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).
Procedure for the final bedding and testing of dynamo brushes and commutator.
| Identifier | ExFiles\Box 62\3\ scan0370 | |
| Date | 22th June 1933 guessed | |
| -3- bedding observed and improved from time to time, if necessary. At the same time the commutator should be frequently wiped with a clean rag to ensure that it is quite free from a grease or varnish deposit. This should continue until the brushes are reasonably well bedded over the whole surface. Particular notice should be taken of any undue brush noise which may develop on this test. On any brush which is noisy, it should be again checked that the clearances between the brush and its holder both axially and circumferentially, and between the bottom of the holder and the commutator, do not exceed the specified amount. Also that the bedding of the spring on the bevel of the brush and of the brush on the commutator are O.K. Failing to quieten noisy brushes in this way, the armature should be removed and the commutator skimmed, before proceeding with the final running test. (4) Final bedding of brushes. With end cover removed and field resistance short circuited, the dynamo shall now be run on load for 3½ hours at an output of 16.0 .5 amperes at 13.0 volt. This should render the brush bedding finally satisfactory and allow time for the machine to heat up. | ||