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).
Starter motor torque, power, and efficiency performance with particular reference to the S.S. starter motor.
| Identifier | WestWitteringFiles\T\2July1929-December1929\ Scan018 | |
| Date | 1st July 1929 | |
| R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. Ry. c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} Wor.{Arthur Wormald - General Works Manager} ORIGINAL EFC4/AD27. 7.29. STARTER MOTOR TORQUE X7625 POWER AND EFFICIENCY PERFORMANCE WITH PARTICULAR REFERENCE TO THE S.S. STARTER MOTOR. In comparing the running brake torque, power and efficiency performance of starter motors of varied electrical design, we always now adhere to the rule that the supply voltage (E) at the motor terminals is 12.00 less 1.00 volt for every 50 amperes of current passing. In line with the fact of the static force exerted by an electric current in the neighbourhood of its circuit being the fundamental one of electromagnetism, we take as the central consideration in a series starter motor, the magnitude of the torque actually exerted on the armature conductors & in relation to the current passing. (NB. & We say "torque on conductors" with a view to excluding the hysteretic torque on the armature core, which torque we consider as belonging to the category of mechanical torque losses, though actually the greater proportion of conductor torque is on the teeth themselves). It is not only comparatively easy practically to observe this torque-ampere relation statically by duly eliminating the effects of bearing friction, core hystereses etc. but it is also the actual case that this | ||