Electronic expansion valve

Abstract

The utility model provides an electronic expansion valve, and relates to the field of valves. The electronic expansion valve comprises a valve body, a limiting piece, a driving nut, a rotor assembly and a valve needle assembly. The valve body is provided with a mounting cavity, a first opening and a second opening, the limiting piece is installed in the installation cavity and fixedly connected with the valve body so that the installation cavity can be divided into an upper cavity body and a lower cavity body, and the limiting piece is provided with a sliding groove. The valve needle assembly is installed in the lower cavity and corresponds to the first opening and the second opening. The driving nut is movably installed in the sliding groove and connected with the valve needle assembly. The rotor assembly is installed in the upper cavity, a rotating shaft of the rotor assembly is matched with the driving nut through threads, the rotor assembly rotates to drive the driving nut to move along the sliding groove, and therefore the valve needle assembly is driven to move. The limiting piece is provided with a balance through hole, and the balance through hole is communicated with the upper cavity and the lower cavity. And the rotor assembly can be better lubricated.

Description

Technical Field

[0001] The utility model relates to the field of valves, and more specifically, to an electronic expansion valve. Background Art

[0002] An electronic expansion valve is a precision control component for a refrigeration system, mainly used to regulate the refrigerant flow rate to ensure that the system maintains an ideal evaporation temperature and pressure under different working conditions. Its working principle is based on electromagnetic drive and a precision valve structure to achieve precise control of the refrigerant flow rate.

[0003] The inventor found that for an electronic expansion valve that drives the valve needle assembly to move with a nut, since a limiting member for restricting the rotation of the nut needs to be provided inside the valve body, the limiting member divides the valve body of the electronic expansion valve into two independent upper and lower chambers, such as the invention patent of CN202311034551.5. The limiting member will cause the refrigerant and the lubricating oil carried by the refrigerant not to flow into the upper chamber, so that the rotating components of the rotor assembly cannot be well lubricated, affecting the service life of the electronic expansion valve. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an electronic expansion valve, which can achieve better lubrication of the rotor assembly.

[0005] The embodiments of the utility model are implemented as follows:

[0006] The utility model provides an electronic expansion valve, including a valve body, a limiting member, a driving nut, a rotor assembly, and a valve needle assembly;

[0007] The valve body has an installation cavity, a first opening, and a second opening communicating with the installation cavity. One of the first opening and the second opening is for fluid inflow, and the other is for fluid outflow;

[0008] The limiting member is installed in the installation cavity and fixedly connected to the valve body to divide the installation cavity into an upper cavity and a lower cavity. The limiting member is provided with a chute;

[0009] The valve needle assembly is installed in the lower cavity and corresponds to the first opening and the second opening;

[0010] The driving nut is movably installed in the chute and connected to the valve needle assembly;

[0011] The rotor assembly is installed in the upper cavity, and the rotating shaft of the rotor assembly is in nut fit with the driving nut. The rotation of the rotor assembly can drive the driving nut to move along the chute, thereby driving the valve needle assembly to move;

[0012] Among them, a balance through-hole is provided on the limiting member, and the balance through-hole communicates with the upper cavity and the lower cavity.

[0013] In an alternative embodiment, the valve needle assembly includes a large valve needle and a small valve needle;

[0014] The large valve needle is provided with an assembly cavity, a third opening and a fourth opening communicating with the assembly cavity. The third opening corresponds to the first opening, and the fourth opening corresponds to the second opening;

[0015] The small valve needle is installed in the assembly cavity and is connected to the drive nut;

[0016] The small valve needle can move relative to the large valve needle to adjust the flow rate between the third opening and the fourth opening. The small valve needle can also drive the large valve needle to move to adjust the flow rate between the first opening and the second opening;

[0017] The small valve needle is axially provided with a through balance flow channel. The bottom end of the balance flow channel corresponds to the third opening. When both the large and small valve needles are in the closed state, the bottom end of the balance flow channel communicates with the first opening;

[0018] The small valve needle is further provided with a first branch channel communicating with the balance flow channel, and the first branch channel also communicates with the balance through-hole.

[0019] In an alternative embodiment, the limiting member includes a limiting member body and an assembly ring platform provided on the outer peripheral edge of the limiting member body, and the assembly ring platform is provided near the bottom end of the limiting member;

[0020] The assembly ring platform is connected to the valve body, and the balance through-hole is provided on the assembly ring platform;

[0021] The chute is recessed along the direction from the bottom end to the top end of the limiting member;

[0022] A side hole is provided at a position of the limiting member body above the assembly ring platform, and the side hole communicates with the chute and the upper cavity.

[0023] In an alternative embodiment, the electronic expansion valve further includes a spring;

[0024] The valve body is provided with an assembly groove, and the assembly groove has a bottom surface and a top surface;

[0025] The top end of the large valve needle is provided with a spring seat, and a part of the spring seat extends into the assembly groove. When the large valve needle is in the closed state, the spring seat abuts against the bottom surface;

[0026] The spring is arranged on the outer peripheral edge of the small valve needle, and the bottom end of the spring abuts against the spring seat, and the top end abuts against the assembly ring platform;

[0027] The first branch channel communicates with the balance through hole through the assembly groove.

[0028] In an alternative embodiment, a limiting platform is formed in the middle of the small valve needle;

[0029] The inner peripheral edge of the spring seat extends into the assembly cavity to form an abutting portion;

[0030] During the lifting process of the small valve needle, the limiting platform can abut against the abutting portion to drive the large valve needle to move upward.

[0031] In an alternative embodiment, the electronic expansion valve further includes a bearing;

[0032] The rotor assembly includes a magnetic member and a rotating shaft, the magnetic member is mounted on the rotating shaft, and the bearing is provided with a thread for cooperating with the drive nut;

[0033] The top of the limiting member body is provided with a bearing installation groove, and the bearing is installed in the bearing installation groove;

[0034] One end of the rotating shaft provided with a thread passes through the inner ring of the bearing and is threadedly connected to the drive nut, and the rotating shaft cooperates with the bearing.

[0035] In an alternative embodiment, the magnetic member includes a mounting block and a magnet, the magnet is arranged on the outer peripheral edge of the mounting block, and the lower end of the magnet extends out of the mounting block to enclose and form the avoidance chamber;

[0036] The rotating shaft is fixedly connected to the mounting block;

[0037] The limiting member body partially extends into the avoidance chamber.

[0038] In an alternative embodiment, the electronic expansion valve further includes a first inner sealing ring and a second sealing ring;

[0039] A first sealing ring groove is arranged on the outer wall of the small valve needle and / or the inner wall of the assembly cavity, and the first sealing ring is installed in the first sealing ring groove;

[0040] A second sealing ring groove is arranged on the outer wall of the large valve needle and / or the inner wall of the installation cavity, and the second sealing ring is installed in the second sealing ring groove.

[0041] In an alternative embodiment, the first sealing ring groove is arranged on the inner wall of the large valve needle;

[0042] The large valve needle includes a first section, a second section, and an annular spacer. The first sealing ring groove is provided at the end of the first section;

[0043] The second section is provided with a socket groove, and the annular spacer is installed in the socket groove. One end of the first section provided with the first sealing ring groove is inserted into the socket groove, so that both sides of the annular spacer are in contact with the end of the first section and the bottom wall of the socket groove respectively.

[0044] In an alternative embodiment, the second sealing ring groove is provided on the outer peripheral edge of the first section;

[0045] A welding groove is provided at the end of the peripheral edge of the first section where it is located at the end of the second section.

[0046] The beneficial effects of the electronic expansion valve provided by the embodiment of the present utility model are as follows: including:

[0047] In this application, a balance through hole is provided on the limiting member for installing the drive nut. The balance through hole can communicate the upper cavity and the lower cavity formed by separating the upper limiting member, thereby balancing the pressures in the upper cavity and the lower cavity, and enabling the electronic expansion valve to achieve precise control. Most importantly, the balance through hole can also allow the refrigerant and the lubricating oil carried by the refrigerant in the lower cavity to flow into the upper cavity through the balance through hole, and lubricate the rotating parts of the rotor assembly, such as the rotating part between the rotating shaft and the nut. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0049] Figure 1 It is a schematic cross-sectional structure diagram of the large valve needle and the small valve needle of the electronic expansion valve provided by the embodiment of the present utility model in the closed state;

[0050] Figure 2 It is a schematic cross-sectional structure diagram of the large valve needle of the electronic expansion valve provided by the embodiment of the present utility model in the closed state and the small valve needle in the open state;

[0051] Figure 3 It is a schematic cross-sectional structure diagram of the large valve needle and the small valve needle of the electronic expansion valve provided by the embodiment of the present utility model in the open state;

[0052] Figure 4 It is a schematic cross-sectional structure diagram of the valve needle assembly of the electronic expansion valve provided by the embodiment of the present utility model.

[0053] Icons: 100 - Electronic expansion valve; 110 - Valve body; 111 - Installation cavity; 113 - First opening; 115 - Second opening; 117 - Upper cavity; 119 - Lower cavity; 121 - Assembly groove; 130 - Limiting member; 131 - Slide groove; 133 - Balance through hole; 135 - Assembly ring platform; 137 - Limiting member body; 139 - Side hole; 141 - Bearing installation groove; 150 - Driving nut; 170 - Rotor assembly; 171 - Magnetic member; 173 - Rotating shaft; 175 - Installation block; 177 - Magnet; 179 - Avoidance chamber; 190 - Valve needle assembly; 191 - Large valve needle; 193 - Small valve needle; 195 - Assembly cavity; 196 - Third opening; 197 - Fourth opening; 199 - Balance flow channel; 201 - First branch channel; 203 - Spring seat; 205 - Limiting platform; 207 - First sealing ring groove; 209 - Second sealing ring groove; 211 - First section; 213 - Second section; 215 - Annular cushion block; 217 - Welding groove; 221 - Spring; 223 - Bearing; 225 - First inner sealing ring; 227 - Second sealing ring. Detailed implementation manners

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0056] It should be noted that like reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0057] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present utility model is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0058] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0059] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0060] Embodiment

[0061] For the existing electronic expansion valve that drives the valve needle assembly to move with a nut, since a limiting member for restricting the rotation of the nut needs to be provided in the valve body, the limiting member will divide the valve body of the electronic expansion valve into two independent upper and lower chambers, such as the invention patent of CN202311034551.5. The limiting member will cause the refrigerant and the lubricating oil carried by the refrigerant not to flow into the upper chamber, so that the rotating components of the rotor assembly cannot be well lubricated, affecting the service life of the electronic expansion valve.

[0062] Please refer to Figures 1 to 4, the present utility model provides an electronic expansion valve 100, which includes a valve body 110, a limiting member 130, a driving nut 150, a rotor assembly 170 and a valve needle assembly 190. The valve body 110 has an installation cavity 111, a first opening 113 and a second opening 115 communicated with the installation cavity 111. One of the first opening 113 and the second opening 115 is for fluid inflow, and the other is for fluid outflow. The limiting member 130 is installed in the installation cavity 111 and fixedly connected to the valve body 110 to divide the installation cavity 111 into an upper cavity 117 and a lower cavity 119. The limiting member 130 is provided with a sliding groove 131. The valve needle assembly 190 is installed in the lower cavity 119 and corresponds to the first opening 113 and the second opening 115. The driving nut 150 is movably installed in the sliding groove 131 and connected to the valve needle assembly 190. The rotor assembly 170 is installed in the upper cavity 117, and the rotating shaft 173 of the rotor assembly 170 is in nut fit with the driving nut 150. When the rotor assembly 170 rotates, it can drive the driving nut 150 to move along the sliding groove 131, so as to drive the valve needle assembly 190 to move. Among them, a balance through hole 133 is provided on the limiting member 130, and the balance through hole 133 communicates the upper cavity 117 and the lower cavity 119.

[0063] In this embodiment, by providing a balance through hole 133 on the limiting member 130 for installing the driving nut 150, the balance through hole 133 can communicate the upper cavity 117 and the lower cavity 119 separated by the upper limiting member 130, so as to balance the pressures of the upper cavity 117 and the lower cavity 119, and the electronic expansion valve 100 can achieve precise control. Most importantly, the balance through hole 133 can also enable the refrigerant and the lubricating oil carried by the refrigerant in the lower cavity 119 to flow into the upper cavity 117 through the balance through hole 133, and can lubricate the rotating parts of the rotor assembly 170, such as the rotating part between the rotating shaft 173 and the nut.

[0064] In this embodiment, the valve needle assembly 190 includes a large valve needle 191 and a small valve needle 193. The large valve needle 191 is provided with an assembly cavity 195, as well as a third opening 196 and a fourth opening 197 that communicate with the assembly cavity 195. The third opening 196 corresponds to the first opening 113, and the fourth opening 197 corresponds to the second opening 115. The small valve needle 193 is installed in the assembly cavity 195 and is connected to the drive nut 150. The small valve needle 193 can move relative to the large valve needle 191 to adjust the flow rate between the third opening 196 and the fourth opening 197. The small valve needle 193 can also drive the large valve needle 191 to move to adjust the flow rate between the first opening 113 and the second opening 115. The small valve needle 193 is axially provided with a through balance flow channel 199. The bottom end of the balance flow channel 199 corresponds to the third opening 196. When both the large and small valve needles 193 are in the closed state, the bottom end of the balance flow channel 199 communicates with the first opening 113. The small valve needle 193 is also provided with a first branch channel 201 that communicates with the balance flow channel 199, and the first branch channel 201 also communicates with the balance through hole 133.

[0065] Please refer to Figures 1 to 4 , in this embodiment, by axially arranging a through balance flow channel 199 in the small valve needle 193, the pressure at both ends of the small valve needle 193 can be balanced, so that it is convenient to realize closing and opening the valve, and at the same time, the accurate control of the opening degree of the small valve needle 193 can be realized. The first branch channel 201 is provided, and the first branch channel 201 can balance the pressure at both ends of the large valve needle 191, so that it is convenient to open and close the large valve needle 191, and the large valve needle 191 can be prevented from jittering due to the pressure difference at both ends. Most importantly, by connecting the first branch channel 201 with the balance through hole 133, the first branch channel 201 can flow through the balance through hole 133 to the upper chamber of the flow channel, so as to realize the lubrication of the rotor assembly 170.

[0066] In this embodiment, the limiting member 130 includes a limiting member body 137 and an assembly ring platform 135 provided on the outer peripheral edge of the limiting member body 137, and the assembly ring platform 135 is provided near the bottom end of the limiting member 130. The assembly ring platform 135 is connected to the valve body 110, and the balance through hole 133 is provided in the assembly ring platform 135. The chute 131 is recessed along the bottom end of the limiting member 130 towards the top end. A side hole 139 is provided at a position of the limiting member body 137 above the assembly ring platform 135, and the side hole 139 communicates with the chute 131 and the upper cavity 117.

[0067] In this embodiment, the balance is achieved by arranging on the assembly ring platform 135, and side holes 139 communicating with the chute 131 are arranged on the side wall of the limiting member body 137. In this way, the refrigerant and lubricating fluid flowing from the balance through hole 133 to the upper chamber can flow into the chute 131 through the side holes 139, so that while balancing the pressure at the top of the balance small valve needle 193, the nut and the chute 131 can also be lubricated, making it easier for the nut to slide relative to the chute 131. Secondly, the lubricating oil entering the chute 131 can also lubricate between the rotor assembly 170 and the driving nut 150, enabling the two to complete relative rotation better.

[0068] It should be noted that in this embodiment, there is a clearance fit between the driving nut 150 and the chute 131, and the clearance allows the cooling medium to flow. Of course, in some other embodiments of the present application, holes corresponding to the side holes 139 are also arranged on the side wall of the driving nut 150, so that the lubricating fluid carried by the refrigerant can enter the threaded hole of the driving nut 150.

[0069] In this embodiment, the electronic expansion valve 100 further includes a spring 221. The valve body 110 is provided with an assembly groove 121, the assembly groove 121 has a bottom surface, and the bottom surface of the assembly ring platform 135 forms the top surface of the assembly groove 121. A spring seat 203 is arranged at the top end of the large valve needle 191, and the spring seat 203 partially extends into the assembly groove 121 and abuts against the bottom surface when the large valve needle 191 is in the closed state. The spring 221 is arranged on the outer periphery of the small valve needle 193, and the bottom end of the spring 221 abuts against the spring seat 203, and the top end abuts against the assembly ring platform 135. The first branch channel 201 communicates with the balance through hole 133 through the assembly groove 121.

[0070] In this embodiment, by arranging the assembly groove 121, a communication cavity can be formed between the first branch channel 201 and the balance through hole 133, so that the lubricating fluid flows out from the first branch channel 201 and then flows into the balance through hole 133 through the assembly groove 121. And by arranging the spring 221, the small valve needle 193 can also act independently in the initial stage of lifting.

[0071] Please refer to Figures 1 to 4 , in this embodiment, a limiting platform 205 is formed in the middle of the small valve needle 193. The inner peripheral edge of the spring seat 203 extends into the assembly cavity 195 to form an abutting portion. During the lifting process of the small valve needle 193, the limiting platform 205 can abut against the abutting portion to drive the large valve needle 191 to move upward.

[0072] The spring seat 203 of this embodiment is arranged in this way so that the spring seat 203 has three functions. First, it is used for installing the spring 221; second, it drives the valve needle to move upward when the small valve needle 193 moves upward; third, it abuts against the bottom wall of the assembly groove 121 when the large valve needle 191 moves downward, limiting the lowest point of the large valve needle 191 moving downward, thereby reducing the number of parts, improving the convenience of assembly, and saving costs and space.

[0073] In this embodiment, the electronic expansion valve 100 further includes a bearing 223. The rotor assembly 170 includes a magnetic component 171 and a rotating shaft 173, the magnetic component 171 is mounted on the rotating shaft 173, and the bearing 223 is provided with a thread that matches the driving nut 150. The top of the stopper body 137 is provided with a bearing mounting groove 141, and the bearing 223 is installed in the bearing mounting groove 141. One end of the rotating shaft 173 provided with a thread passes through the inner ring of the bearing 223 and is connected to the driving nut 150 by a thread, and the rotating shaft 173 matches the bearing 223.

[0074] In the prior art, the bearing 223 used to install the rotating shaft 173 is installed at the top, that is, above the magnetic component 171. This method will cause the rotor assembly 170 to have poor stability during operation and cannot be well lubricated. In the embodiment, the top of the limiter body 137 of the bearing installation groove 141 corresponds to the bottom of the magnetic component 171, close to the upper middle of the height direction of the rotor assembly 170, and close to the center. In this way, the rotor is more stable when rotating, and this arrangement can achieve all-round lubrication of the bearing 223, which can increase the service life of the bearing 223, thereby increasing the service life of the electronic expansion valve 100.

[0075] Please refer to Figures 1 to 4 In this embodiment, the magnetic member 171 includes a mounting block 175 and a magnet 177. The magnet 177 is disposed on the outer periphery of the mounting block 175, and the lower end of the magnet 177 extends out of the mounting block 175 to enclose a avoidance chamber 179. The rotating shaft 173 is fixedly connected to the mounting block 175. The stopper body 137 partially extends into the avoidance chamber 179.

[0076] In this embodiment, the magnetic rotor component is arranged in this way, so that the magnetic rotor component can form an avoidance cavity 179, so that after assembly, the bearing 223 is located in the avoidance cavity, so as to be more stable at the center of gravity of the rotor assembly 170. In addition, the rotor assembly 170 and the stopper 130 can overlap in the height direction, so that the electronic expansion valve 100 can be made more compact and the space utilization rate of the electronic expansion valve 100 can be higher.

[0077] In this embodiment, the electronic expansion valve 100 further includes a first inner sealing ring 225 and a second sealing ring 227. A first sealing ring groove 207 is provided on the outer wall of the small valve needle 193 and / or the inner wall of the assembly cavity 195, and the first sealing ring is installed in the first sealing ring groove 207. A second sealing ring groove 209 is provided on the outer wall of the large valve needle 191 and / or the inner wall of the installation cavity 111, and the second sealing ring 227 is installed in the second sealing ring groove 209.

[0078] In this embodiment, corresponding first and second sealing rings 227 are provided between the large valve needle 191 and the small valve needle 193 and between the large valve needle 191 and the valve body 110, thereby overcoming the problem of internal leakage.

[0079] In this embodiment, the first sealing ring groove 207 is provided on the inner wall of the large valve needle 191. The large valve needle 191 includes a first section 211, a second section 213, and an annular spacer 215. The first sealing ring groove 207 is provided at the end of the first section 211. The second section 213 is provided with a socket groove, and the annular spacer 215 is installed in the socket groove. One end of the first section 211 provided with the first sealing ring groove 207 is inserted into the socket groove, so that both sides of the annular spacer 215 are in contact with the end of the first section 211 and the bottom wall of the socket groove respectively.

[0080] Since a through balance flow channel 199 is provided in the small valve needle 193 and its diameter is relatively small, if the first sealing ring groove 207 is provided on the outer periphery of the small valve needle 193, the diameter of the small valve needle 193 needs to be increased to ensure the structural strength. When the diameter of the small valve needle 193 is increased, the diameters of the large valve needle 191 and the valve body 110 need to be adjusted, which is not conducive to the miniaturized design of the electronic expansion valve 100. In this embodiment, the first sealing ring groove 207 is provided on the inner periphery of the large valve needle 191. However, the diameter of the assembly cavity 195 inside the large valve needle 191 is relatively small, which causes problems such as inconvenient processing of the first sealing groove and poor installation of the first sealing ring. To solve this problem, the large valve needle 191 is provided in two sections in this embodiment, which is convenient for processing the first sealing ring groove 207. After processing, the two sections are fixedly connected, so that the installation of the first sealing ring can be realized without affecting the volume of the electronic expansion valve 100.

[0081] Please refer to Figures 1 to 4 , further, the first section 211 and the second section 213 are connected by welding, and a welding groove 217 is provided at the end of the periphery of the first section 211 located at the end of the second section 213. In this way, the first section 211 and the second section 213 can be welded along the welding groove 217 during welding. After welding, the weld seam and welding scar are in the welding groove 217 and do not affect the outer surface of the large valve needle 191. In this way, no further processing of the large valve needle 191 is required after welding, and the sliding fit between the outer surface of the large valve needle 191 and the valve body 110 can be realized.

[0082] In this embodiment, the second sealing ring groove 209 is arranged on the outer peripheral edge of the first section 211, which facilitates the installation of the second sealing ring 227.

[0083] In summary, the working principle and beneficial effects of the electronic expansion valve 100 provided by the embodiment of the present invention are as follows:

[0084] In this embodiment, by arranging the balance through hole 133 on the limiting member 130 for installing the driving nut 150, the balance through hole 133 can communicate the upper cavity 117 and the lower cavity 119 formed by separating the upper limiting member 130, so as to balance the pressures of the upper cavity 117 and the lower cavity 119, and the electronic expansion valve 100 can achieve precise control. Most importantly, the balance through hole 133 can also enable the refrigerant and the lubricating oil carried by the refrigerant in the lower cavity 119 to flow into the upper cavity 117 through the balance through hole 133, and lubricate the rotating parts of the rotor assembly 170, such as the rotating part between the rotating shaft 173 and the nut.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electronic expansion valve, characterized in that: It comprises a valve body (110), a stopper (130), a drive nut (150), a rotor assembly (170) and a valve needle assembly (190); The valve body (110) has an installation cavity (111) and a first opening (113) and a second opening (115) communicating with the installation cavity (111), one of the first opening (113) and the second opening (115) being used for fluid inflow, and the other being used for fluid outflow; The limiting member (130) is installed in the installation cavity (111) and is fixedly connected to the valve body (110) to separate the installation cavity (111) into an upper cavity (117) and a lower cavity (119); the limiting member (130) is provided with a slide groove (131); The valve needle assembly (190) is installed in the lower cavity (119) and corresponds to the first opening (113) and the second opening (115); The driving nut (150) is movably mounted in the slide groove (131) and connected to the valve needle assembly (190); The rotor assembly (170) is installed in the upper cavity (117), and the rotating shaft (173) of the rotor assembly (170) is threadedly matched with the driving nut (150), and the rotor assembly (170) rotates to drive the driving nut (150) to move along the slide groove (131), thereby driving the valve needle assembly (190) to move; Wherein, a balancing through hole (133) is provided on the limiting member (130), and the balancing through hole (133) is connected to the upper cavity (117) and the lower cavity (119).

2. The electronic expansion valve according to claim 1, characterized in that: The valve needle assembly (190) comprises a large valve needle (191) and a small valve needle (193); The large valve needle (191) is provided with an assembly cavity (195) and a third opening (196) and a fourth opening (197) communicating with the assembly cavity (195), wherein the third opening (196) corresponds to the first opening (113), and the fourth opening (197) corresponds to the second opening (115); The small valve needle (193) is installed in the assembly cavity (195) and connected to the driving nut (150); The small valve needle (193) can move relative to the large valve needle (191) to adjust the flow between the third opening (196) and the fourth opening (197); the small valve needle (193) can also drive the large valve needle (191) to move to adjust the flow between the first opening (113) and the second opening (115); The small valve needle (193) is provided with a balancing flow channel (199) penetrating along the axial direction, and the bottom end of the balancing flow channel (199) corresponds to the third opening (196). When the large valve needle (191) and the small valve needle (193) are both in a closed state, the bottom end of the balancing flow channel (199) is in communication with the first opening (113); The small valve needle (193) is also provided with a first branch channel (201) communicating with the balancing flow channel (199), and the first branch channel (201) is also communicating with the balancing through hole (133).

3. The electronic expansion valve according to claim 2, characterized in that: The limiting member (130) comprises a limiting member body (137) and an assembly ring (135) arranged on the outer periphery of the limiting member body (137), and the assembly ring (135) is arranged close to the bottom end of the limiting member (130); The assembly ring (135) is connected to the valve body (110), and the balancing through hole (133) is arranged on the assembly ring (135); The slide groove (131) is recessed along the bottom end of the limiting member (130) toward the top end; The position of the limiting member body (137) located above the assembly ring platform (135) is provided with a side hole (139), and the side hole (139) is communicated with the slide groove (131) and the upper cavity (117).

4. The electronic expansion valve according to claim 3, characterized in that: The electronic expansion valve further comprises a spring (221); The valve body (110) is provided with a mounting groove (121), and the mounting groove (121) has a bottom surface and a top surface; A spring seat (203) is provided at the top end of the large valve needle (191), and a portion of the spring seat (203) extends into the assembly groove (121). When the large valve needle (191) is in a closed state, the spring seat (203) abuts against the bottom surface; The spring (221) is arranged on the outer periphery of the small valve needle (193), and the bottom end of the spring (221) abuts against the spring seat (203), and the top end abuts against the assembly ring (135); The first branch channel (201) is in communication with the balancing through hole (133) via the assembly groove (121).

5. The electronic expansion valve according to claim 4, characterized in that: A limiting platform (205) is formed in the middle of the small valve needle (193); The inner periphery of the spring seat (203) extends into the assembly cavity (195) to form an abutment portion; During the lifting process of the small valve needle (193), the limiting platform (205) can abut against the abutment portion to drive the large valve needle (191) to move upward.

6. The electronic expansion valve according to any one of claims 3 to 5, characterized in that: The electronic expansion valve further comprises a bearing (223); The rotor assembly (170) comprises a magnetic component (171) and a rotating shaft (173), wherein the magnetic component (171) is mounted on the rotating shaft (173), and the bearing (223) is provided with a thread that matches with the driving nut (150); A bearing installation groove (141) is provided at the top of the stopper body (137), and the bearing (223) is installed in the bearing installation groove (141); One end of the rotating shaft (173) provided with a thread passes through the inner ring of the bearing (223) and is connected to the driving nut (150) through a thread, and the rotating shaft (173) is matched with the bearing (223).

7. The electronic expansion valve according to claim 6, characterized in that: The magnetic component (171) comprises a mounting block (175) and a magnet (177), wherein the magnet (177) is arranged on the outer periphery of the mounting block (175), and the lower end of the magnet (177) extends out of the mounting block (175) to enclose a avoidance chamber (179); The rotating shaft (173) is fixedly connected to the mounting block (175); The limiting member body (137) partially extends into the avoidance chamber (179).

8. The electronic expansion valve according to any one of claims 2 to 5, characterized in that: The electronic expansion valve further comprises a first inner sealing ring (225) and a second sealing ring (227); The outer wall of the small valve needle (193) and / or the inner wall of the assembly cavity (195) is provided with a first sealing ring groove (207), and the first sealing ring is installed in the first sealing ring groove (207); The outer wall of the large valve needle (191) and / or the inner wall of the installation cavity (111) is provided with a second sealing ring groove (209), and the second sealing ring (227) is installed in the second sealing ring groove (209).

9. The electronic expansion valve according to claim 8, characterized in that: The first sealing ring groove (207) is arranged on the inner wall of the large valve needle (191); The large valve needle (191) comprises a first section (211), a second section (213) and an annular gasket (215), and the first sealing ring groove (207) is arranged at the end of the first section (211); The second section (213) is provided with a plug-in groove, the annular gasket (215) is installed in the plug-in groove, and the first section (211) is provided with one end of the first sealing ring groove (207) plugged into the plug-in groove, so that the two sides of the annular gasket (215) are respectively in contact with the end of the first section (211) and the bottom wall of the plug-in groove.

10. The electronic expansion valve according to claim 9, characterized in that: The second sealing ring groove (209) is arranged on the outer periphery of the first section (211); A welding groove (217) is provided at the periphery of the first section (211) at the end of the second section (213).

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