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2589results about "Servometer circuits" patented technology

Linear actuator assembly and system

A linear actuator system includes a linear actuator and an integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with two fluid drivers, each fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes the pump in a normal mode of operation in which the prime movers are independently driven and switches to a fail-safe mode of operation in which only one prime mover is operated.
Owner:PROJECT PHOENIX LLC

Hydraulic control system of asymmetric hydraulic cylinder

The invention provides a hydraulic control system of an asymmetric hydraulic cylinder, and relates to the technical field of hydraulic control, the hydraulic control system comprises a bidirectional hydraulic pump, a hydraulic motor and an energy accumulator, the bidirectional hydraulic pump is in transmission connection with a first servo motor, and a first oil port and a second oil port of the bidirectional hydraulic pump are connected with a rod cavity and a rodless cavity through a first oil way and a second oil way respectively; a first one-way valve is arranged between the second oil port and the rodless cavity; the hydraulic motor is in transmission connection with the generator which is connected with the electric energy storage unit. The hydraulic motor is connected with the first one-way valve in parallel; the energy accumulator communicates with the first oil way and the second oil way through a second one-way valve and a third one-way valve correspondingly. Four-quadrant seamless switching can be achieved, the structure is simpler, the complexity of a pipeline in a hydraulic system is remarkably reduced, energy collection can be conducted on oil discharged by a rodless cavity, and energy consumption is further reduced.
Owner:TAIYUAN UNIVERSITY OF TECHNOLOGY

Hydraulic pump station oil supply control system and oil supply device thereof

The invention discloses an oil supply control system of a hydraulic pump station, and relates to the technical field of hydraulic systems. The oil supply control system of the hydraulic pump station comprises an oil tank; the oil inlet end of the oil supply pump communicates with the oil tank, and the oil outlet end of the oil supply pump is connected to the oil suction end of the variable plunger pump through an oil supply path; a heat exchanger and a filter are sequentially arranged in the oil supply path and used for conducting temperature adjustment and particle filtration on oil. The oil supply path is connected with a bypass pipeline in parallel, the bypass pipeline is communicated with the oil tank through a one-way valve, the opening pressure of the one-way valve is smaller than 2 bar, and the one-way valve is used for guaranteeing the positive pressure of the oil suction end of the variable pump. The oil outlet end of the variable displacement piston pump is connected to an external hydraulic system and is provided with a high-pressure filter; the detection device is arranged in the oil supply path and used for collecting oil temperature and / or pressure signals; and the control module is connected with the detection device and the execution components and is configured to control the start and stop states of the oil supply pump, the variable displacement piston pump and the heat exchanger according to the comparison result of the detection result and a preset threshold value.
Owner:CHENGDU YUHENG TECH CO LTD

Apparatus for operating a load-controlled hydraulic supply of an agricultural tractor

An apparatus for operating a load-controlled hydraulic supply of an agricultural tractor includes a hydraulic pump which is adjustable with respect to the displacement volume for supplying pressurized hydraulic fluid, a proportional valve which is electrically actuatable, a primary hydraulic consumer to carry out a superordinate hydraulic function and to be directly connected to a conveying outlet of the hydraulic pump, a secondary hydraulic consumer to carry out a subordinate hydraulic function and to be connected to the conveying outlet of the hydraulic pump via the proportional valve, and a control unit configured to move the proportional valve into a closed valve position when the control unit recognizes that at least one of a required power of the primary and secondary hydraulic consumers exceeds the conveying capacity of the hydraulic pump and the subordinate hydraulic function of the secondary hydraulic consumer is inactive.
Owner:DEERE & CO

Work machine

An object of the present invention is to provide a work machine that can increase the operation speed of an actuator by a regenerating function while ensuring accuracy of position control of the actuator. For this purpose, a controller computes a target actuator supply flow rate by subtracting a regeneration flow rate from a target actuator flow rate, computes a target flow control valve opening amount on the basis of the target actuator supply flow rate, computes a target pump flow rate equal to or more than the sum of a plurality of the target actuator supply flow rates, controls flow control valves according to the target flow control valve opening amount, and controls a hydraulic pump according to the target pump flow rate.
Owner:HITACHI CONSTRUCTION MACHINERY CO LTD

Electrically-driven metering pump load-sensitive system, control method and engineering machinery

The invention relates to the technical field of engineering machinery, and particularly discloses an electrically-driven metering pump load-sensitive system, a control method and engineering machinery, the electrically-driven metering pump load-sensitive system comprises a control unit, a driving motor assembly, a metering pump, a pilot hydraulic control unit, a pilot handle assembly, a load-sensitive valve assembly, an actuator assembly, a sensor assembly and a pressure difference control module; the driving motor drives the metering pump to supply oil to the load-sensitive valve assembly so as to drive the actuator assembly to operate; the control unit receives the maximum outlet pressure and the maximum load pressure of the pump collected by the pressure sensor, receives a system target pressure difference signal of the pressure difference control module at the same time, and synchronously controls the rotating speed of the motor and the valve target pressure difference output by the proportional pressure reducing valve. The system aims to solve the problems that a traditional upstream compensation load sensitive system lacks a flow saturation resisting function, and a downstream compensation load sensitive system has extra reversing energy consumption and fixed system pressure difference setting.
Owner:HUAQIAO UNIVERSITY

Intelligent control method for hoisting equipment based on multi-sensor cooperation

The invention relates to the technical field of hoisting equipment intelligent control based on multi-sensor cooperation, and discloses a hoisting equipment intelligent control method based on multi-sensor cooperation. A control unit reads and stores parameters such as air density, windward projection area, wind load arm length, arm section rotational inertia, rated output force of a hydraulic cylinder, sampling period and the like, and static self-inspection and dynamic calibration are performed on a wind speed sensor, a rotary encoder and a pressure sensor respectively; multiple paths of wind speeds are collected in parallel during operation, fused wind speeds are obtained through weighted fusion after abnormities are removed, and the wind load torque is calculated and limited by combining the windward area and the force arm length; reading two continuous encoder angle differences, performing amplitude limiting, calculating an angular velocity and kinetic energy, performing adaptive adjustment according to kinetic energy deviation, and performing amplitude limiting on a damping coefficient to generate a damping torque; and the amplitude-limited wind load torque and damping torque are synthesized into total control torque, and after amplitude limiting, the total control torque is converted into amplitude-limiting hydraulic cylinder operation output force which is issued and executed by a control unit.
Owner:INVAMAND LIFTING EQUIPMENT (ZHEJIANG) CO LTD

Rate matching hydraulic actuators on common control manifold

An actuation assembly includes a control valve, a first actuator and a second actuator fluidly connected to the control valve via plumbing. The first actuator has a first extend port and the second actuator having a second extend port. A flow control device fluidly connected to the first actuator and the second actuator is operable to balance a flow rate of a fluid at the first actuator with the flow rate of the fluid at the second actuator. The flow control device is arranged within the plumbing, at a position between the control valve and the first extend port and the second extend port.
Owner:HAMILTON SUNDSTRAND CORP

Crane upper and lower structure interlocking system, and crane

Disclosed in the present invention are a crane upper and lower structure interlocking system, and a crane. In the system, a third-stage pump of a hydraulic pump set is connected to an oil inlet P of an outrigger extension and retraction valve, and an extension and retraction switching valve in the outrigger extension and retraction valve is connected to the oil inlet P of the outrigger extension and retraction valve. A first working oil port and second working oil port of a locking valve are both connected to a fifth working oil port of the extension and retraction switching valve; a third working oil port of the locking valve is connected to a rod cavity of each of a horizontal oil cylinder, a vertical oil cylinder and a fifth outrigger oil cylinder; and a fourth working oil port of the locking valve is connected to a sixth working oil port of the extension and retraction switching valve. When a boom is in a non-stowed state, the locking valve is deenergized and operates in a right-hand position; at this moment, regardless of whether the extension and retraction switching valve is in an upper position or a lower position, an oil outlet thereof is directly connected to an oil return port through the locking valve to enable pressure unloading, and the horizontal oil cylinder, the vertical oil cylinder and the fifth outrigger oil cylinder remain motionless, thereby achieving locking. The present invention can achieve unloading of an oil inlet line when misoperation of an outrigger handle occurs during upper-structure operation, achieving the locking function against misoperation.
Owner:XUZHOU HEAVY MASCH CO LTD

Hydraulic system for working machine, and working machine

A hydraulic system includes a prime mover, a variable displacement first hydraulic pump to be driven by the prime mover to deliver hydraulic fluid, a first hydraulic actuator to be driven by fluid delivered by the first hydraulic pump, a variable displacement second hydraulic pump to be driven by the prime mover to deliver hydraulic fluid, a second hydraulic actuator to be driven by fluid delivered by the second hydraulic pump, and first and second restrictors configured or programmed to restrict an output of the respective first and second hydraulic pumps based on a load on the prime mover. The first restrictor is configured or programmed to change an output restriction of the first hydraulic pump based on priority information about the first and second hydraulic actuators and / or the second restrictor is configured or programmed to change an output restriction of the second hydraulic pump based on the priority information.
Owner:KUBOTA CORP

Plunger pump system, control method and filter press

The invention relates to a plunger pump system, a control method and a filter press. The plunger pump system comprises an oil storage container, an oil pump device, a plunger device and a hydraulic device. The hydraulic device comprises two hydraulic assemblies, each hydraulic assembly comprises an oil cylinder and a piston, the piston divides the oil cylinder into a rod cavity and a rodless cavity, and the rod cavities of the two hydraulic assemblies or the rodless cavities of the two hydraulic assemblies are communicated with each other. The oil pump device and the hydraulic device are connected through an oil supply pipeline, a liquid flow reversing device and a one-way valve are connected to the oil supply pipeline, the flow direction of hydraulic oil in two branch pipelines of the oil supply pipeline is controlled by the liquid flow reversing device to be periodically switched, and the flow directions of the hydraulic oil in the branch pipelines are opposite at the same moment. One end of the electric control overflow device is connected between an oil pump device and a one-way valve, the other end of the electric control overflow device is connected with an oil storage container, and the electric control overflow device is controlled to conduct an oil outlet of the oil pump device and the oil storage container during reversing of the liquid flow reversing device and discharge impact of hydraulic oil reversing on the plunger pump system.
Owner:WENZHOU UNIV OUJIANG COLLEGE +1

Hydraulic pressure control unit

The present invention obtains a hydraulic pressure control unit capable of accurately evaluating viscosity of a hydraulic fluid.The hydraulic pressure control unit according to the present invention includes a controller including an evaluation section that evaluates the viscosity of the hydraulic fluid. The evaluation section evaluates the viscosity on the basis of a reduced amount of a current value of a current flowing through a wire (314) at a time when the current value is temporarily reduced in a process in which the current value is increased toward a target current value at beginning of application of the current to the wire (314) of an electromagnetic valve (31).
Owner:ROBERT BOSCH GMBH

Paper-plastic mold positioning auxiliary system for monitoring hydraulic pressure in real time through AI

The invention discloses a paper-plastic mold positioning auxiliary system capable of monitoring hydraulic pressure in real time through an AI. The paper-plastic mold positioning auxiliary system comprises an AI control center, a hydraulic monitoring unit, an air pressure monitoring unit, a positioning auxiliary execution unit, an abnormity protection unit and a data acquisition and transmission module. The hydraulic monitoring unit is used for collecting hydraulic oil cylinder pressure, temperature, hydraulic oil viscosity and equipment operation duration data; the air pressure monitoring unit collects air pressure, flow and valve delay time data of a pipeline valve; the data acquisition and transmission module transmits data to the AI control center, and the AI control center analyzes abnormity through a model and calculates a correction amount; the positioning auxiliary execution unit coordinates the positioning of the servo motor and the hydraulic oil cylinder; and the abnormal protection unit receives the early warning and starts a protection action. The system solves the problems of hydraulic monitoring lag and the like, realizes hydraulic and air pressure cooperative monitoring and positioning compensation, ensures production coherence and equipment safety, and is adaptive to automatic production of paper-plastic molds.
Owner:FOSHAN CITY MEIWANBANG TECH CO LTD

Impact-cutting composite rock breaking hydraulic system and method for mining heading machine

According to the impact-cutting composite rock breaking hydraulic system and method for the mining heading machine, hydraulic damping and impact hammer collaborative operation are integrated, and the problems that a traditional heading machine is low in rock breaking efficiency, poor in stability and insufficient in adaptability are solved. The system comprises a cutting arm hydraulic damping system and an impact hammer hydraulic impact system, and multi-parameter closed-loop regulation and control are achieved through a controller. The device is characterized in that a double overflow protection mechanism is adopted, a proportional overflow valve and an external control overflow valve cooperate with each other, a hydraulic control one-way valve is combined for compensating an oil path, and the pressure difference of a hydraulic cylinder is dynamically kept stable; the impact hammer system adjusts the pressure of an energy accumulator through a proportional pressure reducing valve and is matched with a hydraulic control switch valve to realize variable impact energy control; based on feedback of a vibration sensor and a pressure sensor, damping and impact parameters of the cutting arm are adjusted in a self-adaptive mode through a nonlinear algorithm, and intelligent rock breaking operation under different rock stratum hardness is achieved. According to the system, the impact resistance stability, the rock breaking efficiency and the operation intelligence level of the heading machine are remarkably improved.
Owner:ANHUI UNIV OF SCI & TECH

Digital hydraulic system and control method

The invention discloses a digital hydraulic system and a control method. The system comprises a digital hydraulic valve, at least one hydraulic pump assembly and a controller. The digital hydraulic valve comprises at least one working unit, and each working unit comprises a main valve, a front differential pressure compensator and a pilot driving module used for driving and controlling the position of a valve element of the main valve. The differential pressure compensator adopts electric proportional control; the pilot driving module comprises a valve element displacement sensor used for detecting the actual displacement of a valve element of the main valve. The hydraulic pump assembly comprises a hydraulic pump, a variable displacement mechanism, a lead screw and a servo motor, the servo motor converts rotary motion into linear motion through the lead screw to directly control the variable displacement mechanism, and displacement control over the hydraulic pump assembly is achieved. An outlet of the hydraulic pump is connected to an inlet of the differential pressure compensator, an outlet of the differential pressure compensator is connected to an inlet of the working linkage main valve, and a working opening of the working linkage main valve is connected with the oil cylinder or the motor. And the servo motor, the differential pressure compensator and the pilot driving module are respectively in signal connection with the controller.
Owner:JIANGSU ADVANCED CONSTR MASCH INNOVATION CENT LTD

Hydraulic drive apparatus

A hydraulic drive apparatus includes a hydraulic pump that discharges a working fluid; a flow dividing valve that divides a pump passage connected to the hydraulic pump into first and second passages, and changes an opening degree of each passage according to a signal that is input to the flow dividing valve; a travel system hydraulic circuit that is connected to the first passage and controls a flow of the working fluid to a travel motor; a loading system hydraulic circuit that is connected to the second passage and controls a flow of the working fluid to a loading actuator; a pressure sensor that detects a pressure supplied to the travel motor; and a control device that controls, by outputting the signal to the flow dividing valve, the opening degree of the first and second passages according to the pressure detected by the pressure sensor.
Owner:KAWASAKI JUKOGYO KK

Deceleration control method for high-speed motor-driven hydraulic system

The invention relates to the technical field of logistics warehouse storage equipment, in particular to a speed reduction control method for a high-speed motor driven hydraulic system, which comprises the following steps: S1, the output torque of a high-speed motor is transmitted to a gear pump through a motor shaft, a planetary reducer and a planet carrier in sequence to drive the gear pump to work; s2, acquiring a three-phase current instantaneous signal and a direct current bus voltage signal, and performing preprocessing and frequency spectrum conversion to determine a current frequency spectrum; s3, in the current frequency spectrum, extracting an energy value in a preset frequency band with the meshing frequency and harmonic waves of the planetary gear as the center, and calculating to obtain a disturbance characterization value of the planetary gear; s4, determining a torque smooth adjustment coefficient according to the planet wheel disturbance characterization value; and S5, dynamically adjusting a dynamic response parameter of a torque control ring of the high-speed motor according to the torque smooth adjustment coefficient. The problems that in the prior art, a high-rotating-speed motor and a hydraulic pump are not matched in rotating speed, and mechanical disturbance is difficult to restrain are solved.
Owner:ZHEJIANG POTENTIAL DRIVE INTELLIGENT CONTROL EQUIPMENT CO LTD

Novel energy-saving efficient rail unloading device hydraulic system

The invention discloses a novel energy-saving efficient hydraulic system of a rail unloading device. The novel energy-saving efficient hydraulic system comprises a hydraulic oil tank, a plunger pump set, a conveyor, a winch, a cooling mechanism and a radiator. The conveyor comprises bottom supporting wheels, conveying pressing wheels are arranged over the bottom supporting wheels, each conveying pressing wheel is provided with a pair of rail pressing oil cylinders, and the conveying pressing wheels are pressed on the steel rails through the rail pressing oil cylinders for conveying; the liquid inlet end of the plunger pump set is communicated with the hydraulic oil tank through a pipeline, the liquid outlet end of the plunger pump set is communicated with the motor liquid supply subsystem and the cylinder body liquid supply subsystem, the liquid outlet end of the winch motor is communicated with the liquid inlet end of the cooling mechanism through a liquid return pipeline, and the liquid outlet ends of the two conveying motors are communicated with the liquid inlet end of the cooling mechanism through the liquid return pipeline. The liquid outlet end of each rail pressing oil cylinder communicates with the liquid inlet end of the cooling mechanism through a liquid return pipeline, the liquid outlet end of the cooling mechanism communicates with the liquid inlet end of the radiator, the liquid outlet end of the radiator communicates with the hydraulic oil tank, the rail pressing oil cylinders, the rail conveying machine and the winch can be driven, and high efficiency and energy saving are achieved.
Owner:CRRC SHENYANG CO LTD

Electrically driven hydraulic work machine

In a hydraulic drive system used for an electrically driven hydraulic work machine that drives a hydraulic pump by an electric motor and supplies a hydraulic fluid to plural actuators to carry out work, the power consumption of the hydraulic pump is kept from exceeding a value decided in advance. For this purpose, a controller calculates target power to be consumed by the hydraulic pump on the basis of the capacity of the hydraulic pump, the delivery pressure of the hydraulic pump sensed by a pressure sensor, and a target revolution speed of the electric motor, and limits the target revolution speed of the electric motor in such a manner that the target power falls within a range of the maximum allowable power.
Owner:HITACHI CONSTRUCTION MACHINERY TIERRA CO LTD

Hydraulic fluid release valve assemblies

Hydraulic fluid release valve assemblies are described herein. The hydraulic fluid release valve assemblies may include a hydraulic unit base with a hydraulic fluid return channel and a hydraulic fluid release valve that is at least partially inserted in the hydraulic fluid return channel. The hydraulic fluid release valve assembly may further include a driving assembly to contact with the hydraulic fluid release valve to apply a pushing force on the hydraulic release valve to open the hydraulic fluid release valve, and an electrically powered driver connected to the driving assembly, the electrically powered driver, when actuated, causes the driving assembly to move to apply the pushing force to the hydraulic fluid release valve.
Owner:ROADTEK ENTERPRISES INC

Work machine

A work machine includes a flow control valve that controls the flow rate of a hydraulic operating fluid supplied from a hydraulic pump to a hydraulic cylinder, a solenoid valve that generates an operation pressure for operating the flow control valve, and a controller. The controller executes learning processing of changing in a stepwise manner the operation pressure generated by the solenoid valve, sensing the pressure of the hydraulic cylinder, and storing the operation pressure when the pressure of the hydraulic cylinder has become a reference value, as a learning result operation pressure. The controller calculates a differential pressure across the flow control valve and computes a target opening area of the flow control valve on the basis of the differential pressure across the flow control valve and a target flow rate of the hydraulic operating fluid that passes through the flow control valve. The controller computes a target value of the operation pressure generated by the solenoid valve, on the basis of an opening characteristic table, the target opening area, and the learning result operation pressure, and controls the solenoid valve on the basis of the target value of the operation pressure.
Owner:HITACHI CONSTRUCTION MACHINERY CO LTD

Portable Fluid Tank System with Multi-State Control Interface and Remote Operation

A portable fluid tank system can include wireless control capabilities. The portable fluid tank system can include a fluid tank with an internal volume for fluid storage and a fluid actuation system for controlled fluid movement and pressurization. An electronics housing within the portable fluid tank system can accommodate a removable energy storage device, providing power to the actuation system. The portable fluid tank system can include a multi-state control interface, facilitating direct user interaction or remote operation via a wireless communication module. The module can receive and execute commands from a remote transmitting device, enabling remote activation and control of the fluid actuation system.
Owner:BLACK & DECKER CORP

Hydraulic system and passenger restraint system

A hydraulic system for a passenger restraint device includes a hydraulic pump and a hydraulic section. The hydraulic section includes a hydraulic accumulator, a valve arrangement and a hydraulic cylinder unit with a piston. The valve arrangement is connected to the hydraulic pump, the hydraulic accumulator and the hydraulic cylinder unit. The piston can be moved between an open position and a first closed position. The hydraulic pump can pressurize the hydraulic cylinder unit so that the piston moves from the first closed position to the open position. The hydraulic accumulator is configured so that the piston moves from the open position to the first closed position. The hydraulic cylinder unit can be pressurized in a first switching position of the valve arrangement with a first pressure stage and in a second switching position of the valve arrangement with a second pressure stage lower than the first pressure stage.
Owner:HAWE HYDRAULIK SE

Hydraulic control system and control method for turnover plow

The invention relates to the technical field of turnover plow hydraulic control, in particular to a turnover plow hydraulic control system and method, and the structure of the turnover plow hydraulic control system comprises a main control valve; the main valve communicates with the main control valve, and a throttling opening is formed in the end of the main valve; the first reversing valve is communicated with the main valve; the second reversing valve is communicated with the main valve; a large cavity of the amplitude modulation oil cylinder is communicated with the second reversing valve, and a small cavity of the amplitude modulation oil cylinder is communicated with the first reversing valve; a large cavity of the overturning oil cylinder is communicated with the first reversing valve, and a small cavity of the overturning oil cylinder is communicated with the second reversing valve; the pilot valve is communicated with the throttling opening of the main valve; the amplitude modulation oil cylinder and the overturning oil cylinder can be locked with each other and act in sequence. According to the hydraulic control system and method for the turnover plow, the problem that an existing turnover plow is complex to control can be solved.
Owner:LOVOL HEAVY IND CO LTD

Working machine

A working machine includes: at least one support member connectable to a work attachment to do work by making contact with an object to be contacted; at least one hydraulic cylinder to move the work attachment connected to the at least one support member, a rod-side pressure detector to detect a rod-side hydraulic pressure of hydraulic fluid in communication with a rod-side fluid chamber of the at least one hydraulic cylinder; a bottom-side pressure detector to detect a bottom-side hydraulic pressure of hydraulic fluid in communication with a bottom-side fluid chamber of the at least one hydraulic cylinder; and a controller to calculate a relationship in pressure between the rod-side hydraulic pressure and the bottom-side hydraulic pressure and evaluate, based on the calculated relationship in pressure, a contact state which is a state of contact of the work attachment with the object.
Owner:KUBOTA CORP

Electric drive for a vehicle

An electric drive for a vehicle comprises: an electric machine, a stator connected to a housing and comprising stator end-windings, a rotor rotatable relative to the stator, and a driveshaft connected to the rotor; a transmission to transmit a rotary movement from the driveshaft to a driveline; a sump containing fluid to cool and / or lubricate the electric machine and the transmission; a hydraulic arrangement comprising at least one bi-directional pump, a first suction line hydraulically connected with the pump, a stator path for cooling the stator, a second suction line connected with the pump, and a transmission path for cooling the transmission; a valve arrangement with multiple valves configured such that fluid is either supplied from the sump through the first suction line to the stator path, or through the second suction line to the transmission path.
Owner:GKN AUTOMOTIVE LTD

Hydraulic-pump flow-rate calibration system

A hydraulic-pump flow-rate calibration system includes: a variable capacitance type hydraulic pump that supplies an operating fluid to a hydraulic actuator; a regulator that changes the dispense flow rate of the hydraulic pump according to a flow rate command signal; a flow rate detection device that detects the flow rate of the operating fluid; a control device that outputs the flow rate command signal to the regulator to control the regulator; and a calibration device that calculates an actual measurement characteristic of the dispense flow rate for the flow rate command signal, and performs, on a preset reference characteristic, calibration based on the actual measurement characteristic. The actual measurement characteristic is calculated as a result of the flow rate of the operating fluid being detected by the flow rate detection device during output of a predetermined flow rate command signal from the control device to the regulator.
Owner:KAWASAKI JUKOGYO KK

Contractile and extensile fluidic artificial muscle actuator

A fluidic artificial muscle actuator may include at least one inflatable bladder defining a first inflatable segment coupled to a first member and to a second member arranged at opposite ends of the first inflatable segment, and a second inflatable segment coupled to a third member and to a fourth member arranged at opposite ends of the second inflatable segment, and an effector coupled to the first inflatable segment and to the second inflatable segment for providing an actuator output. The first inflatable segment is configured to contract in a longitudinal direction with increase in fluid pressure in the first inflatable segment and the second inflatable segment is configured to extend in the longitudinal direction with increase in fluid pressure in the second inflatable segment.
Owner:KATHOLIEKE UNIV LEUVEN

Constant pressure and load sensitive switching hydraulic control system and control method

The invention discloses a constant pressure and load sensitive switching hydraulic control system and method, and belongs to the technical field of hydraulic control, the constant pressure and load sensitive switching hydraulic control system comprises a power mechanism, a variable pump and an oil tank, the variable pump comprises a load sensitive valve, the load sensitive valve is connected with a shuttle valve outlet of a shuttle valve, and an electric proportional overflow valve is connected with the variable pump; the electric proportional overflow valve is further connected with a first inlet of the shuttle valve, a P port of the reversing valve is connected with the variable pump, and an A port of the reversing valve is connected with a second inlet of the shuttle valve; the pressure sensor assembly is used for reading the outlet pressure of the variable pump and transmitting the outlet pressure to the controller. The pressure sensor assembly is further used for reading the load-sensitive feedback pressure and transmitting the load-sensitive feedback pressure to the controller. Constant pressure and negative sensitive switching is automatically carried out along with increase of the load pressure, the load-sensitive system can be prevented from working under the low-pressure condition, and the problems that under the low-pressure condition, an execution element of the load-sensitive system is slow in action, and the system efficiency is low can be effectively solved.
Owner:CHINA RAILWAY CONSTR HEAVY IND

Load-controlled hydraulic supply for an attachment attached to an agricultural tractor

A load-controlled hydraulic supply for an attachment attached to an agricultural tractor includes a hydraulic high-pressure source providing a volume flow in a supply line, a return line leading to a hydraulic reservoir, and a load-indicating line connected to a device for pressure limiting. The volume flow is adjusted based on pressure feedback prevailing at the load-indicating line.
Owner:DEERE & CO