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).
Failures and design modifications for the Phantom III steering rollers.
| Identifier | ExFiles\Box 153\1\ scan0295 | |
| Date | 5th May 1939 | |
| 1300? F.T. HARDY W/S To: SG.{Arthur F. Sidgreaves - MD} From HY.{Tom Haldenby - Plant Engineer} c. to HS.{Lord Ernest Hives - Chair} o.{Mr Oldham} to C. d.{John DeLooze - Company Secretary} to RM.{William Robotham - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} SY.4/HG.D.5.39 PHANTOM III - STEERING ROLLERS The present position in regard to failures of the inner races and rollers of the cam follower on Phantom III steerings must be regarded as serious, since trouble is being experienced fairly frequently and, up till now, we have had no positive cure to apply to existing steerings. It was realised some little time ago that the hardening of the inner race was insufficiently deep, and this was increased to a depth of .040" practically twelve months ago in order to provide a better race for replacement of existing pieces which failed. The evidence we now have indicates that the life of these races is not appreciably greater than formerly, there having been two repetition complaints in service on these races, viz:- 3.BT{Capt. J. S. Burt - Engineer}-47. Holmes. after twelve months use 3.AZ-20. Blackmer. " " (15,000 miles. In the case of 3.BT{Capt. J. S. Burt - Engineer}-47. Holmes, W.report that the rocker shaft splines were found twisted, which indicates that the failure of the roller was precipitated by an accidental blow. Simultaneously, with the use of these races with deeper hardening, it was realised that something much better was required for retrospective use. The steering on 3B-MK had been fitted with an improved design of roller follower using 5/16" dia. balls instead of the original 3/16" rollers in order to stand up to the greater loads imposed by Wraith wheel movement. This design has now run 50,000 miles on 3B-MK, and an endurance test on the bench has shown that it has an enormously better life than the original design. This design has now been modified so that it can be fitted to existing steerings, and the available space has permitted the use of .297" dia. balls as compared with .312" on 3B-MK.{R. E. B. Meade-King} Bench tests so far carried out have given extremely encouraging (continued) | ||