Electronic expansion valve

Abstract

The application discloses an electronic expansion valve, which comprises a motor cover and a gear box, the motor cover and the gear box are fixedly connected to form a fixed fitting part, the electronic expansion valve is provided with a containing groove part, the containing groove part is located on the outside of the fixed fitting part, and the containing groove part is at least partially filled with a potting member, and the potting member is in sealing cooperation with the outside end of the fixed fitting part. In the application, the containing groove part located on the outside of the fixed fitting part is formed, and the potting member is formed by at least partial potting in the containing groove part, so that the potting member can be in sealing cooperation with the outside end of the fixed fitting part, and the potting sealing scheme is obviously more reliable.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more specifically to an electronic expansion valve. Background Technology

[0002] The electronic expansion valve mainly includes a valve body for flow regulation and a coil component for driving the lead screw and valve needle in the valve body. The coil component includes a permanent magnet stepper motor, a gear reduction mechanism with reduction function, and a threaded pair structure that converts the rotational motion of the permanent magnet stepper motor into the vertical motion of the lead screw in the valve body.

[0003] In an electronic expansion valve structure, a permanent magnet stepper motor is built into a coil component. The coil component includes a motor cover for housing the motor and a gearbox for housing the gear reduction mechanism. The gearbox and the motor cover are pressed and fixed together, and a sealing ring is set between them for sealing. However, during the riveting process, the sealing ring is easily squeezed, damaged, and deformed, making it difficult to guarantee the sealing effect. This ultimately leads to the problem of poor sealing performance of the coil component. Summary of the Invention

[0004] This application provides an electronic expansion valve, including a motor cover and a gearbox. The motor cover and the gearbox are fixedly connected to form a fixed mating part. The electronic expansion valve is provided with a receiving groove, which is located outside the fixed mating part. At least part of the receiving groove is filled with a potting compound, which is sealed to the outer end of the fixed mating part.

[0005] In one specific embodiment, the gearbox has a first cavity through which the lead wire of the motor of the electronic expansion valve passes, and the receiving groove is an annular second cavity formed between the motor cover and the outer peripheral wall of the gearbox. The first cavity and the second cavity are connected, and the first cavity is filled with a potting compound. The potting compound in the first cavity and the potting compound filled in the second cavity are connected and form an integral structure.

[0006] In one specific embodiment, the wall of the first cavity is provided with a notch, the notch connects the first cavity and the second cavity, and the notch is filled with a potting compound to connect the potting compound in the first cavity and the potting compound in the second cavity.

[0007] In one specific embodiment, the inner peripheral wall of the motor cover is provided with an internal thread section, and the outer peripheral wall of the gearbox includes an external thread section. The motor cover and the gearbox are connected by the mating internal thread section and the external thread section.

[0008] In one specific embodiment, the motor cover includes an inner peripheral wall segment, the outer peripheral wall of the motor cover includes an outer peripheral wall segment, a step is formed between the outer peripheral wall segment and the external thread segment, and the step, the outer peripheral wall segment and the inner peripheral wall segment enclose and form the second cavity.

[0009] In one specific embodiment, the inner peripheral wall of the motor cover includes an inner peripheral wall segment, the outer peripheral wall of the motor cover includes an outer peripheral wall segment, a step is formed between the inner peripheral wall segment and the internal thread segment, and the step, the outer peripheral wall segment and the inner peripheral wall segment enclose and form the second cavity.

[0010] In one specific embodiment, the inner peripheral wall of the motor cover is provided with an annular first abutment portion, the gearbox is provided with an annular second abutment portion, and the electronic expansion valve includes a first sealing ring, which is pressed between the first abutment portion and the second abutment portion.

[0011] In one specific embodiment, the bottom of the gearbox is provided with a connecting sleeve, and the electronic expansion valve further includes a transmission nut and a second sealing ring. The transmission nut is used to connect with the gear reduction mechanism inside the gearbox. The transmission nut is press-fitted into the connecting sleeve. At least one of the outer peripheral wall of the transmission nut and the inner peripheral wall of the connecting sleeve is provided with an annular mounting groove, and a portion of the second sealing ring is located in the mounting groove.

[0012] In one specific embodiment, the motor cover and / or the gearbox are injection molded.

[0013] In this application, a receiving groove is formed on the outside of the fixed mating part, and a potting element is formed in at least part of the receiving groove. The potting element can seal with the outer end of the fixed mating part, and the potting sealing solution is obviously more reliable. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the electronic expansion valve in an embodiment of this application;

[0015] Figure 2 for Figure 1 A schematic diagram of the intermediate coil components before potting;

[0016] Figure 3 for Figure 2 Bottom view of the intermediate coil component;

[0017] Figure 4 for Figure 2 A schematic diagram of the gearbox of the intermediate coil component;

[0018] Figure 5 for Figure 2 A schematic diagram of the intermediate coil component after potting;

[0019] Figure 6 for Figure 5 Bottom view of the intermediate coil component;

[0020] Figure 7 for Figure 2 Schematic diagram of the structure of the motor cover;

[0021] Figure 8 for Figure 7 Axial sectional view of the motor cover.

[0022] Figure 1-8 The annotations in the attached figures are explained as follows:

[0023] 10 - Valve body;

[0024] 11-Valve inlet; 12-Valve outlet; 13-Valve seat;

[0025] 20 - Coil components;

[0026] 21-Motor cover; 211-Internal thread section; 212-First abutment part; 213-Third abutment part; 214-Reinforcing rib; 125-Conical section; 126-Cylindrical section;

[0027] 22-Motor;

[0028] 23-Gearbox; 231-External thread section; 232-Second outer peripheral wall section; 233-Connecting sleeve; 234-Partition section; 235-Straight wall section; 236-Step; 237-Bottom wall section; 23a-Notch section; 23b-First cavity;

[0029] 24-Gear reduction mechanism; 25-Nut; 26-Sealing ring;

[0030] 271 - First potting resin; 272 - Second potting resin; 273 - Third potting resin;

[0031] 28 - Lead wire; 29 - Sheath; 201 - Connecting nut; 202 - Transmission nut. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the electronic expansion valve in the embodiments of this application.

[0034] The electronic expansion valve in this embodiment includes a valve body 10 and a coil component 20. The valve body 10 includes a valve seat 13, a valve inlet 11, a valve outlet 12, and core components such as a valve stem and a valve needle. The coil component 20 is used to drive the valve stem and valve needle to move. The coil component 20 includes a motor cover 21, a gearbox 23, a motor 22, a connecting nut 201, a gear reduction mechanism 24 with a reduction function, and a threaded pair structure that converts the rotational motion of the motor 22 into the vertical motion of the lead screw. The motor 22 can be a permanent magnet stepper motor. The coil component 20 can be threadedly connected and fixed to the valve body 10 by the connecting nut 201. During operation, the high-pulse frequency current drives the motor 22 to rotate, directly driving the gear reduction mechanism 24. Through the threaded pair structure and the bellows, the valve needle of the valve body 10 rises or falls, thereby changing the valve opening to automatically adjust the refrigerant flow rate and keep the refrigerant circuit system in optimal condition.

[0035] Please continue to refer to this. Figure 2-4 , Figure 2 for Figure 1 A schematic diagram of the intermediate coil components before potting; Figure 3 for Figure 2 Bottom view of the intermediate coil component; Figure 4 for Figure 2 A schematic diagram of the gearbox 23 of the intermediate coil component.

[0036] In this embodiment, the gearbox 23 of the electronic expansion valve is provided with a first cavity 23b through which the lead wire 28 of the power supply 22 passes. Figure 2 The first cavity 23b extends axially through the gearbox 23. The motor 22 is located inside the motor cover 21 and above the gearbox 23. The lead wire 28 passes through the first cavity 23b of the gearbox 23 to the outside of the gearbox 23 for external connection. In this embodiment, the axial and up / down directions are... Figure 2 As shown in the orientation definition, the motor cover 21 is located above the gearbox 23. It can be seen that when the orientation of the electronic expansion valve changes, the positional relationship of each component will also change accordingly, and is not limited by the up and down directions.

[0037] The electronic expansion valve is also provided with a sheath 29, through which the lead wire 28 passes to protect and limit the sheath 29. The sheath 29 is at least partially inserted into the first cavity 23b. Figure 2 In the middle, part of the sheath 29 is inserted into the upper part of the first cavity 23b, and part is located above the gearbox 23. It can be seen that the sheath 29 can be omitted.

[0038] It is worth noting that in this embodiment, the motor cover 21 and gearbox 23 are fixedly connected to form a fixed mating part. The two can be connected by threads as in this embodiment, or by welding (such as ultrasonic welding). The threaded joint structure or weld position at the fixed connection location is the fixed mating part. The electronic expansion valve also includes a receiving groove located outside the fixed mating part. It can be seen that after the motor cover 21 and gearbox 23 are fixed in this embodiment, a cavity for accommodating the motor 22 is formed between them. The side of the fixed mating part closest to and connected to the cavity is its inner side, and the opposite side is its outer side. The receiving groove is located outside the fixed mating part. Figure 2 From a specific perspective, the outer side is below the fixed mating part, and the inner side is above the fixed mating part. Specifically, in this embodiment, an annular second cavity 20a is formed between the outer peripheral wall of the motor cover 21 and the gearbox 23. The second cavity 20a is the aforementioned receiving groove located outside the fixed mating part.

[0039] The gearbox 23 is generally cylindrical, including cylindrical sidewalls. The outer surface of the cylindrical sidewalls forms its outer peripheral wall. The lower end of the motor cover 21 extends to the outer side of the outer peripheral wall of the gearbox 23, forming a second cavity 20a between them. Figure 3 As shown, in this embodiment, the first cavity 23b and the second cavity 20a are connected.

[0040] Let's look again. Figure 5 , 6 , Figure 5 for Figure 2 A schematic diagram of the intermediate coil component after potting; Figure 6 for Figure 5 Bottom view of the intermediate coil component.

[0041] In this embodiment, the first cavity 23b and the second cavity 20a are potted to form potted components, that is, potting resin is filled into the first cavity 23b and the second cavity 20a to form potted components. Figure 6 The first potting resin 271 and the second potting resin 273 shown, and the connecting channel between the first cavity 23b and the second cavity 20a are filled with the third potting resin 273. The first potting resin 271, the second potting resin 273, and the third potting resin 273 are all potting components. With this arrangement, the outer peripheral wall of the motor cover 21 and the gearbox 23 is sealed by the second potting resin 272, and the first cavity 23b is sealed by the first potting resin 271. Furthermore, the first potting resin 271, which is filled into the first cavity 23b, can wrap around the lead wire 28 located in the first cavity 23b, further limiting the position of the lead wire 28. Figure 5 As shown, during potting, it can be done from bottom to top. A sheath 29 is inserted into the first cavity 23b. The first potting resin 271 stops at the position of the sheath 29 and will not enter the space between the top of the gearbox 23 and the motor cover 21 used to accommodate the motor 22.

[0042] Compared to the prior art solution of sealing the motor cover and gearbox with a sealing ring, this embodiment clearly shows that by forming a receiving groove located outside the fixed mating part, and at least partially filling the receiving groove to form a potting compound, the potting compound can be connected to the outer end of the fixed mating part. Figure 2 The bottom of the fixed mating part is sealed, and the potting seal solution is obviously more reliable.

[0043] Furthermore, as an alternative, the first cavity 23b and the second cavity 20a, which serves as a receiving groove, are connected. The connecting channel between the two is filled with a third potting resin 273. Thus, the first potting resin 271 and the second potting resin 272 can be connected by the third potting resin 273 to form a whole, which is not easy to separate, thereby further ensuring the sealing effect of the first cavity 23b and the second cavity 20a.

[0044] Specifically, such as Figure 4 As shown, the outer peripheral wall of the gearbox 23 includes a first outer peripheral wall segment and a second outer peripheral wall segment 232 distributed along the axial direction. Both outer peripheral wall segments are cylindrical. The first outer peripheral wall segment is provided with external threads, forming an external thread segment 231. The external thread segment 231 is radially protruding relative to the second outer peripheral wall segment 231, thus forming a step 236 between the external thread segment 231 and the second outer peripheral wall segment 232. (See below...) Figure 4 In the gearbox 23, it is generally cylindrical, and part of its second outer peripheral wall section 232 constitutes the wall of the first cavity 23b. The gearbox 23 includes a straight wall section 235 extending upward along the bottom wall section 237 of the gearbox 23. The straight wall section 235 and the arc-shaped part of the second outer peripheral wall section 232 enclose and form a cavity. The cavity is also provided with two partition sections 234. The two partition sections 234, the part of the second outer peripheral wall section 232, and the straight wall section 235 enclose and form part of the first cavity 23b.

[0045] Combined Figure 2 and Figure 7 , 8 understand, Figure 7 for Figure 2 A schematic diagram of the structure of the motor cover 21;

[0046] Figure 8 for Figure 7 Axial sectional view of the motor cover 21.

[0047] In this embodiment, the inner peripheral wall of the motor cover 21 is provided with an internal thread section, forming an internal thread section 211. The internal thread section 211 and the external thread section 231 of the gearbox 23 are threaded together for connection. This connection method is easy to operate. After the threaded connection, since there is a step 236 between the second outer peripheral wall section 232 and the external thread section 231, the part of the inner peripheral wall of the motor cover 21 located below the internal thread section 211 is defined as the first inner peripheral wall section 217. The first inner peripheral wall section 217 can be threaded or unthreaded, that is, the first inner peripheral wall section 217 is a part of the internal thread section 211. There is a gap between the first inner peripheral wall section 217 and the second outer peripheral wall section 232. The inner peripheral wall of the motor cover 21, the second outer peripheral wall section 232, and the step 236 can be enclosed to form an annular groove. The groove opening faces away from the motor. Figure 2 The annular groove with its opening facing downwards forms the aforementioned second cavity 20a. At this time, with... Figure 2 From the perspective of the bottom up, the potting resin can enter the first cavity 23b and the second cavity 20a. The step 236 can restrict the potting resin from entering the space of the motor cover 21 used to house the motor 22.

[0048] like Figure 4 As shown, the wall of the first cavity 23b is provided with a notch 23a. Specifically, the notch 23a is provided on the portion of the second outer peripheral wall segment 232 corresponding to the first cavity 23b. The notch 23a forms a connecting channel between the first cavity 23b and the second cavity 20a. During the potting process, the notch 23b is also filled with potting resin. Figure 5 , 6 The third potting resin 273 is shown. During potting, liquid potting resin can be poured into the first cavity 23b and slowly enter the second cavity 20a through the notch 23a. Finally, potting resin is poured into the first cavity 23b, the notch 23a, and the second cavity 20a. It can be seen that the wall of the first cavity 23b is not limited to having the notch 23a as a connecting channel; for example, it can also be a through hole, etc., but the notch 23a facilitates the flow of potting resin.

[0049] It should be noted that the aforementioned second cavity 20a is formed by the stepped outer peripheral wall of the gearbox 23 and the inner peripheral wall of the motor cover 21. It can be seen that the internal thread section 211 of the motor cover 21 is radially protruding and can also form a step with the first inner peripheral wall section 217. The step of the inner peripheral wall of the motor cover 21, the second outer peripheral wall section 232 and the first inner peripheral wall section 217 of the motor cover 21 can also form the second cavity.

[0050] In fact, the second cavity 20a is not limited to the structure of the annular groove described above. It can be formed as long as it is an annular cavity surrounding the outer peripheral wall of the gearbox 23 and the motor cover 21. For example, the outer peripheral wall of the gearbox 23 is provided with an annular groove, which fits against the inner peripheral wall of the motor cover 21 to form a closed annular cavity as the second cavity 20a. At the same time, it connects to the first cavity 23a and can also provide space for potting.

[0051] Let's look again. Figure 7 The inner peripheral wall of the motor cover 21 is provided with an annular first abutment portion 213, the first abutment portion 213 specifically being... Figure 7 The gearbox 23, as shown, has an annular step and an annular second abutment portion. This second abutment portion can be the annular step at the top of the gearbox 23, located above the external thread section 231. The electronic expansion valve also includes a first sealing ring 36, which is pressed between the first abutment portion 213 and the second abutment portion, as shown. Figure 5 As shown, the second potting resin 272 forms the first seal between the motor cover 21 and the gearbox 23, and the first sealing ring 25 forms the second seal to further improve the sealing effect.

[0052] In addition, the inner peripheral wall of the motor cover 21 is provided with an annular third abutment portion 212, which forms a two-stage step with the first abutment portion 213. The bottom of the motor housing 22 can be provided with a radially extending annular flange, which is clamped between the third abutment portion 212 and the annular top surface of the gearbox 23, thereby achieving the purpose of axially limiting the motor 22.

[0053] Figure 2 , 4 In the gearbox 23, a connecting sleeve 233 is provided at the bottom. The electronic expansion valve also includes a transmission nut 202 and a second sealing ring 26. The transmission nut 202 is used to connect with the gear reduction mechanism 24 inside the gearbox 23. The transmission nut 202 is press-fitted into the connecting sleeve 233. At least one of the outer peripheral wall of the transmission nut 202 and the inner peripheral wall of the connecting sleeve 233 is provided with an annular mounting groove. Part of the second sealing ring 26 is located in the mounting groove. In this way, after the transmission nut 202 is pressed into the connecting sleeve 233, the two can reliably seal. Figure 2 As shown, the electronic expansion valve includes a connecting nut 201, and the connecting nut 201 and the transmission nut 202 are connected by a portion extending out of the connecting sleeve 233. The connecting nut 201 is used to connect with the valve body 10.

[0054] In the above embodiments, both the gearbox 23 and the motor cover 21 can be injection molded from resin material, resulting in a simple structure and reducing the number of parts. Figure 5As shown, the motor cover 21 includes a tapered section 215 and a cylindrical section 216 connected to each other. The diameter of the cylindrical section 216 is larger than the maximum diameter of the tapered section 215. A transition section 217 is provided between the two for connection. The internal thread section 211 and the first inner peripheral wall section 217 are both provided on the inner peripheral wall of the cylindrical section 216.

[0055] like Figure 5 As shown, in this embodiment, the outer side of the motor cover 21 is provided with a reinforcing rib 214. The reinforcing rib 214 is specifically a triangular rib. One straight edge of the triangular rib is connected to the outer surface of the conical section 215, and the other straight edge is connected to the transition portion 217 between the cylindrical section 216 and the conical section 215. The reinforcing rib 214 can improve the strength of the motor cover 21.

[0056] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An electronic expansion valve, characterized in that, The device includes a motor cover and a gearbox, which are fixedly connected to form a fixed mating part. The electronic expansion valve has a receiving groove located outside the fixed mating part. A cavity for accommodating the motor is formed between the motor cover and the gearbox. The side of the fixed mating part that is close to and connects with the cavity is its inner side, and the opposite side is its outer side. At least part of the receiving groove is filled with a potting compound, which is sealed to the outer end of the fixed mating part.

2. The electronic expansion valve according to claim 1, characterized in that, The gearbox has a first cavity through which the lead wire of the motor of the electronic expansion valve passes. The receiving groove is an annular second cavity formed between the motor cover and the outer peripheral wall of the gearbox. The first cavity and the second cavity are connected, and the first cavity is filled with a potting compound. The potting compound in the first cavity and the potting compound filled in the second cavity are connected and form an integral structure.

3. The electronic expansion valve according to claim 2, characterized in that, The wall of the first cavity is provided with a notch, the notch connects the first cavity and the second cavity, and the notch is filled with a potting compound to connect the potting compound in the first cavity and the potting compound in the second cavity.

4. The electronic expansion valve according to claim 3, characterized in that, The second cavity is an annular groove, and the opening of the annular groove faces away from the motor.

5. The electronic expansion valve according to claim 4, characterized in that, The inner peripheral wall of the motor cover is provided with an internal thread section, and the outer peripheral wall of the gearbox includes an external thread section. The motor cover and the gearbox are connected by the mating internal thread section and the external thread section.

6. The electronic expansion valve according to claim 5, characterized in that, The motor cover includes an inner peripheral wall section, and the outer peripheral wall of the motor cover includes an outer peripheral wall section. A step is formed between the outer peripheral wall section and the external threaded section. The step, the outer peripheral wall section, and the inner peripheral wall section enclose and form the second cavity.

7. The electronic expansion valve according to claim 5, characterized in that, The inner peripheral wall of the motor cover includes an inner peripheral wall segment, and the outer peripheral wall of the motor cover includes an outer peripheral wall segment. A step is formed between the inner peripheral wall segment and the internal thread segment. The step, the outer peripheral wall segment, and the inner peripheral wall segment enclose and form the second cavity.

8. The electronic expansion valve according to any one of claims 1-7, characterized in that, The inner circumferential wall of the motor cover is provided with an annular first abutment portion, the gearbox is provided with an annular second abutment portion, and the electronic expansion valve includes a first sealing ring, which is pressed between the first abutment portion and the second abutment portion.

9. The electronic expansion valve according to any one of claims 1-7, characterized in that, The bottom of the gearbox is provided with a connecting sleeve. The electronic expansion valve also includes a transmission nut and a second sealing ring. The transmission nut is used to connect with the gear reduction mechanism inside the gearbox. The transmission nut is press-fitted into the connecting sleeve. At least one of the outer peripheral wall of the transmission nut and the inner peripheral wall of the connecting sleeve is provided with an annular mounting groove. A portion of the second sealing ring is located in the mounting groove.

10. The electronic expansion valve according to any one of claims 1-7, characterized in that, The motor cover and / or the gearbox are injection molded.

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