Abstract: Operating an engine system includes cold starting an engine, closing spill valves to pressurize fuel in a plurality of plunger cavities, opening injection valves in some of a plurality of fuel injectors to inject fuel into firing cylinders in an engine cycle, and opening spill valves in some of the plurality of fuel injectors while injection valves therein remain closed to bleed fuel to a lower pressure space in the engine cycle. The pressurization of fuel in the fuel injectors remaining closed parasitically loads the engine to increase a fuel burned amount hastening warm up and limiting misfire. Related apparatus and control logic is also disclosed.

Abstract: A secondary steering pump system may include a secondary steering pump, a bypass valve having a first bypass position configured for placing the secondary steering pump in fluid communication with a hydraulic tank and a second use/testing position configured for placing the secondary steering pump in fluid communication with a steering control circuit. The system may also include a solenoid valve configured for actuation by a solenoid and for selectively actuating the bypass valve from the first position to the second position. The system may also include a pressure sensor configured for sensing pressure in the system.

Abstract: Provide a hydraulic circuit that can prevent damage to the oil cooler while suppressing excessive rise in the temperature of the operating oil.

Abstract: There is provided a construction machine that is capable of measuring a minute leakage flow rate of a one-sided tilting variable displacement hydraulic pump. The construction machine includes a pressure sensor that detects a pressure of a hydraulic pump, a bleed-off adjusting device that is enabled to adjust a bleed-off flow rate of the hydraulic pump, and an input device that gives an instruction for measurement of a leakage flow rate of the hydraulic pump.

Abstract: An excavator may include a lower traveling body; an upper turning body pivotally installed to the lower traveling body; an engine installed in the upper turning body; a main pump driven by the engine; and a processor and a memory that stores program instructions causing the processor to control a flow rate of hydraulic oil discharged by the main pump. The program instructions can cause the processor to, when a load of the engine increases, delay a response of the main pump 14 until an actual torque of the engine rises up to a level corresponding to the load of the engine.

Abstract: The object of the present invention resides in provision of a construction machine in which a hydraulic cylinder can be driven in a high efficiency by an accumulator. To this end, the construction machine including: a hydraulic cylinder; a first accumulator that accumulates return fluid from the hydraulic cylinder with a first set pressure; a tank that stores hydraulic fluid therein; a first hydraulic pump that delivers the hydraulic fluid sucked from the tank; a hydraulic actuator that is driven by the first hydraulic pump; and a second accumulator that accumulates return fluid from the hydraulic actuator with a second set pressure, includes a first control valve placed in a first hydraulic line that connects the first accumulator and the hydraulic cylinder to each other, and a second control valve placed in a second hydraulic line that connects the second accumulator and the hydraulic cylinder to each other. The second set pressure is set to a value higher than that of the first set pressure.

Abstract: A method for controlling a powertrain of a vehicle having a dual-clutch transmission (DCT) includes: operating the DCT while the vehicle is in motion with a high or low transmission gear drivingly engaged; receiving a shift request to engage an other one of the high and low transmission gears; reducing an engine torque output and first and second clutch torques; shifting a subtransmission to a neutral gear setting; selecting a first gear or a second gear to drive the subtransmission; shifting the main transmission to engage the selected first or second gear; after shifting the main transmission, shifting the subtransmission to the other one of the high and low transmission gears; and after shifting the subtransmission, controlling the engine torque output and the first and second clutch torques according to a driver request at an accelerator of the vehicle.

Abstract: A hydraulic system has two hydraulic circuits, each with a pressure generating unit acting on an actuator unit. The generating units are slot-controlled radial piston pumps and form a pump assembly with a single common pump support and single common rotor. The rotor is rotatable on a free protruding section of a common support hub and has piston-receiving bores on axially offset planes. The hub has two first and two second fluid bores. The first bores communicate with first pump connections and first control openings on the hub on a first plane, and the second fluid bores communicate with second pump connections and second control openings on the hub on a second plane. A first and a second adjustment frame, each having an eccentric ring and acting on the pump pistons, are disposed on respective planes perpendicular to the main axis and independently guided in a linearly movable manner.

Abstract: A pipeline includes a pipeline body in which fluid flows and a throttle formed at a specific position of the pipeline body as a flow passage sectional shape of the pipeline body is changed from that of a remaining portion of the pipeline body. The specific position at which the throttle is provided is a position in the pipeline body and corresponds to a position that serves as an abdominal part of the pipeline in a vibration mode where a resonance frequency is the closest to a pulsation frequency of pressure pulsation caused by the fluid.

Abstract: An electronically commutated hydraulic machine is coupled to a drivetrain. Working chambers of the hydraulic machine are connected to low and high pressure manifold through electronically controlled valves. The phase of opening and closing of the valves has a default. In order to avoid cycle failure due to acceleration events, for example due to backlash in the drivetrain, the phase of opening or closing of the electronically controlled valves is temporarily advanced or retarded from the default timing.

Abstract: A hydraulic system for an automatic transmission of a motor vehicle, including a high pressure circuit in which a pressure accumulator, at least one clutch and a gear selector are connected, and comprising a low pressure circuit for cooling the clutch, wherein the high pressure circuit and the low pressure circuit have at least one hydraulic pump that can be driven by an electric motor, and including a control unit that actuates the electric motor of the hydraulic pump when a pressure accumulator charging requirement is detected, wherein the high and low pressure circuits are connected via a bypass line to an integrated accumulator charging valve.

Abstract: A control device generates an operation signal for controlling a pressure of hydraulic oil on a downstream side of the swing motor in a hydraulic device based on an azimuth direction, a swing speed, and a target stopping azimuth direction of a swing body during braking of a swing motor.

Abstract: A thick matter pump includes a hydraulically-driven two-cylinder piston-pump configured to generate a thick matter delivery pressure. The thick matter pump also includes a hydraulic pump configured to apply hydraulic fluid to the two-cylinder piston-pump via a drive line. The hydraulic pump includes a pressure regulator that is adjustable to a target value of pressure of the hydraulic fluid for limiting the thick matter delivery pressure, and the thick matter delivery pressure is adjustably limited. The pressure of the hydraulic fluid is limited in the drive line, via an adjustable pressure-limiting valve, to an adjustable maximum pressure. The target pressure of the pressure regulator and the maximum pressure of the hydraulic fluid are adjustable through a joint adjusting element.

Abstract: An HCU (37) includes a battery low temperature reducing output calculating section (71A) that determines, when it is determined that an electricity storage device (31) is in a low temperature state by a battery temperature Tb, a battery low temperature reducing output PbL that is made to a larger value as the battery temperature Tb is lower, a hydraulic oil low temperature reducing output calculating section (71B) that determines, when it is determined that hydraulic oil is in a low temperature state by a hydraulic oil temperature To, a hydraulic oil low temperature reducing output PoL that is made to a larger value as the hydraulic oil temperature To is lower, and an output command calculating section (80) that controls a vehicle body operation based upon a sum of the battery low temperature reducing output PbL and the hydraulic oil low temperature reducing output PoL.

Abstract: A seal tube assembly of a pump system is provided. The seal tube assembly includes a single seal tube having a first axial end sealably coupled to a first vane pump and a second axial end sealably coupled to a second vane pump. The single seal tube includes transverse contact surfaces at the first axial end and transverse contact surfaces at the second axial end. The single seal tube is formed to define a first seal tube cavity at the first axial end and a second seal tube cavity at the second axial end.

Abstract: A hydraulic driving system includes a flow control valve device, a bleed-off valve device, a discharge pressure sensor, a relief valve, an operating element, and a controller. The controller executes calibration in which: in a state where the bleed-off valve device blocks between a hydraulic pump and a tank, the controller changes a movement command current supplied to the flow control valve device and makes the discharge pressure sensor detect a discharge pressure; the controller detects at least one of an opening start current that is a current when the flow control valve device starts opening and a closing completion current that is a current when closing of the flow control valve device is completed; and based on the detected at least one current, the controller adjusts a correspondence relation between an operation amount of the operating element and the at least one current.

Abstract: Provided are an apparatus and a method for controlling spool displacement of a construction machine, which are capable of improving regeneration efficiency of the construction machine, and improving a fuel efficiency characteristic of the construction machine by reducing pressure loss in the operating mode by adjusting the quantity of spool displacement in a regeneration mode when a current pressure of a main pump is less than a predetermined operating pressure, and determining whether the construction machine is in an operating mode or the regeneration mode in real time according to an operating angle of a joystick and the current pressure of the main pump when the current pressure of the main pump is greater than or equal to the predetermined operating pressure to variably change the quantity of spool displacement in the operating mode.

Abstract: A variable displacement pump supplies hydraulic oil to turning motor via a turning control valve; pair of supply/discharge lines connect turning motor and turning control valve; a pair of make-up lines connect pair of supply/discharge lines to tank, each line having check valve; turning operation device including operating lever and outputting operation signal corresponding to inclination angle of operating lever; a flow rate adjuster adjusts tilting angle of pump; and controller controls flow rate adjuster, such that tilting angle of pump increases in accordance with increase in operation signal outputted from turning operation device. Controller: turning acceleration and at time of constant speed turning, controls flow rate adjuster such that discharge flow rate of pump changes on first regulation line; turning deceleration, controls flow rate adjuster such that discharge flow rate of pump changes on second regulation line, second regulation line having slope less than slope of first regulation line.

Abstract: A fluid working machine of the type comprising working chambers of cyclically varying volume and low and high pressure valves to regulate the flow of working fluid into and out of the working chamber, from low and high pressure manifolds, in which the valves are electronically controlled on each cycle of working chamber volume, by way of valve actuation signals, to determine the net displacement of working chambers. Additional valve actuator signals are generated in response to determination that a valve or working chamber has been inactive to adapt the valve to operate more reliably when subsequently actuated, but without significantly altering the net displacement of working chambers.

Abstract: A hydraulic system for an automatic transmission, in particular a dual-clutch transmission, of a motor vehicle. A high-pressure circuit, in which a pressure accumulator, at least one clutch, and gear selectors are connected, and a low-pressure circuit for cooling the clutch. The high-pressure circuit and the low-pressure circuit have at least one hydraulic pump, which can be driven by an electric motor. The hydraulic system also has a control unit, which activates the electric motor of the hydraulic pump when a requirement to charge the pressure accumulator is identified. The high-pressure and low-pressure circuits are connected via a bypass line to an integrated accumulator charging valve, which in a non-charging position fluidically connects the hydraulic pump to the low-pressure circuit and in a charging position fluidically connects the hydraulic pump to the high-pressure circuit.

Abstract: A control device for an automatic transmission includes: a transmission gear ratio control section configured to control the transmission gear ratio so that a rotation speed of the output element rapidly becomes closer to a rotation speed of the internal combustion engine, a first engagement control section configured to perform a first engagement control to be brought to the full engagement state after the rotation of the internal combustion engine is increased in the slip engagement state while a torque transmission capacity of the lockup clutch is increased when the lockup clutch is switched through the slip engagement state to the full engagement state by an ON operation of an accelerator of the vehicle, the transmission gear ratio control being prohibited during the first engagement control by the first engagement control section.

Abstract: An auxiliary flow adjustment system and method are disclosed for controlling an auxiliary hydraulic function on a machine in accordance with commands from an operator. The auxiliary flow adjustment system includes operator controls that control a hydraulic control valve. The control valve controls flow rate and flow direction to the auxiliary hydraulic function. When the auxiliary flow adjustment system is activated, the operator can use the operator controls to select a desired flow rate and flow direction for the auxiliary function and maintain the desired flow rate and direction without further use of the operator controls. When the flow adjustment system is activated while a non-zero flow rate is selected, the desired flow rate and direction can be set to the current settings. A resume control can retrieve and command the previously stored desired flow rate and direction. Controls can be used to increase and decrease the set flow rate.

Abstract: A heavy-duty lift truck designed as a mast-based apparatus comprising a mast, a load accepting means is mounted on the mast in such a way that it can be raised and lowered, and the heavy-duty lift truck is designed at least for a load capacity of 8 tons, with the heavy-duty lift truck comprising a powertrain with a travel drive that comprises an electric drive unit whereby the heavy-duty lift truck has greater energy efficiency.

Abstract: An operation device includes: an operating unit; a pilot valve that outputs a pilot pressure corresponding to an operating amount of the operating unit; an operating amount detection sensor that outputs an operating amount signal corresponding to the operating amount of the operating unit; a first bar code provided on the pilot valve and containing pilot pressure actual measurement information indicating a relationship between the operating amount of the operating unit and an actual measurement value of the pilot pressure outputted from the pilot valve; and a second bar code provided on the pilot valve and containing operating amount signal actual measurement information indicating a relationship between the operating amount of the operating unit and an actual measurement value of the operating amount signal outputted from the operating amount detection sensor.

Abstract: A fluid system for a machine that includes a linkage. The fluid system includes an actuator, an accumulator, a pilot circuit, and a pressure reducing valve. The actuator is configured to manipulate the linkage. The accumulator is configured to store a fluid discharged by the actuator under pressure. The pilot circuit is fluidly coupled to the accumulator and is configured to receive the fluid from the accumulator. Further, the pressure reducing valve is positioned between the accumulator and the pilot circuit to regulate the pressure of the fluid delivered to the pilot circuit from the accumulator.

Abstract: A method and system is provided for controlling a hydraulic actuator in a work machine by opening a load holding valve in a measured fashion in order to leak hydraulic pressure back into a depressurized portion of the hydraulic circuit, thereby minimizing or eliminating jerkiness in the actuator when the actuator is under an external load.

Abstract: In a hydraulic system which is biased to a minimum system pressure using a bias valve or other flow obstruction disposed in a tank line, there is provided in a bypass line to the bias valve an evacuating and filling valve through which the hydraulic system is first evacuatable and subsequently fillable with a hydraulic fluid. The valve closes the bypass when a differential pressure overcomes a preadjusted force of a spring element. For this purpose, the valve possesses a displaceably mounted valve body with an integrated throttle and a seal face which closes a through opening when the valve body is shifted against the bias force of the spring element due to the pressure difference.

Abstract: Provided is a construction machine including an engine, a hydraulic pump with a supercharger, and a hydraulic actuator, being capable of attaining both of a quick rise of engine speed and an operation of the hydraulic actuator during the rise of the engine speed. The construction machine further includes a supercharging pressure detector to detect a supercharging pressure of the supercharger and a controller to control absorption torque of the hydraulic pump, namely, pump torque. Until engine speed of the engine reaches target engine speed, the controller calculates target pump torque from a predetermined relationship between engine no-load speed and the target pump torque, corrects the target pump torque so as to make it smaller as the detected supercharging pressure is lower, and limits actual pump torque to the corrected target pump torque, until engine speed reaches target engine speed from engine speed lower than the target engine speed.

Abstract: The pumps and pressure controllers described herein aim to pump fluid in two directions, such as from a first port to a second port and vice versa. The pressure controllers aim to control pressure in a system or device, such as a test device, accurately and precisely at a variety of different pressure levels. Generally described, the pumps and pressure controllers described herein may include two or more control valves, which may be actuatable in such a manner so that the pump or pressure controller can switch between operating as a vacuum pump and operating as a compressor. In some embodiments, the pressure controllers may be able to adjust a pressure in the device by small increments thereby providing increased control of the pressure in the device over the prior art. Furthermore, the pressure controllers may be able to control the pressure of a system having low pressure levels.

Abstract: Reach truck 1 with a control system 2 for controlling the lowering movement of a fork 10, the control system 2 comprising a height sensor 20, for determining the lifting height h of the fork 10 of the reach truck 1, a proportional electrical hydraulic valve 50 connected to a lifting cylinder 70 of the reach truck 1, for controlling an oil flow of the lifting cylinder 70, and a control unit 30, connected to the height sensor 20 for receiving the actual lifting height h signal and controlling the proportional electrical hydraulic valve 50, wherein the control unit 30 automatically decreases the maximum lowering speed v of the fork 10, by controlling the proportional electrical hydraulic valve 50, according a predetermined maximum speed v curve depending on the lifting height h of the fork 10, and in some embodiments only on the lifting height h of the fork 10, such that the fork 10 is softly stopped at the ground.

Abstract: A gearbox hydraulic circuit includes a hydraulic pump connected to a fluid reservoir to generate a flow of pressurised fluid. A pressure circuit connected to the hydraulic pump conveys the flow of pressurised fluid. A pressure control valve disposed in the pressure circuit between the first line and the second line of the pressure circuit maintains the pressure of the pressurised fluid in the first line. A shunt connected to the pressure circuit is operable to route the flow of pressurised fluid from the first line to the second line to reduce the pressure in the first line.

Abstract: A hydraulic soft-start system includes a flow control valve which is in fluid communication with a pressure source and an inlet of a motor. The system includes a first flow restricting orifice and a second flow restricting orifice disposed between a pilot for actuating the flow control valve and the inlet of the motor. A first flow is passed from the pressure source via the first orifice to an inlet of the motor, placing the motor in a partially-actuated state. The flow control valve is actuated after a threshold pressure of the pilot is reached allowing a second flow to pass from the pressure source to the motor inlet. The second flow is higher than the first flow, thereby placing the motor in a fully-actuated state.

Abstract: A hydraulic drive circuit is provided that can achieve high responsiveness, high precision, and high efficiency at a low cost in a hydraulic drive system popularly used in an industrial machine such as a press machine, a construction machine, and the like.

Abstract: A method of controlling a pump for a hybrid transmission includes commanding a first line pressure of the transmission and deriving a first torque value—an open-loop torque value—from the first line pressure command, and commanding the pump to operate at the first torque value. The method monitors actual speed of the pump and derives a second torque value—a closed-loop torque value—therefrom. A third torque value is derived from the first and second torque values, and the pump commanded to operate at the third torque value. A first speed value may be derived from the first line pressure command, and the second torque value derived from the difference between the monitored and the first speed values. Deriving the third torque value may include a substantially-linear combination of the first and second torque values.

Abstract: A fluid-working machine has a working chamber of cyclically varying volume, high and low pressure manifolds, and high and low pressure valves for regulating the flow of fluid between the working chamber and the high and low pressure manifolds respectively. A controller actively controls at least one said valve to determine the net displacement of working fluid of the working chamber on a cycle by cycle basis. At least one said valve is a variable timing valve and the controller causes the valve to open or close at a time determined taking into account one or more properties of the performance of the fluid working machine measured during an earlier cycle of working chamber volume.

Abstract: A thermal management system is provided. The thermal management system includes a first hydraulic system for circulating a first hydraulic fluid at a first temperature, a second hydraulic system for circulating a second hydraulic fluid at a second temperature that is higher than the first temperature, and a heat exchanger coupling the first hydraulic system to the second hydraulic system, wherein the heat exchanger is configured to exchange heat between the first hydraulic fluid and the second hydraulic fluid.

Abstract: A hydraulic fluid flow management system and method includes three subsystems. The first subsystem is an engine mounted hydraulic fluid pump electrically operated flow control proportioning valve combination. The second subsystem is a hydraulic fluid flow distribution manifold assembly. The third subsystem is a computer operated controller and display which governs the operation of the electrically operated flow control proportioning valve combination.

Abstract: A work vehicle includes an engine, an idling stop execution portion, a determination portion, a counting portion, and an idling stop time period adjustment portion. The engine can rotate in a first idling state and a second idling state in which the engine rotates at the number of rotations higher than a prescribed number of rotations. The idling stop execution portion performs an idling stop operation for stopping the engine. The determination portion determines whether or not stop has been made from the second idling state. The counting portion counts the number of times of stop of the engine from the second idling state. An idling stop time period adjustment portion makes a prescribed time period of the second idling state longer than a current time period, when the number of times of stop of the engine is equal to or greater than the prescribed number of times.

Abstract: A hydraulic device includes a switch-over valve 1140 provided at a section of a sub-passage 1105 located downstream of a location where a first bypass passage 1117 is connected and located upstream of a primary regulator 1110. The switch-over valve 1140 is switched between a blocked state, where supply of hydraulic oil to a section of the sub-passage 1105 located downstream of the switch-over valve 1140 is blocked, and a communication state, where supply of hydraulic oil to the section of the sub-passage 1105 located downstream of the switch-over valve 1140 is permitted. In the hydraulic device, when the switch-over valve 1140 is switched to the communication state, as a discharge performance of a main pump 1102 increases, a first check valve 1118 closes. Supply paths for hydraulic oil discharged from the sub-pump 1103 are automatically switched in accordance with the discharge performance of the main pump 1102.

Abstract: There is provided a hydraulic circuit which can further improve a responsive characteristic in a pressure reducing operation and a reliability in the pressure reducing operation of a relief valve device, when a main circuit pressure exceeds a predetermined pressure.

Abstract: A circuit pressure control unit includes a relief valve and a variable throttle valve. The relief valve is connected to a connecting passage communicating with an actuator upstream. The variable throttle valve is disposed upstream of the relief valve and is configured to change an opening degree thereof according to a control signal from a controller.

Abstract: An outlet port of a hydraulic pump/motor and a bottom chamber of a lift cylinder are connected to each other by a hydraulic fluid passage. A hydraulic fluid passage that is connected to a hydraulic fluid tank is formed to branch off the hydraulic fluid passage. A flow control valve controls the hydraulic fluid delivered from the lift cylinder when the fork is lowered, thereby regulating the flow rate of hydraulic fluid supplied to the hydraulic pump/motor and the flow rate of hydraulic fluid supplied to the hydraulic fluid tank. If regenerative operation can be performed, the flow control valve is closed and hydraulic fluid is delivered to the hydraulic pump/motor. If regenerative operation cannot be performed, the flow control valve is opened and hydraulic fluid is delivered to the hydraulic fluid tank. In either case, the fork can be lowered at an instructed speed.

Abstract: A fluid pressure control device includes a first control valve that switches to supply a working fluid to the pressure chamber of a cylinder on which a load pressure by the load acts so as to control the extension operation of the cylinder, a second control valve that switches to discharge the working fluid in the pressure chamber so as to control the contraction operation of the cylinder, an operate check valve that is interposed between the pressure chamber and the second control valve and that interrupts the discharge of the working fluid from the pressure chamber when the operate check valve is switched to a closed state and a pilot valve that performs, with a pilot pressure, a pilot operation on the second control valve and that switches, with the pilot pressure, the operate check valve to an opened state.

Abstract: A hydraulic system includes a pump (22) that draws fluid from a reservoir (24) and an actuator (26) having a first port and a second port. A metering valve arrangement (28) controls fluid flow through the actuator and includes a meter-in valve (30a, 30d) positioned between the pump and the first port and a meter-out valve (30b, 30c) positioned between the second port and the reservoir. A controller (34) controls operation of the metering valve arrangement. In a meter-in mode, the controller controls a fluid flow rate through the actuator by controlling an orifice size of the meter-in valve. In a meter-out mode, the controller controls a fluid flow rate through the actuator by controlling an orifice size of the meter-out valve. The controller determines the fluid flow rate through the actuator based on data derived from the meter-out valve in both the meter-in mode and the meter-out mode.

Abstract: The present disclosure relates to a hydraulic system of a construction machine. The hydraulic system of the construction machine includes: an electronic proportional pressure reducing valve configured to control a flow rate, to which a maximum pressure is input as a control current value, and which is set to a minimum flow rate; a gear pump configured to provide pilot operation oil to the EPPRV; a shuttle valve configured to compare a pressure of first pilot operation oil passing through the EPPRV and a pressure of a flow rate control signal, and output second pilot operation oil having the greater pressure; a hydraulic pump of which a swash plate angle is controlled by the second pilot operation oil; and a pump control device configured to control a pressure of the EPPRV to be decreased from a maximum pressure by a predetermined inclination when the flow rate control signal is generated.

Abstract: A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump.

Abstract: A lock valve is switched from lock condition to release condition when a lock member is switched from lock position to release position. When pilot pressure is at least a predetermined pressure when the elapsed time from the point at which the lock member is switched from lock position to release position is at least a first predetermined time, the lock valve is maintained in the release condition. When pilot pressure is at least the predetermined pressure, the continuous time duration is greater than the second predetermined time when the elapsed time is less than the first predetermined time, the lock valve is switched to the lock condition. When pilot pressure is at least the predetermined pressure, the continuous time duration is no more than the second predetermined time when the elapsed time is less than the first predetermined time, the lock valve is allowed to be switched.

Abstract: A cushioned swing circuit provides the reduction of oscillation common in the operation of heavy equipment such as with boom members. The circuit utilizes a transfer of high pressure fluid flow (caused by the inertial of the swing during rapid deceleration) from one leg of the circuit to the other leg of the circuit or to the sump which serves as decompression for the oil that would ordinarily be trapped in the leg. These phenomena create the swing cushioning effect.

Abstract: A load sensing system includes a first assembly of actuators for controlling a first hydraulic function, a pump adapted to supply the actuators with pressurized hydraulic fluid, an electrically controlled valve adapted to control the output pressure of the pump via a hydraulic signal, a first pressure sensor for detecting a load pressure of the first actuator assembly, and a control unit adapted to receive a signal with information about the load pressure detected by the first pressure sensor and to generate a control signal, corresponding to the detected load pressure, to the electrically controlled valve.

Abstract: The invention relates to a power cylinder comprising a piston-in-cylinder unit having at least one pressure connection, an integral valve arrangement for controlling the pressure volume flow from the pressure connection into the cylinder space and an integrated control and/or regulation unit for actuating the valve arrangement.