CN110296259B

CN110296259B - Electronic expansion valve and refrigeration system with same

Info

Publication number: CN110296259B
Application number: CN201810246493.5A
Authority: CN
Inventors: 不公告发明人
Original assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Current assignee: Zhejiang Sanhua Intelligent Controls Co Ltd
Priority date: 2018-03-23
Filing date: 2018-03-23
Publication date: 2021-02-26
Anticipated expiration: 2038-03-23
Also published as: CN110296259A

Abstract

The invention provides an electronic expansion valve and a refrigerating system with the same, wherein the electronic expansion valve comprises: the valve seat is provided with a valve cavity and a valve port; a screw rod and a nut; the core body assembly is fixedly connected with the nut and provided with a sealing piece; the driving mechanism comprises a rotor and a coil, the rotor is connected with the screw rod, and the core body assembly can be close to or far away from the valve port under the driving of the nut; a check ring is arranged between the valve seat and the core body assembly, the check ring is provided with an integral part and a gap part, and the sealing element can be matched with the integral part or the gap part; the shell, with disk seat fixed connection, the shell has the rotor chamber, and when the sealing member was in coordination with complete portion, the sealing effect that the rotor chamber and valve chamber passed through the sealing member did not communicate each other, moves to when in coordination with breach portion on the sealing member, has the clearance between sealing member and the breach portion, and the rotor chamber passes through clearance and valve chamber intercommunication. The technical scheme of the invention can effectively solve the problem of high production cost of the electronic expansion valve in the prior art.

Description

Electronic expansion valve and refrigeration system with same

Technical Field

The invention relates to the technical field of refrigeration control, in particular to an electronic expansion valve and a refrigeration system with the same.

Background

In the current electronic expansion valve structure, the electronic expansion valve is composed of a driving part (coil, rotor) and a flow regulating part (nut, screw rod, shell, valve needle, valve seat core, adapter tube, etc.), and the driving force for realizing the opening and closing of the valve is formed by driving the rotor by the coil, the rotor and the coil with fixed specifications output constant driving force, along with the increase of the aperture of the valve port, the pressure formed inside the valve body after the upgrade of the system refrigerant is larger, the driving force requirement required by the product is larger when the valve is switched from the closed valve state to the open valve state, on one hand, the smoothness of the open valve is influenced, on the other hand, the driving force required by the product needs to be improved by the.

Disclosure of Invention

The invention mainly aims to provide an electronic expansion valve and a refrigeration system with the same, which can reduce the pressure difference formed inside a valve body so as to reduce the driving force required by a product and reduce the manufacturing cost of the product.

In order to achieve the above object, the present invention provides an electronic expansion valve comprising: the valve seat is provided with a valve cavity and a valve port communicated with the valve cavity; the screw rod is matched with the nut through threads; the core body assembly is fixedly connected with the nut, at least part of the core body assembly is movably arranged in the valve cavity, and the core body assembly is provided with a sealing piece; the driving mechanism comprises a rotor and a coil, the rotor is connected with the screw rod, the rotor drives the screw rod to rotate through the coil, the nut moves along the axial direction through the thread matching effect of the nut and the screw rod, and the core body assembly can be close to or far away from the valve port under the driving of the nut; a check ring is arranged between the valve seat and the core body assembly, at least part of the core body assembly extends into the inner cavity of the check ring, the check ring is provided with an integral part and a gap part, the integral part is positioned below the gap part, and the sealing element can be matched with the integral part or the gap part; the shell, with disk seat fixed connection, the shell has the rotor chamber, and the retaining ring is fixed to be set up in the disk seat, and when sealing member and complete portion cooperate, the rotor chamber passes through the sealed effect of sealing member with the valve chamber and does not communicate each other, moves to when cooperating with breach portion on the sealing member, has the clearance between sealing member and the breach portion, and the rotor chamber passes through clearance and valve chamber intercommunication.

The present invention also provides a refrigeration system comprising: the electronic expansion valve is the electronic expansion valve.

By applying the technical scheme of the invention, when the electronic expansion valve is in a valve-closed state, namely the core body assembly abuts against the valve port, and a refrigerant enters from the valve port, the cavity pressure in the valve body is higher, the core body assembly can not abut against the valve port possibly due to insufficient pressure relief of the refrigerant, the pressures of the valve cavity and the rotor cavity can be kept balanced to ensure that the electronic expansion valve is kept in the valve-closed state through the sealing cooperation of the sealing element and the whole part of the check ring, and when the electronic expansion valve is in the valve-opened state, namely the core body assembly is relatively far away from the valve port, the refrigerant enters the rotor cavity from the valve port, enters the pressure is higher and lower, pressure accumulation is easily formed, the refrigerant flows out through a gap between the sealing element and the gap part of the check ring through the cooperation of the sealing element and the gap part of the check ring, and the pressure is gradually released, when the valve needs to be opened or closed, the driving force required by the coil is small, the coil does not need to be enlarged, and the manufacturing cost is 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 longitudinal sectional view showing an embodiment one of an electronic expansion valve according to the present invention, in which a core assembly of fig. 1 is in a valve-closed state;

fig. 2 shows an enlarged schematic view at a of the electronic expansion valve of fig. 1;

fig. 3 is a perspective view of a retainer ring of the electronic expansion valve of fig. 1;

FIG. 4 shows a longitudinal cross-sectional view of the retaining ring of FIG. 3;

FIG. 5 is a schematic longitudinal cross-sectional view of the electronic expansion valve, wherein the core assembly of FIG. 5 is in an open valve state;

fig. 6 is an enlarged schematic view of the electronic expansion valve of fig. 5 at B;

fig. 7 is a schematic longitudinal sectional view illustrating a core assembly of the electronic expansion valve of fig. 1;

FIG. 8 is a schematic illustration in partial cross-sectional view of the electronic expansion valve of FIG. 1, wherein FIG. 8 shows dimensions D1, D2, D3, and D4;

fig. 9 is a schematic longitudinal sectional view showing a second embodiment of the electronic expansion valve according to the present invention, in which the core assembly of fig. 9 is in a valve-closed state;

fig. 10 shows an enlarged structural view at C of the electronic expansion valve of fig. 9;

fig. 11 is a perspective view of a retainer ring of the electronic expansion valve of fig. 9;

FIG. 12 shows a longitudinal cross-sectional view of the retainer ring of FIG. 11;

fig. 13 is a schematic longitudinal sectional view of the electronic expansion valve, in which the core assembly of fig. 13 is in an open valve state; and

fig. 14 shows an enlarged structural view at D of the electronic expansion valve of fig. 13.

Wherein the figures include the following reference numerals:

1. a valve cavity; 2. a rotor cavity; 4. a communicating cavity; 10. a valve seat; 11. a valve seat body; 12. a connecting seat; 121. mounting holes; 122. a notch portion; 123. a finishing section; 13. a valve port; 14. a first interface; 15. a second interface; 20. a core assembly; 21. a first core segment; 211. an annular groove; 22. a second core segment; 25. a second step surface; 30. a screw rod; 40. a nut; 41. a projection; 50. a drive mechanism; 51. a rotor; 52. a coil; 60. a housing; 70. a seal member; 80. a support member; 81. a limiting groove; 120. a retainer ring; 150. an opening; 160. a first step surface.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 to 7, the electronic expansion valve according to the first embodiment includes a valve seat 10, a lead screw 30, a nut 40, a core assembly 20, a driving mechanism 50, a retainer ring 120, and a housing 60. The valve seat 10 has a valve chamber 1 and a valve port 13 communicating with the valve chamber 1. The lead screw 30 is threadedly engaged with the nut 40. The core assembly 20 is fixedly connected with the nut 40, at least part of the core assembly 20 is movably arranged in the valve chamber 1, and the core assembly 20 is provided with a sealing member 70. The driving mechanism 50 includes a rotor 51 and a coil 52, the rotor 51 is connected to the lead screw 30, the rotor 51 drives the lead screw 30 to rotate through the coil 52, the nut 40 moves in the axial direction through the screw-thread cooperation with the lead screw 30, and the core assembly 20 can approach or be away from the valve port 13 by the driving of the nut 40. The retainer ring 120 is disposed between the valve seat 10 and the core assembly 20, at least a portion of the core assembly 20 extends into an inner cavity of the retainer ring 120, the retainer ring 120 has a complete portion 123 and a notched portion 122, the complete portion 123 is located below the notched portion 122, and the sealing member 70 can be engaged with the complete portion 123 or the notched portion 122. The housing 60 is fixedly connected with the valve seat 10, the housing 60 is provided with a rotor cavity 2, the retainer ring 120 is fixedly arranged on the valve seat 10, when the sealing member 70 is matched with the complete part 123, the rotor cavity 2 is not communicated with the valve cavity 1 through the sealing effect of the sealing member 70, when the sealing member 70 is moved upwards to be matched with the notch part 122, a gap is formed between the sealing member 70 and the notch part 122, and the rotor cavity 2 is communicated with the valve cavity 1 through the gap.

By applying the technical scheme of the invention, when the electronic expansion valve is in a valve-closed state, namely the core body assembly 20 abuts against the valve port 13, when a refrigerant enters from the valve port 13, the cavity pressure in the valve body is higher, the core body assembly 20 can not abut against the valve port 13 possibly due to insufficient pressure relief of the refrigerant, through the sealing cooperation effect of the sealing element 70 and the whole part of the check ring 120, the pressures of the valve cavity 1 and the rotor cavity 2 can be kept balanced, so that the electronic expansion valve keeps in a valve-closed state, when the electronic expansion valve is in a valve-opened state, namely the core body assembly 20 is relatively far away from the valve port 13, the pressure of the refrigerant entering the rotor cavity 2 from the valve port 13 is higher and lower, pressure accumulation is easily formed, through the cooperation effect of the sealing element 70 and the notch part of the check ring 120, the refrigerant flows out through the gap between the sealing element 70 and the notch part of the check ring, the pressure difference force formed in the valve body is relatively small, the driving force required by the coil is small when the valve needs to be opened or closed, the valve does not need to be realized in a mode of increasing the coil and the like, and the manufacturing cost is reduced.

When the "complete portion" is fitted to the seal 70, there is no gap between the seal 70 and the portion of the complete portion fitted thereto, and the valve chamber 1 and the rotor chamber 2 cannot communicate with each other through the gap. The shape of the above-mentioned "complete portion" is not limited (e.g., cylindrical, square column, etc.) as long as no gap is ensured between the seal 70 and the portion of the complete portion fitted therewith. When the "notched portion" is fitted to the seal, a gap is provided between the seal 70 and the portion of the complete portion fitted thereto, so that the valve chamber 1 and the rotor chamber 2 can communicate through the gap. The shape of the "notch portion" is not limited (for example, a polygonal column, or an irregular shape) as long as a gap is secured between the seal 70 and a portion of the "notch portion" that is fitted thereto.

Note that the notch portion is fitted to the seal 70, and the meaning of "fitted" does not necessarily mean contact fitting, and the notch portion may correspond to (not contact) the seal 70, and a gap may be provided between an outer wall of the notch portion and the inside of the seal 70.

In the first embodiment, since it is necessary to form a gap between the retainer ring 120 and the core assembly 20, the gap can be formed by merely changing the shape and structure of one of the retainer ring 120 and the core assembly 20. Preferably, in the first embodiment, the structure of the retainer ring 120 is modified such that the retainer ring 120 includes the complete portion and the notched portion without modifying the shape of the core assembly 20 and the valve seat 10. Therefore, a new core assembly and a valve seat do not need to be designed, so that the universality is increased, and the production cost is greatly reduced.

As shown in fig. 1 to 6, in the first embodiment, the retainer ring 120 includes a first cylinder section and a second cylinder section located at an upper portion of the first cylinder section, an inner surface of the second cylinder section gradually expands from bottom to top, the first cylinder section forms a complete portion, and the second cylinder section forms a gap portion. The seal 70 is in contact sealing with the inner surface of the first barrel section when the core assembly 20 is in the valve closed state, and the seal 70 is spaced from the inner surface of the second barrel section when the core assembly 20 is in the valve open state. Specifically, when the core assembly 20 is switched from the closed valve state to the open valve state, the seal 70 gradually moves into the second cylinder section. Since the inner surface of the second cylinder section gradually expands from bottom to top (the inner diameter gradually increases from bottom to top), as the sealing member 70 gradually moves into the second cylinder section (the outer diameter of the sealing member 70 does not change), the distance between the outer surface of the sealing member 70 and the inner surface of the second cylinder section gradually increases, so that the fluid can enter the rotor cavity 2 through the gap between the outer surface of the sealing member 70 and the inner surface of the second cylinder section. The structure is simple and easy to process.

As shown in fig. 1, 2, 5, and 6, in the first embodiment, the inner wall of the valve seat 10 has the first step surface 160, the retainer ring 120 is fixed to the first step surface 160, the outer wall of the core assembly 20 has the second step surface 25, the second step surface 25 is lower than the first step surface 160, and the second step surface 25 can be brought into abutting engagement with the first step surface 160. When the second step surface 25 is in abutting engagement with the first step surface 160, the core assembly 20 is located at the upper dead center point. The structure is simple and easy to realize.

As shown in fig. 1 to 6, in the first embodiment, the valve seat 10 includes a valve seat body 11 and a connecting seat 12 fixed to the valve seat body 11, the connecting seat 12 and the inside of the valve seat body 11 form a valve cavity 1, the valve port 13 is disposed on the valve seat body 11, a mounting hole 121 is disposed on the connecting seat 12, the mounting hole 121 includes a mounting section and a guiding section having a larger aperture than the mounting section and located below the mounting section, an outer wall of the core assembly 20 is matched with the guiding section, and a first step surface 160 is formed on a connecting surface of the mounting section and the guiding section. The structure is simple and easy to process. Further, the guide section can guide the core assembly 20 so that the core assembly 20 can move in a predetermined direction.

As shown in fig. 1 to 6, in the first embodiment, the core assembly 20 includes a first core segment 21 and a second core segment 22 located below the first core segment 21, the connection face of the first core segment 21 and the second core segment 22 forms a second step face 25, and the seal member 70 is provided on the outer wall of the first core segment 21. The structure is simple and easy to process.

As shown in fig. 1, 2, 5 to 7, in the first embodiment, the sealing member 70 is a sealing ring, and the first core segment 21 is provided with an annular groove 211 for accommodating the sealing ring. The structure is simple, the processing is easy, and the installation is convenient. In addition, the upper and lower surfaces of the seal ring can be attached to the upper and lower groove walls of the annular groove 211, so that the sealing area is increased, and the sealing performance is improved.

As shown in fig. 8, in the first embodiment in which the core assembly 20 includes the first core section 21 and the second core section 22 located below the first core section 21, the cross-sectional area of the first core section 21 is set to SD1, and the cross-sectional area of the valve port 13 is set to SD2, the following relationships are satisfied: (SD2-SD1) is less than or equal to 40mm². Specifically, in the first embodiment, the core assembly 20 includes the first core segment 21 fixedly connected to the nut 40 and the second core segment 22 blocking the valve port 13, the outer diameter of the second core segment 22 is larger than the outer diameter of the first core segment 21 to form the second step surface 25, and the outer diameter of the second core segment 22 is larger than the diameter of the valve port 13 to enable the core assembly 20 to block the valve port 13. The first core section 21 has an outer diameter D1 and the valve port 13 has a diameter D2The second core segment 22 has an outer diameter D3 and the core assembly 20 has an inner diameter D4. When the horizontal pipe communicated from the second connector 15 is pressurized and the core assembly 20 is located at the closed position, the internal stress of the valve seat 10 is balanced, the horizontal pipe pressure acts on the core assembly 20, the core assembly 20 is acted by the area difference (SD3-SD2) and the pressure P to form an upward pressure difference F1, and the area difference (SD3-SD1) and the pressure P to form a downward pressure difference F2; F1-F2 are the resultant forces experienced by the core assembly 20. Wherein, F1-F2 (SD3-SD2) P- (SD3-SD1) P (SD3-SD2-SD3+ SD1) P (SD1-SD2) P. Therefore, in order to reduce the force applied to the core assembly 20, the absolute value of the difference between the outer diameter D1 of the first core segment 21 and the through diameter D2 of the valve port 13 is less than or equal to 1mm, i.e., D1 ≈ D2, so that the resultant force of the upper and lower forces of the core assembly 20 tends to zero, the requirement for the driving force during the opening action of the core assembly 20 is extremely small, the volume of the coil 52 does not need to be increased, and the production cost is reduced.

Preferably, in this embodiment, the stepped hole includes a first hole section with a larger inner diameter and a second hole section located below the first hole section, and the outer diameter of the second core section 22 is smaller than that of the second hole section, so that the core assembly 20 can be installed from top to bottom in a forward direction without providing a valve seat core, thereby reducing the number of assembling steps.

As shown in fig. 1 to 6, in the first embodiment, the core assembly 20 has the communicating chamber 4 therein, the nut 40 is located in the communicating chamber 4 and fixed on the core assembly 20, and the flow passing structure is provided between the nut 40 and the core assembly 20, so that the communicating chamber 4 and the rotor chamber 2 are communicated with each other through the flow passing structure. Above-mentioned structure makes when core subassembly 20 is in the closed valve state, and the refrigerant flows into the intercommunication chamber 4 from valve port 13, and the refrigerant can continue to get into in the rotor chamber 2 so that intercommunication chamber 4 and rotor chamber 2's pressure balance through the structure that overflows to when making core subassembly 20 upwards remove, the decurrent resistance that nut 40 received reduces, finally realizes core subassembly 20 and opens more smooth purpose.

In the first embodiment, the nut 40 is provided with an overflowing hole, and the overflowing hole forms the overflowing structure. The structure is simple and easy to process.

As shown in fig. 1 to fig. 6, in the first embodiment, the electronic expansion valve further includes a supporting member 80, the supporting member 80 is fixedly disposed on the valve seat 10, a limiting groove 81 is disposed on the supporting member 80, a protruding portion 41 is disposed on the nut 40, and the protruding portion 41 extends into the limiting groove 81 and is engaged with the limiting groove 81. Specifically, when the nut 40 tends to rotate along its axis under the drive of the lead screw 30, the limit groove 81 can stop the projection 41 so that the nut 40 cannot rotate along its axis and can move up and down along its axis (i.e., can move up and down only along its axis).

As shown in fig. 1 to 6, in the first embodiment, the supporting member 80 is cup-shaped, and the bottom of the supporting member 80 is provided with an upwardly extending opening, which forms a limiting groove 81. The structure is simple, easy to realize and low in cost.

Preferably, the core assembly 20 is located at the upper dead point when the upper surface of the projection 41 abuts the top surface of the limiting groove 81. The upper stop point may be defined by the upper surface of the protruding portion 41 abutting against the top surface of the stopper groove 81, or the second step surface 25 abutting against the first step surface 160. Or may be formed by combining the two forms.

As shown in fig. 9 to 14, the electronic expansion valve according to the second embodiment is different from the electronic expansion valve according to the first embodiment in the specific structure of the retainer ring 120. Specifically, as shown in fig. 9 to 12, in the second embodiment, the top of the check ring 120 is provided with an opening 150 extending downward, the barrel section of the check ring 120 where the opening 150 is located forms the notch portion 122, and the remaining barrel section of the check ring 120 partially forms the complete portion 123. When the core assembly 20 is in a valve-closed state, the seal 70 is in contact seal with the inner surface of the retainer ring 120 below the opening 150, and when the core assembly 20 is in a valve-open state, the seal 70 corresponds to the opening 150, so that the valve chamber 1 and the rotor chamber 2 can communicate through the opening 150. Specifically, when the core assembly 20 is switched from the valve-closed state to the valve-open state, the seal 70 gradually moves upward. When the lower surface of the seal 70 is higher than the bottom surface of the opening 150, fluid can enter the rotor chamber 2 through the opening 150, so that the valve chamber 1 and the rotor chamber 2 can rapidly reach pressure equilibrium. The structure is simple and easy to process.

The operation of the electronic expansion valve will be described in detail, wherein, as shown in fig. 8, D1 is the outer diameter of the first core section 21, D2 is the diameter D2 of the valve port 13, D3 is the outer diameter of the second core section 22, D4 is the inner diameter of the core assembly 20, SD1 is the sectional area of the first core section 21, SD2 is the area of the valve port 13, SD3 is the area of the second core section 22, and SD4 is the sectional area of the inner bore of the core assembly 20:

(1) the core body assembly is in a valve closing state, and when the horizontal pipe enters pressure:

the sealing element 70 can be in sealing contact with the inner surface of the retainer ring 120 to realize sealing (circumferential sealing) of the first transfer passage 3, the valve cavity 1 is vertically isolated from the rotor cavity 2 through the sealing element 70, and the rotor cavity 2 is vertically communicated with the communicating cavity 4; the valve cavity 1 and the communicating cavity 4 are sealed and isolated through the abutting of the core body assembly and the valve port 13. The pressure of the refrigerant in the transverse pipe acts on the core assembly 20, and the core assembly 20 is acted by the area difference (SD3-SD2) and the pressure P to form an upward differential pressure; the core assembly 20 is also subjected to an area differential (SD3-SD1) to create a downward differential pressure force with the pressure P. In order to drive the resultant up and down force of the core assembly 20 toward zero, in this embodiment, D1 is sized approximately equal to D2. In this way, the core assembly 20 requires very little driving force during the opening operation because the configuration described above is such that F (SD3-SD2) × P- (SD3-SD1) × P (SD3-SD2-SD3+ SD1) × P (SD1-SD2) × P ≈ 0. Preferably, in this embodiment, (SD2-SD1) ≦ 40mm²。

(2) The core body assembly is in an open valve state, and when the horizontal pipe is pressurized:

the core assembly 20 moves upwards, the sealing member 70 and the core assembly 20 form partial sealing, the valve cavity 1 and the rotor cavity 2 are communicated through a gap between the sealing member 70 and the notch part, and the pressure intensity tends to be consistent. The rotor cavity 2 and the communicating cavity 4 are communicated up and down, and the pressure tends to be consistent. The cross tube pressure acts on the core assembly 20 and the core assembly 20 is acted upon by the area difference (SD3-SD4) and the pressure P to form an upward differential pressure force. The difference in area of second step surface 25 of core assembly 20 (SD3-SD1) acting with pressure P creates a downward differential pressure + the difference in area of the top of core assembly 20 (SD1-SD4) acting with pressure P creates a downward differential pressure; the area difference of the upper stress and the lower stress is zero, and the pressure intensity of each part of the valve cavity 1, the rotor cavity 2 and the communicating cavity 4 tends to be consistent. The resultant up and down force of the core assembly 20 tends to zero. The requirement on driving force is small when the core body assembly is opened and closed.

(3) When the core assembly is in a valve closing state and the pressure of a vertical pipe communicated from the first connector 14 is increased:

the sealing element 70 can be in sealing contact with the inner surface of the complete part to realize sealing (circumferential sealing), the valve cavity 1 and the rotor cavity 2 are vertically isolated through the sealing element 70, and the rotor cavity 2 is vertically communicated with the communicating cavity 4; the valve cavity 1 and the communicating cavity 4 are sealed and isolated through the abutting of the core body assembly and the valve port 13. Stack pressure acts on the core assembly 20, and the core assembly 20 is acted upon by the area difference (SD2-SD4) and the pressure P to form an upward differential pressure; the downward pressure difference is formed by the area difference (SD1-SD4) and the pressure P; since D1 ≈ D2, F ═ P- (SD2-SD4) — (SD1-SD4) × P ═ P (SD2-SD4-SD1+ SD4) × (SD2-SD1) ≈ P0, the resultant up-down force of the core assembly 20 tends to zero; the demand for driving force during opening is extremely small.

(4) The core body subassembly is in the state of opening the valve, and during the standpipe entered pressure:

the core body assembly 20 moves upwards, the sealing element 70 and the core body assembly 20 form partial sealing, the valve cavity 1 and the rotor cavity 2 are communicated through a gap between the sealing element 70 and the gap part, pressure accumulation (pressure value is obviously larger than the pressure value at the valve port 13, and downward differential pressure is additionally generated) formed in the rotor cavity 2 in the process of vertical pipe pressure inlet is avoided, and the pressure tends to be consistent. The rotor cavity 2 and the communicating cavity 4 are communicated up and down, and the pressure tends to be consistent. Stack pressure acts on the core assembly 20, and the core assembly 20 is acted upon by the area difference (SD3-SD4) and the pressure P to form an upward differential pressure; the difference in area of second step surface 25 of core assembly 20 (SD3-SD1) acts with pressure P to create a downward differential pressure force + the difference in area of the top of core assembly 20 (SD1-SD4) acts with pressure P to create a downward differential pressure force. The area difference of the upper and lower stressed surfaces is zero [ (SD3-SD4) - (SD3-SD1) - (SD1-SD4) ], which is 0. The pressure intensity of each part of the valve cavity 1, the rotor cavity 2 and the communicating cavity 4 tends to be consistent. The resultant up and down force of the core assembly 20 tends to zero. The requirement on driving force is small when the core body assembly is opened and closed.

The present application further provides a refrigeration system, wherein an embodiment of the refrigeration system according to the present application comprises an electronic expansion valve, and the electronic expansion valve is the above-mentioned electronic expansion valve. The electronic expansion valve has the advantages of good action performance of the core body assembly and low cost, so the electronic expansion valve with the electronic expansion valve also has the advantages.

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:

the valve seat (10) is provided with a valve cavity (1) and a valve port (13) communicated with the valve cavity (1);

the screw rod (30) and the nut (40), wherein the screw rod (30) is matched with the nut (40) through threads;

the core assembly (20), the core assembly (20) is fixedly connected with a nut (40), at least part of the core assembly (20) is movably arranged in the valve cavity (1), and the core assembly (20) is provided with a sealing member (70);

the driving mechanism (50) comprises a rotor (51) and a coil (52), the rotor (51) is connected with the screw rod (30), the rotor (51) drives the screw rod (30) to rotate through the coil (52), the nut (40) moves along the axial direction through the thread matching action with the screw rod (30), and the core body assembly (20) can be close to or far away from the valve port (13) through the driving of the nut (40);

a retainer ring (120) is arranged between the valve seat (10) and the core assembly (20), at least part of the core assembly (20) extends into an inner cavity of the retainer ring (120), the retainer ring (120) is provided with a complete part (123) and a gap part (122), the complete part (123) is positioned below the gap part (122), and the sealing element (70) can be matched with the complete part (123) or the gap part (122);

the outer shell (60) is fixedly connected with the valve seat (10), the outer shell (60) is provided with a rotor cavity (2), the retainer ring (120) is fixedly arranged on the valve seat (10), when the sealing element (70) is matched with the complete part (123), the rotor cavity (2) is not communicated with the valve cavity (1) through the sealing effect of the sealing element (70), when the sealing element (70) moves upwards to be matched with the notch part (122), a gap is formed between the sealing element (70) and the notch part (122), and the rotor cavity (2) is communicated with the valve cavity (1) through the gap.

2. The electronic expansion valve according to claim 1, wherein the retainer ring (120) comprises a first cylinder section and a second cylinder section located at an upper portion of the first cylinder section, an inner surface of the second cylinder section gradually expands from bottom to top, the first cylinder section forms the complete portion (123), and the second cylinder section forms the gap portion (122).

3. An electronic expansion valve according to claim 1, wherein the top of the retainer ring (120) is provided with a downwardly extending opening (150), the barrel section of the retainer ring (120) where the opening (150) is located forms the gap portion (122), and the remaining barrel section part of the retainer ring (120) forms the complete portion (123).

4. An electronic expansion valve according to claim 1 or 2, wherein the inner wall of the valve seat (10) has a first step surface (160), the retainer ring (120) is fixed to the first step surface (160), the outer wall of the core assembly (20) has a second step surface (25), the second step surface (25) is lower than the first step surface (160), and the second step surface (25) is capable of abutting engagement with the first step surface (160).

5. The electronic expansion valve according to claim 4, wherein the valve seat (10) comprises a valve seat body (11) and a connecting seat (12) fixed to the valve seat body (11), the connecting seat (12) and the interior of the valve seat body (11) form the valve chamber (1), the valve port (13) is disposed on the valve seat body (11), a mounting hole (121) is disposed on the connecting seat (12), the mounting hole (121) comprises a mounting section and a guiding section with a larger aperture than the mounting section and located below the mounting section, the outer wall of the core body assembly (20) is matched with the guiding section, and the connecting surface of the mounting section and the guiding section forms the first step surface (160).

6. An electronic expansion valve according to claim 4, wherein the core assembly (20) comprises a first core section (21) and a second core section (22) located below the first core section (21), a connection face of the first core section (21) and the second core section (22) forming the second step face (25), the sealing member (70) being provided on an outer wall of the first core section (21).

7. An electronic expansion valve according to claim 6, wherein the sealing member (70) is a sealing ring, and the first core section (21) is provided with an annular groove (211) accommodating the sealing ring.

8. An electronic expansion valve according to claim 1, wherein the core assembly (20) comprises a first core section (21) and a second core section (22) located below the first core section (21), the cross-sectional area of the first core section (21) being set to SD1, and the cross-sectional area of the valve port (13) being set to SD2, satisfying the following relationship: (SD2-SD1) is less than or equal to 40mm²。

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

support piece (80), fixed set up in valve seat (10), be provided with spacing groove (81) on support piece (80), be provided with bulge (41) on nut (40), bulge (41) stretch into to in spacing groove (81) and with spacing groove (81) cooperation.

10. An electronic expansion valve according to claim 9, wherein the support member (80) is cup-shaped, the bottom of the support member (80) being provided with an upwardly extending opening, which opening forms the limiting groove (81).

11. A refrigeration system comprising: an electronic expansion valve according to any of claims 1 to 10.