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).
W.W. slow speed servo motor with 550 thread, detailing torque ratios and bearing loads.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan106 | |
| Date | 1st April 1924 | |
| R.R. 402A (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/LGS.4.24. W.W. SLOW SPEED SERVO MOTOR WITH 550 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). The average ratio of torque output/applied torque for various pedal pressures are as follows :- Pedal press: lbs. | 29 | 53 | 78 | 106 | 132 | 157 | 183 Torque output/Applied torque | 5.3 | 4.05 | 3.6 | 3.3 | 3.1 | 2.87 | 2.6 LOAD ON 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. APPLIED LOAD LOAD LIFTED BRIDGE 11.375 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. | ||