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).
Cause of noise in a lighting dynamo, attributing it to laminated pole pieces and suggesting a comparative test.
Identifier | ExFiles\Box 38\3\ Scan314 | |
Date | 1st March 1925 | |
X3362 To FFC. from E.{Mr Elliott - Chief Engineer} c. to CJ. E2/M3.1.25. RE LIGHTING DYNAMO AT WW. X.3362. X.1640. X.294. In response to your query concerning the above, I have no information regarding three armatures for this machine. I can only tell you that it has been run with one of the three armatures you mention and runs very silently. Our latest information concerning dynamo noise as supplied by Mr. Bentley during his recent visit here to see Mr. Royce was that it was mainly caused by the laminated ends of the pole pieces which set up a vibration. The long attenuated ends of the pole piece stampings could not be effectively fixed together, and when replaced by solid pole piece ends it is said that the singing noise disappears. It would no doubt be advantageous to make a comparative test of this at the Works. E.{Mr Elliott - Chief Engineer} | ||