CN114471969B

CN114471969B - Vibration damping centrifuge

Info

Publication number: CN114471969B
Application number: CN202210308832.4A
Authority: CN
Inventors: 喻文; 徐昌平; 李前程
Original assignee: Changsha Yingtai Instrument Co ltd
Current assignee: Changsha Yingtai Instrument Co ltd
Priority date: 2022-03-28
Filing date: 2022-03-28
Publication date: 2024-02-13
Anticipated expiration: 2042-03-28
Also published as: CN114471969A

Abstract

The invention discloses a vibration damping centrifuge, which comprises a support base, wherein the support base is connected with an outer shell through a plurality of first support rods, a centrifugal motor is fixedly connected to the support base, the output end of the centrifugal motor is fixedly connected with a coupler, the upper end of the coupler is fixedly connected with a first rotating shaft extending into the outer shell, the first rotating shaft is connected with an inner shell arranged in the outer shell through a rotating unit, a support unit is matched between the outer shell and the inner shell, a connecting plate is fixedly connected to the support base, an air cylinder is fixedly connected to the connecting plate, the output end of the air cylinder is fixedly connected with an upper cover, the inner shell and the outer shell are connected through the connecting unit, the centrifugal motor rotates to drive the first rotating shaft to rotate, the first rotating shaft rotates to drive a rotating plate to rotate under the action of a pawl and a torsion spring, and then the inner shell is driven to rotate, and further centrifugal operation is carried out.

Description

Vibration damping centrifuge

Technical Field

The invention relates to the technical field of centrifuges, in particular to a vibration damping centrifuge.

Background

The centrifugal machine is a machine for separating each component in liquid and solid particles or a mixture of liquid and liquid by utilizing centrifugal force, and is mainly used for separating solid particles from liquid in suspension or separating two liquids with different densities and mutual incompatibility in emulsion (such as cream separated from milk); it can also be used to remove liquids from wet solids, such as drying wet clothing with a washing machine; the special overspeed tube separator can also separate gas mixtures with different densities; by utilizing the characteristic that the sedimentation speeds of solid particles with different densities or particle sizes in liquid are different, some sedimentation centrifuges can also grade the solid particles according to the densities or particle sizes; the applicant searches and finds a Chinese patent with the name of vibration reduction chemical centrifuge, the patent publication number is CN109604073A, and the turntable seat is driven to rotate by the first servo motor, so that the material mixture is subjected to centrifugal operation; the rotating shaft is fixed, so that the rotating shaft can rotate stably; the height of the top plate can be adjusted through the first electric telescopic rod, so that the sealing operation of the outer shell is facilitated; the second servo motor can drive the circular plate and the scraping plate to rotate, so that the mixture is convenient to stir, and the mixture is uniformly distributed; plays a role in stabilizing the motor base; the height of the circular plate can be adjusted through the second electric telescopic rod, so that the uniform distribution of materials is facilitated; the whole vibration reduction chemical centrifuge can stir the upper end of the mixture, is convenient for the uniform distribution of the mixture, can reduce the vibration generated during the operation of the centrifuge and reduce the energy consumption; however, there are some drawbacks in use, in which the top plate is adjusted in height by the first electric telescopic rod to achieve the purpose of stirring the mixture, a gap is formed between the top plate and the inner and outer shells, the sealing degree is not good enough, so that the mixture is leaked in the centrifuging process, and in addition, the inner shell is not rotated by rotating the turntable during centrifuging, so that the centrifuging effect is not good enough.

Disclosure of Invention

The invention aims to provide a vibration damping centrifuge, which solves the following technical problems:

firstly, it carries out the high regulation to the roof through first electric telescopic handle in order to reach the purpose of stirring the mixture, can have the clearance between roof and inner housing and the shell body, can appear that the leakproofness is not enough good to the problem that the mixture was revealed appears in the in-process of centrifugation, still another, during the centrifugation, the rotation through the carousel drives the mixture and rotates and carry out the centrifugation, and the inner housing itself does not rotate, can lead to appearing the not enough problem of centrifugal effect like this.

The aim of the invention can be achieved by the following technical scheme:

the utility model provides a vibration damping centrifuge, includes the support base, support and be connected with the outside casing through a plurality of first bracing pieces on the base, fixedly connected with centrifugal motor on the support base, centrifugal motor's output fixedly connected with shaft coupling, the upper end fixedly connected with of shaft coupling stretches into the inside first pivot of outside casing, first pivot passes through the inside casing connection that sets up in rotation unit and the outside casing, the cooperation is provided with the supporting element between outside casing and the inside casing, still fixedly connected with connection plate on the support base, fixedly connected with cylinder on the connection plate, the output fixedly connected with upper cover of cylinder, be connected through the connecting element between upper cover and inside casing and the outside casing.

As a further scheme of the invention: the side of inside casing has seted up first joint groove, sliding connection has ejection of compact annular plate in the first joint groove, the side fixedly connected with joint of ejection of compact annular plate is protruding in first joint inslot, the side of inside casing has seted up with ejection of compact annular plate complex discharge hole, ejection of compact annular plate passes through the rubber elasticity layer and is connected with outside casing, be provided with the discharge gate with the rubber elasticity layer intercommunication on the outside casing, be provided with control valve on the discharge gate.

As a further scheme of the invention: the rotating unit comprises a rotating outer ring fixedly connected with the lower end of an inner shell, the lower end of the rotating outer ring is connected with the outer shell through a bearing, a plurality of rotating plates distributed in a circumferential array are fixedly connected to the side face of a first rotating shaft, a plurality of first connecting plates matched with the rotating plates and distributed in a circumferential array are fixedly connected to the inner side of the rotating outer ring, a plurality of pawls are rotatably connected to the end parts of the first connecting plates, and torsion springs are arranged on the rotating shaft at the joint of the pawls and the first connecting plates.

As a further scheme of the invention: the connecting unit comprises a first annular connecting groove and a second annular connecting groove which are respectively matched with the outer shell and the inner shell and are formed in an upper cover, the first annular connecting groove is internally connected with a second connecting plate through a plurality of first springs used for providing elasticity, two first connecting rings are fixedly connected onto the second connecting plate, sealing gaskets are connected between the first connecting rings, the second annular connecting groove is internally connected with a second connecting ring through a plurality of second springs used for providing elasticity, a third annular connecting groove matched with the inner shell is formed in the second connecting ring, and a plurality of first balls in contact with the side surfaces of the inner shell are rotationally connected onto the inner wall of the third annular connecting groove.

As a further scheme of the invention: the supporting unit comprises a plurality of supporting curved plates distributed in a circumferential array, the side faces of the supporting curved plates are connected with the side wall of the outer shell through third springs for providing elastic force, and the inner sides of the supporting curved plates are rotationally connected with a plurality of second balls in contact with the side faces of the inner shell.

As a further scheme of the invention: and a stirring unit is also matched between the upper cover and the inner shell.

As a further scheme of the invention: the stirring unit comprises a stirring main board, the stirring main board is connected with an upper cover through a supporting component, the lower end of the stirring main board is fixedly connected with a plurality of first stirring rods distributed in a circumferential array, the center of the lower end of the stirring main board is fixedly connected with a rotating shaft, the first rotating shaft stretches into the inner part of the inner shell, the side face of the first rotating shaft is fixedly connected with a first stirring board, the first stirring board is fixedly connected with a plurality of second stirring rods distributed in an array, the upper end of the first rotating shaft is in a regular pentagonal structure, and the lower end of the rotating shaft is provided with a polygonal connecting groove matched with the first rotating shaft.

As a further scheme of the invention: the supporting component comprises a second clamping groove which is formed in the upper cover and matched with the stirring main board, a fourth annular connecting groove is formed in the side face of the stirring main board, a plurality of second supporting rods which are distributed in an array mode are fixedly connected in the upper cover, the upper ends of the second supporting rods are all rotationally connected with first supporting wheels, the first supporting wheels are in rolling contact with the lower end face of the stirring main board, a plurality of gas springs which are used for providing elasticity are fixedly connected to the side wall of the second clamping groove, the end portions of the gas springs are all rotationally connected with second supporting wheels, and the second supporting wheels are in rolling contact with the side wall of the fourth annular connecting groove.

The invention has the beneficial effects that:

(1) Through the setting of rotating the unit, centrifugal motor rotates and drives first pivot and rotates rather than the axis of rotation of joint, at this moment, stirring mainboard rotates, first puddler rotates, the second puddler rotates, carry out centrifugal stirring to the mixture in the inside casing, the pawl is inoperative at this moment, can not drive the rotation of rotating the board, can not drive and rotate the outer ring and rotate, when centrifugal motor counter-rotating, stirring mainboard rotates, first puddler rotates, second puddler rotates, carry out centrifugal stirring to the mixture in the inside casing, at the same time, under the effect of pawl and torsional spring, first pivot rotates and drives the rotation board and rotates, rotate the outer ring and rotate, then drive the inside casing and rotate, further carry out centrifugal operation;

(2) Through the setting of connecting unit, the sealed pad that sets up between first go-between and it is contacted with the up end of outside casing, seals, and the third annular spread groove that sets up on the go-between is through first ball and inside casing contact, further seals, prevents from appearing the gap between inside casing and the outside casing from this, can not appear the condition that the mixture was revealed.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic view of the overall structure of a vibration damping centrifuge of the present invention;

FIG. 2 is an enlarged schematic view of the structure of FIG. 1 at A;

FIG. 3 is a schematic view showing a part of the structure of a rotating unit of the vibration-damping centrifuge of the present invention;

FIG. 4 is a schematic view of the structure of the vibration-damping centrifuge according to the present invention in which a first shaft is connected to a rotating shaft;

FIG. 5 is a schematic view showing a part of the structure of a stirring unit in the vibration-damping centrifuge of the present invention;

FIG. 6 is a schematic view of the structure of a second ball on a support curve in a vibration canceling centrifuge according to the present invention;

FIG. 7 is a schematic cross-sectional view of the upper cover of the vibration-damping centrifuge of the present invention;

fig. 8 is an enlarged schematic view of the structure at B in fig. 7.

In the figure: 1. a support base; 2. a first support bar; 3. an outer housing; 4. a centrifugal motor; 5. a coupling; 6. a first rotating shaft; 7. a connecting plate; 8. a cylinder; 9. an upper cover; 10. a first clamping groove; 11. a discharging annular plate; 12. the clamping bulge; 14. a rubber elastic layer; 15. a discharge port; 16. a control valve; 171. rotating the outer ring; 172. a bearing; 173. a rotating plate; 174. a first connection plate; 175. a pawl; 176. a torsion spring; 181. a first annular connecting groove; 182. a second annular connecting groove; 183. a first spring; 184. a second connecting plate; 185. a first connection ring; 186. a sealing gasket; 187. a second spring; 188. a second connecting ring; 189. a third annular connecting groove; 190. a first ball; 201. supporting the curved plate; 202. a third spring; 203. a second ball; 211. stirring a main board; 212. a first stirring rod; 213. a rotating shaft; 214. a first stirring plate; 215. a second stirring rod; 216. polygonal connecting grooves; 221. a second clamping groove; 222. a fourth annular connecting groove; 223. a second support bar; 224. a first support wheel; 225. a gas spring; 226. a second support wheel; 23. an inner housing.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Referring to fig. 1-8, the present invention is a vibration damping centrifuge, including a support base 1, wherein an outer casing 3 is connected to the support base 1 through a plurality of first support rods 2, a centrifugal motor 4 is fixedly connected to the support base 1, an output end of the centrifugal motor 4 is fixedly connected to a coupling 5, an upper end of the coupling 5 is fixedly connected to a first rotating shaft 6 extending into the outer casing 3, the first rotating shaft 6 is connected to an inner casing 23 disposed in the outer casing 3 through a rotating unit, a supporting unit is cooperatively disposed between the outer casing 3 and the inner casing 23, a connecting plate 7 is fixedly connected to the support base 1, a cylinder 8 is fixedly connected to the connecting plate 7, an output end of the cylinder 8 is fixedly connected to an upper cover 9, and the upper cover 9 is connected to the inner casing 23 and the outer casing 3 through a connecting unit.

The side of inside casing 23 has seted up first joint groove 10, and sliding connection has ejection of compact annular plate 11 in the first joint groove 10, and the side fixedly connected with joint of ejection of compact annular plate 11 is protruding 12 in first joint groove 10, and the discharge hole with ejection of compact annular plate 11 complex is seted up to the side of inside casing 23, and ejection of compact annular plate 11 passes through rubber elasticity layer 14 and is connected with outside casing 3, is provided with discharge gate 15 on the outside casing 3, is provided with control valve 16 on the discharge gate 15.

When the device is actually used, the mixture is placed in the inner shell 23, then the rotation unit is started to drive the inner shell 23 to rotate, the mixture in the rotation unit is subjected to centrifugal operation, the support unit supports the inner shell 23, the adverse effect caused by vibration during centrifugation is reduced, the connection unit ensures stable connection between the upper cover 9 and the inner shell 23 and the outer shell 3, the problem that the mixture is leaked during centrifugation is avoided, and products after the centrifugation are output through the discharge port 15.

Example 2

Referring to fig. 3 and 5, the rotating unit includes a rotating outer ring 171 fixedly connected to the lower end of the inner housing 23, the lower end of the rotating outer ring 171 is connected to the outer housing 3 through a bearing 172, a plurality of rotating plates 173 distributed in a circumferential array are fixedly connected to the side of the first rotating shaft 6, a plurality of first connecting plates 174 distributed in a circumferential array and engaged with the rotating plates 173 are fixedly connected to the inner side of the rotating outer ring 171, pawls 175 are rotatably connected to the ends of the plurality of first connecting plates 174, and torsion springs 176 are provided on the rotating shaft at the junction of the pawls 175 and the first connecting plates 174.

A stirring unit is also provided between the upper cover 9 and the inner housing 23.

The stirring unit includes stirring mainboard 211, stirring mainboard 211 passes through supporting component and upper cover 9 is connected, the lower extreme fixedly connected with of stirring mainboard 211 a plurality of circumference array distribution's first puddler 212, the lower extreme central point of stirring mainboard 211 puts still fixedly connected with axis of rotation 213, first pivot 6 stretches into the inside of inside casing 23, the first stirring board 214 of side fixedly connected with of first pivot 6, fixedly connected with a plurality of array distribution's second puddler 215 on the first stirring board 214, the upper end of first pivot 6 sets up to regular pentagon structure, the polygon spread groove 216 with first pivot 6 complex is seted up to the lower extreme of axis of rotation 213.

When the above rotating unit and stirring unit are actually used, the centrifugal motor 4 rotates to drive the first rotating shaft 6 to rotate and drive the rotating shaft 213 clamped with the first rotating shaft to rotate, at this time, the stirring main plate 211 rotates, the first stirring rod 212 rotates, the second stirring rod 215 rotates to centrifugally stir the mixture in the inner shell 23, at this time, the pawl 175 does not act, the rotating plate 173 cannot be driven to rotate, the rotating outer ring 171 cannot be driven to rotate, when the centrifugal motor 4 reversely rotates, the stirring main plate 211 rotates, the first stirring rod 212 rotates, the second stirring rod 215 rotates to centrifugally stir the mixture in the inner shell 23, and at the same time, the first rotating shaft 6 rotates to drive the rotating plate 173 to rotate under the action of the pawl 175 and the torsion spring 176, the rotating outer ring 171 rotates to further drive the inner shell 23 to rotate, and further centrifugal operation is performed.

Example 3

Referring to fig. 7 and 8, the connection unit includes a first annular connection groove 181 and a second annular connection groove 182 formed in the upper cover 9 to be engaged with the outer case 3 and the inner case 23, respectively, the first annular connection groove 181 is connected to the second connection plate 184 through a plurality of first springs 183 for providing elastic force, the second connection plate 184 is fixedly connected to two first connection rings 185, a gasket 186 is connected between the two first connection rings 185, the second annular connection groove 182 is connected to a second connection ring 188 through a plurality of second springs 187 for providing elastic force, a third annular connection groove 189 engaged with the inner case 23 is formed in the second connection ring 188, and a plurality of first balls 190 contacting with the side surface of the inner case 23 are rotatably connected to the inner wall of the third annular connection groove 189.

When the above-mentioned connection unit is in actual use, the first connection ring 185 and the sealing pad 186 disposed therebetween are in contact with the upper end surface of the outer housing 3 to seal, and the third annular connection groove 189 disposed on the second connection ring 188 is in contact with the inner housing 23 via the first ball 190 to further seal, thereby preventing a gap from occurring between the inner housing 23 and the outer housing 3 and preventing leakage of the mixture.

Example 4

Referring to fig. 1 and 6, the support unit includes a plurality of support curved plates 201 distributed in an array, the side surfaces of the plurality of support curved plates 201 are connected to the side wall of the outer housing 3 by third springs 202 for providing elastic force, and a plurality of second balls 203 contacting the side surfaces of the inner housing 23 are rotatably connected to the inner sides of the plurality of support curved plates 201.

The supporting curved plate 201 is supported by the contact of the second ball 203 with the sidewall of the inner housing 23 by the elastic force of the third spring 202, preventing vibration.

Example 5

Referring to fig. 8, the supporting assembly includes a second clamping groove 221 formed in the upper cover 9 and matched with the stirring main board 211, a fourth annular connecting groove 222 is formed in a side surface of the stirring main board 211, a plurality of second supporting rods 223 distributed in an array are fixedly connected in the upper cover 9, the upper ends of the plurality of second supporting rods 223 are rotatably connected with first supporting wheels 224, the first supporting wheels 224 are in rolling contact with the lower end surface of the stirring main board 211, a plurality of gas springs 225 for providing elasticity are fixedly connected to the side wall of the second clamping groove 221, the end parts of the plurality of gas springs 225 are rotatably connected with second supporting wheels 226, and the second supporting wheels 226 are in rolling contact with the side wall of the fourth annular connecting groove 222.

When the support assembly is actually used, the first support wheel 224 and the second support wheel 226 support the side surface of the stirring main board 211, and under the action of the gas spring 225, adverse effects caused by vibration during centrifugation can be effectively prevented.

The working principle of the invention is as follows: placing the mixture into the inner shell 23, starting the rotating unit to drive the inner shell 23 to rotate, centrifuging the mixture in the rotating unit, supporting the inner shell 23 by the supporting unit, reducing the adverse effect of vibration during centrifugation, ensuring stable connection between the upper cover 9 and the inner shell 23 and the outer shell 3 by the connecting unit, ensuring that the problem of mixture leakage cannot occur during centrifugation, and outputting the centrifuged product through the discharge hole 15; the centrifugal motor 4 rotates to drive the first rotating shaft 6 to rotate and drive the rotating shaft 213 clamped with the first rotating shaft 6 to rotate, at the moment, the stirring main plate 211 rotates, the first stirring rod 212 rotates, the second stirring rod 215 rotates to centrifugally stir the mixture in the inner shell 23, at the moment, the pawl 175 does not act and can not drive the rotating plate 173 to rotate, the rotating outer ring 171 is not driven to rotate, when the centrifugal motor 4 reversely rotates, the stirring main plate 211 rotates, the first stirring rod 212 rotates, the second stirring rod 215 rotates to centrifugally stir the mixture in the inner shell 23, and at the same time, the first rotating shaft 6 rotates to drive the rotating plate 173 to rotate and the rotating outer ring 171 to rotate under the action of the pawl 175 and the torsion spring 176, and then the inner shell 23 is driven to rotate for further centrifugal operation; the first connection ring 185 and the gasket 186 provided therebetween are in contact with the upper end surface of the outer housing 3 to seal, and the third annular connection groove 189 provided on the second connection ring 188 is in contact with the inner housing 23 via the first balls 190 to further seal, thereby preventing the occurrence of a gap between the inner housing 23 and the outer housing 3 without the occurrence of leakage of the mixture.

The foregoing describes one embodiment of the present invention in detail, but the disclosure is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. All equivalent changes and modifications within the scope of the present invention are intended to be covered by the present invention.

Claims

1. The utility model provides a vibration damping centrifuge, includes support base (1), its characterized in that, be connected with outside casing (3) on support base (1) through a plurality of first bracing pieces (2), fixedly connected with centrifugal motor (4) on support base (1), the output fixedly connected with shaft coupling (5) of centrifugal motor (4), the upper end fixedly connected with of shaft coupling (5) stretches into inside first pivot (6) of outside casing (3), first pivot (6) are connected with inside casing (23) that set up in outside casing (3) through the rotation unit, cooperation is provided with the supporting element between outside casing (3) and inside casing (23), still fixedly connected with connection plate (7) on support base (1), fixedly connected with cylinder (8) on connection plate (7), the output fixedly connected with upper cover (9) of cylinder (8), be connected with between upper cover (9) and inside casing (23) and outside casing (3) through the connection unit;

the rotating unit comprises a rotating outer ring (171) fixedly connected to the lower end of an inner shell (23), the lower end of the rotating outer ring (171) is connected with an outer shell (3) through a bearing (172), a plurality of rotating plates (173) distributed in a circumferential array are fixedly connected to the side face of a first rotating shaft (6), a plurality of first connecting plates (174) distributed in a circumferential array and matched with the rotating plates (173) are fixedly connected to the inner side of the rotating outer ring (171), pawls (175) are rotatably connected to the end parts of the first connecting plates (174), and torsion springs (176) are arranged on rotating shafts at the connecting positions of the pawls (175) and the first connecting plates (174);

the connecting unit comprises a first annular connecting groove (181) and a second annular connecting groove (182) which are respectively matched with the outer shell (3) and the inner shell (23) and are formed in the upper cover (9), the first annular connecting groove (181) is connected with a second connecting plate (184) through a plurality of first springs (183) for providing elastic force, two first connecting rings (185) are fixedly connected to the second connecting plate (184), a sealing gasket (186) is connected between the two first connecting rings (185), a second connecting ring (188) is connected in the second annular connecting groove (182) through a plurality of second springs (187) for providing elastic force, a third annular connecting groove (189) matched with the inner shell (23) is formed in the second connecting ring (188), and a plurality of first balls (190) in contact with the side face of the inner shell (23) are rotationally connected to the inner wall of the third annular connecting groove (189);

the supporting unit comprises a plurality of supporting curved plates (201) distributed in a circumferential array, the side faces of the supporting curved plates (201) are connected with the side wall of the outer shell (3) through third springs (202) for providing elastic force, and a plurality of second balls (203) in contact with the side faces of the inner shell (23) are rotatably connected to the inner sides of the supporting curved plates (201).

2. The vibration damping centrifuge according to claim 1, characterized in that a first clamping groove (10) is formed in the side surface of the inner shell (23), a discharging annular plate (11) is connected in the first clamping groove (10) in a sliding mode, a clamping protrusion (12) which is clamped in the first clamping groove (10) is fixedly connected to the side surface of the discharging annular plate (11), a discharging hole matched with the discharging annular plate (11) is formed in the side surface of the inner shell (23), the discharging annular plate (11) is connected with the outer shell (3) through a rubber elastic layer (14), a discharging hole (15) communicated with the rubber elastic layer (14) is formed in the outer shell (3), and a control valve (16) is arranged on the discharging hole (15).

3. A vibration-damping centrifuge as claimed in claim 1, characterized in that a stirring unit is also provided between the upper cover (9) and the inner housing (23).

4. A vibration damping centrifuge according to claim 3, characterized in that the stirring unit comprises a stirring main board (211), stirring main board (211) is connected with upper cover (9) through supporting component, the lower extreme fixedly connected with of stirring main board (211) is a plurality of circumference array distribution's first puddler (212), the lower extreme central point of stirring main board (211) puts still fixedly connected with axis of rotation (213), inside that first pivot (6) stretched into inside casing (23), the side fixedly connected with first stirring board (214) of first pivot (6), fixedly connected with second puddler (215) of a plurality of array distributions on first stirring board (214), the upper end of first pivot (6) sets up to regular pentagon structure, polygon spread groove (216) with first pivot (6) complex are seted up to the lower extreme of axis of rotation (213).

5. The vibration damping centrifuge according to claim 4, wherein the supporting component comprises a second clamping groove (221) which is formed in the upper cover (9) and is matched with the stirring main board (211), a fourth annular connecting groove (222) is formed in the side face of the stirring main board (211), a plurality of second supporting rods (223) which are distributed in an array are fixedly connected in the upper cover (9), the upper ends of the second supporting rods (223) are rotatably connected with first supporting wheels (224), the first supporting wheels (224) are in rolling contact with the lower end face of the stirring main board (211), a plurality of gas springs (225) which are used for providing elastic force are fixedly connected to the side wall of the second clamping groove (221), the end parts of the plurality of gas springs (225) are rotatably connected with second supporting wheels (226), and the second supporting wheels (226) are in rolling contact with the side wall of the fourth annular connecting groove (222).