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).
Curing wheel oscillations and precession by altering the inclination of the pivots.
| Identifier | ExFiles\Box 28\4\ Scan154 | |
| Date | 6th July 1915 guessed | |
| To R.{Sir Henry Royce} from Da.{Bernard Day - Chassis Design} Copy to J.{Mr Johnson W.M.} -2- Da{Bernard Day - Chassis Design}2/G6715 Contd. There are other things which affect the precession at the same time, viz, friction at the road surface, which "hurries" precession on the off-side (in this case) and retards it on the near side, but not to the same extent, as the cross coupling rod will not allow it to move through the same angle, while further hurry-ing is caused by the off-side wheel striking the side of the hole in coming out. You will remember that you originally sug-gested that altering the inclination of the pivots would cure these oscillations, and I believe this is a thoroughly scientific way of dealing with this trouble, as it provides the simplest way in which the total inertia of the system may be increased or reduced, owing to the weight of the car being carried to a greater or less extent on the swinging system. The forward or backward leaning of the pivots will cause hurrying or retarding the precession in the opposite sense, i.e. if one hurries the other retards, and there will, no doubt, be a few cases where resonance is struck anywhere on the backward lean and right up to the vertical, and consequently forward lean will be found necessary before the resonance is overcome. Contd. | ||