Oval drilling device based on gear transmission control and design method of drill bit

Abstract

The invention relates to a drilling technology, in particular to an oval drilling device based on gear transmission control and a design method of a drill bit. The drilling device comprises an outer cover structure, an upper end cover is arranged at an opening in the upper end of a lower outer cover shell, and a lower end cover bottom support is arranged at an opening in the lower end of the outer cover structure; the upper end cover and the lower end cover bottom support encircle the interior of the lower outer cover shell to form a movable cabin; a main transmission rod is arranged in the movable cabin in a penetrating mode, a drilling head is installed at the lower end of the main transmission rod, and a transmission structure matched with the main transmission rod is arranged in the movable cabin. Under the action of the transmission structure, when the drilling head rotates, the center of the drilling head does reverse revolution motion, and the rotation period is the same as the revolution period. The device can be used for drilling elliptical drill holes, can play a better pressure relief effect, and can also realize a directional presplitting effect. In addition, one-time hole-forming drilling can be achieved, and double-axis symmetric smooth curve-shaped drill holes such as an oval hole, a round hole, a square hole, a rectangular hole and a rhombus hole with four arc-shaped chamfers at four corners can be drilled.

Description

Technical Field

[0001] This invention relates to a drilling technology, specifically a design method for an elliptical drilling device and drill bit based on gear transmission control. Background Technology

[0002] Drilling equipment commonly includes mining drilling equipment, and existing mining drilling equipment uniformly adopts the method of drilling circular boreholes. It primarily provides hydraulic power to the pump station, and the drilling rig converts this hydraulic power into torque and propulsion. The hollow drill rod transmits torque and propulsion and provides a water channel for drilling fluid flushing. The end of the drill rod uses drill bits such as diamond drill bits or roller cone drill bits to drill holes in the rock mass; regardless of size, the borehole shape is uniformly circular.

[0003] Circular borehole technology is simple and inexpensive to operate, but due to the uneven stress distribution in the formation, it cannot better adapt to stress variations and achieve diversified and efficient utilization. According to rock mechanics calculations, under the same cross-sectional area, elliptical boreholes with their major axis parallel to the direction of maximum principal stress exhibit better stability. In mining engineering applications such as borehole decompression, borehole blasting, and hydraulic pre-fracturing, circular boreholes do not clearly demonstrate directionality and differentiation, thus hindering their development and utilization according to different mine needs.

[0004] In addition, even if the application scenarios are not limited to ore drilling, existing drilling equipment requires multiple positioning and drilling when drilling elliptical, circular, square, rectangular, rhomboid and other biaxially symmetrical smooth curve shapes with rounded corners, resulting in poor forming effect and possibly requiring multiple drill bit replacements. Summary of the Invention

[0005] The purpose of this invention is to provide a design method for an elliptical drilling device and drill bit based on gear transmission control, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An elliptical drilling device based on gear transmission control includes an outer cover structure, wherein openings are provided at both the upper and lower ends of the lower outer cover shell in the outer cover structure.

[0008] An upper end cover is provided at the upper opening of the lower outer shell, and a lower end cover base is provided at the lower opening of the outer shell structure. The upper end cover and the lower end cover base enclose the interior of the lower outer shell to form a movable cabin.

[0009] The main drive rod is installed in the movable cabin, and a drill bit is installed at the lower end of the main drive rod. The movable cabin is equipped with a transmission structure that cooperates with the main drive rod.

[0010] Under the action of the transmission structure, the drilling head rotates and its center makes reverse revolution motion, and the revolution period is the same as the rotation period.

[0011] The elliptical drilling device based on gear transmission control as described above: the transmission structure comprises a driving revolution gear mounted in the center of the main transmission rod, the driving revolution gear is engaged with a first driven revolution gear, the first driven revolution gear is engaged with a second driven revolution gear, and the second driven revolution gear and the driving revolution gear are both engaged with an inner gear ring mounted in the movable cabin.

[0012] The central axes of the first driven revolution gear, the second driven revolution gear and the driving revolution gear are coplanar and pass through the central axis of the inner gear ring.

[0013] The elliptical drilling device based on gear transmission control as described above: the radius ratio and the tooth number ratio of the inner gear ring and the driving revolution gear are both 2, and the radius and the tooth number of the first driven revolution gear and the second driven revolution gear are both 1 / 2 of the driving revolution gear.

[0014] The elliptical drilling device based on gear transmission control as described above: the upper edge of the upper end cover is connected with the lower edge of the upper outer shell through an end cover thrust bearing, and the lower edge of the upper end cover is connected with the inner edge of the lower outer shell through an end cover deep groove ball bearing.

[0015] The elliptical drilling device based on gear transmission control as described above: the bottom of the lower outer shell is provided with an outer shell base, and the lower end cover support is rotationally connected on the outer shell base through a support deep groove ball bearing.

[0016] The upper and lower ends of the first driven revolution gear and the second driven revolution gear are rotationally matched with the upper end cover and the lower end cover support, respectively.

[0017] The elliptical drilling device based on gear transmission control as described above: one end of the main transmission rod extends out of the lower end cover support and is matched with the drill screw sleeve on the drilling head through a drill head limiting clamp.

[0018] A plurality of drill teeth are arranged on the side of the drilling head away from the lower end cover support.

[0019] The elliptical drilling device based on gear transmission control as described above: the upper part of the lower outer shell is fixedly connected with the upper outer shell through outer shell connecting bolts, an inspection window shell is mounted on the upper outer shell, a top cover is fixedly connected on the inspection window shell through an inspection window axial connecting bolt, and a middle transition drill rod is rotationally arranged in the center of the top cover.

[0020] The outer edge of the middle transition drill rod is formed with a transition drill rod shoulder, and is rotationally connected with the top cover through a transition drill rod thrust bearing, and the end of the middle transition drill rod extending into the maintenance window shell is connected with the main transmission rod through a universal joint structure.

[0021] The universal joint structure comprises two groups of universal joint assemblies, which are respectively connected with the end of the main transmission rod extending into the upper outer shell and the end of the middle transition drill rod extending into the maintenance window shell.

[0022] The two groups of universal joint assemblies are respectively a first universal joint assembly and a second universal joint assembly, the first universal joint assembly is connected with the transmission spline shaft and the middle transition drill rod, the second universal joint assembly is connected with the transmission spline sleeve and the main transmission rod, and the transmission spline shaft is in sliding connection with the transmission spline sleeve.

[0023] The transmission spline shaft is internally provided with an internal high-pressure rubber pipe, and the end of the middle transition drill rod is connected with one end of the internal high-pressure rubber pipe through a first high-pressure rubber pipe quick connector.

[0024] The end of the main transmission rod is provided with a second high-pressure rubber pipe quick connector, and the second high-pressure rubber pipe quick connector is connected with the other end of the internal high-pressure rubber pipe.

[0025] The outer wall of the lower outer shell is provided with a gear ring angle adjusting bolt penetratingly arranged thereon, and the end of the gear ring angle adjusting bolt extending into the lower outer shell is in connection with the outer wall of the internal gear ring.

[0026] The outer wall of the lower outer shell is provided with a plurality of flow guide grooves along the axial direction.

[0027] A design method of a drill bit of the elliptical drilling device, the method comprising the following steps: drawing an ellipse to be drilled on a plane determined by X-axis and Y-axis according to a designed size, wherein the major axis of the ellipse coincides with the X-axis, the minor axis coincides with the Y-axis, and the center of the ellipse coincides with the origin of the plane; drawing a circle with the origin of the plane as the center and a revolution radius r as the radius, wherein the revolution radius is smaller than the length of the minor axis of the ellipse; drawing rays from the origin in the first quadrant of the plane at a fixed angle interval, each ray intersecting the circle and the ellipse, the angle between the ray and the positive direction of the X-axis being θ, and the distance between the two intersection points of the ray and the circle and the ellipse being R'; taking points with a length of R' from the origin in a direction with an angle of 2θ with respect to the positive direction of the X-axis on a new plane to obtain a plurality of points; and connecting the points by a smooth curve to obtain an upper half of a horizontal projection outer contour line of the drill bit, and taking a mirror image of the contour line with respect to the X-axis to obtain a complete horizontal projection outer contour line of the drill bit.

[0028] Mark the edge position corresponding to the zero angle of the drilling head as the 0° line; during installation, the origin position of the horizontal projection outer contour line of the drilling head is directly opposite the center of the main transmission rod, and the drill teeth are arranged inside the contour line and tangent to the inner edge of the contour line, and the drill teeth are within the range of the contour line in the horizontal direction;

[0029] When the drilling head performs a revolution while rotating, and the revolution period is the same as the revolution period, each point on the drilling head moves on an elliptical trajectory with a long semi-axis length of R+r and a short semi-axis length of R-r, R is the distance of the point to the rotation center axis of the drilling head, and r is the revolution radius of the drilling head center; when the point is on the extension line of the line connecting the revolution center and the rotation center of the drilling head, the line connecting the point and the revolution center of the drilling head is the long semi-axis of the elliptical trajectory of the point, and the short semi-axis is perpendicular to the long semi-axis; the elliptical trajectories of the points on the drilling head are superimposed after being projected on the same horizontal plane, and the shape of the elliptical hole to be drilled is obtained;

[0030] When R is greater than r, the rotation direction of the elliptical trajectory of the point is the same as the rotation direction of the drilling head; when R is less than r, the rotation direction of the elliptical trajectory of the point is the same as the revolution direction of the drilling head.

[0031] Compared with the prior art, the beneficial effects of the present application are:

[0032] In the present application, according to theoretical calculation, if an elliptical drilling is used for pressure relief, and the long axis direction of the ellipse is perpendicular to the required pressure relief direction, the drilling is easier to break, and better pressure relief effect can be achieved. When the drilling is used for blasting or water pressure pre-splitting, the tensile stress at both ends of the long axis of the elliptical drilling is greater, which can effectively control the crack orientation and offset the influence of part of the ground stress on the cracking position, thereby realizing the effect of directional pre-splitting. The present application has a wide application prospect in mine rock burst prevention, roof pre-splitting for gob-side entry retaining, oil and gas exploitation, coal bed methane exploitation and the like.

[0033] In addition, the elliptical drilling device in the present application can also realize one-time hole drilling of elliptical, circular, square, rectangular, rhombus and other double-axis symmetric smooth curve shapes with four corners being arc chamfers in non-mining drilling application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 FIG. 1 is a structural schematic view of the elliptical drilling device based on gear transmission control.

[0035] Figure 2 FIG. 2 is a sectional view of the elliptical drilling device based on gear transmission control.

[0036] Figure 3 FIG. 3 is a structural schematic view of the elliptical drilling device based on gear transmission control from another perspective.

[0037] Figure 4 FIG. 4 is a drilling hole formed by the elliptical drilling device.Figure 3 The diagram shows the structure after the upper outer shell and the lower outer shell are separated.

[0038] Figure 5 In order to be in Figure 4 This is a structural diagram showing the structure after the upper and lower outer shells have been completely removed.

[0039] Figure 6 In order to be in Figure 5 The diagram shows the disassembled components of the central transition drill pipe, the first universal joint active fork spline sleeve, and the first universal joint cross shaft.

[0040] Figure 7 In order to be in Figure 6 The diagram shows the structure after completely removing the central transition drill rod, the first universal joint active fork spline sleeve, the first universal joint cross shaft, and the transmission spline sleeve.

[0041] Figure 8 In order to be in Figure 7 The diagram shows the disassembled upper end cover, end cover thrust bearing, and end cover deep groove ball bearing.

[0042] Figure 9 In order to be in Figure 8 This is a schematic diagram after removing the upper end cover, end cover thrust bearing, and end cover deep groove ball bearing.

[0043] Figure 10 for Figure 9 A structural view from another angle.

[0044] In the diagram: 1. Centrally mounted transition drill pipe; 2. Transition drill pipe shoulder; 3. Transition drill pipe thrust bearing; 4. Top cover; 5. Inspection window housing; 6. Inspection window axial connecting bolts; 7. First universal joint drive fork spline sleeve; 8. Inspection window circumferential connecting bolts; 9. First high-pressure hose quick connector; 10. First universal joint driven fork; 11. First universal joint cross shaft; 12. Drive spline shaft; 13. Drive spline sleeve; 14. Internal high-pressure hose; 15. Second universal joint cross shaft; 16. Second universal joint driven fork; 17. Second high-pressure hose quick connector; 18. Upper outer housing; 19. Main drive. 20. Lower outer casing; 21. Upper end cover; 22. End cover thrust bearing; 23. Outer casing connecting bolt; 24. End cover deep groove ball bearing; 25. Transmission rod thrust bearing; 26. Transmission rod shoulder; 27. Driving planetary gear; 28. First driven planetary gear; 29. ​​Second driven planetary gear; 30. Internal gear ring; 31. Internal gear ring bracket; 32. Gear ring angle adjusting bolt; 33. Lower end cover base; 34. Base deep groove ball bearing; 35. Outer casing base; 36. Guide groove; 37. Drill bit spline sleeve; 38. Drill bit limit clip; 39. Drill bit; 40. Drill teeth. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0046] Please see Figures 1 to 10 As an embodiment of the present invention, the elliptical drilling device based on gear transmission control includes an outer cover structure, wherein the outer cover structure includes a lower outer cover shell 20 and an upper outer cover shell 18. The lower outer cover shell 20 has openings at both its upper and lower ends, and the outer contour of the lower outer cover shell 20 is elliptical and the inner contour is circular.

[0047] Among them, an upper end cover 21 is provided at the upper opening of the lower outer shell 20, and a lower end cover base 33 is provided at the lower opening of the outer shell structure. The upper end cover 21 and the lower end cover base 33 enclose the interior of the lower outer shell 20 to form an active cabin.

[0048] The main drive rod 19 is installed in the movable cabin, and a drill bit 39 is installed at the lower end of the main drive rod 19. The movable cabin is provided with a transmission structure that cooperates with the main drive rod 19.

[0049] The transmission structure includes a drive gear 27 mounted in the center of the main drive rod 19.

[0050] The driving orbital gear 27 meshes with the first driven orbital gear 28, the first driven orbital gear 28 meshes with the second driven orbital gear 29, and both the second driven orbital gear 29 and the driving orbital gear 27 mesh with the internal gear ring 30, which is installed in the movable cabin.

[0051] The radius ratio and tooth number ratio of the internal gear ring 30 and the driving orbital gear 27 are both 2, and they have the same module. The radius and tooth number of the first driven orbital gear 28 and the second driven orbital gear 29 are both 1 / 2 of the driving orbital gear 27, and they have the same module. The central axes of the first driven orbital gear 28, the second driven orbital gear 29, and the driving orbital gear 27 are coplanar and pass through the central axis of the internal gear ring 30.

[0052] In the design process of the elliptical drilling device of the present invention, through calculation and design, and with the help of the transmission structure, the drilling head 39 rotates while its center revolves in the opposite direction, and the rotation period and the revolution period are strictly consistent. Each point of the drilling head 39 performs elliptical motion, and the length of the major semi-axis of the trajectory of this point is H; wherein, the distance from this point to the rotation center axis of the drilling head 39 is R, the revolution radius of the center of the drilling head 39 is r, and H is the sum of R and r; and the length of the minor semi-axis of the trajectory of this point is the difference between R and r.

[0053] The center of the trajectory at this point is the center of revolution. The direction of the major semi-axis is the direction when the point is exactly on the extension of the line connecting the center of revolution and the center of rotation of the drill bit 39. The direction of the minor semi-axis is perpendicular to it. When R is greater than r, the direction of rotation of the trajectory at this point is the same as the direction of rotation; when R is less than r, the direction of rotation of the trajectory at this point is the same as the direction of revolution.

[0054] By designing the above parameters, the problem of the drill bit 39 rotating along an elliptical trajectory was solved.

[0055] The present invention also provides a design method for the drill bit of the elliptical drilling device as described above, for determining the horizontal projected outer contour line of the drill bit 39, as follows:

[0056] The elliptical hole to be drilled is drawn on the plane defined by the X-axis and Y-axis according to the design dimensions. The major axis of the ellipse coincides with the X-axis, the minor axis coincides with the Y-axis, and the center of the ellipse coincides with the origin of the plane. A circle is drawn with the origin of the plane as the center and the revolution radius r as the radius (the revolution radius is less than the length of the minor axis of the ellipse). Rays are drawn from the origin at fixed angular intervals (such as 3°) in the first quadrant of the plane (including the positive X-axis and the positive Y-axis). The smaller the angular interval, the higher the accuracy. Each ray intersects the circle and the ellipse respectively. When the angle between the ray and the positive X-axis is θ, the distance between the two intersection points of the ray and the circle and the ellipse is R'. On the new plane, starting from the origin, a point with a length of R' is taken in the direction with an angle of 2θ with the positive X-axis. The points are connected with a smooth curve to obtain the upper half of the horizontal projection outer contour of the drill head (39). The contour is then mirrored with respect to the X-axis to obtain the complete horizontal projection outer contour of the drill head (39).

[0057] A mark is made at the edge position when its angle = 0°, called the 0° line of the drill head 39, for easy later installation. During installation, the origin of the horizontal projection outer contour line of the drill head 39 is aligned with the center of the main drive rod 19. Drill teeth 40 tangent to the inner edge of this contour line are arranged inside it. These can be arranged vertically as needed, but must not exceed the range of this contour line in the horizontal direction. Flushing fluid guide holes are arranged inside the drill head 39 according to flushing requirements. The upper part of the drill head 39 connects to the main drive rod 19 using a spline connection. The upper part of the drill head 39 is a spline sleeve with anti-dislodgement holes for installing U-shaped clips to prevent the drill head from falling off.

[0058] Because the drill bit 39 rotates on its own axis and revolves around the sun simultaneously, and when the rotation period and revolution period are the same, each point on the drill bit 39 moves along a trajectory with a major semi-axis of R+r and a minor semi-axis of Rr. R is the distance from the point to the rotation center axis of the drill bit 39, and r is the revolution radius of the drill bit 39. The direction of the major semi-axis is the direction when the point is exactly on the extension of the line connecting the revolution center and the rotation center of the drill bit 39, and the direction of the minor semi-axis is perpendicular to it. The elliptical trajectories of all points on the drill bit, when projected onto the same horizontal plane, form the shape of the elliptical hole to be drilled. When R is greater than r, the rotation direction of the trajectory of that point is the same as the rotation direction; when R is less than r, the rotation direction of the trajectory of that point is the same as the revolution direction. Therefore, when using drill teeth 40 with directional requirements, outside the circle R=r on the drill bit 39, the positive direction of drill teeth 40 is the same as the rotation direction; inside the circle R=r, the positive direction of drill teeth 40 is the same as the revolution direction. Therefore, at each point where R≤r, the long axis of its trajectory will change direction significantly. In these areas, non-directional drill teeth 40 should be used as much as possible. Alternatively, the overlapping area of ​​the trajectories can be increased by densifying the drill teeth, thereby achieving a better drilling effect.

[0059] By designing the horizontal projection outline of the drill head 39 and the parameters of the drill teeth 40, the trajectories of each drill tooth 40 of the drill head 39 are superimposed to form the required elliptical drill hole.

[0060] As a further embodiment of the present invention, the lower edge of the upper outer cover housing 18 is connected to the upper edge of the upper end cover 21 through the end cover thrust bearing 22, and the lower edge of the upper end cover 21 is connected to the inner edge of the lower outer cover housing 20 through the end cover deep groove ball bearing 24.

[0061] The end cap thrust bearing 22 ensures that the lower edge of the upper outer cover housing 18 can rotate with the upper edge of the upper end cap 21 and provide an upward thrust resistance, thereby transmitting drilling propulsion force. The end cap deep groove ball bearing 24 effectively constrains the radial runout of the upper end cap 21.

[0062] As a further embodiment of the present invention, an outer cover base 35 is provided at the bottom of the lower outer cover housing 20, and a lower end cover base 33 is rotatably connected to the outer cover base 35 via a bottom support deep groove ball bearing 34.

[0063] The upper and lower ends of the first driven planetary gear 28 and the second driven planetary gear 29 are respectively rotatably engaged with the upper end cover 21 and the lower end cover base 33.

[0064] The upper end cover 21 and the lower end cover base 33 can be used to axially constrain the first driven planetary gear 28 and the second driven planetary gear 29, preventing misalignment between the meshing gears.

[0065] As a further embodiment of the present invention, an internal gear ring bracket 31 is provided between the lower end cover base 33 and the first driven planetary gear 28 and the second driven planetary gear 29, and a transmission rod shoulder 26 is provided in the center of the main transmission rod 19. The transmission rod shoulder 26 is connected to the upper end cover 21 through a transmission rod thrust bearing 25.

[0066] Since the first driven planetary gear 28 and the second driven planetary gear 29 are strictly confined between the upper end cover 21 and the lower end cover base 33, the meshing stability between the driving planetary gear 27, the first driven planetary gear 28, the second driven planetary gear 29, and the internal gear ring 30 can be ensured.

[0067] As a further embodiment of the present invention, one end of the main drive rod 19 extends out of the lower end cover base 33 and engages with the drill bit spline sleeve 37 on the drill bit 39 through the drill bit limiting clip 38;

[0068] Multiple drill teeth 40 are provided on the side of the drill head 39 that is away from the lower end cover base 33.

[0069] The main drive rod 19 is detachably connected to the drill bit 39 by the drill bit limiting clip 38, so as to replace and repair the drill bit 39.

[0070] As a further embodiment of the present invention, the upper part of the lower outer cover housing 20 is fixedly connected to the upper outer cover housing 18 by the outer cover connecting bolt 23. The upper outer cover housing 18 is equipped with an inspection window housing 5. The top cover 4 is fixed to the inspection window housing 5 by the inspection window axial connecting bolt 6. A centrally placed transition drill rod 1 is rotatably inserted through the center of the top cover 4.

[0071] The outer edge of the centrally located transition drill rod 1 forms a transition drill rod shoulder 2, and it is rotatably engaged with the top cover 4 through the transition drill rod thrust bearing 3. One end of the centrally located transition drill rod 1 that extends into the inspection window housing 5 is connected to the main drive rod 19 through a universal joint structure.

[0072] In addition, the inspection window housing 5 is a two-part structure, which is connected by the circumferential connecting bolts 8 of the inspection window.

[0073] In this embodiment, since the main drive rod 19 rotates on its own axis while also revolving in a circular motion, it is necessary to use a universal joint structure to connect the main drive rod 19 to the intermediate transition drill rod 1, which only maintains its own rotation; then, the intermediate transition drill rod 1 is connected to the front ordinary drill rod to bear and transmit its torque and propulsion force.

[0074] As a further embodiment of the present invention, the universal connection structure includes two sets of universal joint assemblies, which are respectively connected to one end of the main drive rod 19 that extends into the upper outer cover housing 18 and one end of the centrally placed transition drill rod 1 that extends into the inspection window housing 5.

[0075] The two universal joint assemblies are the first universal joint assembly and the second universal joint assembly. The first universal joint assembly connects the drive spline shaft 12 and the central transition drill rod 1, and the second universal joint assembly connects the drive spline sleeve 13 and the main drive rod 19. The drive spline shaft 12 and the drive spline sleeve 13 are in sliding fit.

[0076] By means of the telescopic and sliding transmission spline shaft 12 and transmission spline sleeve 13, the distance between the two sets of universal joint assemblies can be varied, and under the action of the two sets of universal joint assemblies, it can be ensured that the rotational torque of the centrally located transition drill rod 1 can be transmitted to the main transmission rod 19.

[0077] As a further embodiment of the present invention, the first universal joint assembly includes a first universal joint cross shaft 11 pivotally connected to the centrally placed transition drill rod 1 via a first universal joint active fork spline sleeve 7, and also includes a first universal joint driven fork 10 fixed to the end of the transmission spline shaft 12. The first universal joint cross shaft 11 and the first universal joint driven fork 10 are also pivotally connected.

[0078] The second universal joint assembly includes a second universal joint cross shaft 15 pivotally connected to the end of the transmission spline sleeve 13, and a second universal joint driven fork 16 fixedly disposed at the end of the main drive rod 19. The second universal joint cross shaft 15 and the second universal joint driven fork 16 are also pivotally connected.

[0079] A set of universal joints is formed by the first universal joint assembly, the second universal joint assembly, the transmission spline sleeve 13, and the transmission spline shaft 12, thereby ensuring that the main transmission rod 19, which rotates on its own axis and revolves in a circular motion, is connected to the centrally placed transition drill rod 1 and can transmit torque synchronously.

[0080] As a further embodiment of the present invention, the transmission spline shaft 12 is provided with a built-in high-pressure hose 14, and one end of the centrally placed transition drill rod 1 is connected to one end of the built-in high-pressure hose 14 through a first high-pressure hose quick connector 9.

[0081] One end of the main drive rod 19 is provided with a second high-pressure hose quick connector 17, and the second high-pressure hose quick connector 17 is connected to the other end of the built-in high-pressure hose 14.

[0082] The problem of conveying drilling flushing fluid can be solved by using the first high-pressure hose quick connector 9, the built-in high-pressure hose 14, and the second high-pressure hose quick connector 17.

[0083] As a further embodiment of the present invention, a gear ring angle adjusting bolt 32 is provided through the outer wall of the lower outer cover housing 20, and one end of the gear ring angle adjusting bolt 32 extending into the interior of the lower outer cover housing 20 cooperates with the outer wall of the inner gear ring 30.

[0084] Multiple guide grooves 36 are provided on the outer wall of the lower outer casing 20 along the axial direction.

[0085] The gear ring angle adjusting bolt 32 engages with the thread in the fixing hole on the internal gear ring 30 to adjust the bolt position. Specifically, a fixing block is formed on the outer wall of the internal gear ring 30. One side of the fixing block has a toothed key that engages with the spline groove below the cylindrical surface of the outer edge of the internal gear ring 30 to fix the internal gear ring 30. The fixing block has a hole in the middle. Before adjusting the angle, the fixing block is pulled back into the groove by adjusting the gear ring angle adjusting bolt 32, disengaging it from the spline groove below the cylindrical surface of the outer edge of the internal gear ring 30. After the angle is adjusted, the gear ring angle adjusting bolt 32 is adjusted again to push the fixing block into the spline groove to fix the internal gear ring 30 and prevent relative rotation between the internal gear ring 30 and the lower outer cover housing 20.

[0086] It should be noted that the installation position and angle of the drill bit 39 before drilling begins are crucial. It is necessary to ensure that the elliptical borehole drilled is aligned with the long axis of the elliptical outer contour of the lower outer casing 20. If it is soft rock, it may be necessary for the two to form a certain angle.

[0087] In detail, before use, ensure the device is installed correctly. The long axis of the housing formed by the lower outer casing 20 and the upper outer casing 18 must be parallel to and in the same plane as the center lines of the four gears and the 0° line of the drill head 39. The 0° line of the drill head 39 should be located on the extension of the line connecting the center of the internal gear ring 30 and the center of the main drive rod 19 to the center side of the main drive rod 19. That is, when the center of the main drive rod 19 is to the right of the center of the internal gear ring 30, the 0° line of the drill head 39 should face to the right. At this point, the internal gear ring 30 can be fixed, completing the assembly and fixing of the equipment.

[0088] During drilling, the lower outer casing 20 is secured at the borehole opening using anchor bolts or fixing devices installed on the drilling rig. The installation conditions are then checked again to ensure they are met. Once confirmed, drilling begins. After the lower outer casing 20 enters the borehole, the elliptical borehole wall provides a limiting and positioning effect, preventing rotation of the casing and internal gear ring 30, allowing the drill head 39 to continue drilling through the elliptical borehole. Torque is transmitted to the drill head 39 via the central transition drill rod 1, the first universal joint assembly, the second universal joint assembly, and the main drive rod 19. The propulsion force is transmitted to the drill head 39 via the central transition drill rod 1, the transition drill rod thrust bearing 3, the top cover 4, the inspection window casing 5, the upper outer casing 18, the upper end cover thrust bearing 22, the upper end cover 21, the drive rod thrust bearing 25, and the main drive rod 19 to achieve propulsion. The drilling flushing fluid is delivered to the drill head 39 via the centrally located transition drill rod 1, the built-in high-pressure hose 14, and the main drive rod 19 to achieve drilling flushing. It then flows back to the borehole opening through the guide channels 36 on both sides of the housing and the gap between the drill rod and the borehole. When the rock strata are soft, the interaction between the housing and the borehole wall may cause deformation of the borehole wall, resulting in a deviation in the drilling direction. In this case, angle adjustment is required to correct the deviation. This can be achieved by adjusting the angle relationship between the main directional housing and the internal gear ring 30, or by adjusting the 0° line of the drill head 39 to correspond to the installation position via the drill bit spline sleeve 37. Angle adjustment can also be used to drill spiral elliptical boreholes. In the future, remote adjustment and online adjustment of parameters such as the major and minor axes of the elliptical borehole can be achieved through directional functions, thereby enabling more precise, wider, and better applications of elliptical boreholes.

[0089] The above embodiments are exemplary and not restrictive. Therefore, any technical solutions that can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention are included within the scope of the present invention.

Claims

1. An elliptical drilling device based on gear transmission control, comprising an outer cover structure, wherein the lower outer cover shell (20) of the outer cover structure has openings at both the upper and lower ends; An upper end cover (21) is provided at the upper opening of the lower outer shell (20), and a lower end cover base (33) is provided at the lower opening of the outer shell structure. The upper end cover (21) and the lower end cover base (33) enclose the interior of the lower outer shell (20) to form a movable cabin. The feature is that: The main drive rod (19) is installed in the active cabin, and a drill bit (39) is installed at the lower end of the main drive rod (19). The active cabin is provided with a transmission structure that cooperates with the main drive rod (19). Under the action of the transmission structure, when the drill bit (39) rotates, its center makes a reverse revolution, and the rotation period is the same as the revolution period.

2. The elliptical drilling device based on gear transmission control according to claim 1, characterized in that, The transmission structure includes a drive orbital gear (27) installed in the center of the main drive rod (19). The drive orbital gear (27) meshes with a first driven orbital gear (28). The first driven orbital gear (28) meshes with a second driven orbital gear (29). Both the second driven orbital gear (29) and the drive orbital gear (27) mesh with an internal gear ring (30). The internal gear ring (30) is installed in the active compartment. The central axes of the first driven orbital gear (28), the second driven orbital gear (29), and the driving orbital gear (27) are coplanar and pass through the central axis of the internal gear ring (30).

3. The elliptical drilling device based on gear transmission control according to claim 2, characterized in that, The radius ratio and tooth number ratio of the internal gear ring (30) and the driving orbital gear (27) are both 2, and the radius and tooth number of the first driven orbital gear (28) and the second driven orbital gear (29) are both 1 / 2 of the driving orbital gear (27).

4. The elliptical drilling device based on gear transmission control according to claim 2, characterized in that, The upper edge of the upper end cover (21) is connected to the lower edge of the upper outer cover housing (18) through the end cover thrust bearing (22), and the lower edge of the upper end cover (21) is connected to the inner edge of the lower outer cover housing (20) through the end cover deep groove ball bearing (24).

5. The elliptical drilling device based on gear transmission control according to claim 4, characterized in that, The bottom of the lower outer cover housing (20) is provided with an outer cover housing base (35), and the lower end cover base (33) is rotatably connected to the outer cover housing base (35) via a bottom support deep groove ball bearing (34). The upper and lower ends of the first driven planetary gear (28) and the second driven planetary gear (29) are respectively rotated and engaged with the upper end cover (21) and the lower end cover base (33).

6. The elliptical drilling device based on gear transmission control according to claim 5, characterized in that, One end of the main drive rod (19) extends out of the lower end cover base (33) and engages with the drill bit spline sleeve (37) on the drill bit (39) through the drill bit limiting clip (38); Multiple drill teeth (40) are provided on the side of the drill head (39) facing away from the lower end cap base (33).

7. The elliptical drilling device based on gear transmission control according to claim 6, characterized in that, The upper part of the lower outer cover housing (20) is fixedly connected to the upper outer cover housing (18) by the outer cover connecting bolt (23). The upper outer cover housing (18) is equipped with an inspection window housing (5). The top cover (4) is fixed to the inspection window housing (5) by the inspection window axial connecting bolt (6). The top cover (4) is rotatably provided with a central transition drill rod (1). The outer edge of the central transition drill rod (1) forms a transition drill rod shoulder (2), and it rotates with the top cover (4) through the transition drill rod thrust bearing (3). One end of the central transition drill rod (1) that extends into the inspection window housing (5) is connected to the main drive rod (19) through a universal connection structure.

8. The elliptical drilling device based on gear transmission control according to claim 7, characterized in that, The universal joint structure includes two sets of universal joint assemblies, which are respectively connected to one end of the main drive rod (19) that extends into the upper outer cover housing (18) and one end of the centrally placed transition drill rod (1) that extends into the inspection window housing (5); The two sets of universal joint assemblies are the first universal joint assembly and the second universal joint assembly. The first universal joint assembly connects the drive spline shaft (12) and the central transition drill rod (1), and the second universal joint assembly connects the drive spline sleeve (13) and the main drive rod (19). The drive spline shaft (12) and the drive spline sleeve (13) are in sliding fit.

9. The elliptical drilling device based on gear transmission control according to claim 8, characterized in that, The transmission spline shaft (12) is equipped with a built-in high-pressure hose (14), and one end of the central transition drill rod (1) is connected to one end of the built-in high-pressure hose (14) through the first high-pressure hose quick connector (9). One end of the main drive rod (19) is provided with a second high-pressure hose quick connector (17), and the second high-pressure hose quick connector (17) is connected to the other end of the built-in high-pressure hose (14).

10. The elliptical drilling device based on gear transmission control according to claim 2, characterized in that, A gear ring angle adjustment bolt (32) is provided through the outer wall of the lower outer cover housing (20). One end of the gear ring angle adjustment bolt (32) extends into the interior of the lower outer cover housing (20) and engages with the outer wall of the inner gear ring (30). Multiple guide grooves (36) are provided on the outer wall of the lower outer casing (20) along the axial direction.

11. A method for designing a drill bit for an elliptical drilling apparatus as described in any one of claims 1-10, characterized in that, The method for determining the horizontal projection outline of the drill bit (39) is as follows: Draw the elliptical hole to be drilled on the plane determined by the X-axis and Y-axis according to the design size, wherein the major axis of the ellipse coincides with the X-axis, the minor axis coincides with the Y-axis, and the center of the ellipse coincides with the origin of the plane; draw a circle with the origin of the plane as the center and the revolution radius r as the radius, the revolution radius being less than the length of the minor semi-axis of the ellipse; in the first quadrant of the plane, including the positive X-axis and the positive Y-axis, draw rays from the origin at fixed angular intervals, each ray intersecting the circle and the ellipse respectively, the angle between the ray and the positive X-axis is θ, and the distance between the two intersection points of the ray and the circle and the ellipse is R'; on the new plane, starting from the origin, take a point with a length of R' in the direction with an angle of 2θ with the positive X-axis, connect each point with a smooth curve to obtain the upper half of the horizontal projection outline of the drill bit (39), and then mirror this outline with the X-axis to obtain the complete horizontal projection outline of the drill bit (39); Mark the edge position corresponding to the zero angle of the drill bit (39) as the 0° line; during installation, the origin of the horizontal projection outer contour of the drill bit (39) is directly opposite the center of the main drive rod (19), and drill teeth (40) tangent to the inner edge of the contour are arranged inside the contour. The drill teeth (40) are within the contour range in the horizontal direction. When the drill bit rotates and revolves at the same time, and the rotation period is the same as the revolution period, each point on the drill bit (39) moves on an elliptical trajectory with a major semi-axis length of R+r and a minor semi-axis length of Rr. R is the distance from the point to the rotation center axis of the drill bit (39), and r is the revolution radius of the center of the drill bit (39). When the point is on the extension line of the line connecting the revolution center and the rotation center of the drill bit (39), the line connecting the point to the revolution center of the drill bit (39) is the major semi-axis of the elliptical trajectory of the point, and the minor semi-axis is perpendicular to it. The elliptical trajectories of each point on the drill bit are superimposed on the same horizontal plane to form the shape of the elliptical hole to be drilled. When R is greater than r, the elliptical trajectory of the point rotates in the same direction as the rotation of the drill bit; when R is less than r, the elliptical trajectory of the point rotates in the same direction as the revolution of the drill bit.

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