Direct-driven rotary servo valve

Abstract

The invention relates to a direct drive type rotary servo valve, and relates to the field of hydraulic components, the direct drive type rotary servo valve comprises a valve body, a valve sleeve, a rotor valve core and a servo driving mechanism, a plurality of hydraulic oil ports are formed in the valve body, a plurality of valve cavities communicated with the hydraulic oil ports are formed in the valve body, the valve sleeve is fixed in the valve body, and the rotor valve core is fixed in the valve sleeve. The valve sleeve is arranged in the valve cavity, a plurality of valve sleeve valve ports communicated with the valve cavity are formed in the wall of the valve sleeve, the rotor valve element comprises a valve element part and a rotor part which are integrally formed, the valve element part is rotationally arranged in the valve sleeve, a plurality of valve element oil grooves are formed in the side wall of the valve sleeve, and the servo driving mechanism corresponds to the rotor part so that the rotor valve element can be driven to rotate. The control precision of the servo valve can be improved.

Description

Technical Field

[0001] This application relates to the field of hydraulic components, and particularly to a direct drive rotary servo valve. Background Art

[0002] A hydraulic valve is a hydraulic component used to control the pressure, flow rate, and flow direction of a liquid in a hydraulic transmission. It can operate in manual, hydraulic control, or electric control modes and is an essential component in the field of hydraulic transmission. An electro-hydraulic servo valve, also known as a servo valve, is a hydraulic valve that can control the output modulated flow rate and pressure through a closed-loop control method under the control of an analog electrical signal. It has the advantages of fast dynamic response, high control accuracy, and long service life, and is widely used in high-precision mechatronic systems, aerospace, ships, metallurgy, chemical engineering, and other fields, as well as in the electro-hydraulic servo control systems of large test equipment.

[0003] According to the different movement modes of the spool in the valve body, servo valves can be divided into sliding servo valves and rotary servo valves. A rotary servo valve controls the pressure, flow rate, and flow direction of a liquid by controlling the rotation direction and rotation angle of the spool in the valve body. During the control process, there is no need for axial movement of the spool, and no external leakage will occur. At the same time, the spool can be directly driven by a servo motor to move, without the need for conversion between rotary motion and linear motion, and has the advantages of small leakage, stable operation, and high control accuracy. According to the different spool drive methods, servo valves can be divided into two-stage servo valves and direct drive servo valves. A direct drive servo valve uses a servo drive device to directly drive the spool to move, and has the advantages of a simpler valve structure, high control reliability, and long service life.

[0004] In the existing rotary direct drive servo valve, a servo motor is usually integrated on the valve body, and the servo motor and the spool are connected to each other through a transmission connection structure, which affects the drive efficiency and drive accuracy of the spool. To ensure the flow rate of the liquid, the spool usually has a certain volume and mass, which not only requires a larger driving force from the servo motor but also leads to an extension of the response time of the servo valve. Summary of the Invention

[0005] To improve the control accuracy of the servo valve, this application provides a rotary direct drive servo valve.

[0006] The rotary direct drive servo valve provided by this application adopts the following technical solutions: A direct-drive rotary servo valve includes a valve body, a valve sleeve, a rotor spool, and a servo drive mechanism. The valve body is provided with a plurality of hydraulic oil ports and internally provided with a plurality of valve cavities respectively communicating with the hydraulic oil ports. The valve sleeve is fixed inside the valve body, and its wall is provided with a plurality of valve sleeve valve ports communicating with the valve cavities. The rotor spool includes an integrally formed spool portion and a rotor portion. The spool portion is rotatably arranged inside the valve sleeve, and its side wall is provided with a plurality of spool oil grooves. The servo drive mechanism is correspondingly arranged with the rotor portion to be able to drive the rotor spool to rotate.

[0007] By adopting the above technical solution, by using the plurality of valve sleeve valve ports provided on the valve sleeve and the plurality of spool oil grooves provided on the spool portion, when the rotor spool rotates, the on-off and the size of the flow area between the spool oil grooves and the corresponding valve sleeve valve ports can be changed, so that the flow rate, flow direction and pressure of the liquid can be controlled. By using the rotor portion of the rotor spool, the rotor spool can be rotated under the drive of the servo drive mechanism, so that the spool portion of the rotor spool rotates, forming the rotation of the spool portion directly driven by the servo drive mechanism, avoiding the setting of a transmission connection structure between the spool and the drive shaft of the servo motor, improving the transmission accuracy and transmission efficiency, thereby improving the control accuracy of the servo valve and being beneficial to reducing the response time of the servo valve.

[0008] In a specific feasible implementation, the servo drive mechanism includes a motor housing, a stator and a magnetic encoder. The motor housing is fixed at one end of the valve body, the stator is fixed inside the motor housing, the rotor portion is installed inside the stator, and the magnetic encoder is arranged at the end of the rotor portion.

[0009] By adopting the above technical solution, by using the magnetic encoder arranged at the end of the rotor portion, the angular displacement of the rotor spool can be feedback in real time, so that the displacement of the rotor spool can be closed-loop controlled through the servo control circuit, forming an accurate control of the flow area between the spool oil grooves and the valve sleeve valve ports, and improving the control accuracy of the servo valve.

[0010] In a specific feasible implementation, the direct-drive rotary servo valve of the present application further includes a rotor seat. The rotor seat is fixed between the motor housing and the valve body on the valve body, and the rotor portion is covered inside the rotor seat through the gap between the rotor portion and the stator.

[0011] By adopting the above technical solution, by using the rotor seat fixed between the motor housing and the valve body, the isolation between the liquid passage of the servo valve and the electric control circuit can be formed, avoiding the influence of liquid leakage on the electric control circuit.

[0012] In a specific feasible embodiment, the rotor spool valve further includes a connecting portion disposed between the spool portion and the rotor portion. An end portion of the spool portion is provided with a first bearing mount, the connecting portion is provided with a second bearing mount, an end portion of the rotor portion is provided with a third bearing mounting portion, and two ends of the valve body are respectively provided with a first bearing mounting hole and a second bearing mounting hole. An end portion within the rotor seat is provided with a third bearing mounting hole. Bearings are installed between the first bearing mount and the first bearing mounting hole, between the second bearing mount and the second bearing mounting hole, and between the third bearing mounting portion and the third bearing mounting hole.

[0013] By adopting the above technical solution, the use of three bearings respectively disposed at different positions of the rotor spool valve is beneficial to improving the rotation smoothness of the rotor spool valve, reducing the rotation resistance of the rotor spool valve, and increasing the response speed of the rotor spool valve.

[0014] In a specific feasible embodiment, a hollow cavity is provided inside the rotor portion, and a permanent magnet mounting post is provided on the rotor portion, and an annular permanent magnet is provided on the permanent magnet mounting post.

[0015] By adopting the above technical solution, the use of a hollow cavity provided inside the rotor portion can effectively reduce the mass of the relatively large-diameter rotor portion, reduce the moment of inertia of the rotor spool valve, and increase the response speed of the spool valve rotation. The use of the annular permanent magnet provided on the permanent magnet mounting post of the rotor portion can drive the rotor portion to generate a rotational movement under the action of the current in the stator coil. Compared with the traditional multi-piece tile-shaped permanent magnet structure, it not only eliminates the risk of permanent magnet detachment, but also can reduce the pole pitch, improve the cogging torque of the motor, increase the rotational stability of the rotor portion, and improve the control accuracy of the servo valve.

[0016] In a specific feasible embodiment, the hydraulic oil ports on the valve body include a P port, a T port, an A port, and a B port. A main valve hole is provided inside the valve body. The valve cavity includes a T1 cavity, an A cavity, a P cavity, a B cavity, and a T2 cavity arranged in sequence on the main valve hole of the valve body. The T1 cavity and the T2 cavity are communicated with the T port, and the A cavity, the P cavity, and the B cavity are respectively communicated with the A port, the P port, and the B port.

[0017] By adopting the above technical solution, by using the T1 chamber, A chamber, P chamber, B chamber and T2 chamber sequentially arranged on the main control of the valve body, it is beneficial to control the communication state between the A chamber and B chamber and the T1 chamber and T2 chamber or the P chamber, thereby controlling the flow state of the liquid in the A chamber and B chamber, and forming the control of the liquid flow direction. By using the P port, T port, A port and B port arranged on the valve body, they can be respectively connected to the external pressure liquid, oil tank and two working oil ports, so that the pressure liquid can flow from the P port to the A port or B port through the direct drive rotary servo valve of the present application, driving the hydraulic power device to work, and at the same time, the liquid flowing back from the B port or A port flows back to the oil tank through the T port, realizing the circulation of the pressure liquid.

[0018] In a specific feasible implementation, the valve sleeve valve ports include a valve sleeve T1 port corresponding to the T1 chamber, a valve sleeve A port corresponding to the A chamber, a valve sleeve P port corresponding to the P chamber, a valve sleeve B port corresponding to the B chamber and a valve sleeve T2 port corresponding to the T2 chamber; the valve core oil grooves include a valve core A groove, a valve core P groove and a valve core B groove. The valve core A groove extends from the part of the valve core corresponding to the valve sleeve T1 port to the part corresponding to the valve sleeve A port. The valve core P groove extends from the part of the valve core corresponding to the valve sleeve A port to the part corresponding to the valve sleeve B port. The valve core B groove extends from the part of the valve core corresponding to the valve sleeve B port to the part corresponding to the valve sleeve T2 port. The valve sleeve T1 port, valve sleeve A port, valve sleeve P port, valve sleeve B port and valve sleeve T2 port, as well as the valve core A groove, valve core P groove and valve core B groove are arranged such that in different rotation states of the rotor valve core, the valve sleeve T1 port and the valve sleeve A port, the valve sleeve P port and the valve sleeve A port and valve sleeve B port, the valve sleeve B port and the valve sleeve T2 port are all in a first state of being mutually separated, or the valve sleeve T1 port and the valve sleeve A port are connected through the valve core A groove, the valve sleeve P port and the valve sleeve A port are separated and connected to the valve sleeve B port through the valve core P groove, and the valve sleeve B port and the valve sleeve T2 port are separated in a second state, or the valve sleeve T1 port and the valve sleeve A port are separated, the valve sleeve P port and the valve sleeve A port are connected through the valve core P groove and separated from the valve sleeve B port, and the valve sleeve B port and the valve sleeve T2 port are connected through the valve core B groove in a third state.

[0019] By adopting the above technical solution, through the cooperation between the spool A groove, spool P groove, spool B groove and the valve sleeve T1 port, valve sleeve A port, valve sleeve P port, valve sleeve B port and valve sleeve T2 port, different overlapping states can be formed between the spool A groove and the valve sleeve T1 port and valve sleeve A port, between the spool P groove and the valve sleeve A port, valve sleeve P port and valve sleeve B port, and between the spool B groove and the valve sleeve B port and valve sleeve T2 port, as well as the flow area of the flow ports formed by the overlapping with each other, so as to control the flow direction and flow rate of the flowing liquid. By using different rotation states of the rotor spool, a zero position state in which the P port, T port, A port and B port of the servo valve are all blocked, a first liquid supply state in which the P port is connected to the B port and the A port is connected to the T port, and a second liquid supply state in which the P port is connected to the A port and the B port is connected to the T port can be formed, thereby controlling the on-off and supply direction of the liquid supply liquid path.

[0020] In a specific feasible embodiment, the valve sleeve T1 ports include a first valve sleeve T1 port and a second valve sleeve T1 port that are radially opposite to each other on the valve sleeve. The valve sleeve A ports include a first valve sleeve A port and a second valve sleeve A port that are radially opposite to each other on the valve sleeve. The valve sleeve P ports include a first valve sleeve P port and a second valve sleeve P port that are radially opposite to each other on the valve sleeve. The valve sleeve B ports include a first valve sleeve B port and a second valve sleeve B port that are radially opposite to each other on the valve sleeve. The valve sleeve T2 ports include a first valve sleeve T2 port and a second valve sleeve T2 port that are radially opposite to each other on the valve sleeve. The spool A grooves include a first spool A groove and a second spool A groove that are radially opposite to each other on the spool portion. The spool P grooves include a first spool P groove and a second spool P groove that are radially opposite to each other on the spool portion. The spool B grooves include a first spool B groove and a second spool B groove that are radially opposite to each other on the spool portion. When the rotor spool is in the first state, the first spool A groove and the second spool A groove are both separated from the first valve sleeve T1 port and the second valve sleeve T1 port. The first spool P groove and the second spool P groove are both separated from the first valve sleeve A port, the second valve sleeve A port, the first valve sleeve B port, and the second valve sleeve B port. And the first spool B groove and the second spool B groove are both separated from the first valve sleeve T2 port and the second valve sleeve T2 port. When the rotor spool is in the second state, the first spool A groove is respectively connected to the first valve sleeve T1 port and the first valve sleeve A port, the second spool A groove is respectively connected to the second valve sleeve T1 port and the second valve sleeve A port. The first spool P groove is respectively connected to the first valve sleeve P port and the second valve sleeve B port, the second spool P groove is respectively connected to the second valve sleeve P port and the first valve sleeve B port. And the first spool P groove and the second spool P groove are both separated from the first valve sleeve A port and the second valve sleeve A port. The first spool B groove and the second spool B groove are both separated from the first valve sleeve T2 port and the second valve sleeve T2 port. When the rotor spool is in the third state, the first spool A groove and the second spool A groove are both separated from the first valve sleeve T1 port and the second valve sleeve T1 port. The first spool P groove is respectively connected to the first valve sleeve A port and the first valve sleeve P port, the second spool P groove is respectively connected to the second valve sleeve A port and the second valve sleeve P port. And the first spool P groove and the second spool P groove are both separated from the first valve sleeve B port and the second valve sleeve B port. The first spool B groove is respectively connected to the first valve sleeve B port and the first valve sleeve T2 port, the second spool B groove is respectively connected to the second valve sleeve B port and the second valve sleeve T2 port.

[0021] By adopting the above technical solution, by using the paired settings of the valve sleeve T1 port, valve sleeve A port, valve sleeve P port, valve sleeve B port and valve sleeve T2 port in the radial relative positions of the valve sleeve, and the paired settings of the valve core A groove, valve core P groove and valve core B groove in the radial relative positions of the valve core part, it is possible to realize the synchronous change of the relative positions between two groups of valve core A grooves, valve core P grooves and valve core B grooves and two groups of valve sleeve T1 ports, valve sleeve A ports, valve sleeve P ports, valve sleeve B ports and valve sleeve T2 ports. Thus, a larger flow passage cross-sectional area can be formed by using the limited volume of the rotor valve core, improving the flow capacity of the flow passage and reducing the pressure loss of the flow passage.

[0022] In a specific feasible implementation, a first oil return shaft hole is provided on the end face of the valve core part, a first oil return groove is provided on the outer peripheral surface of the valve core part corresponding to the T1 cavity, and a first oil return connection hole is provided between the first oil return groove and the first oil return shaft hole; a second oil return shaft hole is provided on the end face of the rotor part, a second oil return groove is provided on the outer peripheral surface of the valve core part corresponding to the T2 cavity, a second oil return connection hole is provided between the second oil return groove and the second oil return shaft hole, and a rotor part oil return hole communicating with the second oil return shaft hole is provided on the outer peripheral surface of the rotor part adjacent to the valve core part.

[0023] By adopting the above technical solution, by using the first oil return shaft hole, the first oil return connection hole and the first oil return groove that are mutually connected at the end position of the valve core part, an oil return passage connecting the end gap of the valve core part and the T1 cavity can be formed, so that a small amount of liquid leaking to the end face position of the valve core part can flow back to the T1 cavity during the rotation of the rotor valve core. By using the second oil return groove provided at the relative position of the T2 cavity of the valve core part, and the second oil return connection hole, the second oil return shaft hole and the rotor part oil return hole that are mutually connected with the second oil return groove, an oil return passage connecting the end gap of the rotor part and the outer peripheral gap of the rotor part and the T2 cavity can be formed, so that a small amount of liquid leaking to the periphery of the valve rotor part and the end face position of the rotor part can flow back to the T2 cavity during the rotation of the rotor valve core.

[0024] In a specific feasible implementation, valve body cylindrical pin holes are provided on the side walls at both ends of the main hole of the valve body, valve sleeve cylindrical pin holes are provided at the corresponding positions on the outer sides of both ends of the valve sleeve, and the valve sleeve is installed in the main hole of the valve body through the cooperation of elastic cylindrical pins with the valve body cylindrical pin holes and the valve sleeve cylindrical pin holes.

[0025] By adopting the above technical solution, by using the elastic cylindrical pins that cooperate with the valve body cylindrical pin holes and the valve sleeve cylindrical pin holes, the valve sleeve can be stably fixed inside the valve body, preventing the valve sleeve from rotating and sliding inside the valve body.

[0026] In a specific feasible implementation, both the valve sleeve and the rotor valve core are formed by 3D printing with ZrO2 ceramic material.

[0027] By adopting the above technical solution, the valve sleeve and the rotor valve core made of ZrO2 ceramic material can reach a hardness of 85 HRC after firing, making the hardness of the rotor valve core and the valve sleeve far exceed the hardness of common particulate contaminants in the oil fluid. Therefore, it can avoid damage to the rotor valve core and the valve sleeve caused by particulate contaminants mixed in the oil fluid, and improve the anti-pollution ability, reliability and service life of the direct drive rotary servo valve of the present application. Using 3D printing technology to manufacture the valve sleeve and the rotor valve core can reduce the processing amount during the manufacturing process, reduce the raw material cost and processing cost, and can conveniently form the cavity structure inside the rotor valve core, avoiding machining process holes on the wall of the rotor valve core, so as to greatly reduce the mass of the rotor valve core on the basis of ensuring the structural strength of the rotor valve core, and greatly improve the response speed and response frequency of the rotor valve core.

[0028] In a specific feasible implementation, there is a clearance fit between the outer peripheral surface of the rotor valve core and the valve sleeve.

[0029] By adopting the above technical solution, using the clearance fit between the outer peripheral surface of the rotor valve core and the valve sleeve can prevent close contact between the rotor valve core and the valve sleeve, thereby reducing the wear between the rotor valve core and the valve sleeve during the rotation process, improving the service life and reliability of the servo valve, and being beneficial to improving the frequency response of the servo valve.

[0030] In summary, the present application includes at least one of the following beneficial technical effects: 1. By using the valve core part and the rotor part respectively arranged at both ends of the rotor valve core, the valve core part and the rotor part can form an integral synchronous movement, thereby avoiding the need to set up a connection structure connecting the servo drive mechanism and the valve core in the servo valve, and improving the control accuracy and response speed of the servo valve.

[0031] 2. By using the magnetic encoder arranged at the end of the rotor part, when a rotor seat is arranged between the rotor part and the stator to form isolation from each other, the angular displacement of the rotor valve core can be detected in real time, so that the rotation angle of the rotor valve core can be accurately closed-loop controlled through the servo control circuit, improving the flow control accuracy of the servo valve.

[0032] 3. By using the cooperation between the valve sleeve valve orifice arranged on the valve sleeve and the valve core oil groove arranged on the outer peripheral surface of the valve core part, the on-off and flow area between different valve core oil grooves and the corresponding valve sleeve oil ports can be conveniently controlled by controlling the rotation direction and rotation angle of the rotor valve core, realizing the control of the liquid flow direction, flow rate and pressure; and arranging the valve core oil groove axially along the valve core part on the outer peripheral surface of the valve core part can set multiple independent valve core oil grooves on the valve core part, and can greatly increase the flow cross-sectional area of the valve core oil groove, improving the flow rate of the direct drive rotary servo valve of the present application and reducing the pressure drop when the liquid passes through.

[0033] 4. Using ZrO2 ceramic material to 3D print the rotor spool and valve sleeve can not only form more cavities inside the rotor spool, reduce the mass of the rotor spool, and improve the response speed of the rotor spool, but also improve the hardness and wear resistance of the rotor spool and valve sleeve, and enhance the anti-pollution ability and service life of the direct drive rotary servo valve of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of an embodiment of the present application.

[0035] Figure 2 It is a cross-sectional schematic diagram of an embodiment of the present application.

[0036] Figure 3 It is a schematic diagram of the valve body in an embodiment of the present application.

[0037] Figure 4 It is Figure 3 the sectional view in the A-A direction in

[0038] Figure 5 It is Figure 3 the sectional view in the B-B direction in

[0039] Figure 6 It is a schematic diagram of the valve sleeve in an embodiment of the present application.

[0040] Figure 7 It is Figure 6 the sectional views in the C-C, D-D, E-E, F-F, and G-G directions in

[0041] Figure 8 It is a schematic diagram of the rotor spool in an embodiment of the present application.

[0042] Figure 9 It is a schematic diagram of the rotor spool from another angle in an embodiment of the present application.

[0043] Figure 10 It is Figure 9 the sectional views in the H-H, I-I, and J-J directions in

[0044] Figure 11 It is Figure 9 the sectional view in the K-K direction in

[0045] Figure 12 It is a schematic diagram of the rotor spool in the first state in an embodiment of the present application.

[0046] Figure 13 It is Figure 12 the sectional views in the L1-L1, M1-M1, N1-N1, O1-O1, and P1-P1 directions in

[0047] Figure 14 Schematic diagram of the servo valve function when the rotor spool is in the first state in an embodiment of the present application.

[0048] Figure 15 Schematic diagram when the rotor spool is in the second state in an embodiment of the present application.

[0049] Figure 16 For Figure 15 Cross-sectional views in the orientations of L2-L2, M2-M2, N2-N2, O2-O2, and P2-P2 in

[0050] Figure 17 Schematic diagram of the servo valve function when the rotor spool is in the second state in an embodiment of the present application.

[0051] Figure 18 Schematic diagram when the rotor spool is in the third state in an embodiment of the present application.

[0052] Figure 19 For Figure 18 Cross-sectional views in the orientations of L3-L3, M3-M3, N3-N3, O3-O3, and P3-P3 in

[0053] Figure 20 Schematic diagram of the servo valve function when the rotor spool is in the third state in an embodiment of the present application.

[0054] Description of reference numerals: 1. Valve body; 101. P port; 102. T port; 103. A port; 104. B port; 11. First bearing mounting hole; 12. Second bearing mounting hole; 13. Main hole of valve body; 131. T1 cavity; 132. A cavity; 133. P cavity; 134. B cavity; 135. T2 cavity; 136. Cylindrical pin hole of valve body; 2. Valve sleeve; 21. T1 port of valve sleeve; 211. First T1 port of valve sleeve; 212. Second T1 port of valve sleeve; 22. A port of valve sleeve; 221. First A port of valve sleeve; 222. Second A port of valve sleeve; 23. P port of valve sleeve; 231. First P port of valve sleeve; 232. Second P port of valve sleeve; 24. B port of valve sleeve; 241. First B port of valve sleeve; 242. Second B port of valve sleeve; 25. T2 port of valve sleeve; 251. First T2 port of valve sleeve; 252. Second T2 port of valve sleeve; 26. Cylindrical pin hole of valve sleeve; 3. Rotor spool; 301. First spool A groove; 302. Second spool A groove; 303. First spool P groove; 304. Second spool P groove; 305. First spool B groove; 306. Second spool B groove; 31. Spool part; 311. First bearing mounting seat; 312. First oil return shaft hole; 313. First oil return groove; 314. First oil return connection hole; 315. Second oil return groove; 316. Second oil return connection hole; 32. Rotor part; 321. Third bearing mounting part; 322. Hollow cavity; 323. Permanent magnet mounting column; 324. Second oil return shaft hole; 325. Oil return hole of rotor part; 33. Connection part; 331. Second bearing mounting seat; 34. Ring permanent magnet; 4. Servo drive mechanism; 41. Motor housing; 42. Stator; 43. Magnetic encoder; 44. End cover of housing; 5. Rotor seat; 51. Third bearing mounting hole. Detailed implementation manners

[0055] The following will describe the detailed implementation manners of the present application with reference to the accompanying drawings. It should be understood that the detailed implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0056] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0057] In this specification, the terms "first", "second", and "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Therefore, the features defined with "first", "second", and "third" may explicitly or implicitly include one or more of the said features.

[0058] An embodiment of the direct drive rotary servo valve of the present application, as Figure 1 and Figure 2 shown, includes a valve body 1, a valve sleeve 2, a rotor spool 3, and a servo drive mechanism 4. While the valve body 1 constitutes the external shape of the direct drive rotary servo valve of the present application, it also serves as the installation carrier for other structural components of the direct drive rotary servo valve of the present application. The valve body 1 is designed using generative AI and fabricated by 3D printing, capable of forming a flow channel with equal wall thickness and a structure without process holes, which can significantly reduce raw materials, thus having the advantages of light weight, small volume, and high power density. Of course, the valve body 1 can also be formed using other existing processing methods. As Figures 3 to 5 A plurality of hydraulic oil ports connected to an external hydraulic system are provided on the valve body 1, and the flow direction and flow rate of the hydraulic oil input from the external hydraulic system are controlled through the plurality of hydraulic oil ports. A plurality of valve cavities are provided inside the valve body 1, and the plurality of valve cavities are respectively in communication with the plurality of hydraulic oil ports.

[0059] As Figure 6 and Figure 7 shown, the valve sleeve 2 is a sleeve fixed inside the valve body 1, usually made of wear-resistant metal material, and of course, it can also be made of other wear-resistant materials such as wear-resistant ceramics or wear-resistant polymer materials. A plurality of valve sleeve valve ports are provided on the wall of the valve sleeve 2, and each valve sleeve valve port communicates the valve cavity outside the valve sleeve 2 with the pipe cavity inside the valve sleeve 2.

[0060] As Figures 8 - 11 shown, the rotor spool 3 is an integrally formed structural member made of a suitable material such as metal, ceramic, or polymer material. One end of the rotor spool 3 is machined into a spool portion 31 for controlling the flow direction and flow rate of the hydraulic oil, and the other end is machined into a rotor portion 32 for driving the rotation of the rotor spool 3. The spool portion 31 is installed inside the pipe cavity of the valve sleeve 2 and can rotate inside the pipe cavity of the valve sleeve 2. A plurality of spool oil grooves recessed inwardly from the outer peripheral surface of the spool portion 31 are provided. When the rotor spool 3 rotates at different angles in the valve sleeve 2, the spool oil grooves can form different degrees of communication states or blocking states with different valve sleeve valve ports, thereby controlling the flow rate and flow direction of the hydraulic oil flowing into the valve cavity in the valve body 1 through the hydraulic oil ports. The rotor portion 32 is usually located outside the valve body 1, and a power component adapted to the servo drive mechanism 4 is provided on the rotor portion 32, so that the rotor portion 32 can form a rotational movement relative to the servo drive mechanism 4, driving the spool portion 31 at the other end to rotate inside the valve sleeve 2.

[0061] The servo drive mechanism 4 is fixed on the valve body 1 and is arranged at a position corresponding to the rotor part 32. Usually, it is sleeved around the periphery of the rotor part 32 and forms a servo drive device similar to a servo motor in combination with the rotor part 32. Generally, a rotor structure composed of a coil or a permanent magnet is arranged on the rotor part 32, and a stator structure composed of a coil is arranged on the part of the servo drive mechanism 4 located around the rotor structure. When an electric current is passed through the coil of the stator structure, the rotor structure can be driven, and the rotor valve core 3 is driven to rotate relative to the servo drive mechanism 4 by the rotor structure, forming a direct drive for the rotor valve core 3. A servo control circuit is arranged in the servo drive mechanism 4, and the rotation of the rotor structure can be closed-loop controlled by using the servo control circuit, forming an accurate control of the rotation position of the rotor valve core 3.

[0062] Compared with the direct-drive servo valve formed by arranging a servo motor in the valve body in the traditional way, the rotor valve core 3 in the direct-drive rotary servo valve of the present application has both the function of a valve core and the function of a rotor. The control of the rotation state of the rotor part 32 by the servo control circuit directly controls the rotation state of the valve core part 31, so the control of the rotation position of the valve core part 31 is more accurate. In the traditional direct-drive servo valve, the servo control system of the servo motor only controls the rotation position of the motor rotor, and then the rotation of the motor rotor is transmitted to the valve core through the transmission structure to drive the valve core to rotate. Therefore, the control of the rotation position of the valve core by the servo control system in the traditional direct-drive servo valve is an indirect control transmitted through the transmission structure, and the transmission of the transmission structure will inevitably bring transmission errors, which will surely affect the control accuracy of the servo valve.

[0063] In some embodiments of the direct-drive rotary servo valve of the present application, such as Figure 1 and Figure 2As shown in the figure, the servo drive mechanism 4 includes a motor housing 41, a stator 42, and a magnetic encoder 43. The motor housing 41 is a housing disposed around the servo drive mechanism 4. The motor housing 41 is fixed to one end of the valve body 1 and is used to position and protect other structures of the servo drive mechanism 4. The stator 42 is fixed inside the motor housing 41. When the motor housing 41 is installed on the valve body 1, the rotor part 32 is located inside the stator 42. Generally, a permanent magnet is provided on the rotor part 32, the stator 42 is a stator coil with an iron core, and a housing end cover 44 is provided at the end of the motor housing 41. A PCBA (printed circuit board assembly) is provided inside the housing end cover 44. The PCBA carries a servo control circuit. The PCBA is electrically connected to the stator wire. The servo control circuit can control the current in the electronic coil in the stator 42 to form a driving force for the rotor structure on the rotor part 32 and drive the rotor spool 3 to rotate. A plug connected to an external power supply and a control system is provided on the housing end cover 44. The plug is connected to the PCBA, so that the operation of the servo valve can be controlled by using an external control system. The magnetic encoder 43 is fixedly provided at the end of the rotor part 32 and is electrically connected to the PCBA. The magnetic encoder 43 can accurately detect the rotation angle of the rotor spool 3 and transmit the detected angle signal to the PCBA. Through the servo control circuit, precise closed-loop control of the rotation position of the rotor spool 3 is achieved, and the opening size of the connection channel between the spool oil groove and the valve sleeve valve port is controlled accordingly, thereby achieving precise control of the flow rate.

[0064] In a preferred embodiment of the direct drive rotary servo valve of the present application, as Figure 2 shown, the direct drive rotary servo valve of the present application further includes a rotor seat 5. The rotor seat 5 is generally in a cylindrical shape with one end open and one end closed. Its open end is fixed to the valve body 1 and is fixed between the motor housing 41 and the valve body 1. The rotor seat 5 covers the rotor part 32 inside the rotor seat 5 through the gap between the rotor part 32 and the stator 42, forming an isolation between the rotor part 32 and the stator 42. The setting of the rotor seat 5 separates a space communicating with the inside of the valve body 1 inside the motor housing 41, isolating the valve structure space inside the servo valve from the electric control structure space, preventing the hydraulic oil in the valve structure space from leaking into the electric control structure space and causing pollution and interference to the control and drive circuits in the servo drive mechanism 4.

[0065] As a specific embodiment of the direct drive rotary servo valve of the present application, as Figure 8 and Figure 9 shown, a connecting part 33 is further provided on the rotor spool 3. The connecting part 33 is provided between the spool part 31 and the rotor part 32. A first bearing mounting seat 311 is provided at the end of the spool part 31, a second bearing mounting seat 331 is provided on the connecting part 33, and a third bearing mounting part 321 is provided at the end of the rotor part 32.

[0066] As shown Figure 4 In the figure, first bearing mounting holes 11 corresponding to the first bearing mounting seats 311 and second bearing mounting holes 12 corresponding to the second bearing mounting seats 331 are respectively provided at both ends of the valve body 1; as shown Figure 2 In the figure, a third bearing mounting hole 51 is provided inside the end of the rotor seat 5. A bearing is respectively installed between the first bearing mounting seat 311 and the first bearing mounting hole 11, between the second bearing mounting seat 331 and the second bearing mounting hole 12, and between the third bearing mounting portion 321 and the third bearing mounting hole 51. By using three bearings to form the supports at both ends and the middle of the rotor valve core 3, the rotor valve core 3 can stably rotate inside the valve body 1, which is beneficial to improving the position accuracy of the rotor valve core 3 and the response speed of rotation.

[0067] In some embodiments of the direct drive rotary servo valve of the present application, as shown Figure 2 and Figure 11 In the figure, a hollow cavity 322 is provided inside the rotor portion 32. The rotor valve core 3 can be integrally formed by 3D printing, and the hollow cavity 322 can be formed during the 3D printing process.

[0068] A cylindrical permanent magnet mounting column 323 is machined on the outer peripheral surface of the rotor portion 32, and a radially magnetized annular permanent magnet 34 is sleeved and installed on the permanent magnet mounting column 323. The annular permanent magnet 34 is usually made of a ferromagnetic material into a circular ring shape and is radially magnetized as required to form a rotor permanent magnet ring structure. Compared with the tile-shaped permanent magnet used in the servo motor in the existing direct drive servo valve, the magnet ring is integrally sleeved on the permanent magnet mounting column 323, eliminating the risk of permanent magnet shedding. Moreover, for the annular permanent magnet 34 formed by magnetizing on the same circular ferromagnetic material, the pole pitch is smaller, improving the cogging torque between the rotor portion 32 and the stator 42, which is beneficial to improving the rotation accuracy of the rotor valve core 3 and thus improving the control accuracy of the servo valve.

[0069] In order to improve the driving efficiency of the servo drive mechanism 4 for the annular permanent magnet 34, the permanent magnet mounting column 323 usually has a relatively large outer diameter. The setting of the hollow cavity 322 can effectively reduce the mass of the rotor valve core 3. Combining with the driving mode of the servo drive mechanism 4 directly driving the rotor portion 32, the response speed of the rotor valve core 3 is faster. Therefore, the direct drive rotary servo valve of the present application has a higher frequency response, and its frequency response can reach 300HZ, far exceeding that of the servo valve with a traditional structure.

[0070] In some embodiments of the direct drive rotary servo valve of the present application, as shown Figures 3 to 5As shown, the hydraulic oil ports provided on the valve body 1 include a P port 101, a T port 102, an A port 103, and a B port 104. Inside the valve body 1, there is a main valve body hole 13 running through both ends of the valve body 1. A plurality of valve cavities are formed by extending from the side wall of the main valve body hole 13 towards the periphery. The plurality of valve cavities are arranged at intervals on the side wall of the main valve body hole 13, including a T1 cavity 131, an A cavity 132, a P cavity 133, a B cavity 134, and a T2 cavity 135 arranged in sequence. The T1 cavity 131 and the T2 cavity 135 are interconnected through a flow channel provided inside the side wall of the valve body 1 and are connected to the T port 102 through the flow channel inside the side wall of the valve body 1; the bottom of the A cavity 132 is connected to the A port 103 through a flow channel provided inside the side wall of the valve body 1; the bottom of the P cavity 133 is connected to the P port 101 through a flow channel provided inside the side wall of the valve body 1; the bottom of the B cavity 134 is connected to the B port 104 through a flow channel provided inside the side wall of the valve body 1. The cavities and flow channels inside the valve body 1 are formed by 3D printing and then processed by a grinding flow process, making the flow channels smoother and the turning more smooth, which can effectively reduce the pressure loss during liquid flow and improve the flow capacity of the liquid. Compared with traditional servo valves of the same specifications, combined with the high-power density equal-wall-thickness structure formed by generative AI design, the rated flow of the servo valve can be increased by 1 to 2 times.

[0071] In a preferred embodiment of the direct-drive rotary servo valve of the present application, as Figures 6 to 11 shown, the valve sleeve valve ports provided on the valve sleeve 2 include a valve sleeve T1 port 21, a valve sleeve A port 22, a valve sleeve P port 23, a valve sleeve B port 24, and a valve sleeve T2 port 25. The valve sleeve 2 is fixed inside the main valve body hole 13 of the valve body 1, such that the valve sleeve T1 port 21 is located inside the T1 cavity 131, the valve sleeve A port 22 is located inside the A cavity 132, the valve sleeve P port 23 is located inside the P cavity 133, the valve sleeve B port 24 is located inside the B cavity 134, and the valve sleeve T2 port 25 is located inside the T2 cavity 135.

[0072] The spool oil grooves provided on the rotor spool 3 include a spool A groove, a spool P groove, and a spool B groove provided at different positions on the spool portion 31. When the rotor spool 3 is installed in the valve sleeve 2, the spool A groove extends axially along the outer peripheral surface of the spool portion 31 from a position corresponding to the valve sleeve T1 port 21 to a position corresponding to the valve sleeve A port 22; the spool P groove extends axially along the outer peripheral surface of the spool portion 31 from a position corresponding to the valve sleeve A port 22 to a position corresponding to the valve sleeve B port 24; the spool B groove extends on the outer peripheral surface of the spool portion 31 from a position corresponding to the valve sleeve B port 24 to a position corresponding to the valve sleeve T2 port 25.

[0073] By respectively setting the different circumferential positions of the T1 port 21, A port 22, P port 23, B port 24 and T2 port 25 of the valve sleeve on the valve sleeve 2, and the different circumferential positions of the spool A groove, spool P groove and spool B groove on the outer circumferential surface of the rotor spool 3, when the relative position of the rotor spool 3 in the valve sleeve 2 is in a set state, such as Figure 12 and Figure 13 shown, it can be ensured that the T1 port 21 and A port 22 of the valve sleeve do not communicate with the spool A groove simultaneously. That is, at least one of the T1 port 21 and A port 22 of the valve sleeve is closed by the outer circumferential surface of the rotor spool 3, so that the T1 port 21 and A port 22 of the valve sleeve are in a disconnected state; and, any two of the P port 23, A port 22 and B port 24 of the valve sleeve do not communicate with the spool P groove simultaneously. That is, at least two of the P port 23, A port 22 and B port 24 of the valve sleeve are closed by the outer circumferential surface of the rotor spool 3, so that any two of the P port 23, A port 22 and B port 24 of the valve sleeve are in a disconnected state; at the same time, the B port 24 and T2 port 25 of the valve sleeve do not communicate with the spool B groove simultaneously. That is, at least one of the B port 24 and T2 port 25 of the valve sleeve is closed by the outer circumferential surface of the rotor spool 3, so that the B port 24 and T2 port 25 of the valve sleeve are in a disconnected state. At this time, the state of the rotor spool 3 in the valve sleeve 2 is called the first state, and the servo valve is in the neutral state where the P port 101, T port 102, A port 103 and B port 104 are disconnected from each other in pairs as shown in Figure 14 .

[0074] When the rotor spool 3 rotates to another state in the valve sleeve 2, such as Figure 15 and Figure 16 shown, it can be ensured that the T1 port 21 and A port 22 of the valve sleeve communicate with the spool A groove simultaneously. That is, the T1 port 21 and A port 22 of the valve sleeve communicate with each other through the spool A groove; and, the P port 23 and B port 24 of the valve sleeve communicate with the spool P groove simultaneously, while the A port 22 does not communicate with the spool P groove. That is, the P port 23 and B port 24 of the valve sleeve communicate with each other through the spool P groove, while the A port 22 is closed by the outer circumferential surface of the rotor spool 3; at the same time, the B port 24 and T2 port 25 of the valve sleeve do not communicate with the spool B groove simultaneously. That is, at least one of the B port 24 and T2 port 25 of the valve sleeve is closed by the outer circumferential surface of the rotor spool 3, so that the B port 24 and T2 port 25 of the valve sleeve are in a disconnected state. At this time, the state of the rotor spool 3 in the valve sleeve 2 is called the second state, and the servo valve is in the functional state where the P port 101 is connected to the B port 104 and the A port 103 is connected to the T port 102 as shown in Figure 17 .

[0075] When the rotor spool 3 rotates to another state in the valve sleeve 2, such as Figure 18 and Figure 19 shown, it can make the T1 port 21 of the valve sleeve and the A port 22 of the valve sleeve not communicate with the A groove of the spool simultaneously. That is, at least one of the T1 port 21 of the valve sleeve and the A port 22 of the valve sleeve is blocked by the outer peripheral surface of the rotor spool 3, so that the T1 port 21 of the valve sleeve and the A port 22 of the valve sleeve are in a disconnected state; and, the A port 22 of the valve sleeve and the P port 23 of the valve sleeve communicate with the P groove of the spool simultaneously, while the B port 24 of the valve sleeve does not communicate with the P groove of the spool. That is, the A port 22 of the valve sleeve and the P port 23 of the valve sleeve communicate with each other through the P groove of the spool, and the B port 24 of the valve sleeve is blocked by the outer peripheral surface of the rotor spool 3; at the same time, the B port 24 of the valve sleeve and the T2 port 25 of the valve sleeve communicate with the B groove of the spool simultaneously. That is, the B port 24 of the valve sleeve and the T2 port 25 of the valve sleeve communicate with each other through the B groove of the spool. At this time, the state of the rotor spool 3 in the valve sleeve 2 is called the third state, and the servo valve is in the functional state shown in Figure 12 where the P port 101 is connected to the A port 103, and the B port 104 is connected to the T port 102.

[0076] During the rotation of the rotor spool 3 from the first state to the second state or the third state, as the rotation angle of the rotor spool 3 changes, the communication areas between the T1 port 21 of the valve sleeve, the A port 22 of the valve sleeve, the P port 23 of the valve sleeve, the B port 24 of the valve sleeve and the T2 port 25 of the valve sleeve and the corresponding A groove of the spool, P groove of the spool or B groove of the spool gradually increase or gradually decrease. In this way, by controlling the rotation angle of the rotor spool 3, the flow area between the corresponding oil ports of the servo valve can be accurately controlled.

[0077] As a specific embodiment of the direct drive rotary servo valve of the present application, as shown in Figure 6 and Figure 7 shown, the T1 port 21 of the valve sleeve includes a first valve sleeve T1 port 211 and a second valve sleeve T1 port 212 that are radially opposite to each other in the valve sleeve 2; the A port 22 of the valve sleeve includes a first valve sleeve A port 221 and a second valve sleeve A port 222 that are radially opposite to each other in the valve sleeve 2, the P port 23 of the valve sleeve includes a first valve sleeve P port 231 and a second valve sleeve P port 232 that are radially opposite to each other in the valve sleeve 2, the B port 24 of the valve sleeve includes a first valve sleeve B port 241 and a second valve sleeve B port 242 that are radially opposite to each other in the valve sleeve 2, and the T2 port 25 of the valve sleeve includes a first valve sleeve T2 port 251 and a second valve sleeve T2 port 252 that are radially opposite to each other in the valve sleeve 2.

[0078] As shown in Figures 8 to 11As shown, the spool A groove includes a first spool A groove 301 and a second spool A groove 302 that are radially opposed to each other in the spool portion 31. The spool P groove includes a first spool P groove 303 and a second spool P groove 304 that are radially opposed to each other in the spool portion 31. The spool B groove includes a first spool B groove 305 and a second spool B groove 306 that are radially opposed to each other in the spool portion 31.

[0079] As Figure 12 and Figure 13 shown, when the rotor spool 3 is in the first state, both the first valve sleeve T1 port 211 and the second valve sleeve T1 port 212 are closed by the outer peripheral surface of the spool portion 31, so that the first valve sleeve T1 port 211 and the second valve sleeve T1 port 212 are in a disconnected state from the first spool A groove 301 and the second spool A groove 302; both ends of the first spool P groove 303 and the second spool P groove 304 that are opposite to the first valve sleeve A port 221, the second valve sleeve A port 222, the first valve sleeve B port 241 and the second valve sleeve B port 242 are closed by the inner surface of the valve sleeve 2, so that the first valve sleeve A port 221, the second valve sleeve A port 222, the first valve sleeve B port 241 and the second valve sleeve B port 242 are in a disconnected state from the first spool P groove 303 and the second spool P groove 304; at the same time, both the first valve sleeve T2 port 251 and the second valve sleeve T2 port 252 are closed by the outer peripheral surface of the spool portion 31, so that the first valve sleeve T2 port 251 and the second valve sleeve T2 port 252 are in a disconnected state from the first spool B groove 305 and the second spool B groove 306.

[0080] As Figure 15 and Figure 16 shown, when the rotor spool 3 rotates clockwise to the second state, one end of the first spool A groove 301 communicates with the first valve sleeve T1 port 211, and the other end communicates with the first valve sleeve A port 221; at the same time, one end of the second spool A groove 302 communicates with the second valve sleeve T1 port 212, and the other end communicates with the second valve sleeve A port 222. Two liquid flow channels are formed between the T1 chamber 131 and the A chamber 132, one formed by the communication of the first valve sleeve A port 221, the first spool A groove 301 and the first valve sleeve T1 port 211, and the other formed by the communication of the second valve sleeve A port 222, the second spool A groove 302 and the second valve sleeve T1 port 212. The A port 103 is connected to the T port 102, and the flow cross-sectional area between the T1 chamber 131 and the A chamber 132 is larger.

[0081] The parts of the first spool P groove 303 and the second spool P groove 304 corresponding to the first sleeve A port 221 and the second sleeve A port 222 are both closed by the inner surface of the sleeve 2, so that the first spool P groove 303 and the second spool P groove 304 are both in a separated state from the first sleeve A port 221 and the second sleeve A port 222, and the P port 101 and the A port 103 are separated from each other; while the first sleeve P port 231 and the second sleeve B port 242 are both connected to the first spool P groove 303, and at the same time the second sleeve P port 232 and the first sleeve B port 241 are both connected to the second spool P groove 304, forming two liquid flow channels between the P chamber 133 and the B chamber 134, which are respectively formed by the mutual connection of the first sleeve P port 231, the first spool P groove 303 and the second sleeve B port 242, and the liquid flow channel formed by the mutual connection of the second sleeve P port 232, the second spool P groove 304 and the first sleeve B port 241. The P port 101 and the B port 104 are connected to each other, and the flow cross-sectional area between the P chamber 133 and the B chamber 134 is larger.

[0082] The first sleeve T2 port 251 and the second sleeve T2 port 252 are both closed by the outer peripheral surface of the spool part 31, so that the first spool B groove 305 and the second spool B groove 306 are both in a separated state from the first sleeve T2 port 251 and the second sleeve T2 port 252, and the B port 104 and the T port 102 are separated from each other.

[0083] As Figure 18 and Figure 19 shown, when the rotor spool 3 rotates counterclockwise to the third state, the first sleeve T1 port 211 and the second sleeve T1 port 212 are both closed by the outer peripheral surface of the spool part 31, so that the first spool A groove 301 and the second spool A groove 302 are in a separated state from the first sleeve T1 port 211 and the second sleeve T1 port 212, and the A port 103 and the T port 102 are separated from each other.

[0084] The A port 221 of the first valve sleeve and the P port 231 of the first valve sleeve are interconnected with the P groove 303 of the first valve core. At the same time, the A port 222 of the second valve sleeve and the P port 232 of the second valve sleeve are both interconnected with the P groove 304 of the second valve core. Two liquid flow channels are formed between the P chamber 133 and the A chamber 132, one formed by the interconnection of the P port 231 of the first valve sleeve, the P groove 303 of the first valve core, and the A port 221 of the first valve sleeve, and the other formed by the interconnection of the P port 232 of the second valve sleeve, the P groove 304 of the second valve core, and the A port 222 of the second valve sleeve. The P port 101 is interconnected with the A port 103, and the flow cross-sectional area between the P chamber 133 and the A chamber 132 is larger. The parts of the P groove 303 of the first valve core and the P groove 304 of the second valve core corresponding to the B port 241 of the first valve sleeve and the B port 242 of the second valve sleeve are both closed by the inner surface of the valve sleeve 2, so that the P groove 303 of the first valve core and the B port 241 of the first valve sleeve, and the P groove 304 of the second valve core and the B port 242 of the second valve sleeve are all in a cut-off state, and the P port 101 is cut off from the B port 104.

[0085] One end of the B groove 305 of the first valve core is interconnected with the B port 241 of the first valve sleeve, and the other end is connected to the T2 port 251 of the first valve sleeve. At the same time, one end of the B groove 306 of the second valve core is interconnected with the B port 242 of the second valve sleeve, and the other end is connected to the T2 port 252 of the second valve sleeve. Two liquid flow channels are formed between the B chamber 134 and the T2 chamber 135, one formed by the interconnection of the B port 241 of the first valve sleeve, the B groove 305 of the first valve core, and the T2 port 251 of the first valve sleeve, and the other formed by the interconnection of the B port 242 of the second valve sleeve, the B groove 306 of the second valve core, and the T2 port 252 of the second valve sleeve. The B port 104 is connected to the T port 102, and the flow cross-sectional area between the B chamber 134 and the T2 chamber 135 is larger.

[0086] Similarly, during the rotation of the rotor valve core 3 from the first state to the second state or the third state, as the rotation angle of the rotor valve core 3 changes, the communication areas between the T1 port 211 of the first valve sleeve, the T1 port 212 of the second valve sleeve, the A port 221 of the first valve sleeve, the A port 222 of the second valve sleeve, the P port 231 of the first valve sleeve, the P port 232 of the second valve sleeve, the B port 241 of the first valve sleeve, the B port 242 of the second valve sleeve, the T2 port 251 of the first valve sleeve, the T2 port 252 of the second valve sleeve and the corresponding A groove 301 of the first valve core, the A groove 302 of the second valve core, the P groove 303 of the first valve core, the P groove 304 of the second valve core, the B groove 305 of the first valve core or the B groove 306 of the second valve core gradually increase or gradually decrease. In this way, by controlling the rotation angle of the rotor valve core 3, the flow area between the corresponding oil ports of the servo valve can be accurately controlled.

[0087] In some embodiments of the direct drive rotary servo valve of the present application, such as Figures 9 to 11As shown in the figure, a first oil return shaft hole 312 is provided along the central axis of the rotor spool 3 on the end face of the spool portion 31 at one end of the rotor spool 3. An axially extending first oil return groove 313 is provided on the outer peripheral surface of the spool portion 31, and the first oil return groove 313 extends to a position corresponding to the T1 chamber 131 inside the valve body 1, so that during the rotation of the rotor spool, the first oil return groove 313 can be connected to the T1 chamber 131 through the T1 port 21 of the valve sleeve. Two or more first oil return grooves 313 can also be provided on the outer peripheral surface of the spool portion 31, and the two or more first oil return grooves 313 are evenly distributed on the outer peripheral surface of the spool portion 31. A first oil return connection hole 314 is provided between the first oil return groove 313 and the first oil return shaft hole 312, so that a small amount of hydraulic oil leaking to the end of the rotor spool 3 along the gap between the rotor spool 3, the valve sleeve 2 and the main hole 13 of the valve body can flow back to the T1 chamber 131 through the first oil return shaft hole 312, the first oil return connection hole 314 and the first oil return groove 313.

[0088] A second oil return shaft hole 324 is provided along the central axis of the rotor spool 3 on the end face of the rotor portion 32, and the second oil return shaft hole 324 extends axially along the rotor spool 3 to a position corresponding to the T2 chamber 135 inside the valve body 1 within the spool portion 31. An axially extending second oil return groove 315 is provided on the outer peripheral surface of the spool portion 31 at a position corresponding to the T2 chamber 135. One or more second oil return grooves 315 can be provided. When multiple second oil return grooves 315 are provided, the multiple second oil return grooves 315 are evenly distributed on the outer peripheral surface of the spool portion 31. A second oil return connection hole 316 is provided between the second oil return groove 315 and the second oil return shaft hole 324; one or more rotor portion oil return holes 325 are provided on the outer peripheral surface of the rotor portion 32 adjacent to one end of the spool portion 31, and the rotor portion oil return holes 325 are connected to the second oil return shaft hole 324. A small amount of hydraulic oil leaking in the direction of the rotor portion 32 can flow back to the T2 chamber 135 through the oil return channel composed of the rotor portion oil return hole 325, the second oil return shaft hole 324, the second oil return connection hole 316 and the second oil return groove 315.

[0089] In a preferred embodiment of the direct drive rotary servo valve of the present application, as Figure 4 and Figure 6As shown in the figure, on the side walls of the main valve body holes 13 at both ends of the valve body 1, valve body dowel holes 136 are provided. At the same time, corresponding to these positions, on the outer surfaces at both ends of the valve sleeve 2, valve sleeve dowel holes 26 are provided. The number of the valve body dowel holes 136 of the valve body 1 and the valve sleeve dowel holes 26 at both ends of the valve sleeve 2 may be the same or different, but the number of the valve body dowel holes 136 and the valve sleeve dowel holes 26 at the same end is the same. After the valve sleeve 2 is inserted into the main valve body hole 13, an elastic dowel pin is inserted into the dowel hole formed by the valve body dowel hole 136 and the valve sleeve dowel hole 26 to install and fix the valve sleeve 2 in the main valve body hole 13, preventing the valve sleeve 2 from rotating and sliding within the main valve body hole 13. The end of the valve body 1 is closed by a valve end cover, and an O-ring seal is provided between the valve end cover and the valve body 1 to prevent the leakage of hydraulic oil. The valve end cover can be fixed to the valve body 1 by screws.

[0090] In some embodiments of the direct drive rotary servo valve of the present application, both the valve sleeve 2 and the rotor spool 3 are made of ZrO2 ceramic material by 3D printing. The hardness of the valve sleeve 2 and the rotor spool 3 made of ZrO2 ceramic material after firing can reach 85 HRC, far exceeding the hardness of the usual particulate contaminants in the oil. In this way, even if there are particulate contaminants in the oil, it will not cause damage to the rotor spool 3 or the valve sleeve 2. Therefore, the direct drive rotary servo valve of the present application has a longer service life, stronger anti-pollution ability and higher reliability.

[0091] In some embodiments of the direct drive rotary servo valve of the present application, after the rotor spool 3 is installed in the valve sleeve 2, a clearance fit is formed between the outer peripheral surface of the rotor spool 3 and the valve sleeve 2. In this way, the rotor spool 3 and the valve sleeve 2 do not contact each other. When the rotor spool 3 rotates in the valve sleeve 2, the wear of the rotor spool 3 and the valve sleeve 2 is smaller, thus reducing the contact wear between the spool and the valve sleeve of the traditional servo valve and effectively extending the service life and reliability of the direct drive rotary servo valve of the present application.

[0092] In the description of the present application, the description referring to terms such as "one embodiment", "specific embodiment", "preferred embodiment", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0093] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited by this. Therefore, all equivalent changes made according to the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A direct drive rotary servo valve, characterized in that: It includes a valve body (1), a valve sleeve (2), a rotor spool (3) and a servo drive mechanism (4). Multiple hydraulic oil ports are provided on the valve body (1), and multiple valve cavities respectively communicating with the hydraulic oil ports are arranged inside. The valve sleeve (2) is fixed inside the valve body (1), and multiple valve sleeve valve ports communicating with the valve cavities are arranged on the wall portion. The rotor spool (3) includes an integrally formed spool portion (31) and a rotor portion (32). The spool portion (31) is rotatably arranged inside the valve sleeve (2), and multiple spool oil grooves are arranged on the side wall. The servo drive mechanism (4) is correspondingly arranged with the rotor portion (32) to be able to drive the rotor spool (3) to rotate.

2. The direct drive rotary servo valve according to claim 1, characterized in that: The servo drive mechanism (4) includes a motor housing (41), a stator (42), and a magnetic encoder (43). The motor housing (41) is fixed at one end of the valve body (1), the stator (42) is fixed inside the motor housing (41), the rotor portion (32) is installed inside the stator (42), and the magnetic encoder (43) is arranged at the end of the rotor portion (32).

3. The direct drive rotary servo valve according to claim 2, wherein: It further includes a rotor seat (5). The rotor seat (5) is fixed between the motor housing (41) and the valve body (1) on the valve body (1), and the rotor portion (32) is wrapped inside the rotor seat (5) through the gap between the rotor portion (32) and the stator (42).

4. The direct-drive rotary servo valve according to claim 3, wherein: The rotor spool (3) further includes a connecting portion (33). The connecting portion (33) is arranged between the spool portion (31) and the rotor portion (32). A first bearing mounting seat (311) is arranged at the end of the spool portion (31), a second bearing mounting seat (331) is arranged on the connecting portion (33), a third bearing mounting portion (321) is arranged at the end of the rotor portion (32). First bearing mounting holes (11) and second bearing mounting holes (12) are respectively arranged at both ends of the valve body (1), and a third bearing mounting hole (51) is arranged at the end inside the rotor seat (5). Bearings are installed between the first bearing mounting seat (311) and the first bearing mounting hole (11), between the second bearing mounting seat (331) and the second bearing mounting hole (12), and between the third bearing mounting portion (321) and the third bearing mounting hole (51).

5. The direct drive rotary servo valve according to claim 2, wherein: A hollow cavity (322) is arranged inside the rotor portion (32), a permanent magnet mounting post (323) is arranged on the rotor portion (32), and an annular permanent magnet (34) is arranged on the permanent magnet mounting post (323).

6. The direct drive rotary servo valve according to claim 1, wherein: The hydraulic oil ports on the valve body (1) include a P port (101), a T port (102), an A port (103), and a B port (104). A main valve hole (13) is provided inside the valve body (1). The valve cavity includes a T1 cavity (131), an A cavity (132), a P cavity (133), a B cavity (134), and a T2 cavity (135) arranged in sequence on the main valve hole (13). The T1 cavity (131) and the T2 cavity (135) are communicated with the T port (102), and the A cavity (132), the P cavity (133), and the B cavity (134) are respectively communicated with the A port (103), the P port (101), and the B port (104).

7. The direct drive rotary servo valve according to claim 6, wherein: The valve sleeve valve ports include a valve sleeve T1 port (21) corresponding to the T1 cavity (131), a valve sleeve A port (22) corresponding to the A cavity (132), a valve sleeve P port (23) corresponding to the P cavity (133), a valve sleeve B port (24) corresponding to the B cavity (134), and a valve sleeve T2 port (25) corresponding to the T2 cavity (135); the spool oil grooves include a spool A groove, a spool P groove, and a spool B groove. The spool A groove extends from the part of the spool portion (31) corresponding to the valve sleeve T1 port (21) to the part corresponding to the valve sleeve A port (22), the spool P groove extends from the part of the spool portion (31) corresponding to the valve sleeve A port (22) to the part corresponding to the valve sleeve B port (24), and the spool B groove extends from the part of the spool portion (31) corresponding to the valve sleeve B port (24) to the part corresponding to the valve sleeve T2 port (25). The valve sleeve T1 port (21), the valve sleeve A port (22), the valve sleeve P port (23), the valve sleeve B port (24), and the valve sleeve T2 port (25), as well as the spool A groove, the spool P groove, and the spool B groove are arranged such that in different rotation states of the rotor spool (3), the valve sleeve T1 port (21) and the valve sleeve A port (22), the valve sleeve P port (23) and the valve sleeve A port (22) and the valve sleeve B port (24), and the valve sleeve B port (24) and the valve sleeve T2 port (25) can all be in a first state of being mutually separated, or the valve sleeve T1 port (21) and the valve sleeve A port (22) are communicated through the spool A groove, the valve sleeve P port (23) is separated from the valve sleeve A port (22) and is communicated with the valve sleeve B port (24) through the spool P groove, and the valve sleeve B port (24) and the valve sleeve T2 port (25) are separated in a second state, or the valve sleeve T1 port (21) and the valve sleeve A port (22) are separated, the valve sleeve P port (23) and the valve sleeve A port (22) are communicated through the spool P groove and are separated from the valve sleeve B port (24), and the valve sleeve B port (24) and the valve sleeve T2 port (25) are communicated through the spool B groove in a third state.

8. The direct drive rotary servo valve according to claim 7, characterized in that: The valve sleeve T1 port (21) includes a first valve sleeve T1 port (211) and a second valve sleeve T1 port (212) which are oppositely arranged radially in the valve sleeve (2). The valve sleeve A port (22) includes a first valve sleeve A port (221) and a second valve sleeve A port (222) which are oppositely arranged radially in the valve sleeve (2). The valve sleeve P port (23) includes a first valve sleeve P port (231) and a second valve sleeve P port (232) which are oppositely arranged radially in the valve sleeve (2). The valve sleeve B port (24) includes a first valve sleeve B port (241) and a second valve sleeve P port (242) which are oppositely arranged radially in the valve sleeve (2). The valve sleeve T2 port (25) includes a first valve sleeve T2 port (251) and a second valve sleeve T2 port (252) which are oppositely arranged radially in the valve sleeve (2). The spool A groove includes a first spool A groove (301) and a second spool A groove (302) which are oppositely arranged radially in the spool part (31). The spool P groove includes a first spool P groove (303) and a second spool P groove (304) which are oppositely arranged radially in the spool part (31). The spool B groove includes a first spool B groove (305) and a second spool B groove (306) which are oppositely arranged radially in the spool part (31). When the rotor spool (3) is in the first state, the first spool A groove (301) and the second spool A groove (302) are both disconnected from the first valve sleeve T1 port (211) and the second valve sleeve T1 port (212). The first spool P groove (303) and the second spool P groove (304) are both disconnected from the first valve sleeve A port (221), the second valve sleeve A port (222), the first valve sleeve B port (241) and the second valve sleeve B port (242). And the first spool B groove (305) and the second spool B groove (306) are both disconnected from the first valve sleeve T2 port (251) and the second valve sleeve T2 port (252). When the rotor spool (3) is in the second state, the first spool A groove (301) is respectively communicated with the first valve sleeve T1 port (211) and the first valve sleeve A port (221), the second spool A groove (302) is respectively communicated with the second valve sleeve T1 port (212) and the second valve sleeve A port (222). The first spool P groove (303) is respectively communicated with the first valve sleeve P port (231) and the second valve sleeve B port (242), the second spool P groove (304) is respectively communicated with the second valve sleeve P port (232) and the first valve sleeve B port (241). And the first spool P groove (303) and the second spool P groove (304) are both disconnected from the first valve sleeve A port (221) and the second valve sleeve A port (222). The first spool B groove (305) and the second spool B groove (306) are both disconnected from the first valve sleeve T2 port (251) and the second valve sleeve T2 port (252).When the rotor spool (3) is in the third state, the first spool A groove (301) and the second spool A groove (302) are both disconnected from the first valve sleeve T1 port (211) and the second valve sleeve T1 port (212). The first spool P groove (303) is respectively communicated with the first valve sleeve A port (221) and the first valve sleeve P port (231), the second spool P groove (304) is respectively communicated with the second valve sleeve A port (222) and the second valve sleeve P port (232), and the first spool P groove (303) and the second spool P groove (304) are both disconnected from the first valve sleeve B port (241) and the second valve sleeve B port (242). The first spool B groove (305) is respectively communicated with the first valve sleeve B port (241) and the first valve sleeve T2 port (251), and the second spool B groove (306) is respectively communicated with the second valve sleeve B port (242) and the second valve sleeve T2 port (252).; 9. The direct-drive rotary servo valve according to claim 6, wherein: A first oil return shaft hole (312) is provided on the end face of the valve core part (31). A first oil return groove (313) is provided on the outer peripheral surface of the valve core part (31) corresponding to the T1 chamber (131). A first oil return connection hole (314) is provided between the first oil return groove (313) and the first oil return shaft hole (312); A second oil return shaft hole (324) is provided on the end face of the rotor part (32). A second oil return groove (315) is provided on the outer peripheral surface of the valve core part (31) corresponding to the T2 chamber (135). A second oil return connection hole (316) is provided between the second oil return groove (315) and the second oil return shaft hole (324). A rotor part oil return hole (325) communicating with the second oil return shaft hole (324) is provided on the outer peripheral surface of the rotor part (32) adjacent to the valve core part (31).

10. The direct-drive rotary servo valve according to claim 6, characterized in that: Valve body cylindrical pin holes (136) are provided on the side walls at both ends of the valve body main hole (13). Valve sleeve cylindrical pin holes (26) are provided at corresponding positions on the outer sides of both ends of the valve sleeve (2). The valve sleeve (2) is installed in the valve body main hole (13) through the cooperation of elastic cylindrical pins with the valve body cylindrical pin holes (136) and the valve sleeve cylindrical pin holes (26).

11. The direct drive rotary servo valve according to any one of claims 1-10, characterized in that: Both the valve sleeve (2) and the rotor valve core (3) are made of ZrO2 ceramic material by 3D printing.

12. The direct-drive rotary servo valve according to any one of claims 1-10, characterized in that: A clearance fit is provided between the outer peripheral surface of the rotor valve core (3) and the valve sleeve (2).

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