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).
Specifications and test results of a motor, including dimensions and electrical characteristics.
| Identifier | ExFiles\Box 51\5\ Scan172 | |
| Date | 31th October 1921 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 7/T31.10.21. lubrication are provided. There is no additional insulation other than that on the coils, between the field coils and the carcase. The end plates are secured by longitudinal studs let into the ends of the carcase. The proportions of armature and carcase seem to be right, the leading dimensions being --- Carcase diameter 4.625" " length 4.725" " thickness .312" Armature diameter 2.75" " active length 2.90" The weight of the machine complete is 20 lbs. (This includes armature shaft provided by R.R.) Further particulars of this motor are as follows :- Weight of armature including driving end plate and bearing - 8.6 lbs. Air gap - .027" .69 mm. Number of wound poles - 4. Arrgt. of coils - two series two parallel. Resistance of field circuit - .0070 ohm at 18ºC. Numbere of armature slots - 25. " comm: bars - 25. Armature resistance - .0125 ohm at 18ºC Commutator diameter - 1.62". Useful length - 1.13" Brush contact area - 2 x .875 x .28 = .490 sq." Ratio of field resistance to armature - .560. Length of armature overhang at driving end .80. Length of commutator connections (excluding spokes) 1.15" Ditto (including spokes) 1.35" On the brake test this motor behaved very well. Attached are blueprints of the curves obtained with a volt ampere characteristic of supply to the motor to our standard amount of 1 volt drop from 12 volts per 50 amperes. Contd. | ||