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).
Comparison of Rolls-Royce and Westinghouse motors, and notes on 4-EX equipment.
| Identifier | ExFiles\Box 23\2\ Scan075 | |
| Date | 4th November 1921 | |
| ROLLS-ROYCE - 7 - 4/11/21 to give higher efficiency and higher speed than the Rolls-Royce starting motor, throughout the normal operating range. Referring to curve 102168, the higher efficiencies obtained on the 56 CG motor at the higher current and torque values, where high efficiency is needed in cold weather, is readily apparent. The maximum horsepower of our motor is 1.7, and it will be noted that this horse power occurs at the higher torque values, where it is needed in cold weather; while the maximum horse power of the Rolls-Royce motor, 1.35, occurs at lower current value and drops off for the higher torques where it is really needed. Complete performance of the Rolls-Royce and Westinghouse motors are shown on the following curves: ROLLS-ROYCE LUCAS MOTOR {102168, 102170 RR WESTINGHOUSE 56 CG MOTOR {102167, 102168 W 4. NOTES ON 4-EX EQUIPMENT 1. The sample motor and generator supplied the 4-EX car, made on our order ES-132 - 3 - 4, was built up in our Sample Department. Most of the work was done by hand, and the regular production of this equipment will show an improvement over the samples submitted. It was necessary to build this sample equipment in a short time, and all the materials necessary were not available at East Springfield Works, and we had to use materials which we had in stock. When this equipment is put into production changes will be made as follows:- (a) Greater clearance will be provided for across over between terminals on both the motor and generator. (b) The micarta duck insulating channels under the brush holders and under the motor frame terminal, will be longer, providing greater creepage distance. We had available at East Springfield only our stock lengths of such material at the time the 4-EX equipment was built. The equipment supplied for Mr. Belknap's car will have longer insulating channels. (c) The motor and generator were purposely finished differently so that Rolls-Royce would have the opportunity of choosing between the two. (d) Micarta sheet 1/64" thick will be used to insulate the motor and generator field connections.from the frame. None of this thin micarta sheet was available when samples were built, and it was necessary to use fish paper in its place. | ||