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).
Investigation into an axle failure on a 10,000 mile Bentley, concluding overload as the likely cause.
| Identifier | ExFiles\Box 84\4\ scan0012 | |
| Date | 22th December 1933 | |
| To WOR.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} c.c. Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Sft.{Mr Swift} Da.{Bernard Day - Chassis Design} re Axle Failure on 10,000 mile Bentley. BY.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} and E.{Mr Elliott - Chief Engineer} have examined the bevel pinion bearing on which the inner race and balls have failed on the forward drive and are in agreement that the most probable cause of the trouble is overload. By.{R.W. Bailey - Chief Engineer} who has the most experience with these bearings is clearly of this opinion. In the other axle which gave trouble it is reported that the balls alone failed. The lubricant under test, e.g. Mobiloils equivalent of Witmores Compound has silted up the oilways but as the bearing when taken apart was quite oily and shows no sign of overheating, this is not considered to have been a contributary cause. It will be remembered that this axle was designed for the Peregrine and was not originally intended to take the torque and speed of the Bentley. The pinion bearing a double row new departure type combined thrust and journal was made by BY.{R.W. Bailey - Chief Engineer} the same size as that used on the 20/25 axle since on the latter it was considered to be a little on the heavily loaded side. On the 20/25 this bearing carries thrust alone the journal load being dealt with separately by a roller journal and hence on the Bentley where both thrust and journal load are encountered and larger torques and speeds, the duty is relatively more. Another point that is agreed is the effect of synchro-mesh gear changes at high speed in momentarily throwing a heavy thrust load on these races, an effect likely to be more pronounced on the Bentley. BY.{R.W. Bailey - Chief Engineer} is communicating with the Hoffmann Co. to get their confirmation of the materials being O.K. and we are taking immediate action to scheme a bearing of higher rating applicable to the existing axle. | ||