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 report into a complaint about dirt accumulating in dynamo ER55 from chassis 82-HC.
| Identifier | ExFiles\Box 70\3\ scan0290 | |
| Date | 16th May 1927 | |
| To EFC. BC.137. May 16th 1927. COMPLAINT DYNAMO ER55. EX CHASSIS 82-HC. This machine was sent to us by production with a complaint to the effect that "dirt" was constantly accumulating in the end-cover. By dirt it is presumed that brush dust is meant. From an examination of the dynamo with following points were noted :- With the exception of the end cover, the machine was found to be quite clean, having apparently been cleaned up by production. On the inside of the end cover there was a greasy deposit of a mixture of oil and carbon dust. The control brushes were found to have the early nominal setting of 120º from the positive brushes (the actual angle being about 119º). All brushes were blackened and somewhat pitted. The amount of wear of the brushes was not thought to be great. The machine was run and the representative peak output observed. This was very high; 14.8 amperes. Rather bad sparking was observed at the control brushes at high speeds. It is thought that, due to the control brush setting of 119º, the high output of the machine, with the consequent high average temperature, and with the addition of sparking, has caused a more rapid some disintegration of the brushes than usual. The machine in all other respects appears to be quite normal. It should, however, be modified in respect of the control brush angle, to make it similar to the standard machine. EFC/C.A.Pignatt. | ||