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).
Self-starter motor brake test.
| Identifier | ExFiles\Box 34\3\ Scan160 | |
| Date | 12th April 1918 | |
| To R.{Sir Henry Royce} from EFC. c. to CJ. c. to By.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to BY/HBO. X.2642 EFC3/T12.4.18. X.2642 - R.R. SELF STARTER MOTOR BRAKE TEST Further to our telegram, we have now plotted out the curves representing the test of the R.R. self starter motor with the 45 slot armature and with the field coils two in series and two in parallel, using 12 volts. Some of the figures given in the telegram need slight modification now that fair curves have been plotted out. The maximum power obtained is still 1.35 H.P. at 900 R.P.M., but the maximum efficiency reached by the curve is now .714 at 1520 R.P.M. the figure previously given being one isolated reading. The results obtained on this test are rather surprising inasmuch as we obtain a horse power nearly equal to that of the Lucas motor and an efficiency slightly greater. What however, is perhaps more notable upon inspection of the curves is that the efficiency curve in this case is a very flat topped one as compared with any curve we have had previously, for the present efficiency lies above the value .685 throughout a speed range of 1300 to 2300 or a torque range of about 20 lb-inches to 62 lb-inches, This is a feature which does not occur in any of the other tests we have made. As regards the starting of the chassis engine, it is suggested that it might be more economical and be less drain Contd. | ||