CN214480104U

CN214480104U - Worm loose joint transmission mechanism and refrigerator door opening device comprising same

Info

Publication number: CN214480104U
Application number: CN202120883948.1U
Authority: CN
Inventors: 宋洪典; 邓佳骏; 周勇
Original assignee: Jiangsu Leili Motor Co Ltd
Current assignee: Jiangsu Leili Motor Co Ltd
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2021-10-22
Anticipated expiration: 2031-04-27

Abstract

The utility model discloses a worm loose joint transmission mechanism and a refrigerator door opener comprising the same, which comprises a positioning block, a worm, a transmission part and a motor, wherein the positioning block is movably connected with the worm, and the motor, the worm and the transmission part rotate coaxially; one end of the worm, facing the motor, is provided with a connecting hole, and the transmission part is positioned between a motor shaft of the motor and a radial gap of the connecting hole; and the transmission part is in interference fit with the motor shaft, and the transmission part is in clearance fit with the connecting hole. The utility model discloses a worm axial movable mounting means compares in fixed mounting means, can avoid falling the atress drunkenness condition of a direction to reach the effect that promotes motor life.

Description

Worm loose joint transmission mechanism and refrigerator door opening device comprising same

Technical Field

The utility model relates to an intelligence house design technical field especially relates to a worm loose joint drive mechanism and contain its refrigerator door opener.

Background

In the existing door opening mechanism scheme, the traditional transmission comprises a motor, a worm, a helical gear and other parts. The worm is connected with the motor in a mode of interference pressure welding and the like, but the axial movement of a motor shaft connected with the worm is caused due to the fact that the worm and helical gear transmission has component force along the axial direction of the worm. Due to volume and cost limitations, current motor models are all as compact as possible. The axial force existing in the worm helical gear transmission inevitably influences the service life of the motor.

In addition, in the existing door opening mechanism scheme, the rack resetting structure mainly comprises a notch gear, a rack, a resetting spring, a shock pad and other parts. After the last gear of the notch gear is meshed with the rack, the rack is instantly retracted to the original point by the return spring and is contacted with the shock pad until the movement is stopped. At present, the hardness of the shock pad is generally controlled to be a small value due to the requirement of noise, and after the mechanism runs for a long time, the shock pad is worn greatly, so that the position of each rack stop is different. When the stop position error of rack is great, the breach gear can not mesh with the rack is accurate, can lead to here card dead this moment to the motor stall leads to the trouble to take place.

SUMMERY OF THE UTILITY MODEL

In order to solve the mechanism worm of opening door among the prior art and to be connected with the motor through interference crimping mode, can lead to the motor shaft of connecting the worm to have the risk of axial float to influence the technical problem in the life-span of motor, the utility model provides a worm loose joint drive mechanism and contain its refrigerator door opener and solve above-mentioned problem.

The utility model provides a worm loose joint transmission mechanism, which comprises a positioning block, a worm, a transmission part and a motor, wherein the positioning block is movably connected with the worm, and the motor, the worm and the transmission part coaxially rotate; one end of the worm, facing the motor, is provided with a connecting hole, and the transmission part is positioned between a motor shaft of the motor and a radial gap of the connecting hole; and the transmission part is in interference fit with the motor shaft, and the transmission part is in clearance fit with the connecting hole.

Preferably, the positioning block and the worm are connected with the worm shaft in a matched mode through the worm shaft hole, and the inner diameter of the worm shaft hole is larger than the outer diameter of the worm shaft.

Preferably, the radial inner surface of the transmission member is a circumferential surface in interference fit with the motor shaft, and the outer surface of the transmission member is a non-circular surface.

Furthermore, the connecting hole includes with motor shaft clearance fit's motor shaft hole and with driving medium clearance fit's die cavity, the motor shaft pass the driving medium stretches into in the motor shaft hole.

The utility model also provides a refrigerator door opener, including casing, gear drive subassembly, rack and above worm loose joint drive mechanism, locating piece and motor and casing fixed connection, the motor passes through the gear drive subassembly and drives the rack and make linear motion.

Furthermore, a buffer pad and a return spring are arranged in the shell, the buffer pad is fixedly connected with the shell, one end of the return spring is connected with the buffer pad, and the other end of the return spring is connected with the rack; the gear transmission assembly comprises one or more stages of circular gears which are meshed in sequence and a notch gear which is meshed with the last stage of circular gear, when the notch gear is meshed with the rack, the notch gear drives the rack to move linearly, and meanwhile, the reset spring extends.

Furthermore, the shell is provided with a positioning block assembly hole, and the positioning block is provided with a positioning column suitable for being inserted into the positioning block assembly hole.

Furthermore, a shifting rod, a switch spring and a microswitch are arranged in the shell, one end of the switch spring is fixed with the shell, the other end of the switch spring is connected with the shifting rod, and the middle part of the shifting rod is rotationally connected with the shell; the switch spring and the notch gear are respectively positioned at two ends of the deflector rod; one end of the notch gear is provided with a notch cylinder, the outer surface of the notch cylinder consists of a circumferential surface and a non-circular surface which is inwards recessed along the radial direction, when the deflector rod is contacted with the circumferential surface, the switch spring is in a stretching state, and the deflector rod extrudes the microswitch; when the deflector rod is in contact with the non-circular surface, the switch spring drives the deflector rod to be separated from the microswitch.

Furthermore, the notch gear is provided with a plurality of saw teeth which are continuously connected with each other, the rack is provided with a positioning tooth and a plurality of transmission teeth which are continuously connected with each other, and the positioning tooth is positioned in front of the running direction of the rack when the refrigerator door opener opens the door; the minimum distance between the transmission teeth and the positioning teeth is larger than the maximum distance between two adjacent saw teeth.

Further, the minimum distance between the positioning tooth and the transmission tooth closest to the positioning tooth is A, the maximum distance between two adjacent saw teeth is B, and then 1.5B > A > B.

The utility model has the advantages that:

(1) worm loose joint drive mechanism and contain its refrigerator door opener, adopt the movable mounting means of worm axial, compare in fixed mounting means, can avoid falling the atress drunkenness condition of a direction to reach promotion motor life's effect.

(2) Worm loose joint drive mechanism and contain its refrigerator door opener, when the reset position of rack changes, the first tooth and the second tooth of breach gear are gone into in succession between location tooth and the driving gear in the rotation of breach gear, then the first tooth of breach gear collides and promotes the location tooth with the location tooth, thereby promote the rack and remove, the card that has ensured that the sawtooth can be accurate is gone into between the driving gear, realize breach gear and driving gear accurate meshing promptly, avoided because the rack resets after the position changes the breach gear that leads to and the rack takes place the dead condition of card when will meshing.

Drawings

The present invention will be further explained with reference to the drawings and examples.

FIG. 1 is an exploded view of the worm loose joint transmission mechanism of the present invention;

FIG. 2 is a front view of the worm loose joint transmission mechanism of the present invention;

FIG. 3 is a cross-sectional view taken along line M-M of FIG. 2;

FIG. 4 is an exploded view of an embodiment of a door opener for a refrigerator according to the present invention;

FIG. 5 is a schematic view showing the state of the notched gear engaging with the positioning teeth during the door opening process of the door opener of the refrigerator of the present invention;

FIG. 6 is a schematic view showing the state of the notched gear engaging with the transmission gear during the door opening process of the door opener of the refrigerator of the present invention;

FIG. 7 is a schematic view showing a state in which the last saw tooth of the notch gear is engaged with the transmission gear in the process of opening the door of the door opening device of the refrigerator according to the present invention;

FIG. 8 is a schematic view showing a state where the motor stops operating after the door opener of the refrigerator of the present invention is reset;

fig. 9 is a schematic view of the meshing relationship between the notched gear and the rack in the present invention;

fig. 10 is a partial schematic view of the middle-lower shell of the present invention.

In the figure, 1, a positioning block, 101, a worm shaft hole, 102, a positioning column, 2, a worm, 201, a connecting hole, 2011, a motor shaft hole, 2012, a cavity, 202, a worm shaft, 3, a transmission part, 4, a motor, 401, a motor shaft, 5, a rack, 501, positioning teeth, 502, transmission teeth, 6, a shell, 601, a lower shell, 6011, a positioning block assembling hole, 602, a shell cover, 7, a helical gear, 8, a transmission gear, 9, a notch gear, 901, a sawtooth, 10, a reset spring, 11, a cushion pad, 12, a deflector rod, 1201, a convex column, 13, a switch spring, 14, a microswitch, 15, a notch cylinder, 1501, a circumferential surface, 1502 and a non-circular surface.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

A worm loose joint transmission mechanism comprises a positioning block 1, a worm 2, a transmission part 3 and a motor 4, wherein the positioning block 1 is movably connected with the worm 2, and the motor 4, the worm 2 and the transmission part 3 coaxially rotate; one end of the worm 2 facing the motor 4 is provided with a connecting hole 201, and the transmission piece 3 is positioned between a motor shaft 401 of the motor 4 and a radial gap of the connecting hole 201; and driving medium 3 and motor shaft 401 interference fit, driving medium 3 and connecting hole 201 clearance fit.

The positioning block 1 is used for being fixed with a shell 6 of a refrigerator door opener, the motor 4 drives the worm 2 to rotate through the transmission piece 3, the positioning block 1 is used for supporting the end part of the worm 2, the coaxiality of the worm 2 is guaranteed, the positioning block 1 is movably connected with the worm 2, namely, no axial and circumferential movement limitation exists between the positioning block 1 and the worm 2, the positioning block 1 cannot be driven by the rotating movement and the axial movement of the worm 2 to move, the transmission piece 3 is in interference fit with the motor 4, namely, the transmission piece 3 is relatively fixed with the motor 4, the transmission piece 3 is used for converting the periphery of the motor shaft 401 into a non-circular surface, the worm 2 can rotate along with the motor 4, but no axial movement connection exists between the worm 2 and the motor 4.

The worm 2 can move axially relative to the motor 4 after being installed through the position adjustment of the transmission piece 3, and when the worm 2 rotates clockwise, the rack 5 moves forwards. At this time, the rotation directions of the worm 2 and the helical gear 7 are both right-handed, and the axial force is deviated to the direction of the motor 4, namely the worm 2 is always pressed on the motor shaft 401 and the transmission member 3 by the axial force, and the motor shaft 401 is continuously pressed. When the refrigerator door body encounters a blocking or power-off condition, the motor 4 rotates reversely or manually pushes the rack 5 to reset, the worm 2 rotates anticlockwise at the moment, namely, the worm 2 is pressed on the positioning block 1 by axial force all the time, and the motor shaft 401 does not have any force at the moment and belongs to a free state.

Conversely, when the rotation direction of the worm 2 and the helical gear 7 is left-hand rotation, the worm 2 rotates clockwise, the transmission gear 8 rotates anticlockwise, the notch gear 9 rotates clockwise, and the rack 5 moves forward. At this time, the axial force deviates to the direction of the positioning block 1, namely the axial force always presses the worm 2 on the positioning block 1, and at this time, no force exists in the axial direction of the motor, and the motor belongs to a free state. When the refrigerator door body encounters a blocking or power-off condition, the motor 4 rotates reversely or the rack 5 is pushed manually to reset, the worm 2 rotates anticlockwise at the moment, the axial force of the worm 2 is deviated to the direction of the motor 4, namely the worm 2 is always pressed on the motor shaft 401/transmission part 3 by the axial force, and the motor shaft 401 continuously bears pressure.

In conclusion, compared with a fixed installation mode, the installation mode of the axial movement of the worm can avoid the situation of force movement in one direction, so that the effect of prolonging the service life of the motor 4 is achieved.

Example one

As shown in fig. 1-3, a worm loose joint transmission mechanism comprises a positioning block 1, a worm 2, a transmission member 3 and a motor 4, wherein the positioning block 1 is movably connected with the worm 2, and the motor 4, the worm 2 and the transmission member 3 coaxially rotate; one end of the worm 2 facing the motor 4 is provided with a connecting hole 201, and the transmission piece 3 is positioned between a motor shaft 401 of the motor 4 and a radial gap of the connecting hole 201; and driving medium 3 and motor shaft 401 interference fit, driving medium 3 and connecting hole 201 clearance fit.

The positioning block 1 and the worm 2 are matched and connected through a worm shaft hole 101 and a worm shaft 202, and the inner diameter of the worm shaft hole 101 is larger than the outer diameter of the worm shaft 202. As shown in fig. 1, the left end of the worm 2 has a worm shaft 202, one end of the positioning block 1 facing the worm 2 has a worm shaft hole 101, and the positioning block 1 is in clearance fit with the worm 2.

The radial inner surface of driving medium 3 is the periphery that connects with motor shaft 401 interference, and the surface of driving medium 3 is non-circular face, and driving medium 3 overlaps on motor shaft 401, and worm 2 then overlaps on driving medium 3, realizes fixing between them through the interference fit of driving medium 3 and motor shaft 401, and the design of the non-circular face of driving medium 3 surface can avoid driving medium 3 and worm 2 relative rotation, and driving medium 3 and worm 2 can relative axial motion simultaneously, and driving medium 3 surface as shown in fig. 1 is the quadrangle of fillet all around.

The connection hole 201 may adopt, but is not limited to, the following structure: connecting hole 201 includes motor shaft hole 2011 with motor shaft 401 clearance fit and the die cavity 2012 with driving medium 3 clearance fit, and motor shaft 401 passes driving medium 3 and stretches into in motor shaft hole 2011.

Example two

A refrigerator door opener comprises a shell 6, a gear transmission assembly, a rack 5 and a worm loose joint transmission mechanism, wherein a positioning block 1 and a motor 4 are fixedly connected with the shell 6, and the motor 4 drives the rack 5 to do linear motion through the gear transmission assembly.

As shown in fig. 4, the housing 6 is a split structure, and is composed of a lower housing 601 and a housing cover 602, and the gear assembly, the rack 5 and the worm gear mechanism are mainly installed in the lower housing 601 and are finally sealed by the housing cover 602. The gear transmission component is a gear with multi-stage meshing.

In order to enable the rack 5 to drive the refrigerator to automatically reset after the refrigerator is opened, and the reverse rotation of the motor 4 is not needed to drive the gear to reset, in the embodiment, a buffer pad 11 and a return spring 10 are further arranged inside the shell 6, the buffer pad 11 is fixedly connected with the shell 6, one end of the return spring 10 is connected with the buffer pad 11, and the other end of the return spring is connected with the rack 5; the gear transmission assembly comprises one or more stages of circular gears which are meshed in sequence and a notch gear 9 meshed with the last stage of circular gear, when the notch gear 9 is meshed with the rack 5, the notch gear 9 drives the rack 5 to do linear motion, and meanwhile, the reset spring 10 extends.

In this embodiment, the gear transmission assembly adopts three-stage gear engagement transmission, and includes a helical gear 7 in transmission fit with the worm 2, a notch gear 9 in transmission fit with the rack 5, and a transmission gear 8 in transmission fit with the helical gear 7 and the notch gear 9 at the same time. The gear driving the rack 5 to rotate is the notch gear 9, the saw teeth 901 on the notch gear 9 are not distributed on the whole circumference, that is, the outer edge of the notch gear 9 is provided with a notch area without the saw teeth 901, and the helical gear 7 and the transmission gear 8 are circular gears distributed with the saw teeth 901 on the whole circle.

The motor 4 is electrified to rotate and is sequentially driven by the worm 2, the helical gear 7, the transmission gear 8 and the notch gear 9, so that the notch gear 9 rotates. The sawtooth 901 of the notch gear 9 is matched with the tooth part on the rack 5 to convert the rotary motion of the transmission gear 8 into the linear motion of the rack 5. Thereby causing the rack 5 to be pushed forward to eject the refrigerator door (as shown in fig. 5-7).

Wherein, due to the gap area of the notched gear 9, when the notched gear 9 is engaged with the rack 5 to the last tooth (as shown in fig. 5), the transmission gear 8 continues to rotate, the notched gear 9 is completely disengaged from the rack 5, and the rack 5 is rapidly pulled back (as shown in fig. 8) under the action of the return spring 10 until contacting with the cushion pad 11 to stop the linear motion.

The positioning block 1 and the housing 6 can be fixed by adopting the following structure, but not limited to: the housing 6 has a positioning block assembly hole 6011 thereon, and the positioning block 1 has a positioning post 102 adapted to be inserted into the positioning block assembly hole 6011 thereon. As shown in fig. 10, a positioning block fitting hole 6011 is located in the lower case 601, and two positioning block fitting holes 6011 and the positioning columns 102 are provided, respectively.

EXAMPLE III

On the basis of the second embodiment, the second embodiment adds a structural design of automatic stop, and can automatically stop according to the rotating position of the notch gear 9, specifically, the housing 6 is also internally provided with a shift lever 12, a switch spring 13 and a microswitch 14, one end of the switch spring 13 is fixed with the housing 6, the other end of the switch spring 13 is connected with the shift lever 12, and the middle part of the shift lever 12 is rotatably connected with the housing 6; the switch spring 13 and the notch gear 9 are respectively positioned at two ends of the driving lever 12; one end of the notch gear 9 is provided with a notch cylinder 15, the outer surface of the notch cylinder 15 is composed of a circumferential surface 1501 and a non-circular surface 1502 which is inwards recessed along the radial direction, when the shift lever 12 is in contact with the circumferential surface 1501, the switch spring 13 is in a stretching state, and the shift lever 12 extrudes the microswitch 14; when the lever 12 contacts the non-circular surface 1502, the switch spring 13 pulls the lever 12 away from the microswitch 14.

As shown in fig. 5, the upper end of the shift lever 12 is connected to the switch spring 13, one side of the lower end of the shift lever 12 is attached to the surface of the notched cylinder 15, and the other side of the lower end of the shift lever 12 extends to form a convex pillar 1201 to press the microswitch 14, the distance from each point on the circumferential surface 1501 to the rotation center of the notched cylinder 15 is the same, and the distance from each point on the non-circular surface 1502 to the rotation center of the notched cylinder 15 is smaller than the distance from each point on the circumferential surface 1501 to the rotation center of the notched cylinder 15. Under the normal state, as shown in fig. 5-7, the toggle lever 12 is pressed against the circumferential surface 1501 and the micro switch 14 is pressed all the time under the action of the switch spring 13 (the switch spring 13 is in the stretching state, and the toggle lever 12 is biased to rotate clockwise), when the notch gear 9 rotates to the non-circular surface 1502 to contact with the toggle lever 12 (as shown in fig. 8), the limit of the toggle lever 12 is reduced (i.e. the toggle lever 12 rotates clockwise by a small distance), the toggle lever 12 is still pressed against the notch cylinder 15 under the action of the switch spring 13, and the press of the toggle lever 12 and the micro switch 14 is released. Thereby realizing the running period signal of the notch gear 9.

To sum up: the motor 4 is electrified to rotate, the worm 2 and the helical gear 7 sequentially transmit the power to the notch gear 9, the notch gear 9 rotates until the first sawtooth 901 is meshed with the rack 5, the rack 5 moves forwards until the last sawtooth 901 of the notch gear 9 is meshed with the rack 5, and at this time, the refrigerator door body is completely opened. When the last saw tooth 901 of the notch gear 9 is completely engaged with the rack 5, the rack 5 is retracted under the action of the return spring 10. The notch gear 9 continues to rotate until the non-circular surface 1502 of the notch cylinder 15 contacts the shift lever 12, the shift lever 12 is released from contact with the microswitch 14 under the force of the switch spring 13, at which point a signal is sent and the motor 4 stops rotating and waits for the next cycle to run.

Example four

According to the technical problem that when the reset position of the rack 5 changes in the prior art, the notch gear 9 and the rack 5 are easy to be stuck, the structure of the rack 5 is improved as follows in the embodiment: the notch gear 9 is provided with a plurality of saw teeth 901 which are continuously connected with each other, the rack 5 is provided with a positioning tooth 501 and a plurality of transmission teeth 502 which are continuously connected with each other, and the positioning tooth 501 is positioned in front of the running direction of the rack 5 when the refrigerator door opener opens the door; the minimum distance between the driving tooth 502 and the positioning tooth 501 is greater than the maximum distance between two adjacent saw teeth 901.

When the reset position of the rack 5 changes, the first sawtooth 901 and the second sawtooth 901 of the notch gear 9 are sequentially clamped between the positioning tooth 501 and the transmission tooth 502 in the rotation of the notch gear 9 (the larger the minimum distance between the transmission tooth 502 and the positioning tooth 501 is, the more the sawtooth 901 is clamped between the transmission tooth 502 and the positioning tooth 501), then the first sawtooth 901 of the notch gear 9 collides with the positioning tooth 501 and pushes the positioning tooth 501, thereby pushing the rack 5 to move, ensuring that the sawtooth 901 can be accurately clamped between the transmission teeth 502, namely realizing the accurate meshing of the notch gear 9 and the transmission tooth 502, and avoiding the jamming of the notch gear 9 and the rack 5 when the rack 5 is about to be meshed due to the change of the reset position of the rack 5.

Based on the transmission principle of the gear and the rack 5, the pitch line and the pitch circle are always in a tangent relation. As shown in fig. 9, assuming that the minimum distance between the positioning tooth 501 and the transmission tooth 502 closest to the positioning tooth 501 on the pitch line position rack 5 is a, and the maximum distance between two adjacent saw teeth 901 on the notch gear 9 is B, in order to ensure the smooth meshing between the notch gear 9 and the rack 5, 1.5B > a > B. And in order to enable the transmission teeth 502 and the saw teeth 901 to be meshed smoothly, the module of the notch gear 9 and the rack 5 is the same (the module is preferably 1.5-2.5), that is, the notch gear 9 can be meshed with the transmission teeth 502 before the notch gear 9 is disengaged from the positioning teeth 501.

In the description of the present invention, it is to be understood that the terms "central", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In this specification, the schematic representations of the terms are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments.

In light of the foregoing, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A worm loose joint drive mechanism which is characterized in that: the positioning device comprises a positioning block (1), a worm (2), a transmission part (3) and a motor (4), wherein the positioning block (1) is movably connected with the worm (2), and the motor (4), the worm (2) and the transmission part (3) coaxially rotate;

one end of the worm (2) facing the motor (4) is provided with a connecting hole (201), and the transmission piece (3) is positioned between a motor shaft (401) of the motor (4) and a radial gap of the connecting hole (201); and the transmission piece (3) is in interference fit with the motor shaft (401), and the transmission piece (3) is in clearance fit with the connecting hole (201).

2. The worm articulating drive of claim 1, wherein: the positioning block (1) and the worm (2) are connected with the worm shaft (202) in a matched mode through the worm shaft hole (101), and the inner diameter of the worm shaft hole (101) is larger than the outer diameter of the worm shaft (202).

3. The worm articulating drive of claim 1, wherein: the radial inner surface of the transmission piece (3) is a circumferential surface which is in interference fit with the motor shaft (401), and the outer surface of the transmission piece (3) is a non-circular surface.

4. The worm articulating drive of claim 3, wherein: connecting hole (201) include with motor shaft (401) clearance fit's motor shaft hole (2011) and with driving medium (3) clearance fit's die cavity (2012), motor shaft (401) pass driving medium (3) stretch into in the motor shaft hole (2011).

5. A refrigerator door opener characterized in that: the worm loose joint transmission mechanism comprises a shell (6), a gear transmission assembly, a rack (5) and the worm loose joint transmission mechanism as claimed in any one of claims 1 to 4, wherein the positioning block (1) and the motor (4) are fixedly connected with the shell (6), and the motor (4) drives the rack (5) to do linear motion through the gear transmission assembly.

6. The door opening device for a refrigerator according to claim 5, wherein: a buffer pad (11) and a return spring (10) are further arranged inside the shell (6), the buffer pad (11) is fixedly connected with the shell (6), one end of the return spring (10) is connected with the buffer pad (11), and the other end of the return spring is connected with the rack (5);

the gear transmission assembly comprises one or more stages of circular gears meshed in sequence and a notch gear (9) meshed with the last circular gear, when the notch gear (9) is meshed with the rack (5), the notch gear (9) drives the rack (5) to move linearly, and meanwhile, the reset spring (10) extends.

7. The door opening device for a refrigerator according to claim 5, wherein: the shell (6) is provided with a positioning block assembly hole (6011), and the positioning block (1) is provided with a positioning column (102) suitable for being inserted into the positioning block assembly hole (6011).

8. The door opening device for a refrigerator according to claim 6, wherein: a shifting rod (12), a switch spring (13) and a microswitch (14) are further arranged in the shell (6), one end of the switch spring (13) is fixed with the shell (6), the other end of the switch spring (13) is connected with the shifting rod (12), and the middle of the shifting rod (12) is rotatably connected with the shell (6); the switch spring (13) and the notch gear (9) are respectively positioned at two ends of the deflector rod (12);

one end of the notch gear (9) is provided with a notch cylinder (15), the outer surface of the notch cylinder (15) consists of a circumferential surface (1501) and a non-circular surface (1502) which is inwards recessed along the radial direction, when the deflector rod (12) is in contact with the circumferential surface (1501), the switch spring (13) is in a stretching state, and the deflector rod (12) extrudes the microswitch (14); when the shifting rod (12) is in contact with the non-circular surface (1502), the switch spring (13) drives the shifting rod (12) to be separated from the microswitch (14).

9. The door opening device for a refrigerator according to claim 6, wherein: the notched gear (9) is provided with a plurality of continuous saw teeth (901), the rack (5) is provided with a positioning tooth (501) and a plurality of continuous transmission teeth (502), and the positioning tooth (501) is positioned in front of the running direction of the rack (5) when the refrigerator door opener opens the door;

the minimum distance between the transmission teeth (502) and the positioning teeth (501) is larger than the maximum distance between two adjacent saw teeth (901).

10. The door opening device for a refrigerator of claim 9, wherein: and the minimum distance between the positioning teeth (501) and the transmission teeth (502) closest to the positioning teeth (501) is A, and the maximum distance between two adjacent saw teeth (901) is B, so that 1.5B > A > B.