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).
Gyroscopic origins of steering wobbles.
Identifier | ExFiles\Box 28\4\ Scan153 | |
Date | 6th July 1915 | |
Misc. To R.{Sir Henry Royce} from Da.{Bernard Day - Chassis Design} Copy to J.{Mr Johnson W.M.} 6th July, 1915. Da{Bernard Day - Chassis Design}2/G6715. RE STEERING WOBBLES. With reference to your note to Mr.Johnson re the above, I am not sure whether it has been previously pointed out that the wobbles are gyroscopic in origin, and that the oscillations noticed are those commonly observed when starting up precession in a gyroscope at a low speed of "spin". The tendency to oscillate is doubtless there everytime any unevenness is encountered by the axle, but it can only come into pronounced action when the violent oscillations, due to the low speed, produce resonance with the system controlling the wheels. At a high speed of revolution of the road wheels, the precession is not rapid enough to strike any resonant period. When, say, the off-side wheel falls into a pot hole on an otherwise smooth road, precession is started up about the axis at right angles to the axis of "spin" and the (horizontal) axis of torque, in a right handed direction, looking from above, and the oscillations arise owing to the inertia of the system alternately "hurrying" and retarding the precession. Contd. | ||