Ball valve seals and ball valves

Abstract

A ball valve seal is arranged between the valve seat and the valve body of the ball valve, and the seal comprises an inner support, a compensation member and two relatively arranged sealing rings, the sealing ring is connected to the inner support and the inner support is limited by the sealing ring, both ends of the sealing ring are provided with an arc groove, the arc groove is provided with a compensation member, the outer side of each sealing ring forms a barb, the barb extends from the outer side of the sealing ring to the inner side of the sealing ring, the inner side of each sealing ring forms an annular groove, the two annular grooves are connected to form an elastic support groove, the inner support is installed in the elastic support groove, the outer periphery of the inner support forms a fitting surface and an elastic support surface at the position corresponding to each sealing ring, the fitting surface and the elastic support surface are adjacent to each other, and the elastic support surface is an inclined surface, such a setting reduces the stress concentration at the contact position between the seal and the ball and the valve seat, while providing a better sealing effect, reducing the torsional force, and facilitating the opening and closing of the ball valve.

Description

Technical Field

[0001] The present invention relates to the technical field of ball valves, and more specifically, the present invention relates to a ball valve sealing structure. Background Art

[0002] The ball valve opening and closing part (ball) is driven by the valve seat and rotates around the axis of the ball valve. It can also be used for fluid regulation and control. The hard-sealed V-type ball valve has a strong shear force between its V-type ball core and the metal valve seat with hard alloy surfacing, which is particularly suitable for media containing fibers, tiny solid particles, etc. The multi-way ball valve can not only flexibly control the confluence, diversion, and flow direction switching of the medium on the pipeline, but also close any channel and connect the other two channels. This type of valve should generally be installed horizontally in the pipeline. Ball valves are divided into pneumatic ball valves, electric ball valves and manual ball valves according to the driving mode. The existing ball valve sealing structure mainly uses the convex structure on the periphery to achieve elastic line sealing. The main principle is: the sealing member includes an elastic ring and an elastic convexity covering the elastic ring, the elastic convexity contacts the valve seat, and the elastic ring also presses the elastic convexity to compress the ball and the valve seat, thereby achieving the seal between the valve seat and the ball. However, the existing seal design is prone to increased stress at the contact site, which leads to increased torsional force, slowing down the valve opening and closing speed and reducing the sensitivity of the valve. In addition, changes in temperature rise are also more likely to cause deformation of the seal, affecting the sealing effect. Summary of the invention

[0003] In view of this, a ball valve and a sealing device applied to the ball valve are provided.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A ball valve seal is arranged between the valve seat and the valve body of the ball valve, the seal comprising an inner support, a compensation member and two relatively arranged sealing rings, the sealing ring is connected to the inner support and the inner support is limited by the sealing ring, arc grooves are provided at both ends of the sealing ring, a compensation member is provided in the arc groove, a barb is formed on the outer side of each sealing ring, the barb extends from the outer side of the sealing ring to the inner side of the sealing ring, an annular groove is formed on the inner side of each sealing ring, the two annular grooves are connected to form an elastic support groove, the inner support is installed in the elastic support groove, the outer periphery of the inner support forms a fitting surface and an elastic support surface at the position corresponding to each sealing ring, the fitting surface and the elastic support surface are adjacent to each other, and the elastic support surface is an inclined surface.

[0006] Preferably, a notch is provided on the outer side of the inner support member so that a step is formed on the outer side of the inner support member, and the barb is snap-connected with the notch.

[0007] Preferably, the sealing member has two end surfaces, the arc groove is opened from the corresponding end surface toward the direction where the notch is located, and the elastic support surface is obliquely intersected with the corresponding two end surfaces and the corresponding fitting surface.

[0008] Preferably, the step includes a first step surface and a second step surface, the first step surface is closer to the center line of the sealing ring relative to the second step surface, and the second step surface is a fitting surface.

[0009] Preferably, the intersection angle between the fitting surface and the elastic supporting surface is greater than 120 degrees, the end edge of the barb is chamfered, and the angle between the surface where the chamfer is located and the center line of the sealing ring is less than 60 degrees.

[0010] Preferably, the inner support member is an elastic ring, and the two ends of the inner support member hold the corresponding sealing ring tightly. The two ends of the inner support member are conical, and the inner side of the sealing ring is arc-shaped and convex inwardly relative to the inner ring surface of the inner support member.

[0011] Preferably, each sealing ring is provided with at least two arc-shaped grooves, the two arc-shaped grooves are spaced apart inside and outside, and compensators are provided in the arc-shaped grooves.

[0012] Preferably, the compensator is an elastic member.

[0013] A ball valve comprises a valve body, a valve seat, a valve cover, a valve stem and a sphere, wherein the valve body is provided with a medium inlet and a medium outlet, the valve seat is located in the valve body, the valve seat forms an inner cavity and is provided with flow channels corresponding to the medium inlet and the medium outlet, the sphere is located in the inner cavity, the valve cover is sealed and connected to both sides of the valve body, the bottom of the valve stem is connected to the sphere, the top of the valve stem is connected to a driving mechanism, and a ball valve sealing structure described in any one of the above items is installed between the valve seat and the sphere.

[0014] Preferably, a bottom mounting opening is provided at the bottom of the valve body, the bottom mounting opening is communicated with the inner cavity, a support rod is fixed at the bottom mounting opening, and the upper portion of the support rod extends into the inner cavity and is connected to the ball.

[0015] The beneficial effects of the present invention are as follows: a seal is arranged between the valve ball and the valve seat, and the seal is subjected to pressure from the valve body and the ball. The elastic supporting surface and the chamfer cause the seal to produce elastic deformation, and the elastic force generated by the deformation compensates for the pressure of the system. After this arrangement, the stress concentration at the contact position between the seal and the ball and the valve seat is reduced, and while providing a better sealing effect, the torsional force is reduced, thereby facilitating the opening and closing of the ball valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A cross-sectional view of the sealing member of the present invention along the center line direction;

[0018] Figure 2 It is a schematic diagram of the structure inside the seal of the present invention;

[0019] Figure 3 This is a schematic diagram of the ball valve structure of the present invention;

[0020] Figure 4 for Figure 3 A magnified image of point A;

[0021] Figure 5 This is a schematic diagram of the structure inside a seal according to another embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] The present invention provides the following technical solutions:

[0025] Reference Figures 1 to 5The above is a preferred embodiment of the ball valve seal provided by the present invention, the ball valve seal is suitable for being installed between the valve seat and the ball, the seal comprises an inner support 1, a compensation member 2 and two relatively arranged sealing rings 3, the sealing ring 3 is connected to the inner support 1 and the inner support 1 is limited by the sealing ring 3, arc grooves 4 are provided at both ends of the sealing ring 3, the compensation member 2 is provided in the arc groove 4, a barb 6 is formed on the outer side of each sealing ring 3, the barb 6 extends from the outer side of the sealing ring 3 to the inner side of the sealing ring 3, an annular groove 7 is formed on the inner side of each sealing ring 3, the two annular grooves 7 are connected to form an elastic support groove 8, the inner support 1 is installed in the elastic support groove 8, the outer periphery of the inner support 1 forms a fitting surface 101 and an elastic support surface 102 at the position corresponding to each sealing ring 3, the fitting surface 101 and the elastic support surface 102 are adjacently arranged, and the elastic support surface 102 is an inclined surface. In this embodiment, the inner support member 1 is provided as a whole for illustration. In a specific implementation, the inner support member 1 can also be provided as two inner support sub-members 11 with the same structure. The two inner support sub-members 11 are respectively installed in the corresponding annular grooves 7. Figures 1-2 The outer side of the sealing ring 3 is arc-shaped and protrudes at the position corresponding to the arc groove 4, so that the uniformity of the thickness of the sealing ring is ensured, and the protruding arc is used to form a line seal by the extrusion force during installation, thereby ensuring the sealing effect.

[0026] The material of the inner support member 1 is high-quality thermoplastic material injection molding. Specifically, its material can be polyetheramide, polyester, styrene / ethylene / butylene / styrene block copolymer, polyurethane, polyolefin elastomer and their mixtures. The flexural modulus of the thermoplastic elastomer is at least 5MPa. In this embodiment, the material of the sealing ring is modified PTFE material.

[0027] Preferably, a notch 12 is provided on the outer side of the inner support member 1 so that a step 13 is formed on the outer side of the inner support member 1, and the barb 6 is snap-connected with the notch 12. The step 13 includes a first step surface 131 and a second step surface 132, the first step surface 131 is closer to the center line of the sealing ring 3 relative to the second step surface 132, and the second step surface 132 is the above-mentioned fitting surface 101.

[0028] The sealing member has two end faces 8, and the arc groove 4 is opened from the corresponding end face 8 toward the direction where the notch 12 is located. The elastic support surface 102 is obliquely intersected with the corresponding two end faces 8 and the corresponding fitting surface 101.

[0029] The intersection angle between the fitting surface 101 and the elastic support surface 102 is greater than 120 degrees, and the end edge of the barb 6 is provided with a chamfer 61, and the angle a between the surface 610 where the chamfer 61 is located and the center line of the sealing ring is less than 60 degrees. After the seal is installed between the valve body and the ball, the seal will be subjected to the pressure from the valve body and the ball. The elastic support surface 102 and the chamfer 61 cause the seal to produce elastic deformation, and the elastic force generated by the deformation compensates for the pressure of the system. After such a setting, the stress concentration at the contact position between the seal and the ball and the valve seat is reduced, and while providing a better sealing effect, the torsional force is reduced, which facilitates the opening and closing of the ball valve.

[0030] like Figure 5 In the present embodiment, the inner support member 1 is an elastic ring, and the two ends of the inner support member 1 support the corresponding sealing ring 3, and the two ends of the inner support member 1 are conical, and the inner side of the sealing ring 3 is arc-shaped and protrudes inward relative to the inner ring surface of the inner support member 1. When the inner support member 1 is an elastic ring, the inner support member 1 can also be composed of a metal frame 11-1 and an elastomer 11-2 coated on the outer side of the metal frame 11-1. The elastomer 11-2 is formed on the outer periphery of the metal frame 11-1 in the form of injection molding. The metal frame 11-1 can be a continuous metal ring. The thickness ratio of the metal ring to the thickness of the entire inner support member 1 is preferably selected between 1:10 and 1:15. When the thickness of the metal ring is relatively thick, it affects the elastic properties of the inner support member 1. After such a setting, the deformation of the seal caused by temperature difference can be effectively reduced, which helps to improve the sealing of the system and improve the stability of the structure.

[0031] At least two arc grooves 4 are provided for each sealing ring 3. The two arc grooves 4 are spaced apart inside and outside, and a compensating member 2 is provided in each arc groove 4. The compensating member 2 is a spring, and the spring may include, for example, a spring with a circular cross-section, such as a helical spring, a double helical spring, a U-shaped spring, a C-shaped spring, a V-shaped spring or a spring of any other shape, and the spring is suitable for providing a radially outward biasing force. In this embodiment, the compensator is made of a flat metal spiral wound and welded end to end into a circular ring. Multiple compensating members 2 can be provided in each arc groove 4, and each compensating member 2 is concentrically sleeved with each other. This can increase the pressure resistance of the sealing ring.

[0032] As shown in the figure, the present invention also provides a ball valve, which includes a valve body 12, a valve seat 13, a valve cover 14, a valve stem 15, and a ball 16. The valve body 12 is provided with a medium inlet 121 and a medium outlet 122. The valve seat 13 is located in the valve body 12, and the valve seat 13 forms an inner cavity 131 and is provided with a flow channel 132 corresponding to the medium inlet 121 and the medium outlet 122. The ball 16 is located in the inner cavity 131. The valve cover 14 is sealed and connected to both sides of the valve body 12. The bottom of the valve stem 15 is fixedly connected to the ball 16, and the top of the valve stem 15 is connected to the driving mechanism. The ball valve seal is installed between the valve seat 13 and the ball 16. The inner ring of the ball valve seal is in close contact with the outer periphery of the ball 16, and the outer ring of the ball valve seal is in sealing contact with the valve seat 13. Specifically, a sealing groove 18 is provided on the side of the valve seat 13 facing the ball, and the ball valve seal is sealed and installed in the sealing groove 18. Double sealing is formed by the pressing contact between the inner support member, the sealing ring and the spherical surface.

[0033] An annular groove 7 is provided in the seal for installing the inner support 1, and the inner support 1 can not only strengthen the axial force of the seal, but also reduce the stress concentration between the sealing contact ball and the seal: the forces on the surfaces where the fitting surface 101 and the elastic support surface 102 are located are perpendicular to the corresponding surfaces, and a force F intersecting with the fitting surface 101 is formed at the elastic support surface 102. After such a setting, there is a force F in the direction perpendicular to the elastic support surface 102 and a force perpendicular to the fitting surface between the seal and the valve seat, and the force F will compensate and balance with the force in the direction perpendicular to the fitting surface, thereby reducing the stress concentration at the contact position between the seal and the ball and the valve seat, reducing the torsion between the seal and the ball, and facilitating the opening of the ball.

[0034] In order to match the spherical surface, the inner diameter of the sealing ring near the center of the sphere is larger than the inner diameter of the sealing ring relative to the center of the sphere, and can correspond to the arc surface of the sphere when matched with the inner support. In other words, the sizes of the two sealing rings are not the same.

[0035] A bottom installation opening 123 is provided at the bottom of the valve body 12 , and the bottom installation opening 123 is communicated with the inner cavity 131 . A support rod 17 is fixed inside the bottom installation opening 123 , and the upper portion of the support rod 17 extends into the inner cavity 131 and is connected to the ball 16 .

[0036] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ball valve seal, arranged between a valve seat and a valve body of a ball valve, characterized in that: The sealing member includes an inner support member, a compensation member and two relatively arranged sealing rings, the sealing ring is connected to the inner support member and the inner support member is limited by the sealing ring, arc grooves are provided at both ends of the sealing ring, a compensation member is provided in the arc groove, a barb is formed on the outer side of each sealing ring, the barb extends from the outer side of the sealing ring to the inner side of the sealing ring, an annular groove is formed on the inner side of each sealing ring, the two annular grooves are connected to form an elastic support groove, the inner support member is installed in the elastic support groove, the outer periphery of the inner support member forms a fitting surface and an elastic support surface at the position corresponding to each sealing ring, the fitting surface and the elastic support surface are adjacent to each other, the elastic support surface is an inclined surface, a notch is provided on the outer side of the inner support member so that a step is formed on the outer side of the inner support member, and the barb is snap-connected with the notch.

2. The ball valve seal according to claim 1, characterized in that: The sealing member has two end surfaces, the arc groove is opened from the corresponding end surface toward the direction where the notch is located, and the elastic support surface is obliquely intersected with the corresponding two end surfaces and the corresponding fitting surface.

3. The ball valve seal according to claim 2, characterized in that: The step includes a first step surface and a second step surface. The first step surface is closer to the center line of the sealing ring relative to the second step surface, and the second step surface is a fitting surface.

4. The ball valve seal according to claim 1, 2 or 3, characterized in that: The intersection angle between the fitting surface and the elastic supporting surface is greater than 120 degrees, the end edge of the barb is chamfered, and the angle between the surface where the chamfer is located and the center line of the sealing ring is less than 60 degrees.

5. The ball valve seal according to claim 4, characterized in that: The inner support is an elastic ring, and the two ends of the inner support hold the corresponding sealing ring tightly. The two ends of the inner support are conical, and the inner side of the sealing ring is arc-shaped and convex inwardly relative to the inner ring surface of the inner support.

6. The ball valve seal according to claim 4, characterized in that: Each sealing ring is provided with at least two arc-shaped grooves, the two arc-shaped grooves are arranged at intervals inside and outside, and compensation pieces are arranged in the arc-shaped grooves.

7. The ball valve seal according to claim 1, characterized in that: The compensating member is an elastic member.

8. A ball valve, characterized in that: The utility model comprises a valve body, a valve seat, a valve cover, a valve stem and a ball. The valve body is provided with a medium inlet and a medium outlet. The valve seat is located in the valve body. The valve seat forms an inner cavity and is provided with flow channels corresponding to the medium inlet and the medium outlet. The ball is located in the inner cavity. The valve cover is sealed and connected to both sides of the valve body. The bottom of the valve stem is connected to the ball, and the top of the valve stem is connected to the driving mechanism. A ball valve seal as described in any one of claims 1 to 7 is installed between the valve seat and the ball.

9. The ball valve according to claim 8, characterized in that: A bottom installation opening is arranged at the bottom of the valve body, the bottom installation opening is communicated with the inner cavity, a support rod is fixed at the bottom installation opening, and the upper part of the support rod extends into the inner cavity and is connected with the ball.

Images