Hard sealing ball valve

Abstract

A hard sealing ball valve comprises a valve body, a valve rod and a valve seat, the valve rod extends into the valve body to be connected with a valve element, the valve element is provided with an upper rotating shaft and a lower rotating shaft, the upper rotating shaft and the lower rotating shaft are provided with spiral guide rails, the guide rails are eccentrically arranged so that the rotating center of the valve element can coincide with the center of the guide rails, and the valve seat is arranged in the valve body. A connecting structure is arranged between the valve element and the valve body, the upper rotating shaft and the lower rotating shaft enable the guide rail to be far away from the center of the valve element when the valve element is in an open state through the connecting structure, and at the moment, the sealing state of the valve seat and the valve element is relieved. The valve element is close to the center of the valve element in a closed state, and at the moment, the valve seat and the valve element form a sealed state.

Description

Technical Field

[0001] The invention relates to a hard-sealed ball valve, belonging to the field of valves. Background Art

[0002] With the advancement of science and technology and the development of society, the pressure of various pipeline media is getting higher and higher, the media is becoming more and more diverse, and the automation requirements are increasing. Therefore, the requirements for valve performance are also getting higher and higher. Low torque, long life, and material compatibility with media are increasingly mentioned. How to reduce the torque of the valve, how to increase the life of the valve sealing surface, and how to develop sealing surface materials suitable for various media have become the research and development goals of various valve manufacturers.

[0003] The ball and seat sealing surfaces of existing hard-seal ball valves are in constant contact during the opening and closing process. This constant friction between the sealing surfaces results in high valve torque and increased wear on the valve's sealing surfaces. The sealing surface can only be made of high-hardness materials, which limits the selection of materials for friction resistance. These materials are complex to process and difficult to maintain, and many media lack suitable sealing surface materials due to compatibility or corrosiveness. The valve seat cannot be forced to seal, and traditional structures can only reduce the preload to reduce valve torque. This makes the valve's sealing performance unreliable and often results in leakage. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a hard-sealed ball valve.

[0005] A hard-seal ball valve comprises a valve body, a valve stem, and a valve seat. The valve stem extends into the valve body and is connected to a valve core. The valve core is provided with an upper rotating shaft and a lower rotating shaft, each of which is provided with a spiral guide rail. The guide rail is eccentrically arranged so that the rotation center of the valve core coincides with the center of the guide rail. A connecting structure is provided between the valve core and the valve body. The upper and lower rotating shafts, through the connecting structure, allow the guide rail to move away from the center of the valve core when the valve core is open, thereby releasing the seal between the valve seat and the valve core; and to move closer to the center of the valve core when the valve core is closed, thereby forming a seal between the valve seat and the valve core. A mechanical structure disengages the sealing surface from the ball surface during the valve opening process, eliminating friction between the sealing surfaces. This reduces torque, reduces wear on the valve during opening and closing, and extends the service life of the valve. This effectively avoids continuous friction throughout the opening process, thereby significantly reducing the valve's opening and closing torque. During the closing process, the sealing surface is pulled toward the ball surface, forming a forced seal and ensuring more reliable valve sealing performance. Because the sealing surfaces of hard-seal valves experience significant friction during opening and closing, they typically require a carbide coating or overlay. Commonly used materials include tungsten carbide, nickel-based alloys, and Stellite. The seals are also fixed, leaving few options for material and seal pair combinations. This invention, however, eliminates wear between the sealing surfaces, expanding the selection of valve seal materials and offering a wider range of low-cost, easily processed, and corrosion-resistant materials.

[0006] Preferably, the guide rails are symmetrically arranged on the end surfaces of the upper and lower rotating shafts, with the guide rails gradually moving away from the center from the inside to the outside. This symmetrical arrangement ensures balanced lifting torques acting on both ends of the rotating shaft during opening and closing, reduces eccentric loads and additional bending moments, and ensures smoother rotation of the valve core, reducing operational vibration and noise.

[0007] Preferably, the upper and lower rotating shafts are fixed via a fixed plate, and the connecting structure includes a fixed base fixed to the valve seat, a spring rod fixedly connected to the fixed base, a spring member being sheathed on the outside of the spring rod, a spring sleeve being sheathed on the outside of the spring rod, the other end of the spring sleeve being fixed to the connecting guide rod, one end of the connecting guide rod being slidably mounted on the guide rail, and the other end being fixed to the fixed plate. The combination of the spring member and the spring rod allows the preload force to be fine-tuned by replacing the spring stiffness or adjusting the preload torque, thereby meeting the sealing requirements under different media and operating conditions while avoiding the excessive opening torque caused by excessive preload force. The spring assembly absorbs some of the kinetic energy at the moment the valve core closes, buffering the collision between the guide rod and the guide rail, reducing transient impact wear, and further extending the service life of the guide rail and sealing surface. The continuous action of the spring on the guide rod ensures that the valve core is subjected to a constant preload force under both static and dynamic conditions, ensuring that the sealing surface always remains tightly fitted, effectively preventing micro-leakage caused by thermal expansion and contraction or medium pressure fluctuations.

[0008] Furthermore, the spring housing is provided with a first limiting step, and the spring rod is provided with a second limiting step. The ends of the spring member abut against the first and second limiting steps, respectively, for limiting position. The spring rod extends out of the spring housing and is fixedly connected to the fixed base. The first and second limiting steps together define the maximum compression and minimum relaxation of the spring. Regardless of the number of opening and closing cycles, the spring always operates within the same range, maintaining a constant preload. This effectively prevents permanent deformation or failure of the spring due to accidental overpressure or overtension, and avoids the risk of valve leakage or failure due to spring relaxation or fatigue fracture.

[0009] Furthermore, one side of the connecting guide rod is cylindrical and plugged into the guide rail, and the other side is provided with a fixing portion for fixing with the spring sleeve by threading. The valve seat is provided with a threaded hole, and the fixed base is fixed to the valve seat by a fastening screw. An adjustment pad for adjusting the preload force of the spring member by thickness is provided between the valve seat and the fixed base. The guide rod adopts a cylindrical plug-in fit to the guide rail to ensure that the end face of the guide rod is completely coaxial with the guide rail, avoiding wear or jamming due to eccentricity; the combination of the threaded fixing portion and the spring sleeve ensures the firmness of the connection and vibration resistance. An adjustment pad is provided between the valve seat and the fixed base. By replacing or superimposing gaskets of different thicknesses, the preload stroke and preload force of the spring member can be accurately adjusted to meet different working conditions and media requirements without replacing the spring or changing the overall structure.

[0010] Preferably, the valve seat is provided with a first step and a second step, the first step is provided with an inclined pressure relief surface, and the second step is provided with a sealing surface for abutting the valve core in the closed state. When the medium is opened, it first acts on the inclined pressure relief surface of the first step, and the residual high pressure is quickly discharged to the valve body outlet, avoiding the instantaneous impact of high pressure directly hitting the sealing surface or the actuator, and greatly reducing vibration and impact loads. The inclined pressure relief surface shares the high-pressure load in the initial opening section, so that the second step and its sealing surface only bear the full pressure when close to the closed state, significantly reducing the number of cyclic pressure shocks and wear on the sealing surface. In the remaining stroke after the pressure relief is completed, the sealing surface of the second step fits precisely with the valve core, and the aforementioned spiral guide rail and spring preload mechanism are used to form a secondary tight closure, taking into account the dual needs of rapid pressure relief and reliable sealing.

[0011] Furthermore, the fixed plate is provided with a guide channel through which the spring sleeve passes to connect to the valve seat. Several spaced-apart stoppers are located within the guide channel. This guide channel provides a fixed motion path for the spring sleeve, ensuring that the spring-guide rod assembly slides smoothly in the desired direction during opening and closing, preventing lateral deviation due to uneven force or vibration. The restraining effect of the stoppers suppresses lateral vibration of the spring sleeve, reducing friction and collision with the channel walls and other components, thereby reducing operating noise and slowing wear.

[0012] Preferably, the valve body further comprises a central body and left and right bodies disposed on either side. Positioning grooves are provided on either side of the central body, and latching teeth are provided on the left and right bodies to engage with the positioning grooves. The central body is provided with wedge-shaped teeth to engage with the grooves above the latching teeth. The central body and left and right bodies are quickly aligned with the latching teeth and the positioning grooves, without the need for additional locating pins or cumbersome fixtures, achieving a "three-in-one" assembly, significantly simplifying the assembly process and shortening the production cycle. The grooves above the latching teeth cooperate with the wedge-shaped teeth to form a self-locking structure during assembly. As the left and right bodies are pressed into the central body, the wedge-shaped teeth generate radial extrusion force, causing the valve body interface to fit tightly together, effectively preventing leakage from the flange surface.

[0013] The present invention has the following beneficial effects: The valve's ball seat, through its unique structure, can propel the ball and seat sealing surfaces apart during opening. This creates no contact during the opening and closing process, generating no friction and preventing damage to the sealing surfaces. During closing, the seat sealing surface is slowly pulled toward the ball sealing surface, tightening the tension and forming a forced seal, resulting in a more reliable seal. Because the ball and seat generate no friction during the opening and closing process, the valve's sealing surface can be made of a wider range of materials, allowing for a variety of combinations. A more economical and easily processed sealing surface material can be selected based on the specific operating conditions and applicable media. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0015] Figure 1 It is a schematic structural diagram of the present invention in an open state;

[0016] Figure 2 It is a schematic structural diagram of the present invention in a closed state;

[0017] Figure 3 for Figure 1 Detailed enlarged schematic diagram in the figure;

[0018] Figure 4 for Figure 2 Detailed enlarged diagram in FIG;

[0019] Figure 5 Schematic diagram of the end surface structure of the lower rotating shaft;

[0020] Figure 6 Schematic diagram of the end face structure of the upper rotating shaft;

[0021] Figure 7 A schematic diagram of the structure in which the guide rail is arranged on the mounting block;

[0022] Figure 8 This is a cross-sectional structural diagram of the mounting block;

[0023] In the figure, 1. valve body; 11. middle body; 111. positioning groove; 112. wedge-shaped teeth; 12. left and right bodies; 121. latching teeth; 2. valve stem; 3. valve core; 31. upper rotating shaft; 311. guide rail; 32. lower rotating shaft; 33. fixing plate; 331. guide channel; 332. limit block; 4. valve seat; 41. first step; 411. pressure relief surface; 42. second step; 421. sealing surface; 5. connecting structure; 51. fixing base; 511. fastening screw; 512. adjusting pad; 52. spring rod; 521. second limit step; 53. spring member; 54. spring sleeve; 541. first limit step; 55. connecting guide rod; 6. mounting block; 61. mounting groove; 62. anti-slip pad. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0025] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. Subsequent embodiments will not explain this one by one.

[0026] The terms "upper," "lower," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side" used herein are merely references to the directions or positions in the accompanying drawings. These terms are intended to illustrate and facilitate understanding of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] like Figure 1-8The figure shows an embodiment of a hard-sealed ball valve of the present invention, comprising a valve body 1, a valve stem 2 and a valve seat 4. The valve stem 2 extends to the interior of the valve body 1 and is connected to a valve core 3. An upper rotating shaft 31 and a lower rotating shaft 32 are provided on the valve core 3. A spiral guide rail 311 is provided on the upper rotating shaft 31 and the lower rotating shaft 32. The guide rail 311 is eccentrically arranged so that the rotation center of the valve core 3 coincides with the center of the guide rail 311. A connecting structure 5 is provided between the valve core 3 and the valve body 1. The upper rotating shaft 31 and the lower rotating shaft 32 are connected by the connecting structure 5 so that the guide rail 311 is away from the center of the valve core 3 when the valve core 3 is in an open state. At this time, the valve seat 4 and the valve core 3 are released from a sealed state; when the valve core 3 is in a closed state, it is close to the center of the valve core 3. At this time, the valve seat 4 and the valve core 3 form a sealed state. During the opening process of the valve, the sealing surface 421 and the spherical surface are disengaged through a mechanical structure, so that there is no friction between the sealing surfaces 421, thereby reducing torque, reducing valve wear during the switching process, extending the service life of the valve, and effectively avoiding continuous friction throughout the opening process, thereby significantly reducing the opening and closing torque of the valve. During the closing process of the valve, the sealing surface 421 is pulled toward the spherical surface, so that the sealing surface 421 forms a forced seal, making the valve sealing performance more reliable. Since the sealing surface 421 of a hard-sealed valve has great friction during the switching process, the material generally needs to be a cemented carbide coating or a surfacing layer. The commonly used materials are only tungsten carbide, nickel-based alloys, and Stellite. The combination between the sealing pairs is also fixed, and there are very few optional material and sealing pair combinations. The present invention can eliminate wear between the sealing surfaces 421, thereby increasing the choice of valve sealing pair materials, and there are more low-cost, easy-to-process, and corrosion-resistant materials to choose from.

[0028] The guide rails 311 are symmetrically arranged on the end surfaces of the upper and lower rotating shafts 31 and 32, gradually moving away from the center from the inside out. This symmetrical arrangement ensures balanced lifting torques acting on both ends of the rotating shafts during opening and closing, reducing eccentric loads and additional bending moments, making the valve core 3 rotate more smoothly and reducing operational vibration and noise.

[0029] The upper and lower rotating shafts 31 and 32 are secured via a fixed plate 33. The connecting structure 5 includes a fixed base 51 secured to the valve seat 4. A spring rod 52 is fixedly connected to the fixed base 51. The spring rod 52 is sheathed with a spring element 53. This spring element 53 is sheathed with a spring sleeve 54. The other end of the spring sleeve 54 is secured to a connecting guide rod 55. One end of the connecting guide rod 55 is slidably mounted on the guide rail 311, and the other end is secured to the fixed plate 33. The combination of the spring element 53 and the spring rod 52 allows for fine-tuning of the preload force by changing the spring stiffness or adjusting the preload torque. This not only meets the sealing requirements for different media and operating conditions, but also avoids excessive opening torque caused by excessive preload. The spring assembly absorbs some of the kinetic energy when the valve core 3 closes, cushioning the collision between the guide rod and the guide rail 311, reducing transient impact wear, and further extending the service life of the guide rail 311 and the sealing surface 421. The spring continuously acts on the guide rod to ensure that the valve core 3 is subjected to a constant preload force under both static and dynamic working conditions, so that the sealing surface 421 always maintains a tight fit, effectively preventing micro-leakage caused by thermal expansion and contraction or medium pressure fluctuations.

[0030] The spring housing 54 is provided with a first limiting step 541, and the spring rod 52 is provided with a second limiting step 521. The ends of the spring member 53 abut against the first and second limiting steps 541, 521, respectively, for limiting position. The spring rod 52 extends through the spring housing 54 and is fixedly connected to the fixed base 51. The first and second limiting steps 541, 521 together define the maximum compression and minimum relaxation of the spring. Regardless of the number of opening and closing cycles, the spring always operates within the same range, maintaining a constant preload. This effectively prevents permanent deformation or failure of the spring due to accidental overpressure or overtension, and avoids the risk of valve leakage or failure due to spring relaxation or fatigue fracture.

[0031] One side of the connecting guide rod 55 is cylindrically plugged into the guide rail 311. The other side features a fixing portion for threaded connection with the spring sleeve 54. The valve seat 4 is provided with a threaded hole, and the fixing base 51 is fixed to the valve seat 4 via a set screw 511. An adjustment washer 512 is positioned between the valve seat 4 and the fixing base 51 to adjust the preload force of the spring element 53 by thickness. The guide rod's cylindrical plug-in design ensures perfect coaxiality with the guide rail 311, preventing wear or sticking due to eccentricity. The threaded fixing portion and spring sleeve 54 ensure a secure connection and vibration resistance. An adjustment washer 512 is positioned between the valve seat 4 and the fixing base 51. By replacing or stacking shims of varying thickness, the preload stroke and preload force of the spring element 53 can be precisely adjusted to meet varying operating conditions and media requirements without having to replace the spring or modify the overall structure.

[0032] In the embodiment of the present application, unlike the aforementioned embodiment, the valve seat 4 is provided with a first step 41 and a second step 42. The first step 41 is provided with an inclined pressure relief surface 411, and the second step 42 is provided with a sealing surface 421 for contact with the valve core 3 in the closed state. When the medium is opened, it first acts on the inclined pressure relief surface 411 of the first step 41, quickly directing residual high pressure to the outlet of the valve body 1. This prevents the transient high pressure from directly impacting the sealing surface 421 or the actuator, significantly reducing vibration and shock loads. The inclined pressure relief surface 411 shares the high pressure load during the initial opening phase, allowing the second step 42 and its sealing surface 421 to bear full pressure only when nearing the closed state, significantly reducing the number of cyclic pressure shocks and wear experienced by the sealing surface 421. For the remainder of the stroke after pressure relief is complete, the sealing surface 421 of the second step 42 precisely aligns with the valve core 3. The aforementioned spiral guide 311 and spring preload mechanism form a secondary tight seal, achieving both rapid pressure relief and reliable sealing.

[0033] In the embodiment of the present application, unlike the aforementioned embodiment, a guide channel 331 is provided on the fixing plate 33, through which the spring sleeve 54 is connected to the valve seat 4. Several spaced-apart stoppers 332 are provided within the guide channel 331. The guide channel 331 provides a fixed motion path for the spring sleeve 54, ensuring that the spring-guide rod assembly slides smoothly in the desired direction during the opening and closing process, avoiding lateral deviation caused by uneven force or vibration. The restraining effect of the stoppers 332 suppresses lateral vibration of the spring sleeve 54, reducing friction and collision with the channel walls and other components, thereby reducing operating noise and slowing wear.

[0034] In the embodiment of the present application, unlike the above-mentioned embodiment, the valve body 1 further includes a central body 11 and left and right bodies 12 provided on both sides. Positioning grooves 111 are provided on both sides of the central body 11. The left and right bodies 12 are provided with latching teeth 121 that engage with the positioning grooves 111. The central body 11 is provided with wedge-shaped teeth 112 that engage with the grooves above the latching teeth 121. The central body 11 and the left and right bodies 12 are quickly aligned with the positioning grooves 111 through the latching teeth 121. No additional positioning pins or cumbersome fixtures are required, achieving a "three-in-one" assembly, greatly simplifying the assembly process and shortening the production cycle. The grooves above the latching teeth 121 cooperate with the wedge-shaped teeth 112 to form a self-locking structure during assembly. As the left and right bodies 12 are pressed into the central body 11, the wedge-shaped teeth 112 generate radial extrusion force, making the interface of the valve body 1 fit tightly, effectively preventing flange surface leakage.

[0035] In the embodiment of the present application, different from the above-mentioned embodiment, the guide rail 311 is separately provided from the upper rotating shaft 31 and the lower rotating shaft 32, and the guide rail 311 is provided on the mounting block 6 which is detachably provided with the upper rotating shaft 31 and the lower rotating shaft 32. The length of the guide rail 311 on the mounting block 6 can be lengthened or shortened, and can be adjusted according to the specific setting of the valve, with high flexibility.

[0036] The cross-section of the mounting block 6 is wedge-shaped, and mounting grooves 61 are provided on the upper rotating shaft 31 and the lower rotating shaft 32. Anti-slip pads are provided on both sides of the mounting groove 61. After installation, the inner walls of the mounting block 6 and the anti-slip pads form a tight fit connection with the upper rotating shaft 31 and the lower rotating shaft 32, so that the mounting block 6 will not easily fall out of the mounting groove 61. When replacement is needed, only the mounting block 6 needs to be taken out, and disassembly is convenient.

[0037] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

[0038] Although the present invention has been described with reference to several specific embodiments, it should be understood that the invention is not limited to the specific embodiments disclosed, and the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A hard-sealed ball valve, characterized by: The spool is provided with an upper rotating shaft and a lower rotating shaft, and a spiral guide rail is provided on the upper rotating shaft and the lower rotating shaft. The guide rail is eccentrically arranged so that the rotation center of the valve core coincides with the center of the guide rail. A connecting structure is provided between the valve core and the valve body. The upper rotating shaft and the lower rotating shaft are connected to the guide rail so that the guide rail is away from the center of the valve core when the valve core is in an open state, and the valve seat and the valve core are released from a sealed state at this time; and close to the center of the valve core when the valve core is in a closed state, and the valve seat and the valve core are in a sealed state at this time.

2. The hard-sealed ball valve according to claim 1, characterized in that: The guide rails are symmetrically arranged on the end surfaces of the upper rotating shaft and the lower rotating shaft, and the guide rails are arranged gradually away from the center from the inside to the outside.

3. The hard-sealed ball valve according to claim 1, characterized in that: The upper rotating shaft and the lower rotating shaft are fixed by a fixed plate. The connecting structure includes a fixed base fixed on the valve seat. A spring rod is fixedly connected to the fixed base. A spring member is sleeved on the outside of the spring rod. A spring sleeve is sleeved on the outside of the spring rod. The other end of the spring sleeve is fixed on the connecting guide rod. One end of the connecting guide rod is slidably mounted on the guide rail, and the other end is fixed to the fixed plate.

4. The hard-sealed ball valve according to claim 3, characterized in that: A first limiting step is provided in the spring sleeve, a second limiting step is provided on the spring rod, two ends of the spring member are respectively abutted against the first limiting step and the second limiting step for limiting position, and the spring rod passes through the spring sleeve and is fixedly connected to the fixed base.

5. The hard-sealed ball valve according to claim 3, characterized in that: One side of the connecting guide rod is cylindrical and inserted into the guide rail, and the other side is provided with a fixing portion for being fixedly connected to the spring sleeve by a threaded connection. A threaded hole is provided on the valve seat, and the fixed base is fixed to the valve seat by a fastening screw. An adjustment pad is provided between the valve seat and the fixed base for adjusting the preload force of the spring part by thickness.

6. The hard-sealed ball valve according to claim 1, characterized in that: The valve seat is provided with a first step and a second step. The first step is provided with an inclined pressure relief surface, and the second step is provided with a sealing surface for abutting against the valve core in a closed state.

7. The hard-sealed ball valve according to claim 3, characterized in that: The fixing plate is provided with a guide channel, the spring sleeve passes through the guide channel and is connected to the valve seat, and a plurality of spaced-apart limit blocks are provided in the guide channel.

8. The hard-sealed ball valve according to claim 1, characterized in that: The valve body also includes a middle body and left and right bodies arranged on both sides. Positioning grooves are provided on both sides of the middle body. The left and right bodies are provided with locking teeth engaged with the positioning grooves. The middle body is provided with wedge-shaped teeth engaged with the grooves above the locking teeth.

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