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).
The performance and testing of a 57 coil per slot armature and a 20 HP 'E' dynamo on an experimental chassis.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan82 | |
| Date | 14th March 1924 | |
| Contd. -2- EFC3/T14.3.24. another type of brush-gear would be justifiable at the moment. It is doubtful, if, on the whole, there is any net advantage with this 57 coil per slot armature in altering the brushes from their present dimensions. With brushes of their present dimensions, however, it will be inferred from the reports that, as stated above, there is a definite improvement in general commutation. There is at the same time a slight reduction of performance, though this is not sufficient to prevent the attainment of the 85° engine hot curve required under service conditions, still with compliance with our general specification of test. It might, therefore, at the moment be recommended that this armature should be made standard. It is suggested, however, that this is deferred until the completion of the 10,000 mile test on our experimental chassis 6CII, which is about to begin, upon which our 20 HP. dynamo 'E' fitted with this armature will be run. This dynamo will be set to the general specification of test and will therefore have a larger output curve than that called for in the production test. The condition of running, therefore, will be somewhat more exacting, than in the standard condition. Incidentally, E machine as fitted and arranged has already covered 4274 miles on this chassis and the general condition of commutator and brushes is very good. Contd. | ||