A crushing mechanism

Abstract

The application relates to a crushing mechanism which comprises a main frame installed on a crusher, a cone body and a main shaft, an adjusting ring is installed on the main frame, an adjusting sleeve is arranged on the adjusting ring, a threaded part is arranged on the outer ring wall of the adjusting sleeve, the adjusting sleeve is screwed on the adjusting ring, a crushing arc wall is arranged on the inner ring wall of the adjusting sleeve, the main shaft and the cone body are arranged in the main frame, the cone body is installed on the main shaft, an anti-loosening piece for reducing the possibility of loosening of the adjusting sleeve is arranged on the adjusting ring, and ores are located between the crushing arc wall and the cone body during crushing. The application has the effect of improving the applicability of the mine crusher.

Description

Technical Field

[0001] This application relates to the field of crusher technology, and in particular to a crushing mechanism. Background Technology

[0002] General Status of Related Technologies in this Field: Mining crushers are key equipment in the ore processing process, and their performance directly affects production efficiency and product quality. Currently, crushers mainly control the output particle size by adjusting the gap between the moving cone and the fixed cone. With the diversification of ore types and the refinement of crushing processes, higher requirements are placed on the precision and reliability of the crusher's adjustment mechanism.

[0003] In recent years, hydraulic and mechanical adjustment systems have become the two mainstream technical approaches. Hydraulic systems directly drive the moving cone with a hydraulic cylinder. While this allows for precise control of the clearance through hydraulic pressure, it carries the risk of oil leakage and is relatively expensive. Mechanical adjustment systems use gear-driven adjusting screws. Although highly reliable, the threads are prone to wear after prolonged use, causing spontaneous changes in the clearance. Additionally, there is a manual adjustment system using a shim assembly, but this method is inefficient and its accuracy depends heavily on manual experience. All of these structures have certain drawbacks, reducing the applicability of mining crushers. Summary of the Invention

[0004] In order to improve the applicability of mining crushers, this application provides a crushing mechanism.

[0005] The crushing mechanism provided in this application adopts the following technical solution:

[0006] A crushing mechanism includes a main frame, a cone, and a main shaft mounted on a crusher. An adjusting ring is mounted on the main frame, and an adjusting sleeve is provided on the adjusting ring. The outer ring wall of the adjusting sleeve is provided with a threaded portion, and the adjusting sleeve is threaded onto the adjusting ring. A crushing arc wall is provided on the inner ring wall of the adjusting sleeve. The main shaft and the cone are both located inside the main frame, and the cone is mounted on the main shaft. An anti-loosening element is provided on the adjusting ring to restrict the movement of the adjusting sleeve. During crushing, the ore is located between the crushing arc wall and the cone.

[0007] By adopting the above technical solution, when adjusting the crushing gap of the crusher, the adjusting sleeve is rotated to adjust the gap between the crushing arc wall and the cone. Finally, the adjusting sleeve is locked using anti-loosening parts, thus realizing the adjustment of the crushing gap of the crusher. By setting the adjusting sleeve, the crushing gap of the crusher can be adjusted mechanically. Compared with the existing technology, there are fewer parts, fewer operating steps, easier maintenance, and lower cost, which improves the applicability of mining crushers.

[0008] Optionally, the anti-loosening component is an anti-loosening screw ring, which is threaded onto the adjusting sleeve and fits against the adjusting ring. Several anti-loosening bolts are threaded through the anti-loosening component and the adjusting ring, and are threaded onto the adjusting ring.

[0009] By adopting the above technical solution, when the anti-loosening adjusting sleeve is tightened, the anti-loosening component is rotated to press against the top of the adjusting sleeve, and finally the anti-loosening bolt is rotated to engage with the thread of the adjusting ring to lock the anti-loosening component, thus achieving the effect of anti-loosening adjusting sleeve.

[0010] Optionally, the adjusting ring is provided with a stabilizing component, which includes a pressure frame, a stabilizing ring, a fixing block, a connecting block, and a moving block. A bearing ring is connected to the adjusting ring, and a lifting ring is threaded onto the inner ring wall of the bearing ring. The pressure frame is located between the top of the adjusting sleeve and the top of the lifting ring, and is bolted to the top of the adjusting sleeve. Several sliders are slidably fitted onto the bearing ring. One end of the stabilizing ring is rotatably connected to the slider, and the other end has an insertion groove. The fixing block is connected to the pressure frame and enters the insertion groove. The connecting block is connected to the pressure frame, and the moving block is slidably fitted onto the pressure frame. The fixing block is located between the connecting block and the moving block. A pin is connected to the moving block, and a limiting component is provided between the moving block and the connecting block to restrict the movement of the moving block. During installation, the pin passes through the stabilizing ring, the fixing block, and the connecting block.

[0011] By adopting the above technical solution, when stabilizing the adjusting sleeve, the lifting ring is rotated to move it to a specified height. Then, the pressure frame is connected to the top of the adjusting sleeve by bolts, so that the pressure frame abuts against the lifting ring. Then, the slider is moved, the stabilizing ring rises, flips and falls, so that the fixing block enters the insertion slot. Then, the moving block is pushed so that the pin passes through the stabilizing ring, the fixing block and the connecting block. Finally, the movement of the moving block is restricted by the limiting component, thus achieving the effect of assisted stabilization of the adjusting sleeve.

[0012] Optionally, the limiting component includes a rotating rod, a limiting post, and a connecting plate. One end of the rotating rod is rotatably connected to the side wall of the moving block, and the other end has a limiting arc groove. The center of the limiting arc groove coincides with the rotation center of one end of the rotating rod. The limiting post is connected to the side wall of the connecting block and is disposed on the same side as the rotating rod. The connecting plate is connected to the end of the limiting post. When limiting, the limiting post is located in the limiting arc groove, and the other end of the rotating rod is located between the connecting plate and the connecting block.

[0013] By adopting the above technical solution, when restricting the moving block, the moving block is pressed against the stabilizing ring, and then the rotating rod is flipped so that the restricting post enters the restricting arc groove, thereby achieving the effect of restricting the movement of the moving block.

[0014] Optionally, a plurality of grinding chamber walls are detachably connected to the breaking arc wall, the plurality of grinding chamber walls cover the breaking arc wall, and the adjusting sleeve is provided with an installation component that restricts the grinding chamber walls.

[0015] By adopting the above technical solution, the crushing arc wall of the adjusting sleeve is replaced by the grinding bowl wall. The grinding bowl wall itself has high wear resistance and forms a crushing cavity with the cone surface, thereby improving the efficiency of squeezing and impacting the ore and reducing the possibility of damage to the adjusting sleeve.

[0016] Optionally, the mounting assembly includes an extension block, a T-bar, a pressure plate, a limiting block, and a rotating ring. The adjusting sleeve has several mounting cavities, each corresponding to one of the grinding bowl walls. Two reinforcing blocks are disposed within each mounting cavity. The T-bar is disposed within the mounting cavity. The extension block is connected to the grinding bowl wall and enters the mounting cavity. A hook is provided at the end of the extension block, which hooks onto the T-bar. The pressure plate is placed on the two reinforcing blocks. A mounting hole is formed on the pressure plate. The limiting block is connected within the mounting hole. The end of the T-bar passes through the mounting hole. A limiting groove is formed at the end of the T-bar. The limiting block is slidably fitted within the limiting groove. The rotating ring is rotatably connected to the pressure plate and threadedly engaged with the end of the T-bar.

[0017] By adopting the above technical solution, when installing the mortar wall, the extension block is inserted into the installation cavity, so that the hook is placed on the T-bar. Then, the pressure plate is placed on the reinforcing block, the T-bar passes through the installation hole, and the limiting block enters the limiting groove. During this process, the rotating ring is moved so that the rotating ring is threadedly engaged with the end of the T-bar until the T-bar tightens the hook, thereby limiting the degree of freedom of the mortar wall and realizing the installation of the mortar wall.

[0018] Optionally, a baffle is bolted between the adjusting sleeve and the pressure frame.

[0019] By adopting the above technical solution, the baffle is used to collect ore on the one hand and to assist in pressurizing the ore on the other hand, thereby improving the ore crushing efficiency of the crusher.

[0020] Optionally, a retaining ring is connected to the inner ring wall of the baffle, the retaining ring is attached to the top of the broken arc wall, and a number of reinforcing ribs are connected between the inner wall of the baffle and the retaining ring.

[0021] By adopting the above technical solution and setting a retaining ring, the installation position of the retaining cover is determined. Reinforcing ribs are used to improve the structural strength of the retaining cover and reduce the possibility of damage.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. When adjusting the crusher's crushing gap, rotate the adjusting sleeve to adjust the gap between the crushing arc wall and the cone. Finally, use the anti-loosening parts to lock the adjusting sleeve, thus achieving the adjustment of the crusher's crushing gap. By setting the adjusting sleeve, the crusher's crushing gap can be adjusted mechanically. Compared with existing technologies, this method has fewer parts, simpler operation steps, easier maintenance, and lower cost, improving the applicability of mining crushers.

[0024] 2. When stabilizing the adjusting sleeve, rotate the lifting ring to move it to the specified height. Then, connect the pressure frame to the top of the adjusting sleeve with bolts so that the pressure frame abuts against the lifting ring. Then, move the slider so that the stabilizing ring rises, flips, and falls, allowing the fixing block to enter the insertion slot. Then, push the moving block so that the pin passes through the stabilizing ring, the fixing block, and the connecting block. Finally, use the limiting component to restrict the movement of the moving block, thus achieving the effect of stabilizing the adjusting sleeve.

[0025] 3. When installing the mortar wall, insert the extension block into the installation cavity so that the hook rests on the T-bar. Then place the pressure plate on the reinforcing block, pass the T-bar through the installation hole, and let the limiting block enter the limiting groove. During this process, rotate the rotating ring so that the rotating ring engages with the threaded end of the T-bar until the T-bar tightens the hook, thereby limiting the degree of freedom of the mortar wall and realizing the installation of the mortar wall. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the crushing mechanism in the embodiments of this application.

[0027] Figure 2 This is a cross-sectional view used in the embodiments of this application to illustrate the structure of the crushing mechanism.

[0028] Figure 3 This is an exploded view used in the embodiments of this application to illustrate the structure of the adjusting sleeve, the grinding mill wall, and the mounting components.

[0029] Figure 4 yes Figure 3 Enlarged view of point A in the middle.

[0030] Figure 5 This is a cross-sectional view used in the embodiments of this application to illustrate the structure of the installation component.

[0031] Figure 6 This is an exploded view used in the embodiments of this application to illustrate the structure of the installation components.

[0032] Figure 7 This is a schematic diagram of the structure of the limiting component in the embodiments of this application.

[0033] Explanation of reference numerals in the attached drawings: 1. Main frame; 11. Cone; 12. Main shaft; 13. Adjusting ring; 131. Bearing ring; 132. Lifting ring; 133. Sliding block; 2. Adjusting sleeve; 21. Crushing arc wall; 22. Mounting cavity; 23. Reinforcing block; 24. Grout wall; 3. Mounting assembly; 31. Extension block; 311. Hook; 32. T-bar; 321. Restricting groove; 33. Pressure plate; 34. Restricting block; 35. Rotating ring; 4. Anti-loosening component; 41. Anti-loosening bolt; 5. Stabilizing assembly; 51. Pressure frame; 52. Stabilizing ring; 53. Fixing block; 54. Connecting block; 55. Moving block; 551. Pin; 6. Restricting assembly; 61. Rotating rod; 611. Restricting arc groove; 62. Restricting column; 63. Connecting plate; 7. Baffle; 71. Baffle ring; 72. Reinforcing rib plate. Detailed Implementation

[0034] The following is in conjunction with the appendix Figures 1-7 This application will be described in further detail.

[0035] This application discloses a crushing mechanism. (Refer to...) Figure 1 The crushing mechanism includes a main frame 1, a cone 11, and a main shaft 12 mounted on the crusher. The main shaft 12 is located inside the main frame 1, and the cone 11 is mounted on the main shaft 12. An adjusting ring 13 is mounted on the main frame 1.

[0036] Reference Figure 1 , Figure 2 and Figure 3 An adjusting sleeve 2 is provided on the adjusting ring 13. The outer ring wall of the adjusting sleeve 2 has a threaded portion, and the adjusting sleeve 2 is threaded onto the adjusting ring 13. A breaking arc wall 21 is provided on the side wall of the adjusting sleeve 2 near the cone 11. Several mounting cavities 22 are provided inside the adjusting sleeve 2; in this embodiment, eight are used as an example. Two reinforcing blocks 23 are integrally formed within each mounting cavity 22. Mounting grooves are formed on the breaking arc wall 21 at positions corresponding to the mounting cavities 22.

[0037] Reference Figure 3 , Figure 4 and Figure 5 The crushing arc wall 21 is provided with several grinding chamber walls 24. In this embodiment, eight grinding chamber walls 24 are used as an example. The eight grinding chamber walls 24 cover the crushing arc wall 21, and the grinding chamber walls 24 correspond one-to-one with the mounting cavity 22. The adjusting sleeve 2 is provided with a mounting assembly 3, which includes an extension block 31, a T-shaped rod 32, a pressure plate 33, a limiting block 34, and a rotating ring 35. The extension block 31 is fixedly connected to the grinding chamber wall 24, and one end of the extension block 31 extends into the mounting groove and is provided with a hook 311.

[0038] Reference Figure 4 and Figure 5A T-shaped rod 32 is disposed within the mounting cavity 22, and a hook 311 hooks onto the T-shaped rod 32. A pressure plate 33 is placed between two reinforcing blocks, and a mounting hole is formed on the pressure plate 33. A limiting block 34 is fixedly connected to the mounting hole. One end of the T-shaped rod 32 passes through the mounting hole and has a limiting groove 321, within which the limiting block 34 is slidably fitted. A rotating ring 35 is rotatably connected to the pressure plate 33 and is threadedly engaged with the T-shaped rod 32.

[0039] When installing the mortar wall 24, the mortar wall 24 is attached to the broken arc wall 21, the extension block 31 is inserted into the installation cavity 22, and the hook 311 hooks the T-bar 32. The rotating ring 35 is turned, and due to the cooperation between the limiting block 34 and the limiting groove 321 and the cooperation between the rotating ring 35 and the T-bar 32, the T-bar 32 moves to press against the extension block 31, thereby limiting the mortar wall 24 and realizing the installation of the mortar wall 24.

[0040] Reference Figure 2 The adjusting sleeve 2 is provided with an anti-loosening element 4, which is an anti-loosening threaded ring. The surface of the anti-loosening element 4 has several arc-shaped grooves. The anti-loosening element 4 is threaded onto the adjusting sleeve 2 and abuts against the adjusting ring 13. Several anti-loosening bolts 41 are inserted into the arc-shaped grooves, and the anti-loosening bolts 41 pass through the adjusting ring 13 and are threaded onto the adjusting ring 13.

[0041] When adjusting sleeve 2, rotate anti-loosening component 4 to press against adjusting ring 13, and finally rotate anti-loosening bolt 41 to tighten anti-loosening component 4, thus achieving the effect of anti-loosening adjusting sleeve 2.

[0042] Reference Figure 1 , Figure 2 and Figure 6 The adjusting ring 13 is equipped with a stabilizing component 5, which includes a pressure frame 51, a stabilizing ring 52, a fixing block 53, a connecting block 54, and a moving block 55. A bearing ring 131 is fixedly connected to the adjusting ring 13, and a lifting ring 132 is threadedly fitted onto the inner ring wall of the bearing ring 131. One end of the pressure frame 51 is bolted to the top of the adjusting sleeve 2, and the other end abuts against the lifting ring 132. Several planes are formed on the outer ring wall of the bearing ring 131. In this embodiment, four planes are used as an example. A lifting rail is fixedly connected to the plane. The lifting rail is a T-shaped rail, and a slider 133 is slidably fitted onto the lifting rail. One end of the stabilizing ring 52 is hinged to the slider 133, and the other end has an insertion groove.

[0043] Reference Figure 6The fixing block 53 is fixedly connected to the pressure frame 51 and enters the insertion slot. The connecting block 54 is fixedly connected to the pressure frame 51 and is located on one side of the stabilizing ring 52. A moving rail is fixedly connected to the pressure frame 51 at the position corresponding to the other side of the stabilizing ring 52. The moving rail is a T-shaped rail. The moving block 55 is slidably fitted on the moving rail. A pin 551 is fixedly connected to the moving block 55, and the pin 551 passes through the stabilizing ring 52, the fixing block 53, and the connecting block 54.

[0044] Reference Figure 6 and Figure 7 A limiting component 6 is provided between the moving block 55 and the connecting block 54. The limiting component 6 includes a rotating rod 61, a limiting post 62, and a connecting plate 63. One end of the rotating rod 61 is connected to the side wall of the moving block 55, and the other end has a limiting arc groove 611, the center of which coincides with the rotation center of one end of the rotating rod 61. The limiting post 62 is fixedly connected to the side wall of the connecting block 54 and is located on the same side as the rotating rod 61. The connecting plate 63 is fixedly connected to the end of the limiting post 62 away from the connecting block 54.

[0045] When stabilizing the adjusting sleeve 2, rotate the lifting ring 132 to the specified height. One end of the pressure frame 51 is connected to the top of the adjusting sleeve 2 by bolts, and the other end abuts against the top wall of the lifting ring 132. Then move the slider 133 and flip and lower the stabilizing ring 52 so that the fixing block 53 enters the insertion groove. Push the moving block 55 so that the pin 551 is inserted into the stabilizing ring 52, the fixing block 53 and the connecting block 54. Finally, flip the rotating rod 61 so that the limiting post 62 enters the limiting arc groove 611, thereby limiting the movement of the moving block 55 and achieving the effect of further stabilizing the adjusting sleeve 2.

[0046] Reference Figure 1 and Figure 2 A retaining cover 7 is bolted between the adjusting sleeve 2 and the pressure frame 51. A retaining ring 71 is fixedly connected to the inner ring wall of the retaining cover 7. The retaining ring 71 fits against the top of the broken arc wall 21 and is used to position the retaining cover 7. Several reinforcing ribs 72 are fixedly connected to the retaining cover 7 to improve the connection strength of the retaining cover 7.

[0047] The implementation principle of a crushing mechanism according to an embodiment of this application is as follows: During installation, the extension block 31 on the grinding bowl wall 24 is inserted into the mounting cavity 22, so that the hook 311 hooks the T-shaped rod 32. The pressure plate 33 is placed between the two reinforcing blocks 23. The rotating ring 35 is turned to move the T-shaped rod 32 to press against the extension block 31 and stabilize the grinding bowl wall 24. The adjusting sleeve 2 is threaded onto the adjusting ring 13 to adjust the gap between the grinding bowl wall 24 and the surface of the cone 11. Then, the anti-loosening member 4 is rotated until it presses against the adjusting ring 13. The anti-loosening bolt 41 is rotated to stabilize the anti-loosening member 4. Move the lifting ring 132 to the designated position, place the pressure frame 51 between the adjusting sleeve 2 and the lifting ring 132, and secure the pressure frame 51 to the top of the adjusting sleeve 2 with threads. Move the slider 133, and the stabilizing ring 52 moves, flips, and moves in the opposite direction, so that the fixing block 53 enters the insertion groove. Push the moving block 55, and the pin 551 passes through the stabilizing ring 52, the fixing block 53, and the connecting block 54. Flip the rotating rod 61, so that the limiting post 62 enters the limiting arc groove 611 to stabilize the pressure frame 51. Finally, connect the baffle 7 between the adjusting sleeve 2 and the pressure frame 51 with bolts to realize the installation of the crushing mechanism.

[0048] By setting the adjustment sleeve 2, the crushing gap of the crusher can be adjusted mechanically. Compared with the existing technology, it has fewer parts, fewer operating steps, is easier to maintain, and has lower cost, thus improving the applicability of the mining crusher.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A crushing mechanism, comprising a main frame (1), a cone (11), and a main shaft (12) mounted on a crusher, characterized in that: An adjusting ring (13) is mounted on the main frame (1), and an adjusting sleeve (2) is provided on the adjusting ring (13). The outer ring wall of the adjusting sleeve (2) is provided with a threaded portion, and the adjusting sleeve (2) is threadedly fitted onto the adjusting ring (13). A breaking arc wall (21) is provided on the inner ring wall of the adjusting sleeve (2). The main shaft (12) and the cone (11) are both located inside the main frame (1). The cone (11) is mounted on the main shaft (12). A limiting arc wall (21) is provided on the adjusting ring (13). The adjusting sleeve (2) is equipped with an anti-loosening component (4) to prevent movement. During crushing, the ore is located between the crushing arc wall (21) and the cone (11). A stabilizing component (5) is provided on the adjusting ring (13). The stabilizing component (5) includes a pressure frame (51), a stabilizing ring (52), a fixing block (53), a connecting block (54), and a moving block (55). A bearing ring (131) is connected to the adjusting ring (13). A lifting ring (132) is threaded onto the inner ring wall of the bearing ring (131). The pressure frame ( 51) The pressure frame (51) is located between the top of the adjusting sleeve (2) and the top of the lifting ring (132). The pressure frame (51) is bolted to the top of the adjusting sleeve (2). Several sliders (133) are slidably fitted on the bearing ring (131). One end of the stabilizing ring (52) is rotatably connected to the slider (133), and the other end has an insertion groove. The fixing block (53) is connected to the pressure frame (51) and enters the insertion groove. The connecting block (54) is connected to the pressure frame (51). On the frame (51), the movable block (55) is slidably fitted on the pressure frame (51), the fixed block (53) is located between the connecting block (54) and the movable block (55), the movable block (55) is connected with a pin (551), and a limiting component (6) is provided between the movable block (55) and the connecting block (54) to restrict the movement of the movable block (55). During installation, the pin (551) passes through the stabilizing ring (52), the fixed block (53) and the connecting block (54).

2. The crushing mechanism according to claim 1, characterized in that: The anti-loosening component (4) is an anti-loosening screw ring. The anti-loosening component (4) is threaded onto the adjusting sleeve (2) and fits against the adjusting ring (13). Several anti-loosening bolts (41) are threaded through the anti-loosening component (4). The anti-loosening bolts (41) pass through the anti-loosening component (4) and the adjusting ring (13) and are threadedly engaged with the adjusting ring (13).

3. The crushing mechanism according to claim 1, characterized in that: The limiting component (6) includes a rotating rod (61), a limiting post (62), and a connecting plate (63). One end of the rotating rod (61) is rotatably connected to the side wall of the moving block (55), and the other end has a limiting arc groove (611). The center of the limiting arc groove (611) coincides with the rotation center of one end of the rotating rod (61). The limiting post (62) is connected to the side wall of the connecting block (54) and is arranged on the same side as the rotating rod (61). The connecting plate (63) is connected to the end of the limiting post (62). When limiting, the limiting post (62) is located in the limiting arc groove (611), and the other end of the rotating rod (61) is located between the connecting plate (63) and the connecting block (54).

4. The crushing mechanism according to claim 1, characterized in that: A plurality of grinding walls (24) are detachably connected to the broken arc wall (21), and the plurality of grinding walls (24) cover the broken arc wall (21). An installation assembly (3) for limiting the grinding walls (24) is provided on the adjusting sleeve (2).

5. The crushing mechanism according to claim 4, characterized in that: The mounting assembly (3) includes an extension block (31), a T-bar (32), a pressure plate (33), a limiting block (34), and a rotating ring (35). The adjusting sleeve (2) has several mounting cavities (22) inside, one mounting cavity (22) corresponding to one of the grinding bowl walls (24). Two reinforcing blocks (23) are provided in each mounting cavity (22). The T-bar (32) is located in the mounting cavity (22). The extension block (31) is connected to the grinding bowl wall (24). The extension block (31) enters the mounting cavity (22). The end of the extension block (31) The part is provided with a hook (311), which hooks onto the T-shaped rod (32). The pressure plate (33) is placed on two reinforcing blocks (23). The pressure plate (33) has a mounting hole. The limiting block (34) is connected in the mounting hole. The end of the T-shaped rod (32) passes through the mounting hole. The end of the T-shaped rod (32) has a limiting groove (321). The limiting block (34) is slidably fitted in the limiting groove (321). The rotating ring (35) is rotatably connected to the pressure plate (33) and threadedly fitted to the end of the T-shaped rod (32).

6. The crushing mechanism according to claim 1, characterized in that: The adjusting sleeve (2) and the pressure frame (51) are connected by bolts with a cover (7).

7. The crushing mechanism according to claim 6, characterized in that: A retaining ring (71) is connected to the inner ring wall of the baffle (7), the retaining ring (71) is attached to the top of the broken arc wall (21), and a number of reinforcing ribs (72) are connected between the inner wall of the baffle (7) and the retaining ring (71).

Images