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).
Overhaul of calculations for the Sequence Starter Motor No. 2 Scheme.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 135 | |
| Date | 28th May 1927 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. ORIGINAL EFCL/T28.5.27. SEQUENCE STARTER MOTOR NO.2. SCHEME. X7621 Further to our EFC6/T24.5.27, we are overhauling our calculations for the sequence motor in the light of the utilisation of a tapered armature and pole pieces, as suggested by you for better longitudinal functioning. We hope to be able to send you a complete set of calculations for your approval. In the adoption of the 13 to 1 ratio, we were anxious to avoid the complication of departing from the 41 slots and 82 conductors if possible. Brake tests and further calculations, together with considerations of the longitudinal pull and the results of engaging tests, have now indicated the desirability, with this 13 to 1 ratio, of adopting an armature with a larger number of conductors, in which case it becomes necessary to utilise two turns per coil, very similar to that of the 20 HP. In fact, the calculations at present indicate a scale model reproduction of the 20 HP. armature, the recommended actual diameter of which we have not yet finally arrived at, but which may not be as much down on our present dia. of 3.100 as previously suggested by our EFC6/T24.5.27. We hope to be able to put a complete set of calculations before you about the middle of next week. There appears to be so little margin for the 5" motor with the 13 : 1 ratio and teazer winding. EFC. | ||