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).
Steering pivot friction, detailing issues with high and low-speed wobbles observed during tests on the New Phantom axle compared to the 20 HP model.
| Identifier | ExFiles\Box 17\3\ Scan093 | |
| Date | 20th September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} DA.{Bernard Day - Chassis Design} X7430 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG20.9.26. EAC. STEERING. FRICTION IN PIVOTS. X457 In our recent tests in France we have observed that the friction in the pivots on the new type front axle is required for a different purpose to that for which it was recently fitted on the 20 HP. In the 20 HP., the main object of the friction is to overcome low speed wobbles, on the New PhantomCodename for PHANTOM I axle our tests have shewn that the most pressing need is to provide a means of increasing the steering stability and immunity from road shocks, high speed wobbles etc. at high speeds. We have tried out increased friction in the pivots on the new axle on the same lines as that on the 20 HP. and although it prevents low speed wobbles we are very disappointed with it. The general effect is to make the steering very heavy for shunting, to prevent self-centering at low speeds even with high pressure tyres, and yet at high speeds where most friction is required for shocks and wobbles, the extra friction has an almost negligible effect and is not an effective palliative for either complaint. We can only conclude that the vibration at high speeds creates an oil film which is absent at low speeds. We much prefer friction in the ball ends as at present arranged. Under the circumstances we have in all our tests obtained the necessary friction by varying the spring contd :- | ||