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).
Ten tests conducted to eliminate brake squeak.
Identifier | ExFiles\Box 5\3\ 03-page114 | |
Date | 17th April 1925 | |
R.R. 401a (New) (D.B. 17) 25-6-24) J.M.D. EXPERIMENTAL REPORT. -4- Expl. No. REF: Hs{Lord Ernest Hives - Chair}1/LG17.4.25. (1) A plain steel band 1.5" X .125" pulled tightly round the drum. When used w in conjunction with the std. damper on flange, a slight improvement can be made - useless however without flange damper. (2) The same as above with asbestos inserted between the band and the drum. This considerably reduces squeaking when used with or without the standard flange damper but will not entirely eliminate squeaks and is impracticable because it prevents the brake drum getting rid of its heat. (3) A damper fixed on the side face of the drum in the same manner as the standard damper on the flange. This reduces squeaks when used with the standard damper but is useless on its own. (4) Angle aluminium band .75" sq. X .100" thick pulled tightly on to the drum and tried in all positions on the drum. This appeared to do nothing. (5) Angle iron segments bolted to flange in place of standard damper. Asbestos inserted in the angle segments compressing same on both faces. This shewed considerable promise. (6) A one-piece band of angle iron 1.5" X .75" X .125" thick substituted for the segments retaining the asbestos. This was quite successful, never failing to practically eliminate noises whenever fitted but faint squeaks could be heard at times. (7) Aluminium dampers made up in 4 segments held by spring tension on to the drum, no asbestos. These have always been most successful. By means of them we have always been able to eliminate squeaks. It was found that they were more effective when held on to the drum by means of spring pressure compared with when they were bolted up solid. The brakes, if anything, appear to keep cooler with these fitted, than with the standard drum, only. We are trying aluminium dampers nearly half the width of the drum. So far we have had no squeaks and it does not appear to have reduced their efficiency. (8) Lead rivets have been tried left flush with the brake lining. This did nothing. (9) All end and side play carefully taken out of brake shoes. No improvement. (10) Stiffer toggle levers. No improvement. contd :- Hs.{Lord Ernest Hives - Chair} | ||