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).
Relative importance of friction losses in clutch operation.
| Identifier | ExFiles\Box 13\7\ 07-page153 | |
| Date | 9th March 1935 | |
| X7350 E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}6/KT.9.3.35. CLUTCH OPERATION. We have gone into the relative importance of the friction losses of the clutch fingers due to scrubbing of the short end and bearing friction of the pivot, as you suggested. Assuming a coefficient of friction of .5 for unlubricated surfaces and calculating the work done in (1) compressing the clutch springs, (2) overcoming the pivot friction, and (3) overcoming the scrubbing, we find these amounts are in the proportion of 70 : 10 : 2. On the latest type 40/50 car and a load on the clutch pedal of 50 lbs. is required to put the clutch out whereas 35 lbs. will keep the pedal depressed. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||