Regenerative suspension for an off-road vehicle

A hydraulic circuit controls a doubling acting cylinder of a vehicle suspension to provide load leveling and shock absorption functions. A set of solenoid valves control the application of pressurized hydraulic fluid from a supply line to the cylinder and from the cylinder to a tank return line to raise and lower the vehicle for load leveling. The chambers of the cylinder are interconnected by a parallel arrangement (72,217) of a check valve (78,220), orifice (76,218) and a relief valve (74,222). Another parallel arrangement (58) of a check valve (64), orifice (62) and a relief valve (60) couples the cylinder to an accumulator (56). These parallel arranged components enable the doubling acting cylinder to function as a passive shock absorber. A lock-out valve (68) is provided in the preferred embodiment a to defeat the shock absorber operation and provide a very stiff suspension.