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).
Manufacturing and inspection notes for engine gears and crankshaft components.
| Identifier | ExFiles\Box 173\1\ img370 | |
| Date | 4th February 1934 guessed | |
| III a gas jet 5. Inspect. Helix angle must be within 1/4 of a degree (30° Helix Angle). Eccentricity limit .002. 6. Burnish tooth face on a Pratt & Witney three gear burnisher with a pressure of 10 lbs. Burnishing gear moves sideways 3/16 during this operation. Face of burnishing gear cross-hatched to give a file like surface which speeds up the operation to about 1/2 min. Soap water used as cutting fluid. 7. Final inspection, pitch line held within .0005 limit. 8. For production, all gears made the same size, oversize supplied for servicing only. 9. Don't stock gears or blanks. They deteriorate. Erection 1. Crank shaft Centre held to .0015 with regard to Camshaft Centre. 2. Pitch line clearance between Cam wheel and Crank pinion rarely less than .0015 or more than .0025. 3. Producing over 400 engines a day, the average engines turned down on unit-test for noisy gears is 2%. It is unusual. | ||