Triple offset butterfly valve

Abstract

The utility model provides a kind of three eccentric butterfly valve, including actuating mechanism, valve stem and valve plate, actuating mechanism is connected with valve stem by connecting sleeve, connecting sleeve has first connecting part and second connecting part, first connecting part is equipped with first connecting structure between the output end of actuating mechanism, and first connecting structure includes first elastic pre-tightening member, second connecting part is equipped with second connecting structure between valve stem, and second connecting structure includes second elastic pre-tightening member, valve stem and valve plate are detachably connected, third connecting structure is equipped between valve stem and valve plate, and third connecting structure includes third elastic pre-tightening member.The utility model is equipped with multiple connecting structures with pre-tightening assembly by hierarchical arrangement, effectively reduces transmission gap, improves transmission accuracy and adjusting performance, simultaneously reduces operating torque, enhances sealing performance, and can adapt to wear after long-term use, prolongs the service life of valve.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a triple eccentric butterfly valve. Background Technology

[0002] Currently, the conventional triple offset butterfly valve's transmission system typically uses an actuator to drive the valve stem, which in turn drives the valve stem and the valve plate connected to it. With continuous industrial development, the requirements for triple offset butterfly valves are constantly increasing. In addition to meeting standard functions, triple offset butterfly valves are now required to have higher sealing performance, accurate adjustment precision, and low torque, in order to further reduce valve costs and installation space.

[0003] When used in certain regulating conditions, triple eccentric butterfly valves are typically required to have precise regulating capabilities. This necessitates that the valve's basic error, hysteresis, and dead zone all meet certain requirements to satisfy the regulating needs of the operating conditions. However, for ease of manufacturing and cost control, common triple eccentric butterfly valves usually employ flat key connections or conventional rectangular spline connections. But for ease of assembly and a high assembly qualification rate, the clearance between the key and the keyway is usually relatively large. Due to clearance errors in multiple locations, the valve's transmission and regulating accuracy will be affected. Utility Model Content

[0004] This invention provides a triple eccentric butterfly valve to solve the technical problem of low adjustment accuracy of existing triple eccentric butterfly valves.

[0005] This utility model provides a triple eccentric butterfly valve, which includes an actuator, a valve stem, and a valve plate. The actuator and the valve stem are connected by a connecting sleeve. The connecting sleeve has a first connecting part and a second connecting part. A first connecting structure is provided between the first connecting part and the output end of the actuator. The first connecting structure includes a first elastic preload. A second connecting structure is provided between the second connecting part and the valve stem. The second connecting structure includes a second elastic preload. The valve stem and the valve plate are detachably connected. A third connecting structure is provided between the valve stem and the valve plate. The third connecting structure includes a third elastic preload.

[0006] In one embodiment of the present invention, the first connecting structure includes a first flat key and a first keyway. The first flat key is disposed at the output end of the actuator, and the first keyway is disposed on the first connecting part and is correspondingly disposed to the first flat key. The first flat key can be used to snap into the first keyway.

[0007] In one embodiment of the present invention, the first flat key and the first keyway have a first torque transmission portion, and at least a portion of the first elastic preload is disposed in the first torque transmission portion.

[0008] In one embodiment of the present invention, the second connecting structure includes a second flat key and a second keyway. The second flat key is disposed on the valve stem, and the second keyway is disposed on the second connecting portion and is correspondingly disposed to the second flat key. The second flat key can be used to snap into the second keyway.

[0009] In one embodiment of the present invention, the second flat key and the second keyway have a second torque transmission portion, and at least a portion of the second elastic preload is disposed in the second torque transmission portion.

[0010] In one embodiment of the present invention, the third connecting structure includes a third flat key and a third keyway. The third flat key is disposed on the valve stem, and the third keyway is disposed on the third connecting part and is correspondingly disposed to the third flat key. The third flat key can be used to snap into the third keyway.

[0011] In one embodiment of the present invention, the third flat key and the third keyway have a third torque transmission part, and at least a portion of the third elastic preload is disposed in the third torque transmission part.

[0012] In one embodiment of the present invention, the cross-sections of the first elastic pretensioner, the second elastic pretensioner, and the third elastic pretensioner along their length direction are wavy.

[0013] In one embodiment of the present invention, a fixing pin for mutual connection is provided between the valve stem and the valve plate, and the fixing pin passes through the valve plate radially along the valve stem and is connected to the valve stem.

[0014] The beneficial effects of this utility model are as follows: The triple eccentric butterfly valve and its connection structure provided in this application effectively reduce the transmission gaps between the actuator and the valve plate by setting multiple connection structures with pre-tightening components. Compared with the prior art, this utility model improves the transmission accuracy and adjustment performance, while reducing the operating torque, enhancing the sealing performance, and being able to adapt to wear after long-term use, thus extending the service life of the valve. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] In the attached diagram: Figure 1 A cross-sectional view provided for an embodiment of this utility model; Figure 2 This is an enlarged view of point A provided in one embodiment of the present invention; Figure 3 This is a schematic diagram of the third pre-tightening structure provided in one embodiment of the present invention; Figure 4 This is a radial cross-sectional view of the second pre-tightening structure provided in one embodiment of the present invention; Figure 5 This is a front view of an elastic preload provided in one embodiment of the present invention; Figure 6 This is a top view of an elastic preload member provided in one embodiment of the present invention.

[0017] The attached figures are labeled as follows: Actuator 1, first flat key 101, connecting sleeve 2, first connecting part 201, first keyway 202, first elastic preload 203, second connecting part 204, second keyway 205, second elastic preload 206, valve stem 3, second flat key 301, third flat key 302, valve plate 4, third keyway 401, third elastic preload 402, fixing pin 5. Detailed Implementation

[0018] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0021] like Figures 1-6 As shown, this utility model provides a triple eccentric butterfly valve.

[0022] In an exemplary embodiment, the triple eccentric butterfly valve includes an actuator 1, a valve stem 3, and a valve plate 4. The actuator 1 and the valve stem 3 are connected by a connecting sleeve 2. The connecting sleeve 2 has a first connecting portion 201 and a second connecting portion 204. A first connecting structure is provided between the first connecting portion 201 and the output end of the actuator 1. The first connecting structure includes a first elastic pre-tightening member 203. A second connecting structure is provided between the second connecting portion 204 and the valve stem 3. The second connecting structure includes a second elastic pre-tightening member 206. The valve stem 3 and the valve plate 4 are detachably connected. A third connecting structure is provided between the valve stem 3 and the valve plate 4. The third connecting structure includes a third pre-tightening component.

[0023] In this embodiment, modular assembly is achieved while ensuring transmission accuracy by using a tiered connection structure with pre-tightening function. The actuator 1 and valve stem 3 are indirectly connected via a connecting sleeve 2, reducing the difficulty of direct assembly. The first pre-tightening component eliminates assembly gaps and improves torque transmission stability, the second connection structure ensures the driving accuracy of valve stem 3, and the valve stem 3 and valve plate 4 are detachably connected for easy maintenance. The multi-stage pre-tightening components effectively compensate for machining and assembly errors, improving the connection rigidity and positional accuracy of each transmission link. Structurally, this solves the problems of insufficient adjustment accuracy, large torque fluctuations, and difficult maintenance caused by connection gaps in traditional triple eccentric butterfly valves.

[0024] For example, in this embodiment, the first pre-tightening component can be implemented using an elastic pre-tightening element, such as a wave-shaped spring sheet or a helical spring, to eliminate the assembly gap between the first connecting part 201 and the output end of the actuator 1. The second connecting structure can be implemented through a keyway fit, wherein a second elastic pre-tightening element 206 can be provided in the keyway to compensate for machining errors. The third connecting structure also uses a key connection, and works in conjunction with the third pre-tightening component to ensure connection rigidity. The connecting sleeve 2 can be configured as a separate unit or an integral unit for easy assembly and maintenance; in this embodiment, the connecting sleeve 2 is configured as an integral unit.

[0025] It is worth noting that in this embodiment, all three connection structures are connected by flat keys, and elastic pre-tightening elements are set at the key connection points to eliminate the gap between the key and the keyway, achieving an effect similar to a tight contact between the key and the keyway, improving transmission efficiency, enhancing valve precision, and reducing the manufacturing cost of this application.

[0026] In an exemplary embodiment, the first connection structure includes a first flat key 101 and a first keyway 202. The first flat key 101 is disposed at the output end of the actuator 1, and the first keyway 202 is disposed on the first connection portion 201 and is correspondingly disposed to the first flat key 101. The first flat key 101 can be inserted into the first keyway 202, and a first elastic preload 203 is provided between the first keyway 202 and the first flat key 101.

[0027] In this embodiment, the keyway mating structure and the elastic preload component work together to effectively eliminate transmission backlash while ensuring assembly processability. Specifically, the first flat key 101 and the first keyway 202 achieve basic torque transmission, while the first elastic preload component 203 compensates for assembly backlash through continuous elasticity, preventing idle travel during transmission. In this embodiment, the first connection structure, while maintaining the advantages of traditional flat key connections, significantly improves transmission accuracy through elastic preload, effectively controlling the basic error and hysteresis of valve adjustment. The wavy cross-section of the elastic preload component enhances its deformation compensation capability, enabling it to adapt to preload requirements under different working conditions.

[0028] For example, the first flat key 101 can be a metal key body with a rectangular or trapezoidal cross-section, and its length direction is perpendicular to the torque transmission direction. The size of the first keyway 202 is slightly larger than that of the first flat key 101, forming an assembly gap. The first elastic preload member 203 can be a corrugated spring sheet or an elastic rubber pad, the thickness of which is greater than the assembly gap, generating continuous elastic force under compression. In a specific embodiment, multiple first elastic preload members 203 can be arranged at intervals along the length direction of the first flat key 101 to form a segmented preload structure. In addition, a wear-resistant coating can be provided on the contact surface between the first flat key 101 and the first keyway 202 to extend its service life.

[0029] For example, in this embodiment, the first flat key 101 and the first keyway 202 have a first torque transmission portion, and at least a portion of the first flat key 101 is disposed within the first torque transmission portion. Specifically, the first torque transmission portion can be implemented in the following ways: a groove complementary to the shape of the side surface of the flat key is machined on the side wall of the first keyway 202 to facilitate the placement of the first elastic preload member 203; or a protruding structure is provided at the bottom of the first keyway 202 to form a fit with the bottom of the flat key. In this embodiment, the first torque transmission portion is used for torque transmission, i.e., the gap formed between the keyway and the key; the second and third torque transmission portions are similar.

[0030] In one exemplary embodiment, the second connection structure includes a second flat key 301 and a second keyway 205. The second flat key 301 is disposed on the valve stem 3, and the second keyway 205 is disposed on the second connection portion 204 and correspondingly disposed to the second flat key 301. The second flat key 301 can be engaged into the second keyway 205. A second elastic preload member 206 is provided between the second keyway 205 and the second flat key 301. Simultaneously, the second flat key 301 and the second keyway 205 have a second torque transmission portion, with at least a portion of the second flat key 301 disposed within the second torque transmission portion.

[0031] In this embodiment, the second connection structure is similar to the first connection structure described above, in that the elastic preload is placed between the second flat key 301 and the second keyway 205 to form a stable preload force.

[0032] In one exemplary embodiment, the third connection structure includes a third flat key 302 and a third keyway 401. The third flat key 302 is disposed on the valve stem 3, and the third keyway 401 is disposed on the third connection portion and correspondingly disposed to the third flat key 302. The third flat key 302 can be engaged into the third keyway 401. A third elastic preload member 402 is provided between the third keyway 401 and the third flat key 302. The third flat key 302 and the third keyway 401 have a third torque transmission portion, and at least a portion of the third flat key 302 is disposed within the third torque transmission portion.

[0033] In this embodiment, the third connection structure is similar to the first connection structure described above, in that the elastic preload is placed between the third flat key 302 and the third keyway 401 to form a stable preload force.

[0034] The first, second, and third connection structures described above enable multi-stage preload application, ensuring that a preload structure exists at every torque transmission point between the output end of the actuator 1 and the final receiving end of the valve plate 4, thereby improving the valve's transmission efficiency and response accuracy.

[0035] In this embodiment, the cross-sections of the first elastic pretensioner 203, the second elastic pretensioner 206, and the third elastic pretensioner 402 along their length direction are wavy.

[0036] The wavy cross-section of the elastic preload element generates continuous elastic pressure in the keyed connection. When there is an assembly gap between the key and the keyway, the wavy structure of the preload element, after being deformed under pressure, generates a uniformly distributed restoring force, thereby compensating for the fit gap and eliminating transmission backlash. Specifically, when the transmission system is subjected to torque loads, the wavy preload element can absorb vibration impacts through elastic deformation while maintaining stable contact pressure, thus effectively improving transmission accuracy. Simultaneously, the wavy structure ensures that the crests on both sides contact the sidewalls of the keyway and the key, resulting in higher contact pressure uniformity and better anti-relaxation performance, maintaining the adjustment accuracy of the transmission system over a long period.

[0037] It is worth noting that the elastic preload components in this embodiment all use special elastic materials, such as 3J21 (R30003) elastic alloy material. It is an austenitic age-hardening alloy that combines high elasticity and corrosion resistance, with an elastic modulus of up to 210 GPa and a yield strength of up to 2500 Nm. It boasts high fatigue strength (MPa), resistance to stress corrosion cracking and hydrogen embrittlement, is non-magnetic, and has a wide operating temperature range, usable from -269℃ in liquid helium to 500℃. Its corrosion resistance surpasses that of molybdenum-containing stainless steel, and it exhibits no low-temperature embrittlement. It is widely used in ultra-low temperature, highly corrosive, and high-pressure hydrogenation applications in the petroleum and chemical industries, where triple-eccentric butterfly valves are commonly used. For even higher temperatures, 310S stainless steel can be employed; its austenitic structure provides excellent toughness and solves the high-temperature resistance problem, allowing for long-term operation up to 1000℃ and short-term resistance up to 1150℃. It is widely used in typical triple-eccentric butterfly valve applications such as vaporizers, high-pressure hydrogenation systems, high-temperature furnace tubes, and heat exchangers, addressing the issue of adjustment accuracy under extreme conditions.

[0038] In an exemplary embodiment, a fixing pin 5 for interconnection is provided between the valve stem 3 and the valve plate 4. The fixing pin 5 passes through the valve plate 4 radially along the valve stem 3 and is connected to the valve stem 3.

[0039] In this embodiment, a rigid connection between the valve stem 3 and the valve plate 4 is achieved through a radially penetrating fixing pin 5. Specifically, the fixing pin 5 passes through the radial through holes of both the valve stem 3 and the valve plate 4, forming a three-point force-bearing structure, effectively eliminating axial and circumferential clearances. Therefore, the connection method of the fixing pin 5 has a higher contact area and shear resistance, enabling the torque of the actuator 1 to be transmitted to the valve plate 4 more evenly. Due to the radial constraint effect of the fixing pin 5, the angular deviation during the transmission process can be significantly reduced, ensuring that the rotation angle of the valve plate 4 is precisely synchronized with the output of the actuator 1.

[0040] In summary, this utility model effectively reduces transmission clearance, improves transmission accuracy and adjustment performance by setting up multiple pre-tightening components in a graded manner. At the same time, it reduces operating torque, enhances sealing performance, and can adapt to wear after long-term use, thus extending the service life of the valve.

[0041] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A triple eccentric butterfly valve, characterized in that, The device includes an actuator, a valve stem, and a valve plate. The actuator and the valve stem are connected by a connecting sleeve. The connecting sleeve has a first connecting portion and a second connecting portion. A first connecting structure is provided between the first connecting portion and the output end of the actuator. The first connecting structure includes a first elastic preload member. A second connecting structure is provided between the second connecting portion and the valve stem. The second connecting structure includes a second elastic preload member. The valve stem and the valve plate are detachably connected. A third connecting structure is provided between the valve stem and the valve plate. The third connecting structure includes a third elastic preload member.

2. The triple eccentric butterfly valve according to claim 1, characterized in that: The first connection structure includes a first flat key and a first keyway. The first flat key is disposed at the output end of the actuator, and the first keyway is disposed on the first connection part and is corresponding to the first flat key. The first flat key can be used to snap into the first keyway.

3. The triple eccentric butterfly valve according to claim 2, characterized in that: The first flat key and the first keyway have a first torque transmission section, and at least a portion of the first elastic preload is disposed within the first torque transmission section.

4. The triple eccentric butterfly valve according to claim 2, characterized in that: The second connection structure includes a second flat key and a second keyway. The second flat key is disposed on the valve stem, and the second keyway is disposed on the second connection part and is corresponding to the second flat key. The second flat key can be used to snap into the second keyway.

5. The triple eccentric butterfly valve according to claim 4, characterized in that: The second flat key and the second keyway have a second torque transmission section, and at least a portion of the second elastic preload is disposed within the second torque transmission section.

6. The triple eccentric butterfly valve according to claim 4, characterized in that: The third connection structure includes a third flat key and a third keyway. The third flat key is disposed on the valve stem, and the third keyway is disposed on the third connection part and is corresponding to the third flat key. The third flat key can be used to snap into the third keyway.

7. The triple eccentric butterfly valve according to claim 6, characterized in that: The third flat key and the third keyway have a third torque transmission section, and at least a portion of the third elastic preload is disposed within the third torque transmission section.

8. The triple eccentric butterfly valve according to claim 6, characterized in that: The cross-sections of the first, second, and third elastic pretensioners along their length are wavy.

9. The triple eccentric butterfly valve according to claim 1, characterized in that: A fixing pin is provided between the valve stem and the valve plate for mutual connection. The fixing pin passes through the valve plate radially along the valve stem and is connected to the valve stem.

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