Electronic expansion valve
By designing the flow channel and guide sleeve structure in the electronic expansion valve, optimizing the resonance frequency, the noise problem when the fluid flows through is solved, the accuracy of noise reduction and flow control is achieved, and the user experience is improved.
Patent Information
- Application Number
- CN202422395956.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-29
- Filing Date
- 2024-09-29
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-09-29
AI Technical Summary
Existing electronic expansion valves generate resonant noise when fluid flows through, affecting the user experience.
By designing the flow channel to connect the valve cavity and the rotor cavity, combined with the Helmholtz resonance principle, the resonance frequency of the rotor cavity and the valve cavity is optimized to reduce noise; the cross-sectional structure of the guide sleeve and the flow hole design ensure pressure balance and fluid stability; the threaded sections and guide sections of the valve needle assembly are coordinated to achieve accurate flow control.
It effectively reduces the noise when the fluid flows through the electronic expansion valve, improves user comfort and the accuracy of valve port control, and ensures the stability and noise reduction effect of the electronic expansion valve.
Smart Images

Figure CN223243089U_ABST
Abstract
Description
[0001] This application claims priority to a patent application filed with the State Intellectual Property Office of China on September 29, 2023, with application number 2023112840432 and title “Electronic Expansion Valve.” Technical Field
[0002] The utility model relates to the technical field of control valves, in particular to an electronic expansion valve. Background Art
[0003] The electronic expansion valve in the prior art mainly includes a valve needle assembly, a valve seat, a guide sleeve and a rotor assembly. The valve seat has a valve cavity and a valve port. The valve needle assembly can cooperate with the guide sleeve under the drive of the rotor assembly to approach or move away from the valve port, thereby adjusting the flow rate of the fluid at the valve port. When the fluid passes through the valve cavity of the valve seat, the valve seat will vibrate due to the impact of the fluid. At this time, the space inside the rotor assembly will resonate with the valve cavity, causing the fluid to generate resonance noise when flowing through the electronic expansion valve, affecting user use. Utility Model Content
[0004] The utility model provides an electronic expansion valve to solve the problem that the electronic expansion valve in the prior art generates resonance noise when in use.
[0005] The present application provides an electronic expansion valve, the electronic expansion valve comprising: a shell having an installation space; a valve seat, the valve seat having an installation cavity and a valve cavity that are interconnected, and a valve port being provided on the valve seat; a rotor assembly arranged in the shell, the rotor assembly comprising a magnetic rotor and a rotor connecting plate, the magnetic rotor being sleeved on the outer side of the rotor connecting plate, the magnetic rotor having a rotor cavity; a valve needle assembly arranged in the shell, the valve needle assembly being connected to the rotor connecting plate, the valve needle assembly being arranged corresponding to the valve port, and the valve needle assembly being capable of adjusting the flow at the valve port under the drive of the rotor assembly; a guide sleeve, the valve needle assembly being arranged through the guide sleeve, the guide sleeve having a first section and a second section connected in sequence along the axial direction, the first section being partially located in the shell, and the second section being arranged in the installation cavity; a flow channel arranged between the second section and / or the installation cavity, one end of the flow channel being connected to the valve cavity, and the other end of the flow channel being connected to the rotor cavity. When the electronic expansion valve is in a fully closed state, a distance H is between a side of the rotor connecting plate close to the valve cavity and an end of the flow channel close to the rotor cavity. Wherein, A is the flow area of the flow channel, c is the air propagation velocity, L is the axial length of the second section, D1 is the diameter of the rotor cavity, and D2 is the diameter of the first section.
[0006] Applying the technical solution of the present application, the electronic expansion valve includes a shell, a valve seat, a rotor assembly, a valve needle assembly and a guide sleeve. By setting a flow channel to connect the valve cavity and the rotor cavity, the pressure in the valve cavity and the rotor cavity can be ensured to be consistent, which facilitates the rotor assembly to drive the valve needle assembly to rotate. However, this will cause the valve cavity and the rotor cavity to resonate when the fluid flows through the electronic expansion valve, thereby causing the fluid to generate a large noise when flowing through the electronic expansion valve. According to the Helmholtz resonance principle, when the relevant dimensions are designed according to the above formula, the resonant frequency of the rotor cavity and the valve cavity can be reduced to a level that the human ear can sensitively perceive, thereby reducing the noise generated by the fluid when flowing through the electronic expansion valve, ensuring the noise reduction effect, and improving the user experience comfort.
[0007] Furthermore, the sidewall of the second section has a cross-sectional structure, forming a flow channel between the cross-sectional structure and the inner wall of the mounting cavity. This arrangement allows fluid to enter the rotor cavity through the flow channel, ensuring pressure balance within the valve cavity and rotor cavity. It also reduces pressure fluctuations caused by small fluids flowing through the valve cavity, further reducing noise generated when fluids flow through the electronic expansion valve, and improving user comfort.
[0008] Furthermore, a flow hole is provided on the second section, and the flow hole forms a flow channel. In this way, the flow hole can connect the rotor cavity and the installation cavity, thereby reducing the working noise of the electronic expansion valve.
[0009] Furthermore, the sidewall of the second section has multiple cross-sectional structures, which are symmetrically arranged along the axis of the guide sleeve. This arrangement can ensure that the force exerted on the guide sleeve when impacted by the fluid is relatively balanced, reduce the disturbance to the guide sleeve, and ensure the accuracy of the electronic expansion valve in controlling the valve opening.
[0010] Furthermore, the valve needle assembly includes a first threaded segment and a first guide segment connected in sequence. The first guide segment is positioned near the valve port. The guide sleeve includes a second threaded segment and a second guide segment connected in sequence. The first and second threaded segments are threadedly engaged. The valve needle assembly rotates relative to the guide sleeve to move closer to or away from the valve port, and the first and second guide segments engage with each other for guidance. Through this arrangement, the first and second threaded segments engage with each other, and the first and second guide segments engage with each other, enabling movement and guidance of the valve needle assembly relative to the valve port, thereby improving the performance of the electronic expansion valve.
[0011] Furthermore, the guide sleeve includes a third section connected to the second section and located within the valve cavity, with the outer diameter of the third section being smaller than the outer diameter of the second section. This arrangement allows the guide sleeve to be axially limited within the mounting cavity, ensuring operational stability of the electronic expansion valve.
[0012] Furthermore, the diameter of the third section, which is located near the valve port, gradually decreases as it moves away from the rotor cavity. With this arrangement, when the refrigerant fluid enters the valve cavity, the third section can achieve a flow-guiding effect on the fluid, thereby reducing the noise generated when the fluid flows through the valve cavity.
[0013] Furthermore, the first, second, and third sections are integrally formed; or the second section is a metal part, and the guide sleeve is injection-molded with the second section as an insert. This arrangement improves the overall structural stability of the guide sleeve and prevents it from loosening under the impact of the fluid.
[0014] Furthermore, the second section of the guide sleeve is interference-fitted in the mounting cavity. Through the above arrangement, the shaking amplitude of the guide sleeve caused by the impact of the fluid can be reduced, ensuring the stability of the guide sleeve during the operation of the electronic expansion valve.
[0015] Furthermore, the second section of the guide sleeve is riveted to the valve seat. The above arrangement can conveniently limit the position of the guide sleeve and ensure the stability of the guide sleeve.
[0016] Furthermore, the valve seat has a first hole segment and a second hole segment connected to each other. The first hole segment forms a mounting cavity, and the second hole segment forms a valve cavity. A riveting protrusion is annularly provided on the end surface of the valve seat near the rotor assembly. The riveting protrusion is annularly arranged around the periphery of the first hole segment and is configured to cooperate with the end surface of the second segment to secure the guide sleeve to the valve seat. This arrangement prevents the riveting protrusion from obstructing the guide sleeve from entering the mounting cavity, while facilitating the riveting of the second segment of the guide sleeve to the valve seat, thereby facilitating the assembly and processing of the electronic expansion valve. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings constituting part of this application are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:
[0018] Figure 1 The figure shows a schematic structural diagram of an electronic expansion valve provided by the first embodiment of the present utility model;
[0019] Figure 2 Shown Figure 1 A partial enlarged view of point A in the middle;
[0020] Figure 3 A top view of a guide sleeve provided in a first embodiment of the present invention is shown;
[0021] Figure 4 A top view of the guide sleeve and the valve seat provided in the first embodiment of the present utility model is shown;
[0022] Figure 5It shows a schematic structural diagram of the guide sleeve provided by the first embodiment of the utility model;
[0023] Figure 6 Shows a schematic structural diagram of the valve needle assembly provided by the utility model;
[0024] Figure 7 Shows a schematic structural diagram of the valve seat provided by the utility model;
[0025] Figure 8 The figure shows a schematic structural diagram of an electronic expansion valve provided by the second embodiment of the present utility model;
[0026] Figure 9 A top view of the guide sleeve provided in the second embodiment of the present application is shown.
[0027] The above drawings include the following reference numerals:
[0028] 10. Housing;
[0029] 20. Valve seat; 21. Valve cavity; 22. Riveted protrusion; 23. Mounting cavity; 24. First hole section; 25. Second hole section; 201. Valve port;
[0030] 30. Rotor assembly; 31. Magnetic rotor; 32. Rotor connecting plate;
[0031] 40. Valve needle assembly; 41. First threaded section; 42. First guide section;
[0032] 50. Guide sleeve; 51. First section; 52. Second section; 521. Flow hole; 53. Third section; 54. Second threaded section; 55. Second guide section;
[0033] 100. Cross-sectional structure; 200. Circulation channel. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0035] like Figures 1 to 9As shown, an embodiment of the present application provides an electronic expansion valve, comprising a housing 10, a valve seat 20, a rotor assembly 30, a valve needle assembly 40, a guide sleeve 50, and a flow channel 200. The housing 10 has an installation space. The valve seat 20 has an interconnected installation cavity 23 and a valve cavity 21. The installation cavity 23 and the valve cavity 21 are arranged in a stepped manner. A valve port 201 is provided in the valve cavity 21, located at the end of the valve cavity 21 away from the installation cavity 23. The rotor assembly 30 is disposed within the housing 10 and includes a magnetic rotor 31 and a rotor connecting plate 32. The magnetic rotor 31 is sleeved on the outer side of the rotor connecting plate 32 and has a rotor cavity. The valve needle assembly 40 is disposed within the housing 10 and connected to the rotor connecting plate 32. The valve needle assembly 40 is positioned corresponding to the valve port 201 and can adjust the flow rate at the valve port 201 under the drive of the rotor assembly 30. The valve needle assembly 40 is arranged through the guide sleeve 50. The guide sleeve 50 has a first section 51 and a second section 52 connected in sequence along the axial direction. The first section 51 is partially located in the housing 10. The circulation channel 200 is arranged between the second section 52 and / or the installation cavity 23. One end of the circulation channel 200 is connected to the valve cavity 21, and the other end of the circulation channel 200 is connected to the rotor cavity. When the electronic expansion valve is in the fully closed state, the distance between the side of the rotor connecting plate 32 close to the valve cavity 21 and the end of the circulation channel 200 close to the rotor cavity is H. Wherein, A is the flow area of the flow channel 200 , c is the air propagation velocity, L is the axial length of the second section 52 , D1 is the diameter of the rotor cavity, and D2 is the diameter of the first section 51 .
[0036] Applying the technical solution of the present application, the electronic expansion valve includes a housing 10, a valve seat 20, a rotor assembly 30, a valve needle assembly 40 and a guide sleeve 50. By setting a flow channel 200 to connect the valve cavity 21 and the rotor cavity, it can ensure that the pressure in the valve cavity 21 and the rotor cavity is consistent, prevent the pressure difference between the valve cavity 21 and the rotor cavity, and facilitate the rotor assembly to drive the valve needle assembly 40 to rotate. However, this will cause the valve cavity 21 and the rotor cavity to resonate when the fluid flows through the electronic expansion valve, thereby causing the fluid to generate a large noise when flowing through the electronic expansion valve. According to the Helmholtz resonance principle, the resonance frequency Where V is the volume of the rotor cavity, V = π × (D1 2 / 4-D2 2 / 4)×H, H is the distance between the side of the rotor connecting plate 32 close to the valve cavity 21 and the side of the valve seat 20 close to the rotor cavity when the electronic expansion valve is in the fully closed state, A is the flow area of the flow channel 200, c is the air propagation speed, and the minimum frequency of sound that the human ear can sensitively perceive is 1000Hz. By setting the resonant frequency f≤1000Hz, we can get By the above arrangement, when the electronic expansion valve is in the fully closed state, the distance between the side of the rotor connecting plate 32 close to the valve cavity 21 and the side of the flow channel 200 close to the rotor cavity satisfies This can reduce the resonance frequency of the rotor cavity and the valve cavity 21 to a level that the human ear can sensitively feel, thereby reducing the noise generated when the fluid flows through the electronic expansion valve, ensuring the noise reduction effect, and improving the user experience comfort.
[0037] Reference Figures 1 to 5 As shown, in the first embodiment of the present application, the side wall of the second section 52 has a section structure 100, and a circulation channel 200 is formed between the section structure 100 and the inner wall of the installation cavity 23. Through the above arrangement, when the fluid flows through the valve cavity 21, it can enter the rotor cavity through the circulation channel 200, ensuring the pressure balance in the valve cavity 21 and the rotor cavity, reducing the pressure difference that needs to be overcome when the valve needle assembly 40 opens or blocks the valve port 201, and facilitating the electronic expansion valve to quickly adjust the flow rate. At the same time, it can also reduce the pressure fluctuations generated when the fluid flows through the valve cavity 21, further reduce the noise generated when the fluid flows through the electronic expansion valve, and improve the user comfort experience. Among them, when the circulation channel 200 is formed between the section structure 100 and the inner wall of the installation cavity 23, D3 is the diameter of the mounting cavity 23 minus the distance between the side wall of the second section 52 and the inner wall of the mounting cavity 23 , and D4 is the diameter of the second section 52 .
[0038] Furthermore, the side wall of the second section 52 has a plurality of section structures 100, and the plurality of section structures 100 are symmetrically arranged along the axis of the guide sleeve 50. Through the above arrangement, when the fluid enters the rotor cavity from the valve cavity 21 along the circulation channel 200, the plurality of section structures 100 are symmetrically arranged along the axis of the guide sleeve 50, which can ensure that the force exerted on the guide sleeve 50 when impacted by the fluid is relatively balanced, reduce the disturbance exerted on the guide sleeve 50, and ensure the accuracy of the electronic expansion valve in controlling the valve opening. In a specific embodiment of the present application, two section structures 100 are provided, and the two section structures 100 are symmetrically arranged along the axis of the guide sleeve 50. Correspondingly, there are also two circulation channels 200. Through the above arrangement, the two circulation channels 200 can reduce the noise generated when the fluid flows through the electronic expansion valve while ensuring the stability of the guide sleeve 50 in the installation cavity 23, thereby improving the noise reduction effect of the electronic expansion valve.
[0039] Reference Figure 8 and Figure 9 As shown, in the second embodiment of the present application, a through flow hole 521 is provided on the second section 52, and the flow hole 521 forms a flow channel 200. Similar to the cross-sectional structure 100, a plurality of flow holes 521 can also be provided, and the plurality of flow holes 521 are symmetrically arranged along the axis of the guide sleeve 50. When the flow hole 521 forms the flow channel 200, then Wherein, A is the cross-sectional area of the flow hole 521 perpendicular to the extension direction.
[0040] like Figure 5 and Figure 6 As shown, in the present application, the valve needle assembly 40 has a first threaded segment 41 and a first guide segment 42 connected in sequence. The first guide segment 42 is disposed near the valve port. The guide sleeve 50 has a second threaded segment 54 and a second guide segment 55 connected in sequence. The first threaded segment 41 and the second threaded segment 54 are threadedly engaged. The valve needle assembly 40 rotates relative to the guide sleeve 50 to approach or move away from the valve port, and the first guide segment 42 and the second guide segment 55 are guided and engaged. Through the above arrangement, the first threaded segment 41 can rotate relative to the second threaded segment 54 under the drive of the rotor assembly 30. The threaded engagement of the first threaded segment 41 and the second threaded segment 54 enables the valve needle assembly 40 to move up and down toward or away from the valve port, thereby closing or opening the valve port. At the same time, the guiding engagement of the first guide segment 42 and the second guide segment 55 can ensure the precision of the engagement between the valve needle assembly 40 and the valve port, thereby improving the performance of the electronic expansion valve.
[0041] Furthermore, the guide sleeve 50 includes a third section 53, which is connected to the second section 52 and is located within the valve cavity 21. The outer diameter of the third section 53 is smaller than that of the second section 52. This arrangement forms a stepped surface between the second section 52 and the third section 53. The stepped surface can cooperate with the mounting cavity 23 to limit the guide sleeve 50 axially within the mounting cavity 23, preventing the guide sleeve 50 from moving toward the valve cavity 21 under the influence of the valve needle assembly 40, thereby ensuring the stability of the electronic expansion valve.
[0042] Furthermore, the diameter of the third section 53 decreases gradually from the end closest to the valve opening toward the rotor cavity. Because bubbles tend to burst when passing through the valve opening, this arrangement allows the third section 53 to guide bubbles in the refrigerant fluid as it enters the valve cavity 21, allowing them to more smoothly enter the circulation channel 200. This reduces the number of bubbles passing through the valve opening, thereby reducing the noise generated by the fluid flowing through the valve cavity 21.
[0043] In the present application, the first section 51, the second section 52, and the third section 53 are an integrally molded structure; alternatively, the second section 52 is a metal part, and the guide sleeve 50 is injection molded with the second section 52 as an insert. Through the above arrangement, the overall structural stability of the guide sleeve 50 can be improved, and the guide sleeve 50 can be prevented from loosening under the impact of the fluid. At the same time, the integral molding manufacturing process can also facilitate the production and processing of the guide sleeve 50. In a specific embodiment of the present application, the guide sleeve 50 is injection molded with the second section 52 as a metal base, and the injection molding material is made of engineering plastic material. Engineering plastic has good heat resistance, cold resistance, machinability and structural stability, which facilitates the processing and molding of the guide sleeve 50.
[0044] Furthermore, the second section 52 of the guide sleeve 50 is interference-fitted within the mounting cavity 23. This arrangement reduces the possible gap between the outer wall of the second section 52 and the inner wall of the mounting cavity 23, reduces the amplitude of shaking of the guide sleeve 50 caused by fluid impact, and ensures the stability of the guide sleeve 50 during operation of the electronic expansion valve.
[0045] In a specific embodiment of the present application, the second section 52 of the guide sleeve 50 is riveted to the valve seat 20. Through the above arrangement, the position of the guide sleeve 50 can be easily limited, thereby ensuring the stability of the guide sleeve 50.
[0046] like Figure 7 As shown, the valve seat 20 has a first hole section 24 and a second hole section 25 connected to each other. The first hole section 24 forms a mounting cavity 23, and the second hole section 25 forms a valve cavity 21. A rivet protrusion 22 is annularly provided on the end surface of the valve seat 20 near the rotor assembly 30. The rivet protrusion 22 is annularly arranged around the periphery of the first hole section 24. The rivet protrusion 22 is used to cooperate with the end surface of the second section 52 to secure the guide sleeve 50 to the valve seat 20. Through this arrangement, during the installation of the guide sleeve 50, the rivet protrusion 22 will not block the guide sleeve 50 from entering the mounting cavity 23. After the second section of the guide sleeve 50 is interference-fitted into the first hole section 24, the rivet protrusion 22 can be bent, thereby achieving riveting of the second section 52 of the guide sleeve 50 to the valve seat 20. The above method has a simple structure and is easy to process, facilitating the assembly and processing of the electronic expansion valve.
[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.
[0048] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.
[0049] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.
[0050] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0051] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.
[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. An electronic expansion valve, characterized in that: The electronic expansion valve comprises: A housing (10) having an installation space; A valve seat (20), the valve seat (20) having a mounting cavity (23) and a valve cavity (21) that are communicated with each other, and a valve port (201) is provided on the valve seat (20); A rotor assembly (30) is arranged in the housing (10), the rotor assembly (30) comprising a magnetic rotor (31) and a rotor connecting plate (32), the magnetic rotor (31) being sleeved on the outer side of the rotor connecting plate (32), and the magnetic rotor (31) having a rotor cavity; A valve needle assembly (40) is disposed in the housing (10), the valve needle assembly (40) is connected to the rotor connecting plate (32), the valve needle assembly (40) is disposed corresponding to the valve port (201), and the valve needle assembly (40) is capable of adjusting the flow at the valve port (201) under the drive of the rotor assembly (30); a guide sleeve (50), wherein the valve needle assembly (40) is disposed through the guide sleeve (50), and the guide sleeve (50) comprises a first section (51) and a second section (52) connected in sequence along the axial direction, wherein the first section (51) is partially located in the housing (10), and the second section (52) is disposed in the mounting cavity (23); A circulation channel (200) is provided between the second section (52) and / or the installation cavity (23), one end of the circulation channel (200) is in communication with the valve cavity (21), and the other end of the circulation channel (200) is in communication with the rotor cavity. When the electronic expansion valve is in a fully closed state, a distance H is between a side of the rotor connecting plate (32) close to the valve cavity (21) and an end of the circulation channel (200) close to the rotor cavity. Wherein, A is the flow area of the flow channel (200), c is the air propagation velocity, L is the axial length of the second section (52), D1 is the diameter of the rotor cavity, and D2 is the diameter of the first section (51).
2. The electronic expansion valve according to claim 1, characterized in that: The side wall of the second section (52) has a section structure (100), and the flow channel (200) is formed between the section structure (100) and the inner wall of the installation cavity (23).
3. The electronic expansion valve according to claim 1, characterized in that: The second section (52) is provided with a circulation hole (521), and the circulation hole (521) forms the circulation channel (200).
4. The electronic expansion valve according to claim 2, characterized in that: The side wall of the second section (52) has a plurality of the section structures (100), and the plurality of section structures (100) are symmetrically arranged along the axis of the guide sleeve (50).
5. The electronic expansion valve according to claim 1, characterized in that: The valve needle assembly (40) has a first threaded section (41) and a first guide section (42) connected in sequence, the first guide section (42) is arranged close to the valve port (201), the guide sleeve (50) has a second threaded section (54) and a second guide section (55) connected in sequence, the first threaded section (41) and the second threaded section (54) are threadedly matched, the valve needle assembly (40) rotates relative to the guide sleeve (50) to approach or move away from the valve port, and the first guide section (42) and the second guide section (55) are guided and matched.
6. The electronic expansion valve according to claim 1, characterized in that: The guide sleeve (50) further includes a third section (53), the third section (53) being connected to the second section (52), and the third section (53) being located in the valve cavity (21), and the outer diameter of the third section (53) being smaller than the outer diameter of the second section (52).
7. The electronic expansion valve according to claim 6, characterized in that: The diameter of the end of the third section (53) close to the valve port (201) gradually decreases in a direction away from the rotor chamber.
8. The electronic expansion valve according to claim 6, characterized in that: The first section (51), the second section (52) and the third section (53) are an integrally formed structure; or, the second section (52) is a metal part, and the guide sleeve (50) is injection-molded with the second section (52) as an insert.
9. The electronic expansion valve according to claim 1, characterized in that: The second section (52) of the guide sleeve (50) is interference-fitted in the mounting cavity (23).
10. The electronic expansion valve according to claim 1, characterized in that: The second section (52) of the guide sleeve (50) is riveted to the valve seat (20).
11. The electronic expansion valve according to claim 10, characterized in that: The valve seat (20) has a first hole section (24) and a second hole section (25) connected to each other, the first hole section (24) forms the installation cavity (23), and the second hole section (25) forms the valve cavity (21). A riveted protrusion (22) is annularly arranged on the end face of the valve seat (20) close to the rotor assembly (30), and the riveted protrusion (22) is annularly arranged on the periphery of the first hole section (24). The riveted protrusion is used to cooperate with the end face of the second section (52) to fix the guide sleeve (50) on the valve seat (20).