Embedded annular rubber core for annular blowout preventer

Abstract

The invention discloses an embedded annular rubber core for an annular blowout preventer, and relates to the technical field of annular blowout preventers, the embedded annular rubber core comprises a main body rubber core, and the middle part of the main body rubber core is provided with an annular hole arranged along the axial direction; a plurality of metal reinforcing ribs are uniformly distributed in the main body rubber core around the ring hole; the rubber sleeve can be coaxially, detachably and hermetically assembled in the annular hole of the main body rubber core; a barrel cavity of the rubber barrel is a pipe penetrating cavity used for penetrating through a sealing pipe column. The manufacturing difficulty can be reduced through the embedded split structure design, concentrated stress generated in the rubber core in the piston extrusion process can be effectively released, quick disassembly and assembly can be achieved to support local replacement of abraded parts, and then the maintenance cost of the blowout preventer is reduced.

Description

Technical Field

[0001] This invention relates to the field of annular blowout preventer technology, and in particular to an embedded annular rubber core for annular blowout preventers. Background Technology

[0002] Annular blowout preventers (BOPs) play a crucial role in oil drilling and production operations, effectively ensuring wellhead safety and preventing blowouts. The performance of their core directly impacts the reliability and overall safety of well control operations. Traditional annular BOP cores often employ a monolithic design, which presents significant technical bottlenecks and limitations in practical applications. Due to the large size and complex structure of monolithic cores, high-specification requirements are placed on manufacturing molds and molding equipment, necessitating large-scale specialized vulcanizing machines and high-pressure equipment. This not only significantly increases mold development costs and material inputs but also significantly enhances the difficulty of the vulcanization process during core production. Uneven vulcanization temperature control can easily lead to internal defects or deformation, thereby substantially increasing manufacturing costs and extending the production cycle.

[0003] More significantly, after repeated compression and deformation caused by the hydraulic pressure pushing the piston upwards, traditional integral rubber cores experience severe stress concentration at the sealing surface and root. This stress concentration makes the rubber core highly susceptible to tearing and breakage during repeated opening and closing operations. Especially after a certain number of sealing operations, the sealing performance of the rubber core deteriorates significantly, and its service life is insufficient to meet the requirements of long-term continuous operation. This not only affects operational efficiency but may also pose a potential threat to wellhead safety.

[0004] Therefore, how to design an embedded annular rubber core for annular blowout preventers that can reduce manufacturing difficulty through an embedded split structure design, effectively release the concentrated stress generated inside the rubber core during piston extrusion, and enable quick disassembly and assembly to support partial replacement of worn parts, thereby reducing blowout preventer maintenance costs, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention proposes an embedded annular rubber core for annular blowout preventers, aiming to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an embedded annular rubber core for an annular blowout preventer, comprising: The main body of the adhesive core has an axially oriented annular hole in the middle; a plurality of metal reinforcing ribs are evenly distributed around the annular hole inside the main body of the adhesive core. The rubber sleeve is coaxially and detachably sealed and assembled in the annular hole of the main rubber core; the cavity of the rubber sleeve is a through-tube cavity for inserting and sealing the tubing column.

[0007] This invention discloses an embedded annular rubber core for an annular blowout preventer. The annular embedded split-type rubber core structure is constructed through a detachable and sealed assembly design between the main rubber core and the rubber sleeve. This split-type structure not only simplifies the manufacturing process and reduces manufacturing difficulty but also significantly reduces manufacturing costs. The split-type structure effectively releases concentrated stress generated inside the rubber core during piston compression, preventing rubber breakage and improving product durability and service life. In practical applications, the split-type structure allows for quick disassembly and assembly to support partial replacement of worn parts. This is especially important for rubber sleeves used in direct contact with the sealing column, which are prone to wear or damage; these sleeves can be disassembled and replaced individually without replacing the entire rubber core, thus significantly reducing blowout preventer maintenance costs.

[0008] As a further improvement to the above technical solution, the main core includes multiple arc-shaped core segments, which are sequentially sealed and connected to form an annular main core; the inner sidewall of each core segment is provided with a groove along its circumference. The rubber tube includes multiple arc-shaped rubber plates, which are sequentially sealed and connected to form an annular rubber tube. The outer surface of each arc-shaped rubber plate is provided with a retaining strip along the circumference. The retaining strip can be fitted into the retaining groove to detachably attach the arc-shaped rubber plate to the inner wall of the rubber core flap.

[0009] The beneficial effects of the above technical solution are: the arc-shaped rubber plate and the rubber core flap are connected by a detachable snap-fit ​​form, and two adjacent rubber core flaps can be connected by snap-fitting the corresponding arc-shaped rubber plate. At the same time, two adjacent arc-shaped rubber plates can be connected by snap-fitting the corresponding rubber core flaps, which not only ensures the connection stability and improves the sealing performance, but also avoids the internal local stress concentration through the split structure, thereby improving durability.

[0010] As a further improvement to the above technical solution, the annular hole is a conical hole; the outer peripheral wall of the rubber tube is a conical surface adapted to the inner peripheral wall of the conical hole; the rubber tube can be adapted to be sealed and connected in the annular hole.

[0011] The beneficial effects of the above technical solution are: designing the annular hole as a conical hole and the outer circumferential surface of the rubber sleeve as a conical surface can achieve self-centering of the two during assembly, thereby improving assembly efficiency and accuracy.

[0012] As a further improvement to the above technical solution, the inner peripheral wall of the annular hole is provided with a limiting groove along its depth direction, and the outer peripheral wall of the rubber tube is provided with a protrusion along its length direction; the protrusion of the outer peripheral wall of the rubber tube can be engaged in the limiting groove of the inner peripheral wall of the annular hole to fit and limit the rubber tube in the annular hole.

[0013] The beneficial effect of the above technical solution is that the cooperation between the convex strip and the limiting groove further improves the constraint stability of the assembled rubber tube.

[0014] As a further improvement to the above technical solution, the inner peripheral wall of the annular hole is provided with an internal thread; the outer peripheral wall of the rubber tube is provided with an external thread; and the rubber tube is adapted to be screwed into the annular hole.

[0015] The beneficial effect of the above technical solution is that during assembly, the rubber sleeve can be screwed into the annular hole to achieve a stable threaded connection.

[0016] As a further improvement to the above technical solution, a hook groove is provided at one end of the inner peripheral wall of the annular hole; a support hook is provided at one end of the outer peripheral wall of the rubber tube; the support hook of the rubber tube can be adapted to be embedded and hooked in the hook groove of the annular hole, so as to hook and limit the rubber tube in the annular hole.

[0017] The beneficial effects of the above technical solution are: during assembly, the support hook of the rubber tube is embedded in the hook groove of the annular hole, realizing the embedded hook connection and further improving the stability of the connection.

[0018] As a further improvement to the above technical solution, the wear resistance, temperature resistance and mechanical strength of the rubber sleeve are all greater than those of the main rubber core.

[0019] The beneficial effects of the above technical solution are: by improving the wear resistance, temperature resistance and mechanical strength of the rubber sleeve, the service life of the embedded annular rubber core can be significantly improved. While reducing manufacturing difficulty and cost with the split design, the durability performance is guaranteed.

[0020] As a further improvement to the above technical solution, the material of the rubber sleeve is hydrogenated nitrile rubber; the material of the main rubber core is nitrile rubber.

[0021] The beneficial effects of the above technical solution are as follows: the rubber sleeve is made of hydrogenated nitrile rubber material with good wear resistance, high hardness and strong compressive strength, and the main rubber core is made of nitrile rubber material with excellent tear resistance and rebound performance, which greatly improves the compressive strength of the rubber core and correspondingly improves the rebound efficiency, thereby significantly extending the service life of the rubber core.

[0022] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an embedded annular rubber core for an annular blowout preventer, which has the following advantages and beneficial effects: 1. This invention utilizes an embedded, split structure, with the internal annular rubber sleeve and the main rubber core assembled in layers, effectively releasing the concentrated stress generated inside the rubber core during piston compression. The design of uniformly distributed circumferential metal reinforcing ribs, combined with the differentiated configuration of inner and outer layer materials, significantly improves the uniformity of rubber core deformation, eliminating the root tearing and early damage problems caused by stress concentration in traditional integral rubber cores, and extending the service life of the rubber core.

[0023] 2. This invention adopts a split structure design, with radially split rubber core units and detachable connections. This eliminates the reliance on large, integral molds for rubber core manufacturing, reducing mold development costs. Quick-assembly and disassembly structures such as slots, clips, and threaded connections support partial replacement of worn parts. Users can replace only the damaged portion without replacing the entire rubber core. This not only saves maintenance costs but also reduces downtime, improving equipment operating efficiency and economic benefits. While enhancing sealing performance, it also balances economic efficiency and operational convenience, demonstrating high practical value and market competitiveness.

[0024] 3. This invention provides multiple options for the split connection structure of the main rubber core and the rubber sleeve. Dovetail grooves, conical grooves, and threaded connections can be designed, and different connection schemes can be flexibly configured according to well depth and pressure level. The number of radial split units (≥2 pieces) can be customized according to working conditions, breaking through the traditional rubber core specification limitations and suitable for extreme working conditions such as ultra-deep wells and high temperature and high pressure.

[0025] 4. Through its innovative embedded split structure design, this invention has achieved breakthrough progress in terms of core stress release, manufacturing cost, sealing reliability, and adaptability to working conditions, providing core technical support for the safety of oil drilling and production well control. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 A three-dimensional schematic diagram of the combined state of an embedded annular rubber core for an annular blowout preventer according to the present invention; Figure 2 An axial sectional view of an embedded annular rubber core for an annular blowout preventer according to the present invention; Figure 3 A schematic diagram of a metal reinforcing rib structure for an embedded annular rubber core in an annular blowout preventer according to the present invention; Figure 4This invention provides a schematic diagram of the assembly of the core flap and the arc-shaped rubber plate of an embedded annular core for an annular blowout preventer. Figure 5 Another perspective schematic diagram of the assembly of the core flap and the arc-shaped rubber plate of an embedded annular core for an annular blowout preventer according to the present invention. Figure 6 This invention provides a schematic diagram of the insertion and installation of the core flap of an embedded annular core for an annular blowout preventer with an arc-shaped rubber plate. Figure 7 A schematic diagram of the engagement state of the limiting groove and the protrusion of the embedded annular rubber core for an annular blowout preventer according to the present invention; Figure 8 This invention provides a schematic diagram of the split structure of an embedded annular rubber core for an annular blowout preventer, comprising a main rubber core with a limiting groove and a rubber cylinder with protruding strips. Figure 9 This invention provides a schematic diagram showing the state in which an externally threaded rubber sleeve for an embedded annular rubber core of an annular blowout preventer is screwed into the annular hole of a main rubber core with internal threads. Figure 10 This invention provides a schematic diagram of the separate structure of an embedded annular rubber core for an annular blowout preventer, comprising a rubber sleeve with external threads and a main rubber core with internal threads. Figure 11 A schematic diagram of the main body rubber core structure with a hook groove for an embedded annular rubber core for an annular blowout preventer according to the present invention. Figure 12 A schematic diagram of a rubber sleeve structure with a support hook for an embedded annular rubber core for an annular blowout preventer according to the present invention. In the diagram: 1. Main rubber core; 11. Ring hole; 111. Limiting groove; 112. Internal thread; 113. Hook groove; 12. Rubber core flap; 121. Groove; 2. Rubber tube; 21. Through-tube cavity; 22. Arc-shaped rubber plate; 221. Locking strip; 23. Raised strip; 24. External thread; 25. Support hook; 3. Metal reinforcing rib. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. According to embodiments of the present invention, such as Figures 1 to 12 As shown, an embedded annular rubber core for an annular blowout preventer includes: a main rubber core 1 and a rubber sleeve 2.

[0029] The main rubber core 1 has an axially arranged annular hole 11 in the middle; multiple metal reinforcing ribs 3 are evenly distributed around the annular hole 11 inside the main rubber core 1; the rubber sleeve 2 can be coaxially and detachably sealed in the annular hole 11 of the main rubber core 1; the cylinder cavity of the rubber sleeve 2 is a through-tube cavity 21 for inserting and sealing the tube column.

[0030] This embodiment presents an embedded annular rubber core for an annular blowout preventer. The annular embedded split-type rubber core structure is constructed through a detachable and sealed assembly design of the main rubber core 1 and the rubber sleeve 2. This split-type rubber core structure not only simplifies the manufacturing process and reduces manufacturing difficulty but also significantly reduces manufacturing costs. The split-type rubber core structure effectively releases concentrated stress generated inside the rubber core during piston compression, preventing rubber breakage and improving product durability and service life. In practical applications, the split-type rubber core structure allows for quick disassembly and assembly to support partial replacement of worn parts. Especially for the rubber sleeve 2, which is used to penetrate and directly contact the sealing column, wear or damage is common, and it can be disassembled and replaced individually without replacing the entire rubber core, thus significantly reducing blowout preventer maintenance costs.

[0031] Specifically, both the main rubber core 1 and the rubber sleeve 2 are made of rubber; the inner circumferential wall of the rubber sleeve 2 is cylindrical. The main rubber core 1 and the metal reinforcing rib 3 are vulcanized into a single structure, and the overall outer contour of the main rubber core 1 and the metal reinforcing rib 3 is hemispherical. The main rubber core 1, the metal reinforcing rib 3 and the rubber sleeve 2 together constitute a spherical rubber core.

[0032] In some embodiments, the main body core 1 includes a plurality of arc-shaped core segments 12, which are sequentially sealed and connected to form an annular main body core 1; the inner sidewall of the core segment 12 is provided with a groove 121 along its circumference. The rubber tube 2 includes multiple arc-shaped rubber plates 22, which are sequentially sealed and connected to form a circular rubber tube 2; the outer side of the arc-shaped rubber plate 22 is provided with a retaining strip 221 along the circumference; the retaining strip 221 can be fitted into the retaining groove 121 to detachably retain the arc-shaped rubber plate 22 on the inner side wall of the rubber core flap 12.

[0033] The arc-shaped rubber plate 22 and the rubber core flap 12 are connected by a detachable snap-fit ​​mechanism. Two adjacent rubber core flaps 12 can be connected by snap-fitting the corresponding arc-shaped rubber plate 22, and vice versa. This ensures connection stability, improves sealing performance, and avoids internal stress concentration through a split structure, thus improving durability. The outer peripheral wall length of the arc-shaped rubber plate 22 is the same as the inner peripheral wall length of the rubber core flap 12; during assembly, the outer peripheral wall of the arc-shaped rubber plate 22 can also coaxially fit and completely adhere to the inner peripheral wall of the corresponding rubber core flap 12.

[0034] Specifically, the rubber core flap 12 has an embedded metal reinforcing rib 3. The rubber core flap 12 is made of rubber and is integrally vulcanized with the metal reinforcing rib 3.

[0035] Specifically, the card slot 121 extends circumferentially along the core flap 12 to both ends of the core flap 12, forming an open slot. The card strip 221 extends circumferentially along the arc-shaped rubber plate 22 to both ends of the arc-shaped rubber plate 22.

[0036] Specifically, there are multiple slots 121 and multiple locking strips 221, and the number of each is the same. Multiple slots 121 on the inner wall of the core flap 12 are arranged at intervals along the axial direction of the core flap 12. Multiple locking strips 221 on the outer surface of the arc-shaped rubber plate 22 are arranged at intervals along the axial direction of the arc-shaped rubber plate 22 and can be correspondingly fitted into the multiple slots 121 of the corresponding core flap 12. The connection stability can be further improved by the cooperation of multiple slots 121 and locking strips 221.

[0037] Specifically, the slot 121 is a dovetail slot, and the locking strip 221 is a trapezoidal locking strip that can be inserted into the dovetail slot. During assembly, the arc-shaped rubber plate 22 is inserted into the slot 121 of the rubber core 12 by rotating it around the circumference until the trapezoidal locking strip 221 is fully embedded in the dovetail slot 121, forming an axial mechanical lock. The number of dovetail slots is designed to be one or more according to the diameter of the rubber core to ensure that the connection surface is evenly stressed. During disassembly, the internal arc-shaped rubber plate 22 can be unscrewed from the rubber core 12 to separate it, making it easy to replace the arc-shaped rubber plate 22 inside the rubber cylinder 2 with severe wear inside the annular hole.

[0038] In some embodiments, both end faces of the rubber core flap 12 and both end faces of the arc-shaped rubber plate 22 along their circumference are smooth, elastic sealing planes. When multiple rubber core flaps 12 and multiple arc-shaped rubber plates 22 are assembled, their smooth end faces can fit together to achieve a seal.

[0039] In some embodiments, the opposite ends of two adjacent rubber core flaps 12 can be connected by a plug-in or overlapping structure; the opposite ends of two adjacent arc-shaped rubber plates 22 can be connected by a plug-in or overlapping structure.

[0040] In some embodiments, the annular hole 11 is a conical hole; the outer peripheral wall of the rubber sleeve 2 is a conical surface adapted to the inner peripheral wall of the conical hole; the rubber sleeve 2 can be adapted to be sealed in the annular hole 11.

[0041] By designing the annular hole 11 as a conical hole and the outer circumferential surface of the rubber sleeve 2 as a conical surface, the assembly of the two can achieve self-centering, thereby improving assembly efficiency and accuracy.

[0042] In some embodiments, the inner peripheral wall of the annular hole 11 is provided with a limiting groove 111 along its depth direction, and the outer peripheral wall of the rubber tube 2 is provided with a protrusion 23 along its length direction; the protrusion 23 on the outer peripheral wall of the rubber tube 2 can be engaged in the limiting groove 111 of the inner peripheral wall of the annular hole 11 to fit and limit the rubber tube 2 in the annular hole 11.

[0043] The engagement of the protrusion 23 with the limiting groove 111 further enhances the constraint stability of the assembled rubber sleeve 2.

[0044] Specifically, the limiting groove 111 is open at both ends along the axial direction of the main body rubber core 1; the length of the protrusion 23 is the same as the length of the rubber tube 2, and the length of the limiting groove 111 is adapted to the length of the protrusion 23.

[0045] Specifically, there are multiple and identical limiting slots 111 and protrusions 23; the limiting slots 111 are evenly distributed circumferentially along the inner peripheral wall of the annular hole 11; the protrusions 23 are evenly distributed circumferentially along the outer peripheral wall of the rubber tube 2; the multiple protrusions 23 on the outer peripheral wall of the rubber tube 2 can be matched and engaged one-to-one with the multiple limiting slots 111 on the inner peripheral wall of the annular hole 11. The cooperation of multiple limiting slots 111 and protrusions 23 further improves the assembly stability of the rubber tube 2.

[0046] During assembly, the rubber sleeve 2 and the main rubber core 1 are aligned axially, and the protrusion 23 on the outer conical surface of the rubber sleeve 2 is aligned with the limiting groove 111 of the main rubber core 1. The rubber sleeve 2 is then lowered axially, allowing the conical hole to fit against the conical surface for automatic centering. Simultaneously, the protrusion 23 is embedded in the limiting groove 111, forming a radial constraint. This structure can adaptively adjust the contact pressure under high pressure, avoiding localized stress concentration.

[0047] In some embodiments, the inner peripheral wall of the annular hole 11 is provided with an internal thread 112; the outer peripheral wall of the rubber tube 2 is provided with an external thread 24; the rubber tube 2 is adapted to be screwed into the annular hole 11.

[0048] During assembly, the rubber sleeve 2 can be screwed into the annular hole 11 to achieve a stable threaded connection.

[0049] Specifically, the internal thread 112 can be a trapezoidal internal thread or a sawtooth internal thread; the external thread 24 can be a trapezoidal external thread or a sawtooth external thread that is compatible with the internal thread 112, which is suitable for working conditions where the internal rubber sleeve needs to be frequently replaced.

[0050] In some embodiments, a hook groove 113 is provided at one end of the inner peripheral wall of the annular hole 11; a support hook 25 is provided at one end of the outer peripheral wall of the rubber tube 2; the support hook 25 of the rubber tube 2 can be adapted to be inserted and hooked in the hook groove 113 of the annular hole 11, so as to hook and limit the rubber tube 2 in the annular hole 11.

[0051] During assembly, the support hook 25 of the rubber sleeve 2 is pressed into the hook groove 113 of the annular hole 11, realizing the embedded hook connection, achieving load transfer between the inner and outer layers, and further improving the stability of the connection. The support hook 25 is designed with an anti-detachment structure (such as a trapezoidal cross section) to prevent it from coming off under high pressure.

[0052] In some embodiments, the wear resistance, temperature resistance, and mechanical strength of the rubber sleeve 2 are all greater than those of the main rubber core 1.

[0053] By improving the wear resistance, temperature resistance and mechanical strength of the rubber sleeve 2, the service life of the embedded ring rubber core can be significantly improved. The split design reduces manufacturing difficulty and cost while ensuring durability.

[0054] In some embodiments, the material of the rubber sleeve 2 is hydrogenated nitrile rubber; the material of the main rubber core 1 is nitrile rubber.

[0055] The rubber sleeve 2 is made of hydrogenated nitrile rubber material with good wear resistance, high hardness and strong compressive strength. The main rubber core 1 is made of nitrile rubber material with excellent tear resistance and rebound performance, which greatly improves the compressive strength of the rubber core and correspondingly increases the rebound efficiency, thereby significantly extending the service life of the rubber core.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An embedded annular rubber core for an annular blowout preventer, characterized in that, include: The main body core (1) has an axially arranged annular hole (11) in the middle; a plurality of metal reinforcing ribs (3) are evenly distributed around the annular hole (11) inside the main body core (1). The rubber tube (2) can be coaxially and detachably sealed in the annular hole (11) of the main rubber core (1); the tube cavity of the rubber tube (2) is a through-tube cavity (21) for inserting and sealing the tube column.

2. The embedded annular rubber core for an annular blowout preventer according to claim 1, characterized in that, The main body core (1) includes multiple arc-shaped core segments (12), which are sequentially sealed and connected to form an annular main body core (1); the inner sidewall of the core segment (12) is provided with a groove (121) along its circumference. The rubber tube (2) includes multiple arc-shaped rubber plates (22), which are sequentially sealed and connected to form an annular rubber tube (2); the outer side of the arc-shaped rubber plate (22) is provided with a retaining strip (221) along the circumferential direction; the retaining strip (221) can be fitted into the retaining groove (121) to detachably attach the arc-shaped rubber plate (22) to the inner side wall of the rubber core flap (12).

3. The embedded annular rubber core for an annular blowout preventer according to claim 1, characterized in that, The annular hole (11) is a conical hole; the outer peripheral wall of the rubber tube (2) is a conical surface that matches the inner peripheral wall of the conical hole; the rubber tube (2) can be adapted to be sealed and connected in the annular hole (11).

4. The embedded annular rubber core for an annular blowout preventer according to claim 3, characterized in that, The inner peripheral wall of the annular hole (11) is provided with a limiting groove (111) along its depth direction, and the outer peripheral wall of the rubber tube (2) is provided with a protrusion (23) along its length direction; the protrusion (23) on the outer peripheral wall of the rubber tube (2) can be engaged in the limiting groove (111) on the inner peripheral wall of the annular hole (11) to fit and limit the rubber tube (2) in the annular hole (11).

5. The embedded annular rubber core for an annular blowout preventer according to claim 1, characterized in that, The inner circumferential wall of the annular hole (11) is provided with an internal thread (112); the outer circumferential wall of the rubber tube (2) is provided with an external thread (24); the rubber tube (2) is adapted to be screwed into the annular hole (11).

6. The embedded annular rubber core for an annular blowout preventer according to claim 1, characterized in that, The inner peripheral wall of the annular hole (11) is provided with a hook groove (113) at one end; the outer peripheral wall of the rubber tube (2) is provided with a support hook (25) at one end; the support hook (25) of the rubber tube (2) can be fitted and hooked into the hook groove (113) of the annular hole (11) to hook and limit the rubber tube (2) in the annular hole (11).

7. The embedded annular rubber core for an annular blowout preventer according to claim 1, characterized in that, The wear resistance, temperature resistance and mechanical strength of the rubber sleeve (2) are all greater than those of the main rubber core (1).

8. The embedded annular rubber core for an annular blowout preventer according to claim 7, characterized in that, The material of the rubber sleeve (2) is hydrogenated nitrile rubber; the material of the main rubber core (1) is nitrile rubber.

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