Disassembling and assembling method for shafting double-oil-pipe support of ship propeller

Abstract

The invention relates to a disassembly and assembly method for a ship propeller shafting double-oil-pipe support. The disassembly and assembly method can conveniently and quickly complete installation and disassembly of the double-oil-pipe support on the ship propeller shafting at low cost. Mounting: extending the oil pipe support into a specified position of a shaft hole by using a mounting tool according to an inner hole at the right end of a drawing, expanding an outer bushing of the double oil pipe support by using an A-path high-pressure oil pipe under the axial force of 275KN, fixing the oil pipe support in an inner hole of a shaft section with a specified size, and ensuring that the oil pipe support is not loosened and meets the axial displacement binding force of 18.48 KN reached by a test; a hydraulic oil cylinder in the lever type pull claw type hydraulic dismounting mechanism is used for pushing a piston rod to open a six-petal lever pull claw hooped by a spring and then push the neck bush, and meanwhile, a pair of supporting spacer bushes is designed to enable the backward pushing force of the pull claw to interact, so that the purpose of dismounting and separating the inner taper sleeve from the outer taper sleeve is achieved.

Description

Technical Field

[0001] This invention relates to a method for installing and removing dual oil pipe supports for ship propulsion shafts that is cost-effective, convenient, and quick. Background Technology

[0002] Dual-oil-pipe support bushing installation: Adjustable propeller technology is widely used in both civilian and military vessels, providing reliable maneuverability. However, the internal structure of the drive shaft system is complex, with high requirements for the dimensions and geometric tolerances of each component, making manufacturing and installation challenging. Its hydraulic lubrication system is also more complex. Driven by the booming development of maritime trade and the military equipment race among nations, lightweight propeller technology is increasingly being refined and diversified. Scholars have conducted extensive research on the internal structural design and reliability of adjustable propeller shaft systems, but few units possess the capability to independently develop key technologies for ship adjustable propeller shaft systems, and existing technologies are relatively outdated.

[0003] The dual oil pipe support for a certain type of ship shafting, which was independently designed and developed, has an inner and outer support structure with a 1.5° taper fit. Applying a certain axial force causes the inner and outer tapered friction to generate radial force to achieve a fastening effect. However, the internal space of the deep hole is narrow, making installation, operation and observation inconvenient. Due to the lack of a locking device, there is a probability that the dual oil pipe support bushing will loosen after installation.

[0004] Traditional method for disassembling double oil pipe support bushings: Once a loose double oil pipe support is found, all oil pipe supports in the same shaft system must be removed. The axial force during oil pipe installation is 275KN, and the disassembly force is 18.48KN. Reaching this force to disassemble the oil pipe bushing inside a deep borehole more than 10 meters long is a very challenging problem. The most traditional solution is to use a deep hole drilling and boring machine to bore the oil pipe bushing, loosening it before removal. This method requires designing and purchasing specialized deep hole reaming tools to gradually ream the inner bushing. The specific operation is as follows: 1) First, a matching dummy shaft is machined according to the actual dimensions of the thruster shaft. The dummy shaft bracket is then machined according to the journal outer diameter tolerance. Next, the dummy shaft is hoisted onto the deep hole drilling and boring machine table, and its coaxiality is corrected using both the upper and side generatrices as references. After confirming the positioning accuracy, the dummy shaft is removed, and the thruster shaft is hoisted into place along the corrected positioning reference. This solution solves the problem of damage to the outer diameter of the copper bushing caused by repeated alignment in traditional assembly. Its advantages are: ① Establishing a topological equivalence relationship for dimensional transfer between the dummy shaft and the real shaft, ensuring absolute consistency of the positioning reference; ② Isolating direct contact through an intermediate medium, eliminating the risk of mechanical interference during alignment; ③ Adopting a process of one-time correction and two-time replacement, ensuring assembly accuracy while achieving physical protection of key components. 2) High-precision deep hole machining and comprehensive protection are achieved through a multi-level collaborative structure. This device employs a modular design with a φ160 deep hole drill rod and a quick-change rectangular threaded connection, integrating a φ300 rear support bushing system. An embedded PA66 wear-resistant pad forms a self-lubricating interface, providing rigid support for the boring tool while preventing hole wall scratches through flexible contact. A rear chip removal channel is constructed between a φ150 rigid guide head at the front end and the cutting tool holder. A high-pressure oil injection system from the oil receiver creates a three-in-one working mode of cutting, chip removal, and cooling: high-pressure oil flows through the cutting edge for efficient cutting, and chips are forcibly discharged through the rear chip removal hole and the drill rod cavity, simultaneously carrying away cutting heat and completely solving the problem of secondary extrusion and scratches caused by chip accumulation in traditional deep hole machining. The advantages are: ① The composite buffer structure of the support bushing and wear-resistant pad achieves a dynamic balance between rigid support and flexible protection; ② It constructs a collaborative system of a closed high-pressure oil circuit and chip removal channel to overcome the bottleneck of heat accumulation in deep hole machining; ③ Through the three-point positioning mechanism of guide head-tool holder-bushing, it ensures the dimensional stability of aspect ratio hole machining.

[0005] Figure 10 φ210 type front and rear double guide deep hole boring tool.

[0006] 3) The cutting tools are designed with progressively increasing sizes of φ210, φ270, and φ290 for boring. This is to eliminate the tension force provided by the inner tapered bushing and loosen the outer bushing. The bushing is relatively deep from the hole opening, requiring accurate knowledge of the axial position of each bushing. Conventional measuring tools cannot reach deep holes. A Bosch infrared laser rangefinder is used to accurately measure the actual distance between the oil pipe support end face and the hole opening. This facilitates rapid tool entry to approach the starting position. The dotted lines in the diagram indicate the material allowance distribution after each pass. The design involves three progressively increasing removal of the allowance, which prevents the bushing from retracting due to excessive cutting force and facilitates chip removal.

[0007] However, as mentioned above, the traditional method of disassembling support bushings in deep hole boring has the disadvantages of high cost and long time consumption. Summary of the Invention

[0008] Design objective: To overcome the shortcomings of the prior art, this design aims to provide a method for accurately and evenly distributing the double oil pipe supports within the shaft's deep hole during the installation of the double oil pipe supports for ship propeller shafts. This method ensures that the evenly distributed double oil pipe supports are effectively locked and will not loosen. Furthermore, it aims to avoid the shortcomings of the prior art during the disassembly of the double oil pipe supports, allowing for a simple, quick, and low-cost disassembly and detachment of the double oil pipe supports.

[0009] Design Scheme: To achieve the above design objectives, this invention provides two solutions: first, a method for installing a dual-oil-pipe support for a ship's propeller shaft system, along with its associated specialized tools; second, a method for disassembling the dual-oil-pipe support for a ship's propeller shaft system, along with its associated specialized tools.

[0010] 1. Dual oil pipe support installation for ship propulsion shaft system: 1) The theoretical position of the dual oil pipe support in the thruster shaft (see...) Figure 2 ).

[0011] 2) The theoretical position of the dual oil pipe support in the stern shaft (see...) Figure 3 Since the shaft of a ship's propulsion system is often more than 10 meters long, the double oil pipe support bushings need to be accurately and evenly distributed and installed inside the shaft's deep hole. A special oil pump puller is designed to generate an axial clamping force of 275KN to fix it to the inner hole of the drive shaft, and no loosening is allowed.

[0012] 3) Dual oil pipe support installation structure (see...) Figure 1 Insert the oil pipe support into the designated position of the shaft hole according to the inner hole on the right end of the drawing using the installation tool. Use the A-line high-pressure oil pipe to expand the outer bushing of the double oil pipe support with an axial force of 275KN. Fix the oil pipe support in the inner hole of the shaft section of the specified size, ensuring that there is no looseness and that the axial displacement connection force of 18.48KN achieved in the test is met.

[0013] 2. Disassembly of the dual oil pipe support for the ship's propulsion shaft system: This invention develops a lever-type pull-claw hydraulic disassembly mechanism. This mechanism utilizes a hydraulic cylinder to push a piston rod, which opens a six-lobed lever pull claw held in place by a spring, thereby pushing the inner bushing. Simultaneously, a support spacer is designed to counteract the pushing force of the pull claw, thus achieving the purpose of disassembling and detaching the inner and outer tapered sleeves. This mechanism is compact, easy to operate, and has high disassembly efficiency. It can adaptively disassemble the double-cylinder support bushing of the shaft section without the need for large boring equipment. The specific operation method is as follows: [See details] Figure 10 Lever-type pull claw hydraulic disassembly mechanism.

[0014] 1) The retractable ring spring tightens the pull claw, the piston is at the leftmost position of the oil cylinder, there is a gap between the thrust nut and the tail of the pull claw, and it has no axial thrust on the pull claw; 2) Install the complete set of hydraulic disassembly tools into the designated position of the shaft deep hole. The target depth position is determined by precise measurement using a steel strip to ensure that the support spacer and the end face of the double oil pipe support outer cone sleeve are tightly and evenly fitted. 3) Manually switch to turn on the A-line high-pressure oil pump. The piston is moved to the right by the hydraulic oil. At the same time, the thrust nut pushes against the tail of the pull claw and moves to the right together. Due to the resistance of the front spring, the pull claw generates tension and continues to move axially. After the pull claw cone surface contacts the cone surface of the double oil pipe support inner bushing, the oil cylinder continues to generate a strong axial thrust. Finally, under the thrust of the hydraulic cylinder, the inner and outer cone sleeves are displaced to achieve the purpose of loosening and disassembly. 4) After the bushing is loosened, the oil in the A circuit remains under pressure. Currently, the pull claw is in an open position, and the entire hydraulic disassembly device, along with the double oil pipe support, is pulled out of the deep hole to ensure that the entire disassembly process is safe and reliable.

[0015] Compared with the prior art, the present invention has two advantages: first, it can accurately and evenly distribute the double oil pipe support inside the shaft deep hole, and the evenly distributed double oil pipe support can be effectively locked without loosening; second, the mechanism is compact and easy to operate, with high disassembly efficiency, and can adaptively disassemble the double oil cylinder support bushing of the shaft section without the need for large boring equipment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a dual-oil-pipe support installation tool.

[0017] Figure 2 This is a schematic diagram of the theoretical position of the dual oil pipe support in the thruster shaft.

[0018] Figure 3 This is a schematic diagram of the theoretical position of the dual oil pipe support in the stern shaft.

[0019] Figure 4 It is a dual-oil-pipe support installation tool.

[0020] Figure 5 This is a schematic diagram of a dual-oil-pipe support installation tool.

[0021] Figure 6 This is a 3D schematic diagram of the hydraulic cylinder catch.

[0022] Figure 7 This is a schematic diagram of a crescent hook tooling assembly for a φ108*6 seamless steel pipe.

[0023] Figure 8 These are photos of the installation process of a crescent hook head on a φ108*6 seamless steel pipe.

[0024] Figure 9 These are photos of an axial load tensile test.

[0025] Figure 10 This is a schematic diagram of a lever-type claw-type hydraulic disassembly mechanism.

[0026] Figure 11 This is a photo of an actual lever-type claw hydraulic disassembly mechanism. Detailed Implementation

[0027] See attached document Figure 10 —The disassembly and assembly methods of the dual oil pipe supports for the propulsion shaft system of ships are further explained.

[0028] 1. Preparations: (1) Before formal installation, a corresponding simulation test should be conducted, and relevant parameters should be adjusted according to the simulation test results. The pump pressure test results of oil pipes and oil cylinders should be recorded (including the qualification record of pump pressure equipment).

[0029] (2) The actual outer diameter of the outer sleeve is made according to the inner hole size of the shaft, and the fitting clearance is required to be 0.15mm-0.25mm. The sharp edges of the inner and outer sleeves must be completely deburred and the sharp corners rounded.

[0030] (3) Before installation, the installation tools must be cleaned, and the oil pipes and cylinders must be cleaned and the pump pressure test performed.

[0031] (4) Each pair of inner and outer jackets should be paired and numbered. The numbering position should reasonably avoid the installation mating surface. Since the numbering is unique and traceable, a 100% blue oil inspection should be carried out after processing and the inspection results should be recorded. The blue oil should be thoroughly cleaned with cleaning agent and 46# lubricating oil should be applied.

[0032] (5) Before each installation of the tubing support, assemble the installation tools as required and pump pressure to confirm that there is no leakage; measure and confirm the length of the installation tools according to the predetermined installation position.

[0033] (6) Inspection records of the actual dimensions and surface finish of the inner bore of the propeller shaft and tail shaft, and the actual dimensions and surface finish of the inner and outer sleeves. Check and confirm that the inner and outer sleeves installed are the corresponding shaft sections to ensure smooth installation. Record the inspection results.

[0034] (7) Before the oil pipe support is installed, the inner hole of the shaft section must be cleaned and washed (light diesel oil conforming to GB252 can be selected as the cleaning agent), and blown dry. There must be no burrs, fine metal particles, oxide scale, rust, oil stains, colorants, rust-preventive oil and dust. Before applying lubricating oil, check the inner hole size and cleaning results and make a record.

[0035] (8) Before installing the tubing support, confirm the allowance at both ends of the shaft section length to determine the installation position of the tubing support. Record the installation process, including: 1) Number the supports according to the process specifications, and select the most suitable support based on the inner diameter of the shaft and the outer diameter of the support. Record the inner and outer support numbers. 2) Adjust the distance between the measuring support and the shaft end, verify and record the actual position of the oil pipe support installation; 3) Record the entire low-pressure and high-pressure pressing process (pay attention to changes in the inner diameter of the shaft and the dimensions of the support), and record the actual pressing and holding times. (9) Before the oil pipe support is installed, use a mandrel (the diameter of which is 0.15 mm smaller than the minimum value of the inner hole of the shaft section) to check the inner hole of the shaft section to confirm that it can pass through the inner hole of the shaft section for the entire length, and make an inspection record.

[0036] (10) After the oil pipe support is installed, both ends of the shaft section are sealed and protected, and rust prevention is checked regularly.

[0037] (11) Site requirements: There should be a working area with a length of twice the shaft section. The shaft section should be fixed and secure and easy to install. There should be a crane to assist in the work.

[0038] (12) Tooling: Oil pipe support installation tools, pressure gauge, pressure pump, wrench, 10mm mold ejector rod, tape measure, sling, cleaning box, L-HM100 anti-wear hydraulic oil, oil tank, oil absorbent cloth.

[0039] (13) This project should have one project manager, two main installation operators, two installation assistants, and one quality inspector. Before construction, the installation process requirements should be carefully studied and digested. For each construction procedure, a "Process Control Sheet" should be filled out, and corresponding inspection forms and inspection records should be prepared and kept.

[0040] 2. Detailed installation steps: (1) Adjust the distance L between the measuring support and the shaft end (considering the machining allowance of the shaft end face), and verify whether it conforms to the drawing dimensions, where L = drawing dimensions + shaft end allowance; see Figure 4 Dual oil pipe support installation tool.

[0041] (2) After installing the support pipe and measuring bracket, pump the low-pressure oil pipe to pull out the clamping bushing and insert the stop pin; see Figure 5 .

[0042] (3) Install the inner and outer bushings of the double oil pipe support onto the installation tool, pump the high-pressure oil pipe to make the tension nut enter the clamping bushing, remove the stop pin, and release the pressure of the electric oil pump. See Figure 6 3D schematic diagram of hydraulic cylinder catcher.

[0043] (4) Insert the installation tool and the double oil pipe support bushing into the shaft together, so that the measuring support is flush with the end face of the shaft.

[0044] (5) Pump press high pressure oil pipe. When press installation begins, the axial pressure should not be too large. That is, gradually increase the pressure, with each 5MPa press and a 10-15s interval as one step. The final installation pressure is 21.3MPa (axial force 275KN), and it should be maintained for 15-30 minutes. (6) Pump the low-pressure oil pipe so that the cylinder piston moves to the stop. After installation, the oil pipe support installation tool retracts normally from the hole. Pull out the installation tool to ensure that there is no scoring or jamming in the shaft inner hole. 3. Post-installation loosening inspection: After installation, the oil pipe supports are fixedly distributed deep within the shaft bore, spanning tens of meters. Conventional tools are incapable of verifying their complete and secure installation, or determining if any looseness exists. A specially designed φ108*6 seamless steel pipe, coupled with a welded crescent-shaped inspection head, is used to impact the installed double oil pipe supports. Nylon support rings at the pipe's head and tail ensure the seamless steel pipe's axis remains parallel to the shaft bore's axis. Inspectors assess for looseness by pulling the pipe to impact the oil pipe. Before impact, calibration records are made, and the pipe's displacement before and after impact is measured. This tooling, through its ingenious geometric design, can not only inspect the shaft bore support bushings but also extend further to inspect all double oil pipe bushings within the shaft bore. (See...) Figure 7 φ108*6 seamless steel pipe crescent hook tooling assembly.

[0045] 3.1 The specific operation is as follows: 1) The φ108*6 seamless steel pipe is fixed by argon arc welding to the crescent hook head formed by wire cutting. The size of the crescent hook head can be designed to pass through the center of the inner sleeve hole. Two sets of φ260*200 nylon support sleeves are used to place the pipe axis by its own weight. The φ300 inner hole is parallel to the main axis and eccentric by 20mm. A cross mark is engraved on the other end of the seamless steel pipe. The circumferential angle position of the crescent hook head is used as a flip mark. 2) Use an overhead crane to horizontally lift the pipe fixture into the inner hole of the shaft. When entering the hole, the crescent hook head should be at a 90° position facing directly upwards. This will allow it to smoothly enter the small hole supported by the double oil pipes. When the specified depth is reached, gently lower the pipe fixture with the overhead crane so that the φ260*200 nylon support sleeve contacts the hole wall and keeps the pipe axis parallel to the shaft hole axis. 3) Rotate the pipe fixture 180° using a rotary wrench, so that the marked position faces downwards, and the 90° position of the crescent hook head also faces downwards. At this time, the eccentricity difference of 20mm can be used to firmly hook the crescent hook head onto the end face of the oil pipe support bushing. 4) Before impact, mark the orifice with a marker. Then, gently pull the pipe upwards while manually holding it, gradually increasing the force to reposition the hook and impact the tubing bushing. During impact, feel for any significant displacement of the pipe fixture. After impact, use a right-angle ruler to check for any displacement of the orifice mark and record any loosening checks. See [link to relevant documentation]. Figure 8 Photos of the installation process of the crescent hook head on a φ108*6 seamless steel pipe.

[0046] 5) After the impact test, an axial load tensile test is also required. The axial load tensile test involves argon-arc welding an end cap to the outside of the pipe, installing an M24 lifting ring in the center of the cap, and using the same method as in step 4), hooking the crescent hook onto the end face of the oil pipe bushing. A steel wire rope and shackle are then connected to the M24 lifting ring. A fixed pulley is installed at the other end using a 10-ton square box as an anchor point. The steel wire rope is passed through the fixed pulley and pulled vertically upwards by a crane. An electronic scale is installed on the crane to display the real-time axial tensile load. A load tensile force of 3.5 tons is sufficient to meet the strength requirements; see... Figure 9 Photographs of axial load tensile test.

[0047] Reference Figure 10-11 The disassembly method for the dual oil pipe support of the propulsion shaft system of ships is further explained.

[0048] After the dual oil pipe supports are installed inside the shaft, they are carried along with the propeller shaft and serve on the ship for over 20 years. During this long service life, it is inevitable that some bushings will loosen. Once loosening occurs, it can lead to increased ship operating noise and power consumption, or even cause the pitch control oil pipe to jam, preventing the propeller blades from changing pitch and seriously affecting the ship's normal navigation and mission performance. If even one oil pipe support in a shaft becomes loose, the entire shaft needs to be disassembled and all support bushings inspected, which would result in huge maintenance costs and damage to the company's reputation. Therefore, it is particularly important for the technical team to find a scientific and efficient process for disassembling the dual oil pipes.

[0049] This invention addresses the drawbacks of traditional deep-hole boring machine support bushing disassembly methods, which are costly and time-consuming. It designs and develops a lever-type pull-claw hydraulic disassembly mechanism. This mechanism utilizes a hydraulic cylinder to push a piston rod, which opens a six-lobed lever pull claw held in place by a spring, thereby pushing the inner bushing. Simultaneously, a support spacer is designed to counteract the pushing force of the pull claw, thus achieving the disassembly and separation of the inner and outer tapered bushings. This mechanism is compact, easy to operate, and highly efficient. It allows for adaptive disassembly of the dual-cylinder support bushing on the shaft section without the need for large boring equipment. The specific operation method is as follows: [See details] Figure 10 Lever-type pull claw hydraulic disassembly mechanism.

[0050] 1) The retractable ring spring tightens the pull claw, the piston is at the leftmost position of the oil cylinder, there is a gap between the thrust nut and the tail of the pull claw, and it has no axial thrust on the pull claw; 2) Install the complete set of hydraulic disassembly tools into the designated position of the shaft deep hole. The target depth position is determined by precise measurement using a steel strip to ensure that the support spacer and the end face of the double oil pipe support outer cone sleeve are tightly and evenly fitted. 3) Manually switch to turn on the A-line high-pressure oil pump. The piston is moved to the right by the hydraulic oil. At the same time, the thrust nut pushes against the tail of the pull claw and moves to the right together. Due to the resistance of the front spring, the pull claw generates tension and continues to move axially. After the pull claw cone surface contacts the cone surface of the double oil pipe support inner bushing, the oil cylinder continues to generate a strong axial thrust. Finally, under the thrust of the hydraulic cylinder, the inner and outer cone sleeves are displaced to achieve the purpose of loosening and disassembly. 4) After the bushing is loosened, the oil in the A circuit remains under pressure. Currently, the pull claw is in an open position, and the entire hydraulic disassembly device, along with the double oil pipe support, is pulled out of the deep hole to ensure that the entire disassembly process is safe and reliable.

[0051] See attached document Figure 10 High-pressure oil is injected into the internal cavity on the left side of the cylinder. After the high-pressure oil in line A is injected into the piston, it creates a thrust that drives the piston to move the piston rod to the right. At this time, the thrust nut and the piston move to the right together until they stop the pull claw. After the pull claw is subjected to force, because there is a damping spring on the right side of the pull claw bracket, the pull claw will automatically open after receiving the spring resistance. Figure 11 Finally, the inner cone sleeve is held in place, and then high-pressure oil is injected into the cylinder to separate the inner and outer oil pipe bushings, thus achieving the purpose of disassembly.

[0052] It should be understood that although the above embodiments provide a relatively detailed textual description of the design concept of the present invention, these textual descriptions are merely simple textual descriptions of the design concept of the present invention, and not limitations on the design concept of the present invention. Any combination, addition, or modification that does not exceed the design concept of the present invention falls within the protection scope of the present invention.

Claims

1. A method for disassembling a double-oil-tube support of a propeller shaft system of a ship, characterized by the following steps: (1) Adjusting the distance L between the measuring support and the shaft end and the machining allowance of 2 mm for the shaft end face, and verifying whether the dimensions conform to the drawings, wherein L = the dimension of the drawings + the allowance of the shaft end; (2) After the support tube and the measuring support are installed, pump the low-pressure oil tube to pull out the clamping bushing and insert the stop pin; (3) Install the inner and outer bushings of the double-oil-tube support on the installation tool, pump the high-pressure oil tube to make the tension nut enter the clamping bushing, pull out the stop pin, and release the pressure of the electric oil pump; (4) Install the installation tool together with the bushings of the double-oil-tube support into the shaft, and make the measuring support flat with the shaft end face; (5) Pump the high-pressure oil tube, and the axial pressure should not be too large at the beginning of the pressing, i.e., gradually increase the pressure, and stop for 10-15 s as a level, and the final installation pressure is 21.3 MPa, the axial force is 275 KN, and the pressure is maintained for 15-30 min; (6) Pump the low-pressure oil tube to make the oil cylinder piston move to the stop, and the oil tube support installation tool normally retreats from the hole after installation, the installation tool is pulled out, and it is ensured that the shaft hole is not damaged or jammed; (7) Looseness detection after installation: the installed double-oil-tube support is fixed at a depth of 10 meters in the shaft hole, a special detection head of a φ108*6 seamless steel tube is used to impact the installed double-oil-tube support, the head and tail of the steel tube are inlaid with nylon support rings to keep the axis of the seamless steel tube and the axis of the shaft hole always parallel, and the displacement of the tube before and after the impact is detected to judge whether the support is loose, the scale is recorded before the impact, and the displacement of the tube before and after the impact is detected, the tool can not only detect the support bushing of the shaft hole, but also continue to be connected to detect all the double-oil-tube bushings in the shaft hole; The specific operation is as follows: 1) The φ108*6 seamless steel tube is fixed by argon arc welding with the crescent hook head formed by wire cutting, the size of the crescent hook head can pass through the center of the inner bushing hole, 2 φ260*200 nylon support sleeves are used to place the tube axis along the self-weight to keep the φ300 inner hole parallel to the main axis with an eccentricity of 20 mm, and a cross mark is drawn on the other end of the seamless steel tube to serve as a turning mark; 2) Use the crane to horizontally lift the tube tool into the shaft hole, when entering the hole, the crescent hook head is at 90° position facing upward, which can smoothly enter the small hole of the double-oil-tube support, and when reaching the specified depth, the crane gently lowers the tube tool, so that the φ260*200 nylon support sleeve contacts with the hole wall to keep the tube axis parallel to the axis of the shaft hole; 3) Turn the tube tool 180° by rotating the wrench, and rotate the mark position downward, i.e., the crescent hook head is at 90° position facing downward, and at this time, the eccentricity of 20 mm can realize that the crescent hook head hooks the end face of the oil tube support bushing firmly; 4) Before the impact, use a marker to draw a mark line on the hole position, at this time, the crane gently pulls up the tube, holds the tube, and starts to gradually increase the force to hook and impact the oil tube bushing, the hand feels whether there is obvious displacement of the tube tool during the impact, and after the impact, use a right-angle ruler to check whether the mark line of the hole position has displacement, and make a record of the looseness detection. ​ 5) After the impact test, axial load tension test is needed, axial load tension test is to weld an end cover on the outside of the pipe by argon arc welding, install a M24 lifting ring in the middle of the cover, use the same method to hook the crescent hook to the end face of the oil pipe liner, connect the M24 lifting ring with a steel wire rope and a coupling, install a fixed pulley with a 10-ton square box weight as an anchor point on the other end, pass the steel wire rope through the fixed pulley vertically upward, use a hoist to pull it, and install an electronic scale on the hoist to display the real-time axial tension load, which can withstand a load of 3.5 tons to meet the strength requirements; (2) Disassembly method: 1) Contraction ring type spring tight puller, piston at the left side of the cylinder, gap between thrust nut and puller tail, no axial thrust on puller; 2) Install the complete hydraulic disassembly tool in the specified position of the shaft deep hole, and determine the target position by precise measurement with a steel belt to ensure that the support spacer and the double oil pipe support outer cone sleeve end face are tightly and uniformly attached; 3) Manually switch on the A route high pressure pump, move the piston to the right side through hydraulic oil, at the same time, the thrust nut is pushed against the puller tail to move to the right, due to the resistance of the front spring, the puller generates tension and continues to move axially, the puller cone surface contacts the double oil pipe support inner liner cone surface, and the hydraulic cylinder continues to generate strong axial thrust, finally, under the action of the hydraulic cylinder thrust, the inner and outer cone sleeves are displaced to achieve the purpose of loosening and disassembling; 4) After the liner is loosened, the A route oil is always in pressure maintaining state, the puller is in open posture, the complete hydraulic disassembly device is pulled out from the deep hole together with the double oil pipe support, ensuring the safety and reliability of the entire disassembly process.

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