Abstract: A working cylinder which has end-position damping. A piston ring passes over an axially offset pressure medium connection and encloses a pressure medium damping volume. The piston ring includes a ring joint which has a base section and a projection section. The piston ring is of sealing construction. The pressure medium flows out of the pressure medium damping volume via an axial transfer channel, which can be defined by an axial cylinder-tube groove or an axial piston-ring groove. Also, there is a damping piston ring, which is of sealing construction and which has an axial piston-ring groove.

Abstract: This hydraulic drive system includes: first and second circuit systems; first and second hydraulic pumps; a merge valve that opens and closes a merge passage connecting the hydraulic pumps; an operation device that outputs an operation command corresponding to an amount of operation specifying an amount of actuation of first and second hydraulic actuators; and a control device that controls the merge valve according to the operation command from the operation device. The first circuit system includes: a first meter-in control valve that controls a meter-in flow rate of the working fluid that flows to the first hydraulic actuator; and a first meter-out control valve that controls a meter-out flow rate of the working fluid that is drained from the first hydraulic actuator into a tank. The control device controls an opening degree of the first meter-in control valve and an opening degree of the first meter-out control valve.

Abstract: A pressure medium cylinder (1) for moving a toothed bar (3), comprising a toothed bar (3) on at least one side of which is formed a toothing (4). Inside the toothed bar (3), a cavity (6, 6a, 6b) is formed, extending to at least one end (7a, 7b) of the toothed bar. The pressure medium cylinder (1) further comprises a longitudinal structure (8, 8a, 8b), the longitudinal structure (8, 8a, 8b) and the toothed bar (3) being adapted movably in relation to each other, and the longitudinal structure (8, 8a, 8b) is adapted at least partly inside said cavity (6, 6a, 6b). The toothed bar (3) and longitudinal structure (8, 8a, 8b) are adapted in a sealed manner in relation to each other so that the toothed bar and the longitudinal structure are movable in relation to each other by the effect of a pressure medium.

Abstract: Provided is a construction machine. The construction machine includes a boom cylinder driving a boom, a rotation motor rotating a rotary body, an arm cylinder driving an arm, a bucket cylinder driving a bucket, a first main pump supplying working fluid to the boom cylinder and discharging the working fluid in opposite directions, a second main pump supplying working fluid to the rotation motor and discharging the working fluid in opposite directions, and a third main pump supplying working fluid to the arm cylinder or the bucket cylinder.

Abstract: A fluid end includes a housing having a bore extending toward a cavity and a wear sleeve positioned within the bore. The fluid end also includes a plunger positioned within a plunger bore extending through the wear sleeve, the plunger reciprocating within the plunger bore. The fluid end further includes a wear sleeve retainer coupled to the housing and positioned to block axial movement of the wear sleeve, the wear sleeve retainer having external threads along a body that engage internal threads formed in the housing. The fluid end also includes an anti-rotation system, coupled to the housing, the anti-rotation system engaging the wear sleeve retainer to block rotation of the wear sleeve retainer in at least one direction. The fluid end further includes a packing nut coupled to the wear sleeve retainer.

Abstract: The present invention relates to pistons (10) for use in internal combustion engines, having: a piston crown (12) which is adjoined by a piston skirt (14), wherein the piston skirt (14) has surfaces (18) which abut the cylinder wall during use of the piston, wherein the surfaces (16) have one or more friction-reducing coatings (18) and wherein depressions (20) are provided in the coating, which are arranged such that the spacing S between each two adjacent depressions (20) along the axial direction (A) of the piston and the width L of the depressions (20) along the axial direction (A) of the piston satisfy the formula S>2L.

Abstract: The invention relates to an actuator device comprising at least one output element, which can be applied with a fluid and can thereby be moved into at least one retaining position. An actuator is provided which can be operated in a pumping operation by controlling the actuator, in which at least one part of the actuator can be alternatingly moved in a first direction and in a second direction opposite the first direction via the controlling of the actuator, whereby the fluid can be conveyed to the output element in order to apply the output element with the fluid. A discharge channel is also provided, via which the fluid can be discharged from the output element.

Abstract: A torque converter, including: a cover arranged to receive torque and supported for rotation around an axis of rotation; an impeller including an impeller shell connected to the cover and at least one impeder blade; a turbine in fluid communication with the impeller and including a turbine shell and at least one turbine blade; and a stator assembly including a stator including a plurality of stator blades, a side plate including a radially outer surface defining a slot, a one-way clutch axially disposed between the stator and the side plate, and a washer including an annular body portion in contact with the side plate, and an axial protrusion extending past the annular body portion in a first axial direction parallel to the axis of rotation, and disposed in the slot.

Abstract: A pneumatic drive for a medical robot includes a manifold having cylinders extending in a first direction, and respective rods corresponding to the cylinders, the rods extending on one side of the cylinders in the first direction. The manifold includes air supply ports that feed the cylinders with air for moving the respective rods forward and backward. The air supply ports are provided on another side of the manifold in the first direction.

Abstract: A hydraulic power system for a downhole device, including a first motor, a first hydraulic pump, a second hydraulic pump, a first main oil circuit, a second main oil circuit, a switching control module and a first execution module. The first motor has a first output shaft which drives the first hydraulic pump and has an oil outlet connected to an input end of the first main oil circuit and a second output shaft which drives the second hydraulic pump and has an oil outlet connected to an input end of the second main oil circuit; the first execution module is connected to an output end of the first main oil circuit; displacement of the first hydraulic pump is smaller than that of the second hydraulic pump; and the switching control module is connected between the first main oil circuit and the second main oil circuit.

Abstract: The disclosure provides a flow self-compensating load sensing pump/valve coordinated electro-hydraulic system, including a prime mover, an electronically controlled variable pump, a flow control valve, a hydraulic actuator, a shuttle valve, an electronic control joystick, a bypass control valve, two pressure sensors, a bypass throttle valve, and a control system, where an oil outlet of the shuttle valve is connected to a right spring chamber of the bypass control valve, a left chamber and an oil inlet of the bypass control valve are connected to an oil outlet of the electronically controlled variable pump, an oil inlet and an oil outlet of the bypass throttle valve are connected to an oil outlet of the bypass control valve and an oil tank, two ends of the oil inlet and the oil outlet of the bypass throttle valve are provided with the first pressure sensor and the second pressure sensor, respectively.

Abstract: A compressed-air energy storage system of a constant-pressure full-capacity energy-release type, includes two or more liquid-gas coexisting containers, at least one of the two or more liquid-gas coexisting containers is filled with a pressurized liquid, the rest liquid-gas coexisting containers are configured to store a high-pressure air, and the two or more liquid-gas coexisting containers are in communication with each other. When the compressed-air energy storage system of the constant-pressure full-capacity energy-release type operates in an energy storage operating condition, the high-pressure air can be directly stored in the liquid-gas coexisting container without energy conversion loss. When the compressed-air energy storage system operates in an energy release operating condition, the pressurized liquid circulates in the liquid-gas coexisting containers storing the high-pressure air, to realize a constant-pressure full-capacity release of the high-pressure air.

Abstract: To enable to arbitrarily change a hydraulic pump which supplies pressure oil to a hydraulic actuator at first in a hydraulic control system equipped with the hydraulic actuator using both first and second hydraulic pumps as a pressure oil source. An operation means is installed which can arbitrarily change working order of the first flow rate control valves for boom and stick for controlling the supply flow rate from first hydraulic pump to boom cylinder and stick cylinder and second flow rate control valves for boom and stick for controlling the supply flow rate from second hydraulic pump to boom cylinder and stick cylinder.

Abstract: A method for controlling a hydraulic unit with a rotational-speed-controlled pump, which, at an outlet side, provides at least two fluid flows in a manner switched by means of switching valves, for actuating at least one slave cylinder and for providing a volume flow which is controlled based on a rotational speed of the pump. To set the volume flow, an efficiency of the pump is calculated based on a comparison of a known slave cylinder volume of the at least one slave cylinder and a quantity of fluid of the pump for the filling of the at least one slave cylinder.

Abstract: A hydraulic steering arrangement (1) including a supply port (2), a return port (4), a working port arrangement having two working ports (5, 6), a main flow path (7) between the supply port (2) and one of the working ports (5) and a return flow path (8) between the other working port (6) and the return port (4), wherein the main flow path (7) includes a main orifice (A1), a flow meter (9), a first flow meter orifice (A2) upstream the flow meter (9), a second flow meter orifice (A3) downstream the flow meter (9), and a first working port orifice (A4), the return flow path (8) includes a second working port orifice (A5), a load sensing point (17) is arranged between the main orifice (A1) and the first flow meter orifice (A2), a drain orifice (Ad) is arranged between the load sensing point (17) and the return port (4), and a priority valve arrangement (10) is arranged between the supply port (2) and the main orifice (A1). Such a steering arrangement should enable a high steering speed without loss of comfort.

Abstract: A hydraulic excavator drive system (1) includes an arm control valve (31) and an arm switching valve (41). The arm switching valve (41) is connected to an arm pushing supply line (34) by a rod-side line (42) and to an arm crowding supply line (35) by a head-side line (43). The arm switching valve (41) is switched between a neutral position, a recycling position in which the arm switching valve (41) allows the rod-side line (42) to communicate with the head-side line (43) and a second tank line (44), and a meter-out control position in which the arm switching valve (41) allows the head-side line (43) to communicate with the tank line (44). The arm switching valve (41) incorporates therein a check valve (45) that allows a flow from the rod-side line (42) toward the head-side line (43) when the arm switching valve (41) is in the recycling position.

Abstract: A hydraulic system for a work machine, which includes a first hydraulic pump to deliver operation fluid, a second hydraulic pump to deliver pilot fluid, a first hydraulic actuator configured to control flow rate of the operation fluid based on the pilot pressure applied to the pressure receivers, a manual operator configured to operate the first hydraulic actuator, having an operation lever to move toward both directions, operation valves to change pressure of the pilot fluid in accordance with movement of the operation lever, and a discharge fluid tube to drain the pilot fluid from the operation valves. The hydraulic system includes an actuating valve in the discharge fluid tube and configured to reduce pressure of the pilot fluid in the discharge fluid tube.

Abstract: An example valve includes: a first port; a second port; a third port; a poppet configured to be subjected to (i) a first fluid force by fluid of the first port acting on the poppet in a proximal direction toward a poppet seat, and (ii) a second fluid force by fluid of the second port acting on the poppet in a distal direction; a pilot piston configured to be subjected to a pilot fluid force by a pilot fluid signal received at the third port; a check spring applying a spring force on the poppet in the proximal direction; and pilot spring applying a pilot spring force on the pilot piston in the proximal direction.

Abstract: A pneumatic circuit for controlling the activation of a robot with inflatable chambers includes at least one ring oscillator formed from a plurality of valves connected in series to selectively admit fluid pressure to inflate and deflate the chambers. Sequential actuation of the valves induces sequential bending and rotation of combinations of the chambers to effect motion. A switching valve changes the actuation sequence of the oscillator valves to change the direction of motion.

Abstract: Control system and control method of a variable displacement hydraulic pump wherein the system includes a detection sensor for detection of the actually set displacement and a control unit for current control of a couple of solenoids controlling displacement increase and decrease.