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).
Spectre Gearbox transmission knocks, proposing a reduction in gear and keyway clearances.
Identifier | ExFiles\Box 94\1\ scan0189 | |
Date | 13th September 1935 | |
x328 SECRET. [Signature] GRY{Shadwell Grylls}- HDY.{William Hardy}1/HP.13.9.35. To EY. from HDY.{William Hardy} c.c. Hs.{Lord Ernest Hives - Chair} Sft.{Mr Swift} Ws. Be. Hx. SpectreCodename for Phantom III Gearbox. With regard to transmission k̶n̶o̶c̶k̶s̶, we have discussed with Ws. the question of the clearance of some of the gears on the shaft c̶a̶s̶t̶e̶l̶l̶a̶t̶i̶o̶n̶s̶ and it appears that some reduction may be practicable. The parts referred to are the constant mesh wheel and 3rd speed pinion on the layshaft and the 2nd speed wheel and the universal joint coupling on the 3rd motion shaft. Our present tolerances allow a clearance A of from 1 - 3/1000" the key and keyway each having a tolerance of 1/1000". The suggestion is to reduce the clearance to 1/2 - 1½/1000" the tolerance on key and keyway becoming 1/2/1000". According to the Cadillac service book this is their practice. We understand that we are obtaining clearances more nearly 1/1000" than 3/1000" and in this case it would be necessary with the new limits to secure clearances more nearly 1/2/1000" than 1½/1000" to obtain an improvement. HDY.{William Hardy} | ||