Device for testing surface traction capability of downhole tractor

Abstract

Provided in the present application is a device for testing the surface traction capability of a downhole tractor, the device comprising a test frame, a gearbox assembly, a magnetic powder brake and a tension controller, wherein the test frame comprises a main frame and two holding mechanisms, and the two holding mechanisms are respectively connected to two ends of the main frame in the direction of length and are used for holding a downhole tractor; the gearbox assembly comprises a gear box, two first connecting plates, two second connecting plates, a fixing plate, a driving load shaft, two driven output shafts, two measuring wheels and a gear assembly; the magnetic powder brake is connected to the driving load shaft; and the tension controller is in electrical signal connection with the magnetic powder brake. The first connecting plates and the second connecting plates can be connected and fixed to the gear box at a plurality of different mounting positions to adjust the spacing between the two driven output shafts, so as to simulate casings of different diameters; therefore, the traction capability of a downhole tractor in casings of different specifications can be visually tested, thereby saving time and labor while reducing testing costs.

Description

A testing device for the surface traction capability of a downhole crawler. Technical Field

[0001] This application relates to the technical field of downhole crawler testing devices, and more particularly to a testing device for the surface traction capability of a downhole crawler. Background Technology

[0002] During oil drilling, logging instruments need to be delivered to the measurement section. Since the measurement section is mostly a horizontal well, the logging instruments are lowered via cables, and since they do not have their own weight to carry them to the measurement section, a downhole crawler is required. The crawler's traction capacity needs to be tested on the surface to ensure it meets the traction requirements of the logging instruments.

[0003] Existing testing devices for the surface traction capacity of downhole crawlers involve placing the crawler inside the casing to test its crawling effect. This process requires different specifications of casing, and after each test, the crawler must be removed and reinstalled, which is time-consuming, labor-intensive, and costly. Furthermore, the crawling effect cannot be seen inside the casing, making the measurement of traction capacity impossible to visually assess. Technical issues

[0004] In view of this, this application proposes a testing device for the surface traction capability of a downhole crawler, in order to solve the technical problems mentioned in the background art, which require different specifications of casing to be matched, and after each test, the crawler must be taken out and reinstalled in the casing, which is time-consuming, labor-intensive, and costly. In addition, the crawling effect of the downhole crawler cannot be seen inside the casing, and the crawling capability cannot be visually observed. Technical solutions

[0005] This application provides a testing device for the surface traction capability of a downhole crawler, including a test frame, a transmission box assembly, a magnetic powder brake, and a tension controller, wherein:

[0006] The test frame includes a main frame and two clamping mechanisms. The two clamping mechanisms are respectively connected to both ends of the main frame along its length and are used to clamp the downhole crawler.

[0007] The transmission box assembly includes a gearbox, two first connecting plates, two second connecting plates, a fixed plate, a driving load shaft, two driven output shafts, two measuring wheels, and a gear assembly. The two first connecting plates and two second connecting plates are rotatably mounted on the gearbox. The fixed plate is connected to both the gearbox and the main frame. The driving load shaft is rotatably mounted on the fixed plate. The two driven output shafts are rotatably mounted on the first and second connecting plates, respectively. The first and second connecting plates can be connected and fixed to the gearbox at multiple different mounting positions to adjust the distance between the two driven output shafts. The two measuring wheels are respectively mounted on the two driven output shafts for contacting the crawler wheels of the downhole crawler. Therefore, the gear assembly connects the driving load shaft and the two driven output shafts.

[0008] The magnetic powder brake is connected to the active load shaft;

[0009] The tension controller is electrically connected to the magnetic powder brake and is used to control the magnitude of the excitation current of the magnetic powder brake.

[0010] Based on the above technical solutions, preferably, the transmission box assembly further includes a first rotating shaft and a second rotating shaft, the first rotating shaft and the second rotating shaft being symmetrically fixed to the gearbox with the length direction of the main frame as the axis of symmetry; two first connecting plates are rotatably mounted on the first rotating shaft; and two second connecting plates are rotatably mounted on the second rotating shaft.

[0011] Based on the above technical solutions, preferably, the gearbox is symmetrically provided with a plurality of first mounting holes and a plurality of second mounting holes; the first connecting plate is provided with a first connecting hole that matches the first mounting hole, and the second connecting plate is provided with a second connecting hole that matches the second mounting hole;

[0012] The transmission box assembly further includes a first connecting pin and a second connecting pin, wherein the first connecting pin is used to connect the first mounting hole and the first connecting hole, and the second connecting pin is used to connect the second mounting hole and the second connecting hole.

[0013] Based on the above technical solution, preferably, a plurality of first mounting holes are distributed on a circle with the first rotation axis as the center, and a plurality of second mounting holes are distributed on a circle with the second rotation axis as the center.

[0014] Based on the above technical solutions, preferably, the clamping mechanism includes a stationary valve, a movable valve, a hinge pin, a mounting pin, a tie rod screw, and a connecting nut; the stationary valve is fixedly installed at one end of the main frame along its length, and the stationary valve is provided with an ear seat; the movable valve is hinged to the stationary valve through the hinge pin to encircle the downhole crawler; both ends of the mounting pin are installed in the ear seats, the tie rod screw is sleeved on the mounting pin, and the connecting nut is threadedly connected to the tie rod screw and can abut against the outer surface of the movable valve.

[0015] Based on the above technical solutions, preferably, the clamping mechanism further includes a retaining ring, one end of the hinge pin is provided with a limiting boss, and the other end is provided with an annular groove. The limiting boss is used to abut against the end face of the stationary valve, the annular groove is located outside the stationary valve, and the retaining ring is installed in the annular groove.

[0016] Based on the above technical solutions, preferably, the inner wall of the moving valve and the inner wall of the stationary valve are provided with buffer pads.

[0017] Based on the above technical solutions, preferably, the gearbox includes a housing and a cover, the cover and the housing are detachably connected, and the gear assembly is disposed in the housing.

[0018] Based on the above technical solutions, preferably, the gear assembly includes a driving gear, a driven gear, and multiple transmission gears. The driving gear is mounted on the driving load shaft, the driven gear is mounted on the driven output shaft, and the multiple transmission gears are rotatably mounted on the housing and are meshed between the driving gear and the driven gear.

[0019] Based on the above technical solutions, preferably, when the measuring wheel contacts the crawling wheel of the downhole crawler, the radial direction of the measuring wheel is parallel to that of the crawling wheel. Beneficial effects

[0020] In this embodiment, two measuring wheels are respectively mounted on two driven output shafts for contact with the crawling wheels of the downhole crawler. The first connecting plate and the second connecting plate can be connected and fixed to the gearbox at multiple different mounting positions to adjust the distance between the two driven output shafts, simulating casings of different diameters. This allows for visual testing of the traction capacity of the downhole crawler in casings of different specifications, saving time and effort while reducing testing costs. The load of the magnetic powder brake is transmitted to the measuring wheels through the gear assembly. The current value of the excitation current of the magnetic powder brake is controlled by the tension controller, enabling adjustment of the load size and thus measuring the traction capacity of the downhole crawler. The measurement method is simple, reliable, and highly efficient.

[0021] In this embodiment, two first connecting plates are rotatably mounted on the first rotating shaft; two second connecting plates are rotatably mounted on the second rotating shaft, enabling the first and second connecting plates to be rotatably mounted on the gearbox. The first and second rotating shafts are symmetrically fixed to the gearbox about the length direction of the main frame. When switching between different mounting positions, as long as the first and second connecting plates rotate at the same angle, it can be ensured that the two test wheels are always symmetrical about the crawler wheel. There is no need to repeatedly center the downhole crawler, and the position of the downhole crawler will not change, which can also improve the accuracy of the test.

[0022] In this embodiment, the first connecting pin connects the first mounting hole and the first connecting hole to achieve a detachable connection between the first connecting plate and the gearbox. The second connecting pin connects the second mounting hole and the second connecting hole to achieve a detachable connection between the second connecting plate and the gearbox. This facilitates the adjustment of the mounting positions of the first connecting plate and the second connecting plate with the gearbox, making the testing device easier and faster to assemble and improving testing efficiency.

[0023] In this embodiment, the movable valve and the stationary valve are hinged together by the hinge pin to encircle the downhole crawler. The two ends of the mounting pin are installed in the lugs, the tie rod screw is sleeved on the mounting pin, and the connecting nut is threadedly connected to the tie rod screw and can abut against the outer surface of the movable valve. After the movable valve and the stationary valve are encircled on the downhole crawler, the movable valve and the stationary valve are locked by fastening the connecting nut and the tie rod screw, thereby tightly holding the downhole crawler.

[0024] In this embodiment, a limiting boss is provided at one end of the hinge pin, and an annular groove is provided at the other end. The limiting boss abuts against the end face of the stationary valve, and the annular groove is located outside the stationary valve. The retaining ring is installed in the annular groove. The limiting boss and the retaining ring limit both ends of the hinge pin, preventing the hinge pin from sliding out of the stationary valve and the moving valve, thereby improving the reliability and stability of the device. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0026] Figure 1 is a schematic diagram of the structure of the test device for the ground traction capability of the downhole crawler in the embodiment of this application;

[0027] Figure 2 is a schematic diagram of the transmission box assembly in the embodiment of this application;

[0028] Figure 3 is a schematic diagram of the test fixture in an embodiment of this application;

[0029] Figure 4 is a side view of the transmission box assembly in an embodiment of this application;

[0030] Figure 5 is a front view of the transmission box assembly in an embodiment of this application;

[0031] Figure 6 is a rear view of the transmission box assembly in an embodiment of this application.

[0032] Explanation of reference numerals in the attached drawings: 1-Test fixture, 2-Transmission box assembly, 3-Magnetic powder brake, 4-Tension controller;

[0033] 100-Downhole crawler;

[0034] 11-Main frame, 12-Clamping mechanism, 121-Static valve, 1211-Ear seat, 122-Moving valve, 123-Hinge pin, 1231-Limiting boss, 1232-Annular groove, 124-Mounting pin, 125-Tie rod screw, 126-Connecting nut, 127-Retaining ring;

[0035] 21-Gearbox, 2101-Box body, 2102-Box cover, 211-First mounting hole, 212-Second mounting hole, 22-First connecting plate, 221-First connecting hole, 23-Second connecting plate, 231-Second connecting hole, 24-Fixing plate, 25-Driven load shaft, 26-Driven output shaft, 27-Measuring wheel, 28-Gear assembly, 281-Driven gear, 282-Driven gear, 283-Transmission gear, 29-First rotating shaft, 210-Second rotating shaft, 220-First connecting pin, 230-Second connecting pin, 240-First driven shaft, 250-Second driven shaft. Embodiments of the present invention

[0036] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0037] Referring to Figures 1-6, this application provides a testing device for the surface traction capability of a downhole crawler, comprising a test frame 1, a transmission box assembly 2, a magnetic powder brake 3, and a tension controller 4, wherein:

[0038] The test frame 1 includes a main frame 11 and two clamping mechanisms 12. The two clamping mechanisms 12 are respectively connected to both ends of the main frame 11 in the length direction and are used to clamp the downhole crawler 100.

[0039] The transmission box assembly 2 includes a gearbox 21, two first connecting plates 22, two second connecting plates 23, a fixed plate 24, a driving load shaft 25, two driven output shafts 26, two measuring wheels 27, and a gear assembly 28. The two first connecting plates 22 and the two second connecting plates 23 are rotatably mounted on the gearbox 21. The fixed plate 24 is connected to both the gearbox 21 and the main frame 11. The driving load shaft 25 is rotatably mounted on the fixed plate 24. The two driven output shafts 26 are rotatably mounted on the first connecting plate 22 and the second connecting plate 23, respectively. The first connecting plate 22 and the second connecting plate 23 can be connected and fixed to the gearbox 21 at multiple different mounting positions to adjust the distance between the two driven output shafts 26. The two measuring wheels 27 are respectively mounted on the two driven output shafts 26 for contacting the crawler wheels of the downhole crawler 100. Therefore, the gear assembly 28 connects the driving load shaft 25 and the two driven output shafts 26.

[0040] The magnetic powder brake 3 is connected to the active load shaft 25;

[0041] The tension controller 4 is electrically connected to the magnetic powder brake 3 and is used to control the magnitude of the excitation current of the magnetic powder brake 3. By controlling the magnitude of the excitation current of the magnetic powder brake 3, the tension controller 4 can adjust the braking force of the magnetic powder brake 3, thereby adjusting the load applied to the test wheel.

[0042] The testing device for the surface traction capability of the downhole crawler proposed in this application embodiment uses two measuring wheels 27 respectively mounted on two driven output shafts 26 for contact with the crawling wheels of the downhole crawler 100. The first connecting plate 22 and the second connecting plate 23 can be connected and fixed to the gearbox 21 at multiple different mounting positions to adjust the distance between the two driven output shafts 26 to simulate casings of different diameters. The traction capability of the downhole crawler 100 in casings of different specifications can be visually tested, saving time and effort while reducing testing costs. The load of the magnetic powder brake 3 is transmitted to the measuring wheel 27 through the gear assembly 28. The current value of the excitation current of the magnetic powder brake 3 is controlled by the tension controller 4 to achieve adjustable load size, thereby measuring the traction capability of the downhole crawler 100. The measurement method is simple, reliable, and highly efficient.

[0043] In some embodiments, the transmission box assembly 2 further includes a first rotating shaft 29 and a second rotating shaft 210, which are symmetrically fixed to the gearbox 21 about the length direction of the main frame 11. Two first connecting plates 22 are rotatably mounted on the first rotating shaft 29 and are located on both sides of the gearbox 21. Two second connecting plates 23 are rotatably mounted on the second rotating shaft 210 and are located on both sides of the gearbox 21. The second connecting plates 23 and the first connecting plates 22 do not interfere with each other when rotating. By symmetrically fixing the first rotating shaft 29 and the second rotating shaft 210 to the gearbox 21 about the length direction of the main frame 11, when switching different mounting positions, as long as the first connecting plates 22 and the second connecting plates 23 rotate at the same angle, it can be ensured that the two test wheels are always symmetrical about the crawler wheel. There is no need to repeatedly center the downhole crawler 100, and the position of the downhole crawler 100 will not change, which can also improve the accuracy of the test.

[0044] In some embodiments, the gearbox 21 is symmetrically provided with a plurality of first mounting holes 211 and a plurality of second mounting holes 212; the first connecting plate 22 is provided with a first connecting hole 221 that matches the first mounting hole 211, and the second connecting plate 23 is provided with a second connecting hole 231 that matches the second mounting hole 212; the transmission box assembly 2 further includes a first connecting pin 220 and a second connecting pin 230, the first connecting pin 220 being used to connect the first mounting hole 211 and the first connecting hole 221, and the second connecting pin 230 being used to connect the second mounting hole 212 and the second connecting hole 231. As shown in FIG5, there are 4 first mounting holes 211 and 4 corresponding second mounting holes 212, corresponding to four different specifications of sleeves (4.5", 5.5", 7" and 8 5 / 8" for a total of four types). The actual number of first mounting holes 211 and second mounting holes 212 can be set according to the type of sleeve specifications to be simulated. The first connecting pin 220 connects the first mounting hole 211 and the first connecting hole 221, thereby achieving a detachable connection between the first connecting plate 22 and the gearbox 21. The second connecting pin 230 connects the second mounting hole 212 and the second connecting hole 231, thereby achieving a detachable connection between the second connecting plate 23 and the gearbox 21. This facilitates the adjustment of the mounting positions of the first connecting plate 22 and the second connecting plate 23 with the gearbox 21, making the assembly of the testing device more convenient and faster, and improving testing efficiency.

[0045] In some embodiments, a plurality of first mounting holes 211 are distributed on a circle centered on the first rotation axis 29, and a plurality of second mounting holes 212 are distributed on a circle centered on the second rotation axis 210. By arranging the plurality of first mounting holes 211 circumferentially around the first rotation axis 29 and the plurality of second mounting holes 212 circumferentially around the second rotation axis 210, when the first connecting plate 22 and the second connecting plate 23 rotate, the first connecting hole 221 will always be aligned with one of the first mounting holes 211, and the second connecting hole 231 will always be aligned with one of the second mounting holes 212, thus improving the reliability of the device. By setting the spacing between two adjacent first mounting holes 211 and the spacing between two adjacent second mounting holes 212, different specifications of round tubes can be accommodated.

[0046] In some embodiments, the clamping mechanism 12 includes a stationary valve 121, a movable valve 122, a hinge pin 123, a mounting pin 124, a tie rod screw 125, and a connecting nut 126. The stationary valve 121 is fixedly installed at one end of the main frame 11 along its length, and the stationary valve 121 is provided with an ear seat 1211. The movable valve 122 is hinged to the stationary valve 121 through the hinge pin 123 to encircle the downhole crawler 100. The mounting pin 124 is installed at both ends in the ear seat, the tie rod screw 125 is sleeved on the mounting pin 124, and the connecting nut 126 is threadedly connected to the tie rod screw 125 and can abut against the outer surface of the movable valve 122. After the movable valve 122 and the stationary valve 121 are wrapped around the downhole crawler 100, they are secured by tightening the connecting nut 126 and the tie rod screw 125, thus locking the movable valve 122 and the stationary valve 121 and gripping the downhole crawler 100. This gripping structure is easy to assemble and has good gripping ability. The connecting nut 126 can be a wing nut, which is convenient for applying torque. No tools are required, and the connecting nut 126 can be rotated manually, making the operation more convenient.

[0047] In some embodiments, the clamping mechanism 12 further includes a retaining ring 127. One end of the hinge pin 123 is provided with a limiting boss 1231, and the other end is provided with an annular groove 1232. The limiting boss 1231 is used to abut against the end face of the stationary valve 121, and the annular groove 1232 is located outside the stationary valve 121. The retaining ring 127 is installed in the annular groove 1232. By limiting the two ends of the hinge pin 123 with the limiting boss 1231 and the retaining ring 127, the hinge pin 123 is prevented from sliding out of the stationary valve 121 and the movable valve 122, thereby improving the reliability and stability of the device.

[0048] In some embodiments, the inner walls of the moving valve 122 and the stationary valve 121 are provided with buffer pads. The buffer pads allow for a more secure gripping of the downhole crawler 100, preventing radial rotation and axial movement, and improving reliability and stability. The buffer pads can be made of rubber.

[0049] In some embodiments, the gearbox 21 includes a housing 2101 and a cover 2102, the cover 2102 being detachably connected to the housing 2101, and the gear assembly 28 being disposed within the housing 2101. Disposing of the gear assembly 28 within the housing 2101 facilitates lubrication of the gear assembly 28. Simultaneously, the detachable connection between the cover 2102 and the housing 2101 ensures a seal on the housing 2101, preventing accidental operation that could cause the gear assembly 28 to be caught, thus improving the safety of the device. A first mounting hole 211 and a second mounting hole 212 penetrate the housing 2101 and the cover 2102.

[0050] In some embodiments, the gear assembly 28 includes a driving gear 281, a driven gear 282, and a plurality of transmission gears 283. The driving gear 281 is mounted on the driving load shaft 25, the two driven gears 282 are respectively mounted on the two driven output shafts 26, and the plurality of transmission gears 283 are rotatably mounted on the housing 2101 and are meshed between the driving gear 281 and the driven gears 282. The transmission box assembly 2 also includes two first driven shafts 240 and two second driven shafts 250. Four transmission gears 283 are provided. One transmission gear 283 is installed on the first driven shaft 240 and another transmission gear 283 is installed on the second driven shaft 250. The driving gear 281 on the driving load shaft 25 meshes with the transmission gear 283 on the first driven shaft 240. The transmission gear 283 on the first driven shaft 240 meshes with the transmission gear 283 on the second driven shaft 250. The transmission gear 283 on the second driven shaft 250 meshes with the driven gear 282 on the driven output shaft 26, thereby transmitting the load of the magnetic powder brake 3 to the two measuring wheels 27 in two separate paths.

[0051] In some embodiments, when the measuring wheel 27 contacts the crawler wheel of the downhole crawler 100, the measuring wheel 27 is parallel to the radial direction of the crawler wheel. By making the measuring wheel 27 parallel to the radial direction of the crawler wheel, the friction between the measuring wheel 27 and the crawler wheel is increased, and the two measuring wheels 27 respectively contact both sides of the crawler wheel, reducing the possibility of slippage and making the traction capacity test results of the crawler wheel more accurate.

[0052] The working principle of the testing device for the surface traction capability of the downhole crawler in this embodiment is as follows: the downhole crawler 100 is clamped by the clamping mechanism 12, so that the crawling wheel of the downhole crawler 100 contacts the measuring wheel 27 and is aligned in the vertical direction; the crawling wheel of the downhole crawler 100 is driven by electricity, and at this time, the crawling wheel rotates with the measuring wheel 27; if the magnetic powder brake 3 is not loaded by the tension controller 4, the crawling wheel will easily rotate with the measuring wheel 27, and then the torque will be transmitted to the magnetic powder brake 3 through the gear assembly 28; if the magnetic powder brake 3 is loaded by the tension controller 4, it is more difficult to rotate the shaft of the magnetic powder brake 3, and at this time, the load torque is transmitted to the measuring wheel 27 through the gear system in the gearbox 21, and it is more difficult for the crawling wheel to drive the measuring wheel 27 to rotate. The braking torque of the magnetic powder brake 3 can be controlled by adjusting the current through the tension controller 4. This, in turn, changes the load required to rotate the measuring wheel 27 via the gear train in the gearbox 21. This load is adjustable, and the traction capacity of the crawling wheel can be tested by adjusting the load. The first connecting plate 22 and the second connecting plate 23 can be connected and fixed to the gearbox 21 at multiple different mounting positions to adjust the distance between the two driven output shafts 26, simulating sleeves of different diameters.

[0053] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for testing the surface towing capacity of a downhole crawler, wherein, Includes a test fixture, transmission box assembly, magnetic powder brake, and tension controller, among which: The test frame includes a main frame and two clamping mechanisms. The two clamping mechanisms are respectively connected to both ends of the main frame along its length and are used to clamp the downhole crawler. The transmission box assembly includes a gearbox, two first connecting plates, two second connecting plates, a fixed plate, a driving load shaft, two driven output shafts, two measuring wheels, and a gear assembly. The two first connecting plates and two second connecting plates are rotatably mounted on the gearbox. The fixed plate is connected to both the gearbox and the main frame. The driving load shaft is rotatably mounted on the fixed plate. The two driven output shafts are rotatably mounted on the first and second connecting plates, respectively. The first and second connecting plates can be connected and fixed to the gearbox at multiple different mounting positions to adjust the distance between the two driven output shafts. The two measuring wheels are respectively mounted on the two driven output shafts for contacting the crawler wheels of the downhole crawler. Therefore, the gear assembly connects the driving load shaft and the two driven output shafts. The magnetic powder brake is connected to the active load shaft; The tension controller is electrically connected to the magnetic powder brake and is used to control the magnitude of the excitation current of the magnetic powder brake.

2. The testing device for the surface traction capability of the downhole crawler according to claim 1, wherein, The transmission box assembly further includes a first rotating shaft and a second rotating shaft, which are symmetrically fixed to the gearbox about the length direction of the main frame; two first connecting plates are rotatably mounted on the first rotating shaft; and two second connecting plates are rotatably mounted on the second rotating shaft.

3. The testing device for the surface traction capability of the downhole crawler according to claim 2, wherein, The gearbox is symmetrically provided with a plurality of first mounting holes and a plurality of second mounting holes; the first connecting plate is provided with a first connecting hole that matches the first mounting hole, and the second connecting plate is provided with a second connecting hole that matches the second mounting hole; The transmission box assembly further includes a first connecting pin and a second connecting pin, wherein the first connecting pin is used to connect the first mounting hole and the first connecting hole, and the second connecting pin is used to connect the second mounting hole and the second connecting hole.

4. The testing device for the surface traction capability of the downhole crawler according to claim 3, wherein, Multiple first mounting holes are distributed on a circle centered on the first rotation axis, and multiple second mounting holes are distributed on a circle centered on the second rotation axis.

5. The testing device for the surface traction capability of the downhole crawler according to claim 1, wherein, The clamping mechanism includes a stationary valve, a movable valve, a hinge pin, a mounting pin, a tie rod screw, and a connecting nut. The stationary valve is fixedly installed at one end of the main frame along its length, and the stationary valve is provided with an ear seat. The movable valve is hinged to the stationary valve through the hinge pin to encircle the downhole crawler. The mounting pin is installed in the ear seats at both ends, the tie rod screw is sleeved on the mounting pin, and the connecting nut is threadedly connected to the tie rod screw and can abut against the outer surface of the movable valve.

6. The testing device for the surface traction capability of the downhole crawler according to claim 5, wherein, The clamping mechanism also includes a retaining ring. One end of the hinge pin is provided with a limiting boss, and the other end is provided with an annular groove. The limiting boss is used to abut against the end face of the stationary valve. The annular groove is located outside the stationary valve, and the retaining ring is installed in the annular groove.

7. The testing device for the surface traction capability of the downhole crawler according to claim 6, wherein, The inner walls of the moving valve and the inner walls of the stationary valve are provided with buffer pads.

8. The testing device for the surface traction capability of the downhole crawler according to claim 1, wherein, The gearbox includes a housing and a cover, the cover being detachably connected to the housing, and the gear assembly being disposed within the housing.

9. The testing device for the surface traction capability of the downhole crawler according to claim 8, wherein, The gear assembly includes a driving gear, a driven gear, and multiple transmission gears. The driving gear is mounted on the driving load shaft, the driven gear is mounted on the driven output shaft, and the multiple transmission gears are rotatably mounted on the housing and are meshed between the driving gear and the driven gear.

10. The testing apparatus for the surface traction capability of a downhole crawler according to any one of claims 1 to 9, wherein, When the measuring wheel contacts the crawling wheel of the downhole crawler, the radial direction of the measuring wheel is parallel to that of the crawling wheel.

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