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).
Testing alternative, cheaper materials for the servo drive worm wheel on Bentley & 25/30.HP models.
| Identifier | ExFiles\Box 105\4\ scan0201 | |
| Date | 13th December 1937 | |
| To HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} 541 Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}10/AP.13.12.37. SERVO DRIVE - BENTLEY & 25/30.HP. The worm wheel G.54654 is made of phosphor bronze which costs us 3.3 shillings per wheel. As the duty this worm wheel does is not exceptionally severe, we want to try 3 wheels in cheaper metal, and test them on a rig. The material proving most satisfactory can then be put on a car. The material used should be:- 1. Cast Iron. Will Mr.Knagg please send us a copy of the specification he proposes to use. 2. Aluminium RR.56. Solution treat (quench from 525°C) and temper for 24 hours at 175° - 180°C. 3. 0.5% Carbon Steel quenched and tempered to give a Brinell figure of 450. The iron and steel wheels should be lapped in to the worm. The testing will be carried out on the chassis 5.B.1V., using its own gearbox. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||