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).
Performance report on an experimental sequence starter motor with a tapered and outward sliding armature.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan133 | |
| Date | 27th July 1928 | |
| To R.{Sir Henry Royce} from EFC. c. RJ. E.{Mr Elliott - Chief Engineer} c. EY. EFC1/T27.7.28. X. 7625B. SEQUENCE STARTER MOTOR PERFORMANCE. This refers to the first motor with tapered and outward sliding armature experimentally produced, having 45 armature slots and pinion of 5° helix arranged for a 16 : 1 ratio to the engine. It will be remembered that the proposal was to put this 2B. scheme on experimental chassis 9-EX, replacing the old No.1 scheme thereon. This chassis is now in the Expl. Shop for rebuilding. The No.1 starter scheme having been removed from the chassis when rebuilt will incorporate this No.2B. scheme. In regard to the longitudinal or axial functioning of this motor, this, so far as we could judge appeared to be quite O.K. on the bench test on the teazer winding, giving good indication of probable satisfactory performance when arranged on the chassis. It was found that the armature would slide out to its final position (a total movement of .750") with a teazer current of 13.0 amperes (at a voltage between 5 and 6). The armature operated relay contacts were made after a portion .550" of the total movement. Running the motor light on the main circuit at moderately high speed, as for instance on 6 volts, it was found that the liquid friction at the main 1.275" diameter bearing was such that this bearing gets rather hot, even though quite free when at rest. A similar effect was noted on the Bosch motor which has a similar bearing. Contd. | ||