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).
Technical memorandum discussing potential improvements to the Peregrine starter motor's efficiency and torque characteristics.
| Identifier | ExFiles\Box 62\1\ scan0056 | |
| Date | 16th August 1932 | |
| X6134 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wst. c. Hy{Tom Haldenby - Plant Engineer} c. Hy{Tom Haldenby - Plant Engineer}/RD. Hs{Lord Ernest Hives - Chair}/Wst.12/AM16.8.32. PEREGRINE STARTER MOTOR Having reduced the resistance of the windings of this motor we think we can go a step further in improving the efficiency and speed torque characteristic of same. We are now working at a much higher flux density than was assumed in our original calculations so that it should be possible to improve the armature circuit by reducing the number of active conductors at the same time increasing their cross section without loss of iron. If we allow only 8000 lines per sq.cm. instead of 6500 as calculated originally, we could reduce the number of active conductors to 120 which would mean a 15 slot armature instead of 19. The cross sectional area of the armature conductors could then be increased to 15 S.W.G. and an additional increase in the tooth section could also probably be effected. Confirming our conversation, we should be glad if Hy{Tom Haldenby - Plant Engineer}/RD. could ascertain if this is practicable and instruct an armature for test as soon as possible as it will be a valuable experiment. Also the motor will have a much greater acceleration owing to its lower resistance which will be valuable in bumping the engine over the extra high compression peaks. Hs{Lord Ernest Hives - Chair}/Wst. | ||