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).
Overheating of Goshawk dynamos when mounted on a chassis compared to bench test conditions.
| Identifier | WestWitteringFiles\I\July1922\ Scan99 | |
| Date | 18th July 1922 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFC. c. CJ. & FN. c. Py. & EP.{G. Eric Platford - Chief Quality Engineer} c. Fg. & Ds. ORIGINAL EFC2/T18.7.22. X.4383 - HEATING OF GOSHAWK DYNAMOS ON CHASSIS There have now been several cases of Lucas-Goshawk and C.A.V-Goshawk dynamos getting sufficiently hot to run the solder from the commutator connections, and it is thought that there may be very little margin in the case of the R.R. dynamo at equivalent output. It has already been suggested in Hs{Lord Ernest Hives - Chair}7/LG24.5.22 that the dynamo should be provided with some sort of ventilation and, owing to the already referred to recently experienced failures, we are of the opinion that this is necessary for satisfactory running of the dynamo. Tests on the bench indicate that we can set the brushes for a reasonable output without exceeding a carcase temperature of 87°C, measured in the usual way, when the ambient temperature is in the neighbourhood of 18°C. On the chassis, the conditions are somewhat different, the carcase of the dynamo being in direct metallic connection with the crankcase of the engine. This makes the starting temperature of the dynamo a good deal larger. On the other hand, when the dynamo carcase attempts to rise in temperature, there will be a considerably greater loss of heat for the same temperature drop between the carcase and its surroundings than in the case of the bench test, so that it does not follow that the actual dynamo temperature | ||