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 a slow-speed servo motor's frictional losses and coefficient of friction.
| Identifier | ExFiles\Box 73\1\ scan0146 | |
| Date | 14th April 1924 guessed | |
| TESTS WW. SLOW SPEED SERVO MOTOR FRICTIONAL LOSSES. Torque is expressed in lbs. ins. First Table: | Equt. pedal press: | Torque input. | One plate (no dogs) | | Two plates. (with dogs) | | Loss of torque due to 'dogs' Inc.loads. | Loss of plate press: due to dogs. lbs. | | | | Servo torque. | Mech: effcy. (over all) | Increasing loads. | Decreasing loads. | | | | 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 | 687.5 | 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. Second Table: | Load on plate lbs. | VALUE OF µ | | | | No.1. | No.2. | | 100 | ---- | .247 | | 200 | .261 | .261 | | 300 | .275 | .275 | | 400 | .248 | .261 | | 500 | .247 | .269 | | 600 | .247 | .266 | Diagrams labeled NO.1. and NO.2. show two different plate configurations under a load W. Servo torque means - Total torque output less torque due to pedal pressure. | ||