An electronic expansion valve with a buffering effect

Abstract

The present invention discloses an electronic expansion valve with a buffering effect, which includes a stator assembly and a valve seat assembly. The valve seat assembly is installed at the lower part of the stator assembly. The valve seat assembly includes an end cover assembly, a magnetic isolation tube, a valve needle assembly and a valve seat assembly. A lead screw assembly is arranged inside the magnetic isolation tube. The valve needle assembly includes a valve needle and a valve needle spring arranged in the inner hole at the lower end of the valve needle. The lower end of the valve needle is inserted with a valve needle head. A balance flow channel is opened in the middle of the valve needle head. A bushing is sleeved on the outer side of the upper part of the valve needle head. One end of the bushing abuts against the valve needle spring. A valve needle sleeve is arranged at the lower end of the bushing. A valve needle internal leakage O-ring is installed between the inner side of the valve needle sleeve and the valve needle head. The lead screw in the lead screw assembly axially inserts into the central threaded through hole of the valve needle. The present invention has a balance pressure function, a long service life, and a buffering effect when closing the valve, preventing the problem of thread jamming and unable to open the valve.

Description

Technical Field

[0001] The present invention relates to the field of expansion valves, and particularly to an electronic expansion valve with a buffering effect. Background Art

[0002] Energy conservation and emission reduction are urgent problems for mankind today. The throttling device plays a key role in the refrigeration system. By selecting a suitable throttling mechanism to match the refrigeration system, the energy consumption of the entire refrigeration system can be reduced. The working principle of throttling is that when the refrigerant flows through the valve, the flow cross-section suddenly contracts, the fluid velocity increases, and the pressure drops, so as to achieve the functions of regulating the flow rate, controlling the superheat degree, and evaporating liquid level. Therefore, the regulation of the flow rate of the throttling mechanism plays a very important role in the energy conservation and consumption reduction of the refrigeration device. In some occasions where the load changes violently or the operating condition range is relatively wide, traditional throttling elements (such as capillary tubes, thermostatic expansion valves, etc.) can no longer meet the requirements of comfort and energy conservation. The temperature sensing bulb of the thermostatic expansion valve has obvious delay characteristics, making it difficult to quickly and effectively respond to the flow rate change in cooperation with the compressor displacement. Eventually, it leads to the oscillation of the system regulation, causing unstable operation of the machine and even damaging the compressor network. Therefore, the electronic expansion valve is gradually replacing the traditional throttling elements. The electronic expansion valve is superior to the traditional throttling mechanism in superheat control (liquid level control) and flow rate regulation, and has a faster response speed, a wider regulation range, and more significant energy-saving effects, with broad application prospects.

[0003] The heat exchange efficiency of the refrigerant system mainly depends on the pressure of the refrigerant at the high-pressure end in the system and the outlet temperature of the cooling device. The control of the refrigerant flow rate is usually determined according to the outlet temperature and pressure of the cooling device. The flow rate control is relatively complex. Generally, an electronic expansion valve is used to throttle and depressurize the refrigerant from the outlet of the cooling device, and the flow rate of the refrigerant sent from the cooling device to the evaporation device is adjusted according to the temperature at the outlet of the evaporation device or the temperature at other required adjustment points to meet the needs of the continuously changing refrigeration load. However, due to the large pressure difference between the high and low pressures on both sides of the inlet and outlet of the electronic expansion valve in the refrigerant system, the pressure difference acts on the valve needle of the electronic expansion valve, increasing the action resistance of the valve needle. When the electronic expansion valve needs to be opened again after being closed, the valve needle needs to overcome a large pressure difference resistance to open the refrigerant passage, and the valve needle is not easy to open. If a motor with a larger torque is used to overcome the resistance, the volume of the electronic expansion valve coil will increase relatively, the control accuracy will decrease, the installation will be limited by space, the system power consumption will be large, and the cost will increase. And because the stator assembly generates static electricity and magnetic fields during the energization process, and the static electricity and magnetic fields will affect or interfere with the transmission of control signals, thus affecting the action of the valve needle and reducing the control accuracy of the electronic expansion valve. The existing electronic expansion valves generally set up a grounding component to conduct the static electricity and magnetic fields through the grounding component, but the structure of the grounding component is relatively complex and the installation is inconvenient.

[0004] Moreover, due to the frequent rotation of the lead screw and the magnetic rotor, the wear of the lead screw and the magnetic rotor is relatively serious. After long-term use, it is easy to have a jamming problem, and the service life of the entire expansion valve is not good.

[0005] In addition, during the valve closing process of the expansion valve, when the valve needle encounters the lower stroke limit, it suddenly stops, generating a large inertial force, which causes the threads to jam, resulting in excessive axial force on the part structure and leading to the situation where the valve cannot be opened. Therefore, the existing expansion valve needs to be improved. Summary of the Invention

[0006] The present invention provides an electronic expansion valve with a buffering effect, which has high precision, obvious energy-saving effect, simple structure, convenient installation, a balanced pressure function, and a long service life. It has a buffering effect when closing the valve, preventing the problem of thread jamming and inability to open the valve.

[0007] To achieve the above object, the present invention provides the following technical solution: An electronic expansion valve with a buffering effect, comprising a stator assembly and a valve seat assembly. The valve seat assembly is installed at the lower part of the stator assembly. The stator assembly includes a housing and a stator component arranged inside the housing. The valve seat assembly includes an end cover component, a magnetic isolation tube, a valve needle component, and a valve seat component. The magnetic isolation tube is arranged at the upper end of the valve seat component and inserted into the stator assembly. A lead screw component is arranged inside the magnetic isolation tube. The end cover component is located at the upper end of the magnetic isolation tube and consists of an end cover, a cup-shaped bearing, and a spring pressing piece. The spring pressing piece fixes the cup-shaped bearing in the cup-shaped inner cavity in the middle of the end cover. The upper end of the lead screw is inserted into the cup-shaped bearing. A flexible graphite gasket is installed between the lower end of the cup-shaped bearing and the lead screw component. The valve needle component includes a valve needle and a valve needle spring arranged in the inner hole at the lower end of the valve needle. The lower end of the valve needle is inserted with a valve needle head. A balance flow channel is opened in the middle of the valve needle head. A bushing is sleeved on the outer side of the upper part of the valve needle head. One end of the bushing abuts against the valve needle spring. A valve needle sleeve is arranged at the lower end of the bushing. A valve needle inner leakage O-ring is installed between the inner side of the valve needle sleeve and the valve needle head. The lead screw inside the lead screw component is axially inserted into the central threaded through hole of the valve needle, and there is a thread gap between the lead screw and the valve needle.

[0008] Preferably, the lead screw component includes an upper wear-resistant ring, a lower wear-resistant ring, a magnetic rotor support frame, a magnetic rotor, and a lead screw. Among them, the magnetic rotor support frame is injection-molded on the lead screw, the magnetic rotor is bonded to the magnetic rotor support frame, the magnetic rotor support frame is provided with clamping grooves at both the upper and lower parts, and the claws of the upper wear-resistant ring and the lower wear-resistant ring are clamped in the corresponding clamping grooves.

[0009] Preferably, a valve needle sleeve assembly is arranged inside the valve seat assembly. The valve needle sleeve assembly includes a ball bearing and a valve needle sleeve, and the ball bearing is fitted into the concave step of the valve needle sleeve.

[0010] Preferably, at the upper end of the valve needle sleeve located at the edge of the concave step, there is a raised swaged closing part to axially fix the ball bearing. Two limiting grooves are formed on both sides of the valve needle sleeve, and the upper end of the valve needle extends into the limiting grooves for axial sliding.

[0011] Preferably, a sealing structure is arranged outside the valve needle. The sealing structure is a main sealing ring and an O-ring arranged outside the main sealing ring. A pressing ring is axially arranged on the upper side of the main sealing ring, and sliders are arranged on both sides of the upper part of the valve needle and are embedded into the limiting grooves.

[0012] Preferably, the valve seat assembly is composed of a valve seat and a valve base. The valve base is arranged at the lower end of the valve seat, and the upper end of the valve seat is welded and connected to a magnetic isolation tube.

[0013] Preferably, the stator assembly is composed of a housing and a stator component. The stator component is composed of a stator housing, a winding coil, a skeleton, an electromagnetic pole plate, and a Pin needle. There are positioning holes on the stator housing and the electromagnetic pole plate, and positioning pins on the skeleton. The stator housing and the electromagnetic pole plate are plugged and connected to the skeleton through the positioning holes and the positioning pins. The winding coil is wound around the skeleton, and the Pin needle is fixed on the skeleton. One end of the Pin needle is connected to the winding coil, and the other end is externally connected to a communication channel.

[0014] Preferably, a waterproof ring is arranged on the outer side of the upper end of the valve seat.

[0015] Preferably, a circle of grooves with a triangular cross-section is formed on the lower end surface of the cup-shaped bearing.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The valve needle spring is used as a downward buffer to prevent the valve needle from suddenly stopping when encountering the lower stroke limit during the valve closing movement, generating a large inertial force, causing the thread to jam, resulting in excessive axial force on the structure and leading to the situation where the valve cannot be opened. At the same time, the bushing and the valve needle sleeve are in line contact. This contact method can effectively compensate for the coaxiality of the part structure, and at the same time play a guiding role and a returning role. The O-ring for internal leakage of the valve needle mainly plays a sealing and guiding role to prevent liquid from leaking internally through the gap between the bushing, the valve needle sleeve and the valve needle.

[0018] 2. The cup-type bearing is adopted in the end cover assembly as the bearing for the rotation of the lead screw. The cup-type bearing can play a role in fixed guiding and compensation, ensuring good coaxiality after the parts are assembled, preventing the parts from jamming easily, reducing the friction during the rotation of the magnetic rotor, thereby improving the transmission efficiency of the lead screw and enhancing the service life of the valve at the same time.

[0019] 3. The fluid medium can enter the upper cavity of the valve body through the position of the valve needle. The fluid medium will fill the upper cavity of the entire valve seat assembly, and there will be no leakage of the fluid medium, thus reducing the pressure difference between the upper and lower sides of the valve needle, reducing the movement resistance of the valve needle, keeping the low-pressure section at the fluid outlet, contributing to the pressure balance at the upper and lower ends of the valve needle of the electronic expansion valve, and reducing energy consumption.

[0020] 4. The connecting snap ring is connected to the stator housing and is electrically connected to the stator housing. The other end is fixed to the valve body, thus realizing the grounding connection of the stator housing, avoiding the interference of static electricity and magnetic field on the transmission and feedback of the control signal, preventing interference with the operation of the stator assembly, and realizing the fixed connection with the valve body and the positioning connection with the valve base. The structure is simple and the installation is convenient.

[0021] 5. The structural integration degree is high, the number of parts is small, the assembly is more convenient, which is beneficial to lightweight, and the cost has more advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0023] Figure 2 is a three-dimensional exploded structural diagram of the present invention;

[0024] Figure 3 is an exploded structural diagram of the stator assembly of the present invention;

[0025] Figure 4 is a front view semi-sectional structural diagram of the valve seat assembly of the present invention;

[0026] Figure 5 is a sectional structural diagram of the end cover assembly of the present invention;

[0027] Figure 6 is a three-dimensional structural diagram of the lead screw assembly of the present invention;

[0028] Figure 7 is a three-dimensional structural diagram of the valve needle sleeve assembly of the present invention;

[0029] Figure 8 is a front view semi-sectional structural diagram of the valve needle sleeve assembly of the present invention;

[0030] Figure 9 is a three-dimensional structural diagram of the valve needle assembly of the present invention;

[0031] Figure 10The main view semi-sectional structure diagram of the valve needle assembly of the present invention;

[0032] Figure 11 The main view semi-sectional structure diagram of the lower part of the valve seat assembly of the present invention. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] As Figures 1-11 shown, the present invention provides an electronic expansion valve with a buffering effect, including a stator assembly 1 and a valve seat assembly 3. The lower part of the stator assembly 1 is provided with the valve seat assembly 3. The stator assembly 1 includes a housing 11 and a stator component 12 arranged in the housing 11. The valve seat assembly 3 includes an end cover component 31, a magnetic isolation tube 34, a valve needle assembly 38 and a valve seat component 310. The magnetic isolation tube 34 is arranged at the upper end of the valve seat component 310 and inserted into the stator assembly 1. A lead screw assembly 35 is arranged inside the magnetic isolation tube 34. The end cover component 31 is located at the upper end of the magnetic isolation tube 34 and is composed of an end cover 311, a cup-shaped bearing 312 and a spring pressing piece 313. The spring pressing piece 313 fixes the cup-shaped bearing 312 in the cup-shaped inner cavity a in the middle of the end cover 311. The upper end of the lead screw 353 is inserted into the cup-shaped bearing 312. A flexible graphite gasket 33 is installed between the lower end of the cup-shaped bearing 312 and the lead screw assembly 35. The valve needle assembly 38 includes a valve needle 381 and a valve needle spring 383 arranged in the inner hole at the lower end of the valve needle 381. The lower end of the valve needle 381 is inserted with a valve needle head 389. A balance flow channel is opened in the middle of the valve needle head 389. A bushing 386 is sleeved on the outer side of the upper part of the valve needle head 389. One end of the bushing 386 abuts against the valve needle spring 383. A valve needle sleeve 387 is arranged at the lower end of the bushing 386. A valve needle internal leakage O-ring 388 is installed between the inner side of the valve needle sleeve 387 and the valve needle head 389. The lead screw 353 in the lead screw assembly 35 is axially inserted into the central threaded through hole of the valve needle 381. There is a threaded gap between the lead screw 353 and the valve needle 381. The flexible graphite gasket 33 plays an axial buffering role to prevent axial jamming during the operation of the valve.

[0035] Among them, the cup bearing 312 is made of brass by machining. Since brass has good self-lubricating performance, good wear resistance, good mechanical properties, and good cutting performance, the cup bearing 312 plays a role in fixing, guiding, and compensating, ensuring good coaxiality after the parts are assembled. A groove b with a triangular cross-section is opened on the lower end surface of the cup bearing 312, facilitating the lubricating oil to enter the assembly gap with the upper wear-resistant ring 32 along the groove b for better lubrication.

[0036] A sealing structure is provided on the outer side of the valve needle 381. The sealing structure is a main sealing ring 384 and an O-ring 385 arranged outside the main sealing ring 384. A pressure ring 382 is axially arranged on the upper side of the main sealing ring 384. Sliders 381a are arranged on both sides of the upper part of the valve needle 381 and are embedded in the limit grooves 372a.

[0037] The valve needle spring 383 plays a buffering role, preventing the valve needle from suddenly stopping when encountering the lower stroke limit during the valve closing movement, generating a large inertial force, causing the threads to jam, resulting in excessive axial force on the part structure and preventing the valve from opening. The main sealing ring 384 and the O-ring 385 are used in combination to form a dynamic seal, improving the sealing performance and preventing internal leakage inside the valve body. The main sealing ring 384 and the valve needle 381 are in interference fit. The O-ring 388 for valve needle internal leakage mainly plays a role in sealing and guiding, preventing liquid from leaking internally through the gap between the bushing 386, the valve needle sleeve 387, and the valve needle 381. At the same time, since the material of the O-ring 388 for valve needle internal leakage is a flexible material, it can play a guiding role and compensate for the coaxiality of the part structure. The contact between the bushing 386 and the valve needle sleeve 387 is a line contact, which can effectively compensate for the coaxiality of the part structure and at the same time play a guiding role and a returning role.

[0038] Among them, the lead screw assembly 35 includes an upper wear-resistant ring 32, a lower wear-resistant ring 36, a magnetic rotor support frame 351, a magnetic rotor 352, and a lead screw 353. The magnetic rotor support frame 351 is injection-molded on the lead screw 353, and the injection-molding material is PPS + 40% GF. The magnetic rotor 352 is bonded to the magnetic rotor support frame 351, and the bonding material is neodymium iron boron (Nd2Fe14B). Card slots are provided both above and below the magnetic rotor support frame 351, and the claws of the upper wear-resistant ring 32 and the lower wear-resistant ring 36 are stuck in the corresponding card slots for convenient fixing. The upper wear-resistant ring 32 and the lower wear-resistant ring 36 are both made of SUS304 and are both subjected to PHT spraying treatment to enhance their wear resistance without affecting their corrosion resistance.

[0039] A valve needle sleeve assembly 37 is provided inside the valve seat assembly 310. The valve needle sleeve assembly 37 includes a ball bearing 371 and a valve needle sleeve 372. The ball bearing 371 is installed in the concave step of the valve needle sleeve 372. The ball bearing 371 reduces the friction in the power transmission of the screw rod 353 and improves the transmission efficiency of the screw rod.

[0040] The upper end of the valve needle sleeve 372 is located at the edge of the concave step and has a raised riveted end portion to axially fix the ball bearing 371 so that it will not separate from the valve needle sleeve 372. Two limiting grooves 372a are provided on both sides of the valve needle sleeve 372. The upper end of the valve needle 381 extends into the limiting groove 372a for axial sliding, radially fixing the valve needle so that the valve needle 381 only moves axially, while also limiting the movement distance of the valve needle 381. An annular groove is provided at the bottom of the valve needle sleeve 372 for placing a buffer pad.

[0041] The valve seat assembly 310 is composed of a valve seat 3101 and a valve base 3102. The valve base 3102 is arranged at the lower end of the valve seat 3101. The valve seat 3101 and the valve base 3102 are welded together in an annular seam. The upper end of the valve seat 3101 is welded to the magnetic isolation tube 34.

[0042] It is important to note that when installing the valve needle, first install the O-ring 388 into the O-ring groove of the valve needle sleeve 387. The O-ring groove on the valve needle sleeve 387 has rounded edges to facilitate installation of the O-ring 388 and prevent mechanical damage to the O-ring 388. Install the bushing 386 and the valve needle head 389 and perform a girth weld. Then, perform a girth weld to the valve needle 381 and the valve needle sleeve 387. At this point, the valve needle spring 383 is preloaded, and the preload force of the valve needle spring 383 forces the bushing 386 and valve needle sleeve 387 into contact, forming a linear seal. The downward movement of the valve needle 381 is now limited not by the contact surface between the lower surface of the valve needle 381 and the upper surface of the pressure ring 382, but by the contact surface between the lower surface of the valve needle sleeve 387 and the upper surface of the valve needle head 389. The valve needle sleeve assembly 37 and the valve seat assembly 310 are tightly fitted and press-fitted, then annularly welded. Note that the slider 381a on the valve needle 381 must be embedded in the limiting groove 372a of the valve needle sleeve assembly 37. The valve needle assembly 38 is threadedly connected to the screw assembly 35. The magnetic isolation tube 34 is tightly fitted with the valve seat assembly 310 and the end cover assembly 31. The connection between the valve seat assembly 310 and the magnetic isolation tube 34, as well as the connection between the end cover assembly 31 and the magnetic isolation tube 34, need to be cleaned. The magnetic isolation tube is annularly welded to the valve seat assembly 310 and the end cover assembly 31. The stator assembly 1 is connected to the connecting clamp 2 by heat riveting, and there is a pressure point on the lower part of the stator housing 11. The valve seat assembly 3 is connected to the valve body via the threads on the valve seat 3101 of the valve seat assembly 310. The stator assembly 1 is connected to the valve body via the connecting clamp 2 and is pressed onto the valve seat assembly 3.

[0043] Preferably, the stator assembly 1 is composed of a housing 11 and a stator component 12. The stator component 12 is composed of a stator housing 121, a winding coil 122, a skeleton 123, an electromagnetic pole plate 124, and Pin pins 125. The stator housing 121 and the electromagnetic pole plate 124 are provided with positioning holes, and the skeleton 123 is provided with positioning pins. The stator housing 121 and the electromagnetic pole plate 124 are inserted and connected to the skeleton 123 through the positioning holes and the positioning pins. The winding coil 122 is wound around the skeleton 123, and the Pin pins 125 are fixed on the skeleton 123. One end of the Pin pin 125 is connected to the winding coil 122, and the other end is externally connected to a communication channel to realize the electrical connection between the winding coil and an external signal. The housing 11 is an injection molded part, injection molded from a plastic material. To protect the stator component, the stator component 12 is encapsulated, and the encapsulation material outside the stator component 12 is TSG-30 / 4W.

[0044] In addition, a waterproof ring 39 is provided on the outer side of the upper end of the valve seat 3101 to ensure the sealing performance of the installation.

[0045] Working principle: Before the electronic expansion valve starts to work, the fluid medium passes through the balance flow channel at the lower end of the valve needle 381 and then enters the upper cavity of the valve body through the thread gap. Due to the presence of the magnetic isolation tube 34, the fluid medium will fill the entire upper cavity of the valve seat assembly 3, thereby reducing the pressure difference between the upper and lower sides of the valve needle 381 and reducing the movement resistance of the valve needle 381. And due to the presence of the main sealing ring 384 and the O-ring 385, the fluid medium will not leak outwards.

[0046] When the electronic expansion valve starts to work, after the liquid high-pressure fluid medium passes through the throttle of the valve port, the pressure of the high-pressure fluid medium will decrease, becoming a gas-liquid mixed fluid medium, and at the same time releasing heat. The temperature-pressure sensor at the outlet end will input the collected temperature signal and pressure signal into the controller. The controller outputs a signal to the electronic expansion valve after calculation according to the relevant control program, controlling the change of the current magnitude in the winding coil 122 in the stator component 12, thereby controlling the generation of a changing excitation magnetic field by the stator component 12. The magnetic rotor 352 rotates under the action of the excitation magnetic field, thereby driving the lead screw assembly 35 to move, and further driving the valve needle assembly 38 to move through thread transmission, so as to realize the change of the opening degree of the valve port of the electronic expansion valve, and further achieve the purpose of adjusting the flow rate and pressure of the fluid medium.

[0047] Although the present invention has been described above with reference to embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in the present invention can be combined with each other in any way, and the exhaustive description of these combinations is not given in this specification only for the consideration of saving space and resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electronic expansion valve with a buffering effect, comprising a stator assembly (1) and a valve seat assembly (3). The valve seat assembly (3) is installed at the lower part of the stator assembly (1). The stator assembly (1) consists of a housing (11) and a stator component (12) arranged inside the housing (11). It is characterized in that, The described valve seat assembly (3) includes an end cover assembly (31), a magnetic isolation tube (34), a valve needle assembly (38), a valve seat assembly (310), and a valve needle sleeve assembly (37) located above the valve seat assembly (310). The magnetic isolation tube (34) is provided at the upper end of the valve seat assembly (310) and inserted into the stator assembly (1). A lead screw assembly (35) is provided inside the magnetic isolation tube (34). The end cover assembly (31) is located at the upper end of the magnetic isolation tube (34) and consists of an end cover (311), a cup-shaped bearing (312), and a spring pressing piece (313). The spring pressing piece (313) fixes the cup-shaped bearing (312) in the cup-shaped inner cavity (a) in the middle of the end cover (311). The upper end of the lead screw (353) is inserted into the cup-shaped bearing (312). A flexible graphite gasket (33) is installed between the lower end of the cup-shaped bearing (312) and the lead screw assembly (35). The valve needle assembly (38) includes a valve needle (381) and a valve needle spring (383) provided in the inner hole at the lower end of the valve needle (381). A valve needle head (389) is inserted at the lower end of the valve needle (381). A balance flow channel is opened in the middle of the valve needle head (389). A bushing (386) is sleeved on the outer side of the upper part of the valve needle head (389). One end of the bushing (386) abuts against the valve needle spring (383). A sealing guide sleeve (387) is provided at the lower end of the bushing (386). A valve needle internal leakage O-ring (388) is installed between the inner side of the sealing guide sleeve (387) and the valve needle head (389). The lead screw (353) inside the lead screw assembly (35) is axially inserted into the central threaded through hole of the valve needle (381), and there is a threaded gap between the lead screw (353) and the valve needle (381). The described lead screw assembly (35) includes an upper wear-resistant ring (32), a lower wear-resistant ring (36), a magnetic rotor support frame (351), a magnetic rotor (352), and a lead screw (353). Among them, the magnetic rotor support frame (351) is injection-molded on the lead screw (353), the magnetic rotor (352) is bonded to the magnetic rotor support frame (351), the magnetic rotor support frame (351) is provided with clamping grooves on both the upper and lower sides, and the claws of the upper wear-resistant ring (32) and the lower wear-resistant ring (36) are stuck in the corresponding clamping grooves. The described valve needle sleeve assembly (37) includes a ball bearing (371) and a valve needle sleeve (372). The ball bearing (371) is installed at the concave step of the valve needle sleeve (372). At the edge of the upper end of the valve needle sleeve (372) located at the concave step, there is a raised swaging and closing part to axially fix the ball bearing (371). Two limiting grooves (372a) are opened on both sides of the valve needle sleeve (372), and the upper end of the valve needle (381) extends into the limiting grooves (372a) for axial sliding.

2. The electronic expansion valve with a buffering effect according to claim 1, wherein: A sealing structure is provided on the outer side of the valve needle (381). The sealing structure is a main sealing ring (384) and an O-ring (385) provided on the outer side of the main sealing ring (384). A pressing ring (382) is axially provided on the upper side of the main sealing ring (384). Sliders (381a) are provided on both sides of the upper part of the valve needle (381) and are embedded in the limiting grooves (372a).

3. The electronic expansion valve with a buffering effect according to claim 1, characterized in that: The valve seat assembly (310) is composed of a valve seat (3101) and a valve base (3102). The valve base (3102) is provided at the lower end of the valve seat (3101). The upper end of the valve seat (3101) is welded to the magnetic isolation tube (34).

4. The electronic expansion valve with a buffering effect according to claim 1, wherein: The stator assembly (1) is composed of a housing (11) and a stator component (,12). The stator component (12) is composed of a stator housing (121), a winding coil (122), a skeleton (123), an electromagnetic pole plate (124), and a Pin pin (). Positioning holes are provided on the stator housing (121) and the electromagnetic pole plate (124). Positioning pins are provided on the skeleton (123). The stator housing (121) and the electromagnetic pole plate (124) are inserted and connected to the skeleton (123) through the positioning holes and the positioning pins. The winding coil (122) is wound around the skeleton (123). The Pin pin (125) is fixed on the skeleton (123). One end of the Pin pin (125) is connected to the winding coil (122), and the other end is externally connected to a communication channel.

5. The electronic expansion valve with a buffering effect according to claim 3, wherein: A waterproof ring (39) is provided on the outer side of the upper end of the valve seat (3101).

6. The electronic expansion valve with a buffering effect according to claim 1, characterized in that: A groove (b) with a triangular cross-section is formed in a circle on the lower end surface of the cup-shaped bearing (312).

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