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).
Continued report assessing various dynamo machines and their components, including armature and commutator quality.
| Identifier | ExFiles\Box 31\1\ Scan081 | |
| Date | 27th September 1920 | |
| EFC3/T27.9.20. -3- Contd. these have worked upwards from the bottom during rotation. In other respects the armature seems good and well finished, but the commutator appears poor. The armature connections to the com- mutator are badly soldered. The commutator is very much under-cut. X.1402. X.4031. The machine is a plain shunt wound machine which operates in conjunction with a Westinghouse voltage re- gulator which will form the subject of a separate report as time has not yet permitted an inspection of this. The brush gear does not look well finished but may quite likely operate well as the brush holders are castings and not pressings and the brush and brus-way dimensions appear exact. The brush pres- sure is obtained by means of a coiled spring. No insulation is fitted to the brush pig-tail connection. This although perhaps not permitting a direct short circuit seems undesirable. The field coils seem good, also the fitting of the pole pieces. X.1005 Rotax Dynamo. We have recently received from the Rotax Motor Accessories Co., a four-pole third brush controlled Rotax dynamo. The scheme of control is that in which a single field winding is connected between an auxiliary brush and one of the main brushes, as already mentioned in the case of the U.S.A. Bosch above. Therefore it is impossible to use this machine for purposes of comparison with other machines, either as a shunt machine or as a controlled machine. This machine is, on the whole, quite well made and finished, and according to the makers' statements has a quite good performance as regards cutting in speed and output. | ||