Multi-cutterhead driving excavation device and method for ultra-large-section quasi-rectangular shield

Abstract

The invention relates to the technical field of shield tunneling machines, and discloses a super-large-section quasi-rectangular shield multi-cutterhead driving excavation device and a super-large-section quasi-rectangular shield multi-cutterhead driving excavation method. The technical problems that in the prior art, a cutting blind area is difficult to eliminate, energy consumption and abrasion are high due to uneven loads of a driving system, the reliability is insufficient due to overheating of a transmission part, and the control precision of an ultra-large section tunneling posture is poor are solved. The shield comprises a quasi-rectangular shield shell, the shield shell is provided with a plurality of cutterhead assemblies of different sizes, and each cutterhead assembly comprises at least two center cutterheads arranged in the center area of the shield shell and further comprises corner cutterheads arranged in the four corner areas of the shield shell. A plurality of edge cutterheads are arranged in an edge area between the central cutterhead and the corner cutterheads; and a plurality of advancing cutters are fixedly connected to gaps between the cutter head assemblies on the shield shell. The rotating direction can be freely adjusted according to actual geological conditions and excavation requirements, and the conditions of soil layer hardness changes, uneven rock distribution and the like can be effectively handled.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine technology, and in particular to a multi-cutterhead driven excavation device and method for ultra-large cross-section rectangular tunnel boring machines. Background Technology

[0002] With the continuous development of urban underground space, tunnel projects such as subways, integrated utility tunnels, and underground roads have placed higher demands on construction efficiency and space utilization. Compared with traditional circular tunnels, rectangular tunnel sections can utilize underground space more effectively, reduce land acquisition, and minimize disturbance to the surrounding environment, thus becoming one of the important directions for tunnel engineering development. Shield tunneling, as the mainstream tunneling technology, is applied to the construction of rectangular tunnels. To achieve rectangular cross-section excavation, existing technologies mostly adopt multi-cutterhead combined excavation schemes. However, when these existing schemes are applied to ultra-large cross-section rectangular tunnels, many technical bottlenecks have gradually been exposed: First, there are issues with excavation coverage and cutting efficiency. Simple multi-cutterhead layouts are difficult to fully adapt to rectangular sections, especially the complex geometric contours of ultra-large cross-section rectangular sections. Cutting blind zones are easily generated at the four corners of the cross-section and in the long edge area between the center and the corners. To cover these blind zones, the shield machine often needs to repeatedly adjust its posture for "trimming," which seriously affects excavation efficiency and results in poor cross-section quality. Second, there are issues with uneven load and equipment wear. During tunneling, due to variations in soil conditions across different areas of the excavation face, traditional linkage-driven or simple group-driven methods result in some cutterheads being overloaded and others underloaded at the interface between soft and hard surfaces. This leads to extremely uneven load distribution in the drive system, resulting not only in high energy consumption but also abnormal wear and even damage to the cutterheads and transmission components, significantly shortening equipment lifespan. Secondly, there are issues with thermal management and reliability. When tunneling through hard rock or high-strength soil layers, critical transmission components such as the cutterhead spindle bearings generate substantial heat. Existing cooling solutions are often insufficiently direct and efficient, leading to heat accumulation in the bearings, lubricant failure, and a high risk of serious malfunctions such as bearing burn-out and seizure, threatening the safe operation of the entire project. Finally, there are issues with directional control accuracy. Ultra-large cross-section tunnel boring machines (TBMs) experience more complex resistance from the surrounding strata. Traditional methods of attitude control via adjusting the shield jacks are slow and inaccurate, easily causing the tunnel axis to deviate from the design line. The correction process further exacerbates abnormal wear and tear on the equipment.

[0003] Chinese patent document 201710433146.9 discloses a multi-cutterhead drive system, cutterhead, and tunneling equipment for tunneling equipment. The system includes at least one drive unit, which comprises multiple sets of frequency converters and multiple sets of cutterhead drive assemblies corresponding to the cutterhead. Each set of cutterhead drive assemblies includes multiple drive motors. The number of frequency converters in each drive unit is equal to the number of drive motors in each set of cutterhead drive assemblies, and the output terminals of the frequency converters are connected one-to-one with the drive motors. The cutterhead includes a cutterhead body and the aforementioned multi-cutterhead drive system for tunneling equipment, with the multi-cutterhead drive system drivingly connected to the cutterhead body. The tunneling equipment includes a shield body and the aforementioned cutterhead, with the cutterhead located at the front end of the shield body.

[0004] However, the above-mentioned solutions have at least the following technical problems during implementation: Traditional single-cutterhead tunnel boring machines (TBMs) often suffer from low excavation efficiency, severe cutterhead wear, and poor adaptability when facing ultra-large cross-section tunnels due to the large excavation area and complex geological conditions. These problems not only increase construction costs but may also lead to construction delays and even construction safety risks. The construction environment of ultra-large cross-section tunnels typically has the following characteristics: large variations in soil hardness, uneven rock distribution, and abundant groundwater. These complex geological conditions place higher demands on the excavation performance of the TBM. During the excavation process, traditional single-cutterhead TBMs experience significant friction and impact between the cutterhead and the soil, which easily leads to accelerated cutterhead wear and even cutterhead blockage. Therefore, there is an urgent need to propose a multi-cutterhead driven excavation device and method for ultra-large cross-section rectangular TBMs. Summary of the Invention

[0005] In view of the above technical problems, this disclosure provides a multi-cutterhead driven excavation device and method for ultra-large cross-section rectangular shield tunneling, which solves the technical problems in the prior art such as the difficulty in eliminating cutting blind zone, uneven load of drive system leading to high energy consumption and wear, insufficient reliability of transmission parts due to overheating, and poor control accuracy of tunneling posture in ultra-large cross-section tunneling.

[0006] According to one aspect of this disclosure, a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines is provided, comprising a rectangular shield shell, on which multiple cutterhead assemblies of different sizes are arranged. Each cutterhead assembly includes at least two central cutterheads disposed in the central region of the shield shell, and corner cutterheads disposed in the four corner regions of the shield shell. Multiple edge cutterheads are disposed in the edge region between the central and corner cutterheads. Multiple advance cutters are fixedly connected to the shield shell and in the gaps between the cutterhead assemblies. A transmission rod is fixedly connected to the back of each cutterhead assembly, and a flange is fixedly connected to the end of the transmission rod to drive the cutterhead assembly to rotate. A drive module is mounted on the cutterhead assembly via the transmission rod. The drive module includes a motor. A planetary gear structure is mounted on the output shaft of the motor. The planetary gear structure includes a sun gear connected to the motor, which meshes with multiple planetary gears. The outer sides of the multiple planetary gears mesh with a gear ring to drive the cutterhead assembly to rotate.

[0007] In some embodiments of this disclosure, an external support rod is also provided on the back of the cutter head assembly.

[0008] In some embodiments of this disclosure, the surface of the shield shell is provided with multiple cutterhead slots for rotating the cutterhead assembly.

[0009] In some embodiments of this disclosure, a coolant hole is provided inside the cutter head groove, and the coolant hole is connected to an external coolant device.

[0010] In some embodiments of this disclosure, the inner wall of the cutter head groove is provided with a wear-resistant coating, which is a tungsten carbide-based composite material wear-resistant coating.

[0011] A method for multi-cutterhead driven excavation of ultra-large cross-section rectangular shield tunnels includes the following steps: S1: Cutterhead drive: The cutterhead assembly is driven by an external power source connected to the flange mounting plate and external support rod. During the excavation process, the cutterhead assembly adjusts the rotation direction according to the actual geological conditions and excavation requirements, including forward and reverse rotation. S2: Collaborative Excavation: In the early stage of excavation, the advance cutter fixed on the shield shell first contacts the soil and performs pre-cutting and loosening; subsequently, the central cutterhead, corner cutterhead and edge cutterhead rotate in coordination to completely cut the pre-treated soil and form a rectangular tunnel cross section. S3: Cutterhead cooling: During the excavation process, coolant continuously flows into the cutterhead groove through the coolant holes to cool the cutterhead assembly; S4: Wear-resistant protection: The wear-resistant coating of tungsten carbide-based composite material, which is set on the inner wall of the cutterhead groove, resists the friction and impact during the transmission of the cutterhead assembly and protects the shield shell structure.

[0012] In some embodiments of this disclosure, the cutterhead drive in step S1 further includes the following steps: the motor of the drive module is started, driving the sun gear to rotate; the sun gear drives multiple planetary gears meshing with it to rotate around its axis, and under the meshing action with the gear ring, outputs power through the planetary gear structure, transmits it to the cutterhead assembly through the transmission rod, and drives it to rotate; according to the actual geological conditions and excavation requirements, the rotation direction and speed of each cutterhead assembly are independently controlled.

[0013] The beneficial effects of this invention are as follows: The coordinated layout of the center cutterhead, corner cutterheads, and edge cutterheads eliminates cutting blind spots. By using cutterheads of different sizes and positions to complement each other's functions, the center cutterhead is responsible for the core area, the edge cutterheads cover the long side area, and the dedicated corner cutterheads handle the most difficult corners to cut, thus achieving seamless and full-coverage excavation of rectangular cross-sections.

[0014] By decomposing the excavation task of a large cross-section into multiple small drive units, the manufacturing difficulties and high energy consumption problems associated with a single, ultra-large drive system are avoided. Each cutterhead is equipped with an independent drive unit. When an increase in torque is detected in a cutterhead encountering hard rock, its rotational speed can be reduced individually to prevent overload, while maintaining normal excavation of the other cutterheads. This achieves adaptive excavation, significantly reducing peak load and average energy consumption, and protecting the mechanical equipment.

[0015] By independently adjusting the thrust or rotation speed of the left or right cutterhead on one side of the shield, a corrective torque can be generated, enabling real-time and precise deviation correction and solving the technical challenge of easy deviation in the course of ultra-large cross-section shields. In the event of a single cutterhead malfunction or jamming, it can be shut down and dealt with individually without having to shut down the entire line, greatly improving the safety and continuity of the project.

[0016] Multiple advance cutters are fixedly connected in the gaps between the cutterhead assemblies, and their height is adjustable, allowing them to extend above the cutterhead's cutting surface. These advance cutters can cut into hard strata or obstacles before the cutterhead, breaking or loosening them to create better cutting conditions for subsequent cutterhead movements, thereby reducing the overall cutting torque and wear of the cutterhead. In cohesive strata, the advance cutters can fracture the excavation face, disrupting the continuity of the soil and effectively preventing soil from adhering to the cutterhead panel and forming mud cakes, thus maintaining excavation efficiency.

[0017] The cutterhead assembly is mounted within the cutterhead slot via heavy-duty slewing bearings. Coolant holes are formed inside the slot, and the inner wall of the slot is coated with a tungsten carbide-based composite wear-resistant coating. These coolant holes create point-to-point forced cooling channels, directly and efficiently removing heat generated by bearing friction. This completely solves the problems of bearing overheating, lubricant failure, and erosion caused by insufficient traditional cooling, significantly improving the reliability and lifespan of the main drive system. The tungsten carbide-based coating provides a robust protective layer for the cutterhead slot, effectively resisting wear caused by cutterhead vibration and soil erosion, protecting the main structure of the shield tunneling machine, reducing maintenance costs, and extending the overall service life. The heavy-duty slewing bearings provide enormous load-bearing capacity and rotational accuracy, ensuring that the cutterhead can still operate smoothly and efficiently under huge and uneven tunneling loads. Attached Figure Description

[0018] Figure 1 A schematic diagram of a multi-cutterhead driven excavation device for an ultra-large cross-section rectangular shield tunneling machine. Figure 2 A schematic diagram of the advance cutter structure of a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines; Figure 3 Rear view of the cutterhead assembly of a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines; Figure 4 A schematic diagram of the cutterhead slot structure of a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines; Figure 5 A schematic diagram of the cutterhead assembly structure of a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines; Figure 6 A schematic diagram of the planetary gear structure of a multi-cutterhead driven excavation device for an ultra-large cross-section rectangular shield tunnel. The components in the diagram are named as follows: 1. Shield shell; 2. Cutterhead assembly; 3. Leading cutter; 4. Transmission rod; 5. Flange; 6. External support rod; 7. Cutterhead groove; 8. Coolant hole; 9. Wear-resistant coating; 10. Center cutterhead; 11. Corner cutterhead; 12. Edge cutterhead; 13. Sun gear; 14. Planetary gear; 15. Gear ring. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0020] This example discloses a multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines. (See also...) Figures 1 to 5 ; The shield includes a rectangular shield shell 1, on which multiple cutterhead assemblies 2 of different sizes are arranged. Each cutterhead assembly 2 includes at least two central cutterheads 10 located in the central region of the shield shell, and corner cutterheads 11 located in the four corner regions of the shield shell 1. Multiple edge cutterheads 12 are arranged in the edge region between the central cutterheads 10 and the corner cutterheads 11. Multiple advance cutters 3 are fixedly connected to the shield shell 1 and the gaps between the cutterhead assemblies 2. A transmission rod 4 is fixedly connected to the back of the cutterhead assembly 2, and a flange 5 is fixedly connected to the end of the transmission rod 4 to drive the cutterhead assembly 2 to rotate. A drive module is installed on the cutterhead assembly 2 via the transmission rod 4. The drive module includes a motor. A planetary gear structure is installed on the output shaft of the motor. The planetary gear structure includes a sun gear 13 connected to the motor. The sun gear 13 meshes with multiple planetary gears 14, and the outer sides of the multiple planetary gears 14 mesh with a gear ring 15 to drive the cutterhead assembly 2 to rotate.

[0021] An external support rod 6 is also provided on the back of the cutter head assembly 2.

[0022] Multiple cutterhead slots 7 are provided on the surface of the shield shell 1 for rotating installation of the cutterhead assembly 2.

[0023] The cutter head groove 7 has a coolant hole 8 inside, which is connected to an external coolant device.

[0024] The inner wall of the cutter head groove 7 is provided with a wear-resistant coating 9, which is a tungsten carbide-based composite material wear-resistant coating.

[0025] A method for multi-cutterhead driven excavation of ultra-large cross-section rectangular shield tunnels includes the following steps: S1: Cutterhead drive: The cutterhead assembly is driven by an external power source connected to the flange mounting plate and external support rod. During the excavation process, the cutterhead assembly adjusts the rotation direction according to the actual geological conditions and excavation requirements, including forward and reverse rotation. S2: Collaborative Excavation: In the early stage of excavation, the advance cutter fixed on the shield shell first contacts the soil and performs pre-cutting and loosening; subsequently, the central cutterhead, corner cutterhead and edge cutterhead rotate in coordination to completely cut the pre-treated soil and form a rectangular tunnel cross section. S3: Cutterhead cooling: During the excavation process, coolant continuously flows into the cutterhead groove through the coolant holes to cool the cutterhead assembly; S4: Wear-resistant protection: The wear-resistant coating of tungsten carbide-based composite material, which is set on the inner wall of the cutterhead groove, resists the friction and impact during the transmission of the cutterhead assembly and protects the shield shell structure.

[0026] Step S1, the cutterhead drive also includes the following steps: the motor of the drive module starts, driving the sun gear to rotate; the sun gear drives multiple planetary gears meshing with it to rotate around its axis, and under the meshing action with the gear ring, the power is output through the planetary gear structure and transmitted to the cutterhead assembly through the transmission rod to drive it to rotate; according to the actual geological conditions and excavation requirements, the rotation direction and speed of each cutterhead assembly are independently controlled.

[0027] Although some preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0028] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunneling machines, characterized in that: The shield includes a rectangular shield shell, on which multiple cutterhead assemblies of different sizes are arranged. Each cutterhead assembly includes at least two central cutterheads located in the central region of the shield shell, and corner cutterheads located in the four corner regions of the shield shell. Multiple edge cutterheads are arranged in the edge region between the central cutterheads and the corner cutterheads. Multiple advance cutters are fixedly connected to the shield shell and the gaps between the cutterhead assemblies. A transmission rod is fixedly connected to the back of the cutter head assembly, and a flange is fixedly connected to the end of the transmission rod to drive the cutter head assembly to rotate. The cutter head assembly is mounted with a drive module via a transmission rod. The drive module includes a motor. The output shaft of the motor is mounted with a planetary gear structure. The planetary gear structure includes a sun gear connected to the motor. The sun gear meshes with multiple planetary gears. The outer sides of the multiple planetary gears mesh with a gear ring to drive the cutter head assembly to rotate.

2. The ultra-large cross-section rectangular shield tunneling multi-cutterhead driven excavation device as described in claim 1, characterized in that: An external support rod is also provided on the back of the cutter head assembly.

3. The ultra-large cross-section rectangular shield tunneling multi-cutterhead driven excavation device as described in claim 1, characterized in that: The surface of the shield shell has multiple cutterhead slots for rotating the cutterhead assembly.

4. The ultra-large cross-section rectangular shield tunneling multi-cutterhead driven excavation device as described in claim 1, characterized in that: The cutter head groove has a coolant hole inside, which is connected to an external coolant device.

5. The ultra-large cross-section rectangular shield tunneling multi-cutterhead driven excavation device as described in claim 1, characterized in that: The inner wall of the cutter head groove is provided with a wear-resistant coating, which is a tungsten carbide-based composite material wear-resistant coating.

6. A method for multi-cutterhead driven excavation of ultra-large cross-section rectangular shield tunnels, applicable to the multi-cutterhead driven excavation device for ultra-large cross-section rectangular shield tunnels as described in any one of claims 1 to 1, characterized in that, Includes the following steps: S1: Cutterhead drive: The cutterhead assembly is driven by an external power source connected to the flange mounting plate and external support rod. During the excavation process, the cutterhead assembly adjusts the rotation direction according to the actual geological conditions and excavation requirements, including forward and reverse rotation. S2: Collaborative Excavation: In the early stage of excavation, the advance cutter fixed on the shield shell first contacts the soil and performs pre-cutting and loosening; subsequently, the central cutterhead, corner cutterhead and edge cutterhead rotate in coordination to completely cut the pre-treated soil and form a rectangular tunnel cross section. S3: Cutterhead cooling: During the excavation process, coolant continuously flows into the cutterhead groove through the coolant holes to cool the cutterhead assembly; S4: Wear-resistant protection: The wear-resistant coating of tungsten carbide-based composite material, which is set on the inner wall of the cutterhead groove, resists the friction and impact during the transmission of the cutterhead assembly and protects the shield shell structure.

7. The method for multi-cutterhead driven excavation of ultra-large cross-section rectangular shield tunnels as described in claim 6, characterized in that: Step S1 of the cutter head drive also includes the following steps: the motor of the drive module starts and drives the sun gear to rotate; the sun gear drives multiple planetary gears meshing with it to rotate around its axis, and under the meshing action with the gear ring, the power is output through the planetary gear structure and transmitted to the cutter head assembly through the transmission rod to drive it to rotate; The rotation direction and speed of each cutterhead assembly are independently controlled according to the actual geological conditions and excavation requirements.

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