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).
Friction tests on thin and thick leaf springs, comparing greased springs with those using Ferodo interleaving material, and the effects of clipping.
| Identifier | ExFiles\Box 35\2\ scan 246 | |
| Date | 1st November 1920 | |
| Contd. -2- Hs{Lord Ernest Hives - Chair}1/KGS.11.20: will remain constant for years. We have measured the friction in the thin and thick leaf springs when fitted with the interleaving material and we find that the friction is slightly less than with the greased springs. We are running a number of springs with the Ferodo interleaving material and after they have run a few thousand miles we will measure them again for friction to see whether it has altered. We suggest, if it were practicable, it would be better if we could arrange for a constant amount of friction in the spring leaves themselves. We know by the fact that the rusty thin leaf springs gives so much friction that the friction can be carried in the leaves without causing any harm. We made tests to measure the friction in a thick leaf spring by clipping the leaves of the spring tightly together - we used clips similar to those which clip the spring to the centre bearing. We tried these clips in various positions along the springs. Below is the result of the test in which we tried the clips on every leaf of a thick leaf spring. The comparison of the friction is as follows: STANDARD SPRING - 33 lbs. friction. Clips on top leaf 40 lbs. " " 2nd. " 76 " " " 3rd. " 115 " " " 4th. " 85 " " " 5th. " 80 " X.3461. We suggest, from experience, that a thin leaf spring when fitted with interleaving material needs a small amount of extra friction the whole time. Contd. | ||