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).
The co-efficient of friction for various materials and viscous friction in a spring drive damper.
| Identifier | ExFiles\Box 24\2\ Scan277 | |
| Date | 20th December 1927 guessed | |
| contd :- -2- here we increased the pressure up to 22 lbs/sq.in. The co-efficients did not vary very much, with pressure, what variation there was was inversely proportional to the pressure. Material. Co-efficient of friction. Dry. Oily. Red fibre. .126 .100 Bakelite. .135 .115 Cork. .295 .232 Ferodo. .163 .108 Bronze. .137 .114 Viscous friction. All the oily tests were carried out at very slow speeds of relative motion. We found that the friction increased very rapidly with a slight increase in speed of rubbing even with no load whatsoever on the block of material. In some experiments on a multi-plate type of spring drive damper on the 20 HP. engine we have found that if we vary the spring force on the plates from about 140 lbs. to 20 lbs., it is not possible to detect any difference in the smoothness of the engine. The plates are alternate steel and red fibre, and of about 5.85 lbs/sq.in. area. It appears that so long as the springs hold the plates touching, and a plentiful supply of oil is provided to prevent seizing the amount of damping is fixed entirely by the viscous friction which is controlled by the dimension of the plates. Hs{Lord Ernest Hives - Chair}/S.S.Tresilian. | ||