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).
Analysis of issues with a negative brush and holder, attributing the problem to grease and proposing a new holder design.
| Identifier | ExFiles\Box 168a\3\ img119 | |
| Date | 10th October 1938 guessed | |
| -2- The negative brush was then removed, and a small quantity of firm grease, which had been noticed on it, scraped off. It was then gently replaced, when the machine immediately excited. Apart from a slight roughness on the walls of the holder, there appeared to be nothing metallic to prevent the free movement of the brush. It is concluded, therefore, that quite a small amount of grease, in this congealed form, is mechanically strong enough to hold up a brush against rough handling, as indicated above. The new type of holder, with its harder and smoother wall surfaces, and greater brush clearance, will be much less subject to this trouble. At the same time, the necessity for thoroughly cleaning the brushes and holders, in the event of the dynamo failing to charge, should be stressed in the instruction book. RM{William Robotham - Chief Engineer}/KC. | ||