A vibration damper may include a damper tube and a damper piston disposed in the damper tube so as to be reciprocatingly movable. The damper tube may be connected to a piston rod extending out of the damper tube, and the damper piston may movably separate a first oil-filled damper chamber on a piston rod side from a second oil-filled damper chamber remote from the piston rod. A bottom element at one end of the damper tube seals the end of the damper tube. The bottom element may protrude into the end of the damper tube and thereby reduce oil volume of the second damper chamber.

A chassis component has a rotary damper with a housing, a damper shaft rotatably accommodated thereat, a displacing device in the housing, and a magnetic field source. The displacing device has a damper volume with magnetorheological fluid to influence the damping of the rotary motion of the damper shaft relative to the housing. The damper volume is divided into variable chambers by a partition wall connected with the housing and a partition wall connected with the damper shaft. Radial and axial gaps are formed between the partition walls, the damper shaft and the housing. The magnetic field source has a controllable electric coil for influencing the strength of the magnetic field and thus the strength of damping. A substantial part of the magnetic field of the magnetic field source passes through the gaps and influences the gap sections in dependence on the strength of the magnetic field.

A shock absorber includes a bearing unit having a bearing and a bearing holding member, and a seal unit having a seal member and a seal holding member. The seal holding member includes a seal accommodating portion being configured to accommodate the seal member, and an insertion hole through which a piston rod is inserted. The seal member is pressed against an outer circumferential surface of the piston rod and the seal accommodating portion by working-fluid pressure in the extension-side chamber. And the bearing is provided such that a first end surface of the bearing facing the seal member matches an aperture plane of a through hole of the bearing holding member or such that the first end surface of the bearing projects out from the aperture plane of the through hole.

A vibration damping device of an inverted structure includes a cylinder, a rod capable of protruding and retracting in the cylinder, an outer cylinder coupled to the rod and inserted over the outer periphery of the cylinder, and a bush slidably inserted between the outer cylinder and the cylinder. A gap between the outer cylinder and the cylinder is filled with lubricating oil. The bush contains polytetrafluoroethylene and perfluoro alkoxy alkane. The lubricating oil contains an organic molybdenum additive.

A shock absorber includes a compensator and a variable volume chamber. The compensator contains a compressible fluid and the variable volume chamber contains a substantially incompressible fluid. During a compression stroke, an increase in the volume of the incompressible fluid in the variable volume chamber compresses the compensator and thereby increases the available volume in the variable volume chamber.

The actuator comprises a cylinder and a rod. The cylinder comprises an inner cylindrical tube and an outer cylindrical tube which extend coaxially to each other along a longitudinal axis (z). The inner cylindrical tube accommodates a plunger which is rigidly connected to the rod and separates an inner volume of the inner cylindrical tube into a compression chamber and an extension chamber, wherein at least the compression chamber contains oil. The inner cylindrical tube and the outer cylindrical tube enclose with each other a reservoir chamber which is permanently in fluid communication with the extension chamber via at least one first passage provided in the inner cylindrical tube and contains a pressurized gas in a first portion thereof and oil in a remaining portion thereof. The cylinder further comprises an intermediate cylindrical tube which extends along the longitudinal axis (z) between the inner cylindrical tube and the outer cylindrical tube and encloses, along with the inner cylindrical tube, an intermediate chamber permanently in fluid communication with the compression chamber via at least one second passage provided in the inner cylindrical tube. The actuator further comprises a check valve associated to the inner cylindrical tube to allow the oil to flow in the direction from the reservoir chamber to the compression chamber only, and an electrically-operated flow control valve which is associated to the intermediate cylindrical tube for controlling the flow of the oil between the intermediate chamber and the reservoir chamber. The flow control valve is movable between a first operating position, in which it allows the oil to flow between the intermediate chamber and the reservoir chamber, and a second operating position, in which it prevents the oil from flowing between the intermediate chamber and the reservoir chamber.

A shock absorber includes a cylinder including a working chamber therein; a rod configured to be axially movably inserted into the cylinder; and a plurality of tanks configured to be integrally attached to the cylinder, wherein an interior of one of the tanks is comparted into a liquid chamber configured to be communicated with the working chamber and filled with liquid and an air chamber filled with gas, and a sub-air chamber configured to be communicated with the air chamber is formed in the other tank.

A method and apparatus for a shock absorber having a damping fluid compensation chamber with a gas charge. In one aspect, a partition separates a first chamber portion from a second chamber portion, wherein the first portion of the chamber is at a first initial gas pressure and the second portion of the chamber is at a second initial pressure. A valve separates the first and second chamber portions and opening the valve comingles the first and second chamber portions so that the combined chamber portions are at a third pressure. In another aspect, a piston disposed through a wall is in pressure communication with the gas charge and is biased inwardly toward a pressure of the charge, whereby an indicator is movable by the piston in response to the pressure.

A speed retarding device for a rotary nozzle includes a hollow cylindrical housing and a rotatable tubular shaft rotatably carried by the housing. The shaft has a central axial bore and an enlarged drag sleeve portion carried in the housing. A pair of support bearings support the drag sleeve portion of the shaft in the housing. An annular inner seal between each of the support bearings and the drag sleeve portion defines a cavity within the housing receiving a viscous fluid confined within the cavity. The drag sleeve portion includes a peripheral helical groove and a plurality of axial bores extending therethrough parallel to the central bore, one or more blind axial bores each having a closed end an open end, and a piston disposed in each of the one or more blind axial bores each defining an air space between the closed end and the piston.

A rotary damper has a housing and a damper shaft rotatable in the housing. A damper volume contains magnetorheological fluid for influencing the damping of a damper shaft rotation relative to the housing. A partition wall on the shaft and a partition wall formed on the housing divide the damper volume into two variable chambers. A gap is formed between the partition unit of the housing and the damper shaft, and a gap is formed between the partition unit on the damper shaft and the housing. The magnetic field source includes a controllable electric coil for influencing the strength of the magnetic field and thus the strength of damping. A substantial part of the magnetic field of the magnetic field source passes through at least two of the gaps and influences the two gap sections in dependence on the strength of the magnetic field.