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.
The art of gear hobbing has advanced dramatically since the development and introduction of unique machine and tool features such as no backlash, super rigidity, automatic loading of cutting tools, CNC controls, additional machine power and improved cutter materials and coatings. It is essential to utilize all these features to run the machine economically.
It is with great anticipation that we move closer to AGMA's Fall Technical Conference and Gear Expo '87, which is being held on Oct. 4-6 in Cincinnati, OH. This bold undertaking by both AGMA and the exhibitors in the Expo's 160 booths is an attempt to make a major change in the industry's approach to the exposition of gear manufacturing equipment. By combining the Expo with the Fall Technical Conference, those involved in gear manufacturing will have the opportunity to review the latest equipment, trends, and most innovative ideas, while keeping up with the newest technology in the industry.
"Competitiveness" is the newest corporate buzzword. It is being offered as the solution to all our economic problems. Newspapers, magazines and legislation are pushing us to be more "competitive."
For the last few years, the market has been tough for the U.S. gear industry. That statement will cause no one any surprise. The debate is about what to do. One sure sign of this is the enormous attention Congress and the federal government are now placing on "competitiveness."
In ParI 1 several scuffing (scoring) criteria were shown ultimately to converge into one criterion, the original flash temperature criterion according to Blok. In Part 2 it will be shown that all geometric influences may be concentrated in one factor dependent on only four independent parameters, of which the gear ratio, the number of teeth of the pinion, and the addendum modification coefficient of the pinion are significant.
In this discussion of gear roll-finishing particular attention is called to the special tooth nomenclature resulting from the interaction between the rolling die teeth and the gear teeth. To eliminate confusion the side of a gear tooth that is in contact with the "approach" side of a rolling die tooth is also considered to be the approach side. The same holds true for the "trail" side. Thus, the side of the gear tooth that is in contact with the trail side of a rolling die is also considered to be the trail side.
The load capacity rating of gears had its beginning in the 18th century at Leiden University when Prof. Pieter van
Musschenbroek systematically tested the wooden teeth of windmill gears, applying the bending strength formula published by Galilei one century earlier. In the next centuries several scientists improved or extended the formula, and recently a Draft International Standard could be presented.