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).
Investigating oil contamination on the friction faces of brake servo motors.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan236 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. ORIGINAL. EXPERIMENTAL REPORT. Expl. No. REF Hs{Lord Ernest Hives - Chair}/Rml/LG1.12.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. c. to Wor.{Arthur Wormald - General Works Manager} E.A.C. OILY BRAKE SERVO MOTORS. X8980 X8370 We have recently been investigating a number of complaints of varying brake efficiency due to oil getting on to the friction faces of the servo. This occurred even where the latest oil shield had been fitted to the stationary plate of the servo to prevent oil running down from the levers 'Z' on to the friction plates. We have proved to our satisfaction that the amount of oil which can possibly come out of the gearbox on to the servo, when this is filled to the correct level, is negligible. We took a gearbox, removed the servo which we care-fully cleaned free from all oil, as also the ball race at the back, and re-erected it. We lowered the level of oil in the gearbox to the absolute minimum to ensure that under no cir-cumstances could oil be coming from this source. We then lubricated the outer cam lever intensively to represent the action of an over-zealous chauffeur. The car was run 133 miles and the total oil added through the small oiler was 110 drops, 6 drops being the capacity of the lubricator. At the end of this time, the plate of the servo nearest the bearbox 'X' was covered with oil which had reached the periphery of this plate where it collected. The car has since been run 170 miles further under contd :- | ||