Specifications for new designs of 40/50 and Goshawk dynamos and motors, including dimensions and performance requirements.
| Identifier | ExFiles\Box 35\4\ scan 014 | |
| Date | 3rd March 1921 | |
| X.4384 EFC {E. Fowler Clarke - Electrical Engineer} /T3.3.21. X.294. X.543. NEW DESIGNS OF DYNAMOS AND MOTORS. X.3534. 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" 40/50 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 5¾" For the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) dynamo we want 7 amps. average, 9 amps. maximum, 5¼ amps. minimum. Carcase diameter 5". What would be the cost of manufafture 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. Contd. | ||
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).