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 British Piston Ring Co. detailing test results for brake drum liners.
Identifier | ExFiles\Box 85\1\ scan0221 | |
Date | 9th October 1936 | |
Form 17. Continuation Sheet No. 1. THE BRITISH PISTON RING Co. LTD. COVENTRY. 9. 10. 36. Messrs. Rolls Royce, Ltd., ------------------------- obtained in 3 3/4 minutes, thus indicating the improvement in heat conductivity with the aluminium alloy shell. There was no movement whatever between the Drum and the Liner, and there was no change in the Liner hardness after test. The coefficients of friction were as follows - 100 ºF .37 400 ºF .43 650 ºF .45 The coefficients of friction on a steel drum with a similar cast iron Liner were considerably less, the figure at 600 ºF being .29 as compared with .45 for the aluminium Drum. In the case of the Liners which were slotted to form key-ways, the position of the slots in the Liner were slightly defined on the inside of the Liner after running, but this had no detrimental effect on the running properties. Ferodo reported that the outstanding feature of the tests was the high thermal efficiency of the casing compared with the steel casing. This is considered to be of great importance as regards the brake lining, since the lining wear largely increases with temperature. In addition to the above, we can safely say that our "Bricromium" has given such excellent results over a long period when used for Brake Drums Liners, that we advise you to make a test and, therefore, suggest it would be worth while to let us supply you with one or two Liners so that you can make a direct comparison for yourselves between the two materials. Yours faithfully, THE BRITISH PISTON RING CO. LTD., TECHNICAL DEPARTMENT. KMH. | ||