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).
Two alternative proposals for starter motor windings.
| Identifier | ExFiles\Box 64\1\ scan0126 | |
| Date | 30th May 1923 | |
| X.9620 To R.{Sir Henry Royce} from EFC. SECRET EFC2/T3Q.5.23. c. to E.{Mr Elliott - Chief Engineer} E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. X.9620 - STARTER MOTOR. Reference your Rl/M16.5.23. We have two alternative proposals for the windings, the first one of which is represented by the attached calculations. In this first case there are 37 armature slots of width .090" and of depth .4375", or thereabouts. Two conductors per slot have been taken for granted, the size of which will be obtainable after providing for the necessary insulation, for which we have allowed 50% of the cross sectional area of the slot. The field winding we make out to require 3 1/2 turns only, assuming that half a turn is, as we understand, desirable from the point of view of making connections, otherwise 4 turns. The conductor cross section can be any convenient amount greater than .00845 sq.ins. Probably it will be somewhat greater than this, causing possibly the speed to be greater than assumed, and still leave ample room for the teazer winding. In the second proposal we recommend 33 slots, the width to be .100" and the depth .425", and in this case for the field winding with one more turn than previously. The cross section of the conductor can be any convenient amount greater than .00845. The condition of operation given for this motor, taking into account its size in relation thereto, and Contd. | ||