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).
Alterations for a P.2. S.M. 2nd Gearbox before reassembly.
| Identifier | ExFiles\Box 15\5\ Scan394 | |
| Date | 7th July 1934 | |
| N7310 To RHC.{R. H. Coverley - Production Engineer} from HDY.{William Hardy} HDY.{William Hardy}1/HP.7.7.34. c.c. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} P.2. S.M.2nd Gearbox. We have examined the pieces of this box and should like the following alterations made before the box is again assembled:- (1) The spherically mounted bearings for the 2nd speed slider to be made of bronze instead of aluminium. The ends of the bores to be radiused to say .025 R.{Sir Henry Royce} to avoid the scraping off of oil. (2) There is the same excessive wear of the bronze cone by the retaining plate that occurred on the J.3. gearbox although we have stiffened the plate. There is ample thrust area for the load if all is bedding, but the difficulty appears to be to obtain a truly flat surface on the steel ring. The marking on the ring indicates to us that the spigot is distorting the ring and to avoid this the spigot which is now a good fit should be eased to give a push fit. We also suggest that the cone should be lapped on the plate when in place on the layshaft. The chamfer that is provided on the inner diameter of the plate is to lead oil to the thrust surfaces. (3) Our impression is that the spring plunger loading is more than is intended (see N. Sch.3964). Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} is going to check this. (4) Clearances of the S.M. actuating mechanism, of the first box of a new type particularly,should always be liberal as we cannot afford to give much away in friction and there is no time to free the mechanism by use. (5) The cam angle for the 2nd speed gear is to be increased to 50° with the axis of the shaft. We understand that you have had a note from Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}about this. HDY.{William Hardy} | ||