A damping force generating mechanism includes: a flow passage formation part that forms a flow passage through which a liquid flows; and a valve that is configured to control a flow of the liquid in the flow passage. The flow passage formation part includes a first seat part that is provided radially outward of a flow passage port of the flow passage, protrudes from the flow passage port and contacts the valve, a second seat part that is provided radially outward of the first seat part, protrudes from the flow passage port and contacts the valve, and a circulation part having an orifice that allows the liquid to flow from the flow passage port toward the second seat part in a state in which the valve is in contact with the first seat part.

A restriction for a vibration damper, comprising an annular element with variable diameter which is supported by a support and which occupies a restriction position depending on a flow velocity of a damping medium within the restriction proceeding from an open position through a radial closing movement in direction of a flow guiding surface. The annular element has at least two legs supported so as to be movable around a pivot bearing.

Disclosed is a frequency sensitive type shock absorber including a piston rod reciprocating an inside of a cylinder and having a connection passage therein; a piston valve mounted on the piston rod and having a plurality of compression and rebound flow paths penetrating up and down thereof, and partitioning the cylinder into compression and rebound chambers; and a valve assembly mounted on the piston rod to generate a damping force that changes with frequency during a rebound stroke; wherein the valve assembly comprises: a housing coupled to the piston rod and having a pilot chamber in communication with the connection passage; a main retainer coupled to the piston rod and having a main chamber formed on an upper portion thereof in communication with the connecting passage; and a pilot valve coupled to the piston rod and disposed between the housing and the main retainer to partition the pilot chamber and the main chamber.

Provided is a shock absorber that includes a middle chamber formed by a piston, a first damping-force generating device that is provided between an upper chamber and the middle chamber and generates a damping force, a second damping-force generating device that is provided between a lower chamber and the middle chamber and generates a damping force, and a position-based state changing device that changes a state of a passage to a state in which the upper chamber and the lower chamber communicate with each other, a state in which the upper chamber and the middle chamber communicate with each other, or a state in which the lower chamber and the middle chamber communicate with each other depending on a position of the piston.

A hydraulic shock absorber includes a cylinder, a piston ring, a first valve seat forming an extension side oil path, a first valve opening and closing the extension side oil path, a second valve seat forming an inner-side channel through which oil flows separately from a flow of the oil causing the first valve to open the extension side oil path, a second valve opening and closing the inner-side channel, a spool provided to press the second valve toward the inner-side channel, a base member holding the spool, and an axially-movable free piston forming a back pressure chamber communicating with the inner-side channel and that houses the oil between the spool and the base member.

A damping valve includes a damping valve body with an annular groove which has a base and which is limited by an inner valve seat surface and an outer valve seat surface for at least one valve disk. The base of the annular groove has a maximum distance from the valve seat surface along a circumferential area and has a minimum axial distance from the valve seat surface in another circumferential area.

A shock absorber including a piston (3) slidably fitted in a cylinder having hydraulic oil sealed therein. A flow of hydraulic oil, induced in a passage (10) and a sub-passage (29) by sliding movement of the piston in the cylinder in response to the stroke of a piston rod, is controlled by an extension main valve (14) and a compression sub-valve (15) incorporated in the extension main valve, thereby generating a damping force. The amount of deflection of a sub-disk (30) constituting the compression sub-valve when the sub-disk is opened is limited by restricting portions (21). The sub-disk is provided with communicating holes (31) to reduce a differential pressure acting on the sub-disk when opened and also to relax the concentration of stress in the sub-disk, thereby improving the durability of the sub-disk.

A damper assembly includes an outer tube and an inner tube disposed in the outer tube defining a fluid space therebetween. The inner tube defines an inner volume. A piston is slidably disposed in the inner tube and divides the inner volume into a rebound working chamber and a compression working chamber. An active rebound valve is fluidly connected to the rebound working chamber and the fluid chamber, and an active compression valve is fluidly connected to the reserve chamber and the compression working chamber. An intake assembly is positioned in the fluid chamber to control the fluid flow through the active rebound valve and into the compression working chamber during a rebound stroke and to control fluid flow from the compression working chamber through the active compression valve and into the rebound working chamber during a compression stroke.

A hydraulic damper (2) includes a first piston body member (233), a second piston body member (234), a third piston body member (235), and a compression stroke disc assembly (231) compressed at a radially inner side thereof between the first (233) and said second (234) piston body members. The hydraulic damper includes a rebound stroke disc assembly (232) compressed at the radially inner side thereof between the second (234) and third (235) piston body members, and the compression stroke disc assembly (231) additionally includes an annular supporting member (2319) positioning discs (2311-2318) of the compression stroke disc assembly (231) at radially inner side thereof, while a radially inner axial passage (23191) is defined at the radially inner side of the supporting member (2319).

An oleo strut includes an outer cylinder forming a first fluid chamber and an inner cylinder forming a second fluid chamber. The inner cylinder is adapted for sliding concentrically within the outer cylinder in a longitudinal direction. An orifice plate, which is located within the inner cylinder, has holes for fluidly coupling the first fluid chamber with the second fluid chamber. A free-floating washer is constrained in a slot of the orifice plate adjacent the holes and is adapted to move in the longitudinal direction for alternatively blocking and unblocking at least a portion of the holes. During compression of the oleo strut, fluid pushes the washer away from the holes for reducing resistance to fluid flow. During extension of the oleo strut, fluid pushes the washer against the orifice plate covering at least a portion of the holes, which increases the damping force and reduces the extension speed.