Double-shell smooth surface impact idler
By using a double-shell design and a labyrinth-type buffer ring structure, the problems of insufficient vibration resistance and short service life of traditional idler rollers are solved, achieving better shock resistance and extending the service life of the idler rollers, while avoiding rubber ring wear and fire risks.
Patent Information
- Application Number
- CN202520382254.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2035-03-05
AI Technical Summary
Traditional idler rollers have problems such as insufficient vibration resistance, short service life, and easy wear of rubber rings, which may cause fires, especially under high frictional heat conditions.
It adopts a double-shell design, with labyrinth-shaped buffer rings fitted at both ends of the rotating shaft. The labyrinth-shaped buffer rings consist of a first buffer ring and a second buffer ring. The longitudinal section of the bent part is arc-shaped. The space between the outer shell and the inner shell is filled with buffer cotton. A buffer component is set between the inner shell and the rotating shaft. The sliding rod is connected to the rotating sleeve, and the pulley rotates along the inner circumference of the inner shell.
It provides excellent shock resistance, extends the service life of the idler roller, avoids rubber ring wear and fire risks, and ensures that the idler roller works normally under complex working conditions.
Smart Images
Figure CN223721836U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of idler rollers in conveying equipment, in particular to a double-shell smooth surface buffer idler roller. BACKGROUND
[0002] The idler roller used in the conveying system is one of the key components, mainly responsible for bearing and guiding the conveying belt. The traditional idler roller adopts a single-shell design, which faces many challenges in actual use, such as insufficient anti-vibration performance, short service life and the like.
[0003] The standard buffer idler adopts a single-shell structure, and the rubber ring is sleeved on the outer circumferential surface of the shell to absorb the impact of the materials and play a buffering effect. However, the rubber ring will age and wear during use, and the idler roller needs to be replaced frequently on site. In some working conditions, the heat generated by the friction between the buffer rubber ring and the conveying belt is too large, which can cause a fire. CONTENT OF THE UTILITY MODEL
[0004] The application aims to overcome the above technical problems, and provides a double-shell smooth surface buffer idler roller.
[0005] A double-shell smooth surface buffer idler roller comprises:
[0006] A rotating shaft, the two ends of which are provided with limiting rings;
[0007] An end cover, which is sleeved on the two ends of the rotating shaft and abuts against the limiting rings, comprises a labyrinth type buffer ring, the outer edge of the labyrinth type buffer ring comprises a bending part with a longitudinal section in the shape of a circular arc, and
[0008] A shell, which is sleeved on the end cover, comprises an inner shell, an outer shell and a retaining ring, the inner wall surface of the outer shell is provided with a step, the inner wall surface of the retaining ring is matched with the outer circumferential surface of the inner shell, one side of the retaining ring abuts against the step, and the other side abuts against the bending part.
[0009] By adopting the above scheme, the double-shell structure provides good anti-vibration performance in the direction perpendicular to the rotating shaft, the bending part abuts against the retaining ring, the longitudinal section of the bending part is in the shape of a circular arc, so the bending part has good elastic performance and can be deformed in the direction in which the rotating shaft extends, and therefore the bending part can provide good anti-vibration performance in the direction in which the rotating shaft extends.
[0010] In one of the embodiments, the labyrinth type buffer ring comprises a first buffer ring and a second buffer ring, the first buffer ring comprises a first buffer part and a first support part, the second buffer ring comprises a second buffer part and a second support part, the longitudinal sections of the first buffer part and the second buffer part are in the shape of a circular arc and extend in the same direction, and the first buffer part and the second buffer part jointly constitute the bending part.
[0011] By adopting the above scheme, the elastic performance of the bending part of the labyrinth type buffer ring is enhanced by setting two buffer rings, and the elastic performance of the bending part of the two buffer rings is also enhanced.
[0012] In one of the embodiments, the first buffer part abuts against the blocking ring, and the extended end of the second buffer part abuts against the inner side of the first buffer part.
[0013] By adopting the above scheme, when the carrier roller vibrates along the extension direction of the rotating shaft, the first buffer part is deformed by the extrusion of the blocking ring to generate friction with the surface of the blocking ring, and when the first buffer part rebounds, the first buffer part generates friction with the surface of the blocking ring again to aggravate the wear of the blocking ring and the first buffer part. Since the second buffer part abuts against the inner side of the first buffer part, the second buffer part provides elastic force to the first buffer part in a direction away from the blocking ring, so that the first buffer part can be separated from the surface of the blocking ring in the first time to avoid friction between the first buffer part and the surface of the blocking ring when the first buffer part rebounds.
[0014] In one of the embodiments, the first support part and the second support part are both in the shape of "L" in the longitudinal section, the first support part and the second support part are placed in a central symmetry, and the first support part and the second support part form a ring-shaped cavity with a rectangular longitudinal section. The first support part is attached to the inner surface of the inner shell, and the second support part is attached to the outer surface of the rotating shaft.
[0015] By adopting the above scheme, the first support part and the second support part form a circular ring structure with a rectangular longitudinal section, so that the labyrinth type buffer ring can be stably fixed between the rotating shaft and the inner shell without shaking.
[0016] In one of the embodiments, a support ring with an "L" shape in the longitudinal section is arranged in the ring-shaped cavity.
[0017] By adopting the above scheme, when the bending part is deformed by external force along the direction of the rotating shaft, a gap is generated between the labyrinth type buffer ring and the inner shell. When it is rainy or snowy or dusty, rain, snow or dust can enter the inside of the carrier roller. The support ring plays a supporting role between the first buffer ring and the second buffer ring to prevent the generation of the gap between the labyrinth type buffer ring and the inner shell.
[0018] In one of the embodiments, the ring-shaped cavity is filled with buffer cotton.
[0019] By adopting the above scheme, the elastic performance between the first buffer ring and the second buffer ring is enhanced to avoid the deviation of the first buffer ring and the second buffer ring caused by external force.
[0020] In one of the embodiments, an elastic disc is arranged between the supporting ring and the first buffer ring, one side of the elastic disc abuts against the supporting ring, and the other side abuts against the second buffer ring.
[0021] By using the above scheme, when the buffer cotton is extruded, the supporting ring is displaced due to the extrusion of the buffer cotton, and the elastic disc provides elastic force between the first buffer ring and the supporting ring, so that the supporting ring can be reset after displacement.
[0022] In one of the embodiments, the labyrinth buffer ring is provided with a buffer disc on each side, and the buffer disc abuts against the limiting ring.
[0023] By using the above scheme, the buffer disc protects the labyrinth buffer ring, and the outer edge of the buffer disc extrudes the bending part of the labyrinth buffer ring to cause elastic deformation of the bending part, so that the bending part is prevented from being damaged by direct contact with the outside.
[0024] In one of the embodiments, the longitudinal section of the outer shell and the inner shell can be wavy, and the buffer cotton can be filled between the outer shell and the inner shell.
[0025] By using the above scheme, the elastic performance of the shell in the vertical direction of the rotating shaft is enhanced.
[0026] In one of the embodiments, a buffer member is arranged between the inner shell and the rotating shaft, the buffer member includes a rotating sleeve sleeved on the rotating shaft and a plurality of sliding rods, the outer circumferential surface of the rotating sleeve is circumferentially arranged with elastic members, one end of each elastic member away from the rotating sleeve abuts against the sliding rod, and one end of each sliding rod away from the rotating sleeve is connected with a pulley abutting against the inner wall of the inner shell.
[0027] By using the above scheme, the buffer member supports the inside of the shell, when the local pressure of the shell is too large, the local deformation of the shell is too large, and the shell is cracked, the sliding rod can provide support force to the inner circumferential surface of the shell, the elastic members are arranged between the rotating sleeve and the sliding rod, so that the buffer member does not affect the elastic performance of the shell, and the pulley abuts against the inner wall of the inner shell, so that the pulley can rotate along the inner circumferential surface of the inner shell, and the buffer member does not affect the rotating performance of the carrier roller.
[0028] In summary, the present application has at least one of the following beneficial technical effects:
[0029] 1. The application is a double-shell smooth surface buffer roller, the shell of the roller is designed as a double-shell, a labyrinth type buffer ring with a bending part is sleeved at both ends of the rotating shaft, the double-shell provides good anti-vibration performance in the direction perpendicular to the rotating shaft, the bending part is in abutment with the stop ring, the longitudinal section of the bending part is in the shape of a circular arc, so the bending part has good elastic performance and can be deformed in the direction in which the rotating shaft extends, and thus the bending part can provide good anti-vibration performance in the direction in which the rotating shaft extends.
[0030] 2. The first buffer part is in abutment with the stop ring, the extension end of the second buffer part is in abutment with the inner side of the first buffer part, when the roller vibrates in the direction in which the rotating shaft extends, the first buffer part will be extruded by the stop ring to be deformed, so as to rub against the surface of the stop ring, when the first buffer part rebounds, it will rub against the surface of the stop ring again, thus aggravating the wear between the stop ring and the first buffer part, and since the second buffer part is in abutment with the inner side of the first buffer part, the second buffer part will provide the first buffer part with an elastic force in the direction away from the stop ring, so that the first buffer part can be separated from the surface of the stop ring in the first time, avoiding the first buffer part from rubbing against the surface of the stop ring when it rebounds.
[0031] 3. The longitudinal section of the outer shell and the inner shell is designed as a wave shape, at the same time, buffer cotton is filled between the outer shell and the inner shell, and a buffer piece is arranged between the inner shell and the rotating shaft, the buffer piece supports the inside of the shell, when the local pressure of the shell is too large, the local deformation of the shell is too large and cracks will be generated, the sliding rod can provide a supporting force to the inner circumferential surface of the shell, since the elastic piece is connected between the rotating sleeve and the sliding rod, the elastic performance of the shell will not be affected, since the sliding rod and the inner wall of the inner shell are in abutment through the pulley, the pulley can rotate along the inner circumferential surface of the inner shell, and the rotating performance of the roller will not be affected. BRIEF DESCRIPTION OF DRAWINGS
[0032] Figure 1 is a cross-sectional view of a double-shell smooth surface buffer roller according to the first embodiment of the application.
[0033] Figure 2 is a structural schematic view of a labyrinth type buffer ring.
[0034] Figure 3 is a schematic view of the connection relationship between the first buffer ring and the second buffer ring.
[0035] Figure 4 is a partial cross-sectional view of a double-shell smooth surface buffer roller according to the second embodiment of the application.
[0036] Explanation of reference signs: 1, rotating shaft; 11, limiting ring; 2, end cover; 21, labyrinth type buffer ring; 211, bending part; 212, first buffer ring; 2121, first buffer part; 2122, first support part; 213, second buffer ring; 2131, second buffer part; 2132, second support part; 214, annular cavity; 215, support ring; 216, elastic disc; 22, buffer disc; 3, shell; 31, inner shell; 32, outer shell; 321, step; 33, blocking ring; 34, buffer piece; 341, rotating sleeve; 342, sliding rod; 3421, pulley; 343, elastic piece; 4, buffer cotton. DETAILED DESCRIPTION
[0037] Therefore, it is necessary to provide a double-shell smooth surface buffer roller which is durable and can effectively reduce shock.
[0038] Embodiment 1
[0039] Please see Figure 1 , Figure 1 is a structural schematic diagram of a double-shell smooth surface buffer roller according to the first embodiment of the present application, which comprises a rotating shaft 1, an end cover 2 and a shell 3.
[0040] Please see Figures 2-3 , Figure 2 is a structural schematic diagram of a labyrinth type buffer ring. The rotating shaft 1 is used as the core component of the entire roller to support and transmit rotary motion. The material of the rotating shaft 1 can be selected from high-strength steel or aluminum alloy to ensure sufficient strength and lightweight requirements. The rotating shaft 1 is provided with a limiting ring 11 at both ends to prevent the end cover 2 from loosening. The limiting ring 11 can be designed to be detachable in two parts, so that the limiting ring 11 can be detached from the rotating shaft 1, and then the end cover 2 can be detached from the rotating shaft 1, thereby facilitating the quality inspection and replacement of internal parts of the roller. The diameter of the limiting ring 11 is slightly larger than that of the main body part of the rotating shaft 1 to ensure that the end cover 2 can be stably positioned thereon.
[0041] The end cover 2 is sleeved on both ends of the rotating shaft 1 and abuts against the limiting ring 11, which plays a sealing and supporting role. The main component of the end cover 2 is a labyrinth type buffer ring 21. The outer edge of the labyrinth type buffer ring 21 comprises a bending part 211 with a circular arc-shaped longitudinal section. The bending part 211 has good elastic properties and can deform in the extension direction of the rotating shaft 1, thereby providing effective shock resistance. The material of the bending part 211 can be selected from a metal material with elasticity to ensure that it can quickly recover to its original state when subjected to pressure.
[0042] The labyrinth buffer ring 21 comprises a first buffer ring 212 and a second buffer ring 213, the first buffer ring 212 comprises a first buffer part 2121 and a first supporting part 2122, the second buffer ring 213 comprises a second buffer part 2131 and a second supporting part 2132, the first buffer part 2121 and the second buffer part 2131 are both circular arc-shaped in longitudinal section and extend in the same direction, and the first buffer part 2121 and the second buffer part 2131 jointly form a bending part 211 of the labyrinth buffer ring 21. The first buffer part 2121 of the first buffer ring 212 and the second buffer part 2131 of the second buffer ring 213 are both circular arc-shaped and extend in the same direction, so that greater elastic deformation can be generated in the same direction, thereby improving the anti-vibration performance of the carrier roller.
[0043] The first buffer part 2121 abuts against the blocking ring 33, and the extension end of the second buffer part 2131 abuts against the inner side of the first buffer part 2121. When the carrier roller vibrates in the extension direction of the rotating shaft 1, the first buffer part 2121 will be extruded by the blocking ring 33 to deform, thereby generating friction with the surface of the blocking ring 33. When the first buffer part 2121 rebounds, it will again generate friction with the surface of the blocking ring 33, thereby aggravating the wear between the blocking ring 33 and the first buffer part 2121. However, since the second buffer part 2131 abuts against the inner side of the first buffer part 2121, the second buffer part 2131 will provide an elastic force to the first buffer part 2121 in a direction away from the blocking ring 33, so that the first buffer part 2121 can first separate from the surface of the blocking ring 33, thereby avoiding friction between the first buffer part 2121 and the surface of the blocking ring 33 when the first buffer part 2121 rebounds.
[0044] The longitudinal sections of the first supporting part 2122 and the second supporting part 2132 are both "L"-shaped and centrally symmetrically arranged. The first supporting part 2122 is attached to the inner wall surface of the inner shell 31, and the second supporting part 2132 is attached to the outer peripheral surface of the rotating shaft 1. This design forms a ring-shaped cavity 214 with a rectangular longitudinal section between the first supporting part 2122 and the second supporting part 2132, which helps the labyrinth buffer ring 21 to be more stably fixed between the rotating shaft 1 and the inner shell 31 without shaking. The ring-shaped cavity 214 is filled with buffer cotton 4, and the selection of the buffer cotton 4 can be adjusted according to actual needs. Common materials include polyurethane foam, rubber sponge, etc., which all have good shock absorption capacity and wear resistance. The buffer cotton 4 can play a supporting role between the first buffer ring 212 and the second buffer ring 213 to prevent the first buffer ring 212 and the second buffer ring 213 from deviating, and the buffer cotton has elasticity, which can further improve the elastic performance between the first buffer ring 212 and the second buffer ring 213.
[0045] The annular cavity 214 formed by the first buffer ring 212 and the second buffer ring 213 is internally provided with a support ring 215 with a longitudinal section in the shape of "L". An elastic disc 216 is arranged between the support ring 215 and the first buffer ring 212, one side of the elastic disc 216 abuts against the support ring 215, and the other side abuts against the second buffer ring 213. When the bending part 211 is deformed due to external force in the direction of the rotation shaft 1, a gap is generated between the labyrinth type buffer ring 21 and the inner shell 31. When it is raining or snowing or when it is dusty, rain, snow or dust will enter the inside of the carrier roller. The support ring 215 plays a supporting role between the first buffer ring 212 and the second buffer ring 213, preventing a gap from being generated between the labyrinth type buffer ring 21 and the inner shell 31. When the buffer cotton 4 is extruded, the support ring 215 will be displaced due to the extrusion of the buffer cotton 4. The elastic disc 216 can provide elastic force between the first buffer ring 212 and the support ring 215, so that the support ring 215 can be reset after displacement.
[0046] The two sides of the labyrinth type buffer ring are provided with buffer discs 22. The buffer disc 22 located on the side of the labyrinth type buffer ring facing the limiting ring 11 abuts against the limiting ring 11. Since the buffer disc 22 is disc-shaped, it also has elasticity in the extension direction of the rotation shaft 1, which can further enhance the elastic performance of the labyrinth type buffer ring 21. At the same time, the buffer disc 22 plays a protective role for the labyrinth type buffer ring 21. The outer edge of the buffer disc 22 extrudes the bending part 211 of the labyrinth type buffer ring 21, causing the bending part 211 to elastically deform, thereby avoiding damage to the bending part 211 caused by direct contact with the outside world.
[0047] The shell 3 is sleeved on the end cover 2. The shell 3 is a double-layer structure and mainly includes an inner shell 31, an outer shell 32 and a stop ring 33. The cross section of the inner shell 31 and the outer shell 32 can be designed as a circle or other suitable geometric shape to adapt to different application scenarios. The inner wall surface of the outer shell 32 is provided with a step 321 for limiting the stop ring 33. The inner wall surface of the stop ring 33 cooperates with the outer circumferential surface of the inner shell 31. One side of the stop ring 33 abuts against the step 321, and the other side abuts against the bending part 211. The stop ring 33 can be welded with the inner shell 31 and the outer shell 32, thereby realizing the fixation among the inner shell 31, the outer shell 32 and the stop ring 33. The inner shell 31 is internally embedded with a bearing, which is sleeved on the outer circumferential surface of the rotation shaft 1, thereby realizing the rotation of the rotation shaft 1.
[0048] The working principle of the embodiment is that the double-shell structure 3 provides good anti-vibration performance in the direction perpendicular to the rotating shaft 1, and the design of the bending part 211 of the labyrinth type buffer ring 21 can be deformed in the direction in which the rotating shaft 1 extends, so that the carrier roller has significant anti-vibration performance in all directions. The multi-layer structure of the labyrinth type buffer ring 21 not only effectively blocks the intrusion of external impurities, but also deforms multiple times when subjected to vibration, absorbing more impact energy. In addition, in the present application, the labyrinth type buffer ring 21 and its internal structure can be made of metal material, and the outer peripheral surface of the shell 3 and the labyrinth type buffer ring 21 do not have to use elastic materials such as rubber, prolonging the service life of the carrier roller.
[0049] Embodiment 2
[0050] Please refer to Figure 4 , Figure 4 is a partial sectional view of a double-shell smooth surface buffer carrier roller according to the second embodiment of the present application. The structure of the present embodiment is basically the same as that of the above-mentioned embodiment, and the difference lies in that the longitudinal section of the outer shell 32 and the inner shell 31 is designed in a wave shape. The wave-shaped section can disperse and absorb impact forces from different directions, and the buffer cotton 4 filled between the outer shell 32 and the inner shell 31 can further improve the shock absorption performance of the system.
[0051] A buffer member 34 is arranged between the inner shell 31 and the rotating shaft 1, and the buffer member 34 includes a rotating sleeve 341 sleeved on the rotating shaft 1 and a sliding rod 342. The outer peripheral surface of the rotating sleeve 341 is circumferentially arranged with elastic members 343, one end of the elastic members 343 away from the rotating sleeve 341 abuts against the sliding rod 342, and the end of the sliding rod 342 away from the rotating sleeve 341 is connected with a pulley 3421 abutting against the inner wall surface of the inner shell 31. This design enables the sliding rod 342 to provide support force to the inner peripheral surface of the inner shell 31 when the inner shell 31 is subjected to excessive local pressure, thereby avoiding cracking of the inner shell 31 due to excessive local deformation. At the same time, since the elastic members 343 are connected between the rotating sleeve 341 and the sliding rod 342, the elastic performance of the inner shell 31 is not affected, and the sliding rod 342 and the inner wall of the inner shell 31 are abutted by the pulley 3421. The pulley 3421 can rotate along the inner peripheral surface of the inner shell 31, avoiding the influence of the sliding rod on the rotating performance of the carrier roller.
[0052] The working principle of the embodiment is that the cross sections of the outer shell 32 and the inner shell 31 are designed in a wavy shape, which can more effectively disperse and absorb impact forces from different directions, reducing the direct impact on the internal components. The buffer cotton 4 is filled between the outer shell 32 and the inner shell 31, which not only further enhances the shock absorption effect, but also reduces the direct impact between the inner and outer shells 32, prolonging the service life. This design is particularly suitable for idlers that need to work in complex working conditions, such as mines, ports and other places. By setting the buffer 34 between the inner shell 31 and the rotating shaft 1, the problem of cracking of the inner shell 31 when subjected to local high pressure is effectively solved. The sliding rod 342 provides support force to the inner circumferential surface of the inner shell 31, avoiding the risk of excessive local deformation. The elastic element 343 connecting between the rotating sleeve 341 and the sliding rod 342 not only maintains the elastic performance of the inner shell 31, but also does not hinder the normal rotation of the idler. This design is particularly suitable for idlers that need to work under high load conditions, such as large conveyor belts, heavy load transportation equipment, etc.
[0053] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made in terms of structure, shape, principle, etc. based on the present application should be covered within the protection scope of the present application.
Claims
1. A double shell smooth surface buffer roll characterized by, The utility model relates to a rotating shaft buffer device, including: Rotating shaft (1), both ends are equipped with limiting ring (11); End cover (2), the both ends of rotating shaft (1) are equipped with and with limiting ring (11) abut, end cover (2) includes the labyrinth type buffer ring (21), the outer edge of labyrinth type buffer ring (21) includes the bending portion (211) that longitudinal section is round arc, and Shell (3), the both ends of end cover (2) are equipped with, shell (3) includes inner shell (31), outer shell (32) and baffle ring (33), the inner wall surface of outer shell (32) is equipped with step (321), the outer periphery of inner shell (31) is cooperated with the inner wall surface of baffle ring (33), one side of baffle ring (33) is abutted with step (321), and the other side is abutted with bending portion (211).
2. A double shell smooth surface buffer roller as claimed in claim 1, wherein: Labyrinth type buffer ring (21) includes first buffer ring (212) and second buffer ring (213), first buffer ring (212) includes first buffer part (2121) and first support part (2122), second buffer ring (213) includes second buffer part (2131) and second support part (2132), first buffer part (2121) and second buffer part (2131) are all round arc and the same direction of extension with longitudinal section, first buffer part (2121) and second buffer part (2131) jointly constitute bending portion (211).
3. A double shell smooth surface buffer roller as claimed in claim 2, wherein: First buffer part (2121) is abutted with baffle ring (33), and the extension end of second buffer part (2131) is abutted with the inner side of first buffer part (2121).
4. A double shell smooth surface buffer roller as claimed in claim 2, wherein: First support part (2122) and second support part (2132) are all "L" type with longitudinal section, first support part (2122) and second support part (2132) are placed with central symmetry, and the annular cavity (214) with rectangular longitudinal section is formed between first support part (2122) and second support part (2132), first support part (2122) is attached to the inner wall surface of inner shell (31), and second support part (2132) is attached to the outer periphery of rotating shaft (1).
5. A double shell smooth surface buffer roller as claimed in claim 4, wherein: Support ring (215) with longitudinal section of "L" shape is arranged in annular cavity (214).
6. A double shell smooth surface buffer roller as claimed in claim 4, wherein: Annular cavity (214) is filled with buffer cotton (4).
7. A double shell smooth surface buffer roller as claimed in claim 5, wherein: Elastic disc (216) is arranged between support ring (215) and first buffer ring (212), one side of elastic disc (216) is abutted with support ring (215), and the other side is abutted with second buffer ring (213).
8. A double shell smooth surface buffer roller as claimed in claim 1, wherein: Buffer disc (22) is arranged on both sides of labyrinth type buffer ring (21), and buffer disc (22) is abutted with limiting ring (11).
9. A double shell smooth surface buffer roller as claimed in claim 1, wherein: The longitudinal section of outer shell (32) and inner shell (31) can be wavy, and buffer cotton (4) can be filled between outer shell (32) and inner shell (31).
10. A double shell smooth surface buffer roller as claimed in claim 9, wherein: The inner shell (31) is provided with a buffer (34) between the rotating shaft (1), the buffer (34) includes a rotating sleeve (341) sleeved on the rotating shaft (1) and a plurality of sliding rods (342), the outer circumferential surface of the rotating sleeve (341) is circumferentially distributed with elastic elements (343), one end of the elastic element (343) away from the rotating sleeve (341) abuts against the sliding rod (342), and one end of the sliding rod (342) away from the rotating sleeve (341) is connected with a pulley (3421) abutting against the inner wall surface of the inner shell (31).