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).
Test report on the overheating of a Goshawk dynamo, detailing issues with a negative brush and commutator.
| Identifier | WestWitteringFiles\K\October1923\ Scan53 | |
| Date | 10th October 1923 | |
| EFC. AB.88 10th Oct. 1923. X.4383 - FURTHER OVERHEATING TESTS OF GOSHAWK DYNAMO. Some further running of dynamo E, with the negative brush sticking has been carried out. The machine was heat insulated, whilst the bad contact of the negative brush was accentuated; it was thus run for several hours. This time the temperature of the carcase rose to 100°C and the solder was flung off, from the commutator. The approximate operating particulars were as follows :- Dynamo speed 1400 r.p.m. Amperes delivery 9-10 Main volts 14.8 Field volts 10-12. With the brush bedding normally, the output at the same temperature was found to be 8.0 amps. The commutator is slightly roughened, and the negative brush and holder show signs of the sparking, at the trailing edges. During the test, the ammeter was somewhat unsteady but this might not be very noticeable on the dashboard ammeter. EFC. | ||