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 of an improved rig for lapping car engine timing gears, outlining existing faults and suggesting improvements.
| Identifier | ExFiles\Box 143\1\ scan0023 | |
| Date | 9th July 1934 | |
| To EJJ. c. to E.{Mr Elliott - Chief Engineer} c. to Sft.{Mr Swift} 43269 Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}19/KW. 9.7.34. We believe that you are designing an improved rig for lapping Car Engine timing gears. We are very interested in the question of producing quiet timing gears and have carried out a number of experiments on experimental engines. In the near future we hope to be able to standardize a new type of timing gear which, if lapped accurately, will be quiet without subsequent hand bedding. We therefore consider that the present is an excellent opportunity for making the best possible lapping rig in order to ensure the success of the new gears. In our opinion the lapping rigs at present in use by the Production Dept. have the following faults :- (1) Inadequate protection of bearings and slides from the lapping compound. (2) Doubtful accuracy of mounting of gears on the shafts of lapping rig. (3) Insufficient inertia of shafts of lapping rig. Concerning (1) We believe that you are going to adopt the principle used on Gleason lapping machines and we cannot suggest any improvements on this. Concerning (2) The experiments we have carried out have shown us that the mounting of the gears on the rig is of very great importance. We suggest that the spindle nose on which the gear is mounted should be ground with the shaft running in its own bearings and that the use of loose bushes between the arbour and the gear wheel should be avoided wherever possible. | ||