Abstract: A control system includes an actuator, a locking/unlock device, a central control valve, first and second control valves, and a spool control valve. The actuator is arranged so as to move a door of a thrust reverser between direct jet and reverse jet positions. The locking/unlocking device unlockable under load allowing locking and/or unlocking of the door. The locking/unlocking device is movable between a closure position in which it holds the door in the direct jet position and an opening position in which the door is released. The first and second control valves each fed by the central control valve. The spool control valve fed at least by the first and second control valves. The spool control valve is configured so that a pressure difference between two inlets of the first and second control valves provides a displacement of the spool control valve between first and second stable positions.

Abstract: A work vehicle such as a tractor including an engine, a battery, a hydraulic continuously variable transmission, and an electric cylinder, and a power transmission mechanism. The hydraulic continuously variable transmission changes an output of the engine, and changes an angle of a movable swash plate to change a gear ratio thereof. The electric cylinder is driven by electric power supplied from the battery at least while the engine is stopped. With the power generated in the electric cylinder and transmitted, the power transmission mechanism changes the angle of the movable swash plate of the hydraulic continuously variable transmission.

Abstract: A system and method configured to direct the braking energy from a high-pressure port at the motor side of a hydraulic circuit to emergency steering, braking, accumulator(s) charging, and/or various work functions. The system and method are also configured to return hydraulic fluid back to the same high-pressure port when the motor is running as a pump.

Abstract: A work vehicle such as a tractor including an engine, a battery, a hydraulic continuously variable transmission, and an electric cylinder, and a power transmission mechanism. The hydraulic continuously variable transmission changes an output of the engine, and changes an angle of a movable swash plate to change a gear ratio thereof. The electric cylinder is driven by electric power supplied from the battery at least while the engine is stopped. With the power generated in the electric cylinder and transmitted, the power transmission mechanism changes the angle of the movable swash plate of the hydraulic continuously variable transmission.

Abstract: An apparatus for controlling a hydraulic machine, for example a turbine, pump or pump turbine, using variable-speed driven fixed displacement pumps. The apparatus includes a device for carrying out an emergency shut-off that is characterized by low energy consumption and high efficiency while guaranteeing all the operation-relevant and safety-relevant requirements of a hydraulic machine.

Abstract: Pump-controlled hydraulic circuits are more efficient than valve-controlled circuits, as they eliminate the energy losses due to flow throttling in valves and require less cooling effort. Presently existing pump-controlled solutions for single rod cylinders encounter an undesirable performance during certain operating conditions. Novel circuit designs employ use of different charge pressures on a pair of pilot-operated charging-control valves or different piston areas and/or spring constants on a shuttle-type charging control valve to shift a critical loading region in a load-force/actuator-velocity plane to a lower load force range, thereby reducing the undesired oscillations experienced in the response of the typical critical loading region.

Abstract: Provided is a work machine which makes it possible, in a hydraulic closed-circuit system, to prevent occurrence of cavitation when reverse lever operation which is an instruction for a swing in a direction opposite to a swing direction is performed during swing deceleration. A controller is configured to perform control such that a rate of a flow supplied from a bidirectionally tiltable hydraulic pump to a swing motor becomes lower than a pump flow rate according to an operation amount of the swing operation lever when a swing direction corresponding to a swing velocity sensed at a velocity sensor is different from a swing direction corresponding to operation of a swing operation lever.

Abstract: Disclosed are mass flow controllers, apparatuses for manufacturing semiconductor devices, and methods of maintenance thereof. The mass flow controller may control an amount of a gas provided into a chamber. The mass flow controller may be configured to obtain an absolute volume of the gas provided into the chamber at a standard flow rate when the mass flow controller is initially used. The mass flow controller may be configured to obtain a detected flow rate of the gas provided at a measured flow rate after the mass flow controller has been used for a predetermined time. The mass flow controller may be configured to compare the detected flow rate and the standard flow rate to verify a full-scale error in the measured flow rate.

Abstract: The invention relates to a pressure-limiting device designed to be installed in a system comprising a first line (11) and a second line (12) that can comprise pressurised oil, as well as comprising a discharge and/or booster line (10). The limiting device is characterised in that it comprises means (131, 132, 133, 134) forming two valves, each associated with one of the two lines and adapted to open in the event of an overpressure above a pre-determined threshold on the associated line, so as to discharge the corresponding overpressure towards the discharge and/or booster line, said two valves comprising a common support stem (126) that operates in traction under the action of at least one spring defining a pressure corresponding to the pre-determined threshold. The invention also relates to a hydraulic assist system and to a vehicle comprising such a device.

Abstract: A work vehicle such as a tractor including an engine, a battery, a hydraulic continuously variable transmission, and an electric cylinder, and a power transmission mechanism. The hydraulic continuously variable transmission changes an output of the engine, and changes an angle of a movable swash plate to change a gear ratio thereof. The electric cylinder is driven by electric power supplied from the battery at least while the engine is stopped. With the power generated in the electric cylinder and transmitted, the power transmission mechanism changes the angle of the movable swash plate of the hydraulic continuously variable transmission.

Abstract: A system for generating variable frequency tube waves includes a high pressure multiplex pump having a number of plungers, with each plunger operatively coupled to a suction valve on a suction side and a discharge valve on a discharge side. The suction valve or the discharge valve of a first one of the plungers includes an opening, such that the modified plunger on a discharge stroke pushes fluid through the opening in the suction or discharge valve. The system includes a tubular fluidly coupling the high pressure multiplex pump to a wellbore, and a pressure sensor that receives tube waves generated by the high pressure multiplex pump and reflected from the wellbore.

Abstract: A hydraulic system that has a hydraulic pump connected to and in communication with a hydraulic motor, at least one hydraulic cylinder, or both by a first conduit and a second conduit (i.e., a high side and a low side). The hydraulic system has a bypass valve connected to and in communication with the first conduit and the second conduit. The bypass valve has a preset pressure that is above a minimum low side pressure. When a shock load occurs in the hydraulic system and a related drop in pressure on the low side occurs, the bypass valve opens when the preset pressure is passed thereby preventing the pressure from dropping to the minimum low side pressure. The hydraulic system thereby avoids a low loop event that could cause damage to the hydraulic system without the presence of larger charge pumps or accumulators.

Abstract: The invention relates to a device comprising a first hydraulic apparatus (M1) and a second hydraulic apparatus (M2), the two motors (M1, M2) being connected by a first line (11) and a second line (12) enabling the admission or discharge of the oil in said motors (M1, M2), a booster pump (30), arranged between a tank and a booster line, the booster line communicating with at least one of said lines (11, 12), characterized in that the pump (30) is configured to be able to suck oil into the booster line in order to allow the decompression of said first and second lines (11, 12). The invention also relates to a method for evacuating a device of the type described above, in which the booster pump (30) is activated in suction mode in the booster line to enable the disengagement of the machines (M1, M2).

Abstract: The invention relates to a turn drive for a wind turbine. The turn drive comprises a shaft, a hydraulic motor for driving the shaft, and a drive line for supplying a pressurized hydraulic fluid to the hydraulic motor. According to the invention, the drive line is provided with a settable pressure-limiting valve. The invention additionally relates to an associated method for rotating the rotor shaft of the wind turbine. By means of the method according to the invention and the turn drive, the rotor blades can be mounted individually on the hub of the rotor, without the gearbox of the wind turbine becoming overloaded.

Abstract: The present disclosure relates to a load-sense system such as a load-sense steering system that operates in a static load-sense mode for low flows and operates in a dynamic load-sense mode for high flows.

Abstract: A coolant pump assembly having a combined hydraulic drive pump and a coolant circulating pump is disclosed herein, for use in connection with a utility vehicle, such as a ride-on or stand-on mower. Such a vehicle includes at least one combination pump assembly that utilizes a first fluid circuit to hydraulically drive a wheel of the vehicle and a second fluid circuit to cool one or more vehicle components.

Abstract: A hydraulic cylinder causes a work implement to be lowered due to the exhaust of hydraulic fluid from a first chamber and the supply of hydraulic fluid to a second chamber. A hydraulic fluid flowpath has a first flowpath and a second flowpath. The first flowpath connects a first pump port and the first chamber. The second flowpath connects a second pump port and the second chamber. The hydraulic fluid flowpath configures a closed circuit between a hydraulic pump and the hydraulic cylinder. A bleed-off flowpath branches off from the first flowpath. A portion of hydraulic fluid exhausted from the first chamber when lowering the work implement flows into the bleed-off flowpath.

Abstract: A composite valve is used in a hydraulic circuit. The composite valve is interposed between a stack valve and a hydraulic power supplier and between the stack valve and a multifunction valve coupled to a hydraulic device. The composite valve includes: stop valves opening/closing communication between the hydraulic power supplier and the stack valve and stop valves opening/closing communication between the stack valve and the multifunction valve; and bypass circuits respectively including stop valves opening/closing communication between the hydraulic power supplier and the multifunction valve, the bypass circuits provided closer to the hydraulic power supplier than the stop valves. This structure makes it possible to simultaneously perform various functions: repair, checking, and/or maintenance on the stack valve; flushing; and repair, checking, maintenance, and/or a trial run of the hydraulic device. The composite valve has uniform circuit configurations, which facilitates production of the valve.

Abstract: A pump assembly includes a pair of rotatable pumps located in a housing and engaged to a pump support disposed on a support surface on which the rotatable pumps are mounted. The pump support may include a pair of parallel side walls and a pair of bearing supports for a pair of pump shafts. Each pump shaft is driven by a separate pump gear, and a distance between an axis of rotation of a first pump shaft and an axis of rotation of a second pump shaft is less than a sum of: (a) a minor radius of the first pump gear, and (b) a minor radius of the second pump gear.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump having two pump chambers to a low pressure portion and a high pressure portion and performs mode conversion from a full discharge mode to a two circuit mode or a half discharge mode according to variable control pressure of a solenoid valve.

Abstract: There is provided a driving device for a work machine, having a closed hydraulic circuit system for driving cylinders with hydraulic pumps, the driving device making the speed of operation substantially the same in both directions of piston rod extension and contraction.

Abstract: A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump.

Abstract: The present invention provides a flushing circuit for a hydraulic cylinder drive circuit, by which the flushing of the circuit is conducted while protecting precision apparatuses of a control valve unit, because the flushing of a reciprocating hydraulic cylinder and its drive circuit is conducted while bypassing the control valve unit. In a hydraulic oil supply/discharge circuit connecting a tank of hydraulic oil, a hydraulic pump generating pressurized hydraulic oil, and a hydraulic cylinder with one another, a control valve unit in which at least a direction switching valve is provided in the vicinity of the hydraulic pump and the oil tank and a multifunction valve having a bypass circuit in the vicinity of the hydraulic cylinder are provided, and a bypass circuit bypassing the control valve unit is provided to branch from a hydraulic oil supply/discharge circuit between the multifunction valve and the control valve unit.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, the switch valve, and a low-pressure regulator valve.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump having two pump chambers to a low pressure portion and a high pressure portion and performs mode conversion from a full discharge mode to a two circuit mode or a half discharge mode according to variable control pressure of a solenoid valve.

Abstract: A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve.

Abstract: A hydraulic circuit for a construction machine including a center bypass passage including a group of directional control valves arranged in tandem; and a bleed-off valve arranged in the center bypass passage on a downstream side of the group, wherein each directional control valve includes a first internal passage causing the pressurized oil supplied to the directional control valve to flow out to the center bypass passage and a second internal passage supplying the pressurized oil to a cylinder port, wherein a parallel passage is formed by the center bypass passage and the first internal passage by causing the pressurized oil discharged from the hydraulic pump to flow to the center bypass passage on the downstream of the directional control valve, wherein the second internal passage supplies the pressurized oil from the center bypass passage through an opening of a spool and/or the bypass passage to the cylinder port.

Abstract: A fluid delivery system includes a first hydraulic circuit, and a second hydraulic circuit. The first hydraulic circuit includes a first hydraulic pump, and a first hydraulic motor. The first hydraulic motor is fluidly connected to the first hydraulic pump and is configured to be driven by the first hydraulic pump. The second hydraulic circuit includes a second hydraulic pump, and a second hydraulic motor. The second hydraulic pump is mechanically coupled to the first hydraulic motor and configured to be driven by the first hydraulic motor. The second hydraulic motor is disposed in loop with the second hydraulic pump and configured to be driven by the second hydraulic pump. The fluid delivery system further includes a delivery pump mechanically coupled to the second hydraulic motor and fluidly connected to a fluid source. The delivery pump is configured to deliver a pressurized fluid.

Abstract: A hydraulic circuit for a construction machine including a direction control valve group including direction control valves provided in tandem to a center bypass passage, a bleed-off valve provided to the center bypass passage downstream of the direction control valve group, and a control valve controlling an amount of pressure oil to be supplied to the direction control valve.

Abstract: A hydraulic system is disclosed. The hydraulic system may have a primary pump, a hydraulic actuator, and first and second passages fluidly connecting the primary pump to the hydraulic actuator in a closed-loop manner. The hydraulic system may also have a charge circuit, a makeup valve movable to selectively allow charge fluid from the charge circuit to enter the first or second passages, and at least one restricted pilot passage configured to direct pilot fluid to the makeup valve to move the makeup valve and allow the charge fluid into the first and second passages.

Abstract: In a hydraulic drive of a tool, a piston is adapted to be acted upon by a pump via a pressure limiting seat valve and a parallel switching seat valve of a valve arrangement. A restriction is provided in a pressure line upstream of the pressure limiting seat valve which is connected to a tank on the flow-off side. A drain line leads from a working chamber of the piston via the switching seat valve to the tank. A closing side is adapted to be acted upon by pressure and an opening side is adapted to be acted upon by a force generated when the pressure limiting seat valve responds. The pump is adapted to be switched off when the maximum operating pressure has been reached, so that the piston will execute a return stroke. A pressure-increasing restriction is provided on the flow-off side of the pressure limiting seat valve.

Abstract: A method of controlling a float function of a cylinder 25 having a first side and a second side includes connecting the second side of the cylinder to a reservoir 15; connecting the first side of the cylinder to an output of a pump 20 and to the reservoir; and supplying an amount of flow from a pump less than an amount supplied by the pump under loaded conditions. A three-position directional control valve 30 having a pump port, a reservoir port, a first cylinder port, and a second cylinder port may be provided to effectuate aspects of this method.

Abstract: A hydraulic drive system includes a pump, a steering actuator, a loading/unloading apparatus actuator, a drive device, a relief valve, and an input unit. The drive device: flows hydraulic oil from the pump to the loading/unloading apparatus actuator when an operating tool is operated; flows the hydraulic oil from the pump to the steering actuator when a steering has become an operated state from a non-operated state regardless of an operation of the operating tool; and causes the hydraulic oil from the pump to be discharged to a tank via the relief valve to increase the torque of an engine when an increase instruction is inputted to the input unit and the steering is in a non-operated state.

Abstract: A fluid controller includes a valve housing having an inlet port, a return port, first and second control ports and a load sense port. The fluid controller further includes a fluid meter in selective fluid communication with the valve housing and a valve assembly adapted to provide selective fluid communication between the valve housing and the fluid meter. The valve housing includes a main flow path and a load sense flow path. The main flow path is adapted to provide selective fluid communication between the inlet port and the first control port. Fluid in the main flow path passes through the fluid meter. The load sense path is adapted to provide selective fluid communication between the load sense port and the main flow path. The load sense flow path includes a variable load sense orifice that substantially closes prior to a maximum rotational displacement of the valve assembly.

Abstract: The present disclosure relates to a boom cylinder control circuit for a construction machine, and includes: a boom cylinder which has an ascending-side chamber and a descending-side chamber; a boom control unit which provides a working fluid to the boom cylinder; a boom operation part which is operated to drive the boom cylinder by providing a pilot working fluid to the boom control unit; a first floating valve which allows the descending-side chamber and the ascending-side chamber to selectively communicate with or be shut off from a first drain line; a second floating valve which is additionally provided in a flow path between the descending-side chamber, which is connected with the first drain line via the first floating valve, and the first drain line, allows the descending-side chamber to communicate with the first drain line, or shut off discharge of the working fluid from the descending-side chamber to the first drain line, and allows of a reverse flow; and a floating selection operation part which pro

Abstract: The invention relates to a fluid valve arrangement having a bistable fluid valve for at least one fluid line with a valve body which can be moved into two positions for two switching states, a pressure pulse generator being provided for valve switchover in the feed line for switching over a feed line and a return line between two flow lines, and the fluid valve comprising a reversing unit which has two chambers which are separated from one another by a bistable surface element, the two chambers being connected to the two flow lines and the bistable surface element being operatively coupled to the valve body in order to actuate it. As a result, a bistable fluid valve is provided which can be reversed by way of pressure pulses or pressure flanks and otherwise has no energy requirement.

Abstract: A travel control system is disclosed for preventing off-course travel of equipment due to the overloading of a working piece such as a boom during a complex operation involving vehicle travel and simultaneous driving of the working piece.

Abstract: Provided is a slewing-type working machine capable of reducing back pressure generated during slewing.

Abstract: A hydraulic apparatus and a method of controlling the hydraulic apparatus are disclosed. The hydraulic apparatus includes a first pump having a first fixed displacement, a second pump having a second fixed displacement, and a diverter. The diverter includes a first diverter inlet port fluidly coupled to a discharge of the second pump, a first diverter outlet port fluidly coupled to a discharge of the first pump, and a second diverter outlet port fluidly coupled to a low pressure system, the low pressure system having a fluid pressure lower than a fluid pressure of the discharge of the first pump. The diverter is operable to selectively vary fluid communication between the first diverter inlet port and either the first diverter outlet port or the second diverter outlet port based on a reference pressure.

Abstract: A hydraulic system includes an actuator, a pump, rod side and cap side fluid connections between the pump and the rod and cap side chambers, respectively, at least one selectively actuatable regeneration valve that selectively provides flow from the cap side fluid connection to the rod side fluid connection, and a controller. The controller controls the pump to selectively vary the flow rate of the pump in response to a commanded motion to control movement of the piston. The controller actuates the regeneration valve during a retraction of the piston into the cylinder when pump is acting as a motor.

Abstract: A safety system for bypassing counter balance valves of a catwalk hydraulic cylinder from a remote location in a safe and controlled manner. Oil from a base end of the hydraulic cylinder is routed around the counter balance valves and flows through a velocity fuse to a needle valve, a check valve, and a pump outlet.

Abstract: A closed hydrostatic circuit with variable charge and variable flushing systems is disclosed. A variable displacement charge pump is configured to supply charge fluid and pilot control fluid to the hydrostatic circuit. An electronically controlled pressure regulating valve is in communication with an output of the charge pump and is linked to a controller. When the hydrostatic control system detects a high hydraulic temperature condition, the electronically controlled pressure regulating valve, that is in communication with an output of the charge pump and that is linked to a controller, increases the charge pump flow. A bidirectional variable displacement hydrostatic motor is connected in parallel to two input/output lines. A flush valve is in communication with the hydrostatic motor and both input/output lines. The flush valve and hydrostatic motor are both in communication with the flush orifice and a flush relief valve.

Abstract: A control system for a hydraulic system comprises an electronic control module, an electronic system controller, a remote power module, and a solenoid valve. The electronic control module monitors torque output of an internal combustion engine, an electric motor and generator. The electronic system controller monitors torque demand of a first and a second hydraulic circuit. The remote power module is in electrical communication with the electronic system controller. The solenoid valve is in electrical communication with the remote power module. The solenoid valve connects to a combination valve and has a first open position and a closed position. The combination valve is in fluid communication with a first hydraulic circuit and a second hydraulic circuit. The solenoid valve moves to the open position in response to an output signal from the electronic system controller.

Abstract: A hydraulic circuit for a vehicle includes a first loop that includes, in serial order, a first hydraulic pump, a first hydraulic line, a hydraulic motor and a second hydraulic line. A second hydraulic pump and a third valve control low pressure fluid from the second pump to the hydraulic motor casing. The low pressure fluid through the third valve maintains the motor pistons retracted when the motor is not being used. For actuating the motor, the third valve is actuated for disconnecting the second pump and relieving pressure from the motor casing. Low pressure is then provided to the first and second lines for extending the motor pistons. The first and second valves are then actuated for isolating the first and second lines from one another, and the first pump is used to power the motor. The first, second and third valves are advantageously solenoid cartridge valves.

Abstract: A hydraulic control system includes a swing control valve between a pump and a swing motor to control flow to/from the swing motor, and a selector valve between an accumulator and the swing motor to regulate fluid flow. A controller is configured to receive inputs indicative of the pressure differential between the accumulator and conduit between the pump and swing motor, and a swing motor command, calculate a target swing motor flow based on the swing motor command input, and modulate operation of the swing control valve and the selector valve to regulate a swing speed.

Abstract: A hydraulic control apparatus is disclosed that controls a hydraulic pump in a construction machine in which a hydraulic actuator is connected to the hydraulic pump via a directional control valve of a closed center type, and in which a position of the directional control valve is changed according to an operation amount of an operation member. The hydraulic control apparatus includes a virtual negative control pressure calculating part configured to calculate, based on the operation amount of the operation member and a discharge pressure of the hydraulic pump, a virtual negative control pressure when a negative control system is assumed; and a part configured to calculate a control command value for the hydraulic pump based on the virtual negative control pressure.

Abstract: A control system for a machine with a dual path electronically controlled hydrostatic transmission is used to achieve a desired performance and a desired operator feel while performing all of the machine operations. The control system includes pump and motor displacement resolvers, command resolver, ramping blocks, pump and motor steering resolvers, engine load management and a straight tracking subsystem.