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 outlining the reasons for failure of a 20 HP Dynamo, number 132.
| Identifier | ExFiles\Box 57\2\ Scan054 | |
| Date | 6th December 1926 | |
| X 578320 To SFT{Mr Swift}/Mr. Brock. EFC3/T6.12.26. re 20 HP. DYNAMO NO.132. This is a 29 commutator segment machine. The failure of this dynamo has been brought about by the following :- (1) Control brush setting is too far retarded being 113°, whereas it should be 122°. It would appear that the control brush position has been moved when in service. (2) The commutator micas are not under-cut and project a little. This has caused the brushes to be worn away more quickly than normal and the brush dust has brought about partial failure of the insulation of the brushe holders to the carcase. (3) This machine is fitted with brush springs which apparently are not of our make, as they are not standard. In the circumstances we are not surprised that the solder has run in what purported to be normal working. We return the machine herewith. EFC. | ||