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).
Instructions detailing an investigation into machine overheating and noise, attributed to the early setting of control brushes.
| Identifier | ExFiles\Box 70\3\ scan0292 | |
| Date | 29th June 1920 | |
| RR 23a (150 BKS.) (SH57.29-6-20.) MP 224358 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. PC 138 (2) Customer's No. of 120° from the positive brushes as compared with 122° of the standard machine. Overheating of the field coils appeared to have occurred, while heating of the armature appeared to have been chiefly at the commutator. The machine was given a run when it was found that most of the noise came from the brushes, which, through excessive spark wear, were making contact on the leading edges only. Otherwise it seemed reasonably quiet. There is no definite evidence to suggest that the cause of the trouble was anything other than the early setting of the control brushes, resulting in a high output and consequent overheating of the machine. Signed C.A.P. This Sheet must be filed on completion of the work. | ||