Screw drive electronic expansion valve

Abstract

This invention relates to the technical field of thermal management system components for new energy vehicles, and discloses a spiral-driven electronic expansion valve. The valve body has a metal valve body with a throttling end connected to its bottom. An isolation atmospheric pressure chamber and a refrigerant high-pressure chamber are respectively provided within the metal valve body and the throttling end. A stator and a rotor are assembled within the metal valve body. A transmission mechanism is assembled in the isolation atmospheric pressure chamber, including a screw, a screw sleeve, and a guide sleeve. A sealing assembly is assembled between the isolation atmospheric pressure chamber and the refrigerant high-pressure chamber. A flow-dividing step and a spiral guide groove are formed on the inner wall of the throttling end. This invention uses the circumferential rotation of the rotor to drive the screw, while the screw sleeve is limited by the guide sleeve and only moves axially. This eliminates the need for a pre-reserved rotor movement cavity, reducing the valve body volume. Furthermore, the constant magnetic gap between the stator and rotor improves flow control accuracy. The isolation atmospheric pressure chamber, in conjunction with the dynamic sealing assembly, prevents refrigerant from entering the threaded joint, reducing wear and jamming. The flow-dividing and guiding structure of the throttling end, in conjunction with the valve core, suppresses refrigerant cavitation and reduces noise.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal management system components for new energy vehicles, specifically, it relates to a spiral-driven electronic expansion valve. Background Technology

[0002] Electronic expansion valves are essential components of multi-loop integrated thermal management systems for new energy vehicles, including heat pump air conditioning, power battery temperature control, and electric drive cooling. These valves rely on their internal structure to achieve stepless and precise control of refrigerant throttling, pressure reduction, and flow. They are compatible with R1234yf, supercritical CO2, and conventional HFO refrigerants. Currently, commercially available and patented automotive electronic expansion valves generally employ a rotor-driven transmission topology. The overall structure consists of basic components such as a stator, magnetic rotor, transmission screw, valve core, and valve body. The rotor is driven by the motor's magnetic field to synchronously rotate the screw and generate axial floating, thereby changing the valve core opening to regulate refrigerant flow. These valves are widely used in various automotive thermal management modules.

[0003] However, the existing electronic expansion valves require a reserved axial movement cavity for the rotor inside the valve body to match the valve core stroke, resulting in an excessively large overall valve body height and a large space occupation in the vehicle. This makes it difficult to adapt to the compact new generation of thermal management modules. Furthermore, the continuous up-and-down movement of the rotor with the opening degree will cause the stator and rotor magnetic gap and coupling area to change continuously, leading to problems such as motor torque fluctuation, valve core positioning drift, and insufficient flow control accuracy. Long-term eccentric floating of the rotor can also easily cause faults such as rotor rubbing, inner wall wear, movement jamming, and abnormal operating noise.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows: A helical-driven electronic expansion valve includes a metal valve body with a throttling end connected to its bottom. An isolation atmospheric pressure chamber and a refrigerant high-pressure chamber are respectively arranged axially inside the metal valve body and the throttling end. A stator is assembled inside the metal valve body, and a rotor is installed inside the stator. A transmission mechanism is assembled in the isolation atmospheric pressure chamber. The transmission mechanism includes a screw, a screw sleeve, and a guide sleeve. The screw is connected to the rotor, and a screw sleeve meshes with the screw. A guide sleeve is installed on the metal valve body, and the screw sleeve is slidably installed within the guide sleeve. A connecting sleeve is connected to the lower end of the screw sleeve, and a valve core is assembled inside the connecting sleeve. A sealing assembly is assembled between the isolation atmospheric pressure chamber and the refrigerant high-pressure chamber. A flow-diverting step and a helical guide groove are formed on the inner wall of the throttling end.

[0006] In a preferred embodiment of the present invention, a drive assembly is assembled in the metal valve body, the drive assembly is electrically connected to the stator, and an electromagnetic power-off locking unit is integrated inside the drive assembly.

[0007] In a preferred embodiment of the present invention, the stator, rotor and screw are arranged coaxially, and a bearing is fitted on the outside of the screw, with the outer ring of the bearing assembled in a metal valve body.

[0008] In a preferred embodiment of the present invention, the inner wall of the guide sleeve is provided with a guide rail, and the outer wall of the screw sleeve is connected with a guide block, the guide block being slidably fitted and installed inside the guide rail.

[0009] In a preferred embodiment of the present invention, a spring is installed in the connecting sleeve, with one end of the spring abutting against the threaded sleeve and the other end abutting against the valve core.

[0010] In a preferred embodiment of the present invention, the sealing assembly includes a sealing base, a sealing bracket, a pre-tightening compensation spring, and a sealing ring. The sealing base is fixed at the boundary between the isolation atmospheric pressure chamber and the refrigerant high pressure chamber. The sealing bracket is connected to the sealing base. The pre-tightening compensation spring is sleeved on the outer side of the sealing bracket. The sealing ring is sleeved on the outer wall of the valve core.

[0011] In a preferred embodiment of the present invention, the sidewall of the throttling end is provided with a plurality of inlet channels and the center of the bottom end of the throttling end is provided with an outlet channel, and both the inlet channel and the outlet channel are connected to the refrigerant high-pressure chamber.

[0012] In a preferred embodiment of the present invention, the flow-dividing step is arranged in a ring in the throttling end, and three spiral guide grooves are provided, each of which is evenly arranged circumferentially along the axis of the throttling end.

[0013] In a preferred embodiment of the present invention, the inner wall of the metal valve body is provided with a heat insulation lining, and a first sealing ring and a second sealing ring are respectively installed on the metal valve body and the throttling end.

[0014] In a preferred embodiment of the present invention, the screw has a trapezoidal thread pitch of 0.2 mm and a thread helix angle of 5.5°.

[0015] Compared with the prior art, the present invention has the following advantages: This invention drives the screw to rotate by the circumferential rotation of the rotor. The screw sleeve is limited by the guide sleeve and only moves axially. There is no need to reserve a cavity for the rotor to move, which reduces the volume of the valve body. The constant magnetic gap between the stator and rotor improves the accuracy of flow control. The isolation atmospheric pressure chamber cooperates with the dynamic sealing component to prevent refrigerant from entering the threaded pair, reduce wear and jamming, and extend service life. The flow diversion and guiding structure at the throttling end cooperates with the valve core to suppress refrigerant cavitation and reduce operating noise.

[0016] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0017] In the attached diagram: Figure 1 A three-dimensional diagram of a screw-driven electronic expansion valve; Figure 2 This is a cross-sectional view of a helical-driven electronic expansion valve. Figure 3 This is a schematic diagram of the transmission mechanism of a helical-driven electronic expansion valve. Figure 4 An exploded view of the threaded sleeve and guide sleeve of a helical-driven electronic expansion valve; Figure 5 This is a schematic diagram of the threaded sleeve of a helical-driven electronic expansion valve. Figure 6 This is a schematic diagram of the installation of the sealing assembly of a screw-driven electronic expansion valve. Figure 7 A schematic diagram of the sealing assembly of a helical-driven electronic expansion valve; Figure 8 This is a schematic diagram of the assembly of the throttling end and the valve core of a screw-driven electronic expansion valve. Figure 9 This is a schematic diagram of the throttling end of a helical-driven electronic expansion valve.

[0018] In the diagram: 1. Metal valve body; 101. Isolation atmospheric pressure chamber; 102. Refrigerant high pressure chamber; 2. Stator; 3. Rotor; 4. Screw; 5. Bearing; 6. Screw sleeve; 7. Guide sleeve; 8. Guide block; 9. Guide slide rail; 10. Connecting sleeve; 11. Valve core; 12. Spring; 13. Sealing assembly; 131. Sealing base; 132. Sealing bracket; 133. Preload compensation spring; 134. Sealing ring; 14. Throttling end; 15. Thermal insulation liner; 16. Outlet flow channel; 17. Inlet flow channel; 18. Diverting step; 19. Spiral guide groove; 20. First sealing ring; 21. Second sealing ring; 22. Drive assembly. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention. Example

[0020] like Figures 1 to 9As shown, a spiral-driven electronic expansion valve includes a metal valve body 1, with a throttling end 14 connected to the bottom of the metal valve body 1. An isolation atmospheric pressure chamber 101 and a refrigerant high pressure chamber 102 are respectively arranged axially inside the metal valve body 1 and the throttling end 14. A stator 2 is assembled inside the metal valve body 1, and a rotor 3 is installed inside the stator 2. A transmission mechanism is assembled in the isolation atmospheric pressure chamber 101, including a screw 4, a screw sleeve 6, and a guide sleeve 7. The screw 4 is connected to the rotor 3, and the screw sleeve 6 meshes with the screw 4. The guide sleeve 7 is installed on the metal valve body 1, and the screw sleeve 6 is slidably installed inside the guide sleeve 7. A connecting sleeve 10 is connected to the lower end of the screw sleeve 6, and a valve core 11 is assembled inside the connecting sleeve 10. A sealing assembly 13 is assembled between the isolation atmospheric pressure chamber 101 and the refrigerant high pressure chamber 102. A flow-diverting step 18 and a spiral guide groove 19 are formed on the inner wall of the throttling end 14. In this configuration, the metal valve body 1 provides a mounting carrier for all internal parts. The isolated atmospheric pressure chamber 101 houses the transmission structure composed of the screw 4 and the sleeve 6. The refrigerant high pressure chamber 102 houses the refrigerant to be throttled. The rotor 3, in conjunction with the screw 4 and the sleeve 6, completes the conversion from rotary motion to linear motion. The valve core 11, in conjunction with the throttling end 14, changes the refrigerant flow cross-section to achieve flow regulation. The sealing assembly 13 separates the two types of chambers. The flow divider step 18 and the spiral guide groove 19 work together to optimize the refrigerant flow state.

[0021] like Figures 1 to 9 As shown, in a specific embodiment, a drive assembly 22 is assembled in the metal valve body 1. The drive assembly 22 is electrically connected to the stator 2, and an electromagnetic power-off locking unit is integrated inside the drive assembly 22. In this configuration, the drive assembly 22 outputs an excitation current to the stator 2 to generate a rotating magnetic field to drive the rotor 3 to rotate. The power-off locking unit works with the stator 2 and the rotor 3 to lock the rotor rotation, maintaining the current opening degree of the valve core 11 unaffected by refrigerant pressure shocks.

[0022] like Figures 1 to 9 As shown, the stator 2, rotor 3, and screw 4 are arranged coaxially. A bearing 5 is fitted onto the outside of the screw 4, and the outer ring of the bearing 5 is assembled in the metal valve body 1. In this configuration, the coaxial arrangement of the stator 2, rotor 3, and screw 4 ensures the concentricity and stability of the magnetic field transmission and the threaded transmission. The bearing 5, in conjunction with the screw 4, supports the screw 4 to rotate smoothly, reducing rotational friction and preventing eccentric wobbling.

[0023] like Figures 1 to 9 As shown, the inner wall of the guide sleeve 7 is provided with a guide rail 9, and the outer wall of the threaded sleeve 6 is connected with a guide block 8. The guide block 8 is slidably fitted inside the guide rail 9. In this configuration, the guide rail 9 and the guide block 8 cooperate to restrict the threaded sleeve 6 from rotating synchronously with the screw 4, and only allow the threaded sleeve 6 to slide axially.

[0024] like Figures 1 to 9As shown, a spring 12 is further installed in the connecting sleeve 10. One end of the spring 12 abuts against the threaded sleeve 6, and the other end abuts against the valve core 11. In this configuration, the spring 12, together with the threaded sleeve 6 and the valve core 11, continuously outputs axial preload to eliminate gaps and prevent the valve core 11 from adjusting slowly or drifting.

[0025] like Figures 1 to 9 As shown, the sealing assembly 13 further includes a sealing base 131, a sealing bracket 132, a preload compensation spring 133, and a sealing ring 134. The sealing base 131 is fixed at the boundary between the isolated atmospheric pressure chamber 101 and the refrigerant high pressure chamber 102. The sealing bracket 132 is connected to the sealing base 131. The preload compensation spring 133 is sleeved on the outer side of the sealing bracket 132, and the sealing ring 134 is sleeved on the outer wall of the valve core 11. In this configuration, the preload compensation spring 133, in conjunction with the sealing ring 134, continuously presses the sealing ring against the outer wall of the valve core 11, adapting to the axial sliding of the valve core 11 throughout its entire stroke, preventing high-pressure refrigerant from entering the isolated atmospheric pressure chamber 101, and protecting the internal threaded transmission structure.

[0026] like Figures 1 to 9 As shown, furthermore, the sidewall of the throttling end 14 is evenly provided with several inlet channels 17, and the bottom center of the throttling end 14 is provided with an outlet channel 16. Both the inlet channels 17 and the outlet channels 16 are connected to the refrigerant high-pressure chamber 102. In this configuration, the inlet channels 17 and the outlet channels 16 form a complete refrigerant flow path. The high-pressure refrigerant enters the refrigerant high-pressure chamber 102 through the inlet channels 17, and after throttling, it is output to the outside through the outlet channels 16.

[0027] like Figures 1 to 9 As shown, furthermore, the flow-dividing step 18 is arranged in a ring within the throttling end 14, and three spiral guide grooves 19 are provided, each spiral guide groove 19 being evenly arranged circumferentially along the axis of the throttling end 14. In this configuration, the ring-shaped flow-dividing step 18, in conjunction with the circumferentially arranged spiral guide grooves 19, simultaneously diverts and disperses the refrigerant flow, suppresses the generation of cavitation bubbles during throttling, reduces fluid noise, and minimizes valve core erosion and wear.

[0028] like Figures 1 to 9 As shown, furthermore, a heat-insulating liner 15 is laid on the inner wall of the metal valve body 1, and a first sealing ring 20 and a second sealing ring 21 are respectively installed on the metal valve body 1 and the throttling end 14. In this configuration, the heat-insulating liner 15 works with the metal valve body 1 to block heat exchange, reducing frost formation on the valve body and heat stress loss, while the first sealing ring 20 and the second sealing ring 21 work with the valve body and the throttling end to seal the assembly gaps.

[0029] like Figures 1 to 9 As shown, the trapezoidal thread of screw 4 has a pitch of 0.2mm and a thread helix angle of 5.5°. In this configuration, the trapezoidal thread of this specification, in conjunction with the screw sleeve 6, achieves high-precision axial feed with a small stroke, improving the ability to finely adjust the refrigerant flow. Example

[0030] The difference between this embodiment and the previous one is that the trapezoidal thread pitch of the screw 4 is 0.15mm, the thread helix angle is 4°, and two spiral guide grooves 19 are provided on the throttling end 14. In this configuration, the screw 4 with a smaller pitch and thread helix angle, together with the screw sleeve 6, improves the adjustment accuracy. The two spiral guide grooves 19, together with the annular diversion step 18, are suitable for miniaturized low-flow vehicle branch circuits and battery independent temperature control small circuits, resulting in higher adjustment accuracy and faster response. Example

[0031] The difference between this embodiment and the previous one is that the trapezoidal thread pitch of the screw 4 is 0.25mm, the thread helix angle is 7°, and four spiral guide grooves 19 are provided on the throttling end 14. In this configuration, the screw 4 with a larger pitch and thread helix angle, together with the screw sleeve 6, accelerates the valve core lifting and lowering response speed. The four spiral guide grooves 19, together with the diversion step 18, are suitable for commercial vehicle new energy high-flow thermal management systems and multi-unit integrated heat pump circuits, resulting in greater flow capacity.

[0032] The implementation principle of a helical drive electronic expansion valve in this embodiment is as follows: The vehicle thermal management controller collects real-time operating condition data such as battery temperature, cabin load, ambient temperature, and refrigerant inlet and outlet superheat. Combined with the built-in control algorithm, it generates an opening adjustment pulse command and transmits it to the drive assembly 22. The drive assembly 22 feeds alternating excitation current into the winding of the stator 2 in a preset two-phase excitation sequence. After the winding of the stator 2 is energized, it continuously generates a uniform and stable rotating electromagnetic field. Relying on the attraction and repulsion force between the magnetic poles, it continuously applies tangential torque to the rotor 3, causing the rotor 3 to rotate only around its own axis. The rotor 3 is constrained by the internal structure of the valve body and will not move axially up and down. The magnetic gap and effective magnetic field coupling area between the stator and rotor remain constant, and there will be no problems such as torque fluctuation or uneven step distance.

[0033] The rotor 3 rotates synchronously, driving the screw 4 to rotate as well. The bearing 5 supports the screw 4 to ensure stable operation, reduce frictional resistance during screw rotation, and ensure the coaxiality of the screw 4, preventing eccentric wobbling. When the screw 4 rotates continuously, the screw sleeve 6, paired with the guide block 8, is constrained by the guide rail 9 inside the guide sleeve 7 and cannot rotate on its own. The screw 4's circumferential rotation is converted into linear reciprocating motion of the screw sleeve 6 along the axis of the screw 4 by the threaded meshing pair. The axial movement of the screw sleeve 6 synchronously drives the connecting sleeve 10 to rise and fall together. The spring 12 inside the connecting sleeve 10 continuously outputs axial preload to eliminate the meshing gap of the threaded pair, preventing the valve core 11 from experiencing adjustment lag and opening drift. The connecting sleeve 10 drives the valve core 11 to move synchronously along the axis, and the lower tapered end of the valve core 11 changes the size of the flow cross section between it and the throttling end 14.

[0034] The valve body is equipped with a parameter closed-loop detection component, including an LVDT non-contact displacement sensor, an inlet temperature and pressure integrated sensor, and an outlet temperature and pressure integrated sensor. The LVDT displacement sensor collects the axial travel of the valve core 11 in real time, and the inlet and outlet temperature and pressure integrated sensors continuously collect the real-time temperature and pressure parameters of the refrigerant. All collected signals are transmitted back to the vehicle's VCU thermal management system in real time. The controller completes the PID closed-loop control of the opening degree and the adaptive adjustment of the superheat based on the feedback signal. The drive component 22 is equipped with an electromagnetic power-off locking unit. When the motor loses power, the rotor 3 is locked to prevent rotation, thus fixing the current opening degree of the valve core 11 and preventing the opening degree from drifting due to high pressure impact of the refrigerant.

[0035] The refrigerant flows into the high-pressure refrigerant chamber 102 from four inlet channels 17 evenly arranged on the side wall of the throttling end 14. The diversion step 18 diverts and reduces the pressure of the incoming high-pressure refrigerant step by step. The spiral guide groove 19 disperses the two-phase flow of the refrigerant, suppresses the generation of cavitation bubbles during the throttling process, weakens the throttling whistling, optimizes the refrigerant flow state and improves the erosion resistance life of the valve core. After the diversion and guidance, the refrigerant passes through the flow gap formed by the valve core 11 and the throttling end 14 and finally flows out from the outlet channel 16 at the end of the throttling end 14. When the valve core 11 moves upward, the flow cross section increases and the refrigerant flow increases. When the valve core 11 moves downward, the flow cross section decreases and the refrigerant flow decreases. When the valve core 11 is completely in contact with the valve port of the throttling end 14, the flow channel is completely cut off and the refrigerant stops flowing.

[0036] The internal space of the metal valve body 1 is divided into an upper isolation atmospheric pressure chamber 101 and a lower refrigerant high pressure chamber 102. A sealing assembly 13 is installed at the boundary between the two chambers. A pre-tightening compensation spring 133 continuously applies axial pressure to the sealing ring 134 downwards, so that the sealing ring 134 always fits tightly against the outer wall of the valve core 11. During the entire axial sliding process of the valve core 11, the sealing structure adaptively compensates for the wear of the sealing ring and the gap changes caused by thermal expansion and contraction at high and low temperatures, forming a dynamic sealing structure throughout the entire stroke. This prevents the high-pressure refrigerant inside the refrigerant high pressure chamber 102 from flowing upwards into the isolation atmospheric pressure chamber 101 through the gaps in the outer wall of the valve core 11. The isolation atmospheric pressure chamber 101 contains the entire helical thread pair composed of the screw 4 and the screw sleeve 6, keeping the thread pair in a dry atmospheric pressure environment for a long time, thus preventing refrigerant corrosion, sludge adhesion, and low-temperature sticking and jamming problems. Furthermore, the inner wall of the valve cavity of the metal valve body 1 is covered with a heat insulation lining 15, which blocks the heat conduction between the refrigerant and the valve body, reduces the frost phenomenon on the valve body surface, and weakens the damage of cold and heat stress to the valve body structure.

[0037] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A helical-driven electronic expansion valve, comprising a metal valve body (1), characterized in that, The bottom of the metal valve body (1) is connected to a throttling end (14). An isolation atmospheric pressure chamber (101) and a refrigerant high pressure chamber (102) are respectively arranged axially inside the metal valve body (1) and the throttling end (14). A stator (2) is assembled inside the metal valve body (1), and a rotor (3) is installed inside the stator (2). A transmission mechanism is assembled in the isolation atmospheric pressure chamber (101), and the transmission mechanism includes a screw (4), a screw sleeve (6), and a guide sleeve (7). A screw is connected to the rotor (3). The rod (4) is fitted with a screw sleeve (6), the metal valve body (1) is fitted with a guide sleeve (7), the screw sleeve (6) is slidably installed in the guide sleeve (7), the lower end of the screw sleeve (6) is connected to a connecting sleeve (10), the connecting sleeve (10) is fitted with a valve core (11), a sealing assembly (13) is fitted between the isolation atmospheric pressure chamber (101) and the refrigerant high pressure chamber (102), and the inner wall of the throttling end (14) is provided with a flow-dividing step (18) and a spiral guide groove (19).

2. The screw-driven electronic expansion valve according to claim 1, characterized in that, The metal valve body (1) is equipped with a drive assembly (22), which is electrically connected to the stator (2). The drive assembly (22) integrates an electromagnetic power-off locking unit.

3. The screw-driven electronic expansion valve according to claim 1, characterized in that, The stator (2), rotor (3) and screw (4) are arranged coaxially. The screw (4) is fitted with a bearing (5), and the outer ring of the bearing (5) is assembled in the metal valve body (1).

4. The screw-driven electronic expansion valve according to claim 1, characterized in that, The inner wall of the guide sleeve (7) is provided with a guide slide rail (9), and the outer wall of the screw sleeve (6) is connected with a guide block (8). The guide block (8) is slidably fitted and installed inside the guide slide rail (9).

5. The screw-driven electronic expansion valve according to claim 1, characterized in that, A spring (12) is installed in the connecting sleeve (10). One end of the spring (12) abuts against the threaded sleeve (6), and the other end abuts against the valve core (11).

6. The screw-driven electronic expansion valve according to claim 1, characterized in that, The sealing assembly (13) includes a sealing base (131), a sealing bracket (132), a pre-tightening compensation spring (133), and a sealing ring (134). The sealing base (131) is fixed at the boundary between the isolation atmospheric pressure chamber (101) and the refrigerant high pressure chamber (102). The sealing bracket (132) is connected to the sealing base (131). The pre-tightening compensation spring (133) is sleeved on the outside of the sealing bracket (132). The sealing ring (134) is sleeved on the outer wall of the valve core (11).

7. The screw-driven electronic expansion valve according to claim 1, characterized in that, The throttling end (14) has a number of inlet channels (17) evenly distributed on its side wall, and an outlet channel (16) is opened at the center of the bottom end of the throttling end (14). Both the inlet channel (17) and the outlet channel (16) are connected to the refrigerant high-pressure chamber (102).

8. The screw-driven electronic expansion valve according to claim 1, characterized in that, The diversion step (18) is arranged in a ring in the throttling end (14), and three spiral guide grooves (19) are provided, each spiral guide groove (19) being evenly arranged circumferentially along the axis of the throttling end (14).

9. A screw-driven electronic expansion valve according to claim 1, characterized in that, The inner wall of the metal valve body (1) is covered with a heat insulation lining (15), and a first sealing ring (20) and a second sealing ring (21) are respectively installed on the metal valve body (1) and the throttling end (14).

10. A screw-driven electronic expansion valve according to claim 1, characterized in that, The trapezoidal thread pitch of the screw (4) is 0.2 mm, and the thread helix angle is 5.5°.

Images