A method for monitoring a dual-stage, separated gas/fluid shock strut includes receiving, by a controller, a primary chamber temperature sensor reading, a primary chamber pressure sensor reading, and a shock strut stroke sensor reading, calculating, by the controller, a secondary chamber nominal pressure based upon the primary chamber temperature sensor reading, determining, by the controller, a shock strut stroke associated with the secondary chamber nominal pressure, calculating, by the controller, a volume of oil in an oil chamber, a volume of gas in a primary gas chamber, a number of moles of gas in the primary gas chamber, a volume of oil leaked into the primary gas chamber, a volume of gas in a secondary chamber, and a number of moles of gas in the secondary chamber.

A method for monitoring a dual-stage, separated gas/fluid shock strut includes receiving, by a controller, primary chamber temperature and pressure sensor readings, secondary chamber pressure and temperature sensor readings, and a shock strut stroke sensor reading, determining, by the controller, a shock strut stroke at which a secondary chamber is activated, calculating, by the controller, a volume of oil in an oil chamber of the shock strut, a primary chamber gas volume of, a number of moles of gas in, and a volume of oil leaked into, a primary gas chamber of the shock strut, a secondary chamber gas volume in, a volume of oil leaked into, and a number of moles of gas in, the secondary chamber, based upon at least one of the secondary chamber pressure sensor reading, and the secondary chamber temperature sensor reading.

A hydraulic shock absorber comprising a shock absorber tube enclosing a hollow piston rod which moves in an oscillating manner corresponding to successive compression stages and rebound stages. The piston rod connects to a working piston that divides the interior of the shock absorber tube into two working areas. A bypass connects the two working areas of the shock absorber tube. The piston slide valve which is used to block and release the bypass is actuated by the pressure of a control pressure medium. The piston slide valve contains a piston slide which can be displaced by the control pressure medium against the force of a restoring spring, and which blocks or releases the bypass. The shock absorber is configured to be switched to a lower damping effect of the rebound stage by means of a controlled pressure application and without changing the damping effect of the compression stage.

A liquid damper system for restraining vibrations generated in a rotating body includes: a liquid damper which is coaxially rotatable with the rotating body and includes a collision member, the collision member being provided in a casing in which liquid is enclosed and the liquid colliding with the collision member when moving in the circumferential direction; and a relative rotation unit configured to cause the liquid damper to rotate relative to the rotating body. Vibrations of a rotating body are effectively suppressed when a rotating body steadily rotates at a main resonance frequency, in the liquid damper system.

A hydraulic shock-absorber comprises an outer cylindrical tube, an inner cylindrical tube defining with the outer cylindrical tube an annular chamber, a main piston slidably mounted in the inner cylindrical tube and dividing the inner volume of the inner cylindrical tube into an extension chamber and a compression chamber, both containing an incompressible damping fluid, a valve assembly mounted on a bottom wall of the inner cylindrical tube and comprising a first compression valve and a first intake valve, a cup-shaped body mounted in the inner cylindrical tube, inside the compression chamber, and an auxiliary piston rigidly connected to the main piston and configured to slide in the cup-shaped body at least during a final section of the compression phase of the shock-absorber. The shock-absorber further comprises a second compression valve configured as a non-return valve allowing the flow of the damping fluid only in the direction from a working chamber of the cup-shaped body towards a lower portion of the compression chamber.

A dual-stage, separated gas/fluid shock strut arrangement includes a dual-stage, separated gas/fluid shock strut, a pressure/temperature sensor mounted to the primary gas chamber, a stroke sensor, and a monitoring system, comprising a recorder configured to receive a plurality of sensor readings from at least one of the pressure/temperature sensor and the stroke sensor, a landing detector configured to detect a landing event based upon a stroke sensor reading received from the stroke sensor, and a health monitor configured to determine a volume of oil in the oil chamber, a volume of gas in the primary gas chamber, and a volume of gas in the secondary gas chamber.

An automatic pressure regulating pneumatic cylinder includes: a pneumatic cylinder, arranged with a connecting element for sealing the pneumatic cylinder, a piston slidably configured above the connecting element, a upper air chamber formed above the piston, and a lower air chamber formed between the piston and connecting element, the pneumatic cylinder further configured with first and second air entering passages allowing external air to one-way flow into the upper air chamber and a first guide passage allowing the external air to one-way flow into the lower air chamber; an air flow control unit, embedded inside the connecting element, an exhaust floating piston of the air flow control unit allowed to correspondingly form an air passage for opening or closing through normal speed and rapid displacement of the piston and further cause the internal air of the lower air chamber to generate different air pressure resistance for automatic internal pressure regulation.

A dual-stage, separated gas/fluid shock strut arrangement includes a dual-stage, separated gas/fluid shock strut and a monitoring system. The shock strut includes a strut cylinder, a strut piston operatively coupled to the strut cylinder, an oil chamber, a primary gas chamber, and a secondary gas chamber. The monitoring system includes a first pressure/temperature sensor, a second pressure/temperature sensor, a stroke sensor, a recorder configured to receive a plurality of sensor readings from the first pressure/temperature sensor, the second pressure/temperature sensor, and/or the stroke sensor, a landing detector configured to detect a landing event based upon a stroke sensor reading received from the stroke sensor, and a health monitor configured to determine a volume of oil in the oil chamber, a primary chamber gas volume in the primary gas chamber, and a secondary chamber gas volume in the secondary gas chamber.

A support assembly for a load-bearing unit, a gas turbine engine including the support assembly, and a method of operation of the support assembly are provided. The support assembly includes a support element, a damper, and a variable stiffness member. The support element supports the load-bearing unit. The damper supports the support element and is configured to provide dampening of the load-bearing unit. The variable stiffness member is positioned between the damper and the load-bearing unit. The variable stiffness member is configured to provide a serial dampening of the load-bearing unit with the damper. The variable stiffness member includes a shape memory alloy.

A control arrangement for a frequency-dependent damping valve having a control pot and an axaially displaceable control piston that axially limits a control space in the control pot and is connected to the damping valve device via an inlet connection. A spring element is arranged between the control piston and the damping valve that introduces a spring force axially into the control piston and the damping valve. When the control piston displaces towards the damping valve and the spring element increases the pressing pressure of the valve disks to increase the damping force. An axial position of a stop in the control arrangement is adjusted by plastic deformation of the pot base. A deformation portion produced by the plastic deformation and a depression partially receives the guide bush. A cross section of the depression corresponds to an outer cross section of the guide bush received in the depression.