High-cleanliness magnetofluid perfluoroether triple-eccentric sealing butterfly valve

Abstract

A valve body without a bottom cover is adopted, a valve plate is connected with an upper valve rod and a lower valve rod, first magnetofluid sealing devices at the upper end and the lower end of the valve body are arranged outside the upper valve rod, and second magnetofluid sealing devices at the upper end and the lower end of the valve body are arranged outside the lower valve rod. The valve seat comprises a front annular supporting plate, a rear annular supporting plate and an annular sealing piece made of perfluoroether rubber, and the inner ring of the annular sealing piece is provided with a sealing matching part which is exposed out of the clamping piece space and used for being matched with the valve plate in a sealing mode. The situation that a packing structure arranged on the valve body rubs and abrades with the upper valve rod and the lower valve rod to generate particle pollution sources to affect a high-cleanliness pipeline is avoided, no medium fluid unbalanced force is generated on the upper valve rod and the lower valve rod, and the unbalanced force of the upper valve rod and the unbalanced force of the lower valve rod are mutually counteracted. The annular sealing piece made of the perfluoroether rubber smoothly forms a sealing structure when the annular sealing piece and the valve plate are closed in a matched mode, the problem of particle pollution caused by friction between the valve plate and the valve seat in the opening and closing process of the valve is solved, and pollution to a high-cleanliness pipeline is avoided.

Description

Technical Field

[0001] The invention relates to a butterfly valve, in particular to a triple-eccentric butterfly valve required for high-cleanliness pipelines. Background Art

[0002] For pipelines with high cleanliness requirements, such as high-cleanliness nitrogen and oxygen and argon oxygen gas pipelines, the cleanliness requirements are extremely high, and the particle size and cleanliness requirements are lower than the ISO14644 Level 10 level. For the cutting and adjustment of this pipeline system, the current traditional structure of the three-eccentric butterfly valve will cause friction and wear in the packing, sealing pair, bearings and other parts, and will inevitably produce particulate matter during use and operation, which is completely unable to meet the use requirements of high-cleanliness pipelines.

[0003] Among them, the valve stem of the triple-eccentric butterfly valve adopts graphite or PTFE packing for sealing. During the use and operation of the valve stem, graphite or PTFE particles will inevitably be generated. Once the particles enter the valve, they will seriously pollute the interior of the pipeline and destroy the high cleanliness of the pipeline.

[0004] Among them, in the structure of the three-eccentric butterfly valve, a multi-layer sealing ring composed of graphite or PTFE is used to cooperate with the sealing between the valve plate and the valve seat; among them, the multi-layer sealing ring (sealing structure) is installed on the valve plate, and the sealing ring is pressed on the valve plate by screws. The biggest advantage of this structure is that the processing design is simple, and the valve plate (the rotating body component that rotates with the valve stem) is thin and not easy to interfere with the valve body; but the biggest problem when used in high-clean pipelines is that graphite or PTFE itself will produce particulate matter, and the medium will seriously erode the sealing structure of the valve plate during the switching process. Frequent switching actions will also loosen the screws pressed on the valve plate, resulting in flow resistance, causing eddy currents to erode the graphite or PTFE sealing rings, increasing the risk of particulate matter generation, and easily affecting high-clean pipelines.

[0005] In addition, the multi-layer sealing ring uses glue to bond the metal material and non-metallic sealing material together, and then performs profiling processing. The glue will leak during use, and iron filings will remain during the profiling process, which seriously affects assembly and use.

[0006] Among them, the valve plate and valve stem of the three-eccentric butterfly valve are generally connected by pins, but this pin is installed after assembly. As the valve assembly has extremely high cleanliness requirements, all processes must be completed in a Class 100 workshop. Secondary pollution problems will occur during the pin installation process, which cannot meet the requirements for high-cleanliness pipelines.

[0007] In addition, the valve body of the triple-eccentric butterfly valve has a bearing inside to support the operation of the valve stem, which has a good supporting effect, but will cause movement wear. Once the particles generated by wear fall into the valve, they will contaminate the pipeline.

[0008] In addition, the lower part of the triple eccentric butterfly valve also needs to be equipped with a bottom cover and a spiral wound gasket to match the valve stem installation and operation, which can easily lead to unbalanced forces on the upper and lower valve stems. Summary of the Invention

[0009] In view of the technical problems existing in the background technology, the present invention aims to provide a high-cleanliness magnetic fluid perfluoroether triple-eccentric butterfly valve that can be better applied to the requirements of high-cleanliness pipelines.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions: a high-clean magnetic fluid perfluoroether triple-eccentric sealed butterfly valve, comprising a valve body, an upper valve stem, a lower valve stem, a valve plate and a valve seat, characterized in that: the valve body adopts a valve body without a bottom cover, the valve body has an upper through hole and a lower through hole arranged coaxially, the valve body also has a medium channel arranged in a front-to-rear direction, the upper through hole and the lower through hole are respectively located on the upper and lower sides of the medium channel, the upper through hole is for the upper valve stem to match and pass through the assembly, the lower through hole is for the lower valve stem to match and pass through the assembly, the valve plate is arranged in the medium channel of the valve body, the back of the valve plate has an upper connecting seat and a lower connecting seat, the upper connecting seat is connected to the upper valve stem, the lower connecting seat is connected to the lower valve stem, the upper and lower ends of the valve body are connected The ends are respectively provided with a first magnetic fluid sealing device and a second magnetic fluid sealing device, the first magnetic fluid sealing device is arranged outside the upper valve stem, and the second magnetic fluid seal is arranged outside the lower valve stem. The output port of the medium channel of the valve body is provided with a valve seat that cooperates with the valve plate, and the output port is also provided with a clamping device for cooperating with the disassembly and assembly of the fixed valve seat. The clamping device is located on the outside of the valve seat, and the valve seat includes a front annular support plate, a rear annular support plate and an annular sealing piece made of perfluoroether rubber. There is a clamping space between the front annular support plate and the rear annular support plate. The annular sealing piece is supported and clamped in the clamping space. The inner ring of the annular sealing piece has a sealing matching part exposed in the clamping space for sealing with the valve plate.

[0011] The following various optimizations or supplementary explanations can be made on the above technical solutions respectively.

[0012] There is no packing structure between the upper through hole and the upper valve stem, and there is no packing structure between the lower through hole and the lower valve stem.

[0013] Among them, the circumferential outer ring of the valve plate has no sealing components, and the circumferential outer ring of the valve plate is set as the valve plate outer ring sealing fitting surface, which corresponds to the sealing fitting part of the inner ring of the annular sealing piece of the valve seat.

[0014] In addition, the output port of the medium channel is set as a stepped hole, which is located on the front side of the upper valve stem and the lower valve stem. The inner side of the stepped hole is a stepped raised limit portion. The valve seat is set on the front side of the stepped raised limit portion. An annular groove is provided on the side of the stepped raised limit portion facing the valve seat. An annular sealing ring is provided in the annular groove. The clamping device located on the front side of the valve seat cooperates to press the valve seat onto the stepped raised limit portion.

[0015] For example, the clamping device includes a clamping support ring and a clamping fastener, an annular mounting groove is provided on the step hole, the clamping support ring is arranged on the annular mounting groove, and a clamping fastener for pressing the valve seat against the step protrusion limit portion is provided on the clamping support ring; the clamping device also includes an annular gasket, which is arranged between the clamping fastener and the valve seat; the clamping support ring is divided into at least three unit blocks.

[0016] Further optimization is performed, in which the channel wall of the medium channel on the rear side of the step hole is set as a tapered opening narrowing toward the medium output direction, and the valve seat and the clamping device are located on the outside of the tapered surface of the tapered opening extended toward the medium output direction.

[0017] In addition, a positioning device for distinguishing the front and back sides of the annular sealing plate is provided between the front annular support plate, the rear annular support plate and the annular sealing plate. The positioning device includes at least two groups of positioning and anti-rotation structures. Each positioning and anti-rotation structure includes a front positioning hole, a rear positioning hole, a middle positioning hole and a positioning pin. The front positioning hole is set on the front annular support plate, the rear positioning hole is set on the rear annular support plate, the middle positioning hole is set on the annular sealing plate, and the positioning pin fits through the front positioning hole, the middle positioning hole and the rear positioning hole.

[0018] For example, a first annular positioning and balancing groove is provided on the inner side surface of the front annular support plate, and a second annular positioning and balancing groove is provided on the inner side surface of the rear annular support plate. The annular sealing plate has annular positioning and balancing convex ring parts on both the front and back sides, and the annular positioning and balancing convex ring parts are respectively arranged in the first annular positioning and balancing groove and the second annular positioning and balancing groove; the first annular positioning and balancing groove are arranged face to face with the second annular positioning and balancing groove.

[0019] It can also be further optimized, so that a flat key connection is provided between the upper valve stem and the upper connecting seat, a first stepped through hole is provided on the upper connecting seat, a first limit plate is arranged at the lower end of the first stepped through hole, the first limit plate is connected to the lower end of the upper valve stem, and a first fastener is connected between the first limit plate and the upper valve stem; a first limiting groove is provided on the upper valve stem, a first shaft retaining ring is arranged at the first limiting groove, and a first thrust bearing is provided between the first shaft retaining ring and the first magnetic fluid sealing device on the lower side; a flat key connection is provided between the lower valve stem and the lower connecting seat, a second stepped through hole is provided on the lower connecting seat, a second stepped through hole is provided at the upper end of the second step through hole, the second limit plate is connected to the upper end of the lower valve stem, and a second fastener is connected between the second limit plate and the lower valve stem; a second limiting groove is provided on the lower valve stem, a second shaft retaining ring is arranged at the second limiting groove, and a second thrust bearing is provided between the second shaft retaining ring and the second magnetic fluid sealing device on the upper side.

[0020] The upper valve stem is further provided with a first rotation support bearing, and the lower valve stem is further provided with a second rotation support bearing.

[0021] Even, the upper and lower ends of the valve body are respectively connected to an upper bracket and a lower bracket, the first rotation support bearing is arranged on the upper bracket, and the second rotation support bearing is arranged on the lower bracket; the first rotation support bearing and the second rotation support bearing are respectively oil-free bearings.

[0022] The beneficial effects of the present invention are as follows: in the high-cleanliness magnetic fluid perfluoroether triple-eccentric sealed butterfly valve, a valve body without a bottom cover is adopted so that both the upper valve stem and the lower valve stem can extend out of the valve body and cooperate with the corresponding magnetic fluid sealing device for sealing, thereby avoiding the friction and wear between the packing structure set on the valve body and the upper valve stem and the lower valve stem to generate a particle pollution source affecting the high-cleanliness pipeline, meeting the valve requirements for cutting off and regulating the medium fluid in the high-cleanliness pipeline, and the upper valve stem and the lower valve stem can form a relatively symmetrical magnetic fluid sealing structure in the upper and lower valve stems, no medium fluid unbalance force is generated between the upper valve stem and the lower valve stem, and the unbalanced forces of the upper valve stem and the lower valve stem offset each other; its valve seat structure forms a three-layer structure, which not only makes the support structure not easy to deform and ensures that the annular sealing piece made of perfluoroether rubber is not easy to be damaged, but also facilitates repeated disassembly and assembly, and ensures that the annular sealing piece made of perfluoroether rubber therein smoothly forms a sealing structure when cooperating with the valve plate when closed, and the valve plate and the valve seat will not rub against each other during the opening and closing process of the valve, thereby avoiding pollution to the high-cleanliness pipeline.

[0023] This structure is different from installing a split sealing structure on the valve plate. It solves a series of problems such as the medium eroding the sealing structure installed on the valve plate during the valve opening and closing adjustment process, causing particle pollution to the high-clean pipeline and loose screws.

[0024] The rotating support bearing is installed in conjunction with the corresponding bracket outside the valve body to avoid contamination inside the pipeline. In addition, the upper and lower support structures outside the valve body are relatively balanced, and the support effect on the upper and lower valve stems can also be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following describes the details and working principles of the implementation manner and embodiments of the present invention in conjunction with the accompanying drawings.

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 for Figure 1 The hollow arrow in the figure indicates the direction of the medium's forward flow.

[0028] Figure 3 It is a partial schematic diagram of the matching structure of the valve plate, valve seat, etc. when the valve is in the closed state in the present invention.

[0029] Figure 4 It is a partial schematic diagram of the matching structure of the valve plate and the upper valve stem in the present invention.

[0030] Figure 5It is a partial schematic diagram of the matching structure of the upper valve stem and the upper bracket in the present invention.

[0031] Figure 6 This is a schematic diagram of the valve seat and the pressing device in the present invention being located on the outside of the conical surface of the conical port extended in the medium output direction.

[0032] Figure 7 It is a partial schematic diagram of the structure between the front annular support plate, the rear annular support plate and the annular sealing sheet in the present invention.

[0033] In the picture: 1. Valve body; 11. Upper through hole; 12. Lower through hole; 13. Medium channel; 14. Step hole; 15. Step raised stopper; 16. Annular groove; 17. Annular sealing ring; 18. Annular mounting groove; 19. Conical opening; 2. Upper valve stem; 20. First magnetic fluid sealing device; 21. First rotary support bearing; 22. Upper bracket; 3. Lower valve stem; 30. Second magnetic fluid sealing device; 31. Second rotary support bearing; 32. Lower bracket; 2301, thrust bearing sleeve; 2302, assembly hole; 2303, bearing stop plate; 2304, screw; 4. Valve plate; 40. Valve plate outer ring sealing surface; 41. Upper connecting seat; 42. Lower connecting seat; 5. Valve seat; 51. Front annular support plate; 52. Annular sealing sheet; 53. Rear annular support plate; 521. Sealing mating portion; 55. First annular positioning and balancing groove; 56. Second annular positioning and balancing groove; 57. Annular positioning and balancing convex ring portion; 6. Clamping device; 61. Clamping support ring; 62. Clamping fastener; 63. Ring gasket; 71. Front positioning hole; 72. Rear positioning hole; 73. Middle positioning hole; 74. Positioning pin; 75. Flat key; 81. First stepped through hole; 82. First limit plate; 84. First shaft retaining ring; 85. First thrust bearing; 91. Second stepped through hole; 92. Second limit plate; 94. Second shaft retaining ring; 95. Second thrust bearing. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the implementation of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] Referring to the accompanying drawings, a high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve in an embodiment of this embodiment includes a valve body 1, an upper valve stem 2, a lower valve stem 3, a valve plate 4 and a valve seat 5.

[0036] Among them, the valve body 1 adopts a valve body 1 without a bottom cover, and the valve body 1 has an upper through hole 11 and a lower through hole 12 arranged coaxially. The valve body 1 also has a medium channel 13 arranged in a front-to-rear direction. The upper through hole 11 and the lower through hole 12 are respectively located on the upper and lower sides of the medium channel 13. The upper through hole 11 is for the upper valve stem 2 to match and pass through for assembly, and the lower through hole 12 is for the lower valve stem 3 to match and pass through for assembly, so that the upper valve stem 2 and the lower valve stem 3 will also be coaxially aligned up and down.

[0037] Among them, the valve plate 4 is arranged in the medium channel 13 of the valve body 1, and the back of the valve plate 4 has an upper connecting seat 41 and a lower connecting seat 42. The upper connecting seat 41 is connected to the upper valve stem 2, and the lower connecting seat 42 is connected to the lower valve stem 3. The upper valve stem 2 and the lower valve stem 3 will cooperate to support the valve plate 4 to operate in the valve body 1 and cooperate with the opening and closing of the valve. Usually, the end of the upper valve stem 2 or the lower valve stem 3 is used for transmission connection with an external driving component (such as a valve actuator, etc.), and the upper valve stem 2 or the lower valve stem 3 cooperates to input power to drive the valve plate 4 to operate.

[0038] Among them, the upper and lower ends of the valve body 1 are respectively provided with a first magnetic fluid sealing device 20 and a second magnetic fluid sealing device 30. The first magnetic fluid sealing device 20 is arranged outside the upper valve stem 2, and the second magnetic fluid seal is arranged outside the lower valve stem 3. The corresponding magnetic fluid sealing devices cooperate to seal the corresponding valve stems, so that the upper valve stem 2 and the lower valve stem 3 do not leak during operation. In addition, in this valve (i.e., a high-cleanliness magnetic fluid perfluoroether triple-eccentric sealed butterfly valve), there is no need to additionally set a packing structure in the upper through hole 11 and the lower through hole 12 of the valve body 1, thereby avoiding the problem that the traditional packing has a short life and the packing itself is also a source of contamination to the medium. The magnetic fluid sealing device replaces the traditional packing structure seal to avoid the friction of the packing during the operation of the upper valve stem 2 and the lower valve stem 3 to generate particulate matter to contaminate the pipeline. The zero leakage, zero friction, and zero wear characteristics of the magnetic fluid seal completely solve the problem of friction and wear of the packing, eliminate the generation of particulate matter, and achieve almost zero leakage, zero friction, and zero wear, meeting the valve requirements for cutting off and regulating the fluid of the medium in the high-cleanliness pipeline. The valve body 1 adopts a valve body 1 without a bottom cover, so that the upper valve stem 2 and the lower valve stem 3 can both extend out of the valve body 1 and cooperate with the corresponding magnetic fluid sealing device to connect and seal. The upper valve stem 2 and the lower valve stem 3 can form a relatively vertically symmetrical magnetic fluid sealing structure. There is almost no medium fluid unbalance force generated between the upper valve stem 2 and the lower valve stem 3, and the unbalanced forces of the upper valve stem 2 and the lower valve stem 3 almost offset each other.

[0039] Among them, the output port of the medium channel 13 of the valve body 1 is provided with a valve seat 5, and the valve seat 5 cooperates with the valve plate 4 to seal when the valve is closed. A clamping device 6 is also provided in the output port. The clamping device 6 is used to cooperate with the disassembly and assembly of the fixed valve seat 5. The valve seat 5 is used when it is disassembled and fixed in the output port of the medium channel 13. The clamping device 6 is located on the outside of the valve seat 5 (that is, the medium output side). The clamping device 6 cooperates to clamp and fix the valve seat 5 in the output port. The clamping state of the clamping device 6 is released to facilitate the disassembly of the valve seat 5, thereby cooperating to achieve the disassembly and assembly of the valve seat 5.

[0040] The valve seat 5 includes a front annular support plate 51, a rear annular support plate 53 and an annular sealing sheet 52 made of perfluoroether rubber (forming a three-layer structure). There is a clamping space between the front annular support plate 51 and the rear annular support plate 53. The annular sealing sheet 52 is supported and clamped in the clamping space. The inner ring of the annular sealing sheet 52 has a sealing fitting portion 521. The sealing fitting portion 521 will expose the clamping space for sealing with the valve plate 4. The valve seat 5 can ensure that the annular sealing sheet 52 made of perfluoroether rubber therein can smoothly form a sealing structure when it is closed in cooperation with the valve plate 4, and utilizes the high sealing, friction resistance, high resilience and long life of perfluoroether rubber material. Compared with sealing elements made of materials such as graphite and PTFE (polytetrafluoroethylene), there is almost no problem of particle contamination caused by friction during the opening and closing of the valve. The valve seat 5 is easy to disassemble and assemble repeatedly, and is fixed by the pressing device 6 for pressing, disassembling and assembling. The annular sealing piece 52 made of perfluoroether rubber is not easily damaged, so that the valve seat 5 can be thoroughly cleaned and deburred before reassembly after contour processing, avoiding the residue of metal particles during the processing.

[0041] In the high-cleanliness magnetic fluid perfluoroether triple eccentric sealing butterfly valve, a valve body 1 without a bottom cover is adopted so that the upper valve stem 2 and the lower valve stem 3 can both extend out of the valve body 1 and cooperate with the corresponding magnetic fluid sealing device for sealing, thereby avoiding the friction and wear between the packing structure set on the valve body 1 and the upper valve stem 2 and the lower valve stem 3 to generate a particle pollution source affecting the high-cleanliness pipeline, meeting the valve requirements for cutting off and regulating the medium fluid of the high-cleanliness pipeline, and the upper valve stem 2 and the lower valve stem 3 can form a relatively upper and lower symmetrical magnetic fluid sealing structure, and the upper valve stem 2 and the lower valve stem 3 have no medium fluid. When an unbalanced force is generated, the unbalanced forces of the upper valve stem 2 and the lower valve stem 3 offset each other; the valve seat 5 structure forms a three-layer structure, which not only makes the supporting structure not easily deformed, ensuring that the annular sealing piece 52 made of perfluoroether rubber is not easily damaged, but also the valve seat 5 structure is convenient for repeated disassembly and assembly, and ensures that the annular sealing piece 52 made of perfluoroether rubber can smoothly form a sealing structure when closed in cooperation with the valve plate 4, and the valve plate 4 and the valve seat 5 will not cause particle contamination due to friction during the opening and closing of the valve, thereby avoiding pollution to the high-cleanliness pipeline.

[0042] The following optimization or further explanation may be performed based on the above embodiments.

[0043] Among them, there is no packing structure between the upper through hole 11 and the upper valve stem 2, and the upper through hole 11 only needs to allow the upper valve stem 2 to match and pass through for operation. There is no packing structure between the lower through hole 12 and the lower valve stem 3, and the lower through hole 12 only needs to allow the lower valve stem 3 to match and pass through for operation. This part of the matching structure is relatively simple, and avoids friction between the packing during the operation of the upper valve stem 2 and the lower valve stem 3 to generate particulate matter to pollute the pipeline.

[0044] The circumferential outer ring of the valve plate 4 has no sealing components. Instead, the circumferential outer ring of the valve plate 4 is provided as the valve plate outer ring sealing mating surface 40. This outer ring of the valve plate 4 is directly fabricated into the valve plate outer ring sealing mating surface 40 for sealing with the valve seat 5 when the valve is closed. That is, the valve plate outer ring sealing mating surface 40 corresponds to the sealing mating portion 521 of the inner ring of the annular sealing plate 52 of the valve seat 5. In this structure, the valve plate 4 is more simplified, eliminating the need for additional complex sealing structures on the valve plate 4. The use of screws or the like to install sealing structures (such as sealing rings composed of graphite or PTFE) on the valve plate 4 is avoided, preventing the medium from severely eroding the sealing structure of the valve plate 4 during valve opening and closing, and preventing frequent opening and closing operations from loosening the screws pressed against the valve plate 4, resulting in flow resistance, vortex erosion of the graphite or PTFE sealing rings, and increasing the risk of particulate matter generation, which could affect high-purity pipelines. This structure is different from adding a split sealing structure to the valve plate 4. It solves a series of problems such as the medium eroding the sealing structure added to the valve plate 4 during the valve opening and closing process, causing particle contamination of the high-clean pipeline and loosening of screws. The valve plate 4 can adopt an integrated structure.

[0045] Further optimization, in which the output port of the medium channel 13 of the valve body 1 is set as a stepped hole 14, the stepped hole 14 is located on the front side of the upper valve stem 2 and the lower valve stem 3, the inner side of the stepped hole 14 is a stepped raised limit portion 15, the valve seat 5 is arranged on the front side (medium output side) of the stepped raised limit portion 15, and an annular groove 16 is provided on the side of the stepped raised limit portion 15 facing the valve seat 5 (that is, the front side of the stepped raised limit portion 15), and an annular sealing ring 17 is provided in the annular groove 16, which is used to cooperate with the sealing between the valve seat 5 and the valve body 1. When the front valve seat 5 is pressed against the stepped raised limit portion 15, the annular sealing ring 17 prevents the medium from leaking from between the valve seat 5 and the valve body 1, wherein the clamping device 6 located on the front side of the valve seat 5 cooperates to press the valve seat 5 onto the (rear) stepped raised limit portion 15.

[0046] For example, the clamping device 6 includes a clamping support ring 61 and a clamping fastener 62. An annular mounting groove 18 is provided on the step hole 14. The clamping support ring 61 is arranged on the annular mounting groove 18. During installation, the clamping support ring 61 is assembled on the annular mounting groove 18. A clamping fastener 62 is provided on the clamping support ring 61 for pressing the valve seat 5 against the step raised limit portion 15. The clamping support ring 61 cooperates to support the clamping fastener 62, and the clamping fastener 62 can cooperate with the pressure-applying valve seat 5 to press and release. In addition, the clamping device 6 also includes an annular gasket 63, which is arranged between the clamping fastener 62 and the valve seat 5. The annular gasket 63 can be used to relatively evenly balance and disperse the force of the clamping fastener 62, so that the valve seat 5 is more evenly stressed. Among them, the clamping fastener 62 can be evenly distributed and installed on the clamping support ring 61 along the circumferential direction. The clamping fastener 62 can be screwed or a combination of different screws. The clamping support ring 61 is divided into at least three unit blocks. For example, the clamping support ring 61 is set to four unit blocks, such as the common four-ring structure (including four arc-shaped plate unit blocks, which can be unequally divided). The technology is mature and easy to assemble on the annular mounting groove 18.

[0047] In addition, the channel wall of the medium channel 13 on the rear side of the stepped hole 14 can be set as a tapered opening 19, which is small in the front and large in the back, that is, it narrows toward the medium output direction, and the valve seat 5 and the clamping device 6 are located on the outside (that is, the outer circumference position) of the (virtual) cone surface extended from the tapered opening 19 toward the medium output direction (that is, the front direction). This structure ensures that when the medium is output through the medium channel 13, the impact on the valve seat 5, the clamping device 6, etc. is not obvious, which not only extends their service life but also makes their structure relatively more stable.

[0048] In order to facilitate installation and assembly, a positioning device for distinguishing the front and back sides of the annular sealing sheet 52 is provided between the front annular support plate 51, the rear annular support plate 53 and the annular sealing sheet 52. The positioning device distinguishes the front and back sides of the annular sealing sheet 52 so that the annular sealing sheet 52 can be installed in an accurate relative position between the front annular support plate 51 and the rear annular support plate 53, avoiding front and back misalignment, and making installation and assembly more convenient. For example, the positioning device includes at least two groups of positioning and anti-rotation structures, each of which includes a front positioning hole 71, a rear positioning hole 72, a middle positioning hole 73 and a positioning pin 74. The front positioning hole 71 is set on the front annular support plate 51, and the front positioning hole 71 can be set on the inner side of the front annular support plate 51. The rear positioning hole 72 is set on the rear annular support plate 53, and the rear positioning hole 72 can be set on the inner side of the rear annular support plate 53. The middle positioning hole 73 is set on the annular sealing plate 52, and the middle positioning hole 73 is a through hole. The positioning pin 74 passes through the front positioning hole 71, the middle positioning hole 73 and the rear positioning hole 72. For example, the positioning and anti-rotation structures can be set in two or three groups. The positioning and anti-rotation structures rotate around the center point of the ring without overlapping each other, which can better play the role of distinguishing the front and back sides. Of course, it is also possible to directly set a mark on the annular sealing plate 52 to distinguish the front and back sides; or even not to set it.

[0049] In addition, a first annular positioning and balancing groove 55 is provided on the inner side surface of the front annular support plate 51, and a second annular positioning and balancing groove 56 is provided on the inner side surface of the rear annular support plate 53. Annular positioning and balancing protrusions 57 are respectively provided on the front and rear sides of the annular sealing plate 52. The annular positioning and balancing protrusions 57 are respectively disposed in the first annular positioning and balancing groove 55 and the second annular positioning and balancing groove 56. This structure not only enhances the radial positioning value between the annular sealing plate 52 made of perfluoroelastomer and the front and rear annular support plates 51, 53, but also ensures that the deformation and expansion circumference of the annular sealing plate 52 remain consistent when the sealing portion 521 at the inner ring end of the perfluoroelastomer annular sealing plate 52 (the sealing portion 521 can be exposed approximately 15-20 inches of the clamping space, which improves the sealing effect) is sealed with the valve plate 4, thereby ensuring the sealing effect and service life of the annular sealing plate 52. The first annular positioning and balancing groove 55 and the second annular positioning and balancing groove 56 are arranged face to face (i.e., arranged in a front-to-back correspondence), which is relatively reasonable in structure and more balanced in force.

[0050] There are many ways to connect the valve stem and the connecting seat. For example, in the following embodiment, a flat key 75 is provided between the upper valve stem 2 and the upper connecting seat 41 (such as a flat key 75, a keyway and a keyhole, etc.), a first stepped through hole 81 is provided on the upper connecting seat 41, a first limit plate 82 is configured at the lower end of the first stepped through hole 81, the first limit plate 82 is connected to the lower end of the upper valve stem 2, a first fastener (such as a screw) is connected between the first limit plate 82 and the upper valve stem 2; a first limiting groove is provided on the upper valve stem 2, the first limiting groove is configured with a first shaft retaining ring 84, a first shaft retaining ring 84 is provided between the first shaft retaining ring 84 and the first magnetic fluid sealing device 20 on the lower side. There is a first thrust bearing 85; similarly, a flat key 75 is provided between the lower valve stem 3 and the lower connecting seat 42, a second stepped through hole 91 is provided on the lower connecting seat 42, a second limit plate 92 is configured at the upper end of the second stepped through hole 91, the second limit plate 92 is connected to the upper end of the lower valve stem 3, and a second fastener (such as a screw) is connected between the second limit plate 92 and the lower valve stem 3; a second limiting groove is provided on the lower valve stem 3, the second limiting groove is configured with a second shaft retaining ring 94, and a second thrust bearing 95 is provided between the second shaft retaining ring 94 and the second magnetic fluid sealing device 30 on the upper side. Compared to the pinned (matched) valve stem and connector assembly method in triple-eccentric butterfly valves, the matching structure of this embodiment solves the problem of matching pins and avoids secondary contamination during the matching process. It also meets the requirements for assembly, testing, and packaging in a Class 100 workshop. This matching structure also facilitates the smooth assembly of the upper valve stem 2, lower valve stem 3, first magnetic fluid sealing device 20, second magnetic fluid sealing device 30, and valve plate 4 on the valve body 1. A thrust bearing sleeve 2301 can also be provided between the corresponding thrust bearing and the corresponding magnetic fluid sealing device to facilitate stable assembly.

[0051] In addition, the upper valve stem 2 is equipped with a first rotational support bearing 21, and the lower valve stem 3 is equipped with a second rotational support bearing 31. These bearings provide rotational support for the upper and lower valve stems 2 and 3 during operation, ensuring smooth and stable operation. To simplify the structure of the valve body 1 and prevent particle contamination from bearing wear, the upper and lower ends of the valve body 1 are connected to an upper bracket 22 and a lower bracket 32, respectively. The first rotational support bearing 21 is mounted on the upper bracket 22, and the second rotational support bearing 31 is mounted on the lower bracket 32. This not only allows the rotational support bearings to be mounted on the corresponding brackets on the outside of the valve body 1, preventing contamination of the pipeline, but also ensures a relatively balanced upper and lower support structure on the outside of the valve body 1, ensuring effective support for the upper and lower valve stems 2 and 3. Furthermore, the first and second rotational support bearings 21 and 31 are oil-free bearings (such as JFB oil-free bearings), which are less susceptible to particle contamination from wear and tear, and less likely to contaminate the Class 100 workshop where assembly, pressure testing, inspection, and packaging are performed. The corresponding rotation support bearing is connected to the assembly hole 2302 of the corresponding bracket by the bearing limit plate 2303 through the screw 2304.

[0052] Furthermore, the surface of the media channel 13 of the valve body 1 that contacts the media can be polished manually and electrolytically, reducing flow resistance and preventing the generation of particulate matter. This butterfly valve structure addresses friction and wear issues in areas such as packing, seals, and bearings, meeting the requirements for high-purity pipelines.

Claims

1. A high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve, comprising a valve body (1), an upper valve stem (2), a lower valve stem (3), a valve plate (4) and a valve seat (5), Its characteristics are: The valve body (1) adopts a valve body (1) without a bottom cover. The valve body (1) has an upper through hole (11) and a lower through hole (12) arranged coaxially. The valve body (1) also has a medium channel (13) arranged in a front-to-rear direction. The upper through hole (11) and the lower through hole (12) are respectively located on the upper and lower sides of the medium channel (13). The upper through hole (11) is for the upper valve stem (2) to pass through for assembly. The lower through hole (12) is for the lower valve stem (3) to pass through for assembly. The valve plate (4) is arranged in the medium channel (13) of the valve body (1). The back of the valve plate (4) has an upper connecting seat (41) and a lower connecting seat (42). The upper connecting seat (41) is connected to the upper valve stem (2), and the lower connecting seat (42) is connected to the lower valve stem (3). A first magnetic fluid sealing device (20) and a second magnetic fluid sealing device (30) are respectively provided at the upper and lower ends of the valve body (1). The first magnetic fluid sealing device (20) is arranged outside the upper valve stem (2), and the second magnetic fluid sealing device is arranged outside the lower valve stem (3). The output port of the medium channel (13) of the valve body (1) is provided with a valve seat (5) that cooperates with the valve plate (4). The output port is also provided with a clamping device (6) for cooperating with the disassembly and assembly of the fixed valve seat (5). The clamping device (6) is located on the outside of the valve seat (5). The valve seat (5) includes a front annular support plate (51), a rear annular support plate (53) and an annular sealing sheet (52) made of perfluoroether rubber. A sandwich space is formed between the front annular support plate (51) and the rear annular support plate (53). The annular sealing sheet (52) is supported and clamped in the sandwich space. The inner ring of the annular sealing sheet (52) has a sealing mating portion (521) that exposes the clamping space and is used for sealing with the valve plate (4).

2. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: There is no packing structure between the upper through hole (11) and the upper valve stem (2), and there is no packing structure between the lower through hole (12) and the lower valve stem (3). The circumferential outer ring of the valve plate (4) has no sealing component. The circumferential outer ring of the valve plate (4) is set as the valve plate outer ring sealing fitting surface (40). The valve plate outer ring sealing fitting surface (40) corresponds to the sealing fitting portion (521) of the inner ring of the annular sealing sheet (52) of the valve seat (5) in a sealing fit.

3. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: The output port of the medium channel (13) is set as a stepped hole (14), and the stepped hole (14) is located on the front side of the upper valve stem (2) and the lower valve stem (3). The inner side of the step hole (14) is a step raised limiting portion (15). The valve seat (5) is arranged on the front side of the stepped raised limiting portion (15), and an annular groove (16) is provided on the side of the stepped raised limiting portion (15) facing the valve seat (5). An annular sealing ring (17) is provided in the annular groove (16). The pressing device (6) located on the front side of the valve seat (5) cooperates to press the valve seat (5) onto the stepped raised limiting portion (15).

4. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 3, characterized in that: The pressing device (6) includes a pressing support ring (61) and a pressing fastener (62); an annular mounting groove (18) is provided on the step hole (14); the pressing support ring (61) is arranged on the annular mounting groove (18); and a pressing fastener (62) for pressing the valve seat (5) against the step raised limiting portion (15) is provided on the pressing support ring (61); The pressing device (6) also includes an annular gasket (63), An annular gasket (63) is provided between the compression fastener (62) and the valve seat (5); The compression support ring (61) is divided into at least three unit blocks.

5. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 3, characterized in that: The channel wall of the medium channel (13) on the rear side of the step hole (14) is configured as a tapered opening (19) that narrows toward the medium output direction. The valve seat (5) and the pressing device (6) are located outside the conical surface of the conical port (19) which is extended and projected in the medium output direction.

6. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: A positioning device for distinguishing the front and back sides of the annular sealing sheet (52) is provided between the front annular support plate (51), the rear annular support plate (53) and the annular sealing sheet (52). The positioning device includes at least two sets of positioning anti-rotation structures, each positioning anti-rotation structure includes a front positioning hole (71), a rear positioning hole (72), a middle positioning hole (73) and a positioning pin (74). The front positioning hole (71) is provided on the front annular support plate (51). The rear positioning hole (72) is provided on the rear annular support plate (53). The middle positioning hole (73) is provided on the annular sealing sheet (52). The positioning pin (74) fits through the front positioning hole (71), the middle positioning hole (73) and the rear positioning hole (72).

7. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: A first annular positioning and balancing groove (55) is provided on the inner side surface of the front annular support plate (51). A second annular positioning and balancing groove (56) is provided on the inner side surface of the rear annular support plate (53). The annular sealing sheet (52) has an annular positioning balancing convex ring portion (57) on both the front and back sides, and the annular positioning balancing convex ring portion (57) is respectively arranged in the first annular positioning balancing groove (55) and the second annular positioning balancing groove (56); The first annular positioning balancing groove (55) and the second annular positioning balancing groove (56) are arranged face to face.

8. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: A flat key (75) is provided between the upper valve stem (2) and the upper connecting seat (41). A first stepped through hole (81) is provided on the upper connecting seat (41), a first limiting plate (82) is configured at the lower end of the first stepped through hole (81), the first limiting plate (82) is connected to the lower end of the upper valve stem (2), and a first fastener is connected between the first limiting plate (82) and the upper valve stem (2); A first limiting groove is provided on the upper valve stem (2), a first shaft retaining ring (84) is configured in the first limiting groove, and a first thrust bearing (85) is provided between the first shaft retaining ring (84) and the first magnetic fluid sealing device (20) at the lower side; A flat key (75) is provided between the lower valve stem (3) and the lower connecting seat (42). A second stepped through hole (91) is provided on the lower connecting seat (42), a second limiting plate (92) is configured at the upper end of the second stepped through hole (91), the second limiting plate (92) is connected to the upper end of the lower valve stem (3), and a second fastener is connected between the second limiting plate (92) and the lower valve stem (3); A second limiting groove is provided on the lower valve stem (3), and a second shaft retaining ring (94) is configured in the second limiting groove. A second thrust bearing (95) is provided between the second shaft retaining ring (94) and the second magnetic fluid sealing device (30) on the upper side.

9. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 1, characterized in that: The upper valve stem (2) is also provided with a first rotation support bearing (21). The lower valve stem (3) is also provided with a second rotation support bearing (31).

10. The high-cleanliness magnetic fluid perfluoroether triple-eccentric sealing butterfly valve according to claim 9, characterized in that: The upper and lower ends of the valve body (1) are respectively connected to an upper bracket (22) and a lower bracket (32). The first rotary support bearing (21) is arranged on the upper bracket (22), The second rotation support bearing (31) is arranged on the lower bracket (32); The first rotary support bearing (21) and the second rotary support bearing (31) are respectively oil-free bearings.

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