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).
Inspection report on a 20 HP Dynamo No. 132 from chassis 72-AO, detailing issues with the control brush setting and commutator micas.
| Identifier | ExFiles\Box 57\2\ Scan078 | |
| Date | 27th April 1927 | |
| VS{J. Vickers}783do To BY.{R.W. Bailey - Chief Engineer} from EFC. c. SFI/Mr. Brock. EFC2/T27.4.27. 20 HP. DYNAMO No.132 EX CHASSIS 72-AO. As stated in Mr. Brock's note of 25.4.27, we had this machine in for inspection for a similar reason towards the end of last year, and we attach copy of our previous report which apparently was not sent to EY. at the time. On present examination of the machine we find, in respect of the three items previously reported - (1) The control brush setting is again too far retarded, and whether it has been altered and altered back again we do not know, but at any rate it is at the same figure as previously of 113° whereas it should be 122° from the main positive brush. This causes the output to be unduly large and will account for the solder running. We have noted on this machine that the solder has only just run, and the machine is still in the condition in which it would satisfactorily generate. As a result of (2) in our previous note, it appears that the commutator micas have been undercut, but we are of the opinion that they are not sufficiently undercut. In respect of (3), our inspection shews that the brush springs are now correct. The brushes are quite free, but the negative brush shews signs of bad sparking on excessive output. As there appears to be a possibility that the brush has again been moved when the machine was in service, we are on present production machines looking into the question of limiting the amount of movement to be just only sufficient for the requirements of the production test and settings. We return the dynamo herewith to BY.{R.W. Bailey - Chief Engineer} EFC. | ||