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).
Options for axle bearings, comparing pre-loading, radial control, and proposals for a new three-row bearing scheme.
| Identifier | ExFiles\Box 84\4\ scan0337 | |
| Date | 5th November 1937 | |
| - 2 - Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}15/G.5.11.37. is necessary to give the required pre-load. Regarding the axle centre casing, the bore of the nose has been increased, but no change is necessary to the pitch circle or spacing of the studs. As regards the question whether the three row bearing is the best for the job, for existing casings we have no alternative except the combined roller and duplex ball thrust. The duplex bearing must not be preloaded and therefore there would appear to be no prospect of eliminating the over-run axle noise with this bearing. With new casings a larger bearing may be accommodated, and in this case it has been suggested that a bearing of the original type (Phantom 11) with both outer races located radially should be used. The advantage compared with our standard bearing is better radial control. The difficulty is the large size which appears to be necessary. We have asked Messrs. Hoffmann to give us their recommendation for this type. New Departure information indicates that there is no bearing under 100 m/m.{Mr Moon / Mr Moore} outside diameter, which has as high a rating as the proposed three row (76 m/m.{Mr Moon / Mr Moore} outside diameter). The bearing used on the Phantom 11. was 110 m/m.{Mr Moon / Mr Moore} outside diameter, and according to our calculations the combined radial and thrust load was less than on the Bentley, and the speed of rotation was less. Therefore it is not surprising that, as stated in Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}23.9.37. this bearing gave no trouble. With regard to the present type of bearing, we wish to get away from this because of the fundamentally bad radial control and the dependence of the radial rigidity on the preloading, (see curves attached to Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}23.9.37). It may be that the 30 x 83 x 1.9/16 R.{Sir Henry Royce} & M.{Mr Moon / Mr Moore} bearing proposed by Gry.{Shadwell Grylls} will put the job sufficiently right to avoid serious complaints, but we should prefer to give a trial to the more perfect three row scheme, especially as it does not appear to be going to cost or weigh any more. Da{Bernard Day - Chassis Design}/Hdy.{William Hardy} | ||