September/October 2009

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Why Do You Read Gear Technology

A year ago, we sent out a small e-mail survey with one simple question: “Why do you read Gear Technology?” At that time, we were extremely gratified, even somewhat overwhelmed, by the enthusiastic and appreciative response of our readers, and I wrote about the survey and the results in my editorial in the September/October 2008 issue. When we sent out the survey this year with the same question, you’d think we would have been prepared for the results. We weren’t. If anything, our readers are even more appreciative than they were a year ago.

Voices

Gear Expo: Changing with the Times

"One of the reasons AGMA has been successful over our 93-year history is that the association’s agenda, programs and activities reflect the voices of our members," says Joe T. Franklin, Jr., AGMA President.

Technical Articles

Comparison of PM-HSS and Cemented Carbide Tools in High-Speed Gear Hobbing

This article examines the dry hobbing capabilities of two cutting tool materials—powder metallurgical high-speed steel (PM-HSS) and cemented carbide. Cutting trials were carried out to analyze applicable cutting parameters and possible tool lives as well as the process reliability. To consider the influences of the machinability of different workpiece materials, a case hardening steel and a tempered steel were examined.

Tooth Fillet Profile Optimization for Gears with Symmetric and Asymmetric Teeth

The gear tooth fillet is an area of maximum bending stress concentration. However, its profile is typically less specified in the gear drawing and hardly controlled during gear inspection in comparison with the gear tooth flanks. This paper presents a fillet profile optimization technique for gears with symmetric and asymmetric teeth based on FEA and a random search method. It allows achieving substantial bending stress reduction in comparison with traditionally designed gears. This bending stress reduction can be traded for higher load capacity, longer lifetime, lower noise and vibration and cost reduction.

Low Pressure Carburizing of Large Transmission Parts

Often, the required hardness qualities of parts manufactured from steel can only be obtained through suitable heat treatment. In transmission manufacturing, the case hardening process is commonly used to produce parts with a hard and wear-resistant surface and an adequate toughness in the core. A tremendous potential for rationalization, which is only partially used, becomes available if the treatment time of the case hardening process is reduced. Low pressure carburizing (LPC) offers a reduction of treatment time in comparison to conventional gas carburizing because of the high carbon mass flow inherent to the process (Ref. 1).

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).

Feature Articles

Gear Expo 2009 Special Events

Details about the Solutions Center, SME and AGMA special events at the show.

Guide to Gear Expo 2009

Gear Expo floor map and alphabetical listing of exhibitors.

Grinding Gears for Racing Transmissions

When you push 850 horsepower and 9,000 rpm through a racing transmission, you better hope it stands up. Transmission cases and gears strewn all over the racetrack do nothing to enhance your standing, nor that of your transmission supplier.

Gear Expo 2009 Product Preview

Sure, Gear Expo undoubtedly has a ton to offer attendees in education, research and networking alone, but what really draws the crowd in are the physical products and technology on display from exhibitors. Otherwise it would just be another technical meeting or social reception—and AGMA could save a few bucks on space to say the least.

Addendum

Gears: Kid-Tested, Museum-Approved

When children are asked what they want to be when they grow up, the answers are undoubtedly diverse. Some immediately respond with doctor, lawyer or firefighter while others take a more creative approach with answers like spy, princess or superhero. The Addendum Staff has yet to come across a youngster that seems committed to a career in gear manufacturing.

Product News

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.

Product News

The complete Product News section from the September/October 2009 issue of Gear Technology.

Industry News

Industry News

The complete Industry News section from the September/October 2009 issue of Gear Technology.

Events

Events

Advance coverage of EMO Milan 2009, plus our technical calendar.