A vibration damper may include an external tube and at least one internal tube. The external and internal tubes may be disposed in a coaxial manner relative to one another. An annular gap may exist between the external tube and the internal tube, and the annular gap may be fluidically connected to the internal tube. The annular gap may form a compensation chamber for receiving damper oil and damper gas for preloading of the damper oil in the compensation chamber. The vibration damper may further include a separating element disposed in the compensation chamber. The separating element may be axially displaceable and may separate the damper oil from the damper gas in a fluid-tight manner.

A chamber device for a liquid composite spring, includes: an outer wall; an upper liquid chamber formed in an upper portion of the outer wall, the upper liquid chamber being filled with liquid; and a lower liquid chamber formed in a lower portion of the outer wall, the lower liquid chamber being filled with liquid and in communication with the upper liquid chamber. A bottom of the outer wall is provided with a sealing member for sealing the lower liquid chamber. The sealing member is deformable, so that the lower liquid chamber is formed as a flexible chamber. The chamber device for the liquid composite spring has a rigid outer wall and a flexible sealing member. The volume and shape of the lower liquid chamber can be changed through the flexible sealing member, so that the lower liquid chamber is formed as a flexible chamber.

The present invention of damping segmental ring structure for subway tunnels built in grim environments of deformable ground can mitigate the stress-concentration of the tunnel lining structures. The deformable ground can be caused by differential settlement or high-intensity earthquakes. Embodiments of the invention have self-adjustment features and forms for deformation and rotation, which comprise one adapter in the middle, two transitional grooved segmental structures, and an internal steel tube. All three forms comprised 3 or 4 pieces with the same features so they can be easily installed, transported and erected on sites and bolts are used to bolt them together to form an integrity structure with damping characteristics. The damper placed in the middle comprises two loading plates that form the shell of the damper, the internal core of the damper which includes interbedded installed rubber pads and steel plates within the loading plates and spring systems that compress the internal core. The springs are locked to the loading plates using locking clamps and the loading plates are bolted to the transitional grooved segmental ring structures, and the transitional grooved segmental ring structures are bolted themselves in the circumferential direction to form a ring structure and bolted with the regular segmental ring structures in the longitudinal direction. The internal steel tube is concentric with the damper but has a smaller diameter so it can support the damper by fastening the counter-reaction bolts installed in the bent-up flanges of each piece. Waterproof anti-slippery rubber pads are placed in all interfaces between the damper, and the transitional segmental ring structure, the regular segmental ring structure and the internal steel tube. The invention of the damping segmental ring structure has self-adjustment capabilities for deformation and rotation whereas the stiffness remains sufficient to resist soil and groundwater pressure. The invented damping segmental ring structure can be manufactured in factories that manufacture the regular segmental ring structure and can be shipped to and installed on-site using the same equipment that installs the regular segmental ring structure. The internal steel tube provides double-safety for the stiffness of the damper and the supports can be adjusted during tunnel operations.

A shock absorber includes a cylinder and a movable piston rod inserted into the cylinder to be movable to generate a damping force and having one end which extends to the outside of the cylinder. A seal member is fixed to the cylinder to be in sliding contact with the piston rod, and a friction member generates a frictional force with respect to relative movement between the cylinder and the piston rod. The friction member includes first and second friction parts, respectively fixed to one of the cylinder and the piston rod to be in sliding contact with the other of the cylinder and the piston rod. The second friction part is configured to start to slide with respect to relative movement of the cylinder and the piston rod at a timing different from that of the first friction part and generate an adjustable frictional force.

A piston cylinder device (1) comprising a cylinder (2) with a first and a second end and a guide (6), such that a pressure chamber (8) is formed in the cylinder. A piston (12) is moveable in the pressure chamber (8). The guide (6) is fixedly secured to the cylinder (2) by a lock ring (7). A sealing means (9) is arranged to seal between the guide (6) and an inner wall of a tubular wall (3) of the cylinder (2) to prevent fluid leakage from the pressure chamber (8) to the surroundings. The piston cylinder device (1) is provided with a material weakening zone (13) arranged in the inner wall of the tubular wall (3) of the cylinder (2) axially between the lock ring (7) and the second end (20) of the cylinder (2), the material weakening zone (13) being arranged to be deformed or sheared against the lock ring (7) at a predetermined level of impact of the piston (12) against the guide (6). A leakage gap (14) is arranged to interrupt the sealing means (9) upon deformation or shearing of the material weakening zone (13) such that gas from the pressure chamber (8) is allowed to leave the pressure chamber (8) through said leakage gap (14) to the surroundings.

A shock absorber includes an outer tube, an inner tube fitted to the outer tube so as to be able to move forward and backward, a cylinder provided inside the outer tube and extending inside the inner tube, a rod extending from an end portion of the inner tube exposed from the outer tube to an inside of the cylinder, and a piston which is provided on the rod and divides the inside of the cylinder to form a gas chamber. On an outer peripheral surface of the piston, a first lubricating member, a first seal member, and a second seal member are provided in this order from a side closest to the gas chamber to a side away from the gas chamber. The members are in sliding contact with an inner peripheral surface of the cylinder.

A damper assembly includes a damper with a pressure tube and a piston slidably disposed within the pressure tube. A first working chamber is defined on one side of the piston and a second working chamber is defined on an opposite side of the piston such that a volume of the second working chamber decreases during a compression stroke of the piston and the volume of the second working chamber increases during a rebound stroke of the piston. A bellow accumulator assembly is included and in fluid communication with the second working chamber. The bellow accumulator assembly includes a housing, a bellow accumulator disposed within the housing, a pressurized gas chamber defined between the housing and the bellow accumulator and an accumulator chamber defined between the bellow accumulator and the second working chamber.

An air suspension system, includes an air suspension bellows connected to a vehicle frame, and an air suspension piston connected to a link, wherein the air suspension bellows and the air suspension piston are connected to each other and enclose an inner air volume, the air suspension piston has a rolling surface for rolling of the air suspension bellows, the air suspension bellows has a contact portion for rolling on the rolling surface, the rolling surface or the contact portion has at least one opening, wherein contacting areas of the rolling surface and the contact portion define a contact surface, and wherein a fluidic connection for an air flow through the at least one opening between the inner air volume and an environment is enabled and prevented by a change in the contact surface that includes a relative movement of the air suspension bellows to the air suspension piston.

A damper for fittings for furniture or household appliances has a housing in which a piston connected to a piston rod is guided in a linearly displaceable manner, the piston dividing an interior space in the housing into two chambers, wherein at least one flow channel is formed on or in the piston, which flow channel connects the two chambers to one another, wherein a throttle element is provided, which, in a damping position, keeps the cross-section of the at least one flow channel small when the piston moves in a first direction in order to generate high damping forces, and when the piston moves in the second direction opposite to the first direction, increases the cross-section of the at least one flow channel for reducing the damping forces by a movement of the throttle element.

[Problem] To provide a method for manufacturing a sealing device having high pressure-resistance and high durability. Provided is a method for manufacturing a sealing device to be provided between a shaft and an inner surface of a shaft hole in which the shaft is provided, the method comprising: a step for forming an atmosphere-side rigid ring by forming a through-hole in a rigid body by a punching-out process; a step for causing a reinforcement ring for reinforcing an elastic ring to contact the elastic ring in a direction parallel to the axial direction of the shaft, wherein the elastic ring is made of an elastic body, is attached to a liquid-side rigid ring made of a rigid body and disposed inside the shaft hole, is disposed radially inward of the liquid-side rigid ring, and has formed thereon a seal lip that slidably makes sealing contact with the shaft; and a step for causing the atmosphere-side rigid ring to contact the reinforcement ring in a direction parallel to the axial direction of the shaft so that a surface contacted by an end surface of a punch during the punching-out process of the atmosphere-side rigid ring is positioned on an opposite side to the reinforcement ring.