Double eccentric butterfly valve

Abstract

The present invention discloses a double eccentric butterfly valve, comprising a valve body, a valve stem, a butterfly plate, and a valve seat. The upper and lower ends of the valve body are respectively provided with an upper axial hole and a lower axial hole. The valve stem is sequentially inserted into the upper and lower axial holes, and the portion of the valve stem located in the inner cavity of the valve body is linked to the butterfly plate. The valve seat is made of an elastic material and is mounted on the inner wall of the valve body for contacting with the butterfly plate to form a sealing fit when the valve is closed. The butterfly plate comprises a mounting body, a sealing ring, a first linkage assembly, and a second linkage assembly. When the valve is opened, the valve stem drives the sealing ring to move toward the mounting body through the first linkage assembly so that it quickly disengages from the valve seat. When the valve is closed, the valve stem drives the sealing ring to move away from the mounting body through the second linkage assembly so that it quickly approaches the valve seat. The present invention can enable the butterfly plate to quickly disengage from or abut against the floating valve seat at the moment the valve is opened and closed, thereby reducing wear on the valve sealing pair and significantly improving the service life of the valve.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, in particular to a double eccentric butterfly valve. Background Art

[0002] In order to ensure the pressure resistance and stability of the butterfly valve and avoid excessive extrusion between the valve disc and the valve seat, most existing butterfly valves adopt a double eccentric structure. The double eccentric structure means that the valve stem axis deviates from the center of both the butterfly disc and the valve body. After the valve stem drives the butterfly disc to rotate and open, the butterfly disc can quickly separate from the valve seat, greatly eliminating unnecessary excessive extrusion and scraping between the butterfly disc and the valve seat, reducing the torque when the butterfly valve is opened, reducing wear and extending the life of the valve seat.

[0003] In order to further improve the service life of the butterfly valve, a butterfly valve with a floating valve seat structure has emerged in the existing technology. Its valve seat adopts an elastic structure or a combination structure of a metal valve seat and a spring, so that the valve seat can float and compensate in the axial direction. Therefore, even if the valve seat sealing surface or the butterfly plate sealing surface is worn, the valve seat can always be driven by the elastic force to stick to the butterfly plate sealing surface.

[0004] For example, Chinese utility model patent application number CN202022899893.1 discloses a floating valve seat structure for a bidirectional soft-seal butterfly valve. The structure comprises a floating valve seat, which is sealed and pressed into the valve body by a sealing pressure ring. A flange is provided on the inner side of the valve body, cooperating with the floating valve seat. The flange is located on the side away from the sealing pressure ring, and a gap is left between the floating valve seat and the flange of the valve body. The floating valve seat has a trapezoidal groove on its end near the valve body, which contains a first sealing ring. A second sealing ring is provided on the side of the floating valve seat near the sealing pressure ring. A valve plate is provided within the valve body, cooperating with the floating valve seat. The end surface of the valve plate near the floating valve seat is spherical. This design utilizes a soft floating valve seat and an O-ring to achieve bidirectional sealing of the butterfly valve, offering outstanding characteristics such as wear resistance, stable sealing, and low technical difficulty.

[0005] However, this structure increases the contact time between the disc and seat during opening and closing. While this ensures the valve's sealing performance and extends its service life to a certain extent, if the contact time between the disc and seat during opening and closing is further reduced, the wear of the valve seal can be further reduced, significantly extending the valve's service life. Therefore, structural improvements are essential. Summary of the Invention

[0006] The purpose of the present invention is to provide a double eccentric butterfly valve. At the moment of valve opening and closing, the butterfly plate can quickly separate from or press against the floating valve seat, thereby reducing the wear of the valve sealing pair and significantly improving the service life of the valve.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a double-eccentric butterfly valve, comprising a valve body, a valve stem, a butterfly plate and a valve seat, wherein an upper shaft hole and a lower shaft hole are respectively provided at the upper and lower ends of the valve body, the valve stem is sequentially passed through the upper shaft hole and the lower shaft hole, and the valve stem is located in the inner cavity of the valve body and is linked to the butterfly plate, the valve seat is made of elastic material, the valve seat is installed on the inner wall of the valve body and is used to abut against the butterfly plate to form a sealing fit when the valve is closed; the butterfly plate comprises a mounting body, a sealing ring, a first linkage assembly and a second linkage assembly, and the sealing ring is movably connected to the mounting body through the first linkage assembly and the second linkage assembly; when the valve is opened, the valve stem drives the sealing ring to move toward the mounting body through the first linkage assembly so that it quickly separates from the valve seat, and when the valve is closed, the valve stem drives the sealing ring to move toward the direction away from the mounting body through the second linkage assembly so that it quickly approaches the valve seat.

[0008] By adopting the above technical solution, regardless of whether the valve seat is a fixed structure or a floating structure, at the moment of valve opening and closing, the valve stem can drive the sealing ring of the butterfly plate to quickly approach or move away from the valve seat, thereby reducing the wear of the valve sealing pair and significantly improving the service life of the valve.

[0009] The present invention is further configured such that the first linkage component includes a plurality of groups, the first linkage component includes a screw and a return spring, the sealing ring is provided with a guide groove for the side of the installation body to extend into, and a guide plate matching the guide groove is installed on the installation body, the sealing ring is installed with a limit ring at a position corresponding to the outer end of the guide groove, the limit ring is provided with a plurality of screw holes corresponding to the number of the first linkage component, one end of the screw is threadedly connected to the screw hole, the other end of the screw is provided with a smooth rod part, the guide plate is provided with a guide hole matching the smooth rod part, the return spring is sleeved on the outer periphery of the screw, and the two ends of the return spring are respectively abutted against the guide plate and the limit ring.

[0010] By adopting the above technical solution, the first linkage component is used to apply a pre-tightening force to the sealing ring toward the installation body, so that it can quickly detach from the valve seat under specific conditions. In addition, the guide structure design between the screw and the guide plate also makes the sealing ring move more smoothly and reliably.

[0011] The present invention is further configured such that the guide plate is connected to the mounting body via a locking screw, and the mounting body is provided with a recess for the screw head of the locking screw to be embedded in; the sealing ring is provided with a threaded groove at a position corresponding to the outer end of the guide groove, and the limiting ring is threadedly connected to the threaded groove.

[0012] By adopting the above technical solution, the positioning installation of the guide plate and the limit ring can be achieved, the structure is simple and reliable, and the disassembly and assembly are very convenient.

[0013] The present invention is further configured such that the limiting ring includes a mounting ring and a pressure ring, the pressure ring is threadedly engaged with the thread groove, the screw hole is arranged on the mounting ring, the mounting ring is arranged on the inner circumference of the pressure ring, and the inner end of the pressure ring is provided with a conical annular limiting groove, and the outer circumference of the mounting ring is provided with a limiting flange that fits with the annular limiting groove.

[0014] By adopting the above technical solution, the limit ring adopts a combination of an installation ring and a pressure ring, which can realize the adjustment of the position of the screw hole on the installation ring, making it easier to align it with the guide hole, so that the smooth rod part of the screw can be smoothly and quickly inserted into the guide hole when installing the screw.

[0015] The present invention is further configured such that a circular track groove is provided on the inner end face of the thread groove along the circumferential direction, a plurality of grooves connected to the track groove are distributed in a circular array on the inner end face of the mounting ring, balls are rolled in the grooves, and the ball parts extend into the track groove and roll with the track groove.

[0016] By adopting the above technical solution, a rolling structure is provided between the mounting ring and the pressing ring, which can reduce the rotational friction of the mounting ring, making the rotation operation easier and less abrasive.

[0017] The present invention is further configured such that the number of the second linkage components is two groups, the second linkage components include a positioning adjustment sleeve, a linkage ball and a linkage pin, the positioning adjustment sleeve is arranged on the outer periphery of the valve stem, the two groups of positioning adjustment sleeves of the second linkage components are respectively arranged at the upper and lower ends of the butterfly plate, the inner ends of the upper shaft hole and the lower shaft hole are respectively provided with a positioning groove for the outer end of the corresponding positioning adjustment sleeve to be embedded, a positioning recess is provided on the inner circular surface of the positioning groove, a positioning convex portion is provided on the positioning adjustment sleeve that fits with the positioning recess, a circular hole is provided through the side of the positioning adjustment sleeve, and the The linkage ball and the linkage pin are arranged in the circular hole. The outer circular surface of the valve stem is provided with an arc-shaped groove with a length of one-quarter of a circle. The arc-shaped groove includes an inclined groove section with uniformly varying depth and a flat groove section with constant depth. The flat groove section is arranged at the deeper end of the inclined groove section. The linkage ball partially extends into the arc-shaped groove and rolls with the arc-shaped groove. The linkage pin partially extends out of the circular hole and abuts against the end of the sealing ring close to the installation body. When the linkage ball rolls in the inclined groove section, the linkage pin expands and contracts axially in the circular hole, and the sealing ring moves in the direction of approaching or moving away from the installation body.

[0018] By adopting the above technical solution, when the valve stem drives the butterfly plate to rotate and close the valve, the linkage ball slides relatively from the flat groove section to the inclined groove section. When the linkage ball rolls in the flat groove section, the distance between the sealing ring and the installation body remains unchanged. When the butterfly plate is about to seal with the valve seat, the linkage ball moves to the inclined groove section, and when rolling in the inclined groove section, the linkage ball pushes the linkage ball, and the linkage ball pushes the sealing ring toward the valve seat. When the valve is fully closed, the sealing ring is pressed against the valve seat surface, and the reset spring is compressed to store energy; during the opening operation, on the contrary, the linkage ball and the linkage ball gradually move away from the sealing ring. Under the action of the reset spring, the sealing ring quickly separates from the valve seat, thereby greatly reducing the friction generated by the sealing pair during the opening and closing process of the valve.

[0019] The present invention is further configured such that an annular adjustment groove is respectively provided at a position on the outer circumference of the valve stem corresponding to the inner side of the two positioning adjustment sleeves, a linkage sleeve is embedded in the annular adjustment groove, the linkage sleeve comprises a first half ring and a second half ring, the ends of the first half ring and the second half ring are abutted to form a full ring shape, a locking protrusion is respectively provided at both ends of the first half ring, a locking groove which fits with the corresponding locking protrusion is respectively provided at both ends of the second half ring, and the arc groove is provided on the outer circumferential surface of the first half ring.

[0020] By adopting the above technical solution, the arc groove is set on the split linkage sleeve instead of on the valve stem. The linkage sleeve with different arc groove designs can be replaced according to actual conditions to adapt to different valve seats without replacing the entire valve stem, which can reduce production costs. At the same time, the linkage sleeve is wrapped in the corresponding annular adjustment sleeve to play a fixing role, making its installation structure more convenient and stable.

[0021] The present invention is further configured as follows: the valve seat includes a valve seat body, a connecting portion with an L-shaped cross-section arranged at the outer circle of the valve seat body, an elastic movable portion arranged at the inner circle of the valve seat body, and a sealing portion arranged on the inner side of the elastic movable portion; the side portion of the valve body is also equipped with a pressure ring for pressing the valve seat against the inner wall of the valve body through a fastener, and the pressure ring is provided with a movable groove for the sealing portion of the valve seat to extend into; when the sealing portion is subjected to force, the elastic movable portion can move in the movable groove.

[0022] By adopting the above technical solution, the flexible lip-shaped valve seat ensures reliable closing and can automatically compensate for wear. The movable groove allows the valve seat to be deformed and can also limit excessive deformation of the valve seat.

[0023] The present invention is further configured such that a fireproof graphite pad is sandwiched between the valve seat and the inner wall of the valve body, and the fireproof graphite pad is provided with an annular bending portion for pressing against the outer circumferential surface of the sealing ring.

[0024] By adopting the above technical solution, it can be ensured that the valve can still maintain effective sealing under high temperature or fire conditions, preventing secondary disasters caused by medium leakage and ensuring the inherent safety of the system.

[0025] The present invention is further configured as follows: the valve stem includes an upper shaft rod, a lower shaft rod and a linkage sleeve, the lower end of the upper shaft rod is provided with a driving cam, the upper end of the lower shaft rod is provided with a driven cam coaxially arranged with the driving cam, a gasket is provided between the driving cam and the driven cam, the linkage sleeve is sleeved on the driving cam, the gasket and the outer periphery of the driven cam, a plurality of arc-shaped recesses are provided along the circumferential direction on the inner circular surface of the linkage sleeve, an elastic convex portion is formed between each two adjacent arc-shaped recesses, and a clearance hole is provided on the linkage sleeve corresponding to the outer periphery of each elastic convex portion, the outer periphery of the driving cam is provided with a plurality of driving protrusions for embedding the arc-shaped recesses, and the outer periphery of the driven cam is provided with a plurality of driven protrusions for embedding the arc-shaped recesses.

[0026] By adopting the above technical solution, firstly, the valve stem adopts a split structure. Since the valve stem passes through the valve body from top to bottom, and the upper end also extends upward to connect with the drive device, the overall structure is long, and the axial concentricity is difficult to ensure, which makes processing more difficult. Therefore, the split structure is conducive to the processing and assembly of the valve stem; secondly, a linkage sleeve is used to transmit the upper shaft rod and the lower shaft rod. It adopts a tooth engagement method for transmission, and the transmission ratio is high. When the butterfly plate is stuck or has been opened or closed in place, the lower shaft rod does not move, and the torque generated by the upper shaft rod will cause the elastic convex part of the linkage sleeve to deform, thereby causing the upper shaft rod to idle, avoiding excessive torque from damaging the butterfly plate or valve seat, and also preventing the drive device (such as a motor) from being damaged due to overload. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a perspective view of the entire embodiment 1;

[0028] Figure 2 A cross-sectional view of the entire embodiment 1;

[0029] Figure 3 for Figure 2 A schematic diagram of the enlarged structure of the middle part A;

[0030] Figure 4 Schematic diagram of the installation structure of the limit ring in Example 1;

[0031] Figure 5 A three-dimensional diagram of the linkage sleeve in Example 1;

[0032] Figure 6 This is an exploded view of the linkage sleeve in Example 1;

[0033] Figure 7 A cross-sectional view of the entire embodiment 2;

[0034] Figure 8 for Figure 7 A schematic diagram of the enlarged structure of the middle part B;

[0035] Figure 9 Schematic diagram of the matching structure of the upper shaft rod, the lower shaft rod and the linkage sleeve in Example 2.

[0036] In the figure: 1. Valve body; 2. Valve stem; 3. Butterfly plate; 4. Valve seat; 5. Upper shaft hole; 6. Lower shaft hole; 7. Mounting body; 8. Sealing ring; 9. First linkage assembly; 10. Second linkage assembly; 11. Screw; 12. Return spring; 13. Guide groove; 14. Guide plate; 15. Limiting ring; 16. Screw hole; 17. Polished rod; 18. Guide hole; 19. Locking screw; 20. Gap groove; 21. Thread groove; 22. Mounting ring; 23. Pressing ring; 24. Annular limiting groove; 25. Limiting flange; 26. Track groove; 27. Groove; 28. Ball; 29. ​​Positioning adjustment sleeve; 30. Linkage ball; 31. Linkage pin; 32. Positioning groove; 33. Positioning recess ;34. Positioning convex portion;35. Circular hole;36. Arc groove;37. Bevel groove section;38. Flat groove section;39. Annular adjustment groove;40. Linkage sleeve;41. First half ring;42. Second half ring;43. Locking protrusion;44. Locking groove;45. Valve seat body;46. Connecting portion;47. Elastic movable portion;48. Sealing portion;49. Pressing ring;50. Movable groove;51. Fireproof graphite pad;52. Annular bending portion;53. Upper shaft;54. Lower shaft;55. Linkage sleeve;56. Driving cam;57. Driven cam;58. Washer;59. Arc recess;60. Elastic cam;61. Clearance hole;62. Driving protrusion;63. Driven protrusion. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0038] Example 1: As shown in the attached Figures 1 to 6The double eccentric butterfly valve shown in the figure includes a valve body 1, a valve stem 2, a butterfly plate 3 and a valve seat 4. The upper and lower ends of the valve body 1 are respectively provided with an upper shaft hole 5 and a lower shaft hole 6. The valve stem 2 is sequentially inserted into the upper shaft hole 5 and the lower shaft hole 6. An upper shaft sleeve can be set in the upper shaft hole 5 to cooperate with the valve stem 2, and a lower shaft sleeve can be set in the lower shaft hole 6 to cooperate with the valve stem 2. A packing seal assembly is set at the upper end of the upper shaft hole 5 for sealing, and an end cover and a sealing gasket are set at the lower end of the lower shaft hole 6 for sealing; the valve stem 2 is located in the inner cavity of the valve body 1 and is linked to the butterfly plate 3. Specifically, after the valve stem 2 and the butterfly plate 3 are plugged in, the pin is inserted and then welded to fix it. The valve seat 4 is made of elastic material. Made of high quality, the valve seat 4 is mounted on the inner wall of the valve body 1 and is used to abut against the butterfly plate 3 to form a sealing fit when the valve is closed. The butterfly plate 3 includes a mounting body 7, a sealing ring 8, a first linkage assembly 9, and a second linkage assembly 10. The sealing ring 8 is movably connected to the mounting body 7 via the first linkage assembly 9 and the second linkage assembly 10. When the valve is opened, the valve stem 2 drives the sealing ring 8 toward the mounting body 7 through the first linkage assembly 9 so that it quickly separates from the valve seat 4. When the valve is closed, the valve stem 2 drives the sealing ring 8 toward the mounting body 7 through the second linkage assembly 10 so that it quickly approaches the valve seat 4. Regardless of whether the valve seat 4 is a fixed structure or a floating structure, at the moment the valve is opened and closed, the valve stem 2 can drive the sealing ring 8 of the butterfly plate 3 to quickly approach or move away from the valve seat 4, thereby reducing the wear of the valve sealing pair and significantly improving the service life of the valve.

[0039] As attached Figure 2 and attached Figure 3 As shown, the first linkage assembly 9 includes multiple groups, and the first linkage assembly 9 includes a screw 11 and a return spring 12. The sealing ring 8 is provided with a guide groove 13 for the side of the mounting body 7 to extend into, and the mounting body 7 is provided with a guide plate 14 that cooperates with the guide groove 13. The sealing ring 8 is installed at the position of the outer end of the guide groove 13, and the limit ring 15 is provided with a plurality of screw holes 16 corresponding to the number of the first linkage assembly 9. One end of the screw 11 is threadedly connected to the screw hole 16, and the end of the screw 11 is provided with an inner hexagonal groove to facilitate the insertion of a hexagonal wrench to rotate the screw 11. The other end of the screw 11 is provided with a smooth rod portion 17, that is, the outer cylindrical surface is smooth, and a guide hole 18 is opened on the guide plate 14 to cooperate with the smooth rod portion 17. The return spring 12 is sleeved on the outer periphery of the screw 11, and the two ends of the return spring 12 are respectively abutted against the guide plate 14 and the limit ring 15. The first linkage assembly 9 is used to apply a pre-tightening force to the sealing ring 8 toward the installation body 7, so that it can quickly separate from the valve seat 4 under specific conditions. In addition, the guide structure design between the screw 11 and the guide plate 14 also makes the movement of the sealing ring 8 more stable and reliable.

[0040] As attached Figure 3 As shown, the guide plate 14 is connected to the mounting body 7 via a locking screw 19, and the mounting body 7 is provided with a recess 20 for the screw head of the locking screw 19 to be inserted into. The sealing ring 8 has a threaded groove 21 at a position corresponding to the outer end of the guide groove 13, and the limiting ring 15 is threadedly connected to the threaded groove 21. The limiting ring 15 can be provided with a protrusion or recess for the user's hand to apply force, thereby facilitating the rotation of the limiting ring 15. This design achieves the positioning and installation of the guide plate 14 and the limiting ring 15, and has a simple and reliable structure and is very convenient for assembly and disassembly.

[0041] As attached Figure 4 As shown, the limiting ring 15 includes a mounting ring 22 and a pressing ring 23. The pressing ring 23 is threadedly engaged with the thread groove 21. The screw hole 16 is provided on the mounting ring 22. The mounting ring 22 is provided on the inner circumference of the pressing ring 23. The inner end of the pressing ring 23 is provided with a tapered annular limiting groove 24. The outer circumference of the mounting ring 22 is provided with a limiting flange 25 that fits with the annular limiting groove 24. The limiting ring 15 adopts the combination of the mounting ring 22 and the pressing ring 23 to adjust the position of the screw hole 16 on the mounting ring 22, so that it is easy to align it with the guide hole 18, so that the smooth rod portion 17 of the screw rod 11 can be smoothly and quickly inserted into the guide hole 18 when the screw rod 11 is installed.

[0042] As attached Figure 4 As shown, the inner end surface of the thread groove 21 is circumferentially provided with an annular track groove 26. The inner end surface of the mounting ring 22 is provided with a plurality of grooves 27 arranged in a circumferential array and communicating with the track groove 26. Balls 28 are rolled within the grooves 27 and partially extend into the track groove 26 for rolling engagement therewith. The rolling structure provided between the mounting ring 22 and the pressure ring 23 reduces rotational friction of the mounting ring 22, making rotation easier and reducing wear.

[0043] As attached Figure 2 and attached Figure 3As shown, the number of the second linkage components 10 is two groups, and the second linkage components 10 include a positioning adjustment sleeve 29, a linkage ball 30 and a linkage pin 31. The positioning adjustment sleeve 29 is sleeved on the outer periphery of the valve stem 2. The positioning adjustment sleeves 29 of the two groups of second linkage components 10 are respectively arranged at the upper and lower ends of the butterfly plate 3. The inner ends of the upper shaft hole 5 and the lower shaft hole 6 are respectively provided with a positioning groove 32 for the outer end of the corresponding positioning adjustment sleeve 29 to be embedded. A positioning recess 33 is provided on the inner circular surface of the positioning groove 32. A positioning protrusion 34 that fits with the positioning recess 33 is provided on the positioning adjustment sleeve 29. A circular hole 35 is provided on the side of the positioning adjustment sleeve 29. The linkage ball 30 The linkage ball 31 is arranged in the circular hole 35, and the outer circular surface of the valve stem 2 is provided with an arc groove 36 with a length of one-quarter of a circle. The arc groove 36 includes an inclined groove section 37 with a uniformly changing depth and a flat groove section 38 with a constant depth. The flat groove section 38 is arranged at the deeper end of the inclined groove section 37. The linkage ball 30 partially extends into the arc groove 36 and rolls with the arc groove 36. The linkage ball 31 partially extends out of the circular hole 35 and abuts against the end of the sealing ring 8 close to the mounting body 7. When the linkage ball 30 is located in the inclined groove section 37 and rolls, the linkage ball 31 axially expands and contracts in the circular hole 35, and the sealing ring 8 moves in the direction close to or away from the mounting body 7. When the valve stem 2 drives the butterfly plate 3 to rotate and close the valve, the linkage ball 30 slides relatively from the flat groove section 38 to the inclined groove section 37. When the linkage ball 30 rolls in the flat groove section 38, the distance between the sealing ring 8 and the mounting body 7 remains unchanged. When the butterfly plate 3 is about to seal with the valve seat 4, the linkage ball 30 moves to the inclined groove section 37, and when the inclined groove section 37 rolls, the linkage ball 30 pushes the linkage ball 31, and the linkage ball 31 pushes the sealing ring 8 toward the direction close to the valve seat 4. When the valve is fully closed, the sealing ring 8 is pressed against the surface of the valve seat 4, and at this time the return spring 12 is compressed to store energy; in the opening operation, on the contrary, the linkage ball 30 has linked the ball 31 to gradually move away from the sealing ring 8. Under the action of the return spring 12, the sealing ring 8 quickly separates from the valve seat 4, thereby greatly reducing the friction generated by the sealing pair during the opening and closing process of the valve.

[0044] As attached Figure 3 、 5As shown in Figures 6 and 7, an annular adjustment groove 39 is formed on the outer circumference of the valve stem 2 at positions corresponding to the inner sides of the two positioning adjustment sleeves 29. A linkage sleeve 40 is embedded in the annular adjustment groove 39. The linkage sleeve 40 includes a first half ring 41 and a second half ring 42. The ends of the first half ring 41 and the second half ring 42 abut to form a full ring shape. The first half ring 41 is provided with a locking protrusion 43 at both ends, and the second half ring 42 is provided with a locking groove 44 that fits with the corresponding locking protrusion 43 at both ends. The arc groove 36 is provided on the outer circumferential surface of the first half ring 41. The arc groove 36 is provided on the split linkage sleeve 40 instead of on the valve stem 2. The linkage sleeve 40 with different arc groove 36 designs can be replaced according to actual conditions to adapt to different valve seats 4 without replacing the entire valve stem 2, which can reduce production costs. At the same time, the linkage sleeve 40 is wrapped in the corresponding annular adjustment sleeve to play a fixing role, making its installation structure more convenient and stable.

[0045] As attached Figure 3 As shown, the valve seat 4 includes a valve seat body 45, a connecting portion 46 with an L-shaped cross section provided on the outer circumference of the valve seat body 45, an elastic movable portion 47 provided on the inner circumference of the valve seat body 45, and a sealing portion 48 provided inside the elastic movable portion 47. The side of the valve body 1 is also mounted with a pressure ring 49 for pressing the valve seat 4 against the inner wall of the valve body 1 via a fastener. The fastener can be a screw, and the pressure ring 49 is provided with a movable groove 50 for the sealing portion 48 of the valve seat 4 to extend into. When the sealing portion 48 is subjected to force, the elastic movable portion 47 can move in the movable groove 50. The flexible lip-shaped valve seat 4 ensures reliable closure and can automatically compensate for wear. The movable groove 50 both allows deformation of the valve seat 4 and limits excessive deformation of the valve seat 4.

[0046] As attached Figure 3 As shown, a fireproof graphite gasket 51 is sandwiched between the valve seat 4 and the inner wall of the valve body 1. The fireproof graphite gasket 51 is provided with an annular bend 52 for pressing against the outer surface of the sealing ring 8. This design ensures that the valve maintains an effective seal even under high temperature or fire conditions, preventing secondary hazards caused by media leakage and ensuring the intrinsic safety of the system.

[0047] Example 2: Different from the structure in which the valve stem 2 is processed as an integral body in Example 1, in this example, the valve stem 2 adopts a split structure.

[0048] As attached Figures 7-9As shown, the valve stem 2 includes an upper shaft 53, a lower shaft 54 ​​and a linkage sleeve 55. The lower end of the upper shaft 53 is provided with a driving cam 56, and the upper end of the lower shaft 54 ​​is provided with a driven cam 57 coaxially arranged with the driving cam 56. A washer 58 is provided between the driving cam 56 and the driven cam 57. The linkage sleeve 55 is sleeved on the driving cam 56, the washer 58 and the outer periphery of the driven cam 57. The linkage sleeve 55 can be made of plastic or silicone material. A plurality of arc-shaped recesses 59 are circumferentially arranged on the inner surface of the linkage sleeve 55, an elastic convex portion 60 is formed between each two adjacent arc-shaped recesses 59, and a clearance hole 61 is provided on the linkage sleeve 55 corresponding to the outer periphery of each elastic convex portion 60. A plurality of driving protrusions 62 for embedding into the arc-shaped recesses 59 are provided on the outer periphery of the driving convex shaft 56, and a plurality of driven protrusions 63 for embedding into the arc-shaped recesses 59 are provided on the outer periphery of the driven convex shaft 57. First, the valve stem 2 adopts a split structure. Since the valve stem 2 passes through the valve body 1 from top to bottom, and the upper end extends upward for connection with the drive device, the overall structure is long, and the axial concentricity is difficult to ensure, which makes processing more difficult. Therefore, the split structure is conducive to the processing and assembly of the valve stem 2; secondly, a linkage sleeve 55 is used to transmit the upper shaft rod 53 and the lower shaft rod 54. It adopts a tooth meshing transmission method with a high transmission ratio. When the butterfly plate 3 is stuck or has been opened or closed in place, the lower shaft rod 54 does not move, and the torque generated by the upper shaft rod 53 will cause the elastic protrusion 60 of the linkage sleeve 55 to deform, thereby causing the upper shaft rod 53 to idle, avoiding excessive torque from damaging the butterfly plate 3 or the valve seat 4, and also preventing the drive device (such as a motor) from being damaged due to overload.

Claims

1. A double eccentric butterfly valve, comprising a valve body (1), a valve stem (2), a butterfly plate (3) and a valve seat (4), wherein the valve body (1) is provided with an upper shaft hole (5) and a lower shaft hole (6) at the upper and lower ends thereof, the valve stem (2) is sequentially passed through the upper shaft hole (5) and the lower shaft hole (6), and the valve stem (2) is located in the inner cavity of the valve body (1) and is linked to the butterfly plate (3), the valve seat (4) is made of an elastic material, and the valve seat (4) is mounted on the inner wall of the valve body (1) and is used to abut against the butterfly plate (3) to form a sealing fit when the valve is closed; the characteristics are: The butterfly plate (3) comprises a mounting body (7), a sealing ring (8), a first linkage assembly (9) and a second linkage assembly (10); the sealing ring (8) is movably connected to the mounting body (7) through the first linkage assembly (9) and the second linkage assembly (10); when the valve is opened, the valve stem (2) drives the sealing ring (8) through the first linkage assembly (9) to move toward the mounting body (7) so that it quickly separates from the valve seat (4); when the valve is closed, the valve stem (2) drives the sealing ring (8) through the second linkage assembly (10) to move toward the mounting body (7) so that it quickly separates from the valve seat (4); The ring (8) moves in a direction away from the installation body (7) so that it quickly approaches the valve seat (4); the first linkage assembly (9) includes a screw (11) and a return spring (12); a side of the sealing ring (8) close to the installation body (7) is provided with a guide groove (13) for the side of the installation body (7) to extend into, and a guide plate (14) is installed on the installation body (7) to match the guide groove (13); the second linkage assembly (10) includes a positioning adjustment sleeve (29), a linkage ball (30) and a linkage pin (31 ), the positioning adjustment sleeve (29) is sleeved on the outer periphery of the valve stem (2), the positioning adjustment sleeves (29) of the two sets of second linkage components (10) are respectively arranged at the upper and lower ends of the butterfly plate (3), the inner ends of the upper shaft hole (5) and the lower shaft hole (6) are respectively provided with a positioning groove (32) for the outer end of the corresponding positioning adjustment sleeve (29) to be embedded, the inner circular surface of the positioning groove (32) is provided with a positioning recess (33), the positioning adjustment sleeve (29) is provided with a positioning protrusion (34) that fits with the positioning recess (33), the positioning adjustment sleeve (29) is provided with a positioning protrusion (34) that fits with the positioning recess (33), and the positioning adjustment sleeve (29) is provided with a positioning protrusion (34) that fits with the positioning recess (33). A circular hole (35) is provided through the side of the sleeve (29), and the linkage ball (30) and the linkage pin (31) are arranged in the circular hole (35). The outer circular surface of the valve stem (2) is provided with an arc groove (36) with a length of one-quarter of a circle. The arc groove (36) includes an inclined groove section (37) with a uniformly varying depth and a flat groove section (38) with a constant depth. The flat groove section (38) is provided at the deeper end of the inclined groove section (37). The linkage ball (30) partially extends into the arc groove (36) and rolls with the arc groove (36).

2. The double eccentric butterfly valve according to claim 1, characterized in that: The first linkage assembly (9) includes a plurality of groups, a limiting ring (15) is installed at the position of the outer end of the guide groove (13) corresponding to the sealing ring (8), and a plurality of screw holes (16) of the same number as the first linkage assembly (9) are provided on the limiting ring (15), one end of the screw rod (11) is threadedly connected to the screw hole (16), and the other end of the screw rod (11) is provided with a light rod portion (17), and a guide hole (18) matched with the light rod portion (17) is opened on the guide plate (14), and the return spring (12) is sleeved on the outer periphery of the screw rod (11), and the two ends of the return spring (12) are respectively in contact with the guide plate (14) and the limiting ring (15).

3. The double eccentric butterfly valve according to claim 2, characterized in that: The guide plate (14) is connected to the installation body (7) through a locking screw (19), and the installation body (7) is provided with a clearance groove (20) for the screw head of the locking screw (19) to be embedded; the sealing ring (8) is provided with a thread groove (21) at a position corresponding to the outer end of the guide groove (13), and the limiting ring (15) is threadedly connected to the thread groove (21).

4. The double eccentric butterfly valve according to claim 3, characterized in that: The limiting ring (15) includes a mounting ring (22) and a pressing ring (23), the pressing ring (23) is threadedly matched with the thread groove (21), the screw hole (16) is arranged on the mounting ring (22), the mounting ring (22) is arranged on the inner periphery of the pressing ring (23), and the inner end of the pressing ring (23) is provided with a conical annular limiting groove (24), and the outer periphery of the mounting ring (22) is provided with a limiting flange (25) that fits with the annular limiting groove (24).

5. The double eccentric butterfly valve according to claim 4, characterized in that: The inner end surface of the thread groove (21) is provided with a circular track groove (26) along the circumferential direction, and the inner end surface of the mounting ring (22) is provided with a plurality of grooves (27) connected to the track groove (26) distributed in a circumferential array, wherein balls (28) are rolled in the grooves (27), and the balls (28) partially extend into the track groove (26) and roll in cooperation with the track groove (26).

6. The double eccentric butterfly valve according to claim 2, characterized in that: The number of the second linkage components (10) is two groups, and the linkage balls (31) partially extend out of the circular hole (35) and abut against one end of the sealing ring (8) close to the installation body (7). When the linkage ball (30) is located in the inclined groove section (37) and rolls, the linkage balls (31) axially expand and contract in the circular hole (35), and the sealing ring (8) moves in a direction close to or away from the installation body (7).

7. The double eccentric butterfly valve according to claim 6, characterized in that: An annular adjustment groove (39) is respectively provided on the outer periphery of the valve stem (2) at positions corresponding to the inner sides of the two positioning adjustment sleeves (29), and a linkage sleeve (40) is embedded in the annular adjustment groove (39). The linkage sleeve (40) comprises a first half ring (41) and a second half ring (42). The ends of the first half ring (41) and the second half ring (42) are abutted to form a full ring shape. A locking protrusion (43) is respectively provided at both ends of the first half ring (41), and a locking groove (44) that matches the corresponding locking protrusion (43) is respectively provided at both ends of the second half ring (42). The arc groove (36) is provided on the outer circumferential surface of the first half ring (41).

8. The double eccentric butterfly valve according to claim 1, characterized in that: The valve seat (4) includes a valve seat body (45), a connecting portion (46) with an L-shaped cross section arranged at the outer circle of the valve seat body (45), an elastic movable portion (47) arranged at the inner circle of the valve seat body (45), and a sealing portion (48) arranged on the inner side of the elastic movable portion (47). The side of the valve body (1) is also equipped with a pressure ring (49) for pressing the valve seat (4) against the inner wall of the valve body (1) through a fastener, and the pressure ring (49) is provided with a movable groove (50) for the sealing portion (48) of the valve seat (4) to extend into. When the sealing portion (48) is subjected to force, the elastic movable portion (47) can move in the movable groove (50).

9. The double eccentric butterfly valve according to claim 8, characterized in that: A fireproof graphite pad (51) is sandwiched between the valve seat (4) and the inner wall of the valve body (1), and an annular bending portion (52) for pressing against the outer circumferential surface of the sealing ring (8) is provided on the fireproof graphite pad (51).

10. The double eccentric butterfly valve according to claim 1, characterized in that: The valve stem (2) comprises an upper shaft (53), a lower shaft (54) and a linkage sleeve (55); a driving cam (56) is provided at the lower end of the upper shaft (53); a driven cam (57) is provided at the upper end of the lower shaft (54) and is coaxially arranged with the driving cam (56); a washer (58) is provided between the driving cam (56) and the driven cam (57); the linkage sleeve (55) is sleeved on the outer periphery of the driving cam (56), the washer (58) and the driven cam (57); the linkage sleeve (55) A plurality of arc-shaped recesses (59) are provided on the inner circular surface of the drive shaft (55) along the circumferential direction, an elastic convex portion (60) is formed between each two adjacent arc-shaped recesses (59), and a clearance hole (61) is provided on the linkage sleeve (55) at a position corresponding to the periphery of each elastic convex portion (60), a plurality of driving protrusions (62) for embedding into the arc-shaped recesses (59) are provided on the outer periphery of the driving convex shaft (56), and a plurality of driven protrusions (63) for embedding into the arc-shaped recesses (59) are provided on the outer periphery of the driven convex shaft (57).

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