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).
Series of dynamo tests varying the main brush position to determine performance curves.
| Identifier | WestWitteringFiles\J\May1923\ Scan29 | |
| Date | 3rd May 1923 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EPC. C. Ry. & EH. C. CJ. & FN. C. Tas.{T. Allan Swinden} C. Wor{Arthur Wormald - General Works Manager}/Mr. Brock. ORIGINAL X.4383 - WR GODDARD DYNAMO BRUSH POSITION. X 4383 We have now completed the series of dynamo tests referred to in our EFC4/T26.3.23, in which the main brush position has been varied, and for each position, the position of the third brush for the maximum output consistent with a given degree of heating is found. A series of curves of performance of the machine has thus been obtained, all for an approximately equal degree of heating, and the commutation also has been carefully watched. This has not only been done on standard machines (two ?), but also on a machine with reduced gauge of field winding and with increased section of carcase and reduced air gap, and the results obtained on these tests are shown on the accompanying curves. On these sheets, the amounts of retard of main brushes from no load neutral position are tabularly indicated, the curves themselves being numbered correspondingly on the different sheets. on each sheet, N refers to no load neutral position of main brushes. Curve marked 1 refers to previous standard position of approximately 2° retard. The curve marked 4 refers to new standard position(for which we are issuing a standardisation sheet). The various groups of curves are as follows :- Contd. | ||