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 comparative performance tests of different types of clutch linings.
| Identifier | ExFiles\Box 85\2\ scan0081 | |
| Date | 3rd May 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}20/KW.3.5.34. The tests of various types of lining on the standard clutch show that RAD.11 are the best all round of the bonded linings and that any form of treatment reduces the life of the linings. Thus RAD.11 linings heat treated at 800°F.{Mr Friese} have a life of 250 500-3000 slips against 477 for the untreated linings. Chemically treated linings had a life of 355 slips but not quite such good freedom from slipping. It is almost certain that any linings which slip during the first (i.e. 2000-3000 r.p.m.) part of the test would give trouble in a car by slipping and, probably, linings which give only slight trouble during the second part of the test would be quite free from trouble in a car. The new type of clutch to N.Sch.3948 with the fabric on the driven member is a great improvement for wear of linings and is very much less liable to slipping trouble. With chemically treated RAD.11 linings there was no measurable wear after 500 500-3000 r.p.m. slips and no slipping was experienced. This compares with 0.100" of wear after 355 500-3000 r.p.m. slips for the standard clutch. The moulded V.M.20 linings as used by Borg & Beck are not so good for either wear or slipping. Their wear was 0.044" after 500 slips and they would probably give trouble in the car due to slipping if roughly treated. They may however assist in obtaining a smooth engagement. Hs{Lord Ernest Hives - Chair}/F.J.Hardy. | ||