JP7781289B2 - Electronic Expansion Valve - Google Patents

Description

This application claims priority to a patent application filed on January 30, 2022, with application number 202220249836.5, entitled "Electronic Expansion Valve", with the State Intellectual Property Office of the People's Republic of China; priority to a patent application filed on January 30, 2022, with application number 202220249818.7, entitled "Electronic Expansion Valve", with the State Intellectual Property Office of the People's Republic of China; priority to a patent application filed on January 30, 2022, with application number 202220249839.9, entitled "Electronic Expansion Valve", with the State Intellectual Property Office of the People's Republic of China; priority to a patent application filed on January 30, 2022, with application number 202220249837.X, entitled "Electronic Expansion Valve", with the State Intellectual Property Office of the People's Republic of China;

This application relates to the technical field of electronic expansion valves, and more particularly to electronic expansion valves.

Currently, various cooling and heating equipment, such as air conditioners, refrigerators, and heat pump water heaters, typically use electronic expansion valves to regulate the flow rate of fluid. Electronic expansion valves typically consist of a valve seat member, a spindle member, and a drive assembly. The valve seat member typically includes a valve seat and a connecting pipe. The valve seat has a valve port, and the movement of the spindle member adjusts the opening of the valve port to control flow. Conventional electronic expansion valves typically can regulate large flow rates but cannot regulate small flow rates. Therefore, there is a need to design an electronic expansion valve that can regulate not only small flow rates but also large flow rates.

Summary of the application

This application provides an electronic expansion valve that solves the problem that conventional electronic expansion valves are unable to achieve small flow rate adjustment.

To solve the above problems, the present application provides an electronic expansion valve comprising: a valve seat member having a large valve port; and a spindle member provided within the chamber of the valve seat member, the spindle member including a large spindle portion, a small spindle, and a drive assembly, the large spindle portion having a small valve port, the small valve port having a flow control surface, the larger end of the opening of the small valve port being spaced apart from the large valve port; the drive assembly, the small spindle, and the large spindle portion all drivingly connected to the spindle member; the electronic expansion valve has a closed state, a flow control state, and a fully open state, where in the closed state, the small spindle is inserted into the small valve port to seal it and the large spindle portion seals the large valve port; in the flow control state, the large spindle portion seals the large valve port, and the small spindle is axially movable to adjust the opening of the small valve port; and in the fully open state, the large spindle portion avoids the large valve port.

Furthermore, the flow rate adjustment surface is a tapered surface, and in the closed state, the small spindle abuts against the small valve orifice, and/or the end face of the large valve orifice is a sealing flat surface, and in the closed state, one end of the large spindle portion abuts against the sealing flat surface.

Furthermore, the large spindle portion has a restriction chamber and a guide hole that are connected to each other, and the restriction chamber, guide hole, and small valve port are arranged in order. The small spindle includes a restriction rod and a sealing rod that are connected to each other, the restriction rod is arranged in the restriction chamber so as to be axially movable, the sealing rod passes through the guide hole, and the drive assembly and the restriction rod are drivingly connected.

Furthermore, in the axial direction of the spindle member, the limiting chamber has opposing first and second stop surfaces, one side of the limiting rod is stop-engaged with the first stop surface, and the small spindle further includes a stop shoulder provided on the side wall of the limiting rod, the stop shoulder being stop-engaged with the second stop surface.

Furthermore, the spindle member further includes a first elastic member, both ends of which abut against the first stop surface and stop shoulder, respectively.

Furthermore, the outer diameter of the limiting rod is larger than the outer diameter of the sealing rod, the first elastic member is a spring fitted to the limiting rod, and the stop shoulder has an annular structure.

Furthermore, the drive assembly includes a screw and a connecting sleeve, one end of which is connected to the small spindle, the screw and the connecting sleeve being axially limitedly engaged, the screw being axially movable, the screw being capable of moving independently in conjunction with the small spindle within a predetermined stroke, and the screw being capable of moving the large spindle portion in conjunction with the small spindle.

Furthermore, the large spindle portion has an escape port, the connecting sleeve passes through the escape port, and one end of the small spindle away from the small valve port is inserted into the connecting sleeve and fixedly connected to the connecting sleeve.

The drive assembly further includes a bearing, a bushing, and a second elastic member provided within the connecting sleeve. The bearing is fitted onto one end of the screw, one side of the bearing and the connecting sleeve are axially limitedly engaged, and the other side of the bearing, the bushing, the second elastic member, and the small spindle are abutted in order.

Furthermore, the valve seat member has a flow hole, and the large spindle portion has a side opening, which is located on one side of the small valve opening away from the large valve opening, and in the flow rate adjustment state, the flow hole, side opening, small valve opening, and large valve opening are sequentially connected.

Furthermore, the valve seat member includes a valve seat body, a large gasket, a first outer sealing ring, and a second outer sealing ring. The large gasket is located within the chamber of the valve seat body, and the large gasket has a large valve port. The valve seat body has a flow hole. The first outer sealing ring and the second outer sealing ring are fitted to the outer wall of the valve seat body, and the flow hole is located between the first outer sealing ring and the second outer sealing ring.

Applying the technical aspects of the present application, an electronic expansion valve is provided, which includes a valve seat member having a large valve port, and a spindle member provided within the chamber of the valve seat member, the spindle member including a large spindle portion, a small spindle, and a drive assembly, wherein the large spindle portion has a small valve port, the small valve port having a flow control surface, one larger end of the opening of the small valve port being spaced apart from the large valve port, the drive assembly, and the small spindle and large spindle portion are all drivingly connected, and the electronic expansion valve has a closed state, a flow control state, and a fully open state, wherein in the closed state, the small spindle is inserted into the small valve port to seal the small valve port and the large spindle portion seals the large valve port, while in the flow control state, the large spindle portion seals the large valve port, the small spindle is axially movable to adjust the opening of the small valve port, and in the fully open state, the large spindle portion avoids the large valve port. When this embodiment is adopted, the small spindle is inserted into the small valve port to seal it, the large spindle part seals the large valve port, and the drive assembly is drivingly connected to both the small spindle and the large spindle part, so that the axial movement of the small spindle adjusts the opening of the small valve port to achieve small flow rate adjustment. The large spindle part seals or bypasses the large valve port to achieve large flow rate conduction or blocking. Here, when the electronic expansion valve is in a closed state, the small spindle seals the small valve port and the large spindle part seals the large valve port. When the electronic expansion valve is in a flow rate adjustment state, the drive assembly drives the small spindle to move axially to adjust the opening of the small valve port, and the large spindle part seals the large valve port to achieve small flow rate adjustment. When the electronic expansion valve is in the fully open state, the drive assembly drives the small spindle to move it until it completely clears the small valve port, and then the small spindle moves the large spindle section axially in conjunction with the large spindle section until it completely clears the large valve port, thereby achieving the fully open state.

The drawings in the specification that form part of this application are intended to provide a further understanding of the application, and the schematic examples and their descriptions in the application are intended to aid in the interpretation of the application and are not intended to unduly limit the application.

1 shows a cross-sectional view of an electronic expansion valve provided in an embodiment of the present application. 2 shows a cross-sectional view of a spindle member in the electronic expansion valve in FIG. 1 . 2 shows a cross-sectional view of the small spindle and small valve orifice in FIG. 1; 2 shows a cross-sectional view of the large spindle portion and large gasket in FIG. 1. 2 shows a cross-sectional view of an electronic expansion valve provided in an embodiment of the present application. 6 shows a cross-sectional view of the small spindle and small gasket in FIG. 5. 6 shows a cross-sectional view of the small spindle in FIG. 5. 3 shows a cross-sectional view of an electronic expansion valve provided in an embodiment of the present application. FIG. 8 shows a structural schematic diagram of the nut structure. FIG. 8 shows a schematic diagram of the structure of the valve seat ring. 11 shows a cross-sectional view of the seat ring in FIG. 10 . 9 shows a cross-sectional view of the connecting sleeve in FIG. 8 . 9 shows a cross-sectional view of the small spindle in FIG. 8. 4 shows a cross-sectional view of an electronic expansion valve provided in an embodiment of the present application. 15 shows an enlarged view of a portion of FIG. 14. A structural schematic diagram of the spindle member in FIG. 14 is shown.

Here, the above drawings include the following reference numerals:
10 valve seat member, 11 large valve port, 111 sealing plane, 12 first elastic member, 13 flow hole, 14 valve seat body, 15 large gasket, 16 first outer sealing ring, 17 second outer sealing ring, 18 valve seat ring, 181 guide chamber, 1111 annular groove, 182 first through hole,
20 Spindle member, 21 Large spindle part, 211 Small valve port, 212 Restriction chamber, 2121 First stop surface, 2122 Second stop surface, 213 Guide hole, 214 Side opening, 215 Large spindle, 216 Small gasket, 22 Small spindle, 221 Restriction rod, 222 Sealing rod, 2221 Fillet, 223 Stop shoulder, 23 Drive assembly, 231 Screw, 232 Connecting sleeve, 233 Bearing, 234 Bush, 235 Second elastic member, 24 Sealing ring, 41 Nut structure, 411 Nut body, 412 Connecting plate, 4121 Open slot, 42 Screw assembly, 4221 Second through hole,
30 valve sleeve, 31 body structure, 312 first sleeve, 313 second sleeve, 32 sealing sleeve, 321 arcuate surface, 3211 third through hole, 3221 fourth through hole, 34 second inner sealing ring
50 rotor chamber,
60 balancing passage, 61 first passage, 62 second passage, 63 third passage, 64 fourth passage.

The technical aspects of the embodiments of the present application will be described below clearly and completely with reference to the drawings in the embodiments of the present application. However, it should be understood that the described embodiments are merely some of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is, in fact, merely explanatory and does not impose any limitations on the present application, its applications, or uses. All other embodiments that can be obtained by a person skilled in the art based on the embodiments of the present application without any creative effort shall fall within the scope of protection of the present application.

As shown in Figures 1 to 4, an embodiment of the present application includes a valve seat member 10 having a large valve port 11, and a spindle member 20 provided in a chamber of the valve seat member 10. The spindle member 20 includes a large spindle portion 21, a small spindle 22, and a drive assembly 23. The large spindle portion 21 has a small valve port 211. The small valve port 211 has a flow control surface. One end of the larger opening of the small valve port 211 is separated from the large valve port 11. The drive assembly 23, the small spindle 22, and the large spindle portion 21 are all The electronic expansion valve includes a spindle member 20, which is also drivingly connected to the small valve port 211, and has a closed state, a flow rate adjusting state, and a fully open state. In the closed state, the small spindle 22 is inserted into the small valve port 211 and seals it, and the large spindle portion 21 seals the large valve port 11. In the flow rate adjusting state, the large spindle portion 21 seals the large valve port 11, and the small spindle 22 is axially movable to adjust the opening of the small valve port 211. In the fully open state, the large spindle portion 21 avoids the large valve port 11.

When this configuration is adopted, the small spindle 22 is inserted into the small valve port 211 to seal it, the large spindle portion 21 seals the large valve port 11, and the drive assembly 23 is driven and connected to both the small spindle 22 and the large spindle portion 21. The axial movement of the small spindle 22 adjusts the opening of the small valve port 211, thereby achieving small flow rate regulation. The large spindle portion 21 seals or bypasses the large valve port 11, thereby enabling or blocking large flow. When the electronic expansion valve is in a closed state, the small spindle 22 seals the small valve port 211, and the large spindle portion 21 seals the large valve port 11. When the electronic expansion valve is in a flow rate regulation state, the drive assembly 23 drives the small spindle 22 to move axially to adjust the opening of the small valve port 211, and the large spindle portion 21 seals the large valve port 11, thereby achieving small flow rate regulation. When the electronic expansion valve is in the fully open state, the drive assembly 23 drives the small spindle 22 to move it until it completely clears the small valve port 211, and then the small spindle 22 moves the large spindle portion 21 axially in conjunction with the small spindle 22 until the large spindle portion 21 completely clears the large valve port 11, thereby achieving the fully open state. This electronic expansion valve may be mounted on a mounting base or within the valve body.

Specifically, by making the flow rate adjustment surface of the small valve orifice 211 tapered and by aligning the larger end of the opening of the small valve orifice 211 toward the small spindle 22, the engagement between the small spindle 22 and the small valve orifice 211 allows for more accurate flow rate adjustment and meets usage requirements. Furthermore, by providing a flow rate adjustment slope on the small valve orifice 211, the difficulty of machining the small spindle 22 is reduced.

Here, the outer diameter of the small spindle 22 is larger than the minimum diameter of the small valve port 211, and the flow area of the large valve port 11 is larger than the flow area of the small valve port 211. The opening degree of the small valve port 211 means the degree to which the small valve port 211 is open, or may be understood as the size of the flow area of the small valve port 211. The valve seat member has a flow hole, and in the closed state, the flow hole does not communicate with either the large valve port 11 or the small valve port 211. In the flow rate adjustment state, the flow hole communicates with the large valve port 11 via the small valve port 211, and in the fully open state, the flow hole communicates directly with the large valve port 11.

Furthermore, the end face of the large valve port 11 is a sealing plane 111, and in the closed state, one end of the large spindle portion 21 abuts against the sealing plane 111. By providing the end face of the large valve port 11 as a sealing plane 111, it becomes easier for one end of the large spindle portion 21 to abut against the sealing plane 111 when the electronic expansion valve is in the closed state. Compared to an inclined surface sealing method, this sealing method makes it easier to determine and control the sealing point. Therefore, when an equalizing passage connecting the upper and lower ends of the large spindle portion 21 is provided, the sealing point can be controlled to bring the pressure areas of the upper and lower ends of the large spindle portion 21 closer together, thereby achieving pressure equalization at the upper and lower ends.

Specifically, the large spindle portion 21 has a restricting chamber 212 and a guide hole 213 that are connected to each other. The restricting chamber 212, the guide hole 213, and the small valve port 211 are arranged in sequence. The small spindle 22 includes a restricting rod 221 and a sealing rod 222 that are connected to each other. The restricting rod 221 is axially movable within the restricting chamber 212, and the sealing rod 222 passes through the guide hole 213. The drive assembly 23 and the restricting rod 221 are connected to drive the restricting rod 221. Using the above installation method, the drive assembly 23 moves the restricting rod 221 axially in tandem, and the restricting rod 221 moves the sealing rod 222 in tandem in tandem. That is, the sealing rod 222 adjusts the opening of the small valve port 211, thereby achieving the function of adjusting a small flow rate.

Here, in the axial direction of the spindle member 20, the limiting chamber 212 has opposing first and second stop surfaces 2121 and 2122. One side of the limiting rod 221 is lockingly engaged with the first stop surface 2121. The small spindle 22 further includes a stop shoulder 223 on the side wall of the limiting rod 221, which is lockingly engaged with the second stop surface 2122. The provision of the first stop surface 2121 provides a limiting effect when the limiting rod 221 moves toward the minor valve orifice 211. The provision of the stop shoulder 223 and the second stop surface 2122 provides a limiting effect when the limiting rod 221 moves away from the minor valve orifice 211. This limits the range of movement of the limiting rod 221.

Furthermore, the spindle member 20 further includes a first elastic member 12, both ends of which abut against the first stop surface 2121 and the stop shoulder 223, respectively. By arranging both ends of the first elastic member 12 to abut against the first stop surface 2121 and the stop shoulder 223, respectively, when the electronic expansion valve is in a closed state, the first elastic member 12 is in a compressed state, and when the drive assembly 23 moves the limiting rod 221 in conjunction with the stop rod 221 away from the small valve port 211, i.e., in a flow rate adjustment state, the elastic force of the first elastic member 12 is released, which moves the stop shoulder 223 in conjunction with the stop rod 221 away from the small valve port 211, thereby opening the small valve port 211.

In this embodiment, the outer diameter of the limiting rod 221 is larger than the outer diameter of the sealing rod 222, the first elastic member 12 is a spring fitted to the limiting rod 221, and the stop shoulder 223 has an annular structure. By making the outer diameter of the limiting rod 221 larger than the outer diameter of the sealing rod 222, the limiting rod 221 can perform a limiting function. By making the first elastic member 12 a spring fitted to the limiting rod 221, strength is high and costs are low. By making the stop shoulder 223 an annular structure, engagement with the spring is facilitated.

Specifically, the drive assembly 23 includes a screw assembly 42, which includes a screw 231 and a connecting sleeve 232. One end of the connecting sleeve 232 is connected to the small spindle 22. The screw 231 and the connecting sleeve 232 are limitedly engaged in the axial direction. The screw 231 is axially movable, and can move the small spindle 22 independently within a predetermined stroke. The screw 231 can also move the spindle 21 in conjunction with the small spindle 22. By adopting the above installation method, the screw 231 and the connecting sleeve 232 are limitedly engaged in the axial direction, and one end of the connecting sleeve 232 is connected to the small spindle 22. As a result, when the screw 231 moves in the axial direction, the connecting sleeve 232 moves in conjunction with the small spindle 22, and further, the connecting sleeve 232 can move the small spindle 22 in conjunction with the small spindle 22.

Here, the large spindle portion 21 has an escape port, the connecting sleeve 232 passes through the escape port, and the end of the small spindle 22 remote from the small valve port 211 penetrates the connecting sleeve 232 and is fixedly connected to it. The provision of the escape port makes it easy to securely connect the end of the small spindle 22 remote from the small valve port 211 to the connecting sleeve 232, and the secure connection is made by welding, which is reliable and stable.

2, the drive assembly 23 further includes a bearing 233, a bushing 234, and a second elastic member 235 provided within the connecting sleeve 232. The bearing 233 is fitted to one end of the screw 231, with one side of the bearing 233 and the connecting sleeve 232 being axially limitedly engaged, and the other side of the bearing 233, the bushing 234, the second elastic member 235, and the small spindle 22 being abutted in turn. Fitting the bearing 233 to one end of the screw 231 and limiting the axial engagement of one side of the bearing 233 with the connecting sleeve 232 not only limits the bearing 233, but also prevents the connecting sleeve 232 from rotating when the screw 231 rotates, further preventing rotation of the small spindle 22. The other side of the bearing 233, the bushing 234, the second elastic member 235, and the small spindle 22 are in contact with each other in this order. The provision of the bushing 234 not only prevents the second elastic member 235 from directly contacting the bearing 233, but also acts as a guide. The provision of the second elastic member 235 means that when the electronic expansion valve is closed, the second elastic member 235 is compressed. When the screw 231 moves away from the small valve port 211 (i.e., in the flow rate control state), the elastic force of the second elastic member 235 is released, causing the bushing 234 to move away from the small valve port 211, thereby achieving precise control of the opening of the small valve port 211 and further improving the control accuracy of the small flow rate control. The second elastic member 235 may be a spring.

Specifically, the valve seat member 10 has a flow hole 13, and the large spindle portion 21 has a side opening 214. The side opening 214 is located on one side of the small valve port 211, away from the large valve port 11. Here, in the flow rate adjustment state, the flow hole 13, side opening 214, small valve port 211, and large valve port 11 are sequentially connected to each other. By providing the flow hole 13 and side opening 214, the flow hole 13, side opening 214, small valve port 211, and large valve port 11 can be sequentially connected to each other in the flow rate adjustment state.

Optionally, the large spindle portion 21 includes a main body portion, a small valve seat, and a restricting structure. The small valve seat is disposed within the chamber of the main body portion and has a small valve port 211 provided with a flow control surface. The small spindle 22 is movably disposed within the main body portion, and the small spindle 22 and the small valve seat are engaged to adjust the opening of the small valve port 211, with the restricting structure and one side of the small valve seat away from the small spindle 22 being in restricting engagement. Providing a small valve seat is advantageous for more accurately machining the flow control surface. More preferably, the small valve seat may employ a gasket to form a soft seal.

The valve seat member 10 further includes a valve seat body 14, a large gasket 15, a first outer sealing ring 16, and a second outer sealing ring 17. The large gasket 15 is located within the chamber of the valve seat body 14, and has a large valve port 11. The valve seat body 14 has a flow hole 13. The first outer sealing ring 16 and the second outer sealing ring 17 are fitted to the outer wall of the valve seat body 14, and the flow hole 13 is located between the first outer sealing ring 16 and the second outer sealing ring 17. By positioning the large gasket 15 within the chamber of the valve seat body 14 and the large valve port 11 within the large gasket 15, a better sealing effect is achieved when the large valve port 11 is closed, preventing fluid leakage. The provision of the first outer sealing ring 16 and the second outer sealing ring 17 facilitates a sealed connection between the valve seat member 10 of the electronic expansion valve and the external engagement structure, preventing leakage from the flow hole 13.

As shown in Figures 5 to 7, the sealing rod 222 is cylindrical and is used to engage with the inner wall of the small valve orifice 211 to adjust the opening of the small valve orifice 211. Here, the sealing rod 222 has a fillet 2221 on one end facing the small valve orifice 211. When the sealing rod 222 seals the small valve orifice 211, the abutment position between the sealing rod 222 and the inner wall of the small valve orifice 211 forms an annular sealing line, which is located at the fillet 2221.

When this configuration is adopted, the sealing rod 222 is cylindrical and has a fillet 2221 at one end thereof facing the small valve orifice 211. When the sealing rod 222 seals the small valve orifice 211, the abutment position between the sealing rod 222 and the inner wall of the small valve orifice 211 forms an annular sealing line. By arranging the sealing line to be located at the fillet 2221, when the sealing rod 222 seals the small valve orifice 211 and the small valve orifice 211 draws air, the direction of the force received by the sealing rod 222 is The force is directed away from the small valve port 211, and the magnitude of the force is the product of the pressure strength at the intake port and the area difference between the outer diameter of the sealing rod 222 and the diameter of the sealing line. Compared to the prior art, in this embodiment the sealing rod 222 is cylindrical and the sealing line is located at the fillet of the sealing rod 222. This minimizes the area difference between the outer diameter of the sealing rod 222 and the diameter of the sealing line, thereby optimizing the problem of poor closing of the electronic expansion valve. This electronic expansion valve may be mounted on a mounting base or within a valve body.

Here, the radius of the fillet 2221 is R, and R≦1 mm. Limiting the radius R of the fillet 2221 within the above range not only makes it easier to seal the small valve port 211, but also minimizes the area difference between the outer diameter of the sealing rod 222 and the diameter of the sealing line, minimizing the force applied to the sealing rod 222, thereby optimizing the problem of poor valve closure of the electronic expansion valve. As shown in Figure 7, the area of the area surrounded by the outer diameter of the sealing rod 222 is S5, the area of the area surrounded by the sealing line is S6, and the sealing line is located within the fillet 2221.

As shown in FIG. 5, the spindle member 20 further includes a sealing ring 24, which is disposed within the large spindle portion 21, and the sealing rod 222 passes through the sealing ring 24. The sealing ring 24 is disposed within the large spindle portion 21, and the sealing rod 222 passes through the sealing ring 24, providing a seal for the sealing rod 222 and preventing fluid leakage.

Specifically, the large spindle portion 21 includes a large spindle 215 and a small gasket 216 disposed within the large spindle 215. The small gasket 216 has a small valve port 211 and is made of a soft material. By disposing the small gasket 216 within the large spindle 215, it provides a seal for the small valve port 211, preventing fluid leakage. Furthermore, if the small gasket 216 is made of a soft material, the sealing effect can be improved; specifically, the small gasket 216 may be made of plastic or rubber.

Furthermore, as shown in Figures 8 to 13, the electronic expansion valve further includes a valve sleeve 30 connected to the valve seat member 10, a drive assembly 23 provided within the chamber of the valve seat member 10 and the valve sleeve 30, the region between the structure of the drive assembly 23 located within the valve sleeve 30 and the inner wall of the valve sleeve 30 forming a rotor chamber 50, the drive assembly 23 and the small spindle 22 being drivingly connected, and a balancing passage 60 communicating the rotor chamber 50 with the small valve orifice 211.

When this embodiment is adopted, the balancing passage 60 is provided to connect the rotor chamber 50 and the small valve port 211. When the electronic expansion valve is operating, the pressure at the small valve port 211 and the pressure inside the rotor chamber 50 can always be made equal, ensuring optimal balancing effects inside the electronic expansion valve and avoiding problems with poor valve closure caused by a relatively large pressure difference between the rotor chamber 50 and the small valve port 211. In this embodiment, the drive assembly 23 moves the small spindle 22 in conjunction with the small spindle 22, which adjusts the opening of the small valve port 211 and thereby achieves the function of regulating flow rate. This electronic expansion valve may be mounted on a mounting base or within a valve body.

Here, the valve seat member 10 includes a valve seat ring 18 and a valve seat body 14, the valve sleeve 30, the valve seat ring 18, and the valve seat body 14 are connected in sequence, and the drive assembly 23 includes a nut structure 41, which is located within the valve sleeve 30, and the area between the nut structure 41 and the inner wall of the valve sleeve 30 forms a rotor chamber 50. When the above installation method is adopted, by providing the nut structure 41 within the valve sleeve 30, the area between the nut structure 41 and the inner wall of the valve sleeve 30 forms the rotor chamber 50.

Optionally, the electronic expansion valve further includes a rotor member disposed within the valve sleeve 30, the rotor member being used to drive and rotate the screw assembly 42, with a gap between the rotor member and the inner wall of the valve sleeve 30.

Furthermore, the balancing passage 60 includes a first passage 61, a second passage 62, a third passage 63, and a fourth passage 64, which are connected in sequence, with the first passage 61 located within the nut structure 41, the second passage 62 located within the valve seat ring 18, the third passage 63 located within the screw assembly 42, and the fourth passage 64 located within the small spindle 22. By providing the first passage 61 within the nut structure 41, the second passage 62 within the valve seat ring 18, the third passage 63 within the screw assembly 42, and the fourth passage 64 within the small spindle 22, the rotor chamber 50 and the small valve port 211 are connected via the balancing passage 60, avoiding the problem of poor valve closure caused by a relatively large pressure difference between the rotor chamber 50 and the small valve port 211.

Here, the nut structure 41 includes a nut body 411 and a connecting plate 412. The connecting plate 412 is fitted to the nut body 411 and welded to the valve seat ring 18, with the openings or open slots 4121 in the connecting plate 412 forming the first passage 61. Connecting the connecting plate 412 to the valve seat ring 18 using a welding method is stable and reliable. The openings or open slots 4121 in the connecting plate 412 can both form the first passage 61, thereby achieving communication between the rotor chamber 50 and the first passage 61.

In this embodiment, the valve seat ring 18 includes a guide chamber 181 and a first through-hole 182. The inner wall of the guide chamber 181 has an annular groove 1111. A portion of the large spindle portion 21 is located within the guide chamber 181. The first through-hole 182 and the annular groove 1111 are in communication with each other, and the first through-hole 182 and the annular groove 1111 form the second passage 62. The provision of the guide chamber 181 makes it easy to locate a portion of the large spindle portion 21 within the guide chamber 181. Because the first through-hole 182 and the annular groove 1111 are in communication with each other and the first passage 61 and the second passage 62 are in communication with each other, the pressure within the rotor chamber 50 and the pressure within the annular groove 1111 can be kept the same. The annular groove 1111 is also in communication with the third passage 63. Alternatively, the valve seat ring 18 has a guide chamber 181 and a first through hole 182, with part of the large spindle portion 21 located within the guide chamber 181, and the first through hole 182 forming the second passage 62.

Specifically, the screw 231 is threaded onto the nut structure 41, the connecting sleeve 232 is connected to the small valve core 22, the fourth passage 64 is connected to the chamber within the connecting sleeve 232, and the side wall of the connecting sleeve 232 has a second through-hole 4221, which forms the third passage 63. By adopting the above installation method, the connecting sleeve 232 is connected to the small valve core 22 and the fourth passage 64 is connected to the chamber within the connecting sleeve 232, ensuring that the pressure in the chamber within the connecting sleeve 232 is the same as the fourth passage 64. The installation of the second through-hole 4221 ensures that the pressure within the connecting sleeve 232 is the same as the pressure within the annular groove 1111, thereby maintaining the pressure within the rotor chamber 50 and the fourth passage 64 at the same pressure. Here, the screw assembly 42 includes the screw 231 and the connecting sleeve 232.

In this embodiment, the limiting rod 221 and the large spindle portion 21 are engaged in an axial locking engagement, and the sealing rod 222 is used to engage with the small valve port 211. The limiting rod 221 has a third through hole 3211, and the sealing rod 222 has a fourth through hole 3221, with the third through hole 3211 and the third through hole 3211 forming a fourth passage 64. The outer diameter of the limiting rod 221 is larger than that of the sealing rod 222, and the limiting rod 221 and the large spindle portion 21 are engaged in an axial locking engagement, which provides a limiting effect on the small spindle 22 and limits the range of movement of the small spindle 22. Because the third through hole 3211 and the fourth through hole 3221 are connected, and the fourth through hole 3221 is also connected to the small valve port 211, the pressure in the rotor chamber 50 and the pressure in the small valve port 211 can be kept the same, and communication between the rotor chamber 50 and the small valve port 211 is achieved via the equalization passage 60.

In this embodiment, the spindle member 20 further includes a second inner sealing ring 34, which is located between the outer wall of the large spindle portion 21 and the inner wall of the valve seat member 10. By providing the second inner sealing ring 34, it is possible to ensure a tight seal between the outer wall of the large spindle portion 21 and the inner wall of the valve seat member 10.

As shown in Figures 14 to 16, the electronic expansion valve further includes a large gasket 15 disposed within the valve seat member 10 and having a large valve port 11. The large spindle 215 includes a main body structure 31 and a sealing sleeve 32 connected to each other. The end of the sealing sleeve 32 engages with the large gasket 15 to open and close the large valve port 11. The main body structure 31 and the inner wall of the valve seat member 10 are sealingly engaged. The outer peripheral surface of the main body structure 31 has a radial cross-sectional area S3. When the sealing sleeve 32 abuts against the large gasket 15, a contact surface is formed between the sealing sleeve 32 and the large gasket 15 surrounding the large valve port 11. The outer peripheral area of the contact surface is S2, and the inner peripheral area of the contact surface is S1, where S1 < S3 < S2.

In this embodiment, by connecting the rotor chamber 50 and the small valve port 211 via the balancing passage 60, the fluid pressure intensity on both sides of the spindle member 20 is the same, i.e., both are the fluid pressure intensity within the large valve port 11. Thus, when the large valve port 11 is closed and the fluid flows through the electronic expansion valve from the chamber of the valve seat member 10 to the large valve port 11, the fluid pressure intensity is P1, the fluid pressure received by the spindle member 20 is P1 (S2-S3), and the force is applied in the valve closing direction. When the fluid flows through the electronic expansion valve from the large valve port 11 to the chamber of the valve seat member 10, the fluid pressure intensity is P2, the fluid pressure received by the spindle member 20 is P2 (S3-S1), and the force is applied in the valve closing direction. Therefore, with the above configuration, regardless of the direction of fluid flow within the electronic expansion valve, when the large valve port 11 is closed, the force that the fluid applies to the spindle member 20 is always in the valve closing direction, ensuring the reliability of the electronic expansion valve when closed and preventing internal leakage. This electronic expansion valve may be mounted on a mounting base or within the valve body.

In this embodiment, the large gasket 15 is made of a soft material, and the end face of the large gasket 15 engages with the end of the sealing sleeve 32. In this way, when the sealing sleeve 32 is pressed against the large gasket 15, a recess is formed in the large gasket 15, increasing the contact surface area and improving the sealing effect.

Here, the end face of the sealing sleeve 32 facing the large gasket 15 is an arc-shaped surface 321, and the contact surface is located within the arc-shaped surface 321. By providing the end face of the sealing sleeve 32 facing the large gasket 15 as an arc-shaped surface 321, the large gasket 15 can deform more easily when the valve is closed, increasing the area of the contact surface. Optionally, in a cross section passing through the axis of the sealing sleeve 32, the arc-shaped surface 321 can be divided into symmetrical arcs by an extension line of the outer wall of the main structure 31, ensuring that part of the contact surface is located within the outer peripheral surface of the main structure 31 and the other part is located outside the outer peripheral surface of the main structure 31, thereby ensuring S1 < S3 < S2 and improving the reliability of valve closure.

Furthermore, the main body structure 31 and the sealing sleeve 32 are both cylindrical structures, the main body structure 31, the sealing sleeve 32, and the large valve port 11 are arranged coaxially, the main body structure 31 has an outer diameter D3, the sealing sleeve 32 has an outer diameter D2, and the sealing sleeve 32 has an inner diameter D1, where D1 < D3 < D2.

Specifically, in Figure 14, the area surrounded by the outer periphery of the sealing sleeve 32 is designated S4. During use, when the fluid in the electronic expansion valve flows from the chamber of the valve seat member 10 to the large valve port 11, the pressure intensity at the large valve port 11 is less than P1 and can be considered to be in an atmospheric environment. The upward pressure P1 received by the spindle member 20 is the force P1 exerts on the gap between the lower end face of the sealing sleeve 32 and the large gasket 15, i.e., P1(S4-S2). The downward pressure P1 received by the spindle member 20 is the force P1 exerts on the upper end face of the sealing sleeve 32, i.e., P1(S4-S3). Because S3 < S2, the resultant force of the upward and downward forces is the downward force P1(S2-S3). In this way, the direction of the resultant force matches the valve closing direction, ensuring reliable valve closure. When the fluid flow direction of the electronic expansion valve is from the large valve port 11 to the chamber of the valve seat member 10, the pressure intensity within the chamber of the valve seat member 10 is less than P1 and can be considered to be connected to the external atmospheric environment. The upward pressure P2 experienced by the spindle member 20 is P2S1, and the downward pressure intensity experienced by the spindle member 20 is equal to P2, that is, P2S3. Because S1 < S3, the resultant force of the two is downward P2 (S3 - S1). In this way, the direction of the resultant force and the valve closing direction coincide, ensuring reliable valve closure.

With the above design, the force-receiving direction of the sealing sleeve 32 and the valve closing direction always coincide, regardless of whether gas or liquid enters horizontally or vertically. This avoids the problem of the valve not closing completely due to excessive fluid pressure, which could lead to breakdown, and improves the valve closing reliability of the electronic expansion valve.

As shown in FIG. 15 , the main body structure 31 includes a first sleeve 312 and a second sleeve 313 connected to each other, where the second sleeve 313 and the sealing sleeve 32 are integral. The valve seat member 10 includes a seat ring 18 and a seat body 14 connected to each other, the large gasket 15 is located within the seat body 14, the first sleeve 312 is located within the seat ring 18, and the first sleeve 312 and the seat ring 18 are sealingly engaged. As described above, the separate structure of the main body structure 31 facilitates processing and assembly. The integrated structure of the second sleeve 313 and the sealing sleeve 32 improves structural strength. Optionally, the flow holes 13 can be located in the seat body 14 rather than in the seat ring 18, thereby shortening the length of the seat ring 18 and simplifying its structure, thereby facilitating processing of the seat ring 18.

The above is merely a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art may make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims (26)

An electronic expansion valve,
a valve seat member (10) having a large valve port (11);
A spindle member (20) is provided in the chamber of the valve seat member (10), the spindle member (20) including a large spindle portion (21), a small spindle (22) and a drive assembly (23) , the large spindle portion (21) having a small valve orifice (211) a spindle member (20) having a restricting chamber (212) and a guide hole (213) that are connected to each other, the restricting chamber (212), the guide hole (213), and the small valve port (211) being arranged in that order, the small valve port (211) having a flow regulating surface, one end of the larger opening of the small valve port (211) being separated from the large valve port (11), the small spindle (22) including a restricting rod (221) connected to each other and a sealing rod (222) axially movably arranged in the restricting chamber (212) and passing through the guide hole (213), the drive assembly (23), the small spindle (22), and the large spindle portion (21) are all drivingly connected, the drive assembly (23) and the restricting rod (221) being drivingly connected ;
Equipped with
The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state, wherein in the closed state, the small spindle (22) is inserted into the small valve port (211) to seal the small valve port (211), and the large spindle portion (21) seals the large valve port (11); in the flow rate adjusting state, the large spindle portion (21) seals the large valve port (11), and the small spindle (22) is axially movable to adjust the opening degree of the small valve port (211); and in the fully open state, the large spindle portion (21) avoids the large valve port (11).
Electronic expansion valve. the flow rate adjusting surface is a tapered surface,
In the closed state, the small spindle (22) abuts against the small valve opening (211), and/or the end surface of the large valve opening (11) is a sealing plane (111);
2. The electronic expansion valve according to claim 1, wherein in the closed state, one end of the large spindle portion (21) abuts against the sealing flat surface (111). In the axial direction of the spindle member (20), the restricting chamber (212) has a first stop surface (2121) and a second stop surface (2122) facing each other;
One side of the limiting rod (221) is stop-engaged with the first stop surface (2121);
The small spindle (22) further includes a stop shoulder (223) provided on the side wall of the limiting rod (221),
2. The electronic expansion valve of claim 1 , wherein the stop shoulder (223) is stop-engaged with the second stop surface (2122). The spindle member (20) further includes a first elastic member (12),
4. The electronic expansion valve according to claim 3 , wherein both ends of the first elastic member (12) are abutted against the first stop surface (2121) and the stop shoulder (223), respectively. The outer diameter of the limiting rod (221) is greater than the outer diameter of the sealing rod (222);
The first elastic member (12) is a spring fitted to the limiting rod (221),
5. The electronic expansion valve of claim 4 , wherein the stop shoulder (223) is an annular structure. The drive assembly (23) includes a screw assembly (42);
The screw assembly (42) includes a screw (231) and a connecting sleeve (232),
One end of the connecting sleeve (232) is connected to the small spindle (22);
The screw (231) and the connecting sleeve (232) are in axial limited engagement;
The screw (231) is provided so as to be movable in the axial direction,
The screw (231) can move the small spindle (22) independently within a predetermined stroke in conjunction with the small spindle (22); and
2. The electronic expansion valve according to claim 1 , wherein the screw (231) can move the large spindle portion (21) in conjunction with the small spindle (22). The large spindle portion (21) has an escape port,
The connecting sleeve (232) passes through the escape port,
7. The electronic expansion valve according to claim 6 , wherein one end of the small spindle (22) remote from the small valve port (211) penetrates into the connecting sleeve (232) and is fixedly connected to the connecting sleeve (232). The drive assembly (23) further includes a bearing (233), a bushing (234), and a second elastic member (235) provided in the connecting sleeve (232);
The bearing (233) is fitted to one end of the screw (231),
One side of the bearing (233) and the connecting sleeve (232) are in axial limited engagement;
7. The electronic expansion valve according to claim 6 , wherein the other side of the bearing (233), the bush (234), the second elastic member (235), and the small spindle (22) are abutted in this order. An electronic expansion valve,
a valve seat member (10) having a large valve port (11);
a spindle member (20) provided in a chamber of the valve seat member (10), the spindle member (20) including a large spindle portion (21), a small spindle (22), and a drive assembly (23), the large spindle portion (21) having a small valve port (211) with a flow control surface, one end of a larger opening of the small valve port (211) being remote from the large valve port (11), the drive assembly (23), the small spindle (22), and the large spindle portion (21) all being drivingly connected;
Equipped with
The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state, wherein in the closed state, the small spindle (22) is inserted into the small valve port (211) to seal the small valve port (211), and the large spindle portion (21) seals the large valve port (11); in the flow rate adjusting state, the large spindle portion (21) seals the large valve port (11), and the small spindle (22) is provided axially movable to adjust the opening degree of the small valve port (211); and in the fully open state, the large spindle portion (21) avoids the large valve port (11);
The valve seat member (10) has a flow hole (13),
The large spindle portion (21) has a side opening (214),
the side opening (214) is located on one side of the small valve opening (211) away from the large valve opening (11), and in the flow rate adjusting state, the communication hole (13), the side opening (214), the small valve opening (211) and the large valve opening (11) are sequentially communicated with each other;
The valve seat member (10) includes a valve seat body (14), a large gasket (15), a first outer sealing ring (16), and a second outer sealing ring (17);
The large gasket (15) is located in a chamber of the valve seat body (14),
The large gasket (15) has the large valve port (11),
The valve seat body (14) has the flow hole (13),
The first outer sealing ring (16) and the second outer sealing ring (17) are fitted to the outer wall of the valve seat body (14),
The flow hole (13) is located between the first outer sealing ring (16) and the second outer sealing ring (17).
Electronic expansion valve. The sealing rod (222) is cylindrical;
The sealing rod (222) is used to engage with the inner wall of the small valve orifice (211) to adjust the opening degree of the small valve orifice (211);
7. The electronic expansion valve according to claim 6, wherein one end of the sealing rod (222) facing the small valve port (211) has a fillet (2221), and when the sealing rod (222) seals the small valve port (211), the abutment position between the sealing rod (222) and the inner wall of the small valve port ( 211 ) forms an annular sealing line, and the sealing line is located at the fillet (2221). The electronic expansion valve of claim 10 , wherein the fillet (2221) has a radius R, and R≦1 mm. The spindle member (20) further includes a sealing ring (24);
The sealing ring (24) is provided in the large spindle portion (21),
11. The electronic expansion valve of claim 10 , wherein the sealing rod (222) passes through the sealing ring (24). An electronic expansion valve,
a valve seat member (10) having a large valve port (11);
a spindle member (20) provided in a chamber of the valve seat member (10), the spindle member (20) including a large spindle portion (21), a small spindle (22), and a drive assembly (23), the large spindle portion (21) having a small valve port (211) with a flow control surface, one end of a larger opening of the small valve port (211) being remote from the large valve port (11), the drive assembly (23), the small spindle (22), and the large spindle portion (21) all being drivingly connected;
Equipped with
The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state, wherein in the closed state, the small spindle (22) is inserted into the small valve port (211) to seal the small valve port (211), and the large spindle portion (21) seals the large valve port (11); in the flow rate adjusting state, the large spindle portion (21) seals the large valve port (11), and the small spindle (22) is provided axially movable to adjust the opening degree of the small valve port (211); and in the fully open state, the large spindle portion (21) avoids the large valve port (11);
The large spindle portion (21) includes a large spindle (215) and a small gasket (216) provided within the large spindle (215);
The small gasket (216) has the small valve port (211),
The small gasket (216) is made of a soft material.
Electronic expansion valve. An electronic expansion valve,
a valve seat member (10) having a large valve port (11);
a spindle member (20) provided in a chamber of the valve seat member (10), the spindle member (20) including a large spindle portion (21), a small spindle (22), and a drive assembly (23), the large spindle portion (21) having a small valve port (211) with a flow control surface, one end of a larger opening of the small valve port (211) being remote from the large valve port (11), the drive assembly (23), the small spindle (22), and the large spindle portion (21) all being drivingly connected;
a valve sleeve (30) connected to the valve seat member (10);
a drive assembly (23) disposed within the chamber of the valve seat member (10) and the valve sleeve (30), wherein an area between a structure of the drive assembly (23) located within the valve sleeve (30) and an inner wall of the valve sleeve (30) forms a rotor chamber (50);
a balancing passage (60) communicating between the rotor chamber (50) and the small valve port (211);
Equipped with
The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state, wherein in the closed state, the small spindle (22) is inserted into the small valve port (211) to seal the small valve port (211), and the large spindle portion (21) seals the large valve port (11); in the flow rate adjusting state, the large spindle portion (21) seals the large valve port (11), and the small spindle (22) is axially movable to adjust the opening degree of the small valve port (211); and in the fully open state, the large spindle portion (21) avoids the large valve port (11).
Electronic expansion valve. The valve seat member (10) includes a valve seat ring (18) and a valve seat body (14);
The valve sleeve (30), the valve seat ring (18) and the valve seat body (14) are connected in sequence;
The drive assembly (23) includes a nut structure (41);
The nut structure (41) is located within the valve sleeve (30);
15. The electronic expansion valve of claim 14 , wherein the area between the nut structure (41) and the inner wall of the valve sleeve (30) forms the rotor chamber (50). The balancing passage (60) includes a first passage (61), a second passage (62), a third passage (63) and a fourth passage (64) that are connected in sequence,
16. The electronic expansion valve according to claim 15, wherein the first passage (61) is located within the nut structure (41), the second passage (62) is located within the valve seat ring (18), the third passage (63) is located within a screw assembly (42 ) included in the drive assembly (23) , and the fourth passage (64) is located within the small spindle ( 22 ). The nut structure (41) includes a nut body (411) and a connecting plate (412),
The connecting plate (412) is fitted to the nut body (411),
The connecting plate (412) and the seat ring (18) are welded together;
17. The electronic expansion valve of claim 16 , wherein an aperture or open slot (4121) in the connecting plate (412) forms the first passage (61). The seat ring (18) has a guide chamber (181) and a first through hole (182) therein.
The inner wall of the guide chamber (181) has an annular groove (1111),
A portion of the large spindle portion (21) is located within the guide chamber (181);
The first through hole (182) and the annular groove (1111) are in communication with each other,
The first through hole (182) and the annular groove (1111) form the second passage (62); or
The seat ring (18) has a guide chamber (181) and a first through hole (182) therein.
A portion of the large spindle portion (21) is located within the guide chamber (181);
17. The electronic expansion valve of claim 16 , wherein the first through hole (182) defines the second passage (62). The screw assembly (42) includes a screw (231) and a connecting sleeve (232),
The screw (231) is threadedly engaged with the nut structure (41),
The connecting sleeve (232) is connected to the small spindle (22),
The fourth passage (64) communicates with a chamber in the connecting sleeve (232);
The side wall of the connecting sleeve (232) has a second through hole (4221),
The electronic expansion valve according to claim 16 , wherein the second through hole (4221) forms the third passage (63). The small spindle (22) includes a limiting rod (221) and a sealing rod (222) connected to each other;
The limiting rod (221) and the large spindle part (21) are engaged in an axial locking engagement;
The sealing rod (222) is used to engage the valve orifice (211),
The limiting rod (221) has a third through hole (3211),
The sealing rod (222) has a fourth through hole (3221) therein;
The electronic expansion valve according to claim 16 , wherein the third through hole (3211) and the fourth through hole (3221) form the fourth passage (64). The spindle member (20) further includes a second inner sealing ring (34);
15. The electronic expansion valve according to claim 14 , wherein the second inner sealing ring (34) is located between the outer wall of the large spindle portion (21) and the inner wall of the valve seat member (10). An electronic expansion valve,
a valve seat member (10) having a large valve port (11);
a spindle member (20) provided in a chamber of the valve seat member (10), the spindle member (20) including a large spindle portion (21), a small spindle (22), and a drive assembly (23), the large spindle portion (21) having a small valve port (211) with a flow control surface, one end of a larger opening of the small valve port (211) being remote from the large valve port (11), the drive assembly (23), the small spindle (22), and the large spindle portion (21) all being drivingly connected;
a large gasket (15) provided in the valve seat member (10) and having the large valve port (11);
Equipped with
The electronic expansion valve has a closed state, a flow rate adjusting state, and a fully open state, wherein in the closed state, the small spindle (22) is inserted into the small valve port (211) to seal the small valve port (211), and the large spindle portion (21) seals the large valve port (11); in the flow rate adjusting state, the large spindle portion (21) seals the large valve port (11), and the small spindle (22) is provided axially movable to adjust the opening degree of the small valve port (211); and in the fully open state, the large spindle portion (21) avoids the large valve port (11);
The large spindle portion (21) includes a large spindle (215), and the large spindle (215) includes a body structure (31) and a sealing sleeve (32) connected to each other;
The end of the sealing sleeve (32) is used to engage with the large gasket (15) to open and close the large valve port (11);
The body structure (31) and the inner wall of the valve seat member (10) are in sealing engagement;
The radial cross-sectional area of the outer circumferential surface of the main body structure (31) is S3;
When the sealing sleeve (32) is abutted against the large gasket (15), a contact surface is formed between the sealing sleeve (32) and the large gasket (15) surrounding the large valve port (11);
The area of the outer periphery of the contact surface is S2, and the area of the inner periphery of the contact surface is S1, where S1<S3<S2.
Electronic expansion valve. The large gasket (15) is made of a soft material,
23. The electronic expansion valve according to claim 22 , wherein an end face of the large gasket (15) is engaged with an end of the sealing sleeve (32). The end surface of the sealing sleeve (32) facing the large gasket (15) is an arcuate surface (321);
24. The electronic expansion valve of claim 23 , wherein the contact surface is located within the arcuate surface (321). The body structure (31) and the sealing sleeve (32) are both cylindrical structures;
The main body structure (31), the sealing sleeve (32) and the large valve port (11) are arranged coaxially;
23. The electronic expansion valve of claim 22, wherein the outer diameter of the body structure (31) is D3, the outer diameter of the sealing sleeve (32) is D2, and the inner diameter of the sealing sleeve ( 32 ) is D1, where D1<D3<D2. The body structure (31) includes a first sleeve (312) and a second sleeve (313) connected to each other;
23. The electronic expansion valve according to claim 22, wherein the second sleeve (313) and the sealing sleeve (32) are of an integral structure, the valve seat member (10) includes a valve seat ring (18) and a valve seat body (14) connected to each other, the large gasket (15) is located in the valve seat body (14), the first sleeve (312) is located in the valve seat ring (18), and the first sleeve (312) and the valve seat ring ( 18 ) are sealingly engaged with each other.