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).
Wear issues in Phantom III front suspension bearings, attributing the cause to dirt and specifying optimal clearances.
| Identifier | ExFiles\Box 95\2\ scan0030 | |
| Date | 25th February 1936 | |
| To E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EV.{Ivan Evernden - coachwork} c. to By.{R.W. Bailey - Chief Engineer} c. to RHC.{R. H. Coverley - Production Engineer} c. to Wor.{Arthur Wormald - General Works Manager} x346 Ha/Les.{Ivan A. Leslie}/KW.25.2.36. Ph.III Front Suspension Bearings. The bottom yoke bearings of 31-MX{John H Maddocks - Chief Proving Officer} from France had worn badly, but those from the bumper after hundreds of hours are in good condition. An examination of a bearing from 31-MX{John H Maddocks - Chief Proving Officer} under the microscope shows the marks to be due to wear rather than indentation. Mr. Hiekling of Messrs. Ransome & Marles considers the wear to be completely due to dirt. We are having some leather covers made to protect this joint, which will be fitted to 32-MX.{John H Maddocks - Chief Proving Officer} Mr. Hiekling gave us the following general information on needle bearings. He considers the best results are obtained with :- (1) Diametrical clearance at least .002". (2) End clearance .008" to .010". (3) Clearance between the first and last roller to be .001 per roller or half the diameter of one roller. It was originally thought that large clearances were the cause of cross-winding of the rollers. It has now been shown that considerable clearance greatly increases the life of the bearing. If cross-winding still persists with the adequate clearance, the cause is lack of parallelism of the parts. Ha/Les.{Ivan A. Leslie} | ||