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).
Calculations and design considerations for the Goshawk II starter motor.
| Identifier | ExFiles\Box 35\4\ scan 029 | |
| Date | 14th July 1931 | |
| X.4384 To R.{Sir Henry Royce} from EFC. c. CJ. c. E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/Thr. EFC2/T4.7.31. X.4384 - GOSHAWK II STARTER MOTOR. We are sending you herewith calculations in connection with the above motor. The drawings are being proceeded with, also the calculations for the dynamo, which will shortly follow. In order to make the various quantities fit in with the dimensions as arranged at West WitteringHenry Royce's home town and given on the LeC., it has been necessary to arrange the windings so that the motor takes rather more current and proportionately does more horse power than our standard starter motor. In fact the motor is more on the lines of the C.A.V. type ZC motor which we have examined and tested, particulars of which have been given on our tables. The polar flux density and useful flux may appear rather low, but full consideration of the matter will show that this has been necessary to suit the case, it having been noted that the flux and flux densities were comparatively low on the C.A.V. type ZC. With this lower flux, the tooth density, and therefore the ampere turns per pole required, have not come out unreasonably high and we were easily able to get the ampere turns required in the space provided. EFC. | ||