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).
Preliminary trial of a 2A sequence starter motor fitted to an EAC.7 engine.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan025 | |
| Date | 8th December 1927 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} c. BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} SEQUENCE STARTER. Further to our EFC4/T26.11.27 we have now got the 2A motor back on the EAC.7 engine fitted with parallel teeth with rounded corners for engagement. We have had an opportunity of making a preliminary trial of this motor on the engine on the test bed, but without using the proper switching apparatus, i.e. simply applying battery current first to the teazer and then to the main terminal. As surmised it is the case in a large percentage of times of application of the teazer current that the teeth approach one another and jam in the manner which we have described. It was very easy to observe this on the test bed. Approximately one in four or one in five times. Again as described, this can always be got into engagement by releasing and reapplying the teazer current so that it would not mean that the use of the starting handle was necessary. The application of the main current will clear the jam because it begins to move the engine, but with the switching apparatus the main current could not be applied until engagement has taken place. On allowing the engine to start and accelerate the disengagement of the pinion, though not quite as tardy as we might have anticipated, nevertheless does not take place as quickly and neatly as is desirable and as surmised a pronounced whirr is caused in the engine accelerating the motor before this gets out of gear. These parallel teeth are very much better for noisiness when rolling the engine and in consequence the whirr | ||