| Gear Technology Magazine

Summertime...and the Statistics Are Easy

June 1, 2010

With this change of seasons seems to have come a change in mood as well. Manufacturers are optimistic.

At the PEEK of the Polymer Food Chain

June 1, 2010

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.

Getting Wired into EDM

June 1, 2010

Technology emphasizes high accuracies and improved surface finishes.

Single-Pass Honing Holds the Line on PM Sprockets

June 1, 2010

Bore finishing system from Sunnen helps Cloyes Gear and Products achieve high accuracy, productivity and process capability.

Hard Turning Large-Diameter Parts

June 1, 2010

Fuji's VTP-1000 is designed for highly accurate fine finishing of cylindrical components up to one meter in diameter.

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

June 1, 2010

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.

Variation Analysis of Tooth Engagement and Load Sharing in Involute Splines

June 1, 2010

Involute spline couplings are used to transmit torque from a shaft to a gear hub or other rotating component. External gear teeth on the shaft engage an equal number of internal teeth in the hub. Because multiple teeth engage simultaneously, they can transmit much larger torques than a simple key and keyway assembly. However, manufacturing variations affect the clearance between each pair of mating teeth, resulting in only partial engagement.

The Anatomy of a Micropitting-Induced Tooth Fracture Failure

June 1, 2010

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.

Weird Science

June 1, 2010

Who knew what a few hundred bacteria could do with a little cooperation? Andrey Sokolov of Princeton University, Igor Aronson from the Argonne National Laboratory and Bartosz Grzybowski and Mario Apodaca from Northwestern University found out after placing microgears (380 microns long with slanted spokes) in a solution with the common aerobic bacteria Bacillus subtilis. The scientists observed that the bacteria appeared to swim randomly but occasionally collided with the spokes of the gears and turned them.

Letter to the Editor

June 1, 2010

Reader's response to a previous issue.

Faster Honing to Mirror Fishises on Gear Faces and Bores

June 1, 2010

Stringent NVH requirements, higher loads and the trend towards miniaturization to save weight and space are forcing transmission gear designers to increasingly tighten the surface finish, bore size and bore-to-face perpendicularity tolerances on the bores of transmission gears.

Product News

June 1, 2010

The complete Product News section from the June 2010 issue of Gear Technology.

Gear Applications All the Rage at Windpower 2010

June 1, 2010

Capitalizing on a burgeoning new technology where gears are of great import, the gear community gathered en masse at the American Wind Energy Association’s Windpower Expo 2010.