A pneumatic actuator facilitating switching operation

Abstract

This utility model relates to a pneumatic actuator that facilitates switching operations, comprising a valve body, a valve plate, a valve stem, and a sealing ring. An annular locking block at the lower end of the valve stem engages with the valve plate. A handwheel is fixed to the valve stem, and rotation raises and lowers the gate. The valve plate sealing surface has an inclined structure, and the sealing ring has an annular groove that engages with a protruding groove on the valve plate. The outer edge is deformable, deforming along the inclined surface to fit against the inner wall of the valve body when closed, forming a reliable flexible seal. Guide plates are fixed on both sides of the valve body passage. A flow-diverting column is located at the intersection of the mesh holes on the guide plates. The surface of the flow-diverting column has guide grooves to guide the fluid to disperse and flow around the valve, reducing the flow velocity and extending the residence time, thereby mitigating the impact of water hammer on the valve plate when the gate valve is closed quickly.

Description

Technical Field

[0001] This application relates to the field of actuators and fluid control technology, specifically to a pneumatic actuator that facilitates switching operations. Background Technology

[0002] Pneumatic actuators are widely used in process control applications due to their compact structure and rapid response. To meet the needs of commissioning, power outages, abnormal air supply, or emergency response, existing products are typically equipped with manual emergency devices. However, existing technologies still have the following common problems: First, the switching process from automatic to manual is cumbersome, often requiring multiple steps such as unlocking, opening protective components, tightening and loosening fasteners, and engaging / disengaging the clutch, sometimes even requiring tools. This results in long switching times, poor operability, and difficulty in meeting emergency intervention requirements. Second, in some structures, the handwheel is easily driven or can be directly force-applied during normal operation. Accidental activation may apply a disturbing torque to the output shaft, affecting valve position stability. Summary of the Invention

[0003] The technical problem this utility model aims to solve is: addressing the shortcomings of existing pneumatic actuators, such as cumbersome manual switching steps and the easy accidental activation of the handwheel during normal operation, which can interfere with the valve position. In cases of debugging, power outages, abnormal air supply, or emergency handling, the present invention can simplify the switching from pneumatic to manual operation by reducing the number of steps.

[0004] The technical solution of this utility model is as follows: A pneumatic actuator that facilitates switching operations includes an internal transmission mechanism connected to a valve output shaft, with a drive gear connected to the internal transmission mechanism above it, the drive gear meshing on a base; it also includes a manual drive assembly, which includes a worm gear connected to a handwheel and a turbine gear meshing with the worm gear and fixed to a mounting rod, the mounting rod having a limiting groove extending axially; a lead screw and nut assembly, including a lead screw and a nut coaxially arranged, the lead screw and the nut being mounted on the mounting rod, the lead screw being able to slide axially relative to the mounting rod, and the nut being rotatably supported for driving the lead screw to move axially; wherein, a limiting block is provided at the lower end of the lead screw and placed in the limiting groove, so as to restrict the rotation of the lead screw and guide its axial movement when the lead screw and the nut rotate relative to each other.

[0005] Furthermore, the mounting rod is sleeved on the drive gear and slidably connected to the drive gear. The outer end of the mounting rod has a symmetrically arranged limiting groove, and the bottom is integrally formed with a limiting circular plate. The limiting circular plate is sleeved on the base to limit the mounting rod.

[0006] Preferably, in the ready-to-switch state, the lead screw is constrained by the limiting groove, and rotating the nut causes the lead screw to move down and the base to engage with the drive gear. The drive gear is provided with a slot corresponding to the limiting block.

[0007] More specifically, in manual operation mode, rotating the handwheel drives the mounting rod to rotate via the worm gear and the turbine. The mounting rod, through the limiting groove, causes the lead screw and the nut to rotate synchronously, and the torque is transmitted to the internal transmission mechanism via the base and the drive gear.

[0008] Furthermore, the manual drive assembly is installed in a protective housing coaxial with the mounting rod. The protective housing is a horizontally arranged closed housing with a neck integrally extending downward from the middle of the bottom and fixedly connected to the upper end cover of the pneumatic actuator housing. The right side wall is provided with a through shaft hole, through which the worm shaft passes and is connected to the handwheel.

[0009] This invention achieves a two-step switch from pneumatic to manual operation by axially lowering the lead screw nut and engaging it with the limiting block and the drive gear. Operation requires no disassembly or tools, shortening switching time. Under normal conditions, the lead screw is in the disengaged position, with the handwheel side connected to the internal transmission chain, preventing accidental handwheel contact from affecting valve position stability. The axial limiting groove of the mounting rod engages with the limiting block, guiding the axial movement of the lead screw and achieving circumferential synchronization after engagement, ensuring reliable engagement and preventing partial engagement and jamming. The protrusion of the nut serves as a position indicator, making engagement / disengagement and valve position changes readily visible, facilitating on-site confirmation and maintenance. Attached Figure Description

[0010] Figure 1 A schematic diagram of the overall structure of a pneumatic actuator that facilitates switching operations, provided for an embodiment of this application;

[0011] Figure 2 A schematic diagram of the internal structure of a pneumatic actuator that facilitates switching operations, provided for an embodiment of this application;

[0012] Figure 3 A schematic diagram of the manual operation state of a pneumatic actuator that facilitates switching operations, provided for an embodiment of this application;

[0013] Figure 4 for Figure 3 An enlarged structural diagram of area A of a pneumatic actuator that facilitates switching operations is provided in an embodiment of this application;

[0014] Figure 5 A schematic diagram of a lead screw and nut assembly and internal transmission structure of a pneumatic actuator that facilitates switching operations, provided for an embodiment of this application;

[0015] Figure 6 A schematic diagram of the base and drive gear structure of a pneumatic actuator that facilitates switching operations, provided in an embodiment of this application;

[0016] Figure 7A cross-sectional view of a drive assembly for a pneumatic actuator that facilitates switching operations, provided in an embodiment of this application;

[0017] Attached icon numbers:

[0018] 1. Handwheel; 2. Pneumatic actuator housing; 3. Protective housing; 4. Manual drive assembly; 41. Worm gear; 42. Worm wheel; 43. Lead screw and nut assembly; 431. Nut; 432. Lead screw; 433. Limit block; 434. Slot; 435. Mounting rod; 436. Limit groove; 437. Limit baffle; 51. Cylinder body; 52. Internal transmission mechanism; 53. Drive gear; 54. Base; 55. Limiting circular plate. Detailed Implementation

[0019] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application.

[0020] Gate valves are valve devices commonly used in pipeline systems to control the flow of fluid. They have advantages such as simple structure, reliable sealing performance, wide applicability, and convenient maintenance.

[0021] To improve sealing performance, enhance opening and closing flexibility, and extend service life, some technical solutions embed sealing rings on the gate or valve seat, achieving a good sealing effect through the cooperation between the sealing ring and the sealing surface. However, these wedge gate valves with sealing ring structures still face the following technical challenges: during the rapid closing process of the gate valve, the fluid in the system may generate instantaneous back pressure, i.e., water hammer effect. The sealing ring is prone to falling off due to long-term impact, thus affecting sealing reliability, overall service life, and operational safety.

[0022] In this regard, the present invention aims to provide a pneumatic actuator that is easy to switch operations, which can improve sealing performance and solve the problems of easy detachment of sealing rings and easy damage to sealing surfaces caused by water hammer impact due to long-term rapid closure of gate valves, thereby effectively improving the service life and sealing reliability of valves.

[0023] This embodiment discloses a pneumatic actuator that facilitates switching operations, comprising: a valve body assembly 1, on which a valve plate 4 space is provided; a valve plate 4, which is movably disposed within the valve plate 4 space, and an annular groove 61 is provided on the side of the valve plate 4 away from the valve plate 4 space; a valve stem 3, which is rotatable around its own axis and movable along its own axis direction and disposed within the valve plate 4 space; and a sealing ring 6, which is snapped into the annular groove 61 on the valve plate 4; wherein, the valve body assembly 1 has a fluid channel, and a guide plate 5 is provided on the inner wall of the fluid channel, the guide plate 5 being located on both sides of the valve plate 4 space and communicating with the fluid channel and the valve plate 4 space.

[0024] It is understood that the basic components of the wedge gate valve with anti-sealing ring detachment of this utility model include: valve body assembly 1, valve plate 4, valve stem 3, and sealing ring 6. The space of valve plate 4 refers to the cavity structure inside valve body assembly 1 used to accommodate the vertical movement of valve plate 4; valve plate 4 is disposed in this space and can move up and down along valve stem 3 to open and close the channel; valve plate 4 has an annular groove 61 on the side away from the fluid channel for installing a seal; the sealing ring is snapped into the groove of valve plate 4 to seal against the fluid channel of the valve body; valve stem 3 can not only rotate around its axis but also move axially to control the opening and closing of valve plate 4; guide plates 5 are provided on both sides of the fluid channel of the valve body, which connect the channel and the space of valve plate 4 and can guide and mitigate water flow impact.

[0025] Specifically, the user externally drives the valve stem 3 to rotate, causing the valve plate 4 to move up and down within its space. When the valve plate 4 is pressed down to the closed position, the sealing ring 6 presses against the inner wall of the valve body, achieving a seal. The guide plate 5 guides the fluid flow, reducing direct impact on the sealing ring. This structure achieves reliable up-and-down opening and closing, a stable flexible sealing effect, and optimizes the fluid flow pattern through the guide plate 5, thereby improving the durability and sealing reliability of the gate valve.

[0026] In some embodiments, the lower end of the valve stem 3 is provided with an annular locking block 31, and the valve plate 4 is composed of two plates joined together. The annular locking block 31 of the valve stem 3 is rotatably locked between the two valve plates 4. When the valve stem 3 rotates, it drives the valve plate 4 to move in the space of the valve plate 4 along its axial direction.

[0027] It is understandable that this section involves the connection method between valve stem 3 and valve plate 4 and the resulting motion relationship.

[0028] The annular locking block 31 is an annular protrusion located at the lower end of the valve stem 3. It can rotate with the valve stem 3 and also slide relative to it in the valve plate 4. Due to its annular structure, it can form a locking effect on the valve stem 3, while ensuring uniform force distribution and preventing wear.

[0029] The valve plate 4 is formed by the mating of two plates: the valve plate 4 is assembled from two upper and lower pieces or two halves. This mating structure forms an annular clamping cavity in the middle for embedding and locking the annular locking block 31. Compared with the one-piece valve plate 4, the mating structure makes it easier to assemble the annular locking block 31 and makes disassembly and maintenance more convenient.

[0030] Specifically, during assembly, the annular locking block 31 at the lower end of the valve stem 3 is embedded between the valve plate 4 formed by the mating of two plates. The locking block can rotate inside the valve plate 4 but will not disengage. A helical drive structure is provided on the upper part of the valve stem 3. When the handwheel 2 drives the valve stem 3 to rotate, the locking block moves axially along the guide surface of the helical groove, thereby driving the clamped valve plate 4 to move up and down within the space of the valve plate 4, realizing the opening and closing of the valve. Since only the locking block slides relative to the valve plate 4 while the valve stem 3 rotates, the valve stem 3 itself will not move axially. This avoids additional wear between the valve stem 3 and the sealing components and ensures the linear movement of the valve plate 4.

[0031] In some embodiments, the sealing ring 6 is provided with an annular groove 61 communicating with its inner wall, and the valve plate 4 is provided with an annular protrusion 21. The sealing ring 6 is fixed by the groove and the protrusion on the valve plate 4. The sealing surface of the valve plate 4 is inclined, and the outer edge of the sealing ring 6 is arc-shaped or has a deformable structure. When the valve plate 4 is closed, the sealing ring 6 is compressed and deformed along the inclined sealing surface direction, and fits against the channel wall of the valve body assembly 1.

[0032] It can be understood that the annular groove 61 in this paragraph refers to the annular groove opened on the inner wall of the sealing ring 6, and its opening is connected to the inner diameter of the sealing ring; the annular protrusion 21 is the annular protrusion structure corresponding to the outer edge of the valve plate 4. The two cooperate with each other, and the sealing ring 6 is fitted onto the annular protrusion 21 of the valve plate 4 through its own groove, thereby realizing the positioning and fixing of the sealing ring and preventing the sealing ring from falling off during the opening and closing process.

[0033] The inclined sealing surface refers to the sealing contact surface between the valve plate 4 and the valve body, which is designed as an inclined surface rather than a traditional horizontal or vertical surface. This inclined surface intersects with the valve body channel wall along the axial direction of the valve stem 3, which facilitates the gradual compression and fit of the sealing ring 6 during tightening.

[0034] The outer edge of the sealing ring 6 is designed to be arc-shaped or have certain deformable characteristics. The purpose is to allow it to undergo elastic deformation in accordance with the tilt angle of the sealing surface of the valve plate 4 when compressed, thereby forming a larger contact area and a more uniform sealing pressure.

[0035] Specifically, during assembly, the annular groove 61 of the sealing ring 6 is fitted onto the annular protrusion 21 on the outer edge of the valve plate 4, forming a reliable snap-fit ​​relationship. When the valve is closed, the valve plate 4 is pressed downwards by the valve stem 3, and the inclined sealing surface on the valve plate 4 contacts and gradually presses against the arc-shaped outer edge of the sealing ring 6, causing the sealing ring 6 to undergo elastic deformation along the inclined direction. During this deformation process, the outer edge of the sealing ring 6 expands outwards and fits tightly against the inner wall of the valve body channel, ultimately forming a flexible annular seal.

[0036] In some embodiments, the guide plate 5 is fixed on the side of the valve body away from the space of the valve plate 4. The guide plate 5 has multiple grid apertures. A diversion column 51 is provided in the area where the grid apertures intersect and merge. The column extends along the direction of the fluid channel.

[0037] It can be understood that the guide plate 5 is a flow guiding element fixedly installed on the upper end of the valve plate 4, that is, on the side away from the space of the valve plate 4. Its main function is to guide the flow of the medium and buffer the impact. The "fixed installation" here means that the guide plate 5 is fixedly connected to the valve body. The guide plate 5 has multiple regularly arranged small holes, forming a grid-like aperture. These apertures allow the fluid to pass through, but they disperse the flow stream, dividing the overall water flow into multiple smaller unit flows, thereby reducing the concentrated impact of the flow velocity. The grid aperture intersection and confluence area refers to the area where the grid holes on the guide plate 5 meet, which is usually the intersection between the holes.

[0038] The flow divider column 51 refers to the columnar body installed in the aforementioned intersection and confluence area, extending axially along the fluid channel. This column further divides or deflects the flow stream that originally passed through the mesh holes, thus serving to divide and stabilize the flow.

[0039] Specifically, when the medium flows along the fluid channel through the valve plate 4, it first encounters the guide plate 5 and passes through its mesh aperture. Due to the aperture array distribution, the originally concentrated water flow is divided into multiple small streams; these streams are guided and dispersed again after encountering the diversion column 51 in the intersection and confluence area, so that the fluid has been effectively decomposed and its direction changed when it enters the valve cavity. This guiding and diversion structure significantly weakens the impact force of the fluid during the closing or opening of the valve plate 4.

[0040] Based on the structure of the guide plate 5 and the flow divider 51, their role in mitigating water hammer can be further explained. Water hammer refers to the pressure wave generated by the sudden change in liquid momentum when fluid in a pipeline suddenly stops or a valve is quickly closed. Since liquids are almost incompressible, the momentum of the stopped fluid will propagate in the pipeline in the form of shock waves, and this pressure peak is enough to damage pipelines and valves. Common engineering methods are to reduce the flow velocity or extend the closing time to make the momentum change more slow, thereby weakening the impact. In this invention, the multiple grid apertures on the guide plate 5 divide the overall flow into multiple smaller flow streams, which, together with the flow divider 51 at the intersection and confluence, further disperse and deflect the flow direction, thus effectively reducing the flow velocity of each stream; at the same time, the flow divider 51 extends along the direction of the fluid channel, which is equivalent to increasing the guiding length within the grid apertures, so that the fluid needs more time to be completely cut off when passing through the valve body. This "velocity reduction-delay" flow characteristic helps to mitigate the pressure change at the moment of closure, thereby reducing the water hammer effect. This optimized design reduces the impact of water hammer on the sealing ring and valve plate 4, reduces sealing failure and structural damage caused by water hammer, and improves the overall stability and service life of the valve.

[0041] In some embodiments, the diversion column 51 is provided with a guide groove for guiding local fluid flow around it.

[0042] It is understandable that this section emphasizes the guide groove structure provided on the flow divider 51. This is a groove machined on the surface of the flow divider 51 to further improve the fluid guiding effect. The guide groove refers to the groove machined along the outer wall of the flow divider 51, which can be axial or spiral and penetrates the surface of the flow divider 51. Its function is to provide a flow path for local fluid, so that the fluid forms a flow around or swirling flow near the flow divider 51.

[0043] Specifically, when fluid passes through the mesh apertures on the guide plate 5, it partially impacts the diversion column 51 located at the mesh intersection. The guide grooves on the surface of the diversion column 51 provide a bypass path for this fluid, guiding the local fluid to flow around the column along the groove direction or generating swirling flow. This bypass flow increases the flow path length of the local fluid and reduces the flow velocity, making the momentum change more gradual. The reduced flow velocity helps mitigate the water hammer effect generated at the moment of valve closure, as water hammer typically originates from the pressure wave generated when fluid momentum is rapidly interrupted; reducing the flow velocity or extending the fluid stopping time can significantly weaken the water hammer impact.

[0044] In some embodiments, the valve body assembly 1 further includes a handwheel 2, which is fixedly connected to the valve stem 3 and is used to drive the valve stem 3 to rotate around the axis of the valve stem 3.

[0045] It can be understood that handwheel 2 refers to a disc-shaped knob installed on the outside of valve body assembly 1, with its center fixedly connected to the upper end of valve stem 3. Handwheel 2 is generally rigidly connected to valve stem 3 by means of key or thread, and rotating handwheel 2 can directly transmit torque to valve stem 3, causing valve stem 3 to rotate around its own axis.

[0046] Specifically, the operator controls the opening and closing of the gate valve using handwheel 2. When handwheel 2 is turned, valve stem 3 rotates accordingly. Since the lower end of valve stem 3 and the gate plate achieve rotational-linear motion conversion through threads and guide structures, the rotation of valve stem 3 is converted into the axial lifting and lowering of valve plate 4, thereby realizing the opening and closing of the gate valve.

[0047] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pneumatic actuator for easy switching operation, comprising an internal transmission mechanism connected to a valve output shaft, characterized in that, A drive gear is provided above the internal transmission mechanism and connected thereto, and the drive gear meshes with the base. It also includes a manual drive assembly, which includes a worm gear connected to a handwheel and a turbine gear meshing with the worm gear and fixed together with a mounting rod, the mounting rod having a limiting groove extending axially; A lead screw and nut assembly includes a lead screw and a nut arranged coaxially, the lead screw and the nut being mounted on a mounting rod, the lead screw being axially sliding relative to the mounting rod, and the nut being rotatably supported for driving the lead screw to move axially; The lower end of the lead screw is provided with a limiting block and placed in the limiting groove to restrict the rotation of the lead screw and guide its axial movement when the lead screw and nut rotate relative to each other.

2. A pneumatic actuator for facilitating switching operation according to claim 1, wherein, The mounting rod is sleeved on the drive gear and slidably connected to the drive gear. The outer end of the mounting rod has a symmetrically arranged limiting groove, and the bottom is integrally formed with a limiting circular plate. The limiting circular plate is sleeved on the base and is used to limit the mounting rod.

3. A pneumatic actuator for facilitating switching operation according to claim 2, wherein, In the ready-to-switch state, the lead screw is constrained by the limiting groove. Rotating the nut causes the lead screw to move down and the base to engage with the drive gear. The drive gear has a corresponding slot for the limiting block.

4. A pneumatic actuator for facilitating switching operation according to claim 2, wherein In manual operation mode, rotating the handwheel drives the mounting rod to rotate via the worm gear and the turbine. The mounting rod, through the limiting groove, causes the lead screw and the nut to rotate synchronously. The torque is then transmitted to the internal transmission mechanism via the base and the drive gear.

5. A pneumatic actuator for easy switching operation according to claim 4, characterized in that, The nut is provided with limit baffles at both the top and bottom, and one end of the nut protrudes to indicate the rotation position of the internal transmission mechanism in the manual operation state.

6. A pneumatic actuator for easy switching operation according to claim 4, characterized in that, The manual drive assembly is installed in a protective housing coaxial with the mounting rod. The protective housing is a horizontally arranged closed housing with a neck integrally extending downward from the middle of the bottom and fixedly connected to the upper end cover of the pneumatic actuator housing. The right side wall is provided with a through shaft hole, through which the worm shaft passes and is connected to the handwheel.

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