Rotary direct-drive type servo slide valve

Abstract

The utility model relates to the field of hydraulic components, in particular to a rotary direct drive type servo slide valve which comprises a valve body, a valve element, a transmission mechanism 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 element is arranged in the valve body, and the transmission mechanism is arranged in the valve element. The valve element is arranged in the valve body and can slide relative to the valve body so that the connection relation between the valve cavities can be switched, a valve element hole extending in the axial direction is formed in the valve element, and the transmission mechanism extends into the valve element hole from one end of the valve element and is connected to the end area of the other end of the valve element. An eccentric mechanism is arranged on an output shaft of the servo driving mechanism, and the output shaft of the servo driving mechanism is connected with the transmission mechanism through the eccentric mechanism, so that the valve element can be driven to slide through the transmission mechanism, and the control precision of the servo valve can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydraulic components, in particular to a rotary direct drive type servo spool valve. BACKGROUND

[0002] The hydraulic valve is a kind of hydraulic component used to control the pressure, flow and flow direction of liquid in hydraulic transmission, which can act in manual, hydraulic or electric control mode, and is an indispensable component in the field of hydraulic transmission. Electro-hydraulic servo valve, also known as servo valve, is a kind of hydraulic valve that can control the output modulation of flow and pressure through closed-loop control under the control of analog electric signal, which has the advantages of fast dynamic response, high control precision and long service life, and is widely used in high-precision mechatronic systems, aerospace, ships, metallurgy, chemical industry and electro-hydraulic servo control systems of large-scale test equipment.

[0003] According to the different movement modes of the spool in the valve body, the servo valve can be divided into sliding type servo valve and rotary type servo valve. The sliding type servo valve controls the connection of the connecting oil groove on the spool with different valve cavities in the valve body by controlling the sliding of the spool in the valve body, so as to control the pressure, flow and flow direction of the hydraulic oil in the valve cavity. The moving range of the spool is large, and it is easier to accurately control the position of the spool. According to the different driving modes of the spool, the servo valve can be divided into pilot servo valve and direct drive servo valve. The direct drive servo valve uses a servo drive device to directly drive the spool to move, which has the advantages of simple valve structure, high control reliability and long service life.

[0004] The spool of the existing sliding type direct drive servo valve usually slides under the driving of a linear force motor, and the position of the spool is fed back by a displacement sensor, so the control precision is poor. Moreover, the linear force motor is usually arranged at the end of the spool, which leads to a long length of the servo valve and makes it difficult to realize miniaturization. Some sliding type servo valves use rotary servo motors to drive the spool to slide in the valve body through eccentric structure, but the eccentric structure is easy to form lateral stress on the spool, which affects the smoothness of the sliding of the spool in the valve body, thereby affecting the control precision of the servo valve, and even causing the jamming of the sliding of the spool. CONTENT OF THE INVENTION

[0005] In order to improve the control precision of the servo valve, the present application provides a rotary direct drive type servo spool valve.

[0006] The rotary direct drive type servo spool valve provided by the present application adopts the following technical scheme:

[0007] The application discloses a rotary direct-drive type servo spool valve, which comprises a valve body, a valve core, a transmission mechanism and a servo driving mechanism, the valve body is provided with a plurality of hydraulic oil ports, and a plurality of valve cavities are arranged in the valve body and connected with the hydraulic oil ports respectively, the valve core is arranged in the valve body and can slide relative to the valve body to switch the connection relationship between the valve cavities, an axially extending valve core hole is arranged in the valve core, the transmission mechanism extends into the valve core hole from one end of the valve core and is connected with the end area of the other end of the valve core, and the output shaft of the servo driving mechanism is provided with an eccentric mechanism and is connected with the transmission mechanism through the eccentric mechanism to drive the valve core to slide through the transmission mechanism.

[0008] By adopting the technical scheme, the transmission mechanism is connected with the end area of the other end of the valve core from the valve core hole, the distance between the transmission mechanism and the servo driving mechanism is prolonged, the lateral force acting on the valve core due to the swing of the eccentric mechanism is reduced through the elastic deformation of the transmission mechanism, the rotation movement of the servo driving mechanism is converted into the linear movement of the valve core, the smooth movement of the valve core in the valve body is ensured, and the control precision of the servo valve is improved.

[0009] In a specific embodiment, an end area of the valve core hole away from the servo driving mechanism is provided with a transmission connecting plate, the periphery of the transmission connecting plate is integrally connected with the wall of the valve core hole, and the transmission mechanism is integrally connected with the middle part of the transmission connecting plate.

[0010] By adopting the technical scheme, the transmission mechanism is integrally connected with the middle part of the transmission connecting plate, the driving force of the transmission mechanism acting on the valve core is applied to the middle axis of the valve core, the uniformity of the force acting on different positions of the valve core under the traction of the transmission mechanism is improved, and the jamming of the valve core during the sliding process is prevented; the integral connection among the transmission mechanism, the transmission connecting plate and the valve core improves the connection precision and stability, and is beneficial to improving the control precision of the valve core position.

[0011] In a specific embodiment, the transmission mechanism comprises a transmission rod, the end of the transmission rod is connected with the transmission connecting plate, the cross section of the transmission rod is a rectangle with the height being parallel to the output shaft of the servo driving mechanism, and the length of the upper and lower bottom edges of the rectangle is smaller than the height of the rectangle; and deformation buffer holes are arranged on both sides of the height direction of the transmission rod at the connection position of the transmission connecting plate and the transmission rod.

[0012] By adopting the technical scheme, the transmission rod with the cross section of the rectangle with the height greater than the upper and lower side length can provide sufficient pushing force to the valve core, improve the lateral deformation capacity of the transmission rod, reduce the lateral stress formed on the valve core by the circumferential movement of the eccentric mechanism, and ensure smooth movement of the valve core in the valve body; the deformation buffer holes arranged on the upper and lower sides of the connection between the transmission connecting plate and the transmission rod can increase the deformation amount of the connection between the transmission connecting plate and the transmission rod, reduce the transmission of the deformation stress at the connection to the periphery of the transmission connecting plate, and further reduce the lateral stress on the valve core.

[0013] In a specific implementable scheme, the transmission mechanism comprises a transmission sleeve, the eccentric mechanism comprises an eccentric rod, the eccentric rod is connected to the output shaft of the servo driving mechanism and is arranged eccentrically with the output shaft of the servo driving mechanism, and the transmission sleeve is sleeved on the eccentric rod and rotationally connected with the eccentric rod.

[0014] By adopting the technical scheme, the rotational connection between the transmission sleeve and the eccentric rod can push the valve core to move linearly by the eccentric rotation of the eccentric rod, so that the moving position of the valve core can be accurately controlled by controlling the rotation angle of the servo driving mechanism, and the control precision of the valve core position is improved.

[0015] In a specific implementable scheme, the eccentric mechanism further comprises an eccentric connecting wheel, an eccentric connecting rod and an eccentric mechanism rotation shaft, the eccentric connecting wheel is fixed on the output shaft of the servo driving mechanism, the eccentric rod is fixed at the peripheral position of the eccentric connecting wheel, one end of the eccentric connecting rod is connected with the eccentric rod, and the other end is connected with the eccentric mechanism rotation shaft, the eccentric mechanism rotation shaft is coaxially arranged with the output shaft of the servo driving mechanism and rotationally connected with the valve body.

[0016] By adopting the technical scheme, the eccentric mechanism formed by the connection of the eccentric connecting wheel, the eccentric rod, the eccentric connecting rod and the eccentric mechanism rotation shaft can reduce the weight of the eccentric mechanism and reduce the vibration generated by the rotation of the eccentric mechanism. The rotational connection between the eccentric mechanism rotation shaft and the valve body can reduce the stress deformation of the eccentric rod in the rotation process and improve the position stability of the eccentric rod under the stress state, thereby improving the position precision of the valve core.

[0017] In a specific implementable scheme, the rotating direct drive type servo spool of the application further comprises an end cover and an elastic centering device, the end cover is fixed on the valve body, the elastic centering device is arranged on the inner side of the end cover and connected with the valve core, so as to form a pushing force for pushing the valve core to return to the middle position.

[0018] By adopting the technical scheme, the elastic centering device connected with the valve core can form an elastic force towards the center position when the valve core moves away from the center position, so that the valve core can be automatically pulled to the center position when the servo valve loses power, thereby ensuring the safety of the hydraulic device.

[0019] In a specific implementation, the elastic centering device includes a first spring seat, a spring seat connecting piece, a centering spring, and a second spring seat, the spring seat connecting piece is fixed at the end of the valve core and is in sliding connection with the first spring seat and the second spring seat, the centering spring is sleeved on the spring seat connecting piece and is arranged between the first spring seat and the second spring seat, the first spring seat abuts against the end cover, and the second spring seat abuts against the valve body.

[0020] By adopting the technical scheme, the spring seat connecting piece is sequentially connected with the valve core through the first spring seat, the centering spring, and the second spring seat, so that the first spring seat or the second spring seat can compress the centering spring when the valve core moves to the two sides, thereby forming an elastic force for returning the valve core to the center position in a simple structure and achieving automatic return to the center position when the servo valve loses power.

[0021] In a specific implementation, the servo driving mechanism is fixed on the side of the valve body, the output shaft of the servo driving mechanism is arranged perpendicularly to the valve core, the servo driving mechanism includes a motor rotor, a motor stator, a motor shell, and a motor end cover, the motor shell is fixed on the valve body, the motor stator is fixed in the motor shell, the motor rotor is arranged in the motor stator, the motor end cover is fixed at the end of the motor shell away from the valve body, one end of the motor rotor is rotationally connected with the motor shell, the other end is rotationally connected with the motor end cover through an end cover bearing, and a wave washer is arranged between the end of the end cover bearing and the motor end cover.

[0022] By adopting the technical scheme, the output shaft of the servo driving mechanism is arranged perpendicularly to the valve core, so that the transmission rod moves only in the horizontal plane under the driving of the eccentric mechanism, the stress uniformity of the other end of the transmission rod is improved, and the smoothness of the movement of the valve core is improved. The wave washer arranged between the end of the end cover bearing and the motor end cover can apply an axial force to the motor rotor, reduce axial movement during rotation of the motor rotor, improve the stability of rotation of the servo driving mechanism, and ensure the position accuracy of the valve core.

[0023] In one specific implementation, the motor rotor is provided with an inductive magnetic code adjacent to one end of the motor end cover, a sealing cover is provided on the outside of the motor end cover, the sealing cover is sealingly connected with the motor end cover, the inductive magnetic code is located on the inside of the sealing cover, and a PCBA is provided on the outside of the sealing cover, and a magnetic code induction element is provided on the PCBA and corresponds to the inductive magnetic code.

[0024] By adopting the above technical scheme, the rotation angle of the motor rotor can be detected in real time by using the inductive magnetic code provided on the end of the motor rotor and the magnetic code induction element corresponding to the inductive magnetic code, so that the rotation angle of the motor rotor can be controlled in a closed loop, and the control accuracy of the rotation angle of the motor rotor is improved. By using the sealing cover provided between the inductive magnetic code and the magnetic code induction element and sealingly connected with the motor end cover, the installation space of the moving parts of the servo driving mechanism and the installation space of the control elements can be isolated while the rotation angle of the motor rotor is monitored in real time, and the oil liquid infiltrating into the installation space of the moving parts is prevented from contaminating the control elements.

[0025] In one specific implementation, the rotating direct drive type servo spool of the present application further comprises a valve sleeve provided in the valve body, a plurality of valve sleeve holes connected with the valve cavity are provided on the valve sleeve, the valve core is slidingly provided in the valve sleeve, the valve sleeve is gap sealed with the valve body, and the valve core is gap fitted with the valve sleeve.

[0026] By adopting the above technical scheme, the valve sleeve provided in the valve body is conducive to improving the accuracy of the valve port through which the connection oil groove on the valve core and the valve cavity are connected, and improving the control accuracy of the flow rate of the servo valve. The gap sealing between the valve sleeve and the valve body and the gap fitting between the valve core and the valve sleeve can further improve the smoothness of the sliding of the valve core in the valve sleeve and prevent the valve core from being stuck in the valve sleeve under the action of lateral stress.

[0027] In summary, the present application has at least one of the following beneficial technical effects:

[0028] 1. By connecting between the eccentric mechanism and the transmission mechanism provided on the output shaft of the servo driving mechanism, the rotation motion of the servo driving mechanism can be converted into linear motion of the other end of the transmission mechanism, so that the position of the valve core sliding can be more accurately controlled by using the servo driving mechanism with higher control accuracy, and the control accuracy of the servo valve is improved.

[0029] 2. By setting the valve core hole inside the valve core, the transmission mechanism can be connected to the valve core through the valve core hole away from the servo drive mechanism, thereby increasing the length of the transmission mechanism, increasing the elastic deformation of the transmission mechanism, reducing the lateral force of the other end of the transmission mechanism under the same amplitude of rotation of the eccentric mechanism at one end of the transmission mechanism, thereby reducing the lateral stress on the valve core and ensuring the smoothness of the valve core in the valve body.

[0030] 3. By setting the transmission connecting plate inside the valve core hole and the transmission rod integrally connected in the middle of the transmission connecting plate, the driving force of the transmission rod acting on the valve core can act on the axial position of the valve core, which is beneficial to improve the balance of the driving force on the valve core. The deformation buffer hole is arranged on both sides of the transmission rod in the height direction to increase the deformation amount of the connection between the transmission connecting plate and the transmission rod, reduce the transmission of lateral force at the end of the transmission rod to the valve core, improve the stability of the valve core position, and reduce the lateral stress on the valve core.

[0031] 4. By the centering device composed of a first spring seat, a spring seat connector, a centering spring and a second spring seat, a bidirectional centering force acting on the valve core can be formed by a simple structure, which can ensure that the servo valve can return to the center position from different valve positions when the power is lost, and ensure the safety of the hydraulic system. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The schematic diagram of an embodiment of the present application.

[0033] Figure 2 The internal structure schematic diagram of an embodiment of the present application.

[0034] Figure 3 The schematic diagram of an embodiment of the present application after hiding the outer shell.

[0035] Figure 4 The Figure 3 A-A direction view of the present application.

[0036] Figure 5 The Figure 4 B-B direction view of the present application.

[0037] Figure 6 The valve body schematic diagram of an embodiment of the present application.

[0038] Figure 7 The valve core and transmission mechanism integrated structure schematic diagram of an embodiment of the present application.

[0039] Figure 8 The centering mechanism parts explosion diagram of an embodiment of the present application.

[0040] Figure 9Figure 1 is a schematic diagram of a servo drive mechanism in one embodiment of the present application.

[0041] Figure 10 Figure 2 is a schematic diagram of a valve sleeve in one embodiment of the present application.

[0042] Figure 11 Figure 3 is a schematic diagram of a valve core in a middle position in one embodiment of the present application.

[0043] Figure 12 Figure 4 is a schematic diagram of a valve core in a left position in one embodiment of the present application.

[0044] Figure 13 Figure 5 is a schematic diagram of a valve core in a left position in one embodiment of the present application.

[0045] Figure 14 Figure 6 is a schematic diagram of a valve core in a right position in one embodiment of the present application.

[0046] Figure 15 Figure 7 is a schematic diagram of a valve core in a right position in one embodiment of the present application.

[0047] Figure 8 is a schematic diagram of a valve core in a right position in one embodiment of the present application. 1, valve body; 101, P port; 102, T port; 103, A port; 104, B port; 11, valve body main hole; 12, P cavity; 13, A cavity; 14, B cavity; 15, first T cavity; 16, second T cavity; 17, drive mechanism mounting interface; 18, plug; 2, valve core; 21, valve core hole; 22, transmission connecting plate; 221, deformation buffer hole; 23, first connecting groove; 24, second connecting groove; 25, third connecting groove; 26, spring seat mounting groove; 27, spring seat sliding column; 3, transmission mechanism; 31, transmission rod; 32, transmission sliding sleeve; 4, servo drive mechanism; 41, eccentric mechanism; 411, eccentric rod; 412, eccentric connecting wheel; 413, eccentric connecting rod; 414, eccentric mechanism rotation shaft; 42, motor rotor; 43, motor stator; 44, motor shell; 45, motor end cover; 451, end cover bearing; 452, wave washer; 46, inductive magnetic encoder; 47, sealing cover; 48, PCBA; 5, end cover; 6, centering device; 61, first spring seat; 62, spring seat connecting piece; 63, centering spring; 64, second spring seat; 7, valve sleeve; 71, valve sleeve P port; 72, valve sleeve A port; 73, valve sleeve B port; 74, valve sleeve first T port; 75, valve sleeve second T port; 76, valve sleeve stopper; 8, cover; 81, electrical interface. DETAILED DESCRIPTION

[0048] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0049] In the present application, the orientation words such as "left, right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings of the present application, and the description of the orientation and positional relationship of each part in the present application is the same.

[0050] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "arrangement", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, it can be internal communication of two elements or mutual interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the present specification, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features, therefore, the features limited by "first", "second", "third" can explicitly or implicitly include one or more of the features.

[0052] One embodiment of the rotary direct drive servo spool of the present application is shown in Figure 1 and Figure 5 It includes a valve body 1, a spool 2, a transmission mechanism 3 and a servo driving mechanism 4. The valve body 1 is formed by 3D printing, with small volume and light weight, the flow passage in the valve body 1 is smooth and the flow passage pressure loss is small, and the through-flow capacity is large. A plurality of hydraulic oil ports are arranged at the bottom of the valve body 1, such as four hydraulic oil ports P port 101, T port 102, A port 103 and B port 104 for connecting with external hydraulic oil circuit. A plurality of valve cavities are arranged in the interior of the valve body 1 and communicated with the hydraulic oil ports respectively, such as P cavity 12, A cavity 13, B cavity 14, first T cavity 15 and second T cavity 16 are arranged in the interior of the valve body 1, the P cavity 12 is communicated with the P port 101, the A cavity 13 is communicated with the A port 103, the B cavity 14 is communicated with the B port 104, and the first T cavity 15 and the second T cavity 16 are both communicated with the T port 102. A valve body main hole 11 is also arranged at the center of the valve body 1, and the first T cavity 15, the B cavity 14, the P cavity 12, the A cavity 13 and the second T cavity 16 are arranged in the length direction of the valve body main hole 11 in sequence and communicated with the valve body main hole 11.

[0053] The valve core 2 is arranged in the valve body 1, usually in the valve body main hole 11, and can slide in the valve body main hole 11 along the length direction of the valve body main hole 11. A plurality of connecting oil grooves are arranged on the outer circumferential surface of the valve core 2, such as a first connecting groove 23, a second connecting groove 24 and a third connecting groove 25 arranged at different positions in the axial direction of the valve core 2, respectively. When the valve core 2 moves to different positions in the valve body main hole 11, the P cavity 12, the A cavity 13, the B cavity 14, the first T cavity 15 and the second T cavity 16 can form different connection states with the first connecting groove 23, the second connecting groove 24 and the third connecting groove 25, so as to change the on-off, flow direction and flow of the hydraulic oil of the A port 103 and the B port 104.

[0054] As shown in Figure 6 , a drive mechanism mounting interface 17 is arranged on the side surface of the valve body 1 at the side of the valve body main hole 11, and the drive mechanism mounting interface 17 is arranged at one end in the length direction of the valve body main hole 11. The servo drive mechanism 4 is fixed on the valve body 1 through the drive mechanism mounting interface 17, and the output shaft of the servo drive mechanism 4 enters the valve body main hole 11 through the drive mechanism mounting interface 17. An eccentric mechanism 41 is arranged on the output shaft of the servo drive mechanism 4, and the eccentric mechanism 41 is arranged eccentrically with the output shaft of the servo drive mechanism 4. When the output shaft of the servo drive mechanism 4 rotates, the eccentric mechanism 41 can be driven to make eccentric circular motion.

[0055] The transmission mechanism 3 can use various devices that can convert circular motion into linear motion, such as a crank device, a connecting rod device, etc. The transmission mechanism 3 is connected between the eccentric mechanism 41 and the valve core 2, and can convert the eccentric motion of the eccentric mechanism 41 into the sliding of the valve core 2 in the valve body 1. Figure 2 and Figure 4 As shown in , an axially extending valve core hole 21 is arranged in the inside of the valve core 2, and the transmission mechanism 3 extends into the valve core hole 21 from one end of the valve core 2 adjacent to the servo drive mechanism 4 and is connected to the end region of the valve core 2 away from the servo drive mechanism 4. Since the transmission mechanism 3 is connected to the valve core 2 from the valve core hole 21, the connection point is closer to the center position of the valve core 2, which can make the movement of the valve core 2 under the push of the transmission mechanism 3 more stable. The other end of the transmission mechanism 3 is rotationally connected with the eccentric mechanism 41 and can make circular motion with the eccentric mechanism 41 to form a driving force for driving the valve core 2 to slide. The amount of eccentricity between the eccentric mechanism 41 and the output shaft of the servo drive mechanism 4 is determined according to the stroke required for the sliding of the valve core 2.

[0056] The transmission mechanism 3 is connected to the end region of the valve core 2 away from the servo drive mechanism 4 from the eccentric mechanism 41, so that the transmission mechanism 3 has a longer length, which can reduce the tangential force formed at the other end of the transmission mechanism 3 by the circular motion of the one end of the transmission mechanism 3, thereby reducing the tangential stress borne by the valve core 2, and improving the smoothness of the sliding of the valve core 2 under the drive of the transmission mechanism 3.

[0057] In some embodiments of the rotary direct drive servo spool of the present application, as shown in Figure 2 、 Figure 4 and Figure 5 , a transmission connecting plate 22 is arranged at the end region of the spool hole 21 away from the servo drive mechanism 4, the periphery of the transmission connecting plate 22 is integrally connected with the wall of the spool hole 21, and the end of the transmission mechanism 3 is integrally connected at the middle of the transmission connecting plate 22, that is, at the position of the central axis of the spool 2.

[0058] Specifically, the spool 2 and the transmission mechanism 3 are an integral whole structure formed by 3D printing. The transmission mechanism 3 is connected at the middle of the transmission connecting plate 22, and the driving force of the transmission mechanism 3 acting on the transmission connecting plate 22 acts on the center position of the spool 2; while the periphery of the transmission connecting plate 22 is connected with the wall of the spool hole 21, and can uniformly apply the driving force of the transmission mechanism 3 to the four sides of the spool 2, which is conducive to improving the stability of the spool 2 moving under the driving of the transmission mechanism 3. The transmission mechanism 3 is usually made of a material with a large elastic deformation amount, and the region penetrating the length direction of the spool 2 is connected to the eccentric mechanism 41 at a distance from the spool 2, so that the transmission mechanism 3 has a longer deformation length, which is conducive to reducing the tangential force of the transmission mechanism 3 acting on the spool 2, reducing the tangential stress borne by the spool 2, and improving the smoothness of the spool 2 sliding.

[0059] In a preferred embodiment of the rotary direct drive servo spool of the present application, as shown in Figure 2 、 Figure 4 and Figure 5 , the transmission mechanism 3 includes a transmission rod 31 and a transmission sleeve 32, the transmission sleeve 32 is rotationally connected with the eccentric mechanism 41, the transmission rod 31 is connected between the transmission sleeve 32 and the transmission connecting plate 22, and the end of the transmission rod 31 is integrally connected at the middle of the transmission connecting plate 22.

[0060] The transmission rod 31 is a square long strip with a rectangular cross section, and the rectangular cross section is a high square parallel to the output shaft direction of the servo drive mechanism 4, and the length of the upper and lower bottom edges of the cross section rectangle is significantly smaller than the length of the height, that is, the thickness of the transmission rod 31 in the direction perpendicular to the spool 2 is smaller when it moves in a circular motion with the eccentric mechanism 41, which is conducive to improving the deformation amount of the transmission rod 31 swinging and reducing the tangential force of the transmission rod 31 acting on the transmission connecting plate 22. While the higher height of the transmission rod 31 is conducive to ensuring the axial thrust force of the transmission rod 31 acting on the transmission connecting plate 22.

[0061] The positions where the transmission connecting plate 22 is connected with the transmission rod 31 are respectively provided with a deformation buffer hole 221 on both sides in the height direction of the transmission rod 31. The deformation buffer hole 221 can increase the deformation amount of the connecting part of the transmission connecting plate 22 and the transmission rod 31, reduce the transmission of tangential stress to the surrounding area, and further reduce the tangential stress received by the valve core 2.

[0062] In some embodiments of the rotary direct drive type servo spool of the present application, as shown in Figure 7 and Figure 8 The transmission mechanism 3 includes a transmission rod 31 and a transmission sleeve 32, and the eccentric mechanism 41 includes an eccentric rod 411. The eccentric rod 411 can be connected to the output shaft of the servo drive mechanism 4 in various possible connection modes, keeping the eccentric rod 411 parallel to the output shaft of the servo drive mechanism 4 and eccentrically arranged with the output shaft of the servo drive mechanism 4.

[0063] The transmission sleeve 32 is sleeved on the eccentric rod 411 and is usually mounted on the eccentric rod 411 through a needle bearing to be able to rotate on the eccentric rod 411. When the servo drive mechanism 4 rotates, the transmission sleeve 32 can make a circular motion with the eccentric rod 411, and the valve core 2 is dragged to make a linear sliding in the valve body 1 through the transmission rod 31.

[0064] In a preferred embodiment of the rotary direct drive type servo spool of the present application, as shown in Figure 7 The eccentric mechanism 41 includes an eccentric rod 411, an eccentric connecting wheel 412, an eccentric connecting rod 413, and an eccentric mechanism rotation shaft 414. The eccentric connecting wheel 412 is a circular wheel with a diameter slightly larger than the required eccentricity of the eccentric rod 411, and the eccentric connecting wheel 412 is coaxially fixed on the output shaft of the servo drive mechanism 4.

[0065] The eccentric rod 411 is fixed at a peripheral position of the eccentric connecting wheel 412 and can make an eccentric circular motion with the rotation of the eccentric connecting wheel 412.

[0066] One end of the eccentric connecting rod 413 is connected with the eccentric rod 411, and the other end is inclined to the rotation axis of the eccentric connecting wheel 412 and connected with the eccentric mechanism rotation shaft 414.

[0067] The eccentric mechanism rotation shaft 414 is coaxially arranged with the output shaft of the servo drive mechanism 4, and when the servo drive mechanism 4 is installed on the drive mechanism mounting interface 17 of the valve body 1, the eccentric rod 411 is located in the middle of the hole diameter of the valve body main hole 11, and the end of the eccentric mechanism rotation shaft 414 is rotationally connected to the valve body 1 on the opposite side of the valve body main hole 11. Usually, the eccentric mechanism rotation shaft 414 is rotationally connected with the valve body 1 through a bearing, which reduces the rotation resistance of the eccentric mechanism rotation shaft 414, limits the position of the eccentric mechanism rotation shaft 414, and ensures the accuracy of the eccentric rotation track of the eccentric rod 411, thereby ensuring the position accuracy of the valve core 2.

[0068] A plug 18 is arranged at the opening of the valve body main hole 11 at the end where the eccentric mechanism 41 is located, and is screwed with the hole wall at the opening of the valve body main hole 11. When the plug 18 is connected at the opening of the valve body main hole 11, a seal at the opening of the valve body main hole 11 can be formed. When the plug 18 is removed, the structure inside the valve body main hole 11 can be installed or maintained and repaired through the opening of the valve body main hole 11.

[0069] In some embodiments of the rotary direct drive servo spool valve of the present application, as shown in Figure 4 , Figure 8 and Figure 9 , an end cover 5 is further arranged at one end of the valve body main hole 11 on the valve body 1. In the valve body main hole 11 inside the end cover 5, an elastic centering device 6 is arranged between the valve core 2 and the valve body 1.

[0070] The end cover 5 is fixed on the side wall of the valve body 1 outside the end of the valve body main hole 11 by screws, and a sealed installation space is formed between the end of the valve core 2 and the end cover 5. The elastic centering device 6 is arranged in the sealed space inside the end cover 5.

[0071] The elastic centering device 6 can use various devices that can generate a bidirectional elastic force on the valve core 2 and can push the valve core 2 to form a tendency to return to the center position. Under the action of the elastic centering device 6, once the valve core 2 moves away from the center position, whether it moves to the left valve position or the right valve position, the elastic centering device 6 can generate a pushing force on the valve core 2 to push the valve core 2 to return to the center position. In this way, no matter what valve position the valve core 2 is in, once the servo valve loses power accidentally, the valve core 2 can automatically return to the center position under the action of the elastic centering device 6, preventing the hydraulic equipment where the rotary direct drive servo spool valve of the present application is located from accidentally moving after power supply is restored, and ensuring the safety of the hydraulic equipment.

[0072] In a preferred embodiment of the rotary direct drive servo spool valve of the present application, as shown in Figure 4 , Figure 8 and Figure 9 , the elastic centering device 6 includes a first spring seat 61, a spring seat connecting piece 62, a centering spring 63 and a second spring seat 64. The first spring seat 61 and the second spring seat 64 are generally cylindrical in shape, with an outer flange at one end and an inner flange at the other end. The middle part of the inner flange is formed into a sliding hole. The outer flange of the first spring seat 61 is arranged towards the end cover 5, the outer flange of the second spring seat 64 is arranged towards the valve core 2, and the inner flanges of the first spring seat 61 and the second spring seat 64 are arranged opposite to each other.

[0073] A centering spring 63 is disposed between a first spring seat 61 and a second spring seat 64. Both ends of the centering spring 63 are respectively fitted onto the first spring seat 61 and the second spring seat 64, and the ends of the centering spring 63 abut against the inner sides of the outer flanges of the first spring seat 61 and the second spring seat 64. Under the elastic force of the centering spring 63, the outer side of the outer flange of the first spring seat 61 abuts against the end cover 5, and the outer side of the outer flange of the second spring seat 64 abuts against the valve body 1 surrounding the valve body main hole 11, or against the end of the valve sleeve 7 installed in the valve body main hole 11.

[0074] The spring seat connector 62 passes through the sliding hole in the middle of the inner flange of the first spring seat 61 and the second spring seat 64 and is fixed to the end of the valve core 2, such that the inner flange of the first spring seat 61 abuts against the end cap of the spring seat connector 62, and the inner flange of the second spring seat 64 abuts against the valve core 2. A sliding connection is formed between the spring seat connector 62 and both the first spring seat 61 and the second spring seat 64.

[0075] As a specific implementation method, such as Figure 8 As shown, a spring seat mounting groove 26 and a spring seat slide 27 are respectively provided at the end of the valve core 2, with the spring seat slide 27 located at the outer end of the spring seat mounting groove 26. A second spring seat 64 is fitted onto the spring seat slide 27 through a sliding hole in the middle of its inner flange, such that the main body of the second spring seat 64 is located in the spring seat mounting groove 26, and the outer flange of the second spring seat 64 abuts against the side wall of the spring seat mounting groove 26. A first spring seat 61 is fitted onto the spring seat slide 27 through a sliding hole in the middle of its inner flange. A spring seat connector 62 is fixed to the end of the spring seat slide 27 from the inner hole of the first spring seat 61. The diameter of the end cap of the spring seat connector 62 is larger than the diameter of the sliding hole of the first spring seat 61, thus restricting the inner flange of the first spring seat 61 to the spring seat slide 27 through the end cap of the spring seat connector 62. Both the first spring seat 61 and the second spring seat 64 can slide on the spring seat slide 27.

[0076] When the spool 2 moves to the left, the spool 2 pushes the second spring seat 64 to move to the left, while the first spring seat 61 remains stationary under the restriction of the end cover 5, the distance between the second spring seat 64 and the first spring seat 61 is shortened, and the centering spring 63 is compressed. The elastic force of the centering spring 63 acts on the spool 2 through the second spring seat 64, forming a force that pushes the spool 2 to move to the right, which can push the spool 2 to return to the center position when the servo driving mechanism 4 loses power. When the spool 2 moves to the right, the first spring seat 61 is pulled to move to the right through the spring seat connector 62 fixed to the end of the spool 2, while the second spring seat 64 remains stationary under the restriction of the valve body 1 or the valve sleeve 7 under the restriction of the valve body 1, the distance between the first spring seat 61 and the second spring seat 64 is shortened, and the centering spring 63 is compressed. The elastic force of the centering spring 63 acts on the spool 2 through the first spring seat 61 and the spring seat connector 62, forming a force that pushes the spool 2 to move to the left, which can also push the spool 2 to return to the center position when the servo driving mechanism 4 loses power. In this way, whether the spool 2 is in the left position or the right position when the servo driving mechanism 4 loses power, the spool 2 can return to the center position under the action of the elastic centering device 6, ensuring the safety of the hydraulic equipment.

[0077] In some embodiments of the rotating direct drive type servo spool of the present application, as shown in Figure 2 and Figure 3 The servo driving mechanism 4 uses a servo motor. The servo driving mechanism 4 is fixed to the side of the valve body 1, specifically to the driving mechanism mounting interface 17 on the side of the valve body 1. The output shaft of the servo driving mechanism 4 is perpendicular to the length direction of the spool 2.

[0078] The servo driving mechanism 4 includes a motor rotor 42, a motor stator 43, a motor shell 44, and a motor end cover 45. The end of the motor shell 44 is fixed to the valve body 1, so that the central axis of the motor shell 44 intersects the central axis of the valve body main hole 11. The motor stator 43 is fixed to the inner side wall of the motor shell 44, and a stator coil is provided on the motor stator 43; the motor rotor 42 is rotatably connected to the motor shell 44, and a ring of magnetic steel is evenly distributed in the circumferential direction of the motor rotor 42, which is installed in the rotor hole inside the motor stator 43. The motor end cover 45 is fixed to the end of the motor shell 44 away from the valve body 1, and a rotor shaft hole is provided in the middle of the motor end cover 45. One end of the motor rotor 42 is rotatably connected to the motor shell 44, and the other end is installed in the rotor shaft hole and rotatably connected to the end cover bearing 451.

[0079] A bearing mounting seat coaxial with the rotor shaft hole is arranged on the inner side of the motor end cover 45, and an end cover bearing 451 is mounted in the bearing mounting seat. The rotating shaft of the motor rotor 42 is mounted in the inner ring of the end cover bearing 451, and a rotating connection is formed between the end cover bearing 451. The arrangement of the end cover bearing 451 can improve the position stability of the motor rotor 42 during rotation.

[0080] A wave washer 452 is arranged between the end of the end cover bearing 451 and the bottom of the bearing mounting seat of the motor end cover 45. The wave washer 452 can pre-apply a certain axial thrust on the motor rotor 42 to eliminate the backlash of the bearing, improve the position stability of the motor rotor 42 during rotation, and reduce the rotation noise of the motor rotor 42.

[0081] In a preferred embodiment of the rotating direct drive type servo spool of the present application, as shown in Figure 2 An inductive magnetic code 46 is arranged at the end of the motor rotor 42 adjacent to the end of the motor end cover 45. The magnetic periodicity changes at different positions in the circumferential direction of the inductive magnetic code 46.

[0082] A sealing cover 47 covering the peripheral area of the rotor shaft hole is arranged on the outer side of the motor end cover 45. The inductive magnetic code 46 is arranged on the outer side of the motor end cover 45 between the motor end cover 45 and the sealing cover 47. The periphery of the sealing cover 47 is sealingly connected with the motor end cover 45, and the inductive magnetic code 46 is sealed in the mounting space connected with the motor housing 44 to form isolation from the external space.

[0083] A PCBA (Printed Circuit Board Assembly) 48 is arranged on the outer side of the sealing cover 47. The PCBA 48 is provided with a plurality of control elements for controlling the operation of the servo driving mechanism 4, including a magnetic code sensing element for detecting the rotating state of the inductive magnetic code 46. The magnetic code sensing element is arranged on the PCBA 48 at a position opposite to the inductive magnetic code 46, and can detect the rotation angle of the inductive magnetic code 46 from the outside of the sealing cover 47. The stator coil is connected with the PCBA 48 through the motor end cover 45. The control elements on the PCBA 48 can control the current in the stator coil according to the actual position of the motor rotor 42 detected by the magnetic code sensing element, and perform closed-loop control on the motor rotor 42 to improve the control accuracy of the position of the motor rotor 42.

[0084] A cover 8 is further arranged outside the servo drive mechanism 4, and the cover 8 is fixed on the valve body 1 with an opening facing the valve body 1. The servo drive mechanism 4 including the motor housing 44, the motor end cover 45, the sealing cover 47 and the PCBA 48 is covered in the cover 8. An electrical interface 81 is arranged on one side of the cover 8 and electrically connected with the PCBA 48. Specifically, the electrical interface 81 can be provided with three different interfaces of a control signal interface, a CAN signal interface and an RS232 signal interface, or one to two interfaces including the control signal interface, or only one electrical interface 81 is provided to transmit at least one of the above three signals including the control signal through one interface.

[0085] In some embodiments of the rotary direct drive type servo spool of the present application, as shown in Figures 2 to 5 A valve sleeve 7 is further arranged between the valve body 1 and the valve core 2. A structure of one valve sleeve 7 is shown in Figure 10 Specifically, the valve sleeve ports include the valve sleeve first T port 74, the valve sleeve B port 73, the valve sleeve P port 71, the valve sleeve A port 72 and the valve sleeve second T port 75 arranged in sequence in the axial direction of the valve sleeve 7, and the valve sleeve first T port 74, the valve sleeve B port 73, the valve sleeve P port 71, the valve sleeve A port 72 and the valve sleeve second T port 75 are all provided with multiple ports on the same circumferential surface of the valve sleeve 7.

[0086] An end of the valve sleeve 7 close to the valve sleeve first T port 74 is provided with a valve sleeve stop edge 76, and the valve sleeve 7 is installed in the valve body main hole 11 of the valve body 1 so that the valve sleeve stop edge 76 is located at the end where the end cover 5 is located. The valve sleeve 7 is gap sealed with the valve body 1, and the valve sleeve stop edge 76 is pressed against the valve body 1 around the valve body main hole 11 through the inner side end face of the end cover 5 to prevent the axial movement of the valve sleeve 7 in the valve body main hole 11. Of course, the valve sleeve 7 and the valve body 1 can also be sealed by a sealing ring.

[0087] After the valve sleeve 7 is installed in the valve body main hole 11, the valve sleeve first T port 74 is connected with the first T cavity 15, the valve sleeve B port 73 is connected with the B cavity 14, the valve sleeve P port 71 is connected with the P cavity 12, the valve sleeve A port 72 is connected with the A cavity 13, and the valve sleeve second T port 75 is connected with the second T cavity 16.

[0088] The valve core 2 is installed in the valve sleeve cavity of the valve sleeve 7 and can move in the axial direction of the valve sleeve cavity under the drive of the transmission mechanism 3. When the valve core 2 and the valve sleeve 7 are gap fitted, the wear between the valve core 2 and the valve sleeve 7 when the valve core 2 slides can be reduced. At the same time, the gap fitting between the valve core 2 and the valve sleeve 7, and the gap sealing or sealing ring sealing between the valve sleeve 7 and the valve body 1 can buffer the tangential stress brought by the transmission mechanism 3, and ensure the smooth sliding of the valve core 2 in the valve sleeve 7.

[0089] The different axial positions of valve core 2 within valve sleeve 7 allow valve core 2 to be in three different valve position states. When valve core 2 is in the neutral position, such as... Figure 4 As shown, the outer circumferential surface of the valve core 2 closes the valve sleeve A port 72 and valve sleeve B port 73. The first connecting groove 23 is connected to the first T port 74 of the valve sleeve, the second connecting groove 24 is connected to the valve sleeve P port 71, and the third connecting groove 25 is connected to the second T port 75 of the valve sleeve. At this time, the valve position function of the rotary direct-drive servo spool valve of this application is as follows: Figure 11 As shown, the P port 101, T port 102, A port 103 and B port 104 on the valve body 1 are isolated from each other, and there is no hydraulic oil supply in the oil circuits connected to A port 103 and B port 104.

[0090] When valve core 2 is in the left position, such as Figure 12 As shown, the first connecting groove 23 on the outer circumference of the valve core 2 is connected to the first T-port 74 of the valve sleeve, the second connecting groove 24 is connected to both the P-port 71 and the B-port 73 of the valve sleeve, and the third connecting groove 25 is connected to both the A-port 72 and the second T-port 75 of the valve sleeve. At this time, the valve position function of the rotary direct-drive servo spool valve of this application is as follows: Figure 13 As shown, port P 101 on valve body 1 is connected to port B 104, and port A 103 is connected to port T 102. Hydraulic oil from port P 101 flows to the hydraulic equipment through port B 104, and return oil from the hydraulic equipment flows to port T 102 through port A 103, returning to the oil tank. The specific position of the control valve core 2 can also control the valve opening size between the second connecting groove 24 and port B 73 of the valve sleeve, and the valve opening size between the third connecting groove 25 and port A 72 of the valve sleeve, thereby controlling the flow rate of hydraulic oil flowing to the hydraulic equipment through port B 104.

[0091] When valve core 2 is in the right position, such as Figure 14 As shown, the first connecting groove 23 on the outer circumferential surface of the valve core 2 is simultaneously connected to both the valve sleeve B port 73 and the valve sleeve first T port 74; the second connecting groove 24 is simultaneously connected to both the valve sleeve P port 71 and the valve sleeve A port 72; and the third connecting groove 25 is connected to the valve sleeve second T port 75. At this time, the valve position function of the rotary direct-drive servo spool valve of this application is as follows: Figure 15 As shown, port P 101 on valve body 1 is connected to port A 103, and port B 104 is connected to port T 102. Hydraulic oil from port P 101 flows to the hydraulic equipment through port A 103, and return oil from the hydraulic equipment flows to port T 102 through port B 104, returning to the oil tank. The specific position of the control valve core 2 can also control the valve opening size between the first connecting groove 23 and valve sleeve port B 73, and the valve opening size between the second connecting groove 24 and valve sleeve port A 72, thereby controlling the flow rate of hydraulic oil flowing to the hydraulic equipment through port A 103.

[0092] In the description of the application, reference to terms such as "one embodiment", "a specific embodiment", "preferred embodiment" or the like means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0093] The above are preferred embodiments of the application, and are not intended to limit the protection scope of the application, therefore: any equivalent changes made on the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A rotary direct drive servo spool, characterized by: The valve body (1) is provided with a plurality of hydraulic oil ports, and a plurality of valve cavities are arranged inside and communicate with the hydraulic oil ports respectively; the valve core (2) is arranged in the valve body (1) and can slide relative to the valve body (1) to switch the connection relationship between the valve cavities; the valve core (2) is provided with an axially extending valve core hole (21); the transmission mechanism (3) extends into the valve core hole (21) from one end of the valve core (2) and is connected to the end region of the other end of the valve core (2); the output shaft of the servo drive mechanism (4) is provided with an eccentric mechanism (41), and the transmission mechanism (3) is connected with the eccentric mechanism (41) to drive the valve core (2) to slide through the transmission mechanism (3).

2. The rotary direct drive servo valve of claim 1, wherein: The end region of the valve core hole (21) away from the servo drive mechanism (4) is provided with a transmission connecting plate (22), the periphery of the transmission connecting plate (22) is integrally connected with the wall of the valve core hole (21), and the transmission mechanism (3) is integrally connected to the middle part of the transmission connecting plate (22).

3. The rotary direct drive servo valve of claim 2, wherein: The transmission mechanism (3) includes a transmission rod (31), the end of the transmission rod (31) is connected with the transmission connecting plate (22), the cross section of the transmission rod (31) is a rectangle with the height parallel to the output shaft of the servo drive mechanism (4), and the length of the upper and lower bottom edges of the rectangle is smaller than the height of the rectangle; the two sides of the transmission rod (31) in the height direction are provided with deformation buffer holes (221) at the connection position of the transmission connecting plate (22) and the transmission rod (31).

4. The rotary direct drive servo valve of claim 1, wherein: The transmission mechanism (3) includes a transmission sleeve (32), and the eccentric mechanism (41) includes an eccentric rod (411), the eccentric rod (411) is connected to the output shaft of the servo drive mechanism (4) and is eccentrically arranged with the output shaft of the servo drive mechanism (4), and the transmission sleeve (32) is sleeved on the eccentric rod (411) and is rotationally connected with the eccentric rod (411).

5. The rotary direct drive servo valve of claim 4, wherein: The eccentric mechanism (41) further includes an eccentric connecting wheel (412), an eccentric connecting rod (413) and an eccentric mechanism rotating shaft (414), the eccentric connecting wheel (412) is fixed on the output shaft of the servo drive mechanism (4), the eccentric rod (411) is fixed at the peripheral position of the eccentric connecting wheel (412), one end of the eccentric connecting rod (413) is connected with the eccentric rod (411), the other end is connected with the eccentric mechanism rotating shaft (414), the eccentric mechanism rotating shaft (414) is coaxially arranged with the output shaft of the servo drive mechanism (4) and is rotationally connected with the valve body (1).

6. The rotary direct drive servo valve of claim 1, wherein: Further comprising an end cover (5) and an elastic centering device (6), the end cover (5) is fixed on the valve body (1), the elastic centering device (6) is arranged on the inner side of the end cover (5) and is connected with the valve core (2) to form a pushing force to push the valve core (2) to return to the middle position.

7. The rotary direct drive servo valve of claim 6, wherein: The elastic centering device (6) comprises a first spring seat (61), a spring seat connecting piece (62), a centering spring (63) and a second spring seat (64), the spring seat connecting piece (62) is fixed on the end of the spool (2) through the first spring seat (61) and the second spring seat (64), and is in sliding connection with the first spring seat (61) and the second spring seat (64), the centering spring (63) is sleeved on the spring seat connecting piece (62) and is arranged between the first spring seat (61) and the second spring seat (64), the first spring seat (61) abuts against the end cover (5), and the second spring seat (64) abuts against the valve body (1).

8. The rotary direct drive servo valve of claim 1, wherein: The servo drive mechanism (4) is fixed on the side of the valve body (1), the output shaft of the servo drive mechanism (4) is arranged perpendicularly to the spool (2), the servo drive mechanism (4) comprises a motor rotor (42), a motor stator (43), a motor shell (44) and a motor end cover (45), the motor shell (44) is fixed on the valve body (1), the motor stator (43) is fixed in the motor shell (44), the motor rotor (42) is arranged in the motor stator (43), the motor end cover (45) is fixed on the end of the motor shell (44) away from the valve body (1), one end of the motor rotor (42) is in rotary connection with the motor shell (44), the other end is in rotary connection with the motor end cover (45) through an end cover bearing (451), and a wave washer (452) is arranged between the end of the end cover bearing (451) and the motor end cover (45).

9. The rotary direct drive servo valve of claim 8, wherein: One end of the motor rotor (42) adjacent to the motor end cover (45) is provided with an inductive magnetic code (46), a sealing cover (47) is arranged on the outer side of the motor end cover (45), the sealing cover (47) is in sealing connection with the motor end cover (45), the inductive magnetic code (46) is located on the inner side of the sealing cover (47), a PCBA (48) is arranged on the outer side of the sealing cover (47), a magnetic code induction element is arranged on the PCBA (48), and the magnetic code induction element is arranged in correspondence with the inductive magnetic code (46).

10. The rotary direct drive servo valve of any one of claims 1-9, wherein: Further comprising a valve sleeve (7), the valve sleeve (7) is arranged in the valve body (1), a plurality of valve sleeve holes connected with the valve cavity are arranged on the valve sleeve (7), the spool (2) is arranged in sliding mode in the valve sleeve (7), the valve sleeve (7) is in clearance sealing with the valve body (1), and the spool (2) is in clearance fit with the valve sleeve (7).

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