An oleo-pneumatic shock absorber having a casing, a rod slidably mounted in the casing, first and second fluids in the casing, and a gauge. The gauge has a substrate positioned on the shock absorber. The substrate has a first region with a slot sized to fit an ultrasonic transducer arranged to encompass a range of possible oil levels within the shock absorber, a second region corresponding to a range of possible extension states of the shock absorber and a third region comprising one or more traces. Each trace corresponds to a temperature value and is indicative of an optimum relationship between the oil levels and the range of extension states at the respective temperature value associated with the trace.

There is provided a method for detecting failure of a gas-hydraulic damper for a rail vehicle, comprising: receiving a first input signal (S1) indicative of a stroke related parameter of the gas-hydraulic damper determined at a first time instance, determining a first stroke value.Math.based on the first input signal (S1). receiving, at least one second input signal (Si), wherein each subsequent signal (Si) is indicative of a respective stroke related parameter measured at a respective subsequent time instance, determining a respective stroke value based on each of the second input signals (Si), determining a stroke value over time based on the determined stroke values, and determining that there is a failure of the gas-hydraulic damper if the stroke value over time, fulfils a first criterion. Also provided are a system, a gas-hydraulic damper and computer program product.

A method and apparatus for servicing a shock absorber on a landing gear assembly of an aircraft in a weight-on-wheels state is disclosed. The shock absorber includes at least one chamber containing both hydraulic fluid and a gas in fluid communication with each other. The apparatus includes a source of gas and a source of hydraulic fluid. The amount of hydraulic fluid in the chamber is corrected, preferably such that the chamber is then filled with a known amount of degassed hydraulic fluid. The process may be at least semi-automatically performed, for example under the control of a control unit. By delivering a pre-set mass of gas into the chamber, there is no need to rely on a measure of gas pressure or H-dimension (h) when servicing the shock absorber, and more accurate servicing of a shock absorber may thus be provided.

A method and portable apparatus for servicing a shock absorber on a landing gear assembly of an aircraft in a weight-on-wheels state is disclosed. The shock absorber includes at least one chamber containing both hydraulic fluid and a gas in fluid communication with each other. The apparatus includes a source of gas and a source of hydraulic fluid. The amount of hydraulic fluid in the chamber is corrected, preferably such that the chamber is then filled with a known amount of degassed hydraulic fluid. A pre-set mass of gas is then delivered into the chamber under the control of a gas delivery system of the portable apparatus. More accurate servicing of a shock absorber may thus be provided since account is additionally taken of gas dissolved in hydraulic fluid. By delivering a pre-set mass of gas into the chamber, there is no need to rely on a measure of gas pressure or H-dimension (h) when servicing the shock absorber.

A method for execution by a computing entity includes interpreting a magnetic response from a set of magnetic field sensors to produce a piston velocity and a piston position of a piston associated with a head unit device. The head unit device includes a chamber filled with a shear thickening fluid (STF) that includes a multitude of magnetic nanoparticles. The method further includes determining a shear force based on the piston velocity and the piston position. The method further includes determining a desired response for the STF based on the shear force, the piston velocity, and the piston position. The method further includes generating a magnetic activation based on the desired response for the STF and outputting the magnetic activation to a set of magnetic field emitters positioned proximal to the chamber.

A method for inspecting an oil volume at a damper assembly at a solar tracker includes rotating a torque tube of the solar tracker from a first rotational position to a predefined rotational position, that is different than the first rotational position, to reveal an oil sight gauge at the damper assembly. This method also includes, when the torque tube is at the predefined rotational position and the oil sight gauge is revealed, inspecting an oil volume within the damper assembly using the oil sight gauge.

A method for execution by a computing entity includes interpreting an electric response from a set of electric field sensors to produce a piston velocity and a piston position of a piston associated with a head unit device. The head unit device includes a chamber filled with a shear thickening fluid (STF) that includes a multitude of piezoelectric nanoparticles. The method further includes determining a shear force based on the piston velocity and the piston position. The method further includes determining a desired response for the STF based on the shear force, the piston velocity, and the piston position. The method further includes generating an electric activation based on the desired response for the STF and outputting the electric activation to a set of electric field emitters positioned proximal to the chamber.

A method for execution by a computing entity includes interpreting a fluid flow response from a set of radio frequency wireless field sensors to produce a piston velocity and position of a piston associated with a head unit device that includes a chamber filled with a shear thickening fluid (STF) that includes a combination of a multitude of piezoelectric nanoparticles and a multitude of magnetic nanoparticles. The method further includes determining a shear force based on the piston velocity and the piston position. The method further includes determining a desired response for the STF based on the shear force, the piston velocity, and the piston position. The method further includes generating a wireless field activation based on the desired response for the STF and outputting the wireless field activation to a set of radio frequency wireless field emitters positioned proximal to the chamber.