A linear actuator system includes a linear actuator and an integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with two fluid drivers, each fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes the pump in a normal mode of operation in which the prime movers are independently driven and switches to a fail-safe mode of operation in which only one prime mover is operated.

The oscillation cylinder arrangement (100) comprises a working cylinder (10A) and a piston with a rod (27A), arranged to move therein, and a control valve structure (20) for the working cylinder (10A). The control valve structure (20) incorporates a main valve (24) for transmitting a pressure medium to a first sub-chamber or a second sub-chamber of the working cylinder (10A) for a linear movement (A, B) of the piston, as well as impulse valves (22, 23), and lever arms (25, 26) for controlling them, in order to set the operational state of the main valve (24). Control members (27B) fixed to the piston rod (27A) moving in the working cylinder (10A), the control members (27B) being arranged to contact the lever arms (25, 26) of the impulse valves in order to define the extreme positions of the movement of the piston rod (27A).

A technique provides enhanced control over a variety of hydraulically actuated devices, e.g. flow control valves. A hydraulic control module is placed in hydraulic communication with an actuator of a hydraulically actuated device. The hydraulic control module comprises features which prevent hydraulic locking of the system. Additionally, the control module may comprise metering features to enable metered flow of actuating fluid. The features may include valves, mini-indexers, flowline configurations, or other features which maintain the ability to shift the hydraulically actuated device and/or provide metering of the actuating fluid.

A linear actuator system includes a linear actuator and at least one integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.

A hydraulic power pack for use in a hydraulic system includes a reservoir configured to receive hydraulic fluid. A pump is in communication with the reservoir and is fluidly connectable to the hydraulic system. The pump is configured to pump hydraulic fluid from the reservoir into the hydraulic system when connected thereto. A hydraulic fluid sensor is fluidly connectable to the hydraulic system to sense a fluid characteristic of the hydraulic fluid within the hydraulic system. A variable speed drive is operatively coupled to the pump and the hydraulic fluid sensor to receive sensor data therefrom, with the variable speed drive being configured to generate a pump control signal based on the received sensor data. The pump is configured to operate at various speeds based on the pump control signal received from the variable speed drive.

A method and apparatus for remotely positioning a stabilizer wheel of a towable agricultural implement simultaneously, cooperatively and proportionally control the flow of hydraulic fluid to and from both the rod and base ends of the bore of a double-acting hydraulic cylinder, to hold the piston of the hydraulic cylinder at a target position determined from a desired position input signal corresponding to a desired position of the stabilizer wheel with respect to a frame of the agricultural implement.

In a piston unit of a fluid pressure cylinder a plurality of magnets are disposed through holes provided in a ring body. The magnets are disposed in facing relation to detection sensors that are mounted on connecting rods, and are provided in the same quantity as the connecting rods. Further, a guide rod extending from a head cover to a rod cover is inserted through the interior of the ring body. When the piston unit is displaced along the cylinder tube, rotational displacement is restricted by the piston unit being displaced along the guide rod, whereby the magnets are retained to face toward the connecting rods at all times. Therefore, the position of the piston unit is detected by the detection sensors through the magnets.

A double-rod ram (1), preferably for an extruder, comprising an outer cylinder (10), an inner cylinder (20) installed therein and arranged concentrically therewith, a double-acting work piston (41) provided in the inner cylinder to be displaceable and a bypass device (50) with at least one bypass valve (52), wherein the work piston (41) divides the inner cylinder (20) into two compartments (42) and can be loaded with a hydraulic fluid from both compartments (42), wherein the bypass device (50) is so arranged that in a bypass position of the bypass valve (52) a fluid connection between the two compartments (42) is formed by a direct connection, preferably at least one bypass line, and in a work position of the bypass valve (52) no such fluid connection is present.

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 control block for controlling a supply of pressurizing medium to an electrohydraulic or servo hydraulic axle includes a plurality of internally situated hydraulic interfaces configured to fluidically connect at least one of a source of pressurizing medium and a pressurizing medium sink of the axle to any hydraulic cylinder selected from a group of hydraulic cylinders of different structural forms, wherein the internally situated hydraulic interfaces are configured to selectively supply pressurizing medium to the selected hydraulic cylinder. The control block further includes an insert part configured as a function of the structural form of the selected hydraulic cylinder such that each of the plurality of internally situated hydraulic interfaces is one of tapped and blocked for the purpose of the fluidic connection.