A shock absorber assembly with a coil spring and a shock absorber. The shock absorber includes a cylinder; a piston rod; a cylinder piston connected to the piston rod; a reservoir fluidly connected to the cylinder, the reservoir and the cylinder defining a fluid chamber for receiving a hydraulic fluid; a reservoir base valve separating the fluid chamber into a first portion and a second portion, the reservoir base valve defining passages fluidly connecting the first and second portions; a bypass channel fluidly connecting the first portion to the second portion; a bypass valve configured to selectively control fluid flow through the bypass channel; and a check valve disposed in the bypass passage and being configured to: permit fluid flow through the bypass channel from the first portion to the second portion, and impede fluid flow through the bypass channel from the second portion to the first portion.

A device for volume compensation of damping liquid for a damper includes a hollow cylindrical main body containing the damping fluid. A rod extends through an end of the main body to the interior thereof. The rod is secured to a piston inside the body, which divides a compression chamber from an expansion chamber. A compensation chamber is connected to the compression and expansion chambers via internal channels of the rod and piston. A plurality of orifices in the piston open into the compression chamber and into the expansion chamber. A rigid slider moves freely in translation through, around or inside the piston and/or the rod and closes and opens the orifices to connect the compensation chamber to the expansion chamber (or, respectively, the compression chamber) in the compression (or, respectively, expansion) phases. The device may be used in vehicle wheel suspension assemblies.

A hydraulic damper assembly comprises a housing extending between a first end and a second end. A main piston is slidably disposed in the fluid chamber dividing the fluid chamber into a first chamber and a second chamber. A piston rod extends along a center axis and attaches to the main piston. An additional piston is coupled to the piston rod and axially spaced from the main piston. The additional piston includes a main body defining a compression channel and a rebound channel that allow fluid to flow through the additional piston. A securing member secures the additional piston to the piston rod and defines an outer groove. A piston ring is located in the outer groove between the additional piston and the securing member. The piston ring is radially spaced from the securing member to allow the piston ring to be in engagement with the housing.

A hydraulic damper assembly comprises a housing extending between a first end and a second end. A main piston is slidably disposed in the fluid chamber dividing the fluid chamber into a first chamber and a second chamber. A piston rod extends along a center axis and attaches to the main piston. An additional piston is coupled to the piston rod and axially spaced from the main piston. The additional piston includes a main body defining a compression channel and a rebound channel that allow fluid to flow through the additional piston. A securing member secures the additional piston to the piston rod and defines an outer groove. A piston ring is located in the outer groove between the additional piston and the securing member. The piston ring is radially spaced from the securing member to allow the piston ring to be in engagement with the housing.

An extension assembly for a damper includes an extension post having an upper end and a lower end opposite to the upper end. The extension post includes a coupling portion, a narrow portion defining a deformed section, and a wide portion disposed between the coupling portion and the narrow portion. A diameter of the wide portion is greater than a diameter of the narrow portion. The extension assembly includes a retaining member having a sleeve portion received on the narrow portion of the extension post and a plurality of support portions extending from the sleeve portion. Further, the deformed section of the narrow portion secures the retaining member to the narrow portion. The extension assembly further includes a sealing ring disposed around the retaining member. The sealing ring is disposed between the wide portion of the extension post and the plurality of support portions of the retaining member.

A shock absorber has a damping force generator including a spool valve body that is reciprocally engaged with a cylindrical portion of a piston and pressed from both sides by a pair of compression coil springs. The cylindrical portion has first openings for extension and compression strokes, and the spool valve body has second openings for extension and compression strokes. When the piston is displaced relative to the cylinder, the spool valve body is displaced by a difference between pressures in upper and lower cylinder chambers, so that the damping force generator changes a degree of overlap of the first and second openings for the extension stroke in the extension stroke and a degree of overlap of the first and second openings for the compression stroke in the compression stroke.

In accordance with one aspect of the present disclosure, a suspension strut for use on a work machine is provided. The suspension strut may have a forged one piece cylindrical inner housing that includes a hollow rod which forms a circumferential piston at an open end and a lower clevis at a closed end of the hollow rod. The suspension strut may further have a forged one piece cylindrical outer housing that includes a hollow barrel having an interior and an exterior surface, a closed end that forms an upper clevis, an open end, and a port on an outside surface of the hollow barrel. Further, the inner and outer housing may be coupled by a disk shaped end cap attached to the open end of the hollow barrel having an inner diameter that is slideably engaged with an outer surface of hollow rod.

A damper includes a pressure-sensitive damping control circuit that selectively permits fluid flow from a first chamber to a second chamber. A piston varies a volume of the first chamber. A blow-off piston is movable between a closed position, wherein fluid flow through the control circuit is substantially prevented, and an open position, wherein fluid flow through the control circuit is permitted. The damper also includes a first source of pressure. A fluid pressure created by compression of the damper applies an opening force to the blow-off piston moving the blow-off piston in a direction toward the open position against a resistance force provided by the first source of pressure. The resistance force exceeds the opening force until the pressure created by forces tending to insert the piston rod into the first fluid chamber exceeds the pressure in the first source of pressure by a predetermined amount.

A piston assembly that includes a pair of piston members that are formed of compacted powdered metal. The piston members have sets of locking features that include alternating projections and recesses that are spaced circumferentially about and intersect a rod aperture that extends through the piston member. Each projection is formed along a projection axis, which extends radially from a center axis along which the rod aperture is formed, and has a pair of opposite side walls and an end wall that connects the side walls to one another on a side of the projection that is opposite the rod aperture. The recesses on each piston member are configured to matingly and frictionally receive the projections on the other piston member.

Methods of moving an aircraft undercarriage that is movable between a retracted position and a deployed position generally include: using a rotary electromechanical type drive actuator coupled to a portion of the aircraft undercarriage to raise it from the deployed position to the retracted position; disengaging the drive actuator during a descent of the undercarriage from the retracted position to the deployed position and using a hydraulic linear shock absorber coupled to a portion of the undercarriage to regulate the rate of descent and to absorb shock on arrival of the undercarriage in the deployed position; and neutralizing the shock absorber while raising the undercarriage.