Structure for preventing jamming of valve stem of butterfly valve

Abstract

The utility model discloses a structure of preventing butterfly valve stem jamming, including valve body, upper valve stem and lower valve stem, be equipped with upper axle hole and lower axle hole on the valve body, upper valve stem and lower valve stem are adapted to insert into upper axle hole and lower axle hole respectively, the inner ring groove no.

Description

Technical Field

[0001] This utility model relates to the field of butterfly valve technology, and more specifically to a structure for preventing butterfly valve stem jamming. Background Technology

[0002] Butterfly valves are a commonly used type of valve in the valve industry. As the core transmission component connecting the actuator and the butterfly plate, the valve stem needs to pass through the valve body shaft hole and rotate. Therefore, there must be a certain gap between the valve stem and the valve body shaft hole.

[0003] Traditional butterfly valves, as shown in the attached image Figure 1 As shown, the traditional butterfly valve has structural design flaws, lacking effective sealing and anti-impact structures at the valve stem and sliding bearing positions. In actual use, dust, sand, and other particulate impurities in the medium can easily enter the sealing gap between the valve body shaft hole and the valve stem. This not only wears down the bearing surface but also causes the valve stem to rotate inflexibly and become stuck, and in severe cases, even jammed, significantly affecting the valve's safety and service life while increasing maintenance and repair costs. Therefore, this invention proposes a structure to prevent butterfly valve stem jamming. Utility Model Content

[0004] The purpose of this utility model is to provide a structure for preventing butterfly valve stem jamming, which can effectively block impurities from entering, enhance sealing performance, and prevent valve stem jamming.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A structure for preventing butterfly valve stem jamming includes a valve body, an upper valve stem, and a lower valve stem. The valve body has an upper shaft hole and a lower shaft hole, and the upper valve stem and the lower valve stem are respectively adapted to be inserted into the upper shaft hole and the lower shaft hole. The valve body has an inner annular groove I communicating with the upper shaft hole. The inner annular groove I contains, from bottom to top, a bearing washer, a bearing packing, a bearing washer, and a sliding bearing. The valve body also has an inner annular groove II communicating with the lower shaft hole. The inner annular groove II contains, from top to bottom, a bearing washer, a bearing packing, a bearing washer, and a sliding bearing.

[0006] Furthermore, the bearing washer has an inclined surface on the side near the bearing packing, and the inclined surface is adapted to fit the side of the bearing packing.

[0007] Furthermore, the cross-section of the bearing packing is trapezoidal, and the two sides of the trapezoid are in contact with the inclined surfaces of the bearing washers on both sides.

[0008] Furthermore, a sealing fit is formed between the outer peripheral surface of the upper valve stem and the inner wall of the upper shaft hole through bearing washers, bearing packing, and sliding bearings.

[0009] Furthermore, a sealing fit is formed between the outer peripheral surface of the lower valve stem and the inner wall of the lower shaft hole through a bearing washer, bearing packing, and a sliding bearing.

[0010] Furthermore, the bearing packing is made of an elastic sealing material.

[0011] Furthermore, the inner bore of the sliding bearing is clearance-fitted with the outer circumferential surfaces of the upper and lower valve stems.

[0012] Beneficial effects: This utility model constructs a physical protective barrier between the valve stem and the valve body shaft hole by setting inner annular groove one and inner annular groove two correspondingly in the upper and lower shaft holes of the valve body, and assembling bearing washers, bearing packings and sliding bearings in a specific order. This effectively prevents dust, mud, metal shavings and other particulate impurities in the medium from entering the fitting gap, completely avoiding the problems of valve stem inflexibility, jamming or even jamming caused by impurity accumulation and bearing wear in traditional butterfly valves. It ensures that the valve can still maintain smooth opening and closing and opening degree adjustment functions during long-term use, meeting the core requirements for valve operation stability in industrial scenarios. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Figure 1 This is a schematic diagram of the existing technology structure; Figure 2 This is a schematic diagram of the cross-sectional structure of the present invention; Figure 3 This utility model Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 This utility model Figure 2 Enlarged structural diagram at point B; Figure 5 This is a schematic diagram of the bearing washer and bearing filler of this utility model; Figure 6 This is a schematic diagram of the cross-sectional structure of the bearing washer and bearing packing of this utility model.

[0015] Reference numerals in the attached drawings: 1. Valve body; 101. Upper shaft hole; 102. Inner annular groove one; 103. Lower shaft hole; 104. Inner annular groove two; 2. Upper valve stem; 3. Bearing washer; 301. Inclined surface; 4. Bearing packing; 5. Sliding bearing; 6. Lower valve stem; 7. Prior art sliding bearing; 8. Prior art valve stem; 9. Prior art valve body. Detailed Implementation

[0016] like Figure 2As shown in the specific embodiment, a structure for preventing butterfly valve stem jamming includes a valve body 1, an upper valve stem 2 and a lower valve stem 6. The valve body 1 has an upper shaft hole 101 and a lower shaft hole 103, and the upper valve stem 2 and the lower valve stem 6 are respectively adapted to be inserted into the upper shaft hole 101 and the lower shaft hole 103.

[0017] like Figures 2 to 4 As shown, the valve body 1 has an inner annular groove 102 communicating with the upper shaft hole 101. From bottom to top, the inner annular groove 102 contains a bearing washer 3, a bearing packing 4, a bearing washer 3, and a sliding bearing 5. The valve body 1 also has an inner annular groove 104 communicating with the lower shaft hole 103. From top to bottom, the inner annular groove 104 contains a bearing washer 3, a bearing packing 4, a bearing washer 3, and a sliding bearing 5. By correspondingly providing inner annular grooves 102 and 104 in the upper shaft hole 101 and lower shaft hole 103 of the valve body 1... 4. The bearing washer 3, bearing packing 4 and sliding bearing 5 are assembled in a specific order to build a physical protective barrier between the valve stem and the shaft hole of the valve body 1. This effectively prevents dust, mud, metal shavings and other particulate impurities in the medium from entering the fitting gap. It completely avoids the problems of valve stem inflexibility, jamming or even jamming caused by impurity accumulation and bearing wear in traditional butterfly valves. This ensures that the valve can still maintain smooth opening and closing and opening degree adjustment functions during long-term use, meeting the core requirements for valve operation stability in industrial scenarios.

[0018] like Figures 5 to 6 As shown, the bearing washer 3 has an inclined surface 301 on the side near the bearing packing 4. The inclined surface 301 fits and conforms to the side of the bearing packing 4. The design of the inclined surface 301 of the bearing washer 3 makes one side of it fit and conform to the side of the bearing packing 4. Compared with the traditional planar contact, it greatly increases the contact area between the two, reduces the fitting gap, and improves the sealing reliability. In addition, the inclined surface 301 can guide the bearing packing 4 to be squeezed in the gap direction when under pressure, further enhancing the sealing effect. The bearing packing 4 has a trapezoidal cross-section, with its two sides corresponding to the inclined surfaces 301 of the bearing washers 3 on both sides. This trapezoidal cross-section provides the bearing packing 4 with a certain deformation space. When the valve stem rotates or the medium pressure fluctuates, the packing can adapt to the gap changes through slight deformation, maintaining continuous tight contact with the bearing washers 3 and avoiding sealing failure caused by minor gap changes, resulting in stronger dynamic sealing stability. Furthermore, the fitting design of the inclined surfaces 301 of the bearing washers 3 and the trapezoidal cross-section bearing packing 4 forms a multi-component collaborative sealing structure. Under dynamic conditions (when the valve stem rotates), the elastic bearing packing 4 provides continuous sealing force, and its low-friction characteristics ensure flexible valve stem rotation. Under static conditions (when the valve is at a fixed opening), all sealing components fit tightly, effectively resisting the static pressure of the medium and preventing leakage from the valve stem and shaft hole gaps. Compared to traditional butterfly valves that rely solely on the basic seal of the bearing gap, this structure significantly improves sealing reliability and reduces the risk of safety accidents and environmental pollution caused by medium leakage.

[0019] like Figures 3 to 4 As shown, a sealing fit is formed between the outer peripheral surface of the upper valve stem 2 and the inner wall of the upper shaft hole 101 through the bearing washer 3, bearing packing 4, and sliding bearing 5. This clearly defines the sealing fit relationship between the outer peripheral surface of the upper valve stem 2 and the inner wall of the upper shaft hole 101, focusing the sealing action range of the bearing washer 3, bearing packing 4, and sliding bearing 5 on the core gap between the valve stem and the shaft hole. This avoids blind spots caused by ambiguous sealing ranges and ensures that there are no sealing omissions in key areas. The bearing washer 3 provides support and a base for contact, the bearing packing 4 undertakes the core sealing function, and the sliding bearing 5 ensures smooth rotation and assists in sealing. The three have clear division of labor and close cooperation, taking into account both sealing and transmission functions. The outer circumferential surface of the lower valve stem 6 and the inner wall of the lower shaft hole 103 are sealed together by the bearing washer 3, the bearing packing 4, and the sliding bearing 5. This sealing fit is consistent with the sealing fit of the upper valve stem 2, ensuring that the sealing design of the lower valve stem 6 and the lower shaft hole 103 is symmetrical. This makes the protection system of the upper and lower valve stems 6 of the entire butterfly valve balanced, avoiding overall anti-jamming failure due to weak protection on one side, and ensuring the overall operational stability of the valve. In addition, the lower shaft hole 103 is the main area where impurities in the medium are deposited due to gravity. The sealing fit between the lower valve stem 6 and the lower shaft hole 103 can prevent deposited impurities from entering the gap, avoiding jamming of the lower valve stem 6 due to impurity accumulation. The sealing fit reduces the leakage of the lower medium, prevents the corrosion of the lower shaft hole 103 from aggravating, and alleviates the problem of rapid wear and frequent maintenance of the lower components of traditional butterfly valves.

[0020] The bearing packing 4 is made of elastic sealing material. The properties of the elastic material are highly compatible with the sealing function of the bearing packing 4. The elasticity can ensure that the packing is in continuous close contact with other components and compensate for gap changes. At the same time, the low friction coefficient material can reduce the valve stem rotation resistance, balancing sealing and transmission efficiency. The elastic sealing material can be specific materials such as nitrile rubber, fluororubber, and polytetrafluoroethylene. Each material has different advantages. Nitrile rubber has good oil resistance, fluororubber is resistant to high temperature and corrosion, and polytetrafluoroethylene has a low friction coefficient. Appropriate materials can be selected according to different application scenarios to improve the structural adaptability to working conditions.

[0021] The inner bore of the sliding bearing 5 is clearance-fitted with the outer circumferential surfaces of the upper valve stem 2 and the lower valve stem 6. The clearance range between the inner bore of the sliding bearing 5 and the outer circumferential surface of the valve stem is clearly defined. This clearance not only meets the requirement of flexible rotation of the valve stem and avoids jamming caused by interference fit, but also reduces the intrusion of impurities into the channel through the small gap. At the same time, it ensures the support accuracy of the sliding bearing 5 for the valve stem and avoids sealing failure caused by excessive radial runout of the valve stem.

[0022] Working principle: This invention solves the problem of impurities easily entering and causing jamming in the gap between the valve stem and the shaft hole of the valve body 1 in traditional butterfly valves through a dual mechanism of structural protection and sealing cooperation. The gap between the valve stem and the shaft hole of the valve body 1 is the main channel for impurities to enter. This invention solves the problem by opening inner annular groove 102 and inner annular groove 104 at the corresponding upper shaft hole 101 and lower shaft hole 103 on the valve body 1. The bearing washer 3, bearing packing 4, and sliding bearing 5 are assembled in a specific order to form multiple layers of physical barriers at the gaps. The sliding bearing 5 is fixed to the top of the inner ring groove 102 and the bottom of the inner ring groove 104. Its inner diameter forms a precise clearance fit with the outer circumference of the valve stem. This clearance can prevent most particulate impurities from directly entering the core mating area between the valve stem and the shaft hole. At the same time, the structural characteristics of the sliding bearing 5 itself can prevent impurities from seeping in from the mating seam between the bearing and the inner ring groove. The bearing packing 4, as the core barrier component, has a trapezoidal cross section that completely fits the inclined surface 301 of the bearing washer 3 on both sides, forming a surface seal and completely blocking the gaps that impurities may penetrate. Even if a small amount of fine impurities break through the outer barrier of the sliding bearing 5, they will be blocked by the bearing packing 4 and cannot enter the rotating mating surface between the valve stem and the shaft hole. The bearing washer 3 provides stable support for the bearing packing 4 through the inclined surface 301, preventing the packing from shifting or deforming due to valve stem rotation or medium pressure fluctuations, and ensuring the stability of the barrier structure. The bearing packing 4 maintains its anti-impurity effect over a long period. Using elastic sealing material, the bearing packing 4, supported by the bearing washers 3 on both sides, remains in contact with the outer circumference of the valve stem during valve stem rotation, providing continuous sealing force and preventing media leakage. Simultaneously, the low friction characteristics of the elastic material and the lubrication of the sliding bearing 5 reduce frictional resistance during valve stem rotation, ensuring flexible rotation and preventing jamming due to excessive sealing. When the valve is at a specific opening and the valve stem stops rotating, the medium pressure acts on the bearing packing 4, pushing it further into the gap between the valve stem and the shaft hole, making the packing, valve stem, and washer fit more tightly, forming a pressure self-sealing effect that effectively resists static medium pressure and prevents leakage. The upper shaft hole 101 and lower shaft hole 103 employ a symmetrical bearing washer 3, packing, and bearing assembly structure to ensure balanced force on the upper and lower ends of the valve stem, preventing valve stem tilting and rotation jamming due to uneven force on one side, further ensuring smooth transmission.

[0023] Regarding the operating procedure, insert the butterfly plate connecting end of the upper valve stem 2 into the top of the upper shaft hole 101 of the valve body 1, and slowly push it downward to the preset position to ensure that the lower end of the valve stem can be properly connected to the butterfly plate and the upper end can extend to the outside of the valve body 1 to dock with the actuator. When inserting, keep the valve stem and the shaft hole coaxial to avoid scratching the inner wall of the shaft hole. Assemble the inner ring groove 102 component: from bottom to top, put in the first bearing washer 3, put in the trapezoidal bearing packing 4, put in the second bearing washer 3, and press in the sliding bearing 5. Ensure that the inner hole of the sliding bearing 5 fits with the outer circumference of the valve stem, and the outer wall of the bearing is fixed with the inner ring groove by interference fit. Finally, complete the assembly of the upper valve stem 2. Insert the butterfly plate connecting end of the lower valve stem 6 into the bottom end of the lower shaft hole 103 of the valve body 1, and push it upward to the preset position for connection with the butterfly plate. During insertion, keep it coaxial with the upper valve stem 2 to avoid affecting the installation accuracy of the butterfly plate. Assemble the inner ring groove 104 component: from top to bottom, put in the first bearing washer 3, put in the trapezoidal bearing packing 4, put in the second bearing washer 3, and press the sliding bearing 5 into the bottom end of the lower shaft hole 103. Finally, complete the assembly of the lower valve stem 6. After assembly, the valve can be connected to the pipeline system for normal use. The operation process is the same as that of a conventional butterfly valve. The core is to drive the valve stem to rotate through the actuator to realize the valve opening or opening degree adjustment. Start the actuator, and the output torque of the actuator is transmitted to the butterfly plate through the upper valve stem 2, driving the butterfly plate to rotate around the valve stem axis until the valve is fully opened. During the opening process, when the valve stem rotates, the bearing packing 4 maintains a dynamic seal with the valve stem, and the sliding bearing 5 ensures low friction rotation without jamming. The reverse start actuator drives the upper valve stem 2 to rotate the butterfly plate in the opposite direction until the butterfly plate is in contact with the sealing surface of the valve body 1, and the valve is completely closed. After closing, the bearing packing 4 forms a static seal under the action of medium pressure to prevent medium leakage.

[0024] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. A structure for preventing butterfly valve stem jamming, comprising a valve body (1), an upper valve stem (2), and a lower valve stem (6), characterized in that, The valve body (1) is provided with an upper shaft hole (101) and a lower shaft hole (103). The upper valve stem (2) and the lower valve stem (6) are respectively adapted to be inserted into the upper shaft hole (101) and the lower shaft hole (103). The valve body (1) is provided with an inner ring groove (102) communicating with the upper shaft hole (101). The inner ring groove (102) is provided with a bearing washer (3), a bearing packing (4), a bearing washer (3) and a sliding bearing (5) arranged from bottom to top. The valve body (1) is provided with an inner ring groove (104) communicating with the lower shaft hole (103). The inner ring groove (104) is provided with a bearing washer (3), a bearing packing (4), a bearing washer (3) and a sliding bearing (5) arranged from top to bottom.

2. The structure for preventing butterfly valve stem jamming according to claim 1, characterized in that, The bearing washer (3) has an inclined surface (301) on the side near the bearing packing (4), and the inclined surface (301) is adapted to fit the side of the bearing packing (4).

3. The structure for preventing butterfly valve stem jamming according to claim 2, characterized in that, The cross section of the bearing filler (4) is trapezoidal, and the two sides of the trapezoid are in contact with the inclined surfaces (301) of the bearing washers (3) on both sides respectively.

4. The structure for preventing butterfly valve stem jamming according to claim 1, characterized in that, The outer circumferential surface of the upper valve stem (2) and the inner wall of the upper shaft hole (101) are sealed together by bearing washer (3), bearing packing (4) and sliding bearing (5).

5. The structure for preventing butterfly valve stem jamming according to claim 4, characterized in that, The outer circumferential surface of the lower valve stem (6) and the inner wall of the lower shaft hole (103) are sealed together by bearing washer (3), bearing packing (4) and sliding bearing (5).

6. The structure for preventing butterfly valve stem jamming according to claim 1, characterized in that, The bearing packing (4) is made of elastic sealing material.

7. The structure for preventing butterfly valve stem jamming according to claim 6, characterized in that, The inner hole of the sliding bearing (5) is clearance-fitted with the outer circumferential surfaces of the upper valve stem (2) and the lower valve stem (6).

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