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).
Servo efficiency and torque multiplication.
| Identifier | ExFiles\Box 57\1\ Scan153 | |
| Date | 11th June 1925 | |
| R.R. 493A (50B) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/De/L/C11.6.25 'INDIA' F.W.B. (SECRET). SERVO EFFICIENCY. We now gather that WWJ definitely consider that the measurement of the servo efficiency is most easily understood if "torque multiplication" units are employed. In order to prevent any misunderstanding, we give below the way in which we obtain the torque multiplication units, and the exact ratio that these units bear to the output figures which we obtain when measuring the servo efficiency practically. In future we shall always multiply our input figures by 1.55 and consequently any efficiencies which we give for the servo will be in "torque multiplication" units. SUPPOSE A FORCE P. TO BE APPLIED TO CAM LEVER. Then with a torque multiplication of unity F = (1.850 / 1.75) x (4.875 / 8.00) P = .645 P. ∴ "TORQUE MULTIPLICATION" OF SERVO OF ONE F/P = .645 / 1 = .645 contd :- | ||