological systems will be developed, validated, produced and applied in the future.

VIDEO | 2022-12-15

Maintaining a Furnace's Heat Exchanger with Ipsen

If you are experiencing reduced cooling, increased cycle times and/or dirty, contaminated parts then your vacuum furnace's heat exchanger might be the cause.  Over the course of time and production, materials will deposit on the fins of the heat exchanger, which can result in a number of issues. In this video, we examine what a heat exchanger is supposed to look like vs. what it looks like after it has collected layers of contaminants. We also discuss how often the heat exchanger, and its cooling coils should be inspected so as to ensure optimum performance and part quality.

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INDUSTRY NEWS | 2022-11-21

Sandvik Coromant Appoints Nick Falgiatano as Marketing Manager, Sales Area Americas

As of Dec. 1, U.S. Central Regional Sales Manager Nick Falgiatano will be the new marketing manager, Sales Area Americas, for Sandvik Coromant. In his new role, Falgiatano will be accountable for establishing and reaching the strategic objectives of Sales Area Americas.

VIDEO | 2022-09-23

Star SU/Neher PCD 3D Printed Tools

Large tools are often required for the machining of powertrain aluminum prismatic parts, including stator housings and additional components for the growing electric motors market. The weight of these tools can prove problematic with traditional machining equipment, which can cause excessive spindle vibration and noise, poor tool life and potentially scrapped components.  Full control of the tool coolant channels for optimization in both wet and MQL applications.

EVENT | 2022-09-22

Formnext 2022

Formnext (Frankfurt, Germany) is more than an exhibition and conference. It’s an entire platform for companies from the world of additive manufacturing. Here, a veritable who’s who from the realms of design and product development, industrial tooling, production solutions, quality management, and measurement technology comes together with leading providers in basic materials and component construction.

INDUSTRY NEWS | 2022-09-01

Hyperion to Showcase New Materials and Services at IMTS 2022

Hyperion Materials & Technologies manufactures hard and super-hard materials for a wide variety of industries and applications, including cemented carbide blanks for gear cutting and hobbing. Hyperion will showcase its gear tool blanks and many other products and manufacturing solutions at IMTS 2022, Sept. 12 to 17 in Chicago.

INDUSTRY NEWS | 2022-08-29

Desktop Metal's Shop System Running in SolidCAM's Suhl Technology Center

The Desktop Metal Shop System started printing metal parts at the SolidCAM’s Suhl Technology Center in Germany.

INDUSTRY NEWS | 2022-08-17

Sandvik Coromant Wins Best Plant Award

Sandvik Coromant, has earned the 2022 IndustryWeek Best Plants Award for its Westminster, South Carolina, production site. The award is given to North American manufacturing plants that lead their industries in outstanding operational excellence, customer service and employee engagement.

INDUSTRY NEWS | 2022-08-09

Liebherr Mining Expands in Australia

Liebherr-Australia has announced the expansion of their Perth mining facility, which will strengthen the company’s ability to deliver accelerated zero emission solutions to the wider market. Liebherr-Australia’s growing involvement in the development and implementation of zero emission technology with Australian customers illustrates the necessity for this investment in infrastructure and signifies Liebherr’s commitment to these industry-leading projects.

INDUSTRY NEWS | 2022-08-08

Kennametal Expands Beyond Evolution Platform

Kennametal has introduced the new Grooving Universal Positive Profiling geometry (GUP-V), expanding on its Beyond Evolution grooving & cut-off platform. With the addition of the new V-shaped single-sided insert, Beyond Evolution can cover now more applications than ever and helps to save tooling cost.

INDUSTRY NEWS | 2022-07-12

AddUp Partners with ECM Group for Additive Heat Treating Solutions

AddUp, a major player in the field of metal additive manufacturing and the ECM Group, creator of innovative thermal solutions, have signed a partnership to develop high value-added solutions for the thermal treatment of 3D printed metal parts.

INDUSTRY NEWS | 2022-07-01

Sandvik Coromant Offers Productivity Improvement Program

Sandvik Coromant offers its CoroPlus Productivity Improvement Program to provide in-depth analysis of the production cell.

INDUSTRY NEWS | 2022-06-29

TCI Precision Metals Offers Machine-Ready Blanks at IMTS 2022

TCI Precision Metals will be showing its precision Machine-Ready Blanks capabilities to customers at IMTS 2022, McCormick Place, Chicago, IL, September 12-17, 2022, West Building, Booth #432123. 

INDUSTRY NEWS | 2022-06-16

Norton Highlights Xtrimium Gear Grinding Wheels at IMTS 2022

At IMTS 2022, Norton ׀ Saint-Gobain Abrasives (Booth #237042, North Hall) will offer a portfolio of gear grinding products specifically designed by category to provide higher profile accuracy, supreme form holding and burn-free grinding in worm, profile, and bevel applications. Highlighting the range is an innovative dual-worm wheel design that enables two operations in one grinding wheel, substantially saving time and cost. 

INDUSTRY NEWS | 2022-06-14

Ceratizit Doubles Eastern Territory Support Staff

With the recent addition of three new sales engineers and an application specialist, Ceratizit USA has doubled the size of its Eastern Territory sales and support team. In doing so, the company further improves response time and provides added expertise for its customers’ custom tooling challenges.

EVENT | 2022-06-01

Addit3D

Addit3D-International Additive Manufacturing and 3D Fair (Barakaldo, Spain) will feature almost 230 products, services and innovations. Exhibitors include advanced systems and machinery and 3D printing, equipment and printers, industrial applications, raw materials, consumables, 3D printing services, software, 3D scanners, and R&D and training

INDUSTRY NEWS | 2022-05-17

Sandvik Coromant appoints two new members to its management team

Sandvik Coromant has appointed two new members to its management group. Michael Eneberg began his new role as vice president and head of global sales on May 1, 2022, while Nicolas Dellachiesa will join as head of merger and acquisitions (M&A) in June. Reporting to Sandvik Coromant President, Helen Blomqvist, both Eneberg and Dellachiesa will play vital roles in driving the company’s global growth forward.

INDUSTRY NEWS | 2022-05-16

Seco Supports Medical Innovation With Virtual Event and Exclusive Content

Seco and its technical partners will host the company’s second Medical Inspiration Through Innovation (ITI) virtual event on Wednesday, May 18, 2022, in German and on Wednesday, June 22, 2022, in English and Mandarin. 

INDUSTRY NEWS | 2022-05-12

Rego-Fix Offers New and Expanded Product Lines at IMTS 2022

At IMTS 2022 in Booth #431822, Rego-Fix will showcase innovations that extend the company's Swiss precision beyond toolholding. Featured technologies include the 3D-EdgeMaster measuring device and MasterBar test arbors – two new product entries for setup and test measurement.

EVENT | 2022-05-05

International Forging Congress 2022

The International Forging Congress (IFC) is a global event that brings together key players from the international forging community to exchange information and experiences. IFC features forging industry technical and business-oriented presentations. In addition, exhibitors display their forging-related products and services to IFC attendees.

PRODUCT NEWS | 2022-05-03

Jorgensen Total Chip Processing Boosts Recycle Value

As a result of its recent partnership with S.F.H., Jorgensen Conveyor and Filtration Solutions now serves manufacturers as a single source for total metalworking chip and coolant processing systems. With standalone or fully integrated systems that transport, shred, wring and briquette chips and sludge, manufacturers can reduce chip volumes by as much as 90% and significantly increase their chip recycling value. 

INDUSTRY NEWS | 2022-04-22

Sandvik Coromant Examines Shift to Electric Vehicles

The transition to EVs will lower transport emissions, and adoption can be accelerated by increasing their efficiency. EVs that take advantage of aluminum components can travel further per charge, helping to overcome range anxiety. Automotive manufacturers who select machining tools optimized for aluminum will be able to produce high-quality aluminum EV components ― helping to support the shift to greener travel.

PRODUCT NEWS | 2022-04-22

Seco Milling Cutters Reduce Tooling Inventory Costs

Manufacturers who look for versatility and precision in machining can pair up Seco Turbo 16 square shoulder milling cutters and Helical Turbo 16 milling cutters to reduce tooling inventories and costs. Both series offer high material removal rates in steel, stainless steel, cast iron, non-ferrous metals, superalloys and titanium. 

INDUSTRY NEWS | 2022-04-20

Weiler Introduces Full Line of Foundry Abrasives

Weiler Abrasives has announced the availability of its Tiger abrasives line designed to deliver maximum performance in the most demanding foundry applications. With solutions to address all grinding applications in the cleaning room, Tiger products help decrease cycle times and improve operator experience. 

INDUSTRY NEWS | 2022-04-18

Ingersoll Introduces NanoFeed Technology

Ingersoll’s New NanoFeed technology provides exceptional hi-feed milling performance for machining of miniature components & smaller part features.

INDUSTRY NEWS | 2022-04-14

Karl M. Weiler Receives Lifetime Achievement Award

Weiler Abrasives is pleased to announce that Karl M. Weiler, former president, has received the John J. Buckley Lifetime Achievement Award from the Industrial Supply Association (ISA). 

EVENT | 2022-04-13

AGMA Gearbox Systems Design

This course focuses the supporting elements of a gearbox that allow gears and bearings to do their jobs most efficiently. Learn about seals, lubrication, lubricants, housings, breathers, and other details that go into designing gearbox systems.

EVENT | 2022-04-13

AGMA Gear Heat Treatment Operator/Operations

This course provides the heat treat operator and operations team, the means to perform the heat treatment of steel gears in a manner that meets the AGMA and customer requirements in a safe and efficient manner. 

PRODUCT NEWS | 2022-02-09

Allegheny Performance Plastics, Solvay and GETEC Partner on Transmission Gear Conversion

Allegheny Performance Plastics recently teamed up with GETEC Getriebe Technik GmbH, and Solvay, to explore the possibility of replacing a...
INDUSTRY NEWS | 2021-06-11

Buehler Offers Etching and Microstructures of Titanium Alloys Webinar

Buehler is offering an educational webinar on Etching and Microstructure Analysis of Titanium Alloys on, June 30, 2021 at 12:00 pm CST. T...
INDUSTRY NEWS | 2021-05-06

NASA's Lubrication-Free Precision Gear Technology Brought to Earth

Bulk Metallic Glass (BMG) is the next generation of alloys for precision gears. In this webinar, Amorphology provides a rare glimpse into the specialized world of BMG (aka amorphous metal) development for terrestrial applications - focusing on precision gears and complex metal components.
INDUSTRY NEWS | 2021-03-22

Helios Offers Hobbing Solutions for Plastic Gears

External plastic gears, like their metal counterparts, use the hobbing process for productive manufacturing. However, the difference in m...
INDUSTRY NEWS | 2021-03-01

Industry News

The latest news from AGMA, EMAG Group, Star Cutter, MHI and more.
TECHNICAL ARTICLES | 2021-03-01

Case Study of ISO/TS 6336-22 Micropitting Calculation

Micropitting per ISO standard explained.
INDUSTRY NEWS | 2021-02-22

Fatigue Strength and Service Calculation of Gears

Bevel gear design is well-established. Flank geometry optimization is used worldwide to ensure satisfactory low-noise emis...

INDUSTRY NEWS | 2021-02-11

KISSsoft Examines Plastic Gears and Tooth Form Aspects

With injection molded plastic gears, the designer has a great degree of freedom in defining the tooth form because it is not the result o...
GEAR TALK WITH CHUCK | 2020-11-24

Next Step

Once you have an idea what your device will look like, the urge to start designing is strong. Before you start calculating gear ratings, however, t...
GEAR TALK WITH CHUCK | 2020-11-04

Facing Down Contact Ratio

Before we move on from helix angle restrictions, I want to say a few things about face contact ratio. Soon after the appearance of the first helica...
GEAR TALK WITH CHUCK | 2020-10-14

Closing the Gap

We left the gear tribe arguing over how to solve the problems that were cropping up with the new-fangled double helical or herringbone designs. Fas...
GEAR TALK WITH CHUCK | 2020-08-26

Finding Good Candidates

Once you commit to developing the talented team members your business needs, how do you decide who to invest in? The “washout rate” at professional...
GEAR TALK WITH CHUCK | 2020-08-01

IMTS Future Tech

The Digital Manufacturing Revolution Evolves in 2020 IMTS will offer two comprehensive digital programs, IMTS Network and IMTS Sp...

TECHNICAL ARTICLES | 2020-08-01

Gear Blank Tuning

The design of gear blanks or flanges has traditionally been driven by weight reduction. Recently innovative companies have started to use the gear blank design to tune the system dynamics to reduce gear whine.
GEAR TALK WITH CHUCK | 2020-07-29

Are You Experienced?

Few of you are old enough to know why today’s title resonates with us old timers. Back in 1969, long before the kneeling protests, Jimi Hendrix peg...
GEAR TALK WITH CHUCK | 2020-07-24

Help Wanted

Northwest Pennsylvania’s Oil Region has a long history in manufacturing. Many of the widgets that made oil extraction and processing possible were ...
INDUSTRY NEWS | 2020-07-15

Norton Offers Grinding Solution for Ductile and Grey Cast Iron Applications

Norton Winter Ironclad Superabrasive Foundry Wheels offer a solution for ductile and grey cast iron applications such as fettling and sna...
FEATURE ARTICLES | 2020-07-01

Supply Chain Management Users Guide

We asked a few industry suppliers to provide some insight into gear manufacturers' supply chain challenges during the pandemic.
FEATURE ARTICLES | 2020-07-01

Gear Blanking Gets Bigger at Forest City Gear

Forest City Gear is doubling down on its strategy to produce most of its critical gear blanks in-house by adding new capacity, and capabilities, to its state-of-the-art 8,500 sq. ft. precision gear blanking facility.
TECHNICAL ARTICLES | 2020-06-01

Quantitative Residual Stress Measurements for Improved Quality Control and Process Optimization in Gears and Additively Manufactured Components

In this article, the focus is put on one technology, X-ray diffraction (XRD), and more specifically, residual stress measurement by way of XRD for both process development and quality control.
INDUSTRY NEWS | 2020-05-26

GWJ Technology Offers Detailed Online Calculation of Plastic Gears

GWJ Technology has updated its web-based calculation software eAssistant. The calculation of plastic gears is now available.In addition t...
GEAR TALK WITH CHUCK | 2020-05-13

Visiting Old Friends

Seven weeks into the lockdown, we are all looking for “new content.” Even with a full cable “package” there are times when it seems there is nothin...
TECHNICAL ARTICLES | 2020-05-01

Optimal Polymer Gear Design: Metal-to-Plastic Conversion

Nowadays, the progress in polymer materials and injection molding processing has enabled a drastic expansion of plastic gear applications. They are used not only for lightly loaded motion transmissions, but also in moderately loaded power drives in automotive, agriculture, medical, robotics, and many other industries.
GEAR TALK WITH CHUCK | 2020-02-26

After Further Review

Unless it is your team being robbed, you probably hate having a live broadcast interrupted by a video review. We sometimes feel this way during a d...
INDUSTRY NEWS | 2020-02-11

Stagnoli Offers Plastic Gearing for High Performance Applications

The request for higher performance solutions intensifies metal replacement activity in many fields like automotive, medical, aerospace,...
GEAR TALK WITH CHUCK | 2019-11-21

We Can Help You Help Yourself

Do you want to know a secret about every one of our authors? At one point in their lives they decided to step out of their comfort zone and write s...
TECHNICAL ARTICLES | 2019-11-01

A Comparative Study of Polymer Gears Made of Five Materials

The wear behavior of polymer gears made of five different materials has been investigated using an existing polymer gear test rig. Step loading tests at a constant speed of 1,000 rpm were performed. Significant differences in failure modes and performance have been observed for the five polymer gear materials for gear engagements of gears, with the same material as each other.
GEAR TALK WITH CHUCK | 2019-10-10

That Blank Sheet of Paper

Does nature hate a vacuum more than a designer hates a blank sheet of paper? We will never know for sure because nature is too busy to write a blog...
GEAR TALK WITH CHUCK | 2019-10-01

The Things You Learn Along the Way

Long time readers of this blog know that my “gear career” has included plenty of non-gear-related assignments. Of course, if you are a deeply entre...
GEAR TALK WITH CHUCK | 2019-08-29

Appreciating the Gory Details

Big equipment often requires special processing equipment. Those 300-ton locomotives used unique heat treatment on the gears which required the des...
GEAR TALK WITH CHUCK | 2019-08-22

Situational Ethics

Recalling Solidarity protests while watching the Hong Kong Airport occupation reminds me that change is messy. As much as we Americans would like t...
GEAR TALK WITH CHUCK | 2019-08-15

A Global Gear Community

Roman Cisek’s journey from Poland to the United States is an example of how the gear trade has become one big international community. A few weeks ...
GEAR TALK WITH CHUCK | 2019-08-13

Gear Origins: Roman Cisek

I was lucky to get a job as a design engineer – drive train department with a big construction equipment manufacturer (HSW) in Poland, right after ...
FEATURE ARTICLES | 2019-08-01

Taking the Wait Out of High Quality Gear Blanks

Forest City Gear makes the investment to bring gear blanking in-house, giving it complete control over quality and delivery: because failure’s not an option.
GEAR TALK WITH CHUCK | 2019-07-18

Science Experiments

More than once, I got in trouble with management over o...
FEATURE ARTICLES | 2019-07-01

The Measure of a Gear

Plastic gears still have an entire frontier to explore, and how they measure up against their steel cousins is a question still being investigated.
TECHNICAL ARTICLES | 2019-07-01

Bevel Gear Blank Drawing Procedure

With this first installment we begin a series of randomly excerpted chapters from Dr. Hermann J. Stadtfeld's new book — Practical Gear Engineering.
TECHNICAL ARTICLES | 2019-07-01

Experimental and Numerical Study of a Loaded Cylindrical Glass Fiber-Reinforced PA6 Gear

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
GEAR TALK WITH CHUCK | 2019-05-24

Finding the Limits

Jim Richard’s account of his journey from youthful experimenter to designer of cutting edge gear processing equipment illustrates the amazing thing...
GEAR TALK WITH CHUCK | 2019-03-21

My Story: Ernie Reiter

In the last semester of my senior year of mechanical engineering, I recall having a discussion with my study group friends about the purpose of our...
TECHNICAL ARTICLES | 2019-03-01

Experimental Study on the Pitting Detection Capabilities for Spur Gears Using Acoustic Emission and Vibration Analysis Methods

An experimental investigation on spur gears to characterize pitting degradation process using monitoring features.
TECHNICAL ARTICLES | 2019-03-01

New Consideration of Non-Metallic Inclusions Calculating Local Tooth Root Load Carrying Capacity of High-Strength, High-Quality Steel Gears

The effects of non-metallic inclusions in steel matrix on tooth root strength based on theoretical approach of Murakami.
GEAR TALK WITH CHUCK | 2019-02-28

Gone but Not Forgotten

Continuing our discussion of veteran machine tools, it occurs to me that many of our younger readers may not be aware that the United States was on...
GEAR TALK WITH CHUCK | 2019-01-30

From Co-op to Vice President: Octave A. LaBath

I was attending the University of Cincinnati in the college of engineering. After my freshman year in 1960, I started my co-op job with the Cincinn...
GEAR TALK WITH CHUCK | 2019-01-18

Lessons Learned the Hard Way

Chris’ account of p...
GEAR TALK WITH CHUCK | 2018-11-06

Permanent Records

Avoiding corpo...
FEATURE ARTICLES | 2018-11-01

Admire its Purity

As gear manufacturing techniques become more precise and demanding, there is a growing demand for cleaner, higher quality steel.
GEAR TALK WITH CHUCK | 2018-10-09

Where to Next?

We have devoted this year to going over fundamentals of gear and gearbox design and manufacture. Before we move on to other topics, I would like to...
GEAR TALK WITH CHUCK | 2018-10-04

Repairing Gears

Deadlines and budgets do not always allow for “first class” gearbox rebuilds. The challenge for rebuild shops is to find the fastest and most econo...
GEAR TALK WITH CHUCK | 2018-10-02

Necessity as the Mother of Invention

When you offer rebuilding service...
GEAR TALK WITH CHUCK | 2018-09-27

Acceptable Fixes

You do not always have to say “no” when confronted with non-conforming parts. Here are a few “fixes” I have been comfortable authorizing:

INDUSTRY NEWS | 2018-09-26

KISSsoft Offers 55 Plastics for Sizing Gears

Nowadays, gear units are increasingly being made out of different types of plastic. In many cases, this class of materials is a good alte...
GEAR TALK WITH CHUCK | 2018-09-25

Reworking Questions

The most important consideration in deciding whether to rework or scrap and re-make a nonconforming part is functionality. Can the part be made to ...
GEAR TALK WITH CHUCK | 2018-09-20

Frequently Asked Questions

Backlash “adju...
GEAR TALK WITH CHUCK | 2018-09-13

Custom Work: Nonconforming Realities

In the world of custom manufacturing you have to deal with less-than-perfect parts. There is just not enough time or pieces to dial in the producti...
GEAR TALK WITH CHUCK | 2018-09-07

Something is not Right Here

Another benefi...
ASK THE EXPERT | 2018-09-01

Lubrication: Viscosity and Macropitting

A reader asks: Is the ISO VG 320 adequate, or should a higher viscosity grade be used? How can we stop macropitting in gear teeth?
GEAR TALK WITH CHUCK | 2018-08-28

Gear Design: More Than Pretty Pictures

No one has a drafti...
INDUSTRY NEWS | 2018-08-15

IMTS 2018: A Field Guide

Chicago Preps for the Next Manufacturing Technology Extravaganza Matthew Jaster, Senior Editor
INDUSTRY NEWS | 2018-08-13

International Gear Conference 2018

Lyon, France. Mechanical transmission components such as gears, rolling element bearings, CVTs, belts, chains, etc. are present in every industrial...
TECHNICAL ARTICLES | 2018-08-01

Influences of the Residual Stress Condition on the Load-Carrying Capacity of Case-Hardened Gears

Highly loaded gears are usually casehardened to fulfill the high demands on the load-carrying capacity. Several factors, such as material, heat treatment, or macro and micro geometry, can influence the load-carrying capacity. Furthermore, the residual stress condition also significantly influences load-carrying capacity. The residual stress state results from heat treatment and can be further modified by manufacturing processes post heat treatment, e.g. grinding or shot peening.
GEAR TALK WITH CHUCK | 2018-07-05

Planetary Drives: The Same but Different

Those ancient planetary drives I first got involved with in 1979 (
GEAR TALK WITH CHUCK | 2018-07-03

Planetary Gears: Inside Information

The Story So Far

FEATURE ARTICLES | 2018-07-01

Plastic Gear Design Remains a Work in Progress

Despite the development and availability of a number of newly engineered, rugged materials intended for plastic gear applications, some engineers/designers continue to believe metal is better.
GEAR TALK WITH CHUCK | 2018-06-28

Suns and Planets

The first planetary drive I helped take apart had three stages of through hardened spur gears encased in a simple cast iron tube with plates on both ends. Both input and output shafts rotated on taper roller bearings, but everything else had simple bronze bushings.
GEAR TALK WITH CHUCK | 2018-06-26

Planetary Gearboxes: A Wheel Inside a Wheel

We will never ...
GEAR TALK WITH CHUCK | 2018-06-20

Gear Materials: You Don’t Know What You Don’t Know

Before we leave our study of materials, I want to share a few thoughts on heat treating, lab tests, and hardness testing. When you start working wi...
GEAR TALK WITH CHUCK | 2018-06-12

Can We Use This Instead?

Right up there with the dreaded “blank sheet of paper” is the inevitable question of “Can we use this instead?” It came as a real shock to me the f...
GEAR TALK WITH CHUCK | 2018-05-29

Read the Label Carefully

So, what exactly do we mean when we say “use good material” for your gears? Once again, the answer is “it depends.” Even the “best” steel may be wr...
GEAR TALK WITH CHUCK | 2018-05-24

The Right Stuff

Even the most brilliant gear design will fail if the wrong material is used to make the parts. Our understanding of metallurgy and alloying element...
GEAR TALK WITH CHUCK | 2018-05-03

That X Factor

Our international readers are no doubt chuckling over this silly, American “long addendum” terminology. The “civilized world” has long relied on a ...
GEAR TALK WITH CHUCK | 2018-04-12

Moderation Instead of Modification

Few designers would feel comfortable with a face to pinion pitch diameter ratio of 2.00 anymore. Some still prefer to select face width by face con...
GEAR TALK WITH CHUCK | 2018-04-03

How Much Helix Angle?

The most obvious difference between a spur gear and a helical gear is the presence of that “helix” angle. Civilians will call them “straight-cut” a...
GEAR TALK WITH CHUCK | 2018-03-22

Worm Basics - Part 2

Continuing our discussion of the “least you need to know” about worm gearing: 5. Efficiency is highly variable for worms. If it is critical to y...
GEAR TALK WITH CHUCK | 2018-03-15

What About Worms?

It is difficult to know where to start when writing about worm gears, because this market segment has defied “standardization” within the United St...
GEAR TALK WITH CHUCK | 2018-03-13

Bevel Buzzwords

Does technical lingo confuse you? If so, welcome to the bevel gear sector and its special kind of hell. The same “system” that benefited from stand...
TECHNICAL ARTICLES | 2018-03-01

Effect of Non-Metallic Inclusions on Bending Fatigue Performance in High Strength 4140 Steel

Three samples of quenched and tempered 4140 steel, with varying levels of oxygen and sulfur, were submitted to a series of bending fatigue tests.
INDUSTRY NEWS | 2018-02-12

IIoT Spotlight: The Job Shop

As IIoT solutions become more readily available throughout the manufacturing sector, challenges continue when you start looking specifically at the...
TECHNICAL ARTICLES | 2018-01-01

Globalization's Effect Upon Gear Steel Quality

Background on the development of a high-speed, automatic hardness tester for gear steels.
INDUSTRY NEWS | 2017-12-06

KISSsoft Adds Plastic Materials Manager Function

It is often the case that plastics manufacturers don't provide any data that is relevant for calculations when they supply their prod...
GEAR TALK WITH CHUCK | 2017-11-21

Where Have All the Pumpjacks Gone?

The last stronghold for herringbones was — and remains — the venerable oil field pumpjack gearbox. Although known by a variety of other names, noth...
GEAR TALK WITH CHUCK | 2017-11-02

Swag of the Expo Awards

My last blog covered the motivation for the Swag of the Expo award and my inspiration in creating it. Top contenders that did not quite qualify for...
FEATURE ARTICLES | 2017-11-01

Material Assets

You get one shot to make a first impression. One opportunity to show your customers, vendors and suppliers that you provide a steady, reliable product that will generate repeat business. How do you make this happen? What tools and strategies are available to get gear materials (forgings, gear blanks, etc.) shipped faster and more efficiently in today's tech-heavy, fast-paced, manufacturing environment?
FEATURE ARTICLES | 2017-11-01

Cleaner Steels Provide Gear Design Opportunities

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.
TECHNICAL ARTICLES | 2017-11-01

Influence of the Defect Size on the Tooth Root Load Carrying Capacity

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.
GEAR TALK WITH CHUCK | 2017-10-12

Thinking Big

My local newspaper’s lead story today concerned the explosive demolition of a highway bridge in nearby Tionesta, PA. As luck would have it, our mos...
GEAR TALK WITH CHUCK | 2017-10-03

Education vs. Training

Buried deep within the never ending debate on job growth is a fundamental misunderstanding on the difference between education and training. I am a...
GEAR TALK WITH CHUCK | 2017-09-12

Mini Disasters

My last blog highlighted the need for disaster planning. With three hurricanes churning up the Atlantic Ocean as I write, that advice may be a l...
FEATURE ARTICLES | 2017-09-01

Gear Expo 2017 and ASM Heat Treat 2017 Booth Previews

The latest technology on display in Columbus, OH. October 24-26.
TECHNICAL ARTICLES | 2017-09-01

Tooth Contact Analysis - Off Line of Action Contact and Polymer Gears

The aim of the study was to apply such a specialized tooth contact analysis method, well-used within the steel gear community, to a polymer gear application to assess what modifications need be made to these models for them to be applicable to polymer gears.
GEAR TALK WITH CHUCK | 2017-08-01

Failure as Tourist

Civil or transport engineering failures are very public. They tend to get investigated far more thoroughly than typical mechanical engineering prob...
GEAR TALK WITH CHUCK | 2017-07-28

A New Quoting Model?

Anyone actually enjoy quoting? For such an important part of daily business the process of establishing prices to offer a customer seems universall...
GEAR TALK WITH CHUCK | 2017-05-18

Summer Jobs

Recent reports indicate that business is picking up in the gear sector so I hope your firm is thinking about bringing on some summer help. The curr...
FEATURE ARTICLES | 2017-05-01

Upgrading Your Toolbox

Manufacturers focus on tool design, materials, coating, machine tool options and cutting parameters.
TECHNICAL ARTICLES | 2017-05-01

Inclusion-Based Bending Strength Calculation of Gears

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.
GEAR TALK WITH CHUCK | 2017-04-04

What Makes a Good Design?

In my last post I insisted that good design wins in the marketplace. As a student of automotive history, I am compelled to admit that some very gre...
GEAR TALK WITH CHUCK | 2017-01-19

Gears That Time Forgot

My consulting practice covers a very wide range of products — from 4-inch circular pitch mill stands to 180-NDP handheld medical devices — I see th...
GEAR TALK WITH CHUCK | 2017-01-12

The Essential Gear Book?

Continuing our discussion of gear training…   What one book would you advise a newbie to purchase, read, and keep handy in the years ahe...
GEAR TALK WITH CHUCK | 2017-01-10

Language Barrier

I have great admiration for people who can speak multiple languages, a skill that had eluded me despite two fairly serious efforts to learn a secon...
TECHNICAL ARTICLES | 2017-01-01

Repair of Large, Surface-Degraded Industrial Gears - a New Approach

This paper presents a new approach to repair industrial gears by showing a case study where pressure angle modification is also considered, differently from the past repairing procedures that dealt only with the modification of the profile shift coefficient. A computer program has been developed to automatically determine the repair alternatives under two goals: minimize the stock removal or maximize gear tooth strength.
TECHNICAL ARTICLES | 2016-09-01

Increased Tooth Bending Strength and Pitting Load Capacity of Fine-Module Gears

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.
GEAR TALK WITH CHUCK | 2016-08-25

Gear Toys

My recent blog on educating kids on gears coincided with a birthday party invitation for a great nephew. Not having grandchildren of our own — I da...
INDUSTRY NEWS | 2016-08-17

KISSsoft VDI 2736 Receives New Supplement for Calculating Plastic Crossed Helical Gear Deformation and Wear

The application area of plastic gears has grown significantly in the last decade. The requirements from the industry to design stronger, ...
GEAR TALK WITH CHUCK | 2016-08-11

Reboots

  A commercial touting the reboot of MacGyver just appeared on my office TV screen and I recall with fondness its tales of improvi...
TECHNICAL ARTICLES | 2016-08-01

Transient EHL Analysis of Helical Gears

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.
INDUSTRY NEWS | 2016-07-20

Covering All Angles

Klingelnberg Hosts 6th WZL Gear Conference in the USA 2016  Matthew Jaster, Senior Editor ...
TECHNICAL ARTICLES | 2016-07-01

Improved Broaching Steel Technology

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. 1–2). 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.
GEAR TALK WITH CHUCK | 2016-06-23

Revisiting the Bad Old Days

  Unless you are involved with rebuilding old equipment, it may be entirely possible to never see a tooth flank with “progressive pitting.”...
TECHNICAL ARTICLES | 2016-06-01

Worm Gear Efficiency Estimation and Optimization

This paper outlines the comparison of efficiencies for worm gearboxes with a center distance ranging from 28 - 150 mm that have single reduction from 5 to 100:1. Efficiencies are calculated using several standards (AGMA, ISO, DIN, BS) or by methods defined in other bibliographic references. It also deals with the measurement of torque and temperature on a test rig — required for the calibration of an analytical model to predict worm gearbox efficiency and temperature. And finally, there are examples of experimental activity (wear and friction measurements on a blockon- ring tribometer and the measurements of dynamic viscosity) regarding the effort of improving the efficiency for worm gear drivers by adding nanoparticles of fullerene shape to standard PEG lubricant
GEAR TALK WITH CHUCK | 2016-03-15

The Curse of an Engineering Mind

There have been a few times in my life when I wished I could turn off my internal engineer and just be a regular guy. If you ask my wife she could ...
INDUSTRY NEWS | 2016-03-02

McInnes Rolled Rings Completes Heat Treat Expansion

McInnes Rolled Rings has completed an $8 million, 25,000-square-foot expansion to its current manufacturing facility. The addition expand...
INDUSTRY NEWS | 2016-03-01

Industry News

News from around the Gear Industry
VOICES | 2016-03-01

Critique of the ISO 15144-1 Method to Predict the Risk of Micropitting

There exists an ongoing, urgent need for a rating method to assess micropitting risk, as AGMA considers it a "a very significant failure mode for rolling element bearings and gear teeth - especially in gearbox applications such as wind turbines."
FEATURE ARTICLES | 2016-03-01

Plastic Gearing Continues Converting the Unconverted

Plastic gears are everywhere today - throughout your car, at the oceans' lowest depths, in deep space. The question, when is a metal gear a candidate for plastic conversion, can be addressed in three words, i.e. what's the application?
GEAR TALK WITH CHUCK | 2016-02-16

Cold Weather Designs

    Growing up in Milwaukee I learned about cold weather early and got a refresher course every winter. These lessons served me wel...
GEAR TALK WITH CHUCK | 2016-02-09

Discovering Gears

Recently, an attorney told me that his eleven-year-old daughter had “discovered” gears in a science class and was excitedly learning all she could ...
INDUSTRY NEWS | 2016-01-25

Bodycote Launches Interactive History of Metallurgy

Bodycote, announces the launch of their Interactive History of Metallurgy after taking a look back at the long history of metal processin...
GEAR TALK WITH CHUCK | 2015-10-22

3-D Printing Follow-Up

My initial skepticism about 3-D printing’s place in the gear industry took a solid hit during a recent visit to a client. I am used to seeing color...
GEAR TALK WITH CHUCK | 2015-10-08

Old School Technology Boosts High Technology

A popular cable car customizing show recently featured a segment on using 3-D printing to produce a prototype part. There wasn’t anything original ...
GEAR TALK WITH CHUCK | 2015-09-03

When Good Employees Screw Up

A friend of mine is the inspection department for a custom machine shop. He is also the process engineer and, occasionally, a machine operator. Rec...
TECHNICAL ARTICLES | 2015-08-01

Gear Noise Prediction in Automotive Transmissions

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.
GEAR TALK WITH CHUCK | 2015-07-30

New Ways to Make Old Parts

My last post discussed reviewing the ratings and designs of “legacy products,” those venerable parts and gearboxes still being ordered twenty, thir...
INDUSTRY NEWS | 2015-06-30

Gleason Renames its Plastic Gears Division

Gleason Corporation recently announced a new name for its plastic gears division: Gleason Plastic Gears. The division was formerly k...
GEAR TALK WITH CHUCK | 2015-06-02

Areas of Expertise

One of the first things you hear upon becoming a parent is that “children keep you young.” Once, I foolishly thought this referred to your physical...
TECHNICAL ARTICLES | 2015-06-01

Optimal Modifications on Helical Gears for Good Load Distribution and Minimal Wear

Helical gear teeth are affected by cratering wear — particularly in the regions of low oil film thicknesses, high flank pressures and high sliding speeds. The greatest wear occurs on the pinion — in the area of negative specific sliding. Here the tooth tip radius of the driven gear makes contact with the flank of the driving gear with maximum sliding speed and pressure.
GEAR TALK WITH CHUCK | 2015-04-02

Evolving Equipment

[starbox]How long should gear manufacturing equipment last? I posted before about some very “veteran” gear cutting machines that are still earning ...
FEATURE ARTICLES | 2015-03-01

Solving the Forgings Paradox

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.
ASK THE EXPERT | 2015-03-01

Measuring Residual Stress in Gears

I have heard that X-ray diffraction does not tell the whole story and that I should really run a fatigue test. I understand this may be the best way, but is there another method that gives a high degree of confidence in the residual stress measurement?
TECHNICAL ARTICLES | 2015-03-01

Fundamental Study of Detection of Plastic Gear Failure Signs

This paper proposes a new method — using neural oscillators — for filtering out background vibration noise in meshing plastic gear pairs in the detection of signs of gear failure. In this paper these unnecessary frequency components are eliminated with a feed-forward control system in which the neural oscillator’s synchronization property works. Each neural oscillator is designed to tune the natural frequency to a particular one of the components.
GEAR TALK WITH CHUCK | 2015-01-09

It’s All About Context

[starbox] I was one of those kids that loved reading the dictionary to learn new words, and that interest has continued into my golden years. Th...
TECHNICAL ARTICLES | 2015-01-01

On the Correlation of Specific Film Thickness and Gear Pitting Life

The effect of the lubrication regime on gear performance has been recognized, qualitatively, for decades. Often the lubrication regime is characterized by the specific film thickness defined as the ratio of lubricant film thickness to the composite surface roughness. It can be difficult to combine results of studies to create a cohesive and comprehensive data set. In this work gear surface fatigue lives for a wide range of specific film values were studied using tests done with common rigs, speeds, lubricant temperatures, and test procedures.
GEAR TALK WITH CHUCK | 2014-11-07

The Importance of Perseverance

GEAR TALK WITH CHUCK | 2014-09-24

Attitude is Important, Too

[starbox] I don’t know many people who enjoy working with crabby co-workers. Attitude is a key element in team chemistry, so my evaluation system ...
TECHNICAL ARTICLES | 2014-09-01

Micropitting of Large Gearboxes: Influence of Geometry and Operating Conditions

The focus of the following presentation is two-fold: 1) on tests of new geometric variants; and 2) on to-date, non-investigated operating (environmental) conditions. By variation of non-investigated eometric parameters and operation conditions the understanding of micropitting formation is improved. Thereby it is essential to ensure existent calculation methods and match them to results of the comparison between large gearbox tests and standard gearbox test runs to allow a safe forecast of wear due to micropitting in the future.
GEAR TALK WITH CHUCK | 2014-07-24

Leadership 101 — Commitment

[starbox] Much of what I believe about leadership I learned from the scouting program. I was a scout as a boy and when my children reached that ...
GEAR TALK WITH CHUCK | 2014-07-03

Rework or Scrap?

My last posting on surface temper inspection prompts me to think about the problem of non conforming components. It is never fun to throw valuable ...
ASK THE EXPERT | 2014-07-01

Deciding When to Go Plastic

Can my metal gear(s) be replaced with plastic gears?
TECHNICAL ARTICLES | 2014-07-01

Loaded Behavior of Gears Made of Fiber-Reinforced PA6

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.
TECHNICAL ARTICLES | 2014-07-01

Innovative Induction Hardening Process with Pre-heating for Improved Fatigue Performance of Gear Component

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.
GEAR TALK WITH CHUCK | 2014-07-01

You Don’t Know What You Don’t Know

[starbox] If ever a situation cried out for a short, texting-friendly acronym it is the unavoidable problem of “You don’t know what you don’t kn...
GEAR TALK WITH CHUCK | 2014-06-24

Learning from the Past, Looking to the Future

[starbox] There is a new commercial airing that shows flashbacks of a young girl enjoying a family road trip from the rear facing seat in their ...
TECHNICAL ARTICLES | 2014-05-01

Metallurgical Investigation of Tiger Stripes on a Carburized High Speed Pinion

Tiger stripes on a high-speed pinion made of a carburized SAE 9310 steel were investigated. The morphology of the damage was typical of electric discharge damage. The cause of the stripes and potential damage to the gear tooth were analyzed and are presented in this report.
INDUSTRY NEWS | 2014-05-01

Industry News

The complete Industry News section from the May 2014 issue of Gear Technology.
GEAR TALK WITH CHUCK | 2014-05-01

So How Much is This Going to Cost?

[starbox] Estimating is a necessary evil in every shop. Nobody wants to do it, but if it doesn’t get done there is no business. Fortunately, we ...
GEAR TALK WITH CHUCK | 2014-04-08

A Tool Looking for a Task?

[starbox] I have been hearing a lot about 3-D printing and how it will revolutionize manufacturing in the United States. Millions are slated to ...
GEAR TALK WITH CHUCK | 2014-04-03

In Praise of Deadlines

[starbox] It is only April 2nd, but I can already predict that local TV cameras will have the post office staked out 13 days from now as thousan...
GEAR TALK WITH CHUCK | 2014-04-01

An Appreciation of Gray Hair

[starbox] While driving from Dallas Fort Worth Airport to a new client’s factory, I listened to a very troubling story on PRI’s Marketplace. It ...
GEAR TALK WITH CHUCK | 2014-02-18

100 Years of Four Wheel Drive?

GEAR TALK WITH CHUCK | 2014-02-05

Practical Magic

[starbox] Today I have t
GEAR TALK WITH CHUCK | 2014-01-29

Unsung Heroes of the Gear Industry - Metallurgists

Snow covered trees
GEAR TALK WITH CHUCK | 2014-01-14

Who Taught You About Gears?

[starbox]
"The beginning of wisdom is calling things by their proper name" -- Chinese proverb
Who taught you about gears...
TECHNICAL ARTICLES | 2014-01-01

The XL Gears Project

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.
EVENTS | 2013-08-01

EMO 2013 - Intelligence in Production

Preview of some of the exhibits relevant to gear manufacturing at the upcoming EMO 2013.
FEATURE ARTICLES | 2013-08-01

Leading the Way in Lead Crown Correction and Inspection

Forest City Gear applies advanced gear shaping and inspection technologies to help solve difficult lead crown correction challenges half a world away. But these solutions can also benefit customers much closer to home, the company says. Here's how…
ASK THE EXPERT | 2013-06-01

Worn Gear Contact Analysis

How does one perform a contact analysis for worn gears? Our expert responds.
TECHNICAL ARTICLES | 2013-06-01

New Methods for the Calculation of the Load Capacity of Bevel and Hypoid Gears

Flank breakage is common in a number of cylindrical and bevel gear applications. This paper introduces a relevant, physically based calculation method to evaluate flank breakage risk vs. pitting risk. Verification of this new method through testing is demonstrably shown.
FEATURE ARTICLES | 2013-03-01

Talking Truth to Power: Plastic Gears Taking Back Seat to No One

Automotive industry embraces proven yet evolving technology of plastic gears.
PRODUCT NEWS | 2013-01-01

Product News

The complete Product News section from the January/February 2013 issue of Gear Technology.
TECHNICAL ARTICLES | 2013-01-01

Gear Material Selection and Construction for Large Gears

A road map is presented listing critical considerations and optimal use of materials and methods in the construction of large gears.
TECHNICAL ARTICLES | 2013-01-01

Large Pinions for Open Gears - The Increase of Single Mesh Load

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.
TECHNICAL ARTICLES | 2012-11-01

Morphology of Micropitting

Understanding the morphology of micropitting is critical in determining the root cause of failure. Examples of micropitting in gears and rolling-element bearings are presented to illustrate morphological variations that can occur in practice.
TECHNICAL ARTICLES | 2012-10-01

Differential Gears

What are the manufacturing methods used to make bevel gears used in automotive differentials?
TECHNICAL ARTICLES | 2012-10-01

Pitting Resistance of Worm Gears: Advanced Model for Contact Pattern of Any Size, Position, Flank Type

An experimental and theoretical analysis of worm gear sets with contact patterns of differing sizes, position and flank type for new approaches to calculation of pitting resistance.
INDUSTRY NEWS | 2012-10-01

Industry News

The complete Industry News section from the October 2012 issue of Gear Technology.
TECHNICAL ARTICLES | 2012-08-01

Case Study Involving Surface Durability and Improved Surface Finish

Gear tooth wear and micropitting are very difficult phenomena to predict analytically. The failure mode of micropitting is closely correlated to the lambda ratio. Micropitting can be the limiting design parameter for long-term durability. Also, the failure mode of micropitting can progress to wear or macropitting, and then go on to manifest more severe failure modes, such as bending. The results of a gearbox test and manufacturing process development program will be presented to evaluate super-finishing and its impact on micropitting.
PRODUCT NEWS | 2012-08-01

New Technology for Stronger Plastic Gears

Gleason-K2 Plastics eliminates weld lines with no machining.
FEATURE ARTICLES | 2012-06-01

Growing Pains - Renewables Hang on in Turbulent Energy Market

The turbines are still spinning. They’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 makers— tied up in discussions on tax incentives, economic recovery and a lot of finger pointing—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 manufacturing—it’s just not going to play the role envisioned four to five years ago.
TECHNICAL ARTICLES | 2012-05-01

Application of the First International Calculation Method for Micropitting

The first edition of the international calculation method for micropitting—ISO TR 15144–1:2010—was just published last December. It is the first and only official, international calculation method established for dealing with micropitting. Years ago, AGMA published a method for the calculation of oil film thickness containing some comments about micropitting, and the German FVA published a calculation method based on intensive research results. The FVA and the AGMA methods are close to the ISO TR, but the calculation of micropitting safety factors is new.
FEATURE ARTICLES | 2012-03-01

The Plastic Gear Pay-Off

Eliminating noise, weight and wear proves valuable in 2012.
TECHNICAL ARTICLES | 2012-03-01

Controlling Gear Distortion and Residual Stresses During Induction Hardening

Induction hardening is widely used in both the automotive and aerospace gear industries to minimize heat treat distortion and obtain favorable compressive residual stresses for improved fatigue performance. The heating process during induction hardening has a significant effect on the quality of the heat-treated parts. However, the quenching process often receives less attention even though it is equally important.
TECHNICAL ARTICLES | 2012-03-01

The Relative Performance of Spur Gears Manufactured from Steel and PEEK

This paper seeks to compare the data generated from test rig shaft encoders and torque transducers when using steel-steel, steel-plastic and plastic-plastic gear combinations in order to understand the differences in performance of steel and plastic gears.
ADDENDUM | 2012-03-01

The New Now: U.S. Workforce Sustainability

Faithful Addendum readers are accustomed to finding upbeat, whimsical and oddball stories about gears in this space. What follows is not about gears, exactly. Rather, it is, as opposed to the usual bleak news about America losing its manufacturing mojo—a look at a positive, hopeful development in that regard.
VOICES | 2011-11-01

A Proposed Life Calculation for Micropitting

If you make hardened gears and have not seen any micropitting, then you haven’t looked closely enough. Micropitting is one of the modes of failure that has more recently become of concern to gear designers and manufacturers. Micropitting in itself is not necessarily a problem, but it can lead to noise and sometimes other more serious forms of failure. Predicting when this will occur is the challenge facing designers.
PRODUCT NEWS | 2011-11-01

Liebherr's LDF350 Offers Complete Machining in New Dimension

The objective, according to Dr.- Ing. Hansjörg Geiser, head of development and design for gear machines at Liebherr, was to develop and design a combined turning and hobbing machine in which turning, drilling and hobbing work could be carried out in the same clamping arrangement as the hobbing of the gearings and the subsequent chamfering and deburring processes.
TECHNICAL ARTICLES | 2011-11-01

Load-Sharing Model for Polymer Cylindrical Gears

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.
TECHNICAL ARTICLES | 2011-09-01

Size and Material Influence on the Tooth Root, Pitting, Scuffing and Wear Load-Carrying Capacity of Fine-Module Gears

In this study, limiting values for the load-carrying-capacity of fine-module gears within the module range 0.3–1.0 mm were determined and evaluated by comprehensive, experimental investigations that employed technical, manufacturing and material influence parameters.
FEATURE ARTICLES | 2011-09-01

Next Stop Cincinnati

What's not to like about a more focused, user-friendly Gear Expo? Booth Previews.
FEATURE ARTICLES | 2011-08-01

Gear Material Risks and Rewards

Technology investments lead to product innovation at gear materials suppliers.
TECHNICAL ARTICLES | 2011-05-01

Micropitting of Big Gearboxes: Influence of Flank Modification and Surface Roughness

Most research on micropitting is done on small-sized gears. This article examines whether those results are also applicable to larger gears.
TECHNICAL ARTICLES | 2011-01-01

Point-Surface-Origin Macropitting Caused by Geometric Stress Concentration

Point-surface-origin (PSO) macropitting occurs at sites of geometric stress concentration (GSC) such as discontinuities in the gear tooth profile caused by micropitting, cusps at the intersection of the involute profile and the trochoidal root fillet, and at edges of prior tooth damage, such as tip-to-root interference. When the profile modifications in the form of tip relief, root relief, or both, are inadequate to compensate for deflection of the gear mesh, tip-to-root interference occurs. The interference can occur at either end of the path of contact, but the damage is usually more severe near the start-of-active-profile (SAP) of the driving gear.
TECHNICAL ARTICLES | 2010-11-01

Gear Fault Detection Effectiveness as Applied to Tooth Surface Pitting Fatigue Damage

A study was performed to evaluate fault detection effectiveness as applied to gear-tooth pitting-fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study.
FEATURE ARTICLES | 2010-09-01

The Efficiency Experts

Bradley University and Winzeler Gear collaborate on the design and development of an urban light vehicle.
TECHNICAL ARTICLES | 2010-07-01

Effects of Profile Corrections on Peak-to-Peak Transmission Error

Profile corrections on gears are a commonly used method to reduce transmission error, contact shock, and scoring risk. There are different types of profile corrections. It is a known fact that the type of profile correction used will have a strong influence on the resulting transmission error. The degree of this influence may be determined by calculating tooth loading during mesh. The current method for this calculation is very complicated and time consuming; however, a new approach has been developed that could reduce the calculation time.
FEATURE ARTICLES | 2010-06-01

At the PEEK of the Polymer Food Chain

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.
TECHNICAL ARTICLES | 2010-06-01

Bending Fatigue, Impact and Pitting Resistance of Ausform-Finished PM Gears

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.
TECHNICAL ARTICLES | 2010-06-01

The Anatomy of a Micropitting-Induced Tooth Fracture Failure

Micropitting has become a major concern in certain classes of industrial gear applications, especially wind power and other relatively highly loaded, somewhat slow-speed applications, where carburized gears are used to facilitate maximum load capacity in a compact package. While by itself the appearance of micropitting does not generally cause much perturbation in the overall operation of a gear system, the ultimate consequences of a micropitting failure can, and frequently are, much more catastrophic.
TECHNICAL ARTICLES | 2010-03-01

High-Temperature Testing of Stanyl Plastic Gears: A Comparison with Tensile Fatigue Data

This paper shows an experimental study on the fatigue lifetime of high-heat polyamide (Stanyl) gears running in oil at 140°C. Based on previous works (Refs. 1–2), an analysis is made correcting for tooth bending and calculating actual root stresses. A comparison with tensile bar fatigue data for the same materials at 140°C shows that a good correlation exists between gear fatigue data and tensile bar fatigue data. This insight provides a solid basis for gear designers to design plastic gears using actual material data.
TECHNICAL ARTICLES | 2010-01-01

Design, Development and Application of New, High-Performance Gear Steels

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 “dial-in” 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.
PRODUCT NEWS | 2009-09-01

Custom Gear Cycle Times Plummet with Help from Reishauer, Siemens

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.
TECHNICAL ARTICLES | 2009-09-01

Gear Corrosion During the Manufacturing Process

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).
TECHNICAL ARTICLES | 2009-03-01

The Effect of Superfinishing on Gear Micropitting

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.
TECHNICAL ARTICLES | 2009-03-01

Grinding Induced Changes in Residual Stresses of Carburized Gears

This paper presents the results of a study performed to measure the change in residual stress that results from the finish grinding of carburized gears. Residual stresses were measured in five gears using the x-ray diffraction equipment in the Large Specimen Residual Stress Facility at Oak Ridge National Laboratory.
TECHNICAL ARTICLES | 2009-01-01

Gear Failure Analysis Involving Grinding Burn

When gears are case-hardened, it is known that some growth and redistribution of stresses that result in geometric distortion will occur. Aerospace gears require post case-hardening grinding of the gear teeth to achieve necessary accuracy. Tempering of the case-hardened surface, commonly known as grinding burn, occurs in the manufacturing process when control of the heat generation at the surface is lost.
TECHNICAL ARTICLES | 2008-09-01

Innovative Analysis and Documentation of Gear Test Results

In this paper, a method is presented for analyzing and documenting the pitting failure of spur and helical gears through digital photography and automatic computerized evaluation of the damaged tooth fl ank surface. The authors have developed an accurate, cost-effective testing procedure that provides an alternative to vibration analysis or oil debris methods commonly used in conjunction with similar test-rig programs.
TECHNICAL ARTICLES | 2008-08-01

Influence of Grinding Burn on Pitting Capacity

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.
TECHNICAL ARTICLES | 2008-06-01

Study of the Correlation Between Theoretical and Actual Gear Fatigue Test Data on a Polyamide

In the past two years DSM has been conducting fatigue tests on actual molded gears in order to provide design data.
TECHNICAL ARTICLES | 2008-06-01

Material Integrity in Molded Plastic Gears and its Dependence on Molding Practices

The quality of molded plastic gears is typically judged by dimensional feature measurements only. This practice overlooks potential deficiencies in the molding process.
FEATURE ARTICLES | 2008-06-01

Injection Molded Innovation

Alternative business strategies from some alternative gear manufacturers.
TECHNICAL ARTICLES | 2008-05-01

Pitting Load Capacity of Helical Gears

Influences of Load Distribution and Tooth Flank Modifications as Considered in a New, DIN/ISO-Compatible Calculation Method
EVENTS | 2007-11-01

Gear Expo 2007 Recap

The general impression—whether encouraged by AGMA or developed anecdotally—is that Gear Expo 2007 was a reasonable—though certainly relative—success
TECHNICAL ARTICLES | 2007-09-01

Tooth-Bending Effects in Plastic Spur Gears

This paper describes the investigation of a steel-and-plastic gear transmission and presents a new hypothesis on the governing mechanism in the wear of plastic gears.
INDUSTRY NEWS | 2007-07-05

GW Plastics and ABA-PGT Form Strategic Alliance

GW Plastics and ABA-PGT announced the formation of a global strategic alliance for plastic gear systems and integrated motion transfer sy...
ADDENDUM | 2007-07-01

Were Your Childhood Memories in HIGH GEAR

Loyal Gear Technology reader and Interstate Castings vice president Greg Bierck came across “High Gear” at a vintage toy store in Indianapolis, IN.
VOICES | 2007-06-01

Pushing the Envelope with Plastic

We were delighted to see the plastic gear set pictured on the cover of your March/April issue. UFE played the lead role in its design and manufacture.
VOICES | 2007-03-01

Plastic Gear Standards: A Balancing Act

Creating standards for plastic gears calls for a deft touch. The challenge is to set uniform guidelines, yet avoid limiting the creative solutions plastic offers gear designers.
FEATURE ARTICLES | 2007-03-01

Plastic Gears--A Growing Industry Still Seeking Respect

Forty years ago, the plastics industry was practically in its embryonic phase...
TECHNICAL ARTICLES | 2007-03-01

Effects on Rolling Contact Fatigue Performance--Part II

This is part II of a two-part paper that presents the results of extensive test programs on the RCF strength of PM steels.
PUBLISHER'S PAGE | 2007-01-01

What Do You Think

Publisher Michael Goldstein wants to know what you think about the 2007 redesign of Gear Technology magazine
TECHNICAL ARTICLES | 2006-11-01

Gear Design: Multipoint Properties are Key to Selecting Thermoplastic Materials

The palette of thermoplastic materials for gears has grown rapidly, as have the applications themselves. Designers need to be aware of key properties and attributes in selecting the right material.
TECHNICAL ARTICLES | 2006-07-01

How to Achieve a Successful Molded Gear Transmission

Molded plastic gears have very little in common with machined gears other than the fact that both use the involute for conjugate action.
TECHNICAL ARTICLES | 2006-05-01

Influence of Surface Roughness on Gear Pitting Behavior

In earlier studies, surface roughness has been shown to have a significant influence on gear pitting life. This paper discusses how high surface roughness introduces a wear mechanism that delays the formation of pits. Accompanied by a full-page technical review.
INDUSTRY NEWS | 2006-04-19

New Abrasive Nylon Disc Brushes from Weiler Specialize in In-Machine Deburring

The Burr-Rx line of abrasive nylon disc brushes from Weiler Corp. are specially designed for in-machine deburring applications. The br...
INDUSTRY NEWS | 2006-04-07

Asahi America Introduces Plastic Gear Operator

Plasgear from Asahi America is a thermoplastic gear operator from Asahi America. According to the company’s press release, the P...
TECHNICAL ARTICLES | 2005-11-01

Latest Generation of Quieter Plastic Gears Can Take the Heat

Ten years ago, most mainstream gear manufacturers didn't even consider plastics as an option, especially in higher power applications.
PRODUCT NEWS | 2005-09-01

Corus New Gear Steels Reduce Alloys Without Sacrificing Achievable Hardness

Corus Engineering Steels' formula for its new gear steels: Maintain achievable hardness while using fewer alloys, thereby cutting steel costs for gear manufacturers.
FEATURE ARTICLES | 2005-07-01

Superfinishing Gears - The State of the Art, Part II

In a previous article, the authors identified two misconceptions surrounding gear superfinishing. Here, they tackle three more.
TECHNICAL ARTICLES | 2005-07-01

Systematic Investigations on the Influence of Case Depth on the Pitting and Bending Strength of Case Carburized Gears

The gear designer needs to know how to determine an appropriate case depth for a gear application in order to guarantee the required load capacity.
TECHNICAL ARTICLES | 2005-05-01

The Influence of Additive Chemistry on Micropitting

This article discusses the potential effects observed for different antiwear and EP chemistry on the micropitting of cylindrical gears.
INDUSTRY NEWS | 2005-02-13

REM Chemicals and Rosler GmbH Partner in Metal Finishing

REM Chemicals Inc.and Rosler GmbH developed a 20-year global marketing partnership for chemically-accelerated mass finishing processes, m...
TECHNICAL ARTICLES | 2004-11-01

Non-Standard Cylindrical Gears

Curved face width (CFW) spur gears are not popular in the gear industry. But these non-metallic gears have advantages over standard spur gears: higher contact ratio, higher tooth stiffness, and lower contact and bending stresses.
TECHNICAL ARTICLES | 2004-07-01

Load Carrying Capacity of Screw Helical Gears with Steel Pinions and Plastic Wheels

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.
TECHNICAL ARTICLES | 2004-07-01

Influence of Coatings and Surface Improvements on the Lifetime of Gears

Surface coatings or finishing processes are the future technologies for improving the load carrying capacity of case hardened gears. With the help of basic tests, the influence of different coatings and finishing processes on efficiency and resistance to wear, scuffing, micropitting, and macropitting is examined.
TECHNICAL ARTICLES | 2004-05-01

Evaluation of Bending Strength of Carburized Gears

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 it’s important to know which defect limits the strength of a gear.
INDUSTRY NEWS | 2004-04-17

Manufacturing Association Elects New Board of Directors

The Association for Manufacturing Technology has its elected new officers at their 2004 conference in Bonita Springs, FL. David J. Bu...
REVOLUTIONS | 2004-01-01

Revolutions

"Magnetic Filtration" and "Better Blanking from Bar-Stock"
PUBLISHER'S PAGE | 2003-11-01

Postcard from Gear Expo

Where were you? We were hoping to see you here at Gear Expo. We were surprised that you didn't make it. Anyway, we had a really good show, along with more than a hundred other leading companies in the gear industry who exhibited this year.
TECHNICAL ARTICLES | 2003-05-01

Characterizaton of Retained Austenite in Case Carburized Gears and Its Influence on Fatigue Performance

Carburized helical gears with high retained austenite were tested for surface contact fatigue. The retained austenite before test was 60% and was associated with low hardness near the case's surface. However, the tested gears showed good pitting resistance, with fatigue strength greater than 1,380 MPa.
TECHNICAL ARTICLES | 2002-11-01

The Barkhausen Noise Inspection Method for Detecting Grinding Damage in Gears

When hardened steel components are ground, there is always the possibility of damage to the steel in the form of residual stress or microstructural changes. Methods for detecting this sort of damage have always had one or more drawbacks, such as cost, time, complexity, subjectivity, or the use of hazardous chemicals.
TECHNICAL ARTICLES | 2002-11-01

Predicting the Heat-Treat Response of a Carburized Helical Gear

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.
TECHNICAL ARTICLES | 2002-07-01

Gear Surface Durability Development to Enhance Transmission Power Density

Gear pitting is one of the primary failure modes of automotive transmission gear sets. Over the past years, many alternatives have been intended to improve their gear surface durability. However, due to the nature of new process development, it takes a length of time and joint efforts between the development team and suppliers to investigate and verify each new approach.
TECHNICAL ARTICLES | 2002-05-01

Increased Load Capacity of Worm Gears by Optimizing the Worm Wheel Bronze

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.
INDUSTRY NEWS | 2002-05-01

Industry News

Complete Industry News for May/June 2002.
TECHNICAL ARTICLES | 2002-05-01

Optimizing Plastic Gear Geometry: An Inroduction to Gear Optimization

There are numerous engineering evaluations required to design gear sets for optimum performance with regard to torque capacity, noise, size and cost. How much cost savings and added gear performance is available through optimization? Cost savings of 10% to 30% and 100% added capacity are not unusual. The contrast is more pronounced if the original design was prone to failure and not fit for function.
TECHNICAL ARTICLES | 2002-01-01

Consideration of Moving Tooth Load in Gear Crack Propagation Predictions

Effective gear designs balance strength, durability, reliability, size, weight, and cost. Even effective designs, however, can have the possibility of gear cracks due to fatigue. In addition, truly robust designs consider not only crack initiation, but also crack propagation trajectories. As an example, crack trajectories that propagate through the gear tooth are the preferred mode of failure compared to propagation through the gear rim. Rim failure will lead to catastrophic events and should be avoided. Analysis tools that predict crack propagation paths can be a valuable aid to the designer to prevent such catastrophic failures.
TECHNICAL ARTICLES | 2002-01-01

Failure Mechanisms in Plastic Gears

Plastics as gear materials represent an interesting development for gearing because they offer high strength-to-weight ratios, ease of manufacture and excellent tribological properties (Refs. 1-7). In particular, there is a sound prospect that plastic gears can be applied for power transmission of up to 10 kW (Ref. 6).
TECHNICAL ARTICLES | 2001-05-01

Design Formulas for Evaluating Contact Stress in Generalized Gear Pairs

A very important parameter when designing a gear pair is the maximum surface contact stress that exists between two gear teeth in mesh, as it affects surface fatigue (namely, pitting and wear) along with gear mesh losses. A lot of attention has been targeted to the determination of the maximum contact stress between gear teeth in mesh, resulting in many "different" formulas. Moreover, each of those formulas is applicable to a particular class of gears (e.g., hypoid, worm, spiroid, spiral bevel, or cylindrical - spur and helical). More recently, FEM (the finite element method) has been introduced to evaluate the contact stress between gear teeth. Presented below is a single methodology for evaluating the maximum contact stress that exists between gear teeth in mesh. The approach is independent of the gear tooth geometry (involute or cycloid) and valid for any gear type (i.e., hypoid, worm, spiroid, bevel and cylindrical).
TECHNICAL ARTICLES | 2000-09-01

Gear Oil Micropitting Evaluation

During the last decade, industrial gear manufacturers, particularly in Europe, began to require documentation of micropitting performance before approving a gear oil for use in their equipment. The development of micropitting resistant lubricants has been limited both by a lack of understanding of the mechanism by which certain lubricant chemistry promotes micropitting and by a lack of readily available testing for evaluation of the micropitting resistance of lubricants. This paper reports results of two types of testing: (1) the use of a roller disk machine to conduct small scale laboratory studies of the effects of individual additives and combinations of additives on micropitting and (2) a helical gear test used to study micropitting performance of formulated gear oils.
EVENTS | 2000-09-01

Technical Calendar

Complete Technical Calendar for September/October 2000.
INDUSTRY NEWS | 2000-07-01

Industry News

Complete Industry News for July/August 2000.
TECHNICAL ARTICLES | 2000-05-01

A Practical Guide for Molding Better Plastic Geared Transmissions

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.
FEATURE ARTICLES | 1999-11-01

Coordinate Measuring Machines and the Gear Industry

Gears are extremely complex shapes. Coordinate measuring machines, or CMMs, are designed to measure complex shapes. It seems to follow that CMMs world, therefore, be the ideal tool for measuring gears. But the answer is not so simple.
INDUSTRY NEWS | 1999-09-01

Industry News

Industry News for September/October 1999.
PRODUCT NEWS | 1999-09-01

Product News

Welcome to our Product News page. Here we feature new products of interest to the gear and gear products markets.
REVOLUTIONS | 1999-07-01

Revolutions

Welcome to Revolutions, the column that brings you the latest, most up-to-date and easy-to-read information about the people and technology of the gear industry.
REVOLUTIONS | 1999-01-01

Revolutions

Welcome to Revolutions, the column that brings you the latest, most up-to-date and easy-to-read information about the people and technology of the gear industry. Revolutions welcomes your submissions.
TECHNICAL ARTICLES | 1998-11-01

Calculating Spur and Helical Gear Capacity with ISO 6336

This is the third article in a series exploring the new ISO 6336 gear rating standard and its methods of calculation. The opinions expressed herein are htose of the author as an individual. They do not represent the opinions of any organization of which he is a member.
FEATURE ARTICLES | 1998-07-01

Plastic: The Not-So-Alternative Technology

"We're taking over," says Art Milano. It's a bold statement from the engineering manager of Seitz Corporation, one of the largest manufacturers of injection molded plastic gears, but Milano has reason for his optimism. Plastic gears are big business-probably bigger than most gear industry "insiders" realize.
TECHNICAL ARTICLES | 1998-05-01

Relationship Between Wear and Pitting Phenomena in Worm Gears

Worm gears display unique behavior of surfaces because of the presence of wear phenomena in addition to contact pressure phenomena.
TECHNICAL ARTICLES | 1998-01-01

Influence of Gear Design on Gearbox Radiated Noise

A major source of helicopter cabin noise (which has been measured at over 100 decibels sound pressure level) is the gearbox. Reduction of this noise is a NASA and U.S. Army goal. A requirement for the Army/NASA Advanced Rotorcraft Transmission project was a 10 dB noise reduction compared to current designs.
TECHNICAL ARTICLES | 1997-11-01

Gear Shaving Basics - Part I

Gear shaving is a free-cutting gear finishing operation which removes small amounts of metal from the working surfaces of gear teeth. Its purpose is to correct errors in index, helix angle, tooth profile and eccentricity. The process also improves tooth surface finish and eliminates by means of crowned tooth forms the danger of tooth end load concentrations in service.
TECHNICAL ARTICLES | 1997-11-01

Gear Crack Propagation Investigations

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.
INDUSTRY NEWS | 1997-07-01

Hoechst Technical Polymers to Gather Plastic Gear Materials Data

Hoechst Technical Polymers has expanded its interests in plastic gears with the introduction of the new Plastic Gear Evaluation and Research machine P-Gear. The machine is the centerpiece of the company's continuing efforts to promote and develop the use of plastic gears in higher-powered applications.
TECHNICAL ARTICLES | 1996-09-01

Alternative Lubrication Methods for Large Open Gear Drives

The type of lubricant and the method of applying it to the tooth flanks of large open gears is very important from the point of view of lubrication technology and maintenance. When selecting the type of lubricant and the application method, it is important to check whether it is possible to feed the required lubricant quantity to the load-carrying tooth flanks, This is necessary to avoid deficient lubrication, damage to the gear and operational malfunctions. It is important to determine the type of lubricant, which may be fluid or grease-like. The consistency of the lubricant will have a direct impact on the ability of the lubrication system to feed adequately the lubricant to the gear. The interactions between the common types of lubricant and the lubrication application methods for open gear drives are shown in Fig. 1.
TECHNICAL ARTICLES | 1996-07-01

Noise Reduction in Plastic & Powder Metal Gear Sets

The data discussed in this article was taken from an upright vacuum cleaner. This was a prototype cleaner that was self-propelled by a geared transmission. It was the first time that the manufacturer had used a geared transmission in this application.
TECHNICAL ARTICLES | 1996-07-01

Plastic Gear Design Basics

Plastic gears are serious alternatives to traditional metal gears in a wide variety of applications. The use of plastic gears has expanded from low-power, precision motion transmission into more demanding power transmission applications. As designers push the limits of acceptable plastic gear applications, more is learned about the behavior of plastics in gearing and how to take advantage of their unique characteristics.
TECHNICAL ARTICLES | 1996-03-01

The Effect of Metallurgy on the Performance of Carburized Gears

Gears are designed to be manufactured, processed and used without failure throughout the design life of the gear. One of INFAC's objectives (*see p.24) is to help manufacture of gears to optimize performance and life. One way to achieve this is to identify failure mechanisms and then devise strategies to overcome them by modifying the manufacturing parameters.
TECHNICAL ARTICLES | 1995-11-01

Effect of Web & Flange Thickness on Nonmetallic Gear Performance

Gears are manufactured with thin rims for several reasons. Steel gears are manufactured with thin rims and webs where low weight is important. Nonmetallic gears, manufactured by injection molding, are designed with thin rims as part of the general design rule to maintain uniform thickness to ensure even post-mold cooling. When a thin-rimmed gear fails, the fracture is thought the root of the gear, as shown in Fig. 1a, rather than the usual fillet failure shown in Fig. 1b.
TECHNICAL ARTICLES | 1995-07-01

How to Avoid Errors When Measuring Step Gears

There are problems in dimensional measurement that should be simple to solve with standard measuring procedures, but aren't. In such cases, using accepted practices may result in errors of hundreds of microns without any warning that something is wrong.
TECHNICAL ARTICLES | 1995-05-01

EHL Film Thickness, Additives and Gear Surface Fatigue

Aircraft transmissions for helicopters, turboprops and geared turbofan aircraft require high reliability and provide several thousand hours of operation between overhauls. In addition, They should be lightweight and have very high efficiency to minimize operating costs for the aircraft.
TECHNICAL ARTICLES | 1995-03-01

ADI - A Designer Gear Material

If someone were to tell you that he had a gear material that was stronger per pound than aluminum, as wear-resistant as steel, easier to machine than free-machining steel and capable of producing gears domestically for 20% less than those now cut from foreign made forgings, would you consider that material to be "high tech"? Probably. Well, throw out all the pre-conceived notions that you may have had about "high tech" materials. The high-performance material they didn't teach you about in school is austempered ductile iron (ADI).
TECHNICAL ARTICLES | 1995-03-01

Mechanical Behavior and Microstructure of Ausrolled Surfaces in Gear Steels

Ausforming, the plastic deformation of heat treatment steels in their metastable, austentic condition, was shown several decades ago to lead to quenched and tempered steels that were harder, tougher and more durable under fatigue-type loading than conventionally heat-treated steels. To circumvent the large forces required to ausform entire components such as gears, cams and bearings, the ausforming process imparts added mechanical strength and durability only to those contact surfaces that are critically loaded. The ausrolling process, as utilized for finishing the loaded surfaces of machine elements, imparts high quality surface texture and geometry control. The near-net-shape geometry and surface topography of the machine elements must be controlled to be compatible with the network dimensional finish and the rolling die design requirements (Ref. 1).
TECHNICAL ARTICLES | 1993-09-01

Lubricants and Lubrication of Plastic Gears

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.
TECHNICAL ARTICLES | 1993-05-01

Practical Optimization of Helical Gears Using Computer Software

The aim of this article is to show a practical procedure for designing optimum helical gears. The optimization procedure is adapted to technical limitations, and it is focused on real-world cases. To emphasize the applicability of the procedure presented here, the most common optimization techniques are described. Afterwards, a description of some of the functions to be optimized is given, limiting parameters and restrictions are defined, and, finally, a graphic method is described.
INDUSTRY NEWS | 1993-03-01

Gear Material Quality: How To Judge It...Pitting: How To Prevent It

How do we know when the gear material we buy is metallurgically correct? How can we judge material quality when all gear material looks alike?
TECHNICAL ARTICLES | 1992-07-01

Gear Inspection and Measurement

The purpose of gear inspection is to: Assure required accuracy and quality, Lower overall cost of manufacture by controlling rejects and scrap, Control machines and machining practices and maintain produced accuracy as machines and tools wear, Determine hear treat distortions to make necessary corrections.
TECHNICAL ARTICLES | 1992-07-01

Comparing Surface Failure Modes in Bearings and Gears: Appearances vs. Mechanisms

In the 1960's and early 1970's, considerable work was done to identify the various modes of damage that ended the lives of rolling element bearings. A simple summary of all the damage modes that could lead to failure is given in Table 1. In bearing applications that have insufficient or improper lubricant, or have contaminants (water, solid particles) or poor sealing, failure, such as excessive wear or vibration or corrosion, may occur, rather than contact fatigue. Usually other components in the overall system besides bearings also suffer. Over the years, builders of transmissions, axles, and gear boxes that comprise such systems have understood the need to improve the operating environment within such units, so that some system life improvements have taken place.
TECHNICAL ARTICLES | 1992-05-01

Gear Blanking

The term "blanking" refers to the initial metal cutting operations in the process planning sequence which produce the contour of a part starting from rough material. The scope of blanking is: To remove the excess material To machine the part to print specifications, except for those surfaces with subsequent finishing operations. To leave adequate machining stock for finishing operations. To prepare good quality surfaces for location and clamping of the part throughout the process.
MANAGEMENT MATTERS | 1992-05-01

Cost-Cutting ABCs

Cost cutting. It's the aerobics of the 90s for businesses large and small. More than just the latest buzzword or 90-second flash-in-the-panacea, it's a survival technique. Companies that aren't trimming the fat now may not be around in five years to regret that they didn't.
INDUSTRY NEWS | 1992-03-01

Our Experts Discuss Hobbing Ridges, Crooked Gear Teeth, and Crown Shaving

Question: When cutting worm gears with multiple lead stock hobs we find the surface is "ridged". What can be done to eliminate this appearance or is to unavoidable?
TECHNICAL ARTICLES | 1992-01-01

Design Guidelines for High-Capacity Bevel Gear Systems

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
EVENTS | 1991-11-01

Calendar

Complete calendar for November/December 1991
TECHNICAL ARTICLES | 1991-11-01

A Rational Procedure for Designing Minimum-Weight Gears

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.
TECHNICAL ARTICLES | 1991-09-01

SPC Acceptance of Hobbing & Shaping Machines

Today, as part of filling a typical gear hobbing or shaping machine order, engineers are required to perform an SPC acceptance test. This SPC test, while it is contractually necessary for machine acceptance, is not a machine acceptance test. It is a process capability test. It is an acceptance of the machine, cutting tool, workholding fixture, and workpiece as integrated on the cutting machine, using a gear measuring machine, with its work arbor and evaluation software, to measure the acceptance elements of the workpiece.
TECHNICAL ARTICLES | 1991-05-01

Surface Pitting Fatigue Life of Noninvolute Low-Contact-Ratio Gears

Spur gear endurance tests were conducted to investigate the surface pitting fatigue life of noninvolute gears with low numbers of teeth and low contact ratios for the use in advanced application. The results were compared with those for a standard involute design with a low number of teeth. The gear pitch diameter was 8.89 cm (3.50 in.) with 12 teeth on both gear designs. Test conditions were an oil inlet temperature of 320 K (116 degrees F), a maximum Hertz stress of 1.49 GPa (216 ksi), and a speed of 10,000 rpm. The following results were obtained: The noninvolute gear had a surface pitting fatigue life approximately 1.6 times that of the standard involute gear of a similar design. The surface pitting fatigue life of the 3.43-pitch AISI 8620 noninvolute gear was approximately equal to the surface pitting fatigue life of an 8-pitch, 28-tooth AISI 9310 gear at the same load, but at a considerably higher maximum Hertz stress.
VOICES | 1991-01-01

AGMA Responds to Gear Standards Article

The authors of last issue's article comparing AGMA, ISO and BS methods for Pitting Resistance Ratings are commended. Trying to compare various methods of rating gears is like hitting a moving target in a thick forest. The use of different symbols, presentations, terminology, and definitions in these standards makes it very difficult. But the greatest problem lies with the authors' use of older versions of these documents. ISO drafts and AGMA standards have evolved at the same time their work was accomplished and edited.
TECHNICAL ARTICLES | 1991-01-01

AGMA, ISO, and BS Gear Standards Part II - Pitting Resistance Ratings

In Part I differences in pitting ratings between AGMA 218, the draft ISO standard 6336, and BS 436:1986 were examined. In this part bending strength ratings are compared. All the standards base the bending strength on the Lewis equation; the ratings differ in the use and number of modification factors. A comprehensive design survey is carried out to examine practical differences between the rating methods presented in the standards, and the results are shown in graphical form.
TECHNICAL ARTICLES | 1990-11-01

AGMA, ISO, and BS Gear Standards Part I - Pitting Resistance Ratings

A study of AGMA 218, the draft ISO standard 6336, and BS 436: 1986 methods for rating gear tooth strength and surface durability for metallic spur and helical gears is presented. A comparison of the standards mainly focuses on fundamental formula and influence factors, such as the load distribution factor, geometry factor, and others. No attempt is made to qualify or judge the standards other than to comment on the facilities or lack of them in each standard reviewed. In Part I a comparison of pitting resistance ratings is made, and in the subsequent issue, Part II will deal with bending stress ratings and comparisons of designs.
TECHNICAL ARTICLES | 1990-07-01

Efficient Methods for the Synthesis of Compound Planetary Differential Gear Trains for Multiple Speed Ratio Generation

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.
TECHNICAL ARTICLES | 1990-03-01

Influence of Lubrication on Pitting and Micropitting Resistance of Gears

Pitting and micropitting resistance of case-carburized gears depends on lubricants and lubrication conditions. Pitting is a form of fatigue damage. On this account a short time test was developed. The test procedure is described. The "pitting test" was developed as a short time test to examine the influence of lubricants on micropitting. Test results showing the influence of case-carburized gears on pitting and micropitting are presented.
TECHNICAL ARTICLES | 1990-01-01

Surface Fatigue Life on CBN and Vitreous Ground Carburized and Hardened AISA 9310 Spur Gears

Spur gear surface endurance tests were conducted to investigate CBN ground AISI 9310 spur gears for use in aircraft applications, to determine their endurance characteristics and to compare the results with the endurance of standard vitreous ground AISI 9310 spur gears. Tests were conducted with VIM-VAR AISI 9210 carburized and hardened gears that were finish ground with either CBN or vitreous grinding methods. Test conditions were an inlet oil temperature of 320 K (116 degree F), an outlet oil temperature of 350 K (170 degree F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. The CBN ground gears exhibited a surface fatigue life that was slightly better than the vitreous ground gears. The subsurface residual stress of the CBN ground gears was approximately the same as that for the standard vitreous ground gears for the CBN grinding method used.
TECHNICAL ARTICLES | 1989-11-01

Systematic Approach to Designing Plastic Spur and Helical Gears

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.
PUBLISHER'S PAGE | 1989-01-01

Leonardo, the Engineer

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.
TECHNICAL ARTICLES | 1989-01-01

Factors Influencing Fracture Toughness of High-Carbon Martensitic Steels

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.
EVENTS | 1988-11-01

Technical Calendar

November 1-3. SME Gear Processing and Manufacturing Clinic, Sheraton Meridian, Indianapolis, IN. November 5-10. international Conference on Gearing, Zhengzhou, China
TECHNICAL ARTICLES | 1988-09-01

Crowned Spur Gears: Optimal Geometry and Generation

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)
TECHNICAL ARTICLES | 1988-07-01

High Speed Hobbing of Gears With Shifted Profiles

The newer profile-shifted (long and short addendum) gears are often used as small size reduction gears for automobiles or motorcycles. The authors have investigated the damage to each cutting edge when small size mass-produced gears with shifted profiles are used at high speeds.
TECHNICAL ARTICLES | 1987-11-01

Good Gears Start With Good Blanks

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.
TECHNICAL ARTICLES | 1987-09-01

Effects of Hob Quality and Resharpening Errors on Generating Accuracy

The modern day requirement for precision finished hobbed gears, coupled with the high accuracy characteristics of modern CNC hobbing machines, demands high tool accuracy.
TECHNICAL ARTICLES | 1987-07-01

Cutting Fluid Selection and Process Controls for the Gear Manufacturing Industry

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.
TECHNICAL ARTICLES | 1987-05-01

Rotary Gear Honing

Rotary gear honing is a hard gear finishing process that was developed to improve the sound characteristics of hardened gears by: Removing nicks and burrs; improving surface finish; and making minor corrections in tooth irregularities caused by heat-treat distortion.
TECHNICAL ARTICLES | 1987-01-01

Lubricant Jet Flow Phenomena in Spur and Helical 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.
TECHNICAL ARTICLES | 1986-09-01

Improved Gear Life Through Controlled Shot Peening

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.
EVENTS | 1986-07-01

Technical Calendar

October 5-8, 1986 AGMA Fall technical Conference & Gearing Exhibit September 17-19, 1986 Ohio State University Gear Noise Seminar November 11-13, 1986 SME Gear Processing and Manufacturing Clinic November 19-21, 1986 Seminar: Gear System Design for Minimum Noise
TECHNICAL ARTICLES | 1986-05-01

Selection of Material and Compatible Heat Treatments for Gearing

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.
TECHNICAL ARTICLES | 1986-05-01

Identification of Gear Noise with Single Flank Composite Measurement

Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.
FEATURE ARTICLES | 1986-01-01

Effect of Shot Peening on Surface Fatigue Life of Carburized and Hardened AISI 1910 Spur Gears

Gear surface fatigue endurance tests were conducted on two groups of 10 gears each of carburized and hardened AlSI 9310 spur gears manufactured from the same heat of material
TECHNICAL ARTICLES | 1985-07-01

The Design and Manufacture of Plastic Gears Part II

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.
TECHNICAL ARTICLES | 1985-05-01

The Design and Manufacture of Machined Plastic Gears

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.
TECHNICAL ARTICLES | 1985-03-01

Tolerance for Overload Stress

The performance of carburized components can be improved simply by changing the alloy content of the steel.
TECHNICAL ARTICLES | 1985-03-01

Austempered Nodular Cast Irons

Austempering heat treatments (austenitizing followed by rapid cooling to the tempering temperature) have been applied to nodular irons on an experimental basis for a number of years, but commercial interest in the process has only recently come to the surface.
TECHNICAL ARTICLES | 1984-10-01

Endurance Limit for Contact Stress in Gears

With the publishing of various ISO draft standards relating to gear rating procedures, there has been much discussion in technical papers concerning the various load modification factors. One of the most basic of parameters affecting the rating of gears, namely the endurance limit for either contact or bending stress, has not, however, attracted a great deal of attention.
TECHNICAL ARTICLES | 1984-10-01

Austempered Ductile Iron: Technology Base Required for an Emerging Technology

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.
VOICES | 1984-08-01

A Second Rate Society - Never

What was once recognized as the unique genius of America is now slipping away from us and, in many areas, is now seen as a "second rate" capability. Unless action is taken now, this country is in real danger of being unable to regain its supremacy in technological development and economic vigor. First Americans must understand the serious implications of the problem; and second, we must dedicate ourselves to national and local actions that will ensure a greater scientific and technological literacy in America.
TECHNICAL ARTICLES | 1984-08-01

Maximum Surface Temperature of the Thermoplastic Gear in a Non-Lubricated Plastic-Steel Gear Pair

One of the major problems of plastic gear design is the knowledge of their running temperature. Of special interest is the bulk temperature of the tooth to predict the fatigue life, and the peak temperature on the surface of the tooth to avert surface failure. This paper presents the results of an experimental method that uses an infrared radiometer to measure the temperature variation along the profile of a plastic gear tooth in operation. Measurements are made on 5.08, 3.17, 2.54, 2.12 mm module hob cut gears made from nylon 6-6, acetal and UHMWPE (Ultra High Molecular Weight Polyethylene). All the tests are made on a four square testing rig with thermoplastic/steel gear pairs where the plastic gear is the driver. Maximum temperature prediction curves obtained through statistical analysis of the results are presented and compared to data available from literature.
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