A valve stem self-lubricating gate valve

Abstract

The application discloses a valve rod self-lubricating gate valve, which comprises a valve body, a valve seat, a gate plate and a valve rod, the gate plate is slidably installed in the middle cavity of the valve body, the valve seat is provided with two sides corresponding to the gate plate and is fixedly installed on the valve body, one side of the valve seat is matched and sealed with the gate plate, a valve cover is fixedly installed on the valve body, a threaded sleeve is integrally formed on the gate plate, the threaded sleeve and the gate plate are provided with a first threaded hole, a second threaded hole is further arranged on the threaded sleeve, the diameter of the second threaded hole is larger than that of the first threaded hole, the second threaded hole is located at the upper end of the first threaded hole, one end of the valve rod is threadedly connected with the first threaded hole, and the other end is rotationally connected with the valve cover, the application realizes automatic lubrication in the opening and closing process of the gate valve, the lubrication is uniform and sufficient, the friction resistance and wear of the thread are effectively reduced, frequent maintenance is not needed, the sealing performance and service life are significantly improved, and the application is suitable for various fluid pipeline opening and closing scenes.

Description

Technical Field

[0001] This invention discloses a self-lubricating gate valve with a valve stem, belonging to the field of valve technology. Background Technology

[0002] Gate valves are commonly used opening and closing control components in pipeline fluid transportation systems. They rely on the valve stem to drive the gate to rise and fall to achieve pipeline opening and closing. They are widely used in pipeline systems of industries such as water supply and drainage, chemical, petroleum, and power. Existing gate valves use the valve stem and threaded sleeve as the core transmission and cooperation structure. However, during the long-term opening and closing of the gate valve, the threaded mating surfaces of the valve stem and the threaded sleeve rotate frequently relative to each other, which easily causes friction and wear. At the same time, as a common type of gate valve, the height of the valve stem remains unchanged during the opening process of the gate valve, only rotating, while the gate moves up and down. In addition, in order to reduce the size of the gate valve, part of the valve stem is exposed to the medium, which makes the valve stem prone to rust or corrosion. Especially in fluid environments containing impurities, this can more easily affect the opening and closing of the gate valve, and even cause jamming. Therefore, a new gate valve structure needs to be designed to solve these problems. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in the prior art and provide a valve stem self-lubricating gate valve.

[0004] This invention achieves the above-mentioned objective through the following technical solution: a self-lubricating gate valve with a valve stem, comprising a valve body, valve seats, a gate, and a valve stem. The gate is slidably installed in the middle cavity of the valve body. Two valve seats are provided and fixedly installed on both sides of the valve body corresponding to the gate, with one side of the valve seat sealingly engaging with the gate. A valve cover is fixedly installed on the valve body. A threaded sleeve is integrally formed on the gate. The threaded sleeve and the gate have a first threaded hole, and the threaded sleeve also has a second threaded hole. The diameter of the second threaded hole is larger than the diameter of the first threaded hole, and the second threaded hole is located at the upper end of the first threaded hole. One end of the valve stem is threadedly connected to the first threaded hole, and the other end is rotatably connected to the valve cover. A handwheel is installed on the valve stem, and a gap is formed between the valve stem and the bottom of the first threaded hole. The valve stem has an oil storage space for holding lubricating oil. The volume of the oil storage space gradually decreases as the gate valve is opened upwards. The valve stem has a through hole, which includes an oil passage hole and a mounting hole. The diameter of the oil passage hole is smaller than the diameter of the mounting hole, and the oil passage hole is located below the mounting hole. The valve stem also has an oil outlet hole communicating with the mounting hole. A blocking member for elastically sealing the oil passage hole is slidably disposed in the mounting hole. The valve stem also has a driving member, which is used to drive the blocking member upwards to release the sealing of the oil passage hole before the valve stem drives the gate valve to descend and completely close the gate valve. The lower end of the valve stem also has a dispersing member, which is used to make the lubricating oil falling from the oil passage hole splash and disperse it to adhere to the inner wall of the first threaded hole.

[0005] Preferably, the blocking component includes a first plug, a pressure rod, a spring, and a sealing rod. The first plug is threadedly connected to the valve stem. The two ends of the spring abut against the pressure rod and the sealing rod, respectively. The sealing rod blocks the oil passage under the action of the spring, and the pressure rod remains in contact with the first plug under the action of the spring.

[0006] Preferably, there is a transition surface between the mounting hole and the oil passage hole, and one end of the sealing rod has a hemispherical structure, which cooperates with the transition surface to seal.

[0007] Preferably, the driving component includes a sliding rod and a second plug. The sliding rod is horizontally slidably disposed inside the valve stem. One end of the sliding rod has a pressing part that penetrates the valve stem. Both the sealing rod and the sliding rod are provided with wedge-shaped surfaces that cooperate with each other. The second plug is threadedly connected to the valve stem. The sliding rod has a groove through which the sealing rod passes.

[0008] Preferably, the dispersing component includes a baffle and protrusions. Multiple protrusions are provided and distributed at equal angles on the baffle. There is a hollow space between two adjacent protrusions. The dispersing component is fixedly connected to the valve stem by bolts.

[0009] Preferably, the threaded sleeve has a sealing element that seals a first threaded hole and a second threaded hole, the sealing element is threadedly connected to the second threaded hole, and the unthreaded part of the valve stem is rotatably engaged with the sealing element.

[0010] Preferably, the sealing element includes a sealing sleeve, a first pressure plate, and a first sealing ring. One end of the sealing sleeve is threadedly connected to a second threaded hole. The first pressure plate is fixedly connected to the sealing sleeve by bolts. The first sealing ring is located between the first pressure plate and the sealing sleeve. The sealing sleeve has a smooth hole at its center. The valve stem includes a threaded section and a smooth section. The smooth section mates with the smooth hole. The valve stem has an annular groove at the position corresponding to the oil outlet. The diameter of the annular groove is smaller than the diameter of the smooth section, and the height of the annular groove is always lower than the installation height of the first sealing ring. The lower end of the sealing sleeve has a conical surface that facilitates the sliding of the pressure part into the smooth hole.

[0011] Preferably, the valve cover has a mounting post, the threaded sleeve is slidably disposed in the mounting post, a second pressure plate is fixedly mounted on the valve cover, and a second sealing ring is provided between the second pressure plate and the valve cover.

[0012] Preferably, the gate plate is provided with an oil drain hole communicating with the first threaded hole, and the oil drain hole is provided with a third plug in the internal thread.

[0013] Preferably, the valve seat and the gate are engaged by an inclined surface, and an arc-shaped fixing block is provided on the outer side of the valve seat. The arc-shaped fixing block is fixedly connected to the valve body by bolts.

[0014] Compared with the prior art, the beneficial effects of the present invention are: By setting up blocking components, driving components, sealing components, and through holes in the valve stem, and relying on the variable volume oil storage space, the blocking components control the sealing and unblocking of the oil passage. During the opening of the gate valve, the oil is automatically pressurized and guided to achieve continuous dynamic lubrication of the threaded mating surfaces. During the closing of the gate valve, the driving component drives the sealing rod to move and automatically unlock the oil circuit, so that the lubricating oil automatically flows back to the oil storage space. At the same time, during the return flow, the dispersing component achieves the splashing of lubricating oil to achieve the effect of secondary uniform lubrication. The lubrication is sufficient and uniform, which greatly reduces the frictional resistance and wear of the threaded drive. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a self-lubricating gate valve with a valve stem according to the present invention; Figure 2 This is a cross-sectional view of a self-lubricating gate valve stem according to the present invention; Figure 3 This is a schematic diagram of the internal structure of the valve stem and gate in this invention; Figure 4 This is a schematic diagram of the valve seat and gate in this invention; Figure 5 This is a schematic diagram of the structure of the driving component, sealing rod, and spring in this invention; Figure 6 This is a partial structural schematic diagram of the valve stem and the dispersion component in this invention; Figure 7 for Figure 2 A magnified view of a section at point A in the middle; Figure 8 for Figure 3 A magnified view of a section at point B in the middle; Reference numerals: 1. Valve body; 2. Valve cover; 3. Handwheel; 4. Valve stem; 5. Mounting post; 6. Seal; 7. Blocking element; 8. Threaded sleeve; 9. Gate; 10. Oil drain hole; 11. Third plug; 12. Valve seat; 13. Second pressure plate; 14. Second sealing ring; 15. Pressing rod; 16. First pressure plate; 17. First sealing ring; 18. Spring; 19. Driving element; 20. Sealing sleeve; 21. Mounting hole; 22. Sealing rod; 23. Oil passage hole; 24. Arc-shaped fixing block; 25. Second threaded hole; 26. First threaded hole; 27. Wedge-shaped surface; 28. Pressing part; 29. ​​Sliding rod; 30. Slide groove; 31. Second plug; 32. Protrusion; 33. Baffle; 34. Oil outlet hole; 35. Annular groove; 36. Dispersing element; 37. Conical surface; 38. First plug. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figures 1-8 As shown, a self-lubricating gate valve includes a valve body 1, a valve seat 12, a gate 9, and a valve stem 4. The valve body 1 has a central cavity inside, and the gate 9 is slidably installed in this cavity and can slide up and down. To achieve this technical solution, grooves are provided on both sides of the gate 9, such as... Figure 4 The outer edge structure of the gate shown has a convex ridge on the valve body 1 that mates with the groove (not shown in the attached figure). The gate 9 cannot rotate due to the engagement of the groove and the convex ridge, but can only slide up and down. This technical solution is existing technology and will not be described in detail. Two valve seats 12 are fixedly installed on the left and right sides of the valve body 1, and each valve seat 12 is sealed to the gate 9 by a bevel engagement. The bevel engagement helps to reduce wear during opening and closing. To ensure the installation and positioning of the valve seat 12, an arc-shaped fixing block 24 is provided on the outer side of the valve seat 12. The arc-shaped fixing block 24 is fixedly connected to the valve body 1 by bolts.

[0018] A valve cover 2 is fixedly installed on the valve body 1. The lower middle part of the valve stem 4 passes through the valve cover 2 and extends into the gate 9. A threaded sleeve 8 is integrally formed on the gate 9. The threaded sleeve 8 can rise and fall together with the gate 9. The threaded sleeve 8 and the gate 9 have a first threaded hole 26. The threaded sleeve 8 is also provided with a second threaded hole 25. The first threaded hole 26 and the second threaded hole 25 are arranged coaxially. The diameter of the second threaded hole 25 is larger than the diameter of the first threaded hole 26, and the second threaded hole 25 is located directly above the first threaded hole 26. The lower end of the valve stem 4 has an external thread on its outer circumference. The external thread is threadedly connected to the first threaded hole 26. The upper end of the valve stem 4 passes through the valve cover 2 and is equipped with a handwheel 3. The valve stem 4 and the valve cover 2 can be rotatably connected by a bearing. An oil storage space is formed between the lower end face of the valve stem 4 and the bottom of the first threaded hole 26. The oil storage space contains a certain amount of lubricating oil and is used to lubricate the transmission of the threaded sleeve 8 and the valve stem 4 to reduce the relative wear between them.

[0019] A through hole is axially formed at the center of the valve stem 4. This through hole includes, from bottom to top, an oil passage hole 23 and a mounting hole 21. The diameter of the oil passage hole 23 is smaller than the diameter of the mounting hole 21. The lower end of the oil passage hole 23 opens onto the lower end face of the valve stem 4 and communicates with the oil storage space, while its upper end communicates with the mounting hole 21. A blocking element 7 is slidably disposed within the mounting hole 21. The blocking element 7 specifically includes a first plug 38, a pressure rod 15, a spring 18, and a sealing rod 22. The first plug 38 is threaded onto the upper end of the valve stem 4. The pressure rod 15 is a cylindrical rod with an outer diameter equal to the inner diameter of the mounting hole 21, allowing it to slide within the mounting hole 21. The sealing rod 22 has a stepped rod structure; its larger diameter end is equal to the inner diameter of the mounting hole 21, while its smaller diameter end is between the diameters of the oil passage hole 23 and the mounting hole 21. The spring 18 is disposed between the pressure rod 15 and the sealing rod. Between 22, its two ends respectively abut against the two, and the spring 18 always applies a downward elastic force to the sealing rod 22. The connection between the mounting hole 21 and the oil passage hole 23 is provided with a transition surface. The lower end of the sealing rod 22 has a hemispherical structure, which is adapted to the shape of the transition surface. Under the action of the spring 18, the hemispherical end of the sealing rod 22 is pressed tightly against the transition surface, thereby achieving reliable sealing of the oil passage hole 23. An oil outlet hole 34 is also provided on the side wall of the valve stem 4. The inner end of the oil outlet hole 34 is connected to the mounting hole 21, and the outer end opens on the outer peripheral surface of the valve stem 4. The installation height of the oil outlet hole 34 is always located inside the first threaded hole 26, and the valve stem 4 has an annular groove 35 corresponding to the position of the oil outlet hole 34. When the lubricating oil flows out from the oil outlet hole 34, it can flow along the annular groove 35, so as to achieve circumferential uniform lubrication of the inner wall of the first threaded hole 26.

[0020] The driving component 19 includes a sliding rod 29 and a second plug 31. The second plug 31 is threaded into the mounting opening on the side wall of the valve stem 4. The sliding rod 29 is horizontally slidably disposed in the radial channel inside the valve stem 4. One end of the sliding rod 29 extends outward through the side wall of the valve stem 4 to form a pressing part 28. The other end has a sliding space between it and the second plug 31. A groove 30 is provided in the middle of the sliding rod 29 for the smaller diameter part of the sealing rod 22 to pass through. The corresponding parts of the sealing rod 22 and the sliding rod 29 are provided with wedge-shaped surfaces 27 that cooperate with each other. When the sealing rod 22 blocks the oil passage 23 downward under the action of the spring 18, the sealing rod 22 drives the sliding rod 29 to move away from the second plug 31 through the cooperation of the wedge-shaped surfaces 27, so that the length of the pressing part 28 extending out of the side wall of the valve stem 4 reaches the maximum.

[0021] The threaded sleeve 8 is also provided with a sealing element 6, which is used to seal the first threaded hole 26 and the second threaded hole 25 to prevent lubricating oil from leaking from above. The sealing element 6 includes a sealing sleeve 20, a first pressure plate 16, and a first sealing ring 17. The outer periphery of the sealing sleeve 20 is provided with external threads and is threadedly connected to the second threaded hole 25. The upper end cross-section of the sealing sleeve 20 is non-circular, such as hexagonal or square, to facilitate tool installation and allow the sealing sleeve 20 to be smoothly assembled with the threaded sleeve 8. The center of the sealing sleeve 20 is provided with a smooth hole, and the valve stem 4 is provided with a smooth rod section at the corresponding position. The smooth rod section passes through the smooth hole and rotates and seals with it. Plate 16 is fixed to the upper end face of sealing sleeve 20 by bolts. First sealing ring 17 is pressed between first pressure plate 16 and sealing sleeve 20 to achieve sealing between sealing sleeve 20 and valve stem 4. Mounting post 5 is integrally formed on the upper end of valve cover 2. The outer periphery of threaded sleeve 8 slides with the inner wall of mounting post 5. Second pressure plate 13 is also fixed to the upper end of valve cover 2 by bolts. Second sealing ring 14 is pressed between second pressure plate 13 and upper end face of valve cover 2 to prevent pipeline medium from entering the interior of mounting post 5 along the outer wall of threaded sleeve 8. The lower end of sealing sleeve 20 has a conical surface 37 that facilitates the sliding of pressing part 28 into the light hole.

[0022] In addition, the gate 9 is provided with an oil drain hole 10, and the oil drain hole 10 is internally threaded with a third plug 11. When it is necessary to add or replace the lubricating oil, only the third plug 11 needs to be removed for operation, without disassembling other parts. The lower end of the valve stem 4, that is, directly below the oil passage hole 23, is fixedly connected with a dispersion component 36 by bolts. The dispersion component 36 is generally disc-shaped, including a central baffle 33 and multiple protrusions 32 provided on the upper surface of the baffle 33. The multiple protrusions 32 are evenly distributed at equal angles along the circumference, and a hollow gap is formed between two adjacent protrusions 32. When the lubricating oil drips vertically from the oil passage hole 23, it first falls on the central area of ​​the baffle 33. Under the action of the impact force, the lubricating oil is dispersed and splashes in all directions, thereby dispersing and adhering to the inner wall thread of the first threaded hole 26, and then flowing back down along the thread to the oil storage space. In this way, the rotation of the first threaded hole 26 and the valve stem 4 can be achieved with secondary lubrication.

[0023] In this embodiment, during the opening of the gate valve, the lubricating oil is compressed by the valve stem 4, pushing the sealing rod 22 and entering the mounting hole 21. To prevent the lubricating oil from becoming trapped in the oil storage space and mounting hole 21, thus affecting the relative movement between the valve stem 4 and the gate 9, the following limitation is required: the volume of the oil storage space is greater than the volume of the lubricating oil to form a clearance volume. This clearance volume is less than the reduced volume of the oil storage space before the valve stem 4 descends relative to the gate 9 to the opening of the sealing rod 22, ensuring that the valve stem 4 continues to descend and compress after eliminating the clearance. The lubricating oil allows the sealing rod 22 to open and prevents it from blocking the oil passage 23. At the same time, the upper end of the mounting hole 21 is higher than the oil outlet 34. During the downward movement of the valve stem 4 relative to the gate 9, the total volume of the lubricating oil flowing through the oil passage 23 is greater than the internal volume at the junction of the mounting hole 21 and the oil outlet 34. This ensures that the lubricating oil can reach the first thread for lubrication. Moreover, this total volume is less than the total internal volume of the mounting hole 21 and the oil outlet 34 that can be filled with lubricating oil. This ensures that when the gate valve is opened, there is still space at the upper end of the mounting hole 21, thereby eliminating pressure buildup.

[0024] Working principle: In the initial state, the valve is fully closed: a certain amount of lubricating oil is filled into the oil storage space, the sealing sleeve 20 is in the lowest position, the pressing part 28 abuts against the light hole of the sealing sleeve 20, so that the sliding rod 29 drives the sealing rod 22 to overcome the elastic force of the spring 18 and no longer block the oil passage 23, and all the lubricating oil is concentrated at the bottom of the oil storage space.

[0025] Opening process: Turning the handwheel 3 causes the valve stem 4 to rotate in place. Due to the threaded engagement, the valve stem 4 drives the threaded sleeve 8 and the gate 9 to move upward synchronously. When the pressing part 28 disengages from the light hole of the sealing sleeve 20, the sealing rod 22 blocks the oil passage hole 23 under the action of the spring 18. At the same time, during this process, the volume of the oil storage space gradually decreases. When the valve stem 4 squeezes the lubricating oil, the oil pressure of the lubricating oil increases. When the upward thrust generated by the oil pressure exceeds the elastic force of the spring 18, the sealing rod 22 is pushed upward, and the oil passage hole 23 is opened. Under the action of pressure, the lubricating oil enters the mounting hole 21 through the oil hole 23, and then flows out from the oil outlet 34, directly flowing to the thread meshing surface of the first threaded hole 26. As the valve stem 4 continues to rotate and the threaded sleeve 8 rises, the lubricating oil is evenly coated on the thread surface, achieving the first continuous lubrication.

[0026] After the gate is fully opened, the gate 9 rises to its highest position: the volume of the oil storage space no longer changes, the oil pressure of the lubricating oil remains basically unchanged, and the oil passage 23 remains open at this time.

[0027] Closing process: Reverse rotation of handwheel 3 causes threaded sleeve 8 to drive gate 9 downward. At this time, the volume of oil storage space increases, and the oil pressure of lubricating oil inside decreases. Sealing rod 22 re-seals oil passage hole 23 under the action of spring 18, while lubricating oil remains in mounting hole 21. When gate 9 is about to be fully closed but has not yet reached the bottom, conical surface 37 on sealing sleeve 20 moves down with threaded sleeve 8 to contact pressing part 28. Conical surface 37 applies a pushing force to pressing part 28, pushing sliding rod 29 to move towards second plug 31, and relying on wedge surface 27 to drive sealing rod 22 upward to overcome the elastic force of spring 18, thereby making oil passage hole 23 open again.

[0028] The residual lubricating oil in the mounting hole 21 automatically drips down from the oil passage hole 23 under the action of gravity and drips onto the baffle 33 of the dispersing component 36. The dispersing component 36 rotates synchronously with the valve stem 4, and its protrusion 32 disperses the oil droplets and produces a splashing effect, so that the lubricating oil covers the inner wall of the first threaded hole 26 in all directions, and then flows back down to the bottom of the oil storage space, thereby completing secondary lubrication and realizing the recycling of lubricating oil.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A self-lubricating gate valve, comprising a valve body (1), a valve seat (12), a gate (9), and a valve stem (4), wherein the gate (9) is slidably installed in the middle cavity of the valve body (1), two valve seats (12) are provided and fixedly installed on both sides of the valve body (1) corresponding to the gate (9), and one side of the valve seat (12) is sealed with the gate (9), and a valve cover (2) is fixedly installed on the valve body (1), characterized in that, A threaded sleeve (8) is integrally formed on the gate (9). The threaded sleeve (8) and the gate (9) have a first threaded hole (26). The threaded sleeve (8) also has a second threaded hole (25). The diameter of the second threaded hole (25) is larger than the diameter of the first threaded hole (26). The second threaded hole (25) is located at the upper end of the first threaded hole (26). One end of the valve stem (4) is threaded to the first threaded hole (26), and the other end is rotatably connected to the valve cover (2). A handwheel (3) is installed on the valve stem (4). An oil storage space for holding lubricating oil is formed between the valve stem (4) and the bottom of the first threaded hole (26). The volume of the oil storage space gradually decreases as the gate (9) opens the gate valve upward. A through hole is provided in the valve stem (4). The through hole includes an oil passage hole (23) and... Mounting hole (21), the diameter of the oil passage hole (23) is smaller than the diameter of the mounting hole (21), and the oil passage hole (23) is located below the mounting hole (21). The valve stem (4) is also provided with an oil outlet hole (34) communicating with the mounting hole (21). A blocking member (7) for elastically sealing the oil passage hole (23) is slidably provided in the mounting hole (21). The valve stem (4) is also provided with a driving member (19). The driving member (19) is used to drive the blocking member (7) to move upward before the valve stem (4) drives the gate plate (9) to descend and completely close the gate valve to release the blockage of the oil passage hole (23). The lower end of the valve stem (4) is also provided with a dispersing member (36). The dispersing member (36) is used to make the lubricating oil falling from the oil passage hole (23) produce a splashing effect to disperse and adhere to the inner wall of the first threaded hole (26).

2. The self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The blocking component (7) includes a first plug (38), a pressing rod (15), a spring (18), and a sealing rod (22). The first plug (38) is threadedly connected to the valve stem (4). The two ends of the spring (18) abut against the pressing rod (15) and the sealing rod (22) respectively. The sealing rod (22) blocks the oil passage (23) under the action of the spring (18). The pressing rod (15) remains in contact with the first plug (38) under the action of the spring (18).

3. A self-lubricating gate valve with a valve stem according to claim 2, characterized in that, There is a transition surface between the mounting hole (21) and the oil passage hole (23), and one end of the sealing rod (22) is a hemispherical structure, which is sealed in conjunction with the transition surface.

4. A self-lubricating gate valve with a valve stem according to claim 2, characterized in that, The driving component (19) includes a sliding rod (29) and a second plug (31). The sliding rod (29) is horizontally slidably disposed inside the valve stem (4). One end of the sliding rod (29) has a pressing part (28) that penetrates the valve stem (4). Both the sealing rod (22) and the sliding rod (29) are provided with wedge-shaped surfaces (27) that cooperate with each other. The second plug (31) is threadedly connected to the valve stem (4). The sliding rod (29) has a groove (30) through which the sealing rod (22) passes.

5. A self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The dispersing component (36) includes a baffle (33) and a protrusion (32). The protrusion (32) is provided in multiple portions and is distributed at equal angles on the baffle (33). There is a hollow space between two adjacent protrusions (32). The dispersing component (36) is fixedly connected to the valve stem (4) by bolts.

6. A self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The threaded sleeve (8) has a sealing element (6) that seals the first threaded hole (26) and the second threaded hole (25). The sealing element (6) is threadedly connected to the second threaded hole (25). The valve stem (4) has a non-threaded position in the middle that is rotatably engaged with the sealing element (6).

7. A self-lubricating gate valve with a valve stem according to claim 6, characterized in that, The sealing element (6) includes a sealing sleeve (20), a first pressure plate (16), and a first sealing ring (17). One end of the sealing sleeve (20) is threadedly connected to the second threaded hole (25). The first pressure plate (16) is fixedly connected to the sealing sleeve (20) by bolts. The first sealing ring (17) is located between the first pressure plate (16) and the sealing sleeve (20). The center of the sealing sleeve (20) has a smooth hole. The valve stem (4) includes a threaded section and a smooth rod section. The smooth rod section cooperates with the smooth hole. The valve stem (4) has an annular groove (35) at the position corresponding to the oil outlet hole (34). The diameter of the annular groove (35) is smaller than the diameter of the smooth rod section, and the height of the annular groove (35) is always lower than the installation height of the first sealing ring (17). The lower end of the sealing sleeve (20) has a conical surface (37) that facilitates the sliding of the pressing part (28) into the smooth hole.

8. A self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The valve cover (2) has a mounting post (5), the threaded sleeve (8) is slidably disposed in the mounting post (5), and a second pressure plate (13) is fixedly installed on the valve cover (2). A second sealing ring (14) is provided between the second pressure plate (13) and the valve cover (2).

9. A self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The gate (9) is provided with an oil drain hole (10) that communicates with the first threaded hole (26), and the oil drain hole (10) is provided with a third plug (11) in the internal thread.

10. A self-lubricating gate valve with a valve stem according to claim 1, characterized in that, The valve seat (12) and the gate (9) are fitted by an inclined surface. An arc-shaped fixing block (24) is provided on the outside of the valve seat (12). The arc-shaped fixing block (24) is fixedly connected to the valve body (1) by bolts.

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