Magnetofluid sealing butterfly valve with low opening and closing torque

Abstract

The magnetofluid sealing butterfly valve with the low opening and closing torque comprises a valve seat, a valve clack structure is rotationally arranged in the valve seat, and a rotating shaft assembly of the valve clack structure is connected with the output end of a driving mechanism; the driving mechanism comprises a driving device and a linear transmission assembly, the driving device drives the linear transmission assembly to do linear reciprocating motion, and the motion direction of the linear reciprocating motion is perpendicular to the rotation axis direction of the valve clack structure; in the moving process of the linear transmission assembly, the valve clack structure can be stirred to rotate around the rotating axis of the valve clack structure. The valve clack structure comprises a first valve clack structure and a second valve clack structure which are symmetrically arranged, and the first valve clack structure and the second valve clack structure are shifted by the linear transmission assembly to reversely and synchronously rotate around the rotating axis. And a non-contact dynamic sealing structure is arranged in a running fit clearance between the rotating shaft assembly of the valve clack structure and the valve seat. Through magnetofluid sealing and double-valve reverse self-balancing transmission, on the premise that zero leakage and high sealing performance are guaranteed, extremely low opening and closing torque, long service life and maintenance-free performance of the butterfly valve are achieved.

Description

A magnetohydrodynamic sealed butterfly valve with low opening and closing torque Technical Field

[0001] This invention belongs to the field of butterfly valve technology, and more specifically, it is a magnetohydrodynamic sealing butterfly valve with low opening and closing torque. Background Technology

[0002] Butterfly valves, characterized by their small size, minimal installation space requirements, and rapid opening and closing capabilities, are commonly used in transportation systems in industries such as petroleum, chemical, hydropower, water supply and drainage, metallurgy, and gas energy transportation to regulate or cut off the transported media. The sealing mechanism of a butterfly valve relies on the rotation of the valve disc relative to the valve seat, with the disc's contour creating a slight compression between the disc and the seat's interior. Most existing butterfly valves employ a coaxial double-disc design, where a drive mechanism simultaneously rotates the two discs in opposite directions to regulate the flow of media. This results in the two discs needing to overcome both opposing friction and the resistance of the flowing media, significantly increasing the driving torque required for opening and closing. This can easily lead to disc jamming and slowed opening / closing response due to excessive load. Furthermore, the reverse rotation of the two discs is highly dependent on the precision of the coaxial shaft fit. Prolonged operation under heavy loads can cause increased shaft clearance and accelerated wear on the sealing surface. Combined with the scouring and corrosive effects of the media, this further reduces the butterfly valve's sealing performance, increasing the risk of media leakage. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a low opening and closing torque magnetic fluid sealing butterfly valve. Through magnetic fluid sealing and double-lobe reverse self-balancing transmission, the butterfly valve achieves extremely low opening and closing torque and long service life without maintenance while ensuring zero leakage and high sealing performance.

[0004] Technical Solution: To achieve the above objectives, the present invention provides a low-opening-closing torque magnetohydrodynamic sealing butterfly valve, comprising a valve body, the valve body including a valve seat, a valve disc structure rotatably disposed within the valve seat, and a rotating shaft assembly of the valve disc structure connected to the output end of a drive mechanism; the drive mechanism includes a drive device and a linear transmission assembly, the drive device driving the linear transmission assembly to perform linear reciprocating motion, the direction of which is perpendicular to the rotation axis of the valve disc structure; during the motion, the linear transmission assembly can actuate the valve disc structure to rotate around its own rotation axis; the valve disc structure includes a symmetrically arranged first valve disc structure and a second valve disc structure, which, under the actuation of the linear transmission assembly, can rotate synchronously in opposite directions around the rotation axis; a non-contact dynamic sealing structure is provided within the rotational fit gap between the rotating shaft assembly of the valve disc structure and the valve seat.

[0005] Furthermore, the rotating shafts of the first valve disc structure and the second valve disc structure are coaxially connected through shaft hole fitting to form the rotating shaft assembly; the ends of the two rotating shafts are respectively fixedly connected to a first mating plate and a second mating plate, a first rotating drive block is eccentrically disposed on the first mating plate to the rotating axis, and a second rotating drive block is eccentrically disposed on the second mating plate to the rotating axis; the linear transmission assembly includes a drive slider, the drive slider moves radially along the rotating shaft assembly, and a first drive groove and a second drive groove are disposed opposite to each other on the drive slider; during the movement of the drive slider, the first rotating drive block is accommodated and slidably fitted in the first drive groove, and the second rotating drive block is accommodated and slidably fitted in the second drive groove.

[0006] Furthermore, the linear transmission assembly also includes a rotating rod, which is mounted on the output end of the driving device. The driving device drives the rotating rod to rotate around its own axis. The rotating rod is coaxially rotated with the inner cavity of the sleeve. A transmission component is radially extended from the inner wall of the sleeve. The radially protruding portion of the transmission component is accommodated in a driving groove on the circumferential surface of the rotating rod. The driving groove is a spiral groove extending along the axial direction of the rotating rod. When the rotating rod rotates relative to the sleeve, the protruding portion of the transmission component slides in the driving groove to drive the sleeve to move linearly along the axial direction of the rotating rod. The end of the sleeve away from the rotating rod is rigidly fixedly connected to the driving slider to transmit linear drive to the driving slider.

[0007] Furthermore, the transmission component includes a radially mating through hole formed on the sleeve wall, and a movable slider that slides axially within the hole. The end of the movable slider protruding from the inner wall of the sleeve slides slidably within the drive groove. The drive groove is provided with an extreme position corresponding to the open state of the valve disc structure. A groove is provided at this extreme position. When the movable slider slides to this extreme position, it slides down and embeds into the groove under its own gravity, forming a mechanical locking point of the linear transmission component for locking the valve open state.

[0008] Furthermore, the motion slider is provided with an external force application part, which is used to make the motion slider disengage from the groove under the action of external force.

[0009] Furthermore, the two rotating shafts that fit together with the shaft hole include a hollow rotating shaft and a solid rotating shaft. A first valve disc is fixedly installed radially on the hollow rotating shaft, and a second valve disc is fixedly installed radially on the solid rotating shaft. When the first valve disc and the second valve disc rotate to the closed position at the same time, they together constitute a barrier to block the upstream and downstream pipelines of the valve body.

[0010] Furthermore, during the valve opening process, the first valve disc and the second valve disc rotate synchronously in the counter-current direction.

[0011] Furthermore, when the valve is in the closed state, under the pressure of the medium upstream of the valve body, the first valve disc and the second valve disc are pushed towards the valve seat, so that the first valve disc and the second valve disc wedge against the valve seat in the closed position.

[0012] Furthermore, a valve cover is provided on the upper part of the valve seat, and the drive mechanism is integrated inside the valve cover; the drive device is a motor, which is fixedly installed on one side of the valve cover, and a drive hole is opened on the valve cover at the position corresponding to the drive shaft of the motor, and the sleeve slides in cooperation with the drive hole; a drive cavity is provided inside the valve cover, and the drive hole communicates with the drive cavity, and the sleeve drives the drive slider to slide in the drive cavity; a mounting hole for the rotating shaft assembly to extend into is provided at the bottom of the drive cavity, and the part of the rotating shaft assembly extending into the drive cavity is located on the sliding path of the drive slider, and an avoidance groove that cooperates with the end structure of the rotating shaft assembly is opened on the drive slider along its sliding direction; the first drive groove and the second drive groove are arranged opposite to each other on both sides of the avoidance groove.

[0013] Furthermore, the non-contact dynamic sealing structure is a magnetohydrodynamic sealing structure, used to form and fix an circumferential liquid sealing ring within the rotational fit gap between the rotating shaft of the valve disc structure and the valve seat.

[0014] Beneficial effects: Compared with the prior art, the low opening and closing torque magnetohydrodynamic sealing butterfly valve of the present invention has at least the following advantages:

[0015] (1) By using magnetohydrodynamic sealing, the valve shaft sealing friction is reduced to an extremely low level. At the same time, the linear displacement of the symmetrical valve disc is used to directly use the driving force to do effective work, rather than being consumed in overcoming friction at various points, and the symmetrical design of the valve disc is used to internally counteract the fluid torque. This effectively reduces the torque required by the valve during the opening and closing process.

[0016] (2) The groove locks the valve in the open state, so that the valve does not need to be driven by the motor to provide any holding torque when it is fully open. The motor can be completely de-energized, which fundamentally eliminates this part of the torque requirement.

[0017] (3) Fundamentally separate the source of sealing force from the source of motion force. The drive mechanism is only used to guide the valve disc to the sealing position. Its slider-driven and groove-guided design establishes a low-torque motion transmission path and isolates the reverse effect of the sealing clamping force on the drive chain. Once reached, the huge sealing clamping force is borne by the fluid or the structure itself. Ultimately, this enables the valve to achieve a highly reliable and strong seal with minimal drive torque, solving the core contradiction that has long existed in the butterfly valve field. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the structure of a magnetohydrodynamic sealing butterfly valve with low opening and closing torque according to the present invention.

[0019] Figure 2 is a cross-sectional view of the structure of a low-opening-closing torque magnetic fluid sealing butterfly valve of the present invention in the closed state.

[0020] Figure 3 is a magnified view of part A;

[0021] Figure 4 is a schematic diagram of the rotating rod;

[0022] Figure 5 is a half-sectional view of the valve cover;

[0023] Figure 6 is a schematic diagram of the assembly between the drive slider and the two valve disc structures inside the valve cover from the B-direction view.

[0024] Figure 7 is a half-section view of the valve body. Detailed Implementation

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] As shown in Figures 1-7, a low-opening-closing torque magnetohydrodynamic sealing butterfly valve includes a valve body 1, which mainly comprises a valve seat 4, a valve disc structure 6, and a drive mechanism 2. In this embodiment, a valve cover 5 is provided on the upper part of the valve seat 4, and the drive mechanism 2 is integrated inside the valve cover 5; the valve disc structure 6 is rotatably arranged inside the valve seat 4 and is driven to rotate by the drive mechanism 2, thereby realizing the opening and closing of the valve.

[0027] The drive mechanism 2 is the core of this solution, and it mainly includes a drive motor, a rotating rod 18, a sleeve 21, and a drive slider 22. The rotating rod 18, sleeve 21, and drive slider 22 constitute a linear transmission assembly. The rotating rod 18 is fixedly mounted on the output shaft of the drive motor, and the rotating rod 18 is axially inserted into the inner cavity of the sleeve 21 and is driven by the motor to rotate coaxially with the sleeve 21.

[0028] As shown in Figure 4, a driving groove 19 is formed on the circumferential surface of the rotating rod 18. The driving groove 19 is a spiral groove extending axially along the rotating rod 18. As shown in Figure 3, a mating through hole 23 is formed radially on the wall of the sleeve 21. A moving slider 20 is slidably installed in the mating through hole 23. One end of the moving slider 20 protrudes inward from the sleeve and is slidably fitted in the driving groove 19. The end of the sleeve 21 away from the rotating rod 18 is rigidly fixedly connected to the driving slider 22.

[0029] When the motor drives the rotating rod 18 to rotate, the rotational torque applied by the drive motor can be converted into linear motion of the drive slider 22 through the transmission cooperation between the mating through hole 23, the moving slider 20, and the drive groove 19. This makes the main task of the drive mechanism 2 in this solution to generate a precise linear displacement to move the valve disc structure 6 from one position to another. When the valve is closed, the linear transmission assembly itself does not need to bear a huge force for sealing. The sealing force is mainly generated by the valve disc structure or the medium pressure. This allows the main drive chain to be made lighter, with higher mechanical efficiency and less internal friction loss.

[0030] In this design, the valve disc structure 6 includes a first valve disc structure 6a and a second valve disc structure 6b symmetrically arranged. Under the actuation of the linear transmission assembly, they can rotate synchronously in opposite directions around the same rotation axis. The rotation shafts of the first valve disc structure 6a and the second valve disc structure 6b are coaxially connected through shaft hole fittings to form a rotation shaft assembly. A non-contact dynamic sealing structure 3 is provided within the rotational fit gap between the rotation shaft assembly and the valve seat 4. Preferably, the non-contact dynamic sealing structure 3 is a magnetohydrodynamic sealing structure, used to form and fix an circumferential liquid sealing ring within the rotational fit gap between the rotation shaft of the valve disc structure 6 and the valve seat 4.

[0031] In the operation of traditional butterfly valves, the motor torque needs to directly overcome the combined effects of valve shaft sealing friction, valve seat sealing friction, and fluid dynamic torque. All these enormous resistances act on the main drive chain (worm gear or gear), resulting in extremely robust transmission components and high frictional losses.

[0032] This solution first reduces valve shaft sealing friction to an extremely low level through magnetohydrodynamic sealing. Simultaneously, it employs a linear displacement mechanism to actuate the symmetrical valve disc, ensuring that the driving force is directly used for effective work (driving the valve disc to rotate), rather than being consumed in overcoming friction at various points. Furthermore, the symmetrical design of the valve disc internally counteracts fluid torque. This effectively reduces the torque required for valve opening and closing.

[0033] The valve cover 5, as part of the valve seat 4, is fixedly mounted on the top of the valve seat base via a sealing flange. A through hole 16 is provided on the top of the valve seat base. The upper part of the rotating shaft assembly extends through the through hole 16 into the valve cover 5, thereby achieving a transmission connection with the drive mechanism 2 within the valve cover 5. Based on the sealed installation between the valve cover 5 and the valve seat base, the magnetohydrodynamic sealing structure can be optionally placed within the rotational gap between the rotating shaft assembly and the valve cover 5 to achieve a low-friction seal between the valve disc structure 6 and the valve seat 4.

[0034] The drive motor is fixedly installed on one side of the valve cover 5. The valve cover 5 has a drive hole 17 at a position corresponding to the axial direction of the motor drive shaft. The sleeve 21 is slidably fitted in the drive hole 17. The valve cover 5 has a drive cavity 14 inside. The drive hole 17 communicates with the drive cavity 14, so that the sleeve 21 can drive the drive slider 22 to slide in the drive cavity 14. The bottom of the drive cavity 14 is provided with a mounting hole 15 for the rotating shaft assembly to extend into. The part of the rotating shaft assembly that extends into the drive cavity 14 is located on the sliding path of the drive slider 22. The drive slider 22 has a clearance groove along its sliding direction that cooperates with the end structure of the rotating shaft assembly to avoid interference between the linear movement of the drive slider 22 and the rotational movement of the rotating shaft assembly.

[0035] The ends of the two rotating shafts are respectively fixedly connected to a first mating plate 9a and a second mating plate 9b. A first rotating drive block 10a is eccentrically arranged on the first mating plate 9a and on the second mating plate 9b, a second rotating drive block 10b is eccentrically arranged on the second mating plate 9b and on the rotating axis. The drive slider 22 moves radially along the rotating shaft assembly. A first drive groove 30 and a second drive groove 31 are arranged opposite each other on the drive slider 22. The first drive groove 30 and the second drive groove 31 are arranged opposite each other on both sides of the clearance groove, and the first drive groove 30 and the second drive groove 31 are located at the same position in the length direction of the drive slider 22.

[0036] During the movement of the drive slider 22, the first rotation drive block 10a is accommodated and slidably engaged in the first drive groove 30, and the second rotation drive block 10b is accommodated and slidably engaged in the second drive groove 31.

[0037] The drive slider 22 simultaneously drives the rotating drive blocks of two symmetrical valve discs (the left and right valve discs in Figure 2) via the first drive groove 30 and the second drive groove 31. Because the contours of these two drive grooves are symmetrical but designed in opposite directions, when the drive slider 22 moves linearly, the driving force it provides to the left and right valve discs is equal in magnitude and symmetrical in direction. This helps the two valve discs achieve perfect counter-synchronous rotation, thereby maximizing the internal cancellation of hydrodynamic torque. The linear transmission assembly only needs to provide the force to push the drive slider 22, which is far less than the force required to directly overcome the unbalanced torque of a single large valve disc.

[0038] Furthermore, the drive groove 19 is provided with an extreme position corresponding to the open state of the valve disc structure 6. A groove 35 is provided at this extreme position. When the moving slider 20 slides to this extreme position, it slides down and embeds itself into the groove 35 under its own gravity, forming a mechanical locking point for the linear transmission assembly, used to lock the valve in the open state. Based on this, the moving slider 20 is provided with an external force application part, used to disengage the moving slider 20 from the groove 35 under external force. For example, a force-bearing protrusion 24 or a magnetic attraction component fixedly provided at the outer end of the moving slider 20 can be used to unlock it by manually pulling it out or by using an electromagnet.

[0039] When the valve reaches the fully open position, the moving slider 20 slides into the groove 35. At this time, the direction of the resultant force of the rotation axis of the rotating rod 18, the contact line between the moving slider 20 and the sleeve 21, and the gravity acting on the slider causes the slider to be stuck in the groove 35, forming a dead point in the mechanism. To disengage it, a specific external force must be applied (through the protrusion on its top or magnetic attraction). This means that maintaining the valve in the fully open position does not require the drive motor to provide any holding torque. The motor can be completely de-energized. If a traditional valve needs to maintain its position, the motor or actuator must be continuously powered to counteract fluid pressure or vibration. This is not only energy-intensive but also means that the holding torque must be considered when selecting the actuator, leading to an increase in its size and cost. This solution fundamentally eliminates this torque requirement.

[0040] More specifically, as shown in Figure 2, the first valve disc structure 6a includes a first valve disc 7a, a hollow rotating shaft 8, a first mating plate 9a, and a first rotation drive block 10a. The second valve disc structure 6b includes a second valve disc 7b, a solid rotating shaft 11, a second mating plate 9b, and a second rotation drive block 10b.

[0041] The hollow rotating shaft 8 and the solid rotating shaft 11 are coaxially sleeved and rotate in cooperation with each other. The first valve disc 7a is fixedly installed radially on one side of the hollow rotating shaft 8. The hollow rotating shaft 8 has a number of mating notches 12 on the side away from the first valve disc 7a. These mating notches 12 are arranged at equal intervals along the axial direction of the hollow rotating shaft 8.

[0042] The solid rotating shaft 11 has several mating protrusions 13 corresponding to the mating notches 12. The second valve disc 7b is fixed to these protrusions 13, so that the first valve disc 7a and the second valve disc 7b form a hinge-like structure. When the hollow rotating shaft 8 rotates relative to the solid rotating shaft 11, the multiple mating protrusions 13 can slide within the corresponding mating notches 12, thereby causing the first valve disc 7a and the second valve disc 7b to rotate synchronously in opposite directions around the same rotating axis. When the first valve disc 7a and the second valve disc 7b rotate to the closed position at the same time, they together form a barrier to block the upstream and downstream pipelines of the valve body 1.

[0043] Preferably, during valve opening, the first valve disc 7a and the second valve disc 7b rotate synchronously in the counter-current direction. Although counter-current opening generates a torque that hinders rotation due to medium resistance, the dual-disc synchronous counter-rotation structure of this design ensures that the torques of the left and right valve discs are in opposite directions, largely canceling each other out. Combined with magnetohydrodynamic sealing (near-zero friction) and groove self-locking (no holding torque), the total opening and closing torque of the system has been optimized to a very low level. Furthermore, the flow field during counter-current opening is more stable, and the relationship between valve opening degree and flow coefficient (Cv value) is more linear, facilitating precise adjustment. Additionally, during counter-current opening, the water flow first impacts the valve disc edge and front, resulting in a smooth transition and almost no cavitation. Valve lifespan and reliability are paramount.

[0044] Although the closing action of the dual valve discs is still achieved by the drive mechanism 2, it only serves to guide the rotation of the valve discs and does not need to provide and maintain the clamping force required for the seal between the valve discs and the valve seat. When the valve is in the closed state, under the pressure of the medium upstream of the valve body 1, the first valve disc 7a and the second valve disc 7b are pushed towards the valve seat 4, causing the first valve disc 7a and the second valve disc 7b to wedge against the valve seat 4 in the closed position. This fundamentally separates the source of the sealing force from the source of the motion force. The drive mechanism 2 only guides the valve discs to the sealing position; once reached, the huge sealing clamping force is borne by the fluid or structure itself and is not transmitted back to the drive chain. The left and right split + reverse synchronous drive design of this scheme is to achieve torque self-balancing and fundamentally reduce the fluid dynamic torque. The slider actuation + groove guide design of the drive mechanism 2 is to establish a low-torque motion transmission path and isolate the reverse influence of the sealing clamping force on the drive chain. Ultimately, this enabled the valve to achieve a highly reliable and robust seal with minimal driving torque, resolving a long-standing core contradiction in the butterfly valve field.

[0045] Therefore, the drive motor only needs to provide an optimized, relatively small torque during the brief period of valve actuation to overcome the frictional forces of the streamlined and optimized transmission chain and drive the valve disc to rotate. The motor does not need to operate when the valve remains open or closed for extended periods. This achieves the goal of reducing torque in terms of both peak torque demand and continuous energy consumption.

[0046] As shown in Figure 6, the length of the solid rotating shaft 11 is greater than the length of the hollow rotating shaft 8. In the assembled state, as shown in Figure 2, the bottom ends of both are flush, resulting in a height difference in the portion extending into the valve cover 5. The first mating plate 9a is fixedly installed on the upper end of the hollow rotating shaft 8, and the second mating plate 9b is fixedly installed on the upper end of the solid rotating shaft 11, so that the second mating plate 9b is located on the side of the first mating plate 9a away from the valve seat 4, forming a transmission space between the first mating plate 9a and the second mating plate 9b. The drive slider 22 can be slidably arranged between the two mating plates, so that the first rotation drive block 10a and the second rotation drive block 10b respectively engage with the corresponding drive grooves on the drive slider 22 from the upper and lower sides. The clearance grooves opened on the drive slider 22 include a first clearance groove 28 corresponding to the end structure of the solid rotating shaft 11 and a second clearance groove 29 corresponding to the end structure of the hollow rotating shaft 8. This rationally plans the distribution of this part of the structure within the valve cover 5, making the structure more compact.

[0047] The driving slider 22 is roughly a rectangular slider, with internal sliders 27 symmetrically fixedly connected on both sides of the sliding direction. Internal grooves 26 are correspondingly opened on the two side walls of the driving cavity 14. The driving slider 22 slides within the driving cavity 14 through the sliding engagement of the internal sliders 27 and the internal grooves 26.

[0048] As shown in Figure 7, the magnetic fluid sealing structure 3 includes a magnetic fluid and a magnetic component; a magnetic component mounting cavity is formed between the wall of the mounting hole 15 and the outer wall of the hollow rotating shaft 8, and the magnetic component is fixedly installed in the magnetic component mounting cavity; the fit clearance between the inner wall of the hollow rotating shaft 8 and the outer wall of the solid rotating shaft 11 forms a magnetic fluid cavity; the magnetic fluid is contained in the magnetic fluid cavity; the magnetic component includes a permanent magnet 32, a first pole shoe 33, and a second pole shoe 34; the valve seat 4 and the valve cover 5 are sealed together by a sealing gasket, and the second pole shoe 34 is installed... On the side of the sealing gasket away from the valve seat 4, the first pole shoe 33 is spaced apart from the second pole shoe 34 on the side of the second pole shoe 34 away from the valve seat 4, and both the first pole shoe 33 and the second pole shoe 34 are made of magnetically conductive material for conducting and focusing magnetism; the permanent magnet 32 ​​is disposed between the first pole shoe 33 and the second pole shoe 34; the magnetic field generated by the permanent magnet 32 ​​is transmitted through the first pole shoe 33 and the second pole shoe 34 to form a strong magnetic field in the magnetofluid cavity region, so that the magnetofluid is adsorbed into the magnetofluid cavity under the action of the strong magnetic field and forms a continuous dynamic sealing liquid film.

[0049] The magnetic field forms a complete closed loop. The specific path is as follows: one end of the permanent magnet 32 ​​outputs a magnetic field to the first pole piece 33. The first pole piece 33 conducts the magnetic field to the outer wall of the hollow rotating shaft 8 and concentrates and diffuses the magnetic field. The magnetic field penetrates the wall of the hollow rotating shaft 8 to the magnetofluid cavity, adsorbs the magnetofluid in the cavity and conducts it to the outer wall of the solid rotating shaft 11. The solid rotating shaft 11 conducts the magnetic field back to the inner wall of the hollow rotating shaft 8, and then transmits it to the second pole piece 34 through the hollow rotating shaft 8. Finally, it flows back from the second pole piece 34 to the other end of the permanent magnet 32, forming a closed magnetic field loop without magnetic resistance loss, ensuring the stability of the magnetofluid seal.

[0050] The above are the preferred embodiments described in this invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve, comprising a valve body (1), the valve body (1) comprising a valve seat (4), wherein a valve disc structure (6) is rotatably disposed within the valve seat (4), and the rotating shaft assembly of the valve disc structure (6) is connected to the output end of a drive mechanism (2), characterized in that: The drive mechanism (2) includes a drive device and a linear transmission assembly. The drive device drives the linear transmission assembly to perform linear reciprocating motion. The direction of the linear reciprocating motion is perpendicular to the rotation axis of the valve disc structure (6). During the motion, the linear transmission assembly can actuate the valve disc structure (6) to rotate around its own rotation axis. The valve disc structure (6) includes a first valve disc structure (6a) and a second valve disc structure (6b) arranged symmetrically. Under the actuation of the linear transmission assembly, the two valve disc structures can rotate synchronously in opposite directions around the rotation axis. A non-contact dynamic sealing structure (3) is provided in the rotational fit gap between the rotational shaft assembly of the valve disc structure (6) and the valve seat (4).

2. The low opening and closing torque magnetohydrodynamic sealing butterfly valve according to claim 1, characterized in that: The rotating shaft of the first valve disc structure (6a) and the rotating shaft of the second valve disc structure (6b) are coaxially connected through shaft hole fitting to form the rotating shaft assembly; the ends of the two rotating shafts are respectively fixedly connected to a first mating plate (9a) and a second mating plate (9b), a first rotating drive block (10a) is eccentrically arranged on the first mating plate (9a) and a second rotating drive block (10b) is eccentrically arranged on the second mating plate (9b) and a second rotating drive block (10b); the linear transmission assembly includes a drive slider (22), the drive slider (22) moves radially along the rotating shaft assembly, and a first drive groove (30) and a second drive groove (31) are arranged opposite to each other on the drive slider (22); during the movement of the drive slider (22), the first rotating drive block (10a) is accommodated and slidably fitted in the first drive groove (30), and the second rotating drive block (10b) is accommodated and slidably fitted in the second drive groove (31).

3. The low opening and closing torque magnetohydrodynamic sealing butterfly valve according to claim 2, characterized in that: The linear transmission assembly also includes a rotating rod (18), which is installed at the output end of the driving device. The driving device drives the rotating rod (18) to rotate around its own axis. The rotating rod (18) is coaxially rotated with the inner cavity of the sleeve (21). A transmission component is provided radially extending from the inner wall of the sleeve (21). The radially protruding part of the transmission component is housed in a driving groove (19) on the circumferential surface of the rotating rod (18). The driving groove (19) is a spiral groove extending along the axial direction of the rotating rod (18). When the rotating rod (18) rotates relative to the sleeve (21), the protruding part of the transmission component slides in the driving groove (19) to drive the sleeve (21) to move linearly along the axial direction of the rotating rod (18). The end of the sleeve (21) away from the rotating rod (18) is rigidly fixedly connected to the driving slider (22) to transmit linear drive to the driving slider (22).

4. The low opening and closing torque magnetohydrodynamic sealing butterfly valve according to claim 3, characterized in that: The transmission component includes a radially fitted through hole (23) on the sleeve (21) wall and a sliding slider (20) that slides along the hole axis within the hole. The end of the sliding slider (20) protruding from the inner wall of the sleeve slides within the drive groove (19). The drive groove (19) is provided with an extreme position corresponding to the valve opening state. A groove (35) is provided at the extreme position. When the sliding slider (20) slides to the extreme position, it slides down and embeds into the groove (35) under its own gravity, forming a mechanical locking point of the linear transmission component for locking the valve opening state.

5. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 4, characterized in that: The motion slider (20) is provided with an external force application part, which is used to make the motion slider (20) disengage from the groove under the action of external force.

6. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 2, characterized in that: The two rotating shafts that fit together include a hollow rotating shaft (8) and a solid rotating shaft (11). A first valve disc (7a) is fixedly installed on the hollow rotating shaft (8) along the radial direction, and a second valve disc (7b) is fixedly installed on the solid rotating shaft (11) along the radial direction. When the first valve disc (7a) and the second valve disc (7b) rotate to the closed position at the same time, they together constitute a barrier to block the upstream and downstream pipelines of the valve body (1).

7. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 6, characterized in that: During the valve opening process, the first valve disc (7a) and the second valve disc (7b) rotate synchronously in the counter-current direction.

8. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 7, characterized in that: When the valve is in the closed state, under the pressure of the medium upstream of the valve body (1), the first valve disc (7a) and the second valve disc (7b) are pushed towards the valve seat (4), so that the first valve disc (7a) and the second valve disc (7b) wedge against the valve seat (4) in the closed position.

9. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 3, characterized in that: A valve cover (5) is provided on the upper part of the valve seat (4), and the drive mechanism (2) is integrated inside the valve cover (5); the drive device is a motor, which is fixedly installed on one side of the valve cover (5), and a drive hole (17) is opened on the valve cover (5) at the position corresponding to the drive shaft of the motor, and the sleeve (21) slides with the drive hole (17); a drive cavity (14) is provided inside the valve cover (5), and the drive hole (17) communicates with the drive cavity (14), and the sleeve (21) The drive slider (22) is driven to slide within the drive cavity (14); the bottom of the drive cavity (14) is provided with a mounting hole (15) for the rotating shaft assembly to extend into; the part of the rotating shaft assembly extending into the drive cavity (14) is located on the sliding path of the drive slider (22); the drive slider (22) is provided with a clearance groove along its sliding direction that cooperates with the end structure of the rotating shaft assembly; the first drive groove (30) and the second drive groove (31) are arranged opposite to each other on both sides of the clearance groove.

10. A low-opening-closing torque magnetohydrodynamic sealing butterfly valve according to claim 1, characterized in that: The non-contact dynamic sealing structure (3) is a magnetohydrodynamic sealing structure, used to form and fix an circumferential liquid sealing ring in the rotational fit gap between the rotating shaft of the valve disc structure (6) and the valve seat (4).

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