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).
Friction load issues with the Wraith steering ball joints, recommending alterations to the drawings.
| Identifier | ExFiles\Box 9\7\ 07-page066 | |
| Date | 13th July 1937 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Ev.{Ivan Evernden - coachwork} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Handwritten: 650 Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}3/AP.13.7.37 WRAITH STEERING BALL JOINTS. The friction load on the type of ball joint used on thecross steering tubes and the front end of the side steering tube on Wraith and Ph.III. can vary with the position of the bedding between the ball and the pad. If the radius of the ball is greater than the radius of the spherical surface of the pad the friction load can become very large, particularly where the ball pad extends to the centre of the ball. We think that more consistent results will be obtained if the limits on the ball and pad radii are such that the ball is never larger than the pad. A case of this trouble occurred on the first Wraith III. during assembly and was rectified by hand fitting. We recommend that the limits on the drawings should be altered so that the ball is never larger than/pad. Handwritten: the Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||