Rotor assembly and electronic expansion valve

Abstract

The rotor assembly comprises a magnetic rotor, a limiting structure and a limiting rod, a containing channel is formed in the middle of the magnetic rotor, and openings are formed in the two ends of the containing channel; the limiting structure comprises a main body part and a limiting plate which are connected, the limiting plate is arranged at one end of the main body part, and the limiting plate is connected to the wall surface of the accommodating channel; the limiting rod is connected to the limiting structure; wherein the distance between the opening closer to the limiting plate and the limiting plate is D1, the axial length of the magnetic rotor is L, and L and D1 meet the condition that D1 / L is larger than or equal to 1 / 5 and smaller than or equal to 1 / 2. According to the technical scheme, the axial length of the limiting structure is increased, so that the fixing position of the limiting plate is far away from and closer to the opening of the limiting plate, the gravity center of a rotating movement fulcrum of the rotor assembly sinks, the risk of valve jamming caused by shell wiping due to rotor deflection is solved, and safety and reliability are improved; and meanwhile, the Hall sensing sensitivity can be improved by reducing deflection.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic expansion valves, in particular to a rotor assembly and an electronic expansion valve. Background Art

[0002] The electronic expansion valve controls the rotation of the magnetic rotor assembly of the stepper motor by a pulse input power supply, and the rotor assembly causes the valve needle placed on the rotor to move axially through threaded transmission, thereby controlling the flow rate of the fluid passing through the valve.

[0003] The rotor assembly has a limiting structure fixedly connected to the rotor. Limited by the welding angle of the limiting rod of the rotor assembly, the limiting plate is generally arranged near the opening above the magnetic rotor. Such a rotor assembly is prone to deflection during assembly, and the rotor of the electronic expansion valve may deflect during operation, or even the rotor may rub against the housing and become stuck and fail, which will also affect the sensing sensitivity of the Hall sensor in the coil. Utility Model Content

[0004] The main purpose of the utility model is to provide a rotor assembly, aiming to improve the operating reliability of the rotor assembly of an electronic expansion valve.

[0005] To achieve the above-mentioned purpose, the rotor assembly proposed by the utility model comprises:

[0006] The magnetic rotor has a receiving channel in the middle, and both ends of the receiving channel have openings;

[0007] A limiting structure, comprising a main body and a limiting plate connected to each other, wherein the limiting plate is located at one end of the main body and connected to the wall surface of the accommodating channel;

[0008] A limiting rod connected to the limiting structure;

[0009] The distance between the opening closer to the limiting plate and the limiting plate is D1, the axial length of the magnetic rotor is L, and L and D1 satisfy 1 / 5≤D1 / L<1 / 2.

[0010] In one embodiment, D1 satisfies 8mm≤D1≤15mm.

[0011] In one embodiment, the main body is cylindrical, and a mounting ring is protrudingly provided on the main body in the circumferential direction. The mounting ring has an end surface facing the limiting plate, and the limiting rod is welded to the end surface.

[0012] In one embodiment, the distance between the end surface and the limiting plate is D2, and D2 satisfies 5mm≤D2≤10mm.

[0013] In one embodiment, the outer diameter of the limiting plate is greater than the outer diameter of the main body.

[0014] In one embodiment, an annular gap is provided between the limiting plate and the main body, and the annular gap is used for allowing the limiting rod to pass through.

[0015] In one embodiment, the limiting structure further includes a connecting column, one end of which is connected to the limiting plate, and the other end of which is connected to the mounting ring, and a hollow space between the connecting column and the main body is provided for the limiting rod to pass through.

[0016] In one embodiment, when the number of the connecting posts is set to two, the two connecting posts are symmetrically distributed relative to the main body.

[0017] In one embodiment, a connecting platform is protruding from the magnetic rotor toward the accommodating channel, and the limiting plate is connected to the connecting platform.

[0018] In one embodiment, the limiting structure is made of metal.

[0019] The utility model also proposes an electronic expansion valve, which includes a rotor assembly, wherein the rotor assembly includes a magnetic rotor, a limiting structure and a limiting rod, wherein an accommodating channel is opened in the middle of the magnetic rotor, and openings are provided at both ends of the accommodating channel; the limiting structure includes a main body and a limiting plate connected to each other, wherein the limiting plate is located at one end of the main body, and the limiting plate is connected to the wall surface of the accommodating channel; the limiting rod is connected to the limiting structure; wherein the distance between the opening closer to the limiting plate and the limiting plate is D1, the axial length of the magnetic rotor is L, and L and D1 satisfy 1 / 5≤D1 / L≤1 / 2.

[0020] The technical solution of the utility model increases the axial length of the limit structure so that the fixed position of the limit plate is moved away from the opening closer to the limit plate, thereby sinking the center of gravity of the moving fulcrum of the rotation of the rotor assembly, thereby solving the risk of the rotor swing causing the housing to rub and cause the valve to get stuck, thereby improving safety and reliability. At the same time, reducing the swing can also improve the sensitivity of the Hall sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a rotor assembly of the background technology in a cross-sectional perspective;

[0023] Figure 2 It is a schematic structural diagram of the rotor assembly of the utility model in a cross-sectional perspective;

[0024] Figure 3 It is a schematic structural diagram of the rotor assembly of the utility model in a cross-sectional perspective;

[0025] Figure 4 is a structural schematic diagram of a limiting structure;

[0026] Figure 5 It is a structural schematic diagram of the limiting structure in a cross-sectional perspective;

[0027] Figure 6 is a schematic structural diagram of the limiting structure from another cross-sectional perspective;

[0028] Figure 7 This is a partial structural diagram of an electronic expansion valve.

[0029] Description of Figure Numbers:

[0030] Label name Label name 10 Rotor assembly 200 Limiting structure 20 Valve port assembly 210 Main body 30 Nut assembly 211 Installation ring 40 Valve needle assembly 211a End face 50 case 220 Limit plate 100 Magnetic rotor 230 Connecting column 110 Accommodation channel 240 Annular gap 111 Opening 300 Limit rod 120 Connection Station

[0031] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0035] The electronic expansion valve controls the rotation of the magnetic rotor assembly of the stepper motor by a pulse input power supply, and the rotor assembly causes the valve needle placed on the rotor to move axially through threaded transmission, thereby controlling the flow rate of the fluid passing through the valve.

[0036] The rotor assembly has a limiting structure fixedly connected to the rotor. Limited by the welding angle of the limiting rod of the rotor assembly, the limiting plate is generally arranged near the opening above the magnetic rotor. Such a rotor assembly is prone to deflection during assembly, and the rotor of the electronic expansion valve may deflect during operation, or even become stuck and fail between the rotor and the housing, which may also affect the sensing sensitivity of the Hall sensor in the coil.

[0037] The utility model provides a rotor assembly 10, which is used for an electronic expansion valve.

[0038] In the embodiment of the present utility model, Figure 2 and Figure 4 As shown, the rotor assembly 10 includes a magnetic rotor 100, a limiting structure 200 and a limiting rod 300, wherein a receiving channel 110 is provided in the middle of the magnetic rotor 100, and openings 111 are provided at both ends of the receiving channel 110; the limiting structure 200 includes a main body 210 and a limiting plate 220 connected to each other, wherein the limiting plate 220 is located at one end of the main body 210, and the limiting plate 220 is connected to the wall of the receiving channel 110; the limiting rod 300 is connected to the limiting structure 200; wherein a distance between the opening 111 closer to the limiting plate 220 and the limiting plate 220 is D1, and an axial length of the magnetic rotor 100 is L, and L and D1 satisfy 1 / 5≤D1 / L<1 / 2.

[0039] Specifically, the magnetic rotor 100 is arranged in a cylindrical shape, and the magnetic rotor 100 is a magnetic material. A receiving channel 110 is opened in the middle of the magnetic rotor 100, and the receiving channel 110 is used to accommodate the limiting structure 200 and the limiting rod 300. The limiting structure 200 includes a main body 210 and a limiting plate 220 connected to each other, wherein the main body 210 and the limiting plate 220 may be directly connected in the middle, or the main body 210 and the limiting plate 220 may be indirectly connected, which is not specifically limited here. The limiting plate 220 is arranged at one end of the main body 210. Considering that the main body 210 has one end extending into the receiving channel 110 and the other end slightly exposed from the receiving channel 110, the limiting plate 220 is located at the end of the main body 210 extending into the receiving channel 110, so that the limiting plate 220 is connected to the wall of the receiving channel 110 and the limiting plate 220. The limiting structure 200 is used to fix the limiting rod 300 , so the limiting rod 300 is connected to the limiting structure 200 .

[0040] Considering that the accommodating channel 110 has two opposite openings 111, one opening 111 closer to the limiting plate 220 and the other opening 111 farther from the limiting plate 220, the opening 111 closer to the limiting plate 220 has a distance D1 from the limiting plate 220, and the other opening 111 farther from the limiting plate 220 has a distance D2 from the limiting plate 220. Figure 1 The distance D1 between the original limiting plate 220 in the background art and the opening 111 closer to the original limiting plate 220 is significantly larger, so the center of gravity of the overall rotor assembly 10 is toward the bottom of the magnetic rotor 100 (the bottom is the attached Figure 2 and Figure 3 The center of gravity of the rotating fulcrum sinks, which eliminates the risk of the rotor sway causing the housing 50 to rub and cause the valve to get stuck, thereby improving safety and reliability. At the same time, reducing the sway can also improve the sensitivity of the Hall sensor.

[0041] It should be noted that, considering that the distance between the opening 111 closer to the limit plate 220 and the limit plate 220 is D1, D1 / L should be less than 1 / 2. In addition, in order to meet the requirement of the center of gravity of the moving fulcrum of the overall rotor assembly 10 sinking, D1 / L should be greater than or equal to 1 / 5. Within this range, the reliability of the rotor during operation can be better improved.

[0042] The technical solution of the utility model increases the axial length of the limit structure 200 so that the fixed position of the limit plate 220 is moved away from the opening 111 closer to the limit plate 220, thereby sinking the center of gravity of the fulcrum of the rotation of the rotor assembly 10, thereby solving the risk of the rotor swing causing the housing 50 to rub and cause the valve to get stuck, thereby improving safety and reliability. At the same time, reducing the swing can also improve the sensitivity of the Hall sensor.

[0043] In one embodiment, see Figure 3 , the D1 satisfies 8mm≤D1≤15mm.

[0044] Specifically, the value of D1 cannot be too small, otherwise the center of gravity of the moving fulcrum of the overall rotor assembly 10 cannot sink, so D1 should be greater than or equal to 8 mm. The value of D1 cannot be too large, otherwise the limit plate 220 will occupy the installation space of the nut assembly 30, so D1 should be less than or equal to 15 mm. D1 can take any value within the above range. Within this range, the reliability of the rotor during operation can be better improved.

[0045] In one embodiment, see Figure 2 The main body 210 is cylindrically shaped, and a mounting ring 211 is protrudingly provided on the main body 210 in the circumferential direction. The mounting ring 211 has an end surface 211a facing the limiting plate 220, and the limiting rod 300 is welded to the end surface 211a.

[0046] It should be noted that if Figure 1 As shown, in the background technology, the original limit rod 300 is connected to one side of the original limit plate 220, and in this embodiment, the limit rod 300 needs to maintain its braking function, so the installation position of the limit rod 300 is fixed, so the corresponding limit rod 300 main body 210 is protrudingly provided with a mounting ring 211 that matches it, and the limit rod 300 is welded to the end face 211a of the mounting ring 211, and the welding method is specifically laser welding or argon arc welding.

[0047] In one embodiment, see Figure 4 There is an annular gap 240 between the limiting plate 220 and the main body 210, and the annular gap 240 is used for the limiting rod 300 to pass through.

[0048] It should be noted that, considering that the limiting rod 300 has a fixed welding position, the limiting rod 300 needs to pass through the limiting plate 220 and the mounting ring 211 for welding. In this way, an annular gap 240 is provided between the limiting plate and the main body 210, so that the limiting rod 300 can pass through the limiting plate 220 to the mounting ring 211 and be welded to the mounting ring 211. It should be noted that the annular gap 240 here is a gap formed with at least a ring portion for the limiting rod to pass through, and the annular gap 240 can be a regular ring or an irregular ring, which is not specifically limited here.

[0049] In one embodiment, see Figure 4 and Figure 6 The limiting structure 200 also includes a connecting column 230, one end of which is connected to the limiting plate 220, and the other end of which is connected to the main body 210. A hollow space is provided between the connecting column 230 and the main body 210 for allowing the limiting rod 300 to pass through.

[0050] It should be noted that, according to the above embodiment, the limiting plate 220 and the main body 210 are indirectly connected, that is, the limiting plate 220 and the connecting column 230 are connected through the limiting structure 200, one end of the connecting column 230 is connected to the limiting plate 220, and the other end of the connecting column 230 is connected to the main body 210. Considering that the outer diameter of the limiting plate 220 is larger and the outer diameter of the main body 210 is smaller, the cross section of the connecting column 230 in the axial direction of the magnetic rotor 100 is fan-shaped. Among them, the hollow setting between the connecting column 230 and the main body 210 allows the limiting rod 300 to pass through the hollow position and be welded to the mounting ring 211.

[0051] In one embodiment, see Figure 4 and Figure 6 , the number of the connecting pillars 230 is greater than or equal to two.

[0052] It should be noted that the number of connecting columns 230 is greater than or equal to two. It should be noted that the number of connecting columns 230 can be two, three, four or even more. The more connecting columns 230 there are, the more stable the connection between the main body 210 and the limiting plate 220 is.

[0053] For further information, see Figure 4 and Figure 6 The number of the connecting posts 230 is set to two, and the two connecting posts 230 are symmetrically distributed relative to the main body 210 .

[0054] According to the above-mentioned embodiment, the number of the connecting pillars 230 is greater than or equal to two. In this example, the number of the connecting pillars 230 is further limited to two, and the two connecting pillars 230 are symmetrically distributed relative to the main body 210, that is, the two connecting pillars 230 are distributed along the same radial direction of the magnetic rotor 100, so that the connection relationship between the main body 210 and the limiting plate 220 can be more stable.

[0055] In one embodiment, see Figure 2 The magnetic rotor 100 is provided with a connecting platform 120 protruding toward the accommodating channel 110, and the limiting plate 220 is injection-moldedly connected to the connecting platform 120. The distance between the end surface 211a and the limiting plate 220 is D2, and D2 satisfies 5mm≤D2≤10mm.

[0056] Considering that the magnetic rotor 100 is connected to the limiting plate 220 by injection molding, in order to ensure that the magnetic rotor 100 has good structural strength and does not deform during the injection molding process, the magnetic rotor 100 is provided with a connecting platform 120 protruding toward the accommodating channel 110, and the connecting platform 120 is arranged in a ring shape, so the connecting platform 120 is connected to the periphery of the limiting plate 220 by injection molding.

[0057] It should be noted that the material of the magnetic rotor 100 is a mixture of rare earth material and PPS material, while the material of the limit plate 220 is metal material, so the limit plate 220 and the connecting platform 120 are connected by injection molding. However, the injection molding of the limit plate 220 and the connecting platform 120 is easily affected by high temperature, and the mounting ring 211 will generate high temperature during the welding process with the limit rod 300. Considering that the limit plate 220 is set to be made of metal material, the limit plate 220 is easy to conduct heat to the injection molding of the limit plate 220 and the connecting platform 120, thereby causing the injection molding of the limit plate 220 and the connecting platform 120 to be unstable or even fail. In view of this, a certain distance is set between the mounting ring 211 and the limit plate 220, that is, there is a distance D2 between the end face 211a and the limit plate 220. D2 should be greater than or equal to 5 mm. Within this range, the main body 210 has a certain length from the mounting ring 211 to the limit plate 220, so that it can absorb more heat and enable the main body 210 to have a larger surface area for heat dissipation; correspondingly, D2 should not be too large, otherwise the limit plate 220 will be too close to the nut assembly 30, affecting the normal operation of the electronic expansion valve, so D2 should be less than or equal to 10 mm.

[0058] In one embodiment, see Figure 2 The limiting structure 200 is made of metal material and is manufactured by powder metallurgy process.

[0059] Specifically, the limiting structure 200 is made by powder metallurgy process. Powder metallurgy is an industrial technology for preparing metal powder or using metal powder (or a mixture of metal powder and non-metallic powder) as raw material, forming and sintering, to prepare metal materials, composite materials and various types of products. Powder metallurgy technology has a series of advantages such as significant energy saving, material saving, excellent performance, high product precision and good stability, and is very suitable for mass production. In addition, powder metallurgy technology can minimize the segregation of alloy components and eliminate coarse and uneven casting structure. It plays an important role in the preparation of high-performance rare earth permanent magnet materials, rare earth hydrogen storage materials, rare earth luminescent materials, rare earth catalysts, high-temperature superconducting materials, and new metal materials.

[0060] The utility model also proposes an electronic expansion valve, which includes a rotor assembly 10. The specific structure of the rotor assembly 10 refers to the above embodiment. Since the electronic expansion valve adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0061] As a flow control element, the electronic expansion valve has the advantages of large adjustment range, sensitive response, rapid action, precise adjustment, stable and reliable. Its application in the refrigeration system can achieve system optimization control and has been applied to most cars. Of course, it can also be applied to air conditioners and other refrigeration and heating equipment. It can accurately control the flow of refrigerant, thereby accurately controlling the evaporation temperature, and is generally used in places with high temperature control accuracy. It can also work normally above minus 70 degrees, but the thermal expansion valve can only work normally at minus 60 degrees.

[0062] In one embodiment, the electronic expansion valve further comprises a valve needle assembly 40, the valve port assembly 20 has a valve port, and the valve needle assembly 40 is movably arranged on the valve seat to open or close the valve port. A guide sleeve (not shown) is also arranged in the valve seat, and the guide sleeve is fixedly mounted on the valve seat, and the guide sleeve is used to guide the movement of the valve needle assembly 40. Specifically, the valve needle assembly 40 is movably arranged on the valve seat to open or close the valve port. The valve port is used for the valve needle of the valve needle assembly 40 to extend into, thereby blocking the fluid medium in the electronic expansion valve from being discharged outward through the valve port. When the valve needle assembly 40 closes the valve port, that is, the connection port and the valve port are disconnected, the electronic expansion valve is closed; when the valve needle assembly 40 releases the seal on the valve port, that is, the connection port and the valve port are connected to each other, the electronic expansion valve is opened. The guide sleeve can be arranged integrally with the valve seat, or separately, and there is no specific restriction on this.

[0063] In one embodiment, the electronic expansion valve further comprises a housing 50, the housing is connected to the end of the valve seat away from the first connecting pipe, and forms a housing cavity for accommodating the valve needle assembly 40. Specifically, the housing is generally cylindrical in design, and is sleeved on the end of the valve seat away from the valve cavity, and the housing and the valve seat can be fixed by welding. After the housing is connected to the end of the valve seat away from the valve cavity, they enclose a housing cavity for accommodating the valve needle assembly 40, and the valve needle assembly 40 is mounted on the valve seat and located in the housing cavity.

[0064] In one embodiment, the electronic expansion valve further comprises a nut assembly 30 disposed in the accommodating chamber, and the nut assembly 30 is threadedly connected to the valve needle assembly 40. Specifically, the nut assembly 30 comprises a nut, and the nut is threadedly connected to the screw of the valve needle assembly 40, and the rotor assembly 10 is fixedly connected to the screw. Since a nut-screw matching relationship is formed between the nut and the screw, the screw and the rotor assembly 10 fixedly connected to the screw will telescope along the axial direction of the screw, thereby realizing the movement process of the screw driving the valve needle assembly 40.

[0065] The above description is only an optional embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A rotor assembly for an electronic expansion valve, characterized in that: include: The magnetic rotor has a receiving channel in the middle, and both ends of the receiving channel have openings; A limiting structure, comprising a main body and a limiting plate connected to each other, wherein the limiting plate is located at one end of the main body and connected to the wall surface of the accommodating channel; A limiting rod connected to the limiting structure; The distance between the opening closer to the limiting plate and the limiting plate is D1, the axial length of the magnetic rotor is L, and L and D1 satisfy 1 / 5≤D1 / L<1 / 2.

2. The rotor assembly according to claim 1, characterized in that The D1 satisfies 8mm≤D1≤15mm.

3. The rotor assembly according to claim 2, characterized in that The main body is provided in a cylindrical shape, and a mounting ring is protruded from the main body in the circumferential direction. The mounting ring has an end surface facing the limiting plate, and the limiting rod is welded to the end surface.

4. The rotor assembly according to claim 3, characterized in that: The distance between the end surface and the limiting plate is D2, and D2 satisfies 5mm≤D2≤10mm.

5. The rotor assembly according to claim 3, characterized in that: The outer diameter of the limiting plate is greater than the outer diameter of the main body.

6. The rotor assembly according to claim 5, characterized in that An annular gap is provided between the limiting plate and the main body, and the annular gap is used for the limiting rod to pass through.

7. The rotor assembly according to claim 6, characterized in that The limiting structure also includes at least two connecting columns, one end of which is connected to the limiting plate, and the other end of which is connected to the mounting ring, and a hollow space between the connecting column and the main body is provided for the limiting rod to pass through.

8. The rotor assembly according to claim 7, characterized in that When the number of the connecting posts is set to two, the two connecting posts are symmetrically distributed relative to the main body.

9. The rotor assembly according to claim 1, wherein: The magnetic rotor is provided with a connecting platform protruding toward the accommodating channel, and the limiting plate is connected to the connecting platform.

10. The rotor assembly according to claim 1, wherein: The limiting structure is made of metal.

11. An electronic expansion valve, characterized in that: Comprising a rotor assembly as claimed in any one of claims 1 to 10.

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