Abstract: The present disclosure relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate.

Abstract: Construction equipment having an electric control lever is provided, which can intercept a control signal applied to a flow control valve when trouble occurs in the electric control lever or a control unit.

Abstract: A pressure intensifier for ejecting fluid at a constant flow rate includes a hydraulic pump, a hydraulic motor, a supply channel, a first control unit, and a second control unit. The hydraulic pump pumps an introduced fluid to eject the fluid through an ejection channel. The hydraulic motor is driven by the introduced fluid and drives the hydraulic pump to cause the fluid ejected by the hydraulic pump to be intensified. The supply channel allows the hydraulic pump and the hydraulic motor to be supplied with the fluid. The first control unit opens or closes the supply channel, and the second control unit operates the first control unit to cause the first control unit to close the supply channel if the fluid ejected through the ejection channel is larger than a predetermined pressure.

Abstract: A device for use in extracting energy from an incoming fluid flow is presented.

Abstract: A hydraulic system is disclosed for use with a machine. The hydraulic system may have a tank, a motor with a fluid inlet and a fluid outlet, and a pump configured to draw fluid from the tank and discharge the fluid at elevated pressures to the motor. An output of the pump is adjustable to regulate a speed of the motor. The hydraulic system may also have a low-speed valve located between the fluid outlet of the motor and the tank. The low-speed valve may be configured to reduce a positive speed of the motor below a lowest positive speed attainable through control of pump output.

Abstract: A hydrostatic drive system includes a user in the form of a differential cylinder connected in a closed circuit to a high-pressure pump. A piston-side compression chamber and a piston-rod-side compression chamber of the differential cylinder are in communication with the high-pressure pump. The closed circuit includes a protection device having first and second protection valve devices that each includes a pressure relief valve and an anti-cavitation valve. The pressure relief valve of the first protection valve device is provided with an override device, by means of which the opening pressure of the pressure relief valve can be varied. When the high-pressure pump delivers into the piston-rod-side compression chamber, the pressure relief valve of the first protection valve device is adjusted by means of the override device to a reduced opening pressure and the differential volumetric flow flows out via the pressure relief valve to a low-pressure system.

Abstract: A hydrostatic transmission comprises a hydraulic pump, a hydraulic motor, first and second main fluid passages fluidly connecting the hydraulic pump to the hydraulic motor so as to constitute a closed fluid circuit, a charge fluid passage, a plurality of first charge check valves and a plurality of second charge check valves. The plurality of first charge cheek valves are interposed between the charge fluid passage and the first main fluid passage so as to allow only flow of fluid from the charge fluid passage to the first main fluid passage when the first main fluid passage is hydraulically depressed relative to the charge fluid passage. The plurality of second charge check valves are interposed between the charge fluid passage and the second main fluid passage so as to allow only flow of fluid from the charge fluid passage to the second main fluid passage when the second main fluid passage is hydraulically depressed relative to the charge fluid passage.

Abstract: A hydraulic machine in which the volume of working fluid displaced by each cylinder is selectable on each cycle of working chamber volume by active control of one or more electronic valves has a controller configured to select specified groups of cylinders to repetitively carry out active cycles until a change in selection is made. The groups are selected to reduce torque ripple and/or bearing side load. The cam profile may be varied to further reduce torque ripple.

Abstract: A hydraulic excavator includes a rotation motor (31) for rotating an upper rotating structure. The rotation motor (31) includes an electric motor (32), a hydraulic motor (40), and a reduction gearbox (33). The hydraulic motor (40) includes a motor mechanism (50) and a clutch mechanism (70). The motor mechanism (50), which is a vane-type hydraulic motor, is engaged with/disengaged from a motor shaft (37) by the clutch mechanism (70). When rotation speed of the upper rotating structure is low, and a required value of output torque of the rotation motor (31) is high, an operation of driving the output shaft (35) by the hydraulic motor (40) is performed in the rotation motor (31).

Abstract: An exemplary hydraulic system includes a digital valve operable to fluidly connect a hydraulic load to a pressure supply, and an orifice disposed in a flow path between the hydraulic load and the digital valve. A digital controller is operably connected to the digital valve. The digital controller stores a target pressure drop across the orifice and is configured to determine an actual pressure drop across the orifice and formulate a control signal based on the target pressure drop and the actual pressure drop. The controller transmits the control signal to the digital valve for controlling the operation of the valve.

Abstract: A forklift (1) according to the present invention includes: an engine (7); a hydraulically-operated device for cargo handling (2); a pump for cargo handling (5) that is driven by the engine (7); hydraulic piping for cargo handling (8) that connects the pump for cargo handling (5) and the hydraulically-operated device for cargo handling (2); discharge piping (110) that branches from the hydraulic piping for cargo handling (8) and is connected to a tank (4); a switching valve (111) capable of switching the opening and closing of the discharge piping (110); a control device (13) that closes the discharge piping (110) when the rotation speed of the engine (7) is larger than a predetermined value, and opens the discharge piping (110) when the rotation speed of the engine (7) is less than or equal to a predetermined value; and a sub-relief valve (112) that adjusts the flow rate of hydraulic oil that is discharged from the discharge piping (110) to the tank (4), on the bases of the pressure or the flow rate of the h

Abstract: A system and method for performing a floating function in an earthmoving implement of an earthmoving machine without physically connecting chambers within a hydraulic actuator that is adapted to raise and lower the earthmoving implement. The system includes a device for delivering a pressurized fluid to and receiving pressurized fluid from the actuator, a valve for compensating for differences in volume between chambers of the actuator, and an electronic control circuit that includes electronic sensors for sensing the pressures in the chambers of the actuator, and a controller for receiving outputs of the sensors. The controller calculates an amount of the pressurized fluid that, when delivered to or received from the actuator, achieves a substantially constant pressures in the chambers of the actuator and enables the earthmoving implement to float regardless of motion of the actuator.

Abstract: A fluid system and method of operation provides flow force compensation and load sense functions. Each work circuit includes an actuator, a control valve, and a first valve. A valve element of a control valve includes main metering orifices sized and shaped to provide flow force compensation. A load sense check valve associated with a load pressure signal conduit is downstream of the load check valve. The load pressure signal conduit of each work circuit is in fluid communication with one another, and a greater of the load signal pressure of the work circuits is communicated to the load sense check valve of the other work circuit. The control valve associated the lesser load can permit flow forces to reduce the effective area of the orifice, which increases the pressure difference across the valve to maintain approximately constant flow to the actuator.

Abstract: A hydraulic travel drive includes a primary hydraulic machine and at least one secondary hydraulic machine connected in a closed hydraulic circuit via a first and a second working line. A first accumulator is connected via a first valve to the first working line and via a second valve to the second working line. A second accumulator is connected via a third valve to the first working line and via a fourth valve to the second working line. The four valves are non-proportional switching valves each having two defined switching positions. A method for operating the drive includes comparing the high pressure working line to the first accumulator. If pressure in the accumulator is lower than in the working line, the first accumulator is connected to the high pressure working line for charging until pressure in the accumulator corresponds to that of the working line.

Abstract: A hydraulic system includes a hydraulic transmission including a hydraulic pump configured to be coupled to a prime mover, a hydraulic motor configured to be coupled to an output shaft, and fluid lines coupling the hydraulic pump to the hydraulic motor to provide a fluid circuit providing flow communication between the hydraulic pump and the hydraulic motor, such that operation of the hydraulic pump provides fluid flow to the hydraulic motor, and the hydraulic motor supplies torque to the output shaft. A controller is configured to control operation of the hydraulic transmission. The controller is configured to receive signals indicative of pressure in the fluid circuit and reduce an output of the hydraulic pump when the pressure in the fluid circuit reaches a pressure level, and a rate of response of the reduction of the output of the hydraulic pump is varied based on a temperature of fluid in the fluid circuit.

Abstract: A control system for a work implement on a machine is disclosed including a first hydraulic circuit, a second hydraulic circuit, and a controller. The first hydraulic circuit includes a hydraulic cylinder assembly, a pressurized fluid source, and a fluid tank. The hydraulic cylinder assembly includes a head end, a rod end, a cylinder, and a rod. The pressurized fluid source and the fluid tank are selectively connected to the head end or the rod end. The second hydraulic circuit includes a valve configured to receive a connection to tank signal and selectively connect the head end or the rod end to the fluid tank. The controller is configured to generate the connection to tank signal.

Abstract: An engine control device detects the state of work of a working vehicle such as a construction machine or the like, and controls the power output capacity of an engine automatically. A determination is made as to whether excavation or uphill traveling is being performed, based upon the detection signals from a hydraulic oil pressure detector for a hydraulic cylinder of an arm, detectors for arm and bucket operation commands, a shift operation detector for a transmission, a pitch angle detector for the vehicle body, a traveling acceleration detector, and an accelerator opening degree detector. When the result of this determination is that excavation or uphill traveling is being performed, the engine is controlled to operate at a high power capacity, while at other times it is controlled to operate at a low power output capacity.

Abstract: A mixer drum driving device includes a hydraulic motor that rotates a mixer drum, a first hydraulic pump that is driven by an engine to be capable of supplying working oil to the hydraulic motor, an electric motor, a power supply connected to the electric motor, a second hydraulic pump capable of supplying the working oil to the hydraulic motor on the basis of a driving force of the motor, and a flow dividing valve that divides the working oil discharged from the first hydraulic pump and supplies the working oil to the hydraulic motor and the second hydraulic pump. The second hydraulic pump is configured to rotate the electric motor using the working oil. The electric motor is configured to generate electric power so as to charge the power supply when driven to rotate by the second hydraulic pump.

Abstract: An exemplary hydraulic system includes a digital valve operable to fluidly connect a hydraulic load to a pressure supply. A digital controller is operably connected to the digital valve. The digital controller stores a target value of a hydraulic system operating parameter and is configured to formulate a pulse width modulated control signal based on the target value. The digital controller transmits the control signal to the digital valve for controlling the operation of the valve.

Abstract: A hydraulic fluid actuated equipment leveling assembly incorporating a plenum having adjustment ports; an input channel opening the plenum; a disk valve operable for opening and closing the adjustment ports; telescoping and hydraulic ram actuated equipment support pedestals; hydraulic lines spanning between the plenum's adjustment ports, and the pedestal's hydraulic rams; and fluid displacing plungers connected operatively to the hydraulic lines for adjusting the hydraulic line's interior volumes.

Abstract: A hydraulic control system and a hydraulic control method are disclosed. The hydraulic control system comprises a first closed pump (P1) and a first engine (M1) connected with each other, a second closed pump (P2) and a second engine (M2) connected with each other, and a hydraulic motor (P3). The first closed pump (P1), the second closed pump (P2) and the hydraulic motor (P3) are connected in parallel. Compared with the prior art, the present hydraulic control system has advantages of wider engine model selection range, higher reliability and better micro-motion performance.

Abstract: A hydraulic actuator system including an actuator and a valve assembly configured for bi-directional regeneration. The actuator may include a hollow body and a rod disposed within and extending outwardly from the hollow body. The rod may include a first chamber within the rod and a piston disposed at one end of the rod, defining a second chamber and a third chamber within the hollow body. A valve assembly may be in fluid communication with a first conduit, a second conduit, the first chamber, the second chamber, and the third chamber, wherein the valve assembly is configured to selectively couple one of the first conduit and the second conduit to one or more of the first port, the second port, and the third port, wherein one of the first conduit and the second conduit is configured as a pressure source.

Abstract: A hydraulic system is disclosed. The hydraulic system may have a pump, and a hydraulic actuator having a first chamber and a second chamber. The hydraulic system may also have a first pump passage fluidly communicating the pump with the first chamber, a second pump passage connected to the pump, and a regeneration valve. The regeneration valve may be movable from a first position at which the second pump passage is connected to the second chamber and the second chamber is isolated from the first chamber, to a second position at which the second pump passage is blocked and the second chamber is connected to the first chamber.

Abstract: A power generating apparatus includes a rotating shaft, a hydraulic pump driven by the rotating shaft, a hydraulic motor driven by pressurized oil supplied from the hydraulic pump, and a generator coupled to the hydraulic motor. Each of the hydraulic pump and motor includes working chambers each defined by a cylinder and a piston, a high pressure manifold and a low pressure manifold. Each of the high and low pressure manifolds includes branch channels connected to the working chambers and a merging channel connected to a high or low pressure oil line. The branch channels are equipped with high or low pressures valves, joined together and merged into the merging channel.

Abstract: A hydraulic system adapted to recover inertial energy is disclosed. The hydraulic system includes a pump, a variable displacement pump/motor having an input/output shaft, an accumulator, and a valve arrangement. The valve arrangement is operable in: a) a first mode where the variable displacement pump/motor is driven by the pump to rotate the input/output shaft and the load; b) a second mode where the variable displacement pump/motor uses inertial energy from a deceleration of the load to charge the accumulator; and c) a third mode where the variable displacement pump/motor is driven by the accumulator to rotate the input/output shaft and the load. The hydraulic system also includes a controller for controlling operation of the pump, the variable displacement pump/motor and the valve arrangement.

Abstract: A hydraulic drive system for a construction machine has a travel detection device which detects whether or not the operation mode is a traveling operation and a setting changing device. The setting changing device sets the target differential pressure of load sensing control at an absolute pressure Pa when the operation mode is not a traveling operation, and sets the target differential pressure of the load sensing control at an absolute pressure Pa? rather than the absolute pressure Pa. In this way, in the actuator operation other than traveling, a necessary actuator speed can be obtained and supplied with the necessary maximum flow rate. In addition, during the combined operation, a flow rate in accordance with the opening area ratios of flow control valves can be distributed to actuators different in load pressure from one another; and energy efficiency is enhanced due to less energy loss during traveling operation.

Abstract: A lubrication system is provided that includes a pump operatively connected to one or more supply lines for delivery of a lubricant, the system including a first pressure sensor associated with the supply line at a first position, and a second pressure sensor associated with the supply line at a second position downstream of the first position and pump, a controller configured to receive pressure signals and control operation of the pump based upon the pressure differential between the pressures at the first position and second position. The pressure differential may be employed to determine when a pressure at a third position downstream of the second position has been achieved. At least one of the pressure sensors may be positioned adjacent to the pump, the controller further being operable to deactivate the pump in the event that a maximum pump pressure has been met.

Abstract: Disclosed embodiments of power machines, implements and hydraulic systems utilize a hydraulic flow control circuit and method to implement multiple modes of operation while optimizing hydraulic fluid flow to either or both of primary and secondary function devices.

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: Disclosed are hydraulic pump systems and pump suction charging systems which reduce or eliminate cavitation in the systems, as well as methods of operating the same and work machines including the same.

Abstract: A working machine hydraulic circuit, including: a hydraulic motor; a pilot pressure system configured to supply hydraulic fluid at a pilot pressure to one or more components of the working machine; and a make-up pressure system in hydraulic fluid communication with the pilot pressure system and the hydraulic motor, and configured to supply hydraulic fluid to the hydraulic motor from the pilot pressure system if the hydraulic fluid pressure in a part of the hydraulic motor is below a threshold pressure such that, during deceleration of the hydraulic motor, the make-up pressure system is operable to supply fluid from the pilot pressure system to the hydraulic motor to reduce the risk of cavitation in the hydraulic motor.

Abstract: The present invention provides a method of controlling a fluid working machine (12) having a plurality of working cylinders (14) having pistons (16) therein and arranged to drive a shaft (18), in which said cylinders are supplied with pressurized working fluid via a manifold (24), the contents of which may be 5 purged by a de-pressurizer taking one of a number for forms such as to allow re-activation of said machine (10).

Abstract: A system and method of dithering speed and/or torque for shifting a transmission of a vehicle having an engine, a reversible, variable displacement hydraulic motor/pump which can be driven by the engine, a hydraulic accumulator supplied by said motor/pump, and at least one reversible hydraulic driving motor for propelling the vehicle supplied with fluid by the hydraulic accumulator and/or by said motor/pump operating as a pump. A transmission unit connects the engine with the variable displacement hydraulic motor/pump during a first mode of operation (city mode) and connects the engine to a vehicle drive wheel during a second mode of operation. The system utilizes stored hydraulic energy to dither the output of the driving motor in order to achieve quick and smooth shifts between city and highway mode, or between various ranges within the city mode.

Abstract: According to the present disclosure, a hydraulic control apparatus for construction machinery comprises: hydraulic pumps; first and second control valve units which control the flow directions of working oil discharged from the hydraulic pumps to supply the working oil to first and second work machines, respectively, and which control the degree of opening of flow channels which interconnect the first and second work machines and the hydraulic pumps, respectively; and a control unit which controls the first and second control valve units in accordance with operating signals inputted from first and second operating units.

Abstract: A pump system includes a closed-loop fluid circuit and an open-loop fluid circuit. The closed-loop fluid circuit includes a motor for rotating a first component connected to the closed-loop fluid circuit. A closed-loop pump drives the motor up to a first maximum rotational speed. The open-loop fluid circuit includes an open-loop pump for driving a second component connected to the open-loop fluid circuit. A control circuit includes a control valve for switching the outflow from the open-loop pump. The control valve selectively connects the open-loop pump to the closed-loop fluid circuit and simultaneously disconnects the open-loop pump from the open-loop fluid circuit. When the open-loop pump is connected to the closed-loop circuit, the closed-loop pump and the open-loop pump drive the motor at a second rotational speed greater than the first maximum rotational speed.

Abstract: A hydraulic control system is disclosed. The hydraulic control system may have a pump configured to pressurize a fluid, an actuator, a position sensor associated with the actuator and configured to generate a first signal indicative of a position of the actuator, and a circuit fluidly connecting the pump to the actuator. The hydraulic control system may also have a valve associated with the circuit and configured to move from a first position, at which fluid relief from the circuit is inhibited, toward a second position, at which fluid is relieved from the circuit through the valve, when a pressure of fluid within the circuit exceeds a threshold setting of the valve. The hydraulic control system may additionally have a controller in communication with the position sensor and the valve. The controller may be configured to selectively cause adjust the threshold setting of the valve based on the first signal.

Abstract: Disclosed are a system for driving a boom of a hybrid excavator, and a method for controlling same. The disclosed system comprises: an electric motor operating by means of a motor or generator; a capacitor for storing electricity generated by the electric motor; a hydraulic pump motor driven by the electric motor to supply working oil to a boom; a boom control valve having a closed circuit for selectively connecting/disconnecting a discharge line and an inlet line of the hydraulic pump motor to/from a head or a load of the boom; a main pump driven by a driving source arranged separately from the motor so as to supply working oil to a bucket, driving motor, or arm; a boom-assisting valve, which connects a discharge line of the main pump to the discharge line of the hydraulic pump motor, such that working oil discharged from the main pump and the hydraulic pump motor can be combined; and a control unit for controlling the electric motor, the hydraulic pump motor, and the boom control valve.

Abstract: A method and apparatus are provided for hydraulic fluid supply between a hydraulic pump and a hydraulic drive unit, switching hydraulic fluid flow direction to the hydraulic drive unit or stopping hydraulic fluid flow to the hydraulic drive unit when measured hydraulic fluid pressure crosses a predetermined pressure threshold value. The method further comprises calculating an amount of mechanical work done by the hydraulic drive unit and warning an operator or limiting hydraulic fluid flow rate to the hydraulic drive unit when the calculated mechanical work for the drive cycle is less than an expected amount of mechanical work. The apparatus for practicing the method further includes a pressure sensor associated with a hydraulic fluid supply conduit between the pump and the drive unit, and an electronic controller programmed to operate the drive system according to the method.

Abstract: A method and system for operating a machine having first and second movable elements, first and second hydromechanical movers for moving the first and second movable elements, respectively, and first and second hydraulic pumps linked to the first and second hydromechanical movers, respectively. Movement requests for moving the first and second movable elements are processed such that the movement command to the second hydromechanical mover is reduced by a variable amount based on the magnitude of the first movement request. For commanded first hydromechanical mover movements below a certain level, flow to the second hydromechanical mover may optionally not be reduced.

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 control system for construction machine includes a pair of first and second main pumps which are variable-displacement pumps, first and second circuit systems connected to the first and second main pumps and including a plurality of control valves, main switching valves provided between the first and second circuit systems and the first and second main pumps, a hydraulic motor for power generation connected to the first and second main pumps via the main switching valves, a generator coupled to the hydraulic motor for power generation, and a battery for storing power generated by the generator. When at least the main switching valve connected to one circuit system is at a position to cause one main pump connected thereto to communicate with the hydraulic motor for power generation, the main switching valve connected to the other circuit system causes the other main pump to communicate with the other circuit system.

Abstract: A hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan operably connected to and driven by the motor. The circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a pressure limiting valve configured to selectively reduce pressure of a flow of pilot fluid directed to the primary pump. The circuit further includes an override valve configured to selectively connect the supply passage to the pressure limiting valve.

Abstract: Methods and valve arrangements for controlling the flow of pressurized air from a tractor to a trailer reservoir and to a trailer spring brake chamber. In one exemplary embodiment, pressurized air from a tractor is supplied from a tractor to the trailer reservoir and to the trailer spring brake in different filling modes based on a user input. In another exemplary embodiment, pressurized service air is used to charge or partially charge the trailer reservoir.

Abstract: The present disclosure is a construction machine, such as an excavator, which comprises a plurality of hydraulically driven actuators, in which some of the actuators are provided in a one-to-one pump system where hydraulic pumps are connected to the respective actuators such that a working fluid is supplied from the respective pumps, and the remaining actuators are provided in an auxiliary control valve system where the working fluid is distributed by an auxiliary control valve connected to one or more pumps. When an amount of the working fluid of an actuator associated with the auxiliary control valve is insufficient, the actuator associated with the auxiliary control valve is connected to a pump of the one-to-one pump system to share the pump of the one-to-one pump system.

Abstract: A hydraulic system for a mobile machine is disclosed. The hydraulic system may have a first actuator, a first valve arrangement, a second actuator, and a second valve arrangement. The hydraulic system may also have at least one operator interface device movable by an operator to generate a first signal indicative of desired work tool movement in a first manner, and a second signal indicative of desired work tool movement in a second manner; and a controller configured to generate a first flow rate command directed to the first valve arrangement based on the first signal, and generate a second flow rate command directed to the second valve arrangement based on the second signal. The controller may also be configured to selectively generate a third flow rate scaled from the first flow rate command and directed to the second valve arrangement based on only the first signal.

Abstract: A hydraulic pressure control device including a pump driven to generate hydraulic pressure; a first pressure regulation valve that regulates hydraulic pressure in a first passage coupled to a pump along with discharge of oil; a second pressure regulation valve that receives the hydraulic pressure in the first passage and regulates the hydraulic pressure to an engagement pressure to engage a lock-up clutch according to a first signal pressure to output the engagement pressure to a second passage that supplies the oil to an engagement chamber; and a third pressure regulation valve that receives the hydraulic pressure in the first passage or the engagement pressure output to the second passage and regulates the received pressure according to the first signal pressure or a second signal pressure that synchronizes with the first signal pressure to output the resulting pressure to a third passage that supplies the oil to the disengagement chamber.

Abstract: A solenoid valve device includes: a solenoid valve that includes a solenoid that is supplied with driving current to generate magnetic flux, and a valve element that is moved by the magnetic flux generated from the solenoid; and a control device that controls the solenoid valve. The control device includes an alternating current component in the driving current and supplies the driving current including the alternating current component to the solenoid, and detects an impedance of the solenoid.

Abstract: Hydraulic systems and methods for using such systems in a variety of machinery, including but not limited to machines having multiple functions performed by one or more hydraulic circuits. The systems enable valves and actuators within the systems to reconfigure themselves so that flow from assistive loads on one or more actuators can be used to move one or more other actuators subjected to a resistive load.

Abstract: A hydraulic control system for a machine is disclosed. The hydraulic control system may have a hydraulic circuit, a pump configured to supply pressurized fluid, and a first sensor configured to generate a first signal indicative of a pressure of the hydraulic circuit. The hydraulic circuit may also have a first fluid actuator fluidly connected to receive pressurized fluid from the hydraulic circuit, a second sensor configured to generate a second signal indicative of a velocity of the first fluid actuator, and a controller in communication with the first and second sensors. The controller may be configured to receive an input indicative of a desired flow rate for the first fluid actuator, to determine an actual flow rate of the first fluid actuator based on the second signal, and to determine a stall condition of the first fluid actuator based on the desired flow rate, the actual flow rate, and the first signal.

Abstract: A method of controlling a hydraulic circuit having a pump, a hydraulic actuator, and a control valve disposed between the pump and hydraulic actuator is disclosed. The method includes selectively placing the hydraulic circuit between a work mode and a work standby mode based upon the relationship between the hydraulic actuator hydraulic pressure and at least one maximum pressure limit value. The work mode includes moving the control valve to an open position such that the pump and hydraulic actuator are in fluid communication with each other and commanding the pump to generate an output pressure value that is greater than the measured hydraulic actuator hydraulic pressure. The work standby mode includes moving the control valve to a closed position such that the pump is isolated from the hydraulic actuator and commanding the pump to generate an output pressure value that is independent of the measured hydraulic actuator hydraulic pressure.