Top-mounted ball valve

Abstract

The invention discloses a top-mounted ball valve, and relates to the technical field of valves, the top-mounted ball valve comprises a valve body, a ball body is arranged in the valve body, the top-mounted ball valve further comprises a first-stage sealing assembly and a second-stage sealing assembly, the first-stage sealing assembly comprises first valve seats, a first elastic piece is arranged at one end, away from the ball body, of each first valve seat, and a second elastic piece is arranged at the other end of each first valve seat; the second-stage sealing assembly comprises two second valve seats arranged in the valve body in a sliding mode so as to enhance the sealing performance between the first valve seats and the ball body, and the second-stage sealing assembly comprises two second valve seats arranged in the valve body in a sliding mode so as to prevent fluid between the ball body and the second valve seats from leaking. The first elastic piece can move, the problems that the first valve seat is abraded quickly and the service life is short are solved, the second valve seat makes contact with the ball body when the first valve seat is abraded and cannot be sealed, and the problem that the ball valve needs to be frequently replaced or maintained is solved.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to a top-mounted ball valve. Background Art

[0002] At present, the commonly used top-loading pipeline ball valve structure is mostly assembled by pulling the valve seat away from the ball from both sides of the channel to achieve the ball top installation. Special tooling is required, and the assembly is relatively cumbersome. When the connection method is welding connection, the valve can only be cut off from the pipeline for maintenance, and it does not have the function of online maintenance.

[0003] The existing threaded valve seat top-mounted structure compresses the spring when the pre-tightening nut is rotated, and the elastic force of the spring cannot be adjusted after the pre-tightening of the spring is completed. During the contact between the valve seat and the ball, the friction force is large, resulting in a large friction between the ball and the valve seat. Therefore, the valve seat wears more seriously. After long-term wear, it is easy to cause a loose seal between the valve seat and the ball, which will lead to insufficient pre-tightening pressure ratio, thereby causing the medium to leak from between the ball and the sealing ring, reducing the service life of the valve seat, and may lead to more frequent replacement of the valve seat.

[0004] At the same time, when the valve seat is worn to a certain extent, a gap will appear between the valve seat and the ball, causing the medium to leak from between the valve seat and the ball. Therefore, it is necessary to seal the ball and the valve seat again, which increases the maintenance workload. Summary of the invention

[0005] The object of the present invention is to provide a top-entry ball valve to solve the technical problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a top-entry ball valve, comprising a valve body, a ball body is arranged in the valve body, and further comprising: A primary sealing assembly, the primary sealing assembly comprising two first valve seats slidably disposed in the valve body, the ball being located between the two first valve seats and in contact with the two first valve seats, and each of the first valve seats being provided with a plurality of first elastic members capable of moving toward the direction approaching the ball at one end away from the ball, so as to enhance the sealing performance between the first valve seat and the ball; A secondary sealing assembly, the secondary sealing assembly includes two second valve seats slidably arranged in the valve body, when the ball rotates, the two second valve seats move away from the ball so that the two second valve seats are not in contact with the ball, when the two first valve seats are worn to a certain extent and are not sufficient to enhance the sealing between the first valve seat and the ball, the two second valve seats are always in contact with the ball to prevent fluid leakage between the ball and the second valve seats.

[0007] Preferably, the primary sealing assembly also includes a plurality of piston cylinders arranged in the valve body and corresponding to the plurality of the first elastic members, a piston rod is slidably provided in each of the piston cylinders, one end of each of the piston rods close to the corresponding first valve seat passes through the corresponding piston cylinder and is fixed with a pushing member, and each of the first elastic members is located between the corresponding first valve seat and the pushing member.

[0008] Preferably, each first valve seat near the sphere is connected to the valve body through a connecting tube, the other end of the connecting tube is connected to the end of the piston cylinder away from the corresponding first valve seat, a guide groove is provided in the valve body, and a guide piece inserted into the corresponding guide groove is fixedly provided on the inner wall of each first valve seat.

[0009] Preferably, the top and the bottom of the sphere are both provided with receiving grooves, and a lower valve shaft which can be rotatably inserted into the receiving groove at the bottom is provided in the valve body.

[0010] Preferably, a plurality of guide blocks are fixedly provided on the outer side wall of the second valve seat, each of the guide blocks is slidably connected to the valve body, and a second elastic member is provided between an end of each guide block away from the spherical body and the valve body.

[0011] Preferably, the two guide blocks close to the lower valve shaft are each provided with a clearance groove, the lower valve shaft is provided with a plurality of connecting members, a lifting member is fixedly provided on the plurality of connecting members, and a pulling member capable of contacting the side wall of the clearance groove is fixedly provided on the lifting member.

[0012] Preferably, a side of the lifting member away from the lower valve shaft is an inclined surface, and the two piston rods close to the lower valve shaft are both provided with connecting rods capable of contacting the inclined surface of the lower valve shaft.

[0013] Preferably, a third elastic member is provided between each of the connecting members and the lower valve shaft.

[0014] Preferably, a sealing cover is provided on the valve body, a valve cover is provided on the sealing cover, a valve stem is rotatably provided in the valve cover and one end of the valve stem is inserted into the receiving groove at the top, a transmission box is provided on the valve cover, and a rotating handle is provided in the transmission box and is transmission-connected to the valve stem.

[0015] Preferably, a grease injection hole, a sewage outlet and a vent are provided on the valve body, and a support cover is fixedly provided on the valve body, and the support cover is rotatably connected to the ball.

[0016] The beneficial effects of the present invention are: 1. By providing a slidable first valve seat and a first elastic member, when the first valve seat is worn, the elastic force of the first elastic member can push the first valve seat to move toward the sphere, so that the first valve seat and the sphere are sealed, and the sphere and the first valve seat are sealed. The grease injection hole can be filled with grease to reduce the friction between the first valve seat and the sphere, and sealing grease is added to protect and seal the sphere and the first valve seat.

[0017] 2. By setting the piston cylinder and piston rod, when the extrusion pressure between the first valve seat and the ball is insufficient, that is, when the elastic force of the first elastic member is less than the pressure of the medium, the medium is discharged into the connecting pipe, so that the piston rod drives the first elastic member to approach the ball, so that the elastic force of the first elastic member is sufficient to push the first valve seat and the ball to maintain a seal, and as long as the first valve seat is located in the ball seal, the medium will continue to be transported into the piston cylinder, and only when the first valve seat is in contact with the ball and the extrusion pressure is sufficient, the connecting pipe will not be connected with the valve body, thereby ensuring the seal between the first valve seat and the ball.

[0018] 3. By setting the pulling member, during the rotation of the ball, the pulling member can drive the second valve seat away from the ball through the clearance groove and the guide block, so that when the first valve seat can maintain sufficient sealing with the ball, the second valve seat does not participate in the initial sealing, thereby reducing the initial friction of the second valve seat.

[0019] 4. When the friction of the first valve seat reaches a certain degree and the extension of the piston rod and the elastic force of the first elastic member are insufficient to support the seal between the first valve seat and the ball, the inclined surface of the lifting member is pushed by the connecting rod to drive the pulling member to move downward out of the give way groove, so that the second valve seat moves toward the direction of the ball under the action of the second elastic member, so that the second valve seat and the ball remain sealed to prevent medium leakage.

[0020] 5. Since the second valve seat does not rub against the ball at the beginning, the friction between the second valve seat and the ball is reduced, so that the second valve seat will not be worn when sealing between the first valve seat and the ball, so that the second valve seat can be used for a longer time, reducing the maintenance of the ball valve and the replacement efficiency of parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 It is a schematic diagram of the overall full-section plane of the present invention.

[0023] Figure 3 It is a full cross-sectional plan view of the present invention without the sealing cover and the valve cover.

[0024] Figure 4 It is a schematic structural diagram of the second valve seat and the pulling member of the present invention.

[0025] Figure 5 It is a full cross-sectional plan view of the first valve seat of the present invention.

[0026] Figure 6 It is a schematic diagram of the connection relationship between the lifting member and the connecting rod of the present invention.

[0027] Figure 7 It is a schematic diagram of the connection relationship between the pulling member and the guide block of the present invention.

[0028] Figure 8 It is a schematic diagram of the distribution structure of the lifting parts and the connecting parts of the present invention.

[0029] Fig. 9 It is a schematic diagram of the connection relationship between the lower valve shaft and the connecting member of the present invention.

[0030] Fig.10 It is a schematic structural diagram of the sphere and the support cover of the present invention.

[0031] The reference numerals are: 1, valve body; 2, ball; 201, receiving groove; 202, lower valve shaft; 3. Primary sealing assembly; 301. First valve seat; 302. First elastic member; 303. Piston cylinder; 304. Piston rod; 305. Pushing member; 306. Connecting pipe; 307. Guide groove; 308. Guide member; 4. Secondary sealing assembly; 401. Second valve seat; 402. Guide block; 403. Second elastic member; 404. Displacement groove; 405. Connecting member; 406. Lifting member; 407. Pulling member; 408. Connecting rod; 409. Third elastic member; 5. Sealing cover; 6. Valve cover; 601. Valve stem; 7. Transmission box; 8. Turning handle; 9. Support cover. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1 At present, the commonly used top-loading pipeline ball valve structure is mostly assembled by pulling the valve seat away from the ball from both sides of the channel to achieve the ball top installation. Special tooling is required, and the assembly is relatively cumbersome. When the connection method is welding connection, the valve can only be cut off from the pipeline for maintenance, and it does not have the function of online maintenance.

[0034] The existing threaded valve seat top-mounted structure compresses the spring when the pre-tightening nut is rotated, and the elastic force of the spring cannot be adjusted after the pre-tightening of the spring is completed. During the contact between the valve seat and the ball 2, due to the large friction force, there is a large friction between the ball 2 and the valve seat, so the valve seat wears more seriously. After long-term wear, it is easy to cause the seal between the valve seat and the ball 2 to be loose, which will lead to insufficient pre-tightening pressure ratio, thereby causing the medium to leak from between the ball 2 and the sealing ring, reducing the service life of the valve seat, and may lead to more frequent replacement of the valve seat.

[0035] To solve the above technical problems, see Figures 1 to 10 A top-mounted ball valve according to an embodiment of the present invention comprises a valve body 1, a ball body 2 is arranged in the valve body 1, and a primary sealing assembly 3, the primary sealing assembly 3 comprises two first valve seats 301 slidably arranged in the valve body 1, the ball body 2 is located between the two first valve seats 301 and contacts the two first valve seats 301, and each first valve seat 301 is provided with a plurality of first elastic members 302 that can move toward the direction close to the ball body 2 at one end away from the ball body 2, so as to enhance the sealing between the first valve seat 301 and the ball body 2, the primary sealing assembly 3 also comprises a plurality of piston cylinders 303 arranged in the valve body 1 and corresponding to the plurality of first elastic members 302, a piston rod 304 is slidably arranged in each piston cylinder 303, an end of each piston rod 304 close to the corresponding first valve seat 301 penetrates the corresponding piston cylinder 303 and is fixedly provided with a pushing member 305, and each first elastic member 302 is located between the corresponding first valve seat 301 and the pushing member 305. The valve body 1 is provided with a guide groove 307, and a guide member 308 inserted into the corresponding guide groove 307 is fixedly provided on the inner wall of each first valve seat 301. The sphere 2 is provided with a receiving groove 201 at the top and the bottom. A lower valve shaft 202 capable of being inserted into the receiving groove 201 at the bottom is rotatably provided in the valve body 1. A sealing cover 5 is provided on the valve body 1, and a valve cover 6 is provided on the sealing cover 5. A valve stem 601 with one end inserted into the receiving groove 201 at the top is rotatably provided in the valve cover 6. A transmission box 7 is provided on the valve cover 6, and a rotating handle 8 transmission-connected to the valve stem 601 is provided in the transmission box 7. A grease injection hole, a sewage outlet and a vent are provided on the valve body 1. A support cover 9 is fixedly provided on the valve body 1, and the support cover 9 is rotatably connected to the sphere 2.

[0036] In specific use, the ball 2 and the valve body 1 are both provided with medium channels that can communicate with each other, and the connecting pipe 306 is connected with the medium channel 1 of the valve body. In the initial state, the medium channel on the ball 2 is not connected with the medium channel on the valve body 1. The handle 8 is turned to drive the valve stem 601 to rotate through the transmission box 7. The handle 8 drives the valve stem 601 to rotate through the transmission box 7 and the connection method are all prior art, which will not be described in detail here and is not shown in the figure. The valve stem 601 drives the ball 2 to rotate on the valve body 1 and the support cover 9 through the receiving groove 201. During this process, the ball 2 and the first valve seat 301 rub against each other, and the ball 2 drives the lower valve shaft 202 to rotate on the valve body 1. After the ball 2 rotates 90 degrees, the medium channel on the ball 2 is connected with the medium channel on the valve body 1, and the medium begins to flow in the medium channel.

[0037] As the ball 2 is continuously rotated, the first valve seat 301 is gradually worn, and the contact between the first valve seat 301 and the ball 2 is no longer tight. At this time, the first elastic member 302 pushes the first valve seat 301 to move toward the ball 2, so that the first valve seat 301 and the ball 2 are sealed, thereby ensuring the smooth transportation of the medium, avoiding waste of the medium and corrosion of the ball 2 and the valve body 1 caused by medium leakage, increasing the service life of the ball valve, and reducing the frequency of replacement of parts.

[0038] When it is necessary to discharge pollutants, open the drain port to discharge the pollutants. When the seal is insufficient or the friction between the ball 2 and the first valve seat 301 is large, inject grease and sealing grease through the grease injection hole to protect and lubricate the first valve seat 301 and the valve stem 601 of the ball valve to extend the service life of the ball valve. In some high-pressure or residual medium pipeline systems, it is necessary to release the pressure in the valve cavity through the vent port before the ball valve is overhauled or maintained or when the medium needs to be replaced or cleaned to ensure the safety of maintenance personnel. The vent port can easily empty the original medium in the valve cavity and facilitate the entry of new medium. The drain port, grease injection hole and vent port are all existing technologies and are not described in detail here and are not shown in the figure.

[0039] When the first valve seat 301 is not in close contact with the spherical body 2 and the extrusion pressure of the first elastic member 302 is insufficient, the medium is discharged into the connecting pipe 306 at this time, and the medium is discharged into the piston cylinder 303 through the connecting pipe 306. The medium squeezes the piston rod 304, and the piston rod 304 squeezes the pushing member 305, so that the pushing member 305 pushes the first elastic member 302 to move in the direction close to the spherical body 2, thereby changing the position of the first elastic member 302, causing the first elastic member 302 to shrink, and at the same time, the distance between the end of the first elastic member 302 away from the spherical body 2 and the spherical body 2 becomes closer, so that the extrusion pressure of the first elastic member 302 on the first valve seat 301 increases again, so that the first valve seat 301 and the spherical body 2 are kept sealed.

[0040] Generally, when the ball valve used in the field of gasoline or other media works normally, the medium pressure is less than the elastic force of the spring at the valve seat, and the pressure of the medium flow is slightly less than the elastic force of the multiple first elastic parts 302 on the first valve seat 301, and the elastic force of the first elastic part 302 only needs to ensure the tight seal between the first valve seat 301 and the ball 2, so that the thrust of the medium can make the thrust of the position of the first elastic part 302 on the first valve seat 301 smaller than the initial pressure of the first elastic part 302 on the first valve seat 301, so that the elastic force of the first elastic part 302 pushes the first valve seat 301 under a smaller condition, so that the friction between the first valve seat 301 and the ball 2 is smaller, thereby slowing down the wear rate of the first valve seat 301 and ensuring the seal between the first valve seat 301 and the ball 2 at the same time.

[0041] During the movement of the first valve seat 301, due to the guide groove 307 and the guide member 308, the first valve seat 301 moves in the guide groove 307 through the guide member 308, so that the first valve seat 301 only moves axially, preventing the first valve seat 301 from moving circumferentially.

[0042] By providing the slidable first valve seat 301 and the first elastic member 302, when the first valve seat 301 is worn, the elastic force of the first elastic member 302 can push the first valve seat 301 to move toward the sphere 2, so that the first valve seat 301 and the sphere 2 are sealed, and the sphere 2 and the first valve seat 301 are sealed. The grease injection hole can be filled with grease to reduce the friction between the first valve seat 301 and the sphere 2, and the sealing grease is added to protect and seal the sphere 2 and the first valve seat 301. The piston cylinder 303 and the piston Rod 304, when the extrusion pressure between the first valve seat 301 and the spherical body 2 is insufficient, the medium is discharged into the connecting pipe 306, so that the piston rod 304 drives the first elastic member 302 to approach the spherical body 2, so that the elastic force of the first elastic member 302 is sufficient to push the first valve seat 301 and the spherical body 2 to maintain a seal, and as long as the first valve seat 301 is located in the spherical body 2 and sealed, the medium will continue to be transported into the piston cylinder 303, and only when the first valve seat 301 is in contact with the spherical body 2 and the extrusion pressure is sufficient, the connecting pipe 306 will not be connected with the valve body 1, thereby ensuring the seal between the first valve seat 301 and the spherical body 2.

[0043] Embodiment 2 Although the above-mentioned embodiment can maintain the sealing between the first valve seat 301 and the ball 2 by changing the position of the first elastic member 302, when the piston rod 304 moves to the extension limit, the first valve seat 301 will be worn again, which will cause leakage of medium between the first valve seat 301 and the ball 2. Although the service life of the valve seat is improved and the degree of wear of the valve seat is increased, when the wear reaches the extension limit of the piston rod 304, the valve seat needs to be replaced in time, which also leads to the problem of frequent replacement of the valve seat.

[0044] In order to solve the above technical problems, on the basis of the above embodiments, the technical solution adopted includes a secondary sealing component 4, the secondary sealing component 4 includes two second valve seats 401 slidably arranged in the valve body 1, when the ball 2 rotates, the two second valve seats 401 move in the direction away from the ball 2, so that the two second valve seats 401 are not in contact with the ball 2, when the two first valve seats 301 are worn to a certain extent and are not enough to enhance the sealing between the first valve seats 301 and the ball 2, the two second valve seats 401 are always in contact with the ball 2 to prevent fluid leakage between the ball 2 and the second valve seats 401, and a plurality of guide blocks 402 are fixedly provided on the outer wall of the second valve seat 401, each guide block 402 is fixed to the valve body 1 Sliding connection, a second elastic member 403 is provided between the end of each guide block 402 away from the spherical body 2 and the valve body 1, and a yield groove 404 is opened on the two guide blocks 402 close to the lower valve shaft 202, and a plurality of connecting members 405 are provided on the lower valve shaft 202. A lifting member 406 is fixedly provided on the plurality of connecting members 405, and a pulling member 407 capable of contacting the side wall of the yield groove 404 is fixedly provided on the lifting member 406. The side of the lifting member 406 away from the lower valve shaft 202 is an inclined surface, and the two piston rods 304 close to the lower valve shaft 202 are provided with a connecting rod 408 capable of contacting the inclined surface of the lower valve shaft 202, and a third elastic member 409 is provided between each connecting member 405 and the lower valve shaft 202.

[0045] When used based on the above embodiment, when the ball 2 is rotated, the ball 2 drives the connecting member 405 to rotate through the lower valve shaft 202, the connecting member 405 drives the pulling member 407 to rotate through the lifting member 406, and the pulling member 407 pushes the guide block 402 to move away from the ball 2 through the clearance groove 404, thereby preventing the wear of the second valve seat 401 to a certain extent.

[0046] During the extension of the piston rod 304, the piston rod 304 drives the lifting member 406 to move downward through the connecting rod 408, and the lifting member 406 drives the pulling member 407 and the connecting member 405 to move downward, and the third elastic member 409 is compressed. When the piston rod 304 is extended to the limit position, the piston rod 304 can no longer extend in the direction of the ball 2. At the same time, the connecting rod 408 moves the pulling member 407 to the bottom to the limit position through the inclined surface of the lifting member 406, and the lifting member 406 drives the pulling member 407 to move out of the clearance groove 404. At this time, under the action of the second elastic member 403, the guide block 402 pushes the second valve seat 401 to always contact with the ball 2, thereby ensuring the sealing between the ball 2 and the second valve seat 401.

[0047] The pulling member 407 is composed of eight arc plates, and two adjacent arc plates are not concentric and have different diameters, which can ensure that when the pulling member 407 rotates, the arc plates in the middle process can push the guide block 402 to move away from the sphere 2, and the arc plates in the initial and final processes can drive the guide block 402 to move toward the sphere 2, so that the second valve seat 401 maintains close contact with the sphere 2 at the end of the movement.

[0048] The disassembly of the sealing cover 5 and the valve cover 6 and the maintenance of the ball valve are both existing technologies and will not be described in detail here. The first valve seat 301 and the second valve seat 401 are detachably connected to the valve body 1, and the specific disassembly connection structure is not shown, and the disassembly structure and the valve body 1 are expressed as one body in the present invention, and the disassembly connection structure is existing technology and will not be described in detail here.

[0049] By setting the pulling member 407, during the rotation of the ball 2, the pulling member 407 can drive the second valve seat 401 away from the ball 2 through the yield groove 404 and the guide block 402, so that when the first valve seat 301 can maintain a sufficient seal with the ball 2, the second valve seat 401 does not participate in the initial sealing, thereby reducing the initial friction of the second valve seat 401. When the first valve seat 301 rubs to a certain extent and the extension of the piston rod 304 and the elastic force of the first elastic member 302 are insufficient to support the seal between the first valve seat 301 and the ball 2, the inclined surface of the lifting member 406 is pushed by the connecting rod 408 to drive the pulling member 407 to move downward out of the yield groove 404, so that the second valve seat 401 moves toward the direction of the ball 2 under the action of the second elastic member 403, so that the second valve seat 401 and the ball 2 are kept sealed to prevent medium leakage. Since the second valve seat 401 does not rub against the ball 2 at the beginning, it can be used for a longer time, thereby reducing the maintenance of the ball valve and the efficiency of replacing parts.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A top-entry ball valve, characterized in that: The invention comprises a valve body (1), wherein a ball (2) is arranged inside the valve body (1), and further comprises: A primary sealing assembly (3), the primary sealing assembly (3) comprising two first valve seats (301) slidably arranged in the valve body (1), the ball (2) being located between the two first valve seats (301) and in contact with the two first valve seats (301), and each of the first valve seats (301) being provided with a plurality of first elastic members (302) capable of moving in a direction approaching the ball (2) at one end away from the ball (2), so as to enhance the sealing performance between the first valve seat (301) and the ball (2); A secondary sealing assembly (4), the secondary sealing assembly (4) comprising two second valve seats (401) slidably arranged in the valve body (1); when the ball (2) rotates, the two second valve seats (401) both move in a direction away from the ball (2), so that the two second valve seats (401) are not in contact with the ball (2); when the two first valve seats (301) are worn to a certain extent and are insufficient to enhance the sealing between the first valve seat (301) and the ball (2), the two second valve seats (401) are always in contact with the ball (2) to prevent fluid leakage between the ball (2) and the second valve seats (401).

2. A top entry ball valve according to claim 1, characterized in that: The primary sealing assembly (3) further comprises a plurality of piston cylinders (303) arranged in the valve body (1) and corresponding to the plurality of first elastic members (302), a piston rod (304) being slidably arranged in each of the piston cylinders (303), an end of each of the piston rods (304) close to the corresponding first valve seat (301) passing through the corresponding piston cylinder (303) and being fixedly provided with a pushing member (305), and each of the first elastic members (302) being located between the corresponding first valve seat (301) and the pushing member (305).

3. A top entry ball valve according to claim 2, characterized in that: The position of each first valve seat (301) close to the ball (2) is connected to the valve body (1) through a connecting tube (306); the other end of the connecting tube (306) is connected to an end of the piston cylinder (303) away from the corresponding first valve seat (301); a guide groove (307) is provided in the valve body (1); and a guide member (308) inserted into the corresponding guide groove (307) is fixedly provided on the inner wall of each first valve seat (301).

4. A top entry ball valve according to claim 3, characterized in that: The top and bottom of the spherical body (2) are both provided with receiving grooves (201), and a lower valve shaft (202) capable of being inserted into the receiving groove (201) at the bottom is rotatably provided in the valve body (1).

5. A top entry ball valve according to claim 4, characterized in that: A plurality of guide blocks (402) are fixedly provided on the outer side wall of the second valve seat (401), each of the guide blocks (402) being slidably connected to the valve body (1), and a second elastic member (403) is provided between an end of each guide block (402) away from the ball (2) and the valve body (1).

6. A top entry ball valve according to claim 5, characterized in that: A clearance groove (404) is provided on the two guide blocks (402) close to the lower valve shaft (202), a plurality of connecting members (405) are provided on the lower valve shaft (202), a lifting member (406) is fixedly provided on the plurality of connecting members (405), and a pulling member (407) capable of contacting the side wall of the clearance groove (404) is fixedly provided on the lifting member (406).

7. A top entry ball valve according to claim 6, characterized in that: The side of the lifting member (406) away from the lower valve shaft (202) is an inclined surface, and the two piston rods (304) close to the lower valve shaft (202) are both provided with connecting rods (408) capable of contacting the inclined surface of the lower valve shaft (202).

8. A top entry ball valve according to claim 7, characterized in that: A third elastic member (409) is provided between each of the connecting members (405) and the lower valve shaft (202).

9. A top entry ball valve according to claim 8, characterized in that: The valve body (1) is provided with a sealing cover (5), the sealing cover (5) is provided with a valve cover (6), a valve stem (601) is rotatably provided in the valve cover (6) and one end of which is inserted into the receiving groove (201) at the top, the valve cover (6) is provided with a transmission box (7), and a rotating handle (8) is provided in the transmission box (7) and is transmission-connected to the valve stem (601).

10. A top entry ball valve according to claim 9, characterized in that: The valve body (1) is provided with a grease injection hole, a sewage outlet and a venting port. A support cover (9) is fixedly provided on the valve body (1), and the support cover (9) is rotatably connected to the ball (2).

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