A straw length cutting device
Patent Information
- Application Number
- CN202522160857.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2025-09-30
- Filing Date
- 2025-10-13
- Publication Date
- 2026-09-18
- Estimated Expiration
- 2035-10-13
AI Technical Summary
[0004]有鉴于此,本实用新型旨在提出一种吸管定长切割装置,以解决传统吸管定长切割时需借助其他设备进行二次切割造成的生产成本高和工人的劳动强度大的问题
(1)本实用新型所述的一种吸管定长切割装置,通过圆盘一侧设置的第一安装槽和圆盘另一侧具有倾斜安装面结构的第二安装槽,并第一安装槽和第二安装槽内分别固定安装第一切刀和第二切刀,且第一切刀和第二切刀交替作业,可以对吸管进行分段切割,切割完成的吸管的两端分别具有平头和尖头效果,减少对吸管单独切角过程中原料的浪费,降低生产成本。
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Figure CN224765576U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of straw processing equipment, and in particular relates to a straw length cutting device. Background Technology
[0002] A straw, also known as a drinking straw, is a cylindrical hollow plastic or paper product with a pointed end. Its main function is to drink beverages from a cup, and it can also be used to suck out the marrow from cooked animal bones.
[0003] In the existing technology, the device for cutting straws to a fixed length can only cut the straws into a state where both ends are flat when performing straw cutting operations. The pointed end of the straw still needs to be cut a second time with the help of other equipment, which not only increases the investment cost of production equipment, but also increases the labor intensity of workers. Utility Model Content
[0004] In view of this, the present invention aims to propose a straw length cutting device to solve the problems of high production costs and high labor intensity caused by the need for secondary cutting with other equipment when cutting straws to a fixed length in the traditional way.
[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows: A straw length-cutting device includes a base, a traction component, a cutting component, and a collection box. The traction component is provided at the upper end of the base and is used to drive the straw to move linearly. The cutting component is provided on one side of the base and is located at the output end of the traction component. The cutting component is used to cut the straw. The collection box is provided on one side of the base and is located below the cutting component.
[0006] Furthermore, the traction assembly includes a mounting frame, a first traction unit, a second traction unit, and a first motor. The mounting frame is fixedly mounted on the upper end of the base. The first traction unit and the second traction unit are arranged inside the mounting frame and are arranged parallel to each other. The first motor is arranged on one side of the mounting frame and is fixedly mounted on the upper end of the base. The output shaft of the first motor can drive the first traction unit and the second traction unit to rotate respectively.
[0007] Furthermore, each side of the mounting frame is provided with a first circular hole, and a guide tube is fixedly installed around each first circular hole, with the two guide tubes located on the outer periphery of one side of the mounting frame.
[0008] Furthermore, the first traction unit and the second traction unit have the same structure. The first traction unit includes a first connecting frame, a second connecting frame and a driven roller. The first connecting frame is provided with a threaded hole. The two ends of the first connecting frame are respectively fixedly connected to the inner walls of the two sides of the mounting frame. A second connecting frame is provided at each end of the driven roller, and each second connecting frame is fixedly connected to one side of the first connecting frame. Each second connecting frame is provided with a second sliding groove, and the inner ring of the second sliding groove is slidably connected to the outer periphery of one end of the driven roller.
[0009] Furthermore, the first traction unit also includes a threaded rod, a ball bearing, and a handwheel. The outer periphery of the threaded rod is threadedly connected to a threaded hole. One end of the threaded rod is fixedly connected to the middle of one side of the handwheel, and the other end of the threaded rod is rotatably connected to the outer periphery of the ball bearing. The inner ring of the ball bearing is fixedly connected to the outer periphery of one end of the driven roller.
[0010] Furthermore, the first traction unit also includes a drive roller, the two outer ends of which are rotatably connected to the inner walls of both sides of the mounting frame, and the output end of the first motor can drive the drive roller to rotate.
[0011] Furthermore, the cutting assembly includes a housing, a second motor, a main shaft, and a cutting unit. One side of the housing is fixedly connected to one side of the base. The main shaft is installed inside the housing, and its two ends are rotatably connected to the two sides of the housing. One end of the main shaft is fixedly connected to the output shaft of the second motor, and the second motor is fixedly installed on one side of the housing. The cutting unit is installed inside the housing, and its inner ring is fitted around the main shaft. The cutting unit and the output shaft of the second motor form a synchronous rotation structure through the main shaft. The lower end face of the housing is inclined, and a baffle is rotatably installed on one side of the housing. A groove is provided on one side of the baffle, and the inner ring of the groove is located on one side of the traction assembly.
[0012] Furthermore, the cutting unit includes a disc, a mounting block, a positioning sleeve, a first cutter, and a second cutter. The disc has a second circular hole in its center, and the inner ring of the second circular hole slides around the outer edge of the spindle. One side of the disc has a first mounting groove, in which the first cutter is fixedly mounted by a first fixing screw. The other side of the disc has a second mounting groove, the mounting surface of which is inclined, and the second cutter is positioned within it. The mounting block matches the second mounting groove, and one side of the mounting block abuts against one side of the second cutter. The mounting block is fixedly connected to the second mounting groove by a fixing screw, and the mounting block is used to define the relative position of the second cutter within the second mounting groove. There are two positioning sleeves, parallel to each other and facing each other at both ends of the disc. The inner ring of each positioning sleeve is fitted around the outer edge of the spindle, and each positioning sleeve is fixedly connected to the outer edge of the spindle by a second fixing screw. The positioning sleeves are used to define the relative position of the disc on the spindle.
[0013] Compared with the prior art, the straw length cutting device of this utility model has the following advantages: (1) The straw length cutting device of this utility model has a first mounting groove on one side of the disc and a second mounting groove on the other side of the disc with an inclined mounting surface structure. The first cutter and the second cutter are fixedly installed in the first mounting groove and the second mounting groove respectively. The first cutter and the second cutter work alternately, which can cut the straw into segments. The two ends of the cut straw have flat and pointed ends respectively, which reduces the waste of raw materials in the process of cutting the straw individually and reduces the production cost.
[0014] (2) The straw length cutting device of this utility model has two positioning sleeves that are slidably connected to the outside of the main shaft. The two positioning sleeves can be fixed to the outside of the main shaft by fixing screws. The cutting unit whose position is limited by the two positioning sleeves can be adjusted to adapt to straws of different lengths for cutting, thereby improving the utilization rate of the device and reducing production costs. Attached Figure Description
[0015] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a schematic diagram of the overall structure of a straw length cutting device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the traction assembly described in an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the first traction unit removal mounting bracket in an embodiment of the present invention; Figure 4 This is a schematic diagram of the cutting assembly described in an embodiment of the present invention; Figure 5 This is an exploded structural diagram of the cutting unit described in an embodiment of the present invention.
[0016] Explanation of reference numerals in the attached figures: 1-Base; 2-Traction assembly; 21-Mounting bracket; 211-First circular hole; 212-Guide tube; 22-First traction unit; 221-First connecting bracket; 2211-Threaded hole; 222-Second connecting bracket; 2221-Second slide groove; 223-Driven roller; 224-Threaded rod; 225-Ball bearing; 226-Handwheel; 227-Driven roller; 23-Second traction unit; 24-First motor; 3-Cutting assembly; 31-Outer shell; 311-Baffle; 312-Groove; 32-Second motor; 33-Main shaft; 34-Cutting unit; 341-Disc; 342-Mounting block; 343-Positioning sleeve; 344-First cutter; 345-Second cutter; 346-Second circular hole; 347-First mounting groove; 348-Second mounting groove; 4-Collection box. Detailed Implementation
[0017] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0018] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0021] like Figure 1As shown, a straw-length cutting device includes a base 1, a traction component 2, a cutting component 3, and a collection box 4. The traction component 2 is installed at the upper end of the base 1 and is used to drive the straw to move linearly. The cutting component 3 is installed on one side of the base 1 and is located at the output end of the traction component 2. The cutting component 3 is used to cut the straw. The collection box 4 is installed on one side of the base 1 and is located below the cutting component 3. The straw is conveyed to the cutting component 3 by the traction component 2 and cut by the cutting component 3. The straws cut by the cutting component 3 fall into the detachable collection box 4 for collection. The detachable collection box 4 can be replaced after collecting enough straws, which increases the continuity of work, reduces downtime for cleaning, and improves work efficiency.
[0022] like Figures 2-3 As shown, the traction assembly 2 includes a mounting frame 21, a first traction unit 22, a second traction unit 23, and a first motor 24. The mounting frame 21 is fixedly mounted on the upper end of the base 1. The first traction unit 22 and the second traction unit 23 are arranged inside the mounting frame 21, and the first traction unit 22 and the second traction unit 23 are arranged parallel to each other. The first motor 24 is arranged on one side of the mounting frame 21 and is fixedly mounted on the upper end of the base 1. The output shaft of the first motor 24 can drive the first traction unit 22 and the second traction unit 23 to rotate respectively. A first circular hole 211 is provided on each side of the mounting frame 21, and a guide is fixedly installed around the periphery of each first circular hole 211. The tube 212, and the two guide tubes 212 are respectively located on one side of the outer periphery of the mounting frame 21. By setting up a first traction unit 22 and a second traction unit 23 that are parallel to each other, and the output shaft of the first motor 24 is simultaneously connected to the execution end of the first traction unit 22 and the second traction unit 23, a synchronous rotation structure is formed to traction and transport the straw, thereby improving the stability of the straw transport. The axis of the first round hole 211 and the guide tube 212 coincides with the transport plane of the first traction unit 22 and the second traction unit 23, thereby improving the accuracy of the straw transport position and reducing the deviation during the straw transport process. The first motor 24 is existing technology, model GF47-0.75-4.
[0023] The first traction unit 22 and the second traction unit 23 have the same structure. The first traction unit 22 includes a first connecting frame 221, a second connecting frame 222 and a driven roller 223. The first connecting frame 221 is provided with a threaded hole 2211. The two ends of the first connecting frame 221 are respectively fixedly connected to the two sides of the mounting frame 21. The second connecting frame 222 is provided on one side of the first connecting frame 221. The second connecting frame 222 is provided with a second sliding groove 2221, and the inner ring of the second sliding groove 2221 is slidably connected to the outer periphery of one end of the driven roller 223. By setting the driven roller 223 slidably connected in the second sliding groove 2221, the driven roller 223 can adjust its position to adapt to different specifications of suction pipes when traction and transporting the suction pipe, reducing manual adjustment and reducing manual labor.
[0024] The first traction unit 22 and the second traction unit 23 have the same structure. The first traction unit 22 includes a first connecting frame 221, a second connecting frame 222, and a driven roller 223. The first connecting frame 221 has a threaded hole 2211. Both ends of the first connecting frame 221 are fixedly connected to the inner walls of both sides of the mounting frame 21. A second connecting frame 222 is provided at both ends of the driven roller 223, and each second connecting frame 222 is fixedly connected to one side of the first connecting frame 221. Each second connecting frame 222 has a second sliding groove 2221, and the inner ring of the second sliding groove 2221 is slidably connected to the outer periphery of one end of the driven roller 223. The first traction unit 22 also includes a threaded rod 224, a ball bearing 225, and a handwheel 226. The outer periphery of the threaded rod 224 is threadedly connected to the threaded hole 2211, and one end of the threaded rod 224 is fixed. The threaded rod 224 is connected to the middle of one side of the handwheel 226. The other end of the threaded rod 224 is rotatably connected to the outer periphery of the ball bearing 225. The inner ring of the ball bearing 225 is fixedly connected to the outer periphery of one end of the driven roller 223. By setting the threaded rod 224 and the ball bearing 225 rotatably connected to one end of the threaded rod 224, and the inner ring of the ball bearing 225 is sleeved on the outer periphery of one end of the driven roller 223, and the outer periphery of the threaded rod 224 is threadedly connected to the threaded hole 2211, rotating the handwheel 226 can adjust the distance between the driving roller 227 and the driven roller 223 to adapt to the traction and conveying of different specifications of suction tubes. In this embodiment, the fixed distance between the driving roller 227 and the driven roller 223 is 3-4mm. To further illustrate, the outer diameter of the suction tube adapted to this embodiment is 4-5mm. The ball bearing 225 is prior art, model 7310B.
[0025] The first traction unit 22 also includes an active roller 227. The outer ends of the active roller 227 are rotatably connected to the inner walls of both sides of the mounting frame 21. The output end of the first motor 24 can drive the active roller 227 to rotate. The outer periphery of the active roller 227 and the driven roller 223 do not contact each other and the distance is adjustable. The outer periphery of the active roller 227 is an elastic rubber structure to prevent the driven roller 223 from damaging the surface of the straw during traction and transportation, thereby improving the quality of the straw.
[0026] like Figures 4-5 As shown, the cutting assembly 3 includes a housing 31, a second motor 32, a main shaft 33, and a cutting unit 34. One side of the housing 31 is fixedly connected to one side of the base 1. The main shaft 33 is disposed inside the housing 31, and its two ends are rotatably connected to the two sides of the housing 31. One end of the main shaft 33 is fixedly connected to the output shaft of the second motor 32, and the second motor 32 is fixedly installed on one side of the housing 31. The cutting unit 34 is disposed inside the housing 31, and the inner ring of the cutting unit 34 is fitted around the outer edge of the main shaft 33. The cutting unit 34 and the output shaft of the second motor 32 form a synchronous rotation structure through the main shaft 33. The axis of the main shaft 33 is at the same horizontal height as the axis of the guide tube 212. The second motor 32 is existing technology, model 110ST-M02025; the lower end face of the outer shell 31 is inclined, and a baffle 311 is rotatably installed on one side of the outer shell 31. A groove 312 is provided on one side of the baffle 311, and the inner ring of the groove 312 is located on the outer periphery of one end of the traction component 2. By setting the inclined lower end face, the straw is prevented from falling into the outer shell 31 and needing to be picked up manually, reducing manual labor. The baffle 311 prevents the straw from splashing and falling to the ground during the cutting process, causing pollution and reducing material waste. The hinged baffle 311 facilitates the adjustment and maintenance of the cutting unit 34. The baffle 311 is made of transparent acrylic material, which allows real-time observation of the straw cutting process and the working status of the cutting unit 34.
[0027] The cutting unit 34 includes a disc 341, a mounting block 342, a positioning sleeve 343, a first cutter 344, and a second cutter 345. The disc 341 has a second circular hole 346 in the middle, and the inner ring of the second circular hole 346 is slidably sleeved on the outer side of the main shaft 33. The disc 341 has a first mounting groove 347 on one side, and the first cutter 344 is fixedly installed in the first mounting groove 347 by a first fixing screw. The disc 341 has a second mounting groove 348 on the other side. The mounting surface of the second mounting groove 348 is inclined, and the second cutter 345 is installed in the second mounting groove 348. By setting the second mounting groove 348 with an inclined mounting surface, the straw can be cut at an angle, reducing the need for secondary cutting of the straw, reducing equipment investment, improving work efficiency, reducing manual labor, and lowering production costs.
[0028] The mounting block 342 matches the second mounting groove 348, and one side of the mounting block 342 abuts against one side of the second cutter 345. The mounting block 342 is fixedly connected to the second mounting groove 348 by fixing screws. The mounting block 342 is used to limit the relative position of the second cutter 345 in the second mounting groove 348. By setting the mounting block 342 to press and install the second cutter 345, and the second cutter 345 is set at an angle for cutting the pointed end of the straw, the mounting block 342 improves the stability of the installation of the second cutter 345, reduces safety hazards, improves the cutting stability, and improves product quality.
[0029] There are two positioning sleeves 343, which are parallel to each other and facing each other at both ends of the disc 341. The inner ring of each positioning sleeve 343 is respectively fitted onto the outer periphery of the main shaft 33, and each positioning sleeve 343 is fixedly connected to the outer periphery of the main shaft 33 by a second fixing screw. The positioning sleeves 343 are used to limit the relative position of the disc 341 on the main shaft 33. By setting two positioning sleeves 343 that can be fixedly connected to the outer periphery of the main shaft 33, the position of the disc 341 can be adjusted, and the cutting length of the straw can be adjusted to adapt the device to the cutting of straws of different specifications, thereby improving the utilization rate of the device, reducing equipment investment, and reducing production costs.
[0030] The working process of a straw length cutting device: The working process of the straw length cutting device is as follows: The straw to be cut first passes through the guide tube 212 and the first circular hole 211 on one side of the mounting frame 21, and enters the traction assembly 2 composed of the first traction unit 22 and the second traction unit 23. After the first motor 24 starts, it drives the active roller 227 of the first traction unit 22 to rotate synchronously with the second traction unit 23 through the synchronous belt. At the same time, the driven roller 223, under the adjustment of the threaded rod 224, the handwheel 226 and the ball bearing 225, fits against the straw, and cooperates with the active roller 227 to stably pull the straw to a linear displacement until one end of the straw passes through the first circular hole 211, the guide tube 212 and the outer shell 31 of the cutting assembly 3 on the other side of the mounting frame 21. The side baffle 311 has a groove 312; then the second motor 32 starts, driving the main shaft 33 and the cutting unit 34, which is sleeved on the main shaft 33 and whose position is limited by the positioning sleeve 343, to rotate. The first cutter 344 on the disc 341 and the second cutter 345, which is fixed in the second mounting groove 348 by the mounting block 342, cut the straw to a fixed length. The first cutter 344 is used to cut one end of the straw with a flat head, and the second cutter 345 is used to cut one end of the straw with a pointed head. The first cutter 344 and the second cutter 345 work alternately. The cut straw section falls along the lower slope of the outer shell 31 into the collection box 4 located on one side of the base 1 below the cutting assembly 3, completing one straw cutting and collection process.
[0031] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A straw cutting-to-length apparatus, characterized by: The device includes a base (1), a traction component (2), a cutting component (3), and a collection box (4). The traction component (2) is installed at the upper end of the base (1) and is used to drive the straw to move linearly. The cutting component (3) is installed on one side of the base (1) and is located at the output end of the traction component (2). The cutting component (3) is used to cut the straw. The collection box (4) is installed on one side of the base (1) and is located below the cutting component (3).
2. A straw length cutting device according to claim 1, wherein: The traction assembly (2) includes a mounting frame (21), a first traction unit (22), a second traction unit (23), and a first motor (24). The mounting frame (21) is fixedly installed on the upper end of the base (1). The first traction unit (22) and the second traction unit (23) are arranged inside the mounting frame (21), and the first traction unit (22) and the second traction unit (23) are arranged parallel to each other. The first motor (24) is arranged on one side of the mounting frame (21), and the first motor (24) is fixedly installed on the upper end of the base (1). The output shaft of the first motor (24) can drive the first traction unit (22) and the second traction unit (23) to rotate respectively.
3. A straw length cutting device according to claim 2, wherein: The mounting bracket (21) has a first circular hole (211) on each side. A guide tube (212) is fixedly installed on the periphery of each first circular hole (211), and the two guide tubes (212) are located on the periphery of one side of the mounting bracket (21).
4. A straw length cutting device as claimed in claim 2, wherein: The first traction unit (22) and the second traction unit (23) have the same structure. The first traction unit (22) includes a first connecting frame (221), a second connecting frame (222) and a driven roller (223). The first connecting frame (221) is provided with a threaded hole (2211). The two ends of the first connecting frame (221) are respectively fixedly connected to the inner walls of the two sides of the mounting frame (21). The two ends of the driven roller (223) are respectively provided with a second connecting frame (222), and each second connecting frame (222) is respectively fixedly connected to one side of the first connecting frame (221). Each second connecting frame (222) is provided with a second sliding groove (2221), and the inner ring of the second sliding groove (2221) is slidably connected to the outer periphery of one end of the driven roller (223).
5. A straw length cutting device as claimed in claim 4, wherein: The first traction unit (22) also includes a threaded rod (224), a ball bearing (225) and a handwheel (226). The outer periphery of the threaded rod (224) is threadedly connected to the threaded hole (2211). One end of the threaded rod (224) is fixedly connected to the middle of one side of the handwheel (226). The other end of the threaded rod (224) is rotatably connected to the periphery of the ball bearing (225), and the inner ring of the ball bearing (225) is fixedly connected to the periphery of one end of the driven roller (223).
6. A straw length cutting device as defined in claim 4, wherein: The first traction unit (22) also includes an active roller (227), the outer ends of which are rotatably connected to the inner walls of the two sides of the mounting frame (21), and the output end of the first motor (24) can drive the active roller (227) to rotate.
7. A straw length cutting device as defined in claim 1, wherein: The cutting assembly (3) includes a housing (31), a second motor (32), a main shaft (33), and a cutting unit (34). One side of the housing (31) is fixedly connected to one side of the base (1). The main shaft (33) is installed inside the housing (31), and the outer peripheries of the two ends of the main shaft (33) are rotatably connected to the two sides of the housing (31). One end of the main shaft (33) is fixedly connected to the output shaft of the second motor (32), and the second motor (32) is fixedly installed on one side of the outer periphery of the housing (31). The cutting unit (34) is installed inside the housing (31), and the inner ring of the cutting unit (34) is sleeved around the outer periphery of the main shaft (33). The cutting unit (34) forms a synchronous rotation structure with the output shaft of the second motor (32) through the main shaft (33). The lower end face of the outer shell (31) is inclined, and a baffle (311) is rotatably provided on one side of the outer shell (31). A groove (312) is provided on one side of the baffle (311), and the inner ring of the groove (312) is located on the outer periphery of one end of the traction assembly (2).
8. A straw length cutting device according to claim 7, characterized in that: The cutting unit (34) includes a disc (341), a mounting block (342), a positioning sleeve (343), a first cutter (344), and a second cutter (345). The disc (341) has a second circular hole (346) in the middle, and the inner ring of the second circular hole (346) is slidably sleeved on the outer side of the spindle (33). The disc (341) has a first mounting groove (347) on one side, and the first cutter (344) is fixedly installed in the first mounting groove (347) by a first fixing screw. The disc (341) has a second mounting groove (348) on the other side, and the mounting surface of the second mounting groove (348) is an inclined surface, and the second cutter (345) is installed in the second mounting groove (348). The mounting block (342) matches the second mounting groove (348), and one side of the mounting block (342) abuts against one side of the second cutter (345). The mounting block (342) is fixedly connected to the second mounting groove (348) by fixing screws. The mounting block (342) is used to define the relative position of the second cutter (345) in the second mounting groove (348). There are two positioning sleeves (343). The two positioning sleeves (343) are parallel to each other and opposite to each other at both ends of the disc (341). The inner ring of each positioning sleeve (343) is respectively fitted around the outer side of the main shaft (33), and each positioning sleeve (343) is fixedly connected to the outer side of the main shaft (33) by a second fixing screw. The positioning sleeves (343) are used to limit the relative position of the disc (341) on the main shaft (33).