Electronic expansion valve and refrigeration equipment

Abstract

The utility model discloses an electronic expansion valve and refrigeration equipment, and relates to the technical field of refrigeration equipment, the electronic expansion valve comprises a valve seat assembly and a coil assembly sleeved outside the valve seat assembly, the valve seat assembly comprises a valve seat shell, a rotor, a screw rod, a valve core assembly and a nut, the valve seat shell is provided with a valve port; the rotor is arranged in the valve seat shell; the screw rod is arranged in the rotor and is in transmission connection with the rotor, the screw rod is provided with a thread, and the thread is a double-line thread; the valve element assembly is arranged in the rotor. The nut is arranged outside the lead screw in a sleeving mode and connected with the valve element assembly, and the inner wall of the nut is provided with double threads matched with the threads on the lead screw. The screw rod rotates to drive the nut and the valve element assembly to ascend and descend in the axial direction of the screw rod so as to close and open the valve port. According to the technical scheme, the flow capacity of the electronic expansion valve can be improved.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration equipment technology, and in particular to an electronic expansion valve and a refrigeration device. Background Technology

[0002] In refrigeration and air conditioning systems, electronic expansion valves play a crucial role in the precise control of refrigerant flow, and their flow capacity directly affects the system's cooling or heating performance and energy efficiency. When valve orifice diameters and opening steps are the same, improving the flow capacity (KV value) of electronic expansion valves has become a key focus in the industry. Traditionally, increasing the screw pitch is the primary method for improving flow capacity. However, according to national standard thread specifications, as the screw pitch increases, the outer diameter of the screw also increases accordingly. This not only significantly increases the cost of raw materials required for screw manufacturing but also requires greater driving force to rotate the screw during transmission, leading to increased costs for the drive coil. Furthermore, a larger screw outer diameter also increases the overall size of the electronic expansion valve, posing numerous challenges when placing it within the limited space of refrigeration and air conditioning equipment.

[0003] Therefore, developing a technology that can both improve the flow capacity of electronic expansion valves and reduce costs and size has become an urgent problem for the industry. Utility Model Content

[0004] This utility model proposes an electronic expansion valve and a refrigeration device, aiming to improve the flow capacity of the electronic expansion valve when the valve port diameter and the number of valve opening steps are the same.

[0005] To achieve the above objectives, the present invention proposes an electronic expansion valve, comprising a valve seat assembly and a coil assembly sleeved outside the valve seat assembly, wherein the valve seat assembly includes:

[0006] A valve seat housing having a valve port;

[0007] A rotor, wherein the rotor is disposed inside the valve seat housing;

[0008] A lead screw is disposed inside the rotor and is drivenly connected to the rotor. The lead screw has a thread, which is a double-threaded thread.

[0009] A valve core assembly, wherein the valve core assembly is disposed inside the rotor;

[0010] A nut is fitted over the lead screw and connected to the valve core assembly. The inner wall of the nut has a double-threaded structure that matches the thread on the lead screw. The rotation of the lead screw causes the nut and the valve core assembly to move up and down along the axial direction of the lead screw to close and open the valve port.

[0011] In one embodiment, the lead screw has a trapezoidal thread of 30°±5°, a pitch between 0.3mm and 0.7mm, a nominal diameter of less than 6mm, and a lead between 0.6mm and 1.4mm.

[0012] In one embodiment, the thread profile of the lead screw is a standard thread with a thread angle of 60°±5°, a pitch between 0.4mm and 0.6mm, a nominal diameter of less than 6mm, and a lead between 0.6mm and 1.4mm.

[0013] In one embodiment, the length of the thread is between 6 mm and 18 mm.

[0014] In one embodiment, the electronic expansion valve further includes a fixing plate, which is sleeved on the end of the lead screw away from the valve core, and the outer periphery of the fixing plate is fixedly connected to the rotor.

[0015] In one embodiment, the lead screw has a multi-stage structure, including a first stage, a second stage, a third stage, and a fourth stage arranged sequentially. The diameter of the first stage is smaller than the diameter of the second stage, and the diameter of the second stage is smaller than the diameter of the third stage. The first stage is located away from the valve core assembly, the fixing plate is installed on the first stage, the second stage is used to install the bearing, and the thread is located on the fourth stage.

[0016] In one embodiment, the valve seat housing includes a lower valve seat, an upper valve seat, and a housing, wherein the upper valve seat is used to connect the lower valve seat and the housing; a receiving space is formed between the lower valve seat, the connecting housing, and the housing.

[0017] In one embodiment, one end of the upper valve seat is inserted into the lower valve seat, and the other end is inserted into the housing; the upper valve seat has a hollow cavity, and the lead screw and the nut are located in the hollow cavity.

[0018] In one embodiment, the end of the upper valve seat that is inserted into the lower valve seat has a mounting cavity, and the valve core assembly is located within the mounting cavity.

[0019] This utility model also proposes a refrigeration device, including the aforementioned electronic expansion valve.

[0020] The technical solution of this utility model improves the flow capacity of the electronic expansion valve by using a lead screw with double thread, when the valve port diameter and the number of valve opening steps are the same. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the valve port closed state of an embodiment of the electronic expansion valve provided by this utility model;

[0023] Figure 2 A schematic diagram of the valve port open state structure of an embodiment of the electronic expansion valve provided by this utility model;

[0024] Figure 3 A schematic diagram of the lead screw structure of an embodiment of the electronic expansion valve provided by this utility model;

[0025] Figure 4 A schematic diagram of the trapezoidal threaded lead screw of the electronic expansion valve provided by this utility model;

[0026] Figure 5 A schematic diagram of the structure of the lead screw of the electronic expansion valve provided by this utility model using a common thread.

[0027] Explanation of icon numbers:

[0028] 100. Valve seat assembly; 10. Valve seat housing; 10a. Valve port; 11. Lower valve seat; 12. Upper valve seat; 121. Hollow cavity; 122. Mounting cavity; 13. Housing; 20. Rotor; 30. Lead screw; 31. First stage; 32. Second stage; 33. Third stage; 34. Fourth stage; 40. Valve core assembly; 50. Nut; 60. Fixing plate; 70. Bearing.

[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0031] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0032] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0033] When electronic expansion valves have the same valve port diameter and opening frequency, improving their flow capacity (KV value) has become a key focus in the industry. Traditionally, increasing the screw pitch is the primary method for improving flow capacity. However, according to national standard thread specifications, as the screw pitch increases, the outer diameter of the screw also increases accordingly. This not only significantly increases the cost of raw materials required for screw manufacturing but also requires greater driving force to rotate the screw during transmission, leading to increased costs for the drive coil. Furthermore, a larger screw outer diameter also increases the overall size of the electronic expansion valve, posing numerous challenges when placing it within the limited space of refrigeration and air conditioning equipment.

[0034] Therefore, this utility model proposes an electronic expansion valve.

[0035] Please see Figure 1 , Figure 2 and Figure 3In one embodiment of this utility model, the electronic expansion valve is used in a refrigeration device, such as an air conditioner. The electronic expansion valve includes a valve seat assembly 100 and a coil assembly (not shown in the figure), with the coil assembly sleeved on the valve seat assembly 100. The valve seat assembly 100 includes a valve seat housing 10, a rotor 20, a lead screw 30, a valve core assembly 40, and a nut 50. The valve seat housing 10 has a valve port 10a for refrigerant to flow out. The rotor 20 is disposed inside the valve seat housing 10. The lead screw 30 is disposed inside the rotor 20 and is drively connected to the rotor 20. The lead screw 30 has a thread, which is a double-threaded thread. The valve core assembly 40 is disposed inside the rotor 20. The nut 50 is sleeved on the outside of the lead screw 30 and connected to the valve core assembly 40. The inner wall of the nut 50 has a double-threaded thread adapted to the screw on the lead screw 30. The rotation of the lead screw 30 causes the nut 50 and valve core assembly 40 to move up and down along the axial direction of the lead screw 30 to close and open the valve port 10a, thereby regulating the flow of refrigerant.

[0036] Specifically, the valve seat housing 10, as the external main structure of the electronic expansion valve, provides space for the installation and protection of internal components. It possesses sufficient strength and sealing to withstand pressure and environmental factors during operation, ensuring stable operation of internal components. The rotor 20, located inside the valve seat housing 10, is one of the key components for the electronic expansion valve to achieve its transmission function. During operation, it receives the magnetic force from the external coil assembly through principles such as electromagnetic induction, achieving rotational motion. The lead screw 30 is located inside the rotor 20. The rotation of the rotor 20 drives the lead screw 30 to rotate around its axis. The surface of the lead screw 30 is machined with double-threaded steel. Compared to single-threaded steel, double-threaded steel allows the lead screw 30 to rotate fewer turns for the same axial movement distance, thereby improving transmission efficiency and enabling faster movement of the valve core assembly to meet the need for rapid refrigerant flow regulation. The valve core assembly 40, also located inside the rotor 20, is the core component that directly controls refrigerant flow; its position directly affects the refrigerant flow rate. Nut 50 is sleeved on the outside of lead screw 30, and its inner wall is machined with double-threaded teeth that match the threads on lead screw 30, forming a threaded transmission pair with lead screw 30. Nut 50 is connected to valve core assembly 40, converting the rotational motion of lead screw 30 into linear motion of nut 50 and valve core assembly 40, thereby achieving precise control of valve core position. Coil assembly is sleeved on valve seat assembly 100 and mainly consists of electromagnetic components such as coils. By energizing, it generates a magnetic field that interacts with rotor 20, driving rotor 20 to rotate and providing power for the operation of electronic expansion valve. It is a key component for realizing the automated control of electronic expansion valve.

[0037] The lead screw 30 of this application adopts a double-thread design, which allows the valve core assembly 40 to move to the target position more quickly with the same number of valve opening steps, increasing the refrigerant flow channel. Compared with the traditional single-thread design, this significantly improves the flow capacity KV value of the electronic expansion valve, effectively enhancing the cooling or heating effect of refrigeration equipment. The double-thread design eliminates the need to increase the screw outer diameter as in traditional methods that increase the screw pitch, reducing the amount of raw materials required for screw processing and lowering raw material costs. Simultaneously, since a larger driving force is not needed to rotate the lead screw 30, the specifications of the drive coil do not need to be increased, further reducing the cost of the drive coil and achieving effective control of the overall cost of the electronic expansion valve.

[0038] In one embodiment, please refer to Figure 4 The screw 30 has a trapezoidal thread with a pitch P between 0.3mm and 0.7mm, a nominal diameter D below 6mm, and a lead between 0.6mm and 1.4mm.

[0039] Specifically, in this embodiment, the lead screw 30 adopts a double-start trapezoidal thread structure with a thread profile angle of 30°±5°. This angle design makes the force on both sides of the thread profile more uniform when subjected to axial force, effectively enhancing the load-bearing capacity and transmission stability of the lead screw 30. The pitch D is in the range of 0.3mm-0.7mm, and the nominal diameter P is controlled below 6mm to limit the nominal diameter of the thread and avoid increasing the cost of raw materials and the overall size of the electronic expansion valve due to excessive size. The lead range is 0.6mm-1.4mm, which can accelerate the movement speed of the valve core and improve the response efficiency of the electronic expansion valve.

[0040] In another embodiment, please refer to Figure 5 The thread profile of the lead screw 30 is a standard thread with a thread angle of 60°±5°, a pitch between 0.4mm and 0.6mm, a nominal diameter of less than 6mm, and a lead between 0.6mm and 1.4mm.

[0041] Specifically, in this embodiment, the lead screw 30 adopts a double-start ordinary thread structure, with a thread profile of a standard triangular profile with a thread angle of 60°±5°. This angle design conforms to conventional thread standards, has a mature processing technology, and is convenient for mass production. The pitch D is controlled between 0.4mm and 0.6mm, and the nominal diameter P ≤ 6mm, strictly limiting the outer diameter of the lead screw 30 to avoid increased raw material costs and valve body expansion due to excessively thick lead screw 30, thus adapting to the layout requirements of compact refrigeration equipment. The lead range is 0.6mm-1.4mm. Combined with the characteristics of double-start threads (lead = pitch × number of starts), it achieves faster transmission speed than single-start threads at the same pitch, shortening the time for the valve core to move to the target position, improving the response speed of the electronic expansion valve to changes in system load, while maintaining a smaller number of rotations and reducing drive energy consumption.

[0042] Furthermore, the length of the thread is between 6mm and 18mm.

[0043] Specifically, the thread length of the lead screw 30 is controlled between 6mm and 18mm, a size range that balances transmission stability and structural compactness. Sufficient engagement length ensures the effective number of engagement turns between the nut 50 and the lead screw 30 thread, preventing stress concentration, increased wear, or slippage during transmission due to excessively short threads, thus improving the reliability of the transmission system. With a nominal diameter ≤ 6mm, limiting the thread length prevents the overall size of the lead screw 30 from becoming too long, compressing the internal space of the valve seat assembly 100, meeting the miniaturization requirements of the electronic expansion valve, and facilitating integrated installation in refrigeration equipment such as air conditioners. A reasonable thread length range facilitates standardized cutting processes, reducing tool travel and machining time, while also lowering the risk of deformation of the lead screw 30 due to an excessively large length-to-diameter ratio, ensuring thread accuracy and surface quality.

[0044] Furthermore, the electronic expansion valve also includes a fixing plate 60, which is sleeved on the end of the lead screw 30 away from the valve core assembly, and the outer periphery of the fixing plate 60 is fixedly connected to the rotor 20.

[0045] Specifically, in this embodiment, the fixing plate 60 is sleeved on the end of the lead screw 30 away from the valve core assembly (the top end of the lead screw 30), and is cylindrical or bushing-shaped. Its inner wall is adapted to the outer periphery of the top end of the lead screw 30, ensuring coaxial installation with the lead screw 30. The outer periphery of the fixing plate 60 is fixedly connected to the inner wall of the rotor 20, forming a rigid transmission node. For example, the inner wall of the rotor 20 is machined with a positioning groove, and the protrusions on the outer periphery of the fixing plate 60 are embedded in the groove for fixation, ensuring that the rotational power is transmitted without slippage. The fixing plate 60 is fixed to the top end of the lead screw 30 by welding.

[0046] Furthermore, the lead screw 30 has a multi-stage structure, including a first stage 31, a second stage 32, a third stage 33, and a fourth stage 34 arranged sequentially. The diameter of the first stage 31 is smaller than the diameter of the second stage 32, and the diameter of the second stage 32 is smaller than the diameter of the third stage 33. The first stage 31 is located away from the valve core assembly 40, the fixing plate 60 is installed on the first stage 31, the second stage 32 is used to install the bearing 70, and the thread is located on the fourth stage 34.

[0047] Specifically, in this embodiment, the lead screw 30 has a four-stage stepped shaft structure. From top to bottom, the lead screw 30 consists of a first stage 31, a second stage 32, a third stage 33, and a fourth stage 34. The first stage 31 is used to mount the fixing plate 60 and transmit the driving force of the rotor 20. Its small diameter design reduces the tip moment of inertia and improves transmission response speed. The second stage 32 has a bearing 70 (such as a deep groove ball bearing 70) mounted on its outer circumference, providing radial support for the lead screw 30 and reducing radial runout and wear during transmission. Its moderate diameter balances the mounting space of the bearing 70 with the strength of the lead screw 30. The third stage 33 has the largest diameter, forming a shoulder structure to provide axial positioning for the bearing 70. The larger diameter enhances the bending strength of the middle section of the lead screw 30 and withstands the axial thrust of the nut 50. The fourth stage 34 has surface-machined threads (such as double-start trapezoidal threads or double-start ordinary threads) that mate with the inner thread of the nut 50, converting rotational motion into linear motion of the valve core assembly 40.

[0048] Furthermore, the valve seat housing 10 includes a lower valve seat 11, an upper valve seat 12, and a housing 13, with the upper valve seat 12 used to connect the lower valve seat 11 and the housing 13. A receiving space is formed between the lower valve seat 11, the connecting housing, and the housing 13.

[0049] Specifically, the valve seat housing 10 adopts a split assembly structure, consisting of three parts: a lower valve seat 11, an upper valve seat 12, and a housing 13. The lower valve seat 11, as the basic component of the valve seat housing 10, is located at the bottom of the electronic expansion valve and typically has inlet and outlet channels for the refrigerant. Its internal shape matches the valve core assembly 40 to form the initial channel for refrigerant flow. The lower valve seat 11 needs to have good pressure resistance and sealing performance to withstand the pressure in the refrigeration system and prevent refrigerant leakage. The upper valve seat 12 acts as a connecting hub, used to fix and connect the lower valve seat 11 and the housing 13, ensuring the structural strength and stability of the entire valve seat housing 10. The housing 13, together with the lower valve seat 11 and the upper valve seat 12, forms a receiving space. The housing 13 typically has a structure for mounting the coil assembly, so that the coil assembly can be fitted onto the housing 13 and interact with the internal rotor 20 to achieve a driving function. Simultaneously, the housing 13 also protects the internal components from external environmental influences.

[0050] The upper valve seat 12 is fixed together with the lower valve seat 11 and the outer casing 13 by means of threaded connection, snap-fit ​​connection or welding, forming a closed receiving space. This space is used to install internal components such as rotor 20, lead screw 30, valve core assembly 40 and nut 50, so that each component can work together in a relatively stable and sealed environment, ensuring that the electronic expansion valve can achieve precise control of refrigerant flow.

[0051] Furthermore, one end of the upper valve seat 12 is inserted into the lower valve seat 11, and the other end is inserted into the housing 13; the upper valve seat 12 has a hollow cavity 121, and the rotating shaft and nut 50 are located in the hollow cavity 121. The end of the upper valve seat 12 inserted into the lower valve seat 11 also has a mounting cavity 122 communicating with the hollow cavity 121, and the valve core assembly 40 is located in the mounting cavity 122.

[0052] Specifically, in this embodiment, the upper valve seat 12 is a hollow shaft structure, with its bottom axial end inserted into the lower valve seat 11; the top axial end of the upper valve seat 12 is inserted into the outer casing 13, and the fixing method can be screw fixing. A valve cavity is formed between the upper valve seat 12 and the lower valve seat 11. The bottom surface of the lower valve seat 11 has a valve port 10a, and the circumferential side wall of the lower valve seat 11 has an inlet. The inlet pipe is inserted into the inlet to deliver refrigerant into the valve cavity and out through the valve port 10a to the outside. The upper valve seat 12 has a hollow cavity 121 extending through its center axially. The lead screw 30 and the nut 50 are both disposed within the hollow cavity 121, and the position of the lead screw 30 within the hollow cavity 121 remains unchanged; the lead screw 30 only rotates along its axis. A nut 50 is fitted over the lead screw 30. The inner wall of the nut 50 has threads. When the lead screw 30 rotates, it drives the nut 50 to move up and down along the axial direction of the lead screw 30 within the hollow cavity 121. This causes the valve core assembly 40, which is fixedly connected to the nut 50, to move up and down, moving closer to or away from the valve port 10a, thereby adjusting the flow cross-sectional area of ​​the refrigerant and thus regulating the refrigerant flow rate. The upper valve seat 12 has a mounting cavity 122 at one end inserted into the lower valve seat 11. The mounting cavity 122 communicates with the hollow cavity 121, and its inner diameter is larger than that of the hollow cavity 121. The valve core assembly 40 is movably disposed within the mounting cavity 122. Driven by the nut 50, the valve core assembly 40 moves up and down along the axial direction of the mounting cavity 122, moving relative to the valve port 10a.

[0053] This utility model also proposes a refrigeration device, which can be an air conditioner. The refrigeration device includes the aforementioned electronic expansion valve, the specific structure of which is described in the above embodiments. Since the refrigeration device adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0054] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. An electronic expansion valve, comprising a valve seat assembly and a coil assembly sleeved outside the valve seat assembly, characterized in that, The valve seat assembly includes: A valve seat housing having a valve port; A rotor, wherein the rotor is disposed inside the valve seat housing; A lead screw is disposed inside the rotor and is drivenly connected to the rotor. The lead screw has a thread, which is a double-threaded thread. A valve core assembly, wherein the valve core assembly is disposed inside the rotor; A nut is fitted over the lead screw and connected to the valve core assembly. The inner wall of the nut has a double-threaded structure that matches the thread on the lead screw. The rotation of the lead screw causes the nut and the valve core assembly to move up and down along the axial direction of the lead screw to close and open the valve port.

2. The electronic expansion valve as described in claim 1, characterized in that, The lead screw has a trapezoidal thread of 30°±5°, a pitch between 0.3mm and 0.7mm, a nominal diameter of less than 6mm, and a lead between 0.6mm and 1.4mm.

3. The electronic expansion valve as described in claim 1, characterized in that, The thread profile of the lead screw is a standard thread with a thread angle of 60°±5°, a pitch between 0.4mm and 0.6mm, a nominal diameter of less than 6mm, and a lead between 0.6mm and 1.4mm.

4. The electronic expansion valve as described in claim 2 or 3, characterized in that, The length of the thread is between 6mm and 18mm.

5. The electronic expansion valve as described in claim 4, characterized in that, The electronic expansion valve also includes a fixing plate, which is sleeved on the end of the lead screw away from the valve core assembly, and the outer periphery of the fixing plate is fixedly connected to the rotor.

6. The electronic expansion valve as described in claim 5, characterized in that, The lead screw has a multi-stage structure, including a first stage, a second stage, a third stage, and a fourth stage arranged sequentially. The diameter of the first stage is smaller than the diameter of the second stage, and the diameter of the second stage is smaller than the diameter of the third stage. The first stage is located away from the valve core assembly. The fixing plate is installed on the first stage. The second stage is used to install the bearing. The thread is located on the fourth stage.

7. The electronic expansion valve as described in claim 6, characterized in that, The valve seat housing includes a lower valve seat, an upper valve seat, and a housing. The upper valve seat is used to connect the lower valve seat and the housing. A receiving space is formed between the lower valve seat, the connecting housing, and the housing.

8. The electronic expansion valve as described in claim 7, characterized in that, One end of the upper valve seat is inserted into the lower valve seat, and the other end is inserted into the outer casing; the upper valve seat has a hollow cavity, and the lead screw and the nut are located in the hollow cavity.

9. The electronic expansion valve as described in claim 8, characterized in that, The upper valve seat has a mounting cavity at one end that is inserted into the lower valve seat, and the valve core assembly is located within the mounting cavity.

10. A refrigeration device, characterized in that, Includes the electronic expansion valve as described in any one of claims 1 to 9.

Images