CN111852810B

CN111852810B - Two-dimensional pressure servo variable pump

Info

Publication number: CN111852810B
Application number: CN201910361010.0A
Authority: CN
Inventors: 阮健; 郑飞侠; 王熙; 宋占凯; 赵建涛; 吴圣; 孟彬
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2024-11-26
Anticipated expiration: 2039-04-30
Also published as: CN111852810A

Abstract

A two-dimensional pressure servo variable pump comprises a front cover, a pump body, a rear cover, a duplex plunger pump, and a pressure servo variable mechanism; the pressure servo variable mechanism comprises a two-dimensional pulse width modulation mechanism and a two-dimensional pressure servo valve; the duplex plunger pump comprises a two-dimensional pulse width modulation mechanism and a two-dimensional pressure servo valve; a driving gear, a driven gear, and a deep groove ball bearing are arranged in the front cover, the driving gear is fixedly connected to a motor coupling, and the driven gear is fixedly connected to the two-dimensional pulse width modulation mechanism; the duplex plunger pump comprises an upper pump core and a lower pump core; both left and right ends of the upper cylinder body of the upper pump core are fixedly connected to an upper left guide rail and an upper right guide rail having the same equal acceleration and equal deceleration curved surface track, and the phase difference between the upper left guide rail and the upper right guide rail is 90 degrees; the transmission shaft shift fork of the two-dimensional pulse width modulation mechanism cooperates with a roller assembly to shift a first valve core through a roller shaft, and the first valve core rotates circumferentially in a first valve sleeve while sliding axially, and the rotation and axial sliding of the first valve core are relatively independent.

Description

Two-dimensional pressure servo variable pump

Technical Field

The invention relates to a pressure servo variable pump, in particular to a pressure adjustable constant pressure servo variable pump, which belongs to a hydraulic pump and a hydraulic motor in the field of fluid transmission and control.

Background

In the working process of the plunger pump, the plunger reciprocates in the cylinder body to change the sealed working volume, thus completing the oil sucking and discharging processes. Each plunger cavity of the axial plunger pump is periodically switched back and forth between the oil suction port and the oil discharge port, and the switching process of the oil ports is realized through a flow distribution mechanism of the pump.

The axial plunger pump mainly has two flow distribution modes of valve flow distribution and end face flow distribution. The valve flow distribution is realized mainly by a one-way valve, but the one-way valve has certain opening pressure and has certain hysteresis in response. The end face flow distribution requires the cylinder body of the pump to rotate so that the plunger cavity is alternately communicated with the oil sucking and discharging window on the flow distribution plate to suck and discharge oil. The plunger pump cylinder body is provided with a plurality of plunger holes, the diameter of the cylinder body is larger, and the high pressure and high rotating speed are required to be higher in design requirements on the key friction pair of the cylinder body and the valve plate, so that the design difficulty is increased. The inclination angle of the swash plate of the axial plunger pump is generally required to be within 20 degrees, so that the range of flow distribution is limited.

The variable actuating mechanism of the traditional servo pump mostly controls a hydraulic cylinder through a servo valve to drive a variable mechanism of the pump to realize variable displacement. The working oil of the variable mechanism is directly supplied by the system or is supplied by a small pump coaxial with the variable pump. The mode is mature in technology and good in response performance, but the additional hydraulic actuating mechanism is complex in structure, and the system failure rate is increased.

The existing two-dimensional pumps all adopt valve groups such as two-dimensional unloading valves, two-dimensional pressure stabilizing valves and the like to realize pressure and flow regulation, and have more parts, more control and regulation positions and larger pressure flow pulsation.

Compared with a common plunger pump, the invention has the advantages of simple flow distribution process and wide flow distribution range; compared with a common servo pump, the system pressure and flow distribution is realized through the pressure servo variable mechanism, the system pressure is constant and adjustable, a servo motor or a complex hydraulic actuating mechanism is not needed, the structure is novel and compact, the adjusting range is wide, the continuous adjustment is realized, the sensitivity is high, and the response speed is high.

Disclosure of Invention

In order to overcome the defects of low response speed, complex structure, small adjustment range, more complex hydraulic actuating mechanism, more parts required by a two-dimensional servo pump flow distribution structure, more control adjustment positions, larger pressure pulsation and the like of a traditional plunger pump flow distribution mode, the invention provides the two-dimensional pressure servo variable pump with the advantages of novel and compact structure, small volume, light weight, adjustable pressure, high pressure sensitivity, high response speed and the like.

The technical scheme adopted by the invention is as follows:

two-dimensional pressure servo variable pump, its characterized in that: comprises a front end cover, a pump body, a rear end cover, a duplex plunger pump and a pressure servo variable mechanism. The pressure servo variable mechanism comprises a two-dimensional pulse width modulation mechanism and a two-dimensional pressure servo valve.

The front end cover is fixedly connected with the pump body through screws; the rear end cover is fixedly connected with the pump body through screws; the duplex plunger pump is fixed in the pump body; the two-dimensional pulse width modulation mechanism and the two-dimensional pressure servo valve are fixedly connected with the pump body through screws.

And a driving gear, a driven gear and a first deep groove ball bearing are arranged in the front end cover, the driving gear is fixedly connected with a motor coupler, and the driven gear is fixedly connected with a two-dimensional pulse width modulation mechanism.

The pump body is provided with an oil inlet hole, an oil outlet hole, a first through hole, a second through hole and a third blind hole. The oil outlet is arranged at the top of the pump body, the first through hole is arranged at the lower part of the pump body and is communicated with the oil inlet, and the duplex plunger pump is arranged. The second through hole is arranged at the upper part of the pump body and is provided with a two-dimensional pulse width modulation mechanism. The third blind hole is arranged on the upper part of the pump body and is provided with a two-dimensional pressure servo valve.

The duplex plunger pump comprises an upper pump core and a lower pump core, wherein the upper pump core is close to the front end cover, and the lower pump core is close to the rear end cover.

The upper pump core comprises an upper cylinder body, an upper plunger, an upper left end structural shaft, an upper right end structural shaft, a first concentric ring, a second concentric ring, an upper left guide rail, an upper right guide rail and a first positioning pin. The upper plunger is arranged in the upper cylinder body, the left end and the right end of the upper plunger are respectively fixedly connected with an upper left end structural shaft and an upper right end structural shaft by first locating pins, and the left side and the right side of the upper plunger are respectively provided with a first concentric ring and a second concentric ring. The left end and the right end of the upper cylinder body are fixedly connected with an upper left guide rail and an upper right guide rail which are provided with equal acceleration and deceleration curved surface rails, the equal acceleration and deceleration curved surface rails of the upper left guide rail and the upper right guide rail are in 90-degree staggered positions in the circumferential direction, namely the highest point and the lowest point of the equal acceleration and deceleration curved surface rails of the upper left guide rail are respectively corresponding to the lowest point and the highest point of the equal acceleration and deceleration curved surface rails of the upper right guide rail.

A shoulder is arranged in the middle of the upper plunger, four rectangular distribution grooves which are uniformly distributed are formed in the surface of the upper plunger, and the notch positions of the four rectangular distribution grooves are staggered.

Four flow distribution windows are uniformly distributed on the upper cylinder body, two oil inlets and two oil outlets are respectively arranged alternately, the oil inlets and the oil outlets are communicated with low-pressure oil, the oil outlets are communicated with high-pressure oil, and the oil inlets and the oil outlets are not communicated with each other. And two sides of the oil outlet are sealed by sealing rings. The flow distribution window is arranged corresponding to the flow distribution groove on the upper connecting plunger.

The upper left end structure shaft comprises a first structure shaft main body, a first large roller, a second large roller, a first small roller pair and a second small roller pair. The second large roller and the first large roller have the same structure to form a first large roller group. The second small roller pair and the first small roller pair have the same structure and form a first small roller group. The first large roller comprises a conical roller bearing sleeve and a second deep groove ball bearing, wherein the outer part of the conical roller bearing sleeve is a conical surface, the inner part of the conical roller bearing sleeve is a round hole, and an inner hole of the conical roller bearing sleeve is sleeved on the outer circle of the second deep groove ball bearing and fixedly connected with the outer circle of the second deep groove ball bearing. The first small roller pair comprises a large cylindrical roller and a small cylindrical roller, the large cylindrical roller comprises a cylindrical bearing sleeve and a third deep groove ball bearing, the outside of the cylindrical bearing sleeve is a cylinder, the inside of the cylindrical bearing sleeve is a round hole, and an inner hole of the cylindrical bearing sleeve is sleeved on the outer circle of the third deep groove ball bearing and fixedly connected with the outer circle of the third deep groove ball bearing. The small cylindrical roller comprises a cylindrical roller sleeve and a copper sleeve, wherein the outside of the roller sleeve is a cylinder, the inside of the roller sleeve is a round hole, and an inner hole of the roller sleeve is sleeved on the outer circle of the copper sleeve and fixedly connected with the copper sleeve. The first large roller and the second large roller are fixedly connected to two ends of the first structural shaft main body through nuts and are arranged in an axisymmetric mode. The first small roller pair and the second small roller pair are fixedly connected to two ends of the first structural shaft main body through second locating pins and are arranged in a central symmetry mode.

The upper right end structure shaft and the left end structure shaft are identical in structure.

The rolling surfaces of the large roller groups of the upper left end structure shaft and the upper right end structure shaft are respectively matched with the corresponding upper left guide rail and upper right guide rail, and the rolling surfaces of the small roller groups of the upper left end structure shaft are matched with the tracks of the motor coupler; the rolling surface of the small roller group of the upper-connected right-end structural shaft is matched with a track carried by a shifting fork structure of the third structural shaft main body.

The space enclosed by the first concentric ring, the upper connecting plunger and the upper connecting cylinder body together forms a first left cavity, the space enclosed by the second concentric ring, the upper connecting plunger and the upper connecting cylinder body together forms a first right cavity, and the volumes of the first left cavity and the first right cavity are staggered along with the reciprocating motion of the plunger.

The lower pump core comprises a lower cylinder body, a lower plunger, a lower left end structural shaft, a lower right end structural shaft, a third concentric ring, a fourth concentric ring, a lower left guide rail, a lower right guide rail and a third positioning pin. The lower plunger is arranged in the lower cylinder body, the left end and the right end of the lower plunger are respectively fixedly connected with a lower left end structural shaft and a lower right end structural shaft through third locating pins, and the left side and the right side of the lower plunger are respectively provided with third concentric rings and fourth concentric rings. And the left end and the right end of the lower cylinder body are fixedly connected with a lower left guide rail and a lower right guide rail which are provided with equal acceleration and deceleration curved surface tracks. The arrangement mode of the lower left guide rail and the lower right guide rail is the same as that of the upper left guide rail and the upper right guide rail.

The lower connecting cylinder body and the upper connecting cylinder body are identical in structure.

The lower plunger is identical to the upper plunger in structure, and the upper plunger and the lower plunger are concentrically arranged.

The lower left end structure shaft comprises a third structure shaft main body and a third large roller group. The third structure shaft main body is provided with a shifting fork structure and is matched and connected with the small roller group of the upper connecting right end structure shaft, so that the upper connecting pump core and the lower connecting pump core are staggered by 45 degrees in space. The right end structure shaft of the lower link comprises a fourth structure shaft main body and a fourth large roller group. The third large roller group and the fourth large roller group are identical to the first large roller group of the upper left end structural shaft in structure and are identical in placement mode. The rolling surfaces of the third large roller group and the fourth large roller group of the lower left end structural shaft and the lower right end structural shaft are respectively matched with the lower left guide rail and the lower right guide rail on the lower cylinder body.

The space enclosed by the third concentric ring, the lower connecting plunger and the lower connecting cylinder body together forms a second left cavity, the space enclosed by the fourth concentric ring, the lower connecting plunger and the lower connecting cylinder body together forms a second right cavity, and the volumes of the second left cavity and the second right cavity are staggered along with the reciprocating motion of the plunger.

When the duplex plunger pump works, because the upper right end structure shaft is connected with the lower left end structure shaft in a matched manner, the upper plunger and the lower plunger are made to rotate circumferentially together, and the large roller groups of the upper left and right structure shafts and the large roller groups of the lower left and right structure shafts are arranged on the left equal acceleration and deceleration curved surface rails and the right equal acceleration and deceleration curved surface rails respectively, when the large roller groups rotate circumferentially, the upper plunger and the lower plunger are constrained by the curved surface rails and do reciprocating motion in the axial direction. Along with the reciprocating motion of the plunger, the volumes of the first left chamber, the first right chamber, the second left chamber and the second right chamber are changed in a staggered way, the distributing grooves on the plunger are communicated with the distributing windows on the corresponding cylinder body in an alternating way, the chambers with gradually increased volumes absorb oil from the oil tank, and the chambers with gradually reduced volumes discharge oil outwards, so that continuous oil absorption and discharge are realized.

The two-dimensional pulse width modulation mechanism is characterized in that: the novel valve comprises a transmission shaft, a zero spring, a roller shaft, a left roller assembly, a right roller assembly, a front concentric ring, a first valve core, a first valve sleeve, a rear concentric ring and a first valve core plug. The transmission shaft shifting fork and the roller assembly are matched to shift the first valve core through the roller shaft, so that the first valve core axially slides while circumferentially rotating in the first valve sleeve, the first valve core rotates and axially slides relatively independently, the front concentric ring and the rear concentric ring are respectively fixedly connected to two ends of the first valve sleeve, and the zero spring is arranged between the first valve core and the transmission shaft and is in a compression state.

One end of the transmission shaft is a cylindrical end and is connected with the transmission mechanism; the other end of the transmission shaft is in a door frame shape, two U-shaped shifting forks are connected, the shifting fork surface is an axial incomplete cylindrical surface track, and the left roller assembly and the right roller assembly are matched, so that the first valve core axially slides while rotating circumferentially; the axial middle end surface of the transmission shaft is provided with a circular groove for fixing the zero spring.

The two flat end surfaces of the zero spring are respectively fixed at the circular groove of the transmission shaft and the stepped shaft at the left end of the first valve core, the zero spring is in a compressed state in the initial and working processes, the first valve core in the initial state is guaranteed to be at the rightmost end, and the zero position of the first valve core is maintained.

The roller shaft is a stepped cylindrical shaft, a shoulder is arranged in the middle of the roller shaft, and the diameter of the middle cylinder is larger than that of the cylinders on the two sides; the middle shoulder shaft is inserted into a cylindrical hole at the left end of the first valve core and fixedly connected, and the two end shafts are respectively inserted into central round holes of the left roller assembly and the right roller assembly and fixedly connected.

The right roller assembly and the left roller assembly are identical in structure and comprise a first bearing sleeve and a fourth deep groove ball bearing, the outer portion of the first bearing sleeve is a spherical surface, the inner portion of the first bearing sleeve is a round hole, the two ends of the first bearing sleeve are flat end surfaces, an inner hole of the first bearing sleeve is sleeved on the outer circle of the fourth deep groove ball bearing and fixedly connected with the outer circle of the fourth deep groove ball bearing, and the spherical surface of the first bearing sleeve is matched with the cylindrical surface of the U-shaped shifting fork of the transmission shaft.

The front concentric ring is annular, two end faces are planes, the outer circle of the front concentric ring is fixedly connected with the first valve sleeve, and the inner hole is sleeved on the left end shaft of the first valve core.

The rear concentric ring is in a circular shape, two end faces are planes, a stepped hole is formed in the inner hole to provide avoidance space for the second circular through hole of the first valve core, the outer circle of the rear concentric ring is fixedly connected with the first valve sleeve, and the inner hole is sleeved on the right end shaft of the first valve core.

The inner hole of the first valve sleeve is a central through hole and is matched with the first valve core, and the two ends of the first valve sleeve are respectively provided with a front stepped hole and a rear stepped hole which are respectively fixedly connected with the front concentric ring and the rear concentric ring; the excircle of first valve pocket is equipped with four ring channels, is control oil groove, first oil outlet groove, first oil inlet groove and first oil return groove respectively from a left side to the right side, evenly is equipped with a plurality of same radial control oilholes on the control oil groove, evenly is equipped with a plurality of same radial oil outlet holes on the first oil outlet groove, evenly is equipped with a plurality of same radial diamond on the first oil inlet groove and joins in marriage the flow window, and the summit of diamond joins in marriage the flow window and is in the coplanar and this plane perpendicular to first case axis, evenly is equipped with a plurality of same radial oil return holes on the first oil return groove.

The left-most end of the first valve core is provided with a stepped shaft for installing a zero spring, the right side of the stepped shaft is provided with a round through hole of a roller shaft, and the stepped shaft is fixedly connected with the roller shaft and used for transmitting torque to the first valve core to enable the first valve core to rotate; the first valve core is provided with three shoulders, a first shoulder, a second shoulder and a third shoulder are sequentially arranged from left to right, a first circular through hole is radially formed in a first valve core shaft between the first shoulder and the second shoulder, a second circular through hole is radially formed in the first valve core shaft which is close to the right end face of the third shoulder, a central flow passage is axially formed in the center of the first valve core, a central flow passage opening is plugged by the first valve core plug, and the first circular through hole and the second circular through hole are communicated through the central flow passage of the first valve core; the second shoulder of the first valve core is provided with two staggered triangular flow distribution windows which are respectively a left triangular flow distribution window and a right triangular flow distribution window, the peaks of the two triangular flow distribution windows are in the same plane, and the plane is perpendicular to the axis of the first valve core.

The excircle sphere of the first bearing sleeve is in clearance fit with the U-shaped shifting fork of the transmission shaft, single-side contact can be realized when the bearing sleeve is stressed, forward and reverse rotation can be realized, the transmission shaft drives the first valve core to rotate through the left roller assembly, the right roller assembly and the roller shaft, and the first valve core axially slides under the action of hydraulic pressure to drive the first bearing sleeve to axially roll on the U-shaped shifting fork of the transmission shaft.

The outer circles of the front concentric ring and the rear concentric ring are respectively fixedly connected in a front stepped hole and a rear stepped hole of two end faces of the first valve sleeve, the inner holes of the front concentric ring are sleeved on the left end shaft of the first valve core for gap sealing, and the inner holes of the rear concentric ring are sleeved on the right end shaft of the first valve core for gap sealing.

The first valve core is rotatably arranged in the first valve sleeve, the front concentric ring and the first shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a control containing cavity, the control containing cavity is communicated with a control oil groove through a control oil hole, and the control oil groove is communicated with control pressure oil; the first shoulder and the second shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a high-pressure containing cavity, the high-pressure containing cavity is communicated with the first oil outlet groove through an oil outlet hole and is communicated with the first oil inlet groove through a diamond flow distribution window, the first oil inlet groove is communicated with high-pressure oil of a hydraulic pump, and the first oil outlet groove is communicated with a system oil way; the second shoulder and the third shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a low-pressure containing cavity, the low-pressure containing cavity is communicated with a first oil return groove through an oil return hole, and the first oil return groove is communicated with a low-pressure oil tank; the third shoulder of the first valve core and the rear concentric ring seal the inner cavity of the first valve sleeve to form a feedback cavity, the feedback cavity is communicated with the high-pressure cavity through the first circular through hole, the central flow passage and the second circular through hole of the first valve core, and the pressures of the two cavities are the same; the first valve sleeve control oil groove, the first oil outlet groove, the first oil inlet groove and the first oil return groove are not communicated with each other outside the first valve sleeve. The first valve core is axially slid under the action of hydraulic pressure while rotating at a constant speed in the first valve sleeve, so that the flow distribution time proportion of the left triangular flow distribution window and the right triangular flow distribution window of the first valve core and the flow distribution window of the first valve sleeve are respectively changed, and the oil outlet flow is changed to realize flow distribution.

The two-dimensional pressure servo valve is characterized in that: the valve body comprises a valve body module, a displacement sensor module and an electro-mechanical converter module, wherein the displacement sensor module is matched with the valve body module; the displacement sensor module monitors the displacement of the 2D piston in the valve body module in real time and the torque motor electric signal of the electromechanical converter module to form closed loop feedback.

The valve body module comprises a second valve core, a second valve core shell, a 2D piston, a left gasket, a right gasket, concentric rings, a pressure regulating spring, a second valve sleeve, a valve sleeve plug and a fourth positioning pin. The second valve core is arranged in an inner hole of the second valve core shell, the 2D piston is arranged on the right side of the second valve sleeve, the valve sleeve plug is fixedly connected to the left end part of the second valve sleeve through a fourth locating pin, and the second valve core shell is located through the valve sleeve plug and is fixed on the left side of the second valve sleeve. The left gasket is connected at the right-hand member of second case, and the right gasket is connected at the left end of 2D piston, is connected with pressure regulating spring between left gasket and the right gasket, and 2D piston right side is provided with concentric ring.

The second valve sleeve is provided with three annular grooves, the second oil inlet groove, the second oil outlet groove and the second oil return groove are respectively arranged from left to right, a plurality of identical radial oil inlet holes are uniformly formed in the second oil inlet groove, a plurality of identical radial oil outlet holes are uniformly formed in the second oil outlet groove, and a plurality of identical radial oil return holes are uniformly formed in the second oil return groove. A pair of damping chute matched with the high-low pressure groove on the 2D piston shoulder is arranged on the inner hole wall on the right side of the second valve sleeve. And the second valve sleeve is provided with O-shaped sealing rings at two sides of each oil port, so that the local sealing of the servo valve is ensured.

The 2D piston is arranged in the second valve sleeve, and the second valve sleeve has two movement directions of circumferential rotation and axial sliding; the left end of the 2D piston is provided with a shoulder, the shoulder is provided with a pair of high-pressure grooves and a pair of low-pressure grooves in a matching way, the shoulder is matched with a pair of damping inclined grooves formed in the inner hole wall of the second valve sleeve, the pair of high-pressure grooves are communicated with the oil inlet hole, the pair of low-pressure grooves are communicated with the oil return hole, the shoulder, the concentric ring and the second valve sleeve of the 2D piston are sealed to form a left sensitive cavity and a right sensitive cavity, the shoulder of the 2D piston is provided with a pair of high-pressure grooves and a pair of low-pressure grooves which are intersected with the pair of damping inclined grooves to form four tiny opening areas in series connection to form a hydraulic resistance half bridge, the pressure change of the left sensitive cavity is controlled, the right sensitive cavity is communicated with the oil inlet hole, the pressure of the left sensitive cavity and the right sensitive cavity is controlled by the hydraulic resistance half bridge, and the generated pressure difference drives the 2D piston to axially move.

The left end shoulder of the second valve core shell is uniformly provided with 4 identical radial through holes which are communicated with the oil inlet holes; and 4 identical radial through holes are uniformly formed in the annular groove on the right side of the second valve core shell and are communicated with the oil outlet. The second valve core shell is matched with the valve sleeve in a plug manner to form a control cavity.

The left side and the right side of the second valve core are respectively provided with a shoulder which is matched with the second valve core shell, and the opening degree of the oil ports of the oil inlet and the oil return port is changed when the second valve core axially moves. The left end face of the second valve core is of a disc type structure, when the second valve core moves left and right, an extrusion oil film is formed between the disc type structure of the second valve core and a closed containing cavity formed by the second valve core shell and the valve sleeve plug, and the function of the extrusion oil film is to introduce an extrusion oil film damping coefficient, increase viscous damping of a system and improve damping ratio so that the system is more stable. The second valve core is internally provided with a central flow passage which is connected with a through hole on the right side of the second valve core and is communicated with the control cavity.

When the 2D piston rotates clockwise (seen leftwards from one side of the transmission mechanism), the intersecting area of the high-pressure groove and the damping chute is reduced, the intersecting area of the low-pressure groove and the damping chute is increased, at the moment, the pressure of the left sensitive cavity is reduced, the pressure of the right sensitive cavity is unchanged, and the 2D piston moves leftwards. In the left moving process, the intersection area of the high-pressure groove and the damping chute is increased, the intersection area of the low-pressure groove and the damping chute is reduced, the pressure of the left sensitive cavity is gradually increased, and the 2D piston is finally stabilized at a certain position. The left end face of the second valve core is subjected to rightward hydraulic pressure increase, when the rightward hydraulic pressure is smaller than the pressure regulating spring force, the second valve core continues to move left, the valve port opening continues to increase, and the output pressure continues to increase; when the rightward hydraulic force is equal to the pressure regulating spring force, the second valve core stops moving leftwards and is stabilized at a certain position, and meanwhile, the pressure of the oil outlet is kept to be basically constant.

The electric-mechanical converter module adopts a torque motor and comprises a shell, an armature, a permanent magnet, a magnetizer, a clamping piece, a motor housing, a coil, a spring rod, a spring seat, a limit rod and a connecting plate, wherein the shell and the motor housing are connected with the connecting plate, the shell is fixedly connected with the connecting plate through screws, one end of the spring is connected with the spring rod, and the other end of the spring is connected with the spring seat fixed on the shell. The electro-mechanical converter module is connected with the valve body through a connecting plate. The two-dimensional pressure servo valve adopts a dry torque motor, so an O-shaped sealing ring is also arranged on the motor housing and the connecting plate, and the output part is sealed to prevent oil from entering the space surrounding the armature, the coil and the permanent magnet.

The electromechanical transducer module includes a magnetic circuit portion, a transmission portion, and a motor housing. The connecting plate is connected with the motor housing through screws. The magnetic circuit part is composed of 2 coils, 2 magnetizers, 1 armature and 2 permanent magnets. When the coil is not electrified, the armature remains balanced; energizing the coil creates a magnetic path that breaks the equilibrium state before the armature deflects. The transmission part comprises a spring, a spring seat, a spring rod, a limit rod and a motor pin. And the shell and the clamping piece are used for fixing and positioning the parts. And when the armature deflects, the 2D piston and the spring rod are driven to rotate. One end of the spring is connected with the spring rod, and the other end of the spring is connected with a spring seat fixedly connected to the shell, so that the rotary motion of the spring rod can be effectively transmitted to the spring, and the spring is ensured to return to zero automatically under abnormal conditions, so that the armature and the 2D piston return to the initial positions.

The displacement sensor module comprises an LVDT connecting rod and an LVDT sensor (composed of an iron core and a coil framework), wherein the LVDT sensor is matched with the circular arcs of the shell and the clamping piece, and the clamping piece is pressed against the LVDT sensor through a screw to fix the LVDT sensor; the spring rod is connected with the LVDT connecting rod in a mutually perpendicular manner; the LVDT connecting rod is connected with the iron core, and the iron core adopts clearance fit with the LVDT sensor, can directly move in the LVDT sensor hole. The LVDT sensor is connected with the 2D piston of the valve body module through a threaded connecting rod.

In the moment motor working process, the armature iron drives the spring rod and the 2D piston to rotate, the 2D piston moves linearly in combination with the 2D servo spiral theorem, meanwhile, the spring rod and the iron core are driven to move linearly, and the displacement of the iron core is transmitted to the controller in the form of an electric signal in combination with the LVDT principle, so that closed-loop control of the displacement of the second valve core is realized.

A plurality of oil ways are arranged in the pump body, and a first oil inlet groove of the two-dimensional pulse width modulation mechanism is communicated with an oil outlet of the duplex plunger pump through the oil ways; the first oil outlet groove of the two-dimensional pulse width modulation mechanism is communicated with the oil outlet of the pump body; the first oil return groove of the two-dimensional pulse width modulation mechanism is communicated with a system oil tank; the control oil groove of the two-dimensional pulse width modulation mechanism is communicated with the second oil outlet groove of the two-dimensional pressure servo valve; the first oil inlet groove of the two-dimensional pulse width modulation mechanism is communicated with the second oil inlet groove of the two-dimensional pressure servo valve; the first oil return groove of the two-dimensional pulse width modulation mechanism is communicated with the second oil return groove of the two-dimensional pressure servo valve.

The specific working process is as follows:

When an external motor is started, the upper plunger is driven by the motor coupler to rotate at a constant speed, and the upper plunger and the lower plunger are connected in a matched mode, so that the upper plunger and the lower plunger are circumferentially rotated together, large roller groups of the upper left structural shaft and the lower left structural shaft are arranged on corresponding upper left rails and lower left rails, large roller groups of the upper right structural shaft and the lower right structural shaft are arranged on corresponding upper right rails and lower right rails, and the large roller groups are constrained by curved surface rails and do reciprocating motion in the axial direction. Therefore, the upper plunger and the lower plunger can axially and continuously reciprocate along with the continuous rolling of the large roller group on the corresponding left acceleration curved surface track, the right acceleration curved surface track and the like.

The continuous circumferential rotation and axial reciprocating motion of the plunger piston enable grooves on the plunger piston to be in periodic communication with windows on the cylinder body, the containing cavity with gradually increased volume absorbs oil from the oil tank through the communicated grooves and windows, and the cavity with gradually reduced volume discharges oil in the cavity through the communicated rectangular grooves and windows; the reciprocating motion of the plunger piston makes the volumes of the left cavity and the right cavity constantly alternate, so as to realize continuous oil sucking and discharging.

Oil discharged by the duplex plunger pump is introduced into the pressure servo variable mechanism through the pump fluid channel. Due to the gear transmission, the pressure servo variable mechanism and the upper pump core start to work simultaneously.

The pressure servo variable mechanism has two working states of constant pressure variable and pressure servo.

When the two-dimensional pressure servo valve does not receive a given signal or a given feedback signal of the system, the system pressure is unchanged in the working process of the constant pressure variable state, and at the moment, if the system flow is changed, the system pressure is also slightly changed. When the system demand flow is increased, the system pressure is reduced, namely the pressure of the feedback cavity is reduced, the balance state of the left end and the right end of the first valve core of the two-dimensional pulse width modulation mechanism is broken, the resultant force of the left end of the first valve core is larger than the resultant force of the right end of the first valve core, so that the first valve core of the two-dimensional pulse width modulation mechanism moves rightwards, the opening degree of an oil inlet and an oil outlet is increased, the opening time is prolonged, more flow flows into the system to supply energy to the system, the pressure of the feedback cavity is increased, and the original force balance state of the first valve core is maintained. Conversely, when the required flow of the system is reduced, the pressure of the system is increased, namely the pressure of the feedback cavity is increased, the balance state of the left end and the right end of the first valve core is broken, the resultant force of the left end of the first valve core is smaller than the resultant force of the right end of the first valve core, the first valve core moves leftwards, the opening degree of the oil inlet and the oil return opening is increased, the opening time is prolonged, more flow flows back to the oil tank to reduce the oil supply amount in the system, and the pressure of the feedback cavity is reduced, so that the original force balance state is maintained.

When the two-dimensional pressure servo valve receives a given signal or a given feedback signal of a system, in the working process of the pressure servo state, the torque motor drives the 2D piston to circumferentially rotate, a certain displacement is axially output due to the change of the pressure difference between the left sensitive cavity and the right sensitive cavity, the force is transmitted to the second valve core through the pressure regulating spring, the hydraulic pressure born by the second valve core is unbalanced with the pressure regulating spring force, the axial movement occurs, the opening degree of the valve port changes, the output pressure changes until the hydraulic pressure born by the left end surface of the second valve core and the pressure regulating spring force reach balance again, the outlet pressure of the servo valve is basically constant, and the system pressure is constant again. The oil outlet of the two-dimensional pressure servo valve is communicated with the control containing cavity of the two-dimensional pulse width modulation mechanism, so that the pressure of the oil outlet of the two-dimensional pressure servo valve changes, the original balance state of a first valve core of the two-dimensional pulse width modulation mechanism is broken, the first valve core moves axially, the ratio of the time required by the left triangular flow distribution window and the right triangular flow distribution window of the first valve core to the total time required by the right triangular flow distribution window of the first valve sleeve to be scanned alternately respectively changes correspondingly, the oil outlet flow and the oil return flow change correspondingly, the flow entering the system changes correspondingly, the feedback Rong Qiangya force changes correspondingly, and the first valve core reaches a new balance state when the axial resultant force of the first valve core is balanced again, and the system pressure is kept constant again.

When the system pressure needs to be reduced, the pressure difference between the left sensitive cavity and the right sensitive cavity of the 2D piston is reduced, the second valve core moves rightwards to reduce the opening of the valve port, the pressure oil port is communicated with the control cavity, the hydraulic pressure of the right end face of the second valve core is reduced, and the hydraulic pressure and the pressure regulating spring force are balanced. When the output pressure is larger than the set pressure value, the hydraulic pressure received by the left end face of the second valve core is larger than the pressure regulating spring force, the second valve core continues to move right, the opening of the valve port continues to decrease, the output pressure continues to decrease, when the output pressure reaches the set value of the valve, the hydraulic pressure received by the second valve core reaches balance again, at the moment, the opening of the valve port becomes smaller, the reduction of the pressure of the oil outlet is realized, and the pressure of the oil outlet is kept to be basically a fixed value. The oil outlet pressure of the two-dimensional pressure servo valve is reduced, so that the control Rong Qiangya force of the two-dimensional pulse width modulation mechanism is reduced, the resultant force of the left end of the first valve core is smaller than the resultant force of the right end of the first valve core, the first valve core moves leftwards, the opening degree of the valve inlet is reduced (until the valve is completely closed), the oil outlet pressure is reduced along with the loss of oil in the system, and the first valve core reaches a new balance state until the resultant force of the two ends of the first valve core is equal again, so that the pressure reduction effect is realized, and the pressure of the system is kept constant.

Conversely, when the system pressure needs to be increased, the pressure difference between the left sensitive cavity and the right sensitive cavity of the 2D piston is increased, the second valve core moves leftwards to increase the opening degree of the valve port, the hydraulic pressure of the left end face of the second valve core to the right is increased, and the hydraulic pressure is balanced with the pressure regulating spring force. When the output pressure is smaller than the set pressure value, the hydraulic pressure born by the left end face of the second valve core is smaller than the pressure regulating spring force, the second valve core continues to move leftwards, the opening of the valve port continues to increase, and the output pressure continues to increase; when the output pressure reaches the set pressure value of the valve, the hydraulic pressure born by the second valve core reaches balance again, at the moment, the opening of the valve port becomes larger, the pressure of the oil outlet is increased, and the pressure of the oil outlet is kept to be basically a fixed value. The oil outlet pressure of the two-dimensional pressure servo valve is increased, so that the control Rong Qiangya force of the two-dimensional pulse width modulation mechanism is increased, the resultant force of the left end of the first valve core is larger than the resultant force of the right end of the first valve core, the first valve core moves rightwards, the opening degree of the valve port of the oil return port is reduced (until the valve port is completely closed), the oil outlet pressure is increased along with a large amount of inflow of oil in the system, and the first valve core reaches a new balance state until the resultant forces of the two ends of the first valve core are equal again, so that the supercharging effect is realized, and the pressure of the system is kept constant.

Through the action, the continuous oil sucking and discharging work of the duplex plunger pump is realized, the synchronous work of the duplex plunger pump and the pressure servo variable mechanism is realized, the pressure servo variable pump keeps the system constant pressure when the system flow changes, and the system pressure tends to be stable again after becoming larger or smaller when the external given signal is realized, so that a new constant pressure environment is formed.

The axial direction involved in the duplex plunger pump refers to the direction of the central axis of the plunger; the radial direction refers to the direction perpendicular to the central axis of the plunger; the circumferential direction refers to the direction in which the plunger rotates about the central axis; the reference to axisymmetry refers to symmetry about the plunger central axis; reference to central symmetry refers to point symmetry about the plunger center.

The axial direction related in the two-dimensional pulse width modulation mechanism refers to the direction in which a first valve core central shaft of the pulse width modulation mechanism is located; the radial direction refers to the direction of the central axis of the first valve core of the vertical pulse width modulation mechanism; the circumferential direction refers to the direction in which the first spool of the pulse width modulation mechanism rotates about the central axis.

The axial direction involved in the two-dimensional pressure servo valve refers to the direction in which the 2D piston central shaft of the two-dimensional pressure servo valve is located; the related radial direction refers to the direction of the central axis of the 2D piston of the vertical two-dimensional pressure servo valve; the circumferential direction refers to the direction in which the 2D piston of the two-dimensional pressure servo valve rotates about the central axis.

The beneficial effects of the invention are as follows:

1. the invention realizes constant-pressure flow distribution with adjustable system pressure through the pressure servo variable mechanism, and has wide pressure flow adjusting range, continuous adjustment, high sensitivity and high response speed.

2. Compared with the traditional servo pump, the pressure flow servo variable valve does not need a servo motor when in servo variable, and can simultaneously realize the regulation of the pressure flow of the system;

3. The signal input range of the two-dimensional pressure servo valve is wide, a required signal can be input by the user, and the feedback signal can be given according to the system pressure or a certain partial pressure of the system, so that the pressure and flow regulation can be realized.

4. The two-dimensional (2D) pump valve group control flow distribution before is replaced, an adjusting mechanism is reduced, and the design is simplified.

Drawings

FIG. 1a is a schematic diagram of a two-dimensional pressure servo variable displacement pump.

FIG. 1b is a schematic diagram of a two-dimensional pressure servo variable mechanism.

Fig. 2 is a schematic diagram of the pump body.

Fig. 3a is a schematic diagram of the structure of the pump core connected in series.

Fig. 3b is an exploded view of the pump core of the upper pump.

Fig. 4 is an exploded view of the left end structural shaft of the upper link.

Fig. 5a is a schematic diagram of the structure of the pump core connected in series.

Fig. 5b is an exploded view of the tandem pump core.

Figures 6a 1-6 c2 are schematic diagrams of the working principle of the duplex plunger pump,

Wherein fig. 6a1 is a schematic view of the movement of the upper plunger to the leftmost end;

FIG. 6a2 is a cross-sectional view taken along A-A of FIG. 6a 1;

FIG. 6b1 is a schematic view of the pull-up plunger as it moves to a neutral position;

FIG. 6b2 is a cross-sectional view taken along A-A of FIG. 6b 1;

FIG. 6c1 is a schematic view of the pull-up plunger as it moves to the far right;

Fig. 6c2 is a cross-sectional view taken along A-A of fig. 6c 1.

Fig. 7 is a schematic diagram of a two-dimensional pulse width modulation mechanism.

Fig. 8a is a schematic diagram of a first valve housing structure of a two-dimensional pulse width modulation mechanism.

Fig. 8b is a sectional view A-A of fig. 8 a.

Fig. 9a is a schematic diagram of a first valve core structure of the two-dimensional pulse width modulation mechanism.

Fig. 9B is a B-B cross-sectional view of fig. 8 a.

Fig. 10 is a schematic diagram of a two-dimensional pulse width modulation mechanism drive shaft.

Fig. 11 is a schematic structural diagram of a right roller assembly of the two-dimensional pulse width modulation mechanism.

Fig. 12 is a schematic diagram of a two-dimensional pulse width modulation mechanism roller shaft.

Fig. 13a is a schematic diagram of a two-dimensional pulse width modulation mechanism first valve sleeve flow distribution window principle.

Fig. 13b is a schematic diagram of a two-dimensional pulse width modulation mechanism first valve core flow distribution window principle.

Fig. 13c is a schematic diagram of the principle of flow distribution when the first valve core of the two-dimensional pulse width modulation mechanism is in the middle position.

Fig. 13d is a schematic diagram of the flow distribution principle when the first valve core of the two-dimensional pulse width modulation mechanism moves down.

Fig. 14a is a schematic perspective view e of a two-dimensional pressure servo valve.

Fig. 14b is an axial cross-sectional view of fig. 14 a.

Fig. 15a is a schematic diagram of a two-dimensional pressure servo valve 2D piston structure.

Fig. 15b is a C-C cross-sectional view of fig. 15 a.

FIG. 16a is a schematic view of a two-dimensional pressure servo valve second valve housing.

Fig. 16b is a D-D cross-sectional view of fig. 16 a.

Fig. 17a is a schematic perspective view of a second spool of the two-dimensional pressure servo valve.

Fig. 17b is an axial cross-sectional view of fig. 17 a.

Fig. 18a is a schematic perspective view of a second spool housing of the two-dimensional pressure servo valve.

Fig. 18b is an axial cross-sectional view of fig. 18 a.

Fig. 19a is a schematic perspective view of a two-dimensional pressure servo valve torque motor.

Fig. 19b is an axial cross-sectional view of fig. 19 a.

Fig. 20 is a schematic diagram of the working principle of a two-dimensional pressure servo variable pump.

Detailed Description

The technical solution of the present invention is further described below with reference to fig. 1a to 20.

The working principle of this example:

the two-dimensional pressure servo variable pump is characterized in that: comprises a front end cover 1, a pump body 8, a rear end cover 9, a duplex plunger pump 6 and a pressure servo variable mechanism 10. The pressure servo variable mechanism comprises a two-dimensional pulse width modulation mechanism 11 and a two-dimensional pressure servo valve 12.

The front end cover 1 is fixedly connected with the pump body 8 through screws; the rear end cover 9 is fixedly connected with the pump body 8 through screws; the duplex plunger pump 6 is fixed in the pump body 8; the two-dimensional pulse width modulation mechanism 11 and the two-dimensional pressure servo valve 12 are fixedly connected with the pump body through screws.

The front end cover 1 is internally provided with a driving gear 2, a driven gear 4 and a first deep groove ball bearing 3, the driving gear 2 is fixedly connected with a motor coupler, and the driven gear 4 is fixedly connected with a two-dimensional pulse width modulation mechanism 11.

The pump body is provided with a first through hole (namely an oil inlet hole) m1, a second through hole m2, a third blind hole m3 and an oil outlet hole m4. The first through hole m1 is arranged at the lower part of the pump body 8, the duplex plunger pump 6 is installed, the second through hole m2 is arranged at the upper part of the pump body 8, the two-dimensional pulse width modulation mechanism 11 is installed, the third blind hole m3 is arranged at the upper part of the pump body 8, and the two-dimensional pressure servo valve 12 is installed.

The duplex plunger pump 6 comprises an upper pump core 5 and a lower pump core 7, wherein the upper pump core 5 is close to the front end cover 1, and the lower pump core 7 is close to the rear end cover 9.

The upper pump core 5 comprises an upper cylinder 509, an upper plunger 504, an upper left end structural shaft 501, an upper right end structural shaft 507, a first concentric ring 503, a second concentric ring 505, an upper left guide rail 510, an upper right guide rail 508 and first positioning pins 502 and 506. The upper plunger 504 is installed in an upper cylinder 509, the left end and the right end of the upper plunger 504 are respectively fixedly connected with an upper left end structural shaft 501 and an upper right end structural shaft 507 by first positioning pins 502 and 506, and the left side and the right side of the upper plunger 504 are respectively provided with a first concentric ring 503 and a second concentric ring 505. The left end and the right end of the upper cylinder 509 are fixedly connected with an upper left guide rail 510 and an upper right guide rail 508 which have equal acceleration and deceleration curved surface tracks, the circumferential directions of the equal acceleration and deceleration curved surfaces of the upper left guide rail 510 and the upper right guide rail 508 are staggered by 90 degrees, namely the highest point and the lowest point of the equal acceleration and deceleration curved surface tracks of the upper left guide rail correspond to the lowest point and the highest point of the equal acceleration and deceleration curved surface tracks of the upper right guide rail respectively.

A shoulder is arranged in the middle of the upper plunger 504, four rectangular distribution grooves a, b, c, d which are uniformly distributed are formed in the surface of the upper plunger, and the notch positions of the four rectangular distribution grooves are staggered.

Four distributing windows e, f, g, h are uniformly distributed on the upper cylinder body, and are respectively two oil inlets e and g and two oil outlets f and h, the oil inlets and the oil outlets are alternately arranged, the oil inlets are communicated with low-pressure oil, the oil outlets are communicated with high-pressure oil, and the oil inlets and the oil outlets are not communicated with each other. And two sides of the oil outlet are sealed by sealing rings. The flow distribution window e, f, g, h is disposed corresponding to the flow distribution groove a, b, c, d on the upper plunger 504.

The upper left end structural shaft 501 comprises a first structural shaft main body 501.2, a first large roller 501.1, a second large roller 501.6, a first small roller pair 501.7 and a second small roller pair 501.4. The second large roller 501.6 has the same structure as the first large roller 501.1, and forms a first large roller group 501.16. The second small roller pair 501.4 has the same structure as the first small roller pair 501.7, and forms a first small roller group 501.17. The first large roller 501.1 comprises a conical roller bearing sleeve 501.14 and a second deep groove ball bearing 501.13, the outer part of the conical roller bearing sleeve is a conical surface, the inner part of the conical roller bearing sleeve is a round hole, an inner hole of the conical roller bearing sleeve is sleeved on the outer circle of the second deep groove ball bearing and fixedly connected with the outer circle of the second deep groove ball bearing, and the first large roller 501.1 is fixedly connected with the first structural shaft main body 501.2 by a nut 501.15. The first small roller pair 501.7 comprises a large cylindrical roller and a small cylindrical roller, the large cylindrical roller 501.3 comprises a cylindrical bearing sleeve 501.9 and a third deep groove ball bearing 501.10, the outside of the cylindrical bearing sleeve is a cylinder, the inside of the cylindrical bearing sleeve is a round hole, an inner hole of the cylindrical bearing sleeve is sleeved on the outer circle of the third deep groove ball bearing and fixedly connected with the outer circle of the third deep groove ball bearing, and the large cylindrical roller is fixed on the first structural shaft main body 501.2 by a second positioning pin 501.8. The small cylindrical roller 501.5 comprises a cylindrical roller sleeve 501.11 and a copper sleeve 501.12, the outside of the roller sleeve is a cylinder, the inside of the roller sleeve is a round hole, an inner hole of the roller sleeve is sleeved on the outer circle of the copper sleeve and fixedly connected with the copper sleeve, and the small cylindrical roller is fixed on the first structural shaft main body 501.2. The first large roller 501.1 and the second large roller 501.6 are fixedly connected to two ends of the first structural shaft main body 510.2, and are axially symmetrically arranged. The first small roller pair 501.7 and the second small roller pair 501.4 are fixedly connected to two ends of the first structural shaft main body 501.2 and are arranged in a central symmetry mode.

The upper right structural shaft 507 is identical in structure to the upper left structural shaft 501.

The rolling surfaces of the upper left end structural shaft 501, the first large roller set 501.16 and the second large roller set 507.2 of the upper right end structural shaft 507 are respectively matched with the corresponding upper left guide rail 510 and upper right guide rail 508, and the rolling surface of the first small roller set 501.17 of the upper left end structural shaft 501 is matched with a track carried by a motor coupler; the rolling surface of the second small roller group 507.1 of the upper right structural shaft 507 is matched with the track carried by the shifting fork structure of the lower left structural shaft main body 702.

The space enclosed by the first concentric ring 503, the upper plunger 504 and the upper cylinder 509 forms a first left chamber, the space enclosed by the second concentric ring 505, the upper plunger 504 and the upper cylinder 509 forms a first right chamber, and the volumes of the first left chamber and the first right chamber are staggered along with the reciprocating motion of the plungers.

The lower pump core comprises a lower cylinder 713, a lower plunger 706, a lower left end structural shaft 701, a lower right end structural shaft 709, a third concentric ring 705, a fourth concentric ring 707, a lower left guide rail 714, a lower right guide rail 712, and third locating pins 704, 708. The lower plunger 706 is installed in the lower cylinder 713, the left end and the right end of the lower plunger 706 are respectively and fixedly connected with a lower left end structural shaft 701 and a lower right end structural shaft 709 by third positioning pins 704 and 708, and the left side and the right side of the lower plunger 706 are respectively provided with a third concentric ring 705 and a fourth concentric ring 707. The left and right ends of the lower cylinder 713 are fixedly connected with a lower left guide rail 714 and a lower right guide rail 712 which have equal acceleration and deceleration curved surface rails. The lower left rail 714 and the lower right rail 712 are arranged in the same manner as the upper left rail 510 and the upper right rail 508.

The lower cylinder 713 is identical in construction to the upper cylinder 509.

The lower plunger 706 is identical in construction to the upper plunger 504, and the upper plunger 504 is disposed concentrically with the lower plunger 706.

The lower left end structural shaft 701 comprises a third structural shaft main body 702 and a third large roller group 703. The third structural shaft main body 702 is provided with a shifting fork structure and is matched and connected with the second small roller group 507.1 of the upper-connection right-end structural shaft 507, so that the upper-connection pump core 5 and the lower-connection pump core 7 are staggered by 45 degrees in space.

The lower right structural shaft 709 includes a fourth structural shaft body 711 and a fourth large roller set 710. The third large roller group 703 and the fourth large roller group 710 of the lower left end structural shaft 701 and the lower right end structural shaft 709 are identical in structure and placement to the first large roller group 501.16 of the upper left end structural shaft. The rolling surfaces of the third large roller group 703 and the fourth large roller group 710 of the lower left end structural shaft 701 and the lower right end structural shaft 709 are respectively matched with the lower left guide rail 714 and the lower right guide rail 712 on the lower cylinder 713.

The space enclosed by the third concentric ring 705, the lower plunger 706 and the lower cylinder 713 together forms a second left chamber, the space enclosed by the fourth concentric ring 707, the lower plunger 706 and the lower cylinder 713 together forms a second right chamber, and the volumes of the second left chamber and the second right chamber are staggered along with the reciprocating motion of the plunger.

The two-dimensional pulse width modulation mechanism 11 is characterized in that: comprising a drive shaft 1101, zero spring 1102, roller shaft 1103, left roller assembly 1104, right roller assembly 1105, front concentric ring 1106, first spool 1108, first valve housing 1107, rear concentric ring 1109, first spool plug 1110. The shifting fork of the transmission shaft 1101 is matched with the roller assemblies 1103 and 1104 to shift the first valve core 1108 through the roller shaft 1103, so that the first valve core 1108 axially slides while circumferentially rotating in the first valve sleeve 1107, the circumferential rotation and the axial sliding of the first valve core 1108 are relatively independent, the front concentric ring 1106 and the rear concentric ring 1109 are respectively fixedly connected to two ends of the first valve sleeve 1107, and the zero spring 1102 is arranged between the first valve core 1108 and the transmission shaft 1101 and is in a constantly compressed state.

One end of the transmission shaft 1101 is a cylindrical end and is connected with the driven gear 2; the other end of the transmission shaft is in a door frame shape, two U-shaped shifting forks are connected, the shifting fork surface is an axial incomplete cylindrical surface track, and the left and right roller assemblies 1104 and 1105 are matched to enable the first valve core 1108 to axially slide while rotating circumferentially; the axial intermediate end face of the drive shaft 1101 has a circular recess for securing the zero spring 1102.

The two flat end surfaces of the zero spring 1102 are respectively fixed at the circular groove of the transmission shaft 1101 and the stepped shaft at the left end of the first valve core 1108, the zero spring 1102 is in a compressed state in the initial and working processes, the first valve core 1108 is ensured to be at the rightmost end in the initial state, and the zero position of the first valve core is maintained.

The roller shaft 1103 is a stepped cylindrical shaft, a shoulder is arranged in the middle of the roller shaft, and the diameter of the middle cylinder is larger than that of the cylinders on two sides; the middle shoulder shaft is inserted into the left end cylindrical hole of the first valve core 1108 and fixedly connected, and the two end shafts are respectively inserted into the central round holes of the left roller component 1104 and the right roller component 1105 and fixedly connected.

The right roller assembly 1105 is identical to the left roller assembly 1104 in structure, and comprises a first bearing sleeve 1105.1 and a fourth deep groove ball bearing 1105.2, wherein the outer part of the first bearing sleeve 1105.1 is a spherical surface, the inner part of the first bearing sleeve is a round hole, the two ends of the first bearing sleeve are flat end surfaces, an inner hole of the first bearing sleeve is sleeved on the outer circle of the fourth deep groove ball bearing and fixedly connected with the outer circle of the fourth deep groove ball bearing, and the spherical surface of the first bearing sleeve 1105.1 is matched with a U-shaped shifting fork cylindrical surface of the transmission shaft 1102.

The front concentric ring 1106 is circular, two end surfaces are plane, the outer circle of the front concentric ring 1106 is fixedly connected with the first valve sleeve 1107, and an inner hole is sleeved on the left end shaft of the first valve core 1108.

The rear concentric ring 1109 is in a circular ring shape, two end surfaces are plane, a stepped hole is arranged in the inner hole to provide avoidance space for the second circular through hole b2 of the first valve core 1108, the outer circle of the rear concentric ring 1109 is fixedly connected with the first valve sleeve 1107, and the inner hole is sleeved on the right end shaft of the first valve core 1108.

The inner hole of the first valve sleeve 1107 is a central through hole and is matched with the first valve core 1108, and the two ends of the first valve sleeve 1107 are respectively provided with a front stepped hole and a rear stepped hole which are respectively fixedly connected with the front concentric ring 1106 and the rear concentric ring 1109; the excircle of first valve pocket 1107 is equipped with four ring channels from left to right and is control oil groove K1, first oil outlet groove A1, first oil inlet groove P1 and first oil return groove T1 respectively, and K1 evenly is equipped with a plurality of same radial control oilholes K1 on the control oil groove, evenly is equipped with a plurality of same radial oil outlet holes A1 on the first oil outlet groove A1, evenly is equipped with a plurality of same radial diamond on the first oil inlet groove P1 and joins in marriage a class window P, and the summit of diamond joins in marriage a class window P is in the coplanar and this plane perpendicular to first case axis, evenly is equipped with a plurality of same radial oil return holes T1 on the first oil return groove T1.

The leftmost end of the first valve core 1108 is provided with a stepped shaft for installing a zero spring 1102, the right side of the stepped shaft is provided with a round through hole of a roller shaft, and the stepped shaft is fixedly connected with the roller shaft 1103 and is used for transmitting torque to the first valve core 1108 to enable the first valve core to rotate; the first spool 1108 has three shoulders, namely a first shoulder 1108.1, a second shoulder 1108.2 and a third shoulder 1108.3 in sequence from left to right, a first spool shaft between the first shoulder 1108.1 and the second shoulder 1108.2 is radially provided with a first circular through hole B1, a first spool shaft close to the right end surface of the third shoulder 1108.3 is radially provided with a second circular through hole B2, the center of the first spool is axially provided with a center flow passage B1, the center flow passage is blocked by a first spool plug 1110, and the first circular through hole B1 and the second circular through hole B2 are communicated through the first spool center flow passage B1; the second shoulder 1108.2 of the first valve core is provided with two staggered triangular flow distribution windows which are a left triangular flow distribution window p1 and a right triangular flow distribution window p2 respectively, the vertexes of the two triangular flow distribution windows are in the same plane, and the plane is perpendicular to the axis of the first valve core.

The outer spherical surface of the first bearing sleeve 1105.1 is in clearance fit with the U-shaped shifting fork of the transmission shaft, single-side contact can be realized when the bearing sleeve is stressed, forward and reverse rotation can be realized, the transmission shaft drives the first valve core 1108 to rotate through the left roller component 1104, the right roller component 1105 and the roller shaft 1103, and the first valve core 1108 axially slides under the action of hydraulic force to drive the first bearing sleeve 1105.1 to axially roll on the U-shaped shifting fork of the transmission shaft 1101.

The outer circles of the front concentric ring 1106 and the rear concentric ring 1109 are respectively fixedly connected in a front stepped hole and a rear stepped hole on two end faces of the first valve sleeve 1107, the inner hole of the front concentric ring 1106 is sleeved on the left end shaft of the first valve core 1108 for gap sealing, and the inner hole of the rear concentric ring 1109 is sleeved on the right end shaft of the first valve core 1108 for gap sealing.

The first valve core 1108 is rotatably disposed in the first valve housing 1107, the front concentric ring 1106 and the first valve core first shoulder 1108.1 seal the inner cavity of the first valve housing 1107 to form a control cavity K1.1, the control cavity K1.1 communicates with the control oil groove K1 through the control oil hole K1, and the control oil groove K1 communicates with control pressure oil; the first valve core first shoulder 1108.1 and the second shoulder 1108.2 seal the inner cavity of the first valve sleeve 1107 to form a high-pressure containing cavity A1.1, the high-pressure containing cavity A1.1 is communicated with the first oil outlet groove A1 through an oil outlet hole A1 and is communicated with the first oil inlet groove P1 through a diamond flow distribution window P, the first oil inlet groove P1 is communicated with high-pressure oil of a hydraulic pump, and the first oil outlet groove A1 is communicated with a pump body oil way; the first valve core second shoulder 1108.2 and the third shoulder 1108.3 seal the inner cavity of the first valve sleeve 1107 to form a low-pressure containing cavity T1.1, the low-pressure containing cavity T1.1 is communicated with a first oil return groove T1 through an oil return hole T1, and the first oil return groove T1 is communicated with a low-pressure oil tank; the inner cavity of the first valve sleeve is sealed by the third shoulder 1108.3 of the first valve core and the rear concentric ring 1109 to form a feedback containing cavity A1.2, the feedback containing cavity A1.2 is communicated with the high-pressure containing cavity A1.1 through the first circular through hole B1, the central flow passage B and the second circular through hole B2 of the first valve core, and the pressure of the two cavities is the same; the first valve housing control oil groove K1, the first oil outlet groove A1, the first oil inlet groove P1, and the first oil return groove T1 are not communicated with each other outside the first valve housing 1107. Two staggered triangular flow distribution windows, namely a left triangular flow distribution window p1 and a right triangular flow distribution window p2, are formed in the second shoulder 1108.2 of the first valve core, the first valve sleeve diamond flow distribution window p is located on the motion track of the second shoulder 1108.2 of the first valve core, the first valve core 1108 axially slides under the action of hydraulic pressure while rotating at a constant speed in the first valve sleeve 1107, so that the flow distribution time proportion of the left triangular flow distribution window p1 and the right triangular flow distribution window p2 of the first valve core to the first valve sleeve diamond flow distribution window p is changed, and the oil outlet flow is changed to realize flow distribution.

In order to explain the flow distribution principle of the two-dimensional pulse width modulation mechanism, the left triangular flow distribution window p1, the right triangular flow distribution window p 2and the first valve sleeve diamond flow distribution window p of the first valve core are circumferentially unfolded, and are simplified into schematic diagrams, such as fig. 13a, 13b, 13c and 13d. The left-right linear motion of the first valve core in the schematic diagram represents the circumferential rotation of the first valve core in the schematic diagram, and the vertical movement of the first valve core in the schematic diagram represents the axial sliding of the first valve core in the schematic diagram. In fig. 13a and 13b, P0 is an oil inlet, equivalent to the first oil inlet groove P1, A0 is an oil outlet, equivalent to the first oil outlet groove A1, T0 is an oil return port, equivalent to the first oil return groove T1.

The first valve core 1108 can freely rotate circumferentially and axially slide in the first valve housing 1107, as the first valve core 1108 rotates, the left triangular distribution window p1 and the right triangular distribution window p2 of the first valve core 1108 alternately communicate with the diamond distribution windows p of the first valve housing 1107 to form periodic changes, because the left triangular distribution window p1 and the right triangular distribution window p2 of the first valve core 1108 are in large number with the diamond distribution windows p of the first valve housing 1107, the valve port area gradient is large, so that the magnitude of the valve port opening has little influence on the flow rate passing through the valve port, the flow rate passing through the valve port can be regarded as an amount which is irrelevant to the valve port opening and is only related to the valve port opening time, namely, the ratio of time required by the left triangular distribution window p1 and the right triangular distribution window p2 of the first valve core 1108 to alternately sweep through the diamond distribution windows p of the first valve housing 1107 respectively accounts for the total time in any period, the distribution ratio of the oil inlet flow rate is the distribution ratio of the oil inlet flow rate, and the oil outlet flow rate and the return flow rate are distributed according to the ratio.

As shown in fig. 13c and 13d, the flow Q of the oil inlet P0 on the ordinate, the time T on the abscissa, and the time Δt1 required for the triangular distribution window P1 on the left side of the first valve core 1108 to sweep through the diamond distribution window P of the first valve housing 1107 are set, the time Δt2 required for the triangular distribution window P2 on the right side of the first valve core 1108 to sweep through the diamond distribution window P of the first valve housing 1107 are set, the flow q·Δt1/Δt of the oil outlet A0 is set, and the flow q·Δt2/Δt of the oil return port T0 is set. As can be seen from comparing fig. 13c and 13d, the axial sliding of the first spool changes the duty cycle of Δt1 and Δt2, thereby changing the flow of oil into the hydraulic system, and thus the manner in which the system flow is regulated by this structure can be regarded as pulse width modulation controlled by the first spool position.

The two-dimensional pressure servo valve 12 is characterized in that: the valve body comprises a valve body module, a displacement sensor module and an electro-mechanical converter module, wherein the displacement sensor module is matched with the valve body module; the displacement sensor module monitors the displacement of the 2D piston in the valve body module in real time and the torque motor electric signal of the electromechanical converter module to form closed loop feedback.

The valve body module includes a second valve spool 1203, a second spool housing 1204, a 2D piston 1212, a left shim 1205, a right shim 1207, concentric rings 1208, a pressure regulating spring 1206, a second valve sleeve 1213, a valve sleeve plug 1201, and a fourth dowel pin 1202. The second valve core 1203 is disposed in an inner hole of the second valve core housing 1204, the 2D piston 1212 is disposed on the right side of the second valve sleeve 1213, the valve sleeve plug 1201 is fixedly connected to the left end of the second valve sleeve 1213 through the fourth positioning pin 1202, and the second valve core housing 1204 is positioned by the valve sleeve plug 1201 and is fixed on the left side of the second valve sleeve 1213. The left gasket 1205 is connected to the right end of the first valve core 1203, the right gasket 1207 is connected to the left end of the 2D piston 1212, a pressure regulating spring 1206,2D is connected between the left gasket 1205 and the right gasket 1207, and a concentric ring 1208 is disposed on the right side of the piston 1212.

The second valve sleeve 1213 is provided with three annular grooves, namely a second oil inlet groove P2, a second oil outlet groove A2 and a second oil return groove T2 from left to right, a plurality of identical radial oil inlet holes P3 are uniformly formed in the second oil inlet groove P2, a plurality of identical radial oil outlet holes A2 are uniformly formed in the second oil outlet groove A2, and a plurality of identical radial oil return holes T2 are uniformly formed in the second oil return groove T2. A pair of damping chutes are formed on the right inner bore wall of the second valve sleeve 1213 and cooperate with the high and low pressure grooves c1, c2 on the shoulder 1212.1 of the 2D piston 1212. And the second valve sleeve is provided with O-shaped sealing rings at two sides of each oil port, so that the local sealing of the servo valve is ensured.

The 2D piston 1212 is mounted in the second valve sleeve 1213, with both circumferential rotation and axial sliding directions of motion in the second valve sleeve 1213; the left end of the 2D piston 1212 is provided with a shoulder 1212.1, a pair of high-pressure grooves c1 and a pair of low-pressure grooves c2 are matched on the shoulder, the shoulder is matched with a pair of damping inclined grooves formed on the inner hole wall of the second valve sleeve 1213, the pair of high-pressure grooves c1 are communicated with the oil inlet hole p3, the pair of low-pressure grooves c2 are communicated with the oil return hole t2 through a central flow passage B3, the shoulder 1212.1 of the 2D piston, the concentric ring 1208 and the second valve sleeve 1213 are sealed to form a left sensitive cavity D1 and a right sensitive cavity D2, the pair of high-pressure grooves c1 and the pair of low-pressure grooves c2 on the shoulder 1212.1 of the 2D piston are intersected with the pair of damping inclined grooves to form four tiny opening areas in series to form a hydraulic resistance half bridge, the pressure change of the left sensitive cavity D1 is controlled, the right sensitive cavity D2 is communicated with the oil inlet hole p3, and the pressure of the left sensitive cavity D1 and the right sensitive cavity D2 is controlled by the hydraulic resistance half bridge, and the generated pressure difference drives the 2D piston 1212 to move axially.

The left end shoulder 1204.1 of the second valve core shell 1204 is uniformly provided with 4 radial through holes e1 which are the same as each other and are communicated with the oil inlet p 3; 4 identical radial through holes e2 are uniformly formed in the annular groove on the right side of the second valve core shell and are communicated with the oil outlet a 2. The second valve core housing 1204 cooperates with the valve sleeve plug 1201 to form a control chamber K3.

The second valve core 1203 is provided with a first shoulder 1203.1, a second shoulder 1203.2, which is matched with the first valve core sleeve 1204, and the opening degree of the oil port is changed when the second valve core 1203 moves axially. The left end face S3 of the second valve core is of a disc type structure, when the second valve core 1203 moves leftwards and rightwards, an extrusion oil film is formed between the disc type structure of the second valve core and the control cavity K3, and the function of the extrusion oil film is to introduce an extrusion oil film damping coefficient, increase viscous damping of a system and improve damping ratio so that the system is more stable. The right side of the first shoulder 1203.1 of the second valve core is provided with a through hole e3 which is communicated with the oil outlet a2 and is communicated with the control cavity K3 through a central flow passage B2.

When the 2D piston 1212 rotates clockwise (as viewed from the side of the transmission mechanism to the left), the area of intersection of the high pressure groove c1 and the damping chute decreases, the area of intersection of the low pressure groove c2 and the damping chute increases, at this time, the pressure of the left sensitive chamber D1 decreases, the pressure of the right sensitive chamber D2 does not change, and the 2D piston 1212 moves to the left. In the left moving process, the intersection area of the high-pressure groove c1 and the damping chute is increased, the intersection area of the low-pressure groove c1 and the damping chute is reduced, the pressure of the left sensitive cavity D1 is gradually increased, the pressure of the left sensitive cavity D1 is finally equal to the pressure of the right sensitive cavity D2, and the 2D piston is stabilized at a certain position. The 2D piston 1212 moves leftwards to generate leftwards force, the force is transmitted to the second valve core 1203 through the pressure regulating spring 1206, the right end of the second valve core 1203 is stressed to be larger, the primary hydraulic pressure balance is invalid, the second valve core 1203 moves leftwards to increase the opening of a valve port, the pressure of an oil outlet a2 is increased, the oil outlet a2 is communicated with the control cavity K3, so that the left end surface S3 of the second valve core is subjected to rightward hydraulic pressure to be increased, when the rightward hydraulic pressure is smaller than the pressure regulating spring force, the second valve core 1203 continues to move leftwards, the opening of the valve port continues to be increased, and the output pressure continues to be increased; when the rightward hydraulic force is equal to the pressure regulating spring force, the second valve spool 1203 stops moving leftward and stabilizes at a certain position while maintaining the pressure of the oil outlet at a substantially constant value.

The electromechanical transducer module adopts a torque motor 1210, and comprises a motor housing 1209, a housing 1210.1, an armature 1210.2, a permanent magnet 1210.3, a magnetizer 1210.4, a clamping piece 1210.5, a coil 1210.6, a spring 1210.7, a spring rod 1210.8, a spring seat 1210.10, a limiting rod 1210.9 and a connecting plate 1210.11, wherein the housing 1210.1 and the motor housing 1209 are connected with the connecting plate 1210.11, the housing 1210.1 is fixedly connected with the connecting plate 1210.11 through screws, one end of the spring 1210.7 is connected with the spring rod 1210.8, and the other end is connected with the spring seat 1210.10 fixed on the housing. The electromechanical transducer module is connected to the pump body 8 by a connection plate 1210.11. The two-dimensional pressure servo valve 12 employs a dry torque motor, so an O-ring seal is also placed over the motor housing 1209 and the connection plate 1210.11 to seal the output member from oil entering the space around the armature 1210.2, coil 1210.6 and permanent magnet 1210.3.

The electromechanical transducer module includes a magnetic circuit portion, a transmission portion, and a motor housing. The magnetic circuit part is composed of 2 coils 1210.6, 2 magnetizers 1210.4, 1 armature 1210.2 and 2 permanent magnets 1210.3. When the coil is not energized, the armature remains balanced 1210.2; energizing coil 1210.6 creates a magnetic path that breaks the equilibrium state before armature 1210.2 deflects. The driving part comprises a spring 1210.7, a spring seat 1210.10, a spring rod 1210.8 and a limit rod 1210.9. While the housing 1210.1 and the clip 1210.5 are used to secure and position the parts. The armature 1210.2, when deflected, will rotate the 2D piston 1212 and spring rod 1210.8. Spring 1210.7 is connected at one end to the spring rod 1210.8 and at the other end to a spring seat 1210.10 attached to the housing so that rotational movement of spring rod 1210.8 is effectively transferred to spring 1210.7, ensuring that spring 1210.7 automatically returns to zero in the event of an anomaly, thereby returning armature 1210.2 and 2D piston 1212 to an initial position.

The displacement sensor (LVDT sensor) module comprises an LVDT connecting rod 1210.12 and an LVDT sensor (comprising an iron core 1210.13 and a coil skeleton 1210.14), the LVDT sensor is matched with the circular arcs of the housing 1210.1 and the clamping piece 1210.5, the clamping piece 1210.5 is tightly pressed against the LVDT sensor through screws, the LVDT sensor is fixed, the spring rod 1210.8 is connected with the LVDT connecting rod 1210.12 in a mutually perpendicular mode, the LVDT connecting rod 1210.12 is connected with the iron core 1210.13, and the iron core 1210.13 is in clearance fit with the LVDT sensor and can directly move in an inner hole of the LVDT sensor. The LVDT sensor is connected to the 2D piston 1212 of the valve body module by a threaded connecting rod.

In the moment motor working process, the armature 1210.2 drives the spring rod 1210.8 and the 2D piston 1212 to rotate, the 2D piston moves linearly in combination with the 2D servo screw theorem, meanwhile, the spring rod 1210.8 and the iron core 1210.13 are driven to move linearly, and the displacement of the iron core 1210.13 is transmitted to the controller in the form of an electric signal in combination with the LVDT principle, so that closed-loop control of the displacement of the 2D piston is realized.

A plurality of oil ways are arranged in the pump body, and the first oil inlet groove P1 of the two-dimensional pulse width modulation mechanism is communicated with the oil outlet K of the duplex plunger pump through the oil ways; the first oil outlet groove A1 of the two-dimensional pulse width modulation mechanism is communicated with the oil outlet M4 of the pump body; the first oil return groove T1 of the two-dimensional pulse width modulation mechanism is communicated with a system oil tank; the control oil groove A1 of the two-dimensional pulse width modulation mechanism is communicated with the second oil outlet groove A2 of the two-dimensional pressure servo valve; the first oil inlet groove P1 of the two-dimensional pulse width modulation mechanism is communicated with the second oil inlet groove P2 of the two-dimensional pressure servo valve; the first oil return groove T1 of the two-dimensional pulse width modulation mechanism is communicated with the second oil return groove T2 of the two-dimensional pressure servo valve.

The working principle of this example:

When an external motor is started, the upper plunger 504 rotates at a constant speed under the drive of a motor coupler, and because of the matched connection of the upper right-end structural shaft 507 and the lower left-end structural shaft 701, the upper plunger and the lower plunger 706 are circumferentially rotated together, and the large roller groups of the upper left structural shaft 501 and the lower left structural shaft 701 are arranged on the corresponding upper left rail 510 and the lower left rail 714, and the large roller groups of the upper right structural shaft 507 and the lower right structural shaft 709 are arranged on the corresponding upper right rail 508 and the lower right rail 712, so that the large roller groups do reciprocating motion in the axial direction due to the constraint of the curved surface rails while do rotary motion. Therefore, as the large roller set continuously rolls on the corresponding left, right and other acceleration and deceleration curved surface tracks, the upper plunger 504 and the lower plunger 706 can axially and continuously reciprocate.

First, the pump core 5 is seen, and as the upper plunger 504 reciprocates, the volumes of the first left chamber and the second right chamber change regularly. When the upper plunger 504 moves axially from the leftmost end to the rightmost end, the first left chamber volume becomes gradually larger, and the first right chamber volume becomes gradually smaller; similarly, as the upper plunger 504 moves axially from the rightmost end to the leftmost end, the first right chamber volume becomes progressively larger and the first left chamber volume becomes progressively smaller. The lower pump core 7 and the upper pump core 5 move in the same way.

When the duplex plunger pump works, the distributing groove on the plunger is communicated with the window on the cylinder body, the containing cavity with gradually increased volume absorbs oil from the oil tank through the communicating distributing groove and the window, the containing cavity with gradually reduced volume discharges oil outwards through the communicating distributing groove and the window, and the reciprocating motion of the plunger enables the volumes of the left cavity and the right cavity to be constantly staggered and changed, so that continuous oil absorption and discharge are realized.

As shown in fig. 6a1 to 6c2, a schematic diagram of the working principle of the two-dimensional duplex plunger pump is shown (the above-mentioned duplex pump core is taken as an example). The upper plunger rotates clockwise (seen from left to right), a, b, c, d is a rectangular distribution groove on the upper plunger. e. f, g and h are flow distribution windows of the upper cylinder, e and g are oil absorption windows, and f and h are oil discharge windows. As shown in fig. 6a2, when the upper plunger moves to the leftmost end, the rectangular distribution groove a, b, c, d is not in communication with the window e, f, g, h. When the upper plunger rotates and moves to the right, as shown in fig. 6b2, the rectangular distribution grooves a, b, c, d are respectively communicated with the window e, f, g, h. The first left cavity with the gradually enlarged cavity absorbs oil from the oil tank through the communication channels a-e and c-g due to self-absorption; the first right chamber with gradually smaller volume extrudes oil in the chamber through the communication channels b-f and d-h. As shown in fig. 6c2, when the upper plunger is moved to the far right, the rectangular distribution groove a, b, c, d and the window e, f, g, h on the upper plunger are no longer in communication. When the upper plunger continues to rotate, the upper plunger starts to move leftwards, and the first right cavity starts to absorb oil from the oil tank through the communication channels b-g and d-e; the first left cavity extrudes oil through communication channels a-f and c-h, and the oil discharged by two cylinders of the double plunger pump is communicated on the pump body and discharged from the same oil outlet.

The oil discharged from the twin plunger pump 6 is introduced into the pressure servo variable mechanism 10 through the pump fluid passage. The pressure servo variable mechanism 10 starts to operate simultaneously with the twin plunger pump 6 due to the gear transmission.

The pressure servo variable mechanism 10 has two working states of constant pressure variable and pressure servo.

During the working process in the constant pressure variable state, the two-dimensional pressure servo valve 12 does not receive a given signal or a given feedback signal of the system, the system pressure is unchanged, and if the system flow changes, the system pressure also changes slightly. When the demand flow of the system increases, the pressure of the system decreases, that is, the pressure of the feedback cavity A1.2 of the two-dimensional pulse width modulation mechanism decreases, the balance state of the left and right ends of the first valve core 1108 of the two-dimensional pulse width modulation mechanism is broken, the resultant force of the left end S1 of the first valve core is larger than the resultant force of the right end S2 of the first valve core, so that the first valve core 1108 of the two-dimensional pulse width modulation mechanism moves rightwards, the opening degree of the oil inlet P1 increases, the opening time is prolonged, more flow flows into the system to supply energy for the system, and the pressure of the feedback cavity A1.2 increases, so that the first valve core maintains the original force balance state. Conversely, when the system demand flow is reduced, the system pressure is increased, that is, the pressure of the feedback cavity a1.2 is increased, the balance state of the left end and the right end of the first valve core is broken, the resultant force of the left end S1 of the first valve core is smaller than the resultant force of the right end S2 of the first valve core, the first valve core 1108 moves leftwards, the opening degree of the oil return port T1 is increased, the opening time is prolonged, more flow flows back to the oil tank to reduce the oil supply amount in the system, and the pressure of the feedback cavity a1.2 is reduced, so that the original force balance state is maintained.

When the two-dimensional pressure servo valve 12 receives a given signal or a system given feedback signal in the working process of the pressure servo state, the torque motor 1210 drives the 2D piston 1212 to move and axially output a certain displacement, and transmits force to the second valve core 1203 through a spring, the hydraulic pressure born by the second valve core 1203 is unbalanced and axially moves, the opening degree of the valve port changes, so that the output pressure changes until the hydraulic pressure born by the left end face S3 of the second valve core and the spring force are balanced again, the outlet pressure of the servo valve is basically constant, and the system pressure is constant again. The oil outlet A2 of the two-dimensional pressure servo valve is communicated with the control containing cavity K1.1 of the two-dimensional pulse width modulation mechanism, the pressure of the oil outlet A2 of the two-dimensional pressure servo valve changes, the original balance state of the first valve core 1108 of the two-dimensional pulse width modulation mechanism is broken, the first valve core 1108 moves axially, the ratio of the time required by the left triangular distributing window p1 and the right triangular distributing window p2 of the first valve core to the total time required by the left triangular distributing window p and the right triangular distributing window p2 of the first valve core to the total time respectively and alternately changes correspondingly, the oil outlet flow and the oil return flow change correspondingly, the flow entering the system changes correspondingly, the pressure of the feedback containing cavity A1.2 changes correspondingly, and the first valve core 1108 reaches a new balance state until the axial resultant force of the first valve core 1108 balances again, and the system pressure is kept constant again.

When the system pressure needs to be reduced, the pressure difference between the 2D piston sensitive cavity D1 and the pressure cavity D2 is reduced, the second valve core 1203 moves rightwards to reduce the opening of the valve port, the pressure oil port p3 is communicated with the control cavity K3, the rightward hydraulic pressure of the left end face S3 of the second valve core is reduced, and the hydraulic pressure is balanced with the pressure regulating spring force. When the output pressure is larger than the set pressure value, the hydraulic pressure received by the left end face S3 of the second valve core is larger than the pressure regulating spring force, the second valve core 1203 continues to move right, the opening degree of the valve port continues to decrease, the output pressure continues to decrease, when the output pressure reaches the set value of the valve, the hydraulic pressure received by the second valve core 1203 reaches balance again, at the moment, the opening degree of the valve port becomes smaller, the reduction of the pressure of the oil outlet is realized, and the pressure of the oil outlet is kept to be basically a fixed value. The pressure of an oil outlet A2 of the two-dimensional pressure servo valve is reduced, so that the pressure of a control cavity K1.1 of the two-dimensional pulse width modulation mechanism is reduced, the resultant force of the left end S1 of the first valve core is smaller than the resultant force of the right end S2, the first valve core 1108 moves leftwards, the opening degree of a valve port of an oil inlet p1 is reduced (until the valve port is completely closed), the pressure of the oil outlet A1 is reduced along with the loss of oil in a system, and until the resultant force of two ends of the first valve core 1108 is equal again, the first valve core 1108 reaches a new balance state, the pressure reduction effect is realized, and the pressure of the system is kept constant.

Conversely, when the system pressure needs to be increased, the pressure difference between the 2D piston sensing chamber D1 and the pressure chamber D2 is increased, the second valve core 1203 moves leftward to increase the valve port opening, the hydraulic pressure of the second valve core left end face S3 to the right increases, and the force balances with the pressure regulating spring force. When the output pressure is smaller than the set pressure value, the hydraulic pressure received by the left end face S3 of the second valve core is smaller than the pressure regulating spring force, the second valve core 1203 continues to move leftwards, the opening degree of the valve port continues to increase, and the output pressure continues to increase; when the output pressure reaches the set pressure value of the valve, the hydraulic pressure borne by the first valve core 1203 reaches balance again, at this time, the opening of the valve port becomes large, the pressure of the oil outlet is increased, and the pressure of the oil outlet A2 is kept to be basically constant. The pressure of an oil outlet A2 of the two-dimensional pressure servo valve is increased, so that the pressure of a control cavity K1.1 of the two-dimensional pulse width modulation mechanism is increased, the resultant force of the left end S1 of the first valve core is larger than the resultant force of the right end S2, the first valve core 1108 moves rightwards, the opening degree of a valve port of an oil return port p2 is reduced (until the valve port is completely closed), the pressure of the oil outlet A1 is increased along with a large amount of inflow of oil in a system until the resultant force of two ends of the first valve core 1108 is equal again, the first valve core 1108 achieves a new balance state, the supercharging effect is achieved, and the pressure of the system is kept constant.

The embodiments described in the present specification are merely examples of implementation forms of the inventive concept, and the scope of protection of the present invention should not be construed as being limited to the specific forms set forth in the embodiments, and the scope of protection of the present invention and equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. Two-dimensional pressure servo variable pump, its characterized in that: the device comprises a front end cover, a pump body, a rear end cover, a duplex plunger pump and a pressure servo variable mechanism; the pressure servo variable mechanism comprises a two-dimensional pulse width modulation mechanism and a two-dimensional pressure servo valve;

The front end cover is fixedly connected with the pump body through a screw; the rear end cover is fixedly connected with the pump body through a screw; the duplex plunger pump is fixed in the pump body; the two-dimensional pulse width modulation mechanism and the two-dimensional pressure servo valve are fixedly connected with the pump body through screws;

A driving gear, a driven gear and a first deep groove ball bearing are arranged in the front end cover, the driving gear is fixedly connected with a motor coupler, and the driven gear is fixedly connected with a two-dimensional pulse width modulation mechanism;

The pump body is provided with an oil inlet hole, an oil outlet hole, a first through hole, a second through hole and a third blind hole; the oil outlet is arranged at the top of the pump body, the first through hole is arranged at the lower part of the pump body and communicated with the oil inlet, and a duplex plunger pump is arranged; the second through hole is arranged at the upper part of the pump body and is provided with a two-dimensional pulse width modulation mechanism; the third blind hole is arranged at the upper part of the pump body and is provided with a two-dimensional pressure servo valve;

The duplex plunger pump comprises an upper pump core and a lower pump core, wherein the upper pump core is close to the front end cover, and the lower pump core is close to the rear end cover;

The upper pump core comprises an upper cylinder body, an upper plunger, an upper left end structural shaft, an upper right end structural shaft, a first concentric ring, a second concentric ring, an upper left guide rail, an upper right guide rail and a first positioning pin; the upper plunger is arranged in the upper cylinder body, the left end and the right end of the upper plunger are respectively fixedly connected with an upper left end structural shaft and an upper right end structural shaft by first positioning pins, and the left side and the right side of the upper plunger are respectively provided with a first concentric ring and a second concentric ring; the left end and the right end of the upper cylinder body are fixedly connected with an upper left guide rail and an upper right guide rail which are provided with equal acceleration and deceleration curved surface rails, the equal acceleration and deceleration curved surface rails of the upper left guide rail and the upper right guide rail are mutually staggered at 90 degrees in the circumferential direction, namely the highest point and the lowest point of the equal acceleration and deceleration curved surface rails of the upper left guide rail are respectively corresponding to the lowest point and the highest point of the equal acceleration and deceleration curved surface rails of the upper right guide rail;

a shoulder is arranged in the middle of the upper plunger, four rectangular distribution grooves which are uniformly distributed are formed in the surface of the upper plunger, and the notch positions of the four rectangular distribution grooves are staggered;

Four flow distribution windows are uniformly distributed on the upper connecting cylinder body, and are respectively provided with two oil inlets and two oil outlets, the oil inlets and the oil outlets are alternately arranged, the oil inlets are communicated with low-pressure oil, the oil outlets are communicated with high-pressure oil, and the oil inlets and the oil outlets are not communicated with each other; two sides of the oil outlet are sealed by sealing rings; the flow distribution window is arranged corresponding to the flow distribution groove on the upper connecting plunger;

The upper left end structure shaft comprises a first structure shaft main body, a first large roller, a second large roller, a first small roller pair and a second small roller pair; the second large roller and the first large roller have the same structure and form a first large roller group; the second small roller pair and the first small roller pair have the same structure and form a first small roller group; the first large roller comprises a conical roller bearing sleeve and a second deep groove ball bearing, wherein the outer part of the conical roller bearing sleeve is a conical surface, the inner part of the conical roller bearing sleeve is a round hole, and an inner hole of the conical roller bearing sleeve is sleeved on the outer circle of the second deep groove ball bearing and fixedly connected with the outer circle; the first small roller pair comprises a large cylindrical roller and a small cylindrical roller, the large cylindrical roller comprises a cylindrical bearing sleeve and a third deep groove ball bearing, the outside of the cylindrical bearing sleeve is a cylinder, the inside of the cylindrical bearing sleeve is a round hole, and an inner hole of the cylindrical bearing sleeve is sleeved on the outer circle of the third deep groove ball bearing and fixedly connected with the outer circle; the small cylindrical roller comprises a cylindrical roller sleeve and a copper sleeve, the outside of the roller sleeve is a cylinder, the inside of the box body is provided with a round hole, the inner hole of the roller sleeve is sleeved on the outer circle of the copper bush is fixedly connected; the first large roller and the second large roller are fixedly connected to two ends of the main body of the first structural shaft through nuts and are arranged in an axisymmetric mode; the first small roller pair and the second small roller pair are fixedly connected to two ends of the main body of the first structural shaft through second positioning pins and are arranged in a central symmetry mode;

The upper right end structure shaft and the left end structure shaft are completely identical in structure;

the rolling surfaces of the large roller group of the upper left end structure shaft and the upper right end structure shaft are respectively matched with the corresponding upper left guide rail and upper right guide rail, and the rolling surface of the small roller group of the upper left end structure shaft is matched with a track carried by a motor coupler; the rolling surface of the small roller group of the upper-connected right-end structural shaft is matched with a track carried by a shifting fork structure of a third structural shaft main body;

the space enclosed by the first concentric ring, the upper connecting plunger and the upper connecting cylinder body together forms a first left cavity, the space enclosed by the second concentric ring, the upper connecting plunger and the upper connecting cylinder body together forms a first right cavity, and the volumes of the first left cavity and the first right cavity are staggered along with the reciprocating motion of the plunger;

The lower pump core comprises a lower cylinder body, a lower plunger, a lower left end structural shaft, a lower right end structural shaft, a third concentric ring, a fourth concentric ring, a lower left guide rail, a lower right guide rail and a third positioning pin; the lower plunger is arranged in the lower cylinder body, the left end and the right end of the lower plunger are respectively fixedly connected with a lower left end structural shaft and a lower right end structural shaft by third positioning pins, and the left side and the right side of the lower plunger are respectively provided with third concentric rings and fourth concentric rings; the left end and the right end of the lower cylinder body are fixedly connected with a lower left guide rail and a lower right guide rail which are provided with equal acceleration and deceleration curved surface tracks; the arrangement mode of the lower left guide rail and the lower right guide rail is the same as that of the upper left guide rail and the upper right guide rail;

the lower connecting cylinder body and the upper connecting cylinder body are identical in structure;

The lower plunger is identical to the upper plunger in structure, and the upper plunger and the lower plunger are concentrically arranged;

The lower left end structure shaft comprises a third structure shaft main body and a third large roller group; the third structure shaft main body is provided with a shifting fork structure and is matched and connected with the small roller group of the upper-connection right-end structure shaft, so that the upper-connection pump core and the lower-connection pump core are staggered by 45 degrees in space; the right end structure shaft of the lower link comprises a fourth structure shaft main body and a fourth large roller group; the third large roller group and the fourth large roller group have the same structure as the first large roller group of the upper left end structural shaft, and the placement modes are the same; the rolling surfaces of the third large roller group and the fourth large roller group of the lower left end structure shaft and the lower right end structure shaft are respectively matched with a lower left guide rail and a lower right guide rail on the lower cylinder body;

the space enclosed by the third concentric ring, the lower connecting plunger and the lower connecting cylinder body together forms a second left cavity, the space enclosed by the fourth concentric ring, the lower connecting plunger and the lower connecting cylinder body together forms a second right cavity, and the volumes of the second left cavity and the second right cavity are staggered along with the reciprocating motion of the plunger;

The two-dimensional pulse width modulation mechanism comprises a transmission shaft, a zero spring, a roller shaft, a left roller assembly, a right roller assembly, a front concentric ring, a first valve core, a first valve sleeve, a rear concentric ring and a first valve core plug; the transmission shaft shifting fork and the roller assembly are matched to shift the first valve core through the roller shaft, so that the first valve core axially slides while circumferentially rotating in the first valve sleeve, the first valve core rotates and axially slides relatively independently, the front concentric ring and the rear concentric ring are respectively fixedly connected to two ends of the first valve sleeve, and the zero spring is arranged between the first valve core and the transmission shaft and is in a compression state;

One end of the transmission shaft is a cylindrical end and is connected with the transmission mechanism; the other end of the transmission shaft is in a door frame shape, two U-shaped shifting forks are connected, the shifting fork surface is an axial incomplete cylindrical surface track, and the left roller assembly and the right roller assembly are matched, so that the first valve core axially slides while rotating circumferentially; the axial middle end surface of the transmission shaft is provided with a circular groove for fixing the zero spring;

The two flat end surfaces of the zero spring are respectively fixed at the circular groove of the transmission shaft and the stepped shaft at the left end of the first valve core, the zero spring is in a compressed state in the initial and working processes, the first valve core in the initial state is ensured to be at the rightmost end, and the zero position of the first valve core is maintained;

the roller shaft is a stepped cylindrical shaft, a shoulder is arranged in the middle of the roller shaft, and the diameter of the middle cylinder is larger than that of the cylinders at the two sides; the middle shoulder shaft is inserted into a cylindrical hole at the left end of the first valve core and fixedly connected, and the two end shafts are respectively inserted into a central round hole of the left roller assembly and a central round hole of the right roller assembly and fixedly connected;

The right roller assembly and the left roller assembly have the same structure and comprise a first bearing sleeve and a fourth deep groove ball bearing, the outside of the first bearing sleeve is a spherical surface, the inside of the first bearing sleeve is a round hole, the two ends of the first bearing sleeve are flat end surfaces, an inner hole of the first bearing sleeve is sleeved on the outer circle of the fourth deep groove ball bearing and fixedly connected with the outer circle of the fourth deep groove ball bearing, and the spherical surface of the first bearing sleeve is matched with the cylindrical surface of the U-shaped shifting fork of the transmission shaft;

The front concentric ring is annular, two end faces are planes, the outer circle of the front concentric ring is fixedly connected with the first valve sleeve, and the inner hole is sleeved on the left end shaft of the first valve core;

The rear concentric ring is in a circular shape, two end surfaces are plane, a stepped hole is formed in the inner hole to provide avoidance space for a second circular through hole of the first valve core, the outer circle of the rear concentric ring is fixedly connected with the first valve sleeve, and the inner hole is sleeved on the right end shaft of the first valve core;

The inner hole of the first valve sleeve is a central through hole and is matched with the first valve core, and the two ends of the first valve sleeve are respectively provided with a front stepped hole and a rear stepped hole which are respectively fixedly connected with the front concentric ring and the rear concentric ring; four annular grooves are formed in the outer circle of the first valve sleeve, a control oil groove, a first oil outlet groove, a first oil inlet groove and a first oil return groove are formed in the outer circle of the first valve sleeve from left to right, a plurality of identical radial control oil holes are uniformly formed in the control oil groove, a plurality of identical radial oil outlet holes are uniformly formed in the first oil outlet groove, a plurality of identical radial diamond-shaped flow distribution windows are uniformly formed in the first oil inlet groove, the peaks of the diamond-shaped flow distribution windows are in the same plane and perpendicular to the axis of the first valve core, and a plurality of identical radial oil return holes are uniformly formed in the first oil return groove;

The leftmost end of the first valve core is provided with a stepped shaft for installing a zero spring, the right side of the stepped shaft is provided with a round through hole of a roller shaft, and the stepped shaft is fixedly connected with the roller shaft and is used for transmitting torque to the first valve core to enable the first valve core to rotate; the first valve core is provided with three shoulders, a first shoulder, a second shoulder and a third shoulder are sequentially arranged from left to right, a first circular through hole is radially formed in a first valve core shaft between the first shoulder and the second shoulder, a second circular through hole is radially formed in the first valve core shaft which is close to the right end face of the third shoulder, a central flow passage is axially formed in the center of the first valve core, a central flow passage opening is plugged by the first valve core plug, and the first circular through hole and the second circular through hole are communicated through the central flow passage of the first valve core; two rows of staggered triangular flow distribution windows are respectively a left triangular flow distribution window and a right triangular flow distribution window on the second shoulder of the first valve core, the vertexes of the two rows of staggered triangular flow distribution windows are in the same plane, and the plane is perpendicular to the axis of the first valve core;

The outer spherical surface of the first bearing sleeve is in clearance fit with the U-shaped shifting fork of the transmission shaft, single-side contact can be realized when the transmission shaft is stressed, forward and reverse rotation can be realized, the transmission shaft drives the first valve core to rotate through the left roller assembly, the right roller assembly and the roller shaft, and the first valve core axially slides under the action of hydraulic force to drive the first bearing sleeve to axially roll on the U-shaped shifting fork of the transmission shaft;

the outer circles of the front concentric ring and the rear concentric ring are respectively fixedly connected in a front stepped hole and a rear stepped hole on two end surfaces of the first valve sleeve, the inner holes of the front concentric ring are sleeved on the left end shaft of the first valve core for gap sealing, and the inner holes of the rear concentric ring are sleeved on the right end shaft of the first valve core for gap sealing;

The first valve core is rotatably arranged in the first valve sleeve, the front concentric ring and the first shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a control containing cavity, the control containing cavity is communicated with a control oil groove through a control oil hole, and the control oil groove is communicated with control pressure oil; the first shoulder and the second shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a high-pressure containing cavity, the high-pressure containing cavity is communicated with the first oil outlet groove through an oil outlet hole and is communicated with the first oil inlet groove through a diamond flow distribution window, the first oil inlet groove is communicated with high-pressure oil of a hydraulic pump, and the first oil outlet groove is communicated with a system oil way; the second shoulder and the third shoulder of the first valve core seal the inner cavity of the first valve sleeve to form a low-pressure containing cavity, the low-pressure containing cavity is communicated with a first oil return groove through an oil return hole, and the first oil return groove is communicated with a low-pressure oil tank; the third shoulder of the first valve core and the rear concentric ring seal the inner cavity of the first valve sleeve to form a feedback cavity, the feedback cavity is communicated with the high-pressure cavity through the first circular through hole, the central flow passage and the second circular through hole of the first valve core, and the pressures of the two cavities are the same; the first valve sleeve control oil groove, the first oil outlet groove, the first oil inlet groove and the first oil return groove are not communicated with each other outside the first valve sleeve; two staggered triangular flow distribution windows are formed in the second shoulder of the first valve core and are a left triangular flow distribution window and a right triangular flow distribution window respectively, the first valve sleeve diamond flow distribution window is positioned on the motion track of the second shoulder of the first valve core, the first valve core axially slides under the action of hydraulic pressure while rotating at a constant speed in the first valve sleeve, so that the flow distribution time duty ratio of the left triangular flow distribution window and the right triangular flow distribution window of the first valve core and the flow distribution time duty ratio of the right triangular flow distribution window of the first valve sleeve are changed respectively, and the oil outlet flow is changed to realize flow distribution;

the two-dimensional pressure servo valve consists of a valve body module, a displacement sensor module and an electric-mechanical converter module, wherein the displacement sensor module is matched with the valve body module, and the electric-mechanical converter module is matched with the valve body module; the displacement sensor module monitors the displacement of the 2D piston in the valve body module and the torque motor electric signal of the electromechanical converter module in real time to form closed loop feedback;

The valve body module comprises a second valve core, a second valve core shell, a 2D piston, a left gasket, a right gasket, concentric rings, a pressure regulating spring, a second valve sleeve, a valve sleeve plug and a fourth positioning pin; the second valve core is arranged in an inner hole of the second valve core shell, the 2D piston is arranged on the right side of the second valve sleeve, the valve sleeve plug is fixedly connected to the left end part of the second valve sleeve through a fourth locating pin, and the second valve core shell is positioned through the valve sleeve plug and is fixed on the left side of the second valve sleeve; the left gasket is connected to the right end of the second valve core, the right gasket is connected to the left end of the 2D piston, a pressure regulating spring is connected between the left gasket and the right gasket, and concentric rings are arranged on the right side of the 2D piston;

The second valve sleeve is provided with three annular grooves, namely a second oil inlet groove, a second oil outlet groove and a second oil return groove from left to right, wherein a plurality of identical radial oil inlet holes are uniformly formed in the second oil inlet groove, a plurality of identical radial oil outlet holes are uniformly formed in the second oil outlet groove, and a plurality of identical radial oil return holes are uniformly formed in the second oil return groove; a pair of damping chute matched with the high-low pressure groove on the shoulder of the 2D piston is formed on the inner hole wall on the right side of the second valve sleeve; the second valve sleeve is provided with O-shaped sealing rings at two sides of each oil port, so that the local sealing of the servo valve is ensured;

The 2D piston is arranged in the second valve sleeve, and the second valve sleeve has two movement directions of circumferential rotation and axial sliding; the left end of the 2D piston is provided with a shoulder, the shoulder is provided with a pair of high-pressure grooves and a pair of low-pressure grooves in a matching way, the shoulder is matched with a pair of damping inclined grooves formed on the inner wall of the second valve sleeve, the pair of high-pressure grooves are communicated with the oil inlet hole, the pair of low-pressure grooves are communicated with the oil return hole, the shoulder, the concentric ring and the second valve sleeve of the 2D piston are sealed to form a left sensitive cavity and a right sensitive cavity, the shoulder of the 2D piston is provided with a pair of high-pressure grooves and a pair of low-pressure grooves which are intersected with the pair of damping inclined grooves to form four tiny opening areas in series to form a hydraulic resistance half bridge, the pressure change of the left sensitive cavity is controlled, the right sensitive cavity is communicated with the oil inlet hole, the pressure of the left sensitive cavity and the right sensitive cavity is controlled by the hydraulic resistance half bridge, and the generated pressure difference drives the 2D piston to axially move;

The left end shoulder of the second valve core shell is uniformly provided with 4 identical radial through holes which are communicated with the oil inlet holes; 4 identical radial through holes are uniformly formed in the annular groove on the right side of the second valve core shell and are communicated with the oil outlet; the second valve core shell is in plug fit with the valve sleeve to form a control cavity;

The left side and the right side of the second valve core are respectively provided with a shoulder which is matched with the second valve core shell, and the opening degrees of the oil ports of the oil inlet and the oil return port are changed when the second valve core axially moves; the left end face of the second valve core is set to be a disc type structure, when the second valve core moves left and right, an extrusion oil film is formed between the disc type structure of the second valve core and a closed containing cavity formed by the second valve core shell and the valve sleeve plug, and the function of the extrusion oil film is to introduce an extrusion oil film damping coefficient, increase the viscous damping of the system and improve the damping ratio so that the system is more stable; the second valve core is internally provided with a central flow passage which is connected with a through hole on the right side of the second valve core and is communicated with the control cavity;

The electric-mechanical converter module comprises a torque motor, and comprises a shell, an armature, a permanent magnet, a magnetizer, a clamping piece, a motor housing, a coil, a spring rod, a spring seat, a limiting rod and a connecting plate, wherein the shell and the motor housing are connected with the connecting plate, the shell is fixedly connected with the connecting plate through a screw, one end of the spring is connected with the spring rod, and the other end of the spring is connected with the spring seat fixed on the shell; the electromechanical converter module is connected with the valve body through a connecting plate; the two-dimensional pressure servo valve adopts a dry torque motor, so an O-shaped sealing ring is also arranged on the motor housing and the connecting plate, and the output part is sealed to prevent oil from entering the space surrounding the armature, the coil and the permanent magnet;

The electromechanical transducer module includes a magnetic circuit portion, a transmission portion, and a motor housing; the connecting plate is connected with the motor housing through screws; the magnetic circuit part consists of 2 coils, 2 magnetizers, 1 armature iron and 2 permanent magnets; when the coil is not electrified, the armature remains balanced; when the coil is electrified, a magnetic path is generated, the balance state before the coil is destroyed, and the armature deflects; the transmission part comprises a spring, a spring seat, a spring rod, a limit rod and a motor pin; when the armature deflects, the 2D piston and the spring rod are driven to rotate; one end of the spring is connected with the spring rod, and the other end of the spring is connected with a spring seat fixedly connected to the shell;

The displacement sensor module comprises an LVDT connecting rod and an LVDT sensor consisting of an iron core and a coil framework, and the LVDT sensor is fixed on the shell; the spring rod is connected with the LVDT connecting rod in a mutually perpendicular manner; the LVDT connecting rod is connected with the iron core, the iron core is in clearance fit with the LVDT sensor, and the iron core moves directly in an inner hole of the LVDT sensor; the LVDT sensor is connected with the 2D piston of the valve body module through a threaded connecting rod.

2. The two-dimensional pressure servo variable pump of claim 1, wherein: the LVDT sensor is matched with the circular arcs of the shell and the clamping piece, and the clamping piece is pressed against the LVDT sensor through the screw, so that the LVDT sensor is fixed.