Electronic expansion valve

Abstract

The electronic expansion valve comprises a shell, a valve body, a valve element and a driving mechanism, the valve body is fixedly connected to the shell, the valve element is arranged on the inner side of the valve body in a contained mode, and the driving mechanism can drive the valve element to axially move relative to the valve body, so that the expansion valve is opened or closed. The driving mechanism comprises a nut arranged in the shell, and a containing cavity is formed in the nut; the main shaft is partially arranged in the containing cavity, and the lower end of the main shaft is connected to the valve element; a rotor disposed in the housing and driving the spindle to rotate relative to the nut; and the guide piece is arranged on the nut in a non-rotatable manner and is at least partially arranged on the inner side of the accommodating cavity. External threads are formed on the peripheral surface of the main shaft, guide teeth are formed on the guide piece, and the guide teeth can be meshed with the external threads to form a spiral transmission structure, so that the rotary motion of the main shaft is allowed to be converted into the axial motion of the main shaft, and the valve element connected to the main shaft is driven to move in the axial direction.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and in particular to an electronic expansion valve. Background Art

[0002] An electronic expansion valve, also known as a throttle valve, is designed to reduce the pressure of a flowing fluid by locally narrowing the flow cross-section, thereby causing the volume to increase or expand. Prior art, such as patent document CN104180567B, discloses an electronic expansion valve operated by a motor. Power to the stator rotates the rotor, which in turn rotates the main shaft. A helical transmission structure between the main shaft and the nut then converts the main shaft's rotational motion into linear axial motion, thereby driving a valve core connected to the main shaft into and out of the valve port to open or close the expansion valve.

[0003] The electronic expansion valve utilizes two springs to define the upper and lower extreme positions of the main shaft. Specifically, a large spring and a small spring are mounted on the outer circumference of the nut, and a stop rod is welded to the rotor assembly. As the rotor rotates, the stop rod moves the small spring upward and downward along the outer thread of the large spring, thereby defining the two axial extreme positions of the main shaft.

[0004] However, this stop structure is relatively complex, and since the stop rod is long, the welding point between the stop rod and the rotor is easily broken, thereby causing the electronic expansion valve to fail. Summary of the Invention

[0005] In order to overcome the above problems, the present invention provides a novel electronic expansion valve, which can suppress the problem that the welding point of the stop rod is easily broken, thereby ensuring the normal operation of the expansion valve.

[0006] The cam is secured to the valve body with a spring which is secured to the valve stem and has a cam face which is secured to the valve body with a spring which is secured to the valve stem during operation. The nut is arranged in the accommodating cavity, and the lower end of the main shaft is connected to the valve core; a rotor is arranged in the housing and drives the main shaft to rotate relative to the nut; and a guide member is non-rotatably arranged on the nut and at least partially arranged on the inner side of the accommodating cavity, wherein an external thread is formed on the outer peripheral surface of the main shaft, and guide teeth are formed on the guide member, and the guide teeth can engage with the external thread to form a spiral transmission structure to allow the rotational motion of the main shaft to be converted into axial motion of the main shaft, thereby driving the valve core connected to the main shaft to move axially.

[0007] Thus, the electronic expansion valve according to the present invention converts the rotational motion of the spindle relative to the nut into linear axial motion by embedding a thin sheet-shaped guide member in the nut and forming guide teeth on the guide member to form a spiral transmission structure with the external threads on the outer circumference of the spindle. This drives the valve core connected to the lower end of the spindle into or out of the valve port, thereby closing or opening the expansion valve. As a result, this electronic expansion valve has a compact structure and is easy to install.

[0008] According to a preferred embodiment of the present invention, the guide member further includes a first stopper provided on a first side of the guide tooth in the axial direction to limit further axial movement of the main shaft toward the first side, thereby defining a first limit position of the main shaft.

[0009] According to a preferred embodiment of the present invention, the external thread has a first cut surface at the end facing the first side, and the first cut surface can abut against the first stop portion to limit further rotation of the external thread and confine the main shaft at a first extreme position.

[0010] According to a preferred embodiment of the present invention, the guide member further includes a second stop portion, which is provided on a second side opposite to the first side in the axial direction of the guide tooth to limit further axial movement of the main shaft toward the second side, thereby defining a second extreme position of the main shaft.

[0011] According to a preferred embodiment of the present invention, the external thread has a second cut surface at the end facing the second side, and the second cut surface can abut against the second stop portion to limit further rotation of the external thread and confine the main shaft at a second extreme position.

[0012] According to a preferred embodiment of the present invention, the guide member is in the shape of a thin sheet, a through hole is formed on the side wall of the nut, and the guide member is at least partially inserted into the through hole, so that the guide tooth is exposed in the accommodating cavity to engage with the external thread on the outer peripheral surface of the main shaft to form the spiral transmission structure.

[0013] According to a preferred embodiment of the present invention, the guide member includes an inserting portion, the inserting portion is inserted into the inner side of the accommodating cavity through the through hole, and the guide teeth are formed on the inserting portion.

[0014] According to a preferred embodiment of the present invention, the guide member further includes a body portion connected to the insertion portion, wherein the body portion is disposed outside the side wall and abuts against an outer peripheral surface of the side wall.

[0015] According to a preferred embodiment of the present invention, an axial extension length of the main body portion is greater than an axial extension length of the insertion portion, thereby forming a step between the main body portion and the insertion portion.

[0016] The electronic expansion valve of the present invention has two cut surfaces formed at opposite axial ends of the external thread, and two stoppers formed on the upper and lower sides of the guide teeth. These cut surfaces abut against the stoppers, limiting the upper and lower extremes of axial movement of the main shaft relative to the nut. This radial stop structure is simple and, compared to structures that use a stop rod to define the main shaft's extreme positions, can also prevent the expansion valve from malfunctioning due to the welds of the stop rod fracturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described below with reference to the accompanying drawings. Elements with the same function are represented by the same reference numerals in the drawings.

[0018] Figure 1 A schematic cross-sectional view illustrating an electronic expansion valve according to an exemplary embodiment of the present invention;

[0019] Figure 2 A schematic structural diagram illustrating a spiral transmission structure in an electronic expansion valve according to an exemplary embodiment of the present invention;

[0020] Figure 3 A partial schematic diagram illustrating a main shaft of an electronic expansion valve according to an exemplary embodiment of the present invention;

[0021] Figure 4A partially enlarged view illustrating a stopping structure of a spiral transmission structure in an electronic expansion valve according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following embodiments of the present invention are further described in detail with reference to the accompanying drawings and examples, wherein the same or similar components in the drawings are designated by the same reference numerals. The following detailed description of the embodiments and the accompanying drawings are intended to illustrate the principles of the present invention and are not intended to limit the scope of the invention. That is, the present invention is not limited to the described embodiments.

[0023] In the following description of the present invention, it should be noted that, unless otherwise specified, terms such as "upper," "lower," "inner," "outer," "top," and "bottom" indicating directions or positional relationships are intended solely to facilitate description and simplify the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The directional terms used in the following description refer to directions shown in the drawings and do not limit the specific structure of the present invention.

[0024] In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. In addition, it should be understood that the term "torque-resistant connection" refers to the connection between two elements in a manner that does not rotate relative to each other, so that torque can be transmitted between the two elements, and the torque-resistant connection can be achieved through interference fit, bolt connection, gear connection, welding, etc., or by forming the two elements mentioned as one piece. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0025] In order to better understand the present invention, Figure 1 The electronic expansion valve according to the embodiment of the present invention is described. Figure 1 A schematic cross-sectional view of an electronic expansion valve according to an exemplary embodiment of the present invention is shown, wherein: Figure 1 The electronic expansion valve is shown in a closed state. In the following description, the axial direction of the electronic expansion valve refers to the up-down direction in the figure, and the radial direction of the electronic expansion valve refers to the left-right direction in the figure.

[0026] The electronic expansion valve comprises a housing 1, a valve body 2, a valve core 3, and a drive mechanism, and optionally includes a housing seat 4 and a valve body seat 5. The valve body 2 is fixedly connected to the housing 1, and the valve core 3 is accommodated inside the valve body 2. The drive mechanism drives the valve core 3 to move axially relative to the valve body 2, thereby opening or closing the expansion valve. The housing seat 4 accommodates and supports the housing 1 and the drive mechanism, while the valve body seat 5 accommodates and supports the valve body 2.

[0027] The housing 1 is constructed as a sleeve with one end closed and the other open. The housing 1 is at least partially inserted into the housing seat 4, with the open end of the housing 1 exposed to the underside of the housing seat 4, thereby securely connecting the housing 1 to the valve body 2. A housing cavity A is formed within the housing 1, wherein a portion of the drive mechanism is disposed.

[0028] The valve body 2 is at least partially housed in the valve body seat 5. The upper end of the valve body 2 is cylindrically inserted into the housing cavity A and fixedly connected to the open end of the housing 1. A valve cavity B is formed within the valve body 2 to accommodate the valve core 3, which is capable of axial movement relative to the valve body 2. The valve body 2 has a split-piece construction, comprising a valve base 21 at the upper end and a valve core seat 22 at the lower end. The valve base 21 and the valve core seat 22 define the valve cavity B. A portion of the valve base 21 is housed in the valve body seat 5, while another portion is exposed above the upper side of the valve body seat 5, securely connected to the housing 1. The portion of the valve base 21 housed in the valve body seat 5 can be securely connected to the mounting hole of the valve body seat 5 using external threads or other means. The upper end of the valve core seat 22 is cylindrically inserted into the lower end of the valve base 21, thereby securely connecting the valve core seat 22 to the valve base 21. The valve core seat 22 is completely housed in the valve body seat 5. The bottom of the valve core seat 22 is provided with an axially penetrating valve port 221 for the insertion of a valve needle 32 described below.

[0029] The valve body seat 5 is formed with an opening 51 that extends radially toward the valve body 2 (particularly the valve core seat 22) and is connected to the external fluid. A through hole 222 is formed on the side wall of the valve core seat 22, and the through hole 222 is respectively connected to the opening 51 of the valve body seat 5 and the valve port 221 provided at the bottom of the valve core seat 22. When the valve core 3 is pulled out of the valve port 221 to open the expansion valve, the fluid can sequentially pass through the opening 51 of the valve body seat 5, the through hole 222 on the side wall of the valve core seat 22, and the valve port 221 at the bottom of the valve core seat 22, until it reaches the lower area of ​​the valve core seat 22. Preferably, a fluid inlet chamber 52 is also formed in the valve body seat 5. The fluid inlet chamber 52 is formed around the outer circumferential surface of the valve core seat 22, and the outer diameter of the fluid inlet chamber 52 is larger than the outer diameter of the valve core seat 22. The fluid inlet chamber 52 can be fluidically connected to the opening 51 of the valve body seat 5 and the through hole 222 of the valve core seat 22 respectively, so that when the valve needle is inserted into the valve port 221, excess fluid flowing out of the valve core seat 22 through the through hole 222 can be temporarily stored in the fluid inlet chamber 52.

[0030] The drive mechanism is used to move the valve core 3 axially relative to the valve body 2. The drive mechanism includes a motor 6, a nut 7, a spindle 8, and a guide 9. The motor 6 includes a stator 61 and a rotor 62. The stator 61 is disposed outside the housing cavity A and supported by the housing seat 4. The stator 61 radially surrounds the housing 1. The rotor 62 is arranged inside the housing cavity A. Powering the stator 61 causes the rotor 62 to rotate about the rotation axis (i.e., the longitudinal axis of the electronic expansion valve).

[0031] The nut 7 is arranged in the housing cavity A and is fixedly connected relative to the housing 1. An accommodating cavity C is formed in the nut 7 for the main shaft 8 to pass through.

[0032] The main shaft 8 is cylindrical and extends axially, and is partially accommodated in the accommodating cavity C of the nut 7. An external thread 82 is formed on the outer peripheral surface of the portion of the main shaft 8 accommodated in the accommodating cavity C. The main shaft 8 can be driven by the rotor 62 to rotate relative to the nut 7. Specifically, the main shaft 8 can be fixedly connected to the rotor 62 via a connecting member 81, so that the main shaft 8 can rotate synchronously with the rotor 62. Figure 1 As shown, the connecting member 81 is plate-shaped and has an axially extending through-hole at its center for the main shaft 8 to pass through. The connecting member 81 is torque-resistantly connected to the main shaft 8 at the through-hole and torque-resistantly connected to the rotor 62 at its outer periphery, thereby achieving synchronous rotation of the main shaft 8 and the rotor 62.

[0033] For force transmission, it is conceivable that the cross-sections of the through-hole of the connecting member 81 and the spindle 8 are not circular, but rather are configured as non-rotationally symmetrical shapes. This allows for easy transmission of torque from the connecting member 81 to the spindle 8. For example, the through-hole can be configured as a polygon, preferably a quadrilateral. Furthermore, any non-rotationally symmetrical configuration is conceivable to facilitate torque transmission. However, the cross-sections of the through-hole and the spindle 8 can be circular, and force transmission between the connecting member 81 and the spindle 8 can be achieved, for example, by a welded connection, preferably with multiple weld points between the spindle 8 and the through-hole.

[0034] In one example, the connection between rotor 62 and connecting member 81 can be materially bonded, form-fitting, or force-fitting. For example, this torque-resistant connection can be achieved by inserting the outer circumference of connecting member 81 into a groove formed radially inside rotor 62. Importantly, torque can be transmitted from rotor 62 to connecting member 81. In principle, it is also conceivable for connecting member 81 and rotor 62 to be constructed as a single-piece component.

[0035] The guide member 9 is non-rotatably disposed on the nut 7 and is at least partially exposed in the accommodating cavity C. A guide tooth 911 is formed on the guide member 9 and is capable of engaging with the external thread 82 on the outer circumferential surface of the main shaft 8 to form a helical transmission structure. This helical transmission structure allows the rotational motion of the main shaft 8 to be converted into a linear axial motion of the main shaft 8.

[0036] That is, since the main shaft 8 can be driven by the rotor 62 to rotate relative to the nut 7, and the guide member 9 is non-rotatably arranged on the nut 7, the external thread 82 on the outer circumference of the main shaft 8 and the guide teeth 911 on the guide member 9 form a spiral transmission structure, so that the main shaft 8 can rotate synchronously with the rotor 62 while also being able to move axially downward (that is, from the upper side to the lower side) or upward (that is, from the lower side to the upper side) along the rotation axis, thereby driving the valve core 3 connected to the main shaft 8 to move axially. Figure 1 The specific structure of the valve core 3 will be described below.

[0037] The valve core 3 is accommodated in the valve body cavity B and is connected to the lower end of the main shaft 8 , and is capable of axially moving relative to the valve body 2 in response to the axial movement of the main shaft 8 .

[0038] The valve core 3 includes a sleeve portion 31 and a valve needle 32 connected to the bottom side of the sleeve portion 31. Preferably, the valve needle 32 is formed integrally with the sleeve portion 31. The valve needle 32 is formed into a tapered shape, with its size gradually decreasing in a direction away from the sleeve portion 31, so that the valve needle 32 is more easily inserted into the valve port 221.

[0039] The sleeve portion 31 is hollow and cylindrical, with a bushing 11 housed at its upper end. The bushing 11 is configured as a hollow cylinder for the spindle 8 to pass through. An interference fit is established between the bushing 11 and the sleeve portion 31. For example, the outer diameter of the bushing 11 is larger than the inner diameter of the sleeve portion 31, allowing the bushing 11 to be pressed into the sleeve portion 31. In other words, the bushing 11 is connected to the sleeve portion 31 by means of a press fit. The spindle 8 rotatably passes through the bushing 11 to be partially disposed within the sleeve portion 31. For example, a clearance fit is formed between the bushing 11 and the spindle 8, allowing the spindle 8 to rotate relative to the bushing 11.

[0040] Disposed within the sleeve portion 31 are elements for transmitting force and limiting torque between the main shaft 8 and the valve core 3, such as a pressure spring 12 and a spring seat 13 for supporting the pressure spring 12. The pressure spring 12 is, for example, a cylindrical coil spring. The spring seat 13 is fixedly attached to the lower end of the main shaft 8, allowing it to rotate synchronously with the main shaft 8 and also move axially with it. The spring seat 13 comprises a head and a stem. The head is closer to the bushing 11 than the stem, and the pressure spring 12 is sheathed on the outer circumference of the stem. In other words, the pressure spring 12 is supported inwardly by the outer circumference of the stem. Therefore, the spring seat 13 serves as a guide for the pressure spring 12. Furthermore, because the inner circumference of the sleeve portion 31 prevents the pressure spring 12 from bending, overall, the pressure spring 12 is supported by both the inner circumference of the sleeve portion 31 and the outer circumference of the stem. The opposing ends of the pressure spring 12 rest against the underside of the head of the spring seat 13 and the bottom of the sleeve portion 31, respectively.

[0041] Therefore, in the electronic expansion valve according to an embodiment of the present invention, when the rotor 62 drives the main shaft 8 to rotate, the main shaft 8 can achieve linear motion in the axial direction due to the spiral rotation structure. When the main shaft 8 moves downward, the lower end of the main shaft 8 presses against the spring seat 13. The spring seat 13, in turn, acts on the sleeve portion 31 with damping via the pressure spring 12. This drives the valve needle 32 toward the valve core seat 22, thereby forming a sealed connection with the valve port 221 of the valve core seat 22, thereby closing the expansion valve. Conversely, when the main shaft 8 moves upward, the lower end of the main shaft 8 drives the valve core 3 upward via the spring seat 13 and the bushing 11, withdrawing the valve core 3 from the valve port 221 of the valve core seat 22 to open the expansion valve, thereby allowing fluid to pass through the valve port 221 of the valve core seat 22. In other words, the valve needle 32 can be inserted into the valve port 221 to close the expansion valve, or withdrawn from the valve port 221 to open the expansion valve, in response to the axial movement of the valve core 3.

[0042] As described above, since a spiral transmission structure is formed between the guide member 9 and the main shaft 8, the rotational motion of the main shaft 8 driven by the rotor 62 can be converted into axial linear motion, thereby driving the valve needle 32 connected to the lower end of the main shaft 8 to insert into or leave the valve port 221.

[0043] In one embodiment, Figure 1As shown, the guide member 9 is in the form of a thin sheet. A through hole is formed in the side wall of the nut 7. The guide member 9 is at least partially inserted into the through hole, so that the guide teeth 911 are exposed in the accommodating cavity C, thereby engaging with the external threads 82 on the outer circumference of the main shaft 8 to form a spiral transmission structure. The guide member 9 is fixed to the nut 7 through the through hole and is non-rotatable relative to the nut 7. Therefore, when the main shaft 8 rotates relative to the nut 7, it engages with the external threads on the outer circumference of the main shaft 8 to form a threaded rotation structure. Preferably, the through hole is opened at a substantially central position along the axial direction of the side wall of the nut 7, and thus the guide member 9 is also arranged at a substantially central position along the axial direction of the nut 7. However, it should be understood that the guide member 9 can also be arranged at a substantially upper or lower position along the axial direction of the nut 7 according to actual needs.

[0044] In one embodiment, Figure 1 and Figure 2 As shown, the guide member 9 includes an insertion portion 91, which is inserted into the inner side of the accommodating cavity C through a through hole, and a guide tooth 911 is formed on the insertion portion 91, so that the guide tooth 911 can be exposed in the accommodating cavity C to engage with the external thread 82 on the outer peripheral surface of the main shaft 8 to form a spiral transmission structure.

[0045] In another embodiment, the guide member 9 further includes a body portion 92 connected to the insert portion 91. The body portion 92 is disposed outside the sidewall of the nut 7 and abuts against the outer circumferential surface of the sidewall. The body portion 92 extends axially longer than the insert portion 91, thereby forming a step between the body portion 92 and the insert portion 91. This step serves to limit the insertion depth of the insert portion 91 into the accommodating cavity C. Preferably, the body portion 92 and the insert portion 91 are integrally formed.

[0046] In addition, in the process of converting the rotational motion of the main shaft 8 into axial motion by means of the above-mentioned spiral transmission structure to drive the valve core 3 to move axially to open and close the electronic expansion valve, it is necessary to use a stop structure to limit or determine the upper and lower limit positions. Figures 2 to 4 To describe the stop structure of the spiral transmission structure.

[0047] In one embodiment, the guide member 9 includes a first stop 912 and a second stop 913. The first stop 912 is provided on a first side of the guide teeth 911 in the axial direction to limit further axial movement of the spindle 8 toward the first side, thereby defining a first limit position of the spindle 8. The second stop 913 is provided on a second side of the guide teeth 911 in the axial direction, opposite the first side, to limit further axial movement of the spindle 8 toward the second side, thereby defining a second limit position of the spindle 8. For example, in the accompanying drawings, the first side refers to the upper side, and the second side refers to the lower side. The first stop 912 and the second stop 913 are preferably formed integrally with the guide teeth 911. It should be understood that both the first stop 912 and the second stop 913 are formed on the insertion portion 91 and are exposed in the accommodating cavity C to define the two axial limit positions of the spindle 8.

[0048] like Figures 2 to 4 As shown, the external thread 82 has a first cut surface 821 at its distal end facing the first side. When the spindle 8, for example, moves counterclockwise upward to a certain extent, the first cut surface 821 can abut against the first stop 912 to limit further counterclockwise rotation of the external thread 82, thereby confining the spindle 8 to a first limit position, i.e., the upper limit position. Preferably, the surface of the first cut surface 821 is flat, so that when the first cut surface 821 abuts against the first stop 912, it can form a surface-to-surface contact with the first stop 912, thereby reliably limiting further counterclockwise rotation of the external thread 82.

[0049] The external thread 82 has a second cut surface 822 at its distal end facing the second side. When the spindle 8 moves clockwise downward to a certain extent, for example, the second cut surface 822 can abut against the second stop 913, thereby limiting further clockwise rotation of the external thread 82 and thereby confining the spindle 8 at its second, or lower, limit position. Preferably, the surface of the second cut surface 822 is flat, so that when the second cut surface 822 abuts against the second stop 913, it forms surface-to-surface contact with the second stop 913, thereby reliably limiting further clockwise rotation of the spindle 8.

[0050] Therefore, the electronic expansion valve according to the present invention can limit the two axial extreme positions of the main shaft 8 by abutting the two opposing end surfaces 821 and 822 of the external thread 82 against the first stop portion 912 and the second stop portion 913 of the guide member 9, respectively. This ensures that the main shaft 8 drives the valve needle 32 within a predetermined travel range, thereby ensuring reliable operation of the entire expansion valve. This radial stop structure is relatively simple and, compared to structures that use a stop rod to limit the main shaft's extreme positions, can also prevent the stop rod's welded joints from fracturing, thereby ensuring the normal operation of the expansion valve.

[0051] Furthermore, during operation of the electronic expansion valve, when the rotor 62 drives the main shaft 8, the main shaft 8 causes the spring seat 13 to rotate, which in turn causes the pressure spring 12 to rotate. However, the sleeve portion 31 of the valve core 3 and the bushing 11 housed therein are kept from rotating as much as possible. Consequently, the spring seat 13, which rotates, and the bushing 11, which does not rotate, move relative to each other, causing wear due to their contact. Similarly, the pressure spring 12, which rotates, and the sleeve portion 31, which does not rotate, also move relative to each other, causing wear.

[0052] To reduce this wear, in one embodiment, a first thrust bearing 14 is provided between the rotational spring seat 13 and the minimally rotational bushing 11, and a second thrust bearing 15 is provided between the rotational pressure spring 12 and the minimally rotational bottom of the sleeve portion 31. The first thrust bearing 14 is, for example, a ball bearing, thereby generating rolling friction between the spring seat 13 and the bushing 11, and the second thrust bearing 15 is, for example, a ball bearing, thereby generating rolling friction between the compression spring 12 and the bottom of the sleeve portion 31. Because the frictional resistance of rolling friction is lower than that of sliding friction, wear of the wear components can be reduced, thereby reducing the drive load of the motor.

[0053] In one embodiment, bushing 11 is constructed from a different material than main shaft 8. For example, the first material used to manufacture main shaft 8 is harder than the second material used to manufacture bushing 11, resulting in bushing 11 being constructed from a softer material than the first material, that is, a material having a lower hardness. This allows bushing 11 to primarily wear, and bushing 11 can be a wear component designed to be easily replaceable. If bushing 11 becomes worn, it can be simply replaced without having to replace the entire valve core 3. Consequently, maintenance costs can be significantly reduced.

[0054] In one embodiment, a washer 16 is further disposed between the pressure spring 12 and the second thrust bearing 15 . Specifically, the pressure spring 12 abuts against the second thrust bearing 15 via the washer 16 . The washer 16 can be made of a material softer than the first material, that is, a material with a lower hardness. This allows wear to primarily occur at the washer 16 , making it a wear component designed to be easily replaceable. If the washer 16 becomes worn, it can be simply replaced without having to replace the entire valve core 3 . This significantly reduces maintenance costs.

[0055] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and equivalents may be substituted for elements thereof without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. An electronic expansion valve, comprising: Housing (1); a valve body (2) fixedly connected to the housing (1), wherein the valve body (2) is formed with a valve port (221) at a lower end away from the housing (1); a valve core (3) housed in the valve body (2) in an axially movable manner, a valve needle (32) being formed at a lower portion of the valve core (3), the valve needle (32) being capable of being inserted into or withdrawn from the valve port (221) in response to the axial movement of the valve core (3); as well as A driving mechanism, used for causing the valve core (3) to move axially relative to the valve body (2), the driving mechanism comprising: a nut (7) arranged in the housing (1), wherein a receiving cavity (C) is formed in the nut (7); a main shaft (8) partially disposed in the accommodating chamber (C), the lower end of the main shaft (8) being connected to the valve core (3); a rotor (62) disposed in the housing (1) and driving the spindle (8) to rotate relative to the nut (7); and A guide member (9) is non-rotatably arranged on the nut (7) and at least partially arranged on the inner side of the accommodating chamber (C), wherein an external thread (82) is formed on the outer peripheral surface of the main shaft (8), and a guide tooth (911) is formed on the guide member (9), and the guide tooth (911) can be engaged with the external thread (82) to form a spiral transmission structure to allow the rotational motion of the main shaft (8) to be converted into the axial motion of the main shaft (8), thereby driving the valve core (3) connected to the main shaft (8) to move axially.

2. The electronic expansion valve according to claim 1, wherein: The guide member (9) further includes a first stopper (912) which is arranged on a first side in the axial direction of the guide tooth (911) to limit further axial movement of the main shaft (8) toward the first side, thereby defining a first limit position of the main shaft (8).

3. The electronic expansion valve according to claim 2, wherein: The external thread (82) has a first cut surface (821) at the end facing the first side, and the first cut surface (821) can abut against the first stop portion (912) to limit the external thread (82) from continuing to rotate and limit the main shaft (8) to a first extreme position.

4. The electronic expansion valve according to claim 2, wherein: The guide member (9) further includes a second stop portion (913) which is arranged on a second side opposite to the first side in the axial direction of the guide tooth (911) to limit further axial movement of the main shaft (8) toward the second side, thereby defining a second extreme position of the main shaft (8).

5. The electronic expansion valve according to claim 4, wherein: The external thread (82) has a second cut surface (822) at the end facing the second side, and the second cut surface (822) can abut against the second stop portion (913) to limit the external thread (82) from continuing to rotate and limit the main shaft (8) to a second extreme position.

6. The electronic expansion valve according to any one of claims 1 to 5, wherein: The guide member (9) is in the form of a thin sheet, a through hole is formed on the side wall of the nut (7), and the guide member (9) is at least partially inserted into the through hole, so that the guide teeth (911) are exposed in the accommodating cavity (C) to engage with the external thread (82) on the outer peripheral surface of the main shaft (8) to form the spiral transmission structure.

7. The electronic expansion valve according to claim 6, wherein: The guide member (9) includes an inserting portion (91), the inserting portion (91) is inserted into the inner side of the accommodating cavity through the through hole, and the guide teeth (911) are formed on the inserting portion (91).

8. The electronic expansion valve according to claim 7, wherein: The guide member (9) further includes a main body portion (92) connected to the insertion portion (91), wherein the main body portion (92) is arranged outside the side wall and abuts against the outer peripheral surface of the side wall.

9. The electronic expansion valve according to claim 8, wherein: The axial extension length of the main body portion (92) is greater than the axial extension length of the insertion portion (91), thereby forming a step between the main body portion (92) and the insertion portion (91).

10. The electronic expansion valve according to any one of claims 1 to 5, wherein: The guide member (9) is arranged at a substantially middle position of the nut (7) in the axial direction.

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