Abstract: An excavator including a lower traveling body; an upper turning body turnably mounted to the lower traveling body; a work attachment attached to the upper turning body; an imaging device mounted to the upper turning body; a hydraulic actuator; a hydraulic pump configured to supply hydraulic oil to the hydraulic actuator; an electric motor configured to drive the hydraulic pump; an operation device of an electric type configured to operate the hydraulic actuator; and a control device configured to control the electric motor, wherein in response to determining that the operation device is not operated, the control device causes the hydraulic pump to automatically stop, and subsequently, in response to determining that an operation with respect to the operation device is started, the control device causes the hydraulic pump to be automatically activated.

Abstract: Agricultural implements and hydraulic circuits for agricultural implements are disclosed herein. An agricultural implement includes a fluid source, a plurality of fluid demand devices, a delivery control valve, and a priority valve. The fluid source is configured to supply hydraulic fluid. The plurality of fluid demand devices are each configured to receive hydraulic fluid supplied by the fluid source during operation of the agricultural implement. The delivery control valve is fluidly coupled between the fluid source and a first fluid demand device. The delivery control valve is configured to selectively deliver hydraulic fluid supplied by the fluid source to the first fluid demand device during operation of the agricultural implement. The priority valve is fluidly coupled between the delivery control valve and the first fluid demand device.

Abstract: The invention relates to a construction machine, road milling machine, stabiliser, recycler, surface miner, and a to method for controlling a construction machine. The construction machine has a machine frame 2 supported by a chassis 1 and a plurality of hydraulic systems 15, 16, each of which has at least one hydraulic component 18, 22, at least one hydraulic pump 17, 21 for conveying hydraulic fluid for the at least one hydraulic component and at least one hydraulic line 28, 31 for transporting the hydraulic fluid from the at least one hydraulic pump to the at least one hydraulic component. The drive device of the construction machine comprises at least one internal combustion engine 24. A power transmission device 44 is provided for transmitting at least part of the drive power from the internal combustion engine 24 to the hydraulic pumps 17, 21.

Abstract: A hydraulic system comprises a valve distributor comprising one or more sections connectable to respective uses, a supply apparatus comprising a pump and a supply channel, a discharge channel connected to a low-pressure tank, a use signal channel coming from the section of the valve distributor and further comprises a hydraulic regulating device connected via said channels which includes a 2-position 3-way proportional valve configured so as to provide operative fluid at a conditioned pressure, different with respect to the pressure that is characteristic of the operative condition of use, to the supply apparatus and at least one proportional pressure reducing valve.

Abstract: In a hydraulic machine, first travel control valve and a first attachment control valve are in fluid communication with a second hydraulic source. A confluence control valve is in fluid communication with a first hydraulic source and, in a confluence position, directs fluid from the first hydraulic source to the first attachment control valve. A first signal line and a first pilot line are connected to the confluence control valve. When the first travel control valve is in a non-neutral position and the first attachment control valve is in a first non-neutral position, first signal pressure is generated in the first signal line to move the confluence control valve to the confluence position. First pilot pressure, when generated in the first pilot line, moves the confluence control valve to the confluence position.

Abstract: A drive device for driving a fluid pressure cylinder has an air supply source which supplies air, a switching valve which switches between the supply and discharge of the air to and from the fluid pressure cylinder, bypass piping which connects the head-side cylinder chamber and rod-side cylinder chamber of the fluid pressure cylinder, and a bypass switching valve which switches between the states of flow of air through the bypass piping. Air in the head-side cylinder chamber is supplied to the rod-side cylinder chamber through the bypass piping by setting the bypass switching valve to an open state in a return stroke of the fluid pressure cylinder.

Abstract: The present invention provides an engineering machinery hydraulic system with compensation differential pressure controllable, uses an electronic pressure compensating valve to solve the problem of flow mismatch under conditions of pressure over-limit and flow saturation, and realizes proportional shunt control and high-precision flow distribution of the system. The engineering machinery hydraulic system disclosed in the present invention has the advantages of low energy consumption, fast response speed, and high flow control precision.

Abstract: A method for controlling a hydraulic actuator (2) of a system (1) by means of a valve having a valve element is described. A position of the valve element determines a pressure supplied to a hydraulic actuator (2). In such a method a variable dead band should be minimized. To this end a start position of the valve element is preadjusted as a function of at least one parameter outside the hydraulic actuator (2).

Abstract: Each of left and right direction switching valves includes: a pump port connected to a pump; a first compensation port connected to an upstream side of a corresponding pressure compensation valve; a second compensation port connected to a downstream side of the corresponding pressure compensation valve; a pair of supply/discharge ports connected to a corresponding travel motor; and a communication port. The communication ports of the left and right direction switching valves are connected by a communication line. When a spool shifts from a neutral position by the travel operation device, the pump port communicates with the first compensation port and the second compensation port communicates with one of the supply/discharge ports and the communication port. Each direction switching valve is configured wherein a degree of communication between the second compensation port and communication port increases in a shifting amount of the spool from the neutral position.

Abstract: A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an engine provided in the upper turning body, a hydraulic pump and a hydraulic oil tank provided in the upper turning body, a plurality of hydraulic actuators driven by the hydraulic pump, and a hydraulic circuit connected to the hydraulic pump, wherein the hydraulic circuit includes a plurality of control valves configured to control flows of hydraulic oil between the hydraulic pump and the plurality of hydraulic actuators, and a unified bleed-off valve configured to collectively control bleed-off flowrates of the plurality of control valves, wherein the hydraulic circuit is configured so that a discharge pressure of the hydraulic pump becomes equal to or less than a predetermined pressure during start-up of the engine.

Abstract: The present invention relates to a hydraulic system comprising a first actuator, a first variable displacement pump fluidly connected to the first actuator via a first circuit and adapted to drive the first actuator. The system further comprises a second actuator and a second pump fluidly connectable to the second actuator via a second circuit and adapted to drive the second actuator, wherein the second pump is fluidly connectable to the first actuator via a first control valve, and wherein the second pump is fluidly connectable to the second actuator via a second control valve.

Abstract: A hydraulic system includes a first fixed displacement pump having a first pump output and a second fixed displacement pump having a second pump output. A first actuator requires a first required flow rate to perform a first function. A second actuator requires a second required flow rate to perform a second function. A combined flow control valve is controllable between a first state connecting fluid communication between the first fixed displacement pump and the tank so that only the second pump output is directed to the second actuator, and a second state disconnecting fluid communication between the first fixed displacement pump and the tank to combine the first pump output and the second pump output such that the combined first pump output and the second pump output is directed to the first actuator.

Abstract: A hydraulic drive system includes a hydraulic pump, a boom-dedicated control valve, a turning-dedicated control valve, a boom-dedicated operation unit, a turning-dedicated operation unit, and a driving control unit.

Abstract: A system and method for providing heating to a seat of a mobile hydraulic equipment. The system includes a heat exchanger disposed in or adjacent the seat for recycling the heat from a return hydraulic fluid received from a diverter manifold to heat the operator's seat. A valve disposed within the diverter manifold routes the return fluid to one or more of the heat exchanger or a return fluid reservoir based on a control signal received from a controller.

Abstract: A working machine has a body and a load handling apparatus coupled to the body. The load handling apparatus is moveable with respect to the body by an electrically driven actuator assembly. A controller is configured to receive a tilt signal representative of a moment of tilt of the working machine and issue a control signal configured to control an electrical drive element of the electrically driven actuator assembly based on the value of the tilt signal relative to a tilt threshold.

Abstract: A system for controlling hydraulic fluid flow within a work vehicle includes a pilot conduit configured to receive a pilot flow of hydraulic fluid from a fluid supply conduit such that the operation of a compensator valve is controlled based on a pressure of the pilot flow within the pilot conduit. Furthermore, a pilot conduit valve is configured to adjust the pressure of the pilot flow within the pilot conduit. In addition, the system includes a load sense conduit configured to receive a bleed flow of the hydraulic from the fluid supply conduit such that the operation of the pump is controlled based on a pressure of the bleed flow within the load sense conduit. Moreover, a load sense valve is configured to adjust the pressure of the bleed flow within the load sense conduit.

Abstract: A hydraulic system includes a hydraulic pump, a first hydraulic actuator, a second hydraulic actuator, a first control valve to control the first hydraulic actuator, and a second control valve to control the second hydraulic actuator, the second control valve being arranged on a downstream side of the first control valve. The hydraulic system includes a first fluid tube in which a return fluid flows toward the second control valve. The first fluid tube couples the first control valve to the second control valve. The hydraulic system includes a second fluid tube in which a supply fluid flows toward to the first hydraulic actuator. The second fluid tube being connected to the first hydraulic actuator. The hydraulic system further a third fluid tube in which the return fluid in the first fluid tube flows toward the second fluid tube.

Abstract: This hydraulic system is provided with: a hydraulic pump; a pilot-type control valve; an electromagnetic proportional valve; a controller; and a pilot pressure switching unit which is capable of switching the electromagnetic proportional valve supply pressure to a first pressure during a normal operation, or to a second pressure lower than the first pressure. The control valve is provided with a bleed-off passage, and is capable of controlling the operating oil pressure supplied to the actuator, according to the opening area thereof. During an emergency operation, the electromagnetic proportional valve supply pressure is switched from the first pressure to the second pressure, the electromagnetic proportional valve is brought into a fully opened state, and the operating oil discharge amount from the hydraulic pump increases and decreases, and the operating oil pressure increases and decreases, and thus the operating speed of the actuator is controlled.

Abstract: There is provided a hydraulic drive device for a working machine with which a number of times of maintenance can be reduced. A controller (20) opens a first on-off valve (25a), closes a second on-off valve (25b), switches a first directional switching valve (30a) to a first position (A), and switches a second directional switching valve (30b) to a third position (C), thereby pressure oil from a hydraulic pump (1a) is supplied from the first on-off valve to an actuator (5a) through the first directional switching valve. When history data of the first on-off valve is determined to satisfy a prescribed condition, the controller closes the first on-off valve, opens the second on-off valve, switches the first directional switching valve to a second position (B), and switches the second directional switching valve to a fourth position (D), thereby pressure oil from the hydraulic pump is supplied from the second on-off valve to the actuator through the second directional switching valve.

Abstract: The present invention is related to a cooling device for a forklift brake system, which is capable of maintaining a predetermined level of heat-radiation performance by reducing heat when heat is generated in a service brake that is provided at a forklift driving shaft. A cooling device for a forklift brake system according to an exemplary embodiment of the present invention allows cooling oil to bypass a cooler when a pressure of the cooling oil is abnormally increased or there is a concern that a pressure of the cooling oil is increased, thereby preventing the cooler from being damaged.

Abstract: A downhole tractor having a hydraulic system for driving a plurality of hydraulic cylinders and a plurality of hydraulic motors. The system comprises: a hydraulic power pack; a first hydraulic supply line for supplying hydraulic fluid to the plurality of hydraulic cylinders; a second hydraulic supply line for supplying hydraulic fluid to plurality of hydraulic motors; a valve section comprising a respective part of first hydraulic supply line and a further respective part of second hydraulic supply line, valve section further comprising an inlet for receiving hydraulic fluid, and a set of valves, and a hydraulic bypass supply line coupled to hydraulic power pack for supplying hydraulic fluid directly to the inlet of valve section bypassing at least part of first hydraulic supply line and second hydraulic supply line. The first and the second hydraulic supply line each comprise two parts connected via respective part in the valve section.

Abstract: A hydraulic system includes first and second valve assemblies connected to a common pump. The first valve assembly includes a main valve housed inside a manifold. A pressure compensator valve maintains a constant pressure drop across a variable orifice of the main valve. A pressure limiter valve is in communication with the main valve and the pressure compensator valve, and allows an actuator connected to the first valve assembly to operate independently of the second valve assembly so that fluid flow to a work port of the first valve assembly is not interrupted by operation of the second valve assembly.

Abstract: A load-sensitive multi-path valve testing device includes the first, second, and third pressure sensors connected to the T, P, and LS ports of the load-sensitive multi-path valve; an oil outlet of an electronically controlled variable displacement pump connected to the P port of the load-sensitive multi-path valve via an oil supply pipeline; a first proportional relief valve and a first flow sensor connected on the oil supply pipeline; control oil ports of each commutation linkage respectively connected to a control oil source by two proportional pressure reducing valves; two working oil ports of each commutation linkage respectively connected to an oil tank by two proportional relief valves; flow sensors and pressure sensors arranged on two working oil ports of each commutation linkage. A testing method includes: using the device for pressure loss tests, micro-motion characteristic tests and flow saturation resistant characteristic tests.

Abstract: A hydraulic system includes one or more hydraulic subsystems that have a source of additional flow for supplying an auxiliary system. The hydraulic system may include one or more actuator systems, a boost system, and a further hydraulic system, such as a steering system. The source of additional flow for supplying the auxiliary system may include: sizing the boost system for providing both full boost function and auxiliary function, sizing the steering system for providing both full steering function and auxiliary function, utilizing available flow from an unused actuator function, and/or utilizing a selector manifold for actively selecting the source of auxiliary flow based on the flow and pressure demands of the respective hydraulic systems. Such a hydraulic system enables flow to be available to an auxiliary function regardless of the flow requirements for the actuator functions and/or other vehicle functions, while also minimizing interactions and flow disruptions to the various hydraulic subsystems.

Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus, and a piston that separates the piston chamber from the annulus. The hydraulic drive also includes a first hydraulic pump hydraulically connected with the piston chamber, a second hydraulic pump hydraulically connected with the annulus, a third hydraulic pump, and a directional control valve that has a first switching position and a second switching position. The third hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber, and the third hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: Pressure compensating valves not fully closing at the stroke end are employed, and upon the operator's operation for the traveling, pilot primary pressure is reduced and supplied to remote control valves 34c-34h of non-travel operating devices. Thus, the inflow of the hydraulic fluid into non-travel actuators is suppressed and a necessary amount of hydraulic fluid for travel motors is secured in travel combined operation. Accordingly, when saturation occurs in a construction machine's hydraulic drive system performing the load sensing control due to combined operation with a great load pressure difference between two actuators, deceleration/stoppage of an actuator on the low load pressure side is prevented by preventing full closure of the pressure compensating valve on the low load pressure side, while also preventing deceleration/stoppage of a high load pressure actuator by securing a necessary amount of hydraulic fluid for the high load pressure actuator.

Abstract: A dual mode control system for a work vehicle includes a hydraulic system configured to drive a loader assembly and a dozer assembly coupled to the work vehicle. The hydraulic system includes a fluid delivery system comprising a plurality of flow paths fluidly coupled to a hydraulic pump. The hydraulic system includes a valve assembly configured to regulate diversion of fluid into a first and a second hydraulic cylinders coupled to the fluid delivery system to adjust the loader assembly, or into a third cylinder coupled to the fluid delivery system to adjust the dozer assembly. The dual mode control system also includes a controller operably coupled to the valve assembly, and one or more user interfaces coupled to the controller to enable an operator to provide inputs to cause the controller to adjust the valve assembly, and to thereby adjust the loader assembly or the dozer assembly.

Abstract: Provided is a hydraulic drive device that is provided in a work device and with which it is possible to obtain a high energy-saving effect with a low-cost configuration while being equipped with a plurality of hydraulic actuators. The hydraulic drive device is provided with: first and second actuator groups; closed circuits connected to hydraulic actuators included in the first actuator group; a pump section including closed circuit pumps; open circuits which include a plurality of variable throttle valves for changing the flow rate of working fluid supplied from a hydraulic pump included in the pump section to a hydraulic actuator; and circuit switching sections having a first state in which the closed circuits are opened and the opened circuits are blocked, and a second state in which the closed circuits are blocked and the open circuits are opened.

Abstract: An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).

Abstract: A hydraulic drive system for a track device of crawler type has right and left hydraulic track motors. The hydraulic drive system is capable of correcting for skew occurring in the straight line traveling of the track device. A traveling test is conducted upon shipment from a factory. If skew is noted during the test, a plug disposed on the side of a valve opening-side pressure receiving portion of a pressure compensating valve for the track which is lower in speed is removed and, replaced with an adjusting mechanism-mounted plug having an adjusting pin. The pin is operated so as to strengthen a biasing force of a target compensating differential pressure adjusting spring. An opening in the pressure compensating valve is thereby corrected in an opening direction and a flow rate to one of the left and right track motors is thereby adjusted to be equal to the other motor.

Abstract: A hydraulic system is provided to selectively and independently route pressurized fluid to one or more operational systems of a machine. The hydraulic system is capable of switching fluid flow in operation from one of the operational systems to another of the operational systems in the event of hydraulic drive power being required by the latter one of the operational systems. The hydraulic system is also configured to continue supplying a nominal amount of fluid to support one or more auxiliary functions, for example, a lubrication system for bearings associated with the former one of the operational systems while routing the pressurized fluid to the latter one of the operational systems. A recirculation and anti-cavitation arrangement is also provided to allow recirculation of fluid to a hydraulic motor in the former one of the operational systems when pressurized fluid is being routed to the latter one of the operational systems.

Abstract: A hydraulic drive system includes control valve and operating devices, a variable displacement pump, and a flow regulator. When an operating lever inclination angle becomes a value, a control valve opening area becomes a reference. When the operating lever inclination angle maximizes, the opening area maximizes. The flow regulator: until the operating lever inclination angle becomes the value, increases the pump discharge flow rate with the inclination angle, so a differential pressure between pump discharge and actuator load pressures is constant; when the operating lever inclination angle becomes the value, controls the pump discharge flow rate, so a control valve passing flow rate is an actuator maximum flow rate when the differential pressure is constant; and when the operating lever inclination angle is between the value and the maximum, defines a maximum pump discharge flow rate, so the pump discharge flow rate is kept to the actuator maximum flow rate.

Abstract: A control valve device includes a valve body having an actuator port connected to an actuator and a relief passage configured to allow the actuator port to communicate with a return passage, a spool slidably assembled into the valve body and configured to allow the actuator port to selectively communicate with a supply side or a return side, a relief valve configured to open/close the relief passage to control pressure of the actuator port, and an on/off valve assembled into an assembling hole which is formed in the valve body. The on/off valve configured to allow the actuator port to communicate with the relief passage through the assembling hole at the time of valve open.

Abstract: A hydrostatic drive system of a mobile machine includes a hydraulic work system and a hydraulic work pump that is driven by an internal combustion engine and, when operated as a pump, takes in hydraulic fluid with a suction side from a tank and, with a delivery side, delivers into a delivery line that leads to the hydraulic work system. A bypass valve is provided with which, when the hydraulic work pump is operated as a motor to start the shut-off internal combustion engine, the volume flow delivered by the hydraulic work pump operated as a motor to the delivery side is diverted to the tank. The bypass valve, in the motor operation to start the shut-off internal combustion engine, is actuated into an open position that connects the delivery side of the hydraulic work pump with the tank.

Abstract: A reagent preparing device capable of supplying a predetermined reagent, which includes a first liquid and a second liquid different from the first liquid, to a measurement section for measuring a specimen using the reagent, comprising: a pressure generator for generating pressure to transfer liquid; a reagent preparing section for executing a preparation operation of the predetermined reagent using the pressure generated by the pressure generator; and a controller configured for performing operations comprising: determining whether or not the reagent preparing section is executing the preparation operation, and controlling the generation of the pressure by the pressure generator according to the determination result, is disclosed. A reagent preparing method and a specimen processing system are also disclosed.

Abstract: A control system of a hybrid construction machine includes a regeneration passage switching valve having a normal position where flow of working fluid is blocked, and a regeneration position allowing for the working fluid to flow from main passages to a regeneration motor when a working fluid pressure of the main passages reaches a set pressure during operation of the actuators, and an assist switching valve having a normal position proportionally dividing the working fluid of an assist passage into a regeneration passages, a first switching position supplying more working fluid of the assist passage to one of the main passages when that the one has a higher working fluid pressure, and a second switching position supplying more working fluid of the assist passage to the other one of the main passages when that the other one has a higher working fluid pressure.

Abstract: An object to achieve favorable operability, in a combined operation that involves a specific actuator and involves a great difference in load pressure and when an operation of an operating unit for the specific actuator is a fine operation, by reducing energy consumption arising from wasted restricting pressure loss of a pressure compensating valve and by flexibly varying a flow rate of a hydraulic fluid supplied to the specific actuator depending on the load pressure. To achieve this object, a boom cylinder (3a) is provided with an open center type flow control valve (6a) that controls a hydraulic fluid from a main pump (202) and a closed center type flow control valve (6i) that controls a hydraulic fluid from a main pump (102). The main pump (102) is subject to load sensing control. The flow control valve (6a) is opened to control a supply flow rate up to an intermediate zone of an operating range of an operating unit for the boom cylinder (3a).

Abstract: A flow control valve for use in oil well bore holes. The flow control valve includes a plurality of flow paths connected in parallel. The flow control valve operates by successively opening different flow paths, starting with a flow path that requires a reduced force to operate its inlet valve. The flow rate through the flow control valve is controlled by opening and closing different ones of the plurality of flow paths individually or in combination. A flow path that allows fluid to flow at substantially the full flow rate of the valve is provided as one of the parallel paths. A simple mechanical design using poppet valves and at least one cam is described.

Abstract: A hydraulic excavator drive system includes: a first hydraulic pump and a second hydraulic pump, whose respective tilting angles are controllable independently of each other; an arm main control valve and an arm auxiliary control valve each for controlling supply of hydraulic oil to an arm cylinder; and a boom main control valve and a boom auxiliary control valve each for controlling supply of the hydraulic oil to a boom cylinder. An arm operation valve outputs a pilot pressure to the arm main control valve. A boom operation valve outputs a pilot pressure to the boom main control valve. A pair of arm-side regulating valves outputs no pilot pressure to the arm auxiliary control valve and a boom-side regulating valve outputs no pilot pressure to the boom auxiliary control valve when an arm crowding operation and a boom raising operation are performed concurrently.

Abstract: The invention relates to a method and device for controlling a combined rotary/push movement of a load-receiving means of an industrial truck, in particular a three-way stacker, both the rotary movement and the push movement being brought about by means of respective hydraulic elements (32, 34), which are supplied with hydraulic fluid by a single hydraulic pump (22) which is driven by an associated pump motor (24), and a performance characteristic of the hydraulic pump (22) being controlled according to a predetermined progression over time during the rotary/push movement; the industrial truck comprising a valve assembly (30) which is designed to be operated such that, below a threshold value for the hydraulic pressure provided by the hydraulic pump (22), only the rotary movement of the load-receiving means is brought about, while, above the threshold value, both the rotary movement and the push movement are brought about.

Abstract: A control system for hybrid construction machine includes a regeneration motor configured to be rotated by working fluid introduced from a turning circuit, a pressure detector configured to detect a turning pressure during a turning operation of the turning motor or a braking pressure during a braking operation of the turning motor, a switching valve for turning regeneration configured to perform turning regeneration by introducing the working fluid from the turning circuit to the regeneration motor when being switched to an open position by a pressure of pilot fluid, an electromagnetic proportional pressure reducing valve configured to be switched to an open position and generate a pilot secondary pressure for switching the switching valve for turning regeneration to the open position when a pressure detected by the pressure detector reaches a first set pressure, and a pilot switching valve configured to allow the passage of the pilot fluid for switching the switching valve for turning regeneration to the op

Abstract: An engine system utilizing a hydraulic pressure includes an engine, a hydraulic system having at least one hydraulic pump discharging a hydraulic oil for operating an actuator and a hydraulic oil tank storing the hydraulic oil returned from the actuator, a hydraulic power transmission device connected to a hydraulic line between the hydraulic pump and the hydraulic oil tank and configured to transmit a hydraulic pressure of the hydraulic oil as a driving source, and a vehicular auxiliary device driven by using the hydraulic pressure transmitted from the hydraulic power transmission device as the driving source.

Abstract: A hydraulic system of a vehicle is provided, said system including: a first hydraulic circuit (1) having a first pressure source (2) and at least a first hydraulic consumer (3, 4), a second hydraulic circuit (5) having a second pressure source (6) and at least a second hydraulic consumer (7), connecting means (10, 11) allowing a flow of hydraulic fluid at least from said first hydraulic circuit (1) to said second hydraulic circuit (5), and control means (16) for controlling operation of said hydraulic consumers (3, 4, 7). Such a hydraulic system should allow safe operation of a vehicle with low energy consumption of the hydraulic system.

Abstract: An object of the invention is to achieve a travel speed known in the art during travelling operation, improve energy efficiency by reducing energy loss, and obtain favorable travel operability less susceptible to effects from variations in a travel load and changes in a pump delivery pressure when travelling operation is performed through operation of a travel lever over a half stroke range or less. A variable restrictor valve 80 is disposed in parallel with a flow sensing valve 50 of an engine speed sensing valve unit 13. A travel pilot pressure is adapted to act in an opening direction of the variable restrictor valve 80. The variable restrictor valve 80 is set to have a continuously increasing opening area from a full closure to a maximum with an increasing travel pilot pressure.

Abstract: An independent metering valve circuit includes an actuator, a set of independent metering valves, an independent metering valve pre-compensator, an inverse resolver, and a signal conditioning element. The set of independent metering valves are fluidly coupled to the actuator and configured to independently control a flow of a hydraulic fluid to the actuator. The independent metering valve pre-compensator is configured to control the flow of the hydraulic fluid to the set of independent metering valves. The inverse resolver is configured to receive a first pressure signal from the independent metering valve circuit and a second pressure signal from a load-sense hydraulic system and output a third pressure signal. The signal conditioning element is configured to receive the third pressure signal and output a forth pressure signal configured to control a pump fluidly coupled to the load-sense hydraulic system and the independent metering valve circuit.

Abstract: A hydraulic control valve assembly to be integrated into a pressure compensated load sensing system including a fluid source is provided. The hydraulic control valve assembly includes a first working unit to control a first hydraulic function of a machine. The first working unit includes a first directional and return flow control in the form of a first spool, a first function flow control to selectively communicate a working pressure of the first function to the fluid source, and a first downstream flow control. The hydraulic control valve assembly further includes a second working unit arranged downstream of the first working unit. The second working unit to control a second hydraulic function of the machine. The first downstream flow control to selectively restrict a flow a fluid from the fluid source to the second working unit.

Abstract: A hydraulic control assembly for a plurality of consumers includes, for each consumer, a supply metering orifice configured to control fluid flow. A flow-sensing fluid-flow-path extends over detection orifices positioned hydraulically in series, whereby a detection orifice is assigned to each supply metering orifice. The fluid-flow-path is connected to a hydraulic pump upstream of the detection orifices, and a control device of the hydraulic pump downstream of the detection orifices. Each detection orifice is configured to close the fluid-flow-path upon detecting a fluid supply deficiency for a corresponding consumer, whereby the control device is configured to interact with the fluid-flow-path such that fluid flow from the hydraulic pump is increased. When no customers have a supply deficiency, the fluid-flow-path over the detection orifices is fully opened, and the control device is configured to reduce fluid flow from the hydraulic pump.

Abstract: A hydraulic system for use with an agricultural harvester header is provided. The hydraulic system includes a reversible hydraulic pump that drives a reversible hydraulic motor in a forward or harvesting direction and a reverse or header cleaning direction. The system can further include a second reversible pump similarly driving a second reversible hydraulic motor in forward and reverse directions. The pumps and motors can be used to operate various header implements, e.g., the first pump and motor may be used to operate at least a crop cutting knife and the second pump and motor can be used to operate at least one conveyor. The pumps and motors operate within hydraulic circuits which share their hydraulic fluid with the harvester's hydraulic fluid reservoir, thereby reducing system weight, complexity and maintenance requirements.

Abstract: An excavation system is disclosed for a machine having a work tool. The excavation system may have first and second actuators configured to move the work tool in first and second directions, at least a first valve configured to regulate fluid flow through the first actuator, and at least a second valve configured to regulate fluid flow through the second actuator. The excavation system may also have at least one sensor to generate a first signal indicative of a performance of the first actuator, and a controller in communication with the at least a first valve, the at least a second valve, and the at least one sensor. The controller may be configured to make a first determination that the first actuator is experiencing a stall condition based on the first signal, and to selectively command neutralization of the powertrain and movement of the second actuator based on the first determination.

Abstract: The present disclosure relates to a system for reducing fuel consumption in an excavator, and more particularly, to a system for reducing fuel consumption in an excavator, which may reduce fuel consumption when an excavator travels. A technical problem of the present disclosure, which will be achieved, is to provide a system for reducing fuel consumption in an excavator, which may reduce fuel consumption while improving traveling performance of an excavator.