Abstract: A hydraulic suspension system for a vehicle includes a pair of cylinders on opposite sides of the vehicle. Each cylinder is divided by a piston into two chambers. When the vehicle is not making a significant turn, a switching valve connects the chambers in the same cylinder together and when a significant turn occurs, the switching valve cross connects the chambers of the two cylinders. That cross connection increases resistance of the suspension system to roll of the vehicle, as compared to when the cylinder chambers are not cross connected. A load leveling function also is included in the hydraulic suspension system.

Abstract: A hydraulic suspension system for a vehicle includes a pair of cylinders on opposite sides of the vehicle. Each cylinder is divided by a piston into two chambers. When the vehicle is not making a significant turn, a switching valve connects the chambers in the same cylinder together and when a significant turn occurs, the switching valve cross connects the chambers of the two cylinders. That cross connection increases resistance of the suspension system to roll of the vehicle, as compared to when the cylinder chambers are not cross connected. A load leveling function also is included in the hydraulic suspension system.

Abstract: A vehicle has an axle connected to a frame by at least one hydraulic cylinder with two chambers separated by a piston. A hydraulic circuit controls flow of fluid between two cylinder chambers and between the chambers and an accumulator to dampen motion of the frame relative to the axle. The hydraulic circuit includes a control valve and a pair of check valves arranged so that the single control valve is able to lock-out the cylinder to emulate a rigid connection of the frame to the axle, as needed.