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).
Experimental combined starter-generator device, discussing its performance, vibration issues, and potential for fuel economy.
| Identifier | ExFiles\Box 52\3\ Scan373 | |
| Date | 1st August 1919 | |
| Oy10-F28/8/19-7 ably weigh a little over 600 lbs. 21. It supplants the starting motor and its gear, and the generator, since it is made to perform these functions itself. 22. On the experimental car, a bad crankshaft vibration was apparent at the engine speed most often used in running. This vibration may have been due to lack of balance, or perhaps to the greater flywheel effect of the outer armature, as compared with the flywheel usually fitted on the Chalmers car (6-cylinder). This vibration, however, had not upset the windings, after several months of running. 23. The electrical losses of the device (said to range betweem 7% and 15%) are probably compensated for, as far as fuel consumption is concerned, by the ability to run the engine at itsmost efficient speed, and increase the speed of the propeller shaft considerably over the engine speed when running on the level. 24. It was suggested by Mr. Frazer that a further very important economy was possible with this device, in that it was no longer essential for an engine to be made "flexible". 25. A high compression, high efficiency, non-flexible engine could be used, with a centrifugal governor to absolutely prevent its running at more than its highest efficient speed, and, when full power was required, as when climbing hills or speeding on the level, the foot accelerator would be held open and the "speed" lever adjusted to such a position as would just fail to retard the engine below the speed set by the governor. 26. It is proposed that the speed shall be set by a convenient knurled knob mounted on the top of the steering column. Oy | ||