A piston and cylinder type damper has a cylinder (12) with a longitudinal axis (x) containing damping fluid. A piston assembly (10) is mounted in the cylinder (12) for reciprocal movement along the axis (x). The piston assembly (10) divides the interior of the cylinder (12) into two chambers (A, B), and provides a pathway for flow of damping fluid between them. The pathway includes a control passage (24) for restricting flow of damping fluid across the piston assembly (10). A sealing element (21) is provided for selectively sealing the piston assembly (10) against the cylinder (12). The control passage (24) and the sealing element (21) are arranged to be positioned at axially spaced apart locations.

Described herein is a fluid circuit device. The device incorporates at least one pressure balancing valve located between at least two fluid volumes that can be in a pressure differential arrangement wherein the at least one pressure balancing valve acts to address a pressure differential by opening a fluid volume or volumes to a third pressure equalising volume. In use, the fluid circuit device may in one embodiment be used in an energy absorption apparatus.

Described herein is a fluid circuit device. The device incorporates at least one pressure balancing valve located between at least two fluid volumes that can be in a pressure differential arrangement wherein the at least one pressure balancing valve acts to address a pressure differential by opening a fluid volume or volumes to a third pressure equalising volume. In use, the fluid circuit device may in one embodiment be used in an energy absorption apparatus.

A method for damping a movement of a door system of a vehicle that is equipped with a damping system having an adjustable and controllable damping action. A movement of the door system between a closed position and an open position is damped in a controlled manner. A measurement of the change in speed of the speed of movement of the door system is calculated and if the change in speed exceeds a predefined limit value, a set, gentle damping action is changed over to a greater damping action.

Disclosed is a self-centering viscous damper with pre-pressed ring springs. The self-centering viscous damper with pre-pressed ring springs comprises a first inner cylinder, a second inner cylinder, a third inner cylinder, an outer cylinder, a first end cover, a second end cover, a piston, a piston rod, a ring spring, a first connector, a second connector, a first linking nut, a second linking nut, a first outer cover, a second outer cover, a first end and a second end. Due to the interaction between the inner and outer cylinders, the ring springs are further pressed whether a damper is tensioned or pressed. The ring springs have been applied with pre-pressure which overcomes a frictional force and a restoring force when the ring springs are in an initial equilibrium position.

An electrorheological fluid which comprises a dispersion medium containing fluorine atoms in an amount larger than 0 wt % but not larger than 50.0 wt % and particles for electrorheological fluid use that are contained in the dispersion medium in an amount of 10-50 vol % of the total volume of the dispersion medium and the particles, the particles comprising a sulfonic-acid-group-containing polymer having a sulfonic acid group content of 30-70 wt %.

An electrorheological fluid which comprises a dispersion medium containing fluorine atoms in an amount larger than 0 wt % but not larger than 50.0 wt % and particles for electrorheological fluid use that are contained in the dispersion medium in an amount of 10-50 vol % of the total volume of the dispersion medium and the particles, the particles comprising a sulfonic-acid-group-containing polymer having a sulfonic acid group content of 30-70 wt %.

A hydraulic shock absorber includes a control valve. The control valve includes a valve seat formed with a closing face, a valve body configured to come into contact with the closing face, and a valve shaft configured to transmit an operation force applied from a driving unit to the valve body. The control valve is defined with an upstream side flow channel extending from an inlet coupled to the upper end opening, via a space in which the valve body moves, to the closing face, and a downstream side flow channel extending from the closing face to an outlet. The control valve is disposed above the cylinder so that a central axis of the valve shaft is inclined relative to a central axis of the vehicle body side tube and the wheel side tube.

An active control anti-yaw damper (100) is provided. When a piston (2) of the active control anti-yaw damper (100) reciprocates inside a hydraulic cylinder (1), an interior of the hydraulic cylinder (1) is divided into two cylinder blocks (PA, PB) which communicate with an oil reservoir through two main oil lines respectively to form a primary loop between the hydraulic cylinder (1) and the oil reservoir; a reversing valve (PV3) is installed between the two main oil lines and the oil reservoir and is configured to change a flow direction of the primary loop when the active control anti-yaw damper (100) is in an active mode and adjust a displacement of the piston (2) within the hydraulic cylinder (1).

An active control anti-yaw damper (100) is provided. When a piston (2) of the active control anti-yaw damper (100) reciprocates inside a hydraulic cylinder (1), an interior of the hydraulic cylinder (1) is divided into two cylinder blocks (PA, PB) which communicate with an oil reservoir through two main oil lines respectively to form a primary loop between the hydraulic cylinder (1) and the oil reservoir; a reversing valve (PV3) is installed between the two main oil lines and the oil reservoir and is configured to change a flow direction of the primary loop when the active control anti-yaw damper (100) is in an active mode and adjust a displacement of the piston (2) within the hydraulic cylinder (1).