Sealing type stop valve with aligning and positioning functions

Abstract

The invention relates to the technical field of stop valves, in particular to a sealing type stop valve with aligning and positioning functions. The valve comprises a valve body, a driving device is arranged in the valve body, the driving device comprises a valve rod, the valve rod is movably arranged in the valve body in a penetrating mode, a valve seat assembly is fixedly arranged in the valve body, and a valve clack assembly is arranged in an inner cavity of the valve seat assembly in a matched mode; the outer wall of the valve rod is sleeved with a sealing assembly, the top end of the sealing assembly is fixedly connected with the top of the inner wall of the valve body, the bottom end of the sealing assembly is fixedly connected with a guide assembly, and the guide assembly is in sliding fit with the valve clack assembly. The valve clack assembly and the valve rod are arranged to be of a relatively independent structure, the guide assembly is in sliding fit with the valve clack assembly, and through the radial guiding effect of an inlet structure of the valve seat assembly, when the valve clack assembly deviates in the radial direction due to bending of the valve rod and abrasion of parts, the valve clack assembly is forced to relatively slide along the guide assembly, and centering errors are automatically compensated; and the centers of the valve clack assembly and the valve seat assembly are aligned.

Description

Technical Field

[0001] This invention relates to the field of gate valve technology, and more specifically, to a sealing gate valve with self-aligning positioning. Background Technology

[0002] Traditional industrial gate valves, as a common type of forced-seal valve, rely on the tight fit between the valve disc driven by the valve stem and the fixed valve port for their core sealing function. These valves typically consist of a valve body, valve cover, valve stem, and valve disc. The valve disc is rigidly connected to the end of the valve stem via threads or similar means, and during operation, it is driven by the valve stem to perform a linear up-and-down movement, thereby achieving opening and closing.

[0003] During operation, rotating the handwheel or drive device clockwise causes the valve stem to move the valve disc downwards along its axis until the sealing surface of the valve disc presses against the sealing surface of the valve seat, thus blocking the flow of the medium by applying sufficient sealing pressure. Conversely, rotating counterclockwise lifts the valve disc and opens the flow channel. The reliability of its sealing performance, under ideal conditions, depends heavily on the machining accuracy of the sealing surfaces of both the valve disc and the valve seat, as well as the initial alignment during assembly.

[0004] However, during actual long-term operation, the valve stem may experience slight bending or wear due to frequent opening and closing operations, media pressure fluctuations, or external pipeline vibrations. This increases the assembly clearance of various connection parts, causing the valve disc's movement trajectory to deviate from the design axis and become misaligned with the valve port. Since the valve stem and valve disc in traditional structures are rigidly connected and lack automatic compensation, the valve disc cannot easily adjust its angle after misalignment occurs. This results in one-sided contact or partial contact of the sealing surface, leading to severely uneven distribution of sealing pressure, causing media leakage, accelerating local wear of the sealing surface, and reducing the valve's service life and sealing performance.

[0005] Therefore, there is an urgent need for a self-aligning, sealing-type shut-off valve to solve the above problems. Summary of the Invention

[0006] This invention provides a self-aligning, sealing-type gate valve. It features a valve disc assembly independent of the valve stem, and a guide assembly enables a sliding fit between the valve disc assembly and the sealing assembly. Combined with the inlet structure of the valve seat assembly and the synergistic effect of the conical hard seal layer and flexible hose layer of the valve disc assembly, if radial displacement occurs during the closing process, the valve disc automatically slides under the guiding force at the valve seat inlet, compensating for alignment errors. This solves the problems mentioned in the background art.

[0007] When valve discs become misaligned and out of center due to reasons such as valve stem bending and parts wear after long-term operation, valve discs with traditional rigid connections cannot self-adjust, leading to problems such as media leakage and accelerated wear of sealing surfaces.

[0008] To achieve the above objectives, the self-aligning and positioning sealing gate valve includes a valve body, a drive device is provided inside the valve body, the drive device includes a valve stem that is movably inserted inside the valve body, a valve seat assembly is fixedly provided inside the valve body, and a valve disc assembly is adapted to be provided in the inner cavity of the valve seat assembly.

[0009] A sealing assembly is fitted onto the outer wall of the valve stem. The top end of the sealing assembly is fixedly connected to the top of the inner wall of the valve body. A guide assembly is fixedly connected to the bottom end of the sealing assembly. The guide assembly slides with the valve disc assembly.

[0010] When the valve stem drives the valve disc assembly to contact and close with the valve seat assembly, if there is a radial offset in the valve disc assembly, the inlet structure of the valve seat assembly applies a radial guiding force to the valve disc assembly, forcing the valve disc assembly to slide relative to the guide assembly until the sealing center of the valve disc assembly and the sealing center of the valve seat assembly are automatically aligned.

[0011] In the above technical solution, because the valve disc assembly and valve stem are set as relatively independent structures and not rigidly connected, and the guide assembly and valve disc assembly are connected by a sealing assembly to form a sliding fit, and the valve seat assembly inlet structure works in conjunction with the valve disc assembly, when the valve stem drives the valve disc assembly to close, if radial displacement occurs due to valve stem bending or parts wear, the valve seat assembly inlet structure can apply a radial guiding force to the valve disc assembly, forcing the valve disc assembly to slide relative to the guide assembly, automatically compensating for the centering error, ensuring that the sealing center of the valve disc assembly is aligned with the sealing center of the valve seat assembly, avoiding the problem that the valve disc of the traditional rigid connection cannot self-adjust, preventing media leakage, reducing wear on the sealing surface, and ensuring the sealing performance and service life of the valve during long-term operation.

[0012] Based on this, the valve seat assembly includes a support fixed to the inner cavity of the valve body, and an annular cavity connected to the support, the inner wall of the annular cavity forming a sealing port that cooperates with the valve disc assembly.

[0013] Both supports are inclined. One support is fixed to the upper part of the inner wall of one end of the valve body, and its end facing the annular cavity is inclined downward. The other support is fixed to the lower part of the inner wall of the other end of the valve body, and its end facing the annular cavity is inclined upward. The annular cavity between the two supports is vertical, and the valve disc assembly is disposed inside the annular cavity.

[0014] In the above technical solution, the valve disc assembly includes a pressure plate, the top of the pressure plate is provided with a sliding groove, the guide assembly is slidably connected to the inside of the sliding groove, the bottom of the pressure plate is fixedly connected with a hose layer, the bottom of the hose layer is fixedly connected with a hard sealing layer, and the outer wall of the hard sealing layer is sealed and adapted to the inner wall of the annular cavity.

[0015] Preferably, both the flexible tube layer and the hard seal layer are hollow structures, and the flexible tube layer and the hard seal layer are designed as a conical structure along the axial direction.

[0016] The hose layer is made of fluororubber, which can bulge outward under the pressure of the medium to compensate for the sealing gap between the hard seal layer and the annular cavity. The hard seal layer is made of stainless steel and is used to withstand the radial guiding force applied by the valve seat assembly.

[0017] The diameter of the pressure plate is larger than the inner diameter of the annular cavity, which is used to limit the downward limit position of the valve disc assembly. When the pressure plate moves to the top of the support, the valve disc assembly and the valve seat assembly form a sealed fit. The contact limit between the pressure plate and the support ensures that the hard seal layer fits the sealing surface of the annular cavity.

[0018] Based on this, the guide assembly includes a slide rod, a slide plate is fixedly connected to the outer wall of the slide rod, the slide plate and the slide rod are slidably connected inside the groove of the pressure plate, a ball is movably embedded in the slide rod near the bottom, the ball rolls with the bottom surface of the groove of the pressure plate, and the top of the slide rod is fixedly connected to the sealing assembly.

[0019] In another technical solution, the sealing assembly includes a flange plate, which is fixedly connected to the inner wall of the valve body near the top. A bellows is fixedly connected to the bottom of the flange plate, and the bellows is coaxially sleeved on the outer wall of the valve stem. A support plate is provided between the bottom of the bellows and the bottom of the valve stem, and the support plate is fixedly connected to the top of the slide rod.

[0020] The bellows is made of stainless steel and can expand and contract with the axial movement of the valve stem to achieve dynamic sealing and isolate the medium when the valve stem moves axially.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. In a self-aligning sealing gate valve, by setting the valve disc assembly and valve stem as relatively independent structures, and the guide assembly connected to the sealing assembly forms a sliding fit with the valve disc assembly, and relying on the radial guiding effect of the valve seat assembly inlet structure, when the valve disc assembly is radially offset due to valve stem bending or parts wear, it is forced to slide relative to the guide assembly, automatically compensating for the centering error, ensuring that the sealing center of the valve disc assembly and the valve seat assembly are aligned, and solving the problem of media leakage caused by the inability of traditional rigid connection structures to self-adjust.

[0023] 2. In a self-aligning, sealing gate valve, a composite valve disc structure consisting of a fluororubber hose layer and a stainless steel hard seal layer is adopted. Both are designed as a cone shape and are adapted to seal the annular cavity of the valve seat assembly. The stainless steel hard seal layer bears the radial guiding force applied by the valve seat assembly, and the fluororubber hose layer can be squeezed outward by the medium pressure to compensate for the small gap between the hard seal layer and the annular cavity, forming a dual sealing effect that combines rigid sealing and elastic compensation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a cross-sectional view of the internal structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the valve stem end mounting structure of the present invention;

[0027] Figure 4 This is a schematic diagram of the valve seat assembly structure of the present invention;

[0028] Figure 5 This is an exploded view of the valve disc assembly of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure in the unbiased state of the present invention;

[0030] Figure 7 This is a schematic diagram of the structure in the eccentric state of the present invention;

[0031] Figure 8 This is a schematic diagram of the internal structure of the chute of the present invention;

[0032] Figure 9 This is a schematic diagram of the guiding component structure of the present invention;

[0033] Figure 10 This is a schematic diagram of the sealing assembly structure of the present invention.

[0034] The meanings of the labels in the diagram are as follows:

[0035] 1. Valve body; 11. Drive unit; 110. Valve stem;

[0036] 12. Valve seat assembly; 120. Support; 121. Annular cavity;

[0037] 13. Sealing assembly; 130. Flange plate; 131. Bellows; 132. Support plate;

[0038] 14. Valve disc assembly; 140. Pressure plate; 141. Hose layer; 142. Hard seal layer;

[0039] 15. Guide assembly; 150. Slide bar; 151. Slide plate; 152. Ball bearing. Detailed Implementation

[0040] 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, and 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.

[0041] Currently, traditional gate valves, due to their rigid connection, cannot adaptively adjust their valve discs, leading to media leakage and accelerated wear of the sealing surface. This invention provides a self-aligning, sealing gate valve. (See attached image.) Figures 1-3 As shown, the device includes a valve body 1, a drive device 11 is provided inside the valve body 1, the drive device 11 includes a valve stem 110, the valve stem 110 is movably inserted inside the valve body 1, a valve seat assembly 12 is fixedly provided inside the valve body 1, and a valve disc assembly 14 is adapted to be provided in the inner cavity of the valve seat assembly 12.

[0042] A sealing assembly 13 is sleeved on the outer wall of the valve stem 110. The top end of the sealing assembly 13 is fixedly connected to the top of the inner wall of the valve body 1. A guide assembly 15 is fixedly connected to the bottom end of the sealing assembly 13. The guide assembly 15 is slidably engaged with the valve disc assembly 14.

[0043] The bottom end of the valve stem 110 is movably connected to the valve disc assembly 14. This connection allows the valve stem 110 to drive the valve disc assembly 14 to move up and down axially as a whole, while allowing the valve disc assembly 14 to overcome the resistance to the guide assembly 15 under the action of radial guiding force, and generate radial sliding relative to the bottom end of the valve stem 110.

[0044] When the drive device 11 drives the valve stem 110 to move axially and drives the valve disc assembly 14 to approach and close the valve seat assembly 12, if the valve disc assembly 14 experiences radial offset due to factors such as bending of the valve stem 110 or wear of parts, causing its sealing center to be out of axis from the sealing center of the valve seat assembly 12, the inlet structure of the valve seat assembly 12 will first contact the corresponding part of the valve disc assembly 14 and apply a radial guiding force to the valve disc assembly 14. Under the action of this guiding force, the valve disc assembly 14 overcomes the matching resistance between itself and the guide assembly 15 and generates radial sliding relative to the guide assembly 15. This sliding process continues until the sealing center of the valve disc assembly 14 and the sealing center of the valve seat assembly 12 are completely and automatically aligned, ultimately achieving a precise sealing fit between the valve disc assembly 14 and the valve seat assembly 12.

[0045] For details, see Figure 4As shown, the valve seat assembly 12 consists of two supports 120 fixed in the inner cavity of the valve body 1 and an annular cavity 121 connected between the supports 120. The inner wall of the annular cavity 121 forms a sealing port that is adapted to the valve disc assembly 14, providing a fitting basis for sealing when the valve is closed. The combined structure of the two supports 120 and the annular cavity 121 keeps the annular cavity 121 in a vertical state. The valve disc assembly 14 is built into it and can move along the axial direction of the annular cavity 121.

[0046] Both supports 120 are designed to be inclined. One support 120 is fixed to the upper part of the inner wall of one end of the valve body 1 and is inclined downward toward the end of the annular cavity 121. The other support 120 is fixed to the lower part of the inner wall of the other end of the valve body 1 and is inclined upward toward the end of the annular cavity 121, forming a guide channel toward the center of the annular cavity 121.

[0047] When the valve stem 110 drives the valve disc assembly 14 to approach and close the annular cavity 121, and the valve disc assembly 14 has a radial offset, the inclined surface of the inclined support 120 will first contact the valve disc assembly 14. With the guiding effect of the inclined surface, a radial guiding force pointing towards the center of the annular cavity 121 is applied to the valve disc assembly 14. With the sliding engagement of the guide assembly 15 and the valve disc assembly 14, the valve disc assembly 14 is forced to slide radially along the guiding direction, gradually correcting the offset position until the sealing center of the valve disc assembly 14 is aligned with the sealing port center of the annular cavity 121.

[0048] See Figure 5 As shown, the valve disc assembly 14 uses the pressure plate 140 as its supporting base. The groove on the top of the pressure plate 140 provides sliding space for the guide assembly 15, allowing the valve disc assembly 14 to slide radially relative to the guide assembly 15, providing structural support for the self-aligning action. The bottom of the pressure plate 140 is sequentially fixedly connected to the hose layer 141 and the hard sealing layer 142. The outer wall of the hard sealing layer 142 is sealed and adapted to the inner wall of the annular cavity 121, forming a rigid fit base with the annular cavity 121 as the sealing core.

[0049] By designing the hose layer 141 and the hard seal layer 142 as a conical structure along the axial direction to match the sealing shape of the annular cavity 121, when the valve disc assembly 14 approaches the annular cavity 121, the small diameter end of the conical structure can enter the annular cavity 121 first. With the guiding effect of the conical inclined surface, the radial offset of the valve disc assembly 14 is corrected, so that the hard seal layer 142 can gradually fit with the inner wall of the annular cavity 121, improving the accuracy of self-alignment.

[0050] Among them, the hose layer 141 is made of fluororubber. Based on the excellent elasticity and media resistance of the fluororubber hose layer 141, it can bulge outward under the action of media pressure to compensate for the sealing risks caused by the processing error and the small gap after self-alignment between the hard sealing layer 142 and the annular cavity 121.

[0051] In addition, to achieve this function, a pressure guiding channel (not shown in the figure) is provided on the pressure plate 140; when the valve is closed, the upstream medium pressure is introduced into the sealed cavity formed by the hose layer 141 and the hard sealing layer 142 through the pressure guiding channel, thereby driving the hose layer 141 to undergo elastic deformation.

[0052] Among them, the hard seal layer 142 is made of stainless steel. Based on the hard material characteristics of stainless steel, it has sufficient structural strength to stably withstand the radial guiding force applied by the valve seat assembly 12, ensuring that the sealing structure is not damaged during the self-aligning process; the hose layer 141 and the hard seal layer 142 form a dual sealing effect that combines rigid support and elastic compensation, thereby enhancing the valve sealing reliability.

[0053] In the above technical solution, both the hose layer 141 and the hard seal layer 142 adopt a hollow structure design to reduce the overall weight of the valve disc assembly 14, reduce the driving load of the valve stem 110 and the motion resistance during self-alignment, and ensure smooth sliding self-alignment process. At the same time, the hollow structure can reserve deformation space for the elastic bulging of the hose layer 141, avoid structural damage to the hose layer 141 due to lack of internal buffer when squeezed by the medium air pressure, and enhance the structural toughness of the hard seal layer 142, making it less prone to plastic deformation when subjected to radial guiding force.

[0054] In addition, the diameter of the pressure plate 140 is larger than the inner diameter of the annular cavity 121, which is used to limit the downward limit position of the valve disc assembly 14. When the pressure plate 140 moves to the top of the support 120, the valve disc assembly 14 and the valve seat assembly 12 form a sealed fit. Through the contact limit between the pressure plate 140 and the support 120, the hard seal layer 142 is ensured to fit the sealing surface of the annular cavity 121.

[0055] See Figure 6 As shown, when the valve disc assembly 14 has no radial offset and the sealing center is coaxial with the sealing port center of the annular cavity 121, the driving device 11 drives the valve stem 110 to move axially downward. The valve stem 110 synchronously drives the valve disc assembly 14 to move axially downward along the annular cavity 121. Since there is no radial offset, the small diameter end of the conical hard seal layer 142 of the valve disc assembly 14 can be directly and accurately aligned with the sealing port of the annular cavity 121 and slowly enter.

[0056] As the valve disc assembly 14 continues to move downward, the outer wall of the hard sealing layer 142 gradually comes into contact with the inner wall of the annular cavity 121, forming a preliminary rigid seal. During this process, the pressure plate 140 of the valve disc assembly 14 moves downward synchronously. Because the diameter of the pressure plate 140 is larger than the inner diameter of the annular cavity 121, when the pressure plate 140 moves downward to abut against the top of the inclined support 120, it is limited by the support 120 and cannot continue to move downward. At this time, the valve disc assembly 14 reaches the downward limit position, and the hard sealing layer 142 is tightly fitted with the sealing surface of the annular cavity 121 under the pressure of the pressure plate 140, completing the basic seal.

[0057] Meanwhile, as the pressure plate 140 continues to move downward, it will exert axial pressure on the hose layer 141 and the hard seal layer 142 at the bottom of the pressure plate 140. Since both are hollow structures, the compression action will compress the air inside the two layers. Under the action of air pressure, the fluororubber hose layer 141 bulges outward, filling the tiny gap between the hard seal layer 142 and the inner wall of the annular cavity 121 caused by processing errors, forming a dual sealing effect of rigid sealing and elastic compensation, blocking the flow of media.

[0058] See Figure 7 As shown, when the valve disc assembly 14 experiences radial offset due to the bending of the valve stem 110 and wear of parts, and the sealing center is not coaxial with the sealing port center of the annular cavity 121, the driving device 11 drives the valve stem 110 to move axially downward. The valve stem 110 drives the valve disc assembly 14 to move downward toward the annular cavity 121. Due to the radial offset, the conical hard sealing layer 142 of the valve disc assembly 14 cannot be directly and accurately aligned with the sealing port of the annular cavity 121.

[0059] At this time, the inclined surface of the inclined support 120 of the valve seat assembly 12 first contacts the pressure plate 140 of the valve disc assembly 14. With the guiding effect of the inclined surface, a radial guiding force is applied to the pressure plate 140 pointing towards the center of the annular cavity 121. Since the top groove of the pressure plate 140 is slidably engaged with the guide assembly 15, under the action of the radial guiding force, the valve disc assembly 14 as a whole undergoes radial sliding relative to the guide assembly 15, gradually correcting the offset position.

[0060] After the alignment is completed, the valve assembly 14 continues to move downward along the axial direction of the annular cavity 121, and the outer wall of the hard sealing layer 142 gradually fits with the inner wall of the annular cavity 121 to form a preliminary rigid seal; as the downward movement continues, the pressure plate 140 approaches the top of the support 120 and finally abuts against the limit position, and the valve assembly 14 stops moving downward. At this time, the pressure plate 140 exerts axial pressure on the hose layer 141 and the hard sealing layer 142, and the air inside the hollow structure is compressed. The fluororubber hose layer 141 bulges outward under the action of air pressure to compensate for the small gap between the hard sealing layer 142 and the inner wall of the annular cavity 121.

[0061] During this process, the stainless steel hard seal layer 142, with its own structural strength, stably withstands the radial guiding force applied by the support 120, preventing deformation of the sealing structure. The fluororubber hose layer 141, through elastic bulging, fills the gap, forming a double seal to ensure no leakage of the medium.

[0062] See Figure 8 and Figure 9 As shown, the guide assembly 15 has a slide rod 150 as its core load-bearing structure. The top of the slide rod 150 is fixedly connected to the sealing assembly 13. With the help of the fixed relationship between the sealing assembly 13 and the valve body 1, the guide assembly 15 is kept stable as a whole, providing a reference support for the sliding of the valve disc assembly 14.

[0063] The slide plate 151, which is fixed to the outer wall of the slide rod 150, forms a sliding fit with the slide groove opened on the top of the pressure plate 140. The slide plate 151 can limit the sliding direction of the valve disc assembly 14, prevent it from shifting or misaligning during the self-aligning process, and ensure that the valve disc assembly 14 only moves in the radial direction pointing to the center of the annular cavity 121, thus ensuring the self-aligning accuracy.

[0064] Meanwhile, the ball bearing 152, which is movably embedded in the slide rod 150 near the bottom, forms a rolling engagement with the bottom surface of the groove of the pressure plate 140. When the valve disc assembly 14 slides, the sliding friction between the slide plate 151, the slide rod 150 and the groove is converted into rolling friction, reducing the motion resistance. This allows the valve disc assembly 14 to slide smoothly relative to the guide assembly 15 when it is subjected to the radial guiding force of the support 120, avoiding jamming of the self-aligning action or wear of parts due to excessive frictional resistance.

[0065] See Figure 10 As shown, the sealing assembly 13 includes a flange plate 130, which is fixedly connected to the inner wall of the valve body 1 near the top. A bellows 131 is fixedly connected to the bottom of the flange plate 130. The bellows 131 is coaxially sleeved on the outer wall of the valve stem 110. A support plate 132 is provided between the bottom of the bellows 131 and the bottom of the valve stem 110. The support plate 132 is fixedly connected to the top of the slide bar 150.

[0066] Its sealing assembly 13 is fixed to the flange plate 130 as the fixed base and is fixedly connected to the inner wall of the valve body 1 near the top through the flange plate 130, providing the installation positioning reference for the entire sealing assembly 13; when the drive device 11 drives the valve stem 110 to move axially, the valve stem 110 will simultaneously drive the support plate 132 and the slide rod 150 to move axially. At this time, the stainless steel bellows 131 can expand and contract synchronously with the axial movement of the valve stem 110, so that it can always seal the gap between the valve stem 110 and the valve body 1 without hindering the normal movement of the valve stem 110 and the slide rod 150, thereby achieving dynamic sealing during the axial movement of the valve stem 110, effectively isolating the medium in the valve body 1, and preventing the medium from leaking outward along the mating gap between the valve stem 110 and the valve body 1;

[0067] Thus, the slide rod 150 forms an axial linkage with the valve stem 110 through the support plate 132 and the bellows 131, and can rise and fall synchronously with the valve stem 110; at the same time, through the fixed connection between the flange plate 130 and the valve body 1, the radial position of the slide rod 150 is constrained, thereby providing a stable guiding reference for the radial sliding of the valve disc assembly 14 that slides with it during the self-aligning process.

[0068] The bellows 131 is made of stainless steel. As is known to those skilled in the art, its working principle relies on the excellent tensile toughness and structural stability of stainless steel to achieve reciprocating expansion and contraction deformation. It can expand and contract synchronously with the axial movement of the valve stem 110 without hindering the linkage movement of the valve stem 110, the support plate 132, and the slide bar 150. It can also rely on the density and corrosion resistance of the metal material to keep the gap between the valve stem 110 and the valve body 1 closed during the expansion and contraction process, achieving dynamic sealing when the valve stem 110 moves axially. This effectively isolates the medium inside the valve body 1 and prevents the medium from leaking out along the gap of the valve stem 110. At the same time, it can resist the erosion of the medium and the intrusion of external impurities under complex working conditions, and avoid the bellows 131 from long-term expansion and contraction fatigue or corrosion damage. This ensures the long-term sealing performance and structural stability of the sealing assembly 13, provides reliable support for the guide assembly 15, and enhances the overall sealing and protection effect of the valve.

[0069] Working principle:

[0070] First, the valve stem 110 is driven to move axially up and down by the drive device 11, which in turn drives the valve disc assembly 14 to move axially along the annular cavity 121, thereby realizing the opening and closing action of the valve. During this process, the sealing assembly 13 extends and deforms synchronously with the axial movement of the valve stem 110, always sealing the gap between the valve stem 110 and the valve body 1, realizing dynamic sealing and isolating the medium, while providing radially fixed reference support for the guide assembly 15. The guide assembly 15 converts sliding friction into rolling friction through the rolling engagement of the ball 152 and the groove, reducing the resistance when the valve disc assembly 14 moves, while constraining the valve disc assembly 14 to slide only in the radial direction pointing to the center of the annular cavity 121.

[0071] When the valve performs the closing action, the valve disc assembly 14 approaches the annular cavity 121 and is ready to close, and there are two working states depending on whether there is radial offset.

[0072] In the ideal state where the valve disc assembly 14 has no radial offset, the small-diameter end of its conical hard sealing layer 142 can be directly and accurately aligned with the sealing port of the annular cavity 121 and slowly enter. The outer wall of the hard sealing layer 142 gradually fits against the inner wall of the annular cavity 121, forming a preliminary rigid seal. As the valve disc assembly 14 continues to move downward, the pressure plate 140, because its diameter is larger than the inner diameter of the annular cavity 121, eventually abuts against the top of the support 120 and is limited. The valve disc assembly 14 reaches the downward limit position, and the hard sealing layer 142 fits tightly against the sealing surface of the annular cavity 121 under the pressure of the pressure plate 140, completing the basic seal.

[0073] At the same time, the continuous downward movement of the pressure plate 140 will axially compress the hollow hose layer 141 and the hard seal layer 142, compressing the air inside the two layers. The fluororubber hose layer 141 bulges outward under the air pressure, precisely filling the tiny gap between the hard seal layer 142 and the inner wall of the annular cavity 121 caused by processing errors, forming a dual sealing effect of rigid sealing and elastic compensation, blocking the flow of media.

[0074] If the valve disc assembly 14 is radially offset due to factors such as bending of the valve stem 110 or wear of parts, its sealing center will be out of axis from the sealing port center of the annular cavity 121;

[0075] At this time, the inclined surface of the inclined support 120 will first contact the pressure plate 140 of the valve disc assembly 14, and apply a radial guiding force to the pressure plate 140 pointing towards the center of the annular cavity 121 with the guiding effect of the inclined surface; since the sliding groove at the top of the pressure plate 140 is slidably engaged with the guide assembly 15, under the action of the radial guiding force, the valve disc assembly 14 as a whole will slide radially relative to the guide assembly 15. At the same time, the inclined surface of the conical hard seal layer 142 is adapted to the inlet of the annular cavity 121, further assisting in correcting the offset position until the sealing center of the valve disc assembly 14 is completely aligned with the sealing port center of the annular cavity 121.

[0076] After the alignment is completed, the valve disc assembly 14 continues to move downward along the annular cavity 121, repeating the sealing process in the state without offset. The hard seal layer 142 forms a rigid seal. After the pressure plate 140 is limited, it squeezes the hose layer 141 to bulge and compensate for the gap. The stainless steel hard seal layer 142, with its own structural strength, can withstand the radial guiding force applied by the support 120, avoiding plastic deformation of the sealing structure. Finally, the double seal ensures that there is no leakage of the medium.

[0077] When the valve performs the opening action, the drive device 11 drives the valve stem 110 to rise axially, and the valve disc assembly 14 moves upward synchronously. The hard seal layer 142 and the sealing surface of the annular cavity 121 gradually separate, releasing the sealing state and restoring the flow of the medium. At this time, the sealing assembly 13 resets synchronously with the rise of the valve stem 110, and the guide assembly 15 also returns to its initial guiding posture.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-aligning, sealing-type gate valve, comprising a valve body (1), wherein a drive device (11) is provided inside the valve body (1), the drive device (11) comprising a valve stem (110), the valve stem (110) being movably inserted inside the valve body (1), characterized in that: A valve seat assembly (12) is fixedly installed inside the valve body (1), and a valve disc assembly (14) is adapted to be installed in the inner cavity of the valve seat assembly (12). A sealing assembly (13) is sleeved on the outer wall of the valve stem (110). The top end of the sealing assembly (13) is fixedly connected to the top of the inner wall of the valve body (1). A guide assembly (15) is fixedly connected to the bottom end of the sealing assembly (13). The guide assembly (15) is slidably engaged with the valve disc assembly (14). When the valve stem (110) drives the valve disc assembly (14) to contact and close with the valve seat assembly (12), if there is a radial offset in the valve disc assembly (14), the inlet structure of the valve seat assembly (12) applies a radial guiding force to the valve disc assembly (14), forcing the valve disc assembly (14) to slide relative to the guide assembly (15) until the sealing center of the valve disc assembly (14) and the sealing center of the valve seat assembly (12) are automatically aligned.

2. The sealing gate valve with self-aligning positioning according to claim 1, characterized in that: The valve seat assembly (12) includes a support (120) fixed to the inner cavity of the valve body (1) and an annular cavity (121) connected to the support (120), the inner wall of the annular cavity (121) forming a sealing port that cooperates with the valve disc assembly (14).

3. The self-aligning, sealing-type shut-off valve according to claim 2, characterized in that: Both supports (120) are inclined. One support (120) is fixed to the upper part of the inner wall of one end of the valve body (1), and its end facing the annular cavity (121) is inclined downward. The other support (120) is fixed to the lower part of the inner wall of the other end of the valve body (1), and its end facing the annular cavity (121) is inclined upward. The annular cavity (121) between the two supports (120) is vertical. The valve disc assembly (14) is disposed inside the annular cavity (121).

4. The self-aligning, sealing-type shut-off valve according to claim 3, characterized in that: The valve assembly (14) includes a pressure plate (140), the top of which is provided with a sliding groove, and the guide assembly (15) is slidably connected to the inside of the sliding groove. A hose layer (141) is fixedly connected to the bottom of the pressure plate (140), and a hard sealing layer (142) is fixedly connected to the bottom of the hose layer (141). The outer wall of the hard sealing layer (142) is sealed and adapted to the inner wall of the annular cavity (121).

5. The self-aligning, sealing shut-off valve according to claim 4, characterized in that: Both the flexible hose layer (141) and the hard seal layer (142) are hollow structures, and the flexible hose layer (141) and the hard seal layer (142) are designed as a cone shape along the axial direction.

6. The self-aligning, sealing shut-off valve according to claim 4, characterized in that: The hose layer (141) is made of fluororubber, which can be squeezed outward by the medium pressure to compensate for the sealing gap between the hard seal layer (142) and the annular cavity (121). The hard seal layer (142) is made of stainless steel and is used to withstand the radial guiding force applied by the valve seat assembly (12).

7. The self-aligning, sealing shut-off valve according to claim 4, characterized in that: The diameter of the pressure plate (140) is larger than the inner diameter of the annular cavity (121), and it is used to limit the downward limit position of the valve disc assembly (14). When the pressure plate (140) moves to the top of the support (120), the valve disc assembly (14) and the valve seat assembly (12) form a sealed fit. Through the contact limit between the pressure plate (140) and the support (120), the hard seal layer (142) is ensured to fit the sealing surface of the annular cavity (121).

8. The self-aligning, sealing shut-off valve according to claim 4, characterized in that: The guide assembly (15) includes a slide rod (150), and a slide plate (151) is fixedly connected to the outer wall of the slide rod (150). The slide plate (151) and the slide rod (150) are slidably connected inside the groove of the pressure plate (140). A ball bearing (152) is movably embedded in the slide rod (150) near the bottom. The ball bearing (152) rolls with the bottom surface of the groove of the pressure plate (140). The top of the slide rod (150) is fixedly connected to the sealing assembly (13).

9. The self-aligning, sealing-type shut-off valve according to claim 8, characterized in that: The sealing assembly (13) includes a flange plate (130), which is fixedly connected to the inner wall of the valve body (1) near the top. A bellows (131) is fixedly connected to the bottom of the flange plate (130). The bellows (131) is coaxially sleeved on the outer wall of the valve stem (110). A support plate (132) is provided between the bottom of the bellows (131) and the bottom of the valve stem (110). The support plate (132) is fixedly connected to the top of the slide rod (150).

10. The self-aligning, sealing shut-off valve according to claim 9, characterized in that: The bellows (131) is made of stainless steel and can expand and contract with the axial movement of the valve stem (110) to achieve dynamic sealing and isolate the medium when the valve stem (110) moves axially.

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