Electronic expansion valve

Abstract

This invention relates to an electronic expansion valve comprising a stepper motor and a valve core assembly (2), the stepper motor comprising a stator and a rotor. The valve core assembly includes a drive component coupled to the rotor, the drive component having a first rod portion (33) and a downwardly opening first cylindrical portion (34), the first rod portion extending upward from the top of the first cylindrical portion and having external threads. The valve core assembly also includes a stationary nut component having a hollow second rod portion (35) and a downwardly opening second cylindrical portion (36), the second rod portion extending upward from the top of the second cylindrical portion and having internal threads. The first cylindrical portion is received within the second cylindrical portion, the first rod portion passing through the second rod portion, the external threads engaging with the internal threads. A solid valve needle is held in a chamber of the first cylindrical portion through a lower opening of the first cylindrical portion at its upper end. The electronic expansion valve also includes a valve seat having a valve orifice. This electronic expansion valve reduces the accumulation of contaminants in the valve core assembly.

Description

Technical Field

[0001] This application relates to an electronic expansion valve. Background Technology

[0002] Electronic expansion valves are known in practice, for example, in the air conditioning systems of motor vehicles or the temperature regulation systems of power batteries. These known electronic expansion valves may include a stepper motor and a valve core assembly, the stepper motor comprising a stator and a rotor, the rotor being motion-coupled with the valve needle. In known electronic expansion valves, the valve needle has a hollow cylindrical portion that opens upwards. The applicant has found that, on the one hand, the hollow cylindrical portion of the valve needle results in a large valve needle diameter, which is detrimental to the compact design of the electronic expansion valve; on the other hand, as the electronic expansion valve operates for an extended period, dirt gradually accumulates in the upward-opening cylindrical portion of the valve needle, causing the performance of the electronic expansion valve to gradually deteriorate, and even cease to function properly. Summary of the Invention

[0003] The objective of this invention is to provide an electronic expansion valve that can have an improved service life.

[0004] The task is accomplished by an electronic expansion valve comprising a stepper motor and a valve core assembly. The stepper motor includes a stator and a rotor. The valve core assembly includes a drive component coupled to the rotor, the drive component having a first rod portion and a hollow first cylindrical portion connected to the first rod portion, the first cylindrical portion opening downwards, the first rod portion extending upwards from the top of the first cylindrical portion, and the first rod portion having external threads. The valve core assembly also includes a stationary nut component having a hollow second rod portion and a hollow second cylindrical portion connected to the second rod portion, the second cylindrical portion opening downwards, the second rod portion extending upwards from the top of the second cylindrical portion, and the second rod portion having internal threads. The first cylindrical portion is received within the second cylindrical portion, the first rod portion passes through the second rod portion, and the external threads of the first rod portion engage with the internal threads of the second rod portion. A solid valve needle is held in the chamber of the first cylindrical portion through its upper end opening at the lower side of the first cylindrical portion. The electronic expansion valve further includes a valve seat having a valve orifice that interacts with the valve needle, particularly the free end of the valve needle, wherein when the transmission component is driven by the rotor to rotate in a first direction, the valve needle can move toward the valve orifice, thereby reducing the fluid passage gap between the valve needle and the valve orifice, and when the transmission component is driven by the rotor to rotate in a second direction opposite to the first direction, the valve needle can move away from the valve orifice, thereby increasing the fluid passage gap between the valve needle and the valve orifice.

[0005] In the valve core assembly of the electronic expansion valve according to the present invention, both the first cylindrical portion of the transmission member and the second cylindrical portion of the nut member open downwards. In this case, contaminants are less likely to enter the cylindrical portions. On the other hand, even if contaminants unintentionally enter the corresponding cylindrical portions, they tend to leave the corresponding cylindrical portions under their own gravity, making it difficult for them to accumulate. Conversely, in the prior art electronic expansion valves known from practice, the cylindrical portion of the valve needle opens upwards, making it easy for contaminants to accumulate, thus leading to a deterioration in the performance of the electronic expansion valve. Furthermore, in the valve core assembly of the electronic expansion valve according to the present invention, the valve needle can be solid, which facilitates a compact size of the entire valve core assembly including the valve needle, and consequently, a compact size of the entire electronic expansion valve.

[0006] In some embodiments, the transmission component is fixedly connected to the rotor, for example by welding.

[0007] In some embodiments, the rotor may be coupled to the transmission component via a reduction gear mechanism.

[0008] In some embodiments, the valve core assembly includes the valve seat; in other words, the valve seat may be a component of the valve core assembly, or the valve seat may be integrated into the valve core assembly.

[0009] In some embodiments, the transmission component can be driven by a rotor to rotate in a first direction until the valve orifice is completely closed by the valve needle.

[0010] In some embodiments, the valve core assembly includes a spring, preferably a helical spring, disposed in a first cylindrical portion, which elastically supports the valve needle in the first cylindrical portion.

[0011] In some embodiments, the spring is supported at its upper end on the top of the first cylindrical portion, particularly by means of a first spring seat, and at its lower end on the upper end of the valve needle, particularly indirectly on the upper end of the valve needle via a sliding support fixed to the upper end of the valve needle.

[0012] In some embodiments, the lower opening of the first cylindrical portion is closed by a sealing member, and the valve needle extends into the chamber of the first cylindrical portion through the upper end of the sealing member, the sealing member working together with the sliding support member.

[0013] In some embodiments, the sliding support and the closing component have contact surfaces that can slide against each other, particularly complementary conical contact surfaces.

[0014] In some embodiments, the valve assembly further includes a cylindrical cover having a closed top and an open lower end that fits onto the valve seat.

[0015] In some embodiments, the nut component is fixed in the valve seat.

[0016] In some embodiments, the rotor is rotatably supported in a cylindrical cover.

[0017] In some embodiments, the transmission component and nut component are at least largely housed within a cylindrical enclosure.

[0018] In some embodiments, the upper end of the first rod of the transmission component extends from the second rod of the nut member and is connected to the rotor via a connecting member.

[0019] In some embodiments, the upper end of the first rod portion of the transmission component is welded to the connecting member, which is fixed radially inside the rotor. Alternatives to welding, such as press fitting or connection via fastening elements, are also considered.

[0020] In some embodiments, the electronic expansion valve includes a control head assembly.

[0021] In some embodiments, the control head assembly and the valve core assembly are configured as separate structural units.

[0022] In some embodiments, the control head assembly includes an injection-molded structural unit.

[0023] In some embodiments, the control head assembly includes a stator of a stepper motor, and the control head assembly includes a first receiving chamber into which the valve core can be inserted.

[0024] In some embodiments, the first receiving chamber is cylindrical, particularly cylindrical, and the valve core can be inserted into the cylindrical first receiving chamber with a cylindrical cover.

[0025] In some embodiments, the control head assembly further includes a second receiving chamber separate from the first receiving chamber, the second receiving chamber receiving a circuit board configured for controlling a stepper motor, and the control head assembly having an electrical interface.

[0026] In some embodiments, the second receiving chamber has an upper opening that is closed by a cover plate.

[0027] In some embodiments, the control head assembly has a first section and a second section immediately following the first section, the stator of the stepper motor is disposed in the first section, and the second receiving chamber is disposed in the second section.

[0028] In some embodiments, the first receiving chamber extends from the end of the first section away from the second section into a second receiving chamber in the second section.

[0029] In some embodiments, the circuit board is arranged transversely to the longitudinal axis of the first receiving chamber.

[0030] In some embodiments, a Hall sensor is provided in the second receiving chamber, the Hall sensor being configured to detect the rotor stall.

[0031] In some implementations, the Hall sensor is mounted on a circuit board.

[0032] In some embodiments, the control head assembly also includes a conductor electrically connected to the stator housing for grounding the circuit board.

[0033] In some embodiments, the electronic expansion valve further includes a fluid interface component having a fluid inlet and a fluid outlet, a valve seat inserted into the fluid interface component, the fluid inlet of the fluid interface component communicating with the fluid inlet of the valve seat, and the fluid outlet of the valve seat communicating with the fluid outlet of the fluid interface component.

[0034] In some embodiments, the control head assembly is fixed to the fluid interface component, the control head assembly is adjacent to the fluid interface component, and the valve core assembly is received in the control head assembly and the fluid interface component.

[0035] In some embodiments, the control head assembly includes a connecting plate having a first plate region fixed to the end side of the control head assembly facing the fluid interface component and a second plate region bent from the first plate region, the second plate region being fastened to a side surface of the fluid interface component by at least one fastening element, such as two screws.

[0036] In some embodiments, the control head assembly has a plurality of protrusions on the end side that pass through the first plate region, the protrusions being supported on the top side of the fluid interface component.

[0037] In some embodiments, the valve seat has a surrounding flange that supports the top side of the fluid interface component.

[0038] In some embodiments, the solid valve needle includes: a body portion having a first diameter; a first upper section having a second diameter, smaller than the first diameter, immediately adjacent to the body portion; a second upper section having a third diameter, smaller than the second diameter, immediately adjacent to the first upper section; a lower section having a fourth diameter, smaller than the first diameter, immediately adjacent to the body portion; and a tip that tapers downwards from the lower section.

[0039] In some embodiments, the sliding support is fixed to the second upper section, and the first upper section passes through a closing member that closes the lower opening of the first cylindrical portion.

[0040] In some embodiments, the tip works in conjunction with the valve hole of the valve seat.

[0041] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features. Attached Figure Description

[0042] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention to further illustrate its characteristics, features, advantages, and implementation methods. It is understood that the present invention does not limit these specific embodiments.

[0043] Figure 1 A perspective view showing an electronic expansion valve according to an exemplary embodiment of the present invention.

[0044] Figure 2 show Figure 1 A cross-sectional view of an electronic expansion valve.

[0045] Figure 3 show Figure 1 A perspective view of the control head assembly of the electronic expansion valve.

[0046] Figure 4 show Figure 3 Side view of the control head assembly.

[0047] Figure 5 show Figure 3 A cross-sectional view of the control head assembly.

[0048] Figure 6 show Figure 1 A perspective view of the valve core assembly of an electronic expansion valve.

[0049] Figure 7 show Figure 6 A cross-sectional view of the valve core assembly.

[0050] Figure 8 show Figure 6 A perspective view of a structural unit of the valve core assembly.

[0051] Figure 9 show Figure 8 A sectional view of the structural unit. Detailed Implementation

[0052] Several exemplary embodiments will now be described more fully with reference to the accompanying drawings. It should be understood that elements not essential for understanding the invention may be omitted from the drawings for ease of illustration and understanding. In the drawings, the same reference numerals may denote the same parts or parts that function identically. Numerous specific details, such as examples of specific parts, devices, and methods, are set forth in the following description to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that not all of these specific details are necessarily required. The exemplary embodiments should not be construed as limiting.

[0053] An exemplary electronic expansion valve 100 according to the invention is shown in the accompanying drawings. The electronic expansion valve 100 can be used, for example, in a motor vehicle, specifically in the vehicle's air conditioning system or the temperature control system of a power battery. The electronic expansion valve 100 includes a control head assembly 1, a valve core assembly 2, and a fluid interface component 3. The control head assembly 1 and the valve core assembly 2 are configured as two separate structural units. The control head assembly 1 may include an injection-molded structural unit and components mounted to the injection-molded structural unit, such as the circuit board 17 and cover plate 13, which will be described below. The fluid interface component 3 has a fluid inlet 31 and a fluid outlet 32, the fluid inlet 31 of the fluid interface component 3 leading to the fluid inlet 25 of the valve seat 24, which will be described below, and the fluid outlet 43 of the valve seat 24 leading to the fluid outlet 32 ​​of the fluid interface component 3. The control head assembly 1 can be secured to a side surface of the fluid interface component 3 by two fastening elements 15 configured as screws. The valve core assembly 2 of the electronic expansion valve 100 is received within the control head assembly 1 and the fluid interface component 3. The electronic expansion valve 100 includes a stepper motor 5, which includes a stator 20 and a rotor 26. The stator 20 of the stepper motor 5 can be integrated into the control head assembly 1, and the rotor 26 of the stepper motor 5 can be integrated into the valve core assembly 2. Depending on the actual needs, the fluid flow can be either unidirectional or bidirectional. Therefore, generally speaking, the fluid inlet 31 can be referred to as the first fluid interface of the fluid interface component, and the fluid inlet 32 ​​can be referred to as the second fluid interface of the fluid interface component. Correspondingly, the fluid inlet 25 can be referred to as the first fluid interface of the valve seat, and the fluid outlet 43 can be referred to as the second fluid interface of the valve seat.

[0054] Figures 3 to 5 The control head assembly 1 is shown in more detail. The control head assembly 1 includes a first receiving chamber 21. The first receiving chamber 21 may be cylindrical. The valve core assembly 2 can be inserted into the first receiving chamber 21. Specifically, the valve core assembly 2 may have a cylindrical cover 23 (see...). Figure 6 and Figure 7 The control head assembly 1 is inserted into the cylindrical first receiving chamber 21. The control head assembly 1 also includes a second receiving chamber 22 separate from the first receiving chamber 21, in which a circuit board 17 can be disposed, which is configured to control the stepper motor 5. The second receiving chamber 22 may have an upper opening, which is closed by a cover plate 13. The cover plate 13 may be removably or non-removably mounted in the open upper opening of the second receiving chamber 22. The control head assembly 1 may also have an electrical interface 16. The electrical interface 16 enables the circuit board 17 to be connected to an external device and / or power supply. A Hall sensor 18 may be additionally disposed in the second receiving chamber 22. The Hall sensor 18 may be disposed on the circuit board. The Hall sensor 18 is configured to detect stall of the rotor 26. The control head assembly 1 may also include a housing 8 (see stator) for grounding the circuit board 17. Figure 5 19. Conductors connected by electricity.

[0055] The control head assembly 1 can be divided into a first section 11 and a second section 12 immediately following the first section 11. The stator 20 of the stepper motor 5 is disposed in the first section 11. The second receiving chamber 22 can be disposed in the second section 12. The first receiving chamber 21 can extend from the end of the first section 11 away from the second section 12 into the second receiving chamber 22 in the second section 12. The circuit board 17 can be arranged transversely to the longitudinal axis of the first receiving chamber 21.

[0056] The control head assembly 1 may include a connecting plate 14 having a first plate region 14a fixed to an end side of the control head assembly 1 and a second plate region 14b bent from the first plate region 14a. The first plate region 14a may be fixed to an injection-molded body, for example, in an injection molding process. Alternatively, the first plate region 14a may be fixed to the end side of the control head assembly 1 by hot riveting or welding. The second plate region 14b is fastened to the side surface of the fluid interface component 3 by at least one fastening element 15, or in the current embodiment by two screws. The control head assembly 1 may have a plurality of protrusions 6 on the end side passing through the first plate region 14a, the protrusions 6 being supported on the top side of the fluid interface component 3. In an alternative embodiment, the connecting portion 14 may have a first plate region 14a and two opposing second plate regions 14b that bend from the first plate region 14a. The two second plate regions 14b may be substantially parallel to each other and are respectively connected to one side surface of the fluid interface component 3 by means of one or more fastening elements 15.

[0057] Figure 6 and Figure 7The valve core assembly 2 is shown in more detail. This valve core assembly 2 includes a cylindrical cover 23 and a valve seat 24. The cylindrical cover 23 has a closed top and is fitted onto the valve seat 24 with an open lower end. The rotor 26 of the stepper motor 5 is rotatably supported within the cylindrical cover 23. The valve seat 24 may have a surrounding flange 7 and is supported on the top side of the fluid interface component 3 (see [link to documentation]). Figure 2 It goes without saying that a seal 9 can be provided between the valve seat 24 and the fluid interface component 3 to achieve a fluid seal. Figure 7 Two seals 9 are visible. The valve core assembly 2 includes a transmission component 28 coupled to the rotor 26. Here, the transmission component 28 is fixedly connected to the rotor 26, for example, by welding. Specifically, the upper end of the transmission component 28 can be torsionally connected to the rotor 26 via a connecting member 27 disposed radially inside the rotor 26. For example, the upper end of the transmission component 28 can be welded to the connecting member 27, and the connecting member 27 can be fixedly connected to the rotor 26.

[0058] The transmission component 28 has a first rod portion 33 and a hollow first cylindrical portion 34 connected to the first rod portion 33. The first cylindrical portion 34 opens downward, the first rod portion 33 extends upward from the top of the first cylindrical portion 34, and the first rod portion 33 has an external thread 37.

[0059] The valve core assembly 2 further includes a stationary nut member 29 having a hollow second rod portion 35 and a hollow second cylindrical portion 36 connected to the second rod portion 35. The second cylindrical portion 36 is downwardly open, the second rod portion 35 extends upward from the top of the second cylindrical portion 36, and the second rod portion 35 has internal threads. The first cylindrical portion 34 is received in the second cylindrical portion 36, the first rod portion 33 passes through the second rod portion 35, and the external thread 37 of the first rod portion 33 engages with the internal thread of the second rod portion 35. The upper end of the first rod portion 33 protrudes from the second rod portion 35.

[0060] The valve core assembly 2 also includes a solid valve needle 30. The valve needle 30 is held in the chamber of the first cylindrical portion 34 through a lower opening in the first cylindrical portion 34 at its upper end. Specifically, the valve core assembly 2 may include a spring 39, in the current embodiment a helical spring, disposed in the first cylindrical portion 34. The spring 39 is supported at its upper end on the top of the first cylindrical portion 34, in the current embodiment by means of a first spring seat 38. The spring 39 is supported at its lower end on the upper end of the valve needle 30, in the current embodiment indirectly supported on the upper end of the valve needle 30 via a sliding support 40 fixed to the upper end of the valve needle 30. The lower opening of the first cylindrical portion 34 is closed by a closing member 41, through which the upper end of the valve needle 30 extends into the chamber of the first cylindrical portion 34. The closing member 41 can cooperate with the sliding support 40, and they may have complementary tapered contact surfaces that can slide against each other.

[0061] The valve core assembly 2 may include the valve seat 24 mentioned above. The valve seat 24 has a valve hole 43 that interacts with the valve needle 30. The valve hole 43 may interact, in particular, with the free end 42 of the valve needle 30. The free end 42 of the valve needle 30 may taper gradually. When the transmission member 28 is driven to rotate in the first direction by the rotor 26, the rotational movement of the transmission member 28 in the first direction can cause the transmission member 28 to move downward through the engagement of the external thread 37 on the first rod portion 33 of the transmission member 28 with the internal thread in the second rod portion 35 of the nut member 29, and thus the valve needle 30 can move toward the valve hole 43, so that the fluid flow gap between the valve needle 30 and the valve hole 43 can be reduced. Conversely, when the transmission component 28 is driven by the rotor 26 to rotate in a second direction opposite to the first direction, the rotational movement of the transmission component 28 in the second direction can cause an upward movement of the transmission component 28 through the engagement of the external thread 37 on the first rod portion 33 of the transmission component 28 with the internal thread in the second rod portion 35 of the nut component 29. Consequently, the valve needle 30 can move away from the valve hole 43, increasing the fluid passage gap between the valve needle 30 and the valve hole 43. Typically, the transmission component 28 can be driven by the rotor 26 to rotate in the first direction until the valve hole 43 is completely closed by the free end 42 of the valve needle 30. The nut component 29 can be fixed in the valve seat 24, making the nut component 29 stationary. The valve seat 24 may have a surrounding flange 7 supported on the top side of the fluid interface component 3. The transmission component 28 and the nut component 29 can be at least largely received within the cylindrical cover 23.

[0062] In one exemplary application, starting from a first terminal position where the valve needle 30 completely closes the valve orifice 43 of the valve seat 24 with its free end 42 (in which the spring 39 is compressed to a predetermined degree between the transmission member 28 and the valve needle 30), by rotating the transmission member 28 in a second direction, the valve needle 30 initially remains closed to the valve orifice 43, and the spring 39 gradually relaxes; when the closing member 41 contacts the valve needle 30, by continuing to rotate the transmission member 28 in the second direction, the valve needle 30 is lifted from the valve seat 24 until an upper second terminal position. In the second terminal position, the fluid flow gap between the valve needle 30 and the valve orifice 43 is at its maximum, and therefore the electronic expansion valve 100 has its maximum flow capacity at this time. The closing process of the electronic expansion valve 100 from the second terminal position to the first terminal position is performed in reverse. First, by rotating the transmission component 28 in the first direction, the transmission component 28 moves downward together with the valve needle 30 until the valve needle 30 contacts the valve hole 43 of the valve seat 24. Then, by continuing to rotate the transmission component 28 in the first direction, the spring 39 is compressed to a predetermined degree, so that the valve needle 30 can be reliably and interference-resistantly held in the position where the valve hole 43 is completely closed.

[0063] In an exemplary specific design of a solid valve needle 30, the valve needle 30 may include: a body portion 30a having a first diameter; a first upper section having a second diameter, smaller than the first diameter, immediately adjacent to the body portion; a second upper section having a third diameter, smaller than the second diameter, immediately adjacent to the first upper section; a lower section 30b having a fourth diameter, smaller than the first diameter, immediately adjacent to the body portion 30a; and a pointed portion that tapers downwards from the lower section. This pointed portion may form the aforementioned free end portion 42. The fourth diameter may, for example, be approximately equal to the second diameter. The first upper section passes through a closing member 41. A sliding support member 40 is fitted onto the second upper section.

[0064] exist Figure 8 and Figure 9 In the illustrated state, spring 39 presses the sliding support 40 against the closing member 41. When the valve needle 30, with its free end 42, sits in the valve hole 43 of the valve seat 24, the first upper section slides within the closing member 41 as the transmission member 28 continues to move downwards, separating the sliding support 40 and the closing member 41, and compressing the spring 39. The sliding support 40 can be connected to the second upper section in any suitable manner, such as by press-fit, bonding, welding, threaded connection, or other means. The closing member 41 can be connected to the first cylindrical portion 34 in any suitable manner, such as by press-fit, bonding, welding, threaded connection, or other means.

[0065] In addition, as by Figure 8 and Figure 9It can be seen that the transmission component 28, the valve needle 30, and the components received in the first cylindrical portion 34 can form a structural unit 4, which can be assembled with other components of the valve core assembly 2.

[0066] In an alternative embodiment, the solid valve needle 30 may be rigidly fixed at its upper end within the first cylindrical portion 34. In this case, it is preferable that the valve seat 24 is elastically supported, or that the valve seat 24 has an elastically supported movable part that interacts with a valve orifice that cooperates with the valve needle.

[0067] It should be noted that the terminology used herein is for illustrative purposes only and is not intended to limit the disclosure. The singular forms “a” and “the one” as used herein should include the plural forms unless the context explicitly states otherwise. It is understood that the terms “comprising” and “including,” and other similar terms, when used in the application documents, specifically describe the presence of the stated operation, element, and / or component, without excluding the presence or addition of one or more other operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes all arbitrary combinations of one or more of the associated listed items. In the description of the drawings, similar reference numerals always denote similar elements.

[0068] The thickness of the elements in the accompanying drawings may be exaggerated for clarity. It is also understood that if an element is described as being on, coupled to, or connected to another element, then the element may be directly formed on, coupled to, or connected to the other element, or there may be one or more intermediate elements between them. Conversely, if the expressions "directly on," "directly coupled to," and "directly connected to" are used herein, it indicates that there is no intermediate element. Other terms used to describe relationships between elements should be interpreted similarly, such as "between" and "directly between," "attached" and "directly attached," "adjacent" and "directly adjacent," etc.

[0069] Terms such as “top,” “bottom,” “above,” “below,” “over,” “under,” etc., are used to describe the relationship of one element, layer, or region relative to another element, layer, or region, as shown in the accompanying drawings. It is understood that these terms should also encompass other orientations of the device in addition to those described in the accompanying drawings.

[0070] It is understood that although the terms "first," "second," etc., may be used herein to describe different elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. Therefore, a first element may be referred to as a second element without departing from the teachings of the inventive concept.

[0071] It can also be considered that all the exemplary embodiments disclosed herein can be arbitrarily combined with each other. Finally, it should be noted that the above embodiments are merely for understanding the present invention and do not constitute a limitation on the scope of protection of the present invention. For those skilled in the art, modifications can be made based on the above embodiments, and these modifications do not depart from the scope of protection of the present invention.

Claims

1. An electronic expansion valve (100) comprising a stepper motor (5) and a valve core assembly (2), the stepper motor comprising a stator (20) and a rotor (26), characterized in that, The valve core assembly includes a transmission component (28) coupled to the rotor, preferably the transmission component is fixedly connected to the rotor, the transmission component has a first rod portion (33) and a hollow first cylindrical portion (34) connected to the first rod portion, the first cylindrical portion is open downward, the first rod portion extends upward from the top of the first cylindrical portion, and the first rod portion has external threads (37). The valve core assembly also includes a stationary nut component (29) having a hollow second rod portion (35) and a hollow second cylindrical portion (36) connected to the second rod portion, the second cylindrical portion opening downwards, the second rod portion extending upwards from the top of the second cylindrical portion, and the second rod portion having internal threads; The first cylindrical portion (34) is received within the second cylindrical portion (36), the first rod portion (33) passes through the second rod portion (35), and the external thread of the first rod portion engages with the internal thread of the second rod portion; and The solid valve needle (30) is held in the chamber of the first cylindrical part through the lower opening of the first cylindrical part at its upper end; The electronic expansion valve further includes a valve seat (24), preferably the valve core assembly includes the valve seat, the valve seat having a valve hole (43) that interacts with the valve needle, especially with the free end of the valve needle, wherein when the transmission member (28) is driven to rotate in a first direction by the rotor (26), the valve needle (30) can move toward the valve hole (43), so that the fluid passage gap between the valve needle and the valve hole can be reduced, and when the transmission member (28) is driven to rotate in a second direction opposite to the first direction by the rotor (26), the valve needle (30) can move away from the valve hole (43), so that the fluid passage gap between the valve needle and the valve hole can be increased, preferably the transmission member (28) can be driven to rotate in the first direction by the rotor (26) until the valve hole is completely closed by the valve needle.

2. The electronic expansion valve according to claim 1, characterized in that The valve core assembly (2) includes a spring (39), preferably a helical spring, disposed in the first cylindrical portion, which elastically supports the valve needle in the first cylindrical portion; Preferably, the spring is supported at its upper end on the top of the first cylindrical portion (34), especially by means of the first spring seat (38), and at its lower end on the upper end of the valve needle, especially indirectly on the upper end of the valve needle via a sliding support (40) fixed to the upper end of the valve needle. Preferably, the lower opening of the first cylindrical portion is closed by a sealing member (41), and the valve needle extends into the chamber of the first cylindrical portion through the sealing member at its upper end. The sealing member works together with the sliding support member. Preferably, the sliding support member and the sealing member have contact surfaces that can slide against each other, especially complementary conical contact surfaces.

3. The electronic expansion valve according to claim 1 or 2, characterized in that The valve core assembly (2) also includes a cylindrical cover (23) having a closed top and an open lower end that is fitted onto the valve seat (24), the nut member (29) being fixed in the valve seat (24), the rotor (26) being rotatably supported in the cylindrical cover (23), and the transmission member (28) and the nut member (29) being received at least substantially in the cylindrical cover (23).

4. The electronic expansion valve according to any one of claims 1 to 3, characterized in that, The upper end of the first rod portion (33) of the transmission component (28) extends from the second rod portion (35) of the nut component (29) and is fixedly connected to the rotor (26) via the connecting member (27).

5. The electronic expansion valve according to any one of claims 1 to 4, characterized in that The electronic expansion valve includes a control head assembly (1), which is a separate structural unit from the valve core assembly (2). Preferably, the control head assembly includes an injection-molded structural unit. The control head assembly (1) includes a stator (20) of a stepper motor (5). The control head assembly includes a first receiving chamber (21), which is preferably cylindrical. The valve core assembly (2) can be inserted into the first receiving chamber, preferably with a cylindrical cover (23). The control head assembly also includes a second receiving chamber (22) separate from the first receiving chamber. The second receiving chamber receives a circuit board (17), which is configured to control the stepper motor. The control head assembly has an electrical interface (16). Preferably, the second receiving chamber has an upper opening, which is closed by a cover plate (13).

6. The electronic expansion valve according to claim 5, wherein The control head assembly (1) has a first section (11) and a second section (12) immediately following the first section. The stator (20) of the stepper motor is disposed in the first section, and the second receiving chamber (22) is disposed in the second section. The first receiving chamber (21) extends from the end of the first section away from the second section into the second receiving chamber in the second section. The circuit board (17) is arranged transversely to the longitudinal axis of the first receiving chamber.

7. Electronic expansion valve according to claim 5 or 6, characterized in that A Hall sensor (18) is provided in the second receiving chamber (22), the Hall sensor being configured to detect the stall of the rotor, preferably the Hall sensor being provided on a circuit board.

8. The electronic expansion valve according to any one of claims 5 to 7, characterized in that The control head assembly (1) also includes a conductor (19) electrically connected to the stator housing (8) for grounding the circuit board.

9. The electronic expansion valve according to any one of claims 1 to 8, characterized in that The electronic expansion valve further includes a fluid interface component (3), which has a first fluid interface (31) and a second fluid interface (32). The valve seat (24) is inserted into the fluid interface component. The first fluid interface of the fluid interface component is connected to the first fluid interface (25) of the valve seat, and the second fluid interface (43) of the valve seat is connected to the second fluid interface of the fluid interface component.

10. The electronic expansion valve according to any one of claims 5 to 8, characterized in that, The electronic expansion valve further includes a fluid interface component (3), which has a first fluid interface (31) and a second fluid interface (32). The valve seat (24) is inserted into the fluid interface component. The first fluid interface of the fluid interface component is connected to the first fluid interface (25) of the valve seat, and the second fluid interface (43) of the valve seat is connected to the first fluid interface of the fluid interface component. The control head assembly (1) is fixed on the fluid interface component and is adjacent to the fluid interface component. The valve core assembly (2) is received in the control head assembly and the fluid interface component.

11. The electronic expansion valve according to claim 10, wherein The control head assembly (1) includes a connecting plate (14) having a first plate region (14a) fixed to the end side of the control head assembly facing the fluid interface component and a second plate region (14b) bent from the first plate region, the second plate region being fastened to a side surface of the fluid interface component (3) by at least one fastening element (15).

12. The electronic expansion valve according to claim 11, wherein The control head assembly has a plurality of protrusions (6) on the end side that pass through the first plate region, the protrusions being supported on the top side of the fluid interface component (3).

13. The electronic expansion valve according to any one of claims 1 to 12, characterized in that, The valve seat has a surrounding flange (7) that is supported on the top side of the fluid interface component (3).

14. The electronic expansion valve according to any one of claims 1 to 13, characterized in that, The solid valve needle (30) includes: a main body portion (30a) having a first diameter; a first upper section immediately adjacent to the main body portion having a second diameter smaller than the first diameter; a second upper section immediately adjacent to the first upper section having a third diameter smaller than the second diameter; a lower section immediately adjacent to the main body portion having a fourth diameter smaller than the first diameter; and a pointed portion that gradually tapers downward from the lower section; and The sliding support (40) is fixed to the second upper section, and the first upper section passes through the closing member (41) that closes the lower opening of the first cylindrical section; and The tip, as the free end of the valve needle, works together with the valve hole of the valve seat.

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