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).
Analysis of wheel oscillation and the effects of lateral pivot pin inclination on vehicle dynamics.
| Identifier | ExFiles\Box 29\1\ Scan276 | |
| Date | 16th September 1925 | |
| - 4 - Assuming the above outline correctly describes what occurs, as I believe it does, then when violent oscillations begin to be reached a further effect comes into action, this time connected with the lateral inclinations of pivot pin. The normal effect of this lateral inclination of pivot is to self-centre the wheel, but this pre-supposes the chassis weight resting on the axle, and pivot. If, however, the chassis were jacked up and the pivot or stub axle allowed to hang from its pin instead of the wheel always trying to return to a position parallel with frame, it will now tend to always go to extreme lock in one direction or another, and since in addition to lateral inclination the pin or axle has also longitudinal inclination, the position it will fall to will be in each case such that the wheel points outwards (considered in a forward direction) from the frame. The foregoing being conceded, it is now obvious that when the amplitude of oscillation is such that the wheel is thrown off the ground, the stub axle and wheel unit on that side tends to swing backwards on its pivot towards the frame. At the moment the particular point at which the wheel makes this movement is determined by the absorption of the vertical acceleration in the wheel and tyre by the axle and spring mass. This rearward swing of the wheel that Contd. | ||