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).
Operational issues with an epicyclic 3rd speed gearbox.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan106 | |
| Date | 9th April 1931 | |
| [STAMP] RECEIVED 1931 APR 8 SE HS.{Lord Ernest Hives - Chair} HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} ORIGINAL. DA{Bernard Day - Chassis Design}2/M9.4.31. X523. EPICYCLIC 3rd. SPEED GEARBOX. Referring to your HS{Lord Ernest Hives - Chair}/LID{A. J. Lidsey}4/KT31331., we understand that this report is now cancelled. We should like however to refer to two points: (1) When the dogs are clicking the toggle spring is not acting at its most effective leverage for controlling the dogs, and, with the reduction of 50% in strength referred to in your report it may be insufficient. (2) There is no time when the car is in motion when the sun is not under control as to speed and direction of rotation, that is, when operating 1st. or 2nd/ speed the Maybach dogs are home in top or 3rd., and when operating top or 3rd. the planet cage is fast to the propeller shaft and the speed and direction of the sun depends only on engine speed. Neither friction nor planet inertia have anything to do with it. But when the car is stationary it is agreed that an attempt to change the epicyclic unit will involve question of friction and inertia. (a) In going from top to 3rd. the friction in the planet cage system (i.e. 3rd. motion shaft turning in oil, 2 constant mesh trains, 5 bearings, etc,) causes the 3rd. speed dogs to engage instantly, perhaps with slight shock, unless a strong clutch brake is used, in which case the dogs tend to click. (b) It looks as though engaging top from 3rd. when stationary is always going to be difficult. DA.{Bernard Day - Chassis Design} | ||