Abstract: The subject matter of this specification can be embodied in, among other things, a locking apparatus for a rotary actuator includes an outer housing comprising a cylindrical interior surface having a recess. A rotor is disposed within the outer housing. The rotor has an interior cavity and a port extending radially from the interior cavity to the cylindrical exterior surface. A piston is disposed for reciprocal movement within the interior cavity between a first position and a second position and includes a first portion having a first thickness, a second portion having a second thickness larger than the first thickness. A key is disposed for radially reciprocal movement within the port and includes a radially proximal end and a radially distal end. The radially proximal end contacts the first portion and the radially distal end does not extend into the recess when the piston is in the first position.

Abstract: The systems, methods and apparatuses described herein provide a footwear hydraulic system for harvesting power generated by pressing a foot on a surface and providing a cushion for the impact. In certain aspects, a hydraulic system for a footwear may comprise at least one chamber with a first and second compartments separated by an elastic membrane. The first compartment may be filled with gas and the second compartment may be filled with liquid. The gas may provide impact cushion and transient energy storage, and the liquid may pressured to push a generator to produce energy. The pressure may be generated by pressing the footwear on a surface and/or the elastic membrane of the chamber trying to restore its shape.

Abstract: A master brake cylinder arrangement for a hydraulic motor vehicle brake system, comprising a master brake cylinder housing with a cylindrical recess and at least one substantially annular groove which is oriented transversally to a longitudinal axis of the cylindrical recess and which is axially delimited by a protruding housing portion. The master brake cylinder arrangement also comprises at least one pressure piston which can be displaced axially in the cylindrical recess of the master brake cylinder housing and which is guided in a sealed manner by means of at least one seal element arranged in the groove. The housing portion has an edge portion which faces the seal element and an edge portion which faces away from the seal element when viewed in the axis-containing longitudinal section.

Abstract: An exemplary assembly includes a cylinder, a piston, and a lock. The lock is transitionable between an unlocked position that permits extension and retraction of the piston relative to the cylinder, and a locked position that limits retraction of the piston relative to the cylinder. The lock is blocked from transitioning from the locked to the unlocked position when a load supported by the piston exceeds a threshold load. An exemplary method includes transitioning a lock from an unlocked to a locked position. The lock in the unlocked position permits extension and retraction of a piston relative to a cylinder. The lock in the locked position limits retraction of the piston relative to the cylinder. The method further includes holding the lock in the locked position using a load supported by the piston that exceeds a threshold load.

Abstract: A hydraulic fluid energy regeneration system for a work machine capable of securely maintaining a brake pressure even when a solenoid valve or the like is erroneously rendered open by an electrical failure is provided.

Abstract: Hydrostatic transmission and method for decelerating a hydrostatic transmission with a closed hydraulic fluid circuit, in which a hydraulic pump drivable by a drive engine and a hydraulic motor are arranged and connected fluidly to one another through two working lines. Alternately depending on the operational mode and on the conveying direction of the hydraulic pump, one working line is the low pressure line and the other one is the high pressure line. The hydraulic pump as well as the hydraulic motor are adjustable in their respective displacement volumes by means of a control unit. The hydraulic motor comprises a housing in which a hydrostatic drive mechanism having an inlet and an outlet is arranged. In a connecting line connecting the outlet and the inlet a pressure control valve is arranged, which can be flown through in direction to the inlet. The pressure control valve opens if the high pressure present at the outlet exceeds a predetermined pressure limit of the pressure relief valve.

Abstract: A hydraulic drive system of a construction machine includes: a control valve configured such that an opening area of a center bypass passage gradually decreases in accordance with increase in an operation signal; an operation device that outputs the operation signal; a bleed-off line; and a bleed-off valve that includes a pilot port to which a secondary pressure from a solenoid proportional valve is led, the bleed-off valve being configured such that: a bypass passage is open until the operation signal exceeds a first setting value, and the bypass passage is closed when the operation signal exceeds the first setting value; and an unloading passage is opened when the operation signal exceeds a second setting value, and an opening area of the unloading passage gradually decreases until the operation signal that has exceeded the second setting value reaches a third setting value.

Abstract: A variable-speed volume-control direct-drive all-electric hydraulic excavator drive and energy recover system the control drive circuit of which includes the A, B, C energy source, boom cylinder control valve group, arm cylinder control valve group, bucket control valve, swing control valve, swing motor control valve group, left travel control valve, right travel control valve, eight 2-position 2-way valve, I and II 2-position 3-way valve, I and II accumulator. The drive control circuit adopts open control independent-cavity variable-speed pump-control volume direct-drive circuit. Each of the cavities of cylinder is controlled by an energy source and the pressure and flow rate of the cavities are adjusted by the rotational speed and torque control of the generator independently. The present invention is four-quadrant running and have advantages of high efficiency, high integrity, low consumption, redundancy energy source, no need for pilot supply, low noise, integrate recovery of kinetic and potential energy.

Abstract: A hydraulic unit for producing brake pressure for a hydraulic motor-vehicle brake system, including a main body, a cavity arranged in the main body and having at least one first bore segment with a defined target diameter, in which a cylindrical piston moveable in the axial direction is arranged, which, in the cavity, bounds at least one pressure chamber filled with a hydraulic fluid, for producing brake pressure in a brake circuit, and at least a first and a second sealing element for sealing off the cylindrical piston, which sealing elements are arranged at an axial distance from each other. In order to provide a hydraulic unit that can be produced more effectively and economically while the technical requirements nevertheless remain fulfilled, the material of the main body in a surface layer of an inner wall of the cavity in the bore segment has a material microstructure that is work-hardened.

Abstract: A pressurized gas-powered actuator includes a housing and a piston movably positioned within the housing. The piston has a drive pocket formed therein. A gas generator is positioned exterior of the piston and in fluid communication with the drive pocket.

Abstract: A communication path that communicates with a first main pressure chamber is provided in a main piston and a piston rod. A check valve, which opens by being pressed by a booster piston and allows the communication path to communicate with a first sub-pressure chamber when the piston rod reaches a booster start position before a forward stroke end, is disposed in an end portion of the communication path. A plurality of steel balls are disposed in a coupling-member containing chamber formed in the booster piston. An engagement surface and an engagement groove, which engage with the steel balls when the booster piston moves forward due to an action of a pressure fluid supplied to the first sub-pressure chamber 11a through the communication path, are formed in the coupling-member containing chamber and an outer peripheral surface of the piston rod.

Abstract: A hydraulic arrangement for lifting and/or lowering at least one implement carrying arm on an agricultural machine. The arrangement comprises an inlet hydraulic line and an outlet hydraulic line connecting a fluid pump and a fluid reservoir respectively to a first valve means, said arrangement comprising at least one dual acting hydraulic cylinder for lifting/and or lowering the implement carrying arm. The at least one cylinder is connected to the first valve means allowing the cylinder to be switched between a single acting mode wherein the arm can be lifted and a double acting mode wherein the arm can be lifted and lowered.

Abstract: Hydraulic system, distributor and bidirectional valve to activate the hydraulic actuators (3; 3a, 3b) of an operating machine; the hydraulic system (1) having: a first high-pressure oil delivery (4); an oil drain (8); a slide valve with a spool, which is axially sliding and is suited to control a hydraulic actuator (3); a second low-pressure oil delivery (6); an activation valve (15); and a bidirectional valve (21) with a first passage opening (22) that can be hydraulically connected, by the slide valve (9) to the first delivery (4) and a second passage opening (23) hydraulically connected to the actuator (3); wherein, the bidirectional valve has an inlet opening (24) that can be connected, by the activation valve (15) to the second delivery (6) and an outlet opening (25) that can be connected, by the spool (12) to the drain (8).

Abstract: A hydraulic control apparatus includes: a branch path that branches from a passage connected to an oil pump and equipment to which oil is supplied by the oil pump; an accumulator connected to the branch path to accumulate and discharge high-pressure oil supplied from the branch path; a check valve provided in an oil inlet path through which oil flows into the accumulator; a balance valve unit including a reference pressure chamber, a balance valve body that is biased toward an opening side by an opening compression spring, and a control pressure chamber; and a control solenoid that introduces or discharges the high-pressure oil into or from the control pressure chamber.

Abstract: A hydraulic motor circuit for driving an auger is disclosed. The circuit includes a hydraulic motor that receives oil from an oil supply via a supply line and returns oil to the oil supply via a return line. The circuit further includes a main stage pressure relief valve and a first pilot stage relief valve operable if pressure in the return line exceeds a predetermined value corresponding to an allowable inertia load acting on the motor, opening of the first pilot stage relief valve causing the main stage pressure relief valve to open, allowing flow to be diverted from the return line to the supply line and back to the motor. A control valve is configured to block flow to the first pilot stage relief valve when pressure, in the supply line is greater than pressure in the return line. If pressure in the return line exceeds pressure in the supply line, the control valve shifts open and exposes the first pilot stage relief valve to pressure in the return line.

Abstract: A bicycle operating device comprises a base, an operating member, a hydraulic cylinder, a piston, a connecting link, and a guiding structure. The operating member is pivotally coupled to the base. The hydraulic cylinder is mounted to the base. The piston is movably provided in the hydraulic cylinder. The connecting link is pivotally coupled to each of the operating member and the piston to move the piston relative to the hydraulic cylinder in response to a pivotal movement of the operating member relative to the base. The guiding structure is coupled to the piston to guide the piston relative to the base.

Abstract: Provided is a brake apparatus having a detachable pump housing. The brake apparatus having a detachable pump housing includes a master cylinder that receives an operating force of a pedal, a main housing in which the master cylinder is accommodated and a through-hole is formed at one side thereof, a motor that provides a driving force, a pump piston that is accommodated in the main housing, and moves in and out of the main housing through the through-hole by receiving the driving force from the motor, a gear unit that converts the driving force of the motor into a linear motion and transmits the linear motion to the pump piston, and a pump housing in which the pump piston is accommodated and an opening is formed at one side thereof, and that is detachably fastened to the main housing such that the opening communicates with the through-hole.

Abstract: A hydraulic control system may include a closed loop hydraulic circuit with at least one hydraulic motor. A plurality of variable displacement pumps may be fluidly connected in parallel in the closed loop hydraulic circuit. A plurality of hydraulic actuators may be configured to adjust the displacement of the variable displacement pumps. A pilot valve assembly may be configured to supply the hydraulic actuators with hydraulic fluid having a pilot pressure corresponding to a desired displacement of the variable displacement pumps. A pressure regulating device may be configured to limit the pilot pressure of the hydraulic fluid supplied to the hydraulic actuators when a working pressure in the closed loop hydraulic circuit reaches a maximum allowable working pressure.

Abstract: A hydrokinetic torque coupling device comprising an impeller wheel (2) able to hydrokinetically drive a turbine wheel (3) into rotation, with the impeller wheel (2) being rotationally coupled to a cover (5), with the turbine wheel (3) being able to be axially moved between an engaged position and a disengaged position, wherein it comprises an elastically deformable stress overtaking member (25) axially inserted between the turbine wheel (3) and a part (12) of the cover (5), with the stress overtaking member (25) being able to limit the axial displacement of the turbine wheel (3) towards the above-mentioned part (12) of the cover (5), opposite the turbine wheel (3).

Abstract: To provide a hydraulic drive system for a work machine capable of securing a favorable operability in the case where hydraulic fluid discharged from a hydraulic actuator is regenerated for driving other hydraulic actuator.