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).
Analysis of brake adjustment and wear, discussing issues on the Phantom II and the adoption of new linings.
Identifier | ExFiles\Box 12\5\ 05-page146 | |
Date | 1st November 1929 | |
Hs{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}2/ADS.11.29 contd. -3- actually 22-KX ran a 10,000 miles test with this reduced direct brasing and the cam angle altered to restore the total units. (2) The adjustment provided is too coarse and cannot be used until the pedal is on the boards. One notch adjustment on the Phantom II car takes up .019" wear at the shoe centre. It is clear that if we refer to the man with 28.5 direct brasing who heats up his drums descending a hill we note that he requires adjustment when he has only worn .010" off his shoes. In this case the minimum adjustment that he can get, .019, is more than he wants or can use without reducing his initial brake clearance. With 25% reduction in direct brasing, however, the notch adjustment becomes satisfactory, for .020" will be worn before the pedal reaches the boards. (3) The brakes wear out unnecessarily quickly and too <s>large a proportion of the original lining is thrown away when they are worn out.</s> Owing to the prevalence of scored drums and brake squeaks, we have adopted a die-pressed moulded lining instead of the ultra-hard woven lining. This has undoubtedly decreased the wearing qualities of the linings somewhat as have also modern traffic conditions, and the increase in maximum speed and acceleration of the car. However, we only use one third of our liners. The original thickness is .312, about .010 is removed for bedding and the average thickness of liner | ||