A screw pump comprises a body which has a cylindrical duct formed therein. A screw shaft is located in the cylindrical duct and is arranged to transport liquid between an inlet and an outlet of the screw pump. The screw shaft has a screw thread which defines a helical liquid path within the cylindrical duct. The body of the screw pump includes a groove extending along an inside surface of the cylindrical duct, the groove defining, in part, a ball-passage which extends alongside the screw shaft and intersects with the helical liquid path. The ball-passage contains a plurality of balls which are guided along the ball-passage by the screw thread when the screw shaft rotates relative to the body.

A stepper motor driven actuator system is provided. The system includes a stepper motor, a cam, and a gearbox system. The gearbox system operatively connects the stepper motor to the cam. The cam rotates in response to stepping of the stepper motor. The system also includes a valve having a control piston located therein. The control piston is configured to translate in response to rotation of the cam. The system further includes a rotary actuator. The rotary actuator is fluidly connected to the valve, and the rotary actuator is configured to rotate the cam in response to translation of the control piston.

The present invention makes a rotary movement smooth, the rotary movement allowing direct detection of the movement of an output member of a rotary clamp. In a clamp, an output member is accommodated in a cylinder hole. A first valve chamber, to which compressed air is supplied, is provided between a lower wall of a housing and the output member. A second valve chamber is a hollowed out portion of the output member so as to be provided open toward the first valve chamber. A valve rod is inserted into the second valve chamber from the lower wall. A valve rod passage that allows the second valve chamber to communicate with outside air is provided in the valve rod, and a seal section is provided in a peripheral gap where the valve rod and the second valve chamber move relatively to one another. The gap is formed so that, as the valve rod and the second valve chamber are in relative movement, there is a region which is sealed by the seal section against movement of the compressed air through the gap between the valve rod and the second seal chamber and the there is a region which is open from the seal.

The invention relates to a quick-change device (IO) having at least one locking bolt (26) and a motor drive which moves the locking bolt (26) into a locking position and an unlocking position, wherein the drive (16) has an energy connection (28a, 28b) and output means (34) interacting with the locking bolt (26), wherein the drive (16) comprises a rotary drive (30) having a motor and an output shaft (34), wherein the output shaft (34) is mechanically connected to the locking bolt (26), with the result that the locking bolt (26) is movable along an actuation axis. The invention is distinguished by the fact that the drive (16) has an attachment (20) for a shaft-hub connection, on which attachment a tool for manual actuation can be mounted, with the result that a manual actuation acts directly on the output shaft (34) and here the attachment (20) is arranged coaxially to a rotary connection (32a, 32b) of a gear shaft (32c, 32d).

A screw-pump type electro-hydraulic actuator preferably includes an electric motor device, a hydraulic tube, a pump piston, a spline rod, an actuator rod and a hydraulic control circuit. The electric motor device preferably includes an electric motor and a gearbox. One end of the spline rod is engaged with an output of the gearbox. The pump piston preferably includes a piston base, three sets of screw pump rollers, a spline drive gear, a first piston end plate and a second piston end plate. The hydraulic flow circuit includes a first relief valve, a first check valve, a second relief valve, a second check valve and an accumulator. The screw pump rollers are rotatably retained in the piston base between the first and second piston end plates. The spline gear drives the pump driven gears of the three drive screw pump rollers through the spline drive gear to pump hydraulic oil.

The present technology generally provides swing gate actuator assemblies. In particular, some embodiments of the present technology provide a fastener configured to secure an arm of the actuator assembly to a swing gate panel. The fastener can be configured to permit a longitudinal axis of the arm to pivot about a pivot portion on the fastener, thereby reducing the likelihood of gate malfunction in response to a misalignment event.

Actuators and devices are provided for imparting a rotary movement and comprising in a longitudinal direction first and second hydraulic cylinders, characterised in that the first driver is a linear hydraulic cylinder comprising a first piston, and that the second driver is a linear hydraulic cylinder comprising a second piston, and in that the devices include a member for converting linear motion into rotary motion in order to convert a translation movement of the second piston into a rotary movement.

An actuation system for controlling flight control members of a vehicle. Each flight control member is controlled by two or more linear hydraulic actuators. Synchronization members extend between the hydraulic actuators on the same flight control members to synchronize the movements of the hydraulic actuators for consistent movement across the length of the flight control members. Brakes can maintain the positions of the synchronization members and thus the flight control members. Motors can provide for moving the synchronization members to control the positioning of the hydraulic actuators and flight control members.

An actuation system for controlling flight control members of a vehicle. Each flight control member is controlled by two or more linear hydraulic actuators. Synchronization members extend between the hydraulic actuators on the same flight control members to synchronize the movements of the hydraulic actuators for consistent movement across the length of the flight control members. Brakes can maintain the positions of the synchronization members and thus the flight control members. Motors can provide for moving the synchronization members to control the positioning of the hydraulic actuators and flight control members.

The invention relates to a rotary actuator, converting actuator and method for producing rotation. The rotary actuator includes at least two rotation units for producing stepped angular displacements (Rs). The rotation unit includes a cylinder for producing linear movement (L) and a converter for converting the linear movement to rotation. The stepped rotary movements of the rotation units are transmitted by transmission elements to an output shaft.