Fail-safe variable damping suspension for a motor vehicle.

摘要

A fail-safe variable damping suspension for a motor vehicle having sprung and unsprung masses comprises a permanent magnet rotary electric machine (104), a ball screw and nut apparatus (106,108) connecting the sprung and unsprung masses and rotating with said machine in alternate rotary directions as the sprung and unsprung masses move relative to one another; controller means (118,121,124,142) for providing varying control for said machine to vary the damping rate of the suspension; and switch means (120) for connecting said controller means to said machine (104), said switch means, in the event of failure of the suspension, connecting a defined load to said machine (104) to define a fail-safe damping rate for said suspension system.