Recoverable whipstock suitable for directional coring drilling of polar region ice layer
By designing a reusable directional drilling tool suitable for polar ice core sampling, and employing a mechanical anchoring and straightening system, the problems of orientation difficulties and main borehole blockage were solved, achieving precise orientation and reusability, reducing costs and adapting to the polar environment.
Patent Information
- Application Number
- CN202511307962.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-15
- Publication Date
- 2025-11-21
AI Technical Summary
Existing ice layer directional coring technology suffers from problems such as difficulty in orientation, main hole blockage, and complex operation. In particular, retrievable directional drilling tools lack precise orientation capabilities and are prone to freezing and stuck drill accidents.
A recyclable directional drilling device including a retrieval mechanism and a directional drilling mechanism was designed. It adopts a mechanical anchoring and straightening system, and achieves reliable fixation of armored cables and power transmission through cable terminals and power components. Combined with directional drilling wedges and spreading components, it achieves precise orientation at any depth in the main hole without the need for hole enlargement.
It enables controllable skewing at any depth within the main borehole, avoids the randomness of branch borehole orientation, can be reused, reduces costs, is adaptable to polar environments, and is easy to operate and highly reliable.
Smart Images
Figure CN120990486A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of ice layer directional coring drilling, and in particular relates to a recyclable whipstock suitable for polar ice layer directional coring drilling. BACKGROUND
[0002] Glaciers, as the "natural archives" of paleoclimate and environmental change, are widely distributed in the polar and high mountain regions of the earth. Through drilling to obtain ice core samples and scientific analysis, it has become a core means to reveal historical climate information, understand glacier dynamics and predict global environmental evolution. However, the amount of ice core samples obtained by a single drilling is often insufficient to meet the needs of comprehensive and in-depth scientific research, and it is urgent to drill more ice cores on the basis of existing drill holes.
[0003] Ice layer directional coring drilling technology acquires repeated ice cores by drilling branch holes in the main hole at low cost, which makes up for the problem of insufficient or defective single ice core sample quantity, and significantly reduces the logistics cost and environmental disturbance.
[0004] At present, there are three kinds of ice layer directional coring drilling technologies, which are whipstock directional coring drilling technology, drill natural correction directional coring drilling technology and power pushing type directional coring drilling technology. Among them, the whipstock directional coring drilling technology has become the most widely used method due to its simple and reliable, low cost advantage. The whipstock is divided into fixed whipstock and recyclable whipstock. The fixed whipstock has simple structure and mature technology, and is mainly used to bypass the stuck drill accident, but it has a fundamental defect that it permanently blocks the main hole after being lowered into the hole, which makes the main hole unable to be drilled or lowered into the logging instrument subsequently, and the branch hole direction cannot be accurately controlled, only the whipstock can be made at the bottom of the hole, and the directional coring at any depth of the main hole cannot be realized, so the applicability is limited. Although the recyclable whipstock can be recycled to ensure the smoothness of the main hole, there are obvious shortcomings in its design. The lack of directional function leads to random branch hole direction, and when it is matched with hot melt drill, the problem of melt water removal is easy to cause freezing and sticking accidents; when it is matched with electric mechanical drill, complex reaming process is needed, and excessive ice chips may be generated during the reaming process to block the drill hole, or the contact force between the drill tool anti-torque system and the hole wall may decrease due to the enlargement of the diameter of the drill hole, causing the anti-torque system to fail. SUMMARY
[0005] The purpose of the present application is to solve the problems of directional difficulty, main hole blockage and complex operation in the existing ice layer directional coring technology, and to provide a recyclable whipstock which can accurately direct, recycle and does not need to ream and is suitable for polar environment.
[0006] To achieve the above object, the application adopts the following technical scheme: A recyclable whipstock suitable for polar ice layer directional coring drilling, comprising a recycling mechanism and a build-up mechanism; the recycling mechanism comprises a cable terminal and a power assembly; the cable terminal comprises a brass bevel, a lower constraint sleeve and a plug; the brass bevel is arranged in the inner cavity of the lower constraint sleeve, and the brass bevel is conical, the outer shape of the brass bevel matches the inner wall shape of the lower constraint sleeve, and the center of the brass bevel is provided with a central through hole for the cable line of the armored cable to pass through; the plug is installed at the bottom of the lower constraint sleeve, the inside of the plug is provided with a central through hole, and the upper end surface of the plug abuts against the lower end surface of the brass bevel; the armored layer of the armored cable is attached to the outer wall of the brass bevel and the inner wall of the cavity of the lower constraint sleeve, and is fixed to the plug; the cable line of the armored cable passes through the central through holes of the brass bevel and the plug in sequence, and is connected with a water-tight connector after passing out of the plug, and the water-tight cable connected with the water-tight connector supplies power for the power assembly; when the armored cable is subjected to tensile force, the plug is pulled and moves upward, pushes the brass bevel to slide along the inner wall of the lower constraint sleeve, radial extrusion force is generated through taper surface cooperation, so as to compress the armored layer of the armored cable. The power assembly comprises a pressure-resistant cabin, a speed reducer, a righting plate spring and an adjusting mechanism; the pressure-resistant cabin is formed by bolt connection of a pressure-resistant cabin body and pressure-resistant cabin upper and lower end covers arranged at both ends of the pressure-resistant cabin body; the righting plate spring is installed outside the pressure-resistant cabin body through the adjusting mechanism; the speed reducer is arranged inside the pressure-resistant cabin, and the output shaft thereof is connected with the upper driven shaft through a shaft coupling; the build-up mechanism comprises a build-up wedge body and a strutting assembly, the build-up wedge body comprises an upper wedge block, a lower wedge block and a fishing assembly; the fishing assembly is used to realize connection and separation of the upper wedge block and the lower wedge block, the strutting assembly comprises a through-hole shaft, a multi-ear hinge nut seat, a driven support arm, a driving support arm and a strutting piece; the multi-ear hinge nut seat is sleeved outside the through-hole shaft through thread cooperation; the driving support arm is hinged with the multi-ear hinge nut seat; the number of the driven support arms is two, and the upper and lower ends of the strutting piece are hinged with the upper and lower hinge ear seats respectively; the strutting piece is hinged with the driving support arm and the driven support arm simultaneously, and constitutes a linkage mechanism; the through-hole shaft is driven to rotate by the speed reducer in cooperation with the driving shaft, and then drives the multi-ear hinge nut seat to move axially, and drives the strutting piece to expand or contract radially through the driving support arm and the driven support arm.
[0007] Further, the adjusting mechanism comprises an adjusting bolt, a positioning pin, a positioning seat, a fastening bolt and a hoop ring; the outer edge of the upper end cover of the pressure cabin is provided with a threaded hole for mounting the adjusting bolt; the positioning pin passes through the positioning seat and is fixed by a nut; the adjusting bolt is connected with the positioning pin; the positioning seat is fixed on the hoop ring by a bolt; the hoop ring is composed of three arc-shaped plates connected by fastening bolts; the upper end of the righting leaf spring is hinged to the hoop ring, and the lower end is hinged to the outer wall of the cabin body of the pressure cabin; rotating the adjusting bolt drives the hoop ring to move up and down along the outer wall of the cabin body of the pressure cabin to adjust the opening degree of the righting leaf spring.
[0008] Further, the fishing assembly comprises a fixed bearing, a limiting cylinder, a fishing cylinder, a limiting bearing, a reset pin, a reset spring, a bayonet, a guide ring, a positioning disc and a positioning guide tube; the fixed bearing, the limiting cylinder, the fishing cylinder, the limiting bearing, the reset pin, the reset spring and the positioning disc are located in the central through hole of the upper wedge block; the bayonet, the guide ring and the positioning guide tube are located in the central through hole of the lower wedge block, the bayonet and the guide ring are both in a semi-spherical structure and have a through hole in the middle, the bayonet is sleeved on the upper end of the positioning guide tube and is fixed on the positioning guide tube, the guide ring is sleeved on the positioning guide tube and is located between the bayonet and the lower fixed flange disc, the guide ring can freely slide on the outer surface of the guide tube, the fixed bearing is installed on the lower bottom surface of the upper fixed flange disc; the fishing cylinder is fixedly connected with the upper fixed flange disc, and the inside of the fishing cylinder is provided with a boss for placing the limiting bearing; the limiting bearing is provided with a limiting cylinder above, and the upper end of the limiting cylinder is in contact with the fixed bearing; the bottom of the fishing cylinder is provided with a groove for accommodating the reset spring and the reset pin, and the groove corresponds to the groove of the positioning disc; the positioning disc is fixedly connected with the fishing cylinder; the front end of the reset pin is beveled, and when being pressed, the reset pin compresses the reset spring and moves outward along the groove; the positioning guide tube is fixedly connected with the lower fixed flange disc; during lowering, the reset pin is stretched out and abuts against the bottom end surface of the bayonet under the action of the reset spring, so that the upper wedge block and the lower wedge block are connected; during recovery, the reset pin is reconnected with the bayonet after being reset under the action of the axial pressure, so that the fishing recovery is realized.
[0009] Further, the distraction assembly further comprises an upper flange base, a lower flange base, an upper hinged lug seat, a lower hinged lug seat, a positioning bearing and a hinge pin shaft; the upper flange base is fixedly connected with the upper fixed flange disc; the upper hinged lug seat and the lower hinged lug seat are respectively fixed on the bottom of the upper flange base and the top of the lower flange base; the number of the positioning bearings is two, which are respectively installed at the central positions of the upper flange base and the lower flange base to support the through hole shaft; the driving support arm and the driven support arm are both hinged with the distraction piece through the hinge pin shaft.
[0010] Further, the cable terminal further comprises a connecting pipe, a cable terminal nut, a cable terminal upper cover, an upper constraint sleeve cover, a limiting screw, an upper constraint sleeve, a spring and a cable terminal shell; the connecting pipe is in interference fit with the cable terminal upper cover; the connecting pipe is used for allowing the armored cable to pass through and enter the cable terminal; the cable terminal nut is sleeved outside the connecting pipe; the cable terminal upper cover is in threaded connection with the cable terminal shell; the upper constraint sleeve cover, the limiting screw, the upper constraint sleeve, the spring, a brass inclined cone, a lower constraint sleeve and a plug are arranged inside the cable terminal shell; the limiting screw is installed on the cable terminal upper cover, and the front end of the limiting screw extends into the upper constraint sleeve to limit the rotation and axial displacement of the upper constraint sleeve; the spring is arranged inside the upper constraint sleeve, and the upper end of the spring is limited by the upper constraint sleeve cover, and the lower end of the spring is in contact with the lower constraint sleeve; the cable terminal shell is fixedly connected with the upper end cover of the pressure-resistant cabin through bolts.
[0011] Further, the wedge surface of the upper wedge block is oppositely arranged with the wedge surface of the lower wedge block, and the wedge surfaces of the two are consistent in the inclination angle with the vertical direction; the wedge surface of the upper wedge block is provided with a damping washer.
[0012] Further, a shaft coupling positioning flange is arranged outside the shaft coupling, and the shaft coupling positioning flange, the lower end cover of the pressure-resistant cabin and the cabin body are fixedly connected through bolts to constrain the shaft coupling at the central position of the shaft coupling positioning flange.
[0013] Further, a lip-shaped sealing ring is arranged at the lower end cover of the pressure-resistant cabin through which the output shaft of the speed reducer passes.
[0014] Further, the through-hole shaft is a hollow structure, and a key groove is arranged inside the through-hole shaft and used for matching with the key position of the front end of the driving shaft.
[0015] Further, the number of the expansion pieces is four, and the four expansion pieces are uniformly distributed.
[0016] Compared with the prior art, the present application has the following beneficial effects:
[0017] Precise orientation: through the mechanical anchoring and centralizing system, controllable deviation can be realized at any depth and high side in the main hole, and the randomness of the branch hole direction is avoided, wherein the high side refers to one side in a relatively high position in the cross section of the main hole.
[0018] Recyclable and reusable: after the lower wedge block completes the deviation task, the deviation mechanism can be completely recycled through fishing and contraction of the expansion assembly, and the main hole can be repeatedly used, thereby significantly reducing the cost.
[0019] No need to ream: through the modular design and the expansion assembly suitable for different hole diameters, the hole diameter of the common specification electric mechanical drilling tool can be directly adapted, and the complex and time-consuming reaming process and the ice chip problem caused thereby are avoided.
[0020] High reliability: Made of stainless steel, with bearings in key parts to reduce energy loss, the mechanical structure is simple and reliable, and can adapt to harsh polar environments.
[0021] Easy to operate: The lowering and retrieval processes are both completed by ground-controlled geared motors and armored cables, with a clear process and a high degree of automation. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the overall structure of the recyclable slant generator of the present invention;
[0023] Figure 2 This is a schematic cross-sectional view of the recyclable slant generator of the present invention;
[0024] Figure 3 This is a cross-sectional structural diagram of the recyclable slant generator of the present invention during its lowering process;
[0025] Figure 4 This is a cross-sectional structural diagram of the tilting mechanism of the present invention in its working state;
[0026] Figure 5 This is a schematic cross-sectional view of the cable terminal structure of the present invention;
[0027] Figure 6 This is a schematic diagram of the power component structure of the present invention;
[0028] Figure 7 This is a cross-sectional view of the power component of the present invention;
[0029] Figure 8 This is a schematic diagram of the cross-sectional structure of the inclined wedge of the present invention;
[0030] Figure 9 for Figure 8 A magnified view of a section at point A in the middle;
[0031] Figure 10 This is a schematic diagram of the structure of the extended component of the present invention;
[0032] The figure is marked as follows: 1- connecting pipe; 2- cable terminal nut; 3- cable terminal upper cover; 4- upper restraint sleeve cover; 5- limiting screw; 6- upper restraint sleeve; 7- spring; 8- cable terminal shell; 9- brass inclined cone; 10- lower restraint sleeve; 11- plug; 12- watertight connector; 13- pressure cabin upper end cover; 14- adjusting bolt; 15- sealing ring; 16- positioning pin; 17- positioning seat; 18- fastening bolt; 19- hoop ring; 20- pressure cabin body; 21- centralizer plate spring; 22- speed reducer motor; 23- connecting bolt; 24- lip seal ring; 25- pressure cabin lower end cover; 26- coupling; 27- coupling positioning flange; 28- driving shaft; 29- upper fixed flange plate; 30- fixed bearing; 31- upper wedge block; 32- shock absorbing washer; 33- limiting cylinder; 34- fishing cylinder; 35- limiting bearing; 36- reset pin; 37- reset spring; 38- bayonet; 39- guide ring; 40- positioning disc; 41- positioning guide tube; 42- lower wedge block; 43- lower fixed flange plate; 44- upper flange base; 45- upper hinged lug base; 46- positioning bearing; 47- driven support arm; 48- hinged pin shaft; 49- driving support arm; 50- expansion piece; 51- multi-lug hinge nut base; 52- through-hole shaft; 53- lower hinged lug base; 54- lower flange base; 55- drilled hole wall. DETAILED DESCRIPTION
[0033] In order to make the objects, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments. Those skilled in the art should understand that the specific description below is illustrative rather than limiting, and should not limit the protection scope of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should be understood as the usual meaning understood by those skilled in the art in the field of the present application. In order to avoid obscuring the essence of the present application, well-known methods, processes, procedures, elements and circuits are not described in detail.
[0034] As Figures 1 to 10 shown, the present application proposes a recyclable whipstock suitable for polar ice layer directional coring drilling, comprising a recycling mechanism and a build-up mechanism.
[0035] The recovery mechanism includes a cable terminal and a power assembly. The cable terminal is used to realize reliable fixing, tension transmission and power conduction of the armored cable, and the core is to use the taper surface self-locking effect of the brass inclined cone 9 to convert the axial tension into radial clamping force to firmly clamp the armored cable. The power assembly includes a pressure-resistant cabin, a speed reducer motor 22, a righting plate spring 21 and an adjusting mechanism. The pressure-resistant cabin provides a sealed pressure-resistant environment for the speed reducer motor 22; the righting plate spring 21 is installed outside the pressure-resistant cabin body 20 through the adjusting mechanism, and its opening degree is adjusted through the ground to ensure that the recoverable whipstock is centered in the drilling hole and reduces the rotation; the speed reducer motor 22 transmits power to the driving shaft 28 below through the shaft coupling 26.
[0036] The whipstock mechanism includes a whipstock wedge body and a strutting assembly. The whipstock wedge body includes an upper wedge block 31, a lower wedge block 42 and a fishing assembly. The fishing assembly realizes reliable connection and quick separation of the upper wedge block 31 and the lower wedge block 42 through the cooperation of the reset pin 36 and the reset spring 37. The strutting assembly includes a through-hole shaft 52, a multi-ear hinge nut seat 51, a driven support arm 47, a driving support arm 49 and a strutting piece 50. The multi-ear hinge nut seat 51 is sleeved on the outside of the through-hole shaft 52 through threaded cooperation. The driving support arm 49 is hinged with the multi-ear hinge nut seat 51; the strutting piece 50 is hinged with the driving support arm 49 and the driven support arm 47 at the same time, forming a linkage mechanism. The through-hole shaft 52 cooperates with the driving shaft 28, and the speed reducer motor 22 drives the through-hole shaft 52 to rotate through the driving shaft 28, drives the multi-ear hinge nut seat 51 to move axially, and then drives the strutting piece 50 to expand or contract radially through the driving support arm 49 and the driven support arm 47, realizing anchoring and releasing in the drilling hole.
[0037] Specifically, the cable terminal comprises a connecting pipe 1, a cable terminal nut 2, a cable terminal upper cover 3, an upper constraint sleeve cover 4, a limiting screw 5, an upper constraint sleeve 6, a spring 7, a cable terminal shell 8, a brass inclined cone 9, a lower constraint sleeve 10 and a plug 11; the connecting pipe 1 is made of stainless steel and has a hollow tubular structure, which is in interference fit with the cable terminal upper cover 3 to ensure the continuity of the mechanical force transmission of the armored cable. After the armored cable passes through the connecting pipe 1, it enters the inside of the cable terminal, the plug 11 is fixedly connected with the armored layer at the end of the armored cable, and is fixed through the cooperation of the brass inclined cone 9 and the lower constraint sleeve 10, the cable wire at the end of the armored cable is connected with the water-tight cable through a water-tight connector 12 to realize power transmission. The cable terminal nut 2 is threadedly sleeved outside the connecting pipe 1, and the stable fixation of the connecting pipe 1 and the sealing and anti-loosening of the connecting part are realized by screwing the cable terminal nut 2. The cable terminal upper cover 3 serves as a bearing structure, is threadedly connected with the cable terminal shell 8, and is used for closing the upper part of the cable terminal and providing an installation reference and a protection space for the internal components of the cable terminal. The upper constraint sleeve cover 4, the limiting screw 5, the upper constraint sleeve 6, the spring 7, the cable terminal shell 8, the brass inclined cone 9, the lower constraint sleeve 10 and the plug 11 are arranged inside the cable terminal shell 8, the upper constraint sleeve cover 4 is covered on the upper end of the upper constraint sleeve 6, the limiting screw 5 is screwed on the corresponding installation position of the cable terminal upper cover 3, the front end of the limiting screw 5 extends into the upper constraint sleeve 6, thereby limiting and constraining the rotation and axial displacement of the upper constraint sleeve 6, the upper constraint sleeve cover 4 is used for closing the upper end of the upper constraint sleeve 6 and limiting and protecting the spring 7, preventing the spring 7 from coming out and ensuring the working stability of the spring 7. The upper constraint sleeve 6 is sleeved outside the spring 7, the upper end of the spring 7 is limited by the upper constraint sleeve cover 4, the lower end of the spring 7 is supported by the lower constraint sleeve 10, and the spring 7 is arranged inside the upper constraint sleeve 6, so that the spring 7 is only allowed to deform in the axial direction under the radial constraint, thereby improving the working stability and reliability of the spring 7. The lower end surface of the spring 7 and the upper end surface of the lower constraint sleeve 10 are in non-fixed contact with the upper constraint sleeve cover 4, and can be axially deformed when subjected to force, so as to realize the compression and rebound functions of the spring 7; when subjected to tension, the spring 7 is compressed by the lower constraint sleeve 10 and uses elastic deformation to buffer the tension, thereby providing a stable tension to the structure below, realizing mechanical buffering, reducing the damage of external force to the connection between the armored cable and the cable terminal, and ensuring long-term stable connection. The cable terminal shell 8 is a cylindrical shell and contains the internal components, the outer side of the cable terminal shell 8 is connected with the upper end cover 13 of the pressure-resistant cabin through M5 standard bolts, thereby playing a role in supporting the whole, protecting the internal components from the influence of the external environment, and providing a space reference for the installation and cooperation of the internal components.The brass inclined cone 9 is a conical brass member, which is provided with a central through hole for the armored cable to pass through, and is installed in the inner cavity of the lower restraint sleeve 10, with the lower end surface of the brass inclined cone 9 abutting against the plug 11, and the outer side of the brass inclined cone 9 contacting the armored layer of the armored cable. The plug 11 is fixedly connected with the armored layer of the armored cable. When the armored cable is subjected to a pulling force, the plug 11 pushes the brass inclined cone 9 upward. The brass inclined cone 9 converts the axial pulling force into a radial pressure between the brass inclined cone 9 and the lower restraint sleeve 10 through the conical surface structure, so as to compress the armored layer of the armored cable and realize mechanical locking and anti-slippage. Due to the conical surface self-locking effect, the greater the pulling force is, the stronger the radial compression force is, so as to realize reliable fixing of the armored cable. The conical surface is made of brass to balance the strength and wear resistance.
[0038] In operation, the armored cable is inserted from the upper part of the cable terminal, and is fixedly connected with the lower restraint sleeve 10 through the cooperation of the brass inclined cone 9 and the plug 11. That is, after the armored cable passes through the upper restraint sleeve cover 4, the upper restraint sleeve 6 and the spring 7 in sequence, the armored layer of the armored cable is attached to the outer side conical surface of the brass inclined cone 9 and the inner wall of the cavity of the lower restraint sleeve 10, and is fixedly connected with the plug 11. The cable line of the armored cable passes through the central through hole of the brass inclined cone 9 and the plug 11 in the inner part of the lower restraint sleeve 10. When the armored cable is subjected to a pulling force, the plug 11 pushes the brass inclined cone 9 to move upward, the conical surface of the brass inclined cone 9 slides and generates a radial extrusion force with the lower restraint sleeve 10, so as to tightly compress the armored layer of the armored cable by the outer side wall of the brass inclined cone 9, and form a stable connection. After the armored cable passes out of the plug 11, the cable line is connected with the male connector of the watertight connector 12, and the electric energy is transmitted to the lower power assembly through the watertight cable to supply power for the lower power assembly. When subjected to a pulling force, the pulling force is transmitted to the plug 11 through the armored cable, the plug 11 is displaced upward to push the brass inclined cone 9 to extrude the lower restraint sleeve 10 to generate self-locking, the lower restraint sleeve 10 compresses the spring 7, the spring 7 buffers the pulling force, and the lower restraint sleeve 10, the brass inclined cone 9 and the plug 11 cooperate to tightly compress the armored layer of the armored cable by extruding the conical surface of the brass inclined cone 9, so as to make the armored cable and the cable terminal upper cover 3 and the cable terminal shell 8 form a stable whole, and provide a pulling force for the lower structure. The cable terminal shell 8 and the upper end cover 13 of the pressure-resistant cabin are fixed together through M5 standard bolts, so as to realize overall fixing and protection of the cable terminal, and the cooperation of the components guarantees mechanical transmission and power conduction of the cable terminal.
[0039] The power assembly comprises a watertight connector 12, an upper end cover of the pressure cabin 13, an adjusting bolt 14, a sealing ring 15, a positioning pin 16, a positioning seat 17, a fastening bolt 18, a hoop ring 19, a pressure cabin body 20, a righting plate spring 21, a speed reducer 22, a connecting bolt 23, a lip-shaped sealing ring 24, a lower end cover of the pressure cabin 25, a shaft coupling 26 and a shaft coupling positioning flange 27; the pressure cabin body 20 is connected and fixed with the upper end cover of the pressure cabin 13 and the lower end cover of the pressure cabin 25 arranged at both ends of the pressure cabin body 20 through M5 standard bolts to form the pressure cabin, and the sealing ring 15 is arranged between the combination surface of the pressure cabin body 20 and the upper end cover of the pressure cabin 13 and the lower end cover of the pressure cabin 25 at both ends of the pressure cabin body 20, that is, the sealing ring 15 is added between the pressure cabin body 20 and the upper end cover of the pressure cabin 13 and the lower end cover of the pressure cabin 25 arranged at both ends of the pressure cabin body 20, and then the sealing is completed by pressing with the M5 standard bolt; it should be noted that, in the thread standard, M5 represents the thread size with a nominal diameter of 5 mm, M2.5 represents the thread size with a nominal diameter of 2.5 mm, and M8 represents the thread size with a nominal diameter of 8 mm, which meets the requirements of the ISO international standard. The pressure cabin provides support for the entire power assembly and provides sealing and pressure protection for the internal speed reducer 22. Three threaded holes for installing the adjusting bolt 14 are arranged on the outer edge of the upper end cover of the pressure cabin 13, the positioning pin 16 is provided with an opening in the middle, the opening passes through the through hole of the positioning seat 17 and is fixed with the positioning seat 17 by an M8 standard nut, the tail of the adjusting bolt 14 is connected with the positioning pin 16 by an M2.5 screw, and all the positioning seats 17 are fixed on the hoop ring 19 by M5 standard bolts. The hoop ring 19 is composed of three arc-shaped plates with the same structure, and the adjacent arc-shaped plates are connected and fixed by the fastening bolt 18. In the embodiment, the number of righting plate springs 21 is three, the three righting plate springs 21 are uniformly distributed in the circumferential direction, the upper end of the righting plate spring 21 is hinged to the hoop ring 19, and the lower end is hinged to the outer wall of the pressure cabin body 20. By synchronously adjusting the three adjusting bolts 14, the adjusting bolt 14 rotates to drive the positioning seat 17 to move up and down relative to the upper end cover of the pressure cabin 13, and since the positioning seat 17 and the hoop ring 19 are fixedly connected in one body, the hoop ring 19 is driven to move up and down along the outer wall of the pressure cabin body 20, so as to compress the righting plate spring 21, adjust the opening degree of the righting plate spring 21 and make it just tightly contact the borehole wall 55 during fishing, and due to the radial constraint of the righting plate spring 21, the output shaft of the speed reducer 22 is always coaxially aligned with the borehole center, and the friction between the righting plate spring 21 and the borehole wall 55 can offset the overall rotation trend of the entire mechanism, so as to provide precise docking conditions for the fishing mechanism, and finally realize the recycling action of the recyclable whipstock. In the lowering stage, the adjusting bolt 14, the positioning seat 17, the hoop ring 19 and the righting plate spring 21 are not installed. The lower end of the righting plate spring 21 is fixed on the pressure cabin body 20, and the upper end is fixed on the hoop ring 19 by the connecting bolt 23, and the opening and closing of the righting plate spring 21 is completed with the up-down displacement of the hoop ring 19.The watertight connector 12 is installed on the upper end cover 13 of the pressure cabin, and the watertight connector 12 is electrically connected with the speed reducer 22 through a watertight cable to provide power for the speed reducer 22 in the pressure cabin 20. The speed reducer 22 is fixed to the bottom of the pressure cabin 20 through M5 standard bolts to reduce disturbance in the working state. The output shaft of the speed reducer 22 is connected with the coupling 26 to transmit power to the driving shaft 28 at the lower end. The outer side of the coupling 26 is a coupling positioning flange 27. The coupling positioning flange 27, the lower end cover 25 of the pressure cabin and the pressure cabin 20 are fixedly connected by the same M5 bolts. The coupling positioning flange 27 restrains the coupling 26 at the center position. The coupling 26 can rotate freely but cannot displace. The output shaft of the speed reducer 22 penetrates the lower end cover 25 of the pressure cabin, and a lip seal ring 24 is installed at the lower end cover 25 to complete the dynamic seal of the output end and prevent liquid in the borehole from entering the pressure cabin.
[0040] The wedge body comprises an upper fixed flange 29, an upper wedge block 31, a shock pad 32, a lower wedge block 42, a driving shaft 28, a lower fixed flange 43 and a fishing assembly. The upper fixed flange 29 is fixedly connected with the lower end cover 25 of the pressure-resistant cabin. The upper wedge block 31 is fixedly connected with the upper fixed flange 29. The lower wedge block 42 is fixedly connected with the lower fixed flange 43. The upper wedge block 31 and the lower wedge block 42 have central through holes. The wedge surface of the upper wedge block 31 is oppositely arranged with the wedge surface of the lower wedge block 42. The wedge surfaces of the two blocks have the same inclination angle with the vertical direction. The wedge surfaces of the two blocks actually have an inclination angle of 5° with the vertical direction. The shock pad 32 is installed on the wedge surface of the upper wedge block 31 and can effectively reduce the impact between the wedge surfaces during work. The fishing assembly comprises a fixed bearing 30, a limiting cylinder 33, a fishing cylinder 34, a limiting bearing 35, a reset pin 36, a reset spring 37, a bayonet 38, a guide ring 39, a positioning disc 40 and a positioning guide pipe 41. The fixed bearing 30, the limiting cylinder 33, the fishing cylinder 34, the limiting bearing 35, the reset pin 36, the reset spring 37 and the positioning disc 40 are located in the central through hole of the upper wedge block 31. The bayonet 38, the guide ring 39 and the positioning guide pipe 41 are located in the central through hole of the lower wedge block 42. The positioning guide pipe 41 is threadedly connected to the lower fixed flange 43. The upper thread of the positioning guide pipe 41 is connected with the bayonet 38. The bayonet 38 and the guide ring 39 have a hemispherical structure and a central through hole. The through hole of the bayonet 38 is a threaded structure and is fixed with the positioning guide pipe 41. The central through hole of the guide ring 39 is smooth and can freely slide along the positioning guide pipe 41. The upper bottom surface of the guide ring 39 is opposite to the lower bottom surface of the bayonet 38 and is sleeved on the positioning guide pipe 41. The guide ring 39 is interposed between the bayonet 38 and the lower fixed flange 43. The fixed bearing 30 is installed on the lower bottom surface of the upper fixed flange 29, provides additional support for the driving shaft 28, enhances the stability of the driving shaft 28, reduces the radial swing, and the fishing cylinder 34 is fixed with the upper fixed flange 29 by bolts. A boss is arranged in the fishing cylinder 34 for placing the limiting bearing 35. The limiting bearing 35 has the limiting cylinder 33 placed thereon. The upper end of the limiting cylinder 33 is in contact with the fixed bearing 30. The limiting cylinder 33 in the fishing cylinder 34 is used for fixing the position of the limiting bearing 35 and fixing the boss position of the fishing cylinder 34. At the same time, the limiting bearing 35 has a similar effect with the fixed bearing 30, which can more effectively reduce the swing of the driving shaft 28, reduce energy loss and enhance the overall stability. The fishing cylinder 34 has recesses for placing the reset spring 37 and the reset pin 36. The recesses correspond to the recesses of the positioning disc 40. The positioning disc 40 is connected with the fishing cylinder 34 by bolts. When the inclined surface at the front end of the reset pin 36 is extruded, the reset spring 37 is extruded and simultaneously moves outward along the recess.When the upper wedge block 31 and the lower wedge block 42 are separated, the fishing barrel 34 moves downward, the outer edge of the guide ring 39 first presses the front end of the reset pin 36, the reset pin 36 is retracted and moves downward along the arc surface of the guide ring 39, when the reset pin 36 is completely located at the lower end of the guide ring 39, the fishing barrel 34 is pulled upward, the reset pin 36 is also moved upward with the guide ring 39, until the upper plane of the guide ring 39 coincides with the lower plane of the socket 38, continue to pull the fishing barrel 34 upward, the reset pin 36 is gradually retracted and moved upward along the arc surface of the guide ring 39, when the reset pin 36 is retracted to the innermost position, the fishing barrel 34 is quickly pulled to complete the separation of the upper wedge block 31 and the lower wedge block 42; the fishing process is as follows, first, adjust the supporting plate spring 21 on the ground to the same diameter as the hole diameter at the hole inclination position, continue to move downward after the driving shaft 28 is aligned and positioned with the guide pipe 41, when the reset pin 36 is compressed through the bottom surface of the socket 38, the reset pin 36 will restore to its original state, the bottom surface of the socket 38 is supported by the top surface of the reset pin 36, the grabbing of the fishing mechanism is completed, and then the fishing is performed. The positioning guide pipe 41 is fixed with the lower fixed flange plate 43 through threads. The driving shaft 28 has two protruding key positions at the top for transmitting power to the through-hole shaft 52 of the opening assembly. The positioning disc 40 is provided with four grooves for placing the reset spring 37 and the reset pin 36, and the positioning disc 40 is fixed with the fishing barrel 34 through bolts, and in the lowering process, the bottom surface of the socket 38 is clamped by the reset pin 36, so as to stably lower, after reaching the specified position, the control of the speed reducer 22 is rotated to complete the fixation of the opening assembly, and then the gravity of the recovery mechanism is used to actively reduce the tension of the armored cable, when the reset pin 36 is located at the same position of the guide ring 39, the guide ring 39 will press the inclined surface of the reset pin 36, so that the reset spring 36 is compressed, when the reset pin 36 is located at the lower end of the guide ring 39, the armored cable is quickly pulled, the reset pin 36 will drive the guide ring 39 to be attached to the socket 38, and then the upper wedge block 31 is quickly pulled out, and the separation is completed. When recovery is needed, adjust the supporting plate spring 21 to align the driving shaft 28 with the positioning guide pipe 41, first reverse drive the speed reducer 22 to complete the contraction of the opening assembly, and then the reset pin 36 is used to receive the bottom of the socket 38 to take out the whole angle builder from the hole.
[0041] The distraction assembly comprises a through-hole shaft 52, an upper flange base 44, a lower flange base 54, an upper hinged lug base 45, a lower hinged lug base 53, a multi-lug hinge nut base 51, a driving support arm 49, a driven support arm 47, a distraction piece 50, a positioning bearing 46 and a hinge pin shaft 48, the upper flange base 44 is fixedly connected with the lower fixed flange 43, the positioning bearings 46 are installed at the center positions of the upper flange base 44 and the lower flange base 54, the through-hole shaft 52 is installed between the two positioning bearings 46, so that the through-hole shaft 52 can rotate freely without deviation of the shaft center position. The upper hinged lug base 45 and the lower hinged lug base 53 are fixed to the bottom of the upper flange base 44 and the top of the lower flange base 54 respectively, the driven support arm 47 has two groups of upper and lower driven support arms 47, the two groups of driven support arms 47 are connected with the upper and lower ends of the support piece 50 respectively, and the support piece 50 is used to provide tension to the lower flange base 54; the driving support arm 49 is hinged on the multi-lug hinge nut base 51, the through-hole shaft 52 is hollow, and six key grooves are uniformly distributed in the through-hole shaft 52, the key grooves are rounded at the top, so that the two key positions of the driving shaft 28 protrude and slide in, the distraction piece 50 is connected with the upper hinged lug base 45 and the lower hinged lug base 53 by the driven support arm 47, and is hinged at the connecting hinge part by the hinge pin shaft 48; the distraction piece 50 is connected with the multi-lug hinge nut base 51 by the driving support arm 49, and is also hinged at the connecting hinge part by the hinge pin shaft 48, the four distraction pieces 50 are uniformly distributed in the drilling hole wall 55, so as to ensure uniform distribution of stress. When the driving shaft 28 is rotated in the forward direction driven by the reduction motor 22, the multi-lug hinge nut base 51 will gradually move upward with the rotation of the through-hole shaft 52, thereby driving the driving support arm 49 to expand outward, so that the distraction piece 50 expands outward to fix the distraction assembly on the hole wall, thereby completing the lowering process. Conversely, the reduction motor 22 needs to be reversed to contract the driven support arm 47 and the driving support arm 49, and then the armored cable is taken out of the hole.
[0042] The working principle of the application is as follows:
[0043] The working process of the recyclable whipstock for directional coring of ice layer mainly includes two processes of lowering and recovery.
[0044] The lowering process is to lower the recyclable whipstock from the ground to the designated depth of the drilling hole, to complete the fixation of the lower opening assembly, and then to take out the entire recycling mechanism from the drilling hole. According to the actual needs of drilling core taking, after the recyclable whipstock is lowered to the designated depth, the forward rotation of the speed reducer motor 22 is controlled, the output end of the speed reducer motor 22 is connected with the shaft coupling 26 to drive the driving shaft 28 to rotate, the protruding key position at the front end of the driving shaft 28 drives the through-hole shaft 52 of the opening assembly to rotate, because of the restriction of the driving support arm 49 and the driven support arm 47, the multi-ear hinge nut seat 51 will not rotate with the through-hole shaft 52, so that the multi-ear hinge nut seat 51 will move upward along the external thread of the through-hole shaft 52, thereby gradually increasing the upward angle between the driving support arm 49 and the through-hole shaft 52, and gradually opening the support piece 50, when the four support pieces 50 are completely attached to the drilling hole wall 55, and the lateral friction force generated between the four support pieces 50 and the drilling hole wall 55 can support the lateral force applied by the drill bit in the whipstocking state, the speed reducer motor 22 is closed to complete the lowering and opening fixation process. The process of taking out the entire part above the upper wedge block 31 from the drilling hole includes reducing the tension of the armored cable, using the gravity of the upper wedge block 31 and the pressure-resistant cabin, when the upper wedge block 31 is completely attached to the lower wedge block 42, the top surface of the reset pin 36 is coincided with the lower bottom surface of the guide ring 39, then the armored cable is quickly pulled, the reset pin 36 will first drive the guide ring 39 to move upward along the positioning guide pipe 41, when the upper surface of the guide ring 39 is coincided with the lower bottom surface of the bayonet 38, the reset pin 36 slides along the guide ring 39, until it is separated from the bayonet 38, the disengagement of the upper wedge block 31 and the lower wedge block 42 is completed, the lower wedge block 42 remains in the drilling hole to form a whipstocking surface, and the upper wedge block 31 and the part above it are taken out of the ground to complete the lowering process.
[0045] The recovery process includes several processes of fishing assembly docking, expansion assembly contraction and fishing recovery. It is necessary to adjust three adjusting bolts 14 on the ground at the same time. The adjusting bolts 14 rotate to drive the positioning seat 17 and the hoop ring 19 to move up and down along the outer wall of the pressure cabin body 20, compress the centralizing plate spring 21 to expand outward, and when the three centralizing plate springs 21 expand to the same diameter as the diameter of the drill hole wall 55 of the pressure cabin position, the through hole shaft 52 is exactly in the center position of the drill hole wall 55, and at this time the driving shaft 28 can pass through the positioning guide pipe 41 and enter the through hole shaft 52. The shock pad 32 is installed on the wedge surface of the upper wedge block 31. Limited by the thickness of the shock pad 32, after the fishing assembly fishing barrel 34 is lowered, the reset pin 36 can only pass through the bayonet 38 and cannot contact the guide ring 39 position, so when the shock pad 32 contacts the wedge surface of the lower wedge block 42, the docking of the fishing assembly is completed. Secondly, control the reverse rotation of the speed reducer motor 22, the output end of the speed reducer motor 22 is connected with the shaft coupling 26 to drive the driving shaft 28 to rotate, the protruding key position at the front end of the driving shaft 28 drives the through hole shaft 52 of the expansion assembly to rotate, because of the limitation of the driving support arm 49 and the driven support arm 47, the multi-ear hinge nut seat 51 will not rotate with the through hole shaft 52, so that the multi-ear hinge nut seat 51 will move downward along the external thread of the through hole shaft 52, the angle between the driving support arm 49 and the through hole shaft 52 gradually decreases, so that the support piece 50 is gradually contracted, when the four support pieces 50 are all retracted to the initial position, the speed reducer motor 22 is turned off to complete the contraction process of the expansion assembly. Finally, the whole whipstock is slowly pulled out of the drill hole through the armored cable, and the whole recovery process is completed.
Claims
1. A retrievable directional drilling tool suitable for directional coring of polar ice layers, characterized in that, include: The cable recovery mechanism includes a cable terminal and a power assembly. The cable terminal includes a brass cone (9), a lower constraint sleeve (10), and a plug (11). The brass cone (9) is located in the inner cavity of the lower constraint sleeve (10) and is conical. The external shape of the brass cone (9) matches the shape of the inner wall of the lower constraint sleeve (10). The center of the brass cone (9) has a central through hole for the armored cable to pass through. The plug (11) is installed at the bottom of the lower constraint sleeve (10). The plug (11) has a central through hole inside and its upper end face abuts against the lower end face of the brass cone (9). The armor layer is fitted to the outer wall of the brass inclined cone (9) and the inner wall of the cavity of the lower constraint sleeve (10), and fixed to the plug (11); the cable of the armored cable passes through the central through hole of the brass inclined cone (9) and the plug (11) in sequence, and the cable is connected to the watertight connector (12) after passing through the plug (11), and supplies power to the power assembly through the watertight cable connected to the watertight connector (12); the power assembly includes a pressure chamber, a geared motor (22), a straightening leaf spring (21) and an adjustment mechanism; the pressure chamber is formed by bolting together the pressure chamber body (20) and the pressure chamber upper end cover (13) and pressure chamber lower end cover (25) located at both ends of it; the straightening leaf spring (21) is connected to the pressure chamber body (20) and the upper end cover (13) and the lower end cover (25) of the pressure chamber located at both ends of the pressure chamber; the straightening leaf spring (21) is connected to the pressure chamber body (20) and the lower end cover (25) of the pressure chamber located at both ends of the pressure chamber body (20) and the lower end cover (25) ... The adjustment mechanism is installed outside the pressure chamber (20); the geared motor (22) is located inside the pressure chamber, and its output shaft is connected to the drive shaft (28) below via a coupling (26); the tilting mechanism includes a tilting wedge and a spreading assembly. The tilting wedge includes an upper wedge block (31), a lower wedge block (42), and a retrieval assembly; the retrieval assembly is used to connect and separate the upper wedge block (31) and the lower wedge block (42). The spreading assembly includes a through-hole shaft (52), a multi-ear hinge nut seat (51), a driven support arm (47), an active support arm (49), and a spreading plate (50). The multi-ear hinge nut seat (51) is threadedly fitted onto the through-hole shaft (52). The external part; the active support arm (49) is hinged to the multi-ear hinge nut seat (51); the number of driven support arms (47) is two sets, and the two sets of driven support arms (47) are respectively hinged to the upper and lower ends of the support plate (50) through the upper hinge ear seat (45) and the lower hinge ear seat (53); the spreading plate (50) is simultaneously hinged to the active support arm (49) and the driven support arm (47) to form a linkage mechanism; the through hole shaft (52) cooperates with the active shaft (28) and is driven to rotate by the reduction motor (22), thereby driving the multi-ear hinge nut seat (51) to move axially, and driving the spreading plate (50) to open or contract radially through the active support arm (49) and the driven support arm (47).
2. The retrievable directional drilling tool for directional coring of polar ice layers according to claim 1, characterized in that, The adjustment mechanism includes an adjustment bolt (14), a positioning pin (16), a positioning seat (17), a fastening bolt (18), and a clamping ring (19); the outer edge of the pressure chamber upper cover (13) is provided with a threaded hole for installing the adjustment bolt (14); the positioning pin (16) passes through the positioning seat (17) and is fixed by a nut; the adjustment bolt (14) is connected to the positioning pin (16); the positioning seat (17) is fixed to the clamping ring (19) by bolts; the clamping ring (19) is composed of three arc-shaped plates connected by fastening bolts (18); the upper end of the straightening leaf spring (21) is hinged to the clamping ring (19), and the lower end is hinged to the outer wall of the pressure chamber body (20); rotating the adjustment bolt (14) drives the clamping ring (19) to move up and down along the outer wall of the pressure chamber body (20) to adjust the opening degree of the straightening leaf spring (21).
3. The retrievable directional drilling tool for polar ice core drilling according to claim 1, characterized in that, The retrieval assembly includes a fixed bearing (30), a limiting cylinder (33), a retrieval cylinder (34), a limiting bearing (35), a reset pin (36), a reset spring (37), a bayonet (38), a guide ring (39), a positioning plate (40), and a positioning guide tube (41); the fixed bearing (30), the limiting cylinder (33), the retrieval cylinder (34), the limiting bearing (35), the reset pin (36), the reset spring (37), and the positioning plate (40) are located in the central through hole of the upper wedge block (31); the bayonet (38), the guide ring (39), and the positioning guide tube (41) are all located in the central through hole of the upper wedge block (31). The positioning guide tube (41) and the positioning guide tube (42) are located in the central through hole of the lower wedge block (42). The bayonet (38) and the guide ring (39) are both hemispherical structures with a through hole in the middle. The bayonet (38) is sleeved on the upper end of the positioning guide tube (41) and fixed on the positioning guide tube (41). The guide ring (39) is sleeved on the positioning guide tube (41) and is located between the bayonet (38) and the lower fixed flange (43). The guide ring (39) can slide freely on the outer surface of the guide tube (41). The fixed bearing (30) is installed on the upper fixed flange (29). On the bottom surface; the retrieval cylinder (34) is fixedly connected to the upper fixed flange (29), and the retrieval cylinder (34) has a boss inside for placing the limiting bearing (35); a limiting cylinder (33) is provided above the limiting bearing (35), and the upper end of the limiting cylinder (33) contacts the fixed bearing (30); the bottom of the retrieval cylinder (34) has a groove for accommodating the return spring (37) and the return pin (36), which corresponds to the groove of the positioning plate (40); the positioning plate (40) is fixedly connected to the retrieval cylinder (34); the return pin (37) is fixedly connected to the upper fixed flange (29), and the lower fixed flange (29) is fixedly connected to the upper fixed flange (29). 6) The front end is inclined, and when squeezed, it compresses the return spring (37) and moves outward along the groove; the positioning guide tube (41) is fixedly connected to the lower fixed flange (43); during the lowering process, the return pin (36) extends under the action of the return spring (37) and abuts against the bottom end face of the bayonet (38) to realize the connection between the upper wedge block (31) and the lower wedge block (42); during the recovery, the return pin (36) contracts under the action of axial pressure, passes through the guide ring (39), and re-engages with the bayonet (38) after the reset, realizing the retrieval and recovery.
4. The retrievable directional drilling tool for polar ice core drilling according to claim 1, characterized in that, The expansion assembly also includes an upper flange base (44), a lower flange base (54), an upper hinge lug (45), a lower hinge lug (53), a positioning bearing (46), and a hinge pin (48); the upper flange base (44) is fixedly connected to the lower fixed flange (43); the upper hinge lug (45) and the lower hinge lug (53) are respectively fixed to the bottom of the upper flange base (44) and the top of the lower flange base (54); there are two positioning bearings (46), which are respectively installed at the center of the upper flange base (44) and the lower flange base (54) to support the through hole shaft (52); the active support arm (49) and the driven support arm (47) are both hinged to the expansion piece (50) through the hinge pin (48).
5. The retrievable directional drilling tool for directional coring of polar ice layers according to claim 1, characterized in that, The cable terminal also includes a connecting pipe (1), a cable terminal nut (2), a cable terminal cover (3), an upper constraint sleeve cover (4), a limiting screw (5), an upper constraint sleeve (6), a spring (7), and a cable terminal housing (8); the connecting pipe (1) is interference-fitted with the cable terminal cover (3), and the connecting pipe (1) is used for armored cables to pass through and enter the cable terminal; the cable terminal nut (2) is fitted on the outside of the connecting pipe (1); the cable terminal cover (3) is threadedly connected to the cable terminal housing (8); the upper constraint sleeve cover (4), the limiting screw (5), the upper constraint sleeve (6), the spring (7), the brass tapered cone (9), the lower constraint sleeve (10), and the plug (11) are arranged inside the cable terminal housing (8); The limiting screw (5) is installed on the cable terminal cover (3), and its front end extends into the upper constraint sleeve (6) to limit the rotation and axial displacement of the upper constraint sleeve (6); the spring (7) is placed inside the upper constraint sleeve (6), its upper end is limited by the upper constraint sleeve cover (4), and its lower end contacts the lower constraint sleeve (10); the cable terminal shell (8) and the pressure-resistant chamber upper cover (13) are fixedly connected by bolts.
6. The retrievable directional drilling tool for directional coring of polar ice layers according to claim 1, characterized in that, The wedge-shaped surface of the upper wedge block (31) is opposite to the wedge-shaped surface of the lower wedge block (42), and the inclination angle of the wedge-shaped surfaces of the two is consistent with that of the vertical direction; a shock-absorbing pad (32) is installed on the wedge-shaped surface of the upper wedge block (31).
7. The retrievable directional drilling tool for polar ice core drilling according to claim 1, characterized in that, The coupling (26) is provided with a coupling positioning flange (27) on the outside. The coupling positioning flange (27), the lower end cover (25) of the pressure chamber and the pressure chamber body (20) are fixedly connected by bolts, which constrains the coupling (26) to the center position of the coupling positioning flange (27).
8. The retrievable directional drilling tool for directional coring of polar ice layers according to claim 1, characterized in that, A lip seal (24) is installed at the point where the output shaft of the geared motor (22) passes through the lower end cover (25) of the pressure chamber.
9. The retrievable directional drilling tool for directional coring of polar ice layers according to claim 1, characterized in that, The through-hole shaft (52) is a hollow structure with a keyway inside for engaging with the key at the front end of the drive shaft (28).
10. The retrievable directional drilling tool for polar ice core drilling according to claim 1, characterized in that, The number of the spreading pieces (50) is four, and the four spreading pieces (50) are evenly distributed.