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 report on dynamo investigations, covering regulation, brush sparking, failures, and patents.
| Identifier | ExFiles\Box 31\1\ Scan156 | |
| Date | 2nd June 1923 | |
| X1402 To R.{Sir Henry Royce} from EFC. c. CJ. WOR.{Arthur Wormald - General Works Manager} c. Ey. EFC2/T2.6.23. X1402 X4333 As a preliminary answer to your R2/M30.5.23:- (1) We have now made a start on the re-investigation of external dynamo regulation, at present dealing with the Scintilla dynamo, about which we shall shortly be able to report. We think there is no question that the heating will be less on such a machine for the same output. As regards brush sparking, we cannot at the moment answer this definitely. It appears that the main brushes as in the controlled dynamo case, would need a retard to strike an average between the slow speed condition when the regulator is not working, and the high speed condition when the field is weak and much distorted. One would feel, therefore, that sparking might be absent at some intermediate speed, but occur slightly at high and low speeds, with a suitable brush position. (2) (3) & (4). As stated, we have a dynamo running for long period commutator and brush tests, and in due course we hope to carry out tests of brushes in various other materials. (3) We have had very few actual failures of brushes and it is not possible to say definitely that the positive brush fails more easily than the others, though it does not appear to preserve the same polishing of contact surface. The exp. of running the dynamo with reversed polarity will be tried. (B) The question of vibrator regulator patents is being looked into with the assistance of Mr. Walker. Satisfactory reports are being received from production of improved commutation on 20 H.P. dynamos., resulting from the new brush position. EFC. | ||