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 alterations for the 40/50 Dynamo and E.A.C. motor, including armature, carcase, and winding details.
| Identifier | WestWitteringFiles\J\February1923\ Scan21 | |
| Date | 28th February 1923 | |
| R.R. 295A (100 T) (S.H. 159. 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 TO HS.{Lord Ernest Hives - Chair} FROM E.{Mr Elliott - Chief Engineer} c.c. to CJ. ORIGINAL SECRET E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. E1/M28.2.23. x9700 x4383 x9660 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. [Diagram of a pole piece with dimensions: .312, 1.1", .5", 3.530" DIA] (4) Armature to have 29 sections, 8 turns per section as before. Referring now to the starter motor for the EAC. this is to have a 6" carcase and Mr.Royce spoke of the armature as having 33 sections, at the same time remarking that if Mr. Clarke 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 teaser field winding arranged outside of the main field winding as in the view below:- ON EACH POLE. [Diagram of windings with labels: 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 teaser circuit will have from 10 to 12 amps. and sufficient ampere turns to create a field (i) | ||