Abstract: A control plate, for alternatingly fluidically connecting hydrostatic operating chambers, in particular of an oblique axis type axial piston machine, with pressure medium connections, includes a first end face, a second end face, at least a first recess, a first kidney-like control opening, and at least one through-recess. The first face extends transversely to a rotation axis. The second face faces away from the first face. The first recess is bounded in the first end face by the first control opening, and at least partially forms the at least one through recess, which extends toward the second end face from the first end face at an end portion of the first control opening, and which is arranged in or counter to a rotation direction of the rotation axis. An oblique axis construction type axial piston machine includes such a control plate.

Abstract: A pump, including: a cylinder block including two through-bores and two pistons disposed in the through-bores; a drive shaft to rotate the cylinder block; a swash plate to displace the pistons within the through-bores to draw fluid through an inlet port into the through-bores; and expel the fluid from the through-bores into the outlet port; a torque sensor arranged to measure torque on the drive shaft and transmit a torque signal, including the measured torque, to a processor; and an actuator to receive, from the processor, a control signal generated using the torque signal and pivot the swash plate about a first axis, transverse to the axis of rotation, or maintain a circumferential position of the swash plate about the first axis; or pivot the cylinder block about a second axis, transverse to the axis of rotation, or maintain a circumferential position of the cylinder block about the second axis.

Abstract: An actuator is provided. The actuator includes: a housing having an interior elongated hole; a rod dimensioned to fit in the elongated hole; a piston dimensioned to fit in and move along the elongated hole while connected to the rod; mating structure located on at least one of the piston and rod, the mating structure configured to allow the rod to attach to the piston in a manner to create clearance between the rod and the piston to allow the rod and piston to move with respect to each other. A method of attaching a piston to a rod in an actuator may also be provided. The method may include: fitting the piston to the rod; providing a clearance between the piston and the rod; fastening the piston to the rod in a loose manner as to preserve the clearance and allow the piston to move with respect to the rod.

Abstract: A radial piston machine and a piston for a radial piston machine include pistons that are movable in the radial direction and are guided along a lifting surface of a cam ring by a roller. The roller is hydrostatically supported by a pressure groove in a sliding bearing surface of a roller cage. The geometry of the pressure groove is configured such that both the leakage is reduced and the lateral support is improved by enlarging hydrostatic and hydrodynamic surface sections.

Abstract: Disclosed herein are embodiments of inventive multipositioner technology relating to multipositioner apparatus having discrete positioning capability and, relative to each discrete position, incremental positioning capability. As compared with prior art apparatus, embodiments of the inventive technology may afford: operational resolution for larger positional ranges, reduced cylinder length to achieve positioning as desired, enhanced positioning capability and/or robustness of design.

Abstract: Field adjustable piston actuators are described. An example field adjustable piston actuator includes a housing having opposing openings and a chamber. Additionally, the example piston actuator includes a first plate coupled to the housing and adjacent one of the opposing openings. Further, the example piston actuator includes a second plate coupled to a yoke and the housing. The second plate is adjacent the other one of the opposing openings. Further still, the piston actuator includes a volume adjuster to provide field adjustment to change a volume of the chamber.

Abstract: A hydraulic system includes an engine driven variable displacement hydraulic pump which supplies fluid to a hydraulic consumer and an electronic control unit. A flow rate adjusting unit includes a stop that can be brought into engagement with an adjusting piston. In order conform the power output of the pump to the operating conditions of the vehicle, the stop of the flow rate adjusting unit includes adjusting devices that can be controlled by the control unit, so that the maximum flow rate of the pump can be varied by the electronic control unit. The electronic control unit generates a control signal for the adjusting device as a function of a sensed engine speed.

Abstract: A spring-loaded brake cylinder for commercial vehicles includes at least one spring-loaded brake piston that can be actuated by a pre-loaded spring and is supported in a housing. A mechanical emergency release device is provided for the emergency release of the spring-loaded brake cylinder. The emergency release device includes an indicator that has an indicator rod indicating the position of the spring-loaded brake piston. The rod extends through a threaded spindle of the emergency release device and is movable in the axial direction. A stop body is disposed in the region of one end of the indicator rod. The stop body is positively connected to the indicator rod by a detent connection produced by an axial relative movement between the indicator rod and the stop body.

Abstract: A three position servo system. The servo system has a servo housing that has first and second control ports disposed therein in a cavity in fluid communication with the first and second control ports. A servo piston having at least one pressure chamber disposed therein is then used to communicate the pressure within the first and second ports into the first end of the cavity. Thus, when pressure is applied below a threshold pressure to both ports a first position is achieved, when pressure is applied above the threshold pressure in only one port a second position is achieved, and when pressure is applied above the threshold pressure in both ports a third position is achieved. Therefore, the servo system provides three different operating positions.

Abstract: A fluid operated rotary drive comprises a drive housing (2) and an output shaft (4) able to be caused to oscillate in relation to it and having a pivotal abutment arranged on it which cooperates with a counter abutment (34 and 35). The pivotal abutment is able to be positioned about the longitudinal axis (8) of the output shaft (4) in different abutment settings and is able to be clamped in a releasable manner respectively against a clamping face (56) on the housing by means of a clamping means (53).

Abstract: The female screw (8a) is formed on the inner circumference of the forward side of the piston receiving hole (8) in the cylinder body (2) and the movable stopper (9) is screwed into the female screw (8a). The piston (12) is located at the stroke end of the forward side when its end face of the forward side is contact with the end face of the backward side of the movable stopper (9). The rotating knob (4) is rotatably mounted on the end of the forward side of the cylinder body (2). The rotation transmitting pin (16) is projected on the end face of the backward side of the rotating knob. The rotation transmitting hole (9a) is formed on the end face of the forward side of the movable stopper (9). The rotation transmitting pin (16) is slidably inserted into the rotation transmitting hole. When the rotating knob (4) is rotated, the movable stopper (9) is screwed into so that the stroke end position and the moving stroke of the piston (12) can be adjusted.

Abstract: An adjustable mechanism for a valve or actuator is provided. The adjustable mechanism cooperates with one or more pistons, which in turn cooperates with a valve element to limit the axial displacement of the valve element relative to the valve seat. The adjustable mechanism can be adjusted axially, thereby providing a greater or lesser distance for the piston and diaphragm to travel. Embodiments incorporating the adjustable mechanism include a trickle valve, an on/off valve and a mixing valve. The adjustable mechanism also provides to the adjustment of the piston stroke to match or closely mirror the stroke of the vale element.

Abstract: An engine valve actuator for an internal combustion engine is provided. The actuator includes a housing having an opening. An adjustment member is disposed in the housing and defines a fluid chamber having a chamber wall. A piston is also disposed in the opening. The piston defines a piston chamber and has a pressure surface, a protrusion extending from the pressure surface, and a groove disposed in the pressure surface surrounding the protrusion and in fluid communication with the piston chamber. A fluid passageway is adapted to controllably communicate pressurized fluid to the housing opening. A push rod is operatively engageable with the piston and is adapted to controllably actuate an engine valve of the engine.

Abstract: A pusher which has a stroke shorter than that of a piston at either position on a head side or a rod side in a cylinder main body and which serves as both means for pushing the piston from a stroke end back to an intermediate stopping position and means for stopping the piston at the intermediate stopping position is disposed so as to be movable independently from the piston, and pressing means for causing the pusher to displace to the intermediate stopping position is provided.

Abstract: An engine valve actuator for an internal combustion engine is provided. The engine valve actuator includes a housing having an opening. An adjustment member is disposed in the housing and defines a chamber. A piston is disposed in the opening of the housing and has a protrusion adapted to be received in the chamber of the adjustment member. The piston has a first position where the protrusion of the piston is disposed in the chamber and a portion of the piston contacts a corresponding portion of the adjustment member and a second position where the portion of the piston is separated from the corresponding portion of the adjustment member. A fluid passageway is adapted to provide pressurized fluid to the opening. The pressurized fluid acts on the piston to move the piston towards the second position to thereby allow pressurized fluid to enter the chamber to prevent the piston from returning to the first position.

Abstract: The invention relates to an operating device for a rotatable closing element of a valve such that, a desired angle of rotation can easily be set and maintained. This is achieved in that two guide grooves (2f), which are incorporated diametrically opposite each other, are bounded on all sides by a piston shank (2b), in that their respective courses are precisely or more or less symmetrical at all points, in that in each instance the courses have, in relation to the axis of the piston (2), a greater pitch angle in a central portion (angle b) than in their two portions on the end side (angle a) (a>b), and in that the stroke of the piston (2) is limited on one side by application of the front-end piston shank (2b) to the cover element (4) and on the other side by application of a piston base (2a) to a stop element (9; 20; 20.

Abstract: A hydraulic actuator for operating a gate valve. The actuator includes a stationary piston coupled to an actuator housing and a moveable cylinder disposed proximate the piston exterior surface. The piston includes a hollow interior portion adapted to house a manual override mechanism. The piston includes a hydraulic pressure line extending between the piston bottom surface and the side of a cap region in the piston. The manual override mechanism includes an override stem disposed within the piston interior portion, the override stem abutting the cylinder.

Abstract: First and second pistons are provided in a body, the first piston is restricted by the body and the second piston, and the second piston is restricted by the body and a second piston restricting part. Thus, the first piston can be stopped at three positions, and the respective stop positions can be adjusted. Therefore, when rotation speeds of left and right rotating bodies are switched among three levels by a hydraulic motor, a difference of the number of rotations between the left and right rotating bodies can be eliminated, and a vehicle can be suppressed from deviating from a course while it is going straight. Further, a mounting area of the hydraulic pump can be decreased and a structure can be made simple. The rotation speed of the hydraulic motor is changed among the three levels by a simple structure and simple control without using a complex structure such as a servo valve and complex control.

Abstract: A fluid pressure cylinder includes a piston, which is slidably accommodated within a cylinder tube, a hollow piston rod, which is coupled to the above piston, a stopper rod, of which base end is attached to the above head cover so that the location thereof can be adjusted and of which front end is elongated toward within the cylinder tube and passing through a central hole of the above piston and being fitted within the hollow portion of the piston rod and a stopper portion, which is attached to a front end of the above stopper rod and is engaged from the inside of the piston rod to an engaging portion around the above central hole of the above piston at a forwarding stroke end of the above piston.

Abstract: A three position cylinder assembly having an outer cylinder connected between two bases defining a cap end and a head end. A stationary tubular member is secured to the cap end of the outer cylinder at a port to provide fluid access into the outer cylinder. A first and second piston are disposed within the outer cylinder and have reciprocal movement therein. Each piston is connected to a rod which is concentric with the tubular member. The head end has an aperture for receiving the rods for extension beyond the outer cylinder. The tubular member has a stop at an end and the first piston and rod have reciprocal movement along the tubular member, wherein the stop defines a stable mid-position of the cylinder assembly. The second piston and rod have reciprocal movement along the first rod between the first piston and head end, wherein the head end defines a stable fully extended position of the cylinder assembly.

Abstract: A brake cylinder device with a built-in automatic shoe clearance adjustment device which prevents a chance of misassembly, loosing, or omitting the spacer. The brake cylinder device includes an adjustment bolt screwed into a pair of pistons symmetrically slidably positioned inside a cylinder body. A locator spring is positioned between both adjustment bolts. A locator is positioned at the end of the locator spring, and a spacer engages the top end of the locator and has a supporting portion to support the top end on the axis of the adjustment bolt. The supporting portion of the spacer has the front and back surfaces of the same shape.

Abstract: A piston 14 for sliding in a cylinder 12, a rod 16 of the piston 14, and a sleeve 15 fitted over the rod 16 and passing through a rod hole 13 of the cylinder are provided. A lock portion 18 is provided to an outer periphery of a tip end portion of the rod 16. The sleeve 15 having an outer peripheral face for airtightly sliding in the rod hole 13 in the cylinder 12 and an inner peripheral face for airtightly sliding on an outer peripheral face of the rod 16 is provided with an engaging portion 22 on an inner end side to be engaged with an inside of the rod hole 13 of the cylinder and an engaging portion 23 at an outer end side to be engaged with the lock portion 18 of the rod 16. Supply/discharge ports 18A and 19A for supplying and discharging pressure fluid to and from pressure chambers 18 and 19 on opposite sides of the piston 14 in the cylinder are provided and intermediate stop is possible by supplying and discharging pressure fluid to and from the ports.

Abstract: A three-position stop type swing actuator has a main piston freely moving in forward and backward directions in an axial direction within a casing, an output shaft placed at a coaxial position with the main piston in such a manner as to be fixed in an axial direction and freely rotate around an axis, a conversion and transmission mechanism converting a forward and backward motion of the main piston into a rotating and swinging motion of the output shaft, and a sub piston having a stroke smaller than that of the main piston a fluid pressure operating force larger than that of the main piston and arranged within the casing in such a manner as to freely move in the forward and backward directions and be capable of being brought into contact with the main piston so as to restrict a middle stop position of the main piston.