No opening and closing resistance butterfly valve

Abstract

The utility model discloses a butterfly valve without opening and closing resistance, comprising a valve body, a valve stem rotatably supported on the valve body, and a valve disc installed on one side of the valve stem, a valve disc sealing surface is provided on the outer periphery of the valve disc, a movable seat ring is movably provided on the valve body along the axial direction of the valve body, the movable seat ring comprises an annular sealing seat portion located at one end, the other end of the movable seat ring opposite to the sealing seat portion is inserted into an annular cavity between a guide sleeve installed at one end of the valve body and the valve body, the inner peripheral surface of the sealing seat portion is a seat ring sealing surface that fits the valve disc sealing surface, and the seat ring sealing surface and the valve disc sealing surface constitute a butterfly valve sealing pair. The butterfly valve without opening and closing resistance adopting the utility model can avoid the extrusion and scraping of the valve disc and the valve seat during the opening and closing process, and can ensure that the seal is leak-free.

Description

Technical Field

[0001] The utility model relates to a valve, in particular to a butterfly valve. Background Art

[0002] The butterfly valve is a commonly used throttling device in the liquid delivery pipeline. It seals and cuts off the flow by fitting the outer periphery of the valve disc with the valve seat on the valve body. The valve disc is driven to rotate by rotating the valve stem so that the outer periphery of the valve disc is out of contact with the valve seat to open the liquid channel. In order to ensure the sealing performance of the butterfly valve, its sealing pair is basically made of elastic materials, and the elastic deformation of the two sealing surfaces of the sealing pair is used to eliminate the gap between the two sealing surfaces. This makes the valve disc and the valve seat always in an extruded state, the opening and closing process has large resistance, severe scraping, and fast wear, resulting in difficulty in opening and closing during use and a short life. Although single eccentric, double eccentric and triple eccentric structures are used to solve the extrusion problem between the butterfly disc and the valve seat, there are still problems such as incomplete elimination of extrusion scraping, inconvenient design and manufacturing, and large opening and closing resistance. Utility Model Content

[0003] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a butterfly valve with no opening and closing resistance, which can avoid squeezing and scraping between the valve disc and the valve seat during the opening and closing process and can ensure its sealing without leakage.

[0004] In order to solve the above technical problems, the utility model provides a butterfly valve with no opening and closing resistance, including a valve body, a valve stem rotatably supported on the valve body and a valve disc installed on one side of the valve stem, a valve disc sealing surface is provided on the outer periphery of the valve disc, and a movable seat ring is movably provided on the valve body along the axial direction of the valve body, the movable seat ring includes an annular sealing seat portion, the inner circumferential surface of the sealing seat portion is a seat ring sealing surface that fits the valve disc sealing surface, and the seat ring sealing surface and the valve disc sealing surface constitute a butterfly valve sealing pair.

[0005] After adopting the above technical scheme, the movable seat ring can change its position along the axial direction of the valve body. When the movable seat ring is in the inner position, the inner circumferential surface of the sealing seat portion thereon is tightly fitted with the sealing surface of the valve disc, and the butterfly valve is in a sealed closed state. When the butterfly valve needs to be opened, the movable seat ring shifts outward, and the inner circumferential surface of the sealing seat portion is out of contact with the sealing surface of the valve disc and is at a certain distance. Then, the butterfly valve can be easily opened by driving the valve disc to rotate by the valve stem. When the butterfly valve needs to be closed, the valve disc is rotated to a position perpendicular to the axis of the valve body, and then the movable seat ring is driven to shift inward, so that the inner circumferential surface on the sealing seat portion is pressed and fitted with the sealing surface of the valve disc, so that the butterfly valve can be closed and the seal can be ensured to be leak-free. Due to the setting of the movable seat ring, the sealing surface of the valve disc will not have any contact with the inner circumferential surface of the sealing seat portion during the rotation of the valve disc when the butterfly valve is opened and closed, so it is impossible to produce extrusion and scratching between the valve seat, the opening and closing resistance of the butterfly valve is extremely small, and the service life of the butterfly valve is also extended.

[0006] In a preferred embodiment of the utility model, a guide sleeve is fixedly connected to the valve body, and the movable seat ring is inserted between the outer periphery of the inner end of the guide sleeve and the valve body. With this embodiment, the stability of the movable seat ring along the axial displacement of the valve body can be ensured.

[0007] In another preferred embodiment of the utility model, the sealing seat portion is connected to the annular piston portion through a connecting sleeve portion, the outer circumferential diameter of the annular piston portion is larger than the outer circumferential diameter of the connecting sleeve portion, the inner circumference of the annular piston portion is sealedly connected to the outer circumference of the inner end of the guide sleeve, the outer circumference of the annular piston portion and the outer circumference of the connecting sleeve portion are respectively sealedly connected to the corresponding circular surfaces on the valve body, and two connecting holes are provided on the valve body, and the two connecting holes are respectively located on the outer side and the inner side of the annular piston portion. When this embodiment is adopted, the outer end face of the annular piston portion will form a closed annular cavity together with the guide sleeve and the valve body, and the inner end face of the annular piston portion will form another closed annular cavity together with the outer peripheral surface of the connecting sleeve portion and the valve body. The two closed annular cavities will be connected to the external hydraulic source through corresponding connecting holes, so that the movable seat ring can be conveniently and quickly driven to shift axially along the valve body through the hydraulic pressure of the external hydraulic system, ensuring that the valve disc sealing surface and the seat ring sealing surface are out of contact during the rotation of the valve disc when the butterfly valve is opened and closed, and after the butterfly valve is closed, the seat ring sealing surface can maintain a close fit with the valve disc sealing surface under the action of hydraulic pressure, further ensuring that the sealing of the butterfly valve sealing pair is leak-free.

[0008] In another preferred embodiment of the utility model, an elastic sealing ring is installed on the valve disc, and the outer peripheral surface of the elastic sealing ring is the valve disc sealing surface. With this embodiment, the elastic sealing ring can make the valve disc sealing surface and the seat ring sealing surface fit better and more tightly, and the sealing effect is better when the butterfly valve is closed.

[0009] In a further preferred embodiment of the utility model, the elastic sealing ring is embedded in the valve disc through a pressure ring. This embodiment can facilitate the installation and replacement of the elastic sealing ring.

[0010] In another further preferred embodiment of the utility model, the seat ring sealing surface is a conical surface. With this embodiment, the seat ring sealing surface can play a certain wedge-tightening role on the valve disc sealing surface, with a good sealing effect, and at the same time, the axial stroke of the movable seat ring can be shortened, making the butterfly valve structure compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following is a further detailed description of the butterfly valve without opening and closing resistance of the utility model in conjunction with the accompanying drawings and specific embodiments.

[0012] Figure 1 It is a structural schematic diagram of a specific implementation method of the utility model butterfly valve without opening and closing resistance;

[0013] Figure 2 yes Figure 1 A partial enlarged view of position A in the structure shown;

[0014] Figure 3 yes Figure 1 Schematic diagram of the structure of the movable seat ring in the structure shown.

[0015] In the figure: 1-valve stem, 2-connecting hole, 3-valve body, 4-movable seat ring, 41-sealing seat portion, 42-annular piston portion, 43-connecting sleeve portion, 44-seat ring sealing surface, 5-butterfly valve sealing pair, 6-guide sleeve, 7-valve disc, 71-valve disc sealing surface, 8-elastic sealing ring, 9-pressure ring. DETAILED DESCRIPTION

[0016] exist Figure 1 and Figure 2 In the shown butterfly valve with no opening and closing resistance, the valve body 3 is a ring-shaped component, and flanges connected to the corresponding liquid inlet or outlet pipelines are provided at both ends. The valve stem 1 is rotatably and sealedly inserted in the middle of the valve body 3 and is perpendicular to the axis of the inner cavity of the valve body 3. A valve disc 7 is installed on one side of the valve stem 1 at a position located in the inner cavity of the valve body 3. The valve disc 7 is a disc-shaped component, and a valve disc sealing surface 71 is provided on its outer periphery. As a preferred embodiment, an elastic sealing ring 8 is installed on the valve disc 7, and the elastic sealing ring 8 is embedded in the valve disc 7 through a pressure ring 9. The outer peripheral surface of the elastic sealing ring 8 protrudes from the disc body of the valve disc 7, namely the valve disc sealing surface 71. A movable seat ring 4 is movably provided on the valve body 3 along the axial direction of the valve body. The movable seat ring 4 includes an annular sealing seat portion 41 located at the inner end. As a preferred embodiment, a guide sleeve 6 is fixedly connected to one end of the valve body 3. The outer end of the guide sleeve 6 is sealed with the valve body 3 through the sealing ring. The outer periphery of the inner end of the guide sleeve 6 and the valve body 3 form an annular cavity. The end of the movable seat ring 4 opposite to the sealing seat portion 41 is inserted into the annular cavity between the outer periphery of the inner end of the guide sleeve 6 and the valve body 3. See Figure 3 The sealing seat portion 41 is connected to the annular piston portion 42 through the connecting sleeve portion 43. The outer diameter of the annular piston portion 42 is larger than the outer diameter of the connecting sleeve portion 43. The inner periphery of the annular piston portion 42 is sealed and connected to the outer periphery of the inner end of the guide sleeve 6 through a sealing ring. The outer periphery of the annular piston portion 42 and the outer periphery of the connecting sleeve portion 43 are respectively sealed and connected to the corresponding circumferential surfaces on the valve body 3 through sealing rings. The inner circumferential surface of the sealing seat portion 41 is a seat ring sealing surface 44 that fits the valve disc sealing surface 71. The seat ring sealing surface 44 and the valve disc sealing surface 71 constitute a butterfly valve sealing pair 5. The seat ring sealing surface 44 is preferably a conical surface.

[0017] Two communicating holes 2 are provided on the valve body 3, and the two communicating holes 2 are respectively located on the outer side and the inner side of the annular piston portion 42. The inner end of the communicating hole 2 located on the outer side of the annular piston portion 42 is connected to a closed annular cavity formed by the outer end face of the annular piston portion 42, the guide sleeve 6 and the valve body 3, and the inner end of the communicating hole 2 located on the inner side of the annular piston portion 42 is connected to another closed annular cavity formed by the inner end face of the annular piston portion 42, the outer peripheral surface of the connecting sleeve portion 43 and the valve body 3. The outer ends of the two communicating holes 2 are connected to an external hydraulic source. In this way, the movable seat ring 4 can be conveniently and quickly driven to shift axially along the valve body 3 through the hydraulic pressure of the external hydraulic system, so that the valve disc sealing surface 71 and the seat ring sealing surface 44 are out of contact during the rotation of the valve disc 7 when the butterfly valve is opened and closed, thereby avoiding the extrusion and scraping of the valve disc 7 and the valve seat during the opening and closing process, and ensuring that the seal is leak-free.

[0018] The above only lists some preferred embodiments of the present invention, but the present invention is not limited thereto, and many improvements and changes can be made. For example, the movable seat ring 4 can be driven by a mechanism driving mechanism such as a fork supported on the valve body 3 instead of being driven by an external hydraulic system through the connecting hole 2. As such, any improvements and changes made on the basis of the basic principle of the present invention should be deemed to fall within the protection scope of the present invention.

Claims

1. A butterfly valve without opening and closing resistance, comprising a valve body (3), a valve stem (1) rotatably supported on the valve body (3), and a valve disc (7) mounted on one side of the valve stem (1), wherein a valve disc sealing surface (71) is provided on the outer periphery of the valve disc (7), and characterized in that: A movable seat ring (4) is movably provided on the valve body (3) along the axial direction of the valve body. The movable seat ring (4) includes an annular sealing seat portion (41). The inner peripheral surface of the sealing seat portion (41) is a seat ring sealing surface (44) that is in contact with the valve disc sealing surface (71). The seat ring sealing surface (44) and the valve disc sealing surface (71) form a butterfly valve sealing pair (5).

2. The butterfly valve without opening and closing resistance according to claim 1 is characterized in that: A guide sleeve (6) is fixedly connected to the valve body (3), and the movable seat ring (4) is inserted between the outer periphery of the inner end of the guide sleeve (6) and the valve body (3).

3. The butterfly valve without opening and closing resistance according to claim 2 is characterized in that: The sealing seat portion (41) is connected to the annular piston portion (42) via a connecting sleeve portion (43); the outer diameter of the annular piston portion (42) is larger than the outer diameter of the connecting sleeve portion (43); the inner periphery of the annular piston portion (42) is sealingly connected to the outer periphery of the inner end of the guide sleeve (6); the outer periphery of the annular piston portion (42) and the outer periphery of the connecting sleeve portion (43) are respectively sealingly connected to corresponding circumferential surfaces on the valve body (3); two communicating holes (2) are provided on the valve body (3); the two communicating holes (2) are respectively located on the outer side and the inner side of the annular piston portion (42).

4. The butterfly valve without opening and closing resistance according to claim 1 is characterized in that: An elastic sealing ring (8) is installed on the valve disc (7), and the outer peripheral surface of the elastic sealing ring (8) is the valve disc sealing surface (71).

5. The butterfly valve without opening and closing resistance according to claim 4 is characterized in that: The elastic sealing ring (8) is embedded on the valve disc (7) via a pressure ring (9).

6. The butterfly valve without opening and closing resistance according to claim 1 is characterized in that: The seat ring sealing surface (44) is a conical surface.

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