The first part of this article describes the analytical design method developed by the author to evaluate the load capacity of worm gears. The second part gives a short description of the experimental program and testing resources being used at CETIM to check the basic assumptions of the analytical method; and to determine on gears and test wheels the surface pressure endurance limits of materials that can be used for worm gears. The end of the article compares the results yielded by direct application of the method and test results.

In 1985 a new tooling concept for high volume gear production was introduced to the gear manufacturing industry. Since then this tool, the wafer shaper cutter, has proven itself in scores of applications as a cost-effective, consistent producer of superior quality parts. This report examines the first high-production installation at the plant of a major automotive supplies, where a line of twenty shapers is producing timing chain sprockets.

March 19-22, 1989. First International Applied Mechanical Systems Design Conference. Convention Center, Nashville, TN. April 25-27, 1989. ASME 5th Annual Power Transmission & Gearing Conference, Chicago, IL

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

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)

IMTS is back in town, From Sept. 7 through Sept. 15, the largest industrial exhibition in the Western Hemisphere will fill one of the largest exhibition centers in the world. A show of this magnitude is a little like the 500 lb. gorilla in your dining room - hard to ignore.

It is often easy for those outside of the gear industry to get the impression that nothing is changing in our business. After all, all illustrated bimonthly by the covers of this very journal the making of gears has been with us for centuries. However, nothing could be further from the truth.

This issue's editorial is a reprint of the keynote address given by Michael Goldstein at the Computer Aided Gear Design Seminar held at the University of Northern Iowa, Cedar Falls, IA on November 9, 1987.

A medieval philosopher once said that if he knew for certain the world was to end tomorrow, he would be sure to take time to plant an apple tree in his garden today. The recent events in the world financial capitals have seemed a bit like prior notice of something cataclysmic, but like the philosopher, we can still find some reasons for hope in the face of an uncertain future. The good news for our industry is that four important efforts on the part of various organizations promise to have long-term positive effects on both the gear and machine tool businesses.

How is it that we woke up one day in the early 1980s to find that apparently American industry was suddenly inefficient, our workforce unproductive and our management inept? Almost overnight industry found its sales dropping dramatically, while for many companies foreign competition became excruciatingly intense. This sudden change in the economic climate proved fatal for many companies and has been nearly as hard on our collective morale. In a country used to winning, we began to hear ourselves talked of as losers.