CN109723832B

CN109723832B - Electronic expansion valve and refrigeration system with same

Info

Publication number: CN109723832B
Application number: CN201711029773.2A
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: 2017-10-27
Filing date: 2017-10-27
Publication date: 2022-09-13
Anticipated expiration: 2037-10-27
Also published as: CN109723832A

Abstract

The invention provides an electronic expansion valve and a refrigeration system with the same. Wherein, electronic expansion valve includes: a valve seat; a valve needle movably disposed within the cavity, the valve needle having an open position and a closed position; the planetary gear speed reducing mechanism comprises a planetary carrier, a planetary wheel and a gear box which are driven by the driving mechanism to rotate, a first mounting shaft is arranged on the planetary carrier, the planetary wheel is sleeved on the first mounting shaft, the gear box comprises a box body fixedly arranged on the valve seat, a fixed inner gear ring arranged on the box body and a rotating inner gear ring rotatably arranged in the box body, an output shaft is arranged on the rotating inner gear ring, and the planetary wheel is meshed with the fixed inner gear ring and the rotating inner gear ring simultaneously; a transmission mechanism moves the valve needle between the open and closed positions. The technical scheme of the invention can effectively solve the problem that the electronic expansion valve in the prior art can not meet the requirements of high precision and miniaturization while increasing the flow regulation range.

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

Fig. 1 shows a typical structure of a deceleration-type electronic expansion valve for a variable-frequency air conditioner, which mainly comprises two parts, namely a valve body part for flow regulation and a coil part for driving. Wherein the coil part includes: the valve comprises a permanent magnet stepping motor 1 ', a gear reducer 2 ' with three-stage speed reduction, a thread pair structure 5 ' for converting the rotary motion of the motor into the vertical motion of a screw rod 3 ', a valve body comprising a valve seat 10 ', and a spring 7 for controlling the lifting of a valve needle 8 and other core components. The working principle of the electronic expansion valve is described as follows: firstly, an electronic controller of an air conditioning system controls an output shaft of a stepping motor 1 'of an electronic expansion valve to rotate, the motor 1' is matched with a gear reducer 2 'to drive an output shaft of the gear reducer 2' to rotate, the output shaft of the gear reducer 2 'is matched with a screw rod to drive the screw rod to rotate, and then the screw rod is matched with a thread pair structure 5' to enable the screw rod to move up and down. The top end of the screw rod is welded with a steel ball 11 ', the lower end of the steel ball 11' is provided with a bush 6 ', and the lower end of the bush 6' is connected with a valve needle 8. When the screw rod is driven by the driving part to move downwards, the screw rod can prop against the steel ball 11 ', the steel ball 11 ' can prop against the lining 6 ', and the lining 6 ' can prop against the valve needle 8, so that the valve needle 8 and the screw rod can synchronously move downwards until the valve needle 8 is positioned at a closing position, namely a position where the valve needle 8 is abutted against the valve body 10 '. When the valve needle 8 is in the closing position, the spring 7 is under constant tension. When reverse pulse is applied, the screw rod 3' moves upwards, and the valve needle 8 continuously moves upwards under the action of the return elasticity of the spring 7 and the system pressure, so that the opening degree of the valve port part 9 is changed, the flow area is changed, and the purpose of controlling the flow and adjusting the superheat degree is achieved.

Currently, the speed reduction mechanism of the electronic expansion valve is generally a spur gear speed reduction mechanism (ordinary gear train). Fig. 2 shows a specific structure of a gear reducer 2' for three-stage reduction in which a first-stage reduction mechanism is composed of a gear 1a and a gear 1b, a second-stage reduction mechanism is composed of a gear 2a and a gear 2b, and a third-stage reduction mechanism is composed of a gear 3a and a gear 3 b. The motor shaft 12 'is arranged coaxially with the gear 1a, the gear 1a is driven to rotate by the motor shaft 12', and the gear 1b is driven to rotate by the gear 1 a. The gear 1b drives the gear 2a of the second-stage speed reducing mechanism to rotate, and the gear 2a drives the gear 2b to rotate. The gear 2b drives the gear 3a of the third-stage speed reducing mechanism to rotate, and the gear 3a drives the gear 3b to rotate, and finally drives the output shaft 13' to rotate. In the above-described speed reducing mechanism, in order to increase the flow rate control range, the output torque must be increased, and in order to improve the control accuracy, a large speed reduction ratio must be provided without changing other conditions (e.g., without changing the input torque). There are two ways to increase the reduction ratio: one is to increase the reduction ratio of each stage of gears, i.e. to increase the number of teeth of the large gear, but the above structure will inevitably result in the increase of the outer diameter of the large gear, and thus the volume of the gear reducer is increased. The other is to increase the number of gear reduction steps, but the above structure will inevitably result in an increase in the number of gears, and therefore also in an increase in the volume of the gear reducer. Finally, the requirements of high precision and miniaturization cannot be met. In addition, the increase in the number of stages also results in a reduction in the transmission efficiency and stability of the overall system.

Disclosure of Invention

The invention mainly aims to provide an electronic expansion valve and a refrigeration system with the same, and aims to solve the problem that the electronic expansion valve in the prior art cannot meet the requirements of high precision and miniaturization while increasing the flow regulation range.

In order to achieve the above object, according to an aspect of the present invention, there is provided an electronic expansion valve comprising: the valve seat is provided with a cavity and a valve port part communicated with the cavity; a valve needle movably disposed within the cavity, the valve needle having an open position opening the valve port portion and a closed position closing the valve port portion; a drive mechanism including a coil and a rotor; the planetary gear reduction mechanism is provided with an output shaft, the driving mechanism is used as an input end of the planetary gear reduction mechanism, the planetary gear reduction mechanism comprises a planetary carrier, a planetary wheel and a gear box, the planetary carrier and the gear box are driven by the driving mechanism to rotate, the planetary carrier and the gear box are coaxially arranged, the planetary carrier is provided with a first installation shaft, the planetary wheel is sleeved on the first installation shaft, the gear box comprises a box body fixedly arranged on the valve seat, a fixed inner gear ring arranged on the box body and a rotating inner gear ring rotatably arranged in the box body, the output shaft is arranged on the rotating inner gear ring, and the planetary wheel is simultaneously meshed with the fixed inner gear ring and the rotating inner gear ring; and the output shaft drives the valve needle to move along a straight line through the transmission mechanism so as to move the valve needle between the opening position and the closing position.

Further, the first mounting shaft is one or more that set up along the circumferential direction of planet carrier, and the planet wheel is one or more that set up with first mounting shaft one-to-one.

Furthermore, the fixed inner gear ring is arranged at the top of the box body, and the rotating inner gear ring is positioned below the fixed inner gear ring and is rotatably arranged inside the box body.

Furthermore, the fixed inner gear ring is provided with a mounting opening, the top of the box body is provided with a mounting protrusion extending upwards, and the mounting protrusion is matched with the mounting opening so that the fixed inner gear ring is fixed on the top of the box body.

Furthermore, the inner wall of the box body is provided with a supporting structure extending inwards for supporting the rotating inner gear ring.

Further, the planetary gear speed reducing mechanism also comprises a mandrel, wherein the mandrel is arranged in the planet carrier and the output shaft in a penetrating way and is in clearance fit with the planet carrier and the output shaft.

Further, the coil can drive the rotor to rotate after being electrified, and the rotor is matched with the planet carrier so that the planet carrier can rotate synchronously with the rotor.

Further, the electronic expansion valve further includes: the shell covers the upper portion of the valve seat, an accommodating space is formed in the shell, the planetary gear speed reducing mechanism and the transmission mechanism are arranged in the accommodating space, and the shell is supported by the valve seat.

Further, the output shaft is provided with the cooperation groove, drive mechanism includes the lead screw and fixes the nut that sets up in the disk seat, the lead screw includes cooperation section and first linkage segment, the movably setting of at least partial cooperation section is in the cooperation inslot, when the output shaft rotates, the cell wall and the cooperation section cooperation in cooperation groove are so that the lead screw rotates, the outer wall of first linkage segment is provided with the external screw thread, first linkage segment and nut threaded connection to convert the rotary motion of lead screw into linear motion.

Further, the valve seat is internally provided with a step surface, and the electronic expansion valve further comprises: and one end of the spring is abutted with the abutting protrusion at the top of the valve needle, the other end of the spring is abutted with the step surface, and when the driving mechanism drives the valve needle to move from the closing position to the opening position, the valve needle is subjected to upward elastic restoring force of the spring.

According to another aspect of the present invention, there is provided a refrigeration system comprising an electronic expansion valve, the electronic expansion valve being the above-mentioned electronic expansion valve.

By applying the technical scheme of the invention, the electronic expansion valve comprises a planetary gear speed reducing mechanism, the driving mechanism is used as the input end of the planetary gear speed reducing mechanism, the planetary gear speed reducing mechanism is provided with an output shaft, and the output shaft drives the valve needle to move along a straight line through the transmission mechanism so as to enable the valve needle to move between the opening position and the closing position. Because the planetary gear speed reducing mechanism adopts the internal gear, the transmission space is fully utilized, and the space size of the whole speed reducing mechanism is much smaller than that of a spur gear speed reducing mechanism under the same condition. That is, the reduction ratio of the planetary gear reduction mechanism is much larger than that of the spur gear reduction mechanism under the same size condition. The improvement of the reduction ratio enables the stroke control precision of the valve needle to be higher. Therefore, the structure enables the electronic expansion valve to meet the requirements of high precision and miniaturization while increasing the flow regulation range, and solves the problem that the electronic expansion valve in the prior art cannot meet the requirements of high precision and miniaturization while increasing the flow regulation range.

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 electronic expansion valve in the related art;

FIG. 2 shows a schematic diagram of a spur gear reduction mechanism of the electronic expansion valve of FIG. 1;

fig. 3 shows a schematic perspective view of an embodiment of an electronic expansion valve according to the invention;

fig. 4 is a schematic longitudinal sectional view of the electronic expansion valve of fig. 3;

fig. 5 shows an enlarged schematic view at a of the electronic expansion valve of fig. 4;

FIG. 6 is a schematic diagram showing a partial configuration of the electronic expansion valve of FIG. 4;

fig. 7 is a schematic perspective view showing a planetary gear reduction mechanism of the electronic expansion valve of fig. 3;

fig. 8 is a schematic view showing an internal structure of the planetary gear speed reducing mechanism of fig. 7;

FIG. 9 is an exploded schematic view of the planetary gear reduction mechanism of FIG. 7;

fig. 10 shows a schematic view of the planetary gear reduction mechanism of fig. 7 showing the internal structure of the planetary gear;

FIG. 11 is a schematic perspective view showing one angle of a carrier of the planetary gear reduction mechanism of FIG. 7;

fig. 12 is a perspective view showing another angle of the carrier of the planetary gear reduction mechanism of fig. 7;

fig. 13 is a schematic view showing an internal structure of a case body of the planetary gear speed reduction mechanism of fig. 7;

FIG. 14 is a schematic cross-sectional view of a valve seat of the electronic expansion valve of FIG. 3; and

fig. 15 is a perspective view illustrating a rotor of the electronic expansion valve of fig. 3.

Wherein the figures include the following reference numerals:

1. an accommodating space; 6. a cavity; 10. a valve seat; 121. a valve port portion; 1321. a step surface; 20. a valve needle; 21. an abutment projection; 30. a drive mechanism; 31. a coil; 32. a rotor; 321. a top wall; 322. a side wall; 323. a drive shaft; 40. a planetary gear reduction mechanism; 41. a planet carrier; 411. a first mounting shaft; 412. a cover plate; 4121. mounting holes; 413. a second mounting shaft; 414. a rib position; 415. a top plate; 4151. a shaft hole; 42. a planet wheel; 43. a gear case; 431. a box body; 4311. mounting a boss; 4312. a support structure; 432. fixing the inner gear ring; 4321. an installation port; 433. a rotating inner gear ring; 4331. a bottom wall; 4332. a side wall; 44. a mandrel; 45. an output shaft; 451. a mating groove; 50. a transmission mechanism; 51. a screw rod; 511. a mating segment; 512. a first connection section; 52. a nut; 60. a housing; 90. a spring.

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. 3, 4 and 6, the electronic expansion valve of the present embodiment includes: valve seat 10, valve needle 20, drive mechanism 30, planetary gear reduction mechanism 40 and transmission mechanism 50. The valve seat 10 has a cavity 6 and a valve port 121 communicating with the cavity 6. A valve needle 20 is movably arranged in the cavity 6, the valve needle 20 having an open position opening the valve mouth portion 121 and a closed position closing the valve mouth portion 121. The drive mechanism 30 includes a coil 31 and a rotor 32. The planetary gear reduction mechanism 40 has an output shaft 45, the driving mechanism 30 serves as an input end of the planetary gear reduction mechanism 40, the planetary gear reduction mechanism 40 includes a planet carrier 41, planet wheels 42 and a gear box 43 which are driven by the driving mechanism 30 to rotate, the planet carrier 41 and the gear box 43 are coaxially arranged, a first mounting shaft 411 is arranged on the planet carrier 41, the planet wheels 42 are sleeved on the first mounting shaft 411, the gear box 43 includes a box body 431 fixedly arranged on the valve seat 10, a fixed inner gear ring 432 arranged on the box body 431 and a rotating inner gear ring 433 rotatably arranged in the box body 431, the output shaft 45 is arranged on the rotating inner gear ring 433, and the planet wheels 42 are simultaneously engaged with the fixed inner gear ring 432 and the rotating inner gear ring 433. The output shaft 45 drives the valve needle 20 in a linear motion via a transmission 50 to move the valve needle 20 between the open and closed positions.

With the solution of the present embodiment, the electronic expansion valve includes a planetary gear reduction mechanism 40, the driving mechanism 30 is used as an input end of the planetary gear reduction mechanism 40, the planetary gear reduction mechanism 40 has an output shaft 45, and the output shaft 45 drives the valve needle 20 to move along a straight line through the transmission mechanism 50 so as to move the valve needle 20 between the open position and the closed position. Since the planetary gear reduction mechanism 40 employs the ring gear, the transmission space is fully utilized, and therefore the space size of the entire planetary gear reduction mechanism 40 is much smaller than that of a spur gear reduction mechanism under the same conditions. That is, the reduction ratio of the planetary gear reduction mechanism 40 is much larger than that of the spur gear reduction mechanism under the same size condition. The improvement in the reduction ratio leads to higher accuracy in stroke control of the valve needle 20. Therefore, the structure enables the electronic expansion valve to meet the requirements of high precision and miniaturization while increasing the flow regulation range, and solves the problem that the electronic expansion valve in the prior art cannot meet the requirements of high precision and miniaturization while increasing the flow regulation range.

It should be noted that the transmission mechanism 50 can convert the rotational movement of the output shaft 45 into the linear movement of the valve needle 20.

In the present embodiment, the planetary gear reduction mechanism 40 is an NN-type planetary gear reduction mechanism. The NN type planetary gear reduction mechanism is a common reduction mechanism, and N in the NN type planetary gear reduction mechanism indicates inner mesh.

As shown in fig. 3, 4, 6, 8 and 9, in the present embodiment, the planetary gear speed reducing mechanism includes a planet carrier 41, a planet gear 42 and a gear box 43 driven by the driving mechanism 30 to rotate, the planet carrier 41 and the gear box 43 are coaxially arranged, a first mounting shaft 411 is arranged on the planet carrier 41, the planet gear 42 is sleeved on the first mounting shaft 411, the gear box 43 includes a box body 431 fixedly arranged on the valve seat 10, a fixed ring gear 432 arranged on the box body 431, and a rotating ring gear 433 rotatably arranged in the box body 431, the output shaft 45 is arranged on the rotating ring gear 433, and the planet gear 42 is engaged with the fixed ring gear 432 and the rotating ring gear 433 at the same time. Specifically, the drive mechanism 30 drives the carrier 41 to rotate. The rotation of the carrier 41 causes the planetary gears 42 to revolve along the axis of the carrier 41. Since the planetary gear 42 is meshed with the fixed annular gear 432, the fixed annular gear 432 is fixed, and therefore the planetary gear 42 can rotate on its axis. Because planet wheel 42 meshes with rotation ring gear 433 simultaneously, rotation ring gear 433 rotationally sets up in box body 431, consequently, under the drive of planet wheel 42, rotation ring gear 433 can be along its own axis rotation. The rotational speed of the rotating ring gear 433 is greatly reduced compared to the speed input at the input end, and therefore the output speed of the output shaft 45 provided to the rotating ring gear 433 is also reduced.

The first mounting shaft 411 may be one, and when the first mounting shaft 411 is one, the planet gear 42 is one corresponding to the first mounting shaft 411, and the first mounting shaft 411 is located outside the axis of the planet carrier 41 in the circumferential direction.

Preferably, as shown in fig. 3, 4, 6, 8, and 9, the first mounting shaft 411 is provided in plurality (two or more, for example, 2, 3, and 4 …) at intervals in the circumferential direction of the carrier 41, and the planetary gears 42 are provided in plurality (two or more, for example, 2, 3, and 4 …) in one-to-one correspondence with the first mounting shaft 411. The above structure makes the operation of the planetary gear speed reducing mechanism more stable. Preferably, in this embodiment, there are three first mounting shafts 411, and there are three planet wheels 42 arranged in one-to-one correspondence with the first mounting shafts 411.

As shown in fig. 3, 4, 6, 8 to 11, each planetary gear 42 is sleeved on each first mounting shaft 411 in a one-to-one correspondence manner, and during operation, each planetary gear 42 rotates at a high speed, and in order to prevent the planetary gear 42 from coming off from the first mounting shaft 411, as shown in fig. 11, in this embodiment, the planet carrier 41 further includes a plurality of second mounting shafts 413 and a plurality of rib positions 414 disposed in a one-to-one correspondence manner with the plurality of second mounting shafts 413, each rib position 414 is wrapped on the circumferential outer side of each second mounting shaft 413, the first mounting shaft 411 and the second mounting shafts 413 are disposed at intervals, the planetary gear reduction mechanism 40 further includes a cover plate 412, the cover plate 412 is provided with mounting holes 4121 engaged with the first mounting shafts 411 and the second mounting shafts 413, and the top surface of the cover plate 412 abuts against the bottom surface of the rib positions 414. In the above structure, the upper ends of the planetary gears 42 are stopped by the carrier 41, and the lower ends of the planetary gears 42 are stopped by the cover plate 412, so that the planetary gears 42 can be prevented from coming off the first mounting shaft 411. Preferably, in the present embodiment, the planet carrier 41 further includes a top plate 415, and the top plate 415, the first mounting shaft 411, the second mounting shaft 413 and the rib 414 together form the planet carrier 41. The first mounting shaft 411 and the second mounting shaft 413 are spaced apart from each other on the bottom surface of the top plate 415, and the cover plate 412 covers the bottom surfaces of the ribs 414.

As shown in fig. 6 to 8, in the present embodiment, a fixed ring gear 432 is provided at the top of a case body 431, and a rotation ring gear 433 is located below the fixed ring gear 432 and rotatably provided inside the case body 431. The structure is simple and easy to realize. Of course, it should be understood by those skilled in the art that the fixed ring gear 432 may be provided inside the case body 431.

As shown in fig. 7, 9 and 13, in the present embodiment, the fixing ring gear 432 is provided with a mounting hole 4321, the top of the case body 431 is provided with a mounting protrusion 4311 extending upward, and the mounting protrusion 4311 cooperates with the mounting hole 4321 to fix the fixing ring gear 432 on the top of the case body 431. Specifically, in this embodiment, the fixed ring gear 432 includes a first column section located above and a second column section located below, the diameter of the first column section is greater than that of the second column section, a step surface is formed at a connection portion of the first column section and the second column section, and the mounting opening 4321 is provided at an edge of the first column section. When the ring gear is installed, the rotating ring gear 433 is installed inside the box body 431, the installation protrusion 4311 is aligned with the installation hole 4321, the fixed ring gear 432 is placed on the top of the box body 431 after the alignment, and the step surface is abutted to the top surface of the top of the box body 431. Finally, the mounting protrusion 4311 is bent by an external force, so that the mounting protrusion 4311 is hooked at the mounting hole 4321 of the first column section. The structure is simple and easy to assemble.

As shown in fig. 7 to 9 and 13, in the present embodiment, an inwardly extending support structure 4312 is provided on an inner wall of the case body 431 to support the rotation ring gear 433. The structure is simple and easy to realize. Preferably, in this embodiment, the support structure 4312 is an inwardly extending support sheet. Further preferably, the support piece is formed by punching, and a punched hole is left in the box body 431 after punching. The structure is simple, the processing is easy, and the production cost is low.

As shown in fig. 6 to 10, in the present embodiment, the planetary gear speed reduction mechanism further includes a spindle 44, and the spindle 44 is inserted into the carrier 41 and the output shaft 45 and is in clearance fit with the carrier 41 and the output shaft 45. The structure is simple, and the coaxiality of the planet carrier 41 and the gear box 43 can be ensured.

As shown in fig. 4, 8, 12 and 15, in the present embodiment, the driving mechanism 30 includes a coil 31 and a rotor 32, the coil 31 is energized to drive the rotor 32 to rotate, and the rotor 32 is engaged with the carrier 41 to enable the carrier 41 to rotate synchronously with the rotor 32. Specifically, when the coil 31 is energized, a magnetic field is generated, and the rotor 32 starts to rotate at a high speed by the magnetic field. The rotor 32 is provided with a drive shaft 323, and the carrier 41 is provided with a shaft hole 4151 engaged with the drive shaft 323. The rotor 32 drives the carrier 41 to rotate via the drive shaft 323. Preferably, in the present embodiment, the driving shaft 323 includes a driving shaft 323 main body and a rotation prevention column provided at a sidewall edge of the driving shaft 323 main body, wherein a diameter of the rotation prevention column is smaller than that of the driving shaft 323 main body. The shape of the shaft hole 4151 is adapted to the shape of the drive shaft 323. The above structure can prevent the slip phenomenon from occurring between the drive shaft 323 and the carrier 41 during rotation, thereby improving the control accuracy. It is further preferred that there be two anti-rotation posts, disposed on opposite sides of the main body of the drive shaft 323. Of course, those skilled in the art should understand that the planet carrier 41 can also be directly driven to rotate by the motor, for example, the output shaft of the motor directly extends into the shaft hole 4151 of the planet carrier 41 to drive the planet carrier 41 to rotate. In the present embodiment, the shaft hole 4151 is provided in the top plate 415. The shaft hole 4151 is an input end of the planetary gear reduction mechanism 40.

As shown in fig. 15, the rotor 32 includes a top wall 321 and a side wall 322 disposed around the top wall 321, and the driving shaft 323 is disposed on an inner surface of the top wall 321 and extends downward.

As shown in fig. 4, in the present embodiment, the electronic expansion valve further includes: the housing 60 is covered on the upper portion of the valve seat 10, the housing 60 has an accommodating space 1 therein, the planetary gear speed reduction mechanism 40 and the transmission mechanism 50 are disposed in the accommodating space 1, and the housing 60 is supported by the valve seat 10. The structure can prevent sundries such as water vapor, dust and the like from entering the precise planetary gear speed reducing mechanism and the transmission mechanism 50, thereby prolonging the service life of the planetary gear speed reducing mechanism and the transmission mechanism 50.

As shown in fig. 4 to 6, 8 and 9, in the present embodiment, the output shaft 45 is provided with a fitting groove 451, the transmission mechanism 50 includes a screw rod 51 and a nut 52 fixedly disposed on the valve seat 10, the screw rod 51 includes a fitting section 511 and a first connecting section 512, at least a portion of the fitting section 511 is movably disposed in the fitting groove 451, when the output shaft 45 rotates, a groove wall of the fitting groove 451 is fitted with the fitting section 511 to rotate the screw rod 51, an external thread is disposed on an outer wall of the first connecting section 512, and the first connecting section 512 is threadedly connected with the nut 52 to convert a rotational motion of the screw rod 51 into a linear motion. At this time, the engagement section 511 of the screw 51 is gradually separated from the engagement groove 451, and the needle 20 is moved between the open position and the closed position by the screw 51.

As shown in fig. 8, in the present embodiment, the rotation ring gear 433 includes a bottom wall 4331 and a side wall 4332, and internal teeth are provided on an inner surface of the side wall 4332. The bottom wall 4331 is provided with an assembly hole output shaft 45 penetrating through the assembly hole. An end of the output shaft 45 remote from the needle 20 is provided with a first engagement groove that engages with the spindle 44, and an engagement groove 451 is formed on the other end of the output shaft 45.

As shown in fig. 6, in the present embodiment, the valve seat 10 has a step surface 1321 therein, and the electronic expansion valve further includes: one end of the spring 90 abuts against the abutment projection 21 at the tip of the needle 20, and the other end of the spring 90 abuts against the stepped surface 1321. The spring 90 is always in compression within the valve seat 10. When the needle 20 moves from the closing position to the opening position, the bottom surface of the abutment projection 21 receives an upward elastic restoring force of the spring 90 to gradually move the needle 20 away from the valve port portion 121. Specifically, when the valve needle 20 is required to open the valve opening portion 121, the screw 51 rotates and moves upward, and the abutting force of the top of the valve needle 20 is reduced. When the downward force applied to the valve needle 20 by the screw 51 is smaller than the upward elastic restoring force applied to the valve needle 20, the valve needle 20 starts to have a tendency to move upward, and the specific upward movement stroke of the valve needle 20 is determined by the upward movement stroke of the screw 51.

The present application also provides a refrigeration system, the refrigeration system (not shown in the figures) according to the present application comprising: the electronic expansion valve is the electronic expansion valve. The electronic expansion valve has the advantages of high precision, small volume and the like, so that the refrigeration system 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:

a valve seat (10) having a cavity (6) and a valve port portion (121) communicating with the cavity (6);

a valve needle (20) movably arranged within the cavity (6), the valve needle (20) having an open position opening the valve mouth portion (121) and a closed position closing the valve mouth portion (121);

a drive mechanism (30) including a coil (31) and a rotor (32);

a planetary gear reduction mechanism (40) having an output shaft (45), the driving mechanism (30) being an input end of the planetary gear reduction mechanism (40), the planetary gear reduction mechanism (40) including a planet carrier (41), a planet wheel (42) and a gear box (43) driven by the driving mechanism (30) to rotate, the planet carrier (41) and the gear box (43) being coaxially arranged, the planet carrier (41) being provided with a first installation shaft (411), the planet wheel (42) being sleeved on the first installation shaft (411), the gear box (43) including a box body (431) fixedly arranged on the valve seat (10), a fixed ring gear (432) arranged on the box body (431) and a rotating ring gear (433) rotatably arranged in the box body (431), the output shaft (45) being arranged on the rotating ring gear (433), the planet gears (42) are simultaneously meshed with the fixed inner gear ring (432) and the rotating inner gear ring (433), and the upper ends of the planet gears (42) are stopped by the planet carrier (41);

the output shaft (45) drives the valve needle (20) to move along a straight line through the transmission mechanism (50) so as to move the valve needle (20) between the opening position and the closing position;

the rotor (32) is provided with a driving shaft (323), the planet carrier (41) is provided with a shaft hole (4151) matched with the driving shaft (323), and the rotor (32) drives the planet carrier (41) to rotate through the driving shaft (323).

2. An electronic expansion valve according to claim 1, characterized in that the first mounting shafts (411) are one or more arranged in the circumferential direction of the planet carrier (41), and the planet wheels (42) are one or more arranged in one-to-one correspondence with the first mounting shafts (411).

3. The electronic expansion valve according to claim 1, wherein the fixed ring gear (432) is provided at a top of the tank body (431), and the rotational ring gear (433) is located below the fixed ring gear (432) and rotatably provided inside the tank body (431).

4. An electronic expansion valve according to claim 3, wherein the fixed ring gear (432) is provided with a mounting opening (4321), the top of the tank body (431) is provided with an upwardly extending mounting projection (4311), and the mounting projection (4311) cooperates with the mounting opening (4321) to fix the fixed ring gear (432) on the top of the tank body (431).

5. An electronic expansion valve according to claim 3, wherein the inner wall of the tank body (431) is provided with inwardly extending support structures (4312) for supporting the ring gear (433) of rotation.

6. An electronic expansion valve according to claim 1, wherein the planetary gear reduction mechanism further comprises a spindle (44), the spindle (44) is inserted into the planet carrier (41) and the output shaft (45) and is in clearance fit with the planet carrier (41) and the output shaft (45).

7. An electronic expansion valve according to claim 1, wherein the coil (31) is energized to drive the rotor (32) in rotation, the rotor (32) cooperating with the planet carrier (41) to enable the planet carrier (41) to rotate synchronously with the rotor (32).

8. An electronic expansion valve according to any of claims 1-7, further comprising:

the planetary gear speed reducing mechanism comprises a shell (60) covering the upper portion of the valve seat (10), an accommodating space (1) is formed inside the shell (60), the planetary gear speed reducing mechanism (40) and the transmission mechanism (50) are arranged in the accommodating space (1), and the shell (60) is supported by the valve seat (10).

9. An electronic expansion valve according to any of claims 1-7, wherein the output shaft (45) is provided with a fitting groove (451), the transmission mechanism (50) comprises a lead screw (51) and a nut (52) fixedly arranged on the valve seat (10), the lead screw (51) comprises a fitting section (511) and a first connection section (512), at least a part of the fitting section (511) is movably arranged in the fitting groove (451), when the output shaft (45) rotates, a groove wall of the fitting groove (451) is fitted with the fitting section (511) to rotate the lead screw (51), an outer wall of the first connection section (512) is provided with an external thread, and the first connection section (512) is in threaded connection with the nut (52) to convert the rotational motion of the lead screw (51) into a linear motion.

10. An electronic expansion valve according to claim 1, wherein the valve seat (10) has a stepped surface (1321) therein, the electronic expansion valve further comprising:

and a spring (90), one end of the spring (90) is abutted with the abutting projection (21) at the top of the valve needle (20), the other end of the spring (90) is abutted with the step surface (1321), and when the driving mechanism (30) drives the valve needle (20) to move from the closing position to the opening position, the valve needle (20) is subjected to upward elastic restoring force of the spring (90).

11. A refrigeration system comprising an electronic expansion valve, wherein the electronic expansion valve is an electronic expansion valve according to any of claims 1-10.