An on-board mountable power unit, for ride-height adjustment of a Softail type of motorcycle, includes a pair of hydraulic actuators, each adapted to be mounted on the forward end of the rod of a piston and cylinder arrangement of a respective shock absorber of the rear suspension assembly of the motorcycle, after removal of the stub shaft extension of each rod. Each actuator is an hydraulic actuator ram having a housing, with longitudinally spaced forward and trailing ends between which is defined a chamber containing a piston movable between the ends. The piston has an elongate piston-rod that projects through an end plate at the trailing end of the housing, with a trailing end of he piston rod adapted for engagement with the forward end of the rod of the piston and cylinder arrangement of the respective shock absorber. The forward end of the housing has a forward extension, with a forward end of the extension engageable with the transverse bracket connecting the lower side members of the main frame of the motorcycle. Each actuator is able to connect the rod of the piston and cylinder arrangement of a respective shock absorber to the transverse bracket, similar to connection otherwise provided by the stub shaft extensions of the shock absorbers in the usual mounting arrangement for the rear shock absorbers of the motorcycle.

A linear actuator comprising a housing with a proximal end and a distal end, the housing defining a central cavity extending axially through the housing; a piston tube, where a first portion of the piston tube is slidably positioned axially in the housing, and a second portion of the piston tube extends outwardly from the distal end of the housing; an elongated rotatable screw positioned axially within the central cavity of the housing; a nut positioned within the housing and mounted about the screw, the nut configured to move axially within the housing as the screw rotates; and a spring positioned around the screw, the spring positioned within the housing between the nut and the piston tube; wherein the spring is configured to bias the piston tube away from the nut.

A spring-damper system for a wheel suspension of a motor vehicle comprise a support spring of a spring constant k.sub.T and a damper acting in parallel to the support spring. A spring element is arranged in series with the support spring and can be controlled by means of a controller in such a way that a total spring constant k.sub.G of the spring-damper system can be varied.

A vibration damper of a motor vehicle comprises an outer tube and an inner tube which is disposed so as to be coaxial with the latter, and a working piston which is disposed so as to be axially movable within the inner tube and divides the interior of the inner tube into a piston rod-proximal working chamber and a piston rod-distal working chamber, a damping valve device which is disposed in the working piston, wherein the damping valve device has: a coil, an axially movable armature which is at least partially disposed within the coil, a main valve having a main piston which separates a compression main control chamber, a traction main control chamber and a pilot control chamber from one another, a pilot valve which is designed in such a manner that it is able to be passed through by a flow of hydraulic fluid in the traction phase and in the compression phase and has a pilot working chamber and a sliding tappet that is disposed in the pilot working chamber and is axially movable by means of the armature, and a connecting duct which is disposed between the pilot control chamber and the pilot working chamber and fluidically connects those to one another, wherein the main piston comprises a cylinder base region and a cylinder casing region which forms the radially outer face of the main piston.

A hydraulic damper comprises a main tube, a piston assembly, a base valve assembly, and a compression stop assembly. The compression stop assembly includes an insert defining an inner chamber, and a sleeve displaceable along with the main piston assembly and configured to be slidably introduced inside the inner chamber. The sleeve has a diameter lower than the diameter of the main tube defining a first external flow channel between the sleeve and the main tube; the sleeve is attached to the piston assembly by a spring disposed within the sleeve; and the insert is provided with a plurality of axially-spaced holes and has an annular flange adjoining the inner wall of the main tube and separating the compression chamber from a second external flow channel between the radially external outlets of the holes and the base valve assembly.

An embodiment of the present disclosure provides a shock absorber including a piston valve configured to be in a tube, a body valve installed at a lower side of the tube, a piston rod configured to having one end protruding while penetrating the piston valve, an upper guide member interposed between the piston valve and the body valve and having a plurality of upper guide flow paths formed outside a periphery of the upper guide member, and a plurality of upper guide holes formed inside the periphery of the upper guide member, and a hollow cylindrical expansion member having expansion through-holes through which the fluid having passed through the plurality of upper guide flow paths and the plurality of upper guide holes passes, the hollow cylindrical expansion member being configured to block the upper guide flow paths when the hollow cylindrical expansion member adjoins the upper guide member.

Present disclosure A hydraulic stopping damper includes a cylinder in which a work fluid is stored, a piston rod coupled such that one side of the piston rod is to be inserted into an inner space of the cylinder, and a rod guide through which the piston rod passes and coupled to one side of the cylinder. The hydraulic stopping damper includes a rebound spring surrounding the piston rod and disposed in an inner space of the cylinder, and a shock mitigator between the rod guide and the rebound spring, the shock mitigator configured to generate a damping force by a hydraulic pressure of the work fluid when one side of the rebound spring compressed in response to a rebound stroke of the piston rod is inserted into the rod guide.

An embodiment of the present disclosure provides a shock absorber including a piston valve configured to be in a tube, a body valve installed at a lower side of the tube, a piston rod configured to having one end protruding while penetrating the piston valve, an upper guide member interposed between the piston valve and the body valve and having a plurality of upper guide flow paths formed outside a periphery of the upper guide member, and a plurality of upper guide holes formed inside the periphery of the upper guide member, and a hollow cylindrical expansion member having expansion through-holes through which the fluid having passed through the plurality of upper guide flow paths and the plurality of upper guide holes passes, the hollow cylindrical expansion member being configured to block the upper guide flow paths when the hollow cylindrical expansion member adjoins the upper guide member.

An improved oil seal cap for use in a shock absorber for a vehicle including an end wall, and aperture extending through the end wall, and a sidewall extending away from the sidewall in a first direction. The end wall includes a first portion and a second portion, wherein the second portion is raised in a second direction opposite the first direction with respect to the first portion, with the second portion forming a ridge. The oil seal cap is inserted into a reserve tube and cooperates with an oil seal to seal off the top of a shock absorber. The ridge of the end wall is at or above the oil seal and protects the oil seal from impacts of a jounce bumper provided on the shock absorber.

A vibration damper includes an end-stop control valve that progressively adds end-of-stroke damping force to complement the damping force provided by a main piston. The end-stop control valve may include a valve piston assembly that has a valve piston insert, a piston that is disposed radially outside the valve piston insert, and a valve disc stack-up that is supported on a hub of the valve piston insert and a valve seat of the piston. The valve piston insert and the piston may be arranged so as to be longitudinally movable relative to one another. Consequently, the preload of the valve disc stack-up increases as the valve piston assembly contacts a catch piston and begins end-of-stroke damping. Transitioning from an initial preload to a maximum preload during the end-of-stroke damping event progressively increases damping resistance and thereby improves NVH characteristics.