Electronic expansion valve

Abstract

An electronic expansion valve (100). The electronic expansion valve (100) comprises a valve body assembly (10), a valve stem assembly (20), a valve core assembly (30) and an elastic element (40). The valve body assembly (10) has a valve port (101). The valve stem assembly (20) and the valve core assembly (30) are mounted within the valve body assembly (10), and the valve stem assembly (20) is movably connected to the valve core assembly (30). The elastic element (40) is arranged between the valve stem assembly (20) and the valve core assembly (30), and two ends of the elastic element (40) are connected to the valve stem assembly (20) and the valve core assembly (30), respectively. The electronic expansion valve (100) has a fully closed state. When the electronic expansion valve (100) is in the fully closed state, the valve stem assembly (20) compresses the elastic element (40), and a clearance is formed between the valve stem assembly (20) and the valve core assembly (30) in the axial direction.

Description

Electronic expansion valve

[0001] Related applications

[0002] This application claims priority to Chinese patent application filed on February 8, 2025, with application number 202520345637.8, entitled "Electronic Expansion Valve", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of valve technology, and in particular to an electronic expansion valve. Background Technology

[0004] In related technologies, an electronic expansion valve includes a screw, a bearing, a valve needle, and a bearing sleeve. The valve needle is fixedly connected to one end of the bearing sleeve and cooperates with the bearing sleeve to limit the bearing installation inside the bearing sleeve. The screw passes through the bearing sleeve and is connected to the inner ring of the bearing. In this way, the screw, bearing, valve needle, and bearing sleeve are connected as a whole and can move as a whole along the axial direction of the electronic expansion valve. The flow rate at the valve port is adjusted through the valve needle.

[0005] In related technologies, the valve needle abuts against the valve port when the valve is closed. However, since the screw is usually driven by a stepper motor, due to the characteristics of the stepper motor, even when the motor rotor drives the screw to rotate until the valve needle abuts against the valve port and the screw can no longer move in the valve-closing direction, the motor continues to input pulses. This causes the motor rotor to drive the screw to rotate in the opposite direction by a certain angle, that is, the rotor and screw will move a certain distance away from the valve port. As a result, the valve needle will move a certain distance away from the valve port synchronously with the screw, causing the valve needle to disengage from the valve port, increasing the risk of internal leakage in the electronic expansion valve. Summary of the Invention

[0006] Therefore, it is necessary to provide an electronic expansion valve.

[0007] This application provides an electronic expansion valve, which includes a valve body assembly, a valve stem assembly, and a valve core assembly. The valve body assembly has a valve port. The valve stem assembly and the valve core assembly are installed within the valve body assembly and are movably connected. The valve stem assembly can drive the valve core assembly to move axially toward or away from the valve port. The electronic expansion valve also includes an elastic element disposed between the valve stem assembly and the valve core assembly, with its two ends connected to the valve stem assembly and the valve core assembly respectively, for applying a force to the valve core assembly toward the valve port. The electronic expansion valve has a fully closed state. When the electronic expansion valve is in the fully closed state, the valve stem assembly compresses the elastic element, and there is an axial gap between the valve stem assembly and the valve core assembly.

[0008] In one embodiment, in the fully closed state, the axial gap between the valve stem assembly and the valve core assembly is h, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.2.

[0009] In one embodiment, the valve core assembly includes a valve needle and a bearing sleeve. The valve needle is fixedly connected to the bearing sleeve and forms an assembly cavity with the bearing sleeve. A limiting portion is provided at the end of the inner wall of the assembly cavity away from the valve needle. The valve stem assembly includes a screw and a bearing. The bearing is movably installed in the assembly cavity. One end of the screw extends into the assembly cavity and is fixedly connected to the inner ring of the bearing. The limiting portion can axially stop at one end of the bearing. The two ends of the elastic element apply force to the bearing and the valve needle, respectively. When the electronic expansion valve is in the fully closed state, an axial gap h is formed between the limiting portion and the bearing.

[0010] In one embodiment, the electronic expansion valve further includes a gasket disposed between the elastic element and the bearing, with both ends of the gasket abutting against the elastic element and the bearing, respectively.

[0011] In one embodiment, the valve needle has a mounting hole at one end near the assembly cavity, and at least a portion of the elastic element is disposed within the mounting hole.

[0012] In one embodiment, the electronic expansion valve further has a fully open state in which the valve core assembly moves to its limit in a direction away from the valve port, and when the electronic expansion valve is in the fully open state, the elastic element has a preset deformation h.

[0013] In one embodiment, the elastic element is configured as a leaf spring, and when the electronic expansion valve is in the fully open state, the gap between the end face of the elastic element near the end of the screw and the end face of the screw on the portion of the elastic element that abuts against the valve needle is equal to the size h of the preset deformation of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.2.

[0014] In one embodiment, the elastic element is configured as a disc spring, and when the electronic expansion valve is in the fully open state, the gap between the end face of the screw and the end face of the valve needle is equal to the size h of the preset deformation of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.2.

[0015] In one embodiment, the elastic element is configured as a helical spring, and the electronic expansion valve further includes a gasket. One end of the elastic element is connected to the gasket so that the gasket can abut against the bearing. When the electronic expansion valve is in the fully open state, the gap between the end face of the gasket near the valve needle and the end face of the valve needle on the part of the gasket that abuts against the bearing is equal to the size h of the preset deformation of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.2.

[0016] In one embodiment, the valve body assembly is provided with an upper stop mating part, and the valve core assembly is provided with an upper stop part. When the electronic expansion valve is in the fully open state, the upper stop part abuts against the upper stop mating part.

[0017] In one embodiment, the electronic expansion valve further includes a support spring sleeved on the outer periphery of the valve core assembly for applying a force to the valve core assembly toward a direction away from the valve port.

[0018] In one embodiment, the force exerted by the support spring on the valve core assembly is less than the force exerted by the elastic element on the valve core assembly.

[0019] In one embodiment, when the electronic expansion valve is in the fully closed state, the valve core assembly abuts against and seals the valve port.

[0020] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0021] To better describe and illustrate embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and / or examples, or the best mode of these inventions as currently understood.

[0022] Figure 1 is a cross-sectional view (fully open state) of an electronic expansion valve according to an embodiment of this application.

[0023] Figure 2 is an enlarged view of the electronic expansion valve A in Figure 1.

[0024] Figure 3 is a cross-sectional view (fully closed state) of an electronic expansion valve according to an embodiment of this application.

[0025] Figure 4 is an enlarged view of the electronic expansion valve B in Figure 3.

[0026] Figure 5 is a cross-sectional view (fully open state) of an electronic expansion valve according to an embodiment of this application.

[0027] Figure 6 is a cross-sectional view (fully closed state) of an electronic expansion valve according to an embodiment of this application.

[0028] Figure 7 is a cross-sectional view (fully open state) of an electronic expansion valve according to an embodiment of this application.

[0029] Figure 8 is a cross-sectional view (fully closed state) of an electronic expansion valve according to an embodiment of this application.

[0030] Figure 9 is a cross-sectional view (springback state) of an electronic expansion valve according to an embodiment of this application.

[0031] Symbols in the diagram: 100, Electronic expansion valve; 10, Valve body assembly; 101, Valve port; 11, Upper stop mating part; 20, Valve stem assembly; 21, Screw; 22, Bearing; 30, Valve core assembly; 301, Assembly cavity; 302, Mounting hole; 31, Valve needle; 32, Bearing sleeve; 321, Limiting part; 322, Upper stop part; 40, Elastic element; 50, Gasket; 60, Support spring. Detailed Implementation

[0032] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0033] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0037] In related technologies, an electronic expansion valve includes a screw, a bearing, a valve needle, and a bearing sleeve. The valve needle is fixedly connected to one end of the bearing sleeve and cooperates with the bearing sleeve to limit the bearing installation inside the bearing sleeve. The screw passes through the bearing sleeve and is connected to the inner ring of the bearing. In this way, the screw, bearing, valve needle, and bearing sleeve are connected as a whole and can move as a whole along the axial direction of the electronic expansion valve. The flow rate at the valve port is adjusted through the valve needle.

[0038] In related technologies, the valve needle abuts against the valve port when the valve is closed. However, since the screw is typically driven by a stepper motor, due to the characteristics of the stepper motor, even when the motor rotor drives the screw to rotate until the valve needle abuts against the valve port and the screw can no longer move in the valve-closing direction, the motor continues to input pulses. This causes the motor rotor to drive the screw to rotate in the opposite direction by a certain angle, meaning that the rotor and screw will move a certain distance away from the valve port. As a result, the valve needle will move a certain distance away from the valve port synchronously with the screw, causing the valve needle to disengage from the valve port and increasing the risk of internal leakage in the electronic expansion valve.

[0039] Please refer to Figures 1-9. To address the problem of internal leakage caused by the springback of the motor rotor in electronic expansion valves in related technologies, this application provides an electronic expansion valve 100. The electronic expansion valve 100 includes a valve body assembly 10, a valve stem assembly 20, and a valve core assembly 30. The valve body assembly 10 has a valve port 101. The valve stem assembly 20 and the valve core assembly 30 are installed inside the valve body assembly 10. The valve stem assembly 20 and the valve core assembly 30 are movably connected, and the valve stem assembly 20 can drive the valve core assembly 30 to move axially toward or away from the valve port 101, thereby realizing the flow regulation of the valve port 101 by the valve core assembly 30.

[0040] Please refer to Figures 1-9. The electronic expansion valve 100 provided in this application also includes an elastic element 40. The elastic element 40 is disposed between the valve stem assembly 20 and the valve core assembly 30, and its two ends are respectively connected to the valve stem assembly 20 and the valve core assembly 30, for applying a force to the valve core assembly 30 toward the valve port 101. The electronic expansion valve 100 has a fully open state and a fully closed state. When the electronic expansion valve 100 is in the fully open state, the valve core assembly 30 moves to its limit away from the valve port 101, and the valve port 101 has its maximum opening. At this time, the elastic element 40 has a preset deformation that can be deformed. When the electronic expansion valve 100 is in the fully closed state, the valve stem assembly 20 compresses the elastic element 40, and there is an axial gap between the valve stem assembly 20 and the valve core assembly 30.

[0041] It is understood that this application provides an elastic element 40 between the valve stem assembly 20 and the valve core assembly 30. When the electronic expansion valve 100 is fully closed, the elastic element 40 is compressed by the valve stem assembly 20, causing deformation. The deformation of the elastic element 40 is converted into an axial gap between the valve stem assembly 20 and the valve core assembly 30. Subsequently, when the rotor rotates in the reverse direction and springs back, the elastic element 40 can recover accordingly. At the same time, the axial gap between the valve stem assembly 20 and the valve core assembly 30 can compensate for the distance the valve stem assembly 20 moves away from the valve port 101. This avoids the situation in related technologies where, after the rotor rotates in the reverse direction after the valve is fully closed, the valve core assembly 30 moves upward along with the valve stem assembly 20. In other words, this application can ensure that after the rotor rotates in the reverse direction after the valve is fully closed, the valve stem assembly 20 moves upward while the position of the valve core assembly 30 remains unchanged. This ensures stable cooperation between the valve core assembly 30 and the valve port 101 and prevents internal leakage of the electronic expansion valve 100.

[0042] In the fully closed state, the axial gap between the valve stem assembly 20 and the valve core assembly 30 is h, while in the fully open state, the preset deformation of the elastic element 40 is also h.

[0043] Specifically, the electronic expansion valve 100 also has a pre-open valve (pre-close valve) state. It should be noted that the pre-open valve (pre-close valve) state refers to the state when the valve core assembly 30 just abuts against the valve port 101. Taking the switch from the fully open state to the fully closed state as an example, the rotor rotates in the direction of closing the valve, driving the valve stem assembly 20 to move axially in the direction of closing the valve until the valve core assembly 30 just abuts against the valve port 101. This state is the pre-close valve state. During the process of switching from the fully open state to the pre-close valve state, the magnitude h of the preset deformation of the elastic element 40 remains unchanged. That is, the elastic element 40 is not further compressed by the valve stem assembly 20. In the pre-close valve state, the elastic element 40 still maintains the preset deformation h. Subsequently, the rotor rotates further toward the valve-closing direction, causing the valve stem assembly 20 to move further axially toward the valve port 101. At this time, the valve core assembly 30 abuts against the valve port 101, and the position of the valve core assembly 30 remains unchanged. The valve stem assembly 20 continues to move downward to further compress the elastic element 40 until the valve stem assembly 20 can no longer move toward the valve port 101. The distance h that the valve stem assembly 20 can move axially toward the valve port 101 from the pre-closed state to the fully closed state is the magnitude h of the preset deformation of the elastic element 40, which is also the distance that the elastic element 40 can be compressed by the valve stem assembly 20 from the pre-closed state to the fully closed state. Therefore, it can be understood that when the valve stem assembly 20 and the valve core assembly 30 are in the fully closed state, the axial gap h between them or the preset deformation h of the elastic element 40 is the distance that the valve stem assembly 20 can move from the pre-open (pre-closed) state to the fully closed state.

[0044] Furthermore, the stroke of the valve core assembly 30 is H, where 0 < h / H ≤ 0.2. By reasonably setting the value of h, it is ensured that the distance the valve stem assembly 20 moves when the rotor rebounds does not exceed the preset deformation of the elastic element 40, thereby ensuring that the position of the valve core assembly 30 is not affected by the movement of the valve stem assembly 20, and further reducing the probability of internal leakage in the electronic expansion valve 100.

[0045] It should be noted that the stroke of the valve core assembly 30 is the distance that the valve core assembly 30 moves from the fully open position to the fully closed position.

[0046] As shown in Figures 1 and 2, the valve body assembly 10 is provided with an upper stop mating part 11, and the valve core assembly 30 is provided with an upper stop part 322. When the electronic expansion valve 100 is in the fully open state, the upper stop part 322 abuts against the upper stop mating part 11. In this way, an upper stop is achieved when the valve core assembly 30 moves axially. Here, the upper stop part 322 can be formed by the end face of the bearing sleeve 32 away from the valve port 101.

[0047] As shown in Figures 3 and 4, when the electronic expansion valve 100 is in the fully closed state, the valve core assembly 30 abuts against and seals the valve port 101, preventing the valve stem assembly 20 from moving axially towards the valve port 101. Thus, by directly abutting against the valve port 101, the valve core assembly 30 not only achieves a lower stop when moving axially, but also closes the valve port 101, ensuring that no flow passes through the electronic expansion valve 100 when it is closed.

[0048] In one embodiment, as shown in Figures 1-9, the valve core assembly 30 includes a valve needle 31 and a bearing sleeve 32. The valve needle 31 is fixedly connected to the bearing sleeve 32, and together they form an assembly cavity 301. A limiting portion 321 is provided at the end of the inner wall of the assembly cavity 301 away from the valve needle 31. Here, the valve needle 31 and the bearing sleeve 32 can be separate or integrated. The valve stem assembly 20 includes a screw 21 and a bearing 22. The bearing 22 is movably installed within the assembly cavity 301. One end of the screw 21 extends into the assembly cavity 301 and is fixedly connected to the inner ring of the bearing 22. The limiting portion 321 can axially stop at one end of the bearing 22. Forces are applied to the bearing 22 and the valve needle 31 at both ends of the elastic element 40, respectively. When the electronic expansion valve 100 is in the fully closed state, an axial gap h is formed between the limiting portion 321 and the bearing 22.

[0049] It is understood that the elastic element 40 in this embodiment generates a preload after assembly, causing the valve needle 31 and the bearing 22 to tend to move away from each other. In the fully open state, as shown in Figures 2, 5, and 7, the bearing 22 is tightly abutted against the limiting part 321 under the action of the preload of the elastic element 40 to achieve limiting, ensuring the reliability of the preload of the elastic element 40. Furthermore, due to the existence of a preset deformation amount on the elastic element 40, that is, there is a gap between the screw 21 and the valve needle 31 that allows the screw 21 and the bearing 22 to move. During the closing process of the electronic expansion valve 100, the valve stem assembly 20 first drives the valve core assembly 30 to move until the valve needle 31 just abuts against the valve port 101. At this time, it is in the pre-closed state, and the elastic element 40 still maintains the preset deformation amount h. After that, the axial movement of the valve needle 31 is constrained, while the screw 21 can still continue to move and can drive the bearing 22 to further compress the elastic element 40 until the screw 21 can no longer move down to form the fully closed state of the electronic expansion valve 100. At this time, as shown in Figures 4, 6 and 8, during the process of the screw 21 moving from the pre-closed valve state to the fully closed state, the distance it moves axially is equal to the preset deformation of the elastic element 40 reduced by the screw 21. That is, the maximum distance the screw 21 moves axially is equal to the magnitude of the preset deformation of the elastic element 40. Furthermore, since the bearing sleeve 32 and the valve needle 31 are fixedly connected, the magnitude of the preset deformation of the elastic element 40 reduced by the screw 21 can be transferred to the gap between the limiting part 321 and the bearing 22. This gap provides space for the screw 21 to move upward when the rotor rebounds or the valve is opened.

[0050] Figure 9 shows the state of the electronic expansion valve 100 when it rebounds. When the screw 21 rotates upward due to the rotor's rebound, the elastic element 40 returns to its original position, maintaining a preload on the screw 21 and the valve needle 31. That is, during the rotor's rebound, the valve needle 31 is still subjected to a downward preload from the elastic element 40, ensuring a tight fit with the valve port 101 and preventing leakage. The gap h1 between the screw 21 and the valve needle 31, and the gap h2 between the bearing 22 and the limiting part 321, satisfy h1 + h2 = h.

[0051] It should be noted that this example uses a disc spring as the elastic element 40. As shown in Figures 7 and 8, when the electronic expansion valve 100 is fully open, the elastic element 40 abuts against the bearing 22 and the valve needle 31 respectively through its axial edges. Due to the disc spring structure, there is a gap between the end face of the screw 21 and the end face of the valve needle 31, and the size of this gap is equal to the preset deformation h of the elastic element 40, where 0 < h / H ≤ 0.2. Simultaneously, the screw 21 can directly abut against the valve needle 31 in the fully closed state. Therefore, when springback occurs, the gap generated by the movement of the screw 21 exists between the screw 21 and the valve needle 31.

[0052] In other embodiments, the elastic element 40 can also be configured as a leaf spring as shown in Figures 5 and 6. When the electronic expansion valve 100 is fully open, the elastic element 40 abuts against the bearing 22 and the valve needle 31 respectively through its two axial end faces. Based on the structure of the leaf spring, there is a gap between the end face of the elastic element 40 near the screw 21 and the end face of the screw 21 on the part of the elastic element 40 that abuts against the valve needle 31, and the size of this gap is equal to the size h of the preset deformation of the elastic element 40, where 0 < h / H ≤ 0.2. At the same time, the screw 21 can abut against the elastic element 40 when it is fully closed. Therefore, when rebound occurs, the gap generated by the movement of the screw 21 exists between the screw 21 and the elastic element 40.

[0053] Of course, the elastic element 40 can also be configured as a helical spring as shown in Figures 1-4.

[0054] Furthermore, in one embodiment, as shown in Figures 1-4, the electronic expansion valve 100 further includes a gasket 50, which is disposed between the elastic element 40 and the bearing 22, with both ends of the gasket 50 abutting against the elastic element 40 and the bearing 22, respectively. That is, one end of the elastic element 40 is connected to the valve stem assembly 20 through abutting against the gasket 50. This improves the reliability of the fit between the elastic element 40 and the bearing 22, preventing the elastic element 40 from intruding into the bearing 22 and causing the bearing 22 to seize. In addition, the elastic element 40 can also directly apply force to the inner or outer ring of the bearing 22.

[0055] When the elastic element 40 is configured as a helical spring as shown in Figures 1-4, it can typically cooperate with the gasket 50 to reduce the risk of jamming. One end of the elastic element 40 is connected to the gasket 50 so that the gasket 50 can abut against the bearing 22. When the electronic expansion valve 100 is fully open, due to the elastic force of the elastic element 40, a gap exists between the end face of the gasket 50 near the valve needle 31 and the end face of the valve needle 31 at the point where they abut against the bearing 22. This gap is equal to the preset deformation h of the elastic element 40, where 0 < h / H ≤ 0.2. Simultaneously, in the fully closed state, the gasket 50 compresses the elastic element 40, thus tightly abutting against the end of the valve needle 31. Therefore, if a rebound occurs in the fully closed state, the gap created by the movement of the screw 21 and the bearing 22 exists between the gasket 50 and the valve needle 31.

[0056] To improve the reliability of the elastic element 40 after assembly, in one embodiment, as shown in Figures 1-6, the valve needle 31 has a mounting hole 302 at one end near the assembly cavity 301, and at least a portion of the elastic element 40 is disposed within the mounting hole 302. Thus, the mounting hole 302 can provide a certain limiting effect on the elastic element 40, facilitating its installation and deformation.

[0057] In one embodiment, as shown in Figures 1 and 3, the electronic expansion valve 100 further includes a support spring 60, which is sleeved on the outer periphery of the valve core assembly 30 and is used to apply a force to the valve core assembly 30 in a direction away from the valve port 101. That is, the support spring 60 is always in a compressed state during operation.

[0058] Furthermore, the screw 21 has external threads, while the portion of the valve body assembly 10 that threads with the screw 21 has internal threads. In this embodiment, the force applied by the support spring 60 to the valve core assembly 30 can be transmitted to the screw 21, ensuring that the upper end face of the external thread flange always abuts against the lower end face of the internal thread flange. This eliminates the gap between the upper end face of the external thread flange and the lower end face of the internal thread flange, preventing thread movement due to pressure differential, friction, and gravity. In other words, the screw 21 of the electronic expansion valve 100 will not wobble during circumferential rotation due to thread clearance, pressure differential, friction, and gravity, thus avoiding collisions and effectively eliminating mechanical noise.

[0059] Furthermore, the force exerted by the support spring 60 on the valve core assembly 30 is less than the force exerted by the elastic element 40 on the valve core assembly 30. This prevents the valve core assembly 30 from moving upwards due to the greater force exerted by the support spring 60 after the rotor rebounds and drives the screw 21 upwards. This further improves the reliability of the valve core assembly 30's seal on the valve port 101 in the closed state and prevents internal leakage.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. An electronic expansion valve, comprising a valve body assembly, a valve stem assembly, and a valve core assembly, wherein the valve body assembly has a valve port, the valve stem assembly and the valve core assembly are mounted within the valve body assembly, the valve stem assembly and the valve core assembly are movably connected, and the valve stem assembly is capable of driving the valve core assembly to move axially toward or away from the valve port; Its features are, The electronic expansion valve further includes an elastic element disposed between the valve stem assembly and the valve core assembly, with both ends of the elastic element connected to the valve stem assembly and the valve core assembly respectively, for applying a force to the valve core assembly toward the valve port. The electronic expansion valve has a fully closed state. When the electronic expansion valve is in the fully closed state, the valve stem assembly compresses the elastic element, and there is an axial gap between the valve stem assembly and the valve core assembly.

2. The electronic expansion valve according to claim 1, wherein, In the fully closed state, the axial gap between the valve stem assembly and the valve core assembly is h, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.

2.

3. The electronic expansion valve according to claim 1, wherein, The valve core assembly includes a valve needle and a bearing sleeve. The valve needle is fixedly connected to the bearing sleeve and forms an assembly cavity with the bearing sleeve. A limiting part is provided at the end of the inner wall of the assembly cavity away from the valve needle. The valve stem assembly includes a screw and a bearing. The bearing is movably mounted in the assembly cavity. One end of the screw extends into the assembly cavity and is fixedly connected to the inner ring of the bearing. The limiting part can stop axially at one end of the bearing. The two ends of the elastic element apply force to the bearing and the valve needle respectively. When the electronic expansion valve is in the fully closed state, a gap h is formed axially between the limiting part and the bearing.

4. The electronic expansion valve according to claim 3, wherein, The electronic expansion valve also includes a gasket, which is disposed between the elastic element and the bearing, and the two ends of the gasket respectively abut against the elastic element and the bearing.

5. The electronic expansion valve according to claim 3, wherein, The valve needle has a mounting hole at one end near the assembly cavity, and at least a portion of the elastic element is disposed within the mounting hole.

6. The electronic expansion valve according to claim 3, wherein, The electronic expansion valve also has a fully open state in which the valve core assembly moves to its limit in a direction away from the valve port, and when the electronic expansion valve is in the fully open state, the elastic element has a preset deformation h.

7. The electronic expansion valve according to claim 6, wherein, The elastic element is configured as a leaf spring, and when the electronic expansion valve is in the fully open state, the gap between the end face of the elastic element near the end of the screw and the end face of the screw on the part of the elastic element that abuts against the valve needle is equal to the size h of the preset deformation of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.

2.

8. The electronic expansion valve according to claim 6, wherein, The elastic element is configured as a disc spring, and when the electronic expansion valve is in the fully open state, the gap between the end face of the screw and the end face of the valve needle is equal to the preset deformation h of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.

2.

9. The electronic expansion valve according to claim 6, wherein, The elastic element is configured as a helical spring, and the electronic expansion valve further includes a gasket. One end of the elastic element is connected to the gasket so that the gasket can abut against the bearing. When the electronic expansion valve is in the fully open state, the gap between the end face of the gasket near the valve needle and the end face of the valve needle on the part of the gasket that abuts against the bearing is equal to the size h of the preset deformation of the elastic element, and the stroke of the valve core assembly is H, where 0 < h / H ≤ 0.

2.

10. The electronic expansion valve according to claim 6, wherein, The valve body assembly is provided with an upper stop mating part, and the valve core assembly is provided with an upper stop part. When the electronic expansion valve is in the fully open state, the upper stop part abuts against the upper stop mating part.

11. The electronic expansion valve according to claim 1, wherein, The electronic expansion valve also includes a support spring, which is sleeved on the outer periphery of the valve core assembly and is used to apply a force to the valve core assembly to move it away from the valve port.

12. The electronic expansion valve according to claim 11, wherein, The force exerted by the support spring on the valve core assembly is less than the force exerted by the elastic element on the valve core assembly.

13. The electronic expansion valve according to claim 1, wherein, When the electronic expansion valve is in the fully closed state, the valve core assembly abuts against and seals the valve port.

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