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).
The failure of Phantom III steering due to excessive slack and creaks.
| Identifier | ExFiles\Box 95\1\ scan0455 | |
| Date | 25th November 1937 | |
| To - DY.{F R Danby} & Rm.{William Robotham - Chief Engineer} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} - Hs.{Lord Ernest Hives - Chair} Dav C. - Mxr. La.{L. A. Archer} 350 RHC{R. H. Coverley - Production Engineer}/Cy.2/FH.25.11.37. FAILURE OF PHANTOM III STEERING DUE TO EXCESSIVE SLACK, CREAKS. This steering has been particularly troublesome since its introduction. Numerous complaints and requests for improvement in design have been made to the Experimental Design Office. Opinions are somewhat divided on the question of how the creaking occurs, but two possible causes are, the roller slipping on the cam face and the small bearings moving slightly in the jaw of the rocking shaft. General opinion favours the latter view. The method of fitting up is to take a roller and bearing assembly and make this an interference fit with washers in the jaw of the rocking shaft. To do this necessitates driving in the roller, and the washers take a grip on the sides of the jaw and do not go down in unison with the roller. It is then necessary to further knock down the washer until the hole therein is lineable with the cross hole in the jaw. This lining up of the very thin S/M.{Mr Moon / Mr Moore} washers is extremely difficult and often results in their being scrapped. This interference fit puts a pre-load of 6-12 ozs. on the roller bearings, and the washers are changed until this poundage at 3" radius is obtained, and it may be necessary to make this difficult change several times before a satisfactory loading is obtained. The interference cannot be pre-selected with accuracy owing to several factors and the trial and error method is the only one in use. These factors are that the faces of the jaw in the rocking shaft must be parallel to each other and dead square with the spindle. -1- | ||