A servo valve flow passage and servo valve

Abstract

The utility model provides a kind of servo valve flow channel and servo valve, including valve core and valve sleeve;The servo valve flow channel includes the passage being set in the valve body inside servo valve, including inlet flow channel, oil return flow channel, first actuating port flow channel, second actuating port flow channel;Two cavities are arranged in the position of the length direction of the two ends of valve body inside close to valve sleeve, the valve body inside is also provided with balance passage, balance passage is used to connect the two cavities inside valve body, oil liquid in one cavity can flow to another cavity by balance passage when valve core is translated in valve sleeve;Utilize such a kind of servo valve flow channel and servo valve, by setting cavity and balance passage as control oil cavity and control channel in the two ends of valve sleeve, the pressure fluctuation when spool moves is reduced to controllable range, to balance two sides oil pressure, reduce rigid impact and valve core resistance.

Description

Technical Field

[0001] This utility model relates to the field of servo valve technology, and in particular to a servo valve flow channel and a servo valve. Background Technology

[0002] A servo valve is a high-precision, high-response electro-hydraulic control component that converts weak electrical signals into precise hydraulic flow or pressure outputs. It is widely used in hydraulic systems requiring closed-loop control to ensure accurate control of the system's dynamic performance.

[0003] In hydraulic systems with high inertia and drastic changes in external load, the damping design of traditional servo valves is insufficient, making it difficult to simultaneously meet the system's requirements of "stability, accuracy, and speed." System stability requires high damping, while rapid response requires reduced damping, creating a significant contradiction, and dynamic performance also needs to be improved. Utility Model Content

[0004] The main purpose of this invention is to propose a servo valve flow channel and a servo valve, which aims to optimize the oil pressure distribution through the flow path, thus becoming a key direction for improving dynamic performance.

[0005] To achieve the above objectives, this utility model proposes a servo valve flow channel for connecting a servo valve assembly and a hydraulic device. The valve assembly includes a valve core and a valve sleeve. The servo valve flow channel includes a channel disposed inside the valve body of the servo valve, including an oil inlet flow channel, an oil return flow channel, a first actuation port flow channel, and a second actuation port flow channel.

[0006] The valve body also has a space for placing the valve core and valve sleeve. The valve sleeve has multiple sets of through holes along the valve sleeve axis for communicating with the servo valve flow channel. The valve core has an annular step. The valve core can move along the valve sleeve axis inside the valve sleeve. The step is used to block the through holes and adjust the connection relationship between the first actuation port flow channel, the second actuation port flow channel and the oil inlet flow channel and the oil return port flow channel.

[0007] The valve body has two cavities located near the two ends of the valve sleeve along its length. The valve body also has a balance channel that connects the two cavities. When the valve core moves within the valve sleeve, the oil in one cavity can flow to the other cavity through the balance channel.

[0008] Preferably, the oil inlet channel, the oil return channel, the first actuation channel, and the second actuation channel each include a main branch for connecting to the hydraulic equipment, and the main branch is connected to at least one first branch, which is connected to a through hole on the valve sleeve.

[0009] Preferably, the valve sleeve is axially arranged with X sets of through holes, each set of through holes including Y pairs of slots distributed radially along the valve sleeve; wherein, X ranges from 3 to 20, and Y ranges from 1 to 15;

[0010] If the cross-sectional area of ​​the main branch is S, then S≥K1*h*b*Y; where K1 is a multiple, and K1 takes values ​​from 2 to 16, h is the moving distance of the valve core, and b is the width of the slot.

[0011] Let ΔS be the difference between the cross-sectional area of ​​the step and the valve core. Then ΔS ≥ K2 * h * b * Y; where K2 is a multiple and K2 ranges from 2 to 10.

[0012] Preferably, the first branch is connected to a second branch, and the second branch is connected to a through hole on the valve sleeve.

[0013] Preferably, the cross-section of the balancing channel is one of the following: circular, elliptical, square, rectangular, regular polygon with 4 or more sides, or waist-shaped.

[0014] Preferably, the cross-sectional area of ​​the balancing channel varies along the length of the balancing channel.

[0015] Preferably, the ratio of the area of ​​the balance channel cross-section to the area of ​​the valve sleeve inner hole is greater than or equal to 0.01.

[0016] Preferably, the ratio of the volume of the cavity to the volume occupied by the valve core when it is moved to the limit position is greater than 1.

[0017] Preferably, the valve sleeve has at least three rows of square holes along the axial direction, each row of square holes has the same axial dimension, and the shape of the square holes is one of rectangle, circle, ellipse, or polygon.

[0018] This utility model also provides a servo valve, including the servo valve flow channel as described above.

[0019] The technical solution of this utility model reduces the pressure fluctuation during the movement of the slide valve to a controllable range by setting cavities and balance channels at both ends of the valve sleeve as control oil chambers and control channels, thereby balancing the oil pressure on both sides, reducing rigid impact and valve core resistance. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1A schematic diagram of the flow channel of a servo valve provided by this utility model;

[0022] Figure 2 An exploded view of a servo valve flow channel provided by this utility model;

[0023] Figure 3 A cross-sectional view of a servo valve flow channel provided by this utility model;

[0024] Figure 4 A schematic diagram of the bottom of a servo valve flow channel provided by this utility model;

[0025] Figure 5 A schematic diagram of the cavity and balancing channel of a servo valve flow channel provided by this utility model;

[0026] Figure 6 A schematic diagram of the first flow channel of a servo valve flow channel provided by this utility model;

[0027] Figure 7 A schematic diagram of the second flow channel of a servo valve flow channel provided by this utility model;

[0028] Figure 8 A schematic diagram of the third flow channel of a servo valve provided by this utility model;

[0029] Explanation of icon numbers:

[0030] Valve core 11, valve sleeve 12, through hole 13, step 14, first actuation port flow channel 21, second actuation port flow channel 22, oil inlet flow channel 23, oil return port flow channel 24, cavity 25, balance channel 26, main branch 31, first branch 32, second branch 33.

[0031] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0033] It should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of this utility model, such directional indication is only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0034] Furthermore, if the embodiments of this utility model involve descriptions such as "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0035] A servo valve is a high-precision, high-response electro-hydraulic control component that converts weak electrical signals into precise hydraulic flow or pressure outputs. It is widely used in hydraulic systems requiring closed-loop control to ensure accurate control of the system's dynamic performance.

[0036] In hydraulic systems with high inertia and drastic changes in external load, the damping design of traditional servo valves is insufficient, making it difficult to simultaneously meet the system's requirements of "stability, accuracy, and speed." System stability requires high damping, while rapid response requires reduced damping, creating a significant contradiction, and dynamic performance also needs to be improved.

[0037] The main objective of this utility model is to provide a servo valve flow channel for connecting a servo valve assembly and a hydraulic device. The valve assembly includes a valve core 11 and a valve sleeve 12. The servo valve flow channel includes a channel disposed inside the valve body of the servo valve, including an oil inlet flow channel 23, an oil return flow channel 24, a first actuation flow channel 21, and a second actuation flow channel 22.

[0038] The valve body also has a space for placing the valve core 11 and the valve sleeve 12. The valve sleeve 12 has multiple sets of through holes 13 along the axial direction of the valve sleeve 12 for communicating with the servo valve flow channel. The valve core 11 has an annular step 14. The valve core 11 can translate along the axial direction of the valve sleeve 12 inside the valve sleeve 12. The step 14 is used to block the through holes 13 and adjust the connection relationship between the first actuation port flow channel 21, the second actuation port flow channel 22 and the oil inlet flow channel 23 and the oil return port flow channel 24.

[0039] The valve body has two cavities 25 located at both ends of the valve sleeve 12 along its length. The valve body also has a balance channel 26, which connects the two cavities 25 inside the valve body. When the valve core 11 moves within the valve sleeve 12, the oil in one cavity 25 can flow to the other cavity 25 through the balance channel 26.

[0040] In this embodiment, as Figure 1 , Figure 2 , Figure 3 As shown, the servo valve includes a housing, within which a valve assembly is housed. The valve assembly includes a rotating valve stem, a valve core 11, and a valve sleeve 12. The axis of the rotating valve stem is perpendicular to the axis of the valve core 11. A valve body is also housed within the housing. The servo valve flow channel is a passageway located within the valve body. The valve body also contains a space for housing the valve core 11 and the valve sleeve 12, which is connected to the servo valve flow channel.

[0041] The interface on the outside of the servo valve flow channel is used to connect to hydraulic equipment, which includes a hydraulic pump and a hydraulic actuator. Rotating the valve stem drives the valve core 11 to translate within the valve sleeve 12. The step 14 on the valve core 11 can completely or partially block the through hole 13. The translation of the valve core 11 within the valve sleeve 12 can adjust the connection relationship between the first actuation port flow channel 21, the second actuation port flow channel 22, the inlet port flow channel 23, and the return port flow channel 24.

[0042] Specifically: the outer wall of valve core 11, the inner wall of valve sleeve 12, and two adjacent steps 14; or, the outer wall of valve core 11, the inner wall of valve sleeve 12, the end of valve sleeve 12, and the steps 14 form at least two variable fluid spaces, each variable fluid space corresponding to a different through hole 13; when valve core 11 and valve sleeve 12 move axially relative to each other, the correspondence between the variable fluid space and the through hole 13 changes with the movement of valve core 11 and steps 14.

[0043] Step 14 can completely or partially cover a set of through holes 13. When completely covered, the fluid in the flow channel system cannot flow into the variable fluid space corresponding to the set of through holes 13 through the set of through holes 13, and the fluid in the variable fluid space corresponding to the set of through holes 13 cannot flow into the flow channel system through the set of through holes 13.

[0044] When step 14 partially covers a set of through holes 13, the area of ​​these through holes 13 that allows fluid to pass through is the window area. The movement of valve core 11 can also adjust the size of the window area, thereby controlling the flow rate of fluid passing through the window.

[0045] In this embodiment, the valve core 11 is provided with four steps 14. A variable fluid space is formed between two adjacent steps 14, resulting in a total of three variable fluid spaces. The servo valve flow path includes channels disposed inside the valve body of the servo valve, including an oil inlet flow path 23, an oil return flow path 24, a first actuation flow path 21, and a second actuation flow path 22. The valve body is provided with interfaces that connect to the oil inlet flow path 23, the oil return flow path 24, the first actuation flow path 21, and the second actuation flow path 22, respectively. The oil inlet flow path 23 is used to connect to the hydraulic pump, the oil return flow path 24 is used to connect to the oil tank, and the first actuation flow path 21 and the second actuation flow path 22 are used to connect to the actuator.

[0046] The translation of the valve core 11 within the valve sleeve 12 can change the connection relationship between the first actuation port flow channel 21, the second actuation port flow channel 22, the inlet flow channel 23, and the return flow channel 24. For example, when the valve core 11 is in a certain position, the inlet flow channel 23 is connected to the first actuation port flow channel 21, and the second actuation port flow channel 22 is connected to the return flow channel 24. The operation of the hydraulic pump can drive the actuator to move in the forward direction. When the valve core 11 moves to another position, the inlet flow channel 23 is connected to the second actuation port flow channel 22, and the first actuation port flow channel 21 is connected to the return flow channel 24. The operation of the hydraulic pump can drive the actuator to move in the reverse direction.

[0047] In some embodiments, the valve body is integrally formed using additive manufacturing technology.

[0048] In some embodiments, the valve sleeve 12 and the valve body are two separate components, which are assembled after being processed separately.

[0049] In some embodiments, the valve sleeve 12 and the valve body are integrally formed by additive manufacturing technology, and the valve sleeve 12 is a part of the valve body.

[0050] like Figure 4 , Figure 5As shown, two cavities 25 are provided inside the valve body near both ends of the valve sleeve 12 along its length. A balance channel 26 is also provided inside the valve body to connect the two cavities 25. When the valve core 11 moves within the valve sleeve 12, the oil in one cavity 25 can flow to the other cavity 25 through the balance channel 26. During the movement of the valve core 11 within the valve sleeve 12, due to the tight fit between the valve core 11 and the valve sleeve 12, the oil at one end of the valve core 11's movement direction generates positive pressure. This positive pressure may create significant damping, hindering the movement of the valve core 11. With the cavities 25 and the balance channel 26, the oil in the valve core 11's movement direction is transferred to the other side through the balance channel 26, thereby balancing the oil pressure at both ends of the valve core 11. This reduces pressure fluctuations during valve movement to a controllable range, thus balancing the oil pressure on both sides, reducing rigid impacts and valve core 11 resistance.

[0051] Furthermore, the oil inlet channel 23, the oil return channel 24, the first actuation channel 21, and the second actuation channel 22 each include a main branch 31 for connecting the hydraulic equipment. The main branch 31 is connected to at least one first branch 32, and the first branch 32 is connected to the through hole 13 on the valve sleeve 12.

[0052] The oil inlet channel 23, the oil return channel 24, the first actuation channel 21, and the second actuation channel 22 all include a main branch 31 for connecting to the hydraulic equipment. The main branch 31 is connected to several first branches, which are used to connect to the corresponding through holes 13.

[0053] The main branch 31 and the first branch 32 can evenly divide the hydraulic oil into multiple streams and connect them with the corresponding through holes 13, so that the valve core 11 is subjected to uniform force and the drive is more stable.

[0054] In some embodiments, such as Figure 8 As shown, some servo valve flow channels include a main branch 31 and a first branch 32, the first branch 32 being connected to a through hole 13 on the valve sleeve 12. In this servo valve flow channel, one first branch 32 is connected to the through hole 13 on the valve sleeve 12, and another first branch 32 is connected to two second branches 33, the two second branches 33 being connected to the through hole 13 on the valve sleeve 12.

[0055] In some embodiments, such as Figure 6 , Figure 7 As shown, the main branch 31 connects to multiple first branches 32, each first branch 32 connects to multiple second branches 33, and the second branches 33 are connected to the through holes 13 on the valve sleeve 12.

[0056] It should be noted that, for ease of illustration, the servo valve flow channel is shown in solid form in the attached diagram. In reality, the servo valve flow channel is a cavity 25 channel located inside the valve body.

[0057] Furthermore, the first branch 32 is connected to a second branch 33, and the second branch 33 is connected to the through hole 13 on the valve sleeve 12.

[0058] In some embodiments, the cross-sectional area of ​​the main branch 31 is greater than or equal to the sum of the cross-sectional areas of the corresponding first branches, and the cross-sectional area of ​​the first branches is greater than or equal to the sum of the cross-sectional areas of the corresponding second branches.

[0059] In order to avoid the first branch 32 and the second branch 33 restricting the input flow of the main branch 31, the sum of the cross-sectional areas of the first branch 32 is greater than the sum of the cross-sectional areas of the main branch 31, and the sum of the cross-sectional areas of the second branch 33 is greater than the sum of the cross-sectional areas of the first branch 32.

[0060] In some embodiments, in the first branch 32 or the second branch 33 connected to the valve sleeve 12, the end of each first branch 32 or the second branch 33 corresponds one-to-one with the slot on the valve sleeve 12.

[0061] Furthermore, the valve sleeve 12 is axially arranged with X sets of through holes 13, each set of through holes 13 including Y pairs of slots distributed radially along the valve sleeve 12; wherein, X ranges from 3 to 20, and Y ranges from 1 to 15;

[0062] The cross-sectional area of ​​the main branch 31 is S, then S≥K1*h*b*Y; where K1 is a multiple, and K1 takes values ​​from 2 to 16, h is the moving distance of the valve core 11, and b is the width of the slot.

[0063] Let ΔS be the difference between the cross-sectional areas of the step 14 and the valve core 11. Then ΔS ≥ K2 * h * b * Y; where K2 is a multiple and K2 ranges from 2 to 10.

[0064] In the specific implementation process, a motor and a crankshaft connected to the motor output shaft are also provided inside the housing. The valve core 11 is provided with a waist-shaped hole. The rotation of the crankshaft can drive the valve core 11 to translate inside the valve sleeve 12. When the crankshaft rotates in the forward direction, it can open the A group through hole 13 when the valve core 11 slides to the left limit position inside the valve sleeve 12. When the crankshaft rotates in the reverse direction, it can open the B group through hole 13 when the valve core 11 slides to the right limit position inside the valve sleeve 12. The range of A and B is 2-(X-1), so as to ensure that a passage can be formed when the valve core 11 moves to the limit position.

[0065] Furthermore, the cross-section of the balancing channel 26 is one of the following: circular, elliptical, square, rectangular, regular polygon with more than or equal to 4 sides, or waist-shaped.

[0066] Furthermore, the cross-sectional area of ​​the balancing channel 26 varies along the length of the balancing channel 26.

[0067] The oil passage form and cross-section of the balance channel 26 are designed in various ways. In some embodiments, the cross-sectional area is fixed, that is, the cross-sectional area remains unchanged as the balance channel 26 extends along its length. In some embodiments, the cross-sectional area is variable, that is, the cross-sectional area changes as the balance channel 26 extends along its length.

[0068] In some embodiments, the cross-sectional shape of the balancing channel 26 is one of the following: circular, elliptical, square, rectangular, regular polygon with 4 or more sides, or waist-shaped.

[0069] Furthermore, the ratio of the area of ​​the cross-section of the balance channel 26 to the area of ​​the inner hole of the valve sleeve 12 is greater than or equal to 0.01.

[0070] Preferably, the ratio of the area of ​​the cross-section of the balance channel 26 to the area of ​​the inner hole of the valve sleeve 12 is greater than or equal to 0.05.

[0071] In this embodiment, the ratio of the area of ​​the cross-section of the balance channel 26 to the area of ​​the inner hole of the valve sleeve 12 is related to the damping of the movement of the valve core 11 and the frequency response of the servo valve. The ratio of the area of ​​the cross-section of the balance channel 26 to the area of ​​the inner hole of the valve sleeve 12 needs to be adjusted according to the required damping and frequency response.

[0072] Furthermore, the ratio of the volume of the cavity 25 to the volume occupied by the valve core 11 when it moves to the limit position is greater than 1.

[0073] Preferably, the ratio of the volume of cavity 25 to the volume occupied by valve core 11 when it moves to its limit position is greater than 3. The limit position of valve core 11 refers to the extreme position at which the valve core 11 moves along the length of valve sleeve 12 within the valve sleeve 12, driven by the rotation of the motor. The limit position can be a mechanically limited position of valve core 11 and valve sleeve 12, or a limit position based on the motor's angular limit.

[0074] Furthermore, the valve sleeve 12 is provided with at least 3 rows of square holes along the axial direction, and the axial dimensions of each row of square holes are the same. The shape of the square holes is one of rectangle, circle, ellipse, or polygon.

[0075] This utility model also provides a servo valve, including the servo valve flow channel as described above.

[0076] In this embodiment, the servo valve includes a housing, within which a valve assembly is disposed. The valve assembly is connected to a servo valve flow channel, which is used to connect to hydraulic equipment. The valve assembly includes a rotating valve stem, a valve core 11, and a valve sleeve 12. The axis of the rotating valve stem is perpendicular to the axis of the valve core 11. The valve core 11 is coaxial and movably disposed within the valve sleeve 12. A crankshaft is connected to the bottom of the rotating valve stem, and a first bearing is sleeved on the crankshaft. The valve sleeve 12 is disposed within the servo valve flow channel. Multiple sets of through holes 13 for communicating with the servo valve flow channel are formed along the axial direction of the valve sleeve 12. A movable groove cooperating with the crankshaft is formed radially in the middle of the valve sleeve 12. An oblong mounting hole cooperating with the first bearing is formed inside the valve core 11. The length direction of the oblong mounting hole is perpendicular to the axial direction of the valve core 11. At least one step 14 is fixedly sleeved on both sides of the mounting hole on the valve core 11. The step 14 is used to block the through holes 13 at different positions.

[0077] Rotating the valve stem forward or backward causes the crankshaft to rotate accordingly. Due to the eccentric setting of the crankshaft relative to the rotating valve stem, the first bearing moves left or right within the waist-shaped mounting hole inside the valve core 11. This, in turn, pushes the valve core 11 to move left or right within the valve sleeve 12, causing the annular sleeve on the valve core 11 to block the through holes 13 at different positions on the valve sleeve 12. This creates different pathways to control the flow rate and direction of the hydraulic oil, ultimately controlling the hydraulic equipment to perform corresponding actions. During the process of the crankshaft controlling the movement of the valve core 11, the first bearing cooperates with the rotation of the crankshaft. At the same time, the first bearing prevents the crankshaft from directly acting on the valve core 11, thus significantly reducing wear and increasing service life. Furthermore, the first bearing is always within the waist-shaped mounting hole of the valve core 11, making it difficult to disengage. The structure is compact, robust, and stable, meeting the usage requirements.

[0078] In some embodiments, the oil inlet channel 23, the oil return channel 24, the first actuation channel 21, and the second actuation channel 22 are correspondingly arranged according to the through hole 13 on the valve sleeve and the step 14 on the valve core, such as... Figure 4 , Figure 6 , Figure 7 , Figure 8 As shown, the valve sleeve is provided with 5 sets of through holes 13 in the axial direction. From left to right, the first set of through holes 13 and the fifth set of through holes 13 are connected to the oil inlet channel 23, the second set of through holes 13 are connected to the first actuation port channel 21, the third set of through holes 13 are connected to the oil return port channel 24, and the fourth set of through holes 13 are connected to the second actuation port channel 22.

[0079] In some embodiments, the valve sleeve is provided with 5 sets of through holes 13 in the axial direction. From left to right, the first set of through holes 13 and the fifth set of through holes 13 are connected to the return oil port flow channel 24, the second set of through holes 13 are connected to the first actuation port flow channel 21, the third set of through holes 13 are connected to the inlet oil port flow channel 23, and the fourth set of through holes 13 are connected to the second actuation port flow channel 22.

[0080] In various embodiments of this utility model, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this utility model embodiment.

[0081] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A servo valve flow path for connecting a valve assembly of a servo valve and a hydraulic device, the valve assembly comprising a valve core (11) and a valve sleeve (12); characterized in that: The servo valve flow channel includes a channel disposed inside the valve body of the servo valve, including an oil inlet flow channel (23), an oil return flow channel (24), a first actuation flow channel (21), and a second actuation flow channel (22). The valve body is also provided with a space for placing the valve core (11) and the valve sleeve (12). The valve sleeve (12) has multiple sets of through holes (13) for communicating with the servo valve flow channel along the axial direction of the valve sleeve (12). The valve core (11) is provided with an annular step (14). The valve core (11) can be translated along the axial direction of the valve sleeve (12) inside the valve sleeve (12). The step (14) is used to block the through holes (13) and adjust the connection relationship between the first actuation port flow channel (21), the second actuation port flow channel (22), the oil inlet flow channel (23), and the oil return port flow channel (24). The valve body has two cavities (25) located at both ends of the valve sleeve (12) along its length. The valve body also has a balance channel (26) for connecting the two cavities (25) inside the valve body. When the valve core (11) moves within the valve sleeve (12), the oil in one cavity (25) can flow to the other cavity (25) through the balance channel (26).

2. The servo valve flow channel as described in claim 1, characterized in that: The oil inlet channel (23), oil return channel (24), first actuation channel (21), and second actuation channel (22) each include a main branch (31) for connecting the hydraulic equipment. The main branch (31) is connected to at least one first branch (32), and the first branch (32) is connected to the through hole (13) on the valve sleeve (12).

3. The servo valve flow channel as described in claim 2, characterized in that: The valve sleeve (12) is axially arranged with X sets of through holes (13), each set of through holes (13) including Y pairs of slots distributed radially along the valve sleeve (12); wherein, X ranges from 3 to 20, and Y ranges from 1 to 15; The cross-sectional area of ​​the main branch (31) is S, then S≥K1*h*b*Y; where K1 is a multiple, and K1 takes 2~16, h is the moving distance of the valve core (11), and b is the width of the slot. Let the difference between the cross-sectional areas of the step (14) and the valve core (11) be ΔS, then ΔS≥K2*h*b*Y; where K2 is a multiple, and K2 takes values ​​from 2 to 10.

4. A servo valve flow channel as described in claim 2, characterized in that: The first branch (32) is connected to the second branch (33), and the second branch (33) is connected to the through hole (13) on the valve sleeve (12).

5. A servo valve flow channel as described in claim 1, characterized in that: The cross-section of the balance channel (26) is one of the following: circle, ellipse, square, rectangle, regular polygon with more than or equal to 4 sides, or waist shape.

6. A servo valve flow channel as described in claim 1 or 5, characterized in that: The cross-sectional area of ​​the balance channel (26) varies along the length of the balance channel (26).

7. A servo valve flow channel as described in claim 1, characterized in that: The ratio of the area of ​​the cross section of the balance channel (26) to the area of ​​the inner hole of the valve sleeve (12) is greater than or equal to 0.

01.

8. A servo valve flow channel as described in claim 1, characterized in that: The ratio of the volume of the cavity (25) to the volume occupied by the valve core (11) when it moves to the limit position is greater than 1.

9. A servo valve flow channel as described in claim 1, characterized in that: The valve sleeve (12) has at least three rows of square holes along the axial direction. The axial dimensions of each row of square holes are the same, and the shape of the square holes is one of rectangle, circle, ellipse or polygon.

10. A servo valve, characterized in that: Includes the servo valve flow path as described in any one of claims 1-9.

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