Abstract: A hydraulic system for a working machine includes hydraulic actuators actuated with hydraulic fluid delivered from a hydraulic pump, control valves each of which is shiftable among shift positions to control a flowrate of hydraulic fluid flowing to the corresponding hydraulic actuator, a detection fluid passage, an interlocking control valve, and a pressure detection unit. Each control valve includes an input port, an output port, and a flowrate reduction section. One of the control valves includes a flowrate increase section. The interlocking control valve is configured to be shifted in accordance with a shift of the one of the control valves among the shift positions and to be shifted to a blocking position to block a pilot fluid introduced into the interlocking control valve from the detection fluid passage when the one of the control valves is shifted to the increase position.

Abstract: A hydraulic system for a working machine, the system comprising: an electric machine connected to a first hydraulic machine and to a second hydraulic machine via a common axle, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine, wherein the first hydraulic machine is a variable displacement hydraulic machine with unidirectional flow; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side of the first hydraulic machine.

Abstract: A self-sealing and self-centering piston has a domed piston plate and a substantially cylindrical skirt section. The skirt section joins the rear of the piston plate. A gap having a depth is formed between a first portion of the skirt section and a front lamella. A rear lamella adjoins the front lamella. In addition, a second section of the skirt section has a first seal and a second seal.

Abstract: A hydraulic work system can include a continuously variable displacement hydraulic pump that is powered by an engine and is in communication with a hydraulic actuator. A run-time displacement of the hydraulic pump for movement of the hydraulic actuator can be controlled based on a speed of the engine.

Abstract: A work vehicle includes: an operation tool that is operated by an operator; and a controller that determines a target flow rate for hydraulic oil fed to a hydraulic device on a basis of the amount of operation of the operation tool. The controller calculates a bleed-off target flow rate on a basis of the flow rate of hydraulic oil fed from a hydraulic oil pump and the target flow rate for hydraulic oil fed to the hydraulic device, calculates a bleed-off throttle differential pressure on a basis of a pressure of hydraulic oil fed from the hydraulic oil pump and a pressure of hydraulic oil in a hydraulic oil tank, calculates a bleed-off target opening area on a basis of the bleed-off target flow rate and the bleed-off throttle differential pressure, and controls a hydraulic oil control valve such that the bleed-off target opening area is achieved.

Abstract: An excavator includes a control valve configured to control hydraulic oil to be supplied to an actuator, based on pilot pressure; an electric operation device configured to output an operation signal; a gate lock device; a gate lock valve provided on a pilot line supplying the pilot pressure to the control valve, and configured to open or close according to a state of the gate lock device, so as to switch between a locked state and a released state; a proportional valve provided on the pilot line; and a control part configured to receive as input the operation signal, to control the proportional valve, wherein the control part determines, in a case where the gate lock valve is in the locked state by the gate lock device and an operation is performed on the electric operation device, the operation as an operational error.

Abstract: A piston (1) having a piston shaft (2), a ball head (3) at one end of the piston shaft (2), and a slider shoe (4) mounted to the ball head (3), wherein the ball head (3) has a through channel (5), the slider shoe (4) has a sliding surface (6) and a through hole (7) in communication with an end of the through channel (5), and a plastic material (8) is arranged in a gap between the slider shoe (4) and the ball head (3) and forms an inner coating (9) of the through hole (7). The production of such a piston should be facilitated. To this end a sealing surface (14) is arranged at the end of the through channel (5) wherein the sealing surface (14) surrounds the opening of the through channel (5) into the through bore (7) and an inner diameter of the sealing surface (14) is smaller than an inner diameter of the inner coating (9) of the through bore (7).

Abstract: A working fluid supply system is provided with: a first oil pump and a second oil pump driven by an engine; a switching valve configured to cause a discharge passage of the second oil pump to communicate with at least one of a supply passage and a first drain passage; and a controller configured to switch the switching valve. The controller is configured to switch the switching valve by spending a switching time that is set in accordance with a degree of pressure variation predicted to be caused in the supply passage when the switching valve is switched instantaneously.

Abstract: Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

Abstract: The gravity compressed air energy storage system includes: a shaft, into which a pressure-bearing cylinder is movably inserted; a locking component arranged at a top of the pressure-bearing cylinder to support the pressure-bearing cylinder on a ground at a top of the shaft through the locking component in case that the pressure-bearing cylinder is at a lowest limit position; a primary gravity block arranged above the locking component; a spherical connection component arranged and spherically connected between the primary gravity block and the locking component; in which a plurality of guide components are arranged around the primary gravity block; and a plurality of guide rails arranged on the ground and at a peripheral side of the primary gravity block; in which the plurality of guide rails cooperate with the plurality of guide components.

Abstract: A regeneration device includes: a regeneration valve that controls the flow rate of an operating fluid being drained from one port of a cylinder; a non-return valve that allows a regenerative flow of the operating fluid from the regeneration valve to the other port of the cylinder and blocks an opposite flow of the operating fluid; and an exhaust valve that controls the flow rate of the operating fluid output from the regeneration valve being drained to a tank. The regeneration valve controls the flow rate independently of the exhaust valve.

Abstract: A working machine includes a prime mover, a traveling motor a speed shifting valve configured to shift an output speed of the traveling motor between a first speed and a second speed faster than the first speed, an actuation valve to change a hydraulic pressure applied to the speed shifting valve, a brake shiftable between a braking state to brake the traveling motor and a braking releasing state to release the braking, and a controller configured or programmed to control the actuation valve and the brake, and being capable of activate a warm-up mode. The controller, when activating the warm-up mode, shifts the brake into the braking state, and controls the actuation valve so as to make the hydraulic pressure applied to the speed shifting valve equal to or greater than a value corresponding to the second speed.

Abstract: This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism and a boom cylinder The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to starting and stopping of the rotary mechanism. A control system configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, and a boom control valve configured to control the boom cylinder through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

Abstract: An electromechanical brake booster for a braking system of a vehicle. The brake booster includes a spindle nut that is movable into rotation using an electric motor that is intrinsic or external to the brake booster, a spindle situated at the spindle nut and rotatably fixedly held using a support plate in such a way that the spindle and the support plate are movable into pure translatory motion using the spindle nut that is moved into rotation, and a reaction disk receiving element that is also movable using the support plate that is moved into pure translatory motion. The reaction disk receiving element includes a receiving opening in which a reaction disk is situated. The support plate and the reaction disk receiving element are designed as a one-piece component. A method for manufacturing an electromechanical brake booster for a braking system of a vehicle, is also described.

Abstract: A tension assembly that is used with a fluid end of a reciprocating pump. The internal components of the fluid end are subject to high pressure, which negatively impacts the lifetime of any internal component. The tension assembly can be used to apply a preload to an internal component. The tension assembly includes a pair of sleeves or rings, one sleeve being coupled to the fluid end housing and the other sleeve is movable relative to the coupled sleeve. The movable sleeve engages the internal component and as that sleeve is moved inwardly toward the internal component, a force or preload is applied to the internal component, which helps set and retain it in place.

Abstract: A hydraulic system, mining machine and method of controlling a hydraulic actuator. The hydraulic system (HS) is provided with a control valve (23) for controlling movement direction and speed of a hydraulic actuator (HA) connected to the system. Generated force of the hydraulic actuator is controlled independently relative to the control valve by means of counterbalance valves (Cb1, Cb2) and servo valves (Sv1, Sv2) controlling their opening pressure. The counterbalance valves and the servo valves operate as a meter-out control assembly which controls flow of hydraulic fluid discharged from working pressure spaces (16a, 16b) of the hydraulic actuator. The disclosed system may be implemented to control a mining boom (3) of a mining machine (1).

Abstract: Provided is an electrohydrostatic actuation system including an emergency shut-off circuit to be actuated stably with a simple configuration. The electrohydrostatic actuation system includes: a hydraulic cylinder (24) including a piston (25) to which a valve element is connected, a first chamber (24A), and a second chamber (24B); a hydraulic pump (21) configured to supply hydraulic fluid to the first chamber (24A) or the second chamber (24B); a servo motor (M) configured to drive the hydraulic pump (21); a shuttle valve (11) configured to establish communication to a downstream side under a state in which a hydraulic pressure generated by the hydraulic pump (21) is maintained; a solenoid valve (12) configured to receive the hydraulic pressure via the shuttle valve (11) as a pilot pressure; and a logic valve (13) including a first port configured to receive the pilot pressure from the solenoid valve (12), and a second port to be communicated to the first chamber (24A) of the hydraulic cylinder (24).

Abstract: A hydraulic machinery may include: a boom actuator including a large chamber and a small chamber; a tank; and an energy recovery circuit provided between the boom actuator and the tank, wherein the energy recovery circuit includes: a discharge valve provided between the large chamber and the tank to allow or block the flow of fluid from the former to the latter; a regeneration valve connecting the large chamber and the small chamber to allow or block the flow of fluid from the former to the latter; a recovery part for recovering energy; and a first valve provided between the large chamber and the recovery part to allow or block the flow of fluid from the former to the latter.

Abstract: A method of controlling a rotatable load by a hydraulic system, the method includes determining if the hydraulic system is in a first operating state or a second operating state; controlling the rotatable load in a valve control mode if the hydraulic system is in the first operating state, the valve control mode including controlling the rotatable load by controlling a valve arrangement; controlling the rotatable load in a displacement control mode if the hydraulic system is in the second operating state, the displacement control mode including controlling the rotatable load mainly by controlling the displacement of a hydraulic machine; and applying a non-zero absolute minimum displacement limitation to the hydraulic machine at least in the valve control mode.

Abstract: A hydraulic pump to synchronize the operation of a pair of hydraulic actuators wherein each hydraulic actuator comprises a cylinder including a first fluid port and a second fluid port formed in the proximal and distal end portions thereof respectively and having a piston disposed therein coupled to a piston rod at least partially disposed within the corresponding cylinder. The dual hydraulic pump includes a triple gear assembly to alternately feed pressurized hydraulic fluid to the first fluid port of each hydraulic actuator simultaneously or the second fluid port of each hydraulic actuator simultaneously to synchronize the linear movement of each piston and piston rod in a first direction or a second direction.