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 a preliminary experiment on a special brush-holder and findings on commutator skimming to reduce brush noise.
| Identifier | ExFiles\Box 60\1\ Scan238 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-8-12-24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. To _________ Order No. PD 53 (3) Customer's No. _________ A preliminary experiment was made using a special brush-holder in which the leading wall was cut away. From this it was found that the leading and side walls of the holder play little or no part in the control of the brush when running normally; it is only when the armature is turned backwards, or the springs are removed from the brushes, that they come into use. 1 Commutator Skimming. A number of production machines, on which the brushes were noisy, were examined, but apart from slight irregularities along the edges of the segments, the commutators appeared to be perfectly smooth. It was generally found, however, that an improvement was obtained by skimming the commutator and rebedding the brushes. Instructions based on this result were subsequently included in the production test to assist the quietening of brushes on production machines. At the same time the D.O. were approached with a view to ensuring that the insides of brush-holders be made as even and smooth as possible. Signed _________ Cont'd.{John DeLooze - Company Secretary} This Sheet must be filed on completion of the work. | ||