Electronic expansion valve

Abstract

An electronic expansion valve (100). The electronic expansion valve (100) comprises a fixed seat assembly (10), a transmission assembly (20), and a valve core assembly (30). The fixed seat assembly (10) has a valve cavity (11) and a valve port (12). The transmission assembly (20) comprises a screw (21) and a nut (22), and the screw (21) can rotate in the circumferential direction. The nut (22) is in threaded connection with the screw (21) and is in limited fit with the fixed seat assembly (10) along the circumferential direction of the nut (22). The valve core assembly (30) is located inside of the valve cavity (11). The valve core assembly (30) comprises a main core body (31) and an elastic member (33). The main core body (31) is provided with an accommodating slot (311). The elastic member (33) is mounted in the accommodating slot (311), and the nut (22) extends into the accommodating slot (311) and is pressed against the elastic member (33).

Description

Electronic expansion valve

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202311636847.4, filed on November 30, 2023, with application number 202311636847.4, titled “Electronic Expansion Valve”, Chinese patent application No. 202323267740.5, filed on November 30, 2023, with application number 202323267740.5, titled “Limiting Structure for Electronic Expansion Valve and Electronic Expansion Valve”, Chinese patent application No. 202323265027.7, titled “Electronic Expansion Valve”, Chinese patent application No. 202323281183.2, titled “Electronic Expansion Valve”, and Chinese patent application No. 202323266313.5, filed on November 30, 2023, with invention number 202323266313.5, titled “Installation Structure and Electronic Expansion Valve”, the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the field of valve technology, and in particular to an electronic expansion valve. Background Art

[0004] Electronic expansion valves are installed in air conditioning systems to shut off or open the flow of refrigerant. They typically consist of a valve seat assembly, a valve core, a screw, and a nut. The valve seat assembly has a valve cavity with a valve port at one end. A motor drives the screw to rotate. The nut fits over the screw and engages with the screw threads, converting the screw's rotation into axial movement. The valve core is connected to the nut, allowing the nut to move the valve core toward the valve port to seal it, or away from it to open it.

[0005] However, when the valve core blocks the valve port, the blockage is often not tight, resulting in the problem that the refrigerant still flows out through the valve port when the valve is closed. Summary of the Invention

[0006] According to various embodiments of the present application, an electronic expansion valve is provided.

[0007] The present application provides an electronic expansion valve, which includes: a fixed seat assembly, a transmission assembly and a transmission assembly, the fixed seat assembly has a valve cavity and a valve port; the transmission assembly includes a screw and a nut, the screw is limitedly matched with the fixed seat assembly along its own axial direction, and the screw can rotate circumferentially around its own axis; the nut is sleeved on the outer circumference of the screw, the nut is matched with the screw thread, and the outer wall of the nut is limitedly matched with the fixed seat assembly along its own circumference; the valve core assembly is located in the valve cavity, the valve core assembly includes a main core body and an elastic member, the main core body is provided with a receiving groove, the elastic member is installed in the receiving groove, the nut extends into the receiving groove and is pressed against the elastic member; the nut can push the main core body to move toward the valve port through the elastic member, and cause the main core body to block the valve port.

[0008] In one embodiment, the valve core assembly also includes a pressure block, the opening of the accommodating groove is set away from the valve port, the pressure block is located in the accommodating groove, and the pressure block is fixedly connected to the opening position of the accommodating groove; the nut is provided with a limiting protrusion, the limiting protrusion is arranged at the end of the nut close to the valve port, one end of the limiting protrusion is used to press the elastic member, and the other end of the limiting protrusion is used to abut against the pressure block.

[0009] In one embodiment, the valve core assembly further includes a transmission block, and the transmission block is stopped between the limiting protrusion and the elastic member.

[0010] In one embodiment, a stop surface is formed in the accommodating groove, the stop surface is arranged away from the valve port, the elastic member is located on the side of the stop surface close to the valve port, and at least part of the elastic member extends out of the stop surface, and an assembly gap can be formed between the transmission block and the stop surface.

[0011] In one embodiment, the fixing seat assembly includes a connecting sleeve and a guide sleeve. The guide sleeve is arranged on the outer periphery of the connecting sleeve and welded to the guide sleeve. The guide sleeve is arranged close to the valve port relative to the connecting sleeve. The screw is limitedly engaged with the inner wall of the connecting sleeve along its own axial direction, and the outer wall of the nut is limitedly engaged with the inner wall of the connecting sleeve along its own circumference.

[0012] In one embodiment, the inner wall of the guide sleeve forms a limiting surface. When the main core moves in a direction away from the valve port, the main core can stop at the limiting surface. The main core is provided with a limiting ring, which is arranged close to the limiting surface. The limiting ring is used to abut the limiting surface. The thickness of the limiting ring is h, and h≤1.5mm.

[0013] In one embodiment, the fixing seat assembly includes a connecting sleeve and a guide sleeve, the connecting sleeve and the guide sleeve are connected to each other, and the valve cavity is opened in the guide sleeve; the connecting sleeve is provided with a first wall, the first wall is attached to the guide sleeve, and a weld is formed between the first wall and the guide sleeve; at the end of the first wall away from the valve port, a welding groove is formed between the connecting sleeve and the guide sleeve, and the welding groove is connected to the weld; at the end of the first wall close to the valve port, a second channel is formed between the connecting sleeve and the guide sleeve, and the second channel is connected to the valve cavity and the weld.

[0014] In one embodiment, the fixed seat assembly also includes a valve seat and an inlet pipe. The valve seat is sleeved on the outer wall of the guide sleeve, and a valve cavity is formed between the valve seat and the guide sleeve. The inlet pipe is inserted into the side wall of the valve seat and connected to the valve cavity; the guide sleeve includes a guide section and a connecting section. The guide section is arranged close to the connecting sleeve relative to the connecting section. The guide section and the inner wall of the valve seat are clearance-fitted. Along the direction from the connecting sleeve to the valve cavity, the outer diameter of the guide section tends to increase, and the connecting section and the inner wall of the valve seat are interference-fitted; wherein, the inlet pipe, the valve seat, the connecting sleeve and the guide sleeve are welded together by furnace welding.

[0015] In one embodiment, the transmission assembly further includes a rotor and a connecting plate, the connecting plate being fixedly connected to the rotor, the connecting plate being provided with a mounting hole, the screw being inserted into the mounting hole, and the screw being interference fit with the inner wall of the mounting hole; the rotor drives the screw to rotate through the connecting plate.

[0016] In one embodiment, the outer peripheral wall of the main core body is movably sealed with the inner peripheral wall of the valve cavity. The main core body divides the valve cavity into an upper cavity and a lower cavity. The lower cavity is used to connect the inlet pipe and the valve port. The main core body has an upper end face and a lower end face. The upper end face is arranged toward the upper cavity body, and the lower end face is arranged toward the valve port. The main core body is provided with a first channel running through the lower end face and the upper end face; the lower end face is used to block the valve port, and when the lower end face blocks the valve port, the valve port is connected to the upper cavity body through the first channel.

[0017] In one embodiment, an annular mounting position is formed in the first channel, and a limiting protrusion is provided at the end of the transmission assembly. The limiting protrusion is installed in the annular mounting position, and the two ends of the limiting protrusion along its own axial direction respectively abut against two oppositely arranged side walls of the annular mounting position, and a connecting channel is formed between the outer peripheral wall of the limiting protrusion and the inner wall of the annular mounting position, and the connecting channel is connected to the first channel.

[0018] In one embodiment, a notch portion is provided on the outer periphery of the limiting protrusion, the notch portion passes through both ends of the limiting protrusion along the axial direction of the limiting protrusion, and a connecting channel is formed between the notch portion and the inner circumferential wall of the annular mounting position; the notch portion and the upper edge of the annular mounting position are staggered along the radial direction of the annular mounting position, and the notch portion and the lower edge of the annular mounting position are staggered along the radial direction of the annular mounting position, so that the connecting channel connects to the first channel.

[0019] In one embodiment, the electronic expansion valve further includes a pressure block and a transmission block, which are respectively connected to the inner wall of the first channel, and are spaced apart along the axis of the first channel so that an annular mounting position is formed between the transmission block, the inner wall of the first channel and the pressure block; the pressure block is arranged close to the upper end face, and a flow gap is formed between the inner circumferential wall of the pressure block and the outer circumferential wall of the transmission assembly, and the lower end face is connected to the upper end face through the first channel, the connecting channel and the flow gap.

[0020] In one embodiment, the electronic expansion valve also includes an outer shell, which is covered on a side of the fixed seat assembly away from the valve port. A rotor cavity is formed between the outer shell and the fixed seat assembly. A through hole is opened on the side wall of the fixed seat assembly, and the through hole connects the upper cavity and the rotor cavity.

[0021] In one embodiment, the fixed seat assembly includes a connecting sleeve and a guide sleeve, the connecting sleeve is used to install the transmission assembly, and the valve cavity and the through hole are respectively opened in the guide sleeve; the connecting sleeve is provided with a first wall and a second wall, the first wall is welded to the guide sleeve, the second wall is spaced apart from the guide sleeve, and a second channel is formed between the second wall and the guide sleeve, and the second channel connects the upper cavity and the through hole.

[0022] In one embodiment, the outer peripheral wall of the nut includes a cylindrical surface and a convex portion, and the convex portion protrudes radially outward along the cylindrical surface; the fixing seat assembly has an installation channel, and the inner wall of the installation channel includes a centering surface and a limiting surface, the centering surface is in contact with the cylindrical surface, and the limiting surface is in contact with the convex portion; the nut can move relative to the fixing seat assembly along its own axis, and the limiting surface cooperates with the convex portion to limit the nut from circumferential rotation.

[0023] In one embodiment, the shape of the inner wall of the installation channel is the same as the shape of the outer peripheral wall of the nut, and the outer peripheral wall of the nut is attached to the inner wall of the installation channel.

[0024] In one embodiment, there are multiple protrusions, and the multiple protrusions are distributed at intervals along the circumference of the nut.

[0025] In one embodiment, the protrusion is configured as an elongated strip and extends axially along the nut; and the cross-sectional width of the protrusion tends to decrease along the direction from the axis of the nut to the cylindrical surface.

[0026] In one embodiment, the connecting sleeve includes a limiting section and an accommodating section, the inner diameter of the limiting section is smaller than the inner diameter of the accommodating section, the outer wall of the nut is attached to the inner wall of the limiting section, the nut can slide along the inner wall of the limiting section, and the outer wall of the nut is spaced apart from the inner wall of the accommodating section; the limiting section is provided with an avoidance groove, the avoidance groove is provided at the end of the limiting section along its own axial direction, and the avoidance groove is outwardly expanded relative to the axis of the limiting section.

[0027] In one embodiment, the electronic expansion valve further includes a bearing, the fixed seat assembly is provided with an assembly hole, the bearing is installed in the assembly hole, and the screw is passed through the bearing; the inner ring of the bearing is clearance-matched with the screw; or, the outer ring of the bearing is clearance-matched with the inner wall of the assembly hole; or, the inner ring of the bearing is clearance-matched with the screw, and the outer ring of the bearing is clearance-matched with the inner wall of the assembly hole.

[0028] In one embodiment, a first limiting step and a second limiting step are formed on the outer periphery of the screw, and the first limiting step and the second limiting step are arranged at intervals along the axial direction of the screw. The first limiting step is used to stop one end of the bearing, and the second limiting step is used to stop the other end of the bearing. At least one of the first limiting step and the second limiting step can be detachably connected to the screw.

[0029] In one embodiment, the electronic expansion valve further includes an elastic support member, one end of the elastic support member is connected to the first limiting step, and the other end of the elastic support member is connected to a side of the bearing away from the second limiting step.

[0030] In one embodiment, a mounting groove is formed in the assembly hole, the bearing is mounted in the mounting groove, and one end of the bearing along its own axial direction abuts against one side of the mounting groove, and the other end of the bearing along its own axial direction abuts against the other side of the mounting groove.

[0031] In one embodiment, the screw is fixedly connected to the inner ring of the bearing, and the outer ring of the bearing is clearance-fitted with the inner wall of the assembly hole.

[0032] In one embodiment, the electronic expansion valve also includes a limit ring and a retaining spring. A matching groove is provided on the outer peripheral wall of the screw. The limit ring is sleeved on the outer periphery of the screw. The limit ring is provided with an assembly groove corresponding to the matching groove. The assembly groove has an opening, and an assembly gap is formed between the opening and the screw. At least part of the retaining spring is received in the matching groove, and another part of the retaining spring is received in the assembly groove. Moreover, when the end of the limit ring away from the assembly groove is subjected to a force pointing in the direction of the opening along the axis of the screw, the inner wall of the assembly groove can cooperate with the inner wall of the matching groove to clamp the retaining spring. The width of the assembly gap is L, the diameter of the retaining spring is D, and D>L.

[0033] In one embodiment, a guide slope is provided on the outer wall of the screw, and the guide slope is located on one side of the matching groove. Along the direction from the guide slope to the matching groove, the distance from the guide slope to the screw axis tends to increase.

[0034] In one embodiment, the assembly groove is provided with an abutment slope, which is used to abut against the retaining spring; the abutment slope is arranged toward the opening, and along the direction from the bottom of the assembly groove to the opening, the distance from the abutment slope to the axis of the limit ring tends to increase.

[0035] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered to limit the scope of the disclosed inventions, the presently described embodiments and / or examples, and any of the best modes currently understood for these inventions.

[0037] FIG1 is a first cross-sectional view of an electronic expansion valve according to one or more embodiments / some embodiments when the valve port is open;

[0038] FIG2 is an enlarged schematic diagram of FIG1 at point A;

[0039] FIG3 is a cross-sectional view of an electronic expansion valve according to one or more embodiments / some embodiments when the valve port is closed;

[0040] FIG4 is an enlarged schematic diagram of FIG3 at point B;

[0041] FIG5 is an enlarged schematic diagram of point C in FIG3;

[0042] FIG6 is a cross-sectional view of a main core according to one or more embodiments;

[0043] FIG7 is a second cross-sectional view of the electronic expansion valve when the valve port is open according to one or more embodiments;

[0044] FIG8 is an enlarged schematic diagram of FIG7 at D;

[0045] FIG9 is an isometric view of a nut according to one or more embodiments;

[0046] FIG10 is an isometric view of a guide sleeve according to one or more embodiments;

[0047] FIG11 is a third cross-sectional view of the electronic expansion valve when the valve port is open according to one or more embodiments;

[0048] FIG12 is a cross-sectional view of a connecting sleeve according to one or more embodiments;

[0049] FIG13 is a cross-sectional view of a nut installed in a mounting channel according to one or more embodiments;

[0050] FIG14 is a schematic diagram of the assembly of a screw, a bearing, and an elastic support member according to one or more embodiments / some embodiments;

[0051] Figure 15 is an enlarged schematic diagram of Figure 14 at point E. 100, electronic expansion valve; 10, fixed seat assembly; 11, valve chamber; 111, upper chamber; 112, lower chamber; 12, valve port; 13, limiting surface; 15, assembly gap; 16, connecting sleeve; 160, installation channel; 160a, centering surface; 160b, limiting surface; 161a, first wall; 161b, second wall; 162, welding groove; 163, second channel; 164, welding seam; 165, accommodating section; 166, limiting section; 166a, avoidance groove; 17. Guide sleeve; 171. Guide section; 172. Connecting section; 173. Through hole; 18. Valve seat; 19. Assembly hole; 191. Mounting groove; 192. First section; 193. Second section; 194. Stop step; 20. Transmission assembly; 21. Screw; 212. Matching groove; 213. First limiting step; 214. Second limiting step; 215. Guide slope; 216. Limiting step; 22. Nut; 201. Notch; 221. Limiting protrusion; 22 2. Protrusion; 223. Cylindrical surface; 23. Rotor; 24. Connecting plate; 241. Mounting hole; 25. Circlip; 26. Retaining ring; 261. Assembly groove; 261a. Opening; 261b. Abutment slope; 262. Assembly gap; 27. Elastic support member; 28. Guide section; 29. ​​Assembly section; 208. Mounting seat; 30. Valve core assembly; 31. Main core body; 301. First channel; 311. Accommodating groove; 311a. First groove section; 311b. Second groove Segment; 311c, stop surface; 311d, opening; 302, annular mounting position; 312, third channel; 303, connecting channel; 32, pressure block; 321, small diameter section; 322, large diameter section; 33, elastic member; 34, transmission block; 341, abutment section; 342, connecting section; 35, limiting ring; 36, upper end face; 37, lower end face; 38, flow gap; 40, inlet pipe; 401, bearing; 50, outlet pipe; 60, outer shell; 70, rotor cavity. DETAILED DESCRIPTION

[0052] Referring to FIG. 1 and FIG. 2 , the present application provides an electronic expansion valve 100 , which includes a fixing seat assembly 10 , a transmission assembly 20 , and a valve core assembly 30 . The fixed seat assembly 10 has a valve cavity 11 and a valve port 12 connected to the valve cavity 11. The transmission assembly 20 includes a screw 21 and a nut 22. The screw 21 is limited to the fixed seat assembly 10 along its own axial direction, and the screw 21 can rotate circumferentially around its own axis. The nut 22 is sleeved on the outer periphery of the screw 21, and the nut 22 is threadedly matched with the screw 21. The outer wall of the nut 22 is limited and matched with the fixed seat assembly 10 along its own circumference. The valve core assembly 30 is located in the valve cavity 11. The valve core assembly 30 includes a main core body 31 and an elastic member 33. The main core body 31 is provided with a accommodating groove 311. The elastic member is installed in the accommodating groove 311. The lower end of the nut 22 extends into the accommodating groove 311 and is pressed against the elastic member 33. The upper end of the nut 22 is used to abut against the groove wall of the accommodating groove 311. Among them, the nut 22 can drive the main core body 31 to move toward the direction close to the valve port 12 through the elastic member 33 and block the valve port 12; or, the nut 22 can drive the main core body 31 to move toward the direction close to and away from the valve port 12 by abutting with the groove wall of the accommodating groove 311 to open the valve port 12.

[0053] Since the screw rod 21 is axially constrained within the fixed seat assembly 10 and can rotate about its own axis, the screw rod 21 can only rotate relative to the fixed seat assembly 10 and cannot move axially relative to the fixed seat assembly 10. Furthermore, since the nut 22 is sleeved around the outer circumference of the screw rod 21 and threadably engages with the screw rod 21, and the outer wall of the nut 22 is circumferentially constrained within the fixed seat assembly 10, rotation of the screw rod 21 can be converted into axial movement of the nut 22. Furthermore, by opening a receiving groove 311 in the main core body 31, the elastic member is installed in the receiving groove 311, and the nut 22 extends into the receiving groove 311 and is crimped to the elastic member 33. In this way, the nut 22 can push the main core body 31 toward the valve port 12 through the elastic member 33, and when the main core body 31 abuts against the valve port 12, the nut 22 can further press down the elastic member 33, so that the elastic member exerts sufficient elastic force on the main core body 31 to press the main core body 31, which is conducive to more firmly sealing the valve port 12 to avoid internal leakage of the valve port 12.

[0054] The elastic member 33 can be configured as a spring. The transmission assembly 20 also includes a coil, a rotor 23, and a connecting plate 24. The connecting plate 24 is fixedly connected to the rotor 23 and defines a mounting hole 241. The screw 21 is inserted into the mounting hole 241 and has an interference fit with the inner wall of the mounting hole 241. The coil is used to drive the rotor 23 to rotate, and the rotor 23 drives the screw 21 to rotate via the connecting plate 24.

[0055] In the related art, the screw 21 and the connecting plate 24 are often welded to each other to fix the screw 21 and the connecting plate 24. However, the welding heat is uneven or the welding quality is uneven, resulting in a large difference in the coaxiality of the screw 21 and the connecting plate 24 after welding. By setting an interference fit between the screw 21 and the mounting hole 241, the problem of reduced coaxiality due to welding can be avoided.

[0056] Furthermore, as shown in Figures 1 and 3, the valve core assembly 30 also includes a pressure block 32. The opening 311d of the accommodating groove 311 is arranged away from the valve port 12. The pressure block 32 is located in the accommodating groove 311 and is fixedly connected to the opening 311d of the accommodating groove 311. A limiting protrusion 221 is provided at the end of the nut 22 near the valve port 12. One end of the limiting protrusion 221 along its own axial direction is used to press against the elastic member 33, and the other end is used to abut against the pressure block 32. By providing the limiting protrusion 221 and the pressure block 32, when the nut 22 moves in a direction away from the valve port 12, the limiting protrusion 221 abuts against the pressure block 32, thereby applying a supporting force to the pressure block 32 in a direction away from the valve port 12, and then the main core body 31 is driven by the pressure block 32 to move in a direction away from the valve port 12 to open the valve port 12.

[0057] Specifically, the pressing block 32 is annular, and the pressing block 32 is welded to the inner wall of the accommodating groove 311. The limiting protrusion 221 is also annular, and the limiting protrusion 221 is protruding from the outer peripheral wall of the nut 22. The nut 22 and the limiting protrusion 221 are an integrally formed part. In this way, the contact area between the limiting protrusion 221 and the pressing block 32 can be increased, thereby facilitating the limiting protrusion 221 to drive the pressing block 32 to move. Among them, when the nut 22, the main core body 31 and the pressing block 32 are assembled, the limiting protrusion 221 can be first inserted into the accommodating groove 311, and then the pressing block 32 can be welded to the opening 311d of the accommodating groove 311.

[0058] Furthermore, as shown in FIG1 , the pressing block 32 includes a small-diameter section 321 and a large-diameter section 322. The small-diameter section 321 is welded to the inner wall of the receiving groove 311, while the large-diameter section 322 is stopped and welded to the outer periphery of the opening 311d of the receiving groove 311. This helps increase the welding area between the pressing block 32 and the receiving groove 311, thereby improving the firmness of the connection between the pressing block 32 and the main core 31.

[0059] As shown in Figures 1 and 3, the valve core assembly 30 also includes a transmission block 34, which is retained between the limiting protrusion 221 and the elastic member 33. The limiting protrusion 221 is pressed against the elastic member 33 via the transmission block 34. The transmission block 34 is smaller than the nut 22. Therefore, if the contact area with the elastic member 33 needs to be increased, the transmission block 34 can be customized as needed without modifying the nut 22, thus reducing manufacturing complexity.

[0060] As shown in Figures 2 and 6, the accommodating groove 311 is formed with a stop surface 311c disposed away from the valve port 12. The elastic member 33 is located on the side of the stop surface 311c closest to the valve port 12, and at least a portion of the elastic member 33 extends beyond the stop surface 311c, thereby creating an assembly gap 15 between the transmission block 34 and the stop surface 311c. Because the transmission block 34 is stopped between the limiting protrusion 221 and the elastic member 33, the provision of at least a portion of the elastic member 33 extending beyond the stop surface 311c allows the assembly gap 15 to be formed between the transmission block 34 and the stop surface 311c. Thus, when the electronic expansion valve 100 is closed, the travel of the nut 22 is divided into two stages. In the first stage of the valve-closing travel, the nut 22, through the transmission block 34 and the elastic member 33, pushes the main core 31 toward the valve port 12, causing the main core 31 to stop at the valve port 12. Next, the nut 22 enters its second valve-closing stroke: the nut 22 further compresses the elastic member 33 via the transmission block 34, causing the transmission block 34 to move a distance closer to the valve port 12 until the transmission block 34 stops against the stop surface 311c. This second stroke of the nut 22 is equal to the width of the assembly gap 15. This second stroke of the nut 22 allows the elastic member to exert sufficient elastic force on the main core 31, compressing it tightly and thereby more securely sealing the valve port 12 and preventing internal leakage.

[0061] When the electronic expansion valve 100 opens, the nut 22's travel is divided into two stages. The first stage of the valve-opening stroke involves the nut 22 moving away from the valve port 12 until the stopper 221 abuts the pressure block 32. At this point, the spring pushes the transmission block 34, re-forming the assembly gap 15 between the stop surface 311c. The nut 22 then enters the second stage of the valve-opening stroke. The stopper 221, through the pressure block 32, drives the main core 31 away from the valve port 12, thereby opening the valve port. The first stage of the valve-opening stroke of the nut 22 represents the idle travel of the nut 22. The main core 31 remains sealed against the valve port 12, meaning that the valve port 12 remains closed. Furthermore, the elastic member 33 is compressed, exerting an elastic force on the main core 31 toward the valve port 12. This ensures a good seal before the valve port 12 is fully opened. In this way, the valve opening idle stroke of the electronic expansion valve 100 , that is, the clearance of the electronic expansion valve 100 , can be set by setting the width of the assembly gap 15 .

[0062] Furthermore, in one embodiment, as shown in Figures 3 and 6, the accommodating groove 311 includes a first groove section 311a and a second groove section 311b that are interconnected. The first groove section 311a is located near the valve port 12, and the inner diameter of the first groove section 311a is smaller than the inner diameter of the second groove section 311b, so that a stop surface 311c is formed on the bottom wall of the second groove section 311b. The elastic member 33 is located in the first groove section 311a, and the transmission block 34 is located in the second groove section 311b. The transmission block 34 includes an abutting section 341 and a connecting section 342. The abutting section 341 is configured to abut and cooperate with the limiting protrusion 221, and the connecting section 342 is configured to sleeve the elastic member 33. The outer diameter of the abutting section 341 is larger than the outer diameter of the connecting section 342, so that the connecting section 342 can extend into the first groove section 311a. In this way, the elastic member 33 can be conveniently accommodated, and the bottom wall of the second groove section 311 b can form the stop surface 311 c, thereby facilitating the processing of the stop surface 311 c.

[0063] As shown in Figure 3, the fixed seat assembly 10 includes a connecting sleeve 16 and a guide sleeve 17 that are welded together. The guide sleeve 17 is arranged near the valve port 12. The screw 21 is limited in position with the inner wall of the connecting sleeve 16 along its own axial direction. Specifically, a bearing 401 is fixedly installed on the inner wall of the connecting sleeve 16. The screw 21 is passed through the bearing 401, and the screw 21 forms a limiting convex ring at both ends of the bearing 401 to prevent the screw 21 from moving axially and to achieve circumferential rotation of the screw 21. The outer wall of the nut 22 is limited in position with the inner wall of the connecting sleeve 16 along its own circumference to prevent the nut 22 from rotating circumferentially. In this way, the connecting sleeve 16 and the guide sleeve 17 can be processed separately, and then the connecting sleeve 16 and the guide sleeve 17 are welded to enclose and form the valve cavity 11.

[0064] Furthermore, the guide sleeve 17 is sleeved on the outer periphery of the connecting sleeve 16, and the inner wall of one end of the guide sleeve 17 close to the connecting sleeve 16 forms a limit surface 13, and the main core body 31 can be stopped at the limit surface 13. The limit surface 13 is used to limit the main core body 31, thereby limiting the main core body 31 from continuing to move in the direction away from the valve port 12. After the main core body is fully opened, it contacts the limit surface 13, and the stroke of the main core body 31 depends on the distance between the limit surface 13 and the valve port 12. In the present application, since the screw 21 and the rotor 23 do not move axially, when the overall height of the electronic expansion valve 100 remains unchanged, the height of the valve cavity 11 where the rotor is located can be set smaller, and the distance between the limit surface 13 and the valve port 12 can be set larger, thereby increasing the stroke of the main core body 31 and increasing the distance between the main core body 31 and the valve port 12 after the main core body 31 is fully opened, which is beneficial to increasing the maximum flow rate of the electronic expansion valve 100.

[0065] Furthermore, as shown in Figures 3 and 6, a limiting ring 35 is provided at one end of the main core 31 close to the limiting surface 13, and the limiting ring 35 is used to abut the limiting surface 13. The thickness of the limiting ring 35 is h, and h≤1.5mm. Since the limiting ring 35 is used to abut the limiting surface 13, if the cross-sectional area of ​​the limiting ring 35 is too large, the contact area between the limiting ring 35 and the limiting surface 13 will be too large. Since the viscosity of the refrigerant is relatively large, the contact area between the limiting ring 35 and the limiting surface 13 is too large, which makes it easy for the limiting ring 35 and the limiting surface 13 to adhere, thereby reducing the flexibility of the movement of the main core 31. By setting h≤1.5mm, the limiting ring 35 and the limiting surface 13 have a suitable contact area, which is conducive to improving the flexibility of the movement of the main core 31. For example, the value of h can be 1.5mm, 1.4mm, 1.3mm, etc., and can be set according to actual conditions, which are not listed here one by one.

[0066] As shown in Figures 3 and 4, the connecting sleeve 16 is provided with a first wall 161a, which is attached to the guide sleeve 17. A weld 164 is formed between the first wall 161a and the guide sleeve 17. A welding groove 162 is formed between the connecting sleeve 16 and the guide sleeve 17 at the end of the first wall 161a away from the valve port 12, and the welding groove 162 connects to the welding groove 164. A second channel 163 is formed between the connecting sleeve 16 and the guide sleeve 17 at the end of the first wall 161a close to the valve port 12, and the second channel 163 connects the valve cavity 11 and the welding groove 164. The welding groove 162 is used to accommodate solder. The width of the welding groove 164 is relatively small, so the solder can more easily penetrate into the welding groove 164 under capillary action, thereby allowing the connecting sleeve 16 to be welded to the guide sleeve 17 at 161a. Capillary action refers to the process by which liquid flows in a narrow space. In order to prevent the solder from flowing along the weld 164 to the limiting surface 13 and gathering on the limiting surface 13, thereby affecting the abutment between the limiting ring 35 and the limiting surface, a second channel 163 with a larger cross-sectional area is provided so that the solder is not likely to have a capillary phenomenon in the second channel 163, that is, the solder is not likely to diffuse along the surface of the second channel 163. Therefore, the second channel 163 can accommodate excess solder flowing out of the weld 164 without causing this part of the solder to flow to the limiting surface 13.

[0067] As shown in Figures 3 and 5, the fixed seat assembly 10 also includes a valve seat 18, which is sleeved on the outer wall of the guide sleeve 17. The valve cavity 11 is formed between the valve seat 18 and the guide sleeve 17. The guide sleeve 17 includes a guide section 171 and a connecting section 172. The guide section 171 is arranged near the connecting sleeve 16 relative to the connecting section 172. The guide section 171 is clearance-fitted with the inner wall of the valve seat 18. In addition, the outer diameter of the guide section 171 tends to increase along the direction from the connecting sleeve 16 to the valve cavity 11, and the connecting section 172 is interference-fitted with the inner wall of the valve seat 18. The valve seat 18 is used to connect to the inlet pipe 40. The inlet pipe 40 is inserted into the side wall of the valve seat 18 and connects to the valve cavity 11. The refrigerant enters the valve cavity 11 through the inlet pipe 40. During the assembly process of the valve seat 18 and the guide sleeve 17, the guide section 171 can play a guiding role, facilitating the valve seat 18 to be sleeved on the outer side of the guide sleeve 17 along the surface of the guide section 171. Furthermore, the connecting section 172 is interference-fitted with the inner wall of the valve seat 18 , so that the connection between the valve seat 18 and the guide sleeve 17 is more secure.

[0068] Furthermore, the connecting sleeve 16, guide sleeve 17, valve seat 18, and inlet pipe 40 are integrally welded by furnace welding. Compared to laser welding, furnace welding makes it less likely that one side of the connecting sleeve 16, guide sleeve 17, valve seat 18, and inlet pipe 40 will warp, thereby improving the coaxiality of the connecting sleeve 16, guide sleeve 17, and valve seat 18.

[0069] Referring to Figures 7 and 4 , the outer circumferential wall of the main core 31 is movably sealed against the inner circumferential wall of the valve cavity 11, dividing the valve cavity 11 into an upper cavity 111 and a lower cavity 112. The lower cavity 112 is used to connect the inlet pipe 40 and the valve port 12. The main core 31 has an upper end surface 36 and a lower end surface 37. The upper end surface 36 faces the upper cavity 111, and the lower end surface 37 faces the valve port 12. The main core 31 defines a first passage 301 that extends through the lower end surface 37 and the upper end surface 36. The lower end surface 37 is used to block the valve port 12. When the lower end surface 37 blocks the valve port 12, the valve port 12 communicates with the upper cavity 111 through the first passage 301.

[0070] The electronic expansion valve 100 operates as follows: when the lower end surface 37 opens the valve port 12, refrigerant can enter the lower cavity 112 from the inlet pipe 40 and then flow out of the lower cavity 112 through the valve port 12 and the outlet pipe 50. When the lower end surface 37 blocks the valve port 12, the refrigerant flow path is cut off and cannot enter the outlet pipe 50. When the lower end surface 37 blocks the valve port 12, the pressure at the outlet pipe 50 is lower than the pressure within the valve cavity 11. By providing the first channel 301, the outlet pipe 50 is connected to the upper cavity 111, so that the pressure acting on the lower end surface 37 is consistent with the pressure acting on the upper end surface 36, thereby facilitating the transmission assembly 20 to drive the main core 31 upward to open the valve port 12. Moreover, since the outer peripheral wall of the main core 31 and the inner peripheral wall of the valve cavity 11 are sealed together to separate the valve cavity 11 into an upper cavity 111 and a lower cavity 112, when the valve port 12 is closed, the refrigerant in the lower cavity 112 cannot enter the upper cavity 111, and further cannot flow into the outlet pipe 50 through the opening on the upper end face 36 through the first channel 301.

[0071] Specifically, as shown in FIG. 6 and FIG. 7 , the main core body 31 further defines a third channel 312 , and the accommodating groove 311 and the third channel 312 are connected to form the first channel 301 .

[0072] An annular mounting position 302 is formed within the accommodating groove 311. A limiting protrusion 221 is provided at the end of the transmission assembly 20. The limiting protrusion 221 is mounted within the annular mounting position 302. The limiting protrusion 221 abuts against two opposite side walls of the annular mounting position 302 at its two axial ends, and a communication channel 303 is formed between the outer peripheral wall of the limiting protrusion 221 and the inner wall of the annular mounting position 302. In this manner, the limiting protrusion 221 can drive the main core 31 toward the valve port 12 by abutting against one side wall of the annular mounting position 302. Furthermore, the limiting protrusion 221 can drive the main core 31 away from the valve port 12 by abutting against the other side wall of the annular mounting position 302. Furthermore, by forming a connecting channel 303 between the outer peripheral wall of the limiting protrusion 221 and the inner wall of the annular mounting position 302, the first channel 301 can be prevented from being blocked due to the existence of the limiting protrusion 221, that is, the first channel 301 can be ensured to remain connected.

[0073] The transmission assembly 20 includes a rotor 23, a screw 21, and a nut 22. The screw 21 is axially restrained in the fixed seat assembly 10, and the rotor 23 is used to drive the screw 21 to rotate about its own axis. The nut 22 is sleeved around the outer circumference of the screw 21 and engages with the screw 21 thread. The outer wall of the nut 22 is circumferentially restrained in the fixed seat assembly 10, and a limiting protrusion 221 is provided at the end of the nut 22 near the main core 31. In this way, the rotation of the screw 21 is converted into axial movement of the nut 22, which drives the movement of the main core 31 through the limiting protrusion 221.

[0074] As shown in Figures 7 and 9, a notch 201 is provided on the outer periphery of the limiting protrusion 221. The notch 201 extends along the axis of the limiting protrusion 221 and extends through both ends of the limiting protrusion 221. A communication channel 303 is formed between the notch 201 and the inner circumferential wall of the annular mounting portion 302. The notch 201 and the upper and lower edges of the annular mounting portion 302 are radially offset from each other, allowing the communication channel 303 to communicate with the first channel 301. By radially offsetting the inner wall of the notch 201 and the upper and lower edges of the annular mounting portion 302, the two ends of the notch 201 can communicate with each other, preventing the first channel 301 from being blocked by the limiting protrusion 221.

[0075] Specifically, as shown in FIG9 , the notch portion 201 is configured as a through groove extending axially along the limiting protrusion 221. This makes the shape of the notch portion 201 simple and the processing difficulty relatively low. There are multiple notches 201, and the multiple notches 201 are spaced apart circumferentially along the limiting protrusion 221. In this way, multiple spaced-apart connecting channels 303 can be formed, that is, the overall flow area of ​​the connecting channels 303 can be increased, thereby facilitating the rapid flow of gas between the lower cavity 112 and the upper cavity 111, thereby facilitating a faster pressure balance between the lower cavity 112 and the upper cavity 111.

[0076] Furthermore, the plurality of notches 201 may be evenly spaced along the circumference of the limiting protrusion 221 .

[0077] As shown in FIG7 , the electronic expansion valve 100 further includes a pressure block 32 and a transmission block 34 . The pressure block 32 and the transmission block 34 are respectively connected to the inner wall of the first channel 301 and are spaced apart along the axis of the first channel 301 so that an annular mounting position 302 is formed between the transmission block 34, the inner wall of the first channel 301, and the pressure block 32. Because the limiting projection 221 abuts against two opposing side walls of the annular mounting position 302 to drive the main core 31 toward the valve port 12 , the limiting projection 221 is sandwiched along its own axial direction between the opposing upper and lower walls of the annular mounting position 302 . By providing separate pressing blocks 32 and transmission blocks 34, and forming an annular mounting position 302 between the transmission block 34, the inner wall of the first channel 301, and the pressing block 32, the assembly between the transmission assembly 20 and the main core 31 can be facilitated. Specifically, during actual assembly, the transmission block 34 can be first connected to the first channel 301, and then the limiting protrusion 221 can be extended into the first channel 301, and finally the pressing block 32 can be connected to the first channel 301. Furthermore, the pressing block 32 is annular and is welded to the inner wall of the first channel 301.

[0078] Of course, in other embodiments, as shown in FIG. 6 , the transmission block 34 may not be provided, but an annular mounting position 302 may be formed between the stop surface 311 c , the inner wall of the first channel 301 and the pressing block 32 .

[0079] Furthermore, the pressing block 32 is positioned near the upper end surface 36, and a flow gap 38 is formed between the inner circumferential wall of the pressing block 32 and the outer circumferential wall of the nut 22. The lower end surface 37 communicates with the upper end surface 36 via the first channel 301, the connecting channel 303, and the flow gap 38. The provision of the flow gap 38 prevents the presence of the pressing block 32 from blocking the first channel 301. In other words, the provision of the flow gap 38 allows the upper end surface 36 and the lower end surface 37 to maintain electrical continuity.

[0080] As shown in Figures 7 and 10, the electronic expansion valve 100 also includes an outer shell 60, which is covered on the side of the fixed seat assembly 10 away from the valve port 12, and a rotor cavity 70 is formed between the outer shell 60 and the fixed seat assembly 10. A through hole 173 is opened on the side wall of the fixed seat assembly 10, and the through hole 173 connects the upper cavity 111 and the rotor cavity 70.

[0081] The rotor cavity 70 is used to accommodate the rotor 23, the connecting plate 24, and the screw 21. The lower end of the nut 22 extends into the first channel 301, and the upper end is located in the connecting sleeve 16 and is threadedly connected to the screw 21. The rotor cavity 70 is connected to the connecting sleeve 16. The through hole 173 is provided to connect the upper cavity 111 and the rotor cavity 70, so that the pressure on the upper and lower end surfaces of the nut 22 is balanced. Therefore, when the nut 22 moves up and down, it is not affected by the pressure difference between the upper and lower ends of the nut 22. This facilitates the screw 21 to drive the nut 22 to move up and down.

[0082] Specifically, the fixing seat assembly 10 includes a fixedly connected connecting sleeve 16 and a guide sleeve 17. The connecting sleeve 16 is used to mount the transmission assembly 20. The valve cavity is formed in the guide sleeve 17, and the through hole 173 is formed in the guide sleeve 17. In this way, the connecting sleeve 16 and the guide sleeve 17 can be processed separately and then welded together. Compared with providing the fixing seat assembly 10 as an integral molded part, the processing difficulty can be reduced.

[0083] In one embodiment, as shown in Figures 7 and 8, the connecting sleeve 16 is provided with a first wall 161a and a second wall 161b. The first wall 161a is welded to the guide sleeve 17, and the second wall 161b is spaced apart from the guide sleeve 17. In addition, a second channel 163 is formed between the second wall 161b and the guide sleeve 17, and the second channel 163 is connected to the first channel 301.

[0084] Specifically, the first wall 161a is attached to the guide sleeve 17 for welding the guide sleeve 17, the second wall 161b is located at one end of the first wall 161a close to the valve port 12, and a second channel 163 is formed between the second wall 161b and the guide sleeve 17. In this way, in addition to being able to connect the upper cavity 111 and the through hole 173, the second channel 163 can also accommodate excess solder between the first wall 161a and the guide sleeve 17, thereby preventing the solder from flowing into the upper cavity 111.

[0085] Referring to Figures 11 to 13 , the outer peripheral wall of the nut 22 includes a cylindrical surface 223 and a protrusion 222, with the protrusion 222 protruding radially outward from the cylindrical surface 223. The mounting seat assembly 10 has a mounting channel 160. The inner wall of the mounting channel 160 includes a centering surface 160a and a limiting surface 160b. The centering surface 160a mates with the cylindrical surface 223, and the limiting surface 160b mates with the protrusion 222. The nut 22 is capable of axial movement relative to the connecting sleeve 16, and the limiting surface 160b cooperates with the protrusion 222 to limit circumferential rotation of the nut 22. Specifically, the mounting channel 160 is formed in the connecting sleeve 16.

[0086] Because the limiting surface 160b mates with the protrusion 222, and the protrusion 222 protrudes radially outward along the cylindrical surface 223, when the screw 21 and nut 22 are threadedly engaged, the mounting channel 160, through the limiting surface 160b, applies a force on the protrusion 222 in the opposite direction of the screw 21's rotation, thereby preventing the nut 22 from rotating. The cylindrical surface 223 mates more closely with the centering surface 160a, making the nut 22 less likely to become eccentric. This facilitates centering the nut 22, improving the coaxiality between the nut 22 and the connecting sleeve 16, and thereby preventing increased friction when the nut 22 and the screw 21 are threadedly engaged.

[0087] Furthermore, as shown in FIG13 , the shape of the inner wall of the mounting channel 160 matches the shape of the outer wall of the nut 22, and the outer wall of the nut 22 is attached to the inner wall of the mounting channel 160. This further improves the fit between the inner wall of the mounting channel 160 and the outer wall of the nut 22, thereby improving the coaxiality between the nut 22 and the connecting sleeve 16.

[0088] There are multiple protrusions 222, and the multiple protrusions 222 are spaced apart along the circumference of the nut 22. Providing multiple protrusions 222 increases the circumferential restraining area between the nut 22 and the connecting sleeve 16, thereby enhancing the restraining effect of the connecting sleeve 16 on the nut 22 and preventing the nut 22 from rotating. For example, the number of protrusions 222 can be three, four, five, or six, etc., and the specific number can be set according to actual circumstances and is not listed here.

[0089] Furthermore, multiple protrusions 222 are evenly spaced along the circumference of the nut 22. When the screw 21 and nut 22 are threadedly engaged, the inner wall of the mounting channel 160 applies a force opposite to the direction of rotation of the screw 21, thereby preventing the nut 22 from rotating. In other words, the protrusions 222 act as the force-bearing locations of the nut 22. Therefore, by providing multiple protrusions 222 evenly spaced along the circumference of the nut 22, the force applied to the nut 22 along the circumference can be more evenly distributed.

[0090] In one embodiment, as shown in Figure 9, the protrusion 222 is configured as an elongated strip, extending along the axial direction of the nut 22. This strip-shaped protrusion increases the force-bearing area of ​​the nut 22 while also ensuring uniform force distribution along its axial direction. Specifically, the protrusion extends through both ends of the nut 22 along its axial direction. Of course, the protrusion 222 can also be configured as a block or a columnar shape.

[0091] As shown in Figure 13, the cross-sectional width of the protrusion 222 decreases along the direction from the axis of the nut 22 to the cylindrical surface 223. That is, the protrusion 222 is wider at the end closest to the nut 22 and narrower at the end farther from the nut axis. This facilitates insertion of the protrusion 222 into the mounting channel 160, thereby facilitating assembly between the nut 22 and the connecting sleeve 16.

[0092] Furthermore, the cross-sectional width of the protrusion 222 gradually decreases along the direction from the axis of the nut 22 to the cylindrical surface 223. That is, in this embodiment, the cross-sectional shape of the protrusion 222 is triangular, and the surface of the protrusion 222 is defined by two planes arranged at an angle. This makes the surface shape of the protrusion 222 simple and easy to process. Specifically, the protrusion 222 can be formed by turning the nut 22. In other embodiments, the surface of the protrusion 222 can also be configured as a curved surface.

[0093] As shown in Figure 12, the connecting sleeve 16 includes a limiting section 166 and a receiving section 165. The inner diameter of the limiting section 166 is smaller than the inner diameter of the receiving section 165. The outer wall of the nut 22 is attached to the inner wall of the limiting section 166 and can slide along the inner wall of the limiting section 166. The outer wall of the nut 22 is spaced apart from the inner wall of the receiving section 165. In this embodiment, the inner wall of the limiting section 166 constitutes the mounting channel 160. The inner diameter of the limiting section 166 is smaller than the inner diameter of the receiving section 165. In other words, the inner diameter of the receiving section 165 is larger than the inner diameter of the limiting section 166. Therefore, when the nut 22 moves along its own axial direction, the receiving section 165 can accommodate the nut 22 without contacting the outer wall of the nut 22. Furthermore, the limiting section 166 and the receiving section 165 are integrally formed. Specifically, they can be formed by turning or casting. As shown in FIG. 12 , the first wall 161 a and the second wall 161 b are both disposed in the limiting section 166 .

[0094] In one embodiment, as shown in FIG12 , an escape groove 166a is formed on the inner wall of the limiting section 166 corresponding to the protrusion 222. The escape groove 166a is located at the end of the limiting section 166 along its own axial direction, and the escape groove 166a expands outward relative to the axis of the limiting section 166. It should be noted that the "correspondence" between the protrusion 222 and the escape groove 166a means that the location of the escape groove 166a corresponds to the protrusion 222, and the number of the escape grooves 166a corresponds to the number of the protrusion 222. The assembly process of the nut 22 and the connecting sleeve 16 is that the nut 22 passes through the limiting section 166 along its own radial direction. Therefore, by opening avoidance grooves 166a at both ends of the limiting section 166 along its own axial direction, and the avoidance grooves 166a expand outward relative to the axis of the limiting section 166, when the nut 22 and the connecting sleeve 16 are assembled, the avoidance grooves 166a can provide avoidance space for the protrusion 222, thereby preventing the outer edge of the protrusion 222 from scratching the end faces at both ends of the limiting section 166.

[0095] Referring to Figure 11 , the fixed seat assembly 10 is provided with an assembly hole 19, into which a bearing 401 is mounted. The screw 21 is inserted through the bearing 401 and is capable of circumferential rotation about its own axis. The inner ring of the bearing 401 has a clearance fit with the screw 21; alternatively, the outer ring of the bearing 401 has a clearance fit with the inner wall of the assembly hole 19; alternatively, the inner ring of the bearing 401 has a clearance fit with the screw 21, and the outer ring of the bearing 401 has a clearance fit with the inner wall of the assembly hole 19. Because the bearing 401 is fixedly mounted in the assembly hole 19 and the screw 21 is inserted through the bearing 401, the bearing 401 can limit the position of the screw 21, allowing the screw to rotate more smoothly. Furthermore, due to the clearance fit between the inner ring of the bearing 401 and the screw 21, or the clearance fit between the outer ring of the bearing 401 and the inner wall of the assembly hole 19, an accommodating space is formed on at least one side of the inner wall or outer wall of the bearing, thereby preventing the screw 21 and the assembly hole 19 from clamping the bearing 401 too tightly, causing deformation of the bearing 401, and further preventing an increase in the rotational friction of the bearing 401 and the rotational friction of the screw 21.

[0096] Specifically, assembly hole 19 is formed at the end of connecting sleeve 16 that is away from mounting channel 160. As shown in Figure 11, assembly hole 19 has a mounting groove 191 formed therein. Bearing 401 is mounted within mounting groove 191, with both ends of bearing 401 along its axial direction abutting against opposing sidewalls of mounting groove 191. The provision of mounting groove 191 allows bearing 401 to be axially restrained within assembly hole 19.

[0097] Specifically, the transmission assembly 20 also includes a mounting seat 208, and the assembly hole 19 includes a first section 192 and a second section 193 that are connected. The inner diameter of the first section 192 is larger than the inner diameter of the second section 193, so that a stop step 194 is formed at the connection between the first section 192 and the second section 193. The mounting seat 208 is fixedly connected to the inner wall of the first section 192, and a mounting groove 191 is formed between the mounting seat 208 and the stop step 194.

[0098] When assembling the fixing seat assembly 10 and the bearing 401, the bearing 401 can be first placed from the first section 192 with a larger inner diameter, and the bearing 401 can be stopped at the stop step 194; then the mounting seat 208 can be installed into the first section 192 and fixedly connected to the inner wall of the first section 192.

[0099] There are two embodiments of the axial limitation of the screw rod 21 relative to the bearing 401 .

[0100] Example 1:

[0101] As shown in Figure 11, the outer circumference of the screw 21 is formed with a first limiting step 213 and a second limiting step 214 spaced apart along the axial direction of the screw 21. The first limiting step 213 and the second limiting step 214 respectively stop at both ends of the bearing 401 to limit the axial movement of the screw 21. The provision of the first limiting step 213 and the second limiting step 214 ensures that the screw 21 can only rotate circumferentially around its own axis and cannot move along its own axis relative to the bearing 401.

[0102] Furthermore, the electronic expansion valve 100 further includes an elastic support member 27, one end of which is connected to the first limiting step 213, and the other end of which is connected to the side of the bearing 401 facing away from the second limiting step 214. By providing the elastic support member 27, the elastic support member 27 is compressed between the first limiting step 213 and the bearing 401, thereby exerting an elastic force. This elastic force acts on the bearing 401 and is directed toward the second limiting step 214, thereby allowing the bearing 401 to cling to the second limiting step 214. In this way, the axial clearance between the screw 21 and the bearing 401 can be eliminated. At the same time, the elastic force acts on the first limiting step 213 and is directed toward the first limiting step 213, thereby providing an upward supporting force for the screw 21, thereby limiting the axial downward movement of the screw 21 and preventing the screw 21 from moving axially downward. The electronic expansion valve 100 of this embodiment is provided with a rotor 23, which is connected to the screw 21. When the rotor 23 rotates, it drives the screw 21 to rotate. The elastic support member 27 is configured as a compression spring and is sleeved on the outer periphery of the screw 21. The elastic force of the elastic support member 27 is greater than the driving force of the coil, so that under the drive of the rotor 23, the screw will not overcome the elastic force of the elastic support member 27 and move axially downward.

[0103] The first limiting step 213 and the second limiting step 214 are respectively annular, so that the contact area between the first limiting step 213 and the spring can be increased, so that the axial force acting on all sides of the screw rod 21 is more uniformly applied.

[0104] Furthermore, at least one of the first limiting step 213 and the second limiting step 214 is detachably connected to the screw rod 21. Since the screw rod 21 needs to pass through the bearing 401, the first limiting step 213 is detachably connected to the screw rod 21. When the screw rod and the bearing 401 are assembled, the end of the screw rod 21 for mounting the first limiting step 213 can be first passed through the bearing 401, and then the first limiting step 213 can be mounted on the screw rod 21.

[0105] Similarly, the second limiting step 214 is detachably connected to the screw rod 21. When assembling the screw rod 21 and the bearing 401, the end of the screw rod 21 for mounting the second limiting step 214 can be first passed through the bearing 401, and then the second limiting step 214 can be mounted on the screw rod 21. This facilitates assembly of the screw rod 21 and the bearing 401.

[0106] Example 2:

[0107] Screw 21 is fixedly connected to the inner ring of bearing 401, and the outer ring of bearing 401 has a clearance fit with the inner wall of assembly hole 19. Since bearing 401 is installed in assembly hole 19, by fixing screw 21 to the inner ring of bearing 401, screw 21 can drive the inner ring of bearing 401 to rotate without moving axially relative to bearing 401, that is, without moving axially within assembly hole 19. Specifically, screw 21 can be clamped to the inner ring of bearing 401 or connected to the inner ring of bearing 401 via a screw.

[0108] Please refer to Figures 11, 14 and 15. The electronic expansion valve 100 also includes a retaining ring 25. A matching groove 212 is formed on the outer peripheral wall of the screw 21. The first limiting step 213 is configured as a retaining ring 26. The retaining ring 26 is sleeved on the outer periphery of the screw 21. The retaining ring 26 has an assembly groove 261 corresponding to the matching groove 212. The assembly groove 261 has an opening 261a, and the opening 261a forms an assembly gap 262 with the screw 21. The width of the assembly gap 262 is L; the retaining ring 25 is at least partially received in the matching groove 212, and the other part is received in the assembly groove 261. The diameter of the retaining ring is D, and D>L; when the end of the retaining ring 26 facing away from the assembly groove 261 is subjected to a force along the axis of the screw 21 pointing to the opening 261a, the inner wall of the assembly groove 261 can cooperate with the inner wall of the matching groove 212 to clamp the retaining ring 25.

[0109] Because the retaining ring 25 is at least partially received in the mating groove 212 and the other portion is received in the assembly groove 261, when the end of the retaining ring 26 facing away from the assembly groove 261 is subjected to a force directed toward the opening 261a along the axis of the screw 21, the retaining ring 26 can push the retaining ring 25 against the edge of the mating groove 212 near the opening 261a via the inner wall of the assembly groove 261, thereby limiting the retaining ring 25 along the axial direction of the screw 21 between the screw 21 and the retaining ring 26. Furthermore, because the diameter D of the retaining ring 25 is greater than the width L of the assembly gap 262, even if the retaining ring 25 rolls, it cannot escape from the mating groove 212 along the assembly gap L, thereby further stabilizing the assembly of the retaining ring 25.

[0110] As shown in Figure 14, the elastic support member 27 is connected to the end of the retaining ring 26 that faces away from the opening 261a. The elastic support member 27 has a tendency to push the retaining ring 26 along the axis of the screw 21 toward the end where the mating groove 212 is located. The elastic support member 27 provides the retaining ring 25 with a force that points the axis of the screw 21 toward the opening 261a.

[0111] Optionally, the elastic support member 27 can be configured as a spring, which is sleeved on the outer circumference of the screw 21. In this way, when the electronic expansion valve 100 needs to be disassembled, it is only necessary to move the limiting ring 26 toward the elastic support member 27 and then allow the retaining ring 25 to escape from the matching groove 212 to complete the disassembly.

[0112] As shown in Figures 14 and 15, the outer wall of the screw 21 is provided with a guiding bevel 215, which is located on one side of the matching groove 212. Along the direction from the guiding bevel 215 to the matching groove 212, the distance from the guiding bevel 215 to the axis of the screw 21 tends to increase.

[0113] The inner diameter of the retaining spring 25 is typically smaller than the diameter of the mating groove 212, allowing the retaining spring 25 to expand within the mating groove 212, thereby tightening the fit between the screw 21, retaining spring 25, and retaining ring 26. This results in the outer diameter of the screw 21 near the mating groove 212 typically being much larger than the inner diameter of the retaining spring 25, making it difficult for the retaining spring 25 to slide near the mating groove 212 and thus unable to be smoothly installed into the mating groove 212. In this embodiment, a guide bevel 215 is provided, and the distance between the guide bevel 215 and the axis of the screw 21 increases along the direction from the mating groove 212 to the elastic support member 27. This allows the retaining spring 25 to gradually expand as it moves along the guide bevel 215, thereby facilitating its smooth installation into the mating groove 212. In other words, the guide bevel 215 serves as a transition and guide for the retaining spring 25.

[0114] Specifically, as shown in Figure 14, the screw 21 includes a guide section 28 and an assembly section 29. The outer wall of the guide section 28 forms a guide slope 215. The mating groove 212 is located at the end of the assembly section 29 near the guide section 28. The end of the guide section 28 with a larger diameter forms a sidewall of the mating groove 212. This allows the retaining spring 25 to slide directly into the mating groove 212 along the guide slope 215. This helps shorten the travel of the retaining spring 25 in its expanded state, allowing it to be installed more quickly into the mating groove 212.

[0115] Specifically, the guide section 28 is truncated cone-shaped, and the guide section 28 and the assembly section 29 are integrally formed. The screw 21 can be machined by turning to form the guide section 28, the assembly section 29 and the matching groove 212.

[0116] As shown in FIG15 , the assembly groove 261 is provided with an abutting bevel 261b for abutting the retaining spring 25. The abutting bevel 261b is disposed toward the opening 261a, and the distance between the abutting bevel 261b and the axis of the retaining ring 26 increases along the direction from the elastic support member 27 to the mating groove 212. Thus, the force exerted by the abutting bevel 261b on the retaining spring is decomposed into a first force component F1 parallel to the radial direction of the screw 21 and a second force component F2 parallel to the axis of the screw 21. The first force component F1 pushes the retaining spring 25 radially against the inner wall of the mating groove 212, while the second force component F2 pushes the retaining spring 25 against a side edge of the mating groove 212 near the opening 261a, thereby making it difficult for the retaining spring 25 to escape from the mating groove 212.

[0117] The matching groove 212 is configured as an annular groove, and the cross section of the matching groove 212 is rectangular. The matching groove 212 is configured as an annular groove to match the shape of the retaining spring 25. Of course, the cross section of the matching groove 212 can also be configured as an arc.

[0118] In one embodiment, the edge of the opening 261a is chamfered. During assembly of the electronic expansion valve 100, the retaining ring 26 must move from the end closest to the elastic support member 27 along the surface of the screw 21 until the retaining spring 25 is inserted into the assembly groove 261. Therefore, providing a chamfer on the edge of the opening 261a prevents the retaining ring 26 from scratching the retaining spring 25 due to sharp corners during assembly.

[0119] In one embodiment, a limiting step 216 is formed on the outer periphery of the screw 21 , and the limiting step 216 and the matching groove 212 are spaced apart along the axis of the screw 21 . One end of the elastic support member 27 is connected to the limiting step 216 , and the other end is connected to the limiting ring 26 .

[0120] The limiting step 216 can provide supporting force for the elastic support member 27, thereby facilitating compression of the elastic support member 27, and further enabling the elastic support member 27 to apply a force to the limiting ring 26 along the axis of the mounting column toward the opening 261a.

[0121] Optionally, as shown in FIG. 14 , a bearing 401 is sleeved on the outer periphery of the screw 21 , and the bearing 401 forms a limiting step 216 to provide supporting force for the elastic support member 27 .

[0122] The present application has the following advantages: by providing a receiving groove 311 in the main core body 31, the elastic member 33 is installed in the receiving groove 311, and the nut 22 extends into the receiving groove 311 and is pressed against the elastic member 33. In this way, the nut 22 can push the main core body 31 toward the valve port 12 through the elastic member 33. Moreover, when the main core body 31 abuts against the valve port 12, the nut 22 can further press the elastic member 33 downward, so that the elastic member 33 exerts sufficient elastic force on the main core body 31 to press the main core body 31, thereby facilitating a more secure sealing of the valve port 12 to prevent internal leakage of the valve port 12.

[0123] When the lower end surface 37 blocks the valve port 12, the pressure at the outlet pipe 50 is lower than the pressure in the valve cavity 11. By providing the first passage 301, the outlet pipe 50 is connected to the upper cavity 111, so that the pressure acting on the lower end surface 37 is consistent with the pressure acting on the upper end surface 36, thereby facilitating the transmission assembly 20 to drive the main core 31 to open the valve port 12.

[0124] By arranging the cylindrical surface 223 to fit the centering surface 160a, the fit is improved, thereby preventing the nut 22 from becoming eccentric. In other words, it is helpful to center the nut 22, thereby improving the coaxiality between the nut 22 and the fixing seat assembly 10, thereby avoiding the situation where the friction force increases when the nut 22 and the screw 21 are threaded together due to the eccentricity of the nut 22.

[0125] Due to the clearance fit between the inner ring of the bearing 401 and the screw 21, or the clearance fit between the outer ring of the bearing 401 and the inner wall of the assembly hole 19, an accommodating space is formed on at least one side of the inner wall or outer wall of the bearing 401. This prevents the screw 21 and the assembly hole 19 from clamping the bearing 401 too tightly and causing deformation of the bearing 401.

[0126] Because the retaining ring 25 is at least partially received in the mating groove 212 and the other portion is received in the assembly groove 261, when the end of the retaining ring 26 facing away from the assembly groove 261 is subjected to a force directed toward the opening 261a along the axis of the screw 21, the retaining ring 26 can push the retaining ring 25 against the edge of the mating groove 212 near the opening 261a via the inner wall of the assembly groove 261, thereby limiting the retaining ring 25 along the axial direction of the screw 21 between the screw 21 and the retaining ring 26. Furthermore, because the diameter D of the retaining ring 25 is greater than the width L of the assembly gap, even if the retaining ring 25 rolls, it cannot escape from the mating groove 212 along the assembly gap 262, thereby further stabilizing the assembly of the retaining ring 25.

[0127] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An electronic expansion valve, characterized in that: The electronic expansion valve comprises: A fixed seat assembly, the fixed seat assembly having a valve cavity and a valve port; A transmission assembly, the transmission assembly comprising a screw and a nut, the screw being limitedly matched with the fixing seat assembly along its own axial direction, and the screw being able to rotate circumferentially around its own axis; the nut being sleeved on the outer circumference of the screw, the nut being matched with the screw thread, and the outer wall of the nut being limitedly matched with the fixing seat assembly along its own circumference; A valve core assembly, the valve core assembly is located in the valve cavity, the valve core assembly includes a main core body and an elastic member, the main core body is provided with a receiving groove, the elastic member is installed in the receiving groove, the nut extends into the receiving groove and is pressed against the elastic member; The nut can push the main core body to move toward the direction close to the valve port through the elastic member, and make the main core body block the valve port.

2. The electronic expansion valve according to claim 1, wherein: The valve core assembly further includes a pressing block, the opening of the accommodating groove is arranged away from the valve port, the pressing block is located in the accommodating groove, and the pressing block is fixedly connected to the opening position of the accommodating groove; The nut is provided with a limiting protrusion, which is arranged at the end of the nut close to the valve port, one end of the limiting protrusion is used for pressing the elastic member, and the other end of the limiting protrusion is used for abutting against the pressing block.

3. The electronic expansion valve according to claim 2, wherein: The valve core assembly also includes a transmission block, and the transmission block is stopped between the limiting protrusion and the elastic member.

4. The electronic expansion valve according to claim 3, wherein: A stop surface is formed in the accommodating groove, and the stop surface is arranged away from the valve port. The elastic member is located on a side of the stop surface close to the valve port, and at least part of the elastic member extends out of the stop surface. An assembly gap can be formed between the transmission block and the stop surface.

5. The electronic expansion valve according to claim 1, wherein: The fixing seat assembly includes a connecting sleeve and a guide sleeve. The guide sleeve is arranged on the outer periphery of the connecting sleeve and welded with the guide sleeve. The guide sleeve is arranged close to the valve port relative to the connecting sleeve. The screw rod is limitedly matched with the inner wall of the connecting sleeve along its own axial direction, and the outer wall of the nut is limitedly matched with the inner wall of the connecting sleeve along its own circumferential direction.

6. The electronic expansion valve according to claim 5, wherein: The inner wall of the guide sleeve forms a limiting surface. When the main core moves in a direction away from the valve port, the main core can stop at the limiting surface. The main core is provided with a limiting ring, which is arranged close to the limiting surface. The limiting ring is used to abut against the limiting surface, and the thickness of the limiting ring is h, and h≤1.5mm.

7. The electronic expansion valve according to claim 1, wherein: The fixing seat assembly comprises a connecting sleeve and a guide sleeve, the connecting sleeve and the guide sleeve are sleeved and connected with each other, and the valve cavity is opened in the guide sleeve; The connecting sleeve is provided with a first wall, the first wall is attached to the guide sleeve, and a welding seam is formed between the first wall and the guide sleeve; A welding groove is formed between the connecting sleeve and the guide sleeve at one end of the first wall away from the valve port, and the welding groove is connected to the welding seam; At one end of the first wall close to the valve port, a second channel is formed between the connecting sleeve and the guide sleeve, and the second channel communicates with the valve cavity and the welding seam.

8. The electronic expansion valve according to claim 7, wherein: The fixed seat assembly further includes a valve seat and an inlet pipe, wherein the valve seat is sleeved on the outer wall of the guide sleeve, and the valve cavity is formed between the valve seat and the guide sleeve, and the inlet pipe is inserted into the side wall of the valve seat and communicates with the valve cavity; The guide sleeve comprises a guide section and a connecting section, the guide section is arranged close to the connecting sleeve relative to the connecting section, the guide section is clearance-matched with the inner wall of the valve seat, the outer diameter of the guide section increases along the direction from the connecting sleeve to the valve cavity, and the connecting section is interference-matched with the inner wall of the valve seat; Wherein, the inlet pipe, the valve seat, the connecting sleeve and the guide sleeve are integrally welded by furnace welding.

9. The electronic expansion valve according to claim 1, wherein: The transmission assembly also includes a rotor and a connecting plate, wherein the connecting plate is fixedly connected to the rotor, the connecting plate is provided with a mounting hole, the screw is inserted into the mounting hole, and the screw is interference fit with the inner wall of the mounting hole; the rotor drives the screw to rotate via the connecting plate.

10. The electronic expansion valve according to claim 1, wherein: The outer peripheral wall of the main core body is movably sealed with the inner peripheral wall of the valve cavity, the main core body divides the valve cavity into an upper cavity and a lower cavity, the lower cavity is used to connect the inlet pipe and the valve port, the main core body has an upper end face and a lower end face, the upper end face is arranged toward the upper cavity, the lower end face is arranged toward the valve port, and the main core body is provided with a first channel penetrating the lower end face and the upper end face; The lower end surface is used to block the valve port, and when the lower end surface blocks the valve port, the valve port is connected to the upper cavity through the first channel.

11. The electronic expansion valve according to claim 10, wherein: An annular mounting position is formed in the first channel, and a limiting protrusion is provided at the end of the transmission assembly. The limiting protrusion is installed in the annular mounting position, and the two ends of the limiting protrusion along its own axial direction respectively abut against two oppositely arranged side walls of the annular mounting position, and a connecting channel is formed between the outer peripheral wall of the limiting protrusion and the inner wall of the annular mounting position, and the connecting channel is connected to the first channel.

12. The electronic expansion valve according to claim 11, wherein: A notch is provided on the outer periphery of the limiting protrusion, and the notch penetrates through both ends of the limiting protrusion along the axial direction of the limiting protrusion, and the communicating channel is formed between the notch and the inner peripheral wall of the annular mounting position; The notch portion and the upper edge of the annular mounting position are staggered along the radial direction of the annular mounting position, and the notch portion and the lower edge of the annular mounting position are staggered along the radial direction of the annular mounting position, so that the connecting channel is connected to the first channel.

13. The electronic expansion valve according to claim 12, wherein: The electronic expansion valve further comprises a pressure block and a transmission block, wherein the pressure block and the transmission block are respectively connected to the inner wall of the first channel, and the pressure block and the transmission block are arranged at intervals along the axis of the first channel, so that the transmission block, the inner wall of the first channel and the pressure block are surrounded to form the annular installation position; The pressing block is arranged close to the upper end surface, and a flow gap is formed between the inner peripheral wall of the pressing block and the outer peripheral wall of the transmission component. The lower end surface is connected with the upper end surface through the first channel, the connecting channel and the flow gap.

14. The electronic expansion valve according to claim 13, wherein: The electronic expansion valve also includes an outer shell, which is covered on a side of the fixed seat assembly away from the valve port, and a rotor cavity is formed between the outer shell and the fixed seat assembly. A through hole is opened on the side wall of the fixed seat assembly, and the through hole connects the upper cavity and the rotor cavity.

15. The electronic expansion valve according to claim 14, wherein: The fixing seat assembly comprises a connecting sleeve and a guide sleeve, the connecting sleeve is used to install the transmission assembly, and the valve cavity and the through hole are respectively provided in the guide sleeve; The connecting sleeve is provided with a first wall and a second wall, the first wall is welded to the guide sleeve, the second wall is spaced apart from the guide sleeve, and a second channel is formed between the second wall and the guide sleeve, the second channel communicating with the upper cavity and the through hole.

16. The electronic expansion valve according to claim 1, wherein: The outer peripheral wall of the nut includes a cylindrical surface and a convex portion, and the convex portion protrudes radially outward along the cylindrical surface; the fixing seat assembly has an installation channel, and the inner wall of the installation channel includes a centering surface and a limiting surface, the centering surface is in contact with the cylindrical surface, and the limiting surface is in contact with the convex portion; The nut can move along its own axial direction relative to the fixing seat assembly, and the limiting surface cooperates with the convex portion to limit the nut from circumferential rotation.

17. The electronic expansion valve according to claim 16, wherein: The shape of the inner wall of the installation channel is the same as the shape of the outer peripheral wall of the nut, and the outer peripheral wall of the nut is attached to the inner wall of the installation channel.

18. The electronic expansion valve according to claim 16, wherein: There are multiple protrusions, and the multiple protrusions are distributed at intervals along the circumference of the nut.

19. The limit structure for an electronic expansion valve according to claim 16, wherein: The convex portion is configured as a long strip, and the convex portion extends along the axial direction of the nut; Furthermore, along the direction from the axis of the nut to the cylindrical surface, the cross-sectional width of the protrusion tends to decrease.

20. The electronic expansion valve according to claim 16, wherein: The connecting sleeve comprises a limiting section and a containing section, the inner diameter of the limiting section is smaller than the inner diameter of the containing section, the outer wall of the nut is attached to the inner wall of the limiting section, the nut can slide along the inner wall of the limiting section, and the outer wall of the nut is spaced from the inner wall of the containing section; The limiting section is provided with an avoidance groove, which is arranged at the end of the limiting section along its own axial direction, and the avoidance groove is in an outward expansion shape relative to the axis of the limiting section.

21. The electronic expansion valve according to claim 1, wherein: The electronic expansion valve further comprises a bearing, the fixing seat assembly is provided with an assembly hole, the bearing is installed in the assembly hole, and the screw rod is passed through the bearing; The inner ring of the bearing is loosely matched with the screw rod; or, the outer ring of the bearing is loosely matched with the inner wall of the assembly hole; or, the inner ring of the bearing is loosely matched with the screw rod, and the outer ring of the bearing is loosely matched with the inner wall of the assembly hole.

22. The electronic expansion valve according to claim 21, wherein: The outer circumference of the screw rod is formed with a first limit step and a second limit step, the first limit step and the second limit step are arranged at intervals along the axial direction of the screw rod, the first limit step is used to stop one end of the bearing, and the second limit step is used to stop the other end of the bearing, and at least one of the first limit step and the second limit step is detachably connected to the screw rod.

23. The electronic expansion valve according to claim 22, wherein: The electronic expansion valve further comprises an elastic support member, one end of which is connected to the first limiting step, and the other end of which is connected to a side of the bearing away from the second limiting step.

24. The electronic expansion valve according to claim 22, wherein: A mounting groove is formed in the assembly hole, the bearing is mounted in the mounting groove, and one end of the bearing along its own axial direction abuts against one side of the mounting groove, and the other end of the bearing along its own axial direction abuts against the other side of the mounting groove.

25. The electronic expansion valve according to claim 21, wherein: The screw is fixedly connected to the inner ring of the bearing, and the outer ring of the bearing is clearance-matched with the inner wall of the assembly hole.

26. The electronic expansion valve according to claim 1, wherein: The electronic expansion valve also includes a limit ring and a retaining spring. A matching groove is provided on the outer peripheral wall of the screw rod. The limit ring is sleeved on the outer periphery of the screw rod. The limit ring is provided with an assembly groove corresponding to the matching groove. The assembly groove has an opening. An assembly gap is formed between the opening and the screw rod. At least part of the retaining spring is received in the matching groove, and another part of the retaining spring is received in the assembly groove. When the end of the limit ring away from the assembly groove is subjected to a force directed toward the opening along the axis of the screw rod, the inner wall of the assembly groove can cooperate with the inner wall of the matching groove to clamp the retaining spring. The width of the assembly gap is L, the diameter of the retaining spring is D, and D>L.

27. The electronic expansion valve according to claim 26, wherein: The outer wall of the screw is provided with a guiding bevel, and the guiding bevel is located on one side of the matching groove. Along the direction from the guiding bevel to the matching groove, the distance from the guiding bevel to the axis of the screw tends to increase.

28. The electronic expansion valve according to claim 27, wherein: The assembly groove is provided with an abutment slope, and the abutment slope is used to abut against the clamping spring; The abutting inclined surface is arranged toward the opening, and along the direction from the groove bottom of the assembly groove to the opening, the distance between the abutting inclined surface and the axis of the limiting ring tends to increase.

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