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).
Technical memorandum comparing the coefficient of friction of an Alfa Romeo clutch to a Rolls-Royce clutch.
| Identifier | ExFiles\Box 178\4\ img044 | |
| Date | 25th April 1932 | |
| Da.{Bernard Day - Chassis Design} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}6/MA.25.4.32. ALFA ROMEO CLUTCH. With reference to Da.{Bernard Day - Chassis Design}1/M.21.4.32. We think that the actual coefficient of friction of the R.R. clutch is very different from the apparent coefficient of friction. This is because as we put the spring pressure on the clutch the splines tighten up reducing the apparent coefficient of friction to about .15. If we measure the friction of the R.R. clutch in the same way as the Alfa Romeo i.e. measure the torque after the full spring load has been applied to the plate, μ about .3. We think that the reason the Alfa Romeo clutch does not slip is because the torque is much lower than 1182/lbs. sq.in., at the speeds at which the clutch is usually let in, and this has some bearing on the result. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||