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 from The Institution of Automobile Engineers regarding brake lining tests for fading and squeaking.
| Identifier | ExFiles\Box 141\1\ scan0005 | |
| Date | 4th January 1934 | |
| x719. The Institution of Automobile Engineers. TELEPHONE: CHISWICK 0444. TELEGRAMS: CHISWICK 0444. CGW/DA.{Bernard Day - Chassis Design} Your Ref: HS{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}15/KW. RESEARCH DEPARTMENT. 5, Bolton Road, Chiswick, London, W.4. January 4th 1934. F.J. Hardy Esq., Rolls-Royce Ltd., DERBY. Dear Sir, I was very interested to receive your letter of yesterday and the description of the tests which you have been carrying out. You will observe that your experiments indicate fading at a temperature lower than that in our tests; it is possible that this is due to the great difference in rubbing speeds, our tests being carried out at a speed of 1360 ft./min. compared with your speed of 46 ft./min. We have found that pressure has considerable influence on the temperature at which fading occurs and it is possible that speed also has an effect, though we have not yet investigated the matter. With reference to squeaking, our apparatus probably never makes squeaking noises, possibly because the conditions for resonance are not present. We have not been able, therefore, to distinguish between different linings in this connection. There is one further point which we have found affects the temperature at which fading occurs, namely, the extent to which the lining has been run-in. The outer skin of certain materials is much more susceptible to fading than the material under the surface. With reference to your request that we should let you know the names of certain of the materials, we regret that the Executive Sub-Committee has decided | ||