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).
Letter to Ferodo Limited regarding tests on the heat treatment and wear of clutch fabrics.
Identifier | ExFiles\Box 141\3\ scan0251 | |
Date | 13th February 1934 | |
X719 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}5/KW. 13th February, 1934. Messrs. Ferodo Limited, Chapel-en-le-Frith. For attention of Mr. Field. Dear Sirs, Heat Treatment of Clutch Fabrics. We have now carried out a considerable number of tests on the clutch slip we experienced the first time a lining got hot. You will remember that Mr. Longley suggested over the telephone heat treating the linings to 600°F.{Mr Friese} for 1½ hours. Our test is as follows. The engine on the dynamometer is set at 2000 r.p.m. full throttle. The clutch is then released till the engine speeds up to 3000 and then re-engaged. 260 such slips are done in batches of 20. The test is then repeated from 3000 to 500 r.p.m. (i.e. very much more severe) until a total wear of .100 has taken place. We started these tests to determine the relative rate of wear of RAD.11, RAD.5 and RAD.13. We found with all these linings that at some time during the first part of the tests the /u of the linings fell below .15 and would not transmit full torque. After considerable smoking the value of /u rose and no further trouble was experienced. RAD.13 wore away very fast. RAD.5 gave considerable slipping trouble even after heat treating. We therefore confined further tests to RAD.11. Treatment at 600°F.{Mr Friese} was an improvement as regards slipping but the rate of wear had increased. Treatment at 700 and 800°F.{Mr Friese} were successive improvements. After the latter no slipping took place until some way through the second part of the test. The rate of wear however appears to increase as higher temperature treatments are used. | ||