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).
Page detailing the relationship between motor torque, current, and speed with relevant formulas.
| Identifier | WestWitteringFiles\T\2July1929-December1929\ Scan019 | |
| Date | 1st July 1929 guessed | |
| -2- contd. relation of torque (Ts) (pound-inches) (on conductors) to current (C) (amperes) subsists very nearly correctly when the motor is running. There is the relation :- ∅s = β (Ts / C) where ∅s is the effective flux per pole and β is a constant involving the number of poles, number of conductors and number of parallel paths through the armature. When the motor is running with the same current and conductor torque so that ∅s is still very nearly the effective flux per pole, there is the relation ∅s = α (es / N) between the flux, counter E.M.F. es and speed (N) in r.p.m.. α being again a constant involving the same quantities as β. The two relations taken together, or alternatively the conservation of energy principle, are equivalent to the fact that :- es.C = .01184 Ts. N The ordinary running brake test at various values of the brake torque Tr{Capt. F. W. Turner - Finance} gives us the relation of C to Tr{Capt. F. W. Turner - Finance} and the corresponding values of N. The static torque test having given us the relation of C and Ts, es is calculable for the various values of N. N.B. This es is not the same as the counter E.M.F. (which we call ee) which would be observed by driving the armature at the same speed in a field due to the same | ||