Instruction sheet detailing tests conducted on 40/50 dynamo brush noise.
| Identifier | ExFiles\Box 60\1\ Scan236 | |
| Date | 5th June 1930 | |
| RR 238 (150 BKS.) (DB {Donald Bastow - Suspensions} 431-8.12.24) MP 306975 X8673. ROLLS-ROYCE LTD. INSTRUCTIONS. To EFC {E. Fowler Clarke - Electrical Engineer} Order No. PD 53 Customer's No. June 5th 1930 X.8673. 40/50 Dynamo Brush Noise Tests. A number of experiments have been made with a view to overcoming the trouble of brush noise, complaints of which have been made from time to time, in connection with the 40/50 dynamo. It was found soon after the trouble arose that both rebedding the bushes and the application to the commutator of a small quantity of vaseline, were only temporary cures at the most. From observations made on various machines brush noise appeared to exist in two forms, a chattering noise and a shrieking noise, and was thought to be due to one or more of the following. A. {Mr Adams} A high frequency vibration of the brush as the result of a certain condition of friction between the brush and commutator surfaces. B. A lower frequency vibration of the brush due to very small irregularities on the commutator surface. Signed Cont'd. {John DeLooze - Company Secretary} This Sheet must be filed on completion of the work. | ||
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).