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).
Failures and improvements to the Sequence Starter Motor and Gear, Scheme No. 2B.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan154 | |
| Date | 13th October 1928 | |
| To R.{Sir Henry Royce} From EFC. c. BJ. E.{Mr Elliott - Chief Engineer} EY. ORIGINAL EFC2/T13.10.28. SEQUENCE STARTER MOTOR AND GEAR No. 2B SCHEME. Further to our EFC4/110.10.28, there were originally two minor failings causing failure to operate, both of which have now been overcome in this particular gear. They were :- (A) The end on failure previously described (pinion and wheel teeth end to end). (B) A slight binding of the pinion in the gears when partly in gear, i.e. not in gear far enough to bring on the main current. We have had two main armature springs on trial which were arranged to give the same force in the initial position of the armature, but one of which had roughly 50% higher rating than the other. The return force in the end to end position of the teeth was therefore somewhat greater with this stronger spring. The A failure occurred fairly often with the weaker spring and the pinion would not return when the button was released so as to afford another opportunity. With the stronger spring, however, the failure, which still occurs occasionally, is only a failure on the first press, because the armature returns, and another chance is afforded. The armature return has been made still more sure by packing the motor pinion back against the small pinion spring a short distance so that the clearance between the teeth in the initial position is increased, providing for a rather greater compression of the spring before the teeth reach the end on position. This is the present condition. Contd. | ||