Electronic expansion valve

Abstract

This application relates to an electronic expansion valve, which includes a stop seat, a rotor assembly, a lead screw, a valve core assembly, and a valve seat assembly. The valve seat assembly has a valve port. The valve core assembly includes a sliding nut and a valve needle assembly. The end of the lead screw away from the rotor assembly is threadedly engaged with the sliding nut. The sliding nut and the stop seat are engaged by a limiting structure, allowing the lead screw to drive the sliding nut to move the valve core assembly relative to the stop seat along the axial direction of the lead screw, thereby opening or closing the valve port. The limiting structure also prevents the sliding nut from rotating relative to the stop seat around the axis of the lead screw. The electronic expansion valve provided by this application solves the problem of excessive wear between the valve core and the valve seat.

Description

Technical Field

[0001] This application relates to the field of valve body technology, and in particular to an electronic expansion valve. Background Technology

[0002] In existing electronic expansion valves, a coil drives a rotor. The rotor is fixedly connected to a lead screw, and as the rotor rotates, it also drives the lead screw to move up and down along the valve's axis. When the rotor is far from the coil, the coil still needs to provide sufficient driving force; therefore, the coil needs to be large enough. A larger coil increases the overall size of the valve and also increases manufacturing costs.

[0003] How to reduce the overall volume of the valve is the main technical problem that this application aims to solve. Summary of the Invention

[0004] Therefore, it is necessary to provide an electronic expansion valve to solve the problem of excessive wear between the existing valve core and valve seat.

[0005] The electronic expansion valve provided in this application includes a stop seat, a rotor assembly, a lead screw, a valve core assembly, and a valve seat assembly. The valve seat assembly has a valve port. The valve core assembly includes a sliding nut and a valve needle assembly. The end of the lead screw away from the rotor assembly is threadedly engaged with the sliding nut. The sliding nut and the stop seat are engaged by a limiting structure, which allows the lead screw to drive the sliding nut to move the valve core assembly relative to the stop seat along the axial direction of the lead screw, thereby opening or closing the valve port. The limiting structure also prevents the sliding nut from rotating relative to the stop seat around the axis of the lead screw.

[0006] In one embodiment, the circumference of the sliding nut is provided with an anti-rotation protrusion extending radially thereon, and the stop seat is provided with a guide groove extending axially thereon corresponding to the anti-rotation protrusion. The end of the anti-rotation protrusion away from the sliding nut extends into the guide groove and can slide with the guide groove along the axial direction of the stop seat, so that the sliding nut and the stop seat slide with each other along the axial direction of the stop seat. Furthermore, the anti-rotation protrusion and the guide groove constitute a limiting structure.

[0007] In one embodiment, there are multiple anti-rotation protrusions, and the multiple anti-rotation protrusions are evenly distributed along the circumference of the sliding nut.

[0008] In one embodiment, there are also multiple guide grooves, which are evenly distributed along the circumference of the stop seat, and the guide grooves and anti-rotation protrusions are set in a one-to-one correspondence.

[0009] In one embodiment, the number of anti-rotation protrusions and guide grooves is one.

[0010] In one embodiment, the gap between the anti-rotation protrusion and the sidewall of the guide groove is less than or equal to 0.1 mm.

[0011] In one embodiment, the electronic expansion valve further includes a stop ring and a guide rod. The stop seat is provided with an outer guide rail on the outer periphery away from the lead screw. The stop ring is sleeved on the outer periphery of the stop seat and is movably engaged with the outer guide rail. The guide rod is fixedly connected to the rotor assembly or the lead screw so that the rotor assembly can drive the guide rod to push the stop ring to move spirally along the outer guide rail.

[0012] In one embodiment, the stop seat is provided with a first stop portion. When the stop ring stops at the first stop portion, the valve core assembly and the valve port are spaced apart and stop moving. The stop seat is also provided with a second stop portion. When the stop ring stops at the second stop portion, the valve core assembly abuts against the valve port and closes the valve port.

[0013] In one embodiment, the sliding nut includes a main body and a connecting part. The main body is an injection molded part, and the connecting part is a metal part. The sliding nut is threaded to the lead screw through the main body. One end of the connecting part is fixedly connected to the main body, and the other end is welded to the valve needle assembly.

[0014] In one embodiment, the electronic expansion valve further includes a housing that covers the outside of the rotor assembly, a portion of the lead screw, and a portion of the valve core assembly and is welded to the valve seat assembly.

[0015] Compared to existing technologies, by setting a limiting structure, the sliding nut can be prevented from rotating relative to the stop seat around the axis of the lead screw. At this time, the sliding nut can move relative to the lead screw along the axial direction of the lead screw, so that the lead screw can drive the sliding nut to open or close the valve port of the valve core assembly. During normal operation, the rotor assembly and the lead screw do not move axially, which simplifies the overall size of the valve. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A partial structural schematic diagram of an electronic expansion valve according to an embodiment of this application;

[0018] Figure 2 A cross-sectional view of an electronic expansion valve according to an embodiment provided in this application;

[0019] Figure 3 A cross-sectional view of an electronic expansion valve according to another embodiment provided in this application;

[0020] Figure 4A partial structural schematic diagram of an electronic expansion valve according to an embodiment of this application.

[0021] Reference numerals: 100, rotor assembly; 200, lead screw; 300, valve core assembly; 310, sliding nut; 311, anti-rotation protrusion; 314, main body; 315, connecting part; 320, valve needle assembly; 400, valve seat assembly; 410, valve port; 510, stop seat; 511, external thread part; 515, guide groove; 520, stop ring; 530, guide rod; 540, first stop part; 550, second stop part; 800, housing. Detailed Implementation

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] 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.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] 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 is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply 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 that the first feature is at a lower horizontal level than the second feature.

[0026] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of 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 herein includes any and all combinations of one or more of the associated listed items.

[0028] Please see Figures 1-4 In one embodiment, the electronic expansion valve includes a stop seat 510, a rotor assembly 100, a lead screw 200, a valve core assembly 300, and a valve seat assembly 400. The stop seat 510 is fixedly connected to the valve seat assembly 400 and is disposed on the outer periphery of the lead screw 200. The valve seat assembly 400 has a valve port 410. The valve core assembly 300 is movable relative to the valve seat assembly 400 along the axial direction of the lead screw 200. One end of the lead screw 200 is fixedly connected to the rotor assembly 100, and the other end is connected to the valve core assembly 300. The rotor assembly 100 can drive the valve core assembly 300 to move toward or away from the valve port 410 via the lead screw 200.

[0029] Specifically, the electronic expansion valve also includes a stop ring 520 and a guide rod 530. The stop seat 510 has an outer guide rail on its outer periphery opposite to the lead screw 200. The stop ring 520 is sleeved on the outer periphery of the stop seat 510 and movably engages with the outer guide rail. Specifically, the outer guide rail can be an externally threaded portion 511 located on the outer periphery of the stop seat 510 opposite to the lead screw 200. The stop ring 520 is sleeved on the outer periphery of the stop seat 510 and movably threadedly engages with the externally threaded portion 511. Alternatively, the outer guide rail can be a helical spring (not shown) spirally wound around the outside of the stop seat 510. The stop ring 520 moves helically along the extension direction of the helical spring. The guide rod 530 is fixedly connected to the rotor assembly 100 or the lead screw 200, so that the rotor assembly 100 can drive the guide rod 530 to push the stop ring 520 to move helically along the outer guide rail. Furthermore, the lead screw 200 and the valve core assembly 300 are movably threadedly connected.

[0030] The valve core assembly 300 includes a sliding nut 310 and a valve needle assembly 320. The end of the lead screw 200 away from the rotor assembly 100 is threadedly engaged with the sliding nut 310. The sliding nut 310 and the stop seat 510 are engaged by a limiting structure so that the lead screw 200 can drive the sliding nut 310 to move the valve core assembly 300 relative to the stop seat 510 along the axial direction of the lead screw 200 to open or close the valve port 410. The limiting structure can prevent the sliding nut 310 from rotating relative to the stop seat 510 around the axis of the lead screw 200.

[0031] Specifically, it should be noted that the upper part (the portion near the rotor assembly 100) and the lower part (the portion for engaging with the sliding nut 310) of the stop seat 510 can be integrally formed or separately designed. Regardless of the form, the stop seat 510 is fixedly connected to the valve seat assembly (400). By providing a limiting structure, the sliding nut 310 is prevented from rotating relative to the stop seat 510 around the axis of the lead screw 200. At this time, the sliding nut 310 can move relative to the lead screw 200 along the axial direction of the lead screw 200, so that the lead screw 200 can drive the sliding nut 310 to open or close the valve port 410 of the valve core assembly 300. This prevents relative rotation between the sliding nut 310 and the stop seat 510 from causing wear on both.

[0032] It should be noted that the electronic expansion valve also includes a housing 800, which covers the outside of the rotor assembly 100, part of the lead screw 200 and part of the valve core assembly 300 and is welded to the valve seat assembly 400.

[0033] In this embodiment, the sliding nut 310 has a radially extending anti-rotation protrusion 311 on its periphery, and the stop seat 510 has an axially extending guide groove 515 corresponding to the anti-rotation protrusion 311. The end of the anti-rotation protrusion 311 away from the sliding nut 310 extends into the guide groove 515 and can slide with the guide groove 515 along the axial direction of the stop seat 510, so that the sliding nut 310 and the stop seat 510 slide with each other along the axial direction of the stop seat 510. Furthermore, the anti-rotation protrusion 311 and the guide groove 515 constitute a limiting structure.

[0034] Specifically, in one embodiment, there are multiple anti-rotation protrusions 311, and the multiple anti-rotation protrusions 311 are evenly distributed along the circumference of the sliding nut 310. Correspondingly, there are also multiple guide grooves 515, and the multiple guide grooves 515 are evenly distributed along the circumference of the stop seat 510. The guide grooves 515 and the anti-rotation protrusions 311 are arranged in a one-to-one correspondence.

[0035] Thus, when the sidewall of the guide groove 515 restricts the rotation of the anti-rotation protrusion 311, the circumferential force of the sliding nut 310 is uniform, preventing uneven force distribution at various points of the sliding nut 310 from causing deflection and affecting the axial displacement of the sliding nut 310.

[0036] More specifically, the number of anti-rotation protrusions 311 and guide grooves 515 can be two, three, or four, etc., which will not be listed here.

[0037] However, this is not the only embodiment. In other embodiments, the number of anti-rotation protrusions 311 may also be one, which greatly simplifies the structure of the electronic expansion valve.

[0038] In one embodiment, the gap between the anti-rotation protrusion 311 and the sidewall of the guide groove 515 is less than or equal to 0.1 mm.

[0039] It should be noted that each guide groove 515 has two oppositely arranged sidewalls, and the gap between the anti-rotation protrusion 311 and either sidewall is less than or equal to 0.1mm.

[0040] With this configuration, when the anti-rotation protrusion 311 changes its rotation direction, the magnitude of the collision between it and the side wall of the guide groove 515 is reduced, thereby reducing the wear of the anti-rotation protrusion 311 and the side wall of the guide groove 515 and improving the service life of the electronic expansion valve.

[0041] In one embodiment, the stop seat 510 is provided with a first stop portion 540. When the stop ring 520 stops at the first stop portion 540, the valve core assembly 300 and the valve port portion 410 are spaced apart and stop moving.

[0042] In one embodiment, the stop seat 510 is further provided with a second stop portion 550. When the stop ring 520 stops at the second stop portion 550, the valve core assembly 300 abuts against the valve port portion 410 and closes the valve port portion 410.

[0043] By providing the first stop portion 540 and the second stop portion 550, the travel of the stop ring 520 in the external thread portion 511 can be effectively limited, thereby limiting the rotation angle range of the guide rod 530 relative to the stop seat 510. Since the guide rod 530 is fixedly connected to the rotor assembly 100 or the lead screw 200, this arrangement can effectively limit the rotation angle range of the rotor assembly 100, thereby controlling the travel of the valve core assembly 300 relative to the valve port portion 410 and preventing wear between the valve core assembly 300 and the valve port portion 410. Furthermore, this arrangement can also prevent the stop ring 520 from moving to an area outside the external thread portion 511, thus affecting the threaded engagement between the stop ring 520 and the stop seat 510.

[0044] In one embodiment, the sliding nut 310 includes a main body 314 and a connecting part 315. The main body 314 is an injection molded part, and the connecting part 315 is a metal part. The sliding nut 310 is threaded to the lead screw 200 through the main body 314. One end of the connecting part 315 is fixedly connected to the main body 314, and the other end is welded to the valve needle assembly 320.

[0045] The main body 314 is an injection-molded part, which significantly reduces the weight of the sliding nut 310 and simplifies its manufacturing process. The connecting part 315 is a metal part, which facilitates the welding of the valve needle assembly 320 to the sliding nut 310, thereby improving the connection strength between the sliding nut 310 and the valve needle assembly 320. Furthermore, this design allows the same sliding nut 310 to be matched with valve needle assemblies 320 of different specifications; that is, only one sliding nut 310 needs to be manufactured to accommodate valve needle assemblies 320 of different specifications.

[0046] Specifically, the connecting part 315 can be made of copper, stainless steel, aluminum or other alloy materials, which will not be listed here.

[0047] In one embodiment, the connecting portion 315 is embedded in the main body portion 314.

[0048] Specifically, the connecting part 315 is embedded in the main body part 314 through an integral injection molding process, which further reduces the assembly difficulty of the connecting part 315 and the main body part 314 and improves the connection strength between the connecting part 315 and the main body part 314.

[0049] However, this is not the only embodiment. In other embodiments, the connecting portion 315 may also be snapped, glued, welded, or threaded to the main body portion 314.

[0050] 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.

[0051] 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 scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. An electronic expansion valve, characterized in that, It includes a stop seat (510), a rotor assembly (100), a lead screw (200), a valve core assembly (300), and a valve seat assembly (400), wherein the valve seat assembly (400) is provided with a valve port (410). The valve core assembly (300) includes a sliding nut (310) and a valve needle assembly (320). The end of the lead screw (200) away from the rotor assembly (100) is threadedly engaged with the sliding nut (310). The sliding nut (310) and the stop seat (510) are engaged by a limiting structure so that the lead screw (200) can drive the sliding nut (310) to move the valve core assembly (300) relative to the stop seat (510) along the axial direction of the lead screw (200) to open or close the valve port (410). The limiting structure can prevent the sliding nut (310) from rotating relative to the stop seat (510) around the axis of the lead screw (200). The sliding nut (310) has a radially extending anti-rotation protrusion (311) on its periphery. The stop seat (510) has a axially extending guide groove (515) corresponding to the anti-rotation protrusion (311). The end of the anti-rotation protrusion (311) away from the sliding nut (310) extends into the guide groove (515) and can slide with the guide groove (515) along the axial direction of the stop seat (510) so that the sliding nut (310) and the stop seat (510) slide with each other along the axial direction of the stop seat (510). The anti-rotation protrusion (311) and the guide groove (515) constitute the limiting structure. The electronic expansion valve also includes a stop ring (520) and a guide rod (530). The stop seat (510) is provided with an outer guide rail on the outer periphery away from the lead screw (200). The stop ring (520) is sleeved on the outer periphery of the stop seat (510) and is movably engaged with the outer guide rail. The guide rod (530) is fixedly connected to the rotor assembly (100) or the lead screw (200) so that the rotor assembly (100) can drive the guide rod (530) to push the stop ring (520) to move spirally along the outer guide rail. The stop seat (510) is provided with a first stop portion (540). When the stop ring (520) stops at the first stop portion (540), the valve core assembly (300) and the valve port portion (410) are spaced apart and stop moving. The stop seat (510) is also provided with a second stop (550). When the stop ring (520) stops at the second stop (550), the valve core assembly (300) abuts against the valve port (410) and closes the valve port (410).

2. The electronic expansion valve according to claim 1, characterized in that, The number of anti-rotation protrusions (311) is multiple, and the multiple anti-rotation protrusions (311) are evenly distributed along the circumference of the sliding nut (310).

3. The electronic expansion valve according to claim 2, characterized in that, The number of guide grooves (515) is also multiple. The multiple guide grooves (515) are evenly distributed along the circumference of the stop seat (510), and the guide grooves (515) and the anti-rotation protrusions (311) are set in a one-to-one correspondence.

4. The electronic expansion valve according to claim 1, characterized in that, The number of the anti-rotation protrusion (311) and the guide groove (515) is one.

5. The electronic expansion valve according to claim 1, characterized in that, The gap between the anti-rotation protrusion (311) and the sidewall of the guide groove (515) is less than or equal to 0.1 mm.

6. The electronic expansion valve according to claim 1, characterized in that, The sliding nut (310) includes a main body (314) and a connecting part (315). The main body (314) is an injection molded part, and the connecting part (315) is a metal part. The sliding nut (310) is threaded to the lead screw (200) through the main body (314). One end of the connecting part (315) is fixedly connected to the main body (314), and the other end is welded to the valve needle assembly (320).

7. The electronic expansion valve according to claim 1, characterized in that, It also includes a housing (800) which covers the outside of the rotor assembly (100), a portion of the lead screw (200) and a portion of the valve core assembly (300) and is welded to the valve seat assembly (400).

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