An air spring includes a damper, a support ring associated with a portion of the damper, and a piston assembly. The piston assembly includes a first piston member press-fitted to the damper, and a second piston member fitted with the first piston member. The second piston member is supported by the support ring. The two-piece piston assembly allows for a large package for volume at low cost.

End mount assemblies include a mounting bracket dimensioned for securement to an end member of a gas spring and damper assembly. The end mount assembly can include an inner mounting element dimensioned for securement to an elongated damping rod of the gas spring and damper assembly. A first plurality of bushing elements can be operatively disposed between the inner mounting element and the mounting bracket. A second plurality of bushing elements can be operatively disposed between the inner mounting element and the end member. Gas spring and a damper assemblies including such an end mount assembly as well as suspension systems and methods of assembly are also included.

End mount assemblies include a mounting bracket dimensioned for securement to an end member of a gas spring and damper assembly. The end mount assembly can include an inner mounting element dimensioned for securement to an elongated damping rod of the gas spring and damper assembly. A first plurality of bushing elements can be operatively disposed between the inner mounting element and the mounting bracket. A second plurality of bushing elements can be operatively disposed between the inner mounting element and the end member. Gas spring and a damper assemblies including such an end mount assembly as well as suspension systems and methods of assembly are also included.

A valve control device is configured to execute a specific valve control when a valve switching condition at high pressure is satisfied. The specific valve control switches the spring constant change valves for front wheel to a blocking state and switches a spring constant change valves for rear wheel to a communication permission state. The valve switching condition at high pressure is satisfied when oil pressure of hydraulic oil of rear wheel side oil hydraulic cylinders, which is detected by rear wheel side oil pressure detection means, is more than or equal to a predetermined oil pressure threshold and the traveling state determination means determines that a vehicle is in a predetermined traveling state.

A valve control device is configured to execute a specific valve control when a valve switching condition at high pressure is satisfied. The specific valve control switches the spring constant change valves for front wheel to a blocking state and switches a spring constant change valves for rear wheel to a communication permission state. The valve switching condition at high pressure is satisfied when oil pressure of hydraulic oil of rear wheel side oil hydraulic cylinders, which is detected by rear wheel side oil pressure detection means, is more than or equal to a predetermined oil pressure threshold and the traveling state determination means determines that a vehicle is in a predetermined traveling state.

An air suspension in an embodiment includes: a cylinder; a piston rod; a rod-side member disposed on the lower end side of the piston rod; a diaphragm; an axle-side attachment member having an upper end side of which is fixed to an opening at a lower end of the rod-side member, the axle-side attachment member including a fixing section for fixing the piston rod and an attachment hole joined to an axle; a gas passage formed in the axle-side attachment member, one end of the gas passage being opened to an upper end face of the axle-side attachment member and the other end of the gas passage being opened to a side section of the axle-side attachment member; and a valve section provided at the opening of the other end of the gas passage.

An air suspension in an embodiment includes: a cylinder; a piston rod; a rod-side member disposed on the lower end side of the piston rod; a diaphragm; an axle-side attachment member having an upper end side of which is fixed to an opening at a lower end of the rod-side member, the axle-side attachment member including a fixing section for fixing the piston rod and an attachment hole joined to an axle; a gas passage formed in the axle-side attachment member, one end of the gas passage being opened to an upper end face of the axle-side attachment member and the other end of the gas passage being opened to a side section of the axle-side attachment member; and a valve section provided at the opening of the other end of the gas passage.

The invention relates to a heavy-duty trailer (10) in which at least one of the wheels (12) has a MacPherson independent wheel suspension (16). The wheel (12) can be a steered wheel, wherein the steering cylinders (94) of the steering device (40) enclose an angle (a) with the longitudinal direction (L) of the trailer. The transverse control arms (30l, 30r) can also be articulated onto the trailer frame at least in the longitudinal center plane (E) of the trailer (10).

The invention relates to a heavy-duty trailer (10) in which at least one of the wheels (12) has a MacPherson independent wheel suspension (16). The wheel (12) can be a steered wheel, wherein the steering cylinders (94) of the steering device (40) enclose an angle (a) with the longitudinal direction (L) of the trailer. The transverse control arms (30l, 30r) can also be articulated onto the trailer frame at least in the longitudinal center plane (E) of the trailer (10).

An air spring for air suspension system comprises a piston assembly and a damper assembly where the piston assembly is spaced apart from the damper assembly to at least partially define an air chamber. A seal is molded with piston walls to form an integrated piston assembly. The seal includes at least one sealing lip extending radially inward from the piston assembly at an angle that is non-perpendicular to an axis of the damper and the at least one sealing lip contacts the damper assembly when the piston assembly and the damper assembly are assembled together to seal the air chamber.