CN111365479A

CN111365479A - Electronic expansion valve

Info

Publication number: CN111365479A
Application number: CN201811604115.6A
Authority: CN
Inventors: 刘乐强; 许学飞; 贺宇辰
Original assignee: Zhejiang DunAn Hetian Metal Co Ltd
Current assignee: Zhejiang DunAn Hetian Metal Co Ltd
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2020-07-03
Anticipated expiration: 2038-12-26
Also published as: CN111365479B

Abstract

The invention provides an electronic expansion valve, comprising: a valve body; the rotor is rotatably arranged in the valve body; the fixed seat is fixedly arranged in the valve body; the bearing is arranged between the rotor and the fixed seat, one of the inner ring and the outer ring of the bearing is connected with the rotor, and the other one of the inner ring and the outer ring of the bearing is connected with the fixed seat. The technical scheme of through this application can solve the problem that the structure is complicated among the prior art, the noise is big.

Description

Electronic expansion valve

Technical Field

The invention relates to the technical field of electronic expansion valves, in particular to an electronic expansion valve.

Background

At present, an electronic expansion valve is generally composed of a rotor, a screw, a fixing seat, a valve needle assembly and other components, wherein the screw is connected with the rotor, and the valve needle assembly is connected with the screw. The electronic expansion valve drives the screw rod to axially move through the rotor, and further drives the valve needle assembly to axially move, so that the purposes of plugging and opening the valve port are achieved. However, the electronic expansion valve has the problems of complex structure and high noise by adopting the structure.

Disclosure of Invention

The invention provides an electronic expansion valve, which aims to solve the problems of complex structure and high noise in the prior art.

The invention provides an electronic expansion valve, which comprises: a valve body; the rotor is rotatably arranged in the valve body; the fixed seat is fixedly arranged in the valve body; the bearing is arranged between the rotor and the fixed seat, one of the inner ring and the outer ring of the bearing is connected with the rotor, and the other one of the inner ring and the outer ring of the bearing is connected with the fixed seat.

Further, the electronic expansion valve further includes: the screw rod is arranged in the valve body, one end of the screw rod sequentially penetrates through the fixing seat and the bearing and is in threaded connection with the rotor, and the rotor is used for driving the screw rod to move along the axial direction.

Further, the rotor includes: the magnet is sleeved on the outer side of the screw rod; the connecting plate is arranged on the magnet, the screw rod penetrates through the connecting plate and is in threaded connection with the connecting plate, the connecting plate and the fixing seat are respectively located on two sides of the bearing, one of the inner ring and the outer ring of the bearing is connected with the connecting plate, and the other one of the inner ring and the outer ring of the bearing is connected with the fixing seat.

Furthermore, the screw rod is in clearance fit with the fixed seat.

Further, the electronic expansion valve further includes: first limit structure sets up between screw rod and fixing base, and first limit structure is used for limiting the displacement and the rotation of the relative fixing base of screw rod.

Further, first limit structure includes: the stop piece is fixedly arranged on the screw rod and provided with an extending end, and an included angle is formed between the extending direction of the extending end and the axial direction of the screw rod; the guide limiting groove is arranged on the side wall of the fixing seat, the extending direction of the guide limiting groove is the same as the axis direction of the screw, the extending end of the stop piece is positioned in the guide limiting groove, and the guide limiting groove is matched with the stop piece to limit the displacement and the rotation of the screw relative to the fixing seat.

Further, first limit structure includes: the first boss is arranged on the side wall of the screw rod; the second boss is arranged on the inner wall of the fixed seat, and the first boss is matched with the second boss to limit the displacement of the screw rod relative to the fixed seat.

Further, the valve body includes: a sleeve; the valve seat, the rotor, the fixed seat, the bearing and the screw rod are all arranged between the sleeve and the valve seat.

Further, the valve seat has a valve chamber and a mounting hole communicated with the valve chamber, and the electronic expansion valve further comprises: the valve needle assembly is movably arranged in the mounting hole, the screw is connected with the valve needle assembly, and the valve needle assembly is provided with a first position for closing the valve port and a second position for opening the valve port.

Further, the valve body still includes: the sleeve is sleeved on the outer side of the valve needle assembly and is fixedly arranged in the mounting hole, and one end, far away from the bearing, of the fixing seat is connected with the end face of the sleeve.

Further, the valve needle assembly comprises: the valve sleeve is movably arranged in the mounting hole, and one end of the screw is connected with the valve sleeve; the valve needle is movably arranged in the valve sleeve at one end; and the pre-tightening spring is arranged in the valve sleeve and is positioned between the valve sleeve and the valve needle, and the pre-tightening spring is used for providing pre-tightening force for the valve needle.

Further, the valve needle assembly further comprises: and the second limiting structure is arranged between the valve needle and the screw rod and is used for limiting the relative displacement of the valve needle and the screw rod.

Further, the one end that is located the valve sleeve of needle is provided with first spacing hole, and second limit structure includes: the ball body is arranged in the valve sleeve, and is partially arranged in the first limiting hole; the gasket is arranged between the ball body and the screw rod, a second limiting hole is formed in the gasket, the ball body is partially arranged in the second limiting hole, one end of the pre-tightening spring is connected with the valve sleeve, and the other end of the pre-tightening spring is connected with the gasket.

Furthermore, one side of the connecting plate, which faces the bearing, is provided with an annular convex edge, and the annular convex edge is sleeved on the outer side of the bearing.

Furthermore, the fixing seat is provided with a through hole, the cross section of the through hole is of a non-circular structure, the screw is provided with a threaded section and a limiting section, the threaded section of the screw is in threaded connection with the rotor, and the cross section of the limiting section is matched with the cross section of the through hole so as to limit the screw to rotate relative to the fixing seat.

By applying the technical scheme of the invention, the electronic expansion valve comprises a valve body, a rotor, a fixed seat and a bearing. The rotor is rotatably arranged in the valve body, the fixing seat is fixedly arranged in the valve body, one of the inner ring and the outer ring of the bearing is connected with the rotor, and the other one of the inner ring and the outer ring of the bearing is connected with the fixing seat. The rotor can be supported through the fixing seat and the bearing, the structure of the rotor support device is simpler than that of an existing device, the rotor can stably run while the device is simplified, running friction of the device can be reduced through the bearing, and noise generated during running of the device can be reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram illustrating an electronic expansion valve according to an embodiment of the present invention;

FIG. 2 shows a cross-sectional view of the anchor block of FIG. 1;

fig. 3 shows a schematic structural view of the fixing base in fig. 1;

FIG. 4 shows a schematic structural view of the stop plate of FIG. 1;

FIG. 5 shows a cross-sectional view at A-A in FIG. 4;

fig. 6 is a schematic structural diagram illustrating an electronic expansion valve according to a second embodiment of the present invention;

fig. 7 is a schematic structural diagram illustrating an electronic expansion valve according to a third embodiment of the present invention;

fig. 8 is a schematic structural diagram illustrating an electronic expansion valve according to a fourth embodiment of the present invention;

FIG. 9 is a schematic view of the mounting bracket of FIG. 8;

fig. 10 is a schematic structural diagram illustrating an electronic expansion valve according to a fifth embodiment of the present invention.

Wherein the figures include the following reference numerals:

10. a valve body; 11. a sleeve; 12. a valve seat; 12a, a valve cavity; 13. a sleeve; 20. a rotor; 21. a magnet; 22. a connecting plate; 30. a fixed seat; 40. a bearing; 50. a screw; 61. a stopping sheet; 62. a guide limit groove; 63. a first boss; 64. a second boss; 70. a valve needle assembly; 71. a valve housing; 72. a valve needle; 73. pre-tightening the spring; 74. a sphere; 75. and (7) a gasket.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 5, an embodiment of the present invention provides an electronic expansion valve, including: valve body 10, rotor 20, fixing base 30 and bearing 40. Wherein, the rotor 20 rotationally sets up in the valve body 10, and the fixing base 30 is fixed to be set up in the valve body 10, and bearing 40 sets up between rotor 20 and fixing base 30 to, one of them is connected with rotor 20 in the inner circle of bearing 40 and the outer lane, and another is connected with fixing base 30. Specifically, the inner ring of the bearing 40 may be connected to the rotor 20, and correspondingly, the outer ring of the bearing 40 may be connected to the fixed base 30, or the inner ring of the bearing 40 may be connected to the fixed base 30, and correspondingly, the outer ring of the bearing 40 may be connected to the rotor 20.

In the present embodiment, the electronic expansion valve includes: valve body 10, rotor 20, fixing base 30 and bearing 40. Wherein, the rotor 20 is rotationally arranged in the valve body 10, the fixing seat 30 is fixedly arranged in the valve body 10, one of the inner ring and the outer ring of the bearing 40 is connected with the rotor 20, and the other is connected with the fixing seat 30. Through the structure, the fixing seat 30 and the bearing 40 can support the rotor 20, and the stable rotation of the rotor 20 is ensured while the device is simplified. And, through increasing bearing 40 between fixing base 30 and rotor 20, can guarantee the stability of rotor 20 rotation in-process to the noise that the reduction device operation produced.

The electronic expansion valve further comprises a screw 50, specifically, the screw 50 is arranged in the valve body 10, one end of the screw 50 sequentially penetrates through the fixing seat 30 and the bearing 40 and is in threaded connection with the rotor 20, and the rotor 20 is used for driving the screw 50 to move along the axial direction.

Specifically, the rotor 20 includes: a magnet 21 and a connecting plate 22. Wherein, magnet 21 cover is established in the outside of screw rod 50, and connecting plate 22 sets up on magnet 21, and through wearing to establish screw rod 50 on connecting plate 22 to with connecting plate 22 threaded connection, and connecting plate 22 and fixing base 30 are located the both sides of bearing 40 respectively, specifically, the outer lane of bearing 40 is connected with connecting plate 22 in this example, and the inner circle of bearing 40 is connected with fixing base 30. Wherein, connecting plate 22 and fixing base 30 are connected with bearing 40 through the welded mode.

In this embodiment, a coil is disposed outside the valve body 10 of the electronic expansion valve, a magnetic field generated by the coil after being energized acts on the magnet 21 to rotate the rotor 20, the rotor 20 is in threaded connection with the screw 50, the screw 50 is driven by the rotor 20 to move axially, and the valve needle assembly 70 opens or closes the valve port under the action of the screw 50.

In the present embodiment, the screw 50 is in clearance fit with the fixing base 30. Through setting up above-mentioned clearance, play the guide effect when avoiding fixing base 30 to interfere screw rod 50 and carry out axial displacement, promoted the stability of screw rod 50 at rising or decline in-process.

Specifically, the electronic expansion valve further includes a first limiting structure, wherein the first limiting structure is disposed between the screw 50 and the fixing seat 30, and the first limiting structure is used for limiting displacement and rotation of the screw 50 relative to the fixing seat 30. Through setting up first limit structure, can make screw rod 50 and fixing base 30 take place the contact at the in-process that the valve port was opened to the electron expansion valve, play the upper limit effect.

Specifically, as shown in fig. 2 to 5, the first limiting structure includes: a stop piece 61 and a guide limit groove 62. The stop piece 61 is fixedly disposed on the screw 50, and the stop piece 61 has an extending end, and the extending end forms an included angle with the screw 50. The guide limit groove 62 is arranged on the side wall of the fixing seat 30, the extending direction of the guide limit groove 62 is the same as the axial direction of the screw 50, the extending end of the stop piece 61 is positioned in the guide limit groove 62, and the guide limit groove 62, the valve seat 12 and the stop piece 61 are matched to limit the displacement and the rotation of the screw 50 relative to the fixing seat 30, so that the stability of the device structure is improved. The stopping sheet 61 may have one extending end or a plurality of extending ends, and one or more guiding and limiting grooves 62 are disposed on the sidewall of the fixing base 30 corresponding to the stopping sheet 61. In this embodiment, the stop piece 61 is provided with two extending ends, and two guiding and limiting grooves 62 are provided on the corresponding side wall of the fixing base 30.

In the present embodiment, the valve body 10 includes a sleeve 11 and a valve seat 12, and the rotor 20, the fixing seat 30, the bearing 40, and the screw 50 are disposed between the sleeve 11 and the valve seat 12. Through the arrangement, the device is improved in integrity and convenient to mount and dismount.

Specifically, the valve seat 12 has a valve cavity 12a and a mounting hole communicating with the valve cavity 12a, in the present embodiment, the electronic expansion valve further includes a valve needle assembly 70, the valve needle assembly 70 is movably disposed in the mounting hole, the screw 50 is connected with the valve needle assembly 70, and the valve needle assembly 70 has a first position for closing the valve port and a second position for opening the valve port. The rotor rotates to drive the screw rod to move axially, so that the valve needle assembly 70 moves axially between the first position and the second position, thereby achieving the effect of opening or closing the valve port.

Wherein the valve needle assembly 70 includes: valve sleeve 71, needle 72 and preloaded spring 73. A valve housing 71 is movably disposed in the mounting hole, one end of the screw 50 is connected to the valve housing 71, and one end of the needle 72 is movably disposed in the valve housing 71, and a preload spring 73 is disposed in the valve housing 71 between the valve housing 71 and the needle 72, the preload spring 73 for providing preload to the needle 72. By arranging the pre-tightening spring 73, the valve needle 72 can be pre-tightened in the valve sleeve 71, and meanwhile, a buffer effect can be achieved on the valve needle 72, and the valve needle 72 is protected.

As shown in fig. 6, a second embodiment of the present invention provides an electronic expansion valve, and the present embodiment is different from the first embodiment in that the valve needle assembly 70 further includes a second limit structure, and the second limit structure is disposed between the valve needle 72 and the screw 50, and is used for limiting the relative displacement between the valve needle 72 and the screw 50. Through setting up second limit structure, there is the spring pretightning force between needle 72 and the valve port when can guaranteeing to pass to close, guarantees to produce property ability.

Wherein, one end of the valve needle 72 located in the valve sleeve 71 is provided with a first limit hole. Specifically, the second limiting structure includes a ball 74 and a washer 75. The ball 74 is disposed in the valve housing 71, the ball 74 is partially disposed in the first limiting hole, the gasket 75 is disposed between the ball 74 and the screw 50, the gasket 75 is provided with a second limiting hole, and the ball 74 is partially disposed in the second limiting hole, wherein the ball 74 is fixedly connected to one of the first limiting hole and the second limiting hole, and the ball 74 is connected to the first limiting hole by welding in this example. One end of the pre-tightening spring 73 is connected to the valve housing 71, and the other end of the pre-tightening spring 73 is connected to the spacer 75. Through the matching of the first limiting hole, the second limiting hole and the ball 74 and under the acting force of the pre-tightening spring 73, the valve needle 72 can be automatically guided in the valve sleeve 71, and the influence on the product performance caused by the coaxiality problem is avoided.

As shown in fig. 7, a third embodiment of the present invention provides an electronic expansion valve, which is different from the first embodiment in that the valve body 10 further includes a sleeve 13, the sleeve 13 is sleeved outside the valve needle assembly 70, the sleeve 13 is fixedly disposed in the mounting hole, and one end of the fixing seat 30, which is far away from the bearing 40, is connected to an end surface of the sleeve 13. In this embodiment, the sleeve 13 is also configured as a stepped structure, and by connecting the sleeve 13 with the fixing seat 30 and sleeving the sleeve 13 on the outer side of the valve needle assembly 70, the sleeve 13 can guide the valve needle 72, so that the valve needle assembly 70 axially moves along with the screw 50, and the opening state of the valve port is controlled. Compared with the electronic expansion valve provided in the first embodiment, the electronic expansion valve provided in this embodiment has a split valve seat, and the sleeve 13 can be inserted into the valve cavity 12a at the end portion close to the flow passage, thereby realizing a complicated flow passage structure. By adopting the structure, the noise of fluid can be reduced when the device operates, the sleeve 13 is utilized to guide the valve needle 72, the coaxiality of the valve needle 72 is improved, the processing difficulty is reduced, and the performance of the device is ensured.

As shown in fig. 8 and 9, a fourth embodiment of the present invention provides an electronic expansion valve, and the present embodiment is different from the first embodiment in that the first limiting structure includes a first boss 63 and a second boss 64. The first boss 63 is disposed on a side wall of the screw 50, the second boss 64 is disposed on an inner wall of the fixing seat 30, the first boss 63 and the second boss 64 cooperate to limit upward displacement of the screw 50 relative to the fixing seat 30, the valve needle 72 is fixedly connected with the valve sleeve 71, and the first boss 63 and the valve sleeve 71 cooperate to limit downward displacement of the screw 50 relative to the fixing seat 30. In this embodiment, the first boss 63 is formed by providing the annular protrusion on the side wall of the screw 50, the through hole in the fixing seat 30 is provided with the first stepped hole and the second stepped hole which are communicated with each other, the step between the two stepped holes forms the second boss 64, wherein the diameter of the first stepped hole is larger than that of the second stepped hole, the first stepped hole is located below the second stepped hole, the first boss 63 is located in the first stepped hole, and when the first boss 63 moves upwards along with the screw 50 to contact with the second boss 64, the screw 50 stops moving upwards. The first boss 63 cooperates with the valve sleeve 71 to limit the downward displacement of the screw 50 relative to the fixed seat 30 by welding the needle 72 with the valve sleeve 71.

As shown in fig. 9, the fixing base 30 has a through hole, the cross section of the through hole is a non-circular structure, the screw 50 has a threaded section and a limiting section, the threaded section of the screw 50 is in threaded connection with the rotor 20, and the cross section of the limiting section is matched with the cross section of the through hole to limit the screw 50 to rotate relative to the fixing base 30. Because the fixing seat 30 is fixedly arranged on the valve body 10, by adopting the structure, the screw rod 50 can be ensured to only move axially without rotating, and the reliability of the device is improved. The cross section of the through hole can be in the shape of an ellipse, a triangle, a rectangle and the like, and the screw 50 can be limited to rotate relative to the fixing seat 30 as long as the cross section of the limiting section of the screw 50 is matched with the cross section of the through hole.

In other embodiments, the screw 50 may be extended to achieve the same limiting effect as the first limiting structure in the second embodiment, and when the screw 50 opens the valve port and continues to move upward, the screw 50 will contact the inner wall of the sleeve 11, so that the screw 50 stops moving upward, and the upper limiting effect is achieved. It is also possible to design the valve needle 72 and the valve sleeve 71 as an integral structure, and the first boss 63 and the valve sleeve 71 cooperate to perform the lower limit function.

As shown in fig. 10, in a fifth embodiment of the present invention, compared with the electronic expansion valve provided in the first embodiment, an annular convex edge is provided on a side of the connecting plate 22 facing the bearing 40, and the annular convex edge is sleeved on an outer side of the bearing 40. By utilizing the structure, the bearing 40 can be fixed with the connecting plate 22 in an interference fit or necking mode, and compared with the mode of connecting the bearing 40 and the connecting plate 22 together through a welding process, the connecting mode simplifies the processing process and enables the device to be more suitable for batch production.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic expansion valve, comprising:

a valve body (10);

a rotor (20) rotatably disposed within the valve body (10);

the fixing seat (30) is fixedly arranged in the valve body (10);

the bearing (40) is arranged between the rotor (20) and the fixed seat (30), one of an inner ring and an outer ring of the bearing (40) is connected with the rotor (20), and the other one is connected with the fixed seat (30).

2. The electronic expansion valve of claim 1, further comprising:

the screw rod (50) is arranged in the valve body (10), one end of the screw rod (50) penetrates through the fixed seat (30) and the bearing (40) in sequence and is in threaded connection with the rotor (20), and the rotor (20) is used for driving the screw rod (50) to move along the axial direction.

3. An electronic expansion valve according to claim 2, wherein the rotor (20) comprises:

the magnet (21) is sleeved on the outer side of the screw rod (50);

the connecting plate (22) is arranged on the magnet (21), the screw rod (50) penetrates through the connecting plate (22) and is in threaded connection with the connecting plate (22), the connecting plate (22) and the fixing seat (30) are respectively located on two sides of the bearing (40), one of an inner ring and an outer ring of the bearing is connected with the connecting plate (22), and the other one of the inner ring and the outer ring of the bearing is connected with the fixing seat (30).

4. An electronic expansion valve according to claim 2, wherein the screw (50) is a clearance fit with the holder (30).

5. The electronic expansion valve of claim 2, further comprising:

the first limiting structure is arranged between the screw rod (50) and the fixed seat (30) and used for limiting the displacement and the rotation of the screw rod (50) relative to the fixed seat (30).

6. The electronic expansion valve of claim 5, wherein the first stop structure comprises:

the stop piece (61) is fixedly arranged on the screw rod (50), the stop piece (61) is provided with an extending end, and an included angle is formed between the extending direction of the extending end and the axial direction of the screw rod (50);

guide limiting groove (62) sets up on the lateral wall of fixing base (30), the extending direction of guide limiting groove (62) with the axis direction of screw rod (50) is the same, the extension end of ending separation blade (61) is located in guide limiting groove (62), guide limiting groove (62) with end separation blade (61) cooperation is in order to restrict screw rod (50) is relative the displacement and the rotation of fixing base (30).

7. The electronic expansion valve of claim 5, wherein the first stop structure comprises:

a first boss (63) provided on a side wall of the screw (50);

the second boss (64) is arranged on the inner wall of the fixed seat (30), and the first boss (63) is matched with the second boss (64) to limit the displacement of the screw rod (50) relative to the fixed seat (30).

8. An electronic expansion valve according to claim 2, wherein the valve body (10) comprises:

a sleeve (11);

the valve seat (12), the rotor (20), the fixing seat (30), the bearing (40) and the screw (50) are arranged between the sleeve (11) and the valve seat (12).

9. The electronic expansion valve according to claim 8, wherein the valve seat (12) has a valve chamber (12a) and a mounting hole communicating with the valve chamber (12a), the electronic expansion valve further comprising:

a valve needle assembly (70) movably disposed in the mounting hole, the screw (50) being connected with the valve needle assembly (70), the valve needle assembly (70) having a first position closing the valve port and a second position opening the valve port.

10. An electronic expansion valve according to claim 9, wherein the valve body (10) further comprises:

the sleeve (13) is sleeved on the outer side of the valve needle assembly (70), the sleeve (13) is fixedly arranged in the mounting hole, and one end of the fixed seat (30), which is far away from the bearing (40), is connected with the end face of the sleeve (13).

11. An electronic expansion valve according to claim 9, wherein the valve needle assembly (70) comprises:

a valve housing (71) movably disposed in the mounting hole, one end of the screw (50) being connected to the valve housing (71);

a valve needle (72), one end of the valve needle (72) being movably arranged in the valve sleeve (71);

the pre-tightening spring (73) is arranged in the valve sleeve (71) and located between the valve sleeve (71) and the valve needle (72), and the pre-tightening spring (73) is used for providing pre-tightening force for the valve needle (72).

12. An electronic expansion valve according to claim 11, wherein the valve needle assembly (70) further comprises:

and the second limit structure is arranged between the valve needle (72) and the screw rod (50) and is used for limiting the relative displacement of the valve needle (72) and the screw rod (50).

13. An electronic expansion valve according to claim 12, wherein the valve needle (72) is provided with a first position-limiting hole at an end thereof located within the valve sleeve (71), and wherein the second position-limiting structure comprises:

a ball (74) disposed within the valve housing (71), the ball (74) being partially disposed within the first limit bore;

the gasket (75) is arranged between the ball body (74) and the screw rod (50), a second limiting hole is formed in the gasket (75), the ball body (74) is partially arranged in the second limiting hole, one end of the pre-tightening spring (73) is connected with the valve sleeve (71), and the other end of the pre-tightening spring (73) is connected with the gasket (75).

14. An electronic expansion valve according to claim 3, wherein the side of the connection plate (22) facing the bearing (40) is provided with an annular flange, which is arranged around the outside of the bearing (40).

15. The electronic expansion valve according to claim 2, wherein the fixing base (30) has a through hole, the cross section of the through hole is a non-circular structure, the screw (50) has a threaded section and a limiting section, the threaded section of the screw (50) is in threaded connection with the rotor (20), and the cross section of the limiting section is matched with the cross section of the through hole to limit the screw (50) from rotating relative to the fixing base (30).