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Calculations and test results for a standard starter motor.


Identifier  ExFiles\Box 61b\3\  scan0105
Date  17th July 1928 guessed
  
-5-

Example:-

For X.3082. R.R. Standard Starter Motor.

10^5 b / Z P = (10^5 x 2) / (90 x 4) = 10^4 / 18

ℓ = 10^5 / 3 = 10^4 / 25.36 = 394

TN = ℓ e C = 84.5 e C

At 100 amperes :-

Torque on brake test
= 47.5 lb-inches,
whence Φr = 394 x .475 = 187 kilolines.

Torque on static torque test
= 54.0 lb-inches.
whence Φs = 394 x .540 = 213 kilolines.

Volts/Speed on E.M.F. test
= .00875
whence Φe = 675 / 3 = 225 kilolines.

Terminal volts on brake test = 9.80
Speed " " " = 1130 R.P.M.
whence ΦE = (10^5 / 3) x (9.80 / 1130) = 289 kilolines.

ηe = Φs / ΦE = .737, ηm = Φr / Φs = .878.

η = ηe ηm = .647, ηa = Φs / Φe = .947.

EFC. {E. Fowler Clarke - Electrical Engineer}
  
  
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).


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