A combined sealing structure and sealing method for a water turbine ball valve

Abstract

This invention discloses a combined sealing structure and sealing method for a turbine ball valve, comprising a sealing ring, an expansion member capable of expanding upon absorbing water, and a sealing ring. The sum of the radial thickness of the sealing ring and the linear diameter of the sealing ring is greater than the distance from the bottom of the sealing groove to the cylinder body. The expansion member is located near the inner side of the turbine ball valve. This combined sealing structure has two states: an initial state and a sealed state. In the initial state, the sealing ring, sealing ring, and expansion member are arranged along the axial direction of the metal sealing ring, with the sealing ring located between the sealing ring and the expansion member. After the expansion member expands upon contact with water, it compresses the sealing ring, causing the sealing ring to be located inside the sealing ring and supporting it, thus transforming the initial state into the sealed state. In the sealed state, the sealing ring and sealing ring are arranged radially. The inner side of the sealing ring has an engaging groove for engaging the sealing ring. This invention avoids interference fits and completely prevents damage or torsion of the sealing ring, fundamentally overcoming the problems of traditional combined sealing installations.

Description

Technical Field

[0001] This invention relates to the field of sealing, and in particular to a combined sealing structure and sealing method for a water turbine ball valve. Background Technology

[0002] Common combination seals typically consist of a main sealing ring and an elastomer (such as Step seals and Glyd rings). The main sealing ring is primarily made of polytetrafluoroethylene (PTFE) or polyurethane, while the elastomer is mainly made of rubber. This type of seal is often referred to as a compression seal. It achieves the sealing effect between the sealing ring and the metal surface through interference fit, utilizing the supporting force of the elastomer (O-ring) after compression. It can also compensate for wear of the sealing ring.

[0003] Currently, the turbine ball valve structure in large hydroelectric generators uses a combination seal consisting of polyurethane sealing rings and rubber O-rings, such as... Figure 1 As shown. In the sealing installation of small equipment, this combination seal has the advantages of simple installation and reliable sealing. However, for large equipment such as ball valves, this interference fit often inevitably leads to significant problems: When installing a large sealing assembly with an interference fit, because it cannot be slowly inserted by human "feel," mechanical hoisting can easily damage the sealing lip or cause the sealing strip to twist. Furthermore, since the sealing strip has already filled the sealing groove, this damage is not easily detected during leak testing, and leaks often only appear after the unit has been running for a period of time.

[0004] For many years, the solutions to this problem have been to improve the contact surface and insertion angle of the sealing ring and the insertion component, or to increase the material strength of the sealing ring, but none of these solutions can fundamentally solve the problem. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems by providing a combined sealing structure and sealing method for a water turbine ball valve, which avoids interference fit, completely prevents damage to or torsion of the sealing ring, and fundamentally overcomes the problems of traditional combined sealing installation.

[0006] The technical solution adopted in this invention is as follows: A combined sealing structure for a water turbine ball valve, installed between the cylinder body and a metal sealing ring, located in a sealing groove on the metal sealing ring, includes a sealing ring, an expansion member capable of expanding by absorbing water, and a sealing ring, wherein the sum of the radial thickness of the sealing ring and the linear diameter of the sealing ring is greater than the distance from the bottom of the sealing groove to the cylinder body; the expansion member is close to the inner side of the water turbine ball valve; this combined sealing structure has two states: an initial state and a sealed state; wherein:

[0007] In the initial state, the sealing ring, sealing ring and expansion member are arranged along the axial direction of the metal sealing ring, and the sealing ring is located between the sealing ring and the expansion member;

[0008] When the expansion component expands upon contact with water, it compresses the sealing ring, causing the sealing ring to be positioned inside the sealing ring and supporting it, thus transforming the initial state into a sealed state; in the sealed state, the sealing ring and sealing ring are arranged radially.

[0009] The inner side of the sealing ring has an engagement groove for engaging the sealing ring.

[0010] Furthermore, in the initial state, the sum of the axial width of the sealing ring, the wire diameter of the sealing ring, and the axial width of the expansion element before expansion is greater than the axial width of the sealing groove.

[0011] Furthermore, a chamfer is provided on the side of the sealing ring near the sealing ring, and in the initial state, the chamfer is located on the outer arc of the sealing ring.

[0012] Furthermore, the sealing ring has an "L" shaped cross-section; in the initial state, one side of the sealing ring is in contact with the bottom of the sealing groove; the engaging groove is located on the other side of the sealing ring.

[0013] Furthermore, the radial thickness of the sealing ring and the wire diameter of the sealing ring are both smaller than the distance from the bottom of the sealing groove to the cylinder body.

[0014] Furthermore, the surface of the sealing ring that contacts the cylinder body is designed to be wavy.

[0015] Furthermore, when the sealing ring is in contact with the cylinder and there is a clamping force, the farthest distance between the engagement groove and the bottom of the sealing groove is less than the wire diameter of the sealing ring.

[0016] Furthermore, the cross-section of the engaging groove is circular or polygonal.

[0017] Furthermore, the sum of the axial dimension of the fully expanded component and the axial dimension of the sealing ring is not less than the axial dimension of the sealing groove.

[0018] A sealing method for a water turbine ball valve, utilizing the combined sealing structure of the water turbine ball valve, includes the following steps:

[0019] S1: Install the sealing ring, sealing ring and expansion component into the sealing groove. At this time, there is a gap between the sealing ring, sealing ring and expansion component and the cylinder body.

[0020] S2: Water enters the turbine ball valve and enters the sealing groove through the gap between the metal sealing ring and the cylinder. The expansion component absorbs the water and expands.

[0021] S3: During the expansion process, the expansion component gradually pushes the sealing ring. After being pushed, the sealing ring gradually enters the sealing ring, supporting the sealing ring and causing it to expand outward, gradually approaching and squeezing the cylinder body until the sealing ring is completely inside the sealing ring and located in the engagement groove. At this time, there is a clamping force between the sealing ring and the bottom of the sealing groove, between the sealing ring and the sealing ring, and between the sealing ring and the cylinder body, achieving a sealing state and completing the sealing of the turbine ball valve.

[0022] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0023] 1. This invention uses an expansion component to compress the sealing ring, allowing the sealing ring to work with the sealing ring to complete the combined seal between the cylinder body and the metal sealing ring. This completely avoids damaging or twisting the sealing ring, fundamentally overcoming the problems of traditional combined seal installation.

[0024] 2. The present invention adds an expansion component, which is installed on the inner side near the turbine ball valve. It can continuously contact the water inside the turbine ball valve and maintain an expanded state, thereby making the entire sealing space more compact. The sealing stability of the sealing ring and sealing ring combination is better, and it effectively prevents harmful phenomena such as torsion and slippage from occurring during the sliding process. Attached Figure Description

[0025] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0026] Figure 1 A schematic diagram of an existing combined sealing structure;

[0027] Figure 2 This is a schematic diagram of the combined seal disclosed in this invention in its initial state;

[0028] Figure 3 This is a schematic diagram of the combined seal disclosed in this invention in a sealed state;

[0029] The markings in the diagram are: 1-cylinder body; 2-metal sealing ring; 21-sealing groove; 3-sealing ring; 31-locking groove; 32-chamfer; 4-sealing ring; 5-expansion component. Detailed Implementation

[0030] In the description of this specification, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this specification and simplifying the description, and do not indicate or imply that the device or component 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 specification.

[0031] Furthermore, the use of terms such as "horizontal" or "vertical" in this specification does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this specification, it should also be noted that, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” should be interpreted broadly. For example, a link can be a fixed link, a detachable link, or an integral link; it can be a mechanical link or an electrical link; it can be a direct link or an indirect link through an intermediate medium; it can be a connection within two components.

[0033] Example 1

[0034] like Figures 2-3 As shown, a combined sealing structure for a water turbine ball valve is installed between a cylinder body 1 and a metal sealing ring 2, located within a sealing groove 21 on the metal sealing ring 2, for sealing the gap between the cylinder body 1 and the metal sealing ring 2. This combined sealing structure includes a sealing ring 3, an expansion member 5 capable of expanding upon water absorption, and a sealing ring 4. The sum of the radial thickness of the sealing ring 3 and the linear diameter of the sealing ring 4 is greater than the distance from the bottom of the sealing groove 21 to the cylinder body 1. The expansion member 5 is located near the inner side of the water turbine ball valve. This combined sealing structure has two states: an initial state and a sealed state. Wherein:

[0035] In the initial state, the sealing ring 3, the sealing ring 4, and the expansion member 5 are arranged along the axial direction of the metal sealing ring 2, and the sealing ring 4 is located between the sealing ring 3 and the expansion member 5.

[0036] When the expansion component 5 expands upon contact with water, it compresses the sealing ring 4, causing the sealing ring 4 to be located inside the sealing ring 3 and support the sealing ring 3, thus changing the initial state to a sealed state; in the sealed state, the sealing ring 3 and the sealing ring 4 are arranged radially.

[0037] The inner side of the sealing ring 3 has an engagement groove 31 for engaging the sealing ring 4.

[0038] In this embodiment, the main principle is to utilize the expansion member 5 to expand upon contact with water, pushing the sealing ring 4 so that the sealing ring 4 and the sealing ring 3 are located radially on the same cross section. This creates a clamping force between the sealing ring 4 and the bottom of the sealing groove 21, between the sealing ring 4 and the sealing ring 3, and between the sealing ring 3 and the cylinder body 1, achieving a gap between the combined sealing cylinder body 1 and the metal sealing ring 2. This is different from existing sealing methods described in the background art, such as... Figure 1As shown, the sealing ring 3 and sealing ring 4 are only interlocked between the cylinder body 1 and the metal sealing ring 2 and installed in the sealing groove 21 of the metal sealing ring 2. The combined sealing structure disclosed in this specification uses the expansion member 5 to squeeze the sealing ring 4, so that the sealing ring 4 and the sealing ring 3 can complete the combined seal between the cylinder body 1 and the metal sealing ring 2. It will not damage or twist the sealing ring 3 at all, and fundamentally overcomes the problems of traditional combined seal installation.

[0039] It should be noted that limiting "the sum of the radial thickness of the sealing ring 3 and the diameter of the sealing ring 4 to be greater than the distance from the bottom of the sealing groove 21 to the cylinder body 1" is to ensure that when the sealing ring 3 and the sealing ring 4 are in the sealed state (in radial arrangement), there is a clamping force between the sealing ring 4 and the bottom of the sealing groove 21, between the sealing ring 4 and the sealing ring 3, and between the sealing ring 3 and the cylinder body 1. This is the basis for achieving this combined seal.

[0040] In this embodiment, the expansion member 5 is installed near the inner side of the turbine ball valve, which can continuously contact the water inside the turbine ball valve and maintain an expanded state, thereby making the entire sealing space more compact. The sealing stability of the combination of sealing ring 3 and sealing ring 4 is better, effectively preventing harmful phenomena such as torsion and slippage during the sliding process.

[0041] It should be noted that the expansion member 5 can be made of polyurethane.

[0042] In this embodiment, the shape of the expansion member 5 is also annular, but the cross-section can be rectangular or L-shaped.

[0043] In this embodiment, the locking groove 31 can stably constrain the sealing ring 4 within the sealing ring 3, preventing the sealing ring 4 from detaching from the sealing ring 3 when the turbine ball valve experiences a subsequent water outage due to the expansion member 5 reverting to its original position.

[0044] Example 2

[0045] Based on Example 1, further feasible implementation methods are proposed.

[0046] In one feasible implementation, in the initial state, the sum of the axial width of the sealing ring 3, the wire diameter of the sealing ring 4, and the axial width of the expansion member 5 before expansion is greater than the axial width of the sealing groove 21. Due to this dimensional constraint, in the initial state, at least two components will have overlapping parts. In this implementation, since the sealing ring 4 needs to enter the interior of the sealing ring 3, the sealing ring 3, the sealing ring 4, and the expansion member 5 can be installed into the sealing groove 21 by having a partial radial overlap between the sealing ring 3 and the sealing ring 4. This dimensional constraint ensures that the sealing ring 4 can enter the interior of the sealing ring 3, effectively avoiding interference.

[0047] In one feasible implementation, a chamfer 32 is provided on the side of the sealing ring 3 near the sealing ring 4. In the initial state, the chamfer 32 is located on the outer arc of the sealing ring 4, and the sealing ring 4 is guided into the sealing ring 3 by the chamfer 32.

[0048] In one feasible implementation, the sealing ring 3 has an "L"-shaped cross-section. For ease of explanation, the "L"-shaped sealing ring 3 has a vertical arm and a horizontal arm. In the initial state, the vertical arm of the sealing ring 3 contacts the bottom of the sealing groove 21. The engaging groove 31 is provided on the horizontal arm of the sealing ring 3. By having the vertical arm abut against the inner wall of the sealing groove 21 and supporting the entire sealing ring 3 in the initial state, and with the sealing ring 4 and the sealing ring 3 having a radial overlap, the position of the sealing ring 3 is stabilized, ensuring that when the sealing ring 4 enters the interior of the sealing ring 3, it can counteract the axial pushing force on the sealing ring 3, so that the sealing ring 3 will not tilt when subjected to axial pushing force. The horizontal arm mainly plays a sealing role after the sealing ring 4 enters the interior of the sealing ring 3.

[0049] In one feasible implementation, the radial thickness of the sealing ring 3 and the wire diameter of the sealing ring 4 are both smaller than the distance from the bottom of the sealing groove 21 to the cylinder body 1, so that the sealing ring 3 and the sealing ring 4 do not need to be interference-fitted when installed in the sealing groove 21, thereby simplifying the installation operation.

[0050] In one feasible implementation, the surface of the sealing ring 3 that contacts the cylinder body 1 is set in a wave shape, and each protruding wave peak can form a seal with the cylinder body 1, thereby achieving multiple seals and increasing the sealing effect.

[0051] In one feasible implementation, when the sealing ring 3 is in contact with the cylinder 1 and there is a clamping force, the farthest distance between the engaging groove 31 and the bottom of the sealing groove 21 is less than the wire diameter of the sealing ring 4. This dimensional constraint can ensure that the sealing ring 4 will undergo elastic deformation. The resulting elastic force serves as a squeezing force to push the sealing ring 3, keeping the sealing ring 3 pressed against the cylinder 1, and also sealing the contact surface between the sealing ring 3 and the sealing ring 4. On the other hand, it serves as a force to press the bottom of the sealing groove 21, so that the sealing ring 4 and the sealing groove 21 are sealed.

[0052] Furthermore, the cross-section of the engaging groove 31 is circular or polygonal, and the polygonal shape can be rectangular. By setting and limiting the shape of the engaging groove 31, the position of the sealing ring 4 is constrained on the one hand, and at least two seals can be formed at the contact position between the sealing ring 4 and the sealing ring 3, respectively located on both sides of the radial direction, thus achieving multiple seals and increasing the sealing effect.

[0053] In one feasible implementation, the sum of the axial dimension of the fully expanded expansion member 5 and the axial dimension of the sealing ring 3 is not less than the axial dimension of the sealing groove 21, ensuring that the expansion member 5 can completely push the sealing ring 4 into the sealing ring 3.

[0054] Example 3

[0055] A sealing method for a turbine ball valve, employing the combined sealing structure of the turbine ball valve described in any one of Embodiments 1-2, includes the following steps:

[0056] S1: Insert the sealing ring 3, sealing ring 4 and expansion member 5 into the sealing groove 21. At this time, there is a gap between the sealing ring 3, sealing ring 4 and expansion member 5 and the cylinder body 1.

[0057] S2: Water enters the turbine ball valve and enters the sealing groove 21 through the gap between the metal sealing ring 2 and the cylinder 1. The expansion component 5 absorbs water and expands.

[0058] S3: During the expansion process of the expansion component 5, the sealing ring 4 is gradually pushed. After being pushed, the sealing ring 4 gradually enters the sealing ring 3, supporting the sealing ring 3 and causing the sealing ring 3 to expand outward, gradually approaching and squeezing the cylinder body 1, until the sealing ring 4 is completely inside the sealing ring 3 and the sealing ring 4 is located in the engagement groove 31. At this time, there is a clamping force between the sealing ring 4 and the bottom of the sealing groove 21, between the sealing ring 4 and the sealing ring 3, and between the sealing ring 3 and the cylinder body 1, achieving a sealing state and completing the sealing of the turbine ball valve.

[0059] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A combined sealing structure for a water turbine ball valve, characterized in that: Installed between the cylinder body (1) and the metal sealing ring (2), located in the sealing groove (21) on the metal sealing ring (2), it includes a sealing ring (3), an expansion member (5) that can expand by absorbing water, and a sealing ring (4), and the sum of the radial thickness of the sealing ring (3) and the linear diameter of the sealing ring (4) is greater than the distance from the bottom of the sealing groove (21) to the cylinder body (1); the expansion member (5) is close to the inner side of the turbine ball valve; this combined sealing structure has two states: an initial state and a sealed state; wherein: In the initial state, the sealing ring (3), the sealing ring (4) and the expansion member (5) are arranged along the axial direction of the metal sealing ring (2), and the sealing ring (4) is located between the sealing ring (3) and the expansion member (5); When the expansion component (5) expands upon contact with water, it compresses the sealing ring (4), causing the sealing ring (4) to be located inside the sealing ring (3) and support the sealing ring (3), thus changing the initial state into a sealed state; in the sealed state, the sealing ring (3) and the sealing ring (4) are arranged radially. The inner side of the sealing ring (3) has a locking groove (31) for engaging the sealing ring (4); In the initial state, the sum of the axial width of the sealing ring (3), the wire diameter of the sealing ring (4), and the axial width of the expansion member (5) before expansion is greater than the axial width of the sealing groove (21). The sealing ring (3) has an "L" shaped cross section; in the initial state, one side of the sealing ring (3) is in contact with the bottom of the sealing groove (21); the engaging groove (31) is located on the other side of the sealing ring (3); When the sealing ring (3) is in contact with the cylinder (1) and there is a clamping force, the farthest distance between the engagement groove (31) and the bottom of the sealing groove (21) is less than the wire diameter of the sealing ring (4); The sum of the axial dimension of the fully expanded expansion member (5) and the axial dimension of the sealing ring (3) is not less than the axial dimension of the sealing groove (21).

2. The combined sealing structure according to claim 1, characterized in that: A chamfer (32) is provided on the side of the sealing ring (3) near the sealing ring (4). In the initial state, the chamfer (32) is located on the outer arc of the sealing ring (4).

3. The combined sealing structure according to claim 1, characterized in that: The radial thickness of the sealing ring (3) and the wire diameter of the sealing ring (4) are both smaller than the distance from the bottom of the sealing groove (21) to the cylinder body (1).

4. The combined sealing structure according to claim 1, characterized in that: The surface of the sealing ring (3) that contacts the cylinder (1) is designed to be wavy.

5. The combined sealing structure according to claim 1, characterized in that: The cross-section of the engaging groove (31) is circular or polygonal.

6. A sealing method for a water turbine ball valve, characterized in that: The combined sealing structure of the turbine ball valve according to any one of claims 1-5 includes the following steps: S1: Insert the sealing ring (3), sealing ring (4) and expansion component (5) into the sealing groove (21). At this time, there is a gap between the sealing ring (3), sealing ring (4) and expansion component (5) and the cylinder body (1). S2: Water enters the water turbine ball valve and enters the sealing groove (21) through the gap between the metal sealing ring (2) and the cylinder (1). The expansion component (5) absorbs water and expands. S3: During the expansion process of the expansion component (5), the sealing ring (4) is gradually pushed. After being pushed, the sealing ring (4) gradually enters the sealing ring (3) and supports the sealing ring (3), causing the sealing ring (3) to expand outward, gradually approach and squeeze the cylinder body (1) until the sealing ring (4) is completely inside the sealing ring (3) and the sealing ring (4) is located in the engagement groove (31). At this time, there is a pressing force between the sealing ring (4) and the bottom of the sealing groove (21), between the sealing ring (4) and the sealing ring (3), and between the sealing ring (3) and the cylinder body (1), achieving a sealing state and completing the sealing of the turbine ball valve.

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