November/December 2011

Gear Expo 2011 - Tempered Enthusiasm

I came back from Gear Expo in a pretty good mood, and judging by the smiles on the faces of exhibitors I saw, I'm not alone. In fact, the mood at Gear Expo 2011 was the best I've seen in recent memory.

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.

Vacuum Oil Quenching

The October 2011 issue of Gear Technology featured the article “Low-Distortion Heat Treatment of Transmission Components,” which covered the combination of low-pressure carburizing and high pressure gas quenching in an automotive environment. Here, heat treating expert Dan Herring explains why oil quenching is an appropriate choice for many applications.

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.

Flank Breakage on Gears for Energy Systems

Gear flank breakage can be observed on edge zone-hardened gears. It occurs, for example, on bevel gears for water turbines, on spur gears for wind energy converters and on single- and double-helical gears for other industrial applications.

Gear Transmission Density Maximization

This paper presents an approach that provides optimization of both gearbox kinematic arrangement and gear tooth geometry to achieve a high-density gear transmission. It introduces dimensionless gearbox volume functions that can be minimized by the internal gear ratio optimization. Different gearbox arrangements are analyzed to define a minimum of the volume functions. Application of asymmetric gear tooth profiles for power density maximization is also considered.

Best of Times, Worst of Times

An American renaissance in manufacturing is needed—and long overdue.

State of the Gear Industry 2011

In November, Gear Technology conducted an anonymous survey of gear manufacturers. Invitations were sent by e-mail to thousands of individuals around the world. More than 300 individuals responded to the online survey, answering questions about their manufacturing operations and current challenges facing their businesses.

Minimum Setup Time, Maximum Machining Capability

Hainbuch offers workholding solutions for United Gear.

It's No American Dream: Pratt & Whitney GTF Engine Now a Reality...

In the August 2008 issue of Gear Technology, we ran a story (“Gearbox Speed Reducer Helps Fan Technology for ‘Greener” Jet Fuel Efficiency’) on the then ongoing, extremely challenging and protracted development of Pratt & Whitney’s geared turbofan (GTF) jet engine.

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.

Sicmat Releases Raso 200 Dynamic Shaving Machine

The Raso 200 Dynamic has been developed to offer all the characteristics of a gear shaving machine with a competitive price.

Product News

The complete Product News section from the November/December 2011 issue.

Industry News

The complete Industry News section from the November/December 2011 issue of Gear Technology

Technical Calendar

The complete Technical Calendar from the November/December 2011 issue of Gear Technology.

IPTEX 2012 Preview

India is rapidly turning into a global manufacturing hub, thanks to the country’s manufacturing and engineering capabilities, vast pool of skilled expertise and its size. These qualities offer it a strategic advantage for the manufacturing segment. A large number of international companies in varied segments have already set up a manufacturing base in India and others are following suit. It only makes sense to bring this industry segment together under one roof to discuss the current trends and technology prevalent to the marketplace. IPTEX 2012 is scheduled from February 9–11, 2012 at the Bombay Exhibition Center in Mumbai, India.