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).
Causes of wheel wobbling, resonance, and precession in vehicle steering systems.
| Identifier | ExFiles\Box 28\4\ Scan155 | |
| Date | 6th July 1915 guessed | |
| To R.{Sir Henry Royce} from Da.{Bernard Day - Chassis Design} Copy to J.{Mr Johnson W.M.} -3- Da{Bernard Day - Chassis Design}2/G6715 Contd. In these cases, if it is not desired to retain the forward lean of the pivots, the period of resonance must be altered by changing one of the other causes, which affect resonance and precession. I suggest that the following points will be found to affect wobbling, most of which you have enumerated in your note :- (a) Fore and aft inclination of pivot. (b) Transverse inclination of pivot (because the weight of car begins to influence when the wheels are turned.) (c) Distance of wheel from pivot centre(because the moment of the precession is increased) (d) The size and weight of the wheel. (e) The distance between the balls on the cross steering levers as compared with the pivot centres. ? (f) The spring in the side steering tube. (g) The flexibility of the front springs. (h) The flexibility of the tyres. ? see memo of axle These two latter, both on account of the extent of the frictional contact between wheel and road, which you refer to, and also because when the precession is hurried, the wheel tends to rise from the ground and vice versa, and thus flexibility in the spring and tyre might affect the extent to which the wobbling was kept up. In the case of the ordinary gyroscope, oscillations die out by friction, and this, no doubt, | ||