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).
Improvements to the cross steering geometry.
| Identifier | ExFiles\Box 153\1\ scan0151 | |
| Date | 14th June 1938 | |
| DY{F R Danby}/NS.{Norman Scott} c. BY c. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/FJH{Fred J. Hardy - Chief Dev. Engineer} c. Ev{Ivan Evernden - coachwork}/JH c. De/Mc.S 1300. DA.{Bernard Day - Chassis Design}8/G.14.6.38. B.111 and B.50. IMPROVED CROSS STEERING GEOMETRY AH It has been suggested by the Experimental Department that the wandering of 1-B-5 is due to imperfection in the cross steering geometry. We agree that this is not so nearly perfect as on Wraith and P.lll and the reasons for this were set out in E/Ev.{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions}1/M.8.5.37. and Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions}/7/N.21.3.38. We send herewith PD.199, PD.200 and PD.201 and PD.205 giving a complete scheme for a steering having a corrected geometry, at least as good as Wraith. This geometry is shewn on PD.205. The improvement has been achieved by lengthening the steering levers at the wheels, the lengths of the centre steering levers being altered to maintain the same original overall leverage. The cross steering balls at the centre are in their original position, and those on the wheels have been raised. This has the effect of improving the geometry on bump at the expense of the rebound geometry. An experiment by Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} on 1-B-5 indicated that this would be an improvement. Schemes PD.199 and PD.200 shew the cross steering and side steering layouts respectively, and PD.201 the modified torque arm. It will be seen that new levers are required on the wheels and a new centre lever. On PD.199 we indicate the necessary modifications to the front engine bearer pressing. As this is almost adjacent to the front pan we suggest that the lower horizontal member of the triangylar pressing may be deleted. This modification is necessary to clear the steering layout. It will be necessary to change the shape of the oil pipe from the pump to the relief valves as shewn on PD.199. | ||