A stroke adjustment mechanism includes an adjustment block attached to a slide table and a stopper attached to a cylinder body. A side wall portion of the slide table includes three or more screw holes arranged in the moving direction of the slide table. Two adjustment block mounting bolts are inserted into the adjustment block and selectively screwed into adjacent screw holes of the plurality of screw holes.

A telescopic device having a housing and a rod is slidably mounted within a bore of the housing. First and second bearings provide sliding engagement between the rod and the housing. The first bearing is mounted relatively close to the open end of the bore and the second bearing is mounted relatively far from the open end of the bore relative to the first bearing. The second bearing is annular in shape with a central axis, the bearing has a radially outer mounting surface of arcuate cross-section and a radially inner bearing surface for sliding engagement with an outer surface of the rod and wherein the inner sidewall is provided with an annular groove having a second mounting surface of arcuate cross-section to house and retain the second bearing.

An electrohydraulic system for use under water includes an electrohydraulic actuator and a container having an internal space provided for forming a volume which is enclosed from the environment and which is provided for receiving a hydraulic pressurized fluid. A hydraulic cylinder is provided in the internal space of the container, the inside of which is divided into a first cylinder chamber and a second cylinder chamber by a piston to which a first piston rod and a second piston rod are connected. The two active surfaces of the piston are the same or approximately the same size.

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.

A head end seal assembly for a hydraulic cylinder may include a cylinder seal carrier having a seal carrier bore with a main seal groove and a coating ring groove adjacent the main seal groove. A main seal disposed within the main seal groove is fabricated from a resilient material and engages a rod outer surface of a rod to substantially prevent leakage of pressurized fluid from the hydraulic cylinder. A coating ring disposed within the coating ring groove is fabricated from a thermoplastic polymer such as Teflon and engages the rod outer surface such that portions of the thermoplastic polymer are deposited into indentations on the rod outer surface as the rod slides past the coating ring to smooth the surface and reduce abrasion between the rod and the main seal. A second coating ring on the opposite side of the main seal may coat the rod as it moves in the opposite direction.

In a linear actuator, a slide table is attached to a cylinder body via a guide mechanism so as to be movable along the longitudinal direction of the cylinder body. The slide table includes a table body arranged above the cylinder body and extending in the longitudinal direction, and an end plate joined to an end of the table body in the longitudinal direction so as to be substantially orthogonal to the table body. The end plate includes a storage chamber provided on one surface thereof in the longitudinal direction facing a guide mechanism and depressed from the one surface in a direction away from the guide mechanism. For example, when the linear actuator is used in an environment where powder dust and the like is scattered, the storage chamber stores therein a solidified matter made up of the powder dust and the like.

When pressurized fluid is not supplied into or discharged from the first channel 28a of the piston rod 28, that is, when the first channel 28a is isolated from the outside, the cylinder tube 22 is in a stopped state. At this time, fluid inside the first cylinder chamber 36a is compressed, and the pressure is increased accordingly to match the sum of the weights of the cylinder tube 22, the table 18, and the workpiece W.

A hydraulic module including a cylinder (2) which accommodates a piston (3) which delimits a chamber (4) which receives the brake fluid. The piston (3) is connected to the electric motor (5) of the module (1) by a recirculating ball screw (6), whose core (61) is fixedly connected to the piston (3) which itself is guided by needles (21) which are parallel to the axis (xx) of the piston (3) and with which notches (351) on the circumference of the piston (3) interact. The piston (3) is a piece, which is formed from a cylindrical body (32) made from anodized aluminum and an outer ring (35) made from steel, which is forcibly mounted on the edge (34) of the piston and is provided with notches (351) with a cross section which corresponds to the effective cross section of the needles (21).

In particular, an object is to provide a fluid cylinder allowing for accurate stroking while causing rotation with reduced power consumption and a compact configuration. The fluid cylinder of the present invention includes a cylinder body and a shaft member supported within the cylinder body and wherein the shaft member is capable of stroking in an axial direction while rotating by means of a fluid. A rotary driver that rotates the shaft member on the basis of a rotation pressure generated by the fluid and a stroke driver that causes the shaft member to stroke on the basis of a cylinder control pressure generated by the fluid are provided in separate areas within the cylinder body.

A fluid pressure cylinder is provided with a cylinder tube having a sliding hole internally; a piston unit disposed along the sliding hole so as to be capable of moving back and forth, and a piston rod projected in the axial direction from the piston unit. The piston unit can shorten the axial dimension of a piston body by mounting a wear ring to an outer circumferential section of a ring-shaped magnet attached to an outer circumferential section of the piston body.