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).
Design specifications for new dynamos and motors, including dimensions and performance requirements.
| Identifier | ExFiles\Box 61b\3\ scan0113 | |
| Date | 3rd March 1921 | |
| R.R. 255A (100 T) S.H. 798. 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2947 X543 86027 EPC/T3. 3. 21. X. 294 X. 543. NEW DESIGNS OF DYNAMOS AND MOTORS. The outside carcase dimensions settled upon by Mr. Royce during my visit were as follows :- 40/50 dynamo - 6" 40/50 motor and Goshawk dynamo - 5 1/4" Goshawk motor - 4 1/4" The corresponding armature dimensions are :- 40/50 dynamo - 3.5" " motor and Goshawk dynamo - 3" Goshawk motor - 2.75" We want the 40/50 dynamo to cut in at 400, average temperature, to give the full output of 10 amps. at 15 m.p.h. maximum output to be 12 amps. Carcase diameter is 5 3/4" For the Goshawk dynamo we want 7 amps. average, 9 amps. maximum, 5 1/2 amps. minimum. Carcase diameter 5". What would be the cost of manufacture of these dynamos ? X.3526 - 40/50 Dynamo. X.3533 - Goshawk Dynamo. X.3082 - 40/50 Starter Motor. X.3534 - Goshawk " " It is suggested that an armature with 26 slots, 51 sections, two coils per slot, and therefore one dummy coil, be used. The air gaps should be - 4.5" for the 40/50 dynamo .012" for the Goshawk dynamo. .015" for both motors measured radially. | ||