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).
Laboratory test report on a sequence starter motor and its switches.
| Identifier | ExFiles\Box 64\4\ scan0193 | |
| Date | 3rd March 1929 | |
| R.{Sir Henry Royce} from FFC. c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} C. By.{R.W. Bailey - Chief Engineer} F.{Mr Friese} SEQUENCE STARTER MOTOR AND SWITCHES We received for laboratory test a sequence starter motor incorporating (1) Parallel armature (3.100" dia.) (2) 17 SWG. teazer winding. (3) Longitudinal piston damper to LeC. design. (4) Items which were incorporated in our previous tests with non-damped armature motor, recently reported (FFC2/T15.2.29) during which tests we were able to record on our bench rig four hundred consecutive engagements without failure of any kind - viz: (a) Pinion with sharp engaging corners, rounded disengaging corners, and backed off pinion teeth as instructed by F.{Mr Friese} (b) Pinion set back .080" against pinion spring to give .080" greater out of gear tooth clearance. (c) Lower rate spring set up by packing to initial force of 5 lbs. (Armature and piston right back). This motor was subjected to the following procedure:- (1) The usual electrical tests, viz, insulation, winding resistance, winding polarities, armature drop, and neutral points on commutator which were all found to be O.K. (2) A mechanical test of the damper. The motor carcase was suitably held in bench clamps. The pinion nut was suitably grasped in such a way that the armature could be slowly or quickly pulled out and returned by hand in order to observe the damper functioning. After having an initial mechanical clearance fault corrected and packing pieces placed under the three piston return springs, we experienced in this way what, in our judgement, was a satisfactory damper performance. The balance of spring forces was still such that the piston tended on the average to be drawn against its own springs, that is to say that there was, as desired, more damping effect on a vigorous return of the armature than on a vigorous into gear motion. In each case the damper acted, in our estimation, quite effectively, the only appreciable noise in each direction being the slight click when in each case the armature takes up a solid connection to the piston. | ||