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).
Report discussing steering system issues, including lever failures, efficiency, and gyroscopic effects on suspension.
| Identifier | ExFiles\Box 153\4\ scan0154 | |
| Date | 27th May 1943 | |
| -2- Ev.{Ivan Evernden - coachwork}8/JH.27.5.43. It is obvious that if side steering tube springs had been made to give the right elasticity for cornering they would be not ideal for straight ahead work. We are continuing our investigations into the reason for the reduction in section of this lever, however, we know that the Wraith went on to production with the lighter lever. (3) Since the pendulum levers have been made at widely different periods of time, it is hardly likely that material or method of manufacture are responsible for the failures. (4) The initial crack should not be caused by a single overload unless the lever is badly nicked since none of the levers appear to have taken a permanent set. Bending would occur before fracture. It would appear that the initial crack is the result of fatigue due to a repetition of over-loads. When the crack has occurred fatigue from these over-loads goes on until the lever section is so reduced that normal steering loads are sufficient to cause the fatigue to continue. (5) The reverse efficiency of the steering box is slightly greater than forwards. That the steering is reversible can be demonstrated by turning the front wheel when the steering wheel will revolve. This applies in the straight ahead position and also when under load on lock. (6) The gyroscopic effect on the B.V. type suspension is between 1/6th. and 1/8th. of that for a single wheel and a similar wheel movement using an axle. It is therefore 1/12th. to 1/16th. in effect as far as the driver is concerned, because on an axle the 2 wheels are tied together and their effect adds up. Again I apologise for offering you these comments. Ev.{Ivan Evernden - coachwork} | ||