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).
Proposing a modification to the Phantom III back axle to increase pinion clearance and prevent seizure.
| Identifier | ExFiles\Box 92\5\ scan0061 | |
| Date | 4th June 1936 | |
| x302 Rm{William Robotham - Chief Engineer} C.c. E.S. Da.{Bernard Day - Chassis Design} H.S. R.M.S. Hs{Lord Ernest Hives - Chair}/Bm E/HDY.{William Hardy}1/HP.4.6.36. Phantom III Back Axle. The oil retaining screw thread of the pinion has seized on a dynamometer test recently carried out, and on examination of the detail drawings of the pieces concerned G.83893 and G.83825, it is evident that the minimum clearance can be increased by a reduction of the tolerance on the driving flange which at 5/1000" is needlessly large. Our suggestion is that the driving flange is made 1.890 minus 2, which with an unaltered bearing housing diameter of 1.900 plus 2 gives a minimum clearance on the diameter of .010 and a maximum of .014. The present clearances are .007 and .014 so the minimum has been increased by .003 or 42%. The proposed clearances are approximately the same as are allowed at the back end of the gearbox. This modification can be put straight on to production without a test as the increased clearance is within the present limitations. E/HDY.{William Hardy} | ||