When a fluid is supplied to a first pressure-boosting chamber and/or a second pressure-boosting chamber of a pressure booster, either a first electromagnetic valve unit supplies a fluid discharged from a first pressurizing chamber to a second pressurizing chamber, or a second electromagnetic valve unit supplies a fluid discharged from a third pressurizing chamber to a fourth pressurizing chamber.

The present invention relates to a piston cylinder system for a working device, wherein the piston cylinder system comprises at least one tubular element and at least one piston which is guided in the at least one tubular element. The piston cylinder system is characterized in that at least one tubular element consists of high-manganese-steel and the inner side of the at least one tubular element is machined.

An air cylinder includes a tubular cylinder and a piston which is moved by pressure of a fluid supplied to a chamber provided inside the cylinder. A monitoring device includes a heat flux sensor and a detection part. The heat flux sensor is provided to the cylinder and detects heat flux that flows between inside and outside of the cylinder due to compression or expansion of the fluid in the chamber caused in accordance with the movement of the piston. The detection part detects the moving state of the piston based on the output signal of the heat flux sensor.

An apparatus to compress a fluid is disclosed herein. The example apparatus includes a casing, an actuation cylinder and a compression cylinder defined in the casing, a rod slidably coupled between the actuation cylinder and the compression cylinder, and a piston coupled to the rod at an end of the rod, the end of the rod in the compression cylinder, the piston slidable relative to the compression cylinder to compress the fluid therein.

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.

An actuator capable of preventing a malfunction of the actuator due to iron powder contained in working fluid and the abrasion of a cylinder and a piston is provided. The actuator includes a cylinder (51) extending in a vertical direction and having an opening (51a), a piston (52) moving inside the cylinder (51), and a stroke sensor (53) that detects a position of the piston (52). The stroke sensor (53) includes a member to be detected (53b) which is a magnet, and a sensor (53c) which detects the member to be detected (53b). The member to be detected (53b) is located below a lower edge portion (51a1) of the opening (51a).

A rotary drive for actuating a valve element of a valve fitting, having a housing, which has a drive device and a pivot-mounted driven shaft which can be driven by the drive device and which can be coupled to the valve element, and a position detection device for detecting a position of the driven shaft, wherein the position detection device has a magnet module attached to the driven shaft in a torque-proof manner and a sensor module which is fitted onto or into the housing and is designed to detect a magnetic field measurement value according to the magnetic field generated by the magnet module. The the magnet module and/or the sensor module is attached such that it can be removed from the rotary drive, and the rotary drive includes a control device, which is adapted to determine if the magnet module or the sensor module is removed from the rotary drive.

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.

Provided is a monitoring apparatus configured to monitor the pressure state of a fluid in a target apparatus having a chamber in which at least one of compression and expansion of the fluid is performed. The monitoring apparatus includes a heat flux sensor provided for the target apparatus and configured to measure a heat flux between inside and outside of the chamber. The monitoring apparatus includes a determining unit configured to determine the pressure state of the fluid based on a measurement result of the heat flux sensor.

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.