Material suspension conveying mechanism for motor production

Abstract

The application relates to the field of conveying mechanisms, and discloses a material suspension conveying mechanism for motor production, which comprises a bearing plate and a linkage unloading assembly; the linkage unloading assembly is arranged on the rear side of the upper surface of the bearing plate, and is used for realizing automatic unloading in a linkage triggering mode and smearing lubricating liquid on a conveying driving assembly during the conveying of motor production materials; in the application, when the materials are conveyed to the designated positions, the linkage unloading assembly can automatically trigger the unloading action, the materials can be separated from the hooks without manual intervention, the automatic lubricating function of the transmission belt is integrated in the linkage unloading assembly during the automatic unloading, the transmission belt can be continuously and uniformly smeared with the lubricating liquid through the rotating lubricating liquid cylinder and the liquid feeding ball, the wear and the running resistance of the transmission belt are reduced, the energy consumption is reduced, the faults caused by insufficient lubrication are effectively prevented, and the long-term stable operation of the conveying mechanism is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of conveying mechanism, especially to a material suspension conveying mechanism for motor production. BACKGROUND

[0002] As an indispensable power source in modern industry and daily life, the production and manufacturing process of motors involves numerous processes such as stamping, welding, injection molding, assembly, testing, etc. In these processes, a large number of parts, semi-finished products and production auxiliary materials (such as tools, fixtures, cables, etc.) need to be efficiently and orderly transferred between different workstations. The efficiency, stability and reliability of material conveying are directly related to the beat, production cost and product quality of the entire motor production line.

[0003] According to Chinese Patent No. CN117342395A, an intelligent suspension conveying device for hoisting construction materials is disclosed, which belongs to the field of hoisting conveying devices. It includes a safety component composed of a primary trigger block and a secondary locking block. This device solves the problem of manually pressing the safety ring inward to release the blockage of the opening part of the hook before hanging or taking out the handle and connecting rope of the material container each time. The safety component can automatically block and open the opening part of the suspension main hook. When there is no suspended or hoisted construction material in the suspension component, the locking side rod is in a horizontal state and does not block the opening part of the suspension main hook, making it easy to hang and take out the handle and connecting rope of the material container without manual control, saving the step of manual opening and closing and improving the efficiency of hoisting and conveying construction materials. However, this device still has some drawbacks. When the material reaches the designated unloading point in motor production, workers may need to manually remove the material from the hook. The speed and accuracy of manual unloading are greatly affected by human factors, making it difficult to ensure that unloading is completed quickly and accurately each time, especially on high-speed production lines, which can become a bottleneck. Additionally, manual operation may cause material to fall, collide or damage the hook. SUMMARY

[0004] To overcome the shortcomings of the prior art, the present application provides a material suspension conveying mechanism for motor production, which solves the above problems.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: a material suspension conveying mechanism for motor production, comprising:

[0006] a load-bearing plate;

[0007] a conveying drive assembly; the conveying drive assembly is arranged on the upper surface of the load-bearing plate;

[0008] The linkage unloading assembly is arranged on the rear side of the upper surface of the load-bearing plate, and is used to realize automatic unloading in a linkage triggered manner and to apply lubricating liquid to the conveying drive assembly during the conveying of the motor production materials.

[0009] Preferably, the first connecting plate is fixedly connected to the outside of the vertical plate, the second connecting plate is fixedly connected to the outside of the load-bearing plate, the transmission gear is rotatably connected between the second connecting plate and the first connecting plate, the linkage rotating disc is rotatably connected to the upper surface of the first connecting plate, the linkage rotating disc is in transmission connection with the transmission gear, the linkage rod is rotatably connected to the outer edge of the upper surface of the linkage rotating disc, the reciprocating pull rod is rotatably connected to the end of the linkage rod away from the linkage rotating disc, the end of the reciprocating pull rod away from the linkage rod is fixedly connected to the upper surface of the movable sliding block, the movable sliding block is arranged in the limiting groove in the support frame, the unloading drive arm is fixedly connected to the lower surface of the movable sliding block, and the top striking plate is fixedly connected to the lower end of the unloading drive arm.

[0010] Preferably, the linkage rotating disc is sleeved with the linkage belt at the rotatable connection position between the linkage rotating disc and the first connecting plate, the other end of the linkage belt is sleeved on the outside of the rotating shaft, the lubricating liquid cylinder is in transmission connection with the lower end of the rotating shaft, the lubricating liquid is filled in the lubricating liquid cylinder, and a plurality of liquid supply balls are distributed around the outer surface of the lubricating liquid cylinder.

[0011] Preferably, the conveying drive assembly comprises an upright plate, a transmission belt, meshing teeth, an arc-shaped support, a drive motor, a fixed plate and a drive gear, the lower end of the upright plate is fixedly connected to the upper surface of the load-bearing plate, the left side of the front and rear ends of the upright plate is fixedly connected with a fixed plate, the upper surface of the two fixed plates is fixedly connected with a drive motor, the output end of the two drive motors is drivingly connected with a drive gear, and the outer side of the drive gear is in meshing engagement with the meshing teeth on the inner side of the transmission belt.

[0012] Preferably, the material suspension assembly further comprises a connecting column, a suspension plate, a positioning piece, a rotating column, a reset torsional spring and a motor material hook, the connecting column is fixedly connected to the outer side of the transmission belt, and the end, away from the transmission belt, of the connecting column is fixedly connected with a suspension plate.

[0013] Preferably, the outer side of the suspension plate is fixedly connected with a positioning piece at the left and right ends, a rotating column is rotatably connected in the middle of the two positioning pieces, and a reset torsional spring is arranged at the rotatable connection between the rotating column and the two positioning pieces.

[0014] Preferably, the lower end of the rotating column is fixedly connected with a motor material hook.

[0015] Preferably, the lower surface of the load-bearing plate is fixedly connected with three fixed columns, and the outer side of the rear fixed column is fixedly connected with a connecting bracket one and a connecting bracket two at the upper and lower ends, respectively.

[0016] Preferably, the upper surface of the connecting bracket one is fixedly connected with a main material guide plate, the upper surface of the connecting bracket two is fixedly connected with a secondary material guide plate, and one end of the secondary material guide plate is arranged below the main material guide plate.

[0017] Preferably, the inner side of the front and rear ends of the transmission belt is provided with an arc-shaped support, and the two arc-shaped supports are fixedly connected to the front and rear ends of the load-bearing plate, respectively.

[0018] Advantages

[0019] The application provides a material suspension conveying mechanism for motor production.

[0020] 1、The present application, by setting the linkage unloading assembly, when the transmission belt in the process of rotation, motor production material is transported to the rear, with the transmission belt rotation, transmission gear through the meshing tooth inside the meshing tooth and then produce rotary motion, at this time linkage rotating disc with rotation, after the linkage rotating disc rotation, linkage rotating disc upper surface linkage rod drive reciprocating pull rod left and right direction reciprocating movement, reciprocating pull rod drive slide block in the support frame limit groove reciprocating motion, at this time with drive slide block through the unloading drive arm connected to the top of the plate movement, the top of the plate to the left side moves just top in the middle of the motor material hook hanging motor production material, in order to make motor material hook to the left side swing, so that the suspension of the motor production material from its suspension position, in this way reciprocating cycle, linkage rotating disc rotation, its connected to the linkage belt also move, the other end of the linkage belt on the rotating shaft, rotating shaft rotation, the lower end of the rotating shaft and lubricating liquid cylinder connected, so that the lubricating liquid cylinder also rotate, lubricating liquid cylinder inside filled with lubricating liquid, its outer surface around the distribution of a plurality of liquid ball, when the lubricating liquid cylinder rotation, liquid ball with rolling, the lubricating liquid in the cylinder to the cylinder wall outside surface, and evenly spread to the nearby transmission belt inside surface, in this way when the material is transported to the designated position, can automatically trigger unloading action, without manual intervention can make material from the hook, in the realization of automatic unloading, the assembly also integrated automatic lubrication function of the transmission belt. Through the rotating lubricating liquid cylinder and liquid ball, can continue, evenly for the transmission belt spread lubricating liquid, reduce the wear and tear of the transmission belt and running resistance, reduce energy consumption, and effectively prevent the fault caused by insufficient lubrication, guarantee the long-term stable operation of the conveying mechanism;

[0021] 2、The motor production material suspension conveying mechanism of the present application, when the driving motor is started, the output shaft drives the driving gear to rotate, the driving gear meshes with the meshing teeth on the inner side of the transmission belt, when the transmission belt moves, the connecting column moves, the fixed suspension plate on the connecting column is also driven, the motor material hook is connected between the two positioning pieces through the rotating column, and the connecting part is provided with a reset torsional spring, when the transmission belt moves at a normal speed, the motor material hook is kept in a natural suspension state under the action of the reset torsional spring, the material can be stably hung on the hook and move with the transmission belt, when the suspension plate with the material and the hook move to the rear area of the linkage unloading assembly with the transmission belt, the transmission belt continues to move, the meshing teeth on the inner side of the transmission belt mesh with the transmission gear in the linkage unloading assembly, the linkage rotating disc is driven to rotate, when the jacking plate moves to the left and contacts the middle part of the motor material hook, a left force is applied to the hook, part of the resistance of the reset torsional spring is overcome, the rotating column drives the motor material hook to swing to the left by an angle, with the jacking plate moving to the right, the elastic force of the reset torsional spring pushes the rotating motor material hook back to the initial suspension position, and the next material is hung. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a front side three-dimensional structure schematic view of the motor production material suspension conveying mechanism provided by the present application.

[0023] Figure 2 It is a rear side three-dimensional structure schematic view of the motor production material suspension conveying mechanism provided by the present application.

[0024] Figure 3 It is a structure schematic view of the motor production material suspension conveying mechanism provided by the present application from an oblique upper perspective view.

[0025] Figure 4 It is a structure schematic view of the motor production material suspension conveying mechanism provided by the present application from a cross-sectional view.

[0026] Figure 5 It is a structure schematic view of the linkage unloading assembly in the motor production material suspension conveying mechanism provided by the present application.

[0027] Figure 6 It is a structure schematic view of the linkage unloading assembly in the motor production material suspension conveying mechanism provided by the present application from an oblique upper perspective view.

[0028] Figure 7 It is a structure schematic view of the material suspension assembly in the motor production material suspension conveying mechanism provided by the present application.

[0029] Figure 8 A material suspension conveying mechanism for motor production Figure 6 A magnified view of the middle A.

[0030] Legend:

[0031] 1, fixed column; 2, bearing plate; 3, conveying drive assembly; 301, vertical plate; 302, transmission belt; 303, meshing teeth; 304, arc-shaped support column; 305, drive motor; 306, fixed plate; 307, drive gear; 4, linkage unloading assembly; 401, connecting plate one; 402, connecting plate two; 403, transmission gear; 404, linkage rotating disc; 405, linkage rod; 406, reciprocating pull rod; 407, support frame; 408, limiting groove; 409, movable sliding block; 410, unloading drive arm; 411, top impact plate; 412, linkage belt; 413, rotating shaft; 414, lubricating liquid cylinder; 415, liquid feeding ball; 5, material suspension assembly; 501, connecting column; 502, suspension plate; 503, positioning sheet; 504, rotating column; 505, reset torsional spring; 506, motor material hook; 6, connecting bracket one; 7, connecting bracket two; 8, main guide plate; 9, auxiliary guide plate. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0033] Please refer to Figures 1-8 The present application provides two technical solutions, specifically including the following embodiments:

[0034] Embodiment one: a material suspension conveying mechanism for motor production, comprising: a linkage unloading assembly 4; the linkage unloading assembly 4 is arranged on the rear side of the upper surface of the load-bearing plate 2, and is used to realize automatic unloading in a linkage triggered manner and smearing of lubricating liquid on the conveying drive assembly 3 during the conveying of motor production materials; the linkage unloading assembly 4 comprises a connecting plate one 401, a connecting plate two 402, a transmission gear 403, a linkage rotating disc 404, a linkage rod 405, a reciprocating pull rod 406, a support frame 407, a limiting groove 408, a movable sliding block 409, an unloading drive arm 410, a top impact plate 411, a linkage belt 412, a rotating shaft 413, a lubricating liquid cylinder 414 and a liquid feeding ball 415, the connecting plate one 401 is fixedly connected to the outer side of the vertical plate 301, the connecting plate two 402 is fixedly connected to the outer side of the load-bearing plate 2, the transmission gear 403 is rotatably connected between the connecting plate two 402 and the connecting plate one 401, the linkage rotating disc 404 is rotatably connected to the upper surface of the connecting plate one 401, the linkage rotating disc 404 is in transmission connection with the transmission gear 403, the linkage rod 405 is rotatably connected to the outer side edge of the upper surface of the linkage rotating disc 404, the reciprocating pull rod 406 is rotatably connected to the end of the linkage rod 405 away from the linkage rotating disc 404, the end of the reciprocating pull rod 406 away from the linkage rod 405 is fixedly connected to the upper surface of the movable sliding block 409, the movable sliding block 409 is arranged in the limiting groove 408 in the support frame 407, the unloading drive arm 410 is fixedly connected to the lower surface of the movable sliding block 409, the top impact plate 411 is fixedly connected to the inner side of the lower end of the unloading drive arm 410, the linkage belt 412 is sleeved on the outer side of the rotating shaft 413 at the rotating connection position of the linkage rotating disc 404 and the connecting plate one 401, the other end of the linkage belt 412 is sleeved on the outer side of the rotating shaft 413, the lubricating liquid cylinder 414 is in transmission connection with the lower end of the rotating shaft 413, the lubricating liquid cylinder 414 is filled with lubricating liquid, and a plurality of liquid feeding balls 415 are distributed on the outer surface of the lubricating liquid cylinder 414.

[0035] When the transmission belt 302 rotates during operation, the motor production material is transported to the rear. As the transmission belt 302 rotates, the transmission gear 403 rotates by engaging with the meshing tooth 303 on the inside of the transmission belt 302. At this time, the linkage rotating disc 404 rotates, and the linkage rod 405 on the upper surface of the linkage rotating disc 404 drives the reciprocating pull rod 406 to move left and right. The reciprocating pull rod 406 drives the movable sliding block 409 to move reciprocally in the limiting groove 408 of the support frame 407. At this time, the top impact plate 411 connected to the drive sliding block through the unloading drive arm 410 moves, and the top impact plate 411 moves to the left and is just on the middle of the motor material hook 506 hanging the motor production material, so as to make the motor material hook 506 swing to the left, so that the suspended motor production material is separated from its hanging position. In this way, the linkage rotating disc 404 rotates, and the linkage belt 412 connected thereto also moves. The other end of the linkage belt 412 is sleeved on the rotating shaft 413, driving the rotating shaft 413 to rotate. The lower end of the rotating shaft 413 is connected with the lubricating liquid cylinder 414, so that the lubricating liquid cylinder 414 also rotates. The lubricating liquid cylinder 414 is filled with lubricating liquid, and the outer surface is surrounded by a plurality of liquid balls 415. When the lubricating liquid cylinder 414 rotates, the liquid balls 415 roll, bringing the lubricating liquid in the cylinder to the outer surface of the cylinder wall and evenly spreading to the inner surface of the transmission belt 302 nearby. In this way, through mechanical linkage, when the material is transported to the designated position, the unloading action can be automatically triggered without manual intervention. At the same time of realizing automatic unloading, the assembly also integrates the automatic lubrication function of the transmission belt 302. Through the rotating lubricating liquid cylinder 414 and the liquid ball 415, the transmission belt 302 can be continuously and evenly coated with lubricating liquid, reducing the wear and resistance of the transmission belt 302, reducing energy consumption, effectively preventing failure caused by insufficient lubrication, and ensuring the long-term stable operation of the conveying mechanism.

[0036] On the basis of example one, the conveying driving assembly 3 is arranged on the upper surface of the load bearing plate 2. The conveying driving assembly 3 comprises an upright plate 301, a transmission belt 302, meshing teeth 303, arc-shaped supports 304, driving motors 305, fixed plates 306 and driving gears 307. The lower end of the upright plate 301 is fixedly connected to the upper surface of the load bearing plate 2. The left side of the front and rear ends of the upright plate 301 is fixedly connected with the fixed plates 306. The upper surfaces of the two fixed plates 306 are fixedly connected with the driving motors 305. The output ends of the two driving motors 305 are drivingly connected with the driving gears 307. The outer side of the driving gear 307 is in meshing engagement with the meshing teeth 303 on the inner side of the transmission belt 302. The material suspension assembly 5 comprises connecting columns 501, suspension plates 502, positioning pieces 503, rotating columns 504, return torsional springs 505 and motor material hooks 506. The connecting columns 501 are fixedly connected to the outer side of the transmission belt 302. The end of the connecting column 501 away from the transmission belt 302 is fixedly connected with the suspension plate 502. The outer side of the suspension plate 502 is fixedly connected with the positioning pieces 503 at the left and right ends. The rotating column 504 is rotatably connected in the middle of the two positioning pieces 503. The rotating column 504 is rotatably connected with the two positioning pieces 503. The rotating column 504 is provided with the return torsional spring 505 at the rotating connection position. The lower end of the rotating column 504 is fixedly connected with the motor material hook 506. The lower surface of the load bearing plate 2 is fixedly connected with three fixed columns 1. The outer side of the rear fixed column 1 is fixedly connected with the connecting bracket one 6 and the connecting bracket two 7 at the upper and lower ends. The upper surface of the connecting bracket one 6 is fixedly connected with the main material guide plate 8. The upper surface of the connecting bracket two 7 is fixedly connected with the auxiliary material guide plate 9. One end of the auxiliary material guide plate 9 is arranged below the main material guide plate 8. The inner side of the front and rear ends of the transmission belt 302 is provided with the arc-shaped supports 304. The two arc-shaped supports 304 are fixedly connected to the front and rear ends of the load bearing plate 2. When the driving motor 305 is started, the output shaft drives the driving gear 307 to rotate. The driving gear 307 is in meshing engagement with the meshing teeth 303 on the inner side of the transmission belt 302. When the transmission belt 302 moves, the connecting column 501 moves. The fixed suspension plate 502 on the connecting column 501 is also driven to move. The motor material hook 506 is connected between the two positioning pieces 503 through the rotating column 504. The connecting position is provided with the return torsional spring 505. When the transmission belt 302 moves at a constant speed, the motor material hook 506 keeps a natural suspension state in the downward direction under the action of the return torsional spring 505. The material can be stably hung on the hook and moves with the transmission belt 302. When the suspension plate 502 with the material and the hook move to the rear area of the linkage discharging assembly 4 with the transmission belt 302, the transmission belt 302 continues to move. The meshing teeth 303 on the inner side of the transmission belt 302 are in meshing engagement with the transmission gear 403 in the linkage discharging assembly 4. The linkage rotating disc 404 is driven to rotate. When the jacking plate 411 moves to the left and contacts the middle part of the motor material hook 506, a leftward force is applied to the hook to overcome part of the resistance of the return torsional spring 505.The rotating column 504 drives the motor material hook 506 to swing to the left by an angle, and as the top impact plate 411 moves back to the right, the elastic force of the reset torsional spring 505 will push the rotating motor material hook 506 back to the initial hanging position which is roughly downward, so as to prepare for the hanging of the next material. The unloading conveying belt 302 continues to circulate and returns to the front end, waiting for the hanging of new motor production materials, and completes a working cycle.

[0037] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the application shall be included in the protection scope of the present application.

Claims

1. A material suspension conveying mechanism for motor production, characterized by: Include: Load plate (2); Conveying drive assembly (3); the conveying drive assembly (3) is arranged on the upper surface of the load plate (2); Linkage discharge assembly (4); the linkage discharge assembly (4) is arranged on the rear side of the upper surface of the load plate (2), the linkage discharge assembly (4) is used to realize automatic discharge in the process of conveying motor production material in linkage triggering mode and smearing lubricating liquid to the conveying drive assembly (3); the linkage discharge assembly (4) includes connecting plate one (401), connecting plate two (402), transmission gear (403), linkage rotary disc (404), linkage rod (405), reciprocating pull rod (406), support frame (407), limiting groove (408), movable sliding block (409), discharge drive arm (410), top impact plate (411), linkage belt (412), rotary shaft (413), lubricating liquid cylinder (414) and liquid ball (415); The connecting plate one (401) is fixedly connected to the outside of the vertical plate (301), the connecting plate two (402) is fixedly connected to the outside of the load plate (2), the transmission gear (403) is rotatably connected between the connecting plate two (402) and the connecting plate one (401), the linkage rotary disc (404) is rotatably connected to the upper surface of the connecting plate one (401), the linkage rotary disc (404) is in transmission connection with the transmission gear (403), the linkage rod (405) is rotatably connected to the outer edge of the upper surface of the linkage rotary disc (404), the reciprocating pull rod (406) is rotatably connected to the end of the linkage rod (405) away from the linkage rotary disc (404), the end of the reciprocating pull rod (406) away from the linkage rod (405) is fixedly connected to the upper surface of the movable sliding block (409), the movable sliding block (409) is arranged in the limiting groove (408) in the support frame (407), the discharge drive arm (410) is fixedly connected to the lower surface of the movable sliding block (409), the top impact plate (411) is fixedly connected to the inner side of the lower end of the discharge drive arm (410); The linkage belt (412) is sleeved on the rotary connection between the linkage rotary disc (404) and the connecting plate one (401), the other end of the linkage belt (412) is sleeved on the outside of the rotary shaft (413), the rotary shaft (413) is in transmission connection with the lubricating liquid cylinder (414) at the lower end, the lubricating liquid cylinder (414) is filled with lubricating liquid inside, and a plurality of liquid balls (415) are distributed on the outer surface of the lubricating liquid cylinder (414).

2. The material suspension conveying mechanism for motor production according to claim 1, characterized in that: The conveying drive assembly (3) comprises an upright plate (301), a transmission belt (302), meshing teeth (303), arc-shaped supports (304), drive motors (305), fixed plates (306) and drive gears (307), the lower end of the upright plate (301) is fixedly connected to the upper surface of the load-bearing plate (2), the left side of the front and rear ends of the upright plate (301) is fixedly connected with the fixed plates (306), the upper surfaces of the two fixed plates (306) are fixedly connected with the drive motors (305), the output ends of the two drive motors (305) are drivingly connected with the drive gears (307), and the outer side of the drive gears (307) is in meshing engagement with the meshing teeth (303) on the inner side of the transmission belt (302).

3. The material suspension conveying mechanism for motor production according to claim 1, characterized in that: It also comprises a material suspension assembly (5), the material suspension assembly (5) comprises connecting columns (501), suspension plates (502), positioning pieces (503), rotating columns (504), reset torsional springs (505) and motor material hooks (506), the connecting columns (501) are fixedly connected to the outer side of the transmission belt (302), and the ends, away from the transmission belt (302), of the connecting columns (501) are fixedly connected with the suspension plates (502).

4. The material suspension conveying mechanism for motor production according to claim 3, characterized in that: The outer sides of the left and right ends of the suspension plates (502) are fixedly connected with the positioning pieces (503), the rotating columns (504) are rotatably connected in the middle of the two positioning pieces (503), and the rotating columns (504) are provided with the reset torsional springs (505) at the rotating connection positions with the two positioning pieces (503).

5. The material suspension conveying mechanism for motor production according to claim 3, characterized in that: The lower ends of the rotating columns (504) are fixedly connected with the motor material hooks (506).

6. The material suspension conveying mechanism for motor production according to claim 1, characterized in that: The lower surface of the load-bearing plate (2) is fixedly connected with three fixed columns (1), and the outer sides of the upper and lower ends of the rear fixed columns (1) are fixedly connected with the connecting brackets one (6) and the connecting brackets two (7) respectively.

7. The material suspension conveying mechanism for motor production according to claim 6, characterized in that: The upper surface of the connecting bracket one (6) is fixedly connected with the main material guide plate (8), the upper surface of the connecting bracket two (7) is fixedly connected with the auxiliary material guide plate (9), and one end of the auxiliary material guide plate (9) is arranged below the main material guide plate (8).

8. The material suspension conveying mechanism for motor production according to claim 2, characterized in that: The inner sides of the front and rear ends of the transmission belt (302) are provided with the arc-shaped supports (304), and the front and rear ends of the load-bearing plate (2) are fixedly connected with the arc-shaped supports (304) respectively.

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