Underground traction robot

Abstract

The underground traction robot comprises a diameter changing mechanism and a traction mechanism, the diameter changing mechanism comprises a fixing plate, a guide rod, a sliding block, a plurality of supporting arms, a plurality of elastic push rods and a movable driving piece, the guide rod is fixed to the fixing plate, the sliding block is arranged on the guide rod in a sliding mode, and one ends of the supporting arms are hinged to the outer edge of the sliding block in the circumferential direction of the sliding block; the elastic push rods correspond to the supporting arms one to one, one end of each elastic push rod is hinged to the sliding block, and the other end of each elastic push rod is hinged to the middle of the corresponding supporting arm; the traction mechanism comprises a plurality of wheel bodies and a first rotation driving piece. The underground traction robot provided by the invention has the beneficial effects that the overall outer diameter of the traction robot can be adjusted through expansion or contraction of the support arms, so that the traction robot adapts to different shaft inner diameters, and the underground adaptability is improved; in addition, the first rotation driving part is used for driving at least one wheel body to rotate, the fracturing pipe column can be dragged, and the tripping-in smoothness and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fracturing auxiliary devices, and particularly to a downhole traction robot. Background Art

[0002] During the process of oil and gas extraction, the staged fracturing technology is widely used to increase the production of oil and gas wells. The fracturing technology stimulates the oil and gas reservoirs through staged fracturing to improve the permeability of oil and gas. To achieve staged fracturing, bridge plugs are usually used to isolate the fracturing sections and achieve staged injection. However, in complex wellbore structures, especially in cases such as ultra-short radius horizontal wells, small-diameter wells or open-hole sections, problems often occur when running the fracturing string. These problems include increased resistance caused by the contact between the string and the wellbore wall during the running process, or pipe sticking caused by unreasonable pipe string structure design.

[0003] Traditional solutions usually include improving the pipe string material, optimizing the running process, etc. However, in practical applications, these measures are still difficult to solve all the sticking problems, especially in complex wellbore structures. Therefore, a new tool is needed to solve the stability problem during the running of the fracturing string and reduce the diameter for recovery after the running is completed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and propose a downhole traction robot to solve the technical problems that in the prior art, the stability of the fracturing string is not high during the running process of the fracturing string and it often encounters sticking.

[0005] To achieve the above technical purpose, the present invention takes the following technical solutions:

[0006] The present invention provides a downhole traction robot, including:

[0007] A variable diameter mechanism, the variable diameter mechanism includes a fixed plate, a guide rod, a slider, a plurality of arms, a plurality of elastic push rods and a moving driving member. The guide rod is fixed to the fixed plate, the slider is slidably arranged on the guide rod. One end of each of the plurality of arms is circumferentially hinged to the outer edge of the slider. The elastic push rods correspond to the arms one by one. One end of each elastic push rod is hinged to the slider, and the other end of each elastic push rod is respectively hinged to the middle of the corresponding arm. The moving driving member is connected to the slider and is used to drive the slider to move; and,

[0008] A traction mechanism, the traction mechanism includes a plurality of wheel bodies and a first rotation driving member. The wheel bodies are respectively rotatably arranged at the other ends of the plurality of arms. The first rotation driving member is used to drive at least one of the wheel bodies to rotate.

[0009] In some embodiments, the number of the fixed plates is two. A plurality of fixing holes are formed in each of the two fixed plates. The plurality of guide rods are respectively inserted into the corresponding fixing holes in the two fixed plates, and each of the guide rods is fixedly connected to the two fixed plates.

[0010] The number of the sliders is two, corresponding to the two fixed plates respectively. The sliders are respectively slidably arranged at two ends of the guide rods.

[0011] The number of the support arms and the elastic push rods is two groups respectively corresponding to the two sliders. One end of each group of support arms is circumferentially hinged to the outer edge of the corresponding slider along the corresponding slider, one end of each group of elastic push rods is hinged to the corresponding slider, the other end of each group of elastic push rods is respectively hinged to the middle of the corresponding support arm, and the moving driving member is connected to the two sliders and is used for driving the two sliders to move.

[0012] In some embodiments, the elastic push rod includes a first connecting rod, a sleeve, a shaft rod, a pressure sensor, an elastic member and a second connecting rod. One end of the sleeve is fixed to the slider via the first connecting rod. One end of the shaft rod is slidably inserted into the sleeve. One end of the pressure sensor is fixed in the sleeve. One end of the elastic member is connected to the other end of the pressure sensor. The other end of the elastic member is connected to one end of the shaft rod. One end of the second connecting rod is fixedly connected to the other end of the shaft rod. The other end of the second connecting rod is fixed to the middle of the support arm.

[0013] In some embodiments, the variable diameter mechanism further includes two end plates. One end of each of the guide rods is fixed to one end plate, and the other end of each of the guide rods is fixed to the other end plate.

[0014] In some embodiments, the moving driving member includes two lead screws, two nuts and a second rotation driving member. Two ends of the lead screws are respectively rotatably arranged on the corresponding fixed plate and the corresponding end plate. The two nuts are respectively threadedly sleeved on the two lead screws and are respectively fixed to the two sliders. The second rotation driving member is connected to the two lead screws and is used for driving the two lead screws to rotate.

[0015] In some embodiments, the second rotation driving member includes a second rotation driving motor, two main gears, a transmission rod, and two transmission gears. The two ends of the housing of the second rotation driving motor are respectively fixedly connected to the two fixing plates. The output shaft of the second rotation driving motor is coaxially and fixedly connected to one of the lead screws. The two main gears are respectively fixedly sleeved on the two lead screws. The two ends of the transmission rod are rotatably connected to the two fixing plates. The two transmission gears are respectively fixedly sleeved on the two ends of the transmission rod. The two transmission gears are respectively meshed with the two main gears.

[0016] In some embodiments, through holes are formed in the fixing plates, and the two ends of the transmission rod are respectively inserted into the through holes of the two fixing plates;

[0017] The second rotation driving member further includes two bearings. The inner rings of the two bearings are respectively fixedly sleeved on the two transmission rods, and the outer rings of the two bearings are respectively fixedly connected to the two fixing plates.

[0018] In some embodiments, a relief hole is formed in the slider, and the nut is fixed to the slider and coaxially arranged with the relief hole.

[0019] In some embodiments, a rotating shaft is rotatably arranged at the other end of each support arm, and the wheel body is fixed to the rotating shaft.

[0020] In some embodiments, the first rotation driving member includes a first rotation driving motor, a first bevel gear, and a second bevel gear. The housing of the first rotation driving motor is fixed to one of the support arms. The first bevel gear is fixedly sleeved on the output shaft of the first rotation driving motor. The second bevel gear is fixedly sleeved on the corresponding rotating shaft. The second bevel gear is meshed with the first bevel gear.

[0021] Compared with the prior art, the beneficial effects of the downhole traction robot provided by the present invention are as follows: By arranging multiple groups of support arms and elastic push rods, it can ensure that the downhole traction robot is located at the center of the wellbore, preventing the fracturing string from being eccentric and increasing the lowering resistance. At the same time, by expanding or contracting the support arms, the overall outer diameter of the traction robot can be adjusted, so as to adapt to different wellbore inner diameters and improve the downhole adaptability. In addition, by using the first rotation driving member to drive at least one of the wheel bodies to rotate, the fracturing string can be tractioned, improving the lowering smoothness and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic three-dimensional structure diagram of a downhole traction robot provided by an embodiment of the present invention;

[0023] Figure 2 is Figure 1 a partial enlarged view of area A in

[0024] Figure 3 is Figure 1 the front view of the downhole traction robot in

[0025] Figure 4 is Figure 1 the schematic three - dimensional structure diagram of the fixing plate, end plate and slider in

[0026] Figure 5 is Figure 1 the schematic three - dimensional structure diagram of the traction mechanism in

[0027] Figure 6 is Figure 1 the schematic cross - sectional structure diagram of an elastic push rod in

[0028] Figure 7 is Figure 3 the reference diagram of the usage state of the downhole traction robot in

[0029] Explanation of reference numerals: 1 - diameter - changing mechanism, 11 - fixing plate, 111 - fixing hole, 112 - perforation, 12 - guide rod, 13 - slider, 131 - guiding hole, 132 - relief hole, 14 - support arm, 141 - rotating shaft, 15 - elastic push rod, 151 - first connecting rod, 152 - sleeve, 153 - shaft rod, 154 - pressure sensor, 155 - elastic member, 156 - second connecting rod, 16 - moving driving member, 161 - lead screw, 162 - nut, 163 - second rotation driving member, 1631 - second rotation driving motor, 1632 - main gear, 1633 - transmission rod, 1634 - transmission gear, 1635 - bearing, 17 - end plate, 2 - traction mechanism, 21 - wheel body, 22 - first rotation driving member, 221 - first rotation driving motor, 222 - first bevel gear, 223 - second bevel gear, 3 - fracturing string, 4 - wellbore. Detailed implementation manners

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present 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 used to explain the present invention and are not used to limit the present invention.

[0031] In order to solve the technical problem that during the process of lowering the fracturing string, the stability of the fracturing string is not high and it often encounters jamming, the present invention provides a downhole traction robot, which can reduce the resistance of the lowered fracturing string and improve the lowering stability of the fracturing string.

[0032] Please refer to Figures 1 - 6 , Figure 1Schematic diagram of the three-dimensional structure of the downhole traction robot in an embodiment of the present invention. The downhole traction robot includes a diameter-changing mechanism 1 and a traction mechanism 2.

[0033] The diameter-changing mechanism 1 includes a fixed plate 11, a guide rod 12, a slider 13, a plurality of arms 14, a plurality of elastic push rods 15 and a moving driving member 16. The guide rod 12 is fixed to the fixed plate 11. The slider 13 is slidably arranged on the guide rod 12. One ends of the plurality of arms 14 are circumferentially hinged to the outer edge of the slider 13 along the slider 13. The elastic push rods 15 correspond to the arms 14 one by one. One end of each elastic push rod 15 is hinged to the slider 13, and the other end of each elastic push rod 15 is respectively hinged to the middle of the corresponding arm 14. The moving driving member 16 is connected to the slider 13 and is used to drive the slider 13 to move.

[0034] The traction mechanism 2 includes a plurality of wheel bodies 21 and a first rotation driving member 22. The wheel bodies 21 are respectively rotatably arranged at the other ends of the respective arms 14. The first rotation driving member 22 is used to drive at least one of the wheel bodies 21 to rotate.

[0035] During use, the downhole traction robot is fixed to the lower end of the fracturing string 3, and then the downhole traction robot together with the fracturing string 3 is lowered into the wellbore 4. When lowering, the moving driving member 16 is used to drive the slider 13 to move. When the slider 13 moves, each arm 14 is pushed to open via each elastic push rod 15, so that each wheel body 21 abuts against the inner side wall of the wellbore 4. When the pressure of the elastic push rod 15 is lower than the set pressure, the moving driving member 16 drives each arm 14 to open. When the pressure of the elastic push rod 15 is higher than the set pressure, the moving driving member 16 drives each arm 14 to contract. Thus, the friction force between each wheel body 21 and the inner side wall of the wellbore 4 can be kept within a set range, so that it will neither be unable to drive the movement due to too small a friction force nor increase the resistance during the movement due to too large a friction force. At the same time, the first rotation driving member 22 is used to drive at least one of the wheel bodies 21 to rotate, thereby driving the entire device and the fracturing string 3 to move downward, realizing the traction function of the fracturing string 3.

[0036] The technical solution provided by the present invention, by arranging multiple groups of arms 14 and elastic push rods 15, can ensure that the downhole traction robot is located at the center of the wellbore 4, preventing the fracturing string 3 from being eccentric and increasing the lowering resistance; at the same time, by opening or contracting the arms 14, the overall outer diameter of the traction robot can be adjusted, so as to adapt to different wellbore inner diameters, improving the downhole adaptability; in addition, by using the first rotation driving member 22 to drive at least one of the wheel bodies 21 to rotate, the fracturing string 3 can be tractioned, improving the lowering smoothness and stability.

[0037] In one embodiment, please refer toFigures 1 - 4 There are two fixing plates 11. A plurality of fixing holes 111 are formed in each of the two fixing plates 11. Each of the plurality of guide rods 12 is inserted into a corresponding fixing hole 111 on the two fixing plates 11 respectively, and each of the guide rods 12 is fixedly connected to the two fixing plates 11.

[0038] There are two sliders 13, which respectively correspond to the two fixing plates 11. The sliders 13 are respectively slidably arranged at both ends of the guide rods 12.

[0039] The number of the support arms 14 and the elastic push rods 15 is two groups respectively corresponding to the two sliders 13. One end of each group of support arms 14 is circumferentially hinged to the outer edge of the corresponding slider 13 along the corresponding slider 13. One end of each group of elastic push rods 15 is hinged to the corresponding slider 13, and the other end of each group of elastic push rods 15 is respectively hinged to the middle of the corresponding support arm 14. The moving drive member 16 is connected to the two sliders 13 and is used to drive the two sliders 13 to move.

[0040] In the present invention, by providing two groups of fixing plates 11, sliders 13, support arms 14 and the elastic push rods 15, it can be supported on the inner side wall of the wellbore 4 at the upper and lower ends respectively, improving the stability of the downhole traction robot.

[0041] In one embodiment, please refer to Figures 1 - 6 The elastic push rod 15 includes a first connecting rod 151, a sleeve 152, a shaft rod 153, a pressure sensor 154, an elastic member 155 and a second connecting rod 156. One end of the sleeve 152 is fixed to the slider 13 via the first connecting rod 151. One end of the shaft rod 153 is slidably inserted into the sleeve 152. One end of the pressure sensor 154 is fixed in the sleeve 152. One end of the elastic member 155 is connected to the other end of the pressure sensor 154, and the other end of the elastic member 155 is connected to one end of the shaft rod 153. One end of the second connecting rod 156 is fixedly connected to the other end of the shaft rod 153, and the other end of the second connecting rod 156 is fixed to the middle of the support arm 14. When in use, in the normal crawling state, the elastic members 155 are all in a contracted state. When the inner diameter of the wellbore 4 increases, the elastic members 155 are compressed, and the detected value of the pressure sensor 154 increases. At this time, the moving drive member 16 can be used to drive each support arm 14 to contract until the detected value of the pressure sensor 154 is within a preset range.

[0042] It should be understood that since the elastic push rods 15 include upper and lower groups, the detected values of the pressure sensors 154 of the upper and lower groups of elastic push rods 15 may be different. Therefore, the detected value of the pressure sensor 154 of only one group of elastic push rods 15 can be used as the basis for controlling the movement of the moving drive member 16. At the same time, each group of elastic push rods 15 includes three elastic push rods 15, and these three elastic push rods 15 may also be different. At this time, the average value of the detected values of the pressure sensors 154 of the three elastic push rods 15 can be referred to as the basis for controlling the movement of the moving drive member 16.

[0043] In one embodiment, please refer to Figures 1 - 4 , a plurality of guide holes 131 are formed in the slider 13, and the guide rods 12 are respectively inserted into the guide holes 131.

[0044] In one embodiment, please refer to Figures 1 - 4 , the variable diameter mechanism 1 further includes two end plates 17, one end of each guide rod 12 is fixed to one end plate 17, and the other end of each guide rod 12 is fixed to the other end plate 17.

[0045] In one embodiment, please refer to Figures 1 - 4 , the moving drive member 16 includes two lead screws 161, two nuts 162 and a second rotation drive member 163. The two ends of the lead screw 161 are respectively rotatably arranged on the corresponding fixing plate 11 and the corresponding end plate 17. The two nuts 162 are respectively threadedly sleeved on the two lead screws 161 and are respectively fixed to the two sliders 13. The second rotation drive member 163 is connected to the two lead screws 161 and is used to drive the two lead screws 161 to rotate. When the lead screw 161 rotates, it acts on the nut 162. Since the nut 162 is limited by the slider 13 and cannot rotate, the rotation of the lead screw 161 can be converted into the translational movement of the nut 162, thereby driving the slider 13 to move, and then pushing each support arm 14 to open or contract.

[0046] In one embodiment, please refer to Figures 1 - 4, the second rotation driving member 163 includes a second rotation driving motor 1631, two main gears 1632, a transmission rod 1633 and two transmission gears 1634. Both ends of the housing of the second rotation driving motor 1631 are fixedly connected to the two fixing plates 11 respectively. The output shaft of the second rotation driving motor 1631 is coaxially and fixedly connected to one of the lead screws 161. The two main gears 1632 are respectively fixedly sleeved on the two lead screws 161. Both ends of the transmission rod 1633 are rotatably connected to the two fixing plates 11. The two transmission gears 1634 are respectively fixedly sleeved on both ends of the transmission rod 1633. The two transmission gears 1634 are respectively engaged with the two main gears 1632. During use, the second rotation driving motor 1631 drives one of the lead screws 161 to rotate. The main gear 1632 on this lead screw 161 rotates, driving the corresponding transmission gear 1634 to rotate, then driving the transmission rod 1633 to rotate, and then driving the other transmission gear 1634 to rotate and the other lead screw 161 to rotate. Thus, two lead screws 161 can be driven to rotate by one motor, which can save the equipment cost. It should be understood that two motors can also be used to drive the two lead screws 161 to rotate respectively, which can improve the control accuracy but will increase the equipment cost. Such a deformation is also within the protection scope of this application.

[0047] In one embodiment, please refer to Figures 1 - 4 , a through hole 112 is formed in the fixing plate 11. Both ends of the transmission rod 1633 are respectively inserted into the through holes 112 of the two fixing plates 11. The second rotation driving member 163 further includes two bearings 1635. The inner rings of the two bearings 1635 are respectively fixedly sleeved on the two transmission rods 1633. The outer rings of the two bearings 1635 are respectively fixedly connected to the two fixing plates 11, so as to improve the stability of the transmission rod 1633 during rotation.

[0048] In one embodiment, please refer to Figures 1 - 4 , a relief hole 132 is formed in the slider 13. The nut 162 is fixed to the slider 13 and is coaxially arranged with the relief hole 132.

[0049] In one embodiment, please refer to Figures 1 - 4, a rotating shaft 141 is rotatably provided at the other end of each of the support arms 14, and the wheel body 21 is fixed to the rotating shaft 141. The first rotation driving member 22 includes a first rotation driving motor 221, a first bevel gear 222 and a second bevel gear 223. The housing of the first rotation driving motor 221 is fixed to one of the support arms 14. The first bevel gear 222 is fixedly sleeved on the output shaft of the first rotation driving motor 221. The second bevel gear 223 is fixedly sleeved on the corresponding rotating shaft 141. The second bevel gear 223 meshes with the first bevel gear 222. During use, the first rotation driving motor 221 drives the first bevel gear 222 to rotate. The first bevel gear 222 drives the second bevel gear 223 to drive the rotating shaft 141 to rotate, and the rotating shaft 141 drives the wheel body 21 to rotate.

[0050] For a better understanding of the present invention, the following is a detailed description of the technical solution of the present invention in conjunction with Figures 1 to 7 During use, the downhole traction robot is fixed to the lower end of the fracturing string 3, and then the downhole traction robot together with the fracturing string 3 is lowered into the wellbore 4. During the lowering process, the slider 13 is driven to move by the moving driving member 16. When the slider 13 moves, each support arm 14 is pushed to open via each elastic push rod 15, so that each wheel body 21 abuts against the inner side wall of the wellbore 4. When the pressure of the elastic push rod 15 is lower than the set pressure, the moving driving member 16 drives each support arm 14 to open. When the pressure of the elastic push rod 15 is higher than the set pressure, the moving driving member 16 drives each support arm 14 to contract, so that the friction force between each wheel body 21 and the inner side wall of the wellbore 4 can be kept within the set range, so that the friction force is neither too small to drive the movement nor too large to increase the resistance during the movement. At the same time, the first rotation driving member 22 is used to drive at least one of the wheel bodies 21 to rotate, so as to drive the entire device and the fracturing string 3 to move downward, realizing the traction function of the fracturing string 3.

[0051] The technical solution provided by the present invention, by arranging multiple groups of support arms 14 and elastic push rods 15, can ensure that the downhole traction robot is located at the center of the wellbore 4, preventing the fracturing string 3 from being eccentric and increasing the lowering resistance; at the same time, by opening or contracting the support arms 14, the overall outer diameter of the traction robot can be adjusted, so as to adapt to different wellbore inner diameters and improve the downhole adaptability; in addition, by using the first rotation driving member 22 to drive at least one of the wheel bodies 21 to rotate, the fracturing string 3 can be tractioned, improving the smoothness and stability of the lowering.

[0052] The above specific embodiments of the present invention do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An underground traction robot, characterized in that: include: A diameter-changing mechanism, the diameter-changing mechanism comprising a fixed plate, a guide rod, a slider, a plurality of support arms, a plurality of elastic push rods and a movable driving member, the guide rod being fixed to the fixed plate, the slider being slidably arranged on the guide rod, one end of a plurality of support arms being hinged to the outer edge of the slider along the circumference of the slider, the elastic push rods corresponding to the support arms one by one, one end of each of the elastic push rods being hinged to the slider, the other end of each of the elastic push rods being hinged to the middle of the corresponding support arm, the movable driving member being connected to the slider and used for driving the slider to move; and, The traction mechanism comprises a plurality of wheels and a first rotating driving member. The wheels are rotatably arranged at the other end of each of the supporting arms. The first rotating driving member is used to drive at least one of the wheels to rotate.

2. The underground traction robot according to claim 1, characterized in that: There are two fixing plates, each of which is provided with a plurality of fixing holes, and a plurality of guide rods are respectively inserted into the corresponding fixing holes on the two fixing plates, and each guide rod is fixedly connected to the two fixing plates; The number of the sliding blocks is two, and they correspond to the two fixing plates respectively, and the sliding blocks are slidably arranged at the two ends of the guide rod respectively; The number of the support arms and the elastic push rods are both two groups and correspond to the two sliders respectively. One end of each group of the support arms is hinged to the outer edge of the corresponding slider along the circumference of the corresponding slider, one end of each group of the elastic push rods is hinged to the corresponding slider, and the other end of each group of the elastic push rods is hinged to the middle part of the corresponding support arm. The moving drive member is connected to the two sliders and is used to drive the two sliders to move.

3. The underground traction robot according to claim 2, characterized in that: The elastic push rod includes a first connecting rod, a sleeve, a shaft, a pressure sensor, an elastic member and a second connecting rod, one end of the sleeve is fixed to the slider via the first connecting rod, one end of the shaft is slidably inserted in the sleeve, one end of the pressure sensor is fixed in the sleeve, one end of the elastic member is connected to the other end of the pressure sensor, the other end of the elastic member is connected to one end of the shaft, one end of the second connecting rod is fixedly connected to the other end of the shaft, and the other end of the second connecting rod is fixed to the middle of the support arm.

4. The underground traction robot according to claim 2, characterized in that: The diameter-changing mechanism further comprises two end plates, one end of each of the guide rods is fixed to one of the end plates, and the other end of each of the guide rods is fixed to the other end plate.

5. The underground traction robot according to claim 4, characterized in that: The movable driving member includes two screw rods, two nuts and a second rotating driving member. The two ends of the screw rods are respectively rotatably set on the corresponding fixed plate and the corresponding end plate. The two nuts are respectively threaded and rotatably sleeved on the two screw rods and are respectively fixed to the two sliders. The second rotating driving member is connected to the two screw rods and is used to drive the two screw rods to rotate.

6. The underground traction robot according to claim 5, characterized in that: The second rotating driving member includes a second rotating driving motor, two main gears, a transmission rod and two transmission gears. The two ends of the housing of the second rotating driving motor are respectively fixedly connected to the two fixed plates. The output shaft of the second rotating driving motor is coaxially fixedly connected to one of the screw rods. The two main gears are respectively fixedly sleeved on the two screw rods. The two ends of the transmission rod are both rotatably connected to the two fixed plates. The two transmission gears are respectively fixedly sleeved on the two ends of the transmission rod. The two transmission gears are respectively meshed with the two main gears.

7. The underground traction robot according to claim 6, characterized in that: The fixing plate is provided with through holes, and the two ends of the transmission rod are respectively inserted into the through holes of the two fixing plates; The second rotating driving member further comprises two bearings, the inner rings of the two bearings are respectively fixedly sleeved on the two transmission rods, and the outer rings of the two bearings are respectively fixedly connected to the two fixing plates.

8. The underground traction robot according to claim 5, characterized in that: The slider is provided with a clearance hole, and the nut is fixed to the slider and is coaxially arranged with the clearance hole.

9. The underground traction robot according to claim 1, characterized in that: The other end of each support arm is rotatably provided with a rotating shaft, and the wheel body is fixed to the rotating shaft.

10. The underground traction robot according to claim 9, characterized in that: The first rotating driving member includes a first rotating driving motor, a first bevel gear and a second bevel gear. The housing of the first rotating driving motor is fixed to one of the supporting arms. The first bevel gear is fixedly sleeved on the output shaft of the first rotating driving motor. The second bevel gear is fixedly sleeved on the corresponding rotating shaft. The second bevel gear is meshed with the first bevel gear.

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