An eccentric vortex fracturing manifold

Abstract

The application relates to the technical field of fracturing operation, and discloses an eccentric vortex fracturing manifold, which comprises a main body, and two support frames are fixedly connected to the top of the main body. When the backflow medium flows, the backflow speed of the medium can be blocked by the conical channels formed by the plurality of conical plates, and when part of the backflow medium flows through the gap on the fixed ring into the one-way butterfly groove, the backflow speed of the medium is changed by the wing-shaped obstacles in the flow and opposite forces are generated, so that the backflow speed of the backflow medium is slowed down, the backflow of the medium is weakened, the local excessive pressure caused by the intersection and collision of the backflow medium and the normally conveyed medium in the connecting block and the first pipeline is reduced, the risk of damage and leakage of the device due to the excessively high pressure when conveying high-pressure medium is reduced, and the stability of the high-pressure medium flow is ensured.

Description

Technical Field

[0001] This invention relates to the field of fracturing operation technology, specifically to an eccentric vortex fracturing manifold. Background Technology

[0002] In the field of fracturing operations in oil and gas well development, a high-low pressure manifold is used to connect a sand mixing truck and a liquid tank. The fracturing medium is transported to the low-pressure line of the manifold by a low-pressure pump. The fracturing pump draws in the medium through the outlet of the low-pressure line and pressurizes it to a high-pressure state, then transmits it to the high-pressure line of the manifold, and finally transmits it to the wellhead through the high-pressure line.

[0003] In oil and gas extraction, fracturing media are transported underground at high pressure through fracturing manifolds to break through rock layers and achieve extraction. When the high-pressure media breaks through the rock layers through the manifold, the formation of rock fractures causes a sudden increase in pressure within the manifold. The gas or oil ejected when the rock layers fracture can also cause a backflow of the ejected high-pressure media. The increased pressure within the manifold and the backflow of the high-pressure media can easily lead to some of the high-pressure media flowing back into the manifold. The media that is prone to flowing back can meet and collide with the media normally transported within the manifold, which can easily cause an increase in pressure in the area where they meet, resulting in pipeline damage and affecting the normal flow of the media. Summary of the Invention

[0004] The purpose of this invention is to provide an eccentric eddy current fracturing manifold to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention relates to an eccentric eddy current fracturing manifold, comprising a main body, with two support frames fixedly connected to the top of the main body, and further comprising:

[0007] The conveying mechanism is installed inside the main body to prevent backflow of fracturing media;

[0008] A blocking mechanism is installed on the side wall of the conveying mechanism;

[0009] When fracturing media are transported through the main body, the transport mechanism can reduce media backflow during transport and accelerate the normal flow of media by blocking the backflow liquid through the blocking mechanism.

[0010] Furthermore, the main body includes:

[0011] A conveying assembly, installed on top of the main body, is used for conveying liquids;

[0012] The confluence assembly is mounted on top of the support frame via a connecting piece.

[0013] Furthermore, the conveying mechanism includes a retaining ring disposed inside the converging assembly, and the conveying mechanism includes:

[0014] The elastic component is installed on the inner wall of the fixed ring;

[0015] The opening and closing assembly is rotatably mounted on the side wall of the fixed ring via a movable component.

[0016] Furthermore, the blocking mechanism includes several sliding plates slidably disposed on the side wall of the fixed ring, and the blocking mechanism includes:

[0017] A limiting component is fixedly mounted on the side wall of the sliding plate;

[0018] The rotating assembly is mounted on the side wall of the fixed ring.

[0019] Furthermore, the delivery assembly includes a first conduit fixedly connected to the top of the main body, and two valve pipes are fixedly connected to the outer surface of the first conduit;

[0020] The connecting component includes a connecting block fixedly connected to the top of the support frame, a second pipeline bolted between the two connecting blocks, and plug combination valves bolted to both the front and back of the connecting block.

[0021] Furthermore, the bottom bolt of the plug combination valve is bolted to the top outer wall of the support frame;

[0022] The confluence assembly includes a right-angle ring that is fixedly connected to the inner wall of the connecting block.

[0023] Furthermore, the fixing ring is fixedly connected to the inner wall of the connecting block, and the outer surface of the fixing ring has several notches, while the inner wall of the fixing ring has two rectangular grooves.

[0024] The two rectangular slots are arranged in a circular array with the center of the fixed ring as the center.

[0025] Furthermore, the elastic component includes a spring plate slidably connected inside the rectangular groove, a sliding ring fixedly connected between two spring plates, and several Z-shaped plates fixedly connected to the right side of the sliding ring;

[0026] Among them, the side of the fixing ring away from the Z-shaped plate has several rectangular grooves.

[0027] Furthermore, the movable component includes several connecting ears rotatably connected to the side of the fixed ring near the Z-shaped plate, and a tapered plate is rotatably connected to the outer surface of the connecting ears;

[0028] The opening and closing assembly includes a porous ring disposed on the outer surface of several conical plates, and several return springs are fixedly connected to the side of the porous ring near the fixed ring;

[0029] The end of the return spring away from the porous ring is fixedly connected to the side wall of the fixed ring.

[0030] Furthermore, the sliding plate is slidably connected inside the rectangular groove two;

[0031] The limiting component includes an arc-shaped plate fixedly connected to the side wall of the sliding plate. A right-angle block is fixedly connected to the side of the arc-shaped plate near the middle of the fixing ring. Several one-way butterfly grooves are opened on the side of the arc-shaped plate away from the right-angle block.

[0032] Furthermore, the rotating assembly includes a flexible layer fixedly connected to the side of the porous ring away from the return spring, the end of the flexible layer away from the porous ring being fixedly connected to the inner wall of the connecting block, and the outer surface of the flexible layer contacting the side wall of the right-angle ring.

[0033] The inner wall of the flexible layer is rotatably connected to a rotating ring.

[0034] The present invention has the following beneficial effects:

[0035] 1. This invention, through the opening and closing component, the elastic component, and the limiting component, obstructs the flow of the returning medium by the conical channel formed by multiple conical plates, thereby blocking the return velocity of the medium. Simultaneously, when some of the returning medium flows through the notch on the fixed ring, it enters the unidirectional butterfly groove and is obstructed by the wing-shaped barrier, changing direction and generating an opposing force, thus slowing down the return velocity of the returning medium. By weakening the return of the medium, it reduces the localized excessive pressure caused by the collision between the returning medium and the normal conveying medium in the connecting block and the first pipeline, thereby reducing the risk of damage and leakage due to excessive pressure when conveying high-pressure media, thus ensuring the stability of the high-pressure medium flow.

[0036] 2. In this invention, through the opening and closing components and the elastic components, when multiple conical plates close to form a conical channel, the formation of the conical channel can accelerate the flow velocity of the medium and apply a tangential force to the fluid, causing the fluid to rotate while flowing forward, thereby forming a spiral flow pattern. At this time, the medium will form a spiral vortex flow when passing through the conical plates, thereby enhancing the medium's conveying capacity. At the same time, the formation of the spiral vortex can further enhance the strength and stability of the vortex medium flow, thereby optimizing the medium flow and reducing the impact of insufficient vortex strength on the flow pressure of the vortex medium flow when some medium flows back. This reduces the pressure loss of the normal medium flow when it meets the partially flowing back medium, thereby ensuring that the normal medium flows normally in the vortex pressure state while also improving the medium's flow efficiency and pressure stability.

[0037] 3. In this invention, through the opening and closing component and the rotating component, the rotating ring can disturb part of the turbulent liquid when it rotates. At the same time, the medium flowing out through the spiral conical channel is subjected to the reverse turbulent flow at the slope and the rotation of the rotating ring, thereby promoting the rotational flow velocity of the normal flowing medium. This enhances the vortex flow of the normal medium and stabilizes the flow pressure of the normal medium during vortex flow. While further enhancing the stability of the flow pressure, it can also accelerate the flow velocity of the normal medium, thereby enhancing the transportation efficiency of fracturing medium.

[0038] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0041] Figure 2 This is a schematic diagram of the overall partial cross-sectional structure of the present invention;

[0042] Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle;

[0043] Figure 4 This is a schematic diagram of the intersection component of the present invention;

[0044] Figure 5 For the present invention Figure 4 Enlarged view of point B in the middle;

[0045] Figure 6 This is a schematic diagram of the opening and closing component of the present invention;

[0046] Figure 7 This is a partial cross-sectional schematic diagram of the opening and closing component of the present invention;

[0047] Figure 8 This is a schematic diagram of the elastic component of the present invention;

[0048] Figure 9 This is a schematic diagram of the closed state of the conical plate of the present invention;

[0049] Figure 10 This is a schematic diagram of the reflux medium flow direction of the present invention.

[0050] The attached diagram lists the components represented by each number as follows:

[0051] In the diagram: 1. Main body; 101. Support frame; 11. Conveying assembly; 111. First pipeline; 112. Valve pipe; 12. Interchange assembly; 121. Connecting block; 122. Stop valve combination valve; 123. Second pipeline; 124. Right-angle ring; 2. Conveying mechanism; 201. Fixed ring; 202. Rectangular groove; 21. Elastic assembly; 211. Sliding ring; 212. Z-shaped plate; 22. Opening and closing assembly; 221. Connecting ear; 222. Conical plate; 223. Perforated ring; 224. Return spring; 3. Blocking mechanism; 301. Sliding plate; 31. Restricting assembly; 311. Arc plate; 312. Right-angle block; 313. One-way butterfly groove; 32. Rotating assembly; 321. Flexible layer; 322. Rotating ring. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Please see Figures 1-10 As shown, the present invention is an eccentric eddy current fracturing manifold, comprising a main body 1, with two support frames 101 fixedly connected to the top of the main body 1, and further comprising:

[0054] Conveying mechanism 2 is installed inside the main body 1 to prevent backflow of fracturing medium;

[0055] The blocking mechanism 3 is installed on the side wall of the conveying mechanism 2;

[0056] When fracturing medium is transported through the main body 1, the transport mechanism 2 can reduce the backflow of medium during transport, and the blocking mechanism 3 can block the backflow liquid to accelerate the normal flow of medium.

[0057] Entity 1 includes:

[0058] The conveying assembly 11 is installed on the top of the main body 1 and is used to convey liquid;

[0059] The confluence assembly 12 is mounted on top of the support frame 101 via a connecting member.

[0060] The conveying mechanism 2 includes a fixing ring 201 disposed inside the converging assembly 12. The conveying mechanism 2 includes:

[0061] Elastic component 21 is installed on the inner wall of the fixed ring 201;

[0062] The opening and closing component 22 is rotatably mounted on the side wall of the fixed ring 201 via a movable component.

[0063] The blocking mechanism 3 includes a plurality of sliding plates 301 slidably disposed on the side wall of the fixed ring 201. The blocking mechanism 3 includes:

[0064] Restriction component 31 is fixedly disposed on the side wall of sliding plate 301;

[0065] Rotating assembly 32 is mounted on the side wall of fixed ring 201.

[0066] The conveying assembly 11 includes a first pipe 111 fixedly connected to the top of the main body 1, and two valve pipes 112 are fixedly connected to the outer surface of the first pipe 111.

[0067] The connecting component includes a connecting block 121 fixedly connected to the top of the support frame 101. A second pipeline 123 is bolted between the two connecting blocks 121. A plugging combination valve 122 is bolted to both the front and back of the connecting block 121. First, one end of the first pipeline 111 is connected to the sand mixing truck and the other end is connected to the fracturing pump, and the valve pipe 112 is closed. Then, the end of the connecting block 121 is connected to the wellhead.

[0068] The bottom of the plug combination valve 122 is bolted to the top outer wall of the support frame 101;

[0069] The confluence assembly 12 includes a right-angle ring 124 fixedly connected to the inner wall of the connecting block 121. First, one end of the first pipeline 111 is connected to the sand mixing truck and the other end is connected to the fracturing pump, and the valve pipe 112 is closed. Then, the end of the connecting block 121 is connected to the wellhead.

[0070] The fixing ring 201 is fixedly connected to the inner wall of the connecting block 121. The outer surface of the fixing ring 201 has several notches, and the inner wall of the fixing ring 201 has two rectangular grooves 202.

[0071] Among them, the two rectangular slots 202 are arranged in a circular array with the middle part of the fixing ring 201 as the center.

[0072] The elastic component 21 includes a spring plate that is slidably connected inside the rectangular groove 202, a sliding ring 211 that is fixedly connected between the two spring plates, and a plurality of Z-shaped plates 212 that are fixedly connected to the right side of the sliding ring 211.

[0073] Among them, the fixed ring 201 has several rectangular grooves on the side away from the Z-shaped plate 212. When the sliding ring 211 slides, it will press the inclined surface of the right-angle block 312. At this time, the right-angle block 312 will slide upward inside the rectangular groove through the sliding plate 301 after being pressed by the sliding ring 211.

[0074] The movable part includes a number of connecting ears 221 rotatably connected to the fixed ring 201 on the side near the Z-shaped plate 212, and a tapered plate 222 is rotatably connected to the outer surface of the connecting ears 221;

[0075] The opening and closing assembly 22 includes a porous ring 223 disposed on the outer surface of a plurality of conical plates 222, and a plurality of return springs 224 are fixedly connected to the side of the porous ring 223 near the fixed ring 201;

[0076] The end of the return spring 224 away from the porous ring 223 is fixedly connected to the side wall of the fixed ring 201. When the high-pressure medium flows outward and breaks through the rock layer, causing the medium to backflow, the medium will impact the porous ring 223 during the backflow. When the porous ring 223 is impacted, it can push multiple conical plates 222 to close during the sliding process.

[0077] Sliding plate 301 is slidably connected inside rectangular groove 2;

[0078] The limiting component 31 includes an arc-shaped plate 311 fixedly connected to the side wall of the sliding plate 301. A right-angle block 312 is fixedly connected to the side of the arc-shaped plate 311 near the middle of the fixing ring 201. Several one-way butterfly grooves 313 are opened on the side of the arc-shaped plate 311 away from the right-angle block 312. When the porous ring 223 is pushed by the return medium, the sliding of the porous ring 223 will drive the flexible layer 321 to extend and open. When the flexible layer 321 is unfolded, it will be blocked by the right-angle ring 124.

[0079] The rotating assembly 32 includes a flexible layer 321 fixedly connected to the side of the porous ring 223 away from the return spring 224. The end of the flexible layer 321 away from the porous ring 223 is fixedly connected to the inner wall of the connecting block 121, and the outer surface of the flexible layer 321 is in contact with the side wall of the right-angle ring 124.

[0080] The inner wall of the flexible layer 321 is rotatably connected to a rotating ring 322. At this time, the flexible layer 321 will have a slope. Subsequently, when the recirculating medium flows, the accelerated laminar flow at the inlet of the flexible layer 321 and the dynamic pressure at the inlet slope of the flexible layer 321 generate an interaction of reverse turbulence. At the same time, when the recirculating liquid flows, it will impact the rotating ring 322, causing it to rotate and driving the surrounding water flow to generate rotational motion.

[0081] In use, first connect one end of the first pipeline 111 to the sand mixing truck and the other end to the fracturing pump, and close the valve pipe 112. Then connect the end of the connecting block 121 to the wellhead. Subsequently, the high-pressure fracturing medium from the valve pipe 112 is transported into the interior of the connecting block 121 through the plug combination valves 122 on both sides of the connecting block 121. When the high-pressure medium is transported into the interior of the connecting block 121 through the two plug combination valves 122, the high-pressure medium will form an eccentric vortex in the connecting block 121 and the second pipeline 123 and be transported.

[0082] When the high-pressure medium flows in a vortex, the flowing medium passes between multiple conical plates 222 and expands outward under the flow of the medium, forming a circular channel. Simultaneously, the medium flows through several notches on the outer surface of the fixed ring 201, pushing the porous ring 223 to slide on the outer surface of the conical plates 222. Later, when the high-pressure medium flows outward and breaks through the rock layer, causing backflow, the backflow impacts the porous ring 223. When the porous ring 223 is impacted, it pushes the multiple conical plates 222 to close during the sliding process, forming a conical channel. Then, when the multiple conical plates 222 rotate and close, they press the sliding ring 211 against the inner wall of the fixed ring 201 through multiple Z-shaped plates 212. The sliding ring 211, during its sliding, presses against the right-angle block 312. On the inclined surface, the right-angle block 312, after being squeezed by the sliding ring 211, will slide upward through the sliding plate 301 inside the rectangular groove. At this time, the one-way butterfly groove 313 on the arc plate 311 will correspond to the notch on the fixed ring 201. When the returning medium flows, it will be blocked by the conical channel formed by multiple conical plates 222, thereby blocking the return speed of the medium. At the same time, when some of the returning medium flows through the notch on the fixed ring 201, it will enter the one-way butterfly groove 313 and will be blocked by the wing-shaped obstacle, changing its direction and generating the opposite force, thereby slowing down the return speed of the returning medium. By weakening the return of the medium, the local pressure caused by the collision between the returning medium and the normal conveying medium in the connecting block 121 and the first pipeline 111 can be reduced, thereby reducing the risk of damage and leakage due to excessive pressure when the device is conveying high-pressure medium, thus ensuring the stability of the high-pressure medium flow.

[0083] When the recirculating medium pushes the porous ring 223 to slide during the recirculation process, the sliding of the porous ring 223 will compress multiple conical plates 222, causing them to rotate and close relative to each other. When the conical plates 222 close, they will compress the Z-shaped plate 212, causing it to drive the sliding ring 211 to slide. When the conical plates 222 compress the Z-shaped plate 212, the conical plates 222 will be subjected to the reaction force of the Z-shaped plate 212, causing the conical plates 222 to drive the connecting lug 221 to rotate. At this time, the multiple conical plates 222, while closing to form a conical channel, will also exhibit a spiral state, presenting a shape like... Figure 9In the closed state, when multiple conical plates 222 close to form a conical channel, the formation of the conical channel can accelerate the flow velocity of the medium. At the same time, when the normal flowing medium passes through the conical channel in a spiral state, the spiral shape will apply a tangential force to the fluid, causing the fluid to rotate while flowing forward, thus forming a spiral flow pattern. At this time, the medium will form a spiral vortex flow when passing through the conical plate 222, which can enhance the transport capacity of the medium. At the same time, the formation of the spiral vortex can further enhance the strength and stability of the vortex medium flow, thereby optimizing the flow of the medium and reducing the insufficient vortex strength when part of the medium flows back, which affects the flow pressure of the vortex flow. This reduces the pressure loss when the normal medium flows with part of the backflow medium, thus ensuring that the normal medium flows normally in the vortex pressure state while improving the flow efficiency and pressure stability of the medium.

[0084] When the porous ring 223 is pushed by the reflux medium, the sliding of the porous ring 223 will cause the flexible layer 321 to extend and open. When the flexible layer 321 is extended, it will be blocked by the right-angle ring 124. At this time, the flexible layer 321 will have a slope. Then, when the reflux medium flows, the accelerated laminar flow at the inlet of the flexible layer 321 and the dynamic pressure at the inlet slope of the flexible layer 321 will generate a reverse turbulent interaction. At the same time, the reflux liquid will impact the rotating ring 322, causing it to rotate and drive the surrounding water flow to generate a rotational motion. When the rotating ring 322 rotates, it can disturb part of the turbulent liquid. Meanwhile, the medium flowing out through the spiral conical channel will be affected by the reverse turbulent flow at the slope and the rotation of the rotating ring 322, which can promote the rotational flow velocity of the normal flow medium, enhance the vortex flow of the normal medium, and stabilize the flow pressure of the normal medium during vortex flow. This further enhances the stability of the flow pressure and accelerates the flow velocity of the normal medium, thereby enhancing the delivery efficiency of the fracturing medium.

[0085] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An eccentric eddy current fracturing manifold, comprising a main body (1), wherein two support frames (101) are fixedly connected to the top of the main body (1), characterized in that, Also includes: The conveying mechanism (2) is installed inside the main body (1) to prevent backflow of fracturing medium; A blocking mechanism (3) is installed on the side wall of the conveying mechanism (2); When the fracturing medium is transported through the main body (1), the transport mechanism (2) can reduce the backflow of the medium during transport, and the blocking mechanism (3) blocks the backflow liquid to accelerate the normal flow speed of the medium. The conveying mechanism (2) includes a retaining ring (201) disposed inside the converging assembly (12), and the conveying mechanism (2) further includes: An elastic component (21) is installed on the inner wall of the fixing ring (201); An opening and closing assembly (22) is rotatably mounted on the side wall of a fixed ring (201) via a movable component; The blocking mechanism (3) includes a plurality of sliding plates (301) slidably disposed on the side wall of the fixed ring (201), and the blocking mechanism (3) further includes: A limiting component (31) is fixedly disposed on the side wall of the sliding plate (301); Rotating assembly (32), the rotating assembly (32) is mounted on the side wall of the fixed ring (201); The elastic component (21) includes a spring plate that is slidably connected inside the rectangular groove (202), a sliding ring (211) is fixedly connected between the two spring plates, and a plurality of Z-shaped plates (212) are fixedly connected to the right side of the sliding ring (211). The fixing ring (201) has several rectangular grooves on the side away from the Z-shaped plate (212); The movable component includes a plurality of connecting ears (221) rotatably connected to the fixed ring (201) on the side near the Z-shaped plate (212), and a tapered plate (222) is rotatably connected to the outer surface of the connecting ears (221). The opening and closing assembly (22) includes a porous ring (223) disposed on the outer surface of a plurality of conical plates (222), and a plurality of return springs (224) are fixedly connected to the side of the porous ring (223) near the fixed ring (201). The end of the return spring (224) away from the porous ring (223) is fixedly connected to the side wall of the fixed ring (201); The sliding plate (301) is slidably connected inside the rectangular groove 2; The limiting component (31) includes an arc-shaped plate (311) fixedly connected to the side wall of the sliding plate (301). A right-angle block (312) is fixedly connected to the side of the arc-shaped plate (311) near the middle of the fixing ring (201). Several one-way butterfly grooves (313) are provided on the side of the arc-shaped plate (311) away from the right-angle block (312).

2. The eccentric eddy current fracturing manifold according to claim 1, characterized in that: The main body (1) includes: A conveying assembly (11) is installed on the top of the main body (1) for conveying liquid; A junction assembly (12) is mounted on top of a support frame (101) via a connecting member.

3. The eccentric eddy current fracturing manifold according to claim 2, characterized in that: The conveying assembly (11) includes a first pipe (111) fixedly connected to the top of the main body (1), and two valve pipes (112) are fixedly connected to the outer surface of the first pipe (111). The connecting component includes a connecting block (121) fixedly connected to the top of the support frame (101), a second pipeline (123) is bolted between the two connecting blocks (121), and a plug combination valve (122) is bolted to both the front and back of the connecting block (121).

4. An eccentric eddy current fracturing manifold according to claim 3, characterized in that: The bottom of the plug combination valve (122) is bolted to the top outer wall of the support frame (101); The confluence assembly (12) includes a right-angle ring (124) fixedly connected to the inner wall of the connecting block (121).

5. An eccentric eddy current fracturing manifold according to claim 4, characterized in that: The fixing ring (201) is fixedly connected to the inner wall of the connecting block (121). The outer surface of the fixing ring (201) has several notches, and the inner wall of the fixing ring (201) has two rectangular grooves (202). The two rectangular slots (202) are arranged in a circular array with the middle part of the fixing ring (201) as the center.

6. An eccentric eddy current fracturing manifold according to claim 5, characterized in that: The rotating assembly (32) includes a flexible layer (321) fixedly connected to the side of the porous ring (223) away from the return spring (224). One end of the flexible layer (321) away from the porous ring (223) is fixedly connected to the inner wall of the connecting block (121). The outer surface of the flexible layer (321) is in contact with the side wall of the right-angle ring (124). The inner wall of the flexible layer (321) is rotatably connected to a rotating ring (322).

Images