May 2009

Crossroads and Transitions, Part I

Michael Goldstein talks about 25 years of Gear Technology, looking behind as well as ahead.

The Gear Vanity Plate Hall of Fame

Here is the first batch of responses to our request for entries into the Gear Vanity Plate Hall of Fame (see Addendum, March/April 2009).

In-Situ Measurement of Stresses in Carburized Gears via Neutron Diffraction

This paper presents the results of research directed at measuring the total stress in a pair of statically loaded and carburized spur gears. Measurements were made to examine the change in total stress as a function of externally applied load and depth below the surface.

Repair via Isotropic Superfinishing of Aircraft Transmission Gears

The objective of this paper is to demonstrate that transmission gears of rotary-wing aircraft, which are typically scrapped due to minor foreign object damage (FOD) and grey staining, can be repaired and re-used with signifi cant cost avoidance. The isotropic superfinishing (ISF) process is used to repair the gear by removing surface damage. It has been demonstrated in this project that this surface damage can be removed while maintaining OEM specifications on gear size, geometry and metallurgy. Further, scrap CH-46 mix box spur pinions, repaired by the ISF process, were subjected to gear tooth strength and durability testing, and their performance compared with or exceeded that of new spur pinions procured from an approved Navy vendor. This clearly demonstrates the feasibility of the repair and re-use of precision transmission gears.

How Are You Dealing with the Bias Error in Your Helical Gears

This paper initially defines bias error—the “twisted tooth phenomenon.” Using illustrations, we explain that bias error is a by-product of applying conventional, radial crowning methods to produced crowned leads on helical gears. The methods considered are gears that are finished, shaped, shaved, form and generated ground. The paper explains why bias error occurs in these methods and offers techniques used to limit/eliminate bias error. Sometimes, there may be a possibility to apply two methods to eliminate bias error. In those cases, the pros/cons of these methods will be reviewed.

What Now - What Next for India

Global slowdown raises questions for Indian gear market.

Building a Better Mousetrap

At its location in Roscoe, IL, the Forest City Gear facility is surrounded by wildlife splendor. Fruit trees, nature walks and the occasional cute and furry animal sighting create an unlikely landscape for a manufacturing site. Of course, cavorting with the cute and furry does have its drawbacks.

Product News

The complete Product News section from the May 2009 issue of Gear Technology.

Industry News

The complete Industry News section from the May 2009 issue of Gear Technology.

Events

Advance coverage of India's Gears, Motors & Controls Expo 2009, plus our regular calendar of events.