The invention relates to a rotary actuator (1) to be installed between a dipper arm (9) and an excavator tool (12) of an excavator (2). The rotary actuator (1) comprises a first actuator part (20) adapted to be fixed to the dipper arm (9) or to the excavator tool (12), wherein the first actuator part (20) is formed with an inner cylindrical orifice (23) comprising first part guide means (24). The rotary actuator (1) further comprises a second actuator part (21) adapted to be fixed to the other of the dipper arm (9) or the excavator tool (12), wherein at least a part of the second actuator part (21) is arranged inside the inner cylindrical orifice (23) and wherein the second actuator part (21) is rotatably supported by the first actuator part (20) while being substantially axially fixed in relation to the first actuator part (20). Furthermore, an outer cylindrical surface (25) of the second actuator part (21) comprises second part guide means (26). The rotary actuator (1) also comprises a piston part (22) arranged inside the inner cylindrical orifice (23) and around at least a part of the a second actuator part (21), wherein the piston part (22) is axially displaceable in relation to the a first actuator part (20) and the a second actuator part (21) and wherein an outer cylindrical piston part surface (29) is provided with outer piston part guide means (35) arranged to mesh with the first part guide means (24) and an inner cylindrical piston part surface (30) is provided with inner piston part guide means (36) arranged to mesh with the second part guide means (26). The second actuator part (21) is formed as a cantilever and piston means (27) of the piston part (22) extends all the way across the free end (28) of the second actuator part (21). The invention further relates to a method for tilting an excavator tool (12) in relation to a dipper arm (9) of an excavator (2) by means of a rotary actuator (1) and use of a rotary actuator (1).

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.

The invention relates to an actuating device for a rotatable closure part of a valve, in particular a pneumatically or hydraulically actuatable rotary drive for a disk or throttle valve, with a housing, in which a drive piston that is sealed from a cylindrical housing casing is arranged and is suppliable on one side with a pressurizing medium, which preferably has a tubular piston skirt, with a drive shaft, which is guided on one side out of the housing and drives in a rotating manner the closure part indirectly or directly, wherein the drive piston executes either an axial shift movement against the effect of at least one return spring in the case of a one-sided supply with the pressurizing medium or a back and forth shift movement in the case of an alternating supply with a pressurizing medium, wherein the piston skirt experiences an axially oriented guidance in the housing via at least one axial groove formed in it, into which a straight-line guide cam permanently connected with the housing engages, and wherein the piston skirt has at least one helical groove arranged in it, into which a drive bolt permanently arranged on or in the drive shaft is arranged, so that the radially and axially mounted drive shaft experiences a rotation around the axis of rotation due to the axial shift movement of the drive piston oriented in the direction of its axis of rotation.

Provided is a highly durable, compact rotary clamp device. In a housing body, a large diameter hole and a medium-diameter hole are continuously formed in this order from a lower side in an axial direction. A cylindrical protruding member which is hermetically inserted in the large diameter hole is screwed into the housing body. A key member is inserted between the medium-diameter hole and a cylindrical retainer inserted in the medium-diameter hole. The retainer is positioned relative to the housing body in a circumferential direction by the key member.

A pneumatic drive mechanism for converting linear motion from compressed air into rotational motion for use in fare gates and other applications.

A fluid-powered tool actuator usable with a vehicle having an arm and a rotation link for rotation of the tool actuator in a first plane and being laterally tiltable in a second transverse plane. In some embodiments pressurized fluid is communicated using distribution channels and passageways internal to the actuator to limit use of external hydraulic lines. In some embodiments the tool actuator has certain components in a compressive pre-loaded state to reduce their fatigue failure during operation of the tool actuator under load.

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 invention concerns a hydraulically constructed device for mounting between an earthmoving machine and a tool. The device is secured to the earthmoving machine and connected to the earthmoving machine's hydraulic system. The operator can from the panel in the driver's cabin of the earthmoving machine control the device to place the tool in motion. For this, the device can be outfitted with a quick change unit. This hydraulic device functions with or without a quick change unit. The device is built around a housing (10) consisting of at least one main axle (4) and a slide (6). The slide is movable in that the main axles are led through the slide, and furthermore on the outside of the slide there are a number of spiral slots (20) with a conformation corresponding to a number of loose keys (9). The loose keys are fixed in such a way that they create the connection between the housing and the spiral slots. The loose keys are configured such that they are adapted to the slots in the slide and can move in them, and advantageously they remain a replaceable wearing part.

A hydraulic swivel drive for a grab that has two gripping arms or shells movable like tongs, including two swivel shafts parallel to each other and rotatably mounted in a drive housing, whose shaft ends are connectable with the gripper arms or shells, wherein the swivel shafts each have two oppositely threaded screw engagement portions, with which two pistons movable in opposite directions by means of hydraulic pressure for driving the swivel shafts are in screw engagement. Two differently large and differently contoured cylinder pressure chambers can be assigned to each piston in order to optimally adapt the cross-sectional area of the pistons for each of the reciprocating positioning movements and to appropriately select the pressure conditions. To be able to run in the differently contoured and dimensioned cylinder pressure chambers, each of the pistons is provided with different piston portions which are adapted to the respective cylinder pressure chamber.

A hydraulic rotary gearless actuator includes an input stage and an output stage. The input stage includes a piston linearly translatable within an input cylinder. The output stage includes first and second output cylinders defining first and second tracks, respectively, and a trunnion assembly connected to the piston and including first and second rollers engageable with the first and second tracks, respectively. The output stage is configured to convert linear translation of the piston into rotation of the first output cylinder relative to the second output cylinder by the trunnion assembly being driven linearly by the linear translation of the piston and the first and second rollers engaging with the first and second tracks, respectively.