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 discussion on the number of conductors required for E.A.C. and Goshawk starter motors.
| Identifier | ExFiles\Box 35\4\ scan 142 | |
| Date | 30th April 1923 guessed | |
| -3- Contd. higher, so that we are led to the conclusion that the number of conductors requires increasing. Fixing, as we do, the speed N = 1760, and taking a suitable flux density of 6500 in each case, in the case of the E.A.C. motor where ∅ = 194,000 Z should lie between the limits 59 and 66, but owing to the relatively light load, should be actually nearer to 59, and that in the case of the Goshawk motor where ∅ = 161,000 Z should lie between the limits 71 and 80. It will be seen that we cannot fix the dimensions of the machine, the speed and the number of conductors, except within certain limits. This we are wrongly attempting to do in both cases. Attached please find copy of the revised E.A.C. starter motor calculations, which ofcourse only represent our final conclusions during my visit, together with copy of calculations for the adaptation of the Goshawk size of motor as far as estimation of number of conductors only, so perhaps you will now further consider what course we should take with R.{Sir Henry Royce} re this. I will, if you like, explain the matter direct to him, or alternatively you could write sending copies of these calculations. EPC. | ||