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).
Proposed modifications to dynamo pole pieces to reduce noise.
| Identifier | ExFiles\Box 51\1\ Scan341 | |
| Date | 29th February 1924 | |
| EFC {E. Fowler Clarke - Electrical Engineer} 4/T29.2.24. -2- Contd. Apart from the above, we have not yet found any deliberate or straight-forward means of altering the a dynamo to render it less noisy, though there is a certain amount of evidence that the changing of the dynamo pole pieces may reduce this in some cases (and in other cases increase it). Further modifications, however, are ready for trial, namely:- (1) Pole pieces giving increased (.020) air gap. (2) " " " .200 shorter polar embrace. (3) " " " .250 longer " " (4) Pole pieces in which .250 is removed from the trailing edge and added to the leading edge. (5) Pole pieces which are skewed half a slot pitch in the same direction as the skewing of the armature slot. These pole pieces used on the one hand with a standard armature, and on the other hand with a special armature with straight slots, and will give in each case a relative skewing of half a pole pitch. (6) Pole pieces with trailing edge eased off. These pole pieces are already in existence and have been tried, but not with very satisfactory results. This report will also answer to date EP {G. Eric Platford - Chief Quality Engineer} 's note EP {G. Eric Platford - Chief Quality Engineer} 4/H6.2.24, but we should like to point out to EP. {G. Eric Platford - Chief Quality Engineer} that in spite of several requests we have not yet received from his Dept. the information as a result of suggestions of ours last referred to in EFC {E. Fowler Clarke - Electrical Engineer} 1/LG16.2.24. Further reports on the Goshawk dynamo position, firstly on output characteristics and secondly on commutation will follow, after which reports on dynamo output, commutation and noise characteristics will follow in succession. EFC. {E. Fowler Clarke - Electrical Engineer} | ||