TWM580957U - Direct-connection type eccentric reciprocating exercise rack - Google Patents

Abstract

The invention relates to the technical field of health conditioning bed frame, in particular to a direct-connected eccentric reciprocating motion frame, comprising a chassis, a support frame slidably disposed on the chassis, a driving mechanism for driving the support frame to reciprocate relative to the chassis, and driving The mechanism includes an externally-rotating motor and an eccentric link. The external-rotating motor includes a stator mounted on the chassis, and a rotor that is sleeved on the outer side of the stator. The rotor is provided with an eccentric portion, and one end of the eccentric link is rotatably disposed on the eccentric portion. On the outer side, the other end of the eccentric link is rotatably disposed on the support frame; in actual use, the user lies on the support frame, and the eccentric portion of the rotor of the externally-rotating motor directly drives the support frame to move back and forth relative to the chassis via the eccentric link. Compared with the internal rotation motor, the motor does not need to drive the support frame to reciprocate via a pulley, a belt, etc., simplifying the structural design, reducing the manufacturing cost and improving the performance.

Description

Direct-connected eccentric reciprocating frame

The present invention relates to the field of health conditioning technology, and in particular discloses a direct-connected eccentric reciprocating frame.

At present, in the health industry market, the swaying or moving back and forth by the eccentric rotation of the shaft center generates passive movement to the user's body to achieve automatic conditioning of various organs of the human body.

At present, the transmission mode on the market mainly includes an internal rotation motor, and the rotating shaft of the internal rotation motor is equipped with a pulley, and the pulley drives the frame body to drive through the groove belt; if the motor power is insufficient, a minimum of one bridge is needed in the middle (two Wheel) secondary transmission, this method is more complicated in the manufacturing process, and the cost is relatively high. In the process of using the product, since the groove belt is made of rubber material, it is relatively easy to wear or age, and the multi-stage transmission will also The number of parts that are subject to wear increases, the cost of subsequent after-sales service is relatively high, and the frequency of after-sales service is relatively high, making it difficult to satisfy customers.

The purpose of the present invention is to provide a direct-connected eccentric reciprocating frame. The eccentric portion of the rotor of the external-rotating motor directly moves back and forth relative to the chassis via the eccentric link. Compared with the internal-rotating motor, the motor does not need to be driven by the pulley. The belt and the like drive the carriage to reciprocate, simplifying the structural design, reducing the manufacturing cost and improving the customer experience.

In order to achieve the above object, the direct-connected eccentric reciprocating frame of the present invention comprises a chassis, a support frame slidably disposed on the chassis, a driving mechanism for driving the support frame to reciprocate back and forth with respect to the chassis, and the driving mechanism includes an external rotation type. The motor and the eccentric link, the externally-rotating motor includes a stator mounted on the chassis, and a rotor that is sleeved on the outer side of the stator, and the rotor is provided with an eccentric portion, and one end of the eccentric link is rotatably disposed on the outer side of the eccentric portion, and the eccentric connection The other end of the rod is rotatably disposed on the support frame.

Preferably, the stator comprises a shaft body and a magnetic conductive component mounted on the outer side of the shaft body, the shaft body penetrates the rotor, and two ends of the shaft body are respectively mounted on the chassis; the rotor comprises a rotating drum, an eccentric sleeve and a plurality of magnets The rotating sleeve is sleeved on the outer side of the shaft body, the magnetic conductive component is located in the rotating drum, a plurality of magnets are respectively disposed on the inner side of the rotating drum, and a plurality of magnets are arranged in an annular array around the magnetic conductive component; the eccentric sleeve is detachably connected to the rotating body The tube, the eccentric sleeve is disposed on the outer side of the shaft body, and the eccentric portion is disposed on the eccentric sleeve.

Preferably, the rotor further comprises two end caps, the two end caps are respectively installed at two ends of the rotating cylinder, the end cap is rotatably sleeved on the outer side of the shaft body, and the magnetic conductive component is located between the two end caps. The eccentric sleeve is disposed on a side of the end cover away from the magnetically conductive element.

Preferably, the end cover is provided with a plurality of heat dissipation holes, the heat dissipation holes penetrating through the end cover, and the plurality of heat dissipation holes are disposed around the shaft body, and the heat dissipation holes expose the magnetic conductive component.

Preferably, the direct-connected eccentric reciprocating frame has a plurality of guiding elements, and two ends of the supporting frame are respectively slidably disposed on the chassis via a plurality of guiding elements, and the driving mechanism is located between the plurality of guiding elements. The guiding element comprises a linear rod disposed on the support frame and a plurality of rollers rotatably disposed on the bottom frame, the roller is provided with an arc-shaped guiding groove, the curved guiding groove is disposed around the rotation axis between the roller and the chassis, and the linear rod is located in the plurality of Between the rollers, the curved guide groove is used to accommodate the linear rod.

Preferably, the support frame is provided with a plurality of stop bars, and all the rollers of the same guiding element are located between the plurality of stop bars for blocking the rollers.

Preferably, the lower end of the chassis is provided with a plurality of supporting legs, and the supporting legs comprise a threaded rod screwed to the chassis and a supporting cushion disposed on the threaded rod, and the supporting cushion is used for resisting on the ground.

Preferably, the externally-rotating motor further includes a fixing sleeve and a first bearing, the fixing sleeve is provided with a first blind hole, a second blind hole and a shaft hole, and the first blind hole and the second blind hole are respectively fixed from each other by the fixing sleeve The two sides are recessed, and the shaft hole communicates with the first blind hole and the second blind hole. The shaft hole penetrates the bottom wall of the first blind hole and the bottom wall of the second blind hole, and the shaft body penetrates the fixing sleeve through the shaft hole. The free end of the eccentric sleeve protrudes into the first blind hole, the first bearing sleeve is disposed on the outer side of the shaft body, and the first bearing is received in the second blind hole.

Preferably, the externally-rotating motor further includes a base, the base includes a fixed plate and two support plates disposed on the same side of the fixed plate, the two support plates are disposed in parallel with each other, and the left and right ends of the shaft body are respectively disposed on the two The support plate, the rotor, the magnetic guiding component, the fixing sleeve and the first bearing are all located between the two supporting plates, and the external rotating motor is mounted on the chassis via the fixing plate.

Preferably, the eccentric sleeve has a sleeve portion connected to the eccentric portion, the sleeve portion is disposed on the rotating sleeve, the outer diameter of the sleeve portion is larger than the outer diameter of the eccentric portion, and the outer portion of the eccentric portion is provided with two second portions. One end of the eccentric link is sleeved on the outer side of the two second bearings, and the two second bearings are located between the sleeve portion and the fixed sleeve, and the side of the sleeve portion and the fixed sleeve are respectively used for stopping Two second bearings.

The beneficial effect of the creation: in actual use, the user lies on the support frame and activates the driving mechanism, and the eccentric portion of the rotor of the external rotation motor directly drives the support frame to move back and forth relative to the chassis via the eccentric link, compared to the internal rotation The motor does not require the motor to reciprocate via the pulley, belt or the like to drive the support frame, simplifying the structural design, reducing the manufacturing cost and improving the performance.

In order to facilitate the understanding of those skilled in the art, the present invention will be further described below in conjunction with the embodiments and the accompanying drawings, and the contents mentioned in the embodiments are not intended to limit the present invention. Referring to FIG. 1 to FIG. 3, the direct-connected eccentric reciprocating frame of the present invention comprises a chassis 1 and a support frame 2 slidably disposed at an upper end of the chassis 1 for driving the support frame 2 to reciprocate back and forth with respect to the chassis 1 The driving mechanism of the movement comprises a rotary motor 3 and an eccentric link 4, and the external motor 3 comprises a stator 5 mounted on the chassis 1, and a rotor 6 which is sleeved on the outer side of the stator 5. The rotor 6 is arranged There is an eccentric portion 7, one end of the eccentric link 4 is rotatably sleeved on the outer side of the eccentric portion 7, and the outer side of the eccentric portion 7 is sleeved with a bearing, one end of the eccentric link 4 is sleeved on the outer side of the bearing, and the eccentric link 4 is another One end is rotatably disposed on the support frame 2. In this embodiment, the support frame 2 is provided with a connecting member (not labeled), and the other end of the eccentric link 4 is rotatably disposed via the rotating shaft and the free end of the connecting member.

In actual use, the user lies on the support frame 2 and activates the drive mechanism. The eccentric portion 7 of the rotor 6 of the externally-rotating motor 3 directly drives the support frame 2 to move back and forth relative to the chassis 1 via the eccentric link 4 to reach the motion frame. The effect of shaking and moving forward and backward is that the motor does not need to drive the support frame 2 to reciprocate via a pulley, a belt, etc., which simplifies the structural design, reduces the manufacturing cost, and improves the performance. At the same power, the externally-rotating motor 3 can save at least 30% in cost compared with the internal-rotating motor, and the motor consumes less energy, saving the multi-stage transmission mechanism required for the internal-turning motor, and the risk of product failure rate. It is also much lower, it is relatively simple to manufacture, and the manufacturing cost is also low.

The stator 5 includes a shaft body 8 and a magnetic conductive component disposed outside the shaft body 8. The shaft body 8 extends through the rotor 6. The two ends of the shaft body 8 respectively protrude from the two ends of the rotor 6, and the shaft body 8 protrudes. The two ends of the rotor 6 are respectively mounted on the chassis 1; the rotor 6 includes a rotating drum 9, an eccentric sleeve 11 and a plurality of magnets, and the rotating sleeve 9 is rotatably sleeved on the outer side of the shaft body 8, and the magnetic conductive component is located in the rotating cylinder 9. A plurality of magnets are respectively disposed on the inner side of the rotating drum 9, and a plurality of magnets are arranged in an annular array around the magnetic conductive component; the eccentric sleeve 11 is detachably connected to the rotating cylinder 9, and the eccentric sleeve 11 is sleeved on the outer side of the shaft body 8, eccentric The portion 7 is disposed on the eccentric sleeve 11. In actual use, the stator 5 is energized, and under the action of the magnetic conductive component and the plurality of magnets, the drum 9 rotates around the stator 5, and the eccentric sleeve 11 rotates when the drum 9 rotates, and the eccentric sleeve 11 can be eccentrically connected when rotated. The rod 4 drives the support frame 2 to move back and forth relative to the chassis 1.

The rotor 6 further includes two end caps 12, and the two end caps 12 are respectively mounted on the two ends of the rotating cylinder 9, and the end cap 12 is rotatably sleeved on the outer side of the shaft body 8. In this embodiment, the end cap 12 The shaft is placed on the shaft body 8 via a bearing, and the magnetic conductive element is located between the two end covers 12, and the eccentric sleeve 11 is mounted on a side of the end cover 12 away from the magnetic conductive element. One of the end caps 12 of the externally-rotating motor 3 is coupled to the eccentric sleeve 11 for synchronous rotation, and the shaft body 8 of the stator 5 of the externally-rotating motor 3 extends through the eccentric sleeve 11 and is fixed to the chassis 1.

The end cover 12 is provided with a plurality of heat dissipation holes 13 through which the heat dissipation holes 13 are disposed. The plurality of heat dissipation holes 13 are disposed around the shaft body 8. Preferably, the plurality of heat dissipation holes 13 are arranged in an annular array around the shaft body 8. The quality distribution of the cover 12 is substantially evenly arranged. During the rotation of the end cover 12, the moment of inertia of the end cover 12 is lowered to ensure the smoothness of the rotation of the end cover 12; the heat dissipation holes 13 expose the magnetic conductive elements, so that the stator 5 and the rotor 6 are relatively The heat generated when rotating is diffused out through the heat dissipation holes 13, and the heat dissipation efficiency of the externally-rotating motor 3 is improved.

Referring to FIG. 1 to FIG. 4 , the direct-connected eccentric reciprocating frame has a plurality of guiding elements 14 . The two ends of the supporting frame 2 are respectively slidably disposed on the chassis 1 via a plurality of guiding assemblies 14 and driven. The mechanism is located between the plurality of guiding elements 14, the guiding element 14 comprises a linear rod 15 disposed on the support frame 2, and a plurality of rollers 16 disposed on the chassis 1, the linear rod 15 is substantially a strip-shaped cylinder, and the roller 16 is provided with a curved guide groove 17 which is arranged around the rotation axis between the roller 16 and the chassis 1, and the linear rod 15 is located between the plurality of rollers 16, and the bottom rod 15 and the roller 16 are added to the bottom. The sliding friction between the frame 1 and the support frame 2 is converted into rolling friction between the linear rod 15 and the roller 16, and the curved guide groove 17 is used to accommodate the linear rod 15, and the linear rod is blocked by the side wall of the curved guide groove 17. 15. The linear rod 15 is prevented from falling off the roller 16. Preferably, the arcuate channel 17 is annular and the arcuate channel 17 is disposed about the central axis of the roller 16.

The support frame 2 is provided with a plurality of stop bars 18, and all the rollers 16 of the same guide assembly 14 are located between the plurality of stop bars 18 for blocking the rollers 16. During the movement of the support frame 2 relative to the chassis 1, the stop bars 18 are used to block the rollers 16 and thereby limit the travel of the support frame 2.

The bottom end of the chassis 1 is provided with a plurality of supporting legs 19, and the supporting legs 19 include a threaded rod 21 screwed on the chassis 1 and a supporting cushion 22 disposed on the threaded rod 21, and the supporting cushion 22 is used for resisting On the ground, the support cushion 22 is used to absorb the impact of the chassis 1 on the ground. In actual use, the threaded rod 21 is rotated according to the unevenness of the ground, thereby adjusting the height of the support leg 19, so that the chassis 1 can be stably placed on the ground.

Referring to FIG. 1 to FIG. 5, the externally-rotating motor further includes a fixing sleeve 23 and a first bearing 24. The fixing sleeve 23 is provided with a first blind hole 25, a second blind hole 26 and a shaft hole 27, A blind hole 25 and a second blind hole 26 are respectively recessed from the outer surfaces of the two ends of the fixing sleeve 23 away from each other, and the shaft hole 27 communicates with the first blind hole 25 and the second blind hole 26, the center line of the shaft hole 27, The center line of the first blind hole 25 and the center line of the second blind hole 26 are arranged in a line, the aperture of the first blind hole 25 is larger than the aperture of the shaft hole 27, and the aperture of the second blind hole 26 is larger than the aperture of the shaft hole 27, the axis The hole 27 extends through the bottom wall of the first blind hole 25 and the bottom wall of the second blind hole 26. The shaft body 8 penetrates the fixing sleeve 23 via the shaft hole 27, and the free end of the eccentric sleeve 11 (ie, the eccentric portion 7 of the eccentric sleeve 11) protrudes. The first blind hole 25 is disposed in the first blind hole 25, and the bottom wall of the first blind hole 25 is used to block the eccentric portion 7. The first bearing 24 is sleeved on the outer side of the shaft body 8, and the first bearing 24 is received in the second blind hole 26. The bottom wall of the second blind hole 26 serves to block the first bearing 24.

The externally-rotated motor further includes a base 28 including a fixed plate 29 and two support plates 31 disposed on the same side of the fixed plate 29. The fixed plate 29 and the support plate 31 are each substantially rectangular and two support plates. 31 are respectively disposed at the upper end of the fixed plate 29, the two support plates 31 are spaced apart from each other and arranged in parallel, and the left and right ends of the shaft body 8 are respectively disposed on the two support plates 31, the rotor 6, the magnetic conductive component, the fixed sleeve 23, A bearing 24 is located between the two support plates 31, and the externally-rotating motor is mounted on the chassis 1 via the fixing plate 29; in the assembly process of the direct-connected eccentric reciprocating frame, the externally-rotating motor and the eccentric link 4 and the base 28 is first assembled to form a single piece, and then the single piece can be mounted and fixed on the chassis 1 through the fixing plate 29 once, when one or a few components of the single piece are damaged, directly The entire single unit can be removed and a new single piece can be replaced to reduce the after-sales maintenance cost of the direct-connected eccentric reciprocating frame.

The eccentric sleeve 11 has a sleeve portion 32 connected to the eccentric portion 7, and the sleeve portion 32 is disposed on the drum 9, the outer diameter of the sleeve portion 32 is larger than the outer diameter of the eccentric portion 7, and the eccentric portion 7 is from the sleeve portion 32 is integrally formed, and the outer side of the eccentric portion 7 is sleeved with two second bearings 33. Preferably, two second bearings 33 are respectively located at the left and right ends of the eccentric portion 7, and one end of the eccentric link 4 is sleeved at The outer side of the two second bearings 33, the two second bearings 33 are located between the sleeve portion 32 and the fixing sleeve 23, and the side of the sleeve portion 32 and the fixing sleeve 23 are respectively used to block the two second portions. The bearing 33 limits the second bearing 33 by the sleeve portion 32 and the fixing sleeve 23, and prevents the second bearing 33 from moving in the axial direction of the eccentric portion, so that the eccentric link cannot be accurately engaged with the second bearing 33.

The eccentric sleeve 11 further includes a protruding portion (not shown) connected to the sleeve portion 32. The protruding portion and the eccentric portion 7 are respectively located on the left and right sides of the sleeve portion 32, and the protruding portion is used for protruding In the shaft hole (not labeled) of the end cover 12, during the assembly process, the stud portion is first inserted into the shaft hole of the end cover 12, and then the end cover 12 and the eccentric sleeve 11 are fixed by the screw member or the like. Together, the end caps 12 that are fixed together are then sleeved with the eccentric sleeve 11 on the outside of the shaft body 8.

In this embodiment, the eccentric sleeve 11 further has a concentric portion 34 connected to the eccentric portion 7. The outer diameter of the eccentric portion 7 is larger than the outer diameter of the concentric portion 34, and the sleeve portion 32 and the concentric portion 34 are respectively connected to the eccentric portion 7. On the left and right ends, during the assembly of the eccentric sleeve 11 and the fixing sleeve 23, the concentric portion 34 is inserted into the first blind hole 25, and the end surface of the eccentric portion 7 near one end of the concentric portion 34 is in contact with the outer surface of the fixing sleeve 23. The eccentric sleeve 11 is prevented from being over-inserted into the first blind hole 25, ensuring quick and accurate assembly of the eccentric sleeve 11 and the fixing sleeve 23, thereby improving assembly efficiency of both.

The first blind hole 25 at one end of the fixing sleeve 23 is engaged with the concentric portion 34 of the eccentric sleeve 11, and the second blind hole 26 at the other end of the fixing sleeve 23 is matched with the first bearing 24 sleeved outside the shaft body 8. The first bearing 24 and the shaft body 8 are tightly engaged, that is, the inner ring of the first bearing 24 and the shaft body 8 are not rotated relative to each other, and the shaft body 8 and the side wall of the inner hole of the eccentric sleeve 11 have a gap therebetween. That is, the outer surface of the shaft body 8 does not contact the eccentric sleeve 11, and the eccentric sleeve 11 rotates together with the drum 9 of the rotor 6 of the externally-rotating motor, so that the eccentric sleeve 11 and the shaft body 8 are prevented from being worn by direct contact.

The above content is only a preferred embodiment of the present invention. For those skilled in the art, depending on the idea of the present invention, there will be changes in the specific implementation manner and the scope of application, and the contents of this specification should not be construed as being limits.

1‧‧‧ Chassis

2‧‧‧Support frame

3‧‧‧External motor

4‧‧‧Eccentric connecting rod

5‧‧‧ Stator

6‧‧‧Rotor

7‧‧‧Eccentric

8‧‧‧Axis

9‧‧‧ reel

11‧‧‧Eccentric sleeve

12‧‧‧End cover

13‧‧‧ vents

14‧‧‧Guide elements

15‧‧‧Line rod

16‧‧‧Roller

17‧‧‧Shave guides

18‧‧‧stop rod

19‧‧‧Support feet

21‧‧‧Threaded rod

22‧‧‧Support cushion

23‧‧‧ fixed set

24‧‧‧First bearing

25‧‧‧First blind hole

26‧‧‧Second blind hole

27‧‧‧Axis hole

28‧‧‧Base

29‧‧‧Fixed plate

31‧‧‧Support board

32‧‧‧Settings

33‧‧‧second bearing

34‧‧‧Concentric

1 is a schematic perspective view of the creation of the present invention; FIG. 2 is a schematic perspective view of the externally-rotated motor, the eccentric link and the base of the present invention; FIG. 3 is an exploded structure of the externally-rotating motor, the eccentric link and the base of the present invention. Figure 4 is a partially enlarged schematic view of a portion A of Figure 1; Figure 5 is a schematic perspective view of the fixed sleeve of the present invention.

Claims (10)

A direct-connecting eccentric reciprocating frame comprises a chassis, a support frame slidably disposed on the chassis, a driving mechanism for driving the support frame to reciprocate back and forth with respect to the chassis, and the driving mechanism comprises an external rotating motor and an eccentric link The externally-rotating motor includes a stator mounted on the chassis, and a rotor that is sleeved on the outer side of the stator. The rotor is provided with an eccentric portion. One end of the eccentric link is rotatably sleeved on the outer side of the eccentric portion, and the other end of the eccentric link is rotated. Set on the support frame. The direct-connected eccentric reciprocating frame according to claim 1, wherein the stator comprises a shaft body and a magnetic conductive component mounted on the outer side of the shaft body, the shaft body penetrates the rotor, and the two ends of the shaft body are respectively mounted The rotor comprises a rotating drum, an eccentric sleeve and a plurality of magnets, the rotating sleeve is sleeved on the outer side of the shaft body, the magnetic conductive component is located in the rotating cylinder, and the plurality of magnets are respectively disposed on the inner side of the rotating cylinder, and the plurality of magnets are respectively disposed. The eccentric sleeve is detachably connected to the rotating cylinder, the eccentric sleeve is disposed on the outer side of the shaft body, and the eccentric portion is disposed on the eccentric sleeve. The direct-connected eccentric reciprocating frame of claim 2, wherein the rotor further comprises two end caps, and the two end caps are respectively installed at two ends of the drum, and the end cap is rotatably sleeved on On the outer side of the shaft body, the magnetic guiding element is located between the two end covers, and the eccentric set is disposed on a side of the end cover away from the magnetic conductive element. The direct-connected eccentric reciprocating frame according to claim 3, wherein the end cover is provided with a plurality of heat dissipation holes, the heat dissipation holes are penetrated through the end cover, and the plurality of heat dissipation holes are disposed around the shaft body, and the heat dissipation holes are exposed. Magnetic components. The direct-connected eccentric reciprocating frame according to claim 1, wherein the direct-connected eccentric reciprocating frame has a plurality of guiding elements, and two ends of the supporting frame are respectively slidably arranged via a plurality of guiding elements In the chassis, the driving mechanism is located between the plurality of guiding elements, the guiding element comprises a linear rod disposed on the support frame, and a plurality of rollers rotatably disposed on the chassis, the roller is provided with an arc-shaped guiding groove, and the curved guiding groove surrounds The axis of rotation between the roller and the chassis is arranged, the linear rod is located between the plurality of rollers, and the curved guide groove is used for accommodating the linear rod. The direct-connecting eccentric reciprocating frame according to claim 5, wherein the support frame is provided with a plurality of stop bars, and all the rollers of the same guiding element are located between the plurality of stop bars, The rod is used to block the roller. The direct-connected eccentric reciprocating frame according to claim 1, wherein the bottom end of the chassis is provided with a plurality of supporting legs, and the supporting legs comprise a threaded rod screwed to the chassis and a threaded rod. The support cushion is used to support the cushion on the ground. The direct-connecting eccentric reciprocating frame according to the second aspect of the invention, wherein the externally-rotating motor further comprises a fixing sleeve and a first bearing, wherein the fixing sleeve is provided with a first blind hole, a second blind hole and a shaft The first blind hole and the second blind hole are respectively recessed from two sides away from the fixing sleeve, and the shaft hole communicates with the first blind hole and the second blind hole, and the shaft hole penetrates the bottom wall of the first blind hole and the second hole The bottom wall of the two blind holes, the shaft body penetrates the fixing sleeve through the shaft hole, and the free end of the eccentric sleeve protrudes into the first blind hole, the first bearing sleeve is disposed on the outer side of the shaft body, and the first bearing is accommodated in the second blind Inside the hole. The direct-connecting eccentric reciprocating frame according to claim 8, wherein the external-rotating motor further comprises a base, the base comprises a fixing plate and two supporting plates disposed on the same side of the fixing plate, and two supports The plates are arranged parallel to each other, and the left and right ends of the shaft body are respectively disposed on the two support plates, and the rotor, the magnetic conductive component, the fixed sleeve and the first bearing are respectively located between the two support plates, and the externally-rotating motor is installed on the fixed plate via the fixed plate Chassis. The direct-connected eccentric reciprocating frame according to claim 8, wherein the eccentric sleeve has a sleeve portion connected to the eccentric portion, and the sleeve portion is disposed on the rotating sleeve, and the outer diameter of the sleeve portion is larger than the eccentricity The outer diameter of the portion, the outer side of the eccentric portion is sleeved with two second bearings, one end of the eccentric link is sleeved on the outer side of the two second bearings, and the two second bearings are located between the sleeve portion and the fixed sleeve. The side of the sleeve portion and the fixing sleeve that are close to each other are used to block the two second bearings, respectively.