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).
Tests for a starter motor on a 40/50 car with a 3-speed gearbox to achieve a more silent engagement.
| Identifier | ExFiles\Box 75\1\ scan0153 | |
| Date | 1st August 1921 | |
| x3426 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}3/LG10. 8.21. X.3740 - STARTER MOTOR FOR 40/50 CAR WITH 3-SPEED X.3757 GEAR BOX X.3426 Acting on Mr. Royce's instructions, we have tried increasing the resistance in the main switch in order to obtain a more silent engagement. We proved that with the pinion shaft running at 40 to 50 R.P.M. that we obtain the most silent engagement. We arranged the resistance in order to get the motor turning at this speed with the engine and car at normal temperatures. We found, however, that after we had made it correct for normal working temperatures, when the motor was cold it would not turn at all with the first operation of the switch and therefore the starter could not be engaged. We have taken the following tests in order to show the variations in the speed of the motor at different temperatures. The revolutions were taken immediately the switch was closed with a Hasler counter which counts the revs. for five seconds. The motor gradually gains in speed if the switch is left on as we would expect. Hs.{Lord Ernest Hives - Chair} (Upside down footer text: R.R. 235A (100 T) (S.H) 159 (11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800) | ||