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).
Proposal to improve commutation on the Phantom II and Bensport shunt dynamo by using four brushes instead of two.
| Identifier | ExFiles\Box 62\3\ scan0361 | |
| Date | 21th June 1933 | |
| R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By/RD. ✓6142. Hs{Lord Ernest Hives - Chair}/Wst.1/MA.21.6.33. P.II AND BENSPORT SHUNT DYNAMO. In order to improve the commutation on our larger shunt machine we wish to try four brushes symmetrically spaced instead of two. We would like these brushes to be of the single type similar to the 20/25 and thinner and slightly longer than the existing dual brush. The use of four brushes will definitely reduce the current density per brush and coupled with the thinner section will reduce the sparking which is still a problem at high speeds. We should be glad if you will consider this suggestion and if you are in agreement arrange for a modified comm. bearing bracket with the new arrangement of brushes to be instructed. Hs{Lord Ernest Hives - Chair}/Wst. | ||