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).
Technical memorandum comparing a proposed starter motor engagement scheme with an existing one.
| Identifier | ExFiles\Box 62\1\ scan0349 | |
| Date | 5th December 1935 guessed | |
| -2- The engaging solenoid is prevented from re-engaging the pinion, should the starter button not be released when the engine fires, due to the fact that the E.M.F across the motor is fairly high with the armature spinning freely and therefore insufficient current is passed through the engaging solenoid winding to start moving the plunger and pinion into gear. A further feature of this scheme is that the engaging solenoid can also act as the main switch if an armature provided with contacts is mounted on the engaging plunger. The contacts would then be set to operate when the plunger had nearly completed its stroke with the pinion well into mesh with the flywheel. When this scheme is compared with our existing sequence motor the following advantages are apparent :- (1) The power of the motor is increased due to the fact that space now taken up by the auxiliary "teazer" winding is now used for useful main winding. (2) The length of the motor is reduced due to there being no necessity for a long commutator and long bearings now used to accommodate the sliding motion of the whole armature. (3) The mechanical friction of the motor is less, as ball bearings can now be used instead of plain bearings. (4) No dashpot damper is required as the inertia of the moving pinion is negligible compared to the heavy mass of the moving armature as at present. (5) The motor should be cheaper to produce as stampings can be used for the armature there being no machining operation required or necessary to make this taper, as at present. Also the existing main switch will be deleted and incorporated on the motor. | ||