CN112196472A

CN112196472A - Double-drill-bit shaft bottom torque self-balancing reconstruction mechanism

Info

Publication number: CN112196472A
Application number: CN202011269502.6A
Authority: CN
Inventors: 高科; 李旭; 赵研; 李家晟
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2020-11-13
Filing date: 2020-11-13
Publication date: 2021-01-08

Abstract

The invention discloses a double-drill-bit shaft bottom torque self-balancing reconstruction mechanism, which belongs to the technical field of drilling engineering downhole tools and comprises an inner drill bit assembly, a power transmission assembly and a clamping and fixing assembly; by utilizing the characteristic that the inner rotor and the outer rotor rotate reversely when a common torque motor works, the micro motor in the power transmission assembly provides power to pass through a series of transmission parts, so that the core barrel of the inner drill bit assembly extending out of the extending tongue is fixed with the hole wall. When the torque between the extending tongue and the hole wall is larger than the torque between the outer drill bit and the hole wall, the outer drill bit is unlocked to start rotary drilling, the drilling efficiency is improved, and the construction period is shortened.

Description

Double-drill-bit shaft bottom torque self-balancing reconstruction mechanism

Technical Field

The invention relates to the technical field of downhole tools in drilling engineering, in particular to a double-drill-bit shaft bottom torque self-balancing reconstruction mechanism.

Background

In the drilling and boring process, the rotary torque applied to the drill string is large, mainly comes from rotary rock breaking of a drill bit, friction of a well wall or a hole wall, mud resistance in the well and the like, the drill string deforms seriously and becomes spiral under the action of huge counter torque, and the deformation is larger when the well is deeper. Meanwhile, the drill string is easily damaged in advance under the action of the collision friction between the drill string and the well wall during rotation and the abrasion and alternating load, so that well accidents such as drilling tool breakage and the like occur, and huge loss is brought to the whole project. Obviously, the reaction torque generated by the rotation of the drilling tool in the well and the rock breaking damages the whole drill string and ground equipment, and also causes a series of adverse effects of poor well-completion quality, long drilling period, high drilling cost and the like. Therefore, experts in the field at home and abroad try to reduce the disturbance of a drill string on a well wall, some researchers have carried out related research on a torque balance drilling tool system, but the torque balance drilling tool fails to achieve self-balance of torque in a drilling process due to the fact that the bit pressure cannot be adjusted when the torque motor is used for driving the drilling tool. However, the prior art proposes a downhole torque self-balancing cabled drilling tool system, which is described in detail in patent publication No. CN106761480B, and fundamentally solves the bottleneck encountered in previous researches.

However, there is a disadvantage in the current "downhole torque self-balancing cabled drilling tool system", and after the new drill bit is replaced after the set of drilling tool system is tripped out of the well, because the new outer drill bit is within the tolerance range and the outer diameter of the new outer drill bit is larger than that of the replaced old outer drill bit, the drilling tool system may not be smoothly tripped into the well bottom to generate a larger side rotary friction resistance with the well wall, and meanwhile, the inner drill bit cannot reach the well bottom to generate a load, so that the inner and outer drill bits lose the torque balance condition. Therefore, the double-drill-bit shaft bottom torque self-balancing reconstruction mechanism is designed, and plays an important role in perfecting the 'one-kind shaft bottom torque self-balancing cabled drilling tool system'.

Disclosure of Invention

The invention aims to provide a double-drill-bit shaft bottom torque self-balancing reconstruction mechanism which is adapted to a downhole torque self-balancing cabled drilling tool system in the background technology and is mainly used for solving the problems that the friction torque between an outer drill bit and a hole wall is too large, the outer drill bit cannot rotate, the torque of an inner drill bit cannot be offset, and the torque balance of the system is lost.

In order to achieve the purpose, the invention adopts the following technical scheme: a double-bit bottom hole torque self-balancing reconstruction mechanism is characterized by comprising: the inner drill bit assembly, the power transmission assembly and the clamping and fixing assembly;

the inner drill bit assembly comprises an inner drill bit, a core barrel, a core anti-abrasion ring, a core anti-abrasion bearing inner limiting ring, a core anti-abrasion bearing outer limiting ring, a transmission shaft joint and a core anti-abrasion bearing, wherein the central axis of the inner drill bit, the central axis of the core barrel, the central axis of the core anti-abrasion ring, the central axis of the core anti-abrasion bearing inner limiting ring, the central axis of the core anti-abrasion bearing outer limiting ring, the central axis of the transmission shaft joint and the central axis of the core anti-abrasion bearing are positioned on the same straight line; the inner drill bit is positioned below the core barrel, and the drill bit is fixedly connected with the core barrel through a first fixing nut; the side wall of the core barrel is uniformly provided with through holes with the shapes matched with the shapes of the extending tongues along the circumferential direction and used for the extending tongues to extend out or retract into the core barrel, and two circular through holes which are axially arranged along the core barrel are arranged from the top end to the through holes in the side wall of the core barrel and are respectively a first circular through hole of the core barrel and a second circular through hole of the core barrel; the core anti-abrasion bearing inner limiting ring, the core anti-abrasion bearing and the core anti-abrasion bearing outer limiting ring are arranged in the core anti-abrasion ring from bottom to top; the transmission shaft joint is of a hollow structure, a coring barrel extends out of the upper part of the transmission shaft joint, the transmission shaft joint is fixedly connected with the coring barrel through a second fixing nut, and meanwhile, the lower end of the transmission shaft joint is fixedly connected with an inner limiting ring of a core abrasion-proof bearing through an inner limiting ring fixing nut which is radially installed;

the power transmission assembly is integrally positioned above the coring barrel and comprises a reversing guide rod support frame, a rotary driving block, a driving block bearing, a transmission inner gear ring, a micro motor, a transmission pinion, a motor frame and a micro motor bearing, wherein the reversing guide rod support frame is arranged on the radial outermost side of the power transmission assembly, the lower part of the reversing guide rod support frame is fixed in a groove on the upper surface of the coring barrel, the outer wall of the reversing guide rod support frame is provided with at least three arc-shaped grooves used for matching and fixing transmission ribs along the circumferential direction, the arc-shaped grooves and a circular through hole in the side wall of the coring barrel are coaxial and have the same diameter, the inner wall of the reversing guide rod support frame is provided with a positioning blind groove, the positioning blind groove is used for installing a component consisting of a rib clamp and a rib catcher, and the positioning blind groove; a rectangular opening is formed in the reversing guide rod support frame above the positioning blind groove, and circular blind holes are formed in two ends of the rectangular opening and used for placing a reversing guide rod; the rotary driving block is arranged in the reversing guide rod support frame, the rotary driving block is in a hollow cylindrical shape, the inner wall of the rotary driving block is provided with steps which are formed by reducing the diameter from top to bottom, the outer wall of the rotary driving block is provided with rectangular grooves which are obliquely arranged, two ends of each rectangular groove are semicircular, and the rectangular grooves are connected with the rib connectors in a sliding fit manner; the driving block bearing is positioned right below the rotary driving block and is fixed in a groove on the upper surface of the coring barrel; the transmission inner gear ring is fixed on a step on the inner wall of the rotary driving block and is internally meshed with the transmission pinion; the transmission pinion is fixed on an output shaft of the micromotor, the micromotor bearing is arranged on the core taking barrel through a first cylindrical groove formed in the core taking barrel, and the output shaft of the micromotor is placed on the core taking barrel through a second cylindrical groove formed in the core taking barrel; the diameter of the second cylindrical groove is smaller than that of the first cylindrical groove, and the diameter of the second cylindrical groove, the diameter of the output shaft of the micro motor and the inner diameter of the micro motor bearing are the same; the stator part of the micro motor is fixed on the upper surface of an annular motor frame, and the inner ring surface of the motor frame is fixed with the coring barrel;

the clamping and fixing assembly comprises a stretching tongue, a rib connector, a transmission rib, a rib clamp fixing ring, a reversing guide rod and a transmission rib connector, the bottom of the rib connector is a cylinder, the middle part of the rib connector is a rectangular body, two hollow cylinders are arranged at two ends above the rectangular body, openings which are axially communicated are formed in the side walls of the two hollow cylinders, and steps for fixing the rib clamp are arranged on the inner walls of the two hollow cylinders; the number of the rib clamps is two, the two rib clamps are both hollow cylinders, and the two rib clamps are respectively fixed on the rib connector through steps on the inner walls of the two hollow cylinders; the rib clip fixing ring is hollow and cylindrical, the outer side wall of the rib clip fixing ring is provided with a notch which is axially communicated and has a triangular cross section, and the rib clip fixing ring is arranged between the two rib clips; the rib sleeve is sleeved outside the transmission rib and fixed with the transmission rib; the cylindrical part of the tendon catcher is slidably arranged in a rectangular groove which is obliquely arranged on the outer wall of the rotary driving block; the middle of the reversing guide rod is in a circular wheel shape, the outer circumference of the circular wheel shape is provided with a limiting groove for limiting the transmission rib, two sides of the circular wheel shape are respectively connected with a cylinder, the reversing guide rod is arranged in a rectangular opening above the reversing guide rod support frame and is fixed in circular blind holes at two ends of the rectangular opening through the cylinders positioned at two sides of the circular wheel shape; the extended tongue comprises an extended tongue root and an extended tongue tip, and the fixing mode between the extended tongue root and the coring barrel and the fixing mode between the extended tongue root and the extended tongue tip are the same as the fixing mode between the reversing guide rod and the reversing guide rod support frame; the inner wall and the outer wall of the tongue root and the tongue tip are provided with a pore passage for the transmission rib to pass through; the transmission rib is a rope, one end of the transmission rib sequentially passes through a pore channel extending out of the inner wall of the tongue tip, a pore channel extending out of the inner wall of the tongue root, a first circular through hole of the coring barrel, a positioning blind groove on the reversing guide rod support frame, a limiting groove on the reversing guide rod, an arc-shaped groove on the reversing guide rod support frame, a second circular through hole of the coring barrel and a pore channel extending out of the outer wall of the tongue root and finally reaches a pore channel extending out of the outer wall of the tongue tip; the transmission muscle connects for one end is uncovered, the other end confined hollow cylinder structure, and the quantity that the transmission muscle connects is two, and two transmission muscle connect to install respectively at the both ends of transmission muscle to fixed with the transmission muscle, a transmission muscle connects the card simultaneously in lieing in the pore on stretching out the inner wall of tongue point, and stretch out the tongue point and fix together, and another transmission muscle connects the card in lieing in the pore on the outer wall that stretches out the tongue point, and is together fixed with stretching out the tongue point.

Furthermore, the inner wall of the core wear-resisting ring is provided with two step seats formed by reducing diameters from top to bottom, the step seat positioned above is a first step seat, the step seat positioned below is a second step seat, the outer limiting ring of the core wear-resisting bearing is arranged on the first step seat, and the outer limiting ring of the core wear-resisting bearing and the core wear-resisting ring are fixed through an outer limiting ring fixing nut which is radially arranged; the outer wall of the transmission shaft joint is expanded from bottom to top to form a step seat, the bottom of the core abrasion-proof bearing is abutted against the step surface of the second step seat, and the top of the core abrasion-proof bearing is abutted against the step surface of the step seat of the transmission shaft joint.

Furthermore, the included angle between the two side edges of the triangular notch is 30 degrees.

Further, the height of muscle card is less than half of the distance between two hollow cylinders of muscle catcher, and the height of the solid fixed ring of muscle card equals the distance between two muscle cards.

Through the design scheme, the invention can bring the following beneficial effects: the invention provides a double-drill-bit shaft bottom torque self-balancing reconstruction mechanism, which utilizes the characteristic that inner and outer rotors rotate reversely when a common torque motor works, and provides power through a micro motor to enable an extension tongue to extend outwards and be fixed with a hole wall through a series of transmission parts. When the torque between the extending tongue and the hole wall is larger than the torque between the outer drill bit and the hole wall, the outer drill bit is unlocked and starts to drill rotationally. The drilling efficiency is improved, and the construction period is shortened.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limitation and are not intended to limit the invention in any way, and in which:

FIG. 1 is a schematic cross-sectional view of a dual-bit downhole torque self-balancing reconstruction mechanism according to the present invention;

FIG. 2 is an internal schematic view of a reversing guide rod support frame in a double-bit bottom hole torque self-balancing reconstruction mechanism provided by the invention;

FIG. 3 is a front view of a reversing guide rod support frame in a double-drill-bit bottom-hole torque self-balancing reconstruction mechanism provided by the invention;

FIG. 4 is a sectional view taken along line A-A of FIG. 3;

FIG. 5 is a top view of a reversing guide rod support frame in a double-bit bottom-hole torque self-balancing reconstruction mechanism proposed by the present invention;

FIG. 6 is an assembly drawing of a rib catcher, a rib clip and a rib clip fixing ring in the double-bit bottom hole torque self-balancing reconstruction mechanism provided by the invention;

FIG. 7 is a schematic structural diagram of a rotary driving block in a double-bit downhole torque self-balancing reconstruction mechanism according to the present invention;

FIG. 8 is a schematic view of the assembly of the clamping fixture assembly and the rotary driving block in the dual-bit downhole torque self-balancing reconstruction mechanism of the present invention;

FIG. 9 is a cross-sectional view of a core barrel in a dual-bit downhole torque self-balancing reconstruction mechanism in accordance with the present invention;

fig. 10 is a schematic sectional view of the protruding tongue base in the present invention.

The respective symbols in the figure are as follows: 1-inner drill bit, 2-coring barrel, 3-core anti-abrasion ring, 4-core anti-abrasion bearing inner limiting ring, 5-core anti-abrasion bearing outer limiting ring, 6-transmission shaft joint, 7-core anti-abrasion bearing, 8-inner limiting ring fixing nut, 9-second fixing nut, 10-outer limiting ring fixing nut, 11-extending tongue root, 12-extending tongue tip, 13-reversing guide rod supporting frame, 14-rotary driving block, 15-driving block bearing, 16-rib connector, 17-transmission inner gear ring, 18-micro motor, 19-transmission pinion, 20-motor frame, 21-transmission rib, 22-rib clip, 23-rib clip fixing ring, 24-micro motor bearing, 25-first fixing nut, 26-reversing guide rod, 27-a transmission rib connector, 201-a first circular through hole of a core barrel, 202-a second circular through hole of the core barrel and 1401-a rectangular groove.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below with reference to preferred embodiments and the accompanying drawings. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. Well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

As shown in fig. 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, a dual-bit downhole torque-balancing rebuild mechanism includes an inner bit assembly, a power transmission assembly and a clamp fixture assembly.

The inner drill bit assembly comprises an inner drill bit 1, a core barrel 2, a core anti-abrasion ring 3, a core anti-abrasion bearing inner limiting ring 4, a core anti-abrasion bearing outer limiting ring 5, a transmission shaft joint 6 and a core anti-abrasion bearing 7, wherein the central axis of the inner drill bit 1, the central axis of the core barrel 2, the central axis of the core anti-abrasion ring 3, the central axis of the core anti-abrasion bearing inner limiting ring 4, the central axis of the core anti-abrasion bearing outer limiting ring 5, the central axis of the transmission shaft joint 6 and the central axis of the core anti-abrasion bearing 7 are positioned on the same straight line;

the inner drill bit 1 is positioned below the core barrel 2, and the inner drill bit 1 and the core barrel 2 are fixedly connected through a first fixing nut 25 to form an outer main body part of the double-drill-bit shaft bottom torque self-balancing reconstruction mechanism; the core barrel 2 is in a convex shape and is hollow inside, through holes with the shape matched with the shape of the extending tongue are uniformly formed in the side wall of the core barrel 2 along the circumferential direction and are used for enabling the extending tongue to extend out of or retract into the core barrel 2, two circular through holes are formed in the side wall of the core barrel 2 from the top end to the through holes along the axial direction of the core barrel 2, and the circular through holes are respectively a first circular through hole 201 of the core barrel and a second circular through hole 202 of the core barrel and are used for being matched with and installing a transmission rib 21; the core abrasion-proof bearing comprises a core abrasion-proof bearing inner limiting ring 3, a core abrasion-proof bearing outer limiting ring 5, a core abrasion-proof bearing 7, a core abrasion-proof bearing inner limiting ring 4 and a transmission shaft joint 6 which are arranged inside a core barrel 2 from outside to inside in sequence, the top of the core abrasion-proof bearing inner limiting ring 3 is contacted with the inner top wall of the core barrel 2, the core abrasion-proof bearing inner limiting ring 4, the core abrasion-proof bearing 7 and the core abrasion-proof bearing outer limiting ring 5 are arranged inside the core abrasion-proof bearing 3 from bottom to top in sequence, the inner wall of the core abrasion-proof ring 3 is provided with two step seats formed by reducing the diameters from top to bottom, the step seat positioned above is a first step seat, the step seat positioned below is a second step seat, the core abrasion-proof bearing outer limiting ring 5 is arranged on the first step seat, and the core abrasion-proof bearing outer limiting ring 5 and the core abrasion-proof bearing outer limiting ring 3 are fixed through an outer limiting; the core anti-abrasion bearing 7 is arranged on the second step seat; the transmission shaft joint 6 is of a hollow structure, a core barrel 2 extends out of the upper portion of the transmission shaft joint 6, the transmission shaft joint 6 is fixedly connected with the core barrel 2 through a second fixing nut 9, meanwhile, the lower end of the transmission shaft joint 6 is fixedly connected with an inner limiting ring 4 of a core anti-abrasion bearing through an inner limiting ring fixing nut 8 which is radially installed, a step seat is formed on the outer wall of the transmission shaft joint 6 in an expanding mode from bottom to top and used for fixing the core anti-abrasion bearing 7, and therefore the upper portion and the lower portion of the core anti-abrasion bearing 7 are fixed.

The power transmission assembly is integrally positioned above the coring barrel 2 and comprises a reversing guide rod support frame 13, a rotary drive block 14, a drive block bearing 15, a drive ring gear 17, a micro motor 18, a drive pinion 19, a motor frame 20 and a micro motor bearing 24, wherein the reversing guide rod support frame 13 is arranged on the outermost side in the radial direction of the power transmission assembly, the lower part of the reversing guide rod support frame is fixed in a groove on the upper surface of the coring barrel 2, the outer wall of the reversing guide rod support frame 13 is provided with at least three arc-shaped grooves for fixing a drive rib 21 along the circumferential direction, the arc-shaped grooves are coaxial with a circular through hole in the side wall of the coring barrel 2 and have the same diameter, the inner wall of the reversing guide rod support frame 13 is provided with a positioning blind groove, the positioning blind groove is used for installing a component consisting of a rib clamp 22 and a rib connecting handle 16, and; a rectangular opening is formed in the reversing guide rod support frame 13 above the positioning blind groove, and circular blind holes are formed in two ends of the rectangular opening and used for placing the reversing guide rods 26; the rotary driving block 14 is arranged in the reversing guide rod support frame 13, the rotary driving block 14 is in a hollow cylindrical shape, the inner wall of the rotary driving block 14 is provided with steps which are formed by reducing diameters from top to bottom, the outer wall of the rotary driving block 14 is provided with a rectangular groove 1401 which is obliquely arranged, and two ends of the rectangular groove 1401 are in a semicircular shape, so that the rib connector 16 can slide in the rectangular groove; the driving block bearing 15 is positioned right below the rotary driving block 14 and fixed in a groove on the upper surface of the core barrel 2, and the driving block bearing 15 is in contact with the rotary driving block 14 to play a role in reducing friction; the transmission ring gear 17 is fixed on the inner wall step of the rotary driving block 14, and the transmission ring gear 17 is internally meshed with the transmission pinion 19; the transmission pinion 19 is fixed on the output shaft of the micromotor 18, the transmission pinion 19 provides running power by the micromotor 18, two cylindrical grooves with different diameters are formed in the coring barrel 2 right below the transmission pinion 19, the cylindrical groove with the larger diameter is used for installing a micromotor bearing 24, the diameter of the cylindrical groove with the smaller diameter is the same as the diameter of the output shaft of the micromotor 18 and the inner diameter of the micromotor bearing 24 and is used for placing the output shaft of the micromotor 18, therefore, the counter force transmitted to the output shaft of the micromotor 18 when the transmission pinion 19 rotates can be better counteracted, and meanwhile, the friction between the output shaft of the micromotor 18 and the coring barrel 2 is reduced; the stator part of the micromotor 18 is fixed on the upper surface of an annular motor frame 20, and the inner ring surface of the motor frame 20 is fixed with the coring barrel 2;

the clamping and fixing assembly comprises a stretching tongue, a rib connector 16, a transmission rib 21, a rib clamp 22, a rib clamp fixing ring 23, a reversing guide rod 26 and a transmission rib connector 27, the bottom of the rib connector 16 is a cylinder, the middle part of the rib connector is a rectangular body, two hollow cylinders are arranged at two ends above the rectangular body, openings which are communicated along the axial direction are formed in the side walls of the two hollow cylinders, the transmission rib 21 can enter the hollow cylinders from the two through openings, and steps for fixing the rib clamp 22 are arranged on the inner walls of the two hollow cylinders; the number of the rib clips 22 is two, the two rib clips 22 are both hollow cylinders, and the two rib clips 22 are respectively fixed on the rib connector 16 through steps on the inner walls of the two hollow cylinders; the rib clip fixing ring 23 is hollow and cylindrical, the outer side wall of the rib clip fixing ring 23 is provided with a notch which is through along the axial direction and has a triangular cross section, the included angle between the two side edges of the triangular notch is 30 degrees, the rib clip fixing ring 23 is installed between the two rib clips 22, and the transmission rib 21 is brought into the hollow state through the notch on the rib clip fixing ring 23; the height of the rib clip fixing ring 23 is equal to the distance between the two rib clips 22 to ensure the continuous transmission of force, the rib clips 22 are sleeved outside the transmission rib 21 and fixed with the transmission rib 21, so that the transmission rib 21 can move along with the movement of the rib clips 22, the cylindrical part of the rib catcher 16 is slidably installed in a rectangular groove 1401 which is obliquely arranged on the outer wall of the rotary driving block 14, the initial position is the center of the rectangular groove 1401, the rib catcher 16 can slide on the rectangular groove along with the rotation of the rotary driving block 14 driven by the transmission ring gear 17, but the other part of the rib catcher 16 is installed on a positioning blind groove on the inner wall of the reversing guide rod support frame 13, so that the left-right displacement is limited, and only the up-down displacement can be carried out. The rib connector 16 is fixed with the rib clip 22, the rib clip 22 is fixed with the transmission rib 21, and further the transmission rib 21 is driven to move up and down, the middle of the reversing guide rod 26 is in a circular wheel shape, the outer circumference of the circular wheel shape is provided with a limiting groove for limiting the transmission rib 21, two sides of the circular wheel shape are respectively connected with a cylinder, the reversing guide rod 26 is arranged in a rectangular opening above the reversing guide rod support frame 13 and is fixed in circular blind holes at two ends of the rectangular opening through the cylinders positioned at two sides of the circular wheel shape; the extending tongue comprises an extending tongue root 11 and an extending tongue tip 12; the fixing mode between the extended tongue root 11 and the coring barrel 2 and the fixing mode between the extended tongue root 11 and the extended tongue tip 12 are the same as the fixing mode between the reversing guide rod 26 and the reversing guide rod support frame 13; the inner and outer walls of the extended tongue root 11 and the extended tongue tip 12 are provided with pore canals for the transmission rib 21 to pass through, and the diameter of the pore canals is slightly larger than that of the transmission rib 21 and can be used for the transmission rib 21 to pass through. The transmission rib 21 is a rope, one end of the transmission rib 21 sequentially passes through a pore canal extending out of the inner wall of the tongue tip 12, a pore canal extending out of the inner wall of the tongue root 11, a first circular through hole 201 of the coring barrel, a positioning blind groove on the reversing guide rod support frame 13, a limiting groove on the reversing guide rod 26, an arc-shaped groove on the reversing guide rod support frame 13, a second circular through hole 202 of the coring barrel and a pore canal extending out of the outer wall of the tongue root 11 and finally reaches a pore canal extending out of the outer wall of the tongue tip 12; the transmission muscle connects 27 and is one end uncovered, the hollow cylinder structure of other end confined, the quantity that the transmission muscle connects 27 is two, two transmission muscle connect 27 and install respectively at the both ends of transmission muscle 21, and fixed with transmission muscle 21, thereby simultaneously a transmission muscle connects 27 card to be fixed on stretching out tongue point 12 in lieing in the pore on the inner wall that stretches out tongue point 12, thereby another transmission muscle connects 27 card to be fixed on stretching out tongue point 12 in lieing in the pore on the outer wall that stretches out tongue point 12.

The extending tongue can extend outwards and is fixed with the hole wall to provide reaction torque. The core clamping device can also extend inwards to clamp the core, the height of the rib clamp 22 is smaller than half of the distance between the two hollow cylinders of the rib connecting handle 16, half of the distance between the cylinders at the two ends of the rib connecting handle 16, and the height of the rib clamp fixing ring 23 is equal to the distance between the rib clamps 22.

The installation order of the rib clip 22, the rib catcher 16 and the rib clip fixing ring 22 is as follows: firstly, two rib clamps 22 are strung on the transmission rib 21, then the rib catcher 16 is installed, and finally the rib clamp fixing ring 22 is installed.

The working principle and the process of the invention are as follows: the invention utilizes the characteristic that the inner rotor and the outer rotor rotate reversely when the common torque motor works, and the inner drill bit and the outer drill bit are respectively fixed with the stator and the rotor. When the outer drill bit is clamped and stops rotating, the inner torque and the outer torque cannot be offset, the inner drill bit 1 stops rotating by the fact that the extending tongue extends out to be fixedly contacted with the hole wall, when the torque between the inner drill bit 1 and the hole wall is larger than the torque between the outer drill bit and the hole wall, the outer drill bit is unlocked and starts to drill in a rotating mode, the extending tongue is retracted at the moment, and the system drills normally.

When the outer drill bit is contacted with the reducing diameter and is clamped to stop rotating when the outer drill bit is drilled downwards, the ground end controls the transmission shaft joint 6 to be pressurized so that the core barrel 2 and the inner drill bit 1 extend out for a certain distance, when the micro motor 18 starts to work, the output shaft of the micro motor 18 drives the transmission pinion 19 to rotate, the transmission pinion 19 drives the transmission inner gear ring 17 to rotate through inner meshing, because the transmission inner gear ring 17 is fixed with the rotary driving block 14, the rotary driving block 14 is also rotated, and at this time, the tendon catcher 16, which is located at the middle position of the rectangular groove 1401 formed in the outer wall of the rotary driving block 14 at the initial position, is moved obliquely downward under the restriction of the groove, and the tendon 22 in the tendon catcher 16 is in contact with the step seat in the tendon catcher 16 on one side and the tendon fixing ring 23 on the other side, therefore, the rib clip 22 and the rib clip fixing ring 23 move together with the rib connecting hand 16, and drive the transmission rib 21 to generate axial displacement so as to pull the extending tongue to extend outwards to contact with the hole wall and be fixed.

When the core to be obtained is loose and broken, the micro motor 18 can reversely rotate to inwards extend the extending tongue to clamp the core.

Claims

1. A double-bit bottom hole torque self-balancing reconstruction mechanism is characterized by comprising: the inner drill bit assembly, the power transmission assembly and the clamping and fixing assembly;

the inner drill bit assembly comprises an inner drill bit (1), a core barrel (2), a core anti-abrasion ring (3), a core anti-abrasion bearing inner limiting ring (4), a core anti-abrasion bearing outer limiting ring (5), a transmission shaft joint (6) and a core anti-abrasion bearing (7), wherein the central axis of the inner drill bit (1), the central axis of the core barrel (2), the central axis of the core anti-abrasion ring (3), the central axis of the core anti-abrasion bearing inner limiting ring (4), the central axis of the core anti-abrasion bearing outer limiting ring (5), the central axis of the transmission shaft joint (6) and the central axis of the core anti-abrasion bearing (7) are positioned on the same straight line; the inner drill bit (1) is positioned below the core barrel (2), and the drill bit (1) is fixedly connected with the core barrel (2) through a first fixing nut (25); the core barrel (2) is in a convex shape and is hollow inside, through holes with the shape matched with the shape of the extending tongue are uniformly formed in the side wall of the core barrel (2) along the circumferential direction and are used for the extending tongue to extend out or retract into the core barrel (2), two circular through holes are formed in the side wall of the core barrel (2) from the top end to the through holes, and the circular through holes are axially arranged along the core barrel (2) and are respectively a first circular through hole (201) of the core barrel and a second circular through hole (202) of the core barrel; the core anti-abrasion bearing inner limiting ring (4), the core anti-abrasion bearing (7) and the core anti-abrasion bearing outer limiting ring (5) are arranged in the core barrel (2) in sequence from outside to inside, the top of the core anti-abrasion ring (3) is in contact with the inner top wall of the core barrel (2), and the core anti-abrasion bearing inner limiting ring (4), the core anti-abrasion bearing (7) and the core anti-abrasion bearing outer limiting ring (5) are arranged in the core anti-abrasion ring (3) in sequence from bottom to top; the transmission shaft joint (6) is of a hollow structure, the upper part of the transmission shaft joint (6) extends out of the core barrel (2), the transmission shaft joint (6) is fixedly connected with the core barrel (2) through a second fixing nut (9), and the lower end of the transmission shaft joint (6) is fixedly connected with an inner limiting ring (4) of the core anti-abrasion bearing through an inner limiting ring fixing nut (8) which is radially installed;

the power transmission assembly is integrally positioned above the coring barrel (2) and comprises a reversing guide rod support frame (13), a rotary driving block (14), a driving block bearing (15), a transmission inner gear ring (17), a micromotor (18), a transmission pinion (19), a motor frame (20) and a micromotor bearing (24), wherein the reversing guide rod support frame (13) is arranged at the outermost radial side of the power transmission assembly, the lower part of the reversing guide rod support frame is fixed in a groove on the upper surface of the coring barrel (2), the outer wall of the reversing guide rod support frame (13) is provided with at least three arc-shaped grooves for matching and fixing a transmission rib (21) along the circumferential direction, the arc-shaped grooves and a circular through hole in the side wall of the coring barrel (2) are coaxial and have the same diameter, the inner wall of the reversing guide rod support frame (13) is provided with a positioning blind groove, and the positioning blind groove is used for installing a component consisting of a rib clamp (22), the positioning blind groove and the arc-shaped groove are positioned on the same cross section; a rectangular opening is formed in the reversing guide rod support frame (13) above the positioning blind groove, and round blind holes are formed in two ends of the rectangular opening and used for placing a reversing guide rod (26); the rotary driving block (14) is arranged in the reversing guide rod support frame (13), the rotary driving block (14) is hollow and cylindrical, the inner wall of the rotary driving block (14) is provided with steps formed by reducing the diameter from top to bottom, the outer wall of the rotary driving block (14) is provided with a rectangular groove (1401) which is obliquely arranged, two ends of the rectangular groove (1401) are semicircular, and the rectangular groove (1401) is connected with the rib catcher (16) in a sliding fit manner; the driving block bearing (15) is positioned right below the rotary driving block (14) and is fixed in a groove on the upper surface of the core barrel (2); the transmission ring gear (17) is fixed on the step of the inner wall of the rotary driving block (14), and the transmission ring gear (17) is internally meshed with the transmission pinion (19); the transmission pinion (19) is fixed on the output shaft of the micromotor (18), the micromotor bearing (24) is arranged on the core taking barrel (2) through a first cylindrical groove arranged on the core taking barrel (2), and the output shaft of the micromotor (18) is arranged on the core taking barrel (2) through a second cylindrical groove arranged on the core taking barrel (2); the diameter of the second cylindrical groove is smaller than that of the first cylindrical groove, and the diameter of the second cylindrical groove, the diameter of an output shaft of the micro motor (18) and the inner diameter of a micro motor bearing (24) are the same; the stator part of the micromotor (18) is fixed on the upper surface of an annular motor frame (20), and the inner ring surface of the motor frame (20) is fixed with the coring barrel (2);

the clamping and fixing assembly comprises a stretching tongue, a rib catcher (16), a transmission rib (21), a rib clamp (22), a rib clamp fixing ring (23), a reversing guide rod (26) and a transmission rib joint (27), the bottom of the rib catcher (16) is a cylinder, the middle part of the rib catcher is a rectangular body, two hollow cylinders are arranged at two ends above the rectangular body, openings which are communicated along the axial direction are formed in the side walls of the two hollow cylinders, and steps for fixing the rib clamp (22) are arranged on the inner walls of the two hollow cylinders; the number of the rib clamps (22) is two, the two rib clamps (22) are both in a hollow cylindrical shape, and the two rib clamps (22) are respectively fixed on the rib catcher (16) through steps on the inner walls of the two hollow cylindrical bodies; the rib clip fixing ring (23) is in a hollow cylindrical shape, the outer side wall of the rib clip fixing ring (23) is provided with a notch which is axially communicated and has a triangular cross section, and the rib clip fixing ring (23) is arranged between the two rib clips (22); the rib clamp (22) is sleeved outside the transmission rib (21) and fixed with the transmission rib (21); the cylindrical part of the bar catcher (16) is arranged in a rectangular groove (1401) which is obliquely arranged on the outer wall of the rotary driving block (14) in a sliding way; the middle of the reversing guide rod (26) is in the shape of a circular wheel, a limiting groove used for limiting the transmission rib (21) is arranged on the outer circumference of the circular wheel, two sides of the circular wheel are respectively connected with a cylinder, the reversing guide rod (26) is arranged in a rectangular opening above the reversing guide rod support frame (13) and is fixed in circular blind holes at two ends of the rectangular opening through the cylinders positioned on the two sides of the circular wheel; the extending tongue comprises an extending tongue root (11) and an extending tongue tip (12), and the fixing mode between the extending tongue root (11) and the coring barrel (2) and the fixing mode between the extending tongue root (11) and the extending tongue tip (12) are the same as the fixing mode between the reversing guide rod (26) and the reversing guide rod support frame (13); the inner and outer walls of the extended tongue root (11) and the extended tongue tip (12) are provided with pore canals for the transmission rib (21) to pass through; the transmission rib (21) is a rope, one end of the transmission rib (21) sequentially passes through a pore canal extending out of the inner wall of the tongue tip (12), a pore canal extending out of the inner wall of the tongue root (11), a first circular through hole (201) of the coring barrel, a positioning blind groove on the reversing guide rod support frame (13), a limiting groove on the reversing guide rod (26), an arc-shaped groove on the reversing guide rod support frame (13), a second circular through hole (202) of the coring barrel and a passage hole extending out of the outer wall of the tongue root (11) and finally reaches a passage hole extending out of the outer wall of the tongue tip (12); the transmission muscle connects (27) and is uncovered for one end, the hollow cylinder structure of other end confined, the quantity that the transmission muscle connects (27) is two, two transmission muscle connect (27) and install respectively at the both ends of transmission muscle (21), and fixed with transmission muscle (21), a transmission muscle connects (27) card simultaneously in lieing in the pore on the inner wall that stretches out tongue point (12), with stretch out tongue point (12) and fix together, another transmission muscle connects (27) card in lieing in the pore on the outer wall that stretches out tongue point (12), with stretch out tongue point (12) and fix together.

2. The dual-bit downhole torque self-balancing reconstruction mechanism of claim 1, wherein: the inner wall of the core anti-abrasion ring (3) is provided with two step seats formed by reducing diameters from top to bottom, the step seat positioned above is a first step seat, the step seat positioned below is a second step seat, an outer limiting ring (5) of the core anti-abrasion bearing is arranged on the first step seat, and the outer limiting ring (5) of the core anti-abrasion bearing and the core anti-abrasion ring (3) are fixed through an outer limiting ring fixing nut (10) which is radially arranged; the outer wall of the transmission shaft joint (6) expands from bottom to top to form a step seat, the bottom of the core abrasion-proof bearing (7) is abutted against the step surface of the second step seat, and the top of the core abrasion-proof bearing (7) is abutted against the step surface of the step seat of the transmission shaft joint (6).

3. The dual-bit downhole torque self-balancing reconstruction mechanism of claim 1, wherein: the included angle between the two side edges of the triangular notch is 30 degrees.

4. The dual-bit downhole torque self-balancing reconstruction mechanism of claim 1, wherein: the height of the rib clip (22) is smaller than half of the distance between the two hollow cylinders of the rib catcher (16), and the height of the rib clip fixing ring (23) is equal to the distance between the two rib clips (22).