Ball valve with hard seal

Abstract

The utility model discloses a ball valve with hard sealing structure relates to the field of ball valve, including the side of valve seat close to valve ball is equipped with chamfered bevel, and the chamfered bevel and valve ball outer surface form the taper type included angle gap between, be equipped with wedge seal in taper type included angle gap, and the wedge seal includes first bevel and second arc surface, and first bevel is parallel with chamfered bevel and abuts, and second arc surface and valve ball circumferential surface abut, and the elastic piece of fixed mounting along chamfered bevel direction is equipped on valve seat, and the front end of elastic piece is connected with the front end of wedge seal, and elastic piece axially pushes wedge seal and along chamfered bevel and is wedged into taper type sealing gap, and the taper type included angle gap that valve seat chamfered bevel and valve ball outer surface form cooperates wedge seal, and the axial thrust of elastic piece along bevel direction drive, make wedge seal first bevel and chamfered bevel close adhesion, and second arc surface is compressed radially and produces gradient deformation, forms the hard sealing interface of dynamic adaptation with valve ball.

Description

Technical Field

[0001] This utility model relates to the field of ball valves, and in particular to a ball valve with a hard seal structure. Background Technology

[0002] A ball valve is a type of valve that controls fluid flow by rotating a ball. A ball valve typically uses a ball as the closing element inside the valve body, and the ball has a circular orifice. When the orifice is aligned with the pipe axis, the valve is in the open state; when the ball rotates so that the orifice is perpendicular to the pipe axis, the valve is in the closed state.

[0003] Ball valves can be classified into three types according to their structure: floating ball valves, fixed ball valves, and resilient ball valves. Among them, the ball in a fixed ball valve is stationary and does not move under pressure. It can withstand the erosion of the medium during opening and closing, and is therefore widely used in applications involving stationary particles and abrasive media. Existing fixed ball valves all have floating seats. Under medium pressure, the seat moves, pressing the sealing ring tightly against the ball to ensure a seal. However, the lateral pushing pressure is difficult to reliably guarantee the reliability and effectiveness of the seal, especially in low-pressure operating environments, which directly affects the reliability and stability of the ball valve's operation. Utility Model Content

[0004] The purpose of this invention is to provide a ball valve with a hard seal structure, which solves the problem that existing valves rely solely on the movement of the valve seat to press the sealing ring tightly against the ball to ensure a seal, and the lateral pushing pressure of the valve seat movement makes it difficult to reliably guarantee the reliability of the seal.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a ball valve with a hard-seal structure, comprising a valve body, two valve seats fixed in the inner cavity of the valve body, a valve ball abutting between the two valve seats, and a valve stem extending into the valve ball at one end. The valve ball has a ball hole, and the valve body has a fluid channel of the same size as the ball hole. The valve seat has a chamfered bevel on the side near the valve ball, and a gradually narrowing angular gap is formed between the chamfered bevel and the outer surface of the valve ball. A wedge-shaped seal is provided in the gradually narrowing angular gap. The wedge-shaped seal includes a first bevel and a second arc surface. The first bevel is parallel to and abuts against the chamfered bevel, and the second arc surface abuts against the circumferential surface of the valve ball. An elastic element is fixedly installed on the valve seat along the direction of the chamfered bevel. The front end of the elastic element is connected to the front end of the wedge-shaped seal. The elastic element axially pushes the wedge-shaped seal along the chamfered bevel into the gradually narrowing sealing gap.

[0006] Furthermore, the valve seat is provided with a receiving hole extending along the chamfered surface, the opening of the receiving hole facing the side close to the valve ball, and the elastic element is disposed in the receiving hole.

[0007] Furthermore, the wedge-shaped seal has an extension platform at its front end, which extends to the front of the receiving hole, and the spring is connected to the extension platform.

[0008] Furthermore, the elastic element is a spring.

[0009] Furthermore, a limiting platform is provided at the bottom of the valve seat away from the valve ball. The bottom edge of the limiting platform is aligned with the edge of the fluid channel. A limiting groove is provided on the limiting platform, and the limiting groove is located above the bottom edge of the limiting platform. The tail end of the wedge-shaped seal abuts against the limiting groove.

[0010] Furthermore, the wedge-shaped seal also includes a third impact surface, which is an inclined surface that slopes outward from the fluid channel.

[0011] Furthermore, a polytetrafluoroethylene rubber pad is provided on the second arc surface, and the third impact surface is coated with an epoxy resin coating.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] The wedge-shaped seal is formed by a gradually narrowing gap between the chamfered surface of the valve seat and the outer surface of the valve ball. Combined with the axial thrust of the elastic element along the direction of the chamfer, the first chamfered surface of the wedge-shaped seal is tightly fitted with the chamfered surface, and the second arc surface is subjected to radial compression to produce gradient deformation, forming a hard sealing interface that dynamically adapts to the valve ball. This structure utilizes the wedging effect of the gradually narrowing gap and the continuous clamping force of the elastic element to enable the wedge-shaped seal to adaptively enhance the contact stress when the medium pressure fluctuates, significantly improving the sealing reliability under high pressure conditions. At the same time, it avoids the risk of leakage caused by valve ball wear or thermal deformation. The overall structure is simple and compact, requiring no additional guide holes or extended bosses, reducing processing costs and facilitating assembly and maintenance. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings:

[0015] Figure 1 This is a schematic diagram of the valve body of this utility model;

[0016] Figure 2 This is a schematic diagram of the internal structure of the valve body of this utility model;

[0017] Figure 3 For the present utility model Figure 2 Enlarged view of point A in the middle;

[0018] Figure 4 This is a schematic diagram of the gradually narrowing angle gap of this utility model.

[0019] In the figure: 1 Valve body, 11 Fluid passage, 12 Chamfered bevel, 13 Gradual narrowing angle gap, 14 Receiving hole, 2 Valve seat, 21 Limiting platform, 22 Limiting groove, 3 Valve ball, 4 Valve stem, 5 Wedge seal, 51 First bevel, 52 Second arc surface, 53 Third impact surface, 54 Extension platform, 6 Elastic element, 7 Polytetrafluoroethylene rubber pad, 8 Epoxy resin coating. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0021] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be selected to be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0022] like Figures 1 to 4As shown, this utility model provides a ball valve with a hard-seal structure, including a valve body 1, two valve seats 2 fixed in the inner cavity of the valve body 1, a valve ball 3 abutting between the two valve seats 2, and a valve stem 4 with one end extending into the valve ball 3. The valve ball 3 has a ball hole, and the valve body 1 has a fluid channel 11 of the same size as the ball hole. The structure of the valve body 1 and the opening and closing principle between the valve ball 3 and the valve body 1 are existing mature technologies and will not be further described in this application. The valve seat 2 has a chamfered bevel 12 on the side near the valve ball 3, and a gradually narrowing angle gap 13 is formed between the chamfered bevel 12 and the outer surface of the valve ball 3. A wedge-shaped seal 5 is provided in the gradually narrowing angle gap 13. The wedge-shaped seal 5 includes a first inclined surface 51 and a second arc surface 52. The first inclined surface 51 abuts parallel to the chamfered bevel, and the second arc surface 52 abuts against the circumferential surface of the valve ball 3. The valve seat 2 has a fixed section along the direction of the chamfered bevel 12. An elastic element 6 is fixedly installed, and the front end of the elastic element 6 is connected to the front end of the wedge-shaped seal 5. The elastic element 6 axially pushes the wedge-shaped seal 5 along the chamfered slope 12 into the tapered angle gap 13. The wedge-shaped seal 5 has a tapered triangular structure, and the minimum position of the wedge-shaped seal 5 is smaller than the maximum position of the tapered angle gap 13. The wedge-shaped seal 5 is engaged by the tapered angle gap 13 formed by the chamfered slope 12 of the valve seat 2 and the outer surface of the valve ball 3. Combined with the axial thrust of the elastic element 6 along the slope direction, the first slope 51 of the wedge-shaped seal 5 is tightly fitted with the chamfer, and the second arc surface 52 is subjected to radial compression to generate gradient deformation, forming a hard sealing interface that dynamically adapts to the valve ball 3. This structure utilizes the wedge-entry effect of the tapered angle gap 13 and the continuous clamping force of the elastic element 6 to enable the wedge-shaped seal 5 to adaptively enhance the contact stress when the medium pressure fluctuates, significantly improving the sealing reliability under high pressure conditions.

[0023] The valve seat 2 is provided with a receiving hole 14 extending along the chamfered surface 12. The opening of the receiving hole 14 faces the side close to the valve ball 3. The elastic element 6 is disposed in the receiving hole 14. The multiple receiving holes 14 facilitate the installation of the elastic element 6, ensuring that the thrust applied by the elastic element 6 always remains along the direction of the chamfered surface 12, ensuring that the first inclined surface 51 of the wedge-shaped seal 5 always remains parallel and in contact with the chamfered surface, and ensuring the sealing performance of the wedge-shaped seal 5.

[0024] The front end of the wedge seal 5 is provided with an extension platform 54, which extends to the front of the receiving hole 14. The spring is connected to the extension platform 54. The extension platform 54 serves as a rigid connection component between the elastic member 6 and the wedge seal 5, ensuring a stable connection between the elastic member 6 and the wedge seal 5, while allowing the elastic member 6 to maintain an inclined posture to push the wedge seal 5.

[0025] A spring is used as the elastic element 6, which is rigidly connected to the extension platform 54 of the wedge seal 5. The axial preload of the spring drives the wedge seal 5 to continuously wedge into the gradually narrowing angle gap 13 along the chamfered slope 12 of the valve seat 2. This causes the second arc surface 52 of the wedge seal 5 to form a dynamically adapted elastic compression with the circumference of the valve ball 3. The linear elasticity of the spring can efficiently convert the axial thrust into the radial compression force and adaptively adjust the sealing contact stress according to the fluctuation of the medium pressure. This ensures the sealing reliability under high pressure conditions and also offsets the wear or thermal deformation gap between the valve ball 3 and the valve seat 2 through the elastic compensation of the spring. At the same time, the spring structure is simple and compact, without the need for complex guide holes or auxiliary limiting mechanisms, reducing processing costs and facilitating disassembly and maintenance, significantly improving the sealing life and operating condition adaptability of the ball valve.

[0026] A limiting platform 21 is provided at the bottom of the valve seat 2 away from the valve ball 3. The bottom edge of the limiting platform 21 is aligned with the edge of the fluid channel 11. A limiting groove 22 is provided on the limiting platform 21. The limiting groove 22 is located above the bottom edge of the limiting platform 21. The tail end of the wedge seal 5 abuts against the limiting groove 22. When the wedge seal 5 is installed on the valve seat 2, the bottom of the wedge seal 5 will be inserted into the limiting groove 22. The limiting groove 22 can support the tail end of the wedge seal 5, so that the wedge seal 5 can be placed stably on the valve seat 2. This solves the problem that the tail end of the wedge seal 5 will naturally fall down when there is no valve ball 3 to abut against it in the early stage of installation, which caused inconvenience in the early stage of installation.

[0027] The bottom edge of the limiting platform 21 is precisely aligned with the edge of the fluid channel 11 and does not extend into the channel. Its outer wall is parallel to the inner wall of the fluid channel 11, effectively avoiding abrupt changes in cross-section or local eddies caused by the limiting structure extending into the flow channel, thereby significantly reducing fluid resistance and pressure loss. The limiting platform 21 serves as an axial constraint for the wedge seal 5 and ensures that the fluid flows smoothly along the channel.

[0028] The wedge-shaped seal 5 also includes a third impact surface 53, which is an inclined surface that slopes outward from the fluid channel 11. The third impact surface 53 extends from the tail end of the second arc surface 52 to the tail end of the first inclined surface 51, forming an upward inclined surface. The third impact surface 53 of the wedge-shaped seal 5 is an extension surface that slopes outward from the fluid channel 11, and its inclination direction intersects the water flow path at an acute angle. When the medium flows or the pressure inside the valve acts on the third impact surface 53, the fluid kinetic energy and static pressure energy are converted into wedge-shaped seal energy. The axial component of the force of the seal 5 along the chamfered bevel towards the gradually narrowing angle gap 13 drives the wedge seal 5 to further wedge into the gradually narrowing angle gap 13, realizing the water self-tightening effect. This solves the problem of seal loosening caused by fluid impact in the traditional wedge seal 5 of valve seat 2. It not only adaptively compensates for the wear gap between the wedge seal 5 and the valve ball 3 / valve seat 2 through fluid dynamic pressure, but also significantly improves the sealing reliability under high pressure and high speed flow conditions. At the same time, it avoids the need to add a complex external adjustment mechanism, and achieves synergistic enhancement of sealing performance and impact resistance.

[0029] The second arc surface 52 is provided with a polytetrafluoroethylene rubber pad 7, and the third impact surface 53 is coated with an epoxy resin coating 8. The polytetrafluoroethylene rubber pad 7 provided on the second arc surface 52, through its low coefficient of friction and elastic deformation characteristics, forms a flexible sealing interface between the wedge-shaped seal 5 and the circumferential surface of the valve ball 3, and can adaptively compensate for the micro gap between the valve ball 3 and the wedge-shaped seal 5. The epoxy resin coating 8 coated on the third impact surface 53 gives its surface high hardness and wear resistance, which can resist the surface wear caused by high-speed fluid impact and particle scouring, and reduces the adhesion of media through hydrophobic properties, further converting the fluid impact force into the wedge-shaped seal 5 wedging driving force. The two work together to achieve low friction adaptive fitting and impact resistance and wear resistance optimization in dynamic sealing.

[0030] In addition to the preferred embodiments described above, the present invention has other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

Claims

1. A ball valve with a hard-seal structure, comprising a valve body, two valve seats fixed in the inner cavity of the valve body, a valve ball abutting between the two valve seats, and a valve stem extending into the valve ball at one end, wherein the valve ball has a ball hole, and the valve body has a fluid passage of the same size as the ball hole, characterized in that, The valve seat has a chamfered bevel on the side near the valve ball, forming a gradually narrowing angular gap between the chamfered bevel and the outer surface of the valve ball. A wedge-shaped seal is provided within the gradually narrowing angular gap. The wedge-shaped seal includes a first bevel and a second arc surface. The first bevel is parallel to and abuts against the chamfered bevel, and the second arc surface abuts against the circumferential surface of the valve ball. An elastic element is fixedly installed on the valve seat along the direction of the chamfered bevel. The front end of the elastic element is connected to the front end of the wedge-shaped seal. The elastic element axially pushes the wedge-shaped seal along the chamfered bevel into the gradually narrowing sealing gap.

2. The ball valve with a hard-seal structure according to claim 1, characterized in that, The valve seat is provided with a receiving hole extending along the chamfered surface, the opening of the receiving hole facing the side close to the valve ball, and the elastic element is disposed in the receiving hole.

3. The ball valve with a hard-seal structure according to claim 2, characterized in that, The wedge-shaped seal has an extension platform at its front end, which extends to the front of the receiving hole, and the elastic element is connected to the extension platform.

4. The ball valve with a hard-seal structure according to claim 1, characterized in that, The elastic element is a spring.

5. The ball valve with a hard-seal structure according to claim 1, characterized in that, The bottom of the valve seat is provided with a limiting platform at one end away from the valve ball. The bottom edge of the limiting platform is aligned with the edge of the fluid channel. A limiting groove is provided on the limiting platform, and the limiting groove is located above the bottom edge of the limiting platform. The tail end of the wedge-shaped seal abuts against the limiting groove.

6. The ball valve with a hard-seal structure according to claim 5, characterized in that, The wedge-shaped seal also includes a third impact surface, which is an inclined surface that slopes outward from the fluid channel.

7. The ball valve with a hard-seal structure according to claim 6, characterized in that, The second arc surface is provided with a polytetrafluoroethylene rubber pad, and the third impact surface is coated with an epoxy resin coating.

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