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).
Letter to Gleason Works detailing the results of various gear combination tests.
| Identifier | ExFiles\Box 111\4\ scan0074 | |
| Date | 4th October 1938 | |
| c. Da.{Bernard Day - Chassis Design} D.{John DeLooze - Company Secretary} Da.{Bernard Day - Chassis Design} Hdy.{William Hardy} 802? Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}8/MH.{M. Huckerby} 4th. October 1938. Gleason Works, 1000, University Avenue, Rochester, N.Y., U.S.A. Dear Sirs, We thank you for your letter of 24th. Sept. It does not explain the facts as we know them. These are (1) Both the pinion and gear mountings of FD.{Frank Dodd - Bodies}91 are considerably more rigid than our standard axle GB.619. (2) The .650 offset combination 8 1/2" ring gear, either 10/41 or 10/43, will stand on a mild EP{G. Eric Platford - Chief Quality Engineer} (Wakefield Hipress) the dynamometer test which fails the 1 1/2" offset gears. (3) A 10" ring gear .850 offset 8/34 combination is entirely successful on our 12 cylinder engine at a motor torque of 4200 lbs.ins. and a low gear of 3:1. This also runs on mild EP.{G. Eric Platford - Chief Quality Engineer} (4) The score marks on the 1 1/2" offset gears are along the teeth and not at right angles as is usual in the event of pick up. All our dynamometer testing is done at 2000 engine r.p.m. The rear axle is water cooled to 90°C. From these results we have concluded that the trouble has arisen from the increase in hypoid, increase in spiral angle and therefore greater sliding. | ||