A new type of bidirectional sealing lifting rod ball valve

Abstract

The application discloses a novel bidirectional sealing lifting rod ball valve and belongs to the technical field of lifting rod ball valves. The lifting rod ball valve comprises a valve body, a ball, a valve rod, a valve seat and the like; the lifting rod ball valve further comprises a linkage pressurizing assembly; the linkage pressurizing assembly comprises a pressure diaphragm, an upper pressing disc, a lower pressing disc and a connecting pipeline; a pressure cavity, a pressure flow channel one, the connecting pipeline, an annular flow channel and a pressure flow channel two are sequentially communicated and form a pressure channel to exert a reverse force on the valve seat towards a spherical sealing ring. Through the application, the linkage pressurizing assembly is additionally arranged on the whole ball valve; a lowering force exerted on the valve rod by an actuator and the lowering force exerted by the actuator are jointly applied to the linkage pressurizing assembly connected to the valve rod, auxiliary pressure is applied to the valve seat, the medium pressure in the valve body is jointly applied to the valve seat, the valve seat is slightly moved to the left and contacted with the ball, and the high-quality sealing requirement of high medium pressure and low medium pressure can be simultaneously met.

Description

Technical Field

[0001] This invention relates to a novel bidirectional sealing lifting rod ball valve, belonging to the technical field of lifting rod ball valves. Background Technology

[0002] The lifter rod ball valve is a common type of valve, typically used for fluid control and shut-off. It consists of a valve body, ball, stem, and packing.

[0003] The following are the general working principle and main components of a lift rod ball valve:

[0004] Valve body: The valve body is the outer shell of the ball valve, usually made by casting or forging. It has inlet and outlet connections for connecting to piping systems.

[0005] Ball: The ball is a key internal component of the valve, typically made of metal (such as stainless steel or copper alloy). The ball has a channel that allows for the switching and regulation of fluid flow through rotation. When the ball mates with the valve seat, it can cut off the flow of fluid.

[0006] Valve stem: The valve stem is the component that connects the ball to the handle or transmission device, and is usually made of metal. By rotating or moving the valve stem up and down, the position of the ball can be controlled, thereby realizing the opening and closing and regulation of fluid.

[0007] Lifting rod: The lifting rod is a component used to control the up-and-down movement or rotation of the valve stem. It is connected to the valve stem and is raised, lowered, or rotated via a handle or transmission device.

[0008] Packing: The packing is located in the stuffing box between the valve stem and the valve body, and is used to provide a seal and prevent media leakage. Common packing materials include flexible graphite, polytetrafluoroethylene (PTFE), etc.

[0009] A lift-stem ball valve controls the position of the ball by rotating a handle or operating a transmission device, causing the valve stem to rise, fall, or rotate, thereby achieving fluid switching and regulation. When the valve stem rises, the ball separates from the valve seat, allowing fluid to pass through; when the valve stem falls, the ball contacts the valve seat, cutting off the fluid passage.

[0010] Lift rod ball valves are typically characterized by their simplicity, reliability, and excellent sealing performance, making them suitable for fluid control applications in various industrial sectors. They are widely used in industries such as petroleum, chemical, power, and water treatment.

[0011] Ordinary ball valves are switched on and off by simply rotating the valve stem 90° without any lifting action. This results in the ball and seat being in constant contact and friction. After prolonged use, the sealing surfaces of the ball and seat are prone to wear and leakage. Furthermore, ordinary ball valves primarily rely on the pressure of the pipeline medium for sealing. When the pressure of the medium in the pipeline is very low or absent, it is difficult for the valve to achieve zero leakage.

[0012] The biggest advantages of a lift-stem ball valve over a regular ball valve are lower wear during operation and stronger sealing. When opening, the stem first lifts, disengaging the ball from the seat. Then, the stem drives the ball to rotate 90° to the open position. When closing, the stem rotates the ball 90° without contacting the seat, and then the stem descends, pressing the ball firmly against the seat. Compared to a regular ball valve, the lift-stem ball valve converts the contact friction between the ball and seat during opening and closing into friction between the stem groove and the guide pin. The lift-stem ball valve achieves sealing not only through the pressure of the pipeline medium but also through a mechanical wedging force provided by the wedge-shaped surface at the bottom of the stem, forcing the ball to press against the seat.

[0013] Although the performance and functions of existing lifting rod ball valves have been greatly improved, for example, they can not only solve the problem of not being able to quickly replace valve seats during online valve inspection and maintenance, but also are suitable for working conditions requiring bidirectional tight closure or zero leakage. However, there are still some unresolved problems in existing bidirectional sealing lifting rod ball valves:

[0014] (1) The packing of the stuffing box of a lifter rod ball valve usually needs to be tightened to maintain a tight seal. If the tightening force is insufficient or the tightening method is incorrect, the up-and-down movement of the valve stem will cause the packing of the stuffing box to loosen. However, in applications where the valve stem moves too frequently, such as in systems that require frequent flow regulation, the valve stem may need to move up and down frequently to achieve flow regulation. For example, valves in process control systems or flow regulation equipment; in systems that require frequent process switching or media diversion, the valve stem may need to move frequently to switch processes or distribute media, including multi-way valve systems, multi-valve combination systems, etc. If the up-and-down movement frequency of the valve stem is too high, the packing of the stuffing box will not have enough time to stabilize and adapt to the movement of the valve stem, which can easily lead to loosening.

[0015] (2) When the valve stem of the lifting rod ball valve generates a mechanical wedging force downward to push the fulcrum below the ball towards the valve seat, due to the lever principle, the sealing surface of the upper half circle of the spherical sealing ring can be tightly sealed against the sealing surface of the valve seat. However, due to the relatively small wedging force, the sealing surface of the lower half circle of the spherical sealing ring is prone to gap with the sealing surface of the valve seat, causing valve leakage and hindering efficient sealing.

[0016] (3) When the medium pressure acts on the valve seat, it forces the valve seat to move slightly to one side, forming a tight contact with the ball. The contact stress generated by this contact can effectively seal the space on the other side of the valve seat, preventing the medium from leaking or seeping between the valve seat and the ball. As the medium pressure increases, the contact stress between the valve seat and the ball also increases, thereby improving the sealing effect. However, when the medium pressure is low, the pressure between the sealing surface of the ball and the valve seat also decreases, which is insufficient to completely seal the medium. A leakage path can easily be generated between the sealing surfaces of the ball and the valve seat, and the medium may escape from the leakage path. Summary of the Invention

[0017] To address the aforementioned technical problems, the present invention aims to provide a novel bidirectional sealing lifting rod ball valve that not only ensures high-strength sealing between the packing and the valve stem within the stuffing box, but also ensures high-strength sealing between the valve seat and the ball, effectively enhancing the overall sealing performance of the bidirectional sealing lifting rod ball valve.

[0018] The technical problem to be solved by this invention is achieved by the following technical solution:

[0019] A novel bidirectional sealing lifting stem ball valve includes a valve body, a ball, a valve stem, a valve seat, rollers, a valve cover, several sets of sealing packing, a packing gland, a guide pin, and an actuator, wherein:

[0020] The valve body and valve cover are connected by studs and nuts to form a pressure boundary, and a sealing gasket is provided between the valve body and valve cover.

[0021] The inner cavity of the valve cover includes, from top to bottom, a gland cavity, a packing cavity, and a guide cavity;

[0022] The ball is movably disposed in the valve cavity inside the valve body. The ball includes a ball body with a central channel and a spherical sealing ring fixed on the side surface of the ball and capable of contacting and sealing with the valve seat. The top of the ball is provided with a roller hole, and the bottom of the ball is provided with an outward protrusion that contacts the bushing provided at the bottom of the valve body.

[0023] The valve stem is movably and rotatably disposed within the inner cavity of the valve cover, and the valve stem passes through the top of the valve cover, the packing gland in the gland cavity, several sets of sealing packing in the packing cavity, the packing pad, and the guide cavity in sequence from top to bottom; the bottom of the valve stem is provided with a driving part and a wedge-shaped part, the driving part is movably connected to the roller embedded in the roller hole at the top of the ball, and the wedge-shaped part wedges the ball tightly during the downward pressing process and makes the spherical sealing ring of the ball press against the valve seat;

[0024] The valve seat is disposed in an annular mounting groove inside the valve body, and the valve seat and the valve body are provided with a coaxial medium flow channel at their center. The side of the valve seat facing the ball is the sealing surface, and the side of the valve seat facing away from the ball is the pressure-bearing surface.

[0025] The guide pin is provided on the valve cover, and the guide pin passes through the cylindrical hole provided on the top of the valve cover and is inserted into the track groove provided on the valve stem;

[0026] The actuator is connected to the upper end of the valve stem and is used to drive the valve stem to move up and down;

[0027] This invention makes a groundbreaking improvement on the existing bidirectional sealing lift rod ball valve, as follows:

[0028] The valve seat is provided with threaded holes evenly distributed along the inner circumference. The limiting screw is screwed into the valve seat through the thread. The top of the limiting screw is inserted into the annular mounting groove of the valve body. The outer diameter of the top of the limiting screw is smaller than the width of the annular mounting groove of the main valve body.

[0029] The lifting rod ball valve also includes a linkage pressurization assembly, which includes a pressure diaphragm, an upper pressure plate, a lower pressure plate, and connecting pipes.

[0030] The valve cover includes an upper cover body and a lower cover body, which are connected by locking bolts to form a pressure boundary;

[0031] The valve stem has an annular limiting groove in the middle. An upper pressure plate, a pressure diaphragm, and a lower pressure plate are sequentially sleeved on the outside of the annular limiting groove. Sealing rings are respectively provided between the upper pressure plate, the lower pressure plate, and the valve stem. The outer edge of the pressure diaphragm is pressed and sealed by the upper half cover and the lower half cover.

[0032] The pressure diaphragm divides the gland cavity and forms a pressure chamber below the pressure diaphragm; a pressure flow channel is provided on the lower half of the valve cover.

[0033] An annular flow channel is provided on the valve body outside the pressure-bearing surface of the valve seat. Multiple pressure flow channels 2 are provided on the circumference of the valve body between the annular flow channel and the pressure-bearing surface of the valve seat. The pressure chamber, pressure flow channel 1, connecting pipe, annular flow channel and pressure flow channel 2 are connected in sequence to form a pressure channel to apply a reverse force toward the spherical sealing ring to the valve seat.

[0034] A check valve one is connected to the lower half of the cover corresponding to the pressure chamber, and a check valve two is connected to the connecting pipe.

[0035] Furthermore, an eccentricity A is provided between the central axis of the drive part at the bottom of the valve stem and the central axis of the ball body, and the eccentricity A is biased away from the spherical sealing ring on the ball.

[0036] An eccentricity B is provided between the central axis of the outward protrusion at the bottom of the sphere and the central axis of the sphere body, and the eccentricity B is biased towards the side closer to the spherical sealing ring on the sphere.

[0037] The rollers include a lower left roller and an upper right roller. Both the lower left roller and the upper right roller are provided with a vertical cutting plane and an oblique cutting plane. The vertical cutting planes of the two rollers are parallel, and the oblique cutting planes of the two rollers are also parallel.

[0038] The wedge angle of the wedge-shaped part at the bottom of the valve stem is α. When the spherical sealing ring contacts the valve seat, the distance between the bottom edge of the inclined surface of the wedge-shaped part at the bottom of the valve stem and the top edge of the inclined plane of the upper right roller is C.

[0039] The eccentricity B is set to: 0 < B ≤ C * sin(α).

[0040] Furthermore, both ends of the connecting pipe are respectively connected to the pressure flow channel and the annular flow channel via external threaded joints.

[0041] Furthermore, the pressure diaphragm is made of any one of nitrile rubber, neoprene rubber, fluororubber, polyurethane, or polytetrafluoroethylene.

[0042] Furthermore, the second diameter of the pressure channel corresponding to the pressure-bearing surface of the upper semicircle of the spherical sealing ring is not less than the second diameter of the pressure channel corresponding to the pressure-bearing surface of the lower semicircle of the spherical sealing ring.

[0043] Furthermore, a lower support trunnion is provided on the convex part of the sphere, and the outer surface of the lower support trunnion is a spherical surface, and hard alloy is overlaid or sprayed on the spherical surface.

[0044] Furthermore, the plurality of sealing packings include two sets of braided graphite packings and two sets of V-shaped flexible graphite composite packings. The two sets of braided graphite packings are located above the packing pad and below the packing sleeve, respectively. Two sets of V-shaped flexible graphite composite packings are set in the middle of the two sets of braided graphite packings, and a spacer ring is set in the middle of the two sets of V-shaped flexible graphite composite packings. Each set of V-shaped flexible graphite composite packings is formed and stacked by a lower packing, multiple middle packings and an upper packing. The contact surfaces between the middle packings and the lower packings, and between the upper packings and the middle packings, are all V-shaped.

[0045] Furthermore, a lead screw is provided above the track groove at the top of the valve stem, and a shoulder is formed between the lead screw and the valve stem body. When the valve stem is fully opened, the shoulder contacts the lower plane of the top of the valve cover.

[0046] Furthermore, it also includes locating pins, of which there are two, symmetrically distributed on the pitch circle of the connecting studs of the valve body and the valve cover, with one end embedded in the valve body and the other end embedded in the valve cover.

[0047] Furthermore, the wedge-shaped surface of the valve stem wedge portion, the right plane and the left plane of the valve stem drive portion are all overlaid with or sprayed with hard alloy.

[0048] The beneficial effects of this invention are:

[0049] (1) This invention makes an original improvement on the existing bidirectional sealing lifting rod ball valve. A linkage pressurizing component is added to the ball valve as a whole. The actuator applies a downward force to the valve stem to ensure that the valve stem drives the ball to rotate and abut against the valve seat, thereby achieving valve body shut-off. The downward force applied by the actuator is applied to the linkage pressurizing component connected to the valve stem. A pressure chamber is formed at the bottom of the pressure diaphragm. The pressure diaphragm transmits the pressure through pressure flow channel one and connecting pipeline to the annular flow channel and pressure flow channel two on the side of the valve seat. Pressure flow channel two applies auxiliary pressure to the valve seat, which works together with the medium pressure in the valve body to the valve seat, causing it to move slightly to the left and contact the ball. This can simultaneously meet the high-quality sealing requirements of high medium pressure and low medium pressure.

[0050] (2) When the downward force applied by the actuator is applied to the linkage pressurizing component connected to the valve stem, the pressure in the pressure chamber at the bottom of the pressure diaphragm will simultaneously pressurize the packing in the packing chamber, making it tight. Even if the valve stem maintains a high frequency of up and down movement, when the packing in the stuffing box does not have enough time to stabilize and adapt to the movement of the valve stem, the pressure diaphragm will also apply pressure to the packing gland and the packing with each rise and fall of the valve stem, so as to prevent the packing from loosening due to not adapting to the movement of the valve stem.

[0051] (3) An eccentricity A is set between the central axis of the drive part at the bottom of the valve stem and the central axis of the ball body. The eccentric torque A will cause the ball to rotate, thereby changing the opening and closing state of the valve. The wedge angle of the wedge part at the bottom of the valve stem is α. When the spherical sealing ring contacts the valve seat, the distance between the bottom edge of the inclined surface of the wedge part at the bottom of the valve stem and the top edge of the inclined plane of the upper right roller is C. An eccentricity B is set between the central axis of the outer convex part at the bottom of the ball and the central axis of the ball body. The size of the eccentricity B is set as: 0<B≤C*sin(α). The eccentricity B is used to compensate for the uneven sealing degree between the upper and lower parts of the spherical sealing ring and the valve seat due to the "lever principle". It avoids the valve leakage caused by the relatively small wedge force on the sealing surface of the lower half circle of the spherical sealing ring easily generating a gap with the sealing surface of the valve seat.

[0052] (4) By designing the second diameter of the pressure channel corresponding to the pressure surface of the upper half circle of the spherical sealing ring to be no less than the second diameter of the pressure channel corresponding to the pressure surface of the lower half circle of the spherical sealing ring, it can be ensured that even without compensation for the eccentricity B, different pressure channel radii will produce different pressures. The lower half circle pressure channel applies higher pressure to the valve seat pressure surface, which can compensate for the insufficient pressure between the valve seat sealing surface and the lower half circle of the ball, and balance the sealing surface pressure of the upper and lower half circles of the valve seat and the upper and lower half circles of the ball.

[0053] (5) Each set of V-shaped flexible graphite composite packing is formed by stacking a lower packing, multiple middle packings, and an upper packing. The contact surfaces between the middle and lower packings, and between the upper and middle packings, are V-shaped. When the valve body is affected by factors such as changes in medium pressure or temperature, it will deform to a certain extent. If the packing cannot adapt to the deformation of the valve body, a gap will be generated between the packing and the valve body, resulting in medium leakage. The design of V-shaped flexible graphite packing can solve this problem. By stacking and combining the lower, middle, and upper packings, multiple contact surfaces are formed, allowing the packing to better adapt to the deformation of the valve body. When the valve body deforms, the packing can flexibly adjust along the V-shaped contact surfaces to ensure a tight fit between the packing and the valve body, thereby effectively preventing medium leakage. Attached Figure Description

[0054] Figure 1 This is a schematic cross-sectional view of the novel bidirectional sealing lifting rod ball valve in an embodiment of the present invention. Figure 1 ;

[0055] Figure 2 This is a schematic cross-sectional view of the novel bidirectional sealing lifting rod ball valve in an embodiment of the present invention. Figure 2 ;

[0056] Figure 3 This is a schematic diagram of the valve stem structure in an embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram illustrating the working principle of the linkage pressurization component in an embodiment of the present invention;

[0058] Figure 5 This is a schematic cross-sectional view of the sphere in an embodiment of the present invention;

[0059] Figure 6 This is a schematic diagram of the side structure of the sphere in an embodiment of the present invention;

[0060] Figure 7 This is a schematic diagram of the wedge-shaped portion of the valve stem in the wedge-shaped state of the roller oblique cutting plane in an embodiment of the present invention.

[0061] In the picture:

[0062] 1. Valve body; 2. Bushing; 3. Ball; 3a. Roller bore; 3b. Support pin bore; 3c. Spherical sealing ring; 3d. Lower support trunnion; 3e. Outer protrusion; 4. Valve stem; 4a. Track groove; 4b. Shoulder; 4c. Lead screw; 4d. Outer cylindrical surface; 4e. Wedge-shaped surface; 4f. Right bottom plane of valve stem; 4g. Left bottom plane of valve stem; 4h. Drive part; 4i. Wedge-shaped part; 5. Valve seat; 6. Support pin; 7. Roller; 7a. Vertical cutting plane; 7b. Oblique cutting plane; 8. Valve cover; 9. Sealing gasket; 10. Stud; 11. Nut; 12. Packing gasket; 13. Braided graphite packing; 14. V-type flexible graphite composite packing; 15. Spacer ring; 16. Packing sleeve ; 17. Packing gland; 18. Bolt; 19. Cover; 20. Guide pin; 21. Locating pin; 22. Valve seat O-ring; 23. Valve seat gasket; 24. Limit screw; 25. Upper cover body; 26. Upper pressure plate; 27. Lower pressure plate; 28. Pressure diaphragm; 29. ​​Locking bolt; 30. Lower cover body; 31. External threaded connector; 32. Connecting pipe; 33. Gland cavity; 34. Pressure cavity; 35. Packing cavity; 36. Guide cavity; 37. Pressure flow channel one; 38. Annular mounting groove; 39. Upper pressure flow channel two; 40. Annular flow channel; 41. Medium flow channel; 42. Central flow channel; 43. Lower pressure flow channel two; 44. Check valve one; 45. Check valve two. Detailed Implementation

[0063] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0065] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0067] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0068] refer to Figure 1 This invention provides a novel bidirectional sealing lifting rod ball valve, comprising a valve body 1, a ball 3, a valve stem 4, a valve seat 5, a roller 7, a valve cover 8, several sets of sealing packing, a packing gland 17, a guide pin 20, and an actuator, wherein:

[0069] The valve body 1 and valve cover 8 are connected by studs 10 and nuts 11, forming a pressure boundary. A sealing gasket 9 is provided between the valve body 1 and valve cover 8. The valve body 1 is the main body of the valve and is made of metal or alloy material. The valve body 1 serves to connect to the pipeline 32 and is used to control the flow and regulation of fluid. The valve body 1 includes inlet and outlet interfaces for connection to the piping system, as well as internal flow channels and the mounting position of the valve core (ball 3). The studs 10 and nuts 11 are used to fix the valve body 1 and valve cover 8 together, ensuring the overall structure of the valve is stable and can withstand fluid pressure and operating force. The studs 10 and nuts 11 are usually made of high-strength metal material to provide sufficient fastening force and tensile strength.

[0070] To ensure the valve's sealing performance, a sealing gasket 9 is provided between the valve body 1 and the valve cover 8. The sealing gasket 9 is typically made of an elastic material, such as rubber or polytetrafluoroethylene (PTFE), which has good sealing properties and corrosion resistance. When the stud 10 and nut 11 are tightened, the sealing gasket 9 is compressed, forming an effective seal to prevent fluid leakage.

[0071] The inner cavity of the valve cover 8, from top to bottom, includes a gland cavity 33, a packing cavity 35, and a guide cavity 36. The gland cavity 33, located at the top of the valve cover 8, serves as the chamber for the packing gland 17. The packing gland 17 is used to seal the space between the valve stem 4 and the packing to prevent packing loosening or leakage. The gland cavity 33 must maintain the pressure in the packing chamber and the pipeline to ensure good sealing performance.

[0072] The packing cavity 35, located below the gland cavity 33, is used to support the sealing packing. The packing cavity 35 is a space filled with sealing material, which is in close contact with the valve stem 4 to form a seal and prevent media leakage.

[0073] The guide cavity 36 is located at the bottom of the packing cavity 35 and is used to guide the bottom of the valve stem 4. The main function of the guide cavity 36 is to ensure the stability and accuracy of the valve stem 4 during operation and prevent it from deviating from its track.

[0074] The ball 3 is movably disposed in the valve cavity inside the valve body 1. The ball 3 includes a ball body 3 having a central flow channel 42 and a spherical sealing ring 3c fixed on the side surface of the ball 3 and capable of contacting and sealing with the valve seat 5. The top of the ball 3 is provided with a roller hole 3a. Two rollers 7 are embedded in the roller hole 3a at the top of the ball 3 and fixed by spot welding. The bottom of the ball 3 is provided with an outward protrusion 3e that contacts the bushing 2 provided at the bottom of the valve body 1.

[0075] The ball 3 body is a spherical component and a key part of the valve, namely the valve core. The ball 3 body has a central channel for controlling the flow of the medium. During valve operation, the ball 3 body rotates to change the opening and closing state of the fluid channel.

[0076] The spherical sealing ring 3c is fixed to the side surface of the ball 3 body and contacts the valve seat 5 for sealing. When the ball 3 rotates, the spherical sealing ring 3c and the valve seat 5 form a sealing contact to ensure the valve's sealing performance.

[0077] A roller bore 3a is located at the top of the ball 3. A roller 7 is installed within the roller bore 3a, and the roller 7 is movably connected to the valve stem 4. Through the cooperation of the roller 7 and the valve stem 4, the actuator can apply force or torque to the valve stem 4 to rotate the ball 3, thereby controlling the flow of fluid.

[0078] The ball 3 has an outward protrusion 3e at its bottom, which is the protruding part of the ball 3. The outward protrusion 3e contacts the bushing 2 located at the bottom of the valve body 1, providing support and guidance for the ball 3. The bushing 2 is a sleeve fixed to the bottom of the valve body 1, and its contact with the outward protrusion 3e ensures the stability and accuracy of the ball 3 during rotational operation.

[0079] The valve stem 4 is movable up and down and rotated in the inner cavity of the valve cover 8. The valve stem 4 passes through the top of the valve cover 8, the packing gland 17 in the gland cavity 33, several sets of sealing packing, packing pad 12 in the packing cavity 35, and the guide cavity 36 from top to bottom. The bottom of the valve stem 4 is provided with a driving part 4h and a wedge part 4i. The driving part 4h is movably connected to the roller 7 embedded in the roller hole 3a at the top of the ball 3. During the downward pressing process, the wedge part 4i wedges the ball 3 and makes the spherical sealing ring 3c of the ball 3 press against the valve seat 5.

[0080] Among them, such as Figure 3 As shown, the valve stem 4 is a key component connecting the valve actuator and the ball 3. It can move up and down and rotate to control the position of the ball 3 and the opening and closing state of the valve. The valve stem 4 passes through the entire inner cavity of the valve cover 8, and from top to bottom, it passes through the top of the valve cover 8, the packing gland 17 in the gland cavity 33, several sets of sealing packing, packing gasket 12 in the packing cavity 35, and the guide cavity 36.

[0081] The valve stem 4 passes through the gland chamber 33 from the top of the valve cover 8. The gland chamber 33 is a chamber for placing the packing gland 17, which is a component for compacting the packing and providing a seal.

[0082] Furthermore, the valve stem 4 passes through the packing cavity 35, which is used to accommodate several sets of sealing packing. The sealing packing is typically annular and placed in the packing cavity 35 to provide a seal between the valve stem 4 and the valve cover 8. The packing is typically made of wear-resistant and corrosion-resistant materials, such as polytetrafluoroethylene (PTFE).

[0083] The packing gasket 12 is a gasket placed above the packing in the packing cavity 35. It can be used to provide additional sealing and support, ensuring the tightness and stability of the packing.

[0084] The valve stem 4 continues through the packing gasket 12 and enters the guide cavity 36. The guide cavity 36 is located at the bottom of the valve stem 4 and is used to guide the bottom of the valve stem 4. The guide cavity 36 is formed inside the bottom guide sleeve of the valve cover 8, and the interior of the guide cavity 36 contacts the bottom of the valve stem 4 to provide guiding support.

[0085] The bottom of the valve stem 4 is provided with a drive part 4h and a wedge-shaped part 4i. The drive part 4h is movably connected to the roller 7 embedded in the roller hole 3a at the top of the ball 3 to transmit the force or torque applied by the operating mechanism to the ball 3, thereby controlling the movement of the valve. The wedge-shaped part 4i contacts the ball 3 during the downward pressing process, and fixes the ball 3 to the valve seat 5 by applying force, so that the spherical sealing ring 3c of the ball 3 is tightly sealed to the valve seat 5.

[0086] The valve seat 5 is a component installed in the annular mounting groove 38 inside the valve body 1. It is located in the axial inner hole on the right side of the valve body 1 and is fixed to the annular mounting groove 38 of the valve body 1 by a limiting screw 24. The valve seat 5 and the valve body 1 have a coaxial medium flow channel 41 at their center for controlling the flow of fluid. One side of the valve seat 5 facing the ball 3 is the sealing surface, which contacts the spherical sealing ring 3c of the ball 3 to achieve a seal between the ball 3 and the valve seat 5. The other side of the valve seat 5 facing away from the ball 3 is the pressure-bearing surface, which bears the pressure of the medium.

[0087] The valve seat O-ring 22 is located between the outer cylindrical surface 4d of the valve seat 5 and the inner cavity of the main valve body 1, thereby achieving the first radial seal between the valve seat 5 and the valve body 1.

[0088] The valve seat sealing gasket 23 is located between the stepped plane of the valve seat 5 and the inner cavity plane of the main valve body 1, to achieve a second radial seal between the valve seat 5 and the valve body 1.

[0089] Two guide pins 20 are located on the valve cover 8, passing through the cylindrical hole above the valve cover 8 and inserted into the track groove 4a on the valve stem 4. They are symmetrically arranged and secured with a cover 19 and bolts 18 to prevent axial movement. The guide pins 20 guide the movement of the valve stem 4, ensuring its stability and accuracy. By engaging with the track groove 4a of the valve stem 4, they control the up-and-down movement of the valve stem 4, preventing it from deviating from its track.

[0090] Support pins 6 are embedded in the support pin hole 3b at the top of the ball 3 and fixed by spot welding. There are two of them, which restrict the valve stem 4 from moving back and forth and prevent the valve from jamming during opening and closing.

[0091] The actuator is connected to the upper end of the valve stem 4 and is used to drive the valve stem 4 to move up and down. The actuator can be a manually operated handle, an electric drive, or other automated device. By applying force or torque through the actuator, the valve stem 4 can move up and down, thereby changing the position of the ball 3 and the opening and closing state of the valve. The actuator makes valve operation more convenient and controllable.

[0092] The above content basically introduces the structure and principle of the lifting rod ball valve in this invention and existing lifting rod ball valves.

[0093] However, existing lift rod ball valves still have many problems that need to be solved:

[0094] Firstly, because the packing of a lift rod ball valve typically needs to be tightened to maintain a tight seal, insufficient tightening force or incorrect tightening method can cause the packing to loosen due to the up-and-down movement of the valve stem 4. However, in applications where the valve stem 4 moves too frequently, such as in systems requiring frequent flow regulation, the valve stem 4 may need to move up and down frequently to achieve flow regulation. Examples include valves in process control systems or flow regulation equipment. In systems requiring frequent process switching or media diversion, the valve stem 4 may need to move frequently to switch processes or distribute media, including multi-way valve systems and multi-valve combination systems. If the up-and-down movement frequency of the valve stem 4 is too high, the packing of the stuffing box will not have enough time to stabilize and adapt to the movement of the valve stem 4, easily leading to loosening.

[0095] Secondly, when the valve stem 4 of the lifting rod ball valve generates a mechanical wedging force downward to push the fulcrum below the ball 3 towards the valve seat 5, due to the lever principle, the sealing surface of the upper semicircle of the spherical sealing ring 3c can tightly seal against the sealing surface of the valve seat 5. However, due to the relatively small wedging force, the sealing surface of the lower semicircle of the spherical sealing ring 3c is prone to gaps with the sealing surface of the valve seat 5, causing valve leakage and hindering efficient sealing.

[0096] To address this issue, Shanghai Neles Jamesbury Valve Co., Ltd. applied for and published an invention patent entitled "A Lifting Rod Ball Valve" on March 11, 2011, with publication number "CN102734484A" on October 17, 2012. This patent involves cutting an elastic compensation groove on the upper and lower outer surfaces of the spherical sealing ring 3c of the ball 3, perpendicular to the axis of the sealing ring. These two elastic compensation grooves allow the uneven wedging force on the sealing surface of the spherical sealing ring 3c to be evenly distributed on the sealing surface of the valve seat 5 through adaptive elastic deformation, thereby enabling the valve to seal efficiently.

[0097] However, this design has some potential drawbacks and limitations: First, the design complexity of the elastic compensation groove: cutting the elastic compensation groove on the spherical sealing ring 3c of the sphere 3 requires precise machining and manufacturing, which increases manufacturing costs and process requirements. Furthermore, ensuring the reliability and long-term performance of the elastic compensation groove may require further engineering verification and testing.

[0098] Secondly, there is a potential risk of leakage: Although the elastic compensation groove can evenly distribute the wedge force through adaptive elastic deformation, there is a potential risk of leakage. The elastic compensation groove may lose its elasticity under prolonged use or high-pressure conditions, leading to a decrease in sealing performance or leakage.

[0099] Third, maintenance and replacement are difficult: Due to the design of the elastic compensation groove, maintaining and replacing the spherical sealing ring 3c of the sphere 3 may be more complex and time-consuming. If the spherical sealing ring 3c needs to be replaced, it may be necessary to disassemble and re-machine the sphere 3, increasing the difficulty of repair and maintenance.

[0100] Finally, when the medium pressure acts on the valve seat 5, it forces the valve seat 5 to move slightly to one side, forming a tight contact with the ball 3. The contact stress generated by this contact effectively seals the space on the other side of the valve seat 5, preventing the medium from leaking or seeping between the valve seat 5 and the ball 3. As the medium pressure increases, the contact stress between the valve seat 5 and the ball 3 also increases, thereby improving the sealing effect. However, when the medium pressure is low, the pressure between the sealing surfaces of the ball 3 and the valve seat 5 also decreases, which is insufficient to completely seal the medium. Leakage paths can easily form between the sealing surfaces of the ball 3 and the valve seat 5, and the medium may escape through these leakage paths.

[0101] This invention provides a novel bidirectional sealing lifting rod ball valve, which addresses the defects and limitations of existing lifting rod ball valves by making pioneering improvements, as detailed below:

[0102] Screw holes are evenly provided along the inner circumference of the valve seat 5. Limiting screws 24 are screwed into the valve seat 5 through threads and inserted into the annular mounting groove 38 of the main valve body 1 at the top. There are at least four of them. The outer diameter of the top of the limiting screw 24 is slightly smaller than the width of the annular mounting groove 38 of the valve body 1, so the valve seat 5 can move slightly left and right.

[0103] The lifting rod ball valve also includes a linkage pressurization assembly, which includes a pressure diaphragm 28, an upper pressure plate 26, a lower pressure plate 27, and connecting pipelines.

[0104] Specifically, the original one-piece molded valve cover 8 is designed to include an upper cover body 25 and a lower cover body 30. The upper cover body 25 and the lower cover body 30 are connected by locking bolts 29 to form a pressure boundary.

[0105] like Figures 1-3 As shown, an annular limiting groove is provided in the middle of the valve stem 4, and an upper pressure plate 26, a pressure diaphragm 28, and a lower pressure plate 27 are sequentially sleeved outside the annular limiting groove. Sealing rings are provided between the upper pressure plate 26, the lower pressure plate 27, and the valve stem 4. The pressure diaphragm 28 divides the pressure cover cavity 33, forming a pressure cavity 34. A pressure flow channel 37 is provided on the lower half of the valve cover 8, 30.

[0106] like Figure 1 and Figure 2 As shown, a check valve 44 is connected to the lower half cover 30 corresponding to the pressure chamber 34, and a check valve 45 is connected to the connecting pipe 32 of the connecting pipeline. The check valve 44 is used to ensure that the external atmospheric pressure can only enter the pressure chamber and not exit. When the valve stem 4 is lifted upward, the pressure diaphragm 28 rises upward, and the pressure chamber 34 forms a negative pressure, which draws in the external atmospheric pressure. The check valve 45 is used to ensure that the pressure inside the pressure chamber 34 can only exit and not enter. The check valve 45 can prevent the medium pressure inside the medium flow channel 41 of the valve body 1 from entering the pressure chamber 34.

[0107] In addition, such as Figure 1 and Figure 4 As shown, an annular flow channel 40 is provided on the valve body 1 outside the pressure-bearing surface of the valve seat 5. Multiple pressure flow channels 2 are provided on the circumference of the valve body 1 between the annular flow channel 40 and the pressure-bearing surface of the valve seat 5. The pressure chamber 34, pressure flow channel 1 37, connecting pipe, annular flow channel 40 and pressure flow channel 2 are connected in sequence to form a pressure channel, which applies a reverse force to the valve seat 5 toward the spherical sealing ring 3c.

[0108] The purpose of this design is to increase the sealing force between the valve seat 5 and the spherical sealing ring 3c by applying a reverse force to the pressure-bearing surface of the valve seat 5 through a pressure channel. Specifically, this is achieved by dividing the gland cavity 33 into a pressure chamber 34 using a pressure diaphragm 28, and forming a pressure channel using a pressure flow channel two and an annular flow channel 40, allowing pressure to be transmitted to the pressure-bearing surface of the valve seat 5. In this way, the reverse force applied to the valve seat 5 by the pressure channel helps improve sealing performance and ensures effective sealing of the valve in the closed state.

[0109] The advantage of this design lies in the fact that by utilizing the driving force of the valve stem 4 driven by the actuator, the downward driving force of the valve stem 4 not only drives the roller 7 and causes the ball 3 to rotate and seal with the valve seat 5, but also compresses the pressure chamber 34 formed by the pressure diaphragm 28 through the gland chamber 33. This causes the pressure of the gas medium or the gas-liquid mixture in the pressure chamber 34 to exceed the normal pressure. This additional auxiliary medium pressure is transmitted to the pressure-bearing surface of the valve seat 5 through the linkage pressurization component, and combines with the medium pressure originally present in the valve body 1. The pressure diaphragm 28 transmits the pressure through the pressure flow channel 1 37 and the connecting pipeline to the annular flow channel 40 and pressure flow channel 2 on one side of the valve seat 5. Pressure flow channel 2 applies auxiliary pressure to the valve seat 5, which, together with the medium pressure in the valve body 1, acts on the valve seat 5, causing it to move slightly to the left and contact the ball 3. This can simultaneously meet the high-quality sealing requirements of both high and low medium pressures.

[0110] Furthermore, the linkage pressurization component also produces a synergistic effect. During the descent of the valve stem 4, the valve stem 4 will drive the pressure diaphragm 28 to press downward. The original gland cavity 33 is basically in a pressureless state, i.e., at normal atmospheric pressure. After the pressure diaphragm 28 divides the original gland cavity 33 into a pressure cavity 34, the pressure in the pressure cavity 34 at the bottom of the pressure diaphragm 28 will simultaneously pressurize the packing in the packing cavity 35, making it tight. Even if the valve stem 4 maintains a high up-and-down movement frequency, and the packing of the stuffing box itself does not have enough time to stabilize and adapt to the movement of the valve stem 4, the pressure diaphragm 28 will also apply pressure to the packing gland 17 and the packing with each rise and fall of the valve stem 4. This can effectively prevent the packing itself from loosening due to not adapting to the movement of the valve stem 4 in the long term.

[0111] In another embodiment of the present invention, the right plane 4f and the left plane 4g at the bottom of the valve stem are always in contact with the vertical tangent plane 7a of the roller 7, driving the valve stem 4 to rotate 90°. There is an eccentricity between the center of the right plane 4f and the left plane 4g at the bottom of the valve stem and the center of the valve stem 4. That is, there is an eccentricity A between the central axis of the driving part 4h at the bottom of the valve stem 4 and the central axis of the ball 3 body, and the eccentricity A is biased away from the spherical sealing ring 3c on the ball 3. When the valve stem 4 descends, the torque of the driving part 4h of the valve stem 4 and the eccentricity A between them generate an eccentric torque; this eccentric torque causes the ball 3 to rotate, thereby changing the opening and closing state of the valve.

[0112] like Figure 5 and Figure 6As shown, the applicant has made improvements to the existing ball body 3 of the lifting rod ball valve by setting an eccentricity B between the central axis of the outer protrusion 3e at the bottom of the ball body 3 and the central axis of the ball body 3, and the eccentricity B is biased towards the side closer to the spherical sealing ring 3c on the ball body 3; the eccentricity B is set by shifting the outer protrusion 3e to the right side of the ball body 3.

[0113] The roller 7 includes a lower left roller 7 and an upper right roller 7. Both the lower left roller 7 and the upper right roller 7 are provided with a vertical cutting plane 7a and an oblique cutting plane 7b. The vertical cutting planes 7a of the two rollers 7 are parallel, and the oblique cutting planes 7b of the two rollers 7 are also parallel.

[0114] like Figure 7 As shown, the wedge angle of the bottom wedge portion 4i of the valve stem 4 is α. When the spherical sealing ring 3c contacts the valve seat 5, the distance between the bottom edge of the inclined surface of the bottom wedge portion 4i of the valve stem 4 and the top edge of the oblique cutting plane 7b of the upper right roller 7 is C.

[0115] The eccentricity B is set to: 0 < B ≤ C*sin(α).

[0116] The eccentricity B is designed to compensate for the uneven sealing between the upper and lower parts of the spherical sealing ring 3c and the valve seat 5 caused by the lever principle. The lever principle refers to the fact that under the action of force, the part farther from the fulcrum will generate a larger torque. In the valve, the drive part 4h is movably connected to the roller 7 embedded in the roller hole 3a at the top of the ball 3. When the drive part 4h is pressed down, the wedge part 4i will apply downward force, causing the spherical sealing ring 3c of the ball 3 to press against the valve seat 5.

[0117] However, due to the lever principle, the wedging force on the sealing surface of the lower half of the spherical sealing ring 3c is relatively small, which may create a gap between it and the sealing surface of the valve seat 5, leading to valve leakage.

[0118] To address this issue, an eccentricity B is introduced. Eccentricity B is the rightward offset distance between the central axis of the outwardly protruding portion 3e at the bottom of the sphere 3 and the central axis of the sphere 3 body. Adjusting its value can balance the unevenness of the sealing between the upper and lower parts. By increasing or decreasing the eccentricity B, the position of the outwardly protruding portion 3e at the bottom of the sphere 3 can be changed, i.e., the position of the farthest fulcrum in the "lever principle" can be altered. Within the range of 0 < B ≤ C*sin(α), a larger eccentricity B results in a stronger ability to balance the sealing force. This allows the sealing surface of the lower semicircle of the spherical sealing ring 3c to make more uniform contact with the sealing surface of the valve seat 5, reducing gaps, improving sealing performance, and thus preventing valve leakage.

[0119] like Figure 7As shown, the size of the eccentricity B is determined by the distance C between the bottom edge of the wedge surface 4e of the wedge portion 4i at the bottom of the valve stem 4 and the top edge of the oblique cutting plane 7b of the upper right roller 7. When the wedge angle α of the wedge portion 4i is constant, the larger the distance C, i.e., C+n, the larger the eccentricity B that needs to be compensated.

[0120] Unlike the invention patent entitled "A Lifting Rod Ball Valve" with publication number "CN102734484A", this invention improves the bottom protrusion 3e of the ball 3 and adds compensation to the lower half circle of the spherical sealing ring 3c. However, the protrusion 3e of the ball 3 does not have an elastic compensation groove, which may lose elasticity under long-term use or high pressure conditions, leading to a decrease in sealing performance or leakage.

[0121] As another embodiment of the present invention, such as Figure 1 and Figure 2 As shown, both ends of the connecting pipe can be sealed with the pressure flow channel 37 and the annular flow channel 40 via external threaded connectors 31. This connection method ensures the strength and sealing of the connection, preventing media leakage or external impurities from entering the system.

[0122] The external threaded connector 31 allows one end of the connecting pipe to be threaded into the pressure channel 37, while the other end can be threaded into the annular channel 40. The threaded connection provides reliable tightening and sealing, ensuring a tight and leak-free connection between the pipe and the channel.

[0123] The advantages of this connection method are its simplicity, reliability, and ease of installation and disassembly. The design of the external threaded connector 31 ensures a secure connection, capable of withstanding certain pressure and torque while maintaining a sealing performance.

[0124] In another embodiment of the present invention, the pressure diaphragm 28 is made of any one of nitrile rubber, neoprene rubber, fluororubber, polyurethane, and polytetrafluoroethylene. The pressure diaphragm 28 is made of a flexible material to achieve better adaptability and sealing performance.

[0125] The flexible pressure diaphragm 28 uses an elastic material, such as rubber or an elastic polymer in this embodiment, to ensure good elasticity and deformability. This flexible diaphragm can quickly return to its initial state when subjected to pressure or force, thereby maintaining a tight seal. The flexible pressure diaphragm 28 has the following advantages:

[0126] Highly adaptable: The flexible material diaphragm can adapt to different pressure and force changes, ensuring that the sealing performance is not affected.

[0127] Good sealing performance: Because the flexible diaphragm can make close contact with the valve seat 5 or other sealing components, it can effectively prevent media leakage.

[0128] Good fatigue resistance: Flexible materials can withstand multiple bending and deformation, and have high durability and lifespan.

[0129] As another embodiment of the present invention, such as Figure 2 As shown, the diameter of the pressure channel 2 corresponding to the pressure-bearing surface of the upper semicircle of the spherical sealing ring 3c, i.e., the diameter of the upper pressure channel 2 39, is not less than the diameter of the pressure channel 2 corresponding to the pressure-bearing surface of the lower semicircle of the spherical sealing ring 3c, i.e., the diameter of the lower pressure channel 2 43. This design ensures that even without compensation for the eccentricity B, different pressure channel radii will produce different pressures. The lower semicircle pressure channel, i.e., the lower pressure channel 2 43, applies higher pressure to the pressure-bearing surface of the valve seat 5, which can compensate for the insufficient pressure between the sealing surface of the valve seat 5 and the contact surface of the lower hemisphere 3 of the ball 3, and balance the sealing surface pressure of the upper and lower semicircles of the valve seat 5 and the upper and lower semicircles of the ball 3.

[0130] In another embodiment of the present invention, a lower support trunnion 3d is provided on the outer protrusion 3e of the sphere 3, and the outer surface of the lower support trunnion 3d is a spherical surface, which is overlaid or sprayed with hard alloy, effectively improving the wear resistance of the outer surface of the lower support trunnion and extending the service life of the valve. In another embodiment of the present invention, the wedge-shaped surface 4e of the wedge-shaped portion 4i of the valve stem 4, and the right and left planes of the driving portion 4h of the valve stem 4 are all overlaid or sprayed with hard alloy, which also effectively improves the wear resistance of the valve. Furthermore, the outer cylindrical surface 4d in contact with the valve cover 8 is overlaid or sprayed with hard alloy to prevent scratches or wear during valve opening and closing.

[0131] As another embodiment of the present invention, such as Figure 1As shown, several sets of sealing packings include two sets of braided graphite packing 13 and two sets of V-shaped flexible graphite composite packing 14. The two sets of braided graphite packing 13 are located above the packing pad 12 and below the packing sleeve 16, respectively. Two sets of V-shaped flexible graphite composite packing 14 are placed in the middle of the two sets of braided graphite packing 13, and a spacer ring 15 is placed between the two sets of V-shaped flexible graphite composite packing 14. Each set of V-shaped flexible graphite composite packing 14 is formed by stacking a lower packing, multiple middle packings, and an upper packing. The contact surfaces between the middle packing and the lower packing, and between the upper packing and the middle packing, are all V-shaped. When the valve body 1 is affected by factors such as changes in medium pressure or temperature, it will deform to a certain extent. If the packing cannot adapt to the deformation of the valve body 1, a gap will be generated between the packing and the valve body 1, resulting in medium leakage. The design of the V-shaped flexible graphite packing can solve this problem. By stacking and combining the lower, middle, and upper packings, multiple contact surfaces are formed, allowing the packing to better adapt to the deformation of the valve body 1. When the valve body 1 deforms, the packing can be flexibly adjusted along the V-shaped contact surface to ensure a tight fit between the packing and the valve body 1, thereby effectively preventing media leakage.

[0132] As another embodiment of the present invention, such as Figure 3 As shown, a lead screw 4c is provided above the track groove 4a at the top of the valve stem 4. A shoulder 4b is formed between the lead screw 4c and the main body of the valve stem 4. When the valve stem 4 is fully opened, the shoulder 4b contacts the lower plane of the top of the valve cover 8, realizing the anti-fly-out function of the valve stem 4. The valve stem 4 will not fly out under the action of the medium, ensuring the safety of equipment and personnel.

[0133] As another embodiment of the present invention, such as Figure 1 As shown, the ball valve also includes two locating pins 21, symmetrically distributed on the pitch circle of the connecting stud 10 between the valve body 1 and the valve cover 8. One end of each pin is embedded in the valve body 1, and the other end is embedded in the valve cover 8. This ensures the coaxiality of the valve body 1 and the valve cover 8 after assembly and prevents jamming during valve opening and closing.

[0134] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with the described embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0135] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of this invention, "a plurality of" means at least two, such as two or three, unless otherwise explicitly specified.

[0136] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which is defined by the claims and their equivalents.

Claims

1. A novel bidirectional sealing lifting rod ball valve, comprising a valve body (1), a ball (3), a valve stem (4), a valve seat (5), a roller (7), a valve cover (8), several sets of sealing packing, a packing gland (17), a guide pin (20), and an actuator, wherein: The valve body (1) and the valve cover (8) are connected by studs (10) and nuts (11) to form a pressure boundary, and a sealing gasket (9) is provided between the valve body (1) and the valve cover (8). The inner cavity of the valve cover (8) includes, from top to bottom, a gland cavity (33), a packing cavity (35), and a guide cavity (36). The ball (3) is movably disposed in the valve cavity inside the valve body (1). The ball (3) includes a ball body (3) with a central channel and a spherical sealing ring (3c) fixed on the side surface of the ball (3) and capable of contacting and sealing with the valve seat (5). The top of the ball (3) is provided with a roller hole (3a), and the bottom of the ball (3) is provided with an outward protrusion (3e) that contacts the bushing (2) provided at the bottom of the valve body (1). The valve stem (4) is disposed in the inner cavity of the valve cover (8) in a way that allows it to move up and down and rotate. The valve stem (4) passes through the top of the valve cover (8), the packing gland (17) in the gland cavity (33), several sets of sealing packing, packing pad (12) in the packing cavity (35), and the guide cavity (36) from top to bottom. The bottom of the valve stem (4) is provided with a driving part (4h) and a wedge part (4i). The driving part (4h) is movably connected to the roller (7) embedded in the roller hole (3a) at the top of the ball (3). During the downward pressing process, the wedge part (4i) wedges the ball (3) and makes the spherical sealing ring (3c) of the ball (3) press against the valve seat (5). The valve seat (5) is located in the annular mounting groove (38) inside the valve body (1), and the valve seat (5) and the valve body (1) are provided with a coaxial medium flow channel (41). The side of the valve seat (5) facing the ball (3) is the sealing surface, and the side of the valve seat (5) facing away from the ball (3) is the pressure-bearing surface. The guide pin (20) is provided on the valve cover (8). The guide pin (20) passes through the cylindrical hole provided on the top of the valve cover (8) and is inserted into the track groove (4a) provided on the valve stem (4). The actuator is connected to the upper end of the valve stem (4) and is used to drive the valve stem (4) to move up and down; Its features are, The valve seat (5) is provided with screw holes evenly along the inner circumference direction. The limiting screw (24) is screwed into the valve seat (5) through the thread. The top of the limiting screw (24) is inserted into the annular mounting groove (38) of the valve body (1). The outer circle dimension of the top of the limiting screw (24) is smaller than the width of the annular mounting groove (38) of the main valve body (1). The lifting rod ball valve also includes a linkage pressurization assembly, which includes a pressure diaphragm (28), an upper pressure plate (26), a lower pressure plate (27), and connecting pipes; The valve cover (8) includes an upper cover (25) and a lower cover (30), which are connected by locking bolts (29) to form a pressure boundary; The valve stem (4) has an annular limiting groove in the middle. An upper pressure plate (26), a pressure diaphragm (28) and a lower pressure plate (27) are sequentially sleeved on the outside of the annular limiting groove. Sealing rings are respectively provided between the upper pressure plate (26) and the lower pressure plate (27) and the valve stem (4). The outer edge of the pressure diaphragm (28) is pressed and sealed by the upper half cover (25) and the lower half cover (30). The pressure diaphragm (28) divides the pressure cover cavity (33) and forms a pressure cavity (34) below the pressure diaphragm (28). A pressure flow channel (37) is provided on the lower half of the valve cover (8) cover (30). On the valve body (1) outside the pressure-bearing surface of the valve seat (5), an annular flow channel (40) is provided. Multiple pressure flow channels are provided on the circumferential direction of the valve body (1) between the annular flow channel (40) and the pressure-bearing surface of the valve seat (5). The pressure chamber (34), pressure flow channel one (37), connecting pipe, annular flow channel (40) and pressure flow channel two are connected in sequence to form a pressure channel to apply a reverse force to the valve seat (5) toward the spherical sealing ring (3c). Check valve one (44) is connected to the lower half cover (30) corresponding to the pressure chamber (34), and check valve two (45) is connected to the connecting pipe.

2. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, An eccentricity A is provided between the central axis of the drive part (4h) at the bottom of the valve stem (4) and the central axis of the body of the ball (3), and the eccentricity A is biased away from the spherical sealing ring (3c) on the ball (3); An eccentricity B is provided between the central axis of the outward protrusion (3e) at the bottom of the sphere (3) and the central axis of the body of the sphere (3), and the eccentricity B is biased towards the side closer to the spherical sealing ring (3c) on the sphere (3); The roller (7) includes a lower left roller (7) and an upper right roller (7). Both the lower left roller (7) and the upper right roller (7) are provided with a vertical cutting plane (7a) and a slanted cutting plane (7b). The vertical cutting plane (7a) of the two rollers (7) is parallel, and the slanted cutting plane (7b) of the two rollers (7) is also parallel. The wedge angle of the bottom wedge portion (4i) of the valve stem (4) is α. When the spherical sealing ring (3c) contacts the valve seat (5), the distance between the bottom edge of the inclined surface of the bottom wedge portion (4i) of the valve stem (4) and the top edge of the oblique cutting plane (7b) of the upper right roller (7) is C. The eccentricity B is set to: 0 < B ≤ C sin(α).

3. The novel bidirectional sealing lifting rod ball valve according to any one of claims 1, characterized in that, The two ends of the connecting pipe are respectively sealed and screwed to the pressure flow channel (37) and the annular flow channel (40) by external threaded joints (31).

4. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, The pressure diaphragm (28) is made of any one of nitrile rubber, chloroprene rubber, fluororubber, polyurethane, or polytetrafluoroethylene.

5. The novel bidirectional sealing lifting rod ball valve according to any one of claims 1 to 4, characterized in that, The diameter of the pressure channel corresponding to the pressure-bearing surface of the upper semicircle of the spherical sealing ring (3c) is not less than the diameter of the pressure channel corresponding to the pressure-bearing surface of the lower semicircle of the spherical sealing ring (3c).

6. The novel bidirectional sealing lifting rod ball valve according to any one of claims 1 to 4, characterized in that, The sphere (3) has a lower support trunnion (3d) on its outer convex part (3e), and the outer side of the lower support trunnion (3d) is a spherical surface, and hard alloy is overlaid or sprayed on the spherical surface.

7. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, The plurality of sealing packings include two sets of braided graphite packing (13) and two sets of V-shaped flexible graphite composite packing (14). The two sets of braided graphite packing (13) are located above the packing pad (12) and below the packing sleeve (16), respectively. Two sets of V-shaped flexible graphite composite packing (14) are set in the middle of the two sets of braided graphite packing (13), and a spacer ring (15) is set in the middle of the two sets of V-shaped flexible graphite composite packing (14). Each set of V-shaped flexible graphite composite packing (14) is formed and stacked by a lower packing, multiple middle packings and an upper packing. The contact surfaces between the middle packing and the lower packing, and between the upper packing and the middle packing, are all V-shaped.

8. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, A lead screw (4c) is provided above the track groove (4a) at the top of the valve stem (4). A shoulder (4b) is formed between the lead screw (4c) and the main body of the valve stem (4). When the valve stem (4) is fully opened, the shoulder (4b) contacts the lower plane of the top of the valve cover (8).

9. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, It also includes positioning pins (21), there are two positioning pins (21), which are symmetrically distributed on the pitch circle of the connecting stud (10) of the valve body (1) and the valve cover (8), with one end embedded in the valve body (1) and the other end embedded in the valve cover (8).

10. The novel bidirectional sealing lifting rod ball valve according to claim 1, characterized in that, The wedge-shaped surface (4e) of the wedge-shaped part (4i) of the valve stem (4), and the right and left planes of the driving part (4h) of the valve stem (4) are all overlaid or sprayed with hard alloy.

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