Abstract: An in-arm suspension (12) is provided for actively controlling a suspension arm (20) mounted to a vehicle frame (14). The suspension arm (20) has a housing (60) in which the a compressible fluid strut (32) and a fluid control section (90) are enclosed. The compressible fluid strut (32) includes a cylinder (134) and a piston rod (136) which is urged to extend from within the cylinder (134) in response to fluid pressure applied to compressible fluid disposed within the cylinder (134). A damper piston (174) is mounted to an interior portion of the piston rod (136), and moves with the piston rod (136) to pass the compressible fluid through the damper piston 174 and attenuate bounce and rebound of the piston rod (136) within the cylinder (134). A damper lock (210) is mounted to the piston rod (136) for selectively preventing the flow of compressible fluid through the damper piston (174).

Abstract: A strut (12) is configured for an active suspension system (142) which provides electronic control for both the force applied by the strut (12) and the dampening characteristics of the strut (12). A compressible fluid (18) is used within the strut (12), and preferably includes a compressible base fluid and electromagnetic field responsive particles (132) which are suspended in the compressible base fluid. The electromagnetic field responsive particles (132) are preferably closely matched in density and modulas of elasticity to that of the compressible base fluid to prevent sedimentation of the particles (132) and to maintain the elasticity of the compressible fluid (18). The amount compressible fluid (18) within the strut (12) is electronically controlled to determine the force applied by the strut (12) and a field strength applied to the compressible fluid in a fluid flow passage is electronically controlled to determine the dampening characteristics of the strut (12).

Abstract: An active, independent suspension system has dual piston, compressible fluid struts (22). Each of the dual piston struts (22) has an outer cylinder (24) and an outer piston rod (30), which each respectively define exterior peripheries for an outer pressure chamber (32) and an inner pressure chamber (54). Pressures applied to a compressible fluid (56) in respective ones of the outer and inner pressure chambers (32, 54) urge the outer piston to extend from within the outer cylinder (24). A control system (240) is provided for actively controlling an amount of compressible fluid (56) disposed within each of the outer and inner chambers (32, 54).