CN111365466B

CN111365466B - Electronic expansion valve and air conditioning system using same

Info

Publication number: CN111365466B
Application number: CN201811593354.6A
Authority: CN
Inventors: 贺宇辰; 许学飞; 刘乐强
Original assignee: Zhejiang DunAn Hetian Metal Co Ltd
Current assignee: Zhejiang DunAn Hetian Metal Co Ltd
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2022-09-06
Anticipated expiration: 2038-12-25
Also published as: CN111365466A

Abstract

The invention provides an electronic expansion valve which comprises a screw rod, a valve needle and an elastic part, wherein one end of the elastic part acts on the screw rod, the other end of the elastic part acts on the valve needle, a bearing is arranged between the screw rod and the valve needle, the bearing is provided with an inner ring and an outer ring, one of the screw rod and the valve needle is fixed with the inner ring of the bearing, and the other acts on the outer ring of the bearing through the elastic part. The invention also provides an air conditioning system using the electronic expansion valve. The electronic expansion valve provided by the invention has the advantages that the bearing is arranged between the valve needle and the screw rod, so that the rotation of the screw rod is released by the bearing in multipoint rolling contact, the single-point rolling contact sliding friction of the traditional electronic expansion valve is converted into the multipoint rolling contact rolling friction, the friction force required by valve opening is reduced, the damage caused by the friction is reduced, the reliability and the stability of the electronic expansion valve and an air conditioning system using the electronic expansion valve are improved, and the electronic expansion valve has wide application prospect.

Description

Electronic expansion valve and air conditioning system using same

Technical Field

The invention relates to the technical field of refrigeration equipment, in particular to an electronic expansion valve and an air conditioning system using the same.

Background

The electronic expansion valve opens or closes the valve port through the movement of the valve rod component in the guide sleeve and the nut sleeve, can realize the purposes of flow regulation and throttling and pressure reduction, and is widely applied in the technical field of refrigeration equipment. Conventional electronic expansion valves generally have a ball and a spring seat disposed at one end of a screw to contact each other, thereby releasing relative rotation between the screw and a valve needle. But still have great frictional force between ball and the spring holder, the sliding friction form of single-point contact has great frictional force between ball and the spring holder, very easily leads to the frictional damage of contact point, can drive the needle simultaneously and produce the rotation for the valve port, leads to needle, valve port wearing and tearing, and electronic expansion valve's reliability and stability are lower relatively.

Disclosure of Invention

Accordingly, there is a need for an improved electronic expansion valve and an air conditioning system using the same, which have improved reliability and stability.

The invention provides an electronic expansion valve which comprises a screw, a valve needle and an elastic element, wherein one end of the elastic element acts on the screw, the other end of the elastic element acts on the valve needle, a bearing is arranged between the screw and the valve needle, the bearing is provided with an inner ring and an outer ring, one of the screw and the valve needle is fixed with the inner ring of the bearing, and the other of the screw and the valve needle acts on the outer ring of the bearing through the elastic element.

Furthermore, the electronic expansion valve comprises a gasket, the gasket is arranged between the elastic part and the outer ring of the bearing, and the gasket is connected with the outer ring of the bearing under the supporting of the elastic part.

Furthermore, the screw rod is fixed with the inner ring of the bearing, and the valve needle is connected with the outer ring of the bearing through the elastic part and the gasket.

Further, the electronic expansion valve comprises a valve needle sleeve for fixing the valve needle, the side surface of the screw rod extends outwards along the radial direction of the screw rod and forms a protrusion, and the protrusion is flush with the inner side surface of the valve needle sleeve.

Further, interference fit is carried out between the screw and the inner ring of the bearing.

Further, the valve needle is fixed with the inner ring of the bearing, and the screw rod is connected with the outer ring of the bearing through the elastic piece and the gasket.

Further, the valve needle is in interference fit with the inner ring of the bearing.

Furthermore, the electronic expansion valve further comprises a pressing sleeve, wherein a step surface is arranged on the pressing sleeve and abuts against the valve needle to limit the axial movement of the valve needle.

Further, the gasket is provided with a cavity extending along the axial direction of the gasket, and the inner side face of the gasket, close to the valve needle, is provided with a conical surface.

The invention also provides an air conditioning system, which comprises an electronic expansion valve, wherein the electronic expansion valve is any one of the electronic expansion valves.

The electronic expansion valve provided by the invention has the advantages that the bearing is arranged between the valve needle and the screw rod, so that the rotation of the screw rod is released by the bearing in multipoint rolling contact, the single-point rolling contact sliding friction of the traditional electronic expansion valve is converted into multipoint rolling contact rolling friction, the friction force required by valve opening is reduced, the damage caused by friction is reduced, the reliability and the stability of the electronic expansion valve and an air conditioning system using the electronic expansion valve are improved, and the electronic expansion valve has wide application prospect.

Drawings

FIG. 1 is a schematic perspective view of an electronic expansion valve according to a first embodiment of the present invention, with a partial structure omitted;

FIG. 2 is an exploded perspective view of the electronic expansion valve of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the electronic expansion valve shown in FIG. 1 with a portion of the structure omitted;

FIG. 4 is a schematic structural view of a valve body in the electronic expansion valve shown in FIG. 1;

FIG. 5 is a schematic structural view of a guide sleeve in the electronic expansion valve shown in FIG. 3;

fig. 6 is a schematic cross-sectional view of a screw assembly of the electronic expansion valve shown in fig. 1;

FIG. 7 is a schematic cross-sectional view of a screw assembly and a rotor assembly of the electronic expansion valve of FIG. 1;

fig. 8 is a schematic cross-sectional view of an electronic expansion valve according to a second embodiment of the present invention.

Description of the main elements

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

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. 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.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly mounted on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 3, fig. 1 is a schematic perspective view of an electronic expansion valve 100 according to a first embodiment of the present invention, with a portion of the structure omitted, fig. 2 is an exploded perspective view of the electronic expansion valve 100 shown in fig. 1, and fig. 3 is a schematic cross-sectional view of the electronic expansion valve 100 shown in fig. 1, with a portion of the structure omitted. The electronic expansion valve 100 provided by the invention is used for adjusting the flow and pressure of the fluid medium, and realizing the control of the fluid flow.

In the present embodiment, the electronic expansion valve 100 is applied to an air conditioning system, and the fluid medium flowing through the electronic expansion valve 100 is a refrigerant for performing heat and cold exchange in the air conditioning system; the electronic expansion valve 100 is installed at an inlet of an evaporator of the air conditioning system, and the electronic expansion valve 100 is used as a boundary element between a high-pressure side and a low-pressure side of the air conditioning system to throttle and reduce the pressure of the high-pressure liquid refrigerant, so that the dosage of the liquid refrigerant entering the evaporator or other devices is adjusted and controlled, and the dosage of the liquid refrigerant can meet the requirement of an external refrigeration load.

It is understood that in other embodiments, the electronic expansion valve 100 may also be applied to other types of refrigeration equipment besides an air conditioning system, and the fluid medium flowing through the electronic expansion valve 100 may also be other than refrigerant as long as the electronic expansion valve 100 can achieve throttling and pressure reduction of the fluid medium.

The electronic expansion valve 100 includes a valve body 10, a valve needle assembly 20, a screw assembly 30, a guide sleeve 16, a sleeve 40, a rotor assembly 50, and a stator assembly (not shown), wherein the valve needle assembly 20, the screw assembly 30, the sleeve 40, the guide sleeve 16, and the stator assembly are all mounted on the valve body 10, one end of the screw assembly 30 is connected to the valve needle assembly 20, and the other end is connected to the rotor assembly 50.

The valve body 10 is used for carrying a valve needle assembly 20, a screw assembly 30, a guide sleeve 16, a sleeve 40 and a stator assembly, the valve needle assembly 20 is used for controlling the opening or closing of the electronic expansion valve 100, the screw assembly 30 is used for driving the valve needle assembly 20 to move, the sleeve 40 isolates the external environment from the valve needle assembly 20, the screw assembly 30 and the rotor assembly 50, thereby protecting the valve needle assembly 20, the screw assembly 30 and the rotor assembly 50 from medium leakage, the rotor assembly 50 is used for driving the screw assembly 30 to move, and the stator assembly is used for driving the rotor assembly 50 to move.

The stator assembly is powered on to generate a magnetic field and drives the rotor assembly 50 to rotate under the action of the magnetic field force, the rotor assembly 50 drives the screw assembly 30 to move, and the valve needle assembly 20 is driven by the screw assembly 30 to control the electronic expansion valve 100 to open or close, so that the purpose of adjusting the flow and pressure of the fluid medium by the electronic expansion valve 100 is fulfilled.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a valve body 10 of the electronic expansion valve 100 shown in fig. 1, two sides of the valve body 10 are respectively connected to a medium inlet pipe 101 and a medium outlet pipe 102, and a medium fluid enters the electronic expansion valve 100 through the medium inlet pipe 101 and then flows out of the electronic expansion valve 100 through the medium outlet pipe 102. The valve body 10 is sequentially provided with a valve port 11, a valve cavity 12, a through hole 13, an installation cavity 14 and a connecting cavity 15 along the direction of the axis 103, and the valve port 11, the valve cavity 12, the through hole 13, the installation cavity 14 and the connecting cavity 15 are sequentially communicated along the direction of the axis 103.

The valve port 11 is communicated with the medium outlet pipe 102, and the valve port 11 is used for the valve needle assembly 20 to extend into, thereby blocking the fluid medium in the electronic expansion valve 100 from being discharged out through the valve port 11. When the valve needle assembly 20 closes the valve port 11, that is, the valve port 11 is disconnected from the valve cavity 12, the electronic expansion valve 100 is closed; when the valve needle assembly 20 releases the seal of the valve port 11, that is, the valve port 11 and the valve chamber 12 communicate with each other, the electronic expansion valve 100 is opened.

The valve cavity 12 is used for accommodating part of the valve needle assembly 20, and fluid medium flows into the valve port 11 through the valve cavity 12. The through hole 13 is arranged between the valve cavity 12 and the mounting cavity 14, the aperture of the through hole 13 is smaller than the inner diameter of the mounting cavity 14, the bottom of the mounting cavity 14 forms a first annular positioning step 14a, the guide sleeve 16 is accommodated in the valve body 10, and the through hole 13 and the mounting cavity 14 are matched with each other to realize the fixed mounting of the guide sleeve 16. The connecting cavity 15 is also provided with a connecting sheet 17 for fixing the screw assembly 30, and the connecting cavity 15 and the connecting sheet 17 are matched with each other to accommodate and fix the screw assembly 30.

The end surface of the valve body 10, which is provided with the connecting cavity 15, contracts in the direction of the axis 103 and forms a step surface 151, the sleeve 40 is sleeved on one end of the valve body 10, which is provided with the connecting cavity 15, and abuts against the step surface 151, the step surface 151 limits the extending length of the sleeve 40, which is sleeved on the valve body 10, and the end surface of the valve body 10, which is provided with the connecting cavity 15, penetrates through the sleeve 40 so as to limit the radial movement of the sleeve 40.

In the present embodiment, in order to further improve the connection stability between the valve body 10 and the sleeve 40, the valve body 10 and the sleeve 40 are fixedly connected to each other by welding, and in this case, the step surface 151 is a welding fixing surface between the valve sleeve 40 and the valve body 10. It is understood that in other embodiments, the valve body 10 and the sleeve 40 may be fixedly connected by riveting, gluing, or other connecting methods.

In the present embodiment, the valve body 10 is formed of a stainless steel material, and the valve body 10 has a substantially cylindrical shape. It is understood that in other embodiments, the valve body 10 may be made of other materials, not listed here, and the valve body 10 may have other shapes than a cylinder.

Referring to fig. 5, fig. 5 is a schematic structural diagram of the guide sleeve 16 of the electronic expansion valve 100 shown in fig. 3. The guide sleeve 16 is installed in the installation cavity 14 and is in interference fit with the installation cavity 14. Here, the interference fit means: the dimension of the inner diameter of the mounting cavity 14 minus the dimension of the outer diameter of the mating guide sleeve 16 is negative. The guide sleeve 16 is used to guide the movement of the valve needle assembly 20 along the axis 103 of the valve body 10. The connecting piece 17 is installed in the connecting cavity 15 to install the screw assembly 30. Preferably, the connecting piece 17 is mounted in the connecting cavity 15 by means of welding.

In the present embodiment, the guide bush 16 is formed by processing and manufacturing a brass material, that is, the guide bush 16 is a brass guide bush. The brass guide sleeve is relatively soft and facilitates installation between the guide sleeve 16 and the screw assembly 30 and/or the valve body 10. It will be appreciated that in other embodiments, the guide sleeve 16 may be manufactured from materials other than brass.

The guide sleeve 16 is substantially cylindrical. The guide sleeve 16 is provided with a guide hole 161 penetrating the guide sleeve 16 along its axis, and the needle assembly 20 is installed in the guide hole 161 and moves under the guidance of the guide hole 161.

Guide sleeve 16 includes a first cylindrical section 162 mounted within mounting cavity 14, a second cylindrical section 163 for mating with screw assembly 30, and a third cylindrical section 164 located within valve cavity 12.

The first cylindrical section 162 is in interference fit with the mounting cavity 14, so that during the installation process of the guide sleeve 16, the axis of the guide sleeve 16 coincides with the axis 103 of the valve body 10, and the coaxiality between the guide sleeve 16 and the valve port 11 is ensured.

Further, the first cylindrical section 162 is an intermediate section, i.e., located between the second cylindrical section 163 and the third cylindrical section 164. The outer diameter of the first cylindrical section 162 is greater than the outer diameter of the second cylindrical section 163 and the outer diameter of the third cylindrical section 164, respectively. Thus, it should be appreciated that the first cylindrical section 162 forms a step 162a with the second and third

cylindrical sections

163, 164, respectively. A step 162a between the first and third

cylindrical sections

162, 164 cooperates with a first positioning step 14a at the bottom of the mounting cavity 14 to effect positioning of the third cylindrical section 164.

Preferably, the first cylindrical section 162 has a first end 162b disposed opposite and a second end 162c, and the second cylindrical section 163 is connected to the first end 162b of the first cylindrical section 162; the third cylindrical section 164 is connected to the second end 162c of the first cylindrical section 162.

Further, the second end 162c of the first cylindrical section 162 has a guide structure 165 to facilitate mounting of the first cylindrical section 162 to the mounting cavity 14. Preferably, the guide structure 165 includes a guide portion disposed at the second end 162c of the first cylindrical section. Specifically, the guide portion is a round-cornered guide portion or a conical guide portion.

Preferably, the length of the second cylindrical section 163 is 1/4-1/3 times the length of the guide sleeve, and the guide sleeve 16 has sufficient fit dimensions to fit the screw assembly 30, thereby improving the reliability of the connection and reducing the risk of the guide sleeve 16 loosening due to vibration and the like.

Further, the second cylindrical section 163 also has a guide 165 at the first end 162b remote from the first cylindrical section. Here, a guide structure 165 is provided to facilitate installation between the guide housing 16 and the screw assembly 30.

Preferably, the guide structure 165 includes a guide portion 165a disposed on the second cylindrical section 163 distal from the first cylindrical section 162. Specifically, the guide 165a is a round or conical guide.

Referring to fig. 6 and 7, fig. 6 is a schematic cross-sectional view of the screw assembly 30 in the electronic expansion valve 100 shown in fig. 1, and fig. 7 is a schematic cross-sectional view of the screw assembly 30 and the rotor assembly 50 in the electronic expansion valve 100 shown in fig. 1.

The needle assembly 20 includes a needle hub 21 mounted within the guide sleeve 16, and a needle 22 mounted within the needle hub 21. The valve needle 22 has an axis, the axis of the valve needle 22 being arranged coincident with the axis 103 of the valve body 10. One end of the needle 22 is connected to the screw assembly 30 and the other end is engaged with the valve port 11. The screw assembly 30 moves the valve needle 22 to control the opening or closing of the valve port 11, thereby implementing the opening/closing of the electronic expansion valve 100.

The valve needle assembly 20 further comprises a bearing 23, a gasket 24 and an elastic element 25, the bearing 23 and the gasket 24 are arranged at one end of the screw assembly 30 close to the valve needle 22, one end of the elastic element 25 is in contact with the gasket 24, and the other end of the elastic element is in contact with the valve needle 22; one end of the bearing 23 is abutted against the screw assembly 30 and the valve needle sleeve 21, and the other end is contacted with the gasket 24; the spacer 24 is received in the valve needle sleeve 21 and contacts the outer race of the bearing 23.

The screw assembly 30 includes a nut socket 32 and a screw 31 installed in the nut socket 32. The screw 31 has a first end and a second end which are oppositely arranged, the first end of the screw 31 is connected with the rotor assembly 50, and the second end of the screw 31 is arranged in the nut sleeve 32 in a penetrating way and is mutually connected with the bearing 23. Nut sleeve 32 has one end mounted to coupling tab 17 and the other end positioned within sleeve 40.

The screw 31 is provided with a bulge 311 extending along the radial direction of the screw 31, and the bulge 311 is flush with the inner side surface of the valve needle sleeve 21; the outer ring of the bearing 23 abuts against the inner side surfaces of the protrusion 311 and the valve needle sleeve 21, and the inner side surfaces of the protrusion 311 and the valve needle sleeve 21 abut against the outer ring of the bearing 23, so that the bearing 23 is limited by the screw 31 and the valve needle sleeve 21.

The screw 31 is fixedly connected with the inner ring of the bearing 23. In the present embodiment, the screw 31 and the inner ring of the bearing 23 are fixed to each other by interference fit, that is, the size of the screw 31 is larger than the diameter of the inner ring of the bearing 23, and at this time, the screw 31 and the bearing 23 have relatively better connection stability.

It is understood that in other embodiments, the screw 31 and the inner ring of the bearing 23 may be fixed to each other by riveting, gluing, or other connection methods.

The screw 31 is driven by the rotor assembly 50 to rotate, and the screw 31 drives the inner ring of the bearing 23 to rotate due to the fixed connection between the screw 31 and the inner ring of the bearing 23. The rolling bodies in the bearing 23 are in rolling contact with the outer race of the bearing 23, thereby releasing the rotation of the screw 31. The bearing 23 has a plurality of rolling elements therein, so that the release of the rotation of the screw 31 is changed from the single-point rolling contact in the conventional electronic expansion valve 100 to the multi-point rolling contact in the present embodiment. Therefore, the contact force is shared by the rolling bodies, the contact pressure at each contact point is reduced, and the rolling friction is reduced. The rotation of the screw rod is released by the bearing, so that the valve needle does not generate relative rotation friction when contacting with the valve port, and the reliability and the service life of the valve needle and the valve port are improved.

In addition, due to the coaxial installation of the bearing 23 and the screw 31, the contact force on the rolling body is perpendicular to the gravity direction of the screw 31, which also relatively reduces the contact force on the contact point in the conventional electronic expansion valve, and improves the stability and reliability of the electronic expansion valve 100.

In the present embodiment, the elastic member 25 is a spring, and the elastic member 25 has relatively high connection stability. It is understood that in other embodiments, the elastic member 25 may be other types of elastic members such as an elastic column.

Further, the second cylindrical section 163 extends into the nut sleeve 32 from the first end of the nut sleeve 32 and is fixedly connected to the nut sleeve 32. Preferably, the fixed connection comprises a threaded connection or any one of an interference fit or a transition fit. In the present embodiment, the second cylindrical section 163 is in transition fit with the nut sleeve 32, so that the nut sleeve 32 is guided by the second cylindrical section 163, and the axis of the nut sleeve 32 is arranged to coincide with the axis of the guide sleeve 16 and the axis 103 of the valve body 10.

It will be appreciated that the valve body 10 is guided by the first cylindrical section 162, and the nut sleeve 32 is guided by the second cylindrical section 163; therefore, the axes of the valve body 10, the guide sleeve 16 and the nut sleeve 32 coincide to ensure the coaxiality between the valve needle 22 and the valve port 11, so that in the process of movement, the collision between the valve needle 22 and the valve body 10 is reduced, the abrasion of the parts such as the valve needle 22 is reduced, and the service life of the electronic expansion valve 100 is prolonged.

The nut sleeve 32 is in threaded connection with the screw 31, and since the nut sleeve 32 is welded on the connecting piece 17, when the screw 31 is driven by the rotor 51 to rotate, due to the matching relationship of the nut and the screw rod formed between the nut sleeve 32 and the screw rod 31, the screw rod 31 and the rotor assembly 50 fixedly connected with the screw rod 31 and the like can move in a telescopic manner along the axial direction of the screw rod 31, so that the movement process of driving the valve needle assembly 20 by the screw rod 31 is realized.

The nut sleeve 32 can be provided with a second positioning step 321, and the second cylindrical section 163 extends into the nut sleeve 32 and abuts against the second positioning step 321, so that the installation reliability of the guide sleeve 16 is improved, and the axial movement and noise of the guide sleeve 16 are avoided.

The rotor assembly 50 includes a rotor 51 located in the sleeve 40, an adapter plate 52 for mounting the screw 31, a limiting member 53 for limiting a rotation angle of the rotor 51, and a driving plate 54 mounted on the adapter plate 52. The rotor 51 is mounted on the adapter plate 52. The adapter plate 52 is fixedly connected with the screw 31 by welding and the like.

The limiting member 53 includes a spring 531 sleeved on the nut sleeve, and a stop ring 532 installed on the spring 531. One end of the spring 531 is connected to the connecting piece 17. The other end of the spring 531 is provided with a stopper 531 a. The stop collar 532 is wound around the spring 531. Preferably, the outer wall of the nut sleeve 32 is provided with a stop 322 (numbered incorrectly in fig. 7) and the stop 322 is engaged with a stop ring 532 to limit the rotation angle of the rotor 51.

During the rotation of the rotor 51 along the axis 103 to drive the screw 31 with the closing of the needle 22, the stop ring 532 moves along the spring 531; the stop ring 532 abuts against the stop table 322 to limit the rotation angle of the rotor 51, and is a lower limit for the rotor 51. During the process that the rotor 51 rotationally moves along the axis 103 to drive the screw 31 to drive the needle 22 to close the valve port 11, the stop ring 532 moves along the spring 531; the stopper ring 532 abuts against the stopper portion 531a to limit the rotation angle of the rotor 51, which is an upper limit of the rotor 51.

The stator assembly includes a coil and other components, and is configured to generate a magnetic field when energized, and to drive the rotor 51 to rotate under the action of the magnetic field, so as to drive the screw 31 to rotate.

In this embodiment, the valve body 10 is further provided with a fixing plate 18, the fixing plate 18 is used for carrying and fixing the stator assembly, the fixing plate 18 is further provided with a plurality of mounting holes 181, and the mounting holes 181 are used for fixing the stator assembly on the fixing plate 18.

In this embodiment, the electronic expansion valve 100 is an electric electronic expansion valve, the rotor 51 is a motor rotor made of a permanent magnet in a stepping motor, the stator assembly is a motor stator in the stepping motor, the stepping motor receives a logic digital signal provided by a control circuit and then transmits the signal to each phase coil of the motor stator, and the motor rotor made of the permanent magnet is subjected to a magnetic moment to generate a rotary motion, so that a motion process that the stator assembly drives the rotor assembly to rotate is realized.

The working principle of the electronic expansion valve 100 is explained as follows:

after the stator assembly is electrified, a magnetic field is generated, the rotor 51 made of a magnetic material rotates under the driving of the magnetic field, the rotor 51 is fixedly connected with the screw 31 through the guide sheet 54, the rotation of the rotor 51 drives the screw 31 to rotate, the screw 31 and the nut sleeve 32 form nut-screw matching, and the nut sleeve 32 is fixedly arranged on the valve body 10, so that the rotation of the screw 31 relative to the nut sleeve 32 can drive the screw 31 to move relative to the nut sleeve 32 in a telescopic manner, thereby realizing the working process that the stator assembly drives the rotor assembly 50 to move, and the rotor assembly 50 drives the screw assembly 30 to move again;

the screw 31 moves in a telescopic manner relative to the axis 103 direction of the valve body 10 and then drives the valve needle 22 to move through the elastic element 25, the valve needle 22 moves towards the valve port 11 formed in the valve body 10 under the driving of the screw 31, and when the valve needle 22 closes the valve port 11, that is, the valve cavity 12 is disconnected from the valve port 11, the electronic expansion valve 100 is closed; when the valve needle 22 releases the closure of the valve port 11, that is, the valve cavity 12 is communicated with the valve port 11, the electronic expansion valve 100 is opened, and the opening aperture of the valve port 11 in the electronic expansion valve 100 is relatively small, so that the flow rate of the fluid medium is reduced, and the throttle and pressure reduction process of the electronic expansion valve 100 on the fluid medium is realized.

Referring to fig. 8, fig. 8 is a schematic cross-sectional view of an electronic expansion valve 100a according to a second embodiment of the invention. Unlike the first embodiment of the present invention in which the bearing 23 is provided at the end of the screw 31 close to the needle 22, the second embodiment of the present invention in which the bearing 23a is provided at the end of the needle 22a close to the screw 31 a.

It can be understood that the bearing 23 is only disposed between the screw 31 and the valve needle 22, and no matter whether the bearing 23 is disposed on the screw 31 or directly disposed on the valve needle 22, the single-point rolling contact of the conventional electronic expansion valve can be converted into the multi-point rolling contact, so that the friction damage generated by the valve opening can be reduced by using the better distribution characteristic of the multi-point rolling contact, the friction force generated by the valve opening caused by the rotation of the screw driving the valve needle to rotate relative to the valve port can be reduced, and better reliability and stability can be provided.

In the second embodiment of the present invention, the inner ring of the bearing 23a is fitted over the needle 22a and fixed to each other, and the outer ring end surface of the bearing 23a contacts and abuts against the gasket 24 a; one end of the elastic member 25a is connected to the screw 31a, and the other end is sleeved with the gasket 24 a.

When the screw 31a rotates and descends, the elastic element 25a connected with the screw 31a is driven by the screw 31a to rotate, the elastic element 25a drives the gasket 24a to rotate, the rotation of the gasket 24a drives the outer ring of the bearing 23a clamped with the elastic element to rotate, and since the inner ring of the bearing 23a is fixed on the needle 22a, the rotation of the screw 31 is transmitted to the rotation of the outer ring of the bearing 23a relative to the inner ring. The rolling bodies in the bearing 23a convert the single-point rolling contact of the conventional electronic expansion valve into the multi-point rolling contact, and the contact force is borne by the rolling bodies in a sharing manner, so that the contact pressure at each contact point is reduced, and the rolling friction is reduced.

Further, an inner ring of the bearing 23a is in interference fit with an end portion, close to the screw 31, of the valve needle 22a, and the inner ring of the bearing 23a and the valve needle 22a are fixed to each other through interference fit; the mode of fixing the inner ring by interference fit is relatively simple and convenient in assembly, and the assembly efficiency can be improved.

It will be appreciated that in other embodiments, the inner race of the bearing 23a may be glued, riveted, etc. to the valve needle 22a in other ways.

Further, the gasket 24a is pressed against the outer ring of the bearing 23a by the elastic action of the elastic piece 25a, that is, the outer ring of the bearing 23a is mutually pressed and fixed with the gasket 24a by the end surface clamping manner; with this fixing, the mounting of the washer 24a is also relatively simple.

It is understood that in other embodiments, the outer ring of the bearing 23a may be in contact with and fixed to the washer 24a by other means such as a concave-convex fit.

Further, the spacer 24a is substantially hollow cylindrical, and a portion thereof close to the needle 22a extends radially outward itself and forms a projection 241, and the spacer 24a is clamped against the outer ring end face of the bearing 23a by the projection 241.

Further, a portion of the hollow cavity inside the gasket 24a near the needle 22a is provided with a tapered surface (not numbered) configured to match the conical top shape of the needle 22a, thereby improving the fitting relationship between the gasket 24a and the needle 22 a.

Further, in order to axially limit the valve needle 22a and prevent the valve needle 22a from being separated from the inner ring of the bearing 23a under an excessive pressure difference, the valve needle assembly 20 is further provided with a pressing sleeve 26, the pressing sleeve 26 and the valve needle sleeve 21a are fixed to each other, the pressing sleeve 26 is provided with a step surface 261, the pressing sleeve 26 is clamped against the valve needle 22a through the step surface 261, the pressing sleeve and the valve needle 22a are not in direct contact, a small gap is left, friction between the valve needle 22a and the pressing sleeve 261 is avoided, and therefore the valve needle 22a is prevented from being separated from the inner ring of the bearing 23a due to an excessively deep position of the valve needle 22a moving towards the valve port 11a, and normal operation of the electronic expansion valve 100a is prevented from being affected.

In the present embodiment, the pressure sleeve 26 and the needle cover 21a are fixed to each other by welding. It will be appreciated that in other embodiments, the pressing sleeve 26 may be riveted, glued, etc. to the valve needle sleeve 21 a.

Furthermore, thanks to the arrangement of the bearing 23a between the screw 31a and the needle 22a, the play existing between the inner and outer rings of the bearing 23a itself can provide a certain degree of freedom of assembly of the needle 22a, which helps to eliminate coaxiality errors during machining and assembly. For example, a certain swing angle is allowed between the needle 22a and the bearing 23a, and the swing angle can help the needle 22a to reduce the coaxiality error.

The invention also provides an air conditioning system (not shown) using the electronic expansion valve, and the reliability and stability of the whole system are improved due to the use of the electronic expansion valve, so that the air conditioning system has a wider application prospect.

The electronic expansion valve provided by the invention has the advantages that the bearing is arranged between the valve needle and the screw rod, so that the rotation of the screw rod is released by the bearing in multipoint rolling contact, the single-point rolling contact sliding friction of the traditional electronic expansion valve is converted into the multipoint rolling contact rolling friction, the friction force required by valve opening is reduced, the damage caused by the friction is reduced, the reliability and the stability of the electronic expansion valve and an air conditioning system using the electronic expansion valve are improved, and the electronic expansion valve has wide application prospect.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that suitable changes and modifications to the above embodiments are within the scope of the claimed invention as long as they are within the spirit of the present invention.

Claims

1. An electronic expansion valve comprises a screw, a valve needle and an elastic element, wherein one end of the elastic element acts on the screw, the other end acts on the valve needle, and the electronic expansion valve is characterized in that a bearing is arranged between the screw and the valve needle and is provided with an inner ring and an outer ring, one of the screw and the valve needle is fixed with the inner ring of the bearing, the other one of the screw and the valve needle acts on the outer ring of the bearing through the elastic element, and a plurality of rolling bodies are arranged between the inner ring of the bearing and the outer ring of the bearing; the electronic expansion valve also comprises a gasket, the gasket is arranged between the elastic part and the outer ring of the bearing, and the gasket is connected with the outer ring of the bearing under the abutting of the elastic part;

the gasket is hollow cylinder, and the part of it keeping away from the elastic component radially outwards extends along self and forms the arch to make the gasket pass through protruding card supports the outer lane terminal surface of bearing, the cavity in the gasket inside is kept away from the part of elastic component sets up to the conical surface.

2. The electronic expansion valve according to claim 1, wherein the screw is fixed to an inner ring of the bearing, and the valve needle is connected to an outer ring of the bearing via the elastic member and a spacer.

3. The electronic expansion valve according to claim 2, wherein the electronic expansion valve comprises a valve needle sleeve for fixing the valve needle, and a side surface of the screw extends outward in a radial direction thereof and forms a protrusion which is flush with an inner side surface of the valve needle sleeve.

4. The electronic expansion valve of claim 2, wherein the screw is in interference fit with the inner race of the bearing.

5. The electronic expansion valve of claim 1, wherein the valve needle is fixed to an inner ring of the bearing, and the screw is connected to an outer ring of the bearing through the elastic member and a gasket.

6. The electronic expansion valve of claim 5, wherein the valve needle is in an interference fit with an inner race of the bearing.

7. The electronic expansion valve of claim 5, further comprising a pressure sleeve, wherein a step surface is disposed on the pressure sleeve, and the step surface abuts against the valve needle to limit axial movement of the valve needle.

8. An air conditioning system comprising an electronic expansion valve, wherein the electronic expansion valve is according to any of claims 1-7.