A method for replacing the main bearing of a long-distance twin-tunnel dual-track TBM.

Abstract

This invention provides a method for replacing the main bearing of a TBM in a long-distance twin-tunnel, dual-track linkage system. It belongs to the field of tunnel construction technology. The method includes: after the left track continues excavation and the cutterhead surpasses the position of the right track cutterhead, a transverse channel is excavated between the left and right tracks to serve as the main bearing transport channel; simultaneously, the right track cutterhead is fixed, detached, the main unit is retracted, the inner and outer seals of the main drive are disassembled, and the slag collection hopper is removed. This invention uses a twin-tunnel, dual-track linkage method for TBM main bearing replacement. Compared with maintenance methods such as parallel pilot tunnels and inclined shafts, this main bearing replacement method has lower costs, a shorter replacement cycle, and less impact on the other track.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a method for replacing the main bearing of a long-distance twin-tunnel dual-track linked TBM. Background Technology

[0002] In long-distance tunnel construction, due to the considerable length of the tunnel exceeding the service life of the TBM main bearings, or due to complex geological conditions, the TBM main bearings may require emergency repair or replacement during excavation due to wear or damage. The difficulties in repair and replacement lie in three aspects: firstly, the large size and indivisible nature of the TBM main bearings make transportation difficult; secondly, the unique installation location and method of the main bearings make dismantling difficult; and thirdly, the confined space in the tunnel necessitates a large space for repair and replacement work. Existing repair and replacement methods using parallel pilot tunnels, inclined shafts, or vertical shafts suffer from high costs, low efficiency, high difficulty, and poor adaptability, impacting construction progress and safety.

[0003] Taking the method of excavating parallel guide tunnels to transport main bearings as an example, the excavation distance of parallel guide tunnels is long, and it is necessary to select strata with good surrounding rock conditions for machine shutdown and excavation. According to the construction progress, it is estimated that at least 3 months of machine shutdown and waiting will be required, which will affect the construction progress. Summary of the Invention

[0004] This invention provides a method for replacing the main bearing of a long-distance twin-tunnel dual-track linked TBM, in order to solve the technical problems in the prior art.

[0005] To solve the above problems, the present invention provides a method for replacing the main bearing of a long-distance twin-tunnel, dual-track linked TBM, which adopts the following technical solution, including the following steps:

[0006] After the left line continues to be excavated and the cutterhead of the right line is overtaken, a cross passage will be excavated between the left and right lines to serve as the main bearing transportation channel.

[0007] Simultaneously perform right-line cutter head fixing, cutter head disassembly, main unit retraction, disassembly of main drive inner and outer seals, and disassembly of slag collection hopper;

[0008] Build a gantry frame and remove the drive plate and old main bearing;

[0009] A bearing replacement platform is built at the rear end of the portal frame. The old main bearing is hoisted to the bearing replacement platform and flipped from vertical to horizontal using the lifting equipment at the top of the tunnel. The disassembled old main bearing is then transported to the left line through the main bearing transport channel.

[0010] The new main bearing is transported from the left line to the right line. The new main bearing is flipped from horizontal to vertical through the bearing replacement platform. The bearing replacement platform is then removed, and the main unit is pushed forward to the side of the gantry frame.

[0011] Install the new main bearing and drive disc onto the main unit in sequence, remove the gantry frame, and then install the slag collection hopper and the inner and outer seals of the main drive.

[0012] After the main drive is idled for testing and no abnormalities are found, it is connected to the tool head.

[0013] As a further improvement, the angle between the main bearing transport channel and the left or right line meets the requirements for rail transport, and the turning radius of the line is not less than 25m.

[0014] As a further improvement, the cutter head fixing includes the following steps:

[0015] Before fixing the cutterhead, perform one cycle of forward and backward movement to clear the rock debris at the bottom of the tunnel between the working face and the cutterhead. Then, push the cutterhead 5-15cm away from the working face without moving it, rotate the cutterhead to the set position, and then push the cutterhead to press it tightly against the working face.

[0016] The cutter head is fixed laterally, supported at the bottom, and fixed axially to limit its spatial degrees of freedom and prevent it from shifting.

[0017] As a further improvement, the gantry frame is fixedly mounted with a slide rail arranged in the front-to-back direction, and a sliding trolley is provided on the slide rail for driving the new main bearing or drive disc to move.

[0018] As a further improvement, when disassembling the drive plate, the sliding trolley moves to the top of the inner side of the drive plate to support the drive plate. After the drive plate is disassembled from the main unit, the sliding trolley drives the drive plate to move vertically to the front end of the slide rail, and a temporary support for the drive plate is set at the bottom of the drive plate to fix the sliding trolley to the gantry frame.

[0019] When disassembling the old main bearing, another sliding trolley is set on the slide rail and moved to the top of the old main bearing to support it. After the old main bearing is separated from the main machine, the sliding trolley drives the old main bearing to move forward in a vertical posture to the set position, and a temporary support for the old main bearing is set at the bottom of the old main bearing.

[0020] As a further improvement, top turning lugs and bottom turning lugs are installed on the top and bottom of the old main bearing, respectively. The lifting equipment lifts the old main bearing and moves it to the bearing replacement platform. The bottom turning lug is rotatably connected to the lug seat of the bearing replacement platform. The lifting equipment flips the old main bearing from vertical to horizontal and then transfers the old main bearing to the left line.

[0021] As a further improvement, the old main bearing is transported to the rear of the left-side assembly and temporarily stored to avoid obstructing the new main bearing.

[0022] The beneficial effects of the above-mentioned technical solution of the present invention are as follows:

[0023] 1. This invention uses a dual-tunnel, dual-line linkage method for TBM main bearing replacement. Compared with maintenance methods such as parallel pilot tunnels and inclined shafts, the main bearing replacement method of this invention has lower costs, a shorter replacement cycle, and a relatively lower impact on the other line.

[0024] 2. This invention utilizes the structure of the cutter head, employing a seven-point locking and four-position bottom support method to ensure the stability of the cutter head after fixation, which is beneficial for precise docking between the cutter head and the main unit. Specifically, anchor rods are installed in the top five slag scraping chambers and the bottom two slag scraping chambers at 55° angles to the left and right, pads are set at the bottom of the cutter head to support it, and anchor rods are installed in the corresponding cutter holes to prevent axial displacement of the cutter head, thereby ensuring the stability of the cutter head. Attached Figure Description

[0025] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0026] Figure 1 This is a flowchart illustrating the replacement process for the main bearing of a long-distance dual-tunnel, dual-track linked TBM according to the present invention.

[0027] Figure 2 This is a schematic diagram of the new main bearing flatcar transportation method for the main bearing replacement method of the dual-track linkage TBM in long-distance double-tunnel tunnel according to the present invention.

[0028] Figure 3 This is a schematic diagram of the main bearing transportation channel of the long-distance double-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0029] Figure 4 This is a flowchart illustrating the cutterhead fixing process of the long-distance dual-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0030] Figure 5 This is a schematic diagram of the cutterhead fixing method for the main bearing replacement method of the long-distance double-tunnel dual-track linkage TBM of the present invention;

[0031] Figure 6 This is a schematic diagram of the axial anchor bolt arrangement in the long-distance twin-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0032] Figure 7 This is a schematic diagram of the gantry frame for the long-distance twin-tunnel dual-track linkage TBM main bearing replacement method of the present invention;

[0033] Figure 8 This is a schematic diagram of the drive disc fixing method for the main bearing replacement method of the long-distance double-tunnel dual-track linkage TBM of the present invention;

[0034] Figure 9 This is a schematic diagram of the main bearing disassembly and assembly points for the main bearing replacement method of the long-distance dual-tunnel dual-track linkage TBM of the present invention.

[0035] Figure 10 This is a schematic diagram of the bearing replacement platform in the long-distance dual-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0036] Figure 11 This is a flowchart of the new spindle replacement process for the long-distance dual-tunnel dual-track linkage TBM main bearing replacement method of the present invention;

[0037] Figure 12 This is a schematic diagram illustrating the flipping of the new or old main bearing in the long-distance twin-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0038] Figure 13 This is a schematic diagram of the main thruster position in the long-distance double-tunnel dual-track linkage TBM main bearing replacement method of the present invention.

[0039] Figure 14 This is a reference diagram for the maintenance evaluation standard of Embodiment 2 of the present invention, which describes the method for replacing the main bearing of a long-distance twin-tunnel dual-track linked TBM.

[0040] Figure 15 This is a maintenance operation flowchart of Embodiment 2 of the present invention, which describes the method for replacing the main bearing of a long-distance twin-tunnel dual-track linked TBM.

[0041] Figure 16 This is an exploded view of the main bearing of Embodiment 2 of the present invention, which describes the method for replacing the main bearing of a long-distance twin-tunnel dual-track linked TBM.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. New main bearing; 2. Flatbed trolley; 3. Main bearing transport channel; 4. Cutter head; 5. Main unit; 6. Equipment bridge; 7. Slide rail; 8. Gantry frame; 9. Main drive; 10. Sliding trolley; 11. Temporary support; 12. Bearing replacement platform; 13. Old main bearing; 14. Bearing dismantling gantry. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments disclosed. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] In the construction of long-distance tunnels, due to the considerable length of the tunnel, the service life of the TBM main bearings may exceed their expected lifespan, necessitating emergency replacement. The challenges of this replacement lie in three aspects: firstly, the large size and indivisible nature of the TBM main bearings make transportation difficult; secondly, the unique installation location and method of the main bearings make dismantling challenging; and thirdly, the confined space within the tunnel necessitates ample space for replacement and maintenance. Existing methods for maintenance and replacement using inclined shafts, vertical shafts, or detour tunnels suffer from high costs, low efficiency, high difficulty, and poor adaptability, impacting construction progress and safety.

[0046] To address the aforementioned issues, this invention utilizes the linkage between the left and right tunnels. Taking the replacement of the main bearing on the right tunnel as an example, when the main bearing needs to be replaced, the left tunnel continues excavating until the rear assembly surpasses the position of the right tunnel cutterhead. Then, a transverse channel is excavated behind the rear assembly on the left tunnel to serve as a main bearing transport channel. A space sufficient to accommodate the main bearing is reserved between the opening of the main bearing transport channel and the rear assembly on the left tunnel. After the old main bearing of the right tunnel TBM is disassembled, it is first transported to the rear of the left tunnel rear assembly via the main bearing transport channel. Then, the prepared new main bearing is transported to the right tunnel for installation via the main bearing transport channel.

[0047] After introducing the basic principles of the present invention, various non-limiting embodiments of the present invention are described in detail below. Any number of elements in the accompanying drawings is for illustrative purposes only and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0048] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0049] Example 1 of the method for replacing the main bearing of a long-distance twin-tunnel, dual-track linked TBM provided by the present invention, as follows: Figures 1-13 As shown, it includes the following steps:

[0050] S1. Continue tunneling on the left line until the cutterhead on the right line is positioned 4. Then, excavate a transverse channel between the left and right lines to serve as the main bearing transport channel 3.

[0051] S2. Simultaneously perform the following steps: fix the right line cutter head 4, disengage the cutter head 4, move the main unit 5 backward, disassemble the inner and outer seals of the main drive 9, and disassemble the slag collection hopper.

[0052] S3. Construct the gantry frame 8 and remove the drive disc and old main bearing 13;

[0053] S4. Build a bearing replacement platform 12 at the rear end of the gantry frame 8. Use the lifting equipment at the top of the tunnel to hoist the old main bearing 13 to the bearing replacement platform 12 and flip it from vertical to horizontal. Transport the disassembled old main bearing 13 to the left line through the main bearing transport channel 3.

[0054] S5. The new main bearing 1 is transported from the left line to the right line. The new main bearing 1 is flipped from horizontal to vertical through the bearing replacement platform 12. The bearing replacement platform 12 is removed and the main unit 5 is pushed forward to the side of the gantry frame 8.

[0055] S6. Install the new main bearing 1 and drive plate to the main unit 5 in sequence, remove the gantry frame 8, and then install the slag collection hopper and the inner and outer seals of the main drive 9.

[0056] After S7 and main drive 9 are idled for testing and no abnormalities are found, they are connected to tool head 4.

[0057] In step S1, such as Figure 3 As shown, a cross passage is constructed 30 meters behind the rear of the supporting structure (firstly, the nearest connecting passage between the left and right lines is used as the cross passage; if the connecting passage is insufficient, a new cross passage is excavated). Its dimensions are designed to accommodate the special transport flatbed truck 2 for the main bearing. In this embodiment, the width × height of the cross passage is 7.5 × 4.3 m; the angle between the cross passage and the main tunnel meets the requirements for rail transport, and the turning radius of the line is not less than 25 m.

[0058] like Figures 4-6 As shown, fixing the cutter head 4 includes the following steps:

[0059] Before the cutterhead 4 is fixed, it moves back and forth in one cycle. In this embodiment, one cycle is 1.8 meters. It cleans the rock debris at the bottom of the tunnel between the working face and the cutterhead 4. Then, it pushes the cutterhead 4 10cm away from the working face in no-load mode. In manual mode, it rotates the scraper bin where the cutterhead 440# cutter position is located to the bottom of the tunnel. Then, it pushes the cutterhead 4 to press against the working face.

[0060] The cutter head 4 is fixed laterally, supported at the bottom, and fixed axially to limit its spatial degrees of freedom and prevent it from shifting.

[0061] Lateral fixing: 10 anchor bolts are installed in 5 top slag scraper bins, and 6 anchor bolts are installed in 2 bottom slag scraper bins at 55° left and right, for a total of seven fixing points and 72 anchor bolts in total; the anchor bolts are made of φ25 threaded steel, with a cutting length of 3m and an anchoring length of 2.5m.

[0062] Bottom support: The cutter head 4 is supported at the three bottom scraper compartments, with four support points. First, a suitable steel plate is inserted between the outer ring plate of the cutter head 4 and the tunnel wall; then, a support plate is placed between the cone plate on the back of the cutter head 4 and the tunnel wall. The distribution angle of the support plate overlaps with the angle of the pad plate, and they are welded together with the cutter head 4.

[0063] Axial fixing: At the four cutter holes #27, #28, #29, and #30, three anchor bolt holes are made in each cutter hole. A 600*250*20mm steel plate is cut to pass through the anchor bolt and locked. The axial anchor bolt is a 3m long, φ25 glass fiber anchor bolt.

[0064] In step S2, the disengagement of the cutter head 4 includes the following steps:

[0065] Before disengagement, check the fixing status of the cutterhead 4 to ensure it is securely fixed and meets the disengagement conditions before proceeding with the disengagement. Record in detail the data of the guide system and the original orientation of the TBM before disengagement for use when docking with the cutterhead 4. The original orientation of the TBM includes the position of the support shoe, the extension length of the top support shoe cylinder, the extension length of the torque cylinder, the position of the rear edge of the side shield, and the connection point markings between the drive disc and the cutterhead 4 (at least four locations). Mark these locations before disengaging the cutterhead 4.

[0066] Remove the protective caps from all double-ended bolts connecting the cutter head 4;

[0067] Reduce the bolt pull-out pressure in three stages in sequence. On the last stage, completely loosen the bolt, remove the nut, then remove the double-ended bolt, clean it with kerosene, apply hydraulic oil, and store it properly.

[0068] Bolt loosening and removal sequence: 4 to 5 bolts at a time, arranged sequentially from top to bottom and left to right;

[0069] After the bolts are removed, check the connection between the cutter head 4 and the main drive 9 again. Once it is confirmed that they are completely disconnected, the cutter head 4 can be detached. Place four 100-ton thin jacks between the cutter head 4 and the main drive 9. First, use the jacks and the propulsion cylinder to smoothly separate the cutter head 4 from the main drive 9. The separation distance should be more than 50mm.

[0070] Disassembling the inner and outer seals of the main drive 9:

[0071] After the cutter head 4 is successfully disengaged, the main unit 5 moves back 1.2 meters and a sealed disassembly platform is built between the cutter head 4 and the main drive 9. A slide is welded at a suitable position between the main drive 9 and the cutter head 4 for movement after the ring is removed. A lifting lug is welded to the top of the outer sealing pressure ring to suspend the hoist and tighten it.

[0072] Weld 2-3 suspension rods to the back of the cutter head 4 to temporarily store the sealing pressure rings and spacers.

[0073] Weld lifting lugs (3-ton lifting capacity) above the top shield for installing a hand chain hoist. Weld pull plate assemblies, a total of 6, onto the cutterhead 4 for removing and installing the outer sealing clamping ring, outer sealing outer spacer ring, and outer sealing inner spacer ring. Align the holes of the pull plate assembly with the threaded holes of the outer sealing clamping ring.

[0074] Remove the bolts diagonally and mark their positions.

[0075] Remove the hexagonal screws inside the outer sealing ring, the outer sealing protective plate, the outer sealing pressure ring, the outer sealing lip seal, and the outer sealing spacer ring in sequence, and place them at the back suspension point of the cutter head 4 (a steel rod can be inserted through the bolt hole of the cutter head 4 for storage). Measure the wear of the outer sealing wear track and the lip seal.

[0076] Insert bolts into the bolt holes on the top of the drive disc, tighten the lifting plate (capable of lifting 3T weight), and install the hand-operated hoist. Weld pull plate assemblies (6 in total) onto the inner panel of the cutter head 4 for removing and installing the inner seal clamping ring, inner seal outer spacer ring, and inner seal inner spacer ring. Align the holes of the pull plate assemblies with the threaded holes of the outer seal clamping ring. Using the same method as the outer seal disassembly, sequentially remove the hexagonal screws of the inner seal ring, inner seal labyrinth ring 1, inner seal labyrinth ring 2, inner seal, pressure ring, inner seal lip seal, and inner seal spacer ring, and place them at the suspension point on the back of the cutter head 4. Measure the wear of the inner seal wear track and the lip seal.

[0077] Disassembling the slag collection hopper:

[0078] After the seals and ring parts are removed and stored, the work platform is dismantled, and the main unit 5 is moved back to leave space (≥2 meters) for the removal of the slag collection hopper.

[0079] Erect a dismantling platform; weld lifting lugs onto the top shield, and use the slag hopper's own lifting lugs to suspend the hoist, then tighten the hoist.

[0080] Remove the pin between the slag collection hopper and the drive box.

[0081] Lift the slag hopper and move it to a position close to the cutterhead 4.

[0082] like Figure 7 As shown, step S3, assembling the portal frame 8 includes the following steps:

[0083] The main unit 5 retracts until it is 3 meters above the top shield when it is positioned at the installation location of the gantry frame 8;

[0084] Build portal frame 8. The main frame is built from bottom to top. After the bottom is built, it is fixed in time. The main frame is fixed to the tunnel wall by anchor rods.

[0085] After the portal frame 8 is erected, the bottom steel sleepers and slide rails 7 are installed.

[0086] After the bottom steel sleepers are laid, the slide rails 7 are welded to the main beam through the portal frame 8, and the diagonal supports are installed.

[0087] like Figure 8 As shown, removing the drive panel includes the following steps:

[0088] Remove the three (11 to 13) drive disc gear ring connecting bolts on the top left and right sides, and install the sliding trolley 10 bracket with M48×700 double-ended studs and washers. Put rubber pads on the bottom slide rails.

[0089] After the sliding trolley 10 is installed, remove the double-ended studs between the drive plate and the main bearing in three steps according to the diagonal principle, place them in a suitable area, check whether the double-ended studs are damaged, and mark the mounting hole positions of the bolts.

[0090] Mark the position of the motor torque limiter with a line and mark the direction of rotation with a thin line (the length of the line should ensure that the torque limiter can rotate 5 revolutions);

[0091] Using M30 set screws, simultaneously push the base outwards at 8 points, ensuring that the set screws are screwed in consistently to guarantee that the drive disc slides out of the mounting cavity evenly in the circumferential direction. Simultaneously move the sliding trolley 10 to ensure the drive disc is vertical. Four M48×1300 guide rods can be pre-installed in the bottom bolt holes. Meanwhile, have someone on the motor side record the direction and displacement of each motor during disengagement to provide a reference for drive disc docking.

[0092] After the drive disc is completely detached from the mounting cavity, it is moved to the gantry frame 8 and fixed. The bottom is supported and fixed by two support points. The drive disc and the surface of the drive gear ring are thoroughly cleaned with kerosene, and the gear ring is checked for damage (at the same time, the position of the pinion is marked to prevent it from being touched and causing a change in position during subsequent work).

[0093] like Figure 10 As shown, disassembling the old main bearing 13 includes the following steps:

[0094] Another sliding trolley 10 is installed on slide rail 7 and moved to the top of the old main bearing 13 to support it. M56 lifting rings are installed at the three lifting points of the main bearing. Three 2T hoists are used at the corresponding positions on the gantry frame 8 to pull the old main bearing 13 outward simultaneously. It is important to ensure that the hoist feed dimensions are consistent at all points (or use 4RLT-41 flat jacks between the bearing and the drive box, with all four jacks bearing force evenly at the same time) to ensure that the old main bearing 13 slides out of the installation cavity evenly in the circumference.

[0095] After the old main bearing 13 is separated from the main unit 5, the sliding trolley 10 drives the old main bearing 13 to move forward in a vertical posture to the set position, and a temporary support 11 for the old main bearing 13 is set at the bottom of the old main bearing 13.

[0096] In step S4, top turning lugs and bottom turning lugs are installed on the top and bottom of the old main bearing 13, respectively. The lifting equipment lifts the old main bearing 13 and moves it to the bearing replacement platform 12. The bottom turning lug is rotatably connected to the lug seat of the bearing replacement platform 12. The old main bearing 13 is flipped from vertical to horizontal by the lifting equipment, and then the left-side rear fitting is temporarily stored.

[0097] The new main bearing 1 is then transferred to the bearing replacement platform 12.

[0098] Before the main unit 5 is advanced, the temporary track is removed and any debris in front of the main unit 5 that may affect its advancement is cleared.

[0099] The subsequent installation and debugging steps will not be described in detail here.

[0100] Example 2

[0101] This embodiment discloses an emergency maintenance method for the main bearing of a long-distance single-tunnel TBM. The initiation conditions are as follows: if, under relatively good surrounding rock conditions, a large torque fluctuation of 800-1500 kN.M occurs during the no-load thrusting process, the machine should be immediately stopped for inspection. If it is determined that the condition of the old main bearing is deteriorating or has deteriorated drastically (in this embodiment, "old main bearing" refers to the currently used main bearing), after evaluation (evaluation criteria are as follows...), Figure 14 As shown, for example, shallow damage with a depth of less than 3mm is considered minor damage, while damage with a depth of more than 3mm is considered severe damage. If the old main bearing raceway is slightly damaged and only repair is needed to meet the tunneling needs of the remaining section of the project, then the old main bearing repair plan will be initiated after the machine is stopped; otherwise, the old main bearing replacement plan will be initiated.

[0102] like Figure 15 As shown, the emergency repair method for the main bearing of a long-distance single-tunnel TBM includes the following steps:

[0103] S1. Preliminary preparations: If short-distance tunneling is feasible, continue advancing 18 meters. The newly installed inverted arch blocks will not undergo bottom pouring. The initial support will adopt the form of anchor bolts + mesh + initial shotcrete. If tunneling is not possible, the arch frame and inverted arch blocks will be gradually dismantled during the retreat of the main unit, and the arch will be shotcreted simultaneously. At the same time, the old main bearing cage, rollers and other parts will be prepared.

[0104] S2, Cutter head fixed.

[0105] S3, Cutter head disengages.

[0106] S4. Disassemble the inner and outer seals of the main drive.

[0107] S5. Disassemble the slag collection hopper.

[0108] S6. Construct a portal frame.

[0109] S7. Remove the drive disk.

[0110] S8. Disassemble the old main bearing.

[0111] S9. Check and clean the drive box.

[0112] Steps S2 to S9 are the same as those in Example 1, and will not be repeated in this example.

[0113] S10. Build a maintenance platform, install bearing tilting lugs, and build a bearing dismantling gantry and lifting equipment (or other lifting and hoisting equipment).

[0114] S11. Repair of old main bearings; First, use lifting equipment to flip the old main bearing from vertical to horizontal.

[0115] Secondly, disassemble the old main bearing, such as... Figure 16 As shown, disassembling a used main bearing includes the following steps:

[0116] (1) Hang a 10T hoist according to the bearing lifting point position and install it at the lifting point of the inner ring of the bearing with 3 M56 eye bolts;

[0117] (2) Make alignment marks on the inner diameter of the two inner rings, then remove the screws connecting the two inner rings, the hexagonal screws protecting the inner ring locating pins and the plastic rod, and finally lift the inner rings.

[0118] (3) After hoisting the inner ring to a certain height, fix it, remove the main push roller and the cage, and check the raceway surface of the main push roller; then remove the radial roller and the cage, and then take the roller out of the cage.

[0119] (4) Lift the outer ring of the bearing using the lifting points on the tunnel wall and four 10T hoists, and remove the reverse thrust rollers and cage;

[0120] Afterwards, the old main bearing was repaired, and all rollers, cages, seals, and spring units under the thrust raceway were replaced; the raceway was then handled as follows: Figure 14 Process it;

[0121] Finally, reassemble the old main bearing; after repairing all raceway surfaces, install the push rollers and cage; at the same time, evenly distribute 3 sets of radial rollers on the radial raceway; remove the temporary support of the outer ring, allowing the outer ring to slowly fit into the inner ring; install the radial rollers and cage; install the push rollers and cage; remove the fixed support on the inner ring, slowly lower the inner ring, and after the inner ring is installed, install the locking screws and tighten them in place.

[0122] S12. Reinstall the old main bearing, drive disc, slag hopper and other parts into the main unit.

[0123] S13. Main drive no-load test; After the inner and outer seals are installed, remove the installation platform and cut off the auxiliary lifting lugs, and add gear oil to the drive box; After checking for any interference in the drive, run the drive equipment without load; During equipment commissioning, thoroughly check for any abnormalities in the drive box; Check whether there is gear oil in the detection chamber of the main drive inner and outer seal system.

[0124] S14. Install the cutter head.

[0125] In this embodiment, if it involves replacing the old main bearing inner ring or the old main bearing outer ring, the old main bearing inner ring or the old main bearing outer ring can be transferred in the manner described in Embodiment 1 for transferring the new main bearing.

[0126] While various embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of the invention and therefore cover any modular compositions, equivalents, or alternatives within the scope of these claims.

Claims

1. A method for replacing the main bearing of a long-distance twin-tunnel, dual-track TBM, characterized in that, Includes the following steps: After the left line continues to be excavated and the cutterhead of the right line is overtaken, a cross passage will be excavated between the left and right lines to serve as the main bearing transportation channel. Simultaneously perform right-line cutter head fixing, cutter head disassembly, main unit retraction, disassembly of main drive inner and outer seals, and disassembly of slag collection hopper; Build a gantry frame and remove the drive plate and old main bearing; A bearing replacement platform is built at the rear end of the portal frame. The old main bearing is hoisted to the bearing replacement platform and flipped from vertical to horizontal using the lifting equipment at the top of the tunnel. The disassembled old main bearing is then transported to the left line through the main bearing transport channel. The new main bearing is transported from the left line to the right line. The new main bearing is flipped from horizontal to vertical through the bearing replacement platform. The bearing replacement platform is then removed, and the main unit is pushed forward to the side of the gantry frame. Install the new main bearing and drive plate onto the main unit in sequence, remove the gantry frame, and then install the slag collection hopper and the inner and outer seals of the main drive. After the main drive is idled for testing and no abnormalities are found, it is connected to the tool head. The cutter head fixing process includes the following steps: Before fixing the cutterhead, perform one cycle of forward and backward movement to clear the rock debris at the bottom of the tunnel between the working face and the cutterhead. Then, push the cutterhead 5-15cm away from the working face without moving it, rotate the cutterhead to the set position, and then push the cutterhead to press it tightly against the working face. The cutter head is fixed laterally, supported at the bottom, and fixed axially to limit its spatial degrees of freedom and prevent it from shifting. The gantry frame is fixedly installed with a slide rail arranged in the front-to-back direction, and a sliding trolley for driving the new main bearing or drive disc to move is provided on the slide rail. When disassembling the drive plate, the sliding trolley moves to the top of the inner side of the drive plate to support the drive plate. After the drive plate is separated from the main unit, the sliding trolley moves the drive plate vertically to the front end of the slide rail and sets a temporary support for the drive plate at the bottom of the drive plate to fix the sliding trolley to the gantry frame. When disassembling the old main bearing, another sliding trolley is set on the slide rail and moved to the top of the old main bearing to support it. After the old main bearing is separated from the main machine, the sliding trolley drives the old main bearing to move forward in a vertical posture to the set position, and a temporary support for the old main bearing is set at the bottom of the old main bearing.

2. The method for replacing the main bearing of a long-distance twin-tunnel dual-track TBM as described in claim 1, characterized in that: The angle between the main bearing transport channel and the left or right line meets the requirements for rail transport, and the turning radius of the line is not less than 25m.

3. The method for replacing the main bearing of a long-distance twin-tunnel, dual-track TBM as described in claim 1, characterized in that: Top and bottom turning lugs are installed on the top and bottom of the old main bearing, respectively. The lifting equipment lifts the old main bearing and moves it to the bearing replacement platform. The bottom turning lug is rotatably connected to the lug seat of the bearing replacement platform. The lifting equipment flips the old main bearing from vertical to horizontal and then transfers the old main bearing to the left line.

4. The method for replacing the main bearing of a long-distance twin-tunnel, dual-track TBM as described in claim 3, characterized in that: The old main bearing was transported to the rear of the left-side assembly line for temporary storage to avoid obstructing the new main bearing.

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