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).
Modification to a 20 HP dynamo to reduce noise by altering its pole pieces.
| Identifier | ExFiles\Box 165\6\ img134 | |
| Date | 24th March 1927 | |
| X5660 To RHC.{R. H. Coverley - Production Engineer} from EFC. EFC3/T24.3.27. RE NOISY DYNAMOS. We hand you herewith 20 HP. dynamo L.70 which has been sent to us as an instance of a particularly noisy machine. We are also handing you a pole piece upon which we have scribed lines representing cutting away of the poles which we desire, to give the pole staggering effect in the opposite direction to the slot staggering. Would you please have the pole pieces of this machine cut away to this model, as we have reason to believe that this modification may have a considerable influence on the noise. It is not necessary actually to make this modification on the model pole. EFC. | ||