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).
Proposing a redesign of the 40/50 starter motor to improve its speed torque characteristic.
| Identifier | ExFiles\Box 62\1\ scan0057 | |
| Date | 18th August 1932 | |
| X6079 To By.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wst. c. By/RD. E.{Mr Elliott - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}/Wst.8/KT.18.8.32. 40/50 STARTER MOTOR. Owing to the increased compression ratio of the 40/50 engine it is important that we improve the speed torque characteristic of the starter motor. With an engine driven petrol pump, the starting speed should be as high as possible. On 19-EX the normal engine speed when turned over by the motor is only 45 r.p.m. in summer conditions as against a previous figure of 60 to 70 r.p.m. Upon examining a motor we think it possible to redesign this on the lines of the Peregrine motor, using long bolt fixing for the end plates instead of screws in the carcase etc. This would enable us to use a thinner carcase with a corresponding increase in armature diameter. Additionally we should be able to wind the main field similar to the Peregrine with larger cross section Copper bar. We should like Mr. to let us know if it is possible to get a larger cross section field wire in this way and instruct a modified motor for us to test, in order that we can ascertain if there is possible improvement over the present standard 40/50 motor. Hs{Lord Ernest Hives - Chair}/Wst | ||