Machine tool special for milling groove

By setting up a turntable and cleaning mechanism on a special machine tool for milling slots, the turntable drives the cleaning mechanism to clean the debris in the feeding mechanism, and combines the elastic mechanism to achieve thorough cleaning of debris, which solves the problem of debris falling in the working area or Rack problems improve processing efficiency and reduce manual cleaning requirements.

CN119175591AInactive Publication Date: 2024-12-24GAOYOU YONGFA MACHINERY
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202411199135.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-08-29
Publication Date
2024-12-24
Estimated Expiration
Not applicable · inactive patent

AI Technical Summary

Technical Problem

Debris produced during existing milling milling falls on the work area or rack, resulting in inefficiency and requires extensive manual cleaning.

Method used

A special machine tool for milling grooves is designed, including setting up a rotary dial and cleaning mechanism on the workbench, and a feeding mechanism is set up below the rotary dial. The debris generated during milling grooves fall on the feeding mechanism, and cleaned by the cleaning mechanism, and rotated by the turntable. Drive the cleaning mechanism to clean up debris, and combine the elastic mechanism to eject the debris under the bristles to achieve a thorough cleaning.

Benefits of technology

Effectively avoid debris falling on the work area and rack, reduce manual cleaning, reduce costs, improve cleaning efficiency, and ensure more thorough cleaning.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN119175591A_ABST
    Figure CN119175591A_ABST
Patent Text Reader

Abstract

The invention relates to the technical field of machine tools, and particularly discloses a special machine tool for groove milling, which comprises a rack, a workbench is arranged on the rack, the workbench comprises a turntable, and a cleaning mechanism is mounted on the turntable; a material receiving mechanism is arranged below the workbench, chippings generated during groove milling fall on the material receiving mechanism, and the chippings in the material receiving mechanism are cleaned through the cleaning mechanism. According to the groove milling machine, chippings generated during groove milling fall on the material receiving mechanism, then the chippings in the material receiving mechanism are cleaned through the cleaning mechanism, on one hand, the chippings can be prevented from falling on a working area and the rack, on the other hand, the chippings are convenient to collect and clean, and then manpower is reduced; chippings in the material receiving mechanism are cleaned through the cleaning mechanism, the chippings can be cleaned without external power, and the cost can be reduced.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The invention belongs to the technical field of machine tools, and in particular relates to a special machine tool for slot milling. Background Art

[0002] The slot milling machine is mainly used for the secondary processing of automatic lathes. It can be modified to realize the milling of flat slots and other processes, and can also be equipped with drilling, tapping, chamfering and other processes. It is also called a compound machine and a special machine tool. It can also be used for the milling of slots of various non-standard metal materials such as metal materials and plastic materials.

[0003] Currently, the slot milling machines for workpiece processing are generally single-station. The staff places the workpiece on the workbench, clamps it with a fixture, and waits for the slot milling. After the slot milling is completed, the workpiece is removed from the workbench. Only one workpiece can be processed at a time, resulting in low processing efficiency. In addition, the debris generated during slot milling falls on the working area or the frame and needs to be cleaned manually, which consumes a lot of manpower. Summary of the invention

[0004] The object of the present invention is to provide a special machine tool for slot milling to solve the problem in the prior art that when slotting a workpiece, debris falls on a working area or a machine frame.

[0005] To achieve the above object, the present invention provides the following technical solution: a slot milling machine tool, comprising a frame, a workbench is arranged on the frame, the workbench comprises a turntable, and a cleaning mechanism is installed on the turntable;

[0006] A material receiving mechanism is arranged below the workbench, and the debris generated during the slot milling falls on the material receiving mechanism, and the debris in the material receiving mechanism is cleaned by the cleaning mechanism.

[0007] Preferably, the workbench comprises a turntable, a fixing groove is provided on the turntable, the fixing groove is used to fix the fixture, and a screw hole is provided on the side wall of the turntable, the screw hole is used to connect the cleaning mechanism.

[0008] Preferably, the material receiving mechanism comprises a first material receiving ring and a second material receiving ring, both of which are semicircular in shape, and both of which are provided with a groove structure, and the first material receiving ring and the second material receiving ring are connected to form an integral annular structure.

[0009] Preferably, the inner diameter of the annular structure is smaller than the diameter of the turntable, and the outer diameter of the annular structure is larger than the diameter of the turntable.

[0010] Preferably, a material discharge hole is provided at the bottom end of the first material receiving ring, and the first material receiving ring at the material discharge hole is connected to a material discharge pipe.

[0011] Preferably, the inner walls of the first material receiving ring and the second material receiving ring are both provided with large toothed rings, and after the first material receiving ring and the second material receiving ring are connected together, the two large toothed rings are in a ring shape.

[0012] Preferably, the cleaning mechanism comprises a cleaning brush housing and bristles, both of which are arranged in a circular shape, the bristles are located at the lower end of the cleaning brush housing, and a small gear ring is arranged on the side wall of the cleaning brush housing, and the small gear ring is matched with the large gear ring.

[0013] Preferably, a bearing seat is fixed to the upper end of the cleaning brush housing, the bearing seat is fixedly connected to the outer ring of the bearing, the inner ring of the bearing is fixedly connected to the connecting shaft, the connecting shaft passes through the bracket, and the bracket supports the connecting shaft.

[0014] Preferably, the bracket is provided with a U-shaped hole corresponding to the connecting shaft, and the position of the connecting shaft can be adjusted through the provided U-shaped hole. A screw is inserted at one side end of the bracket, and the screw is threadedly connected to the screw hole provided in the turntable.

[0015] Preferably, the elastic mechanism comprises a spring sheet and a protrusion, the spring sheet is arc-shaped, the spring sheet is arranged along the circumferential direction of the annular structure, and the side wall of the spring sheet is provided with at least one protrusion.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. In the present invention, the debris generated during the milling of the groove falls on the material receiving mechanism, and then the debris in the material receiving mechanism is cleaned by the cleaning mechanism. On the one hand, the debris can be prevented from falling on the working area and the frame, and on the other hand, the debris can be easily collected and cleaned, thereby reducing labor.

[0018] 2. In the present invention, when the turntable rotates, the cleaning mechanism is driven to rotate, and the debris in the material docking mechanism is cleaned by the cleaning mechanism. The debris can be cleaned without external power, which can reduce costs.

[0019] 3. In the present invention, the debris at the spring piece is ejected to the bottom of the bristles through the elastic mechanism, and the debris is cleaned after the bristles pass through again, avoiding the debris from accumulating at the corners of the first material receiving ring or the second material receiving ring, so that the cleaning is more thorough. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A perspective view of the present invention;

[0021] Figure 2 It is a front view of the present invention;

[0022] Figure 3 A top view of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of the material receiving mechanism in the present invention;

[0024] Figure 5 It is an exploded view of the workbench in the present invention;

[0025] Figure 6 It is a schematic diagram of the structure of the cleaning mechanism in the present invention;

[0026] Figure 7 It is a structural schematic diagram of the support mechanism in the present invention;

[0027] Figure 8 It is a structural schematic diagram of the elastic mechanism in the present invention.

[0028] In the figure: 1, frame; 2, workbench; 21, turntable; 22, fixing slot; 23, screw hole; 24, workbench motor; 3, vertical milling mechanism; 31, vertical milling head; 32, vertical bed; 33, vertical motor; 4, first transverse milling mechanism; 41, first transverse milling head; 42, first transverse motor; 43, first transverse bed; 5, second transverse milling mechanism; 51, second transverse milling head; 52, second transverse motor; 53, second transverse bed; 6, material receiving mechanism; 61, first material receiving ring; 611, large gear ring; 62, second receiving ring Material ring; 63, fixed foot; 64, discharge hole; 65, discharge pipe; 7, cleaning mechanism; 71, cleaning brush housing; 711, small gear ring; 72, bristles; 73, bearing seat; 74, bearing; 75, connecting shaft; 76, bracket; 761, U-shaped hole; 77, screw; 78, fastening screw; 8, supporting mechanism; 81, first flange; 82, sliding rod; 83, sliding sleeve; 84, second flange; 85, fastening knob; 9, clamp; 10, elastic mechanism; 101, spring piece; 102, protrusion. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0030] Reference Figure 1-Figure 3As shown, the present invention provides a special machine tool for slot milling, including a frame 1, a workbench 2 is arranged on the frame 1, the workbench 2 is used to fix a clamp 9, a vertical milling mechanism 3 is arranged on one side of the workbench 2, a first horizontal milling mechanism 4 is arranged on one side of the workbench 2, and a second horizontal milling mechanism 5 is arranged on one side of the workbench 2. One side of the workbench 2 is a loading station. A worker places a workpiece on the workbench 2 at the loading station and then fixes the workpiece with a clamp 9. The workbench 2 rotates, and the workpiece passes through the vertical milling mechanism 3, the first horizontal milling mechanism 4 and the second horizontal milling mechanism 5 in sequence and then returns to the loading station. The vertical milling mechanism 3 can be used to mill the workpiece vertically, and the first horizontal milling mechanism 4 and the second horizontal milling mechanism 5 can be used to mill the workpiece horizontally. Two horizontal milling mechanisms are provided, and the workpiece can be milled horizontally synchronously, thereby improving the processing efficiency.

[0031] Furthermore, the vertical milling mechanism 3 includes a vertical milling head 31 , a vertical bed 32 and a vertical motor 33 . The vertical motor 33 is fixed on the vertical bed 32 . The vertical motor 33 is used to drive the vertical milling head 31 to vertically mill grooves on the workpiece.

[0032] Furthermore, the first transverse milling mechanism 4 includes a first transverse milling head 41, a first transverse motor 42 and a first transverse bed 43. The first transverse motor 42 is fixed on the first transverse bed 43. The first transverse motor 42 is used to drive the first transverse milling head 41 to transversely mill grooves on the workpiece.

[0033] Furthermore, the second transverse milling mechanism 5 includes a second transverse milling head 51, a second transverse motor 52 and a second transverse bed 53. The second transverse motor 52 is fixed to the second transverse bed 53. The second transverse motor 52 is used to drive the second transverse milling head 51 to transversely mill grooves on the workpiece.

[0034] Furthermore, a material receiving mechanism 6 is provided under the workbench 2. The debris generated during the milling of the grooves falls on the material receiving mechanism 6, and then the debris in the material receiving mechanism 6 is cleaned by the cleaning mechanism 7. On the one hand, it can prevent the debris from falling on the working area and the frame 1. On the other hand, it is convenient to collect the debris and clean it, thereby reducing labor.

[0035] It should be noted that the second transverse milling mechanism 5 can also be replaced by a sweeping and blowing mechanism, which includes an air nozzle, a support frame, an air pipe and an air source. The support frame supports the air nozzle, and the air nozzle can be adjusted to face the workpiece. High-pressure gas is provided by the air source, passed through the air pipe, and sprayed out by the air nozzle to sweep and blow the workpiece after milling to clean up the debris.

[0036] like Figure 4-Figure 5As shown, the workbench 2 includes a turntable 21, on which a fixing groove 22 is opened. The fixing groove 22 is a T-shaped groove. The fixing groove 22 is arranged on the turntable 21, and the fixing groove 22 is used to fix the fixture 9. The turntable 21 is connected to the workbench motor 24 through the main shaft. The workbench motor 24 is fixed on the frame 1, and the turntable 21 and the fixture 9 are driven to rotate by the workbench motor 24.

[0037] In this embodiment, a screw hole 23 is opened on the side wall of the turntable 21, and the screw hole 23 is used to connect the cleaning mechanism 7. When the turntable 21 rotates, the cleaning mechanism 7 is driven to rotate, and the debris in the docking mechanism 6 is cleaned by the cleaning mechanism 7. The debris can be cleaned without external power, which can reduce costs.

[0038] Furthermore, the material receiving mechanism 6 includes a first material receiving ring 61 and a second material receiving ring 62, both of which are semicircular in shape, and both are provided with a groove structure, the first material receiving ring 61 and the second material receiving ring 62 are connected together to form an integral annular structure, and the connection between the first material receiving ring 61 and the second material receiving ring 62 is provided with a fixing foot 63, and a through hole is provided on the fixing foot 63, the fixing feet 63 of the first material receiving ring 61 and the second material receiving ring 62 are abutted together, and then bolts are passed through the through holes of the two fixing feet 63 to fix the first material receiving ring 61 and the second material receiving ring 62 together, thereby facilitating the installation of the first material receiving ring 61 and the second material receiving ring 62.

[0039] Furthermore, the inner diameter of the annular structure formed by connecting the first material receiving ring 61 and the second material receiving ring 62 together is smaller than the diameter of the turntable 21, and the outer diameter of the annular structure is larger than the diameter of the turntable 21, so that the debris falling from the turntable 21 can enter the annular structure and be collected by the annular structure.

[0040] Furthermore, the first receiving ring 61 is close to the loading station, and a discharge hole 64 is opened at the bottom end of the first receiving ring 61. The first receiving ring 61 at the discharge hole 64 is connected to a discharge pipe 65, and the discharge pipe 65 is connected to an external pipe. After the debris enters the discharge pipe 65 through the discharge hole 64, it is discharged or collected from the external pipe.

[0041] In this embodiment, the pipeline connected to the feed pipe 65 can be a hose, and can also be connected to the pipeline through a quick-connect flange.

[0042] In this embodiment, the inner walls of the first material receiving ring 61 and the second material receiving ring 62 are both provided with large toothed rings 611 . After the first material receiving ring 61 and the second material receiving ring 62 are connected together, the two large toothed rings 611 are ring-shaped.

[0043] See also Figure 6As shown, the cleaning mechanism 7 includes a cleaning brush housing 71 and bristles 72. The cleaning brush housing 71 and the bristles 72 are both arranged in a circular shape. The bristles 72 are located at the lower end of the cleaning brush housing 71, and the bristles 72 can be fixed to the cleaning brush housing 71 by screws or a snap-fit ​​structure.

[0044] Furthermore, a small gear ring 711 is provided on the side wall of the cleaning brush housing 71, and the small gear ring 711 is matched with the large gear ring 611. When the turntable 21 rotates, the cleaning brush housing 71 is driven to revolve around the central axis of the turntable 21, and then the small gear ring 711 is driven to rotate by the large gear ring 611, so that the cleaning brush housing 71 and the bristles 72 rotate on their own, realizing the double rotation of the bristles 72. Compared with the existing technology, which only cleans the docking mechanism 6 by letting the bristles 72 revolve along the turntable 21, the double-rotating bristles 72 clean the docking mechanism 6 more thoroughly.

[0045] Furthermore, a bearing seat 73 is fixed to the upper end of the cleaning brush housing 71. The bearing seat 73 is fixedly connected to the outer ring of the bearing 74. The inner ring of the bearing 74 is fixedly connected to the connecting shaft 75. The connecting shaft 75 passes through the bracket 76, and the bracket 76 supports the connecting shaft 75. The connecting shaft 75 is connected to the cleaning brush housing 71 through the bearing 74 and the bearing seat 73, so as to facilitate the rotation of the cleaning brush housing 71.

[0046] Furthermore, the bracket 76 is provided with a U-shaped hole 761 corresponding to the connecting shaft 75, and the position of the connecting shaft 75 can be adjusted through the set U-shaped hole 761, thereby facilitating the adjustment of the distance between the small gear ring 711 and the large gear ring 611, thereby avoiding the situation where the small gear ring 711 cannot mesh with the large gear ring 611 due to installation errors after the connecting shaft 75 in a fixed position is installed.

[0047] Furthermore, the connecting shaft 75 is fixed to the bracket 76 by a fastening screw 78. A screw hole is opened on the side wall of the bracket 76 for the connecting shaft 75, and the screw hole is perpendicular to the connecting shaft 75. The screw hole is connected to the U-shaped hole 761, so that after the fastening screw 78 is screwed into the screw hole, the connecting shaft 75 is fixed by the friction force between the fastening screw 78 and the connecting shaft 75.

[0048] Furthermore, a screw 77 is inserted into one side end of the bracket 76, and the screw 77 is threadedly connected to the screw hole 23 opened in the turntable 21. One end of the screw 77 is set to a cubic structure, and the bracket 76 has a cubic hole corresponding to the cubic structure. The cubic structure of the screw 77 is inserted into the cubic hole, and then the fastening screw 78 is screwed into the screw hole on the side wall of the bracket 76 and connected to the cubic hole. The screw 77 is fixed by the fastening screw 78. Through the design of this structure, it is convenient to install the bracket 76 on the turntable 21. When the turntable 21 rotates, it drives the bracket 76, the connecting shaft 75, the cleaning brush shell 71 and the bristles 72 to revolve along the central axis of the turntable 21, so as to clean the inside of the docking mechanism 6.

[0049] It should be noted that the side wall in the middle of the connecting shaft 75 can be set to a plane, and the fastening screw 78 is in contact with the plane, thereby increasing the friction between the fastening screw 78 and the connecting shaft 75, so that the connecting shaft 75 is fixed more stably.

[0050] See also Figure 7 As shown, the supporting mechanism 8 includes a first flange 81, a sliding rod 82, a sliding sleeve 83 and a second flange 84. The sliding rod 82 is fixed to the first flange 81, the sliding sleeve 83 is fixed to the second flange 84, the sliding rod 82 is inserted into the sliding sleeve 83, and the sliding rod 82 can be slidably connected to the sliding sleeve 83. The first flange 81 is fixed to the lower end of the first material receiving ring 61 or the second material receiving ring 62, and the second flange 84 is fixed to the upper end of the frame 1. A tightening knob 85 is installed on the upper side wall of the sliding sleeve 83. The tightening knob 85 is provided with a threaded column structure, and a screw hole is provided on the sliding sleeve 83 corresponding to the threaded column structure. When the tightening knob 85 is tightened, the sliding rod 82 is fixed by the friction force between the tightening knob 85 and the sliding rod 82, thereby realizing the installation of the material receiving mechanism 6. The sliding rod 82 slides along the sliding sleeve 83 to adjust the distance between the first flange 81 and the second flange 84, so as to facilitate the adjustment of the material receiving mechanism 6 to a horizontal state.

[0051] It should be understood that the more support mechanisms 8 are set, the higher the stability of the supporting material receiving mechanism 6 will be, but the cost will also increase, and more area on the top of the frame 1 will be occupied. Therefore, at least four support mechanisms 8 are set, which respectively support the first material receiving ring 61 and the second material receiving ring 62, so as to play a role of stable support.

[0052] It should be noted that the material receiving mechanism 6 has a simple structure and is light in weight, so a simply designed support mechanism 8 can support the material receiving mechanism 6. In other embodiments, support can also be provided by a support rod.

[0053] like Figure 8 As shown, the elastic mechanism 10 includes a spring sheet 101 and a protrusion 102. The spring sheet 101 is arc-shaped and arranged along the circumferential direction of the annular structure. The side wall of the spring sheet 101 is provided with at least one protrusion 102. The protrusion 102 extends along the width direction of the spring sheet 101, and the outer wall of the protrusion 102 is arc-shaped.

[0054] Furthermore, both ends of the spring piece 101 can be fixed to the inner wall of the first receiving ring 61 or the second receiving ring 62 by welding, so that the spring piece 101 can be deformed along the radial direction of the first receiving ring 61 after being squeezed.

[0055] In a specific implementation, when the cleaning brush shell 71 revolves, the bristles 72 or the cleaning brush shell 71 pass through the spring piece 101, squeeze the spring piece 101, and then pass through the protrusion 102, the spring piece 101 is deformed and separated from the spring piece 101 and the protrusion 102, and the spring piece 101 is reset under the action of elastic force, thereby ejecting the debris at the spring piece 101 to the bottom of the bristles 72. After the bristles 72 pass again, the debris is cleaned up to avoid the debris accumulating at the corners of the first material receiving ring 61 or the second material receiving ring 62, so that the cleaning is more thorough.

[0056] The working principle of the present invention is as follows:

[0057] When in use, the staff fixes the workpiece on the turntable 21 by the clamp 9 at the loading station, and the worktable motor 24 drives the turntable 21 to rotate. When the workpiece moves to the vertical milling mechanism 3, the workpiece can be milled vertically. When the workpiece moves to the first horizontal milling mechanism 4, the workpiece can be milled horizontally. When the workpiece moves to the second horizontal milling mechanism 5, the workpiece can be milled horizontally. If multiple grooves need to be opened in the horizontal direction of the workpiece, the efficiency of milling can be improved. When the workpiece moves to the loading station again, the staff takes out the processed workpiece.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A special machine tool for slot milling, characterized in that: include: A frame (1), wherein a workbench (2) is arranged on the frame (1), wherein the workbench (2) comprises a turntable (21), and a cleaning mechanism (7) is installed on the turntable (21); A material receiving mechanism (6) is provided below the workbench (2). Debris generated during slot milling falls onto the material receiving mechanism (6), and the debris in the material receiving mechanism (6) is cleaned by the cleaning mechanism (7).

2. A slot milling machine tool according to claim 1, characterized in that: The workbench (2) comprises a turntable (21), a fixing groove (22) is provided on the turntable (21), the fixing groove (22) is used to fix the clamp (9), and a screw hole (23) is provided on the side wall of the turntable (21), and the screw hole (23) is used to connect the cleaning mechanism (7).

3. A slot milling machine tool according to claim 1, characterized in that: The material receiving mechanism (6) comprises a first material receiving ring (61) and a second material receiving ring (62); the first material receiving ring (61) and the second material receiving ring (62) are both semicircular in shape, and the first material receiving ring (61) and the second material receiving ring (62) are both provided with a groove structure; the first material receiving ring (61) and the second material receiving ring (62) are connected to form an integral ring structure.

4. A slot milling machine tool according to claim 3, characterized in that: The inner diameter of the annular structure is smaller than the diameter of the rotating disk (21), and the outer diameter of the annular structure is larger than the diameter of the rotating disk (21).

5. A slot milling machine tool according to claim 4, characterized in that: A material discharge hole (64) is formed at the bottom end of the first material receiving ring (61), and the first material receiving ring (61) at the material discharge hole (64) is connected to a material discharge pipe (65).

6. A slot milling machine tool according to claim 5, characterized in that: The inner walls of the first material receiving ring (61) and the second material receiving ring (62) are both provided with large toothed rings (611); after the first material receiving ring (61) and the second material receiving ring (62) are connected together, the two large toothed rings (611) are in a ring shape.

7. A slot milling machine tool according to claim 1, characterized in that: The cleaning mechanism (7) comprises a cleaning brush housing (71) and bristles (72), the cleaning brush housing (71) and the bristles (72) are both arranged in a circular shape, the bristles (72) are located at the lower end of the cleaning brush housing (71), and the side wall of the cleaning brush housing (71) is provided with a small gear ring (711), and the small gear ring (711) is adapted to the large gear ring (611).

8. A slot milling machine tool according to claim 7, characterized in that: A bearing seat (73) is fixed to the upper end of the cleaning brush housing (71); the bearing seat (73) is fixedly connected to the outer ring of the bearing (74); the inner ring of the bearing (74) is fixedly connected to the connecting shaft (75); the connecting shaft (75) passes through the bracket (76); and the bracket (76) supports the connecting shaft (75).

9. A slot milling machine tool according to claim 8, characterized in that: The bracket (76) is provided with a U-shaped hole (761) corresponding to the connecting shaft (75), and the position of the connecting shaft (75) can be adjusted through the provided U-shaped hole (761). A screw rod (77) is inserted into one side end of the bracket (76), and the screw rod (77) is threadedly connected to a screw hole (23) provided on the rotating disk (21).

10. A slot milling machine tool according to any one of claims 1 to 9, characterized in that: The invention also comprises an elastic mechanism (10), wherein the elastic mechanism (10) comprises a spring sheet (101) and a protrusion (102), wherein the spring sheet (101) is arc-shaped, and the spring sheets (101) are arranged along the circumferential direction of the annular structure, and at least one protrusion (102) is arranged on the side wall of the spring sheet (101).