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).
Comparing the silence and performance of various gearbox designs, including Wilson, Lanchester and epicyclic types.
| Identifier | ExFiles\Box 6\4\ 04-page234 | |
| Date | 20th January 1930 | |
| Y5310 R.{Sir Henry Royce} from Da{Bernard Day - Chassis Design}/Hdy.{William Hardy} (held up) C. Hs.{Lord Ernest Hives - Chair} Da.{Bernard Day - Chassis Design} Da{Bernard Day - Chassis Design}/Hdy{William Hardy}1/M20.1.30. X.2061 X.523 X.7310 X.5310 GEARBOX - SILENCE. We have made some calculations on the various types of gearbox to determine the relative pitch speeds and loads, and we send herewith M.Schn.3022 and the sketch attached on which we have tabulated our results. We have assumed that the product of the pitch speed and load (S by L) is an indication of the amount of noise the gear will make. This is not intended to be anything more than a rough guide to the theoretical merit of the gear arrangement, and makes no allowance for the difference between internal and external mesh. The superiority of the single train gear with annulus driven for third speed is marked. The combined results of the 3 trains of the Wilson gear in 3rd speed is fairly good. The value of S by L being half that for the Phantom II 3rd speed. The Lanchester scheme is inferior in principle to the Wilson and this inferiority is reflected in the value S by L for 2nd speed which is larger than for the Wilson 2nd speed in spite of the higher ratio of the former. The epicyclic-back gear (as we have called it for the moment to distinguish it) is not good in 3rd speed. S by L is actually more than for Phantom II although some allowance should be made for the one internal mesh possessed by the former gear. As the ratio of reduction of an epicyclic gear increases so the value of S by L becomes more nearly the same as for a plain back gear. This accounts for the poor showing of the epicyclic-back gear in 3rd. as its first speed train is in action on all gears. The reverse gear on the Wilson box has to counteract the forward torque from the 1st speed train as well as provide reverse torque. Da{Bernard Day - Chassis Design}/Hdy.{William Hardy} | ||