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).
Test results for friction losses on a F.W. slow speed servo motor, with tables for torque and coefficient of friction.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan125 | |
| Date | 12th April 1924 | |
| TESTS ON F.W. SLOW SPEED SERVO MOTOR FRICTION LOSSES Torque is expressed in lbs. ins. TABLE 1 | Equt. pedal press: lbs. | Torque input. | One plate (no dogs) Servo torque. | Mech: efficy. (over all) | Two plates. With dogs. Servo torque. Increasing loads. | Two plates. With dogs. Servo torque. Decreasing loads. | Loss of torque due to 'dogs' Inc. loads. | Loss of plate press: due to 'dogs'. lbs. | |---|---|---|---|---|---|---|---| | 46.5 | 217.5 | 250.5 | .81 | 394.5 | 537.5 | 106.5 | 68 | | 78.7 | 367.5 | 387.5 | .75 | 549.5 | 767.5 | 225.5 | 144 | | 111.0 | 517.5 | 526.5 | .72 | 657.5 | 832.5 | 365.5 | 234 | | 143.0 | 667.5 | 645.5 | .68 | 772.5 | 842.5 | 518.5 | 332 | | 175.0 | 817.5 | 729.5 | .63 | 872.5 | 872.5 | 586.5 | 375 | COEFFICIENT OF FRICTION. TABLE 2 | Load on plate. lbs. | VALUE OF μ No.1 | VALUE OF μ No.2 | |---|---|---| | 100 | ---- | .247 | | 200 | .261 | .261 | | 300 | .275 | .275 | | 400 | .248 | .261 | | 500 | .247 | .269 | | 600 | .247 | .266 | Servo torque means - total torque output less torque due to pedal pressure. DIAGRAMS NO.1. NO.2. | ||