High-frequency pulse filtering type electro-hydraulic servo valve

Abstract

The invention belongs to the field of mechanical hydraulic pressure, and particularly relates to a high-frequency pulsation filtering type electro-hydraulic servo valve which comprises a torque motor part, a hydraulic amplification stage part, a power stage slide valve part, a turbine pressure supplementing part, a pulsation filtering part and a shell. The torque motor part is installed on the upper side of the shell, and the hydraulic amplification stage part, the power stage slide valve part, the turbine pressure supplementing part and the pulsation filtering part are all installed in the shell. It can be guaranteed that the servo valve does not squeal in all hydraulic systems, internal pressure fluctuation of the servo valve can be slowed down, and therefore high-frequency oscillation of the servo valve is effectively avoided.

Description

Technical Field

[0001] The invention belongs to the field of mechanical hydraulics, and in particular relates to a high-frequency pulsation filtering type electro-hydraulic servo valve. Background Art

[0002] At present, electro-hydraulic servo valves are widely used in many important fields such as advanced civil aircraft, steel, power generation, etc. They are mainly used in servo mechanism control systems. Their functions account for more than 1 / 3 of the system, which strongly supports the development of weapons. At present, the requirements of hydraulic servo systems are getting higher and higher, and the operating conditions are getting more and more severe. If there are high-frequency pulsation components in the system or in the external environment, the servo valve will be stimulated to resonate at high frequency. When the frequency is high and the amplitude is large, the servo valve will scream, which is commonly known as howling in the industry. If the howling continues for a short time, the spring tube will fatigue and break, causing fatal failure to the hydraulic system. At present, the hydraulic system in the industry can suppress the servo valve from howling in certain occasions, but it is impossible to completely prevent the servo valve from howling in all hydraulic systems, which brings hidden dangers of failure to the hydraulic system.

[0003] Relevant research shows that the high-frequency pulsation and howling of the servo valve are directly related to the transient cavitation formed at the nozzle-baffle. The cavitation causes the baffle to resonate, and the resonance of the baffle and the resonance of the valve core promote each other. Once the howling occurs, it will not stop actively. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of high-frequency pulsation and howling of the existing servo valve. The present invention proposes a high-frequency pulsation filter type electro-hydraulic servo valve.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A high-frequency pulsation filter type electro-hydraulic servo valve, the servo valve comprising a torque motor part, a hydraulic amplifier part, a power stage slide valve part, a turbine pressure compensation part, a pulsation filter part and a housing; the torque motor part is installed on the upper side of the housing, and the hydraulic amplifier part, the power stage slide valve part, the turbine pressure compensation part and the pulsation filter part are all installed in the housing;

[0007] The torque motor part is arranged on the housing, including an upper magnet, a coil, a permanent magnet, an armature, a lower magnet, a spring tube, and a feedback rod. The permanent magnet is arranged between the upper magnet and the lower magnet, the coil is wound on the armature, the armature and the upper end of the feedback rod are installed on the spring tube, and the lower end of the feedback rod is connected to the power valve core of the power stage slide valve part;

[0008] The hydraulic amplification stage part includes a left nozzle, a baffle, a right nozzle, a left throttle hole component, an oil filter, and a right throttle hole component. The left nozzle and the right nozzle are symmetrically installed on the housing. The baffle is arranged between the left nozzle and the right nozzle. The left throttle hole component and the right throttle hole component are respectively sleeved on the left and right ends of the oil filter. The three parts are installed together in the corresponding oil filter hole of the housing.

[0009] The power-level slide valve part includes a valve sleeve and a power valve core; the power valve core is installed in the valve sleeve and is installed in the valve sleeve hole of the housing together;

[0010] The turbine pressure-compensating part includes a left turbine, a left bearing, a right bearing, and a right turbine; the left turbine is interference-mounted in the inner hole of the left bearing and is interference-mounted in the left hole of the baffle; the shaft of the right turbine is interference-mounted in the inner hole of the right bearing and is interference-mounted in the right hole of the baffle; the left turbine is coaxial with the left nozzle, and the right turbine is coaxial with the right nozzle;

[0011] The pulsation filter part includes a left filter upper spring, a left filter piston, a left filter lower spring, a right filter lower spring, a right filter piston, and a right filter upper spring; the left filter piston is slidably installed in the hole of the housing, the left filter upper spring is sleeved in the upper end cylinder of the left filter piston, the upper side is pressed against the inner wall of the housing hole, and the lower side is pressed against the shoulder end face of the left filter piston, the left filter lower spring is sleeved in the lower end cylinder of the left filter piston, the lower side is pressed against the inner wall of the housing hole, and the upper side is pressed against the shoulder end face of the left filter piston; the right filter piston is slidably installed in the hole of the housing, the right filter upper spring is sleeved in the upper end cylinder of the right filter piston, the upper side is pressed against the inner wall of the housing hole, and the lower side is pressed against the shoulder end face of the right filter piston, the right filter lower spring is sleeved in the lower end cylinder of the right filter piston, the lower side is pressed against the inner wall of the housing hole, and the upper side is pressed against the shoulder end face of the right filter piston;

[0012] The left end of the left nozzle and the left end of the left throttle component are connected to the upper end of the left filter piston through the housing oil passage; the right end of the right nozzle and the right end of the right throttle component are connected to the upper end of the right filter piston through the housing oil passage; the left end of the power valve core and the lower end of the left filter piston, and the right end of the power valve core and the lower end of the right filter piston (20) are connected respectively through the housing oil passage.

[0013] Furthermore, the oil passage of the housing Ps is connected to the oil passage where the oil filter is installed; the oil passages on the right side of the left nozzle and on the left side of the right nozzle are both in communication with the cavity R.

[0014] Furthermore, the left turbine blade of the left turbine and the right turbine blade of the right turbine are symmetrical in curved surface, the flatness of the left turbine end face and the right turbine end face are both 0.002 mm, the diameter of the left turbine end face is 2 to 3 times the diameter of the left nozzle aperture, and the diameter of the right turbine end face is 2 to 3 times the diameter of the right nozzle aperture.

[0015] Furthermore, after the left turbine is installed on the baffle, the perpendicularity between the left turbine end face and the left nozzle hole axis is 0.005mm, and the coaxiality between the left turbine and the left nozzle hole axis is 0.02mm; after the right turbine is installed on the baffle, the perpendicularity between the right turbine end face and the right nozzle hole axis is 0.005mm, and the coaxiality between the right turbine and the right nozzle hole axis is 0.02mm.

[0016] Furthermore, the cylindrical diameter of the left filter piston and the right filter piston is not greater than 1 / 5 of the diameter of the power valve core.

[0017] Furthermore, the cylindricality of the left filter piston and the right filter piston cylinder is 0.001 mm, the surface roughness is Ra0.1, and the matching clearance with the hole of the housing is 0.005-0.010 mm.

[0018] Furthermore, the square root of the ratio of the combined stiffness of the left filter upper spring and the left filter lower spring to the weight of the left filter piston is equal to 0.6 to 0.8 times the system pulsation frequency; the square root of the ratio of the combined stiffness of the right filter upper spring and the right filter lower spring to the weight of the right filter piston is equal to 0.6 to 0.8 times the system pulsation frequency.

[0019] Furthermore, the shaft core diameter of the left turbine end face is smaller than 1 / 5 of the left nozzle aperture; the shaft core diameter of the right turbine end face is smaller than 1 / 5 of the right nozzle aperture.

[0020] Furthermore, the proportion of the solid part of the left turbine end surface on the circumference of the left nozzle outlet to the circumference of the left nozzle outlet is ≥60%, and the proportion of the solid part of the right turbine end surface on the circumference of the right nozzle outlet is ≥60%.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The main reason for the whistling of the nozzle-flapper servo valve is the fast hydraulic flow rate at the nozzle, which leads to negative pressure near the nozzle. The negative pressure will gasify the hydraulic oil and then produce cavitation. The generation and elimination of cavitation will produce high-frequency oscillation. The traditional servo valve cannot solve the cavitation problem near the nozzle. The patent of this invention invented a turbine pressure compensation mechanism. The faster the oil speed, the faster the turbine rotates, which can spread the pressurized oil to the periphery of the nozzle, quickly make up for the negative pressure, avoid the generation of cavitation, and thus avoid the high-frequency oscillation of the servo valve;

[0023] 2) Invented a spring-piston hydraulic filter, which is simple in structure, small in size, and can effectively isolate the vibration between components in the hydraulic system;

[0024] 3) The nozzle chamber and valve core of the traditional servo valve are directly connected by an oil channel. When the servo valve howls, the baffle and the valve core both oscillate at high frequency. The vibration of the baffle brings pressure fluctuations in the nozzle chamber, thereby promoting high-frequency vibrations of the valve core. The vibration of the valve core then brings pressure fluctuations in the nozzle chamber. The baffle and the valve core promote each other's vibrations, and the vibrations cannot converge, so the servo valve continues to oscillate. The patent of the present invention uses a spring-piston hydraulic filter for the servo valve. The pressure fluctuations caused by the vibration of the baffle can be filtered, and the filtered pressure reduces the effect of the vibration of the valve core; the pressure fluctuations caused by the high-frequency vibration of the valve core can be filtered, and then the pressure fluctuations of the baffle are filtered, thereby reducing the fluctuations of the baffle. Furthermore, when there is high-frequency pulsation in the system pressure, the fluctuations of the baffle and the valve core slow down each other. This filter can slow down the pressure fluctuations inside the servo valve, so that the servo valve effectively avoids high-frequency vibrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a principle diagram of a high-frequency pulsation filter type electro-hydraulic servo valve according to an embodiment of the present invention;

[0026] Figure 2 is a structural diagram of a left turbine according to an embodiment of the present invention;

[0027] Figure 3 is a structural diagram of a right turbine according to an embodiment of the present invention;

[0028] Figure 4 is a structural diagram of a left nozzle according to an embodiment of the present invention;

[0029] Figure 5 is a structural diagram of a right nozzle according to an embodiment of the present invention;

[0030] Among them, 1. upper magnetic conductor, 2. coil, 3. permanent magnet, 4. armature, 5. lower magnetic conductor, 6. spring tube, 7. left nozzle, 8. baffle, 9. left turbine, 10. left bearing, 11. left throttle hole component, 12. oil filter, 13. left filter upper spring, 14. left filter piston, 15. left filter lower spring, 16. valve sleeve, 17. power valve core, 18. feedback rod, 19. right filter lower spring, 20. right filter piston, 21. right filter upper spring, 22. right throttle hole component, 23. right bearing, 24. right turbine, 25. right nozzle, 26. housing, 9A, left turbine blade, 9B, left turbine end face, 9C, left turbine end face diameter, 24A, right turbine blade, 24B, right turbine end face, 24C, right turbine end face diameter. DETAILED DESCRIPTION

[0031] In order to more intuitively and clearly describe the structural principles and working methods in the examples of the present invention, the embodiments will be introduced in conjunction with relevant drawings. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] See attached Figure 1 The present invention provides a high-frequency pulsation filter type electro-hydraulic servo valve, the servo valve comprises a torque motor part, a hydraulic amplifier part, a power stage slide valve part, a turbine pressure compensation part, a pulsation filter part and a housing 26; the torque motor part is installed on the upper side of the housing, and the hydraulic amplifier part, the power stage slide valve part, the turbine pressure compensation part and the pulsation filter part are all installed in the housing;

[0033] The torque motor part is arranged on the housing 26, including an upper magnet 1, a coil 2, a permanent magnet 3, an armature 4, a lower magnet 5, a spring tube 6, and a feedback rod 18. The permanent magnet 3 is arranged between the upper magnet 1 and the lower magnet 5, the coil 2 is wound on the armature 4, the armature 4 and the upper end of the feedback rod 18 are installed on the spring tube 6, and the lower end of the feedback rod is connected to the power valve core 17 of the power stage slide valve part;

[0034] The hydraulic amplification stage part includes a left nozzle 7, a baffle 8, a right nozzle 25, a left throttle hole component 11, an oil filter 12, and a right throttle hole component 22. The left nozzle 7 and the right nozzle 25 are symmetrically mounted on the housing, the baffle 8 is arranged between the left nozzle 7 and the right nozzle 25, the left throttle hole component 11 and the right throttle hole component 22 are respectively sleeved on the left and right ends of the oil filter 12, and the three parts are installed together in the corresponding oil filter hole of the housing 26;

[0035] The power stage slide valve part includes a valve sleeve 16 and a power valve core 17; the power valve core 17 is installed in the valve sleeve 16 and is installed in the valve sleeve hole of the housing 26 together;

[0036] The turbine pressure-compensating part comprises a left turbine 9, a left bearing 10, a right bearing 23, a right turbine 24, and a baffle 8; the left turbine 9 is interference-mounted in the inner hole of the left bearing 10, and is interference-mounted in the left hole of the baffle 8; the shaft of the right turbine 24 is interference-mounted in the inner hole of the right bearing 23, and is interference-mounted in the right hole of the baffle 8; the left turbine 9 is coaxial with the left nozzle 7, and the right turbine 24 is coaxial with the right nozzle 25;

[0037] The pulsation filter part includes a left filter upper spring 13, a left filter piston 14, a left filter lower spring 15, a right filter lower spring 19, a right filter piston 20, and a right filter upper spring 21;

[0038] The left filter piston 14 is slidably installed in the hole of the housing 26. The left filter upper spring 13 is sleeved in the upper end cylinder of the left filter piston 14, with the upper side pressing against the housing and the lower side pressing against the shoulder end surface of the left filter piston 14. The left filter lower spring 15 is sleeved in the lower end cylinder of the left filter piston 14, with the lower side pressing against the housing and the upper side pressing against the shoulder end surface of the left filter piston 14.

[0039] The right filter piston 20 is slidably installed in the hole of the housing 26, the right filter upper spring 21 is sleeved in the upper end cylinder of the right filter piston 20, the upper side is pressed against the housing, and the lower side is pressed against the convex shoulder end surface of the right filter piston 20, the right filter lower spring 19 is sleeved in the lower end cylinder of the right filter piston 20, the lower side is pressed against the housing, and the upper side is pressed against the convex shoulder end surface of the right filter piston 20;

[0040] The left end of the left nozzle 7 and the left end of the left throttle component 11 are connected to the upper end of the left filter piston 14 through the oil passage of the housing 26; the right end of the right nozzle 25 and the right end of the right throttle component 22 are connected to the upper end of the right filter piston 20 through the oil passage of the housing 26;

[0041] The left end of the power valve core 17 is connected to the lower end of the left filter piston 14, and the right end of the power valve core 17 is connected to the lower end of the right filter piston 20 through the oil passages of the housing 26;

[0042] The oil passage of the housing 26Ps is connected to the oil passage where the oil filter 12 is installed; the right side of the left nozzle 7 and the left side of the right nozzle 25 are in communication with the cavity R.

[0043] In the present invention, the left turbine blade 9A and the right turbine blade 24A are symmetrical in curved surface, ensuring that when the left nozzle 7 and the right nozzle 25 eject oil at high speed, the left turbine 9 and the right turbine 24 rotate in the same direction, which is conducive to the left and right turbines to compensate for the cavitation near the baffle.

[0044] The flatness of the left turbine end face 9B and the right turbine end face 24B are both 0.002 mm. The high-precision flatness can ensure the balance of the hydraulic pressure between the internal blades of the left turbine 9 and the right turbine 24, and avoid the shock caused by the hydraulic force.

[0045] The diameter 9C of the left turbine end face is 2 to 3 times the aperture of the left nozzle 7, and the diameter 24C of the right turbine end face is 2 to 3 times the aperture of the right nozzle 25. The jets of the left nozzle 7 and the right nozzle 25 can be fully applied to the left turbine end face 9B and the right turbine end face 24B, so that the baffle can effectively adjust the pressure gain and flow gain of the hydraulic amplifier stage and improve the working efficiency.

[0046] In the present invention, after the left turbine 9 is mounted on the baffle 8, the verticality of the left turbine end face 9B and the axis of the left nozzle 7 hole is 0.005mm, and the coaxiality of the left turbine 9 and the axis of the left nozzle 7 hole is 0.02mm; after the right turbine 24 is mounted on the baffle 8, the verticality of the right turbine end face 24B and the axis of the right nozzle 25 hole is 0.005mm, and the coaxiality of the right turbine 24 and the axis of the right nozzle 25 hole is 0.02mm. It can ensure that the hydraulic force on the left turbine blade 9A and the right turbine blade 24A is balanced, the eccentric force of the left turbine 9 and the right turbine 24 is very small, and then the left turbine 9 and the right turbine 24 move smoothly.

[0047] In the present invention, the cylindrical diameter of the left filter piston 14 and the right filter piston 20 is not greater than 1 / 5 of the diameter of the power valve core 17. The flow rate required for the movement of the left filter piston 14 and the right filter piston 20 is very small, which can ensure that the hydraulic pressure at the upper ends of the left filter piston 14 and the right filter piston 20 is quickly transmitted to the two end surfaces of the power valve core 17, and will not affect the response frequency of the power valve core 17, and further, the setting of the left filter piston 14 and the right filter piston 20 will not affect the normal bandwidth of the servo valve.

[0048] In the present invention, the cylindricality of the left filter piston 14 and the right filter piston 20 is 0.001mm, the surface roughness is Ra0.1, and the clearance between the left filter piston 14 and the right filter piston 20 and the hole of the housing is 0.005-0.010mm. This ensures that the left filter piston 14 and the right filter piston 20 can move smoothly in the hole of the housing 26, and have good wear resistance and long service life;

[0049] In the present invention, the square root of the combined stiffness of the left filter upper spring 13 and the left filter lower spring 15 and the weight ratio of the left filter piston 14 is equal to 0.6 to 0.8 times the system pulsation frequency; the square root of the combined stiffness of the right filter upper spring 21 and the right filter lower spring 19 and the weight ratio of the right filter piston 20 is equal to 0.6 to 0.8 times the system pulsation frequency. It can ensure that the pulsation filter mechanism effectively attenuates the amplitude at the system pulsation frequency, thereby greatly reducing the amplitude of the resonant pulsation, greatly reducing the energy of the pulsation, and improving the stability of the servo valve.

[0050] In the present invention, the shaft core diameter 9D of the left turbine end face is less than 1 / 5 of the aperture of the left nozzle 7; the shaft core diameter 24D of the right turbine end face is less than 1 / 5 of the aperture of the right nozzle 25. This ensures that the jets of the left nozzle 7 and the right nozzle 25 act on the left turbine blade 9A and the right turbine blade (24A) over a larger area, so that the left turbine 9 and the right turbine 24 have a higher rotation speed and better compensate for the cavitation near the baffle.

[0051] In the present invention, the proportion of the solid part of the left turbine end face 9B on the circumference of the outlet of the left nozzle 7 accounts for ≥60% of the circumference of the outlet of the left nozzle 7, and the proportion of the solid part of the right turbine end face 24B on the circumference of the outlet of the right nozzle 25 accounts for ≥60% of the circumference of the outlet of the right nozzle 25. The jets of the left nozzle 7 and the right nozzle 25 can act on the left turbine end face 9B and the right turbine end face 24B, ensuring sufficient jet areas of the left turbine end face 9B and the right turbine end face 24B, so that the baffle can effectively adjust the pressure gain and flow gain of the hydraulic amplifier stage, thereby improving work efficiency.

[0052] The working principle of the high-frequency pulsation filter type electro-hydraulic servo valve of the present invention is as follows: the hydraulic pump servo valve inputs the oil supply pressure Ps. When the coil 2 inputs the positive current, the armature 4 is acted upon by the electromagnetic force and moves counterclockwise around the rotation center of the spring tube 6, driving the baffle 8 and the left and right turbine pressure-compensating parts to deflect to the right, thereby reducing the pressure on the left side of the left nozzle 7 and increasing the pressure on the right side of the right nozzle 25. The left and right pulsation filter parts respectively transmit the corresponding pressure downward to the power valve core 17, and the power valve core 17 moves to the left, and the high-pressure oil outputs the pressure and flow through the opening of the power valve core 17 and the valve sleeve 16. In addition, the displacement of the power valve core 17 transmits the force to the spring tube 6 through the feedback rod 18, and finally the force balance is achieved, and the valve core stops at the specified position. Similarly, when the coil 2 inputs the negative current, the movement direction of the internal parts of the servo valve is opposite to that described above. The present servo valve also includes a turbine pressure-compensating part and a pulsation filter part, and its working process is as follows:

[0053] Turbine pressure compensation part: The hydraulic flow rate at the outlet of the left nozzle 7 and the right nozzle 25 is fast, resulting in negative pressure near the nozzle. The negative pressure will gasify the hydraulic oil and then produce cavitation. The generation and elimination of cavitation will produce high-frequency oscillation. A turbine pressure compensation mechanism is set at the nozzle. The faster the oil speed, the faster the turbine rotates, and the pressurized oil can be spread to the periphery of the nozzle, quickly compensating for the negative pressure, avoiding the generation of cavitation, and thus avoiding high-frequency oscillation of the servo valve;

[0054] Pulsation filtering part: The spring-piston hydraulic filter is set between the two nozzles and the power valve core 17. The pressure fluctuation caused by the vibration of the baffle can be filtered, and the filtered pressure can reduce the vibration effect of the valve core; the pressure fluctuation of the high-frequency vibration of the valve core can be filtered, and then the pressure fluctuation of the baffle is filtered, thereby reducing the fluctuation of the baffle. Furthermore, when there is high-frequency pulsation in the system pressure, the fluctuation of the baffle and the valve core slows down each other. This filter can slow down the pressure fluctuation inside the servo valve, so that the servo valve effectively avoids high-frequency vibration.

[0055] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A high-frequency pulsation filter type electro-hydraulic servo valve, characterized in that: It includes a torque motor part, a hydraulic amplifier part, a power stage slide valve part, a turbine pressure compensation part, a pulsation filter part and a housing; the torque motor part is installed on the upper side of the housing, and the hydraulic amplifier part, the power stage slide valve part, the turbine pressure compensation part and the pulsation filter part are all installed in the housing; The torque motor part includes an upper magnet, a coil, a permanent magnet, an armature, a lower magnet, a spring tube, and a feedback rod. The permanent magnet is arranged between the upper magnet and the lower magnet, the coil is wound on the armature, the armature and the upper end of the feedback rod are installed on the spring tube, and the lower end of the feedback rod is connected to the power valve core of the power stage slide valve part; The hydraulic amplification stage part includes a left nozzle, a baffle, a right nozzle, a left throttle hole component, an oil filter, and a right throttle hole component. The left nozzle and the right nozzle are symmetrically installed on the housing. The baffle is arranged between the left nozzle and the right nozzle. The left throttle hole component and the right throttle hole component are respectively sleeved on the left and right ends of the oil filter. The three parts are installed together in the corresponding oil filter hole of the housing. The power-level slide valve part includes a valve sleeve and a power valve core; the power valve core is installed in the valve sleeve and is installed in the valve sleeve hole of the housing together; The turbine pressure-compensating part includes a left turbine, a left bearing, a right bearing, and a right turbine; the left turbine is interference-mounted in the inner hole of the left bearing and is interference-mounted in the left hole of the baffle; the shaft of the right turbine is interference-mounted in the inner hole of the right bearing and is interference-mounted in the right hole of the baffle; the left turbine is coaxial with the left nozzle, and the right turbine is coaxial with the right nozzle; The pulsation filter part includes a left filter upper spring, a left filter piston, a left filter lower spring, a right filter lower spring, a right filter piston, and a right filter upper spring; the left filter piston is slidably installed in the hole of the housing, the left filter upper spring is sleeved in the upper end cylinder of the left filter piston, the upper side is pressed against the inner wall of the housing hole, and the lower side is pressed against the shoulder end face of the left filter piston, the left filter lower spring is sleeved in the lower end cylinder of the left filter piston, the lower side is pressed against the inner wall of the housing hole, and the upper side is pressed against the shoulder end face of the left filter piston; the right filter piston is slidably installed in the hole of the housing, the right filter upper spring is sleeved in the upper end cylinder of the right filter piston, the upper side is pressed against the inner wall of the housing hole, and the lower side is pressed against the shoulder end face of the right filter piston, the right filter lower spring is sleeved in the lower end cylinder of the right filter piston, the lower side is pressed against the inner wall of the housing hole, and the upper side is pressed against the shoulder end face of the right filter piston; The left end of the left nozzle and the left end of the left throttle component are connected to the upper end of the left filter piston through the housing oil passage; the right end of the right nozzle and the right end of the right throttle component are connected to the upper end of the right filter piston through the housing oil passage; the left end of the power valve core and the lower end of the left filter piston, and the right end of the power valve core and the lower end of the right filter piston (20) are connected respectively through the housing oil passage.

2. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The oil passage of the housing Ps is connected to the oil passage where the oil filter is installed; the oil passages on the right side of the left nozzle and on the left side of the right nozzle are both in communication with the cavity R.

3. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The left turbine blade of the left turbine and the right turbine blade of the right turbine are symmetrical in surface, the flatness of the left turbine end face and the right turbine end face are both 0.002mm, the diameter of the left turbine end face is 2 to 3 times the diameter of the left nozzle aperture, and the diameter of the right turbine end face is 2 to 3 times the diameter of the right nozzle aperture.

4. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 3, characterized in that: After the left turbine is installed on the baffle, the perpendicularity between the left turbine end face and the left nozzle hole axis is 0.005mm, and the coaxiality between the left turbine and the left nozzle hole axis is 0.02mm; after the right turbine is installed on the baffle, the perpendicularity between the right turbine end face and the right nozzle hole axis is 0.005mm, and the coaxiality between the right turbine and the right nozzle hole axis is 0.02mm.

5. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The cylindrical diameters of the left filter piston and the right filter piston are no greater than 1 / 5 of the diameter of the power valve core.

6. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The cylindricality of the left filter piston and the right filter piston cylinder is 0.001 mm, the surface roughness is Ra0.1, and the matching clearance with the hole of the shell is 0.005-0.010 mm.

7. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The square root of the ratio of the combined stiffness of the left filter upper spring and the left filter lower spring to the weight of the left filter piston is equal to 0.6 to 0.8 times the system pulsation frequency; the square root of the ratio of the combined stiffness of the right filter upper spring and the right filter lower spring to the weight of the right filter piston is equal to 0.6 to 0.8 times the system pulsation frequency.

8. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The shaft core diameter of the left turbine end face is smaller than 1 / 5 of the left nozzle aperture; the shaft core diameter of the right turbine end face is smaller than 1 / 5 of the right nozzle aperture.

9. A high-frequency pulsation filter type electro-hydraulic servo valve as claimed in claim 1, characterized in that: The proportion of the solid part of the left turbine end surface on the circumference of the left nozzle outlet to the circumference of the left nozzle outlet is ≥60%, and the proportion of the solid part of the right turbine end surface on the circumference of the right nozzle outlet is ≥60%.

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