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).
Analysis of motor torque, speed, and performance characteristics under load and heat.
| Identifier | WestWitteringFiles\G\October1921\ Scan18 | |
| Date | 17th October 1921 | |
| Contd. -3- EFC1/T17.10.21. Two-thirds of this torque, 44 lb-inches, might be all that would be required when the engine was warm. The motor speed we find would be 670, engine speed 80 r.p.m. From the speed-torque curve obtained on the motor from test on the bench, we find that the motor begins to get in distress when the motor torque exceeds 47 lb-inches. The speed curve on the torque base at this point begins to curve downwards in the wrong direction due, we think, to unsuitable amount of brush contact area with the commutator, and of course at this point the whole motor gets very hot, the amperes at this point approaching 150. The curves obtained on the bench test of this motor are plotted on torque and ampere bases, the assumed volt-ampere characteristic being, as previously arranged, a loss of 1 volt from 12 volts for each 30 amperes of current taken. EFC. R.R. 288A (100 T) (S.H. 798, 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2847 | ||