Steel structure end face grinding device for building

Abstract

The invention discloses a building steel structure end face grinding device, and belongs to the technical field of steel structure machining, the building steel structure end face grinding device comprises a workbench, vertical plates are symmetrically and fixedly mounted on the workbench, electric push rods are fixedly mounted on the vertical plates, and a shell is fixedly mounted at the output ends of the electric push rods; a grinding assembly used for grinding the steel structure is arranged on the shell, a mounting plate is fixedly mounted on the workbench, and a first half ring is fixedly mounted on the mounting plate. According to the scheme, through a spring telescopic clamping structure, the device can automatically adapt to cylindrical steel structures with different diameters, a clamp does not need to be replaced, the clamping and debugging time is shortened, a symmetrical grinding structure is adopted, the two sides of the end face of the steel structure can be ground at the same time, the single-time machining time is greatly shortened in cooperation with a to-be-ground part rotary grinding mode, and the machining efficiency is improved. And the shell can prevent chippings from splashing, the cleaning difficulty is reduced, meanwhile, the operation safety is improved, and the effect of improving the machining efficiency of the end face of the building steel structure is achieved.

Description

Technical Field

[0001] This invention relates to the field of steel structure processing technology, and more specifically, to a grinding device for the end face of steel structures used in construction. Background Technology

[0002] Steel structures are widely used in construction, machinery, bridges, and other fields due to their high strength and stability. Among them, steel pipes are used extensively and in huge quantities in construction projects, making them one of the most essential structural materials.

[0003] Among steel structure materials, steel pipes, due to their unique properties, are indispensable in load-bearing structural components, scaffolding and support systems, formwork, and enclosure systems. They have an extremely wide range of applications and are used in massive quantities in construction engineering, making them one of the most core structural materials. To facilitate the use of steel pipes, they often need to be cut. However, the cut ends may be uneven, deformed, or even tilted. Therefore, grinding equipment is needed to eliminate these defects, ensuring that the steel pipe's ends fit perfectly against other steel components without gaps, allowing for the even transmission of axial force and pressure, and preventing localized crushing and eccentric stress.

[0004] Most existing steel structure grinding equipment requires the user to hold a steel pipe and align one end with a high-speed rotating grinding disc for grinding. However, when grinding by hand, the pipe is prone to wobbling, causing the end face to tilt and requiring re-grinding, thus reducing grinding efficiency. Furthermore, hand-grinding prevents simultaneous grinding of both ends of the pipe, further reducing efficiency. In addition, the grinding process generates debris with high speed and sharp edges, posing a serious health hazard to the operator and preventing prolonged grinding operations, thus severely impacting grinding efficiency. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a steel structure end face grinding device for building construction, which can improve grinding efficiency.

[0006] To solve the above problems, the present invention adopts the following technical solution.

[0007] A steel structure end face grinding device for construction includes a worktable, vertical plates symmetrically fixedly mounted on the worktable, an electric push rod fixedly mounted on the vertical plates, a housing fixedly mounted on the output end of the electric push rod, a grinding component for grinding the steel structure provided on the housing, a mounting plate fixedly mounted on the worktable, a first half-ring fixedly mounted on the mounting plate, a mounting frame fixedly mounted on the worktable, an electric telescopic rod fixedly mounted on the mounting frame, and a second half-ring, forming a complete circle with the first half-ring, fixedly mounted on the output end of the electric telescopic rod. The first and second half-rings share a clamping component. The clamping assembly includes a first half gear rotatably mounted on a first half ring, a second half gear rotatably mounted on a second half ring to form a complete gear with the first half gear, a motor fixedly mounted on the mounting plate, and a complete gear meshing with the first half gear fixedly mounted on the output end of the motor, a first arc plate fixedly mounted on the first half gear, and a second arc plate cooperating with the first arc plate on the second half gear.

[0008] Furthermore, an mounting block is fixedly installed on the second half gear, a vertical groove is provided on the mounting block, a plug plate is slidably and sealingly installed in the vertical groove, an mounting rod that slidably and sealingly cooperates with the mounting block is fixedly installed on the plug plate, a first spring is installed between the plug plate and the vertical groove, and the second arc-shaped plate is fixedly connected to the end of the mounting rod away from the first spring.

[0009] Furthermore, a cavity is provided on the second arc-shaped plate, a hole is provided on the bottom wall of the cavity, and an air pipe communicating with the vertical groove is fixedly installed on the top wall of the cavity.

[0010] Furthermore, the polishing assembly includes polishing holes formed on the housing, a polishing disc is provided inside the housing, a linkage block is fixedly installed on the inner top wall of the housing, a vertical rod is slidably installed on the linkage block, a linkage plate is fixedly installed on the vertical rod, and polishing brushes are uniformly fixedly installed on the linkage plate.

[0011] Furthermore, a second spring is installed between the vertical rod and the linkage block, a first magnet is embedded in the vertical rod, and an electromagnet electrically connected to the motor is embedded in the linkage block.

[0012] Furthermore, the housing contains polishing fluid, a liquid pump is fixedly installed on the inner wall of the housing, a water pipe is fixedly installed on the output end of the liquid pump, a cavity is formed on the linkage plate, and water holes are evenly formed on the bottom wall of the cavity.

[0013] Furthermore, a horizontal plate is detachably installed on the side wall of the housing, and a filter plate is fixedly installed on the horizontal plate.

[0014] Furthermore, a plate is detachably mounted on the housing, and the grinding disc is mounted on the side wall of the plate.

[0015] Furthermore, a transparent observation plate is embedded in the housing.

[0016] Furthermore, limiting plates are fixedly installed on both the first half gear and the second half gear, and the limiting plates are respectively rotatably engaged with the corresponding first half ring and second half ring.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This solution uses a spring telescopic clamping structure to automatically adapt to cylindrical steel structures of different diameters without the need to change the clamps, reducing the clamping and debugging time. It also adopts a symmetrical grinding structure, which can grind both sides of the steel structure end face at the same time. Combined with the rotary grinding method of the workpiece to be ground, it greatly shortens the processing time of a single operation. The shell can prevent debris from splashing, reduce the cleaning difficulty, and improve the safety of the operation. It plays a role in improving the processing efficiency of the end face of the building steel structure. (2) This solution opens a cavity and uses air pressure changes to form a negative pressure adsorption effect during the clamping process, so that the arc-shaped clamping plate is tightly attached and fixed to the workpiece to be ground, effectively avoiding the workpiece to be ground from moving, slipping or deviating during grinding, ensuring the grinding accuracy and surface quality of the end face. Furthermore, it uses half gears combined into a complete gear to drive the workpiece to be ground to rotate, and with the fixed grinding components, it achieves uniform circumferential grinding of the workpiece to be ground, solving the problems of uneven end face and angle deviation that are easy to occur in traditional fixed-point grinding, thereby reducing the probability of rework and further improving the processing efficiency of the end face of building steel structure. (3) By setting a grinding brush, after the main grinding is completed, the electromagnet is de-energized, and then the second spring extends and drives the grinding brush to automatically descend to process the burrs on the edge of the workpiece to be ground. At the same time, damping is provided to make the workpiece to be ground stop quickly, which further improves the processing efficiency of the end face of the building steel structure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 For the present invention Figure 1 Enlarged view of point A in the middle; Figure 3 This is a combined diagram of the first half gear, the second half gear, and the full gear of the present invention; Figure 4 This is a combined diagram of the shell, plate, and horizontal plate of the present invention; Figure 5 This is a cross-sectional view of the mounting block, plug plate, and second arc-shaped plate of the present invention; Figure 6 This is a cross-sectional view of the linkage block, vertical rod, and linkage plate of the present invention; Figure 7 This is a cross-sectional view of the housing of the present invention.

[0019] Explanation of the labels in the diagram: 101. Workbench; 102. Vertical plate; 103. Electric actuator; 104. Housing; 105. Mounting plate; 106. First half-ring; 107. Mounting bracket; 108. Electric telescopic rod; 109. Second half-ring; 2. Clamping assembly; 201. First half gear; 202. Second half gear; 203. Motor; 204. Full gear; 205. First arc-shaped plate; 206. Second arc-shaped plate; 301. Mounting block; 302. Plug plate; 303. Mounting rod; 304. First spring; 305. Cavity; 306. Hole; 307. Air tube; 401. Grinding hole; 402. Grinding disc; 403. Linkage block; 404. Vertical rod; 405. Linkage plate; 406. Grinding brush; 407. Second spring; 408. First magnet; 409. Electromagnet; 501. Liquid pump; 502. Water pipe; 503. Cavity; 504. Water hole; 505. Horizontal plate; 506. Filter plate; 601. Plate body; 602. Observation plate; 603. Limiting plate; 604. Part to be polished. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1 to 7 A steel structure end face grinding device for construction includes a worktable 101, on which vertical plates 102 are symmetrically fixedly installed. An electric push rod 103 is fixedly installed on the vertical plates 102. A housing 104 is fixedly installed on the output end of the electric push rod 103. A grinding component for grinding the steel structure is provided on the housing 104. An mounting plate 105 is fixedly installed on the worktable 101. A first half-ring 106 is fixedly installed on the mounting plate 105. An mounting frame 107 is fixedly installed on the worktable 101. An electric telescopic rod 108 is fixedly installed on the mounting frame 107. A second half-ring 109, which forms a complete ring with the first half-ring 106, is fixedly installed on the output end of the electric telescopic rod 108. A clamping component 2 is provided on both the first half-ring 106 and the second half-ring 109. The clamping assembly 2 includes a first half gear 201 rotatably mounted on a first half ring 106, a second half gear 202 rotatably mounted on a second half ring 109 to form a complete gear with the first half gear 201, a motor 203 fixedly mounted on a mounting plate 105, and a full gear 204 meshing with the first half gear 201 fixedly mounted on the output end of the motor 203, a first arc plate 205 fixedly mounted on the first half gear 201, and a second arc plate 206 cooperating with the first arc plate 205 on the second half gear 202.

[0022] A mounting block 301 is fixedly installed on the second half gear 202. A vertical groove is provided on the mounting block 301. A plug plate 302 is slidably and sealingly installed in the vertical groove. A mounting rod 303 that slidably and sealingly cooperates with the mounting block 301 is fixedly installed on the plug plate 302. A first spring 304 is installed between the plug plate 302 and the vertical groove. The second arc-shaped plate 206 is fixedly connected to the end of the mounting rod 303 away from the first spring 304.

[0023] The second arc-shaped plate 206 has a cavity 305, the bottom wall of the cavity 305 has a hole 306, and the top wall of the cavity 305 is fixedly installed with an air pipe 307 that communicates with the vertical groove.

[0024] In use, the workpiece 604 to be polished is placed on the first arc-shaped plate 205. Then, the output end of the electric telescopic rod 108 extends. During the extension of the output end of the electric telescopic rod 108, the second half-ring 109 moves downward, and during the downward movement of the second half-ring 109, the second arc-shaped plate 206 moves downward, thus clamping and fixing the workpiece 604 to be polished together with the first arc-shaped plate 205. After the workpiece 604 to be polished is clamped, the motor 203 drives the first half-gear 201 and the second half-gear 202 to rotate through gears. During the rotation of the first half-gear 201 and the second half-gear 202, the workpiece 604 to be polished rotates through the first arc-shaped plate 205 and the second arc-shaped plate 206. Then, the output end of the electric push rod 103 extends and drives the housing 104 to move. During the movement of the housing 104, the polishing assembly gradually contacts the end of the workpiece 604 to be polished, so that both ends of the workpiece 604 can be polished simultaneously. Meanwhile, the curved plate prevents the workpiece 604 from moving during the grinding process, thus affecting grinding efficiency. The housing 104 also prevents debris from splashing and increasing cleaning difficulty, thereby improving grinding efficiency.

[0025] As the second half gear 202 moves downward, it drives the mounting block 301 downward. During this downward movement, the mounting block 301, via the mounting rod 303, causes the second arc-shaped plate 206 to contact the workpiece 604 to be ground. Then, as the mounting block 301 continues to move downward, the workpiece 604 to be ground moves along the vertical groove via the second arc-shaped plate 206, the plug plate 302, and the mounting rod 303. The plug plate 302 then compresses the first spring 304. Under the force of the first spring 304, the second arc-shaped plate 206 and the first arc-shaped plate 205 grind the workpiece 604 together. This allows for the processing of workpieces 604 of different sizes without the need for frequent replacement of the clamping assembly 2, further improving grinding efficiency.

[0026] As the stopper plate 302 moves along the vertical groove, the pressure in the space within the vertical groove on the side of the stopper plate 302 away from the first spring 304 decreases. Then, air is drawn from the cavity 305 through the air pipe 307 into the space on the side of the vertical groove away from the first spring 304, further reducing the pressure within the cavity 305. The cavity 305 then tends to draw air from the outside through the hole 306. Since the second arc-shaped plate 206 is in contact with the workpiece 604 to be ground at this time, the workpiece 604 will block the hole 306. Then, under pressure, the second arc plate 206 is tightly adsorbed to the workpiece 604 to be ground through the hole 306. The second arc plate 206 can assist in clamping the workpiece 604 to be ground to avoid sliding between the workpiece 604 to be ground and the second arc plate 206, which would affect the grinding efficiency. It should be noted that during the continuous grinding process, the rigid fixation of the workpiece 604 to be ground is mainly achieved by the continuous mechanical clamping force applied by the electric telescopic rod 108, which further improves the grinding efficiency.

[0027] like Figure 6 , Figure 7 As shown, the polishing assembly includes a polishing hole 401 formed on the housing 104, a polishing disc 402 provided inside the housing 104, a linkage block 403 fixedly installed on the inner top wall of the housing 104, a vertical rod 404 slidably installed on the linkage block 403, a linkage plate 405 fixedly installed on the vertical rod 404, and polishing brushes 406 uniformly fixedly installed on the linkage plate 405.

[0028] A second spring 407 is installed between the vertical rod 404 and the linkage block 403. A first magnet 408 is embedded in the vertical rod 404, and an electromagnet 409 electrically connected to the motor 203 is embedded in the linkage block 403.

[0029] By adopting the above technical solution, after the motor 203 starts, the electromagnet 409 is energized and generates an electromagnetic field. Under the action of the electromagnetic field, the first magnet 408 drives the vertical rod 404 to move upward and compresses the second spring 407. When the grinding is finished, as the motor 203 is turned off, the electromagnetic field of the electromagnet 409 disappears. Then, the second spring 407 extends and drives the vertical rod 404 to move downward. During the downward movement of the vertical rod 404, it drives the linkage plate 405 and the grinding brush 406 to move downward. During the downward movement of the grinding brush 406, it gradually comes into contact with the workpiece 604 to be ground. Since the workpiece 604 to be ground will continue to rotate under the action of inertia, the burrs on the edge of the workpiece 604 can be removed. At the same time, the resistance of the workpiece 604 to be ground can be increased, so that the workpiece 604 to be ground can stop rotating in advance. That is, through the deep coordination of mechanical clamping, negative pressure positioning and electromechanical linkage for deburring: when the workpiece 604 to be ground is clamped by the first arc plate 205 and the second arc plate 206, the negative pressure of the cavity 305 provides anti-slip adhesion force; after the motor 203 drives the grinding disc 402 to complete the grinding, the electromagnet 409 is seamlessly triggered by the power-off signal of the motor 203 to release the grinding brush 406, integrating the cutting and post-processing corner clearing processes into the same clamping cycle. Not only can the housing 104 avoid the splashing of chips, but the processing efficiency is also improved.

[0030] After the workpiece 604 stops rotating, the motor 203 drives the first half gear 201 and the second half gear 202 to reset via the full gear 204, and they are positioned on the corresponding first half ring 106 and second half ring 109. Then, the output end of the electric push rod 103 retracts, causing the housing 104 to disengage from the workpiece 604; at the same time, the output end of the electric telescopic rod 108 retracts, causing the second arc plate 206 to disengage from the workpiece 604, thus preparing for the next operation.

[0031] like Figure 6 , Figure 7 As shown, the housing 104 is filled with polishing fluid, a liquid pump 501 is fixedly installed on the inner side wall of the housing 104, a water pipe 502 is fixedly installed on the output end of the liquid pump 501, a cavity 503 is opened on the linkage plate 405, and water holes 504 are evenly opened on the bottom wall of the cavity 503.

[0032] A horizontal plate 505 is detachably installed on the side wall of the housing 104, and a filter plate 506 is fixedly installed on the horizontal plate 505.

[0033] By adopting the above technical solution, during the polishing process, the liquid pump 501 drives the polishing fluid to flow into the cavity 503 through the water pipe 502. Then, the polishing fluid is sprayed through the water hole 504 on the cavity 503 to the contact point between the workpiece 604 to be polished and the polishing disc 402, which avoids damage to the polishing disc 402 due to high temperature during long-term operation and improves polishing efficiency.

[0034] After the polishing fluid flows through the workpiece 604 to be polished, it carries the debris and falls onto the top wall of the filter plate 506. After being filtered by the filter plate 506, the polishing fluid and the polishing fluid below the filter plate 506 converge. When it is necessary to clean the polishing debris, the user removes the level plate 505 and moves the filter plate 506 out of the housing 104, thus facilitating the cleaning of the debris.

[0035] like Figure 1 , Figure 3 , Figure 4 As shown, a plate 601 is detachably mounted on the housing 104, and the grinding disc 402 is mounted on the side wall of the plate 601.

[0036] A transparent observation plate 602 is embedded in the housing 104.

[0037] Limiting plates 603 are fixedly installed on both the first half gear 201 and the second half gear 202, and the limiting plates 603 are respectively rotatably engaged with the corresponding first half ring 106 and second half ring 109.

[0038] By adopting the above technical solution, the user can observe the grinding process through the observation plate 602. Furthermore, when the grinding disc 402 is severely worn, the user can remove the plate 601, replace the grinding disc 402, and then reinstall the plate 601 onto the housing 104, further improving grinding efficiency. In addition, by setting the limiting plate 603, the first half-gear 201 and the second half-gear 202 can be prevented from detaching, thereby improving the stability of the device.

[0039] Instructions for use: First, place the steel structure to be ground 604 on the first arc plate 205, with the end face of the part to be ground 604 facing the grinding components on both sides. Then, start the electric telescopic rod 108 to drive the second half ring 109, the second half gear 202, and the second arc plate 206 to move downwards, so that the first half ring 106 and the second half ring 109 close, and the first half gear 201 and the second half gear 202 form a complete gear. The plug plate 302 moves upwards to create a negative pressure in the vertical groove. Through the air pipe 307, the cavity 305, and the hole 306, a negative pressure adsorption is formed at the contact surface between the second arc plate 206 and the part to be ground 604.

[0040] Then, the motor 203 is started, which drives the first half gear 201 and the second half gear 202 to rotate via the full gear 204. This, in turn, drives the workpiece 604 to be polished to rotate at a constant speed via the first arc plate 205 and the second arc plate 206. Subsequently, the electric push rod 103 pushes the housing 104 and the polishing assembly toward the end face of the workpiece 604, so that the polishing disc 402 approaches and contacts the end face of the workpiece 604. At the same time, the liquid pump 501 inside the housing 104 is started, and the polishing fluid is sprayed onto the polishing area through the water pipe 502, cavity 503, and water hole 504 to achieve cooling, dust reduction, and lubrication.

[0041] After grinding is complete, motor 203 is turned off, electromagnet 409 is simultaneously de-energized, the electromagnetic field disappears, the second spring 407 extends, pushing vertical rod 404, linkage plate 405, and grinding brush 406 downwards. Grinding brush 406 contacts the end face and edge of the workpiece 604 to be ground. The workpiece 604 continues to rotate under inertia, and grinding brush 406 cleans the burrs on the end face while providing resistance to quickly stop the workpiece 604 from rotating.

[0042] After the grinding part 604 has completely stopped, the motor 203 reverses slightly, causing the first half gear 201 and the second half gear 202 to return to the corresponding positions of the half ring, and the liquid pump 501 is turned off, controlling the electric push rod 103 to retract, driving the housing 104 and the grinding assembly back to their original positions.

[0043] Finally, the electric telescopic rod 108 is retracted, the second semi-ring 109 and the second arc plate 206 move upward, the negative pressure adsorption is released, the workpiece to be ground 604 is released, and the processed steel structure workpiece to be ground 604 is taken out, completing a single grinding process.

[0044] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A steel structure end face grinding device for construction, comprising a worktable (101), characterized in that: A vertical plate (102) is symmetrically fixedly installed on the workbench (101). An electric push rod (103) is fixedly installed on the vertical plate (102). A housing (104) is fixedly installed on the output end of the electric push rod (103). A grinding component for grinding steel structure is provided on the housing (104). A mounting plate (105) is fixedly installed on the workbench (101). A first half-ring (106) is fixedly installed on the mounting plate (105). A mounting frame (107) is fixedly installed on the workbench (101). An electric telescopic rod (108) is fixedly installed on the mounting frame (107). A second half-ring (109) that forms a complete ring with the first half-ring (106) is fixedly installed on the output end of the electric telescopic rod (108). A clamping component (2) is provided on both the first half-ring (106) and the second half-ring (109). The clamping assembly (2) includes a first half gear (201) rotatably mounted on a first half ring (106), a second half gear (202) rotatably mounted on a second half ring (109) to form a complete gear with the first half gear (201), a motor (203) fixedly mounted on a mounting plate (105), and a full gear (204) meshing with the first half gear (201) fixedly mounted on the output end of the motor (203), a first arc plate (205) fixedly mounted on the first half gear (201), and a second arc plate (206) cooperating with the first arc plate (205) on the second half gear (202).

2. The steel structure end face grinding device for building construction according to claim 1, characterized in that: A mounting block (301) is fixedly installed on the second half gear (202). A vertical groove is provided on the mounting block (301). A plug plate (302) is slidably and sealed in the vertical groove. A mounting rod (303) that slidably and sealed with the mounting block (301) is fixedly installed on the plug plate (302). A first spring (304) is installed between the plug plate (302) and the vertical groove. The second arc plate (206) is fixedly connected to the end of the mounting rod (303) away from the first spring (304).

3. The steel structure end face grinding device for building construction according to claim 2, characterized in that: The second arc-shaped plate (206) has a cavity (305) with holes (306) on the bottom wall of the cavity (305) and an air pipe (307) connected to the vertical groove is fixedly installed on the top wall of the cavity (305).

4. The steel structure end face grinding device for building construction according to claim 1, characterized in that: The polishing assembly includes a polishing hole (401) formed on the housing (104), a polishing disc (402) is provided inside the housing (104), a linkage block (403) is fixedly installed on the inner top wall of the housing (104), a vertical rod (404) is slidably installed on the linkage block (403), a linkage plate (405) is fixedly installed on the vertical rod (404), and polishing brushes (406) are uniformly fixedly installed on the linkage plate (405).

5. The steel structure end face grinding device for building construction according to claim 4, characterized in that: A second spring (407) is installed between the vertical rod (404) and the linkage block (403). A first magnet (408) is embedded on the vertical rod (404), and an electromagnet (409) electrically connected to the motor (203) is embedded on the linkage block (403).

6. The steel structure end face grinding device for building construction according to claim 5, characterized in that: The housing (104) is filled with polishing fluid. A liquid pump (501) is fixedly installed on the inner side wall of the housing (104). A water pipe (502) is fixedly installed on the output end of the liquid pump (501). A cavity (503) is opened on the linkage plate (405). Water holes (504) are evenly opened on the bottom wall of the cavity (503).

7. The steel structure end face grinding device for building construction according to claim 6, characterized in that: A horizontal plate (505) is detachably installed on the side wall of the housing (104), and a filter plate (506) is fixedly installed on the horizontal plate (505).

8. The steel structure end face grinding device for building construction according to claim 4, characterized in that: A plate (601) is detachably mounted on the housing (104), and the grinding disc (402) is mounted on the side wall of the plate (601).

9. The steel structure end face grinding device for building construction according to claim 1, characterized in that: A transparent observation plate (602) is embedded in the housing (104).

10. A steel structure end face grinding device for building construction according to claim 1, characterized in that: Limiting plates (603) are fixedly installed on both the first half gear (201) and the second half gear (202), and the limiting plates (603) are respectively rotatably engaged with the corresponding first half ring (106) and second half ring (109).

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