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).
Slow-speed servo motor with a 55° thread, including performance data and a diagram.
| Identifier | ExFiles\Box 73\1\ scan0137 | |
| Date | 3rd April 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/ACL/3.4.24. W.W. SLOW SPEED SERVO MOTOR WITH 55° THREAD. The mechanical advantage of the servo was determined and the torque output taken for increasing and decreasing loads. The difference between the readings with the increasing and decreasing loads is an indication of the friction present (see curve attc.) The average ratio of torque output/applied torque for various pedal pressures are as follows :- | Pedal pressure. lbs. | 29 | 53 | 78 | 106 | 132 | 157 | 183 | |---|---|---|---|---|---|---|---| | Torque output/applied torque. | 3.3 | 4.05 | 3.6 | 3.3 | 3.1 | 2.87 | 2.6 | LOAD OF BEARING IN BRIDGE :- The bearing load due to the servo pull and applied load with our arrangement of levers used for the test, was approx. 550 lbs. with a pedal pressure equivalent to 157 lbs. Our levers being arranged as in sketch - Diagram text: BRIDGE, 1.375, APPLIED LOAD, LOAD LIFTED With the 2.87 ratio given above the load taken by each of the three tie dogs for the friction plates is approx. 383 lbs. due to its transmitting half the torque. Hs{Lord Ernest Hives - Chair}/ACL. | ||