Specifications for new designs of dynamos and motors.
| Identifier | ExFiles\Box 39\2\ Scan052 | |
| Date | 3rd March 1921 | |
| R.R. 15A.(10M T) R.H. 726. 10-12-20; G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2947. X.3533 EPC/T3.3.21. X.294 X.343. 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(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo - 5¼" Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) motor - 4¾" The corresponding armature dimensions are :- 40/50 dynamo - 3.5" " motor and Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo - 3" Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) 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 5¼" For the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo we want 7 amps. average, 9 amps. maximum, 6½ amps. minimum. Carcase diameter 5". What would be the cost of manufacture of these dynamos ? X.3526 - 40/50 Dynamo. X.3533 - Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) Dynamo. X.3082 - 40/50 Starter Motor. X.3534 - Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) " " 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(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo. .015" for both motors Measured radially. | ||
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).