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).
Design progress of an 'Anti Groan Device' for various car models and the Goshawk 3 gearbox casing.
| Identifier | WestWitteringFiles\M\October1924-December1924\ Scan60 | |
| Date | 22th December 1924 | |
| TO [redacted] FROM AJS. Copy to [redacted] Copy to [redacted] Copy to - HS.{Lord Ernest Hives - Chair} ORIGINAL AJS1/M22. 12. 24. ANTI GROAN DEVICE - 40/50. X1511 / X3435 Referring to your memo. HY{Tom Haldenby - Plant Engineer}10/H19.12.24., and wire of even date:- (1) CJ. has allowed me to complete the drawing of Goshawk 3. gearbox casing, which I expect to despatch on Wed: (2) ANTI GROAN DEVICE FOR EXISTING CARS. Some work has already been done on this, and the final conclusion come to with R.{Sir Henry Royce} was that a smaller diameter epicyclic gear could be substituted for the present one, the annulus teeth of which would be cut in the steel casing to save room. The original idea of pushing back the epicyclic starter gear in the box was abandoned by R.{Sir Henry Royce} as impracticable. The new epicyclic reduction of smaller dia. will have the same number of teeth in the sun wheel which results in its ratio of reduction compared with the existing one not being so great, necessitating a 20 tooth instead of a 26 tooth chain wheel on the starter motor axis. So far as this design has been gone into at present, (the new epicyclic gear being almost completed) it is anticipated that the muff of the existing engine coupling, and also first motion shaft in gearbox, will be used, and further, it appears to require that the starter motor or its chain wheel should be pushed forward about .125 to be in line with new chain wheel position on gearbox epicyclic. (3) ANTI GROAN DEVICE FOR 'V' SERIES. The cars in this series having a different clutch, will require different parts from those on existing cars as far as the fabric coupling. We shall endeavour of course to use the new epicyclic reduction on both 'V' and old series cars without modification, or a very slight one. Referring to (1) above, this will permit either none or the minimum delay in producing the 20.H.P. gearbox. Referring to (2) and (3) above, we wish by these paragraphs to make clear that these are two distinct jobs, the designs of which will go hand in hand, and will be continued immediately after the Xmas holidays. It is rather difficult to estimate the exact time for the jobs in question, but about a week or ten days should see them both through. AJS. | ||