PDC bit with downhole self-renewing capability

Abstract

The present application belongs to the technical field of PDC drill bit, and discloses a PDC drill bit with downhole self-renewing capability, which comprises a drill bit body, a transmission assembly, a rotating wheel provided with renewal teeth, a first driving assembly and a second driving assembly, the drill bit body is provided with a fixed blade, the fixed blade is provided with cutting teeth, and the drill bit body has a central flow passage; the transmission assembly comprises a transmission shaft, the transmission shaft is connected to the drill bit body; the rotating wheel is fixed to the transmission shaft; the first driving assembly and the second driving assembly are alternatively connected to the transmission shaft, the first driving assembly can drive the rotating wheel to rotate by a fixed angle, and the second driving assembly can drive the rotating wheel to continuously rotate, so that the PDC drill bit can select the capability of downhole self-renewing cutting teeth or improve the rock breaking efficiency according to different strata.

Description

Technical Field

[0001] This invention relates to the field of PDC drill bit technology, and more particularly to a PDC drill bit with downhole self-renewal capability. Background Technology

[0002] PDC drill bits are now widely used in drilling and development. However, abnormal failures of PDC drill bits (such as chipped teeth, polycrystalline diamond layer shedding, chipping, and tooth column erosion leading to premature failure) or when encountering hard formations can cause accelerated wear on the cutting teeth at the nose, shoulder, and outer third of the drill bit's radius. This significantly shortens the drill bit's lifespan and increases the number of tripping operations. In deep and ultra-deep wells, frequent tripping operations consume a significant amount of time and increase drilling costs.

[0003] Most existing long-life PDC drill bits are made by adding multiple rows of teeth (such as inlaid teeth) to the conventional PDC drill bit cutting teeth. Only after the first row of cutting teeth has worn down to its bare minimum does the second row emerge to participate in rock cutting. Clearly, once the first row of cutting teeth has reached zero exposure, regardless of whether new teeth emerge, the cutter blade body will always participate in cutting along with the PDC teeth. This significantly reduces the cutting tooth specific pressure in local areas of the drill bit, weakening its rock-cutting ability. While existing methods for extending PDC drill bit life make the drill bit more durable to some extent, they also severely impact its drilling efficiency. Furthermore, existing PDC drill bits cannot be configured to perform specific functions based on the formation. Summary of the Invention

[0004] The purpose of this invention is to provide a PDC drill bit with downhole self-renewal capability, which allows the PDC drill bit to select the ability of downhole self-renewing cutting teeth or improve rock breaking efficiency according to different formations.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A PDC drill bit with downhole self-renewal capability includes a drill bit body, on which fixed cutter wings are provided, and on which cutting teeth are provided, the drill bit body has a central flow channel, and the PDC drill bit with downhole self-renewal capability further includes:

[0007] A transmission assembly, the transmission assembly including a transmission shaft, the transmission shaft being rotatably connected to the drill bit body;

[0008] A rotating wheel, fixed on the transmission shaft, is provided with renewal teeth;

[0009] A first drive assembly and a second drive assembly are selectively connected to the transmission shaft. The first drive assembly can drive the rotating wheel to rotate at a fixed angle, and the second drive assembly can drive the rotating wheel to rotate continuously.

[0010] In one embodiment, the transmission assembly further includes an axial bevel gear and a radial bevel gear, the radial bevel gear being disposed on the transmission shaft, the axial bevel gear rotating on the inner wall of the central flow channel, and the axial bevel gear and the radial bevel gear meshing with each other; the first drive assembly and the second drive assembly are selectively connected to the radial bevel gear.

[0011] In one embodiment, the transmission shaft includes a first shaft and a second shaft, the first shaft passes through the second shaft, the first shaft rotates relative to the second shaft, and both the first shaft and the second shaft are respectively provided with a rotating wheel and the radial bevel gear, and the two radial bevel gears mesh with the axial bevel gear.

[0012] In one embodiment, the drive shaft is rotatably connected to the two fixed blades.

[0013] In one embodiment, the first drive assembly includes a ratchet cylinder, which is connected to the axial bevel gear via a spline and spline groove arranged along the axial direction of the drill bit body. The outer wall of the ratchet cylinder is provided with a circumferential ratchet groove, and the upper and lower walls of the ratchet groove are provided with a plurality of guide inclined surfaces spaced apart along the circumference of the ratchet cylinder. A limiting step is formed between adjacent guide inclined surfaces. A pin is provided on the inner wall of the central flow channel, and the pin moves within the ratchet groove. A first elastic element is also connected between the ratchet cylinder and the axial bevel gear or between the ratchet cylinder and the drill bit body to keep the ratchet cylinder tending to move away from the axial bevel gear.

[0014] In one embodiment, the axial bevel gear is a double-sided bevel gear, and the first drive assembly includes a worm wheel, a first worm, and a receiving block. The worm wheel is rotatably connected to the inner wall of the central flow channel, and the first worm is rotatably connected to the drill bit body along the axial direction of the drill bit body. The worm wheel meshes with the first worm and the axial bevel gear respectively. The inner wall of the central flow channel is provided with a sliding groove extending along the axial direction of the drill bit body, and part of the receiving block slides in the sliding groove. The receiving block is screwed to the first worm.

[0015] In one embodiment, the first drive assembly includes a second worm gear and a sliding sleeve. One end of the second worm gear is connected to the axial bevel gear, and the sliding sleeve is screwed to the end of the second worm gear away from the axial bevel gear. The sidewall of the sliding sleeve is provided with a plurality of slots spaced apart along the axial direction of the sliding sleeve. The inner wall of the central flow channel is provided with a second elastic element, and the second elastic element is connected to a block. When the sliding sleeve moves toward the axial bevel gear, the block can be inserted into or removed from the slot. When the block is inserted into the slot, the block can restrict the sliding sleeve from moving away from the axial bevel gear.

[0016] In one embodiment, the PDC drill bit with downhole self-renewal capability includes a connector, which is connected to the end of the drill bit body away from the cutting teeth via a third elastic element; the first drive assembly includes a locking cylinder fixed in the central flow channel, a sliding cylinder disposed inside the locking cylinder, the sliding cylinder being connected to the connector, a rotating cylinder connected to the axial bevel gear, the rotating cylinder being located between the locking cylinder and the axial bevel gear, a fifth elastic element connecting the rotating cylinder and the drill bit body to keep the rotating cylinder tending to approach the locking cylinder, the end faces of the rotating cylinder and the locking cylinder facing each other having mating rotating top teeth, the end face of the sliding cylinder facing the rotating cylinder having abutting teeth, the wall thickness of the rotating cylinder being greater than the wall thickness of the locking cylinder, and the abutting teeth being able to abut against the rotating top teeth to rotate the rotating cylinder.

[0017] In one embodiment, the second drive assembly includes a rotating shaft connected to the axial bevel gear, the rotating shaft having a passageway communicating with the axial bevel gear, and blades being provided on the outer wall of the rotating shaft.

[0018] In one embodiment, the PDC drill bit with downhole self-renewal capability includes a connector, the inner diameter of which is smaller than the inner diameter of the central flow channel. The second drive assembly further includes a ball-dropping sleeve, which is slidably connected to the end of the rotating shaft away from the axial bevel gear. A sixth elastic element is connected between the ball-dropping sleeve and the rotating shaft. The sixth elastic element keeps the ball-dropping sleeve inclined to extend into the connector. The ball-dropping sleeve can extend into the connector to cooperate with the connector to seal the gap between the ball-dropping sleeve and the connector.

[0019] In one embodiment, the second drive assembly includes a housing fixed to the inner wall of the central flow channel, and a hydraulic motor is disposed inside the housing. The hydraulic motor is connected to the axial bevel gear via a connecting rod.

[0020] The beneficial effects of this invention are:

[0021] If the formation causes minimal wear on the cutting teeth, the first drive assembly can rotate the rotating wheel at a fixed angle. This allows the replacement teeth on some of the rotating wheels to be replaced when they wear out, giving them self-renewal capabilities and increasing their overall service life. Alternatively, if the cutting teeth have poor cutting ability against the formation, a second drive assembly can be used to ensure continuous rotation of the rotating wheel, allowing all replacement teeth to participate in the cutting process and improving rock-breaking efficiency. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the PDC drill bit with downhole self-renewal capability of the present invention;

[0023] Figure 2 This is a top view of the PDC drill bit with downhole self-renewal capability of the present invention;

[0024] Figure 3 This is a cross-sectional view of the first driving component in Embodiment 1 of the present invention;

[0025] Figure 4 This is a schematic diagram of the ratchet tube in Embodiment 1 of the present invention;

[0026] Figure 5 This is a cross-sectional view of the first driving component in Embodiment 2 of the present invention;

[0027] Figure 6 This is a cross-sectional view of the first driving component in Embodiment 3 of the present invention;

[0028] Figure 7 This is a cross-sectional view of the first driving component in Embodiment 4 of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure of the first driving component in Embodiment 4 of the present invention;

[0030] Figure 9 This is a cross-sectional view of the second driving component in Embodiment 1 of the present invention;

[0031] Figure 10 This is a cross-sectional view of the second driving component in Embodiment 5 of the present invention.

[0032] In the picture:

[0033] 1. Drill bit body; 11. Central flow channel;

[0034] 2. Fix the blade wings;

[0035] 3. Cutting teeth;

[0036] 4. Transmission assembly; 41. Drive shaft; 411. First shaft; 412. Second shaft; 42. Axial bevel gear; 43. Radial bevel gear;

[0037] 5. Rotating wheel;

[0038] 6. Replace teeth;

[0039] 701. Ratchet tube; 702. Ratchet; 703. Guide ramp; 704. Limiting step; 705. First elastic element; 706. Pin;

[0040] 711. Worm gear; 712. First worm; 713. Receiving block; 714. Sliding groove;

[0041] 721. Second worm gear; 722. Supporting elastic element; 723. Sliding sleeve; 724. Groove; 725. Second elastic element; 726. Insert block;

[0042] 731. Third elastic element; 732. Locking cylinder; 733. Sliding cylinder; 734. Rotating cylinder; 735. Fourth elastic element; 736. Fifth elastic element; 737. Rotating top tooth; 738. Abutting tooth;

[0043] 741. Rotating shaft; 742. Through-flow channel; 743. Blade; 744. Throwing sleeve; 745. Sixth elastic element; 746. Throwing;

[0044] 751. Housing; 752. Hydraulic motor; 753. Connecting rod; 754. Bypass valve;

[0045] 8. Connector. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0047] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0050] Example 1:

[0051] like Figures 1 to 10 As shown, this application provides a PDC drill bit with downhole self-renewal capability, which includes a drill bit body 1, a transmission assembly 4, a rotating wheel 5, a first drive assembly, and a second drive assembly. The drill bit body 1 is provided with a fixed cutter wing 2, and the fixed cutter wing 2 is provided with cutting teeth 3. The drill bit body 1 has a central flow channel 11. The transmission assembly 4 includes a transmission shaft 41, which is rotatably connected to the drill bit body 1. The rotating wheel 5 is fixed to the transmission shaft 41 and is provided with renewal teeth 6. The first drive assembly and the second drive assembly are selectively connected to the transmission shaft 41. The first drive assembly can drive the rotating wheel 5 to rotate at a fixed angle, and the second drive assembly can drive the rotating wheel 5 to rotate continuously.

[0052] If the formation causes minimal wear on the cutting teeth, the first drive assembly can rotate the rotating wheel 5 to a fixed angle. This allows the replacement teeth 6 on some of the rotating wheels 5 to be replaced when they wear out, giving them self-renewal capabilities and increasing their overall service life. Alternatively, if the cutting teeth 3 have poor cutting ability against the formation, the second drive assembly can be used to continuously rotate the rotating wheel 5, allowing all the replacement teeth 6 to participate in the cutting process and improving rock breaking efficiency.

[0053] Furthermore, the transmission assembly 4 also includes an axial bevel gear 42 and a radial bevel gear 43. The radial bevel gear 43 is disposed on the transmission shaft 41, and the axial bevel gear 42 rotates on the inner wall of the central flow channel 11. The axial bevel gear 42 and the radial bevel gear 43 mesh with each other.

[0054] For example, the axial bevel gear 42 is rotatably connected to the inner wall of the central flow channel 11 via a bearing housing, thereby enabling it to rotate relative to the drill bit body 1.

[0055] It should be noted that the drill bit body 1 is also provided with a nozzle that connects to the central flow channel 11. This is a conventional structure of PDC drill bits in the prior art, and will not be described in detail here.

[0056] like Figure 3 As shown, the transmission shaft 41 includes a first shaft 411 and a second shaft 412, wherein the second shaft 412 has a through cavity, and the first shaft 411 passes through the second shaft 412. The first shaft 411 can rotate relative to the second shaft 412. The first shaft 411 and the second shaft 412 are respectively provided with rotating wheels 5 and radial bevel gears 43. The two radial bevel gears 43 connected to the first shaft 411 and the second shaft 412 are respectively meshed with the axial bevel gear 42, while the two rotating wheels 5 are in close contact with each other. When the axial bevel gear 42 rotates, it can make the two radial bevel gears 43 rotate in opposite directions, thereby making the two rotating wheels 5 rotate in opposite directions. During cutting, cross scraping can be achieved, forming an uneven track at the bottom of the well, reducing the rock breaking strength and improving the rock breaking efficiency of the drill bit.

[0057] To improve the load-bearing capacity of the first shaft 411 and the second shaft 412, thereby reducing their diameters, in this embodiment, the drive shaft 41 connects to two fixed blade wings 2. The first shaft 411 rotates independently on one of the fixed blade wings 2, and the second shaft 412 rotates independently on the other fixed blade wing 2. Alternatively, both the first shaft 411 and the second shaft 412 can be connected to both fixed blade wings 2. It is understood that a bearing for supporting the first shaft 411 can also be provided within the second shaft 412.

[0058] like Figure 3 and Figure 4As shown, in the current embodiment, the first drive assembly includes a ratchet cylinder 701. The outer surface of the ratchet cylinder 701 and the inner wall of the axial bevel gear 42 are provided with mating splines and spline grooves, allowing them to connect. The splines and spline grooves extend axially along the drill bit body 1. The splines prevent relative rotation between the ratchet cylinder 701 and the axial bevel gear 42. Furthermore, the outer wall of the ratchet cylinder 701 is provided with circumferential ratches 702. The upper and lower walls of the ratchet grooves 702 are each provided with multiple grooves extending circumferentially from the ratchet cylinder 701. The guide slope 703 is provided at intervals. One end of the guide slope 703 gradually extends from the direction close to the axial bevel gear 42 to the direction away from the axial bevel gear 42. A limiting step 704 is formed between adjacent guide slopes 703. The inner wall of the central flow channel 11 is provided with a fixed pin 706. The pin 706 moves in the ratchet groove 702. A first elastic element 705 is also connected between the ratchet cylinder 701 and the axial bevel gear 42 or between the ratchet cylinder 701 and the drill body 1, so that the ratchet cylinder 701 tends to move away from the axial bevel gear 42.

[0059] Therefore, when the rotating wheel 5 needs to rotate to update the updating teeth 6, the drilling fluid pressure can be increased. The drilling fluid acts on the ratchet tube 701, pushing the ratchet tube 701 closer to the axial bevel gear 42, thereby causing the pin 706 to abut against the guide slope 703 of the lower groove wall of the ratchet 702, further increasing the drilling fluid pressure. Since the pin 706 is fixedly set, the ratchet tube 701 will rotate until the pin 706 abuts against the limiting step 704 located on the lower groove wall. During this process, the axial bevel gear 42 will rotate to update the updating teeth 6. After the update is completed, the drilling fluid pressure can be reduced, and the ratchet tube 701 will return to its original position through the first elastic element 705. At this time, the pin 706 is located at the limiting step 704 on the upper groove wall of the ratchet 702, completing the rotation of the rotating wheel 5 at a fixed angle to update the updating teeth 6. In the current embodiment, the first elastic element 705 is a spring. Furthermore, a pressure-bearing surface is provided at the end of the ratchet tube 701 away from the axial bevel gear 42 to receive the drilling fluid.

[0060] like Figure 3As shown, the PDC drill bit with downhole self-renewal capability further includes a connector 8, the inner diameter of which is smaller than the inner diameter of the central flow channel 11. The first drive assembly also includes a ball-dropping sleeve 744, which is connected to the end of the ratchet tube 701 away from the axial bevel gear 42. The ball-dropping sleeve 744 can extend into the connector 8 and cooperate with the connector 8 to seal the gap between the ball-dropping sleeve 744 and the connector 8. Thus, before the ball 746 is dropped, the drilling fluid can pass through the ball-dropping sleeve 744 and the ratchet tube 701 without causing the rotating wheel 5 to rotate. When rotation is required, the ball 746 (which can dissolve in the drilling fluid for a certain period of time) can be dropped into the ball-dropping sleeve 744. This does not increase the injection pressure of the drilling fluid. The ball 746 is used to pressurize the fluid, thereby causing the ratchet tube 701 to move. After the renewal is completed, it is only necessary to wait for the ball 746 to dissolve, thus completing one renewal.

[0061] like Figure 9 As shown, the second drive assembly includes a rotating shaft 741, which can be connected to an axial bevel gear 42. The rotating shaft 741 is provided with a flow channel 742 communicating with the axial bevel gear 42. The outer wall of the rotating shaft 741 is provided with blades 743, so that when the drilling fluid passes through the blades 743, it can drive the blades 743 to rotate, thereby driving the axial bevel gear 42 and the rotating wheel 5 to rotate continuously. Thus, when this second drive assembly is used, all the replacement teeth 6 can participate in the cutting process, improving the rock breaking efficiency.

[0062] Furthermore, to control the timing of rotation, the PDC drill bit with downhole self-renewal capability includes a connector 8, the inner diameter of which is smaller than the inner diameter of the central flow channel 11. The second drive assembly also includes a ball-feeding sleeve 744, which is slidably connected to the end of the rotating shaft 741 away from the axial bevel gear 42. A sixth elastic element 745 is connected between the ball-feeding sleeve 744 and the rotating shaft 741. The sixth elastic element 745 keeps the ball-feeding sleeve 744 inclined to extend into the connector 8, allowing it to extend into the connector 8 to cooperate with the connector 8 in sealing the ball-feeding sleeve. The gap between the ball-feeding sleeve 744 and the connector 8 is sealed in the initial state. Drilling fluid can only flow from the inside of the ball-feeding sleeve 744, preventing the blades 743 on the outside of the rotating shaft 741 from being triggered, and thus preventing the rotating wheel 5 from rotating. When the rotating wheel 5 needs to rotate, the ball 746 is thrown to the ball-feeding sleeve 744, disengaging from the connector 8. This allows drilling fluid to flow from the outside of the ball-feeding sleeve 744, driving the blades 743, thereby causing the rotating wheel 5 to rotate continuously and improving rock-breaking efficiency. It is understood that the blades 743 can be either impeller blades or turbine blades. For example, the sixth elastic element 745 is a spring.

[0063] Example 2:

[0064] Unlike Example 1, as Figure 5 As shown, the axial bevel gear 42 is a double-sided bevel gear, meaning that both ends of the axial bevel gear 42 can mesh with other components. Based on this, the first drive assembly may include a worm gear 711, a first worm 712, and a receiving block 713 that can mesh with the axial bevel gear 42. The worm gear 711 is rotatably mounted on the inner wall of the central flow channel 11 and meshes with the axial bevel gear 42. At the same time, the first worm 712 is rotatably connected to the drill bit body 1 along the axial direction of the drill bit body 1 and meshes with the worm gear 711. Thus, the rotation of the first worm 712 drives the worm gear 711. The rotation of the worm gear 712, in turn, drives the axial bevel gear 42 to rotate. To achieve rotation of the first worm gear 712, a thread is provided on the first worm gear 712, and a threaded hole is provided on the receiving block 713 to allow for screwing. Furthermore, the inner wall of the central flow channel 11 is provided with a sliding groove 714 extending axially along the drill bit body 1. Part of the receiving block 713 slides within the sliding groove 714, so that when the drilling fluid pressure increases, the drilling fluid can push against the receiving block 713 and slide along the interactive groove, subsequently driving the first worm gear 712, worm wheel 711, axial bevel gear 42, and rotating wheel 5 to rotate at a certain angle, updating the teeth 6. It can be understood that when the drilling fluid pressure is lost, the first worm gear 712, worm wheel 711, and axial bevel gear 42 can achieve self-locking through their own meshing.

[0065] Example 3:

[0066] Unlike Example 1, as Figure 6 As shown, the first drive assembly includes a second worm gear 721 and a sliding sleeve 723. One end of the second worm gear 721 is connected to the axial bevel gear 42, and the sliding sleeve 723 is screwed to the end of the second worm gear 721 away from the axial bevel gear 42. The end face of the sliding sleeve 723 away from the second worm gear 721 is provided with a pressure-bearing surface to bear the drilling fluid pressure. When the drilling fluid pressure increases, it can push the sliding sleeve 723 to move, which in turn drives the second worm gear 721 to rotate, thereby driving the axial bevel gear 42 to rotate and the rotating wheel 5 to rotate a certain angle, thus updating the teeth 6.

[0067] After the update is completed, a locking operation is required. To achieve this, in the current embodiment, the sidewall of the sliding sleeve 723 is provided with a plurality of slots 724 spaced apart along the axial direction of the sliding sleeve 723. A second elastic element 725 is provided on the inner wall of the central flow channel 11. The second elastic element 725 is connected to a block 726. Thus, when the sliding sleeve 723 moves toward the axial bevel gear 42, the block 726 can be inserted into or removed from the slot 724. When the block 726 is inserted into the slot 724, the block 726 can restrict the sliding sleeve 723 from moving away from the axial bevel gear 42. Based on this, exemplarily, the side of the block 726 facing away from the axial bevel gear 42 is provided with an inclined surface, and the slot 724 has an inclined surface that cooperates with the inclined surface. Thus, when the sliding sleeve 723 moves toward the axial bevel gear 42, the block 726 can be easily removed from the slot 724 through the cooperation of the inclined surface.

[0068] In the current embodiment, the inner wall of the central flow channel 11 is provided with a placement groove, the second elastic member 725 is connected to the placement groove, and the insert 726 is placed in the placement groove to facilitate the movement of the sliding sleeve 723 toward the axial bevel gear 42. Exemplarily, the second elastic member 725 is a spring. Furthermore, a resisting elastic member 722 is also provided between the sliding sleeve 723 and the drill bit body 1, so that when the insert 726 enters the groove 724, the resisting elastic member 722 keeps the sliding sleeve 723 away from the axial bevel gear 42, thereby enabling the sliding sleeve 723 to continuously resist the insert 726 located in the groove 724, forming a resisting limit lock and maintaining a stable lock.

[0069] Example 4:

[0070] Unlike Example 1, as Figure 7 and Figure 8As shown, the PDC drill bit with downhole self-renewal capability includes a connector 8. The connector 8 is connected to the end of the drill bit body 1 away from the cutting teeth 3 via a third elastic element 731. The connector 8 is used to connect drill pipe and other drilling tools, thereby enabling the connector 8 to have a certain displacement relative to the drill bit body 1 via the third elastic element 731. Based on this, the first drive assembly includes a locking cylinder 732 fixed in the central flow channel 11. The locking cylinder 732 extends axially along the drill bit body 1. A sliding cylinder 733 slides inside the locking cylinder 732. The sliding cylinder 733 and the locking cylinder 732 are provided with mutually cooperating splines and spline grooves, thereby preventing the sliding cylinder 733 and the locking cylinder 732 from rotating relative to each other. The sliding cylinder 733 is connected to the connector 8, so that when pressure is applied to the drilling tools (increasing the drilling pressure), the sliding cylinder 733 can be moved along the locking cylinder 732 via the connector 8. In the current embodiment, the sliding cylinder 733 and the connector 8 are connected via a fourth elastic element 735. The axial bevel gear 42 is connected to a rotating cylinder 734, which is located between the locking cylinder 732 and the axial bevel gear 42. A fifth elastic element 736 is also provided between the locking cylinder 732 and the drill body 1. The fifth elastic element 736 can keep the rotating cylinder 734 close to the locking cylinder 732. The end faces of the rotating cylinder 734 and the locking cylinder 732 facing each other are provided with matching rotating teeth 737, which are arranged circumferentially along the end faces. The wall thickness of the rotating cylinder 734 is greater than the wall thickness of the locking cylinder 732, so that the rotating cylinder 734 can move radially towards the interior of the locking cylinder 732. The sliding cylinder 733 has a protruding end face facing the rotating cylinder 734 with abutting teeth 738. When the sliding cylinder 733 moves toward the rotating cylinder 734, the abutting teeth 738 can abut against the rotating top teeth 737 of the rotating cylinder 734 that protrude from the locking cylinder 732, causing the rotating cylinder 734 to move toward the axial bevel gear 42. During the movement, it can squeeze the fifth elastic element 736. In the process of the abutting teeth 738 abutting against the rotating top teeth 737, the rotating cylinder 734 can rotate at a certain angle, thereby driving the axial bevel gear 42 and the rotating wheel 5 to rotate at a certain angle to update the replacement teeth 6. When the drilling pressure is lost, the third elastic element 731 drives the connector 8 to return to its original position, during which the sliding cylinder 733 returns to its original position, causing the sliding cylinder 733 to disengage from the rotating cylinder 734. The rotating cylinder 734 is driven back to its original position by the restoring force of the fifth elastic element 736. During this period, the rotating cylinder 734 and the rotating top teeth 737 of the locking cylinder 732 re-engage, preparing for the next replacement of the teeth 6.

[0071] Example 5:

[0072] like Figure 10As shown, the second drive assembly includes a housing 751, which is fixed to the inner wall of the central flow channel 11. A hydraulic motor 752 is housed within the housing 751. The hydraulic motor 752 is existing technology, and its specific structure will not be described in detail. The hydraulic motor 752 is connected to the axial bevel gear 42 via a connecting rod 753, which includes, but is not limited to, components such as a universal joint. This allows the rotating wheel 5 to rotate continuously via the hydraulic motor 752, improving rock-breaking efficiency. Furthermore, a bypass valve 754 is connected to the end of the housing 751 furthest from the axial bevel gear 42. This bypass valve 754 controls the flow rate of the drilling fluid, thereby controlling the rotational speed of the hydraulic motor 752. The bypass valve 754 is also existing technology, and its specific structure will not be described in detail.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A PDC drill bit with downhole self-renewal capability, comprising a drill bit body (1), wherein the drill bit body (1) is provided with fixed cutter wings (2), the fixed cutter wings (2) are provided with cutting teeth (3), and the drill bit body (1) has a central flow channel (11); characterized in that, The PDC drill bit with downhole self-renewal capability also includes: The transmission assembly (4) includes a transmission shaft (41) which is rotatably connected to the drill bit body (1); A rotating wheel (5) is fixed on the transmission shaft (41), and the rotating wheel (5) is provided with a renewal tooth (6); A first drive assembly and a second drive assembly are selectively connected to the transmission shaft (41). The first drive assembly can drive the rotating wheel (5) to rotate at a fixed angle, and the second drive assembly can drive the rotating wheel (5) to rotate continuously.

2. The PDC drill bit with downhole self-renewal capability according to claim 1, characterized in that, The transmission assembly (4) further includes an axial bevel gear (42) and a radial bevel gear (43). The radial bevel gear (43) is disposed on the transmission shaft (41). The axial bevel gear (42) rotates on the inner wall of the central flow channel (11). The axial bevel gear (42) and the radial bevel gear (43) mesh with each other. The first drive assembly and the second drive assembly are selectively connected to the radial bevel gear (43).

3. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The transmission shaft (41) includes a first shaft (411) and a second shaft (412). The first shaft (411) passes through the second shaft (412). The first shaft (411) rotates relative to the second shaft (412). The first shaft (411) and the second shaft (412) are each provided with a rotating wheel (5) and the radial bevel gear (43). The two radial bevel gears (43) mesh with the axial bevel gear (42).

4. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The first drive assembly includes a ratchet cylinder (701), which is connected to the axial bevel gear (42) via a spline and spline groove arranged axially along the drill bit body (1). The outer wall of the ratchet cylinder (701) is provided with a circumferential ratchet groove (702). The upper and lower walls of the ratchet groove (702) are provided with a plurality of guide inclined surfaces (703) spaced apart circumferentially along the ratchet cylinder (701). Adjacent guide inclined surfaces (703) A limiting step (704) is formed between the two sides. A pin (706) is provided on the inner wall of the central flow channel (11). The pin (706) moves in the ratchet groove (702). A first elastic element (705) is also connected between the ratchet cylinder (701) and the axial bevel gear (42) or between the ratchet cylinder (701) and the drill bit body (1) so that the ratchet cylinder (701) tends to stay away from the axial bevel gear (42).

5. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The axial bevel gear (42) is a double-sided bevel gear. The first drive assembly includes a worm gear (711), a first worm (712), and a receiving block (713). The worm gear (711) is rotatably connected to the inner wall of the central flow channel (11). The first worm (712) is rotatably connected to the drill bit body (1) along the axial direction. The worm gear (711) is meshed with the first worm (712) and the axial bevel gear (42) respectively. The inner wall of the central flow channel (11) is provided with a sliding groove (714) extending along the axial direction of the drill bit body (1). Part of the receiving block (713) is slidably connected to the sliding groove (714). The receiving block (713) is screwed to the first worm (712).

6. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The first drive assembly includes a second worm gear (721) and a sliding sleeve (723). One end of the second worm gear (721) is connected to the axial bevel gear (42). The sliding sleeve (723) is screwed to the end of the second worm gear (721) away from the axial bevel gear (42). The side wall of the sliding sleeve (723) is provided with a plurality of slots (724) spaced apart along the axial direction of the sliding sleeve (723). The inner wall of the central flow channel (11) is provided with a second elastic element (725). The second elastic element (725) is connected to a block (726). When the sliding sleeve (723) moves toward the axial bevel gear (42), the block (726) can be inserted into or removed from the slot (724). When the block (726) is inserted into the slot (724), the block (726) can restrict the sliding sleeve (723) from moving away from the axial bevel gear (42).

7. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The PDC drill bit with downhole self-renewal capability includes a connector (8), which is connected to the end of the drill bit body (1) away from the cutting teeth (3) via a third elastic element (731); the first drive assembly includes a locking cylinder (732) fixed in the central flow channel (11), a sliding cylinder (733) is provided inside the locking cylinder (732), the sliding cylinder (733) is connected to the connector (8), the axial bevel gear (42) is connected to a rotating cylinder (734), the rotating cylinder (734) is located between the locking cylinder (732) and the axial bevel gear (42), and the rotating cylinder (734) is connected to the rotating cylinder (734). A fifth elastic element (736) is connected between the rotating cylinder (734) and the drill bit body (1) to keep the rotating cylinder (734) close to the locking cylinder (732). The end faces of the rotating cylinder (734) and the locking cylinder (732) facing each other have matching rotating teeth (737). The end face of the sliding cylinder (733) facing the rotating cylinder (734) is provided with abutting teeth (738). The wall thickness of the rotating cylinder (734) is greater than the wall thickness of the locking cylinder (732). The abutting teeth (738) can abut against the rotating teeth (737) to make the rotating cylinder (734) rotate.

8. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The second drive assembly includes a rotating shaft (741) connected to the axial bevel gear (42), the rotating shaft (741) being provided with a passage channel (742) communicating with the axial bevel gear (42), and blades (743) being provided on the outer wall of the rotating shaft (741).

9. The PDC drill bit with downhole self-renewal capability according to claim 8, characterized in that, The PDC drill bit with downhole self-renewal capability includes a connector (8), the inner diameter of which is smaller than the inner diameter of the central flow channel (11). The second drive assembly also includes a ball-dropping sleeve (744), which is slidably connected to one end of the rotating shaft (741) away from the axial bevel gear (42). A sixth elastic element (745) is connected between the ball-dropping sleeve (744) and the rotating shaft (741). The sixth elastic element (745) keeps the ball-dropping sleeve (744) inclined to extend into the connector (8). The ball-dropping sleeve (744) can extend into the connector (8) to cooperate with the connector (8) to seal the gap between the ball-dropping sleeve (744) and the connector (8).

10. The PDC drill bit with downhole self-renewal capability according to claim 2, characterized in that, The second drive assembly includes a housing (751) fixed to the inner wall of the central flow channel (11), and a hydraulic motor (752) is disposed inside the housing (751). The hydraulic motor (752) is connected to the axial bevel gear (42) through a connecting rod (753).

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