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).
Recommendation to increase the size of the 20/25 dynamo brush flexible for improved current capacity and mechanical strength.
| Identifier | ExFiles\Box 62\3\ scan0241 | |
| Date | 7th July 1931 | |
| X.6005 Ey. from Hs{Lord Ernest Hives - Chair}/Pgt. Hs{Lord Ernest Hives - Chair}/Pgt3/AD7.7.31. X6099 X6005. 20/25 DYNAMO BRUSH FLEXIBLE. In view of the recent increases in the output of the 20/25 dynamo and the fact that one brush flexible has to carry the whole of the current, as compared with two on the 40/50 machine, we think that this flexible should be increased in size. Apart from the point of view of its current carrying capacity, however, we have recently had one or two cases of this flexible being badly worn and in one case completely breaking with ordinary handling, which suggests that it is hardly heavy enough mechanically. The present size of this flexible is 124 strands of 45 SWG. wire, and we think that it should be made equal to that on the 40/50 dynamo brush, which is composed of 4 cores, each core consisting of 30 strands of 42 S.W.G. wire. Hs{Lord Ernest Hives - Chair}/Pgt. | ||