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).
Brakes road test, detailing issues with servo liner wear and friction.
Identifier | ExFiles\Box 30\6\ Scan164 | |
Date | 25th January 1924 | |
H.R. 493A (40 H) (SL 42 19-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 9940 REF: Hs{Lord Ernest Hives - Chair}4/LG25.1.24. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} c. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} WOR.{Arthur Wormald - General Works Manager} S E C R E T. BRAKES - ROAD TEST. We have now completed 2100 miles on one car fitted with four-wheel brakes and 2900 miles on another car. We are always keeping one car running and are changing the cars as required for modifications and measurements. The chief fault brought up by the road test is the variation in the co-efficient of friction of the Ferodo on the servo and therefore altering to a great extent the proportion of braking front and rear. Also another point is - rapid wear takes place on the servo once it has been over-heated. We have replaced the ferodo liners on the servo on both cars. On the car which had run 2900 miles, the liner on the wrapping shoe had worn practically away. On the car which had completed 2100 miles, the wear was .090" on the wrapping shoe. We have confirmed on the road that as long as we do not overheat the servo, the wear is not excessive. We have fitted one of these cars now with cast iron liners to the servo brake. There is a certain amount of noise coming from the cast iron liners, otherwise it has so far behaved well. The co-efficient of friction appears to be slightly less than the Ferodo but we are expecting that it will be more consistent. In order to be sure that we are not asking too much from the brakes on the 40/50 HP. we are running the Hispano car contd.. | ||