Cutterhead and full-face tunneling machine using cutterhead

Abstract

This invention relates to the field of trenchless underground engineering equipment, and in particular to a cutterhead and a full-face tunneling machine using the cutterhead. The cutterhead includes a cutterhead body with a muck inlet, and a muck discharge cylinder fixed to the back of the cutterhead body, the muck discharge cylinder having a muck flow disturbance structure. This invention is an improved invention. Specifically, by fixing the muck discharge cylinder to the back of the cutterhead body and setting the muck flow disturbance structure on the muck discharge cylinder, during use, the muck discharge cylinder rotates synchronously with the cutterhead. The muck entering the back of the cutterhead through the muck inlet will be disturbed by the muck flow disturbance structure on the muck discharge cylinder, thereby increasing its fluidity and enabling rapid rearward muck discharge. This solves the problem of secondary wear on the cutterhead and equipment caused by poor muck discharge in inclined shaft tunneling machines.

Description

Technical Field

[0001] This invention relates to the field of trenchless underground engineering equipment, and in particular to a cutterhead and a full-face tunneling machine using the cutterhead. Background Technology

[0002] With the continuous development of full-face tunneling machine technology, its application scenarios have gradually expanded from the initial tunnel excavation to other fields. Today, full-face tunneling machines have begun to be introduced for construction in fields such as coal mines, military industry, and pumped storage.

[0003] Unlike traditional horizontal tunneling or shallow-slope tunneling, new application scenarios are increasingly featuring tunnel projects with steep gradients, which traditional conventional tunneling machines can no longer meet. Based on the emergence of these new demands, the applicant has conducted continuous research on inclined shaft tunneling machines and filed a Chinese utility model patent with authorization announcement number CN214062959U and authorization announcement date of August 27, 2021. This patent provides a cutterhead, cutter transport fixture, and tunneling machine for inclined shaft tunneling.

[0004] The cutterhead in the aforementioned patent includes a cutterhead body, with a support beam fixed to its back. A flange is connected to the support beam, and the flange is used to connect to the main drive so that the cutterhead can obtain the rotational torque required for tunneling. The spaced arrangement of the support beams facilitates muck removal to some extent. However, if the muck between the support beams and the tunnel wall (mainly near the tunnel bottom) becomes solidified on the tunnel wall, it will be difficult to clean. Failure to clean it in time will cause secondary wear to the cutterhead and the entire equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a cutterhead to solve the problem of secondary wear of the cutterhead and equipment caused by poor slag discharge in existing inclined shaft tunneling machines.

[0006] Meanwhile, the present invention also aims to provide a full-face tunneling machine using the above-mentioned cutterhead, so as to solve the problem of secondary wear of the cutterhead and equipment caused by poor slag discharge in inclined shaft tunneling machines.

[0007] To solve the above problems, the cutter head of the present invention adopts the following technical solution: a cutter head, including a cutter head body, wherein the cutter head body is provided with a slag inlet, and a slag outlet cylinder is fixedly provided on the back side of the cutter head body, wherein the slag outlet cylinder is provided with a slag turbulence structure.

[0008] Beneficial Effects: This invention is an improved invention. Specifically, by fixing a slag discharge cylinder to the back of the cutterhead body and setting a slag flow disturbance structure on the slag discharge cylinder, the slag discharge cylinder rotates synchronously with the cutterhead during use. The slag entering the back of the cutterhead through the slag inlet will be disturbed by the slag flow disturbance structure on the slag discharge cylinder, thereby increasing its fluidity and enabling rapid slag discharge. This solves the problem of secondary wear on the cutterhead and equipment caused by poor slag discharge in existing inclined shaft tunneling machines.

[0009] Furthermore, the turbulence structure includes a turbulence plate with a guide section for guiding the slag to the rear end of the discharge cylinder. This guide section is inclined from front to back in the rotation direction of the cutterhead and extends along the cutterhead body. The guide section guides the flow of the slag. Based on its inclination and extension direction, when the discharge cylinder rotates, after the guide plate passes its lowest point, the slag inside the discharge cylinder will automatically flow backward along the guide section under the influence of gravity, and then be quickly discharged.

[0010] Furthermore, the baffle also includes a slag chute section located on the back of the cutterhead body, serving as a slag chute. The slag chute section guides the slag entering from the cutterhead inlet to the back of the cutterhead, directing it to a designated position on the slag discharge cylinder for discharge.

[0011] Furthermore, the outer circumferential surface of the slag discharge cylinder is provided with a slag inlet, and the aforementioned turbulence structure is provided between two adjacent slag inlets. The slag inlet can capture and clean the slag at the bottom of the tunnel, and the turbulence structure between two adjacent slag inlets can act on the captured slag in a timely manner for processing.

[0012] Furthermore, a slag scraper is provided at the slag inlet of the cylinder. The slag scraper can enhance the effect of capturing slag and stones.

[0013] Furthermore, a filter grid is installed at the slag inlet of the cylinder. The filter grid can limit the particle size of the slag entering the slag inlet of the cylinder, preventing large rocks from entering the cutterhead and blocking the slag discharge channel.

[0014] Furthermore, multiple turbulence structures are evenly distributed around the centerline of the cutterhead body. These multiple turbulence structures can achieve better turbulence and prevent slag from solidifying.

[0015] Furthermore, wear-resistant strips are provided on the inner and / or outer wall surfaces of the slag discharge cylinder. These wear-resistant strips serve to protect the slag discharge cylinder.

[0016] Furthermore, the back of the cutterhead body is provided with toggle legs, and the rear ends of each toggle leg are connected to the same flange, which is used to connect to the main drive of the tunneling machine. Using toggle leg connections reduces the distribution of stiffening plates within the cutterhead chamber, facilitating slag removal and cutter replacement.

[0017] The full-face tunneling machine of the present invention adopts the following technical solution: a full-face tunneling machine, including a cutterhead, the cutterhead including a cutterhead body, the cutterhead body being provided with a slag inlet, a slag discharge cylinder being fixed on the back of the cutterhead body, and the slag discharge cylinder being provided with a slag turbulence structure.

[0018] Beneficial Effects: This invention is an improved invention. Specifically, the full-face tunneling machine of this invention has a muck discharge cylinder fixed on the back of the cutterhead body, and a muck flow disturbance structure is set on the muck discharge cylinder. During use, the muck discharge cylinder rotates synchronously with the cutterhead. The muck entering the back of the cutterhead through the muck inlet will be disturbed by the muck flow disturbance structure on the muck discharge cylinder, thereby increasing the fluidity and enabling rapid muck discharge. This solves the problem of secondary wear of the cutterhead and equipment caused by poor muck discharge in inclined shaft tunneling machines.

[0019] Furthermore, the turbulence structure includes a turbulence plate with a guide section for guiding the slag to the rear end of the discharge cylinder. This guide section is inclined from front to back in the rotation direction of the cutterhead and extends along the cutterhead body. The guide section guides the flow of the slag. Based on its inclination and extension direction, when the discharge cylinder rotates, after the guide plate passes its lowest point, the slag inside the discharge cylinder will automatically flow backward along the guide section under the influence of gravity, and then be quickly discharged.

[0020] Furthermore, the baffle also includes a slag chute section located on the back of the cutterhead body, serving as a slag chute. The slag chute section guides the slag entering from the cutterhead inlet to the back of the cutterhead, directing it to a designated position on the slag discharge cylinder for discharge.

[0021] Furthermore, the outer circumferential surface of the slag discharge cylinder is provided with a slag inlet, and the aforementioned turbulence structure is provided between two adjacent slag inlets. The slag inlet can capture and clean the slag at the bottom of the tunnel, and the turbulence structure between two adjacent slag inlets can act on the captured slag in a timely manner for processing.

[0022] Furthermore, a slag scraper is provided at the slag inlet of the cylinder. The slag scraper can enhance the effect of capturing slag and stones.

[0023] Furthermore, a filter grid is installed at the slag inlet of the cylinder. The filter grid can limit the particle size of the slag entering the slag inlet of the cylinder, preventing large rocks from entering the cutterhead and blocking the slag discharge channel.

[0024] Furthermore, multiple turbulence structures are evenly distributed around the centerline of the cutterhead body. These multiple turbulence structures can achieve better turbulence and prevent slag from solidifying.

[0025] Furthermore, wear-resistant strips are provided on the inner and / or outer wall surfaces of the slag discharge cylinder. These wear-resistant strips serve to protect the slag discharge cylinder.

[0026] Furthermore, the back of the cutterhead body is provided with toggle legs, and the rear ends of each toggle leg are connected to the same flange, which is used to connect to the main drive of the tunneling machine. Using toggle leg connections reduces the distribution of stiffening plates within the cutterhead chamber, facilitating slag removal and cutter replacement. Attached Figure Description

[0027] Figure 1 This is a front view of Embodiment 1 of the cutter head of the present invention;

[0028] Figure 2 This is a left view of Embodiment 1 of the cutter head of the present invention;

[0029] Figure 3 This is a perspective view (rear view) of Embodiment 1 of the cutter head of the present invention;

[0030] Figure 4 This is a perspective view (side view) of Embodiment 1 of the cutter head of the present invention;

[0031] Figure 5 yes Figure 3 , 4 Front view of the spoiler in the middle;

[0032] Figure 6 yes Figure 5 Right view of the spoiler in the middle;

[0033] Figure 7 yes Figure 1 A schematic diagram of the slag discharge cylinder in the middle;

[0034] Figure 8 This is a diagram showing the state of the cutterhead in Embodiment 1 of the present invention under steep slope tunneling conditions;

[0035] Figure 9 This is a diagram showing the cutterhead of Embodiment 1 of the present invention in a horizontal tunneling state;

[0036] Figure 10 This is a structural schematic diagram of an embodiment of the full-face tunneling machine of the present invention.

[0037] In the diagram: 101. Cutterhead body; 11. Front panel; 12. Single-blade cutter box hole; 13. Central cutter box hole; 14. Central slag inlet; 15. Slag scraper; 16. Grille; 17. Edge slag inlet; 18. Wear-resistant ring; 19. Outer wear-resistant strip; 110. Inner wear-resistant strip; 111. Torsion leg; 112. Flange; 102. Slag discharge cylinder; 21. Cylinder slag inlet; 103. Baffle plate; 31. Slag chute section; 32. Guide section; 104. Shield slag discharge chute; 201. Main drive; 202. Cutterhead; 203. Protective device. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0040] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0041] Embodiment 1 of the cutter head of the present invention:

[0042] like Figure 1-10 As shown, the main components of the cutterhead include the cutterhead body 101, the slag discharge cylinder 102, and the slag turbulence structure.

[0043] The structure of the cutterhead body 101 is shown in Figures 1-4. It includes a front panel 11 with cutter box holes for mounting multiple roller cutters, which can be used for rock breaking. The cutter box holes are divided into single-edged cutter box holes 12 and a central cutter box hole 13. The single-edged cutter box holes 12 are used to mount single-edged cutters, and the central cutter box hole 13 is used to mount a central double-roller cutter. A central slag inlet 14 is located in the center of the front panel 11. A scraper 15 and a grid 16 are installed at the central slag inlet 14. The central slag inlet 14 allows slag near the working face to enter the cutterhead, and the grid 16 restricts the particle size of the slag to prevent blockage of the slag discharge channel at the back of the cutterhead. An edge slag inlet 17 is located near the edge of the panel 11. The edge slag inlet 17 is also equipped with a scraper 15 and a grid 16. The edge slag inlet 17 can scoop up slag from the bottom of the tunnel wall, and the grid 16 also serves to restrict the particle size of the slag.

[0044] In this embodiment, the front panel of the cutterhead body 101 is provided with four central slag inlets 14 and six edge slag inlets 17. However, those skilled in the art should understand that in other embodiments, the number of central slag inlets 14 and edge slag inlets 17 can be arbitrarily designed as needed. In some cases, the central slag inlets 14 or the edge slag inlets 17 can even be omitted. Providing scrapers and grids at the slag inlets of the cutterhead is prior art; therefore, the structure and installation method of the scrapers and grids will not be described in detail here.

[0045] A slag discharge cylinder 102 is fixedly mounted on the back of the cutterhead body 101. In this embodiment, the slag discharge cylinder 102 is fixed to the back of the cutterhead body 101 by welding, and its diameter is approximately equal to the diameter of the front panel 11. The function of the slag discharge cylinder 102 is to collect slag and drive its movement, thereby quickly discharging the slag. In this embodiment, as... Figure 7 As shown, a slag inlet 21 is provided on the outer circumference of the slag discharge cylinder 102. A scraper 15 and a grid 16 are also provided at the slag inlet 21. The function of the slag inlet 21 is to scrape up the slag and stone at the bottom of the tunnel wall so that it can be discharged backward through the slag discharge cylinder 102. This ensures that there is no slag and stone accumulation on the tunnel wall and that the construction environment is clean.

[0046] It should be particularly emphasized here that although in this embodiment the slag discharge cylinder 102 is fixed to the cutter head body 101 by welding, those skilled in the art should know that in other embodiments, the slag discharge cylinder 102 can also be fixed to the cutter head body 101 by fasteners (threaded fasteners, riveted fasteners, etc.), or fixed to the cutter head body 101 in an integral structure.

[0047] A turbulence-discharging structure is provided on the slag discharge cylinder 102. The function of the turbulence-discharging structure is to agitate the slag and stone inside the slag discharge cylinder 102 by means of the rotational motion of the slag discharge cylinder 102, so that it can flow better and be discharged quickly. In this embodiment, the turbulence-discharging structure is specifically a turbulence plate 103, and the structure of the turbulence plate 103 is as follows. Figure 5 , 6 As shown, the baffle 103 here comprises two main components. One component is the slag chute section 31, which functionally corresponds to the slag chute in the existing cutterhead. It extends radially along the cutterhead body 101, with one end near the edge of the cutterhead body 101 extending rearward and reaching the inner side of the slag discharge cylinder 102. This part located inside the slag discharge cylinder 102 constitutes another important part of the baffle 103, namely the guide section 32. The guide section 32 is inclined from front to back in the rotation direction of the cutterhead and extends back and forth along the cutterhead body 101. The inclination angle here can be set according to the simulated slag flow characteristics. Different slopes result in different slag flow rates, so the inclination angle of the guide section 32 is also different. The purpose is to guide the slag to the shield slag discharge chute 104 and discharge it smoothly to the rear.

[0048] In this embodiment, six slag inlets 21 are provided on the slag discharge cylinder 102. These six inlets 21 are staggered from the edge slag inlets 17 along the circumference of the cutterhead body 101, ensuring the structural strength of the slag discharge cylinder 102 and the cutterhead body 101. The staggered arrangement also improves slag scraping and discharge efficiency. It should be noted that in this embodiment, the six slag inlets 21 are evenly distributed around the centerline of the slag discharge cylinder. However, in other embodiments, the number and arrangement of the slag inlets 21 can be arbitrarily designed according to actual needs. The slag inlets 21 and the edge slag inlets 17 can also be arranged facing each other. In this case, other measures can be used to reinforce the cutterhead body and the slag discharge cylinder to meet strength requirements.

[0049] Considering the synergy between the slag inlet 21 and the turbulence structure, in this embodiment, the number and position of the turbulence structure and the slag inlet 21 are coordinated. Specifically, a turbulence structure is set between any two adjacent slag inlets 21. Therefore, the slag entering the slag discharge cylinder 102 from the slag inlet 21 can be discharged to the rear of the slag discharge cylinder 102 immediately under the guiding action of the nearest turbulence plate 103, and will not flow into the tunnel wall from the adjacent slag inlet.

[0050] To ensure the strength of the cutterhead body 101 and slow down its wear process, in this embodiment, a wear-resistant ring 18 is provided on the outer peripheral surface of the cutterhead body 101. In addition to strengthening and preventing wear, the wear-resistant ring 18 has a certain thickness, which can block the slag and stone at the bottom of the working face, and also prevent the slag and small pieces of slag and stone from flowing into the space between the slag cylinder 102 and the tunnel wall.

[0051] To reduce wear on the cutterhead body 101, outer wear-resistant strips 19 are applied to the outer side of the slag discharge cylinder 102 and the front panel 11. During use, the outer wear-resistant strips 19 contact the surrounding cavity walls before the slag discharge cylinder and the front panel, thus protecting the slag discharge cylinder and the front panel. Additionally, inner wear-resistant strips 110 are provided on the inner side of the slag discharge cylinder, which enhances the structural rigidity of the slag discharge cylinder, improves its wear resistance, and extends its service life.

[0052] A torsion leg 111 is provided on the back of the cutter head body 101. The torsion leg 111 is used to connect the cutter head body 101 to the main drive, transmitting the torque supplied by the main drive to the cutter head body. The torsion leg 111 extends backward parallel to the axis of the cutter head body 101 (in other embodiments, the torsion leg 111 may also have a certain angle with the axis of the cutter head body 101) and is connected to the same flange 112. The flange 112 is used to directly connect to the main drive. In the specific implementation of the present invention, several sets of torsion legs 111 can be set according to the diameter of the cutter head. By setting the torsion leg 111 to replace the various continuous connecting plates (covering the entire radius of the cutter head) in the previous cutter head, the purpose is to reduce the number of cutter compartment connecting plates, which facilitates slag discharge from the cutter compartment and subsequent maintenance.

[0053] Figure 8 The figure shows the state of the cutterhead of the present invention under the condition of tunneling at a large slope (≥30°). As shown in the figure, due to the large tunneling slope, during the tunneling process, the slag will enter the back of the cutterhead through the central slag inlet 14 and the edge slag inlet 17 provided on the front panel 11 of the cutterhead body 101, and then reach the slag discharge cylinder 102. Since the slag discharge cylinder 102 rotates synchronously with the cutterhead body 101, during the rotation, the guide section 32 of the baffle 103 will promote the flow of slag and guide the flowing slag backward, that is, out of the slag discharge cylinder 102, so as to promote the rapid discharge of slag from the slag discharge cylinder 102.

[0054] Figure 9The figure shows the state of the cutterhead of the present invention under horizontal tunneling conditions in Embodiment 1. As shown in the figure, under horizontal tunneling conditions, the slag produced by the cutterhead tunneling will also enter the back of the cutterhead through the central slag inlet 14 and the edge slag inlet 17, and then be guided by the slag chute section 31 of the guide plate 103 to fall into the slag discharge cylinder 102. As the slag discharge cylinder 102 rotates with the cutterhead body, when the guide section 32 of the baffle plate 103 passes the lowest point and begins to rise, the slag will slide down along the guide section 32 of the baffle plate under the action of gravity, and then enter the shield slag discharge trough 104 provided on the shield body. At this time, it is only necessary to process the slag from the shield slag discharge trough 104. The specific processing method can be, for example, by using a belt conveyor to transfer it.

[0055] When using this cutterhead, it can be fixedly installed on the main drive of the TBM main unit via the torsion leg 111 and flange 112, with the main drive providing rotational power. Since the torsion leg 111 is close to the center of the cutterhead and extends in the front-to-back direction, it can replace various continuous connecting plates in the previous cutterhead, aiming to reduce the number of cutter chamber connecting plates and facilitate cutter chamber slag discharge and subsequent maintenance. The slag generated during the tunneling process will enter the back of the cutterhead through the central slag inlet 14 and the edge slag inlet 17, and slide along the slag chute section of the baffle 103 to the bottom of the slag discharge cylinder 102. The slag discharge cylinder 102 rotates synchronously with the cutterhead body 101, promoting the flow of slag during rotation, and the slag is discharged backward through the guide section of the baffle 103. During this process, the slag inlet on the slag discharge cylinder 102 can scoop the slag at the bottom of the tunnel into its interior for processing, thereby keeping the tunnel wall clean.

[0056] In the above embodiments, the slag discharge cylinder used in the cutterhead of the present invention is a cylindrical cylinder with a plate-type wall and a turbulence-inducing structure, which acts as a turbulence-inducing plate as the cutterhead rotates. In other embodiments, the wall of the slag discharge cylinder can also be a hollow wall, for example, a hollow wall formed by multiple mud-beating rods extending rearward from the front panel of the cutterhead. With this structure, each mud-beating rod will directly constitute a turbulence-inducing structure, which will disperse the slag at the bottom of the tunnel and generate a turbulence effect. Of course, based on the same concept as the mud-beating rods, mud-beating plates can also be used instead of mud-beating rods. In this case, in addition to accelerating the disturbance of slag, the mud-beating plate can also act like a bucket to guide the flow of slag.

[0057] Embodiments of the full-face tunneling machine of the present invention:

[0058] like Figure 10As shown, the full-face tunneling machine includes a main drive 201 and a cutterhead 202. Most of the structure of the main drive 201 is existing technology. However, unlike existing technology, a protective device 203 is provided at the center of the front end of the main drive 202 to prevent the slag from falling into the main drive during inclined tunneling and from falling further into the main drive and injuring people. The cutterhead is the cutterhead of this invention, which will not be described in detail here.

Claims

1. A cutter head, comprising a cutter head body, wherein the cutter head body is provided with a slag inlet, characterized in that, A slag discharge cylinder is fixedly mounted on the back side of the cutterhead body, and a slag flow disturbance structure is provided on the slag discharge cylinder. The disturbance structure includes a disturbance plate, which has a guide section for guiding the slag to the rear end of the slag discharge cylinder and a slag discharge section provided on the back side of the cutterhead body as a slag discharge plate. The guide section is inclined from front to back in the rotation direction of the cutterhead and extends along the front and back of the cutterhead body. A cylinder slag inlet is provided on the outer circumferential surface of the slag discharge cylinder, and the disturbance structure is provided between two adjacent cylinder slag inlets. The slag discharge section extends radially along the cutterhead body, with one end near the edge of the cutterhead body extending rearward and into the inner side of the slag discharge cylinder. This part located inside the slag discharge cylinder constitutes the guide section of the disturbance plate.

2. The cutter head according to claim 1, characterized in that, A slag scraper is provided at the slag inlet of the cylinder.

3. The cutter head according to claim 1, characterized in that, A filter grid is provided at the slag inlet of the cylinder.

4. The cutter head according to any one of claims 1-3, characterized in that, Multiple turbulence structures are evenly distributed around the centerline of the cutter head body.

5. The cutter head according to any one of claims 1-3, characterized in that, Wear-resistant strips are provided on the inner and / or outer wall surfaces of the slag discharge cylinder.

6. The cutter head according to any one of claims 1-3, characterized in that, The back of the cutterhead body is provided with torsion legs, and the rear end of each torsion leg is connected to the same flange, which is used to connect to the main drive of the tunneling machine.

7. A full-face tunneling machine, comprising a cutterhead, the cutterhead including a cutterhead body, the cutterhead body having a muck inlet, characterized in that, A slag discharge cylinder is fixedly mounted on the back side of the cutterhead body, and a slag flow disturbance structure is provided on the slag discharge cylinder. The disturbance structure includes a disturbance plate, which has a guide section for guiding the slag to the rear end of the slag discharge cylinder and a slag discharge section provided on the back side of the cutterhead body as a slag discharge plate. The guide section is inclined from front to back in the rotation direction of the cutterhead and extends along the front and back of the cutterhead body. A cylinder slag inlet is provided on the outer circumferential surface of the slag discharge cylinder, and the disturbance structure is provided between two adjacent cylinder slag inlets. The slag discharge section extends radially along the cutterhead body, with one end near the edge of the cutterhead body extending rearward and into the inner side of the slag discharge cylinder. This part located inside the slag discharge cylinder constitutes the guide section of the disturbance plate.

8. The full-face tunneling machine according to claim 7, characterized in that, A slag scraper is provided at the slag inlet of the cylinder.

9. The full-face tunneling machine according to claim 7, characterized in that, A filter grid is provided at the slag inlet of the cylinder.

10. The full-face tunneling machine according to any one of claims 7-9, characterized in that, Multiple turbulence structures are evenly distributed around the centerline of the cutter head body.

11. The full-face tunneling machine according to any one of claims 7-9, characterized in that, Wear-resistant strips are provided on the inner and / or outer wall surfaces of the slag discharge cylinder.

12. The full-face tunneling machine according to any one of claims 7-9, characterized in that, The back of the cutterhead body is provided with torsion legs, and the rear end of each torsion leg is connected to the same flange, which is used to connect to the main drive of the tunneling machine.

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