In a hydrostatic pressure cylinder, a holding member which holds a magnet is mounted on a piston unit to rotate together with a cylinder tube. The cylinder tube is capable of rotating with respect to a rod cover and a head cover. It is thereby possible to change an attachment position of a magnetic sensor by rotating the cylinder tube.

A piston unit is provided with a piston body; a packing mounted on an outer circumferential portion of the piston body; a holding member having a plurality of magnet holding portions that are arranged along a circumferential direction; a plurality of magnets which are held at intervals in the circumferential direction; a first annular yoke disposed on one side in an axial direction of the plurality of magnets; and a second annular yoke disposed on the other side in the axial direction of the plurality of magnets.

An electro-hydraulic actuator includes: a motor output rotative power; an external gear pump activated by the motor; a hydraulic actuator operated by a pressurized working fluid supplied by the external gear pump; a manifold block in which a flow channel forming a working fluid circuit of the hydraulic actuator is incorporated; a first portion to store the motor; a second portion to store the external gear pump, the hydraulic actuator, and a reservoir; and a coupling portion to couple the first portion and the second portion in a liquid-tight state. The coupling portion includes a communication hole through which the first portion and the second portion communicate, a rotational shaft of the motor and a driving shaft of the external gear pump are joined to each other, and the external gear pump is attached to the coupling portion while being stored in the manifold block.

A piston for a fluid-actuated working cylinder, with a piston base unit which is coaxial to a piston longitudinal axis, consisting of a rigid core body which has radial outer peripheral surface and of an annular filling body which is seated in an annular receiving groove. The receiving groove is coaxial to the piston longitudinal axis and in the region of the radial outer peripheral surface is designed with a radially outwardly facing groove opening in the core body. The piston further includes a ring element which consists of plastic. The ring element radially outwardly coaxially encompasses the piston base unit at least in the region of the filling body, being radially supported with a radial inner peripheral surface on the piston base unit, projecting radially beyond the radial outer peripheral surface of the core body and comprising an axially orientated axial support surface radially outside the piston base unit on its two axial face sides. The piston further includes an annular enveloping body which has rubber elastic characteristics.

A field bus solenoid valve assembly has a sensor for detecting the commencement of an actuation cycle for moving a piston in a cylinder and piston assembly. A position sensor detects an end position of a piston in a cylinder and piston assembly at the end of the actuation cycle. A timer times the elapsed time between the initiation of the actuation cycle of the piston and when the position sensor for detecting an end position detects the piston in its end position at the end of the actuation cycle. A comparator operably connected to a storage device and the sensors for comparing elapsed time from the sensors to a normalized time or profile and a predetermined tolerance boundary in the storage device. An alarm device is actuated if the elapsed time is outside of the set tolerance boundary.

A fluid pressure cylinder has a sensor attachment tool mounted thereon. A holder holds the position sensor in a rail structure extending in an axial direction of a cylinder tube and is secured by screwing to a rod cover or a head cover in an arm part provided to one end of the holder.

A clamping device with a housing, with a piston with piston rod running in the housing, and with a monitoring unit arranged at least partially in the housing, wherein the monitoring unit includes at least two sensor units. The sensor units are spaced apart from one another along a longitudinal axis of the piston rod, and are arranged at a distance from the piston rod. The piston and the piston rod, and a metallic signal transmitter arranged on the piston or on the piston rod, are movable in a positively driven manner between a first end position and a second end position. The first sensor unit is arranged at the first end position of the signal transmitter, and the second sensor unit is arranged at the second end position of the signal transmitter. Each sensor unit has a first and second sensor and includes an induction coil and an oscillator.

A downhole valve assembly comprises a sleeve concentric with a housing and movable relative to a port through the housing to control flow of fluid through the port. A sensor assembly provides indicates the relative positions of the sleeve and housing, and comprises first and second sensors on e.g. the housing which detect markers on e.g. the sleeve. The sensor outputs are produced by processing (e.g. combining, integrating, summing, subtracting or otherwise processing) the signal components of each of the first and second sensors to correct for misalignment of the sleeve with the housing. The sensor output provides position information for more than one plane, and the output signal therefore allows for correction of errors in the position information arising from misalignment of the sleeve with the housing.

A hydraulic cylinder is provided with a cylinder tube, a piston unit, and a piston rod. The piston unit has a piston body; packing mounted on the piston body; a holding member mounted on the piston body; and a magnet held by a magnet holding part of the holding member. The magnet holding part has a notch that is open on the outer circumferential surface of the holding member.

Locking linear actuators, thrust reversers for aircraft that include the locking linear actuators, and methods of manufacturing the locking linear actuators. The disclosed locking linear actuators include an actuator housing that defines a bore housing an actuator piston and a lock sleeve. A portion of the actuator piston defines a lock aperture, housing a locking tab capable of radial movement. When the actuator is retracted, the locking tab engages with a step in the surface of the bore to lock the linear actuator, a distal portion of the lock sleeve extends into a portion of the actuator piston to prevent the locking tab from disengaging from the step in the surface of the bore.