Gate valve rod sealing structure

Abstract

The utility model relates to the technical field of sealing, and discloses a gate valve rod sealing structure which comprises a valve body, a valve rod is connected in the valve body in a sliding mode, a hand wheel is fixedly connected to the top end of the valve rod, a gland is connected to the outer wall of the valve rod in a sliding mode, a sealing assembly is arranged on the outer wall of the valve rod, and the sealing assembly comprises a stuffing box. The stuffing box is slidably connected to the outer wall of the valve rod, the inner wall of the stuffing box is fixedly connected with a first spacer ring, polytetrafluoroethylene woven filler is arranged at the bottom of the first spacer ring, flexible graphite filler is arranged at the top of the first spacer ring, and a limiting assembly is arranged in the hand wheel. According to the sealing structure, corrosion of strong corrosive media such as acid and alkali can be resisted through the polytetrafluoroethylene woven filler, gaps are tightly filled with the flexible graphite filler, and a stable sealing layer can be formed, so that the efficient sealing effect is achieved, and the leakage problem caused by filler abrasion and aging of a traditional sealing structure is solved; and the reliability of the sealing structure under complex working conditions is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sealing technical field especially relates to a gate valve stem sealing structure. BACKGROUND

[0002] In all kinds of pipeline systems of industrial production, as the key component of controlling fluid on-off and flow, the reliability of gate valve directly concerns the stable operation of the whole system, and the performance of the sealing structure of the valve stem of the gate valve plays a decisive role, directly influencing the safety of fluid delivery, the service life of equipment and the continuity of production.

[0003] In the traditional sealing field of the valve stem of the gate valve, the common one is a simple single packing sealing structure, which mainly fills the packing such as asbestos and rubber in the packing chamber between the valve stem and the valve cover, and the packing is extruded by tightening the gland, and then the gap between the valve stem and the packing chamber is filled, so as to realize the sealing effect. The technical principle of this structure is relatively basic, mainly utilizing the plasticity of the packing under pressure, and tightly adhering it around the valve stem by external force to form a barrier to prevent fluid leakage.

[0004] However, this traditional single packing sealing structure has obvious defects. In actual industrial application scenarios, especially in the face of complex and changeable working conditions, such as frequent pressure fluctuations, large temperature fluctuations and corrosive conveying medium, the single packing sealing is difficult to maintain stable and effective sealing state. With the increase of use time, the packing is prone to wear and aging. Once these problems occur, the sealing performance will decrease sharply, and the fluid is easy to leak from the gap between the valve stem and the packing chamber. This not only causes waste of resources, but also may cause safety hazards and affect the normal operation of the whole industrial production system. Therefore, a gate valve stem sealing structure is proposed to solve the above problems. CONTENT OF THE UTILITY MODEL

[0005] In order to make up for the above shortcomings, the utility model provides a gate valve stem sealing structure, which aims at improving the problem that the single packing sealing structure of the valve stem of the existing gate valve is easy to cause sealing performance decline and fluid leakage due to packing wear and aging under complex working conditions.

[0006] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A gate valve stem sealing structure, comprising a valve body, the valve body is internally connected with a valve stem in sliding mode, the valve stem is fixedly connected with a hand wheel at the top end, the valve stem is externally connected with a gland in sliding mode, and the valve stem is externally provided with a sealing assembly;

[0008] The sealing assembly includes a packing box, the packing box is connected in sliding mode on the outer wall of the valve rod, the inner wall of the packing box is fixedly connected with a partition ring one, the bottom of the partition ring one is provided with polytetrafluoroethylene woven packing, the top of the partition ring one is provided with flexible graphite packing, the inner wall of the packing box is fixedly connected with a partition ring two, the flexible graphite packing is in contact with the bottom of the partition ring two, the top of the partition ring two is provided with fiber woven packing, the bottom of the partition ring two is provided with a spring one, one end of the spring one is fixedly connected with the bottom of the partition ring two, the other end is fixedly connected with the top of the partition ring one, the inside of the gland is provided with a plurality of sealing rings, the inner wall of the sealing ring is in close contact with the outer wall of the valve rod, the inside of the hand wheel is provided with a limiting assembly.

[0009] As a further description of the above technical scheme:

[0010] The limiting assembly includes a limiting disc and a fixed plate, the inner wall of the limiting disc is fixedly connected with the outer wall of the valve rod, and the fixed plate is fixedly connected with the inner wall of the hand wheel on both sides.

[0011] As a further description of the above technical scheme:

[0012] The inside of the limiting disc is provided with a plurality of limiting holes, and the inside of the fixed plate is fixedly connected with a fixed block.

[0013] As a further description of the above technical scheme:

[0014] The inside of the fixed block is provided with a left-right symmetrical sliding groove, and the inner wall of the fixed block is fixedly connected with a connecting shaft one.

[0015] As a further description of the above technical scheme:

[0016] The bottom of the connecting shaft one is fixedly connected with a fixed rod, and the bottom end of the fixed rod is slidingly connected with a connecting shaft two.

[0017] As a further description of the above technical scheme:

[0018] The outer wall of the fixed rod is provided with a spring two, one end of the spring two is fixedly connected with the side wall of the connecting shaft one, and the other end is fixedly connected with the side wall of the connecting shaft two.

[0019] As a further description of the above technical scheme:

[0020] One end of the connecting shaft two is fixedly connected with a clamping column, and the clamping column is matched with the limiting hole.

[0021] As a further description of the above technical scheme:

[0022] The outer wall of the connecting shaft two is fixedly connected with a left-right symmetrical transmission rod, and the transmission rod slides in the inside of the sliding groove.

[0023] As a further description of the above technical solutions:

[0024] The transmission rod is fixedly connected with a transmission block at one end, and a plurality of anti-skid grooves are formed in the transmission block.

[0025] As a further description of the above technical solutions:

[0026] The transmission block is made of rubber material, and the inner wall of the clamping column is in sliding connection with the outer wall of the fixed rod.

[0027] The utility model has the advantages of the following:

[0028] 1. In the utility model, the polytetrafluoroethylene woven filler can resist the corrosion of strong corrosive media such as acid and alkali, the flexible graphite filler can tightly fill the gap, a stable sealing layer can be formed, the fiber woven filler can maintain the uniformity of the contact pressure of the sealing structure, the service life of the filler is prolonged, the efficient sealing effect is realized, the leakage problem caused by the wear, aging or uneven pressure distribution of the sealing structure of the traditional gate valve stem is solved, and the reliability of the sealing structure under complex working conditions is improved.

[0029] 2. In the utility model, the connecting shaft two is slid on the outer wall of the fixed rod by pulling the transmission block, so that the spring two is further extruded, the spring two is elastically deformed, the clamping column is separated from the limiting hole by the movement of the connecting shaft two to realize unlocking, the hand wheel can be rotated for adjustment after unlocking, the effect of adjusting and limiting the hand wheel is realized, the problem that the valve part is worn and the operation precision is insufficient due to the excessive rotation of the hand wheel without effective limiting is solved, and the accuracy of valve operation and the long-term operation efficiency of equipment are improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A perspective view of a gate valve stem sealing structure is provided for the utility model;

[0031] Figure 2 A structure diagram of a filler basket section of a gate valve stem sealing structure is provided for the utility model;

[0032] Figure 3 A structure diagram of a hand wheel section of a gate valve stem sealing structure is provided for the utility model;

[0033] Figure 4 is Figure 3 An enlarged view of A in the middle.

[0034] Legend:

[0035] 1, valve body; 2, valve stem; 3, hand wheel; 4, gland; 5, stuffing box; 6, spacer ring one; 7, spacer ring two; 8, polytetrafluoroethylene braided packing; 9, flexible graphite packing; 10, fiber braided packing; 11, spring one; 12, sealing ring; 13, limit disc; 14, fixed plate; 15, limit hole; 16, fixed block; 17, connecting shaft one; 18, fixed rod; 19, spring two; 20, connecting shaft two; 21, clamping column; 22, transmission rod; 23, transmission block; 24, anti-skid groove; 25, sliding groove. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0037] Referring to Figure 1 and Figure 2 An embodiment provided by the utility model: a gate valve stem sealing structure, including valve body 1, the valve body 1 inside slidingly connected with valve stem 2, the valve stem 2 top end fixedly connected with hand wheel 3, the valve stem 2 outer wall slidingly connected with gland 4, the gland 4 is disc-shaped, for extruding packing, the valve stem 2 outer wall is provided with sealing assembly, sealing assembly is used to guarantee the overall sealing property of valve;

[0038] The sealing assembly comprises a packing gland 5, which is a cylindrical cavity for providing support for the packing, and is slidingly connected to the outer wall of the valve stem 2. The inner wall of the packing gland 5 is fixedly connected with a spacer ring I 6, which is an annular metal plate for isolating different packings and ensuring the stability between the packings. The bottom of the spacer ring I 6 is provided with a polytetrafluoroethylene braided packing 8, which has excellent chemical corrosion resistance, low friction coefficient and low temperature resistance, and is mainly used to resist the corrosion of strong corrosive media such as acid and alkali. The top of the spacer ring I 6 is provided with a flexible graphite packing 9, which has high temperature resistance, high compression strength and self-lubricating property, and can tightly fill the gap under high temperature, high pressure or strong vibration conditions, form a stable sealing layer, and maintain the uniformity of the contact pressure of the sealing structure. The inner wall of the packing gland 5 is fixedly connected with a spacer ring II 7, the flexible graphite packing 9 is in contact with the bottom of the spacer ring II 7, and the top of the spacer ring II 7 is provided with a fiber braided packing 10, which has high elasticity, wear resistance and good mechanical strength, can compensate for the deformation of the packing caused by pressure fluctuation, vibration or temperature change, maintain the uniformity of the contact pressure of the sealing structure, prolong the service life of the packing, and ensure the reliability and durability of the sealing assembly in long-term use. The bottom of the spacer ring II 7 is provided with a spring I 11, which can provide better stability for the assembly through its elastic deformation. One end of the spring I 11 is fixedly connected to the bottom of the spacer ring II 7, and the other end is fixedly connected to the top of the spacer ring I 6. The inside of the gland 4 is provided with a plurality of sealing rings 12, which can further ensure the sealing performance of the assembly. The inner wall of the sealing ring 12 is in close contact with the outer wall of the valve stem 2. The inside of the hand wheel 3 is provided with a limiting assembly for mechanically limiting the hand wheel 3.

[0039] Specifically, when the valve needs to operate in a high-pressure, high-temperature, strong corrosive medium environment or under conditions of vibration, frequent opening and closing, and the sealing of the valve stem 2 needs to consider corrosion resistance, high temperature and pressure resistance, wear resistance and dynamic elastic compensation, the packing is first filled into the inside of the packing gland 5, and then the gland 4 is rotated to move downward and apply pressure to extrude the packing, so that the packing is deformed and fills the small gap between the valve stem 2 and the packing. The fiber braided packing 10 has high elasticity, wear resistance and excellent mechanical strength, which can compensate for the deformation of the packing caused by pressure fluctuation, vibration or temperature change. This not only reduces the wear of the valve stem 2 during movement, but also effectively improves the sealing effect. The flexible graphite packing 9 can form a stable sealing layer between the valve stem 2 and the packing, significantly reducing friction, and through its self-lubricating property, further reducing the resistance during movement. The polytetrafluoroethylene braided packing 8 has excellent chemical corrosion resistance, low friction coefficient and low temperature resistance, which can effectively prevent the corrosion of strong corrosive media to the packing, ensure the high efficiency and stability of the sealing structure under various harsh conditions, and prolong the service life of the equipment. As the gland 4 is pressed down, the pressure will further extrude the spring I 11, causing the spring I 11 to elastically deform. This deformation plays a role in load compensation, improving the stability of the assembly, and ensuring the reliability and durability of the sealing assembly in long-term use.

[0040] Referring to Figure 3 and Figure 4 , the limiting assembly includes a limiting disc 13 and a fixed plate 14, the inner wall of the limiting disc 13 is fixedly connected to the outer wall of the valve rod 2, and the inner wall of the fixed plate 14 is fixedly connected to the inner wall of the hand wheel 3. The role of the limiting disc 13 and the fixed plate 14 in the limiting assembly is to provide stable connection and support for the limiting assembly, to ensure the movement stability of the limiting assembly. The inside of the limiting disc 13 is provided with a plurality of limiting holes 15. The role of the limiting holes 15 is to cooperate with other components to achieve quick locking and unlocking of the limiting assembly. The inside of the fixed plate 14 is fixedly connected with a fixed block 16. The inside of the fixed block 16 is provided with left-right symmetrical sliding grooves 25. The role of the sliding grooves 25 is to provide a stable sliding path for other components. The inner wall of the fixed block 16 is fixedly connected with a connecting shaft one 17. The bottom of the connecting shaft one 17 is fixedly connected with a fixed rod 18. The bottom end of the fixed rod 18 is slidingly connected with a connecting shaft two 20. The outer wall of the fixed rod 18 is provided with a spring two 19. The role of the spring two 19 is to provide elastic support for the limiting assembly through its own elastic restoring force, to ensure that the limiting assembly can quickly recover after movement. One end of the spring two 19 is fixedly connected to the side wall of the connecting shaft one 17, and the other end is fixedly connected to the side wall of the connecting shaft two 20. One end of the connecting shaft two 20 is fixedly connected with a clamping column 21. The clamping column 21 is matched with the limiting hole 15. Through the cooperation between the clamping column 21 and the limiting hole 15, the effect of quickly limiting the hand wheel 3 can be achieved, which can prevent the hand wheel 3 from being damaged or deviated due to external force or excessive rotation. The outer wall of the connecting shaft two 20 is fixedly connected with left-right symmetrical transmission rods 22. The role of the transmission rods 22 is to further transmit power to ensure the stable movement of subsequent components. The transmission rods 22 slide in the sliding grooves 25. One end of the transmission rods 22 is fixedly connected with transmission blocks 23. The inside of the transmission blocks 23 is provided with a plurality of anti-skid grooves 24. The role of the anti-skid grooves 24 is to increase the friction force with the hands of the operator to prevent the operator from slipping. The transmission blocks 23 are made of rubber material. The inner wall of the clamping column 21 is slidingly connected with the outer wall of the fixed rod 18.

[0041] Specifically, when the artificial operation valve needs to accurately limit the stroke of the valve stem 2, to avoid overloading of the sealing assembly, impact of the valve disc on the valve seat or wear of the parts due to over-rotation of the hand wheel 3, the driving block 23 is pulled to generate a pulling force, so that the driving rod 22 slides inside the fixed block 16, the sliding of the driving rod 22 further drives the synchronous movement of the connecting shaft two 20, thereby extruding the spring two 19, driving the spring two 19 to elastically deform, at the same time, the movement of the connecting shaft two 20 makes the clamping column 21 disengage from the limiting hole 15, thereby achieving unlocking, allowing the hand wheel 3 to rotate freely, when the device is adjusted to the appropriate working state, the elastic restoring force of the spring two 19 pushes the clamping column 21 to re-enter the limiting hole 15, ensuring the limiting function of the hand wheel 3 during operation, thereby effectively preventing safety hazards caused by human operation errors, ensuring the accuracy and safety of the device operation.

[0042] Working principle: When using the sealing structure, first fill the packing into the packing box 5, then rotate the gland 4, the pressure of the downward movement of the gland 4 extrudes the packing, causing the packing to deform, thereby filling the small gap between the valve stem 2, through the high elasticity, wear resistance and good mechanical strength of the fiber woven packing 10, the deformation of the packing caused by pressure fluctuation, vibration or temperature change is compensated, thereby reducing the wear of the valve stem 2 during movement, the flexible graphite packing 9 can form a stable sealing layer, while reducing the friction between the valve stem 2 and the packing, the chemical corrosion resistance, low friction coefficient and low temperature resistance of the polytetrafluoroethylene woven packing 8 can prevent the corrosion of strong corrosive media, thereby achieving efficient and stable sealing of the sealing structure and prolonging the service life of the equipment. At the same time, the spring one 11 is extruded under the pressure of the gland 4, causing the spring one 11 to elastically deform, providing load compensation for the assembly, further improving the stability of the assembly. When adjusting the device by rotating the hand wheel 3, first pull the driving block 23, which will slide the driving rod 22 inside the fixed block 16 under the action of the pulling force, further driving the synchronous movement of the connecting shaft two 20, thereby extruding the spring two 19, causing the spring two 19 to elastically deform, while the movement of the connecting shaft two 20 causes the clamping column 21 to disengage from the limiting hole 15 to achieve unlocking. After unlocking, the operator can freely rotate the hand wheel 3, after the device is adjusted to the appropriate state, the elastic restoring force of the spring two 19 pushes the clamping column 21 to re-enter the limiting hole 15, which can limit the hand wheel 3, thereby ensuring the accuracy and controllability of the operating position, avoiding safety hazards or affecting the accuracy of the device operation caused by human operation errors.

[0043] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application has been described in detail, for the skilled in the art, it still can be modified, or for part of the technical features of the equivalent replacement, the spirit and principles of the present application, the made any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A gate valve stem seal structure comprising a valve body (1) characterised in that: The valve body (1) is slidably connected with a valve stem (2), the top end of the valve stem (2) is fixedly connected with a hand wheel (3), the outer wall of the valve stem (2) is slidably connected with a gland (4), and the outer wall of the valve stem (2) is provided with a sealing assembly. The sealing assembly comprises a stuffing box (5) which is slidably connected to the outer wall of the valve stem (2), the inner wall of the stuffing box (5) is fixedly connected with a spacer ring one (6), the bottom of the spacer ring one (6) is provided with a polytetrafluoroethylene braided packing (8), the top of the spacer ring one (6) is provided with a flexible graphite packing (9), the inner wall of the stuffing box (5) is fixedly connected with a spacer ring two (7), the flexible graphite packing (9) is in contact with the bottom of the spacer ring two (7), the top of the spacer ring two (7) is provided with a fiber braided packing (10), the bottom of the spacer ring two (7) is provided with a spring one (11), one end of the spring one (11) is fixedly connected to the bottom of the spacer ring two (7), the other end is fixedly connected to the top of the spacer ring one (6), the inside of the gland (4) is provided with a plurality of sealing rings (12), the inner wall of the sealing ring (12) is in close contact with the outer wall of the valve stem (2), and the inside of the hand wheel (3) is provided with a limiting assembly.

2. A gate valve stem seal structure as defined in claim 1, wherein: The limiting assembly comprises a limiting disc (13) and a fixed plate (14), the inner wall of the limiting disc (13) is fixedly connected to the outer wall of the valve stem (2), and the fixed plate (14) is fixedly connected to the inner wall of the hand wheel (3) on both sides.

3. A gate valve stem seal structure as defined in claim 2, wherein: The inside of the limiting disc (13) is provided with a plurality of limiting holes (15), and the inside of the fixed plate (14) is fixedly connected with a fixed block (16).

4. A gate valve stem seal structure as claimed in claim 3, wherein: The inside of the fixed block (16) is provided with a left-right symmetrical sliding groove (25), and the inner wall of the fixed block (16) is fixedly connected with a connecting shaft one (17).

5. A gate valve stem seal structure as claimed in claim 4, wherein: The bottom of the connecting shaft one (17) is fixedly connected with a fixed rod (18), and the bottom end of the fixed rod (18) is slidably connected with a connecting shaft two (20).

6. A gate valve stem seal structure as claimed in claim 5, wherein: The outer wall of the fixed rod (18) is provided with a spring two (19), one end of the spring two (19) is fixedly connected to the side wall of the connecting shaft one (17), and the other end is fixedly connected to the side wall of the connecting shaft two (20).

7. A gate valve stem seal structure as defined in claim 6, wherein: One end of the connecting shaft two (20) is fixedly connected with a clamping column (21), and the clamping column (21) is matched with the limiting hole (15).

8. A gate valve stem seal structure as defined in claim 7, wherein: The outer wall of the connecting shaft two (20) is fixedly connected with a left-right symmetrical transmission rod (22), and the transmission rod (22) slides in the sliding groove (25).

9. A gate valve stem seal structure as described in claim 8, wherein: One end of the transmission rod (22) is fixedly connected with a transmission block (23), and the inside of the transmission block (23) is provided with a plurality of anti-skid grooves (24).

10. A gate valve stem seal structure as defined in claim 9, wherein: The transmission block (23) is made of rubber material, and the inner wall of the clamping column (21) is slidably connected with the outer wall of the fixed rod (18).

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