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).
Torque-speed characteristics, stalling conditions, and heat-up times for EAC motors.
| Identifier | ExFiles\Box 64\1\ scan0250 | |
| Date | 13th November 1926 | |
| To AJS. from EFC. c. to BJ. BY.{R.W. Bailey - Chief Engineer} X7620 EFCl/T13.11.26. SEQUENCE STARTER. X.7620. Answering the first portion of your AJSl/M9.11.26, please find attacged a curve of the average torque-speed characteristic of the three EAC. motors which we have tested, this curve being based as is our usual practice, upon a supply of current which drops 1 volt from 12 volts for each 50 amperes of current taken. You will notice that the speed for a torque of 70 lb. ins. is 700 r.p.m., which is rather less than you anticipate in your note. As regards the stalling condition, we find this on the present motor to be approximately 127 lb.ins. Volts 6.60, amperes, 270, watts 1780. The time to heat up from cold (15 C) to a dangerous point in this stalled condition we estimate to be 3 mins. 40 secs. and from hot correspondingly less. With regard to the latter portion of your note, I am going into this matter. EFC. | ||