The disclosure discloses an electro-hydraulic servo actuator capable of implementing long-stroke and high-frequency loading and a control method. The actuator includes: a long hydraulic cylinder with a piston, a short hydraulic cylinder with a piston, a fixed-end rod, low frequency and high frequency electro-hydraulic servo valves, a left rod chamber, a right rod chamber, a force applying end head, and a force applying end rod. With this structure, the displacement of the piston of the short hydraulic cylinder is a combination of small-displacement and high-frequency movement and large-displacement and low-frequency movement, so as to realize the generation of large-displacement and high-frequency movement. Therefore, a target large-displacement and high-frequency excitation is applied to the specimen under load test. The actuator can output high-frequency and large-displacement target excitation of 0.1 Hz to 200 Hz and 0 mm to 1500 mm, and has a simple mechanical structure, advanced control process, and good practicability.

A drive system (1) which is designed in particular as a robot (1a) and which has a fluid-operated linear drive (2), on the drive unit (7) of which linear drive, which drive unit can be driven so as to perform a drive movement (8), there is mounted an electrically and fluidically operable working unit (3). The linear drive (2) is equipped with a control valve device (16) which can be actuated by means of an internal electronic control device (32) in order to move the drive unit (7). Two drive pressure sensor devices (113) and a travel measuring device (114) are connected to the internal electronic control device (32), such that a position-controlled operation of the drive unit (8) is possible. The drive system (1) furthermore includes a flexible electrical cable arrangement (97) and a flexible fluid hose arrangement (95), which are fixed to the drive unit (7) and which serve for the supply of electricity and fluid to the working unit (3).

Provided is an actuator apparatus including a positioning actuator device configured to position a first carrier member of the actuator apparatus. The positioning actuator device includes a first hydraulic fluid actuator having a first clamping means and a second hydraulic fluid actuator having a second clamping means, wherein the first and second hydraulic fluid actuator are configured to alternately clamp around a guide arrangement for moving the positioning actuator device along the guide arrangement. The first carrier member is provided with a first coupling member configured to be releasable coupled to the positioning actuator device. A method of positioning a first carrier member by means of the positioning actuator device is provided.

A fluid actuated linear drive which includes a drive housing and a drive member which is movable relative to the drive housing. The drive force which is necessary for producing the drive movement is provided by a drive fluid which can be fed and discharged through housing channels of the drive housing. The housing channels each with a lateral coupling opening run out at a housing side surface of the drive housing. An L-shaped attachment coupling part which in the position of use is assembled on the drive housing has a coupling limb which is assigned to a housing rear surface and which is provided with two axial coupling openings. The axial coupling openings are in connection with lateral coupling openings via coupling channels. Hence there is the possibility of using the axial coupling openings for the feed and discharge of the drive fluid.

Hydraulic displacement mechanisms, and methods of using hydraulic displacement mechanisms to remove cables jammed or stuck in a conduit or other passageways, are disclosed.

Provided is a fluid actuator capable of safely driving a drive target. An air actuator using air as a working fluid includes an X-axis pressure sensor that measures air pressures PX+ and PX− along one drive axis, which drives a drive target in an X direction, a Y-axis pressure sensor that measures air pressures PY1+, PY1−, PY2+, and PY2− along two drive axes, which drive the drive target in a Y direction, and an acceleration detection unit that detects translational acceleration and rotational acceleration generated in the drive target on the basis of the measured air pressures PX+, PX−, PY1+, PY1−, PY2+, and PY2−.

A hydraulic thruster system for providing an axial force. In one embodiment, the system comprises a pump, a motor for driving the pump, and a hydraulic thruster comprising: a cylinder comprising a plurality of cylinder pistons; a shaft comprising a plurality of shaft pistons; a plurality of first pressure chambers; and a plurality of second pressure chambers, wherein the plurality of shaft pistons are positioned inside the cylinder, between the cylinder pistons to form the plurality of first and a second pressure chambers, wherein the shaft further comprises a first fluid passage connected to the pump and to the first pressure chambers, and a second fluid passage connected to the pump and to the second pressure chambers, and wherein the pump may pump fluid into the first pressure chambers and suction fluid from the second pressure chambers providing an axial force between the shaft and the cylinder.

A hydraulic system, for use under water with a hydraulic actuating drive, includes a hydraulic cylinder and at least one hydraulic machine. At least one rotary drive device and the hydraulic machine are coupled mechanically for a common rotating movement, and the hydraulic machine adjusts at least the hydraulic cylinder. The hydraulic cylinder has at least three cylinder chambers, and the hydraulic system includes a first hydraulic circuit and a second hydraulic circuit. The hydraulic system for use under water is set up, in particular, with a redundant hydraulic actuating drive for manual (mechanical) actuation.

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.

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.