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).
Methodology and data for starter motor torque and flux.
| Identifier | ExFiles\Box 64\2\ scan0217 | |
| Date | 20th November 1928 | |
| X7625B To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} c. BY+ EFC3/T20.11.28. SEQUENCE STARTER MOTOR TORQUE & FLUX. X7625B As referred to in our EFC4/T28.11.28, please now receive - (1) Table of starter motor static torque data. (2) Set of curves of static torque and corresponding calculated flux on an ampere base. The static torque under consideration is that torque quantity obtained by balancing out mechanical and electrical friction effects, e.g. bearing friction and armature hysteresis, by taking the mean of the brake torques which will just allow forward motion and resist backward motion respectively. For convenience we call this quantity the torque on the conductors, being as it is so very nearly the same for the same current when the armature is turning and independently of the speed. The flux referred to is the flux calculated from this static torque and the number of conductors in question, and is considerably less than the flux which would be found by voltage generated in an unloaded armature with the same current passing round the field winding. The volt line on the set of curves represents the characteristic of supply on brake test, but we are not concerned with this in considering, as at present, torque and flux for varying amperes. Contd. | ||