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 for checking and rectifying a noisy dynamo, including brush bedding and output testing procedures.
| Identifier | ExFiles\Box 60\1\ Scan279 | |
| Date | 25th October 1930 guessed | |
| -3- 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 amounts. 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 the end cover removed, the dynamo shall now be run on load at 1950 r.p.m. for 3 1/2 hours charging at a voltage of between 18.5 and 19.0. This should render the brush bedding finally satisfactory. (5) At the termination of the above run, observations shall be made of the output of the machine at this same speed of 1950 r.p.m. which output should lie between 16.5 and 17.5 amperes, the terminal voltage being adjusted to 18.7 ± .1 (6) With the dynamo still in the same hot condition it should be verified that running on open circuit it shews a voltage of at least 13.6 at 900 r.p.m. (7) The dynamo shall again be run on load and its speed varied up and down with a view to testing for mechanical and electrical noise. | ||