Sealing core

Abstract

The present application provides a sealing core, which relates to the field of oil and gas production technology. The sealing core includes: a main sleeve, an outer sealing body is provided on the outer wall of the first end, an inner sealing body is provided on the inner wall of the inner end, a limiting hole and a through hole are provided on the side wall, and the interior is a stepped channel. The diameter of the first-step channel is larger than the diameter of the second-step channel. The limiting hole and the through hole are both located on the side wall corresponding to the first-step channel. The inner wall of the first-step channel is provided with an annular groove in the middle of the limiting hole and the through hole; a limiting block is provided in the limiting hole, and a limiting protrusion protrudes from the outer wall of the main sleeve; an inner sleeve is fitted with a clearance in the first-step channel to limit the limiting block, and the first end of the inner sleeve is fitted with a shear screw and an annular groove to limit the inner sleeve; a top sleeve is connected to the first end of the main sleeve to clamp the outer sealing body and the inner sealing body between the top sleeve and the main sleeve; a lower connecting sleeve is connected to the second end of the main sleeve. The sealing core uses a structure in which a sliding sleeve and a shear screw cooperate to limit the limiting block, thereby avoiding the situation where the limiting block is stuck and cannot be retracted.

Description

Technical Field

[0001] This application relates to the field of oil and gas production technology, and in particular to a sealing core. Background Technology

[0002] Currently, when setting oil and gas wells, a delivery tool is used to lower the hanger and return tube to the predetermined position for setting. The sealing device built into the delivery tool is used during setting. Although the sealing device can provide a reliable annular seal, it has the drawback that it is not possible to verify whether the release was successful after the release operation.

[0003] To solve the aforementioned technical problems, engineers developed a sealing core that allows for the vertical movement of the central tube to check the success of the release. However, this sealing core uses a spring-loaded limiting block structure to maintain relative fixation with the setting cylinder. When the lifting force reaches a certain value, the spring is compressed, and the limiting block is pressed back into the chamber, detaching from the setting cylinder. It can then be removed along with the central tube of the feeding tool. This spring-loaded limiting block structure frequently experiences the limitation block failing to retract, making it impossible to remove the feeding tool and ultimately causing the construction well to be solidified by cement slurry (commonly known as "flagpole insertion").

[0004] Therefore, the aforementioned technical issues still need to be further resolved. Summary of the Invention

[0005] The main objective of this invention is to provide a sealing core that can solve the problem of current spring limiting structures easily getting stuck.

[0006] To address the aforementioned technical problems, this application provides the following technical solutions:

[0007] This application provides a sealing core, comprising:

[0008] The main sleeve has an outer sealing body on its outer wall and an inner sealing body on its inner wall at the first end. The side wall of the main sleeve has a limiting hole and a through hole sequentially arranged from the position near the second end toward the first end. The inside of the main sleeve is a stepped channel, which includes a first-stage channel from the second end to the middle and a second-stage channel from the first end to the middle. The diameter of the first-stage channel is larger than the diameter of the second-stage channel. The limiting hole and the through hole are both located on the side wall corresponding to the first-stage channel. The inner wall of the first-stage channel has an annular groove at the position between the limiting hole and the through hole.

[0009] A limiting block is provided in the limiting hole, with a limiting protrusion protruding from the outer wall of the main sleeve and forming a smooth arc surface on the inner wall of the main sleeve;

[0010] The inner sleeve is fitted with the first-stage channel with a clearance to limit the limiting block. A shearing screw is connected to the first end sidewall of the inner sleeve, and the shearing screw extends into the annular groove to limit the inner sleeve.

[0011] A top sleeve is connected to the first end of the main sleeve, and the outer sealing body and the inner sealing body are sandwiched between the top sleeve and the main sleeve.

[0012] The lower connecting sleeve has its first end connected to the second end of the main sleeve.

[0013] Optionally, in the aforementioned sealing core, the first end of the main sleeve is provided with an external thread, an external sealing mounting step is provided between the external thread and the main sleeve body, an external sealing body is provided on the external sealing mounting step, an internal sealing mounting step is provided inside the first end of the main sleeve, and an internal sealing body is provided on the internal sealing mounting step.

[0014] The first end of the top sleeve is provided with an internal thread, and the first end of the top sleeve is threadedly connected to the first end of the main sleeve. The first end of the top sleeve extends inward and is provided with a first shoulder. The first shoulder and the inner sealing mounting step limit the inner sealing body. The second end of the top sleeve extends outward and is provided with a second shoulder. The second shoulder and the outer sealing mounting step limit the outer sealing body.

[0015] Optionally, in the aforementioned sealing core, the limiting hole is a stepped hole, and the size of the step on the inner wall of the main sleeve is larger than the size of the step on the outer wall of the main sleeve.

[0016] Optionally, in the aforementioned sealing core, the limiting holes are multiple and evenly spaced around the main sleeve.

[0017] Optionally, in the aforementioned sealing core, the limiting block is a segment of a ring and is stepped to mate with the stepped hole, and the limiting protrusion of the limiting block is a conical surface corresponding to the two sides of the first and second ends of the main sleeve.

[0018] Optionally, in the aforementioned sealing core, the limiting block is in the shape of a three-step structure, with the dimensions of the first step to the third step of the limiting block gradually decreasing, and the limiting protrusion protruding from the step surface of the third step;

[0019] The main sleeve has an outer annular groove on its side wall corresponding to the position of the limiting hole, and a spring is arranged in the outer annular groove.

[0020] The first step mates with the step on one side of the inner wall of the main sleeve where the limiting hole is located, the step surface of the third step is flush with the outer wall of the main sleeve, and the step surface of the second step abuts against the rebound spring.

[0021] Optionally, in the aforementioned sealing core, the limiting block is provided with the second step on both sides along the length direction of the main sleeve;

[0022] The outer ring grooves are configured as two corresponding to the second steps on both sides of the limiting block, and the number of rebound springs is two, each disposed in one of the two outer ring grooves.

[0023] Optionally, in the aforementioned sealing core, the first end of the lower connecting sleeve has an external thread, the second end of the main sleeve has an internal thread, and the lower connecting sleeve is threadedly connected to the main sleeve.

[0024] Optionally, in the aforementioned sealing core, the second end of the lower connecting sleeve is a tapered hole with a taper of 10-30 degrees.

[0025] Optionally, in the aforementioned sealing core, the inner wall of the lower connecting sleeve is provided with a plurality of grooves evenly spaced around its circumference, the grooves extending from the second end of the lower connecting sleeve to the middle.

[0026] Optionally, in the aforementioned sealing core, the number of through holes is multiple and evenly spaced around the main sleeve.

[0027] Optionally, in the aforementioned sealing core, the side wall of the second end of the top sleeve is provided with multiple threaded through holes, and a first set screw is screwed into each of the threaded through holes, the first set screw being tightened against the main sleeve.

[0028] Optionally, in the aforementioned sealing core, the end of the first end of the top sleeve is provided with a plurality of cylindrical holes or a plurality of polygonal holes.

[0029] Optionally, in the aforementioned sealing core, the outer wall of the inner sleeve is stepped, including a first-stage outer wall and a second-stage outer wall from the first end to the second end. The first-stage outer wall and the first-stage channel inner wall of the main sleeve are in clearance fit and block the limiting block. The outer diameter of the second-stage outer wall is smaller than that of the first-stage outer wall.

[0030] Optionally, in the aforementioned sealing core, the side wall of the second end of the main sleeve is provided with multiple threaded through holes, and a second set screw is screwed into each threaded through hole, the second set screw being tightened against the lower connecting sleeve.

[0031] Optionally, in the aforementioned sealing core, the inner sealing body and the outer sealing body have the same structure, both consisting of two flat-head retaining rings clamping a V-shaped retaining ring.

[0032] By employing the above technical solution, the sealing core of the present invention has at least the following advantages:

[0033] The sealing core provided in this embodiment of the invention has an inner sealing body and an outer sealing body. It can seal with the outer wall of the central tube connecting the hanger and with the inner wall of the setting tube. That is, the invention can be used to seal the inner annulus at the setting tube, so that the cement slurry during cementing cannot return upward from the inner annulus at this point. It can also be used to hydraulically mount the hanger by pressurizing the central tube. Moreover, the central tube and the sealing core form a sliding seal, and the upward movement of the central tube can be used to verify whether the release tool has been successfully released. Furthermore, the sealing core provided in this embodiment of the invention uses a shearing screw on the inner sleeve to limit its connection with the main sleeve, and a limiting block on the main sleeve to limit its connection with the setting cylinder. The limiting block is blocked and limited by the inner sleeve. Thus, when the tubing needs to be removed after successful release, lifting the central tube drives the lower rubber plug lifting section. Since the diameter of the rubber plug lifting section is larger than that of the central tube, it can push the inner sleeve upward to shear off the limiting screw, and move the inner sleeve upward and towards the first end of the main sleeve, releasing the blocking and limiting of the limiting block. The limiting block can then retract freely, thereby unlocking the entire sealing core, allowing the sealing core to be removed together with the central tube. It can be seen that the limiting method of the inner sleeve with the shearing screw and the limiting method of the inner sleeve blocking the limiting block can effectively avoid the jamming situation that occurs when removing the sealing core, such as the spring limiting block, ensuring smooth removal of the sealing core.

[0034] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0035] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0036] Figure 1 A schematic diagram of a partially cut-off section of a sealing core is shown.

[0037] Figure 2 A schematic diagram of the cross-section of the main sleeve of a sealing core is shown.

[0038] Figure 3 for Figure 2 A cross-sectional diagram of position AA;

[0039] Figure 4A schematic diagram of the axial side view structure of a sealing core limiting block is shown.

[0040] Figure 5 A schematic front view of a limiting block for a sealing core is shown;

[0041] Figure 6 A schematic diagram of a partially cut section of another sealing core is shown;

[0042] Figure 7 A schematic diagram of the main sleeve cross-section of another type of sealing core is shown.

[0043] Figure 8 A schematic diagram of the axial view structure of another type of sealing core limiting block is shown.

[0044] Figure 9 A schematic cross-sectional view of the inner sleeve of a sealing core is shown.

[0045] Figure 10 A schematic cross-sectional view of the top sleeve of a sealing core is shown.

[0046] Figure 11 A schematic cross-sectional view of the lower connecting sleeve of a sealing core is shown.

[0047] Figure 1-11 The labels in the text are:

[0048] Main sleeve 1, limiting hole 11, through hole 12, first-stage channel 13, second-stage channel 14, annular groove 15, outer seal mounting step 16, inner seal mounting step 17, outer annular groove 18, spring spring 19, outer sealing body 2, inner sealing body 3, limiting block 4, limiting protrusion 41, first step 42, second step 43, third step 44, inner sleeve 5, first-stage outer wall 51, second-stage outer wall 52, shear screw 6, top sleeve 7, first shoulder 71, second shoulder 72, lower connecting sleeve 8, tapered hole 81, groove 82, first set screw 9, second set screw 10. Detailed Implementation

[0049] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0050] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.

[0051] like Figures 1-11 As shown, an embodiment of the present invention provides a sealing core comprising:

[0052] The main sleeve 1 has an outer sealing body 2 on its outer wall and an inner sealing body 3 on its inner wall at the first end position. The side wall of the main sleeve 1 has a limiting hole 11 and a through hole 12 arranged sequentially from the position near the second end towards the first end. The interior of the main sleeve 1 is a stepped channel, including a first-stage channel 13 from the second end to the middle and a second-stage channel 14 from the first end to the middle. The diameter of the first-stage channel 13 is larger than the diameter of the second-stage channel 14. The limiting hole 11 and the through hole 12 are both located on the side wall corresponding to the first-stage channel 13. The inner wall of the first-stage channel 13 is provided with an annular groove 15 at the position between the limiting hole 11 and the through hole 12.

[0053] Limiting block 4, the limiting block 4 is disposed in the limiting hole 11, the limiting protrusion 41 protrudes from the outer wall of the main sleeve 1, and a smooth arc surface is formed on the inner wall of the main sleeve 1;

[0054] Inner sleeve 5, which is in clearance fit with the first-stage channel 13 to limit the limiting block 4, and a shearing screw 6 is connected to the first end side wall of the inner sleeve 5, which extends into the annular groove 15 to limit the inner sleeve 5.

[0055] Top sleeve 7, which is connected to the first end of the main sleeve 1, sandwiches the outer sealing body 2 and the inner sealing body 3 between the top sleeve 7 and the main sleeve 1;

[0056] The lower connecting sleeve 8 has its first end connected to the second end of the main sleeve 1.

[0057] Specifically, the outer diameter of the main sleeve 1 needs to be clearance-fitted with the inner diameter of the setting sleeve to ensure that the two can slide relative to each other. The inner diameter of the main sleeve 1 must be large enough for the central tube to pass through. The first end of the main sleeve 1 can be provided with an external thread. The specific form of the external thread can be selected according to the application requirements. This external thread can be a thread that can prevent stripping. There can be multiple limiting holes 11 and through holes 12 on the main sleeve 1. The through holes 12 are used to maintain the internal and external pressure balance, that is, to balance the pressure in the cavity when the central tube slides. The limiting hole 11 can be a hole with a rectangular projection cut on the sleeve wall. The limiting hole 11 needs to cooperate with the limiting block 4 to ensure that the limiting block 4 will not fall out (for example, it can be a stepped hole). The limiting protrusion 41 of the limiting block 4 should protrude from the outer wall of the main sleeve, so as to limit it with the setting sleeve.

[0058] The limiting block 4 is adapted to the limiting hole 11. Since the outer wall of the main sleeve 1 is arc-shaped, the limiting block 4 adapted to the limiting hole 11 is preferably arc-shaped. In order to prevent the limiting block 4 from falling out of the limiting hole 11 and into the main sleeve 1, the limiting block 4 can be a stepped block adapted to the limiting hole 11.

[0059] The inner sleeve 5 is a sliding sleeve that can slide inside the main sleeve 1. Its outer diameter needs to be in clearance fit with the inner diameter of the first-stage channel 13 of the main sleeve 1, ensuring that the two can slide relative to each other without the clearance being too large. The number of shearing screws 6 provided on the first end sidewall of the inner sleeve 5 can be multiple, and the strength, diameter and number of shearing screws 6 are set according to the magnitude of the shearing force that can be achieved in actual production. The inner sleeve 5 can be set to a certain length. When the inner sleeve 5 cuts the shearing screw 6 under the push of the rubber plug lifting section driven by the central tube, it then releases the obstruction of the limiting block 4, allowing the limiting block 4 to slide into the main sleeve 1, thereby completely unlocking the sealing core. Alternatively, the inner sleeve 5 can also be a stepped outer wall, with its first-stage outer wall 51 clearance-fitted with the inner wall of the first-stage channel 13 of the main sleeve 1, and the outer diameter of the second-stage outer wall 52 being smaller than the outer diameter of the first-stage outer wall 51. In this way, when the inner sleeve 5 cuts the shearing screw 6 under the push of the rubber plug lifting section driven by the central tube, the inner sleeve 5 moves towards the first end of the main sleeve 1. After the movement stops, the second-stage outer wall 52 is aligned with the limiting hole 11 and the limiting block 4. At this time, the limiting block 4 can retract, releasing the limitation between itself and the setting sleeve, thus completely unlocking the sealing core.

[0060] The top sleeve 7 can be provided with an internal thread at its first end, and the internal thread requires the main sleeve 1 to be threaded together. Together with the main sleeve 1, it restricts the outer sealing body 2 and the inner sealing body 3 on the inner and outer walls of the first end of the main sleeve 1. The lower connecting sleeve 8 can be threadedly connected to the main sleeve 1.

[0061] The sealing core provided in this embodiment of the invention has an inner sealing body 3 and an outer sealing body 2, which can seal with the outer wall of the central tube connecting the hanger and with the inner wall of the setting tube. That is, the invention can be used to seal the inner annulus at the setting tube so that the cement slurry during cementing cannot return upward from the inner annulus. It can also be used to hydraulically mount the hanger by pressurizing the central tube. Moreover, the central tube and the sealing core form a sliding seal, and the upward movement of the central tube can be used to verify whether the release tool has been successfully released. Furthermore, the sealing core provided in this embodiment of the invention is connected to the main sleeve 1 by setting a shearing screw 6 on the inner sleeve 5, and is connected to the setting sleeve by setting a limiting block 4 on the main sleeve 1. The limiting block 4 is blocked and limited by the inner sleeve 5. In this way, when the tube needs to be removed after successful release, the lifting of the central tube drives the lower rubber plug lifting section. Since the diameter of the rubber plug lifting section is larger than that of the central tube, it can push the inner sleeve 5 to move upward to shear off the limiting screw, and move the inner sleeve 5 upward, that is, towards the first end of the main sleeve 1, releasing the blocking and limiting of the limiting block 4. The limiting block 4 can retract freely, thereby unlocking the entire sealing core, so that the sealing core can be removed together with the central tube. It can be seen that the limiting method of the inner sleeve 5 in conjunction with the shearing screw 6, and the limiting method of the inner sleeve 5 blocking the limiting block 4, can effectively avoid the jamming situation that occurs when removing the sealing core, such as the spring limiting block 4, and ensure the smooth removal of the sealing core.

[0062] like Figures 1-3 and Figure 10 As shown, in a specific implementation, the first end of the main sleeve 1 is provided with an external thread, an external sealing mounting step 16 is provided between the external thread and the main body of the main sleeve 1, an external sealing body 2 is provided on the external sealing mounting step 16, an internal sealing mounting step 17 is provided inside the first end of the main sleeve 1, and an internal sealing body 3 is provided on the internal sealing mounting step 17.

[0063] The first end of the top sleeve 7 is provided with an internal thread, and the first end of the top sleeve 7 is threadedly connected to the first end of the main sleeve 1. The first end of the top sleeve 7 extends inward to provide a first shoulder 71, and the first shoulder 71 and the inner sealing mounting step 17 limit the inner sealing body 3. The second end of the top sleeve 7 extends outward to provide a second shoulder 72, and the second shoulder 72 and the outer sealing mounting step 16 limit the outer sealing body 2.

[0064] Specifically, the widths of the outer sealing mounting step 16 and the inner sealing mounting step 17 need to be adapted to the widths of the outer sealing body 2 and the inner sealing body 3, respectively, so as to ensure that after the outer sealing mounting step 16 and the inner sealing mounting step 17 are fitted with the second shoulder 72 and the first shoulder 71, they can tightly clamp the outer sealing body 2 and the inner sealing body 3 in the middle.

[0065] like Figures 1-3 As shown, in a specific implementation, the limiting hole 11 is a stepped hole. The size of the step on one side of the inner wall of the main sleeve 1 is larger than the size of the step on one side of the outer wall of the main sleeve 1. The stepped hole can be provided on one side of the width direction of the hole (i.e., along the length direction of the main sleeve), or it can be provided with opposite double-sided steps in the width direction of the hole. At the same time, the limiting block must be adapted to the stepped hole.

[0066] like Figures 1-3 As shown, in a specific implementation, the number of limiting holes 11 is multiple and they are evenly spaced around the main sleeve 1.

[0067] Specifically, the preferred number of limiting holes 11 is 4-8, for example, 4, 5, 6, 7 or 8. By setting multiple limiting holes 11 on the main sleeve 1 at uniform intervals, multiple limiting blocks 4 can be evenly distributed. Thus, when the limiting blocks 4 are connected to the setting sleeve, the force on the connection can be uniform, ensuring safe use.

[0068] like Figure 1-Figure 5 As shown, in a specific implementation, the limiting block 4 is a segment of a ring and is stepped to fit the stepped hole. The limiting protrusion 41 of the limiting block 4 is a conical surface corresponding to the two sides of the first and second ends of the main sleeve 1.

[0069] Specifically, by selecting a segment of a circular ring as the limiting block 4, the limiting block 4 can achieve a smooth inner wall after engaging with the limiting hole 11 of the main sleeve 1. The stepped structure can be well adapted to the limiting hole 11, allowing the limiting block 4 to be limited within the limiting hole 11 by the step. The limiting protrusion 41 protrudes from the stepped surface of the limiting block 4. When the limiting block 4 and the inner wall of the main sleeve 1 form a smooth surface, the limiting protrusion 41 protrudes from the outer wall of the main sleeve 11. Setting the limiting protrusion 41 as a conical surface facilitates engagement with the setting sleeve and facilitates retraction under force. The angle of the conical surface can be 10-30 degrees, for example, 15 degrees.

[0070] like Figure 6-Figure 8 As shown, in a specific implementation, the limiting block 4 is in the shape of a three-step structure. The size of the first step 42 to the third step 44 of the limiting block 4 gradually decreases. The limiting protrusion 41 is protrudingly disposed on the step surface of the third step 44. The main sleeve 1 is provided with an outer ring groove 18 on the side wall corresponding to the position of the limiting hole 11. A spring 19 is provided in the outer ring groove 18.

[0071] The first step 42 engages with the step of the limiting hole 11 located on the inner wall of the main sleeve 1, the step surface of the third step 44 is flush with the outer wall of the main sleeve 1, and the step surface of the second step 43 abuts against the spring 19.

[0072] Specifically, when using the sealing core, after successfully releasing the tube and needing to remove it, the central tube is lifted to drive the lower rubber plug lifting section. Since the diameter of the rubber plug lifting section is larger than that of the central tube, it can push the inner sleeve 5 upward to cut off the limiting shearing screw 6. Then the limiting block 4 can retract into the main sleeve 1 and reliably retract under the rebound of the return spring 19, thereby unlocking the entire core and allowing the sealing core to be removed together with the feeding tool.

[0073] like Figure 6-Figure 8 As shown, further, the limiting block 4 is provided with the second step 43 on both sides along the length direction of the main sleeve 1; the outer ring groove 18 is provided with two second steps 43 on both sides of the limiting block 4, and the number of the rebound springs 19 is two and they are respectively provided in the two outer ring grooves 18.

[0074] Specifically, by setting two outer ring grooves 18 and two rebound springs 19, the reliable retraction of multiple limit blocks 4 can be further guaranteed.

[0075] like Figures 1-3 and Figure 11 As shown, in a specific implementation, the first end of the lower connecting sleeve 8 is externally threaded, the second end of the main sleeve 1 is internally threaded, and the lower connecting sleeve 8 is threadedly connected to the main sleeve 1.

[0076] Furthermore, the second end of the lower connecting sleeve 8 is a tapered hole 81 with a taper of 10-30 degrees.

[0077] Specifically, the tapered hole 81 facilitates the insertion of the central tube and other components from the second end of the lower connecting sleeve 8, thus serving as a guide.

[0078] Furthermore, the inner wall of the lower connecting sleeve 8 is provided with a plurality of grooves 82 evenly spaced around its perimeter, and the grooves 82 extend from the second end of the lower connecting sleeve 8 to the middle.

[0079] Specifically, the number of grooves 82 can be 10-20, for example, 12. The grooves 82 can be used to scrape away cement and other impurities adhering to the central pipe.

[0080] like Figure 2 and Figure 3As shown, in a specific implementation, the number of through holes 12 is multiple and evenly spaced around the main sleeve 1. The number can be even or odd, for example, 4, 6, 8, or 3, 5, 7.

[0081] like Figure 1 and Figure 10 As shown, in a specific implementation, the side wall of the second end of the top sleeve 7 is provided with multiple threaded through holes 12, and a first set screw 9 is screwed into each of the threaded through holes 12. The first set screw is tightened against the main sleeve 1. The side wall of the second end of the main sleeve 1 is provided with multiple threaded through holes 12, and a second set screw 10 is screwed into each of the threaded through holes 12. The second set screw 10 is tightened against the lower connecting sleeve 8.

[0082] Specifically, by adding the first set screw 9 and the second set screw 10, the connection stability between the main sleeve 1, the top sleeve 7, and the lower connecting sleeve 8 can be increased, preventing the threaded connection from disengaging and ensuring safe use.

[0083] like Figure 10 As shown, in a specific implementation, the end of the first end of the top sleeve 7 is provided with multiple cylindrical holes or multiple polygonal holes, which are used to fix the top sleeve 7 with tooling during assembly, thereby facilitating assembly.

[0084] like Figure 1 As shown, in a specific implementation, the inner sealing body 3 and the outer sealing body 2 have the same structure, both consisting of two flat-headed retaining rings clamping a V-shaped retaining ring.

[0085] Specifically, both the flat-head retaining ring and the V-shaped retaining ring are structures known to those skilled in the art. Preferably, the flat-head retaining ring is made of polytetrafluoroethylene material and has a groove on one side to accommodate the deformation of the V-shaped retaining ring. The V-shaped retaining ring is made of nitrile rubber material and has a V-shaped interface on one side and a concave shape on the other side to facilitate deformation.

[0086] It is understood that the relevant features in the above-described devices can be referenced interchangeably. Furthermore, the terms "first," "second," etc., in the above embodiments are used to distinguish between embodiments and do not represent the superiority or inferiority of any particular embodiment.

[0087] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0088] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sealing core, characterized in that, include: The main sleeve has an outer sealing body on its outer wall and an inner sealing body on its inner wall at the first end. The side wall of the main sleeve has a limiting hole and a through hole sequentially arranged from the position near the second end toward the first end. The inside of the main sleeve is a stepped channel, which includes a first-stage channel from the second end to the middle and a second-stage channel from the first end to the middle. The diameter of the first-stage channel is larger than the diameter of the second-stage channel. The limiting hole and the through hole are both located on the side wall corresponding to the first-stage channel. The inner wall of the first-stage channel has an annular groove at the position between the limiting hole and the through hole. A limiting block is provided in the limiting hole, with a limiting protrusion protruding from the outer wall of the main sleeve and forming a smooth arc surface on the inner wall of the main sleeve; The inner sleeve is fitted with the first-stage channel with a clearance to limit the limiting block. A shearing screw is connected to the first end sidewall of the inner sleeve, and the shearing screw extends into the annular groove to limit the inner sleeve. A top sleeve is connected to the first end of the main sleeve, and the outer sealing body and the inner sealing body are sandwiched between the top sleeve and the main sleeve. A lower connecting sleeve, the first end of which is connected to the second end of the main sleeve; The first end of the main sleeve is provided with an external thread, and an external sealing installation step is provided between the external thread and the main sleeve body. The external sealing body is provided on the external sealing installation step. An internal sealing installation step is provided inside the first end of the main sleeve, and the internal sealing body is provided on the internal sealing installation step. The first end of the top sleeve is provided with an internal thread, and the first end of the top sleeve is threadedly connected to the first end of the main sleeve. The first end of the top sleeve extends inward and is provided with a first shoulder. The first shoulder and the inner sealing mounting step limit the inner sealing body. The second end of the top sleeve extends outward and is provided with a second shoulder. The second shoulder and the outer sealing mounting step limit the outer sealing body. The limiting block is in the shape of a three-step structure, with the dimensions of the first step to the third step gradually decreasing, and the limiting protrusion is protruding and disposed on the step surface of the third step. The main sleeve has an outer annular groove on its side wall corresponding to the position of the limiting hole, and a spring is arranged in the outer annular groove. The first step mates with the step on one side of the inner wall of the main sleeve where the limiting hole is located, the step surface of the third step is flush with the outer wall of the main sleeve, and the step surface of the second step abuts against the rebound spring.

2. The sealing core according to claim 1, characterized in that, The limiting hole is a stepped hole, and the size of the step on the inner wall of the main sleeve is larger than the size of the step on the outer wall of the main sleeve.

3. The sealing core according to claim 1 or 2, characterized in that, The limiting holes are multiple and evenly spaced around the main sleeve.

4. The sealing core according to claim 2, characterized in that, The limiting block is a segment of a ring and is stepped to fit the stepped hole. The limiting protrusion of the limiting block is a conical surface corresponding to the two sides of the first and second ends of the main sleeve.

5. The sealing core according to claim 1, characterized in that, The limiting block is provided with the second step on both sides along the length direction of the main sleeve; The outer ring grooves are configured as two corresponding to the second steps on both sides of the limiting block, and the number of rebound springs is two, each disposed in one of the two outer ring grooves.

6. The sealing core according to claim 1, characterized in that, The outer wall of the inner sleeve is stepped, including a first-step outer wall and a second-step outer wall from the first end to the second end. The first-step outer wall is in clearance fit with the inner wall of the first-step channel of the main sleeve and blocks the limiting block. The outer diameter of the second-step outer wall is smaller than that of the first-step outer wall.

7. The sealing core according to claim 1, characterized in that, The lower connecting sleeve has an external thread at its first end and an internal thread at its second end, and the lower connecting sleeve is threadedly connected to the main sleeve. The second end of the lower connecting sleeve is a tapered hole with a taper of 10-30 degrees.

8. The sealing core according to claim 7, characterized in that, The inner wall of the lower connecting sleeve is provided with multiple grooves at even intervals around its circumference, and the grooves extend from the second end of the lower connecting sleeve to the middle.

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