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).
Brake servo failures on the Phantom II due to bearing wear and proposing a new ball bearing design.
| Identifier | ExFiles\Box 16\3\ Scan098 | |
| Date | 25th May 1932 | |
| Y7370. R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} E.7/HP.25.5.32. x5370. c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} re Brake Servo. From time to time we have had complaints of brake servos failing to operate satisfactorily, more particularly on Phantom II where the servo duty is greater. Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux} has always complained of this trouble after a car has done 10,000 miles in France. Various reasons have been put forward for these troubles, but we believe we have at last located the cause as being due to the driven part of the servo going out of line with the driving part, due to abnormal wear in the outboard bearing. On the last example we had the servo could be seen trying to lift itself up into line when the brake was applied. We are sending you under separate cover an actual sample taken from 27-EX chassis of the bearing and steel distance piece which carries the shaft. When this bearing was replaced the servo again operated satisfactorily. We suggest that even if it were possible to double the length of this bearing we should only run a correspondingly increased mileage before getting into trouble again, and we therefore propose using a ball bearing at this point, as shown on blueprint LeC.3083 attached. This can be got in without interfering with the interchangeability of any of the shafts, levers, and fittings. The plain bush clamping the ball bearing is useful for picking up the oil from the central | ||