Gate valve shaft seal assist device

Abstract

The utility model relates to a gate valve shaft sealing auxiliary device, and the device comprises a connecting mechanism, an elastic mechanism, a supporting mechanism and a locking mechanism, the supporting mechanism is used for being connected on the outside surface of the gate valve, the connecting mechanism is movably arranged in the supporting mechanism, one end of the connecting mechanism is used for being connected with the gate valve shaft, one end of the elastic mechanism is connected with the connecting mechanism, the other end of the elastic mechanism is connected with the supporting mechanism, the elastic mechanism is used for applying the pull from inside to outside to the gate valve shaft through the connecting mechanism, the locking mechanism is arranged on the connecting mechanism and is used for limiting the rotation of the connecting mechanism. The gate valve shaft sealing auxiliary device effectively makes up the design defect of the insufficient compression force of the original spherical sealing ring and fundamentally solves the steam leakage problem of the gate valve shaft.

Description

Technical Field

[0001] This utility model relates to the field of valve shaft sealing technology, and in particular to an auxiliary device for valve shaft sealing. Background Technology

[0002] Thermal power generation, as one of the dominant forms of global electricity supply, operates on the principle of heating water into high-temperature, high-pressure steam by burning fossil fuels. This steam then drives a turbine to rotate, which in turn powers a generator to produce electricity. In this thermodynamic cycle, steam leakage is prone to occur at the valve shaft of the main steam valve in thermal power units, affecting not only the unit's operating efficiency but also posing safety hazards. Utility Model Content

[0003] Therefore, it is necessary to provide a valve shaft sealing auxiliary device that can solve the problem of air leakage in the main valve shaft.

[0004] A valve shaft sealing auxiliary device, comprising:

[0005] Support mechanism, used to connect to the outer surface of the valve;

[0006] A connecting mechanism is movably mounted on the support mechanism, and one end of the connecting mechanism is used to connect to the valve shaft;

[0007] The elastic mechanism has one end connected to the connecting mechanism and the other end connected to the support mechanism. The elastic mechanism is used to apply a pulling force from the inside to the outside to the valve shaft through the connecting mechanism.

[0008] A locking mechanism is provided on the connecting mechanism to restrict the rotation of the connecting mechanism.

[0009] In one embodiment, the resilient mechanism includes:

[0010] Spring components, with spring components passing through the connecting mechanism;

[0011] An adjustment component is mounted on the connecting mechanism and connected to the spring component. The adjustment component is used to adjust the elastic force of the spring component.

[0012] In one embodiment, the regulating component includes:

[0013] Spring clamping component, which is fitted and attached to the spring component;

[0014] The adjusting component and the spring pressure component are fitted together. The adjusting component can compress the spring component through the spring pressure component to adjust the elastic force of the spring component.

[0015] In one embodiment, the support mechanism includes:

[0016] Support component, the support component is connected to the outer surface of the valve;

[0017] The load-bearing component is mounted on the support and connected to one end of the elastic mechanism.

[0018] In one embodiment, the load-bearing member is provided with a first through hole, and the connecting mechanism passes through the first through hole.

[0019] In one embodiment, the support member has a groove on the side opposite to the load-bearing member, the groove being used to accommodate the locking mechanism.

[0020] In one embodiment, the support member is provided with a second through hole that is aligned with the first through hole, and the connecting mechanism passes through the second through hole.

[0021] In one embodiment, the locking mechanism includes a first locking member and a second locking member;

[0022] Both the first locking member and the second locking member are mounted on the connecting mechanism. The first locking member and the second locking member are used to cooperate with the external support to lock the connecting mechanism and restrict the rotation of the connecting mechanism.

[0023] In one embodiment, the support mechanism is provided with scale lines, which are used to indicate the displacement of the valve shaft;

[0024] The connecting mechanism is equipped with a pointer, which can indicate the displacement of the valve shaft in conjunction with the scale lines.

[0025] In one embodiment, the pointer is provided with a third through hole, and the connecting mechanism passes through the third through hole.

[0026] The aforementioned valve shaft sealing auxiliary device features a connection mechanism whose dimensions are compatible with the original valve shaft interface, requiring no modification or processing of the valve body. Installation is convenient and precise. The elastic mechanism provides a continuous outward pulling force to the valve shaft, ensuring the spherical sealing ring of the valve shaft is fully pressed against the inner wall of the valve, thus resolving steam leakage at the valve shaft. The support mechanism provides a reaction force support point for the spring compression, ensuring the spring force is effectively converted into pulling force on the valve shaft. A locking mechanism prevents accidental rotation of the connection mechanism during valve shaft pulling, guaranteeing the safety and effectiveness of the sealing operation. The connection mechanism, elastic mechanism, support mechanism, and locking mechanism work together to effectively compensate for the insufficient clamping force of the original spherical sealing ring through controllable axial pulling force on the valve shaft, fundamentally solving the valve shaft steam leakage problem. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a valve shaft sealing auxiliary device according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the support mechanism according to an embodiment of the present invention.

[0029] Figure label:

[0030] 10. Connecting mechanism; 110. Pointer; 111. Third through hole; 20. Elastic mechanism; 210. Adjusting component; 211. Adjusting element; 212. Spring compression element; 220. Spring element; 30. Supporting mechanism; 310. Load-bearing element; 311. First through hole; 320. Support element; 321. Second through hole; 322. Groove; 330. Scale line; 40. Locking mechanism; 410. First locking element; 420. Second locking element. Detailed Implementation

[0031] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0032] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0033] 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 that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] The main valve of a thermal power unit in a power plant is an unbalanced flap valve, capable of quickly cutting off the main steam flow in emergencies to ensure the safety of the turbine. However, in actual long-term operation, steam leakage at the valve shaft of the main valve has become increasingly prominent. The traditional sealing design of this valve shaft relies on a spherical sealing ring. The spherical surface of the sealing ring mates with a conical or spherical seat on the valve body. The steam pressure inside the valve acts on the back of the spherical sealing ring, pushing the sealing ring so that its spherical surface presses against the sealing seat of the valve body, theoretically achieving a self-tightening seal.

[0038] However, due to inherent design flaws, such as during unit startup, low load, or pressure fluctuations, the steam pressure is low and cannot provide sufficient force to compress the spherical sealing ring. The initial clamping force provided by this sealing structure is insufficient, causing the spherical sealing ring sealing surface to fail to fully fit against the valve shaft inner wall under certain operating conditions, forming a tiny gap. High-pressure steam can easily leak continuously through this gap. This leakage not only causes a direct loss of high-quality working fluid, reducing unit thermal efficiency and increasing operating costs, but also causes erosion and high-temperature damage to components near the valve, and may even lead to personal safety accidents due to steam leakage.

[0039] In one exemplary embodiment, such as Figure 1 As shown, this utility model provides a valve shaft sealing auxiliary device, including: a connecting mechanism 10, an elastic mechanism 20, a supporting mechanism 30, and a locking mechanism 40.

[0040] The support mechanism 30 is used to connect to the outer surface of the valve.

[0041] Optionally, the support mechanism 30 is used to support the elastic mechanism 20 and provide reaction force support, ensuring that the force is transmitted axially and avoiding the generation of lateral force, thereby preventing the valve shaft from getting stuck or generating additional wear, and ensuring the safety and effectiveness of the sealing operation.

[0042] The connecting mechanism 10 is movably inserted through the support mechanism 30, and one end of the connecting mechanism 10 is used to connect with the valve shaft.

[0043] Optionally, the connecting mechanism 10 can be an M16 double-ended stud, one end of which is threaded to the loading / unloading hole at the end of the main valve shaft, serving as the main body of the main valve shaft sealing auxiliary device. M16 is a common standard part, compatible with the main valve shaft, and offers low cost and high reliability. The pulling force on the main valve shaft is often very large (greater than 50KN). The outermost diameter of the M16 double-ended stud thread is 16 mm, a specification sufficient to ensure that the load is far greater than the pulling force on the main valve shaft without breakage or tensile deformation. Both ends of the connecting mechanism 10 are machined with external threads, while the middle section can be either a smooth, unthreaded rod or threaded, to connect other functional components as needed.

[0044] One end of the elastic mechanism 20 is connected to the connecting mechanism 10, and the other end of the elastic mechanism 20 is connected to the support mechanism 30. The elastic mechanism 20 is used to apply a pulling force from the inside to the outside to the valve shaft through the connecting mechanism 10.

[0045] Optionally, the elastic force of the elastic mechanism 20 is adjustable. The tension is linearly changed by compressing the spring, thereby enabling precise control of the elastic force used to pull the valve shaft axially. This allows the valve shaft to be displaced outward by a preset distance, pressing the spherical sealing ring to enhance the sealing effect, while avoiding excessive stretching that could damage the equipment.

[0046] The locking mechanism 40 is provided on the connecting mechanism 10 and is used to restrict the rotation of the connecting mechanism 10.

[0047] Optionally, the locking mechanism 40 can be set on the threaded section of the connecting mechanism 10 on the side away from the main valve shaft. It can be in the form of a locking nut or an anti-rotation pin, etc., and is used to fix the connecting mechanism 10 after adjustment with external support (such as fixing it with a wrench by hand, fixing the locking nut position with a fixed bracket, etc.) to prevent the connecting mechanism 10 from loosening or rotating during the pulling of the valve shaft, thus ensuring safety.

[0048] The aforementioned valve shaft sealing auxiliary device features a connecting mechanism 10 whose dimensions are adapted to the existing interface of the main valve shaft, requiring no modification or processing of the valve body, making installation convenient and precise. The elastic mechanism 20 provides a continuous and controllable outward pulling force to the valve shaft, pulling it outward and ensuring the spherical sealing ring of the valve shaft is fully pressed against the inner wall of the valve, thus resolving steam leakage at the valve shaft. The support mechanism 30 provides a reaction force support point for the spring compression, ensuring the spring force is effectively converted into a pulling force on the valve shaft. The locking mechanism 40 prevents accidental rotation of the connecting mechanism 10 during valve shaft pulling, ensuring the safety and effectiveness of the sealing operation. The connecting mechanism 10, elastic mechanism 20, support mechanism 30, and locking mechanism 40 work together to effectively compensate for the insufficient clamping force of the original spherical sealing ring through a controllable axial pulling force on the valve shaft, fundamentally solving the steam leakage problem of the main valve shaft.

[0049] The following embodiments illustrate the elastic adjustment structure of this valve shaft sealing auxiliary device.

[0050] In one exemplary embodiment, such as Figure 1 As shown, the elastic mechanism 20 includes an adjustment component 210 and a spring component 220.

[0051] The connecting mechanism 10 passes through the spring member 220. The adjusting component 210 is disposed on the connecting mechanism 10 and connected to the spring member 220. The adjusting component 210 is used to adjust the elastic force of the spring member 220.

[0052] In one exemplary embodiment, such as Figure 1 As shown, the adjustment assembly 210 includes an adjustment member 211 and a spring pressure member 212.

[0053] Adjusting member 211 and spring pressing member 212 are fitted together. Spring pressing member 212 is movably mounted on connecting mechanism 10 and fitted together with spring member 220. Adjusting member 211 can compress spring member 220 through spring pressing member 212 to adjust the elastic force of spring member 220.

[0054] Exemplarily, the elastic mechanism 20 includes an adjusting assembly 210 and a spring 220. A connecting mechanism 10, namely an M16 stud, passes through the central shaft hole of the spring 220. The adjusting assembly 210 is mounted on the threaded portion of the stud near the central main valve shaft and is connected to one end of the spring 220. By operating the adjusting assembly 210, the compression of the spring 220 can be precisely controlled, thereby adjusting the axial tension it exerts on the valve shaft.

[0055] Furthermore, the adjusting assembly 210 includes an adjusting member 211 and a spring-loaded member 212. The adjusting member 211 can be a nut that matches the connecting mechanism 10 and is screwed onto the thread of a double-ended stud. The spring-loaded member 212 can be an annular pressure plate that is sleeved on the stud and located between the adjusting member 211 and the spring member 220. One side of the adjusting member 211 and the spring-loaded member 212 are in close contact, while the other side of the spring-loaded member 212 is in close contact with the end of the spring member 220.

[0056] By tightening the adjusting component 211, it is pushed inward along the threads of the double-ended stud. The adjusting component 211 pushes the spring compression component 212, which in turn evenly transmits pressure to the end face of the spring component 220, compressing the spring component 220. The reaction force generated by the spring component 220 is ultimately converted into an axial tension on the valve shaft through the entire device. By precisely controlling the number of rotations of the adjusting component 211, linear and precise adjustment of the spring compression and the final output tension can be achieved, ensuring that the spherical sealing ring obtains optimal and safe clamping force.

[0057] The following embodiments illustrate the structure of the support mechanism 30 in detail.

[0058] In one exemplary embodiment, such as Figure 1 and Figure 2 As shown, the support mechanism 30 includes a load-bearing component 310 and a support component 320.

[0059] Support 320 is connected to the outer surface of the valve.

[0060] The load-bearing component 310 is mounted on the support component 320 and connected to one end of the elastic mechanism 10.

[0061] For example, the load-bearing member 310 and the support member 320 are both disposed on the connecting mechanism 10. The load-bearing member 310 and the support member 320 are fitted together. The load-bearing member 310 is connected to the spring member 220. The load-bearing member 310 and the support member 320 can cooperate with the spring compression member 212 to support the spring member 220.

[0062] In one exemplary embodiment, such as Figure 2 As shown, the load-bearing member 310 is provided with a first through hole 311, and the connecting mechanism 10 passes through the first through hole 311.

[0063] In one exemplary embodiment, such as Figure 1 and Figure 2 As shown, the support member 320 has a groove 322 on the side opposite to the load-bearing member 310. The groove 322 is used to accommodate the locking mechanism 40.

[0064] In one exemplary embodiment, such as Figure 2 As shown, the support member 320 is provided with a second through hole 321, and the connecting mechanism 10 passes through the second through hole 321.

[0065] For example, both the load-bearing member 310 and the support member 320 are fixedly sleeved on the connecting mechanism 10 (i.e., M16 double-ended studs). The top ends of the load-bearing member 310 and the support member 320 are fixedly connected by welding to form a rigid integral support base. This base and the spring compression member 212 in the adjusting assembly 210 are located at opposite ends of the spring member 220. The two cooperate with each other to support and constrain the spring member 220, ensuring that it is subjected to uniform force and only undergoes axial compression deformation, thereby efficiently converting the spring force into axial tension on the valve shaft.

[0066] For example, the load-bearing member 310 can be a high-strength circular steel plate with a first through hole 311 machined in the center. An M16 double-ended stud passes through the first through hole 311 and is firmly welded to ensure that it has sufficient contact area with the end face of the spring member 220, so as to uniformly bear and transmit the huge reaction force applied by the spring and prevent structural damage due to stress concentration.

[0067] The main body of the support member 320 is cylindrical (i.e., barrel-shaped), with a recessed groove 322 formed from the outside in. This design minimizes the overall weight while ensuring sufficient structural strength and rigidity, and provides ample space for the connection mechanism 10, the elastic mechanism 20, the locking mechanism 40, and their operation. A second through hole 321 is located at the center of the bottom of the support member 320. An M16 double-ended stud passes through the load-bearing member 310 and then exits through this second through hole 321. The load-bearing member 310 and the support member 320, welded together, are fixed to the connection mechanism 10, forming the load-bearing fulcrum of the entire main valve shaft sealing auxiliary device.

[0068] In one exemplary embodiment, such as Figure 1 As shown, the locking mechanism 40 includes a first locking member 410 and a second locking member 420.

[0069] The first locking member 410 and the second locking member 420 are both disposed on the connecting mechanism 10. The first locking member 410 and the second locking member 420 are used to cooperate with the external support to lock the connecting mechanism 10 and restrict the rotation of the connecting mechanism 10.

[0070] For example, the first locking member 410 and the second locking member 420 can be rivet nuts. The two nuts generate opposite preloads on the threads. With the help of external support (such as a person holding a wrench to fix it, a fixed bracket to fix the position of the locking nut, etc.), a huge frictional resistance is generated between the thread side and the stud thread and between the contact surfaces of the two nuts, preventing the stud from spontaneously rotating and loosening under vibration.

[0071] The following embodiments illustrate the tension control mechanism of this valve shaft sealing auxiliary device.

[0072] In one exemplary embodiment, such as Figure 1 As shown, the support mechanism 30 is provided with a scale line 330, which is used to indicate the displacement of the valve shaft.

[0073] A pointer 110 is provided on the connecting mechanism 10, which can display the pull-out amount of the valve shaft in conjunction with the scale line 330.

[0074] In one exemplary embodiment, such as Figure 1 As shown, a third through hole 111 is provided on the pointer 110, and the connecting mechanism 10 passes through the third through hole 111.

[0075] For example, pointer 110 can be a shim pointer used to indicate the amount of valve shaft pull-out, with the reading corresponding to scale line 330. A third through hole 111 is provided in the middle of the shim pointer, through which the connecting mechanism 10 passes to fix pointer 110. Based on design data, the force applied by steam to the sealing ring of a certain main valve shaft is approximately 42KN. After the main valve is opened, the maximum axial movement static friction is 8KN, and the sliding friction is 2KN. Therefore, the force of the sealing auxiliary device spring should be greater than 50KN. Its axial displacement is approximately 3mm. While applying the force, attention should be paid to the reading on scale line 330. Once the maximum displacement is reached, the force should be stopped and the sealing requirements confirmed to prevent excessive displacement from damaging the equipment.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A valve shaft sealing auxiliary device, characterized in that, include: A support mechanism for connecting to the outer surface of the valve; A connecting mechanism is movably inserted through the support mechanism, and one end of the connecting mechanism is used to connect to the valve shaft; An elastic mechanism, one end of which is connected to the connecting mechanism and the other end of which is connected to the supporting mechanism, is used to apply an inward-to-outward pulling force to the valve shaft through the connecting mechanism; A locking mechanism is provided on the connecting mechanism to restrict the rotation of the connecting mechanism.

2. The valve shaft sealing auxiliary device according to claim 1, characterized in that, The elastic mechanism includes: A spring element, through which the connecting mechanism passes; An adjustment component is disposed on the connecting mechanism and connected to the spring member, and the adjustment component is used to adjust the elastic force of the spring member.

3. The valve shaft sealing auxiliary device according to claim 2, characterized in that, The adjustment component includes: A spring pressure member, wherein the spring pressure member is fitted to the spring member; An adjusting member is movably disposed on the connecting mechanism and fitted against the spring compression member. The adjusting member can compress the spring member through the spring compression member to adjust the elastic force of the spring member.

4. The valve shaft sealing auxiliary device according to claim 1, characterized in that, The supporting structure includes: A support member, which is connected to the outer surface of the valve; A load-bearing component is disposed on the support and connected to one end of the elastic mechanism.

5. The valve shaft sealing auxiliary device according to claim 4, characterized in that, The load-bearing component is provided with a first through hole, and the connecting mechanism passes through the first through hole.

6. The valve shaft sealing auxiliary device according to claim 4, characterized in that, The support member has a groove on the side opposite to the load-bearing member, and the groove is used to accommodate the locking mechanism.

7. The valve shaft sealing auxiliary device according to claim 5, characterized in that, The support member is provided with a second through hole that is aligned with the first through hole, and the connecting mechanism passes through the second through hole.

8. The valve shaft sealing auxiliary device according to claim 1, characterized in that, The locking mechanism includes a first locking element and a second locking element; Both the first locking member and the second locking member are disposed on the connecting mechanism. The first locking member and the second locking member are used to cooperate with the external support to lock the connecting mechanism and restrict the rotation of the connecting mechanism.

9. The valve shaft sealing auxiliary device according to any one of claims 1-8, characterized in that, The support mechanism is provided with scale lines, which are used to indicate the displacement of the valve shaft; The connecting mechanism is equipped with a pointer, which can indicate the displacement of the valve shaft in conjunction with the scale lines.

10. The valve shaft sealing auxiliary device according to claim 9, characterized in that, The pointer is provided with a third through hole, and the connecting mechanism passes through the third through hole.

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