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).
Erection and assembly instructions for the Goshawk R.R. starter motor.
| Identifier | ExFiles\Box 35\4\ scan 089 | |
| Date | 29th March 1922 | |
| To By.{R.W. Bailey - Chief Engineer} from EFC. Y4384 EFC3/129.3.22. X.4384 - GOSHAWK R.R. STARTER MOTOR. We give below for inclusion in the arrangement drawing as erection instructions, or independently, as you may think fit, a number of points in connection with the R.R. Goshawk starter motor. (1) The exact location of the brushes on the commutator is important, an advance of 2° making an appreciable difference in the performance of a motor. It is therefore also important to obtain a high degree of accuracy in the making of the brush holders, and also in the dimensions of the brushes received from outside, so that the minimum clearances are obtained consistent with the brushes remaining free in their holders under all conditions. (2) There may be a tendency for the brush spring to catch on the side of the slot in the brush holder and care should be taken in the manufacture to see that the spring remains clear of the slot. central in (3) Great care should be taken not to damage the insulation on the pig-tail of the brushes, as these are liable to come into contact with the surrounding parts of the machine. This is sometimes done in carelessly replacing the end cover. (4) There may be a tendency for the main terminal to work loose. Care should be taken to avoid this. (5) It should be ascertained that the bolted field coil connection inside the carcase has no chance on the one hand of short circuiting on the carcase and no chance on the other hand of fouling the armature. (6) After ascertaining that the above points are O.K. and before putting the motor through its production test, the brushes must be bedded on the commutator so as to make contact for at least 80% of their contact surface. The actual specification of the production test of the motor we are not able to issue at present as we are experimenting to improve the performance of the machine, and to this end, as you know, we are expecting shortly to Contd. | ||