摘要 |
A suspension system for a vehicle road wheel comprises a wheel suspension device (1) having a double-acting hydraulic actuator and a gas spring in parallel, the gas spring being controllable to provide a selectively variable offset, sensor means (6, 90) arranged to sense load changes experienced by the suspension device and to provide an output dependent thereon, and control means (95) responsive to the sensor means output to effect adjustment of the hydraulic actuator pending change of the offset of the gas spring means to accommodate the load changes. Also disclosed is a damping system for damping movement of a piston (64) within a cylinder, the damping system comprising a valve (80) operable to connect spaces (70, 74) within the cylinder at opposite sides of the piston to fluid pressure and/or return lines (84, 85) so as to apply selected positive or negative damping to the movement of the piston. The damping system can be incorporated in the suspension system so that the piston (64) of the hydraulic actuator is damped, under control of signals from the control means (95) applied to the servo-valve (80). |