US Patent 7229079 Center seeking suspension system

A suspension system includes a fluid strut, an accumulator and a reservoir. The accumulator and reservoir are in fluid communication with the fluid strut through an accumulator valve and a reservoir valve respectively. A fluid pump pressurizes the accumulator with an incompressible fluid stored in the reservoir. A piston valve is located within a piston to selectively permit fluid communication between a high pressure side and a low pressure side of the piston. A controller operates each valve and the fluid pump to control flow of the incompressible fluid within the fluid strut to obtain an infinitely variable self centering suspension system.