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).
Investigation into a burst commutator on a Goshawk 11 dynamo, comparing original, modified, and American designs.
| Identifier | ExFiles\Box 50\5\ Scan032 | |
| Date | 27th April 1922 | |
| Hs{Lord Ernest Hives - Chair} X.4333 TO-By.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to CD. c. to MST c. to WDT.✓ c. to HS.{Lord Ernest Hives - Chair} RECEIVED APR 28 1922 E4/M27.4.22. X 4333 (crossed out) GOSHAWK 11. COMMUTATOR ON DYNAMO. X 4383 We should be very interested to know whether the commutator which has burst is to the original LeC design, or the modified pattern produced by Derby. We are inclined to think that the shape of the mica plates has rather a tendency to weaken the commutator. We are sending you herewith a sample bakelite commutator which we have cut up, shewing the method of construction adopted by the Americans. We believe this is a Delco commutator; it was brought here by Mr. Hives. It is not possible to observe any shrinkage from the dove-tailed internal surface of the copper, and we wondered if an enormously increased pressure has been employed during the process of making the moulding. This would be very easy to do and might be of benefit. We also wondered at the same time if any special form of bakelite had been used on this particular commutator as the filling in it seems to be somewhat of a fibrous nature. The sample is also cut in such a manner as to shew the outline of the separator plates. These plates are in bakelite and seem to be well stuck in. We do not know whether it is possible to mould new bakelite on to old but we have always assumed not. (1) | ||