Spiral built-in heating device

Abstract

The invention provides a spiral built-in heating device, which belongs to the technical field of heating devices, and comprises a support frame, a first ring frame and a cable reel arranged on the support frame, and a heating cable arranged on the cable reel. According to the heating cable pay-off device, the cable reel rotates in two different directions, the cable rotates while the heating cable is paid off, the heating cable spirally enters the inner wall of a pipeline in cooperation with the multiple spiral strips arranged on the outer side, the heating cable can rapidly penetrate through a viscous medium on the inner wall of the pipeline in the stretching-in process, and therefore the heating cable can rapidly penetrate through the inner wall of the pipeline. The heating cable is arranged in the guide block, so that the heating cable is prevented from being bent due to direct extension, the difficulty that the heating cable extends into the pipeline is reduced, the heating cable can smoothly reach a proper extension length, the pipeline can be quickly heated, and meanwhile, the plurality of guide assemblies arranged in the guide block intermittently guide the heating cable in the extension process of the heating cable, so that the heating cable can be quickly heated. Therefore, friction of the spiral strip is reduced, the service life of the spiral strip is prolonged, and the heating cable stretching efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of heating devices, and in particular to a spiral built-in heating device. Background Art

[0002] Heating is a basic and critical operation in many industrial production and daily life scenarios. From traditional industrial manufacturing to emerging science and technology fields, from large industrial equipment to small household products, there are different requirements for the performance of heating devices. With the advancement of science and technology and the development of the industry, the technology of heating devices has continued to evolve, from simple heating elements in the early days to complex systems with diverse functions and optimized performance. Heating cables, as a device that converts electrical energy into thermal energy, play a key role in many fields.

[0003] In the prior art, when heating the inside of a pipe, since the pipe is long and the inner diameter is not large, an ordinary heating device is installed on the inner wall of the pipe in a conventional manner, and then the heating cable can be inserted into the inner wall of the pipe to heat it; however, when the common heating cable is extended, it is directly released and slid into the inner wall of the pipe. When there is a viscous medium on the inner wall of the pipe, the heating cable at the end needs to overcome the resistance of the medium and extend into it. During this process, when the resistance is too large, the heating cable will bend and cannot continue to extend. The difficulty of extension is high and the cable cannot be effectively extended to the appropriate depth, thereby affecting the overall heating of the pipe. How to invent a spiral built-in heating device to solve these problems has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] In order to make up for the above shortcomings, the present invention provides a spiral built-in heating device, which aims to solve the problem that the common heating cable cannot go deeper when it encounters viscous medium when inserted into the pipeline.

[0005] The present invention is achieved in that:

[0006] The present invention provides a spiral built-in heating device, comprising a support frame, a first ring frame and a cable drum arranged on the support frame, and a heating cable arranged on the cable drum;

[0007] The upper end of the support frame is fixedly connected to the lower end of the first ring frame, a second ring frame is installed on the inner wall of the first ring frame, an inner gear ring is installed on the inner wall of the second ring frame, a motor is installed on one side of the first ring frame, a driving shaft is installed on the inner wall of the first ring frame close to the motor, a limit frame is installed on one end of the driving shaft, sliders are installed on the inner walls of both sides of the limit frame, and a guide block is installed on the side of the first ring frame away from the motor;

[0008] The outer walls of both sides of the cable drum are provided with annular grooves slidably connected to the outer wall of the slider, fixed shafts are installed on both sides of the cable drum, a connecting shaft is installed at one end of the fixed shaft, a first bevel gear is installed at one end of the connecting shaft, an adjusting shaft is installed on the outer wall of the connecting shaft, a limiting groove slidably connected to the outer wall of the second ring frame is provided at one end of the adjusting shaft, a driving groove is provided inside the adjusting shaft, a rotating shaft, a gear and a second bevel gear are respectively installed on the inner walls of the driving groove, and a distribution box is installed on one side of the cable drum;

[0009] The heating cable is coiled on a cable drum, a plurality of spiral strips are arranged on the outer wall of the heating cable, and an adsorption sleeve is installed on the outer wall of the heating cable close to two spiral strips.

[0010] Preferably, the second ring frame is vertically fixed to the first ring frame, the output end of the motor is fixedly connected to one end of the drive shaft, and the outer wall of the drive shaft is rotatably connected to the inner wall of the first ring frame.

[0011] Preferably, one end of the fixed shaft is fixedly connected to the side wall of the cable drum, both ends of the connecting shaft are respectively fixedly connected to the fixed shaft and one end of the first bevel gear, and the outer wall of the connecting shaft is rotatably connected to the inner wall of the adjusting shaft.

[0012] Preferably, the outer wall of the rotating shaft and the inner wall of the driving groove are rotatably connected, and the two gears are symmetrically fixedly connected to the side walls at both ends of the rotating shaft. A second bevel gear meshing with the first bevel gear is installed on the side wall of the rotating shaft close to one of the gears, and the gear teeth on the outer side of the gear pass through the driving groove, and the gear is meshingly connected to the inner gear ring.

[0013] Preferably, the input end of the heating cable is electrically connected to the distribution box, the outer wall of the heating cable is slidably connected to the inner wall of the guide block, a mounting plate is installed at one end of the guide block, a meter sensor is installed on the mounting plate, a stainless steel sheath is provided on the outside of the heating cable, a plurality of the spiral strips are welded to the side wall of the stainless steel sheath, and the spiral strips and the stainless steel sheath can be bent.

[0014] Preferably, a plurality of equidistant positioning grooves are provided inside the guide block, a plurality of guide grooves are provided on the upper and lower side walls of the positioning groove, and a guide assembly is installed on the inner wall of the positioning groove.

[0015] Preferably, the guide assembly includes an upper half ring, a lower half ring, a tile-shaped magnet and shaft teeth, the outer walls of the upper half ring and the lower half ring are slidably connected to the inner walls of the positioning groove, the upper end side wall of the upper half ring is equipped with an upper guide rod slidably connected to the inner wall of the guide groove close to the upper end, and the side wall of the upper half ring is equipped with a lower tooth plate.

[0016] Preferably, the lower end side wall of the lower half ring is equipped with a lower guide rod slidably connected to the inner wall of the lower guide groove, and the side wall of the lower half ring is equipped with an upper tooth plate, and a through groove slidably connected to the outer wall of the lower tooth plate is opened on one side of the upper tooth plate.

[0017] Preferably, a groove is provided on the side wall of the upper half ring, a counterweight is installed on the inner wall of the lower half ring, a plurality of balls are fixedly connected to the inner walls of the upper half ring and the lower half ring, and tile-shaped magnets that are magnetically attracted to the adsorption sleeve are installed on the inner walls of the upper half ring and the lower half ring close to both sides of the balls, the two ends of the shaft teeth are rotatably connected to the inner wall of the positioning groove, and the shaft teeth are respectively meshed with the lower tooth plate and the upper tooth plate.

[0018] The beneficial effects of the present invention are:

[0019] The cable drum is rotated in two different directions, and the cable itself is rotated while the heating cable is being released. The heating cable is spirally inserted into the inner wall of the pipeline with the help of the multi-segment spiral strips arranged on the outside. The viscous medium on the inner wall of the pipeline can be quickly penetrated during the insertion process, and the bending of the heating cable caused by direct insertion is avoided. The difficulty of inserting the heating cable into the pipeline is reduced, so that the heating cable can smoothly reach a suitable insertion length, thereby quickly heating the pipeline.

[0020] At the same time, the multiple guide components arranged in the guide block intermittently guide the heating cable during the extension process, so that it can be accurately inserted into the inner wall of the pipe. At the same time, during the extension process, the heating cable is effectively prevented from rubbing against the outer spiral strips and the inner wall of the guide block under the action of gravity, thereby reducing the friction of the spiral strips, increasing its service life and improving the efficiency of the extension of the heating cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic structural diagram of a spiral built-in heating device provided in an embodiment of the present invention;

[0023] Figure 2 A spiral built-in heating device provided by the embodiment of the present invention Figure 1 A magnified view of the structure of the middle A area;

[0024] Figure 3 It is a half-section view of a local area of ​​a spiral built-in heating device provided by an embodiment of the present invention;

[0025] Figure 4 A spiral built-in heating device provided by the embodiment of the present invention Figure 3 A magnified view of the structure of the middle B area;

[0026] Figure 5 It is a partial structural cross-sectional view of a spiral built-in heating device provided in an embodiment of the present invention;

[0027] Figure 6 A spiral built-in heating device provided by the embodiment of the present invention Figure 5 A magnified view of the structure of the middle C region;

[0028] Figure 7 It is a schematic diagram of the structure of a guide block in a spiral built-in heating device provided in an embodiment of the present invention;

[0029] Figure 8 It is a half-section diagram of a guide block structure in a spiral built-in heating device provided in an embodiment of the present invention;

[0030] Fig. 9 A spiral built-in heating device provided by the embodiment of the present invention Figure 8 A magnified view of the structure of the middle D region;

[0031] Fig.10 It is a schematic diagram of the structure of a guide component in a spiral built-in heating device provided in an embodiment of the present invention.

[0032] In the figure: 1, support frame; 11, first ring frame; 12, second ring frame; 121, inner ring gear; 13, motor; 14, drive shaft; 15, limit frame; 151, slider; 2, cable drum; 21, ring groove; 22, fixed shaft; 221, connecting shaft; 222, first bevel gear; 23, adjusting shaft; 231, limit groove; 232, drive groove; 24, rotating shaft; 25, gear; 26, second bevel gear; 27, distribution box; 3 , guide block; 31, mounting plate; 32, positioning groove; 33, guide groove; 4, guide assembly; 41, upper half ring; 411, groove; 412, upper guide rod; 413, lower tooth plate; 42, lower half ring; 421, counterweight; 422, lower guide rod; 423, upper tooth plate; 424, through groove; 43, tile magnet; 44, ball; 45, shaft tooth; 5, heating cable; 51, spiral strip; 52, adsorption sleeve; 6, meter sensor. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example, see Figure 1-Figure 10 , a spiral built-in heating device, comprising a support frame 1, a first ring frame 11 and a cable drum 2 arranged on the support frame 1, and also comprising a heating cable 5 arranged on the cable drum 2;

[0035] The upper end of the support frame 1 is fixedly connected to the lower end of the first ring frame 11, the second ring frame 12 is installed on the inner wall of the first ring frame 11, the inner wall of the second ring frame 12 is installed with an inner gear ring 121, a motor 13 is installed on one side of the first ring frame 11, a driving shaft 14 is installed on the inner wall of the first ring frame 11 close to the motor 13, a limit frame 15 is installed on one end of the driving shaft 14, and sliders 151 are installed on the inner walls of both sides of the limit frame 15, and a guide block 3 is installed on the side of the first ring frame 11 away from the motor 13;

[0036] The outer walls of both sides of the cable drum 2 are provided with annular grooves 21 slidably connected to the outer wall of the slider 151, and fixed shafts 22 are installed on both sides of the cable drum 2. A connecting shaft 221 is installed at one end of the fixed shaft 22, and a first bevel gear 222 is installed at one end of the connecting shaft 221. An adjusting shaft 23 is installed on the outer wall of the connecting shaft 221, and a limiting groove 231 slidably connected to the outer wall of the second ring frame 12 is opened at one end of the adjusting shaft 23. A driving groove 232 is opened inside the adjusting shaft 23, and a rotating shaft 24, a gear 25 and a second bevel gear 26 are installed on the inner wall of the driving groove 232 respectively. A distribution box 27 is installed on one side of the cable drum 2;

[0037] The heating cable 5 is wound on the cable drum 2 . The outer wall of the heating cable 5 is provided with a plurality of spiral strips 51 . An adsorption sleeve 52 is installed on the outer wall of the heating cable 5 near the space between two spiral strips 51 .

[0038] Further, the second ring frame 12 is vertically fixed to the first ring frame 11, the output end of the motor 13 is fixedly connected to one end of the drive shaft 14, the outer wall of the drive shaft 14 is rotatably connected to the inner wall of the first ring frame 11, one end of the fixed shaft 22 is fixedly connected to the side wall of the cable drum 2, the two ends of the connecting shaft 221 are respectively fixedly connected to the fixed shaft 22 and one end of the first bevel gear 222, the outer wall of the connecting shaft 221 is rotatably connected to the inner wall of the adjusting shaft 23, the outer wall of the rotating shaft 24 is rotatably connected to the inner wall of the driving groove 232, the two gears 25 are symmetrically fixedly connected to the side walls of the two ends of the rotating shaft 24, and the rotating shaft 24 is close to the rotating shaft 24. A second bevel gear 26 meshing with the first bevel gear 222 is installed on the side wall of one of the gears 25, and the gear teeth on the outside of the gear 25 pass through the driving groove 232. The gear 25 and the inner gear ring 121 are meshingly connected. The input end of the heating cable 5 is electrically connected to the distribution box 27. The outer wall of the heating cable 5 and the inner wall of the guide block 3 are slidingly connected. A mounting plate 31 is installed at one end of the guide block 3, and a meter sensor 6 is installed on the mounting plate 31. A stainless steel sheath is provided on the outside of the heating cable 5, and a plurality of spiral strips 51 are welded to the side wall of the stainless steel sheath. The spiral strips 51 and the stainless steel sheath can be bent.

[0039] It should be noted that: the input end of the heating cable 5 is connected and fixed through the distribution box 27 outside the cable drum 2, and the rear heating cable 5 is coiled on the cable drum 2 and one end of it is extended into the guide block 3. When the inner wall of the pipe is heated, the height of the pipe and the guide block 3 are kept consistent, and the start motor 13 controls the drive shaft 14 to drive the limit frame 15 to rotate. The entire cable drum 2 rotates around the drive shaft 14 under the limit between the slider 151 and the annular groove 21. The guide block 3 and the drive shaft 14 are located on the same axis, so that the heating cable 5 on the cable drum 2 rotates as a whole, and the heating cable 5 located in the guide block 3 rotates at the same time. At the same time, the fixed shafts 22 at both ends of the cable drum 2 drive the adjusting shaft 23 to rotate on the second ring frame 12, and the gear 25 in the adjusting shaft 23 engages with the inner gear ring on the inner side of the second ring frame 12 during the revolution. 121 rotates on its own, and at the same time, the second bevel gear 26 coaxial with the gear 25 rotates, and the first bevel gear 222 is meshed with the first bevel gear 222 to rotate, thereby realizing the rotation of the connecting shaft 221 and the fixed shaft 22, thereby driving the cable drum 2 to rotate twice with the fixed shaft 22 as the axis. During its rotation, the heating cable 5 on the cable drum 2 is continuously and progressively conveyed forward through the guide block 3, so that the heating cable 5 extends into the inner wall of the pipeline during the rotation, and cooperates with the spiral strip 51 on the outer side of the heating cable 5 to spiral into the inner wall of the pipeline, and the meter sensor 6 detects the inserted length in real time, so that the heating cable 5 can quickly penetrate the viscous medium on the inner wall of the pipeline, avoids direct insertion, which is prone to bending of the heating cable 5, reduces the difficulty of the heating cable 5 extending into the pipeline, and allows it to smoothly reach a suitable insertion length, thereby quickly heating the pipeline.

[0040] Furthermore, the guide block 3 is provided with a plurality of equidistant positioning grooves 32 inside, and a plurality of guide grooves 33 are provided on the upper and lower side walls of the positioning groove 32. A guide assembly 4 is installed on the inner wall of the positioning groove 32. The guide assembly 4 includes an upper half ring 41, a lower half ring 42, a tile-shaped magnet 43 and a shaft tooth 45. The outer walls of the upper half ring 41 and the lower half ring 42 are slidably connected to the inner wall of the positioning groove 32. An upper guide rod 412 is installed on the upper end side wall of the upper half ring 41 and is slidably connected to the inner wall of the upper guide groove 33. A lower tooth plate 413 is installed on the side wall of the upper half ring 41, and a lower tooth plate 413 is installed on the lower end side wall of the lower half ring 42 and is slidably connected to the inner wall of the lower guide groove 33. The lower guide rod 422 of the upper half ring 42 is provided with an upper tooth plate 423 on the side wall of the lower half ring 42, a through groove 424 is provided on one side of the upper tooth plate 423 and is slidably connected to the outer wall of the lower tooth plate 413, a groove 411 is provided on the side wall of the upper half ring 41, a counterweight 421 is provided on the inner wall of the lower half ring 42, a plurality of balls 44 are fixedly connected to the inner side walls of the upper half ring 41 and the lower half ring 42, and tile-shaped magnets 43 that are magnetically attracted to the adsorption sleeve 52 are installed on the inner side walls of the upper half ring 41 and the lower half ring 42 near both sides of the balls 44, the two ends of the shaft teeth 45 are rotatably connected to the inner wall of the positioning groove 32, and the shaft teeth 45 are respectively meshed and connected with the lower tooth plate 413 and the upper tooth plate 423.

[0041] It should be noted that the stainless steel sheath on the outside of the heating cable 5 cannot be adsorbed by the magnet. In the process of the heating cable 5 extending into the pipeline through the guide block 3, when the adsorption sleeve 52 between the two spiral strips 51 of the heating cable 5 approaches the guide component 4, a magnetic force is generated between the tile-shaped magnet 43 and the adsorption sleeve 52 on the inner walls of the two semi-rings to attract each other, so that the upper and lower semi-rings approach the adsorption sleeve 52 respectively, until the ball 44 on the inner side of the semi-ring contacts with the adsorption sleeve 52, thereby fixing the heating cable 5 at the center of the guide block 3. In the subsequent movement of the heating cable 5, the ball 44 rolls and guides it to extend until the ball 44 completely leaves the adsorption sleeve 52, at which time the magnetic force between the tile-shaped magnet 43 and the adsorption sleeve 52 disappears, and the lower semi-ring 42 is in the matching The weight block 421 falls downward under the action of the positioning groove 32. At the same time, the meshing shaft tooth 45 rotates during the downward movement of the upper tooth plate 423 on one side, so that the lower tooth plate 413 on the meshing side drives the upper half ring 41 to move upward, so that it enters the top of the positioning groove 32, thereby realizing the separation from the adsorption sleeve 52, so that the spiral strip 51 can smoothly pass through the guide component 4, which intermittently guides the heating cable 5 during the extension process so that it can be accurately inserted into the inner wall of the pipe. At the same time, during the extension process, the heating cable 5 is effectively prevented from rubbing against the inner wall of the guide block 3 on the outer side of the spiral strip 51 under the action of gravity, thereby reducing the friction of the spiral strip 51, increasing its service life and improving the efficiency of the extension of the heating cable 5.

[0042] It should be noted that the specific model and specifications of the motor need to be selected and determined based on the actual specifications of the device, and the specific selection calculation method adopts the existing technology in this field, so it will not be described in detail.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A spiral built-in heating device, comprising a support frame (1), a first ring frame (11) and a cable drum (2) arranged on the support frame (1), characterized in that: It also includes a heating cable (5) arranged on the cable drum (2); The upper end of the support frame (1) is fixedly connected to the lower end of the first ring frame (11); a second ring frame (12) is installed on the inner wall of the first ring frame (11); an inner gear ring (121) is installed on the inner wall of the second ring frame (12); a motor (13) is installed on one side of the first ring frame (11); a driving shaft (14) is installed on the inner wall of the first ring frame (11) close to the motor (13); a limiting frame (15) is installed on one end of the driving shaft (14); sliding blocks (151) are installed on the inner walls of both sides of the limiting frame (15); and a guide block (3) is installed on the side of the first ring frame (11) away from the motor (13); The outer walls of both sides of the cable drum (2) are provided with annular grooves (21) slidably connected to the outer wall of the slider (151); fixed shafts (22) are installed on both sides of the cable drum (2); a connecting shaft (221) is installed at one end of the fixed shaft (22); a first bevel gear (222) is installed at one end of the connecting shaft (221); an adjusting shaft (23) is installed on the outer wall of the connecting shaft (221); a limiting groove (231) slidably connected to the outer wall of the second ring frame (12) is opened at one end of the adjusting shaft (23); a driving groove (232) is opened inside the adjusting shaft (23); a rotating shaft (24), a gear (25) and a second bevel gear (26) are installed on the inner wall of the driving groove (232); and a distribution box (27) is installed on one side of the cable drum (2); The heating cable (5) is wound on a cable drum (2); the outer wall of the heating cable (5) is provided with a plurality of spiral strips (51); and an adsorption sleeve (52) is installed on the outer wall of the heating cable (5) close to two spiral strips (51).

2. A spiral built-in heating device according to claim 1, characterized in that: The second ring frame (12) and the first ring frame (11) are vertically fixed, the output end of the motor (13) is fixedly connected to one end of the drive shaft (14), and the outer wall of the drive shaft (14) is rotatably connected to the inner wall of the first ring frame (11).

3. A spiral built-in heating device according to claim 2, characterized in that: One end of the fixed shaft (22) is fixedly connected to the side wall of the cable drum (2), two ends of the connecting shaft (221) are respectively fixedly connected to the fixed shaft (22) and one end of the first bevel gear (222), and the outer wall of the connecting shaft (221) is rotatably connected to the inner wall of the adjusting shaft (23).

4. A spiral built-in heating device according to claim 3, characterized in that: The outer wall of the rotating shaft (24) is rotatably connected to the inner wall of the driving groove (232); the two gears (25) are symmetrically fixedly connected to the side walls at both ends of the rotating shaft (24); a second bevel gear (26) meshingly connected to the first bevel gear (222) is installed on the side wall of the rotating shaft (24) close to one of the gears (25); the gear teeth on the outer side of the gear (25) pass through the driving groove (232); and the gear (25) is meshingly connected to the inner gear ring (121).

5. A spiral built-in heating device according to claim 4, characterized in that: The input end of the heating cable (5) is electrically connected to the distribution box (27); the outer wall of the heating cable (5) is slidably connected to the inner wall of the guide block (3); a mounting plate (31) is installed at one end of the guide block (3); a meter sensor (6) is installed on the mounting plate (31); a stainless steel sheath is arranged on the outer side of the heating cable (5); a plurality of spiral strips (51) are welded to the side wall of the stainless steel sheath; and the spiral strips (51) and the stainless steel sheath can be bent.

6. The spiral built-in heating device according to claim 1, characterized in that: The guide block (3) is provided with a plurality of positioning grooves (32) inside, the upper and lower side walls of the positioning groove (32) are provided with a plurality of guiding grooves (33), and the inner wall of the positioning groove (32) is provided with a plurality of guiding components (4).

7. A spiral built-in heating device according to claim 6, characterized in that: The guide assembly (4) comprises an upper half ring (41), a lower half ring (42), a tile-shaped magnet (43) and a shaft tooth (45); the outer walls of the upper half ring (41) and the lower half ring (42) are slidably connected to the inner wall of the positioning groove (32); the upper end side wall of the upper half ring (41) is provided with an upper guide rod (412) slidably connected to the inner wall of the upper guide groove (33); and the side wall of the upper half ring (41) is provided with a lower tooth plate (413).

8. A spiral built-in heating device according to claim 7, characterized in that: The lower end side wall of the lower half ring (42) is provided with a lower guide rod (422) which is slidably connected to the inner wall of the lower guide groove (33), and the side wall of the lower half ring (42) is provided with an upper tooth plate (423). A through groove (424) which is slidably connected to the outer wall of the lower tooth plate (413) is formed on one side of the upper tooth plate (423).

9. A spiral built-in heating device according to claim 8, characterized in that: The side wall of the upper half ring (41) is provided with a groove (411), the inner wall of the lower half ring (42) is installed with a counterweight (421), the inner side walls of the upper half ring (41) and the lower half ring (42) are fixedly connected with a plurality of balls (44), the inner side walls of the upper half ring (41) and the lower half ring (42) close to both sides of the balls (44) are both installed with tile-shaped magnets (43) that are magnetically attracted to the adsorption sleeve (52), the two ends of the shaft tooth (45) are rotatably connected to the inner wall of the positioning groove (32), and the shaft tooth (45) is respectively meshed with the lower tooth plate (413) and the upper tooth plate (423).

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