# July/August 1988

Archive > 1988 > July/August 1988

## Technical Articles

Helical Gear Mathematics, Formulas and Examples Part II
The following excerpt is from the Revised Manual of Gear Design, Section III, covering helical and spiral gears. This section on helical gear mathematics shows the detailed solutions to many general helical gearing problems. In each case, a definite example has been worked out to illustrate the solution. All equations are arranged in their most effective form for use on a computer or calculating machine.

High Speed Hobbing of Gears With Shifted Profiles
The newer profile-shifted (long and short addendum) gears are often used as small size reduction gears for automobiles or motorcycles. The authors have investigated the damage to each cutting edge when small size mass-produced gears with shifted profiles are used at high speeds.

The Uses and Limitations of Transmission Error
The concept of "transmission error" is relatively new and stems from research work in the late 1950s by Gregory, Harris and Munro,(1) together with the need to check the accuracy of gear cutting machines. The corresponding commercial "single flank" testing equipment became available in the 1960s, but it was not until about ten years ago that it became generally used, and only recently has it been possible to test reliably at full load and full speed.

## Departments

Unfair Fares (Publishers Page)
"It's not so much the rocks in the road that wear you down as the bit of gravel in your shoe," says the old maxim. Little annoyances over which we seem to have no control are the ones that take their greatest toll and raise our frustration level to the highest point. I feel fortunate to be the editor of a magazine, so I at least have some means to vent my frustration.

A Real Test (Voices)
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.

Industry Forum (Voices)
Letters to the editor on a variety of subjects, including couplings, gear planers and ausforming.