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 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: 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: 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.

Abstract: A valve plate of a hydraulic motor includes first and second pressure ports, and first and second oil grooves, the first and second pressure ports being alternately communicated with a cylinder bore in a cylinder block by bidirectional relative rotation in a state of being in contact with an end face of the cylinder block. Further, pad oil grooves communicating with the first oil groove and opened toward the end face of the cylinder block are provided in outer peripheral portions of the first and second pressure ports in a pad region, and the plurality of pad oil grooves is provided such that a proportion of an opening area to the end face of the cylinder block is larger at two end portions close to the second oil grooves than at a central portion separated from the second oil grooves in a circumferential direction of relative rotation.

Abstract: A hydraulic system, in particular a hydraulic transmission controller, includes a first pump, which provides a large volumetric flow for a cooling and/or lubricating device at an outlet, and a second pump, which provides a high pressure for at least one hydraulic load at an outlet. The hydraulic system also includes an additional active valve, which is connected upstream of the cooling and/or lubricating device, is connected to a system pressure valve and to at least one hydraulic load to be boosted in such a manner that in a boost state, the outlets of the two pumps are connected to the hydraulic load to be boosted via a boost line.

Abstract: An electromechanically drivable brake pressure generator for a hydraulic brake system of a vehicle. The brake pressure generator including a spindle drive unit for converting a rotary movement on the drive side into a translational movement for the purpose of actuating a piston of a hydraulic piston-and-cylinder unit. A gear unit is arranged between the spindle drive unit and an electric drive motor. A drive motor axis and an axis of the spindle drive unit are arranged radially offset from one another. The piston-and-cylinder unit and the electric drive motor are arranged on axially opposite sides of the gear unit.

Abstract: The invention of the present application intends to provide a work machine that can ensure high operability by preventing abrupt actuation of an actuator and a shock to a machine body by use of a bleed-off function at the time of starting of the actuator and that can improve the energy-saving performance by reducing a bleed-off flow rate after the starting of the actuator. For this purpose, a controller opens a bleed-off valve at a timing at which an operation device is being operated and before a flow rate of a hydraulic pump starts increasing, and closes the bleed-off valve at a timing at which the operation device is being operated and after the flow rate of the hydraulic pump has started increasing.

Abstract: The present disclosure is to provide a piston assembly in which a particle does not leak out of a cylinder, and including, in an embodiment, a piston body; a piston rod connected to the piston body; a first groove formed in an outer surface of the piston body; and a particle discharge flow path extending from an internal space of the piston body to the outer surface of the piston body.