From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The carbonizing, testing, and shipping of wheels and pinions, page 2.
| Identifier | ExFiles\Box 49\1\ Scan093 | |
| Date | 26th August 1919 guessed | |
| - 2 - at about 1700°F, and quenched at 1450°F, in oil, and show an average scleroscope reading of 80. Chordal thickness of teeth at pitch line varies from standard to .006 thin. These gears are cut according to standard Gleason practise, allowing 3/10 of working depth of teeth for addendum on wheel, and 7/10 on pinion. The working depth on these spiral teeth is 85% of standard working depth for straight teeth, as Chordal thickness is smaller on spiral teeth than on straight teeth due to the spiral angle, and therefore height of teeth is decreased proportionately. I tested all gears on their regular testing machine, running them both forward and reverse at different settings, and they sounded good despite the fact that the testing machine is located in a small room especially for this purpose. The carbonizing as shown by test piece which was carbonized along with these gears, is approximately .040 deep. Although both Gears and Pinions are marked similarly, it does not of course mean that Bevel Wheel "A" should run with Pinion "A", as they are of course quite interchangeable. No grinding had been done on Pinions as it was understood by them that we should take care of this in Derby. I had the shipping department pack these gears before I left, and ship them by express to Perry Ryer Company, so that they ought to be in New York this morning. DR. | ||