Automatic angle adjusting structure of screw drill and screw drill

Abstract

The invention relates to the technical field of drilling tools, and discloses an automatic angle adjusting structure of a screw drill and the screw drill, and the automatic angle adjusting structure of the screw drill comprises a motor assembly, an adjusting joint and an angle adjusting driving assembly. The angle adjusting driving assembly comprises a driving main shaft, a driving shell, a friction plate set, a driving nut, a driving spring and the like, and pressure transmission is achieved through a lower breather valve. During small-displacement driving, the friction plate sets are kept combined, the driving main shaft drives the driving shell to rotate, and the adjusting connector rotates relative to the double-male connector to achieve angle adjustment. And during large-displacement driving, the internal pressure is increased to separate the friction plate group, and power is directly transmitted to the transmission shaft assembly for normal drilling. Automatic underground angle adjustment is achieved, the angle of a drilling tool can be adjusted in real time according to stratum changes, frequent pulling-out is avoided, and the drilling efficiency and operation safety are remarkably improved.

Description

Technical Field

[0001] The present application relates to the technical field of drilling tools, and in particular to an automatic angle adjustment structure for a screw drill. Background Art

[0002] In directional drilling, screw drill bits are a core tool, and their angled structure directly impacts wellbore trajectory control. Traditional fixed-angle screw drill bits, with their angles fixed at manufacture, are unable to adapt to complex downhole geological conditions. This results in frequent trips to replace drill bits with different angles, severely impacting drilling efficiency.

[0003] To address this issue, existing technologies have proposed wellhead-adjustable screw drills, which allow for angle adjustments at the wellhead, reducing the need for drill tool replacements. However, this solution still requires drilling to the wellhead, preventing real-time adjustments downhole, and resulting in low drilling efficiency.

[0004] Therefore, there is an urgent need for a screw drill that can automatically adjust its angle underground to adapt to the changes in the formations in different well sections in real time, avoid frequent drilling, and improve drilling efficiency and safety. Summary of the Invention

[0005] The purpose of this application is to provide an automatic angle adjustment structure for a screw drill to solve the problems raised in the background technology.

[0006] To achieve the above objectives, this application provides the following technical solutions: In a first aspect, a screw drill automatic angle adjustment structure is provided, comprising: a motor assembly, including a stator and a rotor; An adjustment joint having a first bend angle; Angle adjustment drive assembly, including: A driving main shaft, the upper end of which is drivingly connected to the rotor, the lower end of which is drivingly connected to the transmission shaft assembly, and the outer peripheral wall of which is provided with an external thread; A drive nut, threadedly engaged with the drive spindle via an internal thread; A drive housing, fixedly connected to the adjustment joint; A friction plate group, consisting of alternately stacked active friction plates and driven friction plates, wherein the active friction plates are circumferentially fixed to the drive nut, and the driven friction plates are circumferentially fixed to the drive housing; a spring seat, sleeved on the outer periphery of the driving main shaft and with its lower end surface in contact with the friction plate group; a drive spring disposed in a first slot extending axially between the spring seat and the drive housing, with both ends abutting against the spring seat and the drive housing respectively; A lower breathing valve is provided in the driving housing, one end of which is connected to the first tank body and the other end is connected to the annulus; When the drive spring is in a naturally pre-tightened state, the friction plate group is combined to transmit torque; when the drive spring is compressed by axial force, the friction plate group is separated to cut off torque transmission.

[0007] Furthermore, the active friction plate is connected to the drive nut via a spline, and the driven friction plate is connected to the drive housing via a spline.

[0008] Furthermore, it also includes a double male joint and an adjustment core shaft threadedly connected to the double male joint, the double male joint has a second bend angle, the double male joint is connected to the stator through a stator joint, and the adjustment joint is rotatably connected to the adjustment core shaft.

[0009] Furthermore, a limit pin is provided on the adjustment joint, a limit slot is provided on the adjustment core shaft, and the limit pin is configured to be able to move within the limit slot.

[0010] Furthermore, the stator is in transmission connection with the top drive. When the top drive drives the stator to rotate, the stator drives the double male connectors to rotate synchronously through the stator connector.

[0011] Furthermore, it also includes an angle adjustment piston, which is arranged in the chamber of the adjustment joint and is connected to the adjustment joint through an upper breathing valve. The upper breathing valve connects the interior of the drill bit and the annulus to transmit pressure. A locking spring is provided between the angle adjustment piston and the adjustment joint. When the locking spring is axially compressed, the angle adjustment piston moves upward, and its upper spline engages with the spline groove on the outer periphery of the adjustment core shaft to achieve angle locking.

[0012] Furthermore, the angle adjustment piston is provided with a second groove body extending axially, and one end of the upper breathing valve is provided on the side wall of the adjustment joint, and the other end extends into the second groove body.

[0013] Furthermore, it also includes a universal joint assembly, which includes a rotor joint, a connecting shaft and a transmission shaft joint connected in sequence, the rotor joint is fixedly connected to the rotor, and the transmission shaft joint is fixedly connected to the drive main shaft.

[0014] Furthermore, the transmission shaft assembly includes a main shaft, an upper nut, an upper TC bearing, a string bearing, a lower nut and a lower TC bearing. The main shaft is in transmission connection with the driving main shaft for transmitting the rotational kinetic energy of the drilling tool.

[0015] On the second aspect, a screw drill tool is also provided, including an anti-drop assembly and the above-mentioned automatic angle adjustment structure of the screw drill tool, the anti-drop assembly includes an anti-drop upper joint, an anti-drop nut, an anti-drop retaining ring and an anti-drop shaft, the anti-drop upper joint is connected to the motor assembly, the anti-drop shaft is limited by the anti-drop retaining ring and fixed by the anti-drop nut to prevent the lower component from falling when the drill tool breaks.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: The automatic angle adjustment structure of the screw drill provided in the embodiment of the present application is provided with rotational power by a motor assembly. In the angle adjustment drive assembly, the drive spindle is connected to the rotor and the transmission shaft assembly, a drive nut is sleeved on the outer periphery, the friction plate group is connected to the drive nut and the drive housing, the spring seat sleeve is in contact with the friction plate group on the outer periphery of the drive spindle, the drive spring provides a pre-tightening force between the spring seat and the drive housing, the lower breathing valve connects the inside of the drill tool and the annulus to transmit pressure, and the drive housing is fixed to the adjustment joint.

[0017] When driving with small displacement, the friction plate group remains engaged under the preload of the driving spring, and the driving spindle drives the driving nut to rotate. The torque is transmitted to the driving housing through the friction plate group, causing the adjustment joint to rotate relative to the double male joint to achieve angle adjustment.

[0018] When driving at large displacement, the internal pressure of the drill tool increases, and the pressure acts on the spring seat through the lower breathing valve, compressing the drive spring, separating the friction plate group, and directly transmitting the driving spindle power to the drive shaft assembly to achieve normal drilling.

[0019] This application realizes automatic angle adjustment downhole, which can be adjusted in real time according to the changes in the formation in different well sections, avoiding frequent angle adjustment when drilling, and improving drilling efficiency and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0023] Figure 1 A schematic structural diagram of the angle adjustment drive assembly and the transmission shaft assembly provided in an embodiment of the present application.

[0024] Figure 2 This is a schematic assembly cross-sectional diagram of the stator joint, double male joint, adjustment core shaft, angle adjustment piston and adjustment joint provided in an embodiment of the present application.

[0025] Figure 3 This is an exploded view of the adjustment core shaft and adjustment joint provided in an embodiment of the present application.

[0026] Figure 4 This is a schematic diagram of the structure of the angle adjustment drive assembly provided in an embodiment of the present application.

[0027] Figure 5 for Figure 2 A is an enlarged schematic diagram.

[0028] Figure 6 This is a schematic diagram of the structure of the screw drill provided in the embodiment of the present application.

[0029] Description of reference numerals: 1. Double male connector; 101. Second bend; 2. Stator joint; 3. Adjust the joint; 31. First bend; 32. Limit pin; 4. Angle adjustment drive assembly; 41. Drive spindle; 42. Drive housing; 43. Friction plate assembly; 431. Active friction plate; 432. Driven friction plate; 44. Drive nut; 45. Drive spring; 46. Spring seat; 47. Lower breathing valve; 5. Drive shaft assembly; 51. Main shaft; 52. Upper nut; 53. Upper TC bearing; 54. String bearing; 55. Lower nut; 56. Lower TC bearing; 6. Adjust the mandrel; 61. Limit groove; 7. Angle adjustment piston; 71. Trough body; 8. Upper breathing valve; 9. Locking spring; 10. Universal joint assembly; 11. Anti-drop assembly; 12. Motor assembly. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0032] For ease of description, spatially relative terms may be used herein to describe the relative position or movement of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," "above," "front," "back," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation other than the orientation depicted in the figures. For example, if the device in the figures undergoes a positional flip or a change in posture or a change in motion, then these directional indications will also change accordingly. For example, an element described as "below" or "below" another element or feature will subsequently be oriented as "above" or "above" another element or feature. Thus, the example term "below" can include both above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein will be interpreted accordingly.

[0033] In order to solve the technical problem in the prior art that the screw drill needs to adjust the angle when it is pulled out of the drill hole to the wellhead, resulting in low drilling efficiency, the present application provides an automatic angle adjustment structure for the screw drill, which can automatically adjust the angle underground to adapt to the changes in the formations in different well sections in real time, avoid frequent pulling out of the drill hole, and improve drilling efficiency and safety.

[0034] Figures 1 to 5 An automatic angle adjustment structure for a screw drill provided in an embodiment of the present application includes: a motor assembly 12 comprising a stator and a rotor; The adjustment joint 3 has a first bend angle 31; The angle adjustment drive assembly 4 includes: The driving main shaft 41 is connected to the rotor at the upper end and the transmission shaft assembly 5 at the lower end, and the outer peripheral wall is provided with an external thread; In this embodiment, the stator and rotor in the motor assembly interact with each other, with the rotor performing planetary motion within the specific space formed by the stator. This converts the pressure energy of the drilling fluid into mechanical energy, generating rotational power. The upper end of the drive spindle 41 is in driving connection with the rotor, so the rotational power of the rotor is directly transmitted to the drive spindle 41, causing it to rotate.

[0035] The driving nut 44 is threadedly engaged with the driving spindle 41 via an internal thread; The driving housing 42 is fixedly connected to the adjustment joint 3; The friction plate group 43 is composed of alternatingly stacked active friction plates 431 and driven friction plates 432. The active friction plates 431 are circumferentially fixed to the drive nut 44, and the driven friction plates 432 are circumferentially fixed to the drive housing 42. The spring seat 46 is sleeved on the outer periphery of the driving main shaft 41 and its lower end surface abuts against the friction plate group 43; The drive spring 45 is disposed in a first groove extending axially between the spring seat 46 and the drive housing 42 , with both ends abutting against the spring seat 46 and the drive housing 42 , respectively; The lower breathing valve 47 is provided in the driving housing 42, one end of which is connected to the first tank body and the other end is connected to the annulus; When the drive spring 45 is in a naturally pre-tightened state, the friction plate group 43 is engaged to transmit torque; when the drive spring 45 is compressed by the axial force, the friction plate group 43 is separated to cut off the torque transmission.

[0036] In the above technical solution, when the drive spindle 41 rotates, the external threads on its outer peripheral wall cause it to rotate relative to the drive nut 44, which is threadedly engaged with it via internal threads. When the drive spring 45 is in a naturally preloaded state, the spring seat 46 applies a certain pressure to the friction plate group 43.

[0037] The friction plate assembly 43 consists of alternating active friction plates 431 and passive friction plates 432. The active friction plates 431 are circumferentially fixed to the drive nut 44, while the passive friction plates 432 are circumferentially fixed to the drive housing 42. The drive housing 42 is, in turn, fixedly connected to the adjustment joint 3. Under the action of spring pressure, the active and passive friction plates 431 and 432 are tightly coupled, and friction transfers torque from the drive nut 44 to the drive housing 42 and then to the adjustment joint 3. The adjustment joint 3 has a first bend 31, which, under the action of torque, drives subsequent related components to perform drilling operations in the direction of the set bend.

[0038] Specifically, when operating in a low-displacement drive mode, the flow of motive medium into the drill tool's internal cavity is low, resulting in a relatively low pressure. This low pressure does not exert sufficient force on the lower breathing valve 47 to compress the drive spring 45. Therefore, the drive spring 45 remains naturally preloaded, allowing the friction plate assembly 43 to remain engaged under the axial preload. This allows the rotational torque of the drive nut 44 to be transmitted to the drive housing 42, ultimately driving the adjustment joint 3 to rotate and achieve the angle adjustment function of the drill tool.

[0039] Under high-displacement drive conditions, a large amount of power medium enters the internal cavity of the drill tool, causing the pressure inside the drill tool to increase significantly. This increased pressure acts on the spring seat 46 through the lower breathing valve 47, generating a large axial thrust on the spring seat 46, which in turn compresses the drive spring 45. When the drive spring 45 is compressed to a certain extent, its axial preload on the friction plate group 43 is reduced, causing the friction plate group 43 to separate. After the friction plate group 43 separates, the torque transmission between the drive spindle 41 and the drive housing 42 is cut off. The power of the drive spindle 41 can be directly transmitted to the transmission shaft assembly 5, thus realizing the normal drilling function of the screw drill tool without affecting the drilling efficiency by driving the adjustment joint 3 to rotate.

[0040] Traditional screw drills have fixed angles and are unable to adapt to the complex and changing geological conditions downhole. The automatic angle adjustment structure for the screw drill provided in this application can automatically adjust the angle based on actual needs downhole, eliminating the need to pull the drill out of the wellhead for replacement. This significantly improves the adaptability of drilling operations to different formations and reduces drilling difficulties and accident risks caused by changing geological conditions.

[0041] Furthermore, since frequent trips to replace drill tools at different angles are not required, significant tripping time, labor, and material costs are saved. Furthermore, the drilling angle can be adjusted at low displacements, and the drilling mode can be quickly switched to normal at high displacements, enabling continuous and efficient drilling operations and effectively shortening the drilling cycle.

[0042] It should be noted that in drilling engineering, annulus refers to the annular space between the wellbore and the drill string (or casing), which is the key channel for drilling fluid circulation, cuttings return and pressure control.

[0043] In this embodiment, low-displacement drive refers to the delivery of a relatively low flow rate of motive medium to the screw drill. Within the screw drill system, motive medium (e.g., drilling fluid) enters the motor assembly 12 through a specific channel, driving the rotor to rotate and thereby outputting rotary power. Low displacement means that a relatively small volume of motive medium enters the motor assembly per unit time.

[0044] The high-displacement drive is to input a relatively large flow of power medium into the screw drill. That is, a large amount of power medium enters the motor assembly 12 per unit time, driving the rotor to rotate at a higher speed or with greater force.

[0045] Please refer to Figure 4 In some implementations of this embodiment, the active friction plate 431 is connected to the driving nut 44 through a spline, and the driven friction plate 432 is connected to the driving housing 42 through a spline.

[0046] In the above embodiment, a spline connection consists of multiple teeth evenly distributed around the circumference of the shaft and hub. The active friction plate 431 is equipped with internal splines, while the drive nut 44 is equipped with external splines, with the two meshing with each other through the spline teeth. When the drive nut 44 rotates driven by the drive spindle 41, the meshing of the spline teeth allows the rotational torque to be accurately transmitted to the active friction plate 431. This connection ensures circumferential fixation between the active friction plate 431 and the drive nut 44, ensuring synchronous rotation and thus efficient torque transmission.

[0047] Similarly, the driven friction plate 432 is equipped with external splines, while the drive housing 42 is equipped with internal splines. When the active friction plate 431 drives the friction plate group 43 to rotate, the driven friction plate 432 is circumferentially fixed to the drive housing 42 via a spline connection. Because the drive housing 42 is fixedly connected to the adjustment joint 3, the driven friction plate 432 transmits torque to the drive housing 42, and then to the adjustment joint 3, ensuring the continuity of the entire torque transmission path.

[0048] Please refer to Figure 2 In some implementations of this embodiment, the present application also includes a double male connector 1 and an adjustment core shaft 6 threadedly connected to the double male connector 1, the double male connector 1 has a second bend angle 101, the double male connector 1 is connected to the stator through the stator connector 2, and the adjustment connector 3 is rotatably connected to the adjustment core shaft 6.

[0049] In the above embodiment, the double male connector 1 has a second bend 101 , and the first bend 31 of the adjustment connector 3 and the second bend 101 of the double male connector 1 can face the same direction or different directions.

[0050] For example, the size of the first bend angle 31 is 1°, the size of the second bend angle 101 is 1.5°, and the adjustment joint 3 can rotate between 0°-60°. When the first bend angle 31 and the second bend angle 101 are in opposite directions, during the rotation of the adjustment joint 3, when the rotation angle of the adjustment joint is 0°, the composite angle = |1.5° - 1°| = 0.5°, which is the same direction as the second bend angle 101.

[0051] When the joint rotation angle is adjusted to 60°, according to the formula sqrt(a 2 +b 2 -2abcosθ) can be calculated as the resulting angle ≈ sqrt(3.25 - 3 cos60°) = sqrt(3.25 - 1.5) ≈ 1.32°, which is between the first bend 31 and the second bend 101. Note that a = 1.5° (second bend), b = 1° (first bend), and θ is the angle between the first bend 31 and the second bend 101 (adjusting the joint's rotation angle).

[0052] It can be understood that, between 0° and 60°, the composite angle gradually increases from 0.5° to about 1.32°, and the direction gradually deflects from the direction of the second corner 101 to the direction of the first corner 31 .

[0053] Therefore, when the first bend 31 and the second bend 101 are in opposite directions, the composite angle changes from 0.5° to about 1.32° during the rotation of the adjustment joint 3 , and the direction also changes accordingly.

[0054] Please refer to Figure 3 In particular, a limit pin 32 is provided on the adjustment joint 3 , and a limit slot 61 is provided on the adjustment core shaft 6 . The limit pin 32 is configured to be able to move within the limit slot 61 .

[0055] The shape and size of the limit slot 61 determine the range and trajectory of movement of the limit pin 32, thereby limiting the amplitude and direction of relative movement between the adjustment joint 3 and the adjustment mandrel 6. For example, if the limit slot 61 is arcuate, the limit pin 32 can only move within the arcuate slot. This restricts relative rotation between the adjustment joint 3 and the adjustment mandrel 6 to a specific angular range, thereby achieving precise adjustment of the drilling angle of the screw drill.

[0056] At the same time, the movement of the limit pin 32 within the limit slot 61 also serves to prevent excessive movement. When the limit pin 32 moves to the end of the limit slot 61, it is blocked by the slot wall and cannot move further. This prevents the adjustment joint 3 and the adjustment mandrel 6 from being damaged due to excessive rotation or movement or affecting the normal operation of the screw drill.

[0057] In this embodiment, the limiting groove 61 limits the adjustment joint 3 to rotate between 0° and 60°.

[0058] Furthermore, the stator of the present application is transmission-connected to a top drive (not shown in the drawings). When the top drive drives the stator to rotate, the stator drives the double male connector 1 to rotate synchronously through the stator connector 2 .

[0059] The angle adjustment drive assembly 4 drives the adjustment joint 3 to rotate so that the composite angle is adjusted from a small angle to a large angle, while the top drive drives the double male joint 1 to rotate so that the composite angle is adjusted from a large angle to a small angle. Specifically, when the top drive drives the double male joint 1 to rotate, the drill bit is first lifted off the bottom of the well, the pump is stopped, and the angle adjustment piston 7 is unlocked under the action of the locking spring 9. At this time, the top drive is started at a lower speed, the top drive drives the stator to rotate, the stator drives the stator joint to rotate, and the stator joint drives the double male joint 1 to rotate, and the relative position of the adjustment joint 3 and the double male joint 1 changes. The drive housing 42 is restricted in rotation due to contact with the well wall, and the angle change is small. Then the displacement is directly increased, while the top drive keeps rotating, the internal pressure of the drill tool increases, the friction plate group 43 disengages, the angle adjustment piston 7 moves up, the angle is locked, and the angle adjustment is completed.

[0060] Please refer to Figure 2 In some implementations of this embodiment, an angle adjustment piston 7 is also included. The angle adjustment piston 7 is arranged in the chamber of the adjustment joint 3 and is connected to the adjustment joint 3 through an upper breathing valve 8. The upper breathing valve 8 connects the interior of the drill bit and the annulus to transmit pressure. A locking spring 9 is provided between the angle adjustment piston 7 and the adjustment joint 3. When the locking spring 9 is axially compressed, the angle adjustment piston 7 moves upward, and its upper spline engages with the spline groove on the outer periphery of the adjustment core shaft 6 to achieve angle locking.

[0061] During drilling, a pressure differential exists between the drill string and the annulus. To lock the angle of the screw drill, the pressure inside the drill string and in the annulus is controlled, causing this pressure differential to act on the angle adjustment piston 7. Specifically, when the pressure inside the drill string rises relative to the annulus pressure, this pressure is transmitted through the upper breather valve 8 to the lower portion of the angle adjustment piston 7, generating an upward axial force on the piston.

[0062] As the upward axial force gradually increases, when this force exceeds the elastic force of locking spring 9, locking spring 9 is axially compressed, and the angle adjustment piston 7 begins to move upward. When the angle adjustment piston 7 moves upward to a certain position, the splines on its upper portion engage with the spline grooves on the outer periphery of the adjustment mandrel 6. The engagement of the splines and spline grooves circumferentially fixes the angle adjustment piston 7 to the adjustment mandrel 6, thereby limiting the rotation of the adjustment joint 3 relative to the adjustment mandrel 6 and locking the angle of the screw drill.

[0063] When the angle of the screw drill needs to be adjusted again, the pressure inside the drill is reduced by changing the pressure difference between the inside of the drill and the annulus. At this point, the locking spring 9 begins to return to its original position under the action of its elastic force, pushing the angle adjustment piston 7 downward, separating the spline on its upper part from the spline groove on the outer periphery of the adjustment mandrel 6. This releases the angle lock state, and the adjustment joint 3 can rotate relative to the adjustment mandrel 6 to make a new angle adjustment.

[0064] The present application realizes angle locking by the spline engagement of the angle adjustment piston 7 and the adjustment core shaft 6, which can effectively prevent the drill tool from accidentally changing its angle due to factors such as vibration and torque change during the drilling process, thereby ensuring the accuracy of the drilling trajectory, improving the drilling quality, and reducing the risk of underground accidents that may be caused by the deviation of the drill tool angle.

[0065] It should be noted that the angle adjustment piston 7 is provided with an axially extending second groove 71. One end of the upper breathing valve 8 is located on the sidewall of the adjustment joint 3, while the other end extends into the second groove 71. Because the other end of the upper breathing valve 8 extends into the second groove 71 of the angle adjustment piston 7, fluid flows through the small hole of the upper breathing valve 8 into the second groove 71. Within the second groove 71, the pressure of the fluid directly acts on the corresponding part of the angle adjustment piston 7, generating an upward or downward axial force on the angle adjustment piston 7, depending on the magnitude and direction of the pressure differential.

[0066] It should be noted that, in some implementations of this embodiment, both the upper breathing valve 8 and the lower breathing valve 47 are provided with small holes, and the diameter of the small holes is smaller than the diameter of the rock cuttings.

[0067] In the above embodiment, the upper breathing valve 8 is responsible for transmitting the increased pressure inside the drill tool to the angle adjustment piston 7 when driving at a large displacement, pushing it to move and achieve angle locking; the lower breathing valve 47 plays a role in the process of small displacement driving angle adjustment and large displacement unlocking. The feature that the small hole diameter is smaller than the rock cuttings diameter ensures that the breathing valve will not be blocked by rock cuttings during the pressure transmission process. If rock cuttings enter the breathing valve, it may block the small hole, resulting in the failure of normal pressure transmission, thereby affecting the movement of the angle adjustment piston 7 and the working state of the friction plate group 43, making it impossible for the drill tool to accurately achieve the angle adjustment and locking functions. For example, when drilling at a large displacement, if the small hole of the upper breathing valve 8 is blocked by rock cuttings, the pressure cannot be transmitted to the angle adjustment piston 7, and the angle locking cannot be achieved. The drill tool angle may change unexpectedly during the drilling process, affecting the drilling quality.

[0068] In some implementations of this embodiment, a universal joint assembly 10 is further included. The universal joint assembly 10 includes a rotor joint, a connecting shaft and a transmission shaft joint connected in sequence. The rotor joint is fixedly connected to the rotor, and the transmission shaft joint is fixedly connected to the drive spindle.

[0069] In the above embodiment, the top drive provides power to the stator, which, through the stator joint, drives the dual male joint 1 to rotate for angle adjustment. The universal joint assembly, on the other hand, transmits the rotor's power to the angle adjustment drive assembly 4, providing power for both normal drilling and stable operation of the drill tool after angle adjustment. During angle adjustment, the power transmitted by the top drive and the universal joint assembly cooperates. The top drive adjusts the angle, while the universal joint assembly ensures the basic power requirements of the drill tool during adjustment. After angle adjustment is complete, the universal joint assembly continues to provide power for stable drilling at the target angle.

[0070] Please refer to Figure 1 In some implementations of this embodiment, the transmission shaft assembly 5 includes a main shaft 51, an upper nut 52, an upper TC bearing 53, a string bearing 54, a lower nut 55 and a lower TC bearing 56. The main shaft 51 is connected to the driving main shaft 41 for transmitting the rotational kinetic energy of the drilling tool.

[0071] In the above embodiment, the transmission shaft assembly 5 is the terminal link of the power transmission of the angle adjustment drive assembly 4. After the driving spindle 41 in the angle adjustment drive assembly 4 obtains power, it transmits the power to the main shaft 51 of the transmission shaft assembly 5. The main shaft 51 rotates under the drive of the driving spindle 41. At the same time, the bearing system in the transmission shaft assembly 5 supports and protects the main shaft 51, ensuring that the main shaft 51 can stably transmit power to the drill bit, so that the drill bit can rotate and drill according to the design requirements. When the drilling tool is adjusted in angle, the power transmission path of the angle adjustment drive assembly 4 may change, but the transmission shaft assembly 5 always ensures the transmission connection between the main shaft 51 and the driving spindle 41, providing protection for the power transmission of the drilling tool in different working modes.

[0072] Please refer to Figure 6 The present application also provides a screw drill tool, including an anti-drop assembly 11 and the above-mentioned automatic angle adjustment structure of the screw drill tool. The anti-drop assembly 11 includes an anti-drop upper joint, an anti-drop nut, an anti-drop retaining ring and an anti-drop shaft. The anti-drop upper joint is connected to the motor assembly 12. The anti-drop shaft is limited by the anti-drop retaining ring and fixed by the anti-drop nut to prevent the lower component from falling when the drill tool breaks.

[0073] In the above-described embodiment, the presence of the anti-drop assembly 11 significantly reduces the risk of the lower assembly falling if the drill string breaks. During drilling, if the drill string breaks, the falling of the lower assembly can cause serious downhole accidents, such as stuck or buried drill bits, which not only delay drilling schedules but also result in significant economic losses. The anti-drop assembly can promptly secure the lower assembly, preventing these accidents and ensuring the safety of downhole workers and the drilling equipment.

[0074] It should be noted that the screw drill of the present application has two assembly methods, one is to assemble the first corner 31 and the second corner 101 into a structure with the same initial direction, and the other is to assemble the first corner 31 and the second corner 101 into a structure with opposite initial directions.

[0075] Having already described the configuration with opposite directions, the following describes the case where the first and second bends 31, 101 are initially aligned. Again, using the example of adjusting joint 3 rotating between 0° and 60°, when the first and second bends 31, 101 are aligned, the resulting angle is maximum at 0°, reaching 2.5° (1° + 1.5°).

[0076] When the rotation angle of the adjustment joint 3 is 60°, the direction of the first bend 31 partially deviates from the second bend 101, and the resultant angle is reduced to ≈2.18°.

[0077] It can be understood that as the rotation angle of the adjustment joint 3 increases (0°→60°), the composite angle gradually decreases from 2.5° to ≈2.18°.

[0078] If the rotation continues (θ>60°), the resulting angle will further decrease until the two bends are completely opposite (θ=180°), at which point the resulting angle is the smallest: |1.5° - 1°| = 0.5°.

[0079] That is, when the orientation remains the same, the resulting angle varies from 2.5° (maximum) to 2.18° (θ = 60°). Rotating the adjustment joint 3 reduces the resulting angle, but does not reduce it to less than 0.5° (unless the rotation exceeds 60°).

[0080] At this time, the angle adjustment drive assembly 4 drives the adjustment joint 3 to rotate so that the combined angle is adjusted from a small angle to a large angle (i.e., 2.18°→2.5°), and the top drive drives the double male joint 1 to rotate so that the combined angle is adjusted from a large angle to a small angle (i.e., 2.5°→2.18°).

[0081] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0082] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0084] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0085] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0086] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0087] Obviously, those skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. Thus, as long as these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

[0088] The above description is a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An automatic angle adjustment structure for a screw drill, characterized in that: include: a motor assembly, including a stator and a rotor; An adjustment joint having a first bend angle; Angle adjustment drive assembly, including: A driving main shaft, the upper end of which is drivingly connected to the rotor, the lower end of which is drivingly connected to the transmission shaft assembly, and the outer peripheral wall of which is provided with an external thread; A drive nut, threadedly engaged with the drive spindle via an internal thread; A drive housing, fixedly connected to the adjustment joint; A friction plate group, consisting of alternately stacked active friction plates and driven friction plates, wherein the active friction plates are circumferentially fixed to the drive nut, and the driven friction plates are circumferentially fixed to the drive housing; a spring seat, sleeved on the outer periphery of the driving main shaft and with its lower end surface in contact with the friction plate group; a drive spring disposed in a first slot extending axially between the spring seat and the drive housing, with both ends abutting against the spring seat and the drive housing respectively; A lower breathing valve is provided in the driving housing, one end of which is connected to the first tank body and the other end is connected to the annulus; When the drive spring is in a naturally pre-tightened state, the friction plate group is combined to transmit torque; when the drive spring is compressed by axial force, the friction plate group is separated to cut off torque transmission.

2. The automatic angle adjustment structure of the screw drill according to claim 1, characterized in that: The active friction plate is connected to the drive nut via a spline, and the driven friction plate is connected to the drive housing via a spline.

3. The automatic angle adjustment structure of the screw drill according to claim 1, characterized in that: It also includes a double male joint and an adjustment core shaft threadedly connected to the double male joint, the double male joint has a second bend angle, the double male joint is connected to the stator through a stator joint, and the adjustment joint is rotatably connected to the adjustment core shaft.

4. The automatic angle adjustment structure of the screw drill according to claim 3, characterized in that: A limit pin is provided on the adjustment joint, a limit slot is provided on the adjustment core shaft, and the limit pin is configured to be able to move in the limit slot.

5. The automatic angle adjustment structure of the screw drill according to claim 3, characterized in that: The stator is in transmission connection with the top drive. When the top drive drives the stator to rotate, the stator drives the double male connectors to rotate synchronously through the stator connector.

6. The automatic angle adjustment structure of the screw drill according to claim 1, characterized in that: It also includes an angle adjustment piston, which is arranged in the chamber of the adjustment joint and is connected to the adjustment joint through an upper breathing valve. The upper breathing valve connects the interior of the drill bit and the annulus to transmit pressure. A locking spring is provided between the angle adjustment piston and the adjustment joint. When the locking spring is axially compressed, the angle adjustment piston moves upward and engages its upper spline with the spline groove on the outer periphery of the adjustment core shaft to achieve angle locking.

7. The automatic angle adjustment structure of the screw drill according to claim 6, characterized in that: The angle adjustment piston is provided with a second groove body extending axially, and one end of the upper breathing valve is provided on the side wall of the adjustment joint, and the other end extends into the second groove body.

8. The automatic angle adjustment structure of the screw drill according to claim 1, characterized in that: It also includes a universal joint assembly, which includes a rotor joint, a connecting shaft and a transmission shaft joint connected in sequence, the rotor joint is fixedly connected to the rotor, and the transmission shaft joint is fixedly connected to the driving main shaft.

9. The automatic angle adjustment structure for screw drill according to claim 1, characterized in that: The transmission shaft assembly includes a main shaft, an upper nut, an upper TC bearing, a string bearing, a lower nut and a lower TC bearing. The main shaft is in transmission connection with the driving main shaft for transmitting the rotational kinetic energy of the drilling tool.

10. A screw drill, characterized in that: It includes an anti-drop assembly and an automatic angle adjustment structure for a screw drill as described in any one of claims 1 to 9, the anti-drop assembly includes an anti-drop upper joint, an anti-drop nut, an anti-drop retaining ring and an anti-drop shaft, the anti-drop upper joint is connected to the motor assembly, the anti-drop shaft is limited by an anti-drop retaining ring and fixed by an anti-drop nut to prevent the lower component from falling when the drill tool breaks.

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