Ship tail shaft nut disassembly tool and disassembly method

Abstract

The invention discloses a ship tail shaft nut disassembly and assembly tool and a disassembly and assembly method. The disassembly and assembly tool is capable of effectively reducing the friction resistance generated by the nut and the copper sleeve when they rotate around the steel shaft by arranging a copper sleeve on a steel shaft and rotating with the tail shaft nut, and arranging a ball bearing between the copper sleeve and the steel shaft. Under the same conditions, the disassembly and assembly tool can disassemble and assemble a tail shaft nut with a heavier weight, and can disassemble and assemble a ship tail shaft nut with a maximum weight of 3 tons, and has strong applicability. The disassembly and assembly method will not cause damage to the thread of the nut during the disassembly and assembly process, and at the same time, the operation of screwing the nut in and out is more convenient, which is conducive to saving the physical strength and time of the staff.

Description

Technical Field

[0001] The invention relates to the technical field of shipbuilding, and in particular to a ship tail shaft nut disassembly and assembly tool and a disassembly and assembly method. Background Art

[0002] When repairing a ship, some parts need to be disassembled and inspected. For the tail shaft propeller nut of the ship, its weight is generally in the range of 0.3-3 tons, so its loosening and screwing in and other disassembly and assembly work must be carried out with special tooling.

[0003] At present, the installation method of hydraulic nuts on the stern shaft of large ships is: fix the lifting ring on the hydraulic nut, use a hand winch to drive the wire rope to pull the lifting ring, lift the hydraulic nut to the installation position, and install it on the bolt of the stern shaft of the large ship by hand-holding and dragging by multiple installers, and finally use a hand winch or a crane to further tighten the hydraulic nut through the wire rope. Due to the limitation of the installation position of the hydraulic nut on the stern shaft of large ships, there is no space for the crane to work when the hydraulic nut rises to the installation position, so it can only be lifted by a hand winch, but this will cause the position where the lifting ring is installed on the hydraulic nut to be subjected to a large force, causing excessive stress concentration here, damaging the hydraulic nut, and even breaking it; and the hydraulic nut needs to be aligned with the bolt axially, and it takes multiple installers to cooperate when rotating and installing the hydraulic nut, which consumes physical strength and time, and the installation quality cannot be guaranteed.

[0004] Document 1 (CN103522256A) discloses a special installation tool for hydraulic nuts of large ship tail shafts, please refer to Figure 1 , Figure 1 It is a structural schematic diagram of a special installation tool for a ship's tail shaft in the prior art. As shown in the figure, the special installation tool includes a main body and a lifting lever and a pin fixed on the main body, the lifting lever and the pin are both cylindrical, the lifting rod has a lifting part and a blocking part with an external thread, the blocking part is located at the end of the lifting lever away from the main body, and the diameter of the blocking part is smaller than the diameter of the lifting part; the lifting part is sleeved with a sleeve, the blocking part is sleeved with a baffle, and a nut matching the external thread is arranged on the blocking part on the right side of the baffle; the pin is sleeved with a roller and a retaining ring located on the right side of the roller, and a through hole for a cotter pin to pass through is opened on the retaining ring and the pin, and the cotter pin is located in the through hole.

[0005] The lifting lever and the pin in the above-mentioned special installation tool for the tail shaft of a ship are vertically welded on the main body. The three-section welded structure will cause a stress concentration area on the main body of the installation tool. When lifting a nut with a heavy weight, there will be a risk of fracture at the welding point, which will lead to the interruption of the maintenance project, economic losses and even personal injury to the on-site staff, and there are safety hazards. In addition, the scheme is that the sleeve is sleeved on the lifting part, and the balance adjustment is achieved by sliding it left and right. At the same time, the roller is sleeved on the pin, and the installation is carried out by rotating the roller and the hydraulic nut together. In order to bear the heavy weight of the nut and the moment of inertia generated by its rotation, the sleeve and the roller must be made of stronger materials and also require a larger volume. Therefore, their dead weight will increase, which increases the difficulty of lifting and rotating the nut. In addition, the roller and the pin are sleeved and connected, and the friction coefficient of the contact surface is large. In addition, the pressure generated by the nut on the roller during installation further increases the friction coefficient between the roller and the pin. When rotating, huge friction will be generated between the two, which consumes too much physical strength and time of the staff. Summary of the invention

[0006] In view of the deficiencies and defects in the above-mentioned prior art, the present invention provides a ship tail shaft nut disassembly and assembly tool, which has the advantages of easy operation, high strength, wide application range and no damage to the nut thread during the installation process.

[0007] This application achieves the above-mentioned purpose through the following technical solutions:

[0008] A ship tail shaft nut disassembly and assembly tool, which specifically comprises a steel plate, a steel shaft, a copper sleeve and a bearing group. The steel plate is integrally formed and has a hook-shaped structure, one end of which is provided with a plurality of lifting ring holes, and the other end is fixedly connected to the steel shaft; the copper sleeve is sleeved on the steel shaft; the bearing group is assembled on the steel shaft and is located between the steel shaft and the copper sleeve.

[0009] Compared with the prior art, the ship tail shaft nut disassembly and assembly tool provided by the present invention can effectively reduce the friction resistance generated by the nut and the copper sleeve when they rotate around the steel shaft by providing a copper sleeve that can rotate with the tail shaft nut around the steel shaft, and providing a ball bearing between the copper sleeve and the steel shaft. Under the same conditions, it can disassemble and assemble a heavier tail shaft nut, and can disassemble and assemble a ship tail shaft nut with a maximum weight of 3 tons, and has strong applicability. The thread of the nut will not be damaged during the disassembly and assembly process, and the operation of screwing the nut in and out is more convenient, which is beneficial to saving the staff's physical strength and time.

[0010] Furthermore, the steel plate is U-shaped.

[0011] Furthermore, the steel shaft comprises a steel shaft body, a first connecting portion and a second connecting portion, which are connected in sequence and have increasing diameters in sequence and are all cylindrical, and the second connecting portion is connected to the steel plate.

[0012] Furthermore, the bearing group includes a plurality of ball bearings sleeved on the steel shaft body, each ball bearing includes an inner ring, an outer ring and a plurality of steel balls arranged between the inner and outer rings, wherein the outer ring is tightly matched with the copper sleeve and can rotate synchronously with the copper sleeve, and the inner ring is tightly matched with the steel shaft and fixed on the steel shaft body; the copper sleeve includes a cylindrical body and a first convex ring, the first convex ring is formed by extending inward from the inner surface at one end of the cylindrical body, and the first convex ring is arranged radially outside the first connecting part and is located between the bearing group and the second connecting part.

[0013] Furthermore, it also includes a positioning member for limiting the bearing group.

[0014] Furthermore, the positioning member includes a positioning meson sleeved on the steel shaft body and an elastic retaining ring for limiting the positioning meson, the positioning meson is located on the outside of the bearing group, and the steel shaft body is provided with a second annular groove, the elastic retaining ring is embedded in the second groove and is located axially outside the positioning meson.

[0015] Furthermore, the positioning member further comprises a positioning sleeve sleeved on the steel shaft body, and the positioning member further comprises a positioning sleeve sleeved on the steel shaft body, and one end face or both end faces thereof are fixedly connected to the inner ring of the ball bearing. The positioning sleeve is used to fill the space to prevent the ball bearing from moving between the copper sleeve and the steel shaft.

[0016] Furthermore, the copper sleeve and the steel shaft are provided with gaps in the circumferential and axial directions, which can effectively reduce the friction resistance generated by the copper sleeve and the steel shaft when rotating, and provide a stopping safety when the copper sleeve moves backward; the positioning sleeve, positioning meson, steel shaft and copper sleeve are clearance-matched, which effectively reduces the friction force. At the same time, when the ball bearing of the copper sleeve and the nut bursts and is damaged during the rotation process, all the weight can be instantly transferred to the positioning meson and the positioning sleeve, changing from a rolling form to a sliding form, thereby preventing quality accidents caused by large impacts.

[0017] Furthermore, it also includes an O-ring; a first groove is annularly arranged on the outer surface of the first connecting part, and the O-ring matches the first groove to seal the gap between the copper sleeve and the first connecting part of the steel shaft to prevent foreign debris and moisture from entering and affecting the disassembly and assembly tools.

[0018] In addition, the present invention also provides a method for disassembling and assembling a ship tail shaft nut, which uses the above-mentioned ship tail shaft nut disassembling and assembling tool for disassembling and assembling, and the specific steps are as follows:

[0019] 1) Insert a pin into the pin hole of the nut, and move the pin to rotate the nut backward to loosen it relative to the tail shaft;

[0020] 2) When the nut is loosened and some threads are still engaged with the tail shaft, the eyelet hole is selected as the lifting point and a lifting tool is used to balance the disassembly tool, and the copper sleeve is moved into the nut;

[0021] 3) Adjust the lifting tool so that the copper sleeve bears the net weight of the nut;

[0022] 4) Continue to insert the pin into the pin hole of the nut and turn the nut to rotate it circumferentially and loosen it backward. The copper sleeve rotates with the nut. When the nut is separated from the tail shaft head, it is hung on the disassembly tool;

[0023] 5) When installing the nut, follow the above method in reverse, that is, first hang the nut on the disassembly and assembly tool, so that the copper sleeve bears the net weight of the nut, align the nut with the tail shaft and screw the nut in by moving the pin.

[0024] Compared with the prior art, the ship tail shaft nut disassembly tool and disassembly method provided by the present invention have the following advantages and beneficial effects:

[0025] 1) By using a steel plate with an integrated hook-shaped structure and welding a steel shaft at one end, the force is more uniform compared to a multi-section welded structure, which can effectively avoid the problem of stress concentration areas and fractures caused by force;

[0026] 2) By arranging a ball bearing between the copper sleeve and the steel shaft, the outer ring of the ball bearing rotates synchronously with the copper sleeve, and the inner ring is fixedly connected to the steel shaft. The arrangement of the ball bearing can effectively reduce the friction resistance generated by the nut and the copper sleeve when they rotate around the steel shaft. Under the same conditions as the prior art, it can withstand a heavier tail shaft nut and can meet the requirements of a ship tail shaft nut weighing less than 3 tons, with strong applicability. At the same time, the operation of screwing the nut in and out is easier, which is beneficial to saving the staff's physical strength and time.

[0027] 3) Compared with the method described in Document 1 in which the sleeve is sleeved on the lifting part and the balance is adjusted by moving left and right, the present invention provides a plurality of lifting ring holes, and the balance of the disassembly and assembly tool can be adjusted by selecting one or two of them, which can effectively reduce the weight of the disassembly and assembly tool, making the operation easier, while reducing the difficulty of lifting and reducing safety hazards.

[0028] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a special installation tool for a ship's tail shaft in the prior art.

[0030] Figure 2 It is a schematic diagram of the structure of the ship tail shaft nut disassembly and assembly tool of the present invention;

[0031] Figure 3 is a schematic structural diagram of the steel shaft;

[0032] Figure 4 is a schematic diagram of the structure of the copper sleeve;

[0033] Figure 5 is a structural schematic diagram of the positioning sleeve;

[0034] Figure 6 is a schematic diagram of the structure of the positioning meson;

[0035] Figure 7 yes Figure 2 A partial view of area A in the middle.

[0036] In the figure: steel plate 10; steel shaft 20; copper sleeve 30; bearing assembly 40; positioning member 50;

[0037] Steel plate: 12 eye holes;

[0038] Steel shaft: steel shaft body 21; first connection 22; second connection part 23; first groove 24; second groove 25; O-ring 26;

[0039] Copper sleeve: first connecting portion 32;

[0040] Bearing: inner ring 42; outer ring 44; steel ball 46;

[0041] Positioning parts: positioning sleeve 52; positioning meson 54; elastic retaining ring 56. DETAILED DESCRIPTION

[0042] Example 1

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] Please refer to Figure 2 , Figure 2It is a structural schematic diagram of the ship tail shaft nut disassembly and assembly tool of the present invention. As shown in the figure, the ship tail shaft nut disassembly and assembly tool includes a steel plate 10, a steel shaft 20, a copper sleeve 30, a bearing group 40 and a positioning member 50. The steel plate 10 is integrally formed and has a hook-shaped structure. Specifically, the steel plate is U-shaped, and a plurality of lifting ring holes 12 are arranged on its upper end. The number of the lifting ring holes can be adjusted according to actual conditions, and is 3 in this embodiment; the other end of the steel plate 10 is fixedly connected to the steel shaft 20; the copper sleeve 30 is sleeved on the steel shaft 20; the bearing group 20 is assembled on the steel shaft 20 and is located between the steel shaft 20 and the copper sleeve 30.

[0045] Please refer to Figure 3 , Figure 3 : is a schematic diagram of the structure of the steel shaft. As shown in the figure, the steel shaft 20 includes a steel shaft body 21, a first connecting part 22 and a second connecting part 23, which are connected from left to right in the figure and have increasing diameters, and are both cylindrical. The second connecting part 22 is connected to the steel plate 10. The first connecting part 22 is provided with a first groove 24 and an O-ring 26 in an annular shape. The O-ring 26 matches the first groove 24 and plays a role in preventing foreign debris and water from entering the gap to avoid damage to the hook; the steel shaft body 21 is also provided with a second groove 25.

[0046] Please refer to Figure 4 , Figure 4 It is a schematic diagram of the structure of the copper sleeve. The copper sleeve 30 includes a cylindrical body and a first convex ring 32. The first convex ring 32 is formed by extending inward from the inner surface at one end of the cylindrical body. The first convex ring 32 is arranged on the radial outside of the first connecting part 22 and is located between the bearing group 30 and the second connecting part 23.

[0047] The bearing group 40 includes a plurality of ball bearings sleeved on the steel shaft body 21, each ball bearing includes an inner ring 42, an outer ring 44 and a plurality of steel balls 46 disposed between the inner and outer rings. The number of the ball bearings 40 can be adjusted according to the weight of the installed nut, and in this embodiment, there are 3. The outer ring 44 is tightly matched with the copper sleeve 30 and can rotate synchronously with the copper sleeve 30. The inner ring 42 is tightly matched with the steel shaft 20 and is fixed on the steel shaft body 21 without rotating.

[0048] Please refer to Figure 5 and Figure 6 , Figure 5 and Figure 6The schematic diagrams of the structures of the positioning sleeve and the positioning meson are respectively. The positioning member includes a positioning sleeve 52, a positioning meson 54 and an elastic retaining ring; one end face of the positioning sleeve 52 is fixedly connected to the inner ring 42 of one of the ball bearings 40 or both end faces are in contact with the inner rings 42 of the two ball bearings 40, in this embodiment, it is the latter, and the positioning sleeve 52 is used to fill the space to prevent the ball bearings 40 from moving; the positioning meson 54 is located on the outside of the bearing group 40, and it is fixedly connected to the steel shaft 20 and the inner ring 42 of the ball bearing 40; the elastic retaining ring is embedded in the second groove 25 and is located on the axial outside of the positioning meson 54; the positioning sleeve 52 and the positioning meson 54 are combined to limit the bearing group 40 to prevent the ball bearings 40 from moving between the steel shaft 20 and the copper sleeve 30 and then falling off.

[0049] Please refer to Figure 7 , Figure 7 yes Figure 2 A partial enlarged view of the A area in the middle. As shown in the figure, the copper sleeve 30 and the steel shaft 20 are provided with gaps in the circumferential and axial directions (i.e., a and b in the figure); the positioning sleeve 30 and the copper sleeve 30, the steel shaft body 21, and the outer ring 44 of the ball bearing are clearance-fitted (i.e., c and d in the figure), the positioning meson 54 and the copper sleeve 30 and the outer ring 44 of the ball bearing are also clearance-fitted (i.e., e and f in the figure), and the outer ring 44 of the ball bearing is clearance-fitted with the first connecting plate of the steel shaft (i.e., g in the figure). The above-mentioned gaps can effectively reduce the rotation of the various rotating parts (copper sleeve 30 , ball bearing outer ring 44) and the fixed components (ball bearing inner ring 42, positioning sleeve 52, positioning meson 54, steel shaft first connecting portion 22 and second connecting portion 23); in addition, the gap a can also provide a stop insurance when the copper sleeve 30 moves backward; at the same time, when the ball bearing 40 bursts and is damaged during the rotation of the copper sleeve 30 and the nut, all the weight can be instantly transferred to the positioning sleeve 52 and the positioning meson 54, changing from a rolling form to a sliding form, thereby preventing quality accidents caused by excessive impact.

[0050] During operation, the hand chain hoist and the disassembly and assembly tool are connected by a steel wire or rope, and the balance of the disassembly and assembly tool is adjusted by selecting one or two combined lifting eye holes 12, and then the hand chain hoist is used to move the disassembly and assembly tool to the desired position; the copper sleeve 30 is placed in the nut to be disassembled, and the hand chain hoist is adjusted so that the force applied to the copper sleeve 30 is the net weight of the nut to be disassembled or the nut can be easily moved by manpower; then a pin is inserted into the nut pin hole, and the pin matches the nut pin hole, which is a steel rod in this embodiment. The nut is rotated by moving the steel rod, and the copper sleeve rotates around the steel shaft accordingly, thereby realizing the disassembly and assembly operation of screwing the nut in and out.

[0051] In addition, the present invention also provides a method for disassembling and assembling a ship tail shaft nut, which uses the above-mentioned ship tail shaft nut disassembling and assembling tool for disassembling and assembling, and the specific steps are as follows:

[0052] 1) After the nut is loosened from the propeller, a steel rod is inserted into the pin hole of the nut, and the steel rod is moved manually to rotate the nut backward so that it is relatively loosened from the tail shaft;

[0053] 2) When the nut is loosened and there is still 40-50 threads that fit with the tail shaft, a hand chain hoist is set just above the nut to connect the ship tail shaft nut disassembly and assembly tool, and the hand chain hoist pulley block is adjusted to place the copper sleeve in the nut, and the balance of the disassembly and assembly tool is adjusted by selecting one or two combined lifting ring holes as the lifting point;

[0054] 3) Adjust the hand chain hoist pulley group so that the force on the copper sleeve is the net weight of the nut to be removed or make it easy for manpower to move the nut;

[0055] 4) Insert the steel rod into the nut pin hole and turn the nut to rotate it circumferentially and loosen it backward. The copper sleeve rotates around the steel shaft with the nut. When the nut is separated from the tail shaft head, it is hung on the copper sleeve of the disassembly tool;

[0056] 5) Loosen the propeller from the tail shaft for repair; when installing, follow the above method in reverse, that is, align the nut with the tail shaft and screw it into the thread.

[0057] Compared with the prior art, the ship tail shaft nut disassembly tool and disassembly method provided by the present invention have the following advantages and beneficial effects:

[0058] 1) By using a steel plate with an integrated hook-shaped structure and welding a steel shaft at one end, the force is more uniform compared to a multi-section welded structure, which can effectively avoid the problem of stress concentration areas and fractures caused by force;

[0059] 2) By arranging a ball bearing between the copper sleeve and the steel shaft, the outer ring of the ball bearing rotates synchronously with the copper sleeve, and the inner ring is fixedly connected to the steel shaft. The arrangement of the ball bearing can effectively reduce the friction resistance generated by the nut and the copper sleeve when they rotate around the steel shaft. Under the same conditions as the prior art, it can withstand a heavier tail shaft nut and can meet the requirements of a ship tail shaft nut weighing less than 3 tons, with strong applicability. At the same time, the operation of screwing the nut in and out is easier, which is beneficial to saving the staff's physical strength and time.

[0060] 3) Compared with the method described in Document 1 in which the sleeve is sleeved on the lifting part and the balance is adjusted by moving left and right, the present invention provides a plurality of lifting ring holes, and the balance of the disassembly and assembly tool can be adjusted by selecting one or two of them, which can effectively reduce the weight of the disassembly and assembly tool, making the operation easier, while reducing the difficulty of lifting and reducing safety hazards.

[0061] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A ship tail shaft nut disassembly and assembly tool, characterized by: It comprises a steel plate, a steel shaft, a copper sleeve, a bearing group, and a positioning piece and an O-ring for limiting the bearing group; the steel plate is integrally formed and has a hook-shaped structure, one end of which is provided with a plurality of hanging ring holes, and the other end is fixedly connected to the steel shaft; the copper sleeve is sleeved on the steel shaft; the steel shaft comprises a steel shaft main body, a first connecting part and a second connecting part which are connected in sequence and increase in diameter in sequence and are both cylindrical; a first groove is annularly arranged on the outer surface of the first connecting part, and the O-ring matches the first groove; the second connecting part is connected to the steel plate; the copper sleeve comprises a cylindrical body and a first convex ring, the first convex ring is formed by extending inwardly from the inner surface at one end of the cylindrical body, the first convex ring is arranged on the radially outer side of the first connecting part and is located between the bearing group and the second connecting part; the bearing group is assembled on the steel shaft and is located between the steel shaft and the copper sleeve; the bearing group comprises a plurality of sleeves arranged on the steel shaft main body The invention relates to a ball bearing of a body, each ball bearing comprising an inner ring, an outer ring and a plurality of steel balls arranged between the inner and outer rings, the outer ring of the ball bearing is tightly matched with the copper sleeve and can rotate synchronously with the copper sleeve, the inner ring of the ball bearing is tightly matched with the steel shaft and fixed on the main body of the steel shaft; the positioning member comprises a positioning meson and a positioning sleeve sleeved on the main body of the steel shaft; the positioning meson is located on the outer side of the bearing group, and is fixedly connected with the steel shaft and the inner ring of the ball bearing; one end face or both end faces of the positioning sleeve are fixedly connected with the inner ring of the ball bearing; when the copper sleeve and the nut burst and are damaged during the rotation operation, all the weight can be instantly transferred to the positioning sleeve and the positioning meson; the copper sleeve and the steel shaft are provided with gaps in the circumferential and axial directions; the positioning sleeve is clearance matched with the steel shaft, the copper sleeve and the outer ring of the adjacent ball bearing; the positioning meson is clearance matched with the copper sleeve and the outer ring of the adjacent ball bearing.

2. The ship tail shaft nut disassembly and assembly tool according to claim 1, characterized in that: The steel plate is U-shaped.

3. The ship tail shaft nut disassembly and assembly tool according to claim 1, characterized in that: The positioning member also includes an elastic retaining ring for limiting the positioning meson. The steel shaft body is provided with a second annular groove. The elastic retaining ring is embedded in the second groove and is located axially outside the positioning meson.

4. A method for disassembling and assembling a stern shaft nut of a ship, characterized in that: The disassembly and assembly of the ship tail shaft nut using the ship tail shaft nut disassembly and assembly tool according to any one of claims 1 to 3 specifically comprises the following steps: 1) Insert a pin into the pin hole of the nut, and move the pin to rotate the nut backward to loosen it relative to the tail shaft; 2) When the nut is loosened and some threads are still engaged with the tail shaft, the lifting eye hole is selected as the lifting point and a lifting tool is used to balance the disassembly tool, and the copper sleeve is moved into the nut; 3) Adjust the lifting tool so that the copper sleeve bears the net weight of the nut; 4) Continue to insert the pin into the pin hole of the nut and turn the nut to rotate it circumferentially and loosen it backward. The copper sleeve rotates with the nut. When the nut is separated from the tail shaft head, it is hung on the disassembly tool; 5) When installing the nut, follow the above method in reverse, that is, first hang the nut on the disassembly and assembly tool, so that the copper sleeve bears the net weight of the nut, align the nut with the tail shaft and screw the nut in by moving the pin.

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