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).
Report discussing a carbon brush design issue, a potential cause related to a spindle and brush holder, and a disagreement over material reinforcement.
| Identifier | ExFiles\Box 35\5\ scan 048 | |
| Date | 13th December 1918 guessed | |
| EY7/F61218. -4- Contd. carbon brush was not sufficiently strong to withstand this tendency - they had therefore had to fix the brush. In considering this matter after Mr. Kennington had gone, it occurred to me that probably the Liberty material was poorly designed, inasmuch as the spindle carrying the brush may have been light in section and considerably overhung from its point of support. The centrifugal effect of the brush holder, which is out of balance, would deflect the spindle and therefore create a definite tendency for the brush to move in the direction he indicated. It would seem to me that the best way to deal with this factor would be by balancing the rotating brush or break holder. (4) He contended that it was unnecessary, in the case of the material which they used for moulded insulation, to use the reinforcement which we have shewn in the distributor case. I pointed out that we had found it very necessary. but he was very emphatic upon the point that their material would not require it. This, however, is not a point that I should be disposed to accept his ruling upon, as conditions vary so much that in one case it probably might prove satisfactory, whereas in a second state of conditions it would hopelessly fail. BY.{R.W. Bailey - Chief Engineer} | ||