A new type of high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve

Abstract

This invention discloses a novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve. It includes a piezoelectric rotary actuator, a jet distribution assembly, and a power stage spool valve assembly. The piezoelectric rotary actuator generates a corresponding horizontal rotary angle based on the input voltage signal and transmits this angle to the jet distribution assembly. The jet distribution assembly performs jet vector control of the pre-stage based on the rotary angle. The jet distribution assembly includes an eccentrically positioned feedback rod, the lower end of which is inserted into a mating hole in the valve core of the power stage spool valve assembly. The feedback rod converts the linear motion of the valve core into rotary feedback, thereby achieving mechanical feedback between the pre-stage and power stage of the servo valve. This invention features good heat dissipation, low processing difficulty, low actuator power consumption, and low manufacturing cost. It meets mechanical design principles, enables high-frequency operation, further increases the operating bandwidth of the servo valve, and results in lower hydraulic force in the pre-stage, more compact assembly, less leakage, and higher control precision.

Description

Technical Field

[0001] The invention relates to the field of two-stage electro-hydraulic servo valves, and in particular to a novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve. Background Art

[0002] Hydraulic servo control systems are widely used in the field of aerospace power control that requires high precision, high response, and high power density ratio. Servo valves are the main power regulating elements used in high-performance hydraulic servo control systems. Common servo valves are usually two-stage devices. The first stage uses the slight deflection of the torque motor to achieve the flow pressure distribution of the hydraulic amplifier. The second stage is a power-level slide valve structure used to achieve precise control of the actuator. With the rapid development of smart materials, high-response, high-bandwidth smart materials are one of the best choices for driving the pre-stage of the servo valve. The torque motor of a conventional electro-hydraulic servo valve has the characteristics of high processing and manufacturing cost, difficult assembly process, and difficulty in improving frequency response. The use of controllable deformation of smart materials to achieve precise drive of the pre-stage has become an alternative to torque motors. Summary of the invention

[0003] The purpose of the present invention is to provide a novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve in view of the deficiencies in the prior art.

[0004] To achieve the above-mentioned purpose, the present invention provides a new type of high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve, including a piezoelectric rotary actuator, a jet distribution assembly and a power stage sliding valve assembly which are detachably fixed from top to bottom in sequence, the piezoelectric rotary actuator is used to generate a corresponding horizontal rotation angle according to an input voltage signal, and transmit the rotation angle to the jet distribution assembly, the jet distribution assembly completes the jet vector control of the pre-stage according to the rotation angle, and then controls the operation of the power stage sliding valve assembly, the jet distribution assembly includes a feedback rod eccentrically arranged on its lower side, the lower end of the feedback rod is inserted into the matching hole of the valve core of the power stage sliding valve assembly, and the feedback rod converts the linear motion of the valve core into rotary feedback to realize mechanical feedback between the pre-stage and the power stage of the servo valve.

[0005] Furthermore, the piezoelectric actuator includes a supporting outer ring, a rotating main shaft arranged in the middle of the inner side of the supporting outer ring, and a plurality of piezoelectric bending pieces connected between the inner side of the supporting outer ring and the rotating main shaft. The outer end of the piezoelectric bending piece is fixedly connected to the supporting outer ring, and the inner end thereof is slidably connected to the rotating main shaft. When energized, the piezoelectric bending piece generates polarized bending and drives the rotating main shaft to generate a corresponding rotation angle. A sealing seat is provided on the lower side of the supporting outer ring, and the rotating main shaft is inserted through the sealing seat.

[0006] Furthermore, the jet distribution assembly includes a special-shaped jet disk, which is provided with a jet inlet, a left jet outlet and a right jet outlet. A rotatable deflection control rod is provided in the middle of the special-shaped jet disk, and the upper end of the deflection control rod is threadedly connected to the rotating main shaft. The feedback rod is eccentrically arranged on the lower side of the deflection control rod. A connecting groove is provided on the deflection control rod between the jet inlet and the left jet outlet and the right jet outlet. When the deflection control rod is not rotated, the left jet outlet and the right jet outlet are symmetrically arranged on both sides of the center line of the connecting groove. When the deflection control rod rotates with the rotating main shaft, the connecting groove forms an inconsistent vector angle with the left jet outlet and the right jet outlet, thereby completing the jet vector control of the pre-stage.

[0007] Furthermore, the jet distribution assembly also includes a clamping end cover which is detachably fixedly connected to the supporting outer ring, the special-shaped jet disk is arranged on the inner side of the middle part of the clamping end cover, and an upper pressure plate and a lower pressure plate are respectively provided on the upper and lower sides thereof, and the deflection control rod is interspersed with the upper and lower pressure plates; the deflection control rod and the special-shaped jet disk are spaced to form a drain port, and through holes are respectively provided on the lower pressure plate at positions corresponding to the left jet outlet, the right jet outlet, the jet inlet and the drain port, so that the left jet outlet, the right jet outlet, the jet inlet and the drain port are respectively connected to the left load chamber, the right load chamber, the oil supply port and the oil return port on the power sliding valve assembly.

[0008] Furthermore, the cross section of the connecting groove is trapezoidal, with the side with a larger opening being arranged toward the jet inlet, and the side with a smaller opening being arranged toward the jet left outlet and the jet right outlet.

[0009] Furthermore, a mounting groove is provided on the inner side of the supporting outer ring, the outer end bolt of the piezoelectric bending piece is fixed in the connecting groove, a limiting groove is provided on the outer side of the rotating main shaft at a position corresponding to the piezoelectric bending piece, and the inner end of the piezoelectric bending piece is slidably connected in the limiting groove.

[0010] Furthermore, the piezoelectric bending pieces include 3 to 6 pieces, which are evenly distributed between the inner side of the supporting outer ring and the rotating main shaft.

[0011] Furthermore, a first sealing ring is provided between the lower side of the sealing seat and the upper side of the clamping end cover, and a second sealing ring is provided between the lower side of the clamping end cover and the power stage sliding valve assembly.

[0012] Furthermore, the piezoelectric rotary actuator, the jet distribution assembly and the power stage sliding valve assembly are bolted together.

[0013] Beneficial effects: 1. The present invention has good heat dissipation, low processing difficulty and low cost. The high-frequency micro-deformation of the piezoelectric bending piece is used to realize the rotation, and the actuator power consumption is small.

[0014] 2. The main connection form of the present invention meets the mechanical design principle, can achieve high-frequency action, and further increase the use bandwidth of the servo valve.

[0015] 3. The working principle of this device is different from that of the traditional servo valve. It converts the planar motion of the lever principle of the deflection control rod into a circular rotation. The pre-stage hydraulic force is smaller, the assembly is more compact, the leakage is smaller, and the control accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic structural diagram of a novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to an embodiment of the present invention;

[0017] Figure 2 is a schematic structural diagram of a piezoelectric rotary actuator according to an embodiment of the present invention;

[0018] Figure 3 is a schematic structural diagram of a jet distribution assembly according to an embodiment of the present invention;

[0019] Figure 4 Schematic diagram of the cooperation between the special-shaped jet disk and the deflection control rod according to an embodiment of the present invention;

[0020] Figure 5 Schematic diagram of the structure of a power stage slide valve assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0022] like Figures 1 to 5 As shown, an embodiment of the present invention provides a novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve, comprising a piezoelectric rotary actuator 1, a jet distribution assembly 2 and a power stage slide valve assembly 3. The piezoelectric rotary actuator 1, the jet distribution assembly 2 and the power stage slide valve assembly 3 are detachably fixed together in sequence from top to bottom. The piezoelectric rotary actuator 1 is used to generate a corresponding horizontal rotation angle according to the input voltage signal, and transmit the rotation angle to the jet distribution component 2. The jet distribution component 2 completes the jet vector control of the pre-stage according to the rotation angle, and then controls the operation of the power-stage slide valve component 3. A feedback rod 2-4 is provided on the lower side of the jet distribution component 2. The feedback rod 2-4 is eccentrically arranged on the lower side of the jet distribution component 2. A contact ball head 2-5 is provided at the lower end of the feedback rod 2-4. The contact ball head 2-5 is inserted into the matching hole 3-2 of the valve core 3.1 of the power-stage slide valve component 3. The feedback rod 2-4 converts the linear motion of the valve core 3.1 into rotation feedback to realize the mechanical feedback of the servo valve pre-stage and the power stage.

[0023] like Figure 2 As shown, the piezoelectric actuator 1 of the embodiment of the present invention comprises a supporting outer ring 1.1, a rotating main shaft 1.2 and a plurality of piezoelectric bending pieces 1.4. Among them, the rotating main shaft 1.2 is arranged in the middle of the inner side of the supporting outer ring 1.1, and the piezoelectric bending piece 1.4 is connected between the inner side of the supporting outer ring 1.1 and the rotating main shaft 1.2. The outer end of the piezoelectric bending piece 1.4 is fixedly connected to the supporting outer ring 1.1, and the inner end of the piezoelectric bending piece 1.4 is slidably connected to the rotating main shaft 1.2. When in use, the outer end of the piezoelectric bending piece 1.4 is connected to the control wire, and an AC voltage is input to the piezoelectric bending piece 1.4 through the control wire, so that the piezoelectric bending piece 1.4 can generate polarization movement in the thickness direction. The piezoelectric bending pieces 1.4 of the embodiment of the present invention can generally be 3 to 6, preferably 4, and the piezoelectric bending pieces 1.4 are evenly distributed between the inner side of the supporting outer ring 1.1 and the rotating main shaft 1.2. As a preferred embodiment, a mounting groove 1-1 is provided on the inner side of the supporting outer ring 1.1, and the outer end of the piezoelectric bending piece 1.4 is inserted into the mounting groove 1-1. Concentric holes are opened on the piezoelectric bending piece 1.4 and the mounting groove 1-1, and the bolt 1.7 is passed through the concentric hole and threadedly connected with the nut 1.6, thereby fixing the outer end 1.4 of the piezoelectric bending piece in the mounting groove 1-1. A plurality of limit grooves 1-3 are provided on the outer side of the rotating main shaft 1.2, and the limit grooves 1-3 correspond to the positions of the piezoelectric bending piece 1.4, and the inner end of the piezoelectric bending piece 1.4 is slidably connected in the limit grooves 1-3. This is to ensure the accurate positioning of the piezoelectric bending piece 1.4 under the free length, and also to make the piezoelectric bending piece 1.4 and the rotating main shaft 1.2 generate a certain dynamic friction force to achieve the switching of the motion form. When the outer end of the piezoelectric bending piece 1.4 is energized, under the action of a certain electric field, the piezoelectric bending piece 1.4 will be slightly polarized in the width direction, thereby affecting the radial rotation accuracy of the rotating main shaft 1.2. In addition, in order to prevent the piezoelectric bending piece 1.4 from sliding out from the upper side of the limiting groove 1-3, it is preferred to thread a bolt 1.5 at the upper end of the rotating main shaft 1.2, and use the annular surface of the bolt 1.5 to limit the width direction of the piezoelectric bending piece 1.4. A sealing seat 1.3 is provided on the lower side of the supporting outer ring 1.1, and the rotating main shaft 1.2 is inserted through the sealing seat 1.3, and the sealing seat 1.3 is kept sealed to prevent the oil on the lower side from leaking out along the rotating main shaft 1.2.

[0024] like Figure 5As shown, the power level slide valve assembly 3 of the embodiment of the present invention is a prior art, which includes a valve core 3.1, a valve sleeve 3.2 and a valve body 3.3, an end sealing screw plug 3.4, an outer end cover 3.5 and a fastening screw 3.6. A pressure equalizing groove 3-6 is provided on the valve core 3.1, and the pressure equalizing groove 3-6 is used to reduce the unbalanced liquid pressure of the valve core 3.1 during the axial movement. A right load pressure feedback window 3-3 and a left load pressure feedback window 3-4 are provided on the valve sleeve 3.2, and the left load pressure feedback window 3-4 and the right load feedback window 3-3 are used to realize the introduction of the two-chamber pressure of the actuator for control. The valve body 3.3, the end sealing plug 3.4 and the valve core 3.1 together form the left control chamber 3-5 and the right control chamber 3-7. The right jet receiving hole 3-9, the left jet receiving hole 3-10, the oil outlet hole 3-11, the left load port 3-12, the oil supply port 3-13, the right load port 3-14, the oil return port 3-15 and the oil drain port 3-16 are provided on the upper side of the valve body 3.3. Among them, the left load port 3-12, the oil supply port 3-13, the right load port 3-14 and the oil return port 3-15 are used to form a complete hydraulic system with external connecting pipelines. The right jet receiving hole 3-9, the left jet receiving hole 3-10, the oil outlet hole 3-11 and the oil drain port 3-16 are connected with the jet distribution assembly 2. Since the improvement of this part is not involved, the other structures of the power stage sliding valve assembly 3 are not repeated.

[0025] like Figure 3 and 4As shown, the jet distribution assembly 2 of the embodiment of the present invention includes a special-shaped jet disk 2.1, which is horizontally arranged, and is provided with a jet inlet 2-2, a jet left outlet 2-6 and a jet right outlet 2-7. A deflection control rod 2.5 is rotatably arranged in the middle of the special-shaped jet disk 2.1, and the deflection control rod 2.5 is vertically arranged, and the upper end of the deflection control rod 2.5 is connected to the rotating main shaft 1.2, so that the deflection control rod 2.5 can rotate within a certain range with the rotating main shaft 1.2. The feedback rod 2-4 is eccentrically arranged at the lower side of the deflection control rod 2.5. A connecting groove 2-3 is arranged on the deflection control rod 2.5 between the jet inlet 2-2 and the jet left outlet 2-6 and the jet right outlet 2-7. The high-pressure oil from the power-level slide valve assembly 3 enters through the jet inlet 2-2 of the special-shaped jet disk 2.1, and then flows into the left jet outlet 2-6 and the right jet outlet 2-7 through the connecting groove 2-3. When the piezoelectric rotary actuator 1 is not supplied with control voltage, the deflection control rod 2.5 does not rotate, and the left jet outlet 2-6 and the right jet outlet 2-7 are symmetrically arranged on both sides of the center line of the connecting groove 2-3. The flow rates entering the left jet outlet 2-6 and the right jet outlet 2-7 are the same, thereby making the oil pressures of the left control chamber 3-5 and the right control chamber 3-7 on both sides of the valve core 3.1 the same. At this time, the valve core 3.1 remains in the middle position. When a control voltage is applied to the piezoelectric rotary actuator 1, the deflection control rod 2.5 rotates with the rotary main shaft 1.2. At this time, the connecting groove 2-3 forms inconsistent vector angles with the left jet outlet 2-6 and the right jet outlet 2-7. The flow rates entering the left jet outlet 2-6 and the right jet outlet 2-7 through the connecting groove 2-3 are different, making the pressures in the left control chamber 3-5 and the right control chamber 3-7 different. The high-pressure side pushes the valve core 3.1 to move toward the low-pressure side.

[0026] The jet distribution assembly 2 of the embodiment of the present invention also includes a clamping end cover 2.4 which is detachably fixedly connected to the supporting outer ring 1.1. The special-shaped jet disk 2.1 is arranged on the inner side of the middle part of the clamping end cover 2.4. An upper pressure plate 2.2 and a lower pressure plate 2.3 are respectively provided on the upper and lower sides of the special-shaped jet disk 2.1. The special-shaped jet disk 2.1, the upper pressure plate 2.2 and the lower pressure plate 2.3 are precisely positioned together by cylindrical pins 2.6 and 2.7. The outer sides of the upper pressure plate 2.2 and the lower pressure plate 2.3 and the inner side of the clamping end cover 2.4 can adopt clearance fit or a matching limit structure to prevent the upper pressure plate 2.2 and the lower pressure plate 2.3 from rotating in the clamping end cover 2.4. The deflection control rod 2.5 is interspersed with the upper pressure plate 2.2 and the lower pressure plate 2.3. The upper end of the deflection control rod 2.5 is preferably connected to the rotating main shaft 1.2 by a thread. A threaded hole 1-6 is provided at the lower end of the rotating main shaft 1.2, and an external thread structure 2-9 is provided at the upper end of the deflection control rod 2.5. Strong glue can also be injected after adjustment to prevent it from loosening during counterclockwise high-frequency rotation. The side of the deflection control rod 2.5 is spaced apart from the special-shaped jet disk 2.1 to form a drain port 2-10. Through holes are provided on the lower pressure plate 2.2 at corresponding positions of the left jet outlet 2-6, the right jet outlet 2-7, the jet inlet 2-2 and the drain port 2-10, and the through holes on the lower pressure plate 2.2 correspond to the positions of the left jet receiving hole 3-10, the right jet receiving hole 3-9, the oil outlet 3-11 and the drain port 3-6 on the valve body 3.3.

[0027] Combination Figures 3 to 5 , a part of the high-pressure oil entering the power stage slide valve assembly 3 from the oil supply port 3-13 on the valve body 3.3 flows out of the power stage slide valve assembly 3 through the oil outlet 3-11, and flows to the jet inlet 2-2 through the through hole on the lower pressure plate 2.2 corresponding to the position of the oil outlet 3-11. At the same time, the oil supply port 3-13 transports part of the high-pressure oil to the closed left load port 3-12 and the right load port 3-14; a part of the high-pressure oil entering the jet inlet 2-2 is distributed to the left jet outlet 2-6 and the jet outlet 2-7 through the connecting groove 2-3. The oil flows into the right outlet 2-7; the other part flows into the drain port 2-10. The oil flowing into the left jet outlet 2-6 and the right jet outlet 2-7 flows out of the jet distribution component 2 through the through hole on the lower pressure plate 2.3, and flows into the left control chamber 3-5 and the right control chamber 3-7 of the power stage slide valve component 3 through the left jet receiving hole 3-10 and the right jet receiving hole 3-9, so that the pressure at both ends of the valve core is unequal, thereby controlling the left load port 3-12 and the right load port 3-14 to communicate with the corresponding inlet and outlet of the actuator according to the function of the hydraulic circuit of the slide valve component. The oil flowing into the drain port 2-10 flows out of the jet distribution component 2 through the through hole on the lower pressure plate 2.3, and flows back to the power stage slide valve component 3 through the oil drain port 3-16, and then flows out of the power stage slide valve component 3 through the oil return port 3-15.

[0028] like Figure 4As shown, the cross-section of the connecting groove 2-3 of the embodiment of the present invention is preferably set to a trapezoidal shape, and the side with a larger opening of the connecting groove 2-3 is set toward the jet inlet 2-2 to facilitate the oil to enter the connecting groove 2-3, and the side with a smaller opening is set toward the jet left outlet 2-6 and the jet right outlet 2-7 to improve the sensitivity of control.

[0029] In order to facilitate the fixing of the piezoelectric rotary actuator 1, the jet distribution assembly 2 and the power stage slide valve assembly 3 together, it is preferred to set a first mounting hole 1-2 on the supporting outer ring 1.1, set a second mounting hole 2-1 on the clamping end cover 2.4, and set a threaded hole 3-8 on the valve body 3.3. The first mounting hole 1-2, the second mounting hole 2-1 and the threaded hole 3-8 are preferably four, and are arranged one by one on the same axis, and then bolts are used to pass through the first mounting hole 1-2 and the second mounting hole 2-1 in sequence and screwed into the threaded hole 3-8. In order to ensure the sealing effect between the piezoelectric rotary actuator 1, the jet distribution assembly 2 and the power stage slide valve assembly 3, it is preferred to set a first sealing groove on the lower side of the sealing seat 1.3, set a first sealing ring 1.8 in the first sealing groove, set a second sealing groove 3-1 on the upper side of the valve body 3.3, and set a second sealing ring in the second sealing groove 3-1. The first sealing ring 1.8 and the second sealing ring are preferably O-rings.

[0030] The working principle of the present invention is as follows:

[0031] 1. Rotation generation process: When a control voltage is applied to the outer end of the piezoelectric bending piece 1.4, the piezoelectric bending piece 1.4 will produce an up and down polarized movement. However, since the outer side of the piezoelectric bending piece 1.4 is fixed and its inner side is confined in the limit groove 1-3 of the rotating main shaft 1.2, the tangential friction between the rotating main shaft 1.2 and the piezoelectric bending piece 1.4 forces the rotating main shaft 1.2 to rotate at a small angle, thereby realizing the electro-mechanical rotation movement form.

[0032] 2. Jet vector control process: When the deflection control rod 2.5 does not rotate, the connecting groove 2-3 of the deflection control rod 2.5 is aligned with the jet inlet 2-2 of the jet disk; when the rotating main shaft 1.2 rotates a certain angle due to the up and down polarization of the piezoelectric bending piece 1.4 after power supply, the deflection control rod 2.5 also rotates a corresponding angle, and the connecting groove 2-3 forms a certain angle with the center line of the jet inlet 2-2 on the special-shaped jet disk 2.1. The high-speed jet will be forced to deflect to which side the angle deviates, thus completing the jet vector control stage of the servo valve pre-stage.

[0033] 3. Movement process of power-level slide valve: When the high-speed jet ejected from the jet inlet 2-2 of the special-shaped jet disk 2.1 is deflected by the small-angle rotation of the deflection control rod 2.5, the high-speed jet vector is deflected, and the high-speed oil flow entering the left jet outlet 2-6 and the right jet outlet 2-7 changes. The pressures formed in the left control chamber 3-5 and the right control chamber 3-7 at both ends of the valve core 1 connected thereto are unequal, pushing the valve core 3.1 to move to the side with lower pressure, thereby controlling the left load port 3-12 and the right load port 3-14 to be connected to the corresponding inlet and outlet of the actuator according to the hydraulic circuit function of the slide valve assembly.

[0034] 4. Mechanical feedback process of the power-stage slide valve: The matching hole 3-2 of the valve core cooperates with the feedback rod 2-4 to realize the mechanical feedback of the servo valve pre-stage. The eccentric feedback rod 2-4 on the deflection control rod 2.5 realizes that the linear motion of the power-stage slide valve can be converted into a reverse rotation feedback of a small angle of the deflection control rod 2.5, thereby realizing the mechanical feedback of the servo valve pre-stage and the power stage, ensuring the stability of the servo valve operation.

[0035] The above is only a preferred embodiment of the present invention. It should be noted that for ordinary technicians in this technical field, other parts not specifically described belong to the prior art or common knowledge. Several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A new type of high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve, characterized in that: It comprises a piezoelectric rotary actuator, a jet distribution assembly and a power stage slide valve assembly which are detachably fixed from top to bottom in sequence, the piezoelectric rotary actuator is used to generate a corresponding horizontal rotation angle according to an input voltage signal, and transmit the rotation angle to the jet distribution assembly, the jet distribution assembly completes the jet vector control of the pre-stage according to the rotation angle, and then controls the operation of the power stage slide valve assembly, the jet distribution assembly comprises a feedback rod eccentrically arranged on its lower side, the lower end of the feedback rod is inserted into the valve core matching hole of the power stage slide valve assembly, the feedback rod converts the linear motion of the valve core into rotary feedback, so as to realize the mechanical feedback between the pre-stage and the power stage of the servo valve; The piezoelectric rotary actuator includes a supporting outer ring, a rotating main shaft arranged in the middle of the inner side of the supporting outer ring, and a plurality of piezoelectric bending pieces connected between the inner side of the supporting outer ring and the rotating main shaft. The outer end of the piezoelectric bending piece is fixedly connected to the supporting outer ring, and the inner end thereof is slidably connected to the rotating main shaft. When energized, the piezoelectric bending piece generates polarized bending and drives the rotating main shaft to generate a corresponding rotating angle. A sealing seat is provided on the lower side of the supporting outer ring, and the rotating main shaft is inserted through the sealing seat.

2. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 1 is characterized in that: The jet distribution assembly includes a special-shaped jet disk, which is provided with a jet inlet, a left jet outlet and a right jet outlet. A rotatable deflection control rod is provided in the middle of the special-shaped jet disk, and the upper end of the deflection control rod is threadedly connected to the rotating main shaft. The feedback rod is eccentrically arranged on the lower side of the deflection control rod. A connecting groove is provided on the deflection control rod between the jet inlet and the left jet outlet and the right jet outlet. When the deflection control rod is not rotated, the left jet outlet and the right jet outlet are symmetrically arranged on both sides of the center line of the connecting groove; when the deflection control rod rotates with the rotating main shaft, the connecting groove forms an inconsistent vector angle with the left jet outlet and the right jet outlet, thereby completing the jet vector control of the pre-stage.

3. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 2 is characterized in that: The jet distribution assembly also includes a clamping end cover that is detachably fixedly connected to the supporting outer ring, the special-shaped jet disk is arranged on the inner side of the middle part of the clamping end cover, and an upper pressure plate and a lower pressure plate are respectively provided on the upper and lower sides thereof, and the deflection control rod is interspersed with the upper and lower pressure plates; the deflection control rod and the special-shaped jet disk are spaced to form a drain port, and through holes are respectively provided on the lower pressure plate at positions corresponding to the left jet outlet, the right jet outlet, the jet inlet and the drain port, so that the left jet outlet, the right jet outlet, the jet inlet and the drain port are respectively connected to the left load chamber, the right load chamber, the oil supply port and the oil return port on the power sliding valve assembly.

4. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 2 is characterized in that: The cross section of the connecting groove is in a trapezoidal shape, with a side with a larger opening disposed toward the jet inlet, and a side with a smaller opening disposed toward the jet left outlet and the jet right outlet.

5. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 1 is characterized in that: A mounting groove is provided on the inner side of the supporting outer ring, and the outer end bolt of the piezoelectric bending piece is fixed in the mounting groove. A limiting groove is provided on the outer side of the rotating main shaft at a position corresponding to the piezoelectric bending piece, and the inner end of the piezoelectric bending piece is slidably connected in the limiting groove.

6. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 1 is characterized in that: The piezoelectric bending sheets include 3 to 6 pieces, which are evenly distributed between the inner side of the supporting outer ring and the rotating main shaft.

7. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 3 is characterized in that: A first sealing ring is provided between the lower side of the sealing seat and the upper side of the clamping end cover, and a second sealing ring is provided between the lower side of the clamping end cover and the power stage sliding valve assembly.

8. The novel high-frequency piezoelectric rotary two-stage electro-hydraulic servo valve according to claim 1 is characterized in that: The piezoelectric rotary actuator, the jet distribution assembly and the power stage slide valve assembly are connected by bolts.

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