A high-efficiency sealing valve

Abstract

This invention discloses a high-efficiency sealing valve that solves the problems of uneven lateral force on the piston, one-sided wear of the seal, and transmission jamming and self-locking in traditional pneumatic sealing valves. The sealing valve includes an upper cover, a lower cover, a locking nut, and a valve seat. An internal support plate divides the regulating chamber into an upper pneumatic chamber and a lower transmission chamber. The upper pneumatic chamber contains a guide and limiting slider and a non-self-locking multi-start lead screw, with a helical gear connected to the bottom of the lead screw. The lower transmission chamber contains a gear support and a first piston. The gear support is assembled through a radial guide structure, providing rigid horizontal limiting and allowing for slight vertical displacement and small-angle deflection around the valve axis. Two eccentric gears with a 180° phase difference are mounted on the support, achieving radial force self-balancing, reducing seal wear, and improving valve operation stability.

Description

Technical Field

[0001] This invention relates to the field of sealing valve technology, and in particular to a high-efficiency sealing valve. Background Technology

[0002] Sealing valves are core actuators in fluid transport and control systems, and their operational stability and sealing durability directly determine the safety of the pipeline system. Most conventional pneumatic sealing valves employ a traditional direct-push structure, relying on an air source to directly drive the piston axially, which in turn pushes against the internal diaphragm to open and close the valve.

[0003] This type of traditional structure has obvious technical shortcomings: due to the lack of force balance transmission design, the piston is prone to generating radial lateral force during reciprocating motion, which causes the piston rod and the seals on the outer periphery of the piston to be subjected to unilateral force for a long time, resulting in local excessive wear, which in turn leads to sealing leakage, significantly shortens the service life of the valve, increases the equipment operation and maintenance and replacement costs, and makes it difficult to meet the long-term stable operation requirements of high-end industrial scenarios. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to overcome the problems of uneven lateral force on the piston and easy unilateral wear failure of the seal in traditional direct-push pneumatic sealing valves. It provides a high-efficiency sealing valve that alleviates seal wear, improves valve operation stability, and is equipped with a dedicated airtightness testing process to achieve efficient quality control in batch production.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A high-efficiency sealing valve includes an upper cover, a lower cover, a locking nut, and a valve seat body that are sequentially sealed and assembled from top to bottom. The upper cover has an axially penetrating air inlet for receiving compressed air. The valve seat body has a pre-set air inlet channel and an air outlet channel that cooperate with each other. A diaphragm for sealing and cutting off flow is embedded in the valve seat body at the corresponding opening and closing positions of the channels.

[0007] The upper cover and the lower cover are sealed together by an end face sealing ring, and the two together form a closed adjustment cavity. A support plate is fixed inside the adjustment cavity. The outer periphery of the support plate is sealed and fitted with the inner wall of the lower cover, which strictly separates the adjustment cavity into an upper pneumatic cavity and a lower transmission cavity. There is no gas leakage gap between the cavities.

[0008] The upper pneumatic chamber is equipped with a lead screw and a slider. The lead screw is axially limited and installed at the center of the upper cover via a rolling bearing, allowing it to rotate only around its own axis without axial movement or radial displacement. A helical gear is fastened to the bottom end of the lead screw. The slider has an internal thread that precisely engages with the external thread of the lead screw. The slider's outer circumference is sealed and slides against the inner wall of the lower cover via a sealing ring. Two guide rods are symmetrically arranged on both sides of the slider, with their ends fixedly connected to the upper cover and the support plate, respectively, to limit the slider's circumferential movement and ensure that it can only slide linearly back and forth along the valve axis, preventing rotation. Multiple sets of buffer springs are evenly distributed circumferentially between the lower end face of the slider and the upper end face of the support plate. The ends of the buffer springs are fixedly connected to their corresponding end faces, which are used to quickly reset the slider after the pneumatic chamber is depressurized.

[0009] The lower transmission chamber contains a first piston and a gear bracket. The gear bracket is mounted on the inner side of the bracket plate via a radial guide structure. The radial guide structure includes horizontal partitions and limiting springs symmetrically arranged on both sides of the horizontal structural plate of the gear bracket. The limiting springs are located between the horizontal partitions and the bracket plate. The gear bracket is rigidly limited in the horizontal direction, which can generate displacement compensation in the vertical direction and can deflect around the valve's central axis without the risk of jamming. Two eccentric gears that mesh with helical gears are symmetrically installed on the gear bracket. The initial phase of the two eccentric gears is strictly 180° apart, achieving synchronous meshing and force balance. A protrusion is provided at the center of the top of the first piston. The upper pneumatic chamber vents and drives the slider to move axially downward. The slider is limited by the guide rod and cannot rotate on its own, only generating an axial displacement tendency. Under the constraint of the threaded pair and the guide, it is converted into the rotation of the lead screw. Through the meshing transmission of the helical gear and the eccentric gear, the eccentric gear synchronously pushes against the protrusion on the top of the first piston, driving the first piston to make a pure axial linear motion, thereby pushing the diaphragm to deform and realize the valve opening and closing stroke control and on / off adjustment.

[0010] Furthermore, the helical gear and the two eccentric gears are driven by staggered shaft meshing, with the normal module of both being the same. The helix angle of the helical gear is 8°~20°, and the helix angle of the eccentric gear is the same as that of the helical gear but the direction of rotation is opposite, ensuring smooth meshing and shock-free transmission. The eccentricity e of the eccentric gear ranges from 1mm to 5mm, and the effective axial stroke of the first piston is equal to 2×e. This stroke is exactly equal to the maximum allowable elastic deformation of the diaphragm, accurately matching the working stroke required for valve opening and closing, avoiding excessive stroke leading to diaphragm overload and tearing, or insufficient stroke causing poor sealing and internal leakage.

[0011] Among them, the vertical displacement compensation of the gear bracket is only used to dynamically compensate for the instantaneous meshing center distance fluctuation caused by the rotation of the eccentric gear. It does not change the effective eccentricity of the eccentric gear and the axial stroke of the piston. The axial stroke of the piston is always uniquely determined by the eccentricity, so the transmission accuracy is stable and there is no risk of stroke deviation.

[0012] It should be noted that:

[0013] The vertical direction mentioned in this patent refers to the direction parallel to the valve's central axis, the lead screw axis, and the first piston's movement axis, that is, the overall axial direction of the valve.

[0014] The horizontal direction mentioned in this patent refers to the direction parallel to the meshing radial direction of the eccentric gear-helical gear within a cross-section perpendicular to the valve's central axis, i.e., the radial direction of the entire valve.

[0015] The gear bracket has a rigid limit in the horizontal direction, which can generate displacement compensation of 0.1mm to 0.5mm in the vertical direction, and can deflect by ±5° to ±15° around the valve's central axis. It only performs passive follow-up within the above range, which is used to dynamically compensate for the periodic fluctuations in meshing center distance and backlash caused by the rotation of the eccentric gear.

[0016] Furthermore, the lead screw adopts a non-self-locking multi-start trapezoidal thread structure with a thread lead of 12mm to 18mm, abandoning the traditional single-start self-locking thread. The lead screw can be smoothly rotated by a small axial thrust of the slider, without jamming or self-locking, and the transmission response is sensitive, making it suitable for high-frequency opening and closing conditions.

[0017] Furthermore, the first piston is an integrally formed structure, including a piston rod and a piston disc. The piston rod passes through the central hole of the support plate, and the two are slidably sealed together by a sealing ring. The outer periphery of the piston disc is also slidably sealed together with the inner wall of the lower cover by a sealing ring, forming a double-layer sealing structure. A second piston is fixedly sleeved on the outside of the piston rod. The second piston is located between the support plate and the piston disc, and its outer periphery is slidably sealed together with the inner wall of the lower cover. The second piston and the piston disc together form a completely independent sealed detection chamber. This chamber is completely isolated from the fluid channel and the upper pneumatic chamber, avoiding interference from the medium or gas source with the airtightness detection results.

[0018] Furthermore, a detection hole is radially provided on the side wall of the lower cover corresponding to the sealing detection cavity. One end of the detection hole is connected to the sealing detection cavity, and the other end extends to the outer wall of the lower cover and has an internal thread on the inner wall. It can be directly connected to conventional airtightness testing equipment, and the internal dynamic sealing performance can be quickly tested without disassembling the entire valve.

[0019] Furthermore, the gap between the slider and the support plate forms a pneumatic buffer cavity, and an axially penetrating throttling channel is opened inside the support plate to connect the pneumatic buffer cavity with the upper pneumatic cavity; multiple concentric annular throttling ribs are machined on the lower end face of the slider and the upper end face of the support plate, and the throttling ribs on the upper and lower sides are interlocked and nested to form a labyrinth-like throttling structure, which, together with the throttling channel, constitutes a composite pneumatic damping to buffer the impact force of the slider movement and reduce opening and closing vibration and noise.

[0020] This invention also discloses an automated airtightness testing process for high-efficiency sealing valves, applicable to the aforementioned high-efficiency sealing valves. Based on a six-station rotary testing table combined with an industrial vision positioning system, it achieves fully automated unmanned testing throughout the entire process. The specific steps are as follows: loading and positioning, workpiece docking, equipment self-inspection, airtightness precision measurement, and unloading and sorting. No manual intervention is required throughout the process, resulting in high testing accuracy and fast batch testing efficiency.

[0021] This invention's high-efficiency sealing valve abandons the traditional air-source direct-push structure, adopting a composite transmission mode of pneumatic drive + screw-slider transmission + staggered axis symmetrical eccentric gear meshing, achieving smooth opening and closing operation without jamming or lateral force throughout the entire process. The overall working process and core principle are as follows:

[0022] Under the uniform pushing action of the top protrusion, the first piston only performs a pure axial linear reciprocating motion along the valve's central axis. Its motion direction is completely consistent with the direction of the diaphragm's elastic deformation under pressure. There is no radial relative displacement or lateral motion interference between the two, thus eliminating the potential risk of diaphragm damage due to eccentric load compression from a structural perspective. At the same time, the effective axial stroke of the first piston is strictly matched to ensure that it perfectly matches the allowable elastic deformation of the diaphragm. This ensures that the diaphragm always completes the valve opening and closing sealing action within the rated effective deformation range. This avoids both excessive stroke leading to diaphragm overload tearing and permanent plastic deformation, and insufficient stroke leading to inadequate sealing and internal media leakage, thus guaranteeing sealing durability and opening and closing reliability.

[0023] 1. Working principle of the whole process

[0024] The valve's overall opening and closing action is accomplished through upper pneumatic drive, middle threaded transmission, and lower gear meshing linkage, ensuring smooth and continuous operation and power transmission. Compressed air enters the upper pneumatic chamber through the air inlet of the top cover, increasing the air pressure inside the chamber and pushing the slider to move linearly downwards along the valve axis. The slider is constrained by the circumferential limit of the guide rods on both sides, preventing it from rotating and allowing only smooth axial sliding. The slider and the lead screw are connected by a precision threaded pair. The axial thrust generated by the downward movement of the slider drives the lead screw to rotate circumferentially around its own axis. The lead screw is in an axially limited state, with no axial movement or offset, and simultaneously drives the helical gear fixed at the bottom to rotate at a uniform speed.

[0025] The helical gear acts as the driving gear, synchronously meshing to drive the rotation of two symmetrically arranged eccentric gears in the lower transmission cavity. The initial phase of the two eccentric gears is strictly 180° out of phase, and they achieve synchronous rotation in the same direction under the linkage constraint of the gear bracket. During the rotation of the eccentric gears, they uniformly push against the protrusion on the top of the first piston, causing the first piston to move downward in a pure axial direction. The bottom end of the piston rod then pushes against the diaphragm in the valve seat body, causing the diaphragm to undergo elastic deformation, thereby opening the air intake and air outlet channels and realizing the valve opening and conduction.

[0026] When the upper pneumatic chamber is depressurized and exhausts, the buffer spring between the slider and the support plate releases its elasticity, pushing the slider to return to its axial upward position. The slider's reverse movement drives the lead screw and helical gear to rotate in the opposite direction. The eccentric gear rotates synchronously in the opposite direction and releases the pushing force on the protrusion. The diaphragm returns to its original position due to its own elasticity, driving the first piston to return synchronously upward. The inlet and outlet passages close again, and the valve completes the closure and flow interruption, ending the single opening and closing stroke. At the same time, the pneumatic buffer chamber between the slider and the support plate, together with the throttling channel and the labyrinth-type throttling rib, forms a composite pneumatic damping, buffering the impact force of the slider's movement throughout the entire process and reducing opening and closing vibration and noise. The active helical gear drives the eccentric gear to rotate. The meshing force of the eccentric gear drives the gear support to synchronously perform vertical displacement compensation and a small deflection around the valve's central axis, dynamically compensating for the meshing center distance and side clearance fluctuations. The eccentric gear synchronously pushes against the protrusion on the top of the first piston, converting the rotational motion into the pure axial linear motion of the first piston, achieving smooth valve opening and closing.

[0027] 2. Gear meshing principle of no jamming and no tooth disengagement

[0028] The core design of adaptive backlash compensation: This transmission structure uses helical gears as the reference transmission component, whose axial and radial positions are rigidly fixed throughout the entire process; two eccentric gears are arranged symmetrically at the center and are 180° out of phase, moving synchronously with the gear support. When the eccentric gears rotate, the instantaneous meshing center distance between the outer edge of their gear ring and the helical gears will fluctuate periodically: when one eccentric gear rotates to the closest meshing position, the other side rotates synchronously to the farthest meshing position. The radial forces generated by the two on the gear support are equal in magnitude and opposite in direction, achieving radial force self-balancing and preventing the gear support from shifting in a single direction.

[0029] The gear support adopts a structure with horizontal rigid limiting, vertical displacement compensation, and deflection around the valve's central axis: when the eccentric gear rotates to the closest meshing position, the meshing backlash decreases sharply, and the tooth surface extrusion force drives the gear support to generate displacement compensation in the vertical direction away from the helical gear and deflect around the valve's central axis, increasing the backlash to avoid tooth surface jamming and interference; when the eccentric gear rotates to the farthest meshing position, the meshing backlash increases, and the meshing pull drives the gear support to generate displacement compensation in the vertical direction towards the helical gear and deflect around the valve's central axis, reducing the backlash to avoid tooth slippage and skipping.

[0030] The deflection of the gear bracket is only passively followed, and does not rotate continuously 360° around the valve's central axis. The swing angle is usually ±5° to ±15°, which is precisely matched with the phase of the eccentric gear's rotation. With the help of the radial guide structure and the limit spring, it can automatically return to center, ensuring that the helical gear and the two eccentric gears are stably meshed throughout the entire process, without jamming, tooth disengagement, or unidirectional offset.

[0031] 3. Piston-driven principle with no lateral force and synchronous thrust.

[0032] This structure relies on a symmetrical eccentric gear arrangement and a 180° phase difference synchronous linkage design to achieve pure axial linear drive of the piston, completely eliminating lateral load and ensuring smooth and wear-free reciprocating motion of the piston. The core logic is as follows: two sets of eccentric gears are arranged in a centrally symmetrical manner, with the initial assembly phase of the eccentric parts strictly differing by 180°. Under the unified follow-up rotation of the gear support, synchronous rotation in the same direction, at the same speed, and without lag is achieved. The rotation rhythm is perfectly matched with the follow-up rhythm of the support, eliminating the problems of phase deviation and uneven force in the pushing action from the structural source, and ensuring smooth and consistent piston movement.

[0033] Combining the core meshing transmission logic, the axial pushing force of the two eccentric gears on the piston protrusion is synchronously superimposed when they rotate, and the radial lateral force generated by a single gear completely cancels each other out (the protrusion on the top of the first piston is a symmetrical force-bearing structure, ensuring that the radial force cancels out when the two eccentric gears push against each other). In the end, only a pure axial driving force is formed along the valve's central axis, driving the first piston to move smoothly in a straight line along the axis, fundamentally avoiding piston wear and movement jamming. The specific synchronous drive process has no asynchronous deviation: when the left eccentric gear rotates to the maximum thrust position and the axial pushing stroke reaches its maximum value, the right eccentric gear synchronously rotates to its own maximum thrust position, and the axial pushing forces on both sides synchronously reach their peak values. The superimposed force in the same direction drives the first piston to move forward smoothly; when the left eccentric gear rotates to the minimum thrust position and the axial pushing stroke drops to its minimum value, the right eccentric gear synchronously rotates to its own minimum thrust position, and the pushing forces on both sides synchronously release and fall back, and the piston completes the return preparation. The entire reciprocating motion is highly synchronized.

[0034] Conventional gear-driven valves in this field often employ a single eccentric gear or asymmetrical gear drive, resulting in the piston being constantly subjected to a unidirectional radial force, making lateral load-bearing unavoidable. In contrast, this invention employs two eccentric gears arranged symmetrically at the center, with their eccentric phases strictly differing by 180°, representing an unconventional layout design in this field. The core logic of this design lies in the fact that when the two gears rotate synchronously, the radial and lateral forces generated by each gear are completely opposite in direction, achieving complete cancellation and retaining only a pure axial driving force along the valve's central axis. This ensures the first piston performs a purely axial linear motion throughout its entire stroke, without any radial slippage or lateral load-bearing. Consequently, the piston rod and the seals around the piston's periphery experience uniform force and friction throughout the entire stroke, fundamentally eliminating the problem of unilateral wear and premature failure of traditional valve seals. There is a direct causal relationship between the two: pure axial drive without eccentric load → uniform force on the seals → no localized excessive wear → long-lasting and stable sealing performance → significantly extended valve service life.

[0035] 4. Non-self-locking screw drive: Completely avoids the defects of screw self-locking and reset failure.

[0036] Traditional pneumatic valve screws often use single-start self-locking threads. While they can achieve temporary positioning, they suffer from high opening and closing resistance and are prone to self-locking jamming. Furthermore, after the pneumatic chamber is depressurized, the piston and slider, relying on conventional springs, struggle to overcome the self-locking resistance to reset. Over long-term operation, this can lead to valve lag and failure to close completely. This invention abandons the traditional self-locking screw design and adopts a non-self-locking multi-start large-lead screw, with the thread lead controlled between 12mm and 18mm. This is a targeted innovative design addressing transmission defects and does not represent the conventional screw selection approach in this field.

[0037] This non-self-locking lead screw, combined with the slider guide and limit structure, allows the slider to move axially under pneumatic thrust without overcoming additional self-locking resistance. Only a small axial thrust is needed to smoothly drive the lead screw to rotate circumferentially. The overall transmission resistance is low, and the power response is sensitive, making it perfectly suited for high-frequency opening and closing industrial conditions. With multiple sets of buffer springs evenly distributed circumferentially between the slider and the support plate, after the pneumatic chamber is depressurized, the spring force can quickly push the slider to reverse and reset, simultaneously driving the lead screw and helical gear to rotate in the opposite direction, thereby driving the piston to return smoothly without jamming or lag. This completely avoids the problems of lead screw self-locking and reset failure at the structural level, further ensuring the long-term stable operation of the valve and avoiding valve failure caused by transmission jamming. Attached Figure Description

[0038] Other features and advantages of the invention will become clear from the following description of exemplary embodiments, which is incorporated in and constitutes a part of this specification. The accompanying drawings, which illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0039] In the picture:

[0040] Figure 1 A schematic diagram of the high-efficiency sealing valve of this invention;

[0041] Figure 2 A schematic diagram of the high-efficiency sealing valve of this invention;

[0042] Figure 3 The high-efficiency sealing valve of this invention Figure 2 A magnified view of position A;

[0043] Figure 4 The high-efficiency sealing valve of this invention Figure 3 A magnified view of position B;

[0044] Figure 5 This invention relates to a high-efficiency automated airtightness testing device for sealing valves;

[0045] 10. Top cover; 11. Bottom cover; 12. Locking nut; 13. Valve seat body; 14. Air inlet; 100. Air inlet channel; 101. Air outlet channel; 102. Diaphragm; 200. Adjustment chamber; 201. Upper pneumatic chamber; 202. Lower transmission chamber; 20. Lead screw; 21. Slider; 211. Guide rod; 22. Buffer spring; 23. Support plate; 30. First piston; 31. Piston rod; 32. Piston disc; 33. Second piston; 40. Helical gear; 41. Gear support; 42. Eccentric gear; 43. Protrusion; 50. Sealing detection chamber; 51. Detection hole; 60. Pneumatic buffer chamber; 61. Throttling channel; 62. Throttling rib; 300. Radial guide structure; 301. Horizontal partition; 302. Limiting spring; 400. Multi-station rotary detection table; 401. Vision positioning system. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0047] The high-efficiency sealing valve will now be described in detail with reference to the accompanying drawings and embodiments. Example

[0048] This paper mainly elaborates on the assembly process, component connection relationship and basic opening and closing operation logic of the core structure of the high-efficiency sealing valve, providing complete implementation support for the realization of the valve's basic functions.

[0049] In this embodiment, the main structure of the high-efficiency sealing valve is made of 304 stainless steel, which is corrosion resistant and has high structural strength. It is suitable for conventional medium-pressure, non-corrosive fluid transportation pipelines. The overall assembly is completed in the order from top to bottom: First, the upper cover 10 and the lower cover 11 are sealed and connected by a fluororubber end face sealing ring to form a closed adjustment cavity 200. The bracket plate 23 is fixed in the middle of the adjustment cavity 200 with an interference fit. Its outer periphery is tightly sealed and fitted to the inner wall of the lower cover 11, dividing the cavity into an independent upper pneumatic cavity 201 and a lower transmission cavity 202. The bottom of the lower cover 11 is connected to the locking nut 12 and the valve seat 13 by external threads. The valve seat 13 has a preset air inlet channel 100 and an air outlet channel 101. The diaphragm 102 is made of aging-resistant fluororubber and is embedded in the corresponding opening and closing sealing position inside the valve seat 13.

[0050] Inside the upper pneumatic cavity 201, a lead screw 20 and a slider are assembled. The lead screw 20 is axially limited and installed at the center of the upper cover 10 by a double-row deep groove ball bearing, allowing only circumferential rotation without axial movement. The bottom end of the lead screw 20 is fastened to the helical gear 40 by a flat key. The inner wall of the slider is machined with a precision internal thread, which is clearance-fitted with the external thread of the lead screw 20. The outer circumference of the slider is sealed and slidably connected to the inner wall of the lower cover 11 by an O-ring. Two cylindrical guide rods 211 are symmetrically installed on both sides. The two ends of the guide rods 211 are threadedly fastened to the upper cover 10 and the support plate 23, respectively, to achieve complete circumferential limitation of the slider, allowing only axial linear sliding. Three sets of stainless steel buffer springs 22 are evenly distributed circumferentially between the slider and the support plate 23. The two ends of the springs are respectively bonded and fixed to the corresponding end faces, ensuring stable return spring force.

[0051] The lower transmission cavity 202 is equipped with a first piston 30 and a gear bracket 41. The radial guide structure 300 includes horizontal partitions 301 and limiting springs 302 symmetrically arranged on both sides of the horizontal structural plate of the gear bracket 41. The gear bracket 41 is rigidly limited in the horizontal direction, can generate displacement compensation in the vertical direction, and can deflect around the valve's central axis. Two eccentric gears 42 are symmetrically installed on the gear bracket 41, with a strict eccentric phase difference of 180°, and both are stably meshed with the helical gears 40. The first piston 30 is an integrally forged structure, including a piston rod 31 and a piston disc 32. The piston rod 31 passes through the central hole of the bracket plate 23 and is sealed and slidably fitted. The piston disc 32 is sealed and slidably fitted with the inner wall of the lower cover 11, forming a double-layer seal. A second piston 33 is fixedly sleeved on the outside of the piston rod 31. An independent sealed detection cavity 50 is formed between the second piston 33 and the piston disc 32, which is completely isolated from other cavities.

[0052] In this embodiment, the valve operates as follows: Compressed air is introduced into the upper pneumatic chamber 201 through the air inlet 14 of the upper cover 10. The air pressure pushes the slider axially downward. The slider is limited by the guide rod 211 and cannot rotate on its own. It drives the lead screw 20 to rotate through the threaded pair. The lead screw 20 drives the helical gear 40 to rotate. The helical gear 40 meshes and drives the two eccentric gears 42 to rotate synchronously. The eccentric gears 42 push against the top protrusion 43 of the piston, causing the first piston 30 to move axially downward. The bottom end of the piston rod 31 pushes against the diaphragm 102 and deforms elastically, opening the air inlet channel 100 and the air outlet channel 101, thus opening the valve. After the upper pneumatic chamber 201 is depressurized, the buffer spring 22 pushes the slider upward to reset. The lead screw 20 rotates in the opposite direction, the eccentric gears 42 release their pushing action, and the diaphragm 102 elastically rebounds, causing the first piston 30 to reset, and the valve is completely closed. Among them, the gear bracket 41 has a rigid limit in the horizontal direction, which can generate displacement compensation of 0.1mm to 0.5mm in the vertical direction, and can generate deflection of ±5° to ±15° around the valve's central axis.

[0053] The gear bracket 41 includes a horizontal structural plate in the shape of a ring, with a water center channel for the protrusion 43 to pass through. The horizontal structural plate is embedded in the bracket plate 23. There are horizontal partitions 301 and limiting springs 302 on the upper and lower sides. The limiting springs 302 are arranged between the horizontal partitions 301 and the bracket plate 23. Example

[0054] Based on Example 1, this embodiment refines the specific implementation methods of the sealing detection structure and the pneumatic buffer structure, and clarifies the component processing dimensions and operating logic.

[0055] Implementation of the sealing test structure: A radially penetrating test hole 51 is machined at the center position of the sealing test cavity 50 on the side wall of the lower cover 11. The inner wall of the test hole 51 is machined with a standard internal thread. One end is directly connected to the sealing test cavity 50, and the other end extends to the outer wall of the lower cover 11. The thread specification is compatible with the quick connector of conventional air tightness testers on the market. Without disassembling the entire valve, the test equipment can be directly connected to test the sealing performance of the sealing test cavity 50 and determine whether the dynamic sealing performance of the first piston 30 and the second piston 33 meets the standard. This facilitates factory quality inspection and subsequent operation and maintenance.

[0056] Implementation of the pneumatic buffer structure: The gap between the slider and the support plate 23 forms a pneumatic buffer cavity 60. An axially penetrating throttling channel 61 is machined inside the support plate 23. The diameter of the throttling channel 61 is set to 1.2mm, connecting the pneumatic buffer cavity 60 with the upper pneumatic cavity 201. When the slider moves down, the volume of the buffer cavity decreases, and the internal air slowly flows back through the throttling channel 61, generating pneumatic damping and buffering the instantaneous impact force. When the slider returns to its original position, the volume of the buffer cavity increases, and air slowly enters through the throttling channel 61 to avoid excessively fast return speed, achieving smooth buffering throughout the process and reducing opening and closing vibration and noise. Example

[0057] Based on Examples 1-2, the processing technology of the labyrinth-type throttling structure is refined, and the core transmission parameters such as eccentricity, gears, and lead screw 20 are clarified to ensure transmission accuracy and smooth operation.

[0058] Implementation of core stroke and eccentricity parameters: The eccentricity e of the eccentric gear 42 is limited to 3mm, which is within the preferred range of 1mm to 5mm. The effective axial stroke of the first piston 30 is 6mm, i.e. 2×e. This stroke is completely consistent with the maximum allowable deformation of the fluororubber diaphragm 102 in this embodiment, which accurately matches the valve opening and closing stroke. This ensures that the valve is fully open and flowing, while avoiding overload tearing of the diaphragm 102, and ensuring a tight seal without internal leakage.

[0059] Gear transmission parameters: The normal module of both helical gear 40 and eccentric gear 42 is 2mm. The helix angle of helical gear 40 is 15°, and the helix angle of eccentric gear 42 is also 15°, but the directions of rotation are opposite. The interlocking shaft meshing is smooth, with no tooth surface interference and no transmission noise. The lead screw 20 adopts a non-self-locking three-start trapezoidal thread with a lead of 15mm, which is within the preferred range of 12mm to 18mm. It has no self-locking characteristics, and a small thrust can drive the lead screw 20 to rotate. The transmission response is sensitive and suitable for high-frequency opening and closing conditions once per second. The buffer spring 22 adopts a stainless steel compression spring with three sets connected in parallel. The total elastic force can overcome the frictional resistance throughout the entire process. After depressurization, the slider and piston are reset within 1 second without lag.

[0060] The labyrinth-type throttling structure is implemented as follows: four concentric annular throttling ribs 62 are machined on the lower end face of the slider and the upper end face of the support plate 23, respectively. The throttling ribs 62 are 3mm high and 2mm wide, and the spacing between adjacent ribs is equal to the rib width. After assembly, the upper and lower throttling ribs 62 are interlocked and nested with a nesting gap of 0.5mm, forming a multi-layer labyrinth-type flow limiting channel. Together with the throttling channel 61, it forms a composite aerodynamic damping, which improves the buffering effect compared with the single throttling channel 61 and reduces the operating noise to below 55dB, making it suitable for quiet precision industrial conditions. Example

[0061] For the high-efficiency sealing valves prepared in Examples 1-3, a complete automated airtightness testing process is provided. Based on a six-station rotary testing station, batch automated testing is achieved without human intervention, with high testing accuracy and high efficiency.

[0062] Testing equipment and parameters: A six-station rotary testing table is used, equipped with an industrial vision positioning system, a high-precision airtightness testing robot and pressure sensors. The testing medium is 99.9% pure standard nitrogen, the testing pressure is 0.8MPa, the pressure holding time is 30s, the pressure decay threshold is 0.01MPa, and the decay value is less than the threshold to be considered qualified.

[0063] Specific implementation steps: First, material loading and positioning: The valve to be tested is orderly conveyed to the tooling station of the testing table via a vibrating hopper. The fixture is clamped, and the vision system captures the position of the testing hole 51, calibrating the alignment error to within 0.1mm. Second, workpiece docking: The testing table rotates to the testing station, and the robot arm drives the flexible joint to seal and dock with the threaded connection of the testing hole 51, maintaining a constant docking pressure of 0.3MPa to prevent external air leakage. Third, equipment self-inspection: The system checks the pipeline sealing, sensor accuracy, and equipment operating status one by one to eliminate system errors. Fourth, airtightness precision measurement: Nitrogen gas is introduced into the sealed testing chamber 50 to 0.8MPa and held at pressure for 30s. The pressure sensor monitors the pressure change in real time. Fifth, material unloading and sorting: After the test is completed, the robot arm resets, and the testing table rotates to sort qualified and unqualified workpieces. Unqualified workpieces are marked with the defect type. The testing time for a single unit is controlled within 60s, achieving continuous batch testing.

[0064] Through actual working condition testing and performance evaluation, this invention, compared with traditional sealing valves, adopts a composite transmission structure of upper pneumatic drive + non-self-locking multi-start screw + slider + 180° symmetrical eccentric gear + axial limiting radial floating gear support. This achieves pure axial movement of the first piston without lateral force, fundamentally solving the problems of seal wear, transmission jamming, gear jamming and tooth disengagement, and screw self-locking. Specifically, it has the following significant technical effects:

[0065] 1. Constant center distance gear transmission completely solves the problem of fundamental failure. The gear bracket adopts a structure with rigid horizontal limiting, vertical displacement compensation, and deflection around the valve's central axis. This can dynamically compensate for changes in the meshing clearance of the eccentric gear, avoid tooth slippage, jamming, and jamming, and improve transmission stability.

[0066] 2. Non-self-locking screw 20 slider drive ensures smooth drive and reset. Abandoning the traditional single-start self-locking trapezoidal thread, a non-self-locking large-lead multi-start thread structure is adopted. The axial thrust of the slider does not need to overcome self-locking resistance to easily drive the screw 20 to rotate, completely solving the jamming problem. Combined with multiple sets of high-elasticity buffer springs 22, the pressure relief and reset elasticity is sufficient to quickly overcome various frictional resistances, ensuring precise return of the slider and piston. Valve opening and closing response is fast and lag-free, and there are no reset failures during long-term operation.

[0067] 3. Dedicated guide and limit structure ensures smooth operation and minimizes wear. The slider features a dedicated guide rod 211 limit structure, eliminating circumferential deflection and radial movement during axial sliding. This prevents abnormal wear of the threaded parts and uneven wear of the slider seals. Combined with a 180° symmetrical eccentric gear 42 drive, it counteracts the radial lateral force of the piston, further protecting the sealing components, significantly extending the overall service life of the valve, and reducing maintenance costs.

[0068] 4. Composite buffering and noise reduction for smoother operation. Abandoning the traditional direct-push air structure, it adopts a composite transmission system of slider, lead screw 20, gears, and push rod, resulting in smoother start-stop operation. Combined with a composite buffering structure of pneumatic buffer chamber 60, throttling channel 61, and labyrinthine throttling rib 62, it effectively absorbs the impact force during opening and closing, reduces rigid collisions and vibrations of components, and significantly lowers operating noise, making it suitable for precision industrial scenarios with high requirements for operating conditions.

[0069] 5. Dual sealing + independent testing ensures controllable sealing reliability. The valve employs a double-layer sliding seal with a first piston 30 and a second piston 33, creating a dual leakage protection barrier and improving the overall sealing performance. It is equipped with an independent sealing testing chamber 50 and an external testing port 51, allowing for rapid airtightness testing without disassembly. This facilitates daily maintenance and factory quality inspection, significantly improving testing and maintenance efficiency and enabling full monitoring of sealing performance.

[0070] 6. Compact structure, highly adaptable and practical. It integrates four major functions: transmission, sealing, buffering, and detection. The compact component layout minimizes installation space, making it suitable for various confined installation scenarios. Stable transmission accuracy and sensitive opening and closing response allow it to adapt to high-frequency, long-cycle continuous operation conditions, balancing durability and operational stability, making it suitable for high-pressure, high-precision fluid control scenarios.

Claims

1. A high-efficiency sealing valve, comprising an upper cover (10), a lower cover (11), a locking nut (12), and a valve seat body (13) sequentially and sealed from top to bottom, wherein the upper cover (10) has an axially penetrating air inlet (14); and the valve seat body (13) is provided with an air inlet channel (100), an air outlet channel (101), and a diaphragm (102), characterized in that: The upper cover (10) and the lower cover (11) are sealed together to form an adjustment cavity (200); a support plate (23) is fixedly provided in the adjustment cavity (200), and the support plate (23) divides the adjustment cavity (200) into an independent upper pneumatic cavity (201) and a lower transmission cavity (202). The upper pneumatic cavity (201) is equipped with a lead screw (20) and a slider (21); the slider (21) is sealed and slidably engaged with the inner wall of the lower cover (11), and is circumferentially limited by a guide rod (211) fixed between the upper cover (10) and the support plate (23), and can only slide linearly along the axial direction; the lead screw (20) is threadedly engaged with the slider (21), the lead screw (20) is axially limited and can rotate circumferentially, and its bottom end is fixedly connected to a helical gear (40); multiple sets of circumferentially evenly distributed buffer springs (22) are provided between the slider (21) and the support plate (23). The lower transmission cavity (202) is provided with a first piston (30) and a gear bracket (41); the gear bracket (41) is assembled on the inner side of the bracket plate (23) through a radial guide structure (300). The radial guide structure (300) includes a horizontal partition (301) and a limiting spring (302) symmetrically arranged on both sides of the horizontal structural plate of the gear bracket (41). The gear bracket (41) is rigidly limited in the horizontal direction, can be compensated for displacement in the vertical direction, and can deflect around the valve central axis; two eccentric gears (42) that mesh with the helical gear (40) are symmetrically installed on the gear bracket (41). The two eccentric gears (42) are 180° out of phase; a protrusion (43) is provided on the top side of the first piston (30). After the upper pneumatic cavity (201) is ventilated, it drives the slider (21) to move axially downward. The slider (21) is limited in the circumferential direction and cannot rotate on its own. It drives the lead screw (20) to rotate through the threaded pair. The helical gear (40) meshes with the eccentric gear (42) for transmission. The eccentric gear (42) pushes against the protrusion (43) and drives the first piston (30) to make pure axial linear motion, so as to realize the valve on and off control, eliminate lateral load, and avoid uneven wear of the seal.

2. The high-efficiency sealing valve according to claim 1, characterized in that: The helix angle of the helical gear (40) is 8° to 20°, and the normal module of the helical gear (40) is the same as that of the eccentric gear (42); the lead screw (20) is a non-self-locking transmission lead screw with a multi-start thread structure and a thread lead of 12mm to 18mm.

3. The high-efficiency sealing valve according to claim 1, characterized in that: The first piston (30) includes an integrally formed piston rod (31) and piston disc (32). The piston rod (31) is slidably sealed to the support plate (23), and the piston disc (32) is slidably sealed to the inner wall of the lower cover (11).

4. The high-efficiency sealing valve according to claim 3, characterized in that: The piston rod (31) is fixedly sleeved with a second piston (33). The second piston (33) is located between the support plate (23) and the piston disk (32). The second piston (33) slides and seals with the inner wall of the lower cover (11). The second piston (33) and the piston disk (32) enclose a sealed detection cavity (50).

5. The high-efficiency sealing valve according to claim 4, characterized in that: The side wall of the lower cover (11) is provided with a detection hole (51) corresponding to the sealing detection cavity (50). One end of the detection hole (51) is connected to the sealing detection cavity (50), and the other end extends to the outer wall of the lower cover (11) for connecting an external airtightness detection device.

6. The high-efficiency sealing valve according to claim 1, characterized in that: The slider (21) and the support plate (23) enclose each other to form a pneumatic buffer cavity (60), and the pneumatic buffer cavity (60) is connected to the upper pneumatic cavity (201) through a throttling channel (61).

7. The high-efficiency sealing valve according to claim 6, characterized in that: The lower end face of the slider (21) and the upper end of the support plate (23) are provided with multiple concentric ring throttling ribs (62), which are nested together to form a labyrinthine throttling structure.

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