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).
Modifications to the Bentley Back Axle and associated components like the pinion shaft and thrust bearing.
| Identifier | ExFiles\Box 84\4\ scan0131 | |
| Date | 8th December 1936 | |
| 202 Rm.{William Robotham - Chief Engineer} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} GRY{Shadwell Grylls} E/HDY.{William Hardy}3/HP.8.12.36. Bentley Back Axle. With reference to Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}17/AP.18.11.36 which recommends that we should standardise the extended pinion shaft as on N.Sch.4610, but with various modifications, we understand that this was originally introduced principally to reduce the length of the propeller shaft. It appears, however, that an immediate alteration is not necessary and that the future requirements will be met on the Bentley III by the use of the Wraith gearbox with extension, which results in a propeller shaft length of 47" against the present 52.5". The present safe speed (.7 x whirling speed) of 5,000 r.p.m. becomes 6250 r.p.m. As regards the distortion which sometimes causes contact to be made on the oil retaining screw thread, we understand that this is not regarded as a trouble on production. There is no record of any pieces having to be changed due to this trouble. We recommend, therefore, that we should stiffen the existing designand to meet the poor durability of the thrust bearing we should use the same bearing as is to be used for the Wraith rather than a new bearing to EX.23493 as we shall keep down the number of special bearing types by the former policy. We will investigate means to improve the lubrication of the thrust bearing particularly under conditions of low speed running. The question of die casting shall also be investigated. HDy{William Hardy} E/HDY.{William Hardy} | ||