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).
Technical specifications and calculations for the Peregrine starter motor.
| Identifier | ExFiles\Box 62\1\ scan0040 | |
| Date | 28th May 1932 guessed | |
| PEREGRINE STARTER MOTOR. Engine speed 60 R.P.M. at 0°C. " torque 375 lbs ins at 0°C. Gear Ratio 11 : 1 Motor conductor torque = 44.6 lb ins. " Power = 348 watts. Assume electrical efficiency .40 Electrical power 870 Watts. i.e. 84 amperes at 10.32 volts. --------------------------------------- Flux per pole 122 x 10³ lines No of conductors required therefore = 154 Suggests an armature having 19 slots with 2 coils per slot and 2 turns per coil. Total motor resistance then equals .0744 ohms. RA = .0522 ohms RF = .0065 ohms Crosssectional area of armature conductor = .0022 sq ins for a 4 brush machine. = 17 SWG. --------------------------------------- Field Circuit. No of turns per coil = 3¼ " . Cross section of field copper = .0095 sq.ins. [Handwritten in top right corner]: 375 1 87 ½ 23 2/4 [Typed in bottom right corner]: Hs{Lord Ernest Hives - Chair}/Wst. | ||