Over the years, we have traveled extensively throughout the industrialized world, and became increasingly aware of the availability of enormous amounts of technical writing
concerning research, experiments, and
techniques in the gear manufacturing field. New manufacturing methods, materials, and machines were continuously being developed, but the technical information about them was
not readily available to those that could best use it. There was no central source for disseminating this knowledge.
A gear can be defined as a toothed wheel which, when meshed with another toothed wheel with similar configuration, will transmit rotation from one shaft to another. Depending upon the type and accuracy of motion desired, the gears and the profiles of the gear teeth can be of almost any form.
Presumably, everyone who would be interested in this subject is already somewhat familiar with testing of gears by traditional means. Three types of gear inspection are in common use: 1) measurement of gear elements and relationships, 2) tooth contact pattern checks and 3) rolling composite checks. Single Flank testing falls into this last category, as does the more familiar Double Flank test.
A brief introduction to the subject of Thin Film Coatings and their application to gear hobs and shaper cutters is followed by a detailed description of the Chemical Vapor Deposition Process and the Physical Vapor Deposition Process. Advantages and disadvantages of each of these processes is discussed. Emphasis is placed upon: application engineering of coated gear tools based on laboratory and field test results. Recommendations are suggested for tool design improvements and optimization of gear cutting operations using coated tools. Productivity improvements potentially available by properly utilizing
coated tools are considered in terms of both tool cost and machining cost.
Borazon is a superabrasive material originally developed by General Electric in 1969. It is a high performance material for machining of high alloy ferrous and super alloy materials. Borazon CBN - Cubic Born Nitride - is manufactured with a high temperature, high pressure process similar to that utilized with man-made diamond. Borazon is, next to diamond, the hardest abrasive known; it is more than twice as hard as aluminum oxide. It has an extremely high thermal strength compared to diamond. It is also much less chemically reactive with
iron, cobalt or nickel alloys.
An expression is derived, giving the optimum number of teeth over which the span measurement should be made, for profile-shifted spur and helical gears.
At a time when there are many pressures on the Gear Industry and its representative Association, the
American Gear Manufacturers Association, it seems particularly appropriate that Gear Technology - The
Journal of Gear Manufacturing appears. AGMA is particularly pleased to have the opportunity to write the first editorial for this magazine.
Gear shaving is a free-cutting gear finishing operation which removes small amounts of metal from the working surfaces
of the gear teeth. Its purpose is to correct errors in index, helical angle, tooth profile and eccentricity.