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).
Failures of ignition contact and dynamo brushes for 4-GII electrical equipment.
| Identifier | ExFiles\Box 50\5\ Scan157 | |
| Date | 26th March 1923 | |
| To R. {Sir Henry Royce} From EFC. {E. Fowler Clarke - Electrical Engineer} c. to CJ. E. {Mr Elliott - Chief Engineer} c. to Wor. {Arthur Wormald - General Works Manager} EP. {G. Eric Platford - Chief Quality Engineer} c. to By. {R.W. Bailey - Chief Engineer} X4333 EFC {E. Fowler Clarke - Electrical Engineer} 4/T26.3.23. X.4338 - 4-GII ELECTRICAL EQUIPMENT. Answering your H1/M7.3.23 :- X.3485 (1) Failure of Ignition Contact. We have had one or two similar failures occur on test. This was due to faulty welding. It was immediately taken up with the suppliers and quickly remedied. A pair of contact points incorporating the remedy was sent to Le CanadelHenry Royce's French residence for 4-GII. X4333 (2) Failure of Dynamo Brushes. We regret this failure. You will remember we reported to you in our EFC {E. Fowler Clarke - Electrical Engineer} 1/T2.12.22 some dissatisfaction with the commutator and brush system on the GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine dynamo and we had hoped that with improved dimensions of brushes and brush holders this fault would be overcome. Since that time the dimensions of the holders have been improved and the brush dimensions have been improved by more rejections. We have sometime ago deleted the coppering with which the brushes were originally capped, and this in itself makes for more accurate dimensions. In spite of all this, however, we are still not perfectly satisfiedw with the commutation and we think a good deal of this is due to want of rigidity in the brush holders. Could we not have a more rigid design? We think that excessive wear has been caused in those instances in which it has occurred by the brushes being gripped in the brush holders (due to inaccurate dimensions or growing) just tightly enough to prevent the full pressure on the commutator, but loosely enough to allow the spring to fexd maintain them | ||