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 for a 3 B.HP motor for the Experimental Department.
| Identifier | ExFiles\Box 61\2\ scan0034 | |
| Date | 20th July 1928 | |
| X2065-75 To Hy.{Tom Haldenby - Plant Engineer} from EFC. EFC3/T20.7.28. 3 B.H.P. MOTOR FOR EXPL. DEPT I have considered the various quotations which you have obtained as a result of my EFC1/T13.6.28. and am of the opinion, which is confirmed by those who mostly have to use the motor (or motors, i.e. I understand more than one set of equipment may be required) that the requirements of this dept. in this direction will best be met by - (1) A motor of normal speed of 1400/1500 r.p.m. at 100/110 volts, as quoted approx. in the case of the Size 253 machine by the Crypto Electrical Co. A large variation of speed is required. We realise and are prepared for the fact that the armature series control is not suitable for some purposes, but in such cases we can ourselves overcome this difficulty by supplying a lower voltage for the armature. (2) Separate and independent field and armature regulating resistances, the latter to give the decrease quoted on the first page of their letter WHC/EMB/3215/28/C.Add. of the 3rd. inst., to 940 r.p.m. against constant torque, and the former to give an increase up to 3000 r.p.m. ( We do not mind some falling off of available power at 3000 r.p.m., but it is necessary for our purposes that the motor is of suitable construction to be run up to this speed.) By the above we mean plain regulating armature and field resistances respectively, without any over-load or no-volt release, which two items we do not require. For the purpose for which this equipment is required it is more convenient to arrange the controlling equipment in separate units on a large board which can be moved about from place to place, where the 110 volt supply is available. The board contains apparatus comprising the following:- (a) Two input terminals to which to attach the 110 volt leads. (b) Two input fuses, one on each pole. (c) Double pole switch. Or, alternatively to (b) and (c) taken together, a double pole switch fuse which can Contd. | ||