Drilling equipment

Abstract

The technical field of drilling equipment of the present invention provides a drilling device, including: a casing, a flexible transmission shaft and an elastic component; the casing is cylindrical; the flexible transmission shaft is arranged in the casing, one end of the flexible transmission shaft is used to connect with the output end of the power equipment, and the other end of the flexible transmission shaft extends out of the casing and is connected to the drill bit; a bearing is sleeved in the middle of the flexible transmission shaft; the elastic component is connected to the casing; there are multiple elastic components, and the multiple elastic components are evenly distributed along the circumference of the casing; the elastic component is detachably connected to the outer ring of the bearing; when the axis of the flexible transmission shaft coincides with the axis of the casing, the multiple elastic components are respectively connected to the outer ring of the bearing; when the axis of the flexible transmission shaft is offset relative to the axis of the casing, the elastic component located on the side close to the offset is connected to the outer ring of the bearing, and the elastic component located on the side away from the offset is separated from the outer ring of the bearing; the wear of the flexible transmission shaft of the present invention during rotation.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling equipment, and in particular to a drilling device. Background Art

[0002] When exploiting underground oil and gas resources, the drill bit needs to be driven by a transmission shaft to perform drilling operations. Due to the deep drilling depth, the transmission shaft usually adopts a flexible shaft to adapt to long-distance power transmission.

[0003] During operation of existing drilling equipment, if the drill bit is subjected to uneven force, the flexible shaft will bend adaptively. Accordingly, the axis of the flexible shaft will be offset, causing the flexible shaft to contact the borehole wall and cause sliding friction, thereby causing abnormal wear of the flexible shaft and shortening the life of the flexible shaft. Summary of the invention

[0004] The invention provides a drilling device, which is used to solve or improve the problem that the transmission shaft of the existing drilling equipment is worn out quickly during the drilling process, resulting in a short service life of the transmission shaft.

[0005] The present invention provides a drilling device, comprising: a casing, a flexible transmission shaft and an elastic component; the casing is cylindrical; the flexible transmission shaft is arranged in the casing, one end of the flexible transmission shaft is used to be connected to the output end of the power equipment, and the other end of the flexible transmission shaft extends out of the casing and is connected to the drill bit; a bearing is sleeved on the middle part of the flexible transmission shaft; the elastic component is connected to the casing; there are multiple elastic components, and the multiple elastic components are evenly distributed along the circumference of the casing; the elastic component is detachably connected to the outer ring of the bearing; when the axis of the flexible transmission shaft coincides with the axis of the casing, the multiple elastic components are respectively connected to the outer ring of the bearing; when the axis of the flexible transmission shaft is offset relative to the axis of the casing, the elastic component located on the side close to the offset is connected to the outer ring of the bearing, and the elastic component located on the side away from the offset is separated from the outer ring of the bearing.

[0006] According to a drilling device provided by the present invention, the elastic component includes: a slider and an elastic member; an opening is provided on the casing, the opening extends along the radial direction of the casing, the slider is movably arranged in the opening, one end of the elastic member is connected to the casing, and the other end of the elastic member is connected to the slider; the slider is detachably connected to the outer ring of the bearing.

[0007] According to a drilling device provided by the present invention, the elastic component also includes: a limit block; the limit block is arranged outside the casing, and the length of the limit block along the axial direction of the casing is greater than the aperture of the opening; one end of the limit block is connected to the sliding block, and the other end of the limit block is connected to the other end of the elastic member; the side of the limit block close to the casing is detachably connected to the outer wall of the casing; when the axis of the flexible transmission shaft coincides with the axis of the casing, the limit block abuts against the outer wall of the casing; when the axis of the flexible transmission shaft is offset relative to the axis of the casing, the limit block located on the side close to the offset is separated from the outer wall of the casing, and the limit block located on the side away from the offset abuts against the outer wall of the casing.

[0008] According to a drilling device provided by the present invention, the elastic component also includes: a supporting part and a rotating part; the supporting part and the rotating part are arranged outside the casing, one end of the supporting part is connected to the outer wall of the casing, the other end of the supporting part is hinged to one end of the rotating part, and the rotating part is connected to the limit block; the elastic member is a torsion spring, the axis of the torsion spring is perpendicular to the axis of the casing, the torsion spring is arranged at the hinge between the supporting part and the rotating part, one end of the torsion spring is connected to the supporting part, and the other end of the torsion spring is connected to the rotating part.

[0009] According to a drilling device provided by the present invention, the outer ring of the bearing has a first end and a second end, the first end is detachably connected to the slider, and the second end is connected to the inner ring of the bearing; the thickness of the first end along the axial direction of the casing is smaller than the thickness of the second end along the axial direction of the casing, wherein the thickness of the first end along the axial direction of the casing is smaller than the aperture of the opening, and the thickness of the second end along the axial direction of the casing is greater than the aperture of the opening.

[0010] According to a drilling device provided by the present invention, the drilling device also includes: a first bearing and a second bearing; the first bearing and the second bearing are respectively arranged at the two ends of the casing, and the first bearing and the second bearing are sleeved on the flexible transmission shaft; an oil film is provided between the first bearing and the flexible transmission shaft and between the second bearing and the flexible transmission shaft.

[0011] According to a drilling device provided by the present invention, the drilling device further includes: a hole expansion mechanism; the hole expansion mechanism is connected to the other end of the flexible transmission shaft, and the hole expansion mechanism is arranged between the drill bit and the casing.

[0012] According to a drilling device provided by the present invention, the reaming mechanism includes: a first reaming tooth, an adjusting rod and a reaming shaft; the other end of the flexible transmission shaft is connected to one end of the reaming shaft, and the other end of the reaming shaft is connected to the drill bit; the adjusting rod extends along the radial direction of the reaming shaft, and the adjusting rod is movably arranged on the reaming shaft along the radial direction of the reaming shaft, one end of the adjusting rod is hinged to one end of the first reaming tooth, and the other end of the first reaming tooth is movably arranged on the reaming shaft along the axial direction of the reaming shaft.

[0013] According to a drilling device provided by the present invention, the reaming mechanism also includes: a second reaming tooth; one end of the adjusting rod is hinged to one end of the second reaming tooth, and the other end of the second reaming tooth is movably arranged on the reaming shaft along the axial direction of the reaming shaft; the moving direction of the other end of the second reaming tooth is opposite to the moving direction of the other end of the first reaming tooth.

[0014] The drilling device provided by the present invention is provided with a casing and an elastic component. When drilling construction is carried out, the drill bit and the casing are extended into the well, and the power equipment drives the flexible transmission shaft to drive the drill bit to rotate. The casing separates the inner wall of the well from the flexible transmission shaft, thereby avoiding the friction between the flexible transmission shaft and the inner wall of the well, and reducing the wear of the flexible transmission shaft. When the axial resistance to the drill bit is large or the drill bit is subjected to radial force, due to the long flexible transmission shaft, a certain bending will occur in the middle part of the flexible transmission shaft, that is, a certain deviation will occur in the axis of the flexible transmission shaft. At this time, the bearing in the middle part of the flexible transmission shaft will squeeze the elastic component on the offset side. On the one hand, the elastic component produces The deformation generated can compensate for the offset of the axis of the flexible transmission shaft. On the other hand, the elastic force generated by the deformation of the elastic component can assist the flexible transmission shaft to return to the correct position, thereby ensuring the stable rotation of the flexible transmission shaft; by arranging the elastic component between the bearing and the sleeve, compared with the rigid connection between the bearing and the sleeve, the wear of the bearing caused by uneven radial force is avoided, and the service life of the bearing is extended; the present invention avoids the friction between the flexible transmission shaft and the inner wall of the drilling well by arranging the sleeve, and avoids the friction between the flexible transmission shaft and the inner wall of the sleeve by arranging the bearing in the middle of the flexible transmission shaft, thereby reducing the wear of the flexible transmission shaft and extending the life of the flexible transmission shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1It is a structural schematic diagram of the drilling device provided by the present invention;

[0017] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure at A;

[0018] Reference numerals:

[0019] 1: casing; 2: flexible transmission shaft; 21: bearing; 3: elastic component; 31: slider; 32: elastic member; 33: limit block; 34: supporting part; 35: rotating part; 4: drill bit; 5: drilling; 6: first bearing; 7: second bearing; 8: reaming mechanism; 81: first reaming tooth; 82: adjusting rod; 83: reaming shaft; 84: second reaming tooth. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0022] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0023] Combine the following Figure 1 to Figure 2 A drilling device provided by the present invention is described.

[0024] like Figure 1 and Figure 2As shown, the drilling device shown in this embodiment includes: a casing 1, a flexible transmission shaft 2 and an elastic component 3.

[0025] The casing 1 is cylindrical; the flexible transmission shaft 2 is arranged in the casing 1, one end of the flexible transmission shaft 2 is used to connect with the output end of the power equipment, and the other end of the flexible transmission shaft 2 extends out of the casing 1 and is connected to the drill bit 4; a bearing 21 is sleeved in the middle of the flexible transmission shaft 2; the elastic component 3 is connected to the casing 1; there are multiple elastic components 3, and the multiple elastic components 3 are evenly distributed along the circumference of the casing 1; the elastic component 3 is detachably connected to the outer ring of the bearing 21; when the axis of the flexible transmission shaft 2 coincides with the axis of the casing 1, the multiple elastic components 3 are respectively connected to the outer ring of the bearing 21; when the axis of the flexible transmission shaft 2 is offset relative to the axis of the casing 1, the elastic component 3 located on the side close to the offset is connected to the outer ring of the bearing 21, and the elastic component 3 located away from the offset is separated from the outer ring of the bearing 21.

[0026] Specifically, the drilling device shown in the present embodiment is provided with a casing 1 and an elastic component 3. When drilling construction is carried out, the drill bit 4 and the casing 1 are inserted into the well 5, and the power equipment drives the flexible transmission shaft 2 to drive the drill bit 4 to rotate. The casing 1 separates the inner wall of the well 5 from the flexible transmission shaft 2, thereby avoiding the friction between the flexible transmission shaft 2 and the inner wall of the well 5, and reducing the wear of the flexible transmission shaft 2; when the axial resistance of the drill bit 4 is large or the drill bit is subjected to radial force, due to the long flexible transmission shaft 2, a certain bending will occur in the middle part of the flexible transmission shaft 2, that is, a certain deviation will occur in the axis of the flexible transmission shaft 2. At this time, the bearing 21 in the middle part of the flexible transmission shaft 2 will squeeze the elastic component 3 on the offset side. On the one hand, the elastic component 3 The deformation generated can compensate for the offset of the axis of the flexible transmission shaft 2. On the other hand, the elastic force generated by the deformation of the elastic component 3 can assist the flexible transmission shaft 2 to return to the correct position, thereby ensuring the stable rotation of the flexible transmission shaft 2; by arranging the elastic component 3 between the bearing 21 and the sleeve 1, compared with the rigid connection between the bearing 21 and the sleeve 1, the wear of the bearing 21 caused by uneven radial force is avoided, and the service life of the bearing 21 is extended; in this embodiment, by arranging the sleeve 1, the friction between the flexible transmission shaft 2 and the inner wall of the drilling 5 is avoided, and by arranging the bearing 21 in the middle part of the flexible transmission shaft 2, the friction between the flexible transmission shaft 2 and the inner wall of the sleeve 1 is avoided, thereby reducing the wear of the flexible transmission shaft 2 and extending the life of the flexible transmission shaft 2.

[0027] It should be noted that the elastic component 3 shown in this embodiment can be an elastic body as a whole, such as a rubber block or a spring. The elastic component 3 can also be a mechanical structure with a reset function.

[0028] In some embodiments, Figure 2As shown, the elastic component 3 shown in this embodiment includes: a slider 31 and an elastic member 32; an opening is provided on the sleeve 1, and the opening extends along the radial direction of the sleeve 1. The slider 31 is movably arranged in the opening, one end of the elastic member 32 is connected to the sleeve 1, and the other end of the elastic member 32 is connected to the slider 31; the slider 31 is detachably connected to the outer ring of the bearing 21.

[0029] Specifically, when the axis of the flexible transmission shaft 2 is offset, the axis of the flexible transmission shaft 2 is offset to the left as an example for explanation, wherein the directional words left and right are both represented by Figure 1 and Figure 2 The outer ring of the bearing 21 squeezes the slider 31 on the left side, and the slider 31 slides along the opening toward the outside of the sleeve 1. The slider 31 compresses the elastic member 32 while sliding. On the one hand, the sliding of the slider 31 can compensate for the deviation of the axis of the flexible transmission shaft 2. On the other hand, the elastic force generated by the compression of the elastic member 32 acts on the slider 31, so that the slider 31 pushes the axis of the flexible transmission shaft 2 back to the center, thereby ensuring the stability of the rotation of the flexible transmission shaft 2.

[0030] In some embodiments, Figure 1 and Figure 2 As shown, the elastic component 3 shown in this embodiment also includes: a limit block 33; the limit block 33 is arranged outside the sleeve 1, and the length of the limit block 33 along the axial direction of the sleeve 1 is greater than the aperture of the opening; one end of the limit block 33 is connected to the slider 31, and the other end of the limit block 33 is connected to the other end of the elastic member 32; the side of the limit block 33 close to the sleeve 1 is detachably connected to the outer wall of the sleeve 1; when the axis of the flexible transmission shaft 2 coincides with the axis of the sleeve 1, the limit block 33 abuts against the outer wall of the sleeve 1; when the axis of the flexible transmission shaft 2 is offset relative to the axis of the sleeve 1, the limit block 33 located on the side close to the offset is separated from the outer wall of the sleeve 1, and the limit block 33 located on the side away from the offset abuts against the outer wall of the sleeve 1.

[0031] Specifically, when the axis of the flexible transmission shaft 2 deviates to the left, the outer ring of the bearing 21 pushes the slider 31 and the limit block 33 on the left, so that the limit block 33 on the left is separated from the outer wall of the sleeve 1, and the outer ring of the bearing 21 is separated from the slider 31 on the right. In order to prevent the slider 31 on the right from falling into the sleeve 1 under the action of the elastic member 32, a limit block 33 is provided. The cross-sectional size of the limit block 33 is larger than the aperture of the opening. The opening can stop the limit block 33, thereby preventing the slider 31 from falling into the sleeve 1. At this time, the limit block 33 on the right abuts against the outer wall of the sleeve 1 under the action of the elastic member 32.

[0032] The limiting block 33 and the sliding block 31 may be an integrated structure.

[0033] In some embodiments, Figure 2As shown, the elastic component 3 shown in this embodiment also includes: a supporting part 34 and a rotating part 35; the supporting part 34 and the rotating part 35 are arranged outside the sleeve 1, one end of the supporting part 34 is connected to the outer wall of the sleeve 1, and the other end of the supporting part 34 is hinged to one end of the rotating part 35, and the rotating part 35 is connected to the limit block 33; the elastic member 32 is a torsion spring, the axis of the torsion spring is perpendicular to the axis of the sleeve 1, the torsion spring is arranged at the hinge of the supporting part 34 and the rotating part 35, one end of the torsion spring is connected to the supporting part 34, and the other end of the torsion spring is connected to the rotating part 35.

[0034] Specifically, the supporting portion 34, the torsion spring and the rotating portion 35 form a structure similar to a spring door. The rotating portion 35 can rotate around the hinge point. Under the elastic force of the torsion spring, the limit block 33 can be clamped between the rotating portion 35 and the sleeve 1; when the bearing 21 squeezes the slider 31 on the left side to slide outward, the limit block 33 on the left side generates a force on the rotating portion 35, and the rotating portion 35 overcomes the elastic force of the torsion spring and starts to rotate, thereby forming an avoidance space, which is used for the limit block 33 to move radially along the sleeve 1.

[0035] In some embodiments, Figure 2 As shown, the outer ring of the bearing 21 shown in this embodiment has a first end and a second end, the outer side wall of the outer ring is the first end, and the inner side wall of the outer ring is the second end; the first end is detachably connected to the slider 31, and the second end is connected to the inner ring of the bearing 21; the thickness of the first end along the axial direction of the sleeve 1 is smaller than the thickness of the second end along the axial direction of the sleeve 1, wherein the thickness of the first end along the axial direction of the sleeve 1 is smaller than the aperture of the opening, and the thickness of the second end along the axial direction of the sleeve 1 is greater than the aperture of the opening.

[0036] Specifically, the first end of the outer ring of the bearing 21 can extend into the opening, while the second end of the outer ring of the bearing 21 cannot extend into the opening, that is, the opening can serve as a stop for the second end of the outer ring of the bearing 21, thereby preventing the flexible transmission shaft 2 from contacting and rubbing with the sleeve 1 when excessively bent, thereby reducing the wear of the flexible transmission shaft 2.

[0037] In some embodiments, Figure 1 As shown, the drilling device shown in this embodiment also includes: a first bearing 6 and a second bearing 7; the first bearing 6 and the second bearing 7 are respectively arranged at the two ends of the casing 1, and the first bearing 6 and the second bearing 7 are sleeved on the flexible transmission shaft 2; an oil film is provided between the first bearing 6 and the flexible transmission shaft 2 and between the second bearing 7 and the flexible transmission shaft 2.

[0038] Specifically, the flexible transmission shaft 2 is rotatably connected to the first bearing 6 and the second bearing 7 respectively, a pressure oil film is formed between the first bearing 6 and the flexible transmission shaft 2, and a pressure oil film is formed between the second bearing 7 and the flexible transmission shaft 2. The pressure oil film plays a lubricating role, thereby reducing the wear of the flexible transmission shaft 2; wherein, the flexible transmission shaft 2 can slide axially relative to the first bearing 6 and the second bearing 7, and accordingly, when the drill bit 4 is subjected to a larger axial resistance, the flexible transmission shaft 2 slides axially relative to the second bearing 7, and the middle part of the flexible transmission shaft 2 will be extruded and bent.

[0039] In some embodiments, Figure 1 As shown, the drilling device shown in this embodiment further includes: a hole expansion mechanism 8; the hole expansion mechanism 8 is connected to the other end of the flexible transmission shaft 2, and the hole expansion mechanism 8 is arranged between the drill bit 4 and the casing 1.

[0040] Specifically, the borehole formed by the drill bit 4 has a small diameter. By providing the reaming mechanism 8, the flexible transmission shaft 2 drives the reaming mechanism 8 to rotate to expand the borehole diameter, thereby meeting actual drilling needs.

[0041] In some embodiments, Figure 1 As shown, the reaming mechanism 8 shown in this embodiment includes: a first reaming tooth 81, an adjusting rod 82 and a reaming shaft 83; the other end of the flexible transmission shaft 2 is connected to one end of the reaming shaft 83, and the other end of the reaming shaft 83 is connected to the drill bit 4; the adjusting rod 82 extends along the radial direction of the reaming shaft 83, and the adjusting rod 82 is movably arranged on the reaming shaft 83 along the radial direction of the reaming shaft 83, one end of the adjusting rod 82 is hinged to one end of the first reaming tooth 81, and the other end of the first reaming tooth 81 is movably arranged on the reaming shaft 83 along the axial direction of the reaming shaft 83.

[0042] Specifically, by extending or retracting the adjusting rod 82, the rotation radius of the first reaming tooth 81 is adjusted, thereby realizing the adjustment of the reaming aperture; when it is necessary to increase the reaming aperture, the adjusting rod 82 is extended, the angle between the adjusting rod 82 and the first reaming tooth 81 is reduced, and the other end of the first reaming tooth 81 moves toward the side close to the adjusting rod 82, thereby increasing the projection length of the first reaming tooth 81 on the plane perpendicular to the axial direction of the reaming axis 83; when it is necessary to reduce the reaming aperture, the adjusting rod 82 is retracted, the angle between the adjusting rod 82 and the first reaming tooth 81 is increased, and the other end of the first reaming tooth 81 moves toward the side away from the adjusting rod 82, thereby reducing the projection length of the first reaming tooth 81 on the plane perpendicular to the axial direction of the reaming axis 83.

[0043] In some embodiments, Figure 1As shown, the reaming mechanism 8 shown in this embodiment also includes: a second reaming tooth 84; one end of the adjusting rod 82 is hinged to one end of the second reaming tooth 84, and the other end of the second reaming tooth 84 is movably provided on the reaming shaft 83 along the axial direction of the reaming shaft 83; the moving direction of the other end of the second reaming tooth 84 is opposite to the moving direction of the other end of the first reaming tooth 81.

[0044] Specifically, the first hole-expanding tooth 81 and the second hole-expanding tooth 84 are respectively arranged on both sides of the adjusting rod 82. When the adjusting rod 82 is extended or retracted, the adjusting rod 82 drives the first hole-expanding tooth 81 and the second hole-expanding tooth 84 to move synchronously, and when the other end of the first hole-expanding tooth 81 moves upward, the other end of the second hole-expanding tooth 84 moves downward, and when the other end of the first hole-expanding tooth 81 moves downward, the other end of the second hole-expanding tooth 84 moves upward. By setting the second hole-expanding tooth 84, the overall stability of the hole-expanding mechanism 8 is improved and the quality of hole expansion is guaranteed.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A drilling device, It is characterized in that include: A sleeve, wherein the sleeve is cylindrical; A flexible transmission shaft, wherein the flexible transmission shaft is arranged in the casing, one end of the flexible transmission shaft is used to be connected to the output end of the power equipment, and the other end of the flexible transmission shaft extends out of the casing and is connected to the drill bit; a bearing is sleeved in the middle of the flexible transmission shaft; An elastic component, the elastic component is connected to the sleeve; the elastic components are provided in plurality, and the plurality of elastic components are evenly distributed along the circumference of the sleeve; the elastic component is detachably connected to the outer ring of the bearing; When the axis of the flexible transmission shaft coincides with the axis of the sleeve, the plurality of elastic components are respectively connected to the outer ring of the bearing; when the axis of the flexible transmission shaft deviates relative to the axis of the sleeve, the elastic component located on the side close to the deviation is connected to the outer ring of the bearing, and the elastic component located on the side away from the deviation is separated from the outer ring of the bearing; The elastic component comprises: a slider and an elastic member; The sleeve is provided with an opening, which extends in the radial direction of the sleeve. The slider is movably arranged in the opening. One end of the elastic member is connected to the sleeve, and the other end of the elastic member is connected to the slider. The slider is detachably connected to the outer ring of the bearing.

2. The drilling device according to claim 1, It is characterized in that The elastic component further comprises: a limit block; The limit block is arranged outside the sleeve, and the length of the limit block along the axial direction of the sleeve is greater than the aperture of the opening; One end of the limit block is connected to the slider, and the other end of the limit block is connected to the other end of the elastic member; the side of the limit block close to the sleeve is detachably connected to the outer wall of the sleeve; When the axis of the flexible transmission shaft coincides with the axis of the sleeve, the limit block abuts against the outer wall of the sleeve; when the axis of the flexible transmission shaft is offset relative to the axis of the sleeve, the limit block located on the side close to the offset is separated from the outer wall of the sleeve, and the limit block located on the side away from the offset abuts against the outer wall of the sleeve.

3. The drilling device according to claim 2, It is characterized in that The elastic component further comprises: a supporting portion and a rotating portion; The support part and the rotating part are arranged outside the sleeve, one end of the support part is connected to the outer side wall of the sleeve, the other end of the support part is hinged to one end of the rotating part, and the rotating part is connected to the limit block; The elastic member is a torsion spring, the axis of which is perpendicular to the axis of the sleeve, and the torsion spring is arranged at the hinge between the support part and the rotating part, one end of the torsion spring is connected to the support part, and the other end of the torsion spring is connected to the rotating part.

4. The drilling device according to claim 1, It is characterized in that The outer ring of the bearing has a first end and a second end, the first end is detachably connected to the slider, and the second end is connected to the inner ring of the bearing; The thickness of the first end along the axial direction of the sleeve is smaller than the thickness of the second end along the axial direction of the sleeve, wherein the thickness of the first end along the axial direction of the sleeve is smaller than the aperture of the opening, and the thickness of the second end along the axial direction of the sleeve is greater than the aperture of the opening.

5. The drilling device according to claim 1, It is characterized in that The drilling device further comprises: a first bearing bush and a second bearing bush; The first bearing bush and the second bearing bush are respectively arranged at two ends of the sleeve, and the first bearing bush and the second bearing bush are sleeved on the flexible transmission shaft; An oil film is provided between the first bearing bush and the flexible transmission shaft, and between the second bearing bush and the flexible transmission shaft.

6. The drilling device according to claim 1, It is characterized in that The drilling device further comprises: a hole expansion mechanism; The hole expanding mechanism is connected to the other end of the flexible transmission shaft, and the hole expanding mechanism is arranged between the drill bit and the casing.

7. The drilling device according to claim 6, It is characterized in that The reaming mechanism comprises: a first reaming tooth, an adjusting rod and a reaming shaft; The other end of the flexible transmission shaft is connected to one end of the reaming shaft, and the other end of the reaming shaft is connected to the drill bit; The adjusting rod extends along the radial direction of the reaming shaft, and the adjusting rod is movably arranged on the reaming shaft along the radial direction of the reaming shaft. One end of the adjusting rod is hinged to one end of the first reaming tooth, and the other end of the first reaming tooth is movably arranged on the reaming shaft along the axial direction of the reaming shaft.

8. The drilling device according to claim 7, It is characterized in that The reaming mechanism further comprises: a second reaming tooth; One end of the adjusting rod is hinged to one end of the second reaming tooth, and the other end of the second reaming tooth is movably arranged on the reaming shaft along the axial direction of the reaming shaft; the moving direction of the other end of the second reaming tooth is opposite to the moving direction of the other end of the first reaming tooth.

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