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).
Alterations for a 40/50 dynamo and an E.A.C. starter motor, including specifications and sketches.
| Identifier | ExFiles\Box 64\1\ scan0106 | |
| Date | 28th February 1923 | |
| To Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. to CJ. S E C R E T x9720 E1/M28.2.23. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. x8620 x9700 x4383 RE RR. 40/50 DYNAMO, E.A.C. DYNAMO, AND E.A.C. MOTOR. Before leaving WW. Mr. Royce discussed the question of the above machines and went into particulars of some alterations which he requires made. The larger dynamo intended for the 40/50 and the EAC. chassis is intended to be constructed first as a third brush machine, and the vibrator regulator is to follow. The following are the altered proportions of this dynamo:- (1) Armature dia. 3.5" Length 3.25" (2) Carcase outside dia. 5.5". Length 5.5 to 6" (3) Radial depth of carcase .312. Pole pieces as in sketch below. 3/2 [Sketch of a dynamo pole piece with dimensions] 1.1" .5" 3.530" DIA as before. Armature to have 29 sections, 8 turns per section Referring now to the starter motor for the EAC. this is to have a 5" carcase and Mr. Royce spoke of the armature as having 33 sections, at the same time remarking that if Mr. Clark says the motor is too fast, adopt 37 sections. This would probably be ribbon wound one turn per section. The motor is to be fitted with a teazer field winding arranged outside of the main field winding as in the view below:- (On each pole). [Sketch of motor winding] MAIN WINDING TEAZER WINDING TAPE BINDING The two coils are taped together before the assembly of the machine. The tightening action of the pole piece on the tape binding draws the coils snugly together, and against the carcase of the machine. It is thought the teazer circuit Contd. | ||