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).
Comparing the performance of the original and modified Peregrine starter motors.
| Identifier | ExFiles\Box 62\1\ scan0080 | |
| Date | 3rd November 1932 | |
| X6134 To PN.{Mr Northey} from Hs{Lord Ernest Hives - Chair}/Wst. c. R.{Sir Henry Royce} Sg.{Arthur F. Sidgreaves - MD} c. Mor. E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Sy. c. Hdy.{William Hardy} Hs{Lord Ernest Hives - Chair}/Wst.6/RT.3.11.32. NEW PEREGRINE STARTER MOTOR. Answering your PN.{Mr Northey}6/WTL.11.32., the differences between the original Peregrine motor and the present one with the modified armature are as follows. Taking a torque of 30 lb/ins. on the armature shaft, the original motor produced this torque at a speed of 320 r.p.m. the current being 141 amps. The present modified motor gives, for the same torque (30 lb/ins) a speed of 950 r.p.m, the current being 136 amps. It will be seen therefore that from these results the motor is running considerably more efficient, the B.H.P. being .475 for a current of 136 amps. as against only .136 for a current of 141 amps. on the old motor. The existing motor gives for 140 amps. .52 B.H.P. which is a very creditable figure for this size of motor. These current figures are practically the same as those obtained on the small Bosch motor, of practically the same size, as fitted to the Alfa Romeo. We intend, when time permits, to ascertain the actual working currents of the starter motor fitted to the Peregrine engine at freezing temperatures. Hs{Lord Ernest Hives - Chair}/Wst. | ||