A large-diameter single-double quick-change rotary blowout preventer assembly

Abstract

The present invention discloses a large-diameter single-double quick-change rotary blowout preventer assembly, including a drive assembly, an upper rubber core rotary assembly, and a lower rubber core rotary assembly detachably connected to the bottom of the upper rubber core rotary assembly; the upper rubber core rotary assembly includes an upper center shaft protective sleeve, an upper rubber core shell, an upper rubber core, an upper rubber core skeleton, an upper rubber core drive hanger, and an upper rubber core sealing gland. The large-diameter single-double quick-change rotary blowout preventer assembly takes into account the large-diameter center shaft size and high dynamic sealing pressure. On the premise of ensuring that the center shaft diameter remains unchanged, it can realize the rapid conversion of the high-pressure double rubber core assembly and the low-pressure single rubber core assembly. At the same time, it improves the connection method of the rubber core hanger and the sealing rubber core, the connection method of the upper rubber core sealing gland and the upper rubber core shell, and the fixing method of the rotating sealing bushing, which can effectively prevent the equipment sealing failure caused by loose threads and wear of the sealing bushing due to vibration. The present invention has a compact and simple structure, is easy to disassemble and assemble on site, and has strong practicality.

Description

Technical Field

[0001] The invention relates to the technical field of blowout preventers, in particular to a large-diameter single-double quick-change rotary blowout preventer assembly. Background Art

[0002] The rotary blowout preventer is one of the core equipment for implementing underbalanced (liquid phase, gas phase) drilling, pressure-controlled drilling and other drilling technologies. Its main function is to achieve rotary sealing and drilling of the drill tool under certain wellhead pressure conditions. Generally, a passive rotary blowout preventer is mainly composed of a rotary assembly, a shell, a clamp, etc. Among them, the rotary assembly is the main component of the rotary blowout preventer and is an important component for achieving rotary sealing of the drill tool.

[0003] The rotary blowout preventer rotary assemblies currently in use are generally divided into high-pressure double-rubber core assemblies and low-pressure single-rubber core assemblies. The existing high-pressure double-rubber core assembly has a small central shaft diameter due to structural limitations, and its ability to pass through drilling tools is limited. However, the rotary assemblies with a large central shaft diameter are mostly low-pressure single-rubber cores, and their pressure-bearing capacity is low. For on-site use, it is necessary to purchase and reserve rotary blowout preventer assemblies of different specifications and models according to the situation, which not only increases costs but also is inconvenient to manage.

[0004] The existing high-pressure rotary blowout preventer assembly usually adopts the method of installing the upper rubber core assembly and the lower rubber core assembly to improve its dynamic sealing pressure. The upper rubber core assembly is a sealed chamber as a whole, and the upper rubber core sealing gland and the upper rubber core shell are usually connected by threads or bolts. At the same time, whether it is a high-pressure double rubber core or a low-pressure single rubber core rotary blowout preventer assembly, its sealing rubber core is installed by connecting the rubber core hanger with the rubber core through bolts. The sealing rubber core and the hanger mainly rely on the pre-tightening force of the bolts to make the rubber core end face fit closely with the hanger to achieve sealing.

[0005] During field operations, due to the rotation of the drill bit and the vibration of the wellhead, the upper rubber core shell and the upper rubber core sealing cover of the high-pressure double rubber core rotating assembly are prone to inverting or loosening, and the rubber core hanger and the rubber core fitting surface bolts are loose, which can lead to failure of the rotating assembly seal, wear of the core shaft, scrapping and other unexpected situations.

[0006] In addition, conventional rotary blowout preventer assemblies usually use threads to connect the wear-resistant dynamic seal bushing to the core shaft of the rotating assembly, and then realize dynamic sealing with the dynamic seal component. In order to prevent the dynamic seal bushing from being disengaged or loosened during rotation, it is usually fixed by welding and using sealant. As the use time accumulates, the sealing surface of the wear-resistant dynamic seal bushing will gradually wear and cause the dynamic seal to fail. When disassembling and replacing the dynamic seal bushing, special tools or special treatment are required. Due to the limitations of on-site conditions, forced treatment may damage the core shaft and sealing components, causing damage or scrapping of the bearings, and can only be returned to the factory for repair, which affects the construction progress, has a long maintenance cycle, and high transportation costs. The Chinese patent with publication number CN209494545U provides an easily disassembled rotating blowout preventer rotating assembly, which changes the connection mode between the upper rubber core connecting seat and the upper rubber core mounting tube, between the upper rubber core mounting tube, the upper dynamic sealing sleeve and the core shaft, and between the core shaft, the lower dynamic sealing sleeve and the lower rubber core mounting seat, which alleviates the above-mentioned technical problems to a certain extent. However, the sealing rubber core and the rubber core hanger are still connected and sealed by thread pre-tightening, and the dynamic sealing bushing and the central core shaft are still fixed with screws. Once the thread is loose or the thread head is worn, problems such as failure of the upper rubber core sealing gland and the sealing rubber core hanger, and difficulty in disassembly and assembly of the equipment may still occur. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a large-diameter single-double quick-change rotary blowout preventer assembly, which takes into account the large-diameter center axis size and high dynamic sealing pressure. On the premise of ensuring that the center axis diameter remains unchanged, the high-pressure double rubber core assembly and the low-pressure single rubber core assembly can be quickly converted. At the same time, the connection method between the rubber core hanger and the sealing rubber core, the connection method between the upper rubber core sealing cover and the upper rubber core shell, and the fixing method of the rotating sealing bushing are improved, which can effectively prevent the loosening of the thread and the wear of the sealing bushing caused by vibration, resulting in equipment sealing failure. The present invention has a compact and simple structure, is easy to disassemble and assemble on site, has strong practicality, and is easy to promote.

[0008] The technical solution adopted by the present invention is:

[0009] A large-diameter single-double quick-change rotary blowout preventer assembly, comprising a drive assembly, an upper rubber core rotary assembly and a lower rubber core rotary assembly detachably connected to the bottom of the upper rubber core rotary assembly; the upper rubber core rotary assembly comprises an upper central shaft protective sleeve, an upper rubber core shell, an upper rubber core, an upper rubber core skeleton, an upper rubber core drive hanger and an upper rubber core sealing gland; the upper rubber core shell is a hollow annular cylindrical structure, the bottom inner wall of the upper rubber core shell is provided with an inward boss, the lower rubber core rotary assembly is detachably connected to the boss, and the upper rubber core located at the upper part of the boss The inner wall of the shell is provided with a cylindrical internal thread, and the outer wall cylindrical surface of the upper center axis protection sleeve is provided with a cylindrical external thread matching the cylindrical internal thread of the upper rubber core shell, and the upper center axis protection sleeve is threadedly connected to the inner wall of the upper rubber core shell on the upper part of the boss; the upper rubber core is arranged in the upper rubber core shell, and the upper end surface inner cavity thereof is inlaid with an upper rubber core skeleton, and the upper rubber core skeleton is a circular ring structure with an axial cross section on one side of the axis showing an "L" shape, and the part of the upper rubber core skeleton protruding above the top end surface of the upper rubber core is a cylindrical structure, and the inner wall of the upper rubber core drive hanger includes The invention relates to a rubber core driving hanger, which comprises two parts of cylinders arranged from bottom to top, namely, cylinder one and cylinder two, the inner diameter of cylinder one is larger than the inner diameter of cylinder two, the outer wall of the cylindrical structure of the upper rubber core skeleton is adapted to cylinder one, and the cylindrical structure of the upper rubber core skeleton is detachably connected to the lower end of the upper rubber core driving hanger; the outer wall of the upper rubber core driving hanger comprises two parts of cylinders arranged from top to bottom, namely, cylinder three and cylinder four, the outer diameter of cylinder three is smaller than the outer diameter of cylinder four, the inner wall of the upper rubber core sealing cover comprises two parts of cylinders arranged from top to bottom, namely, cylinder three and cylinder four. The cylinder surface 5 and the cylinder surface 6 are respectively cylindrical surfaces 5 and 6, the inner diameter of the cylinder surface 5 is smaller than the inner diameter of the cylinder surface 6, the cylinder surface 4 is provided with a protrusion 1, and the cylinder surface 6 is provided with a groove 1 matched with the protrusion 1, so as to limit the axial rotation and sliding of the upper rubber core drive hanger relative to the upper rubber core sealing gland; the middle outer wall of the upper rubber core sealing gland is provided with a protrusion 2, and the upper end inner cavity of the upper rubber core shell is provided with a groove 2 matched with the protrusion 2; the outer wall of the driving assembly is provided with a protrusion 3, and the upper end surface of the upper rubber core drive hanger is provided with a groove 3 matched with the protrusion 3. The driving assembly can drive the upper rubber core drive hanger to rotate around the axis.

[0010] Preferably, the outer wall of the cylindrical structure of the upper rubber core skeleton is provided with a threaded blind hole, and the cylindrical surface of the upper rubber core driving hanger is provided with a countersunk hole that passes through the side wall of the upper rubber core driving hanger, and the countersunk side of the countersunk hole is located on the outside of the upper rubber core driving hanger, and the threaded blind hole and the countersunk hole are connected by a rubber core connecting screw to limit the axial rotation and sliding of the upper rubber core, and a sealing ring is provided between the outer wall of the cylindrical structure of the upper rubber core skeleton and the cylindrical surface of the upper rubber core driving hanger, and the sealing ring is located above the rubber core connecting screw.

[0011] Preferably, a sealing ring 2 is provided between the outer wall of the upper rubber core sealing cover below the second protrusion and the inner wall of the upper rubber core shell, and a sealing ring 3 is provided between the cylindrical surface 2 of the upper rubber core driving hanger and the cylindrical surface 5 of the upper rubber core sealing cover.

[0012] Preferably, a plurality of mutually independent protrusions 1 are provided on the cylindrical surface 4 of the upper rubber core driving hanger, and a plurality of mutually independent grooves 1 are provided on the cylindrical surface 6 of the upper rubber core sealing cover, which are respectively matched with the protrusions 1; a plurality of mutually independent protrusions 2 are provided on the middle outer wall of the upper rubber core sealing cover, and a plurality of mutually independent grooves 2 are provided in the upper end inner cavity of the upper rubber core shell, which are respectively matched with the protrusions 2.

[0013] Preferably, the lower rubber core rotating assembly includes an oil injection joint, an upper gland of the assembly, an upper dynamic sealing bushing, an upper sealing sleeve, a straightening bearing, a thrust bearing, a center shaft, an assembly housing, a bearing seat, a lower sealing sleeve, an assembly lower gland, a lower dynamic sealing bushing, a lower rubber core hanger, a lower rubber core, a lower rubber core frame, a lower dynamic sealing assembly, an upper dynamic sealing assembly, and a balanced pressure joint;

[0014] The assembly shell is a hollow annular columnar structure, and its inner cavity is provided with the first, second, third, fourth and fifth step cylinders from top to bottom in sequence. The inner diameters of the first to third step cylinders of the assembly shell change from small to large, and the inner diameters of the third to fifth step cylinders of the assembly shell change from large to small. The upper end surface of the assembly shell is evenly distributed with a plurality of threaded blind holes 2, and the lower end surface of the assembly shell is evenly distributed with a plurality of threaded blind holes 3. The upper end surface of the assembly shell is also provided with a threaded sealing hole 1, and a through hole 1 is provided in the assembly shell, one end of the through hole 1 is connected with the threaded sealing hole 1, and the other end is connected with the inner cavity of the assembly shell. The oil injection joint is arranged in the threaded sealing hole 1, and the radial direction of the assembly shell in the middle part of the first step cylinder of the assembly shell is provided with a through hole 2 penetrating the side wall of the assembly shell, and the through hole 2 is provided with a threaded sealing hole 2 on the side close to the outer wall of the assembly shell, and the balanced pressure joint is arranged in the threaded sealing hole 2;

[0015] The inner cavity of the central shaft is a through hole of equal diameter, and the outer wall of the central shaft is provided with the first, second, third, fourth, fifth, sixth and seventh step cylinders from top to bottom in sequence, the outer diameters of the first to fourth step cylinders of the central shaft change from small to large, and the outer diameters of the fourth to seventh step cylinders of the central shaft change from large to small, the uppermost end surface of the central shaft is provided with a plurality of evenly distributed threaded blind holes four, the boss is provided with a plurality of through holes three corresponding to the threaded blind holes four, the through holes three are connected to the threaded blind holes four by a central shaft connecting bolt, and the upper central shaft protective sleeve is provided on the upper part of the central shaft connecting bolt;

[0016] The upper dynamic sealing bushing is a circular ring structure, which is arranged on the first step cylinder of the central axis. The upper end surface of the upper dynamic sealing bushing is in close contact with the lower end surface of the upper rubber core shell. The inner wall of the upper end of the upper dynamic sealing bushing is provided with a plurality of protrusions four evenly distributed inwardly, and the central axis is provided with a plurality of grooves four respectively matched with the protrusions four, so that the upper dynamic sealing bushing cannot rotate relative to the central axis;

[0017] The upper sealing sleeve and the upper dynamic sealing assembly are arranged together between the outer wall of the upper dynamic sealing bushing and the first step cylindrical surface of the assembly housing;

[0018] The assembly upper gland is an annular structure, connected to the threaded blind hole 2 on the upper end surface of the assembly housing through the upper connecting screw, and the lower end surface of the assembly upper gland is in close contact with the upper end surface of the upper sealing sleeve and the upper dynamic sealing assembly;

[0019] Two groups of centering bearings are respectively arranged between the second step cylindrical surface of the assembly housing and the second step cylindrical surface of the center axis, and between the fifth step cylindrical surface of the assembly housing and the sixth step cylindrical surface of the center axis. Each group of centering bearings includes two centering bearings symmetrically arranged with the axis of the center axis. The top of the outer ring of the centering bearing located above is in close contact with the lower end surface of the upper sealing sleeve, and the top of the inner ring is in close contact with the lower end surface of the upper dynamic sealing bushing. A bearing seat is arranged between the outer wall of the centering bearing located below and the inner wall of the assembly housing. A bearing seat is arranged between the fourth step cylindrical surface of the assembly housing and the third step cylindrical surface of the center axis, and between the fourth step cylindrical surface of the assembly housing and the third step cylindrical surface of the center axis, and between the fourth step cylindrical surface of the assembly housing and the third step cylindrical surface of the center axis. Two groups of thrust bearings are respectively arranged between the fourth step cylindrical surface of the assembly and the fifth step cylindrical surface of the central axis, each group of thrust bearings includes two thrust bearings symmetrically arranged with the axis of the central axis, the two end surfaces of the thrust bearing located above are respectively in contact with the upper end surface of the fourth step cylindrical surface of the assembly housing and the lower end surface of the third step cylindrical surface of the central axis, and the two end surfaces of the thrust bearing located below are respectively in contact with the upper end surface of the fifth step cylindrical surface of the central axis and the lower end surface of the fourth step cylindrical surface of the assembly housing, the bearing seat is arranged on the outer ring of the first straightening bearing, and the upper end surface of the bearing seat is in contact with the upper end surface of the thrust bearing located below;

[0020] The lower dynamic seal bushing is a circular ring structure, which is arranged on the seventh step cylindrical surface of the central shaft and contacts the lower end surface of the centralizing bearing located below. A plurality of inwardly protruding bumps four are evenly arranged on the inner side of the lower end of the lower dynamic seal bushing, and a plurality of grooves four respectively matched with the bumps four are arranged on the outer wall of the lower end of the central shaft, so that the lower dynamic seal bushing cannot rotate relative to the central shaft;

[0021] The assembly lower pressure cover is a ring structure with an axial cross section on one side of the axis in a "convex" shape. A plurality of through holes five corresponding to the threaded blind holes three on the lower end surface of the assembly housing are provided on the outer step of the assembly lower pressure cover. The through holes five are connected to the threaded blind holes three by lower connecting screws. The uppermost end surface of the assembly lower pressure cover contacts the lower end surface of the bearing seat.

[0022] The lower sealing sleeve and the lower dynamic sealing assembly are jointly arranged between the outer wall of the lower dynamic sealing bushing and the inner wall of the lower gland of the assembly, the outer wall of the lower sealing sleeve is provided with a cylindrical external thread, the uppermost inner wall of the lower gland of the assembly is provided with a cylindrical internal thread matching the cylindrical external thread of the lower sealing sleeve, the lower sealing sleeve is threadedly connected to the lower gland of the assembly, and the upper end surface of the lower sealing sleeve contacts the lower end surface of the bearing seat and the centralizing bearing located below;

[0023] The lower rubber core hanger is a circular ring structure with an axial cross-section of a "7" shape on one side of the axis, and the protruding step portion of the side of the lower rubber core hanger faces the inner side of the lower rubber core hanger. The lowermost end surface of the central axis is provided with a plurality of evenly distributed threaded blind holes five, and the upper inner step of the lower rubber core hanger is provided with a plurality of countersunk holes two corresponding to the threaded blind holes five, respectively. The threaded blind holes five and the countersunk holes two are connected by a central axis connecting bolt, and the lower end of the outer wall of the lower rubber core hanger is evenly provided with a plurality of countersunk holes three arranged along the lower rubber core hanger along the circumference, and the countersunk holes three penetrate the lower rubber core hanger. A step is provided at the upper end of the outermost circle of the device, and the inner side of the lower end of the lower pressure cover of the assembly is arranged in the step of the lower rubber core hanger. The inner cavity of the upper end surface of the lower rubber core is inlaid with a lower rubber core skeleton. The lower rubber core skeleton is a circular ring structure with an axial cross-section on one side of the axis showing an "L" shape. The part of the lower rubber core skeleton protruding above the top end surface of the lower rubber core is a cylindrical structure. The outer wall of the cylindrical structure of the lower rubber core skeleton is adapted to the inner wall of the lower end of the lower rubber core hanger. The outer wall of the cylindrical structure of the lower rubber core skeleton is provided with a plurality of threaded blind holes six corresponding to the countersunk holes three, and the threaded blind holes six are connected to the countersunk holes three by rubber core connecting bolts.

[0024] Preferably, a sealing ring four is provided between the upper end surface of the upper dynamic sealing bushing and the lower end surface of the upper rubber core shell, and a sealing ring five is provided between the inner wall of the upper dynamic sealing bushing and the outer wall of the central shaft; the outer wall of the upper sealing sleeve is provided with a through hole four matching the through hole two of the assembly shell, and sealing rings six are provided between the outer wall of the upper sealing sleeve and the inner wall of the assembly shell above and below the through hole four respectively; a step is provided on the outer side of the lower end surface of the upper rubber core shell, the inner side of the upper end of the assembly upper pressure cover is provided in the step of the lower end surface of the upper rubber core shell, and the upper end surface of the step of the lower end surface of the upper rubber core shell is aligned with the upper end surface of the assembly upper pressure cover An upper end sealing assembly is provided between the end faces; a sealing ring seven is provided between the inner wall of the lower dynamic sealing bushing and the seventh step cylindrical surface of the center axis; a sealing ring eight is provided between the cylindrical surface above the outer step of the lower pressure cover of the assembly and the fifth cylindrical surface of the assembly housing; the upper end surface of the lower rubber core hanger and the lower end surface of the lower dynamic sealing bushing are in contact with each other and a sealing ring nine is provided between them; a lower end sealing assembly is provided between the outermost circular upper end surface of the lower rubber core hanger and the lower end surface of the lower pressure cover of the assembly; a sealing ring ten is provided between the outer wall of the cylindrical structure of the lower rubber core skeleton and the lowermost inner wall of the lower rubber core hanger, and the sealing ring ten is located above the threaded blind hole six.

[0025] Preferably, it also includes an upper sealing sleeve and a single rubber core driving sleeve, the side wall of the single rubber core driving sleeve is provided with a countersunk hole four corresponding to the threaded blind hole four along its axis, the countersunk hole four passes through the upper and lower end surfaces of the single rubber core driving sleeve, the upper end surface of the single rubber core driving sleeve is provided with a groove five that is three-phase compatible with the protrusion, the driving assembly can drive the single rubber core driving sleeve to rotate around the axis, after the lower rubber core rotating assembly and the bottom of the upper rubber core rotating assembly are disassembled, the single rubber core driving sleeve is connected to the threaded blind hole four through the central axis connecting bolt, the inner diameter of the single rubber core driving sleeve matches the inner diameter of the inner cavity of the central axis, and the outer diameter of the single rubber core driving sleeve is larger than the outer diameter of the first step cylinder of the central axis; the upper sealing sleeve is arranged on the outer side of the single rubber core driving sleeve and is connected to the single rubber core driving sleeve through a plurality of evenly distributed screws, and an upper sealing component is arranged between the lower end surface of the upper sealing sleeve and the upper end surface of the upper pressure cover of the assembly.

[0026] The beneficial effects of the present invention are:

[0027] 1. Taking into account the large diameter center shaft size and high dynamic sealing pressure, the high-pressure double-core assembly and the low-pressure single-core assembly can be quickly converted under the premise of ensuring the same center shaft diameter. When used on site, it is only necessary to remove the single-core drive sleeve and the upper end sealing sleeve of the single-core rotary blowout preventer assembly, install the upper core shell on the center shaft, and then assemble the upper core hanger, the upper core gland and the upper core and install them in the core shell to convert to a high-pressure double-core assembly. This design can make the equipment multi-purpose and effectively reduce the use and maintenance costs;

[0028] 2. The connection method between the rubber core hanger and the sealing rubber core has been improved. The original end face seal has been improved to a cylindrical seal. Even if the rubber core connection screws are slightly loosened due to vibration during use, the rubber core is always in a sealed state without leakage due to the longer contact surface of the cylindrical seal, which is safer and more reliable.

[0029] 3. The connection method between the upper rubber core sealing gland and the upper rubber core shell has been improved. The existing thread and bolt connection method has been improved to a concave-convex slot connection method. The thread will not be reversed or stripped due to vibration during use, ensuring that the sealing performance of the upper rubber core and the shell is always safe. At the same time, installation and disassembly are easier and the labor intensity is lower.

[0030] 4. The fixing method of the rotating sealing bushing is improved, the end face pressing method is used to limit the axial displacement of the bushing, and the concave and convex groove method is used to limit the rotation of the bushing around the axis. At the same time, by arranging multiple sets of sealing members on the inner wall of the bushing, the bushing can be slightly swung within a small gap range while ensuring the sealing effect, which can effectively reduce the vibration impact during rotation friction, alleviate the bushing wear and extend the service life. The structure is simple, easy to disassemble and assemble, and the function is applicable. The present invention has a compact structure, is safe and reliable, is easy to disassemble and assemble, is easy to maintain, and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of an embodiment of the present invention when it is in a single-rubber core state;

[0032] Figure 2 This is a schematic diagram of the structure of the double-rubber core state of an embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of the top view of the end surface structure after the upper and lower dynamic sealing bushings are matched with the central shaft in an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of the axial cross-section structure of the assembly housing in an embodiment of the present invention;

[0035] Figure 5 Schematic diagram of the axial cross-section structure of the central axis in an embodiment of the present invention;

[0036] Figure numerals: 1, drive assembly, 2, oil filling joint, 3, assembly upper pressure cover, 4, upper dynamic sealing bushing, 5, upper sealing sleeve, 6, straightening bearing, 7, thrust bearing, 8, center shaft, 9, assembly housing, 10, bearing seat, 11, lower sealing sleeve, 12, lower connecting screw, 13, assembly lower pressure cover, 14, lower dynamic sealing bushing, 15, lower rubber core hanger, 16, lower rubber core, 17, lower rubber core frame, 18, rubber core connecting screw , 19. Lower end sealing assembly, 20. Center shaft connecting bolt, 21. Lower dynamic sealing assembly, 22. Upper dynamic sealing assembly, 23. Balanced pressure joint, 24. Upper end sealing assembly, 25. Upper connecting screws, 26. Upper end sealing sleeve, 27. Single rubber core drive sleeve, 28. Upper center shaft protection sleeve, 29. Upper rubber core shell, 30. Upper rubber core, 31. Upper rubber core frame, 32. Upper rubber core drive hanger, 33. Upper rubber core sealing cover. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] Examples, such as Figure 2 , Figure 3As shown, a large-diameter single-double quick-change rotary blowout preventer assembly includes a drive assembly 1, an upper rubber core rotary assembly, and a lower rubber core rotary assembly detachably connected to the bottom of the upper rubber core rotary assembly; the upper rubber core rotary assembly includes an upper central shaft protective sleeve 28, an upper rubber core shell 29, an upper rubber core 30, an upper rubber core skeleton 31, an upper rubber core drive hanger 32 and an upper rubber core sealing gland 33; the upper rubber core shell 29 is a hollow annular cylindrical structure, and the bottom inner wall of the upper rubber core shell 29 is provided with an inward boss, and the lower rubber core rotary assembly is detachably connected to the boss and is located on the upper part of the boss The inner wall of the upper rubber core shell 29 is provided with a cylindrical internal thread, and the outer wall cylindrical surface of the upper center axis protection sleeve 28 is provided with a cylindrical external thread matching the cylindrical internal thread of the upper rubber core shell 29, and the upper center axis protection sleeve 28 is threadedly connected to the inner wall of the upper rubber core shell 29 at the upper part of the boss; the upper rubber core 30 is arranged in the upper rubber core shell 29, and the upper end surface inner cavity thereof is inlaid with an upper rubber core skeleton 31, and the upper rubber core skeleton 31 is a circular ring structure with an axial cross section on one side of the axis center in the shape of an "L" shape, and the part of the upper rubber core skeleton 31 protruding above the top end surface of the upper rubber core 30 is a cylindrical structure, and the upper rubber The inner wall of the core drive hanger 32 includes two parts of cylinders arranged from bottom to top, namely, cylinder one and cylinder two, the inner diameter of cylinder one is larger than the inner diameter of cylinder two, the outer wall of the cylindrical structure of the upper rubber core skeleton 31 is adapted to cylinder one, and the cylindrical structure of the upper rubber core skeleton 31 is detachably connected to the lower end of the upper rubber core drive hanger 32; the outer wall of the upper rubber core drive hanger 32 includes two parts of cylinders arranged from top to bottom, namely, cylinder three and cylinder four, the outer diameter of cylinder three is smaller than the outer diameter of cylinder four, and the inner wall of the upper rubber core sealing cover 33 includes two parts of cylinders arranged from top to bottom The cylinders are divided into cylinder 5 and cylinder 6. The inner diameter of cylinder 5 is smaller than that of cylinder 6. Cylinder 4 is provided with a protrusion 1, and cylinder 6 is provided with a groove 1 matched with protrusion 1 to limit the axial rotation and sliding of the upper rubber core drive hanger 32 relative to the upper rubber core sealing gland 33. The middle outer wall of the upper rubber core sealing gland 33 is provided with a protrusion 2, and the upper inner cavity of the upper rubber core shell 29 is provided with a groove 2 matched with protrusion 2. The outer wall of the drive assembly 1 is provided with a protrusion 3, and the upper end surface of the upper rubber core drive hanger 32 is provided with a groove 3 matched with protrusion 3. The drive assembly 1 can drive the upper rubber core drive hanger 32 to rotate around the axis.

[0039] In one embodiment, a threaded blind hole is provided on the outer wall of the cylindrical structure of the upper rubber core skeleton 31, and a countersunk hole is provided on the cylindrical surface of the upper rubber core driving hanger 32, which passes through the side wall of the upper rubber core driving hanger 32. The countersunk side of the countersunk hole is located on the outer side of the upper rubber core driving hanger 32. The threaded blind hole and the countersunk hole are connected by a rubber core connecting screw 18 to limit the axial rotation and sliding of the upper rubber core 30. A sealing ring is provided between the outer wall of the cylindrical structure of the upper rubber core skeleton 31 and the cylindrical surface of the upper rubber core driving hanger 32, and the sealing ring is located above the rubber core connecting screw 18.

[0040] In one embodiment, a sealing ring 2 is provided between the outer wall of the upper rubber core sealing cover 33 below the protrusion 2 and the inner wall of the upper rubber core shell 29, and a sealing ring 3 is provided between the cylindrical surface 2 of the upper rubber core driving hanger 32 and the cylindrical surface 5 of the upper rubber core sealing cover 33.

[0041] In one of the embodiments, a plurality of mutually independent protrusions 1 are provided on the cylindrical surface 4 of the upper rubber core driving hanger 32, and a plurality of mutually independent grooves 1 are provided on the cylindrical surface 6 of the upper rubber core sealing cover 33, which are respectively matched with the protrusions 1; a plurality of mutually independent protrusions 2 are provided on the middle outer wall of the upper rubber core sealing cover 33, and a plurality of mutually independent grooves 2 are provided in the upper end inner cavity of the upper rubber core shell 29, which are respectively matched with the protrusions 2.

[0042] In one embodiment, the lower rubber core rotating assembly includes an oil injection joint 2, an assembly upper pressure cover 3, an upper dynamic sealing bushing 4, an upper sealing sleeve 5, a straightening bearing 6, a thrust bearing 7, a center shaft 8, an assembly housing 9, a bearing seat 10, a lower sealing sleeve 11, an assembly lower pressure cover 13, a lower dynamic sealing bushing 14, a lower rubber core hanger 15, a lower rubber core 16, a lower rubber core frame 17, a lower dynamic sealing assembly 21, an upper dynamic sealing assembly 22, and a balanced pressure joint 23;

[0043] The assembly housing 9 is a hollow annular columnar structure, and its inner cavity is provided with the first, second, third, fourth and fifth step cylinders from top to bottom in sequence. The inner diameters of the first to third step cylinders of the assembly housing 9 change from small to large, and the inner diameters of the third to fifth step cylinders of the assembly housing 9 change from large to small. The upper end surface of the assembly housing 9 is evenly distributed with a plurality of threaded blind holes 2, and the lower end surface of the assembly housing 9 is evenly distributed with a plurality of threaded blind holes 3. The upper end surface of the assembly housing 9 is also provided with a threaded sealing hole 1. A through hole 1 is provided in the assembly housing 9, one end of which is connected with the threaded sealing hole 1, and the other end is connected with the inner cavity of the assembly housing 9. The oil injection joint 2 is provided in the threaded sealing hole 1. A through hole 2 penetrating the side wall of the assembly housing 9 is provided in the radial direction of the middle part of the first step cylinder of the assembly housing 9. The through hole 2 is provided with a threaded sealing hole 2 on the side close to the outer wall of the assembly housing 9, and the balanced pressure joint 23 is provided in the threaded sealing hole 2.

[0044] The inner cavity of the central shaft 8 is a through hole of equal diameter, and the outer wall of the central shaft 8 is provided with the first, second, third, fourth, fifth, sixth and seventh step cylinders from top to bottom in sequence, and the outer diameters of the first to fourth step cylinders of the central shaft 8 are changed from small to large, and the outer diameters of the fourth to seventh step cylinders of the central shaft 8 are changed from large to small, and the upper end surface of the central shaft 8 is provided with a plurality of evenly distributed threaded blind holes four, and the boss is provided with a plurality of through holes three corresponding to the threaded blind holes four, and the through holes three are connected to the threaded blind holes four by the central shaft connecting bolts 20, and the upper central shaft protective sleeve 28 is provided on the upper part of the central shaft connecting bolts 20;

[0045] The upper dynamic seal bushing 4 is a circular ring structure, and is arranged on the first step cylinder of the central shaft 8. The upper end surface of the upper dynamic seal bushing 4 is in close contact with the lower end surface of the upper rubber core shell 29. The upper end inner wall of the upper dynamic seal bushing 4 is provided with a plurality of protrusions 4 evenly distributed inwardly, and the central shaft 8 is provided with a plurality of grooves 4 respectively matched with the protrusions 4, so that the upper dynamic seal bushing 4 cannot rotate relative to the central shaft 8;

[0046] The upper sealing sleeve 5 and the upper dynamic sealing assembly 22 are arranged together between the outer wall of the upper dynamic sealing bushing 4 and the first step cylindrical surface of the assembly housing 9;

[0047] The assembly upper gland 3 is an annular structure, connected to the threaded blind hole 2 on the upper end surface of the assembly housing 9 through the upper connecting screw 25, and the lower end surface of the assembly upper gland 3 is in close contact with the upper end surface of the upper sealing sleeve 5 and the upper dynamic sealing assembly 22;

[0048] Two groups of stabilizing bearings 6 are respectively arranged between the second step cylindrical surface of the assembly housing 9 and the second step cylindrical surface of the center shaft 8, and between the fifth step cylindrical surface of the assembly housing 9 and the sixth step cylindrical surface of the center shaft 8. Each group of stabilizing bearings 6 includes two stabilizing bearings 6 symmetrically arranged with the axis of the center shaft 8. The top of the outer ring of the stabilizing bearing 6 located above is in close contact with the lower end surface of the upper sealing sleeve 5, and the top of the inner ring is in close contact with the lower end surface of the upper dynamic sealing bushing 4. A bearing seat 10 is arranged between the outer wall of the stabilizing bearing 6 located below and the inner wall of the assembly housing 9. A bearing seat 10 is arranged between the fourth step cylindrical surface of the assembly housing 9 and the third step cylindrical surface of the center shaft 8, and between the fifth step cylindrical surface of the assembly housing 9 and the sixth step cylindrical surface of the center shaft 8. Two groups of thrust bearings 7 are respectively arranged between the fourth step cylinder and the fifth step cylinder of the central axis 8, and each group of thrust bearings 7 includes two thrust bearings 7 symmetrically arranged with the axis of the central axis 8, and the two end surfaces of the thrust bearing 7 located above are respectively in contact with the upper end surface of the fourth step cylinder of the assembly housing 9 and the lower end surface of the third step cylinder of the central axis 8, and the two end surfaces of the thrust bearing 7 located below are respectively in contact with the upper end surface of the fifth step cylinder of the central axis 8 and the lower end surface of the fourth step cylinder of the assembly housing 9, and the bearing seat 10 is arranged on the outer ring of the first straightening bearing 6, and the upper end surface of the bearing seat 10 is in contact with the upper end surface of the thrust bearing 7 located below to be restricted by it;

[0049] The lower dynamic seal bushing 14 is a circular ring structure, which is arranged on the seventh step cylindrical surface of the central shaft 8, and contacts and is restricted by the lower end surface of the centralizing bearing 6 located below. A plurality of inwardly protruding bumps 4 are evenly arranged on the inner side of the lower end of the lower dynamic seal bushing 14, and a plurality of grooves 4 respectively matched with the bumps 4 are arranged on the outer wall of the lower end of the central shaft 8, so that the lower dynamic seal bushing 14 cannot rotate relative to the central shaft 8;

[0050] The assembly lower pressure cover 13 is a ring structure with an axial cross section on one side of the axis in a "convex" shape. A plurality of through holes 5 corresponding to the threaded blind holes 3 on the lower end surface of the assembly housing 9 are provided on the outer step of the assembly lower pressure cover 13. The through holes 5 are connected to the threaded blind holes 3 by the lower connecting screws 12. The uppermost end surface of the assembly lower pressure cover 13 contacts and is restricted by the lower end surface of the bearing seat 10.

[0051] The lower sealing sleeve 11 and the lower dynamic sealing assembly 21 are jointly arranged between the outer wall of the lower dynamic sealing bushing 14 and the inner wall of the assembly lower gland 13. The outer wall of the lower sealing sleeve 11 is provided with a cylindrical external thread, and the uppermost inner wall of the assembly lower gland 13 is provided with a cylindrical internal thread matching the cylindrical external thread of the lower sealing sleeve 11. The lower sealing sleeve 11 is threadedly connected with the assembly lower gland 13, and the upper end surface of the lower sealing sleeve 11 contacts and is restricted by the lower end surface of the bearing seat 10 and the centering bearing 6 located below.

[0052] The lower rubber core hanger 15 is a circular ring structure with an axial cross-section of a "7" shape on one side of the axis, and the protruding step portion of the side of the lower rubber core hanger 15 faces the inner side of the lower rubber core hanger 15. The lowermost end surface of the central axis 8 is provided with a plurality of evenly distributed threaded blind holes 5, and the inner step of the upper end of the lower rubber core hanger 15 is provided with a plurality of countersunk holes 2 corresponding to the threaded blind holes 5, respectively. The threaded blind holes 5 and the countersunk holes 2 are connected by the central axis connecting bolts 20. The lower end of the outer wall of the lower rubber core hanger 15 is evenly provided with a plurality of countersunk holes 3 arranged along the lower rubber core hanger 15 along the circumference, and the countersunk holes 3 penetrate the lower rubber core hanger 15. A step is provided at the upper end of the outermost circle, and the inner side of the lower end of the assembly lower pressure cover 13 is provided in the step of the lower rubber core hanger 15. The inner cavity of the upper end surface of the lower rubber core 16 is inlaid with a lower rubber core skeleton 17. The lower rubber core skeleton 17 is a circular ring structure with an axial cross-section on one side of the axis in an "L" shape. The part of the lower rubber core skeleton 17 protruding above the top end surface of the lower rubber core 16 is a cylindrical structure. The outer wall of the cylindrical structure of the lower rubber core skeleton 17 is adapted to the inner wall of the lower end of the lower rubber core hanger 15. The outer wall of the cylindrical structure of the lower rubber core skeleton 17 is provided with a plurality of threaded blind holes six corresponding to the countersunk holes three. The threaded blind holes six and the countersunk holes three are connected and limited by rubber core connecting bolts.

[0053] In one embodiment, a sealing ring 4 is provided between the upper end surface of the upper dynamic sealing bushing 4 and the lower end surface of the upper rubber core shell 29, and a sealing ring 5 is provided between the inner wall of the upper dynamic sealing bushing 4 and the outer wall of the central shaft 8; the outer wall of the upper sealing sleeve 5 is provided with a through hole 4 matching the through hole 2 of the assembly shell 9, and sealing rings 6 are provided between the outer wall of the upper sealing sleeve 5 and the inner wall of the assembly shell 9 above and below the through hole 4, respectively; a step is provided on the outer side of the lower end surface of the upper rubber core shell 29, and the inner side of the upper end of the assembly upper pressure cover 3 is arranged in the step of the lower end surface of the upper rubber core shell 29, and the upper end surface of the step of the lower end surface of the upper rubber core shell 29 is aligned with the upper end surface of the assembly upper pressure cover 3. An upper end sealing assembly 24 is provided between the end faces; a sealing ring seven is provided between the inner wall of the lower dynamic sealing bushing 14 and the seventh step cylindrical surface of the central axis 8; a sealing ring eight is provided between the cylindrical surface above the outer step of the lower pressure cover 13 of the assembly and the fifth cylindrical surface of the assembly housing 9; the upper end surface of the lower rubber core hanger 15 and the lower end surface of the lower dynamic sealing bushing 14 are in contact with each other and a sealing ring nine is provided therebetween; a lower end sealing assembly 19 is provided between the outermost circular upper end surface of the lower rubber core hanger 15 and the lower end surface of the lower pressure cover 13 of the assembly; a sealing ring ten is provided between the outer wall of the cylindrical structure of the lower rubber core skeleton 17 and the inner wall of the lower end of the lower rubber core hanger 15, and the sealing ring ten is located above the threaded blind hole six.

[0054] In one embodiment, if Figure 1As shown, it also includes an upper end sealing sleeve 26 and a single rubber core driving sleeve 27. The side wall of the single rubber core driving sleeve 27 is provided with a countersunk hole four corresponding to the threaded blind hole four along its axis. The countersunk hole four passes through the upper and lower end surfaces of the single rubber core driving sleeve 27. The upper end surface of the single rubber core driving sleeve 27 is provided with a groove five that is compatible with the three-phase projection. The driving assembly 1 can drive the single rubber core driving sleeve 27 to rotate around the axis. When it needs to be used as a single rubber core state, after the lower rubber core rotating assembly and the bottom of the upper rubber core rotating assembly are disassembled, the single rubber core driving sleeve 27 is connected to the threaded blind hole four through the central axis connecting bolt 20. The inner diameter of the single rubber core driving sleeve 27 matches the inner diameter of the inner cavity of the central shaft 8, and the outer diameter of the single rubber core driving sleeve 27 is larger than the outer diameter of the first step cylinder of the central shaft 8; the upper sealing sleeve 26 is arranged on the outer side of the single rubber core driving sleeve 27 and is connected to the single rubber core driving sleeve 27 through a plurality of evenly distributed screws, and an upper sealing component 24 is arranged between the lower end surface of the upper sealing sleeve 26 and the upper end surface of the assembly upper pressure cover 3, and the lower lower rubber core rotating assembly can form a single rubber core state with the upper sealing sleeve 26 and the single rubber core driving sleeve 27, and be directly used in conjunction with the driving assembly 1.

[0055] The upper rubber core 30 and the lower rubber core 16 can be made of the same material, and can have the same structure and size.

[0056] The upper rubber core frame 31 and the lower rubber core frame 17 can be made of the same material, and can have the same structure and size.

[0057] The upper end sealing component 24 and the lower end sealing component 19 are made by combining a polytetrafluoroethylene rectangular ring and a wave spring.

[0058] By using the large-diameter single-double quick-change rotary blowout preventer assembly of the present invention, the large-diameter center shaft size and the high dynamic sealing pressure are taken into consideration. On the premise of ensuring that the center shaft diameter is the same, the high-pressure double-rubber core assembly and the low-pressure single-rubber core assembly can be quickly converted. When used on site, it is only necessary to remove the single-rubber core drive sleeve and the upper end sealing sleeve of the single-rubber core rotary blowout preventer assembly, install the upper rubber core shell on the center shaft, and then assemble the upper rubber core hanger, the upper rubber core gland and the upper rubber core and install them in the rubber core shell to convert it into a high-pressure double-rubber core assembly. This design can make the equipment multi-purpose and effectively reduce the use and maintenance costs.

[0059] By using the large-diameter single-double quick-change rotary blowout preventer assembly of the present invention, the connection mode between the rubber core hanger and the sealing rubber core is improved, and the original end face seal is improved to a cylindrical seal. Even if the rubber core connecting screws are slightly loosened due to vibration during use, the rubber core is always in a sealed state without leakage due to the long contact surface of the cylindrical seal, which is safer and more reliable.

[0060] By using the large-diameter single-double quick-change rotary blowout preventer assembly of the present invention, the connection method between the upper rubber core sealing gland and the upper rubber core shell is improved, and the existing thread and bolt connection method is improved to a concave-convex groove connection method, which will not cause thread backlash or thread slippage due to vibration during use, ensuring that the sealing performance of the upper rubber core and the shell is always safe, and at the same time, it is easier to install and disassemble, and the labor intensity is lower.

[0061] The large-diameter single-double quick-change rotary blowout preventer assembly of the present invention is used to improve the fixing method of the rotating sealing bushing, and the end face pressing method is used to limit the axial displacement of the bushing, and the concave-convex card groove method is used to limit the rotation of the bushing around the axis. At the same time, by arranging multiple sets of sealing members on the inner wall of the bushing, the bushing can be slightly swung within a small gap range while ensuring the sealing effect, which can effectively reduce the vibration impact during rotation friction, alleviate the bushing wear and extend the service life. The structure is simple, easy to disassemble and assemble, and the function is applicable. The present invention has a compact structure, is safe and reliable, is easy to disassemble and assemble, is easy to maintain, and is easy to promote.

[0062] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A large-diameter single-double quick-change rotary blowout preventer assembly, characterized in that: The invention comprises a driving assembly (1), an upper rubber core rotating assembly and a lower rubber core rotating assembly detachably connected to the bottom of the upper rubber core rotating assembly; the upper rubber core rotating assembly comprises an upper central shaft protective sleeve (28), an upper rubber core shell (29), an upper rubber core (30), an upper rubber core frame (31), an upper rubber core driving hanger (32) and an upper rubber core sealing cover (33); the upper rubber core shell (29) is a hollow annular columnar structure, the bottom inner wall of the upper rubber core shell (29) is provided with an inward boss, the lower rubber core rotating assembly is detachably connected to the boss, and the upper rubber core located on the upper part of the boss The inner wall of the outer shell (29) is provided with a cylindrical internal thread, the outer wall cylindrical surface of the upper central axis protection sleeve (28) is provided with a cylindrical external thread matching the cylindrical internal thread of the upper rubber core outer shell (29), and the upper central axis protection sleeve (28) is threadedly connected to the inner wall of the upper rubber core outer shell (29) at the upper part of the boss; the upper rubber core (30) is arranged in the upper rubber core outer shell (29), and the upper end surface inner cavity thereof is inlaid with an upper rubber core skeleton (31), and the upper rubber core skeleton (31) is a circular ring structure with an axial cross section on one side of the central axis in an "L" shape, and the upper rubber core skeleton (31) protrudes from the upper rubber core (30). The portion above the top end surface is a cylindrical structure, the inner wall of the upper rubber core driven hanger (32) includes two cylindrical surfaces arranged from bottom to top, namely, cylindrical surface one and cylindrical surface two, the inner diameter of cylindrical surface one is larger than the inner diameter of cylindrical surface two, the outer wall of the cylindrical structure of the upper rubber core skeleton (31) is adapted to cylindrical surface one, and the cylindrical structure of the upper rubber core skeleton (31) is detachably connected to the lower end of the upper rubber core driven hanger (32); the outer wall of the upper rubber core driven hanger (32) includes two cylindrical surfaces arranged from top to bottom, namely, cylindrical surface three and cylindrical surface four, the outer diameter of cylindrical surface three is smaller than the inner diameter of cylindrical surface four The outer diameter of the upper rubber core sealing gland (33) is that the inner wall of the upper rubber core sealing gland (33) includes two cylindrical surfaces arranged from top to bottom, namely, cylindrical surface five and cylindrical surface six, the inner diameter of cylindrical surface five is smaller than the inner diameter of cylindrical surface six, cylindrical surface four is provided with a protrusion one, and cylindrical surface six is ​​provided with a groove one matched with protrusion one; the middle outer wall of the upper rubber core sealing gland (33) is provided with a protrusion two, and the upper end inner cavity of the upper rubber core shell (29) is provided with a groove two matched with protrusion two; the outer wall of the drive assembly (1) is provided with a protrusion three, and the upper end surface of the upper rubber core drive hanger (32) is provided with a groove three matched with protrusion three; The outer wall of the cylindrical structure of the upper rubber core skeleton (31) is provided with a threaded blind hole, and the cylindrical surface of the upper rubber core drive hanger (32) is provided with a countersunk hole that passes through the side wall of the upper rubber core drive hanger (32), and the countersunk side of the countersunk hole is located on the outer side of the upper rubber core drive hanger (32), and the threaded blind hole is connected to the countersunk hole by a rubber core connecting screw (18), and a sealing ring is provided between the outer wall of the cylindrical structure of the upper rubber core skeleton (31) and the cylindrical surface of the upper rubber core drive hanger (32), and the sealing ring is located above the rubber core connecting screw (18); The cylindrical surface 4 of the upper rubber core driving hanger (32) is provided with a plurality of mutually independent protrusions 1, and the cylindrical surface 6 of the upper rubber core sealing cover (33) is provided with a plurality of mutually independent grooves 1 respectively matched with the protrusions 1; the middle outer wall of the upper rubber core sealing cover (33) is provided with a plurality of mutually independent protrusions 2, and the upper end inner cavity of the upper rubber core shell (29) is provided with a plurality of mutually independent grooves 2 respectively matched with the protrusions 2.

2. The large-diameter single-double quick-change rotary blowout preventer assembly according to claim 1 is characterized in that: A sealing ring 2 is provided between the outer wall of the upper rubber core sealing gland (33) below the second protrusion and the inner wall of the upper rubber core housing (29), and a sealing ring 3 is provided between the cylindrical surface 2 of the upper rubber core driving hanger (32) and the cylindrical surface 5 of the upper rubber core sealing gland (33).

3. The large-diameter single-double quick-change rotary blowout preventer assembly according to claim 1 is characterized in that: The lower rubber core rotating assembly comprises an oil injection joint (2), an upper assembly pressure cover (3), an upper dynamic sealing bushing (4), an upper sealing sleeve (5), a centering bearing (6), a thrust bearing (7), a center shaft (8), an assembly housing (9), a bearing seat (10), a lower sealing sleeve (11), an assembly lower pressure cover (13), a lower dynamic sealing bushing (14), a lower rubber core hanger (15), a lower rubber core (16), a lower rubber core frame (17), a lower dynamic sealing component (21), an upper dynamic sealing component (22), and a balanced pressure joint (23); The assembly housing (9) is a hollow annular columnar structure, and its inner cavity is provided with first, second, third, fourth and fifth step cylindrical surfaces in sequence from top to bottom. The inner diameters of the first to third step cylindrical surfaces of the assembly housing (9) are gradually increasing from small to large, and the inner diameters of the third to fifth step cylindrical surfaces of the assembly housing (9) are gradually decreasing from large to small. The upper end surface of the assembly housing (9) is uniformly provided with a plurality of threaded blind holes 2, the lower end surface of the assembly housing (9) is uniformly provided with a plurality of threaded blind holes 3, and the upper end surface of the assembly housing (9) is also provided with a threaded sealing hole.

1. A through hole 1 is provided in the assembly housing (9), one end of the through hole 1 is communicated with a threaded sealing hole 1, and the other end is communicated with the inner cavity of the assembly housing (9), the oil injection joint (2) is provided in the threaded sealing hole 1, a through hole 2 is provided in the middle of the first step cylinder of the assembly housing (9) in the radial direction of the assembly housing (9) and penetrates the side wall of the assembly housing (9), the through hole 2 is provided with a threaded sealing hole 2 on a side close to the outer wall of the assembly housing (9), and the balanced pressure joint (23) is provided in the threaded sealing hole 2; The inner cavity of the central shaft (8) is a through hole of equal diameter, and the outer wall of the central shaft (8) is provided with first, second, third, fourth, fifth, sixth and seventh step cylindrical surfaces in order from top to bottom, the outer diameters of the first to fourth step cylindrical surfaces of the central shaft (8) are gradually increasing, and the outer diameters of the fourth to seventh step cylindrical surfaces of the central shaft (8) are gradually decreasing, and the upper end surface of the central shaft (8) is provided with a plurality of evenly distributed threaded blind holes (4), and the boss is provided with a plurality of through holes (3) corresponding to the threaded blind holes (4), and the through holes (3) are connected to the threaded blind holes (4) by a central shaft connecting bolt (20), and the upper central shaft protective sleeve (28) is provided on the upper part of the central shaft connecting bolt (20); The upper dynamic sealing bushing (4) is a circular ring structure, and is arranged on the first step cylindrical surface of the central shaft (8). The upper end surface of the upper dynamic sealing bushing (4) is in close contact with the lower end surface of the upper rubber core shell (29). The inner wall of the upper end of the upper dynamic sealing bushing (4) is provided with a plurality of protrusions four evenly distributed inwardly, and the central shaft (8) is provided with a plurality of grooves four respectively matched with the protrusions four. The upper sealing sleeve (5) and the upper dynamic sealing assembly (22) are arranged together between the outer wall of the upper dynamic sealing bushing (4) and the first step cylindrical surface of the assembly housing (9); The assembly upper gland (3) is an annular structure, connected to the second threaded blind hole on the upper end surface of the assembly housing (9) via an upper connecting screw (25), and the lower end surface of the assembly upper gland (3) is in close contact with the upper end surfaces of the upper sealing sleeve (5) and the upper dynamic sealing assembly (22); Two groups of aligning bearings (6) are respectively arranged between the second step cylindrical surface of the assembly housing (9) and the second step cylindrical surface of the center shaft (8), and between the fifth step cylindrical surface of the assembly housing (9) and the sixth step cylindrical surface of the center shaft (8). Each group of aligning bearings (6) includes two aligning bearings (6) symmetrically arranged with the center shaft (8) as the axis. The top of the outer ring of the aligning bearing (6) located at the top is in close contact with the lower end surface of the upper sealing sleeve (5), and the top of the inner ring is in close contact with the lower end surface of the upper dynamic sealing sleeve (4). A bearing seat (10) is arranged between the outer wall of the aligning bearing (6) located at the bottom and the inner wall of the assembly housing (9). The fourth step cylindrical surface of the assembly housing (9) and the third step cylindrical surface of the center shaft (8) and the assembly housing are provided between the outer wall of the aligning bearing (6) and the inner wall of the assembly housing (9). Two groups of thrust bearings (7) are respectively arranged between the fourth step cylindrical surface of the (9) and the fifth step cylindrical surface of the central axis (8), each group of thrust bearings (7) includes two thrust bearings (7) symmetrically arranged with the central axis (8) as the axis, the two end surfaces of the thrust bearing (7) located at the top are respectively in contact with the upper end surface of the fourth step cylindrical surface of the assembly housing (9) and the lower end surface of the third step cylindrical surface of the central axis (8), and the two end surfaces of the thrust bearing (7) located at the bottom are respectively in contact with the upper end surface of the fifth step cylindrical surface of the central axis (8) and the lower end surface of the fourth step cylindrical surface of the assembly housing (9), the bearing seat (10) is arranged on the outer ring of the straightening bearing (6), and the upper end surface of the bearing seat (10) is in contact with the upper end surface of the thrust bearing (7) located at the bottom; The lower dynamic sealing bushing (14) is a circular ring structure, is arranged on the seventh step cylindrical surface of the central shaft (8), and contacts the lower end surface of the centralizing bearing (6) located below, and a plurality of inwardly protruding protrusions (4) are evenly arranged on the inner side of the lower end of the lower dynamic sealing bushing (14), and a plurality of grooves (4) are respectively matched with the protrusions (4) on the outer wall of the lower end of the central shaft (8); The assembly lower pressure cover (13) is an annular structure with an axial cross section on one side of the central axis in a "convex" shape. A plurality of through holes five corresponding to the threaded blind holes three on the lower end surface of the assembly housing (9) are provided on the outer step of the assembly lower pressure cover (13). The through holes five are connected to the threaded blind holes three via lower connecting screws (12). The uppermost end surface of the assembly lower pressure cover (13) contacts the lower end surface of the bearing seat (10). The lower sealing sleeve (11) and the lower dynamic sealing assembly (21) are jointly arranged between the outer wall of the lower dynamic sealing bushing (14) and the inner wall of the lower gland (13) of the assembly, the outer wall of the lower sealing sleeve (11) is provided with a cylindrical external thread, the uppermost inner wall of the lower gland (13) of the assembly is provided with a cylindrical internal thread matching the cylindrical external thread of the lower sealing sleeve (11), the lower sealing sleeve (11) is threadedly connected to the lower gland (13) of the assembly, and the upper end surface of the lower sealing sleeve (11) contacts the lower end surface of the bearing seat (10) and the centering bearing (6) located below; The lower rubber core hanger (15) is a circular ring structure with an axial cross section on one side of the central axis in the shape of a letter "7", and the protruding step portion of the side of the lower rubber core hanger (15) faces the inner side of the lower rubber core hanger (15), the lowermost end surface of the central axis (8) is provided with a plurality of evenly distributed threaded blind holes (5), the inner step of the upper end of the lower rubber core hanger (15) is provided with a plurality of countersunk holes (2) respectively corresponding to the threaded blind holes (5), the threaded blind holes (5) and the countersunk holes (2) are connected by a central axis connecting bolt (20), the lower end of the outer wall of the lower rubber core hanger (15) is evenly provided with a plurality of countersunk holes (3) arranged along the lower rubber core hanger (15), the countersunk holes (3) penetrate the lower rubber core hanger (15), and the lower rubber core hanger (15) A step is provided at the outermost circle upper end of the assembly lower pressure cover (13), the inner side of the lower end of the assembly lower pressure cover (13) is arranged in the step of the lower rubber core hanger (15), the upper end surface inner cavity of the lower rubber core (16) is inlaid with a lower rubber core frame (17), the lower rubber core frame (17) is a circular ring structure with an axial cross section on one side of the central axis in an "L" shape, the lower rubber core frame (17) protruding above the top end surface of the lower rubber core (16) is a cylindrical structure, the outer wall of the cylindrical structure of the lower rubber core frame (17) is adapted to the inner wall of the lower end of the lower rubber core hanger (15), and the outer wall of the cylindrical structure of the lower rubber core frame (17) is provided with a plurality of threaded blind holes six corresponding to the countersunk holes three, and the threaded blind holes six are connected to the countersunk holes three by rubber core connecting bolts.

4. The large-diameter single-double quick-change rotary blowout preventer assembly according to claim 3 is characterized in that: A sealing ring 4 is provided between the upper end surface of the upper dynamic sealing bushing (4) and the lower end surface of the upper rubber core shell (29), and a sealing ring 5 is provided between the inner wall of the upper dynamic sealing bushing (4) and the outer wall of the central shaft (8); a through hole 4 matching the through hole 2 of the assembly shell (9) is provided on the outer wall of the upper sealing bushing (5), and sealing rings 6 are provided between the outer wall of the upper sealing bushing (5) and the inner wall of the assembly shell (9) above and below the through hole 4, respectively; a step is provided on the outer side of the lower end surface of the upper rubber core shell (29), and the inner side of the upper end of the assembly upper pressure cover (3) is arranged in the step of the lower end surface of the upper rubber core shell (29), and the upper end surface of the step of the lower end surface of the upper rubber core shell (29) and the upper end surface of the assembly upper pressure cover (3) are located between the upper end surface of the step of the lower end surface of the upper rubber core shell (29) and the upper end surface of the assembly upper pressure cover (3). An upper end sealing component (24) is provided; a sealing ring seven is provided between the inner wall of the lower dynamic sealing bushing (14) and the seventh step cylindrical surface of the central axis (8); a sealing ring eight is provided between the cylindrical surface above the outer step of the assembly lower pressure cover (13) and the fifth cylindrical surface of the assembly housing (9); the upper end surface of the lower rubber core hanger (15) and the lower end surface of the lower dynamic sealing bushing (14) are in contact with each other and a sealing ring nine is provided therebetween; a lower end sealing component (19) is provided between the outermost circular upper end surface of the lower rubber core hanger (15) and the lower end surface of the assembly lower pressure cover (13); a sealing ring ten is provided between the outer wall of the cylindrical structure of the lower rubber core skeleton (17) and the inner wall of the lower end of the lower rubber core hanger (15), and the sealing ring ten is located above the threaded blind hole six.

5. The large-diameter single-double quick-change rotary blowout preventer assembly according to claim 4 is characterized in that: The utility model also comprises an upper end sealing sleeve (26) and a single rubber core driving sleeve (27), wherein the side wall of the single rubber core driving sleeve (27) is provided with a countersunk hole four corresponding to the threaded blind hole four along its axis, the countersunk hole four penetrates the upper and lower end surfaces of the single rubber core driving sleeve (27), and the upper end surface of the single rubber core driving sleeve (27) is provided with a groove five which is matched with the three phases of the protrusion. After the lower rubber core rotating assembly and the bottom of the upper rubber core rotating assembly are disassembled, the single rubber core driving sleeve (27) is connected to the threaded blind hole four through the central axis connecting bolt (20). The blind hole is connected in four ways, the inner diameter of the single rubber core drive sleeve (27) matches the inner diameter of the inner cavity of the central shaft (8), and the outer diameter of the single rubber core drive sleeve (27) is larger than the outer diameter of the first step cylinder of the central shaft (8); the upper end sealing sleeve (26) is arranged on the outer side of the single rubber core drive sleeve (27) and is connected to the single rubber core drive sleeve (27) by a plurality of evenly distributed screws, and an upper end sealing component (24) is arranged between the lower end surface of the upper end sealing sleeve (26) and the upper end surface of the assembly upper pressure cover (3).

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