Cantilever type track ball valve

Abstract

The invention discloses a cantilever type track ball valve. The cantilever type track ball valve comprises a valve body, a valve shaft and a hemispherical ball core, a guide assembly is arranged between the valve shaft and the track valve cover and comprises a guide shaft penetrating through the valve shaft and a rolling shaft sleeve arranged at the end of the guide shaft in a sleeving mode, a guide track in sliding fit with the rolling shaft sleeve is arranged on the outer wall of the track valve cover, the lower portion of the track is linear, the upper portion of the track is spiral, and the linear motion of the valve shaft can be converted into lifting and rotating composite motion. A guide hole with a sliding block pin is formed in the upper end of the ball core, and a bent rail is arranged at the lower end of the valve shaft; the lower end of the ball core is supported in the valve body through a trunnion. A scraper is installed on the valve seat assembly and elastically scrapes impurities on the spherical surface of the ball core in the opening and closing process, and a spring is arranged to automatically compensate sealing abrasion. The upper end of the valve shaft is in transmission connection with a straight stroke actuator through a connecting sleeve with a bearing. The actuator is accurate in guiding and stable in operation, has sealing surface self-cleaning and long-acting compensation functions, effectively eliminates impact, and is high in universality and convenient to maintain.

Description

Technical Field

[0001] This invention relates to the field of industrial valve technology, and more specifically, to a cantilevered ball valve suitable for high, medium, and low pressure applications as well as full-bore applications and complex media conditions. Background Technology

[0002] As a new type of valve that combines the advantages of ball valves and gate valves, the track ball valve is widely used in the industrial field due to its frictionless opening and closing, reliable sealing, and rapid on / off switching. Although existing track ball valves have solved the problems of high opening and closing torque and insufficient sealing reliability under high pressure conditions in traditional ball valves, as well as the slow opening and closing speed and easy gate separation and detachment problems in gate valves, the following shortcomings still exist in practical applications: 1. High friction and easy wear of guide structure: Traditional valve stem guides mostly use sliding friction. Under high frequency opening and closing or high pressure conditions, the friction between the guide pin and the spiral groove is large, which leads to accelerated wear of components and easy radial displacement, affecting the uniformity of sealing surface fit.

[0003] 2. Lack of protection and compensation for sealing surfaces: In media containing particles and prone to scaling (such as sewage and slurry), impurities easily deposit on the sealing surface, causing scratches during opening and closing, resulting in internal leakage. At the same time, existing valves lack an effective elastic compensation mechanism, making it difficult to compensate for long-term wear of the sealing surface.

[0004] 3. Large impact vibration of cantilever valve stem: For valve stems with cantilever structure, rigid impact is easily generated at the connection between the valve stem and the ball during rapid opening and closing, especially at the end of the opening stroke, which causes pipeline vibration and reduces the service life of the valve.

[0005] 4. Difficulty in selecting actuators: The stem motion conversion mechanism of traditional ball valves is complex, often requiring specially made actuators or actuators with large output torque, which makes it difficult to meet the needs of high-frequency and fast-response industrial control. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cantilevered orbital ball valve to solve the technical problems of poor stability, easy seal failure, easy packing leakage and difficulty in selecting actuators in existing orbital ball valves.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a cantilevered ball valve, comprising a valve body, a valve shaft rotatably mounted within the valve body, and a hemispherical ball core driven by the valve shaft, characterized in that it further comprises a guide assembly, the guide assembly being disposed between the valve shaft and a track valve cover, for guiding the valve shaft to perform lifting and rotating movements; the guide assembly comprising a guide shaft passing through the valve shaft and a rolling sleeve sleeved at the end of the guide shaft; the outer wall of the track valve cover is provided with a guide track that slides with the rolling sleeve, the guide track being a closed track groove, for converting the linear motion of the valve shaft into rotational motion; The upper end of the ball core is provided with a guide hole, and a slider pin is provided on the side wall of the guide hole. The lower end of the valve shaft is provided with a curved track, which is inserted into the guide hole and slides in contact with the slider pin. The lower end of the ball core is supported in the valve body by a trunnion in a swinging and rotating manner, so as to drive the ball core to move and rotate around the axis when the valve shaft is raised, lowered and rotated.

[0008] Preferably, the lower part of the guide rail is a vertical straight track groove, and the upper part of the guide rail is an "S"-shaped spiral track groove surrounding the outer wall of the track valve cover. Two guide rails and rolling bushings are provided and symmetrically distributed along the axial direction of the valve shaft.

[0009] Preferably, the upper end of the curved track is arc-shaped, the lower end is straight, and its cross-section is non-circular; the cross-sectional shape of the curved track matches the cross-sectional shape of the guide hole, and there is a movement gap between them.

[0010] Preferably, the valve body is provided with a valve seat assembly that seals with the ball core, and the valve seat assembly is installed at the inlet end of the valve body; a sealing ring is provided at the contact end between the valve seat assembly and the ball core, and a scraper is detachably installed on the sealing ring. The inner edge of the scraper makes elastic contact with the spherical surface of the ball core during the opening and closing of the valve to scrape off the attached impurities.

[0011] Preferably, the valve seat assembly further includes a sealing pressure ring, a spring, a sealing pressure sleeve, and a sealing graphite ring. The sealing pressure sleeve is installed on the outside of the sealing ring, and a sealing graphite ring is disposed between the sealing pressure sleeve and the sealing ring. The sealing pressure ring is installed on the outside of the sealing pressure sleeve and is threadedly connected to the inlet end of the valve body. A spring is disposed between the sealing pressure ring and the sealing pressure sleeve.

[0012] Preferably, a packing seal structure is provided between the valve shaft and the track valve cover, the packing seal structure including a graphite packing assembly disposed inside the track valve cover and a packing gland that presses the graphite packing assembly; The graphite packing assembly includes three or more graphite rings. A sealing chamber structure is formed on the lower inner side wall of the track valve cover. The graphite rings are vertically stacked inside the sealing chamber structure and fitted onto the outer wall of the valve shaft. A sealing bushing is press-fitted onto the uppermost graphite ring. A gland mounting groove is symmetrically formed on the side wall of the track valve cover above the sealing chamber structure. The two ends of the packing gland are set in the gland mounting groove, and the middle part of the packing gland is fitted onto the valve shaft. The packing gland can seal and tighten the sealing bushing.

[0013] Preferably, an injection hole is provided on the side wall of the track valve cover, and a one-way valve plug is installed in the injection hole. The one-way valve plug is assembled at the injection hole by means of a threaded connection, which can realize online injection of glue during valve operation. By replenishing the sealant into the stuffing box, the sealing performance of the packing is maintained, thereby significantly extending the service life of the packing.

[0014] Preferably, the upper end of the valve shaft is connected to the linear actuator via a connecting sleeve; the connecting sleeve is provided with a bearing, and the upper end of the valve shaft passes through the bearing, so that the linear actuator can drive the valve shaft to achieve a combined motion of lifting and rotating through linear motion.

[0015] Preferably, a buffer mechanism is provided above the vertical straight track groove of the guide rail. The buffer mechanism includes a buffer block, a buffer spring, and a buffer top screw. Buffer chambers are symmetrically opened in the side wall of the track valve cover above the vertical straight track groove. Buffer top screws, buffer springs, and buffer blocks are installed sequentially from top to bottom in the buffer chambers. The lower end of the buffer block extends out of the buffer chamber and is inserted into the guide rail.

[0016] Preferably, it also includes an anti-blowout structure, which includes an oblique outer conical annular platform located at the lower end of the valve shaft and an oblique inner conical annular groove located at the lower end of the track valve cover, wherein the outer wall of the oblique outer conical annular platform matches the inner wall of the oblique inner conical annular groove.

[0017] Preferably, the track valve cover is connected and fixed to the packing gland by a hinge bolt, a washer, and a nut; the track valve cover is fixed to the valve body by a double-ended bolt, a flat washer, and a fixing nut.

[0018] Compared with the prior art, the technical solution of the present invention has the following outstanding advantages: 1. Precise guidance and smooth operation: This invention adopts an S-shaped guide rail design and sets a rolling bushing at the end of the guide shaft, changing traditional sliding friction to rolling friction, which significantly reduces frictional resistance and component wear during valve shaft movement. At the same time, the double guide shaft structure effectively improves the support stiffness of the cantilever valve shaft, prevents radial displacement under high pressure conditions, ensures uniform stress on the sealing surface, and thus guarantees the opening and closing stability of the valve under high pressure and high frequency conditions.

[0019] 2. Self-cleaning and long-term compensation of the sealing surface: The scraper structure at the valve seat inlet automatically scrapes away impurities adhering to the ball core surface during each valve opening and closing, effectively preventing particulate matter from scratching the sealing surface and significantly improving the valve's adaptability to media containing particles and prone to scaling. Simultaneously, the elastic compensation mechanism composed of springs automatically compensates for wear and deformation of the sealing surface caused by long-term use and temperature changes, ensuring that the sealing pressure remains within a reasonable range and achieving long-term reliable sealing performance.

[0020] 3. Shock elimination and lifespan extension: The buffer mechanism, consisting of a buffer stop, buffer spring, and buffer set screw, effectively absorbs the impact kinetic energy of moving parts at the end of the valve shaft's vertical stroke, preventing rigid collisions. This design significantly reduces vibration and noise generated during valve opening and closing, mitigates fatigue damage to various transmission components, and extends the overall service life of the valve.

[0021] 4. The actuator is highly versatile and suitable for high-frequency operating conditions. Through the structure of an inlaid bearing in the connecting sleeve, the linear motion of the linear actuator is efficiently converted into the "lifting + rotating" composite motion required by the valve shaft, significantly reducing energy loss during transmission. This design allows conventional, low-cost linear actuators to meet the requirements of high-frequency, rapid opening and closing conditions, eliminating the need for customized special actuators and reducing system integration costs and selection complexity.

[0022] 5. Convenient maintenance and wide adaptability to various operating conditions: The track valve cover adopts a hinged bolt connection structure, enabling rapid inspection and replacement of internal components without complete disassembly of the valve cover, significantly improving the convenience of on-site maintenance. Combined with its multiple advantages such as impurity resistance, wear resistance, and self-compensating sealing, this invention is widely adaptable to complex operating conditions such as high pressure, particle content, easy scaling, and alternating high and low temperatures, covering multiple industrial fields including petrochemicals, power, metallurgy, and environmental protection, offering outstanding overall cost-effectiveness. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural schematic diagram of the cantilevered orbital ball valve described in this invention; Figure 2 This is a schematic diagram of the forward structure of the cantilevered orbital ball valve described in this invention; Figure 3 This is a schematic diagram of the side structure of the cantilevered orbital ball valve described in this invention; Figure 4 for Figure 3 Sectional view along axis AA; Figure 5 This is a schematic diagram of the structure of the track valve cover described in this invention; Figure 6 This is a three-dimensional structural diagram of the installation and mating of the valve shaft and the ball core according to the present invention; Figure 7 This is a schematic diagram of the combined installation of the valve shaft and the ball core according to the present invention; Figure 8 for Figure 7 BB-direction sectional view; Figure 9 This is a three-dimensional structural diagram of the valve seat assembly described in this invention; Figure 10 This is a front structural schematic diagram of the valve seat assembly described in this invention; Figure 11 for Figure 10 CC-direction sectional view.

[0024] In the diagram: 1. Valve body; 2. Trunnion; 3. Sealing ring; 4. Spring; 5. Sealing sleeve; 6. Sealing graphite ring; 7. Sealing ring; 8. Scraper; 9. Ball core; 10. Sliding pin; 11. Flat washer; 12. Nut; 13. Double-ended bolt; 14. Graphite packing assembly; 15. Cylindrical pin; 16. Packing gland; 17. Nut; 18. Hinged bolt; 19. Nut; 20. Valve shaft; 21. Guide shaft; 22. Rolling bushing; 23. Buffer stop; 24. Buffer spring; 25. Rail valve cover; 26. Buffer set screw; 27. Connecting sleeve; 28. Bearing; 29. ​​Guide rail; 30. Curved rail; 31. Guide hole; 32. Sealing bushing; 33. One-way valve plug; 34. Injection hole; 35. Angled outer conical surface annular platform; 36. Angled inner conical surface annular groove. Detailed Implementation

[0025] 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.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The following describes embodiments of the invention based on its overall structure.

[0027] like Figures 1 to 11 As shown, in this embodiment, the cantilevered ball valve provided by the present invention mainly includes a valve body 1, a valve shaft 20, a ball core 9, a track valve cover 25, and a drive connection part. The valve body 1 serves as the basic support component of the entire valve, and a fluid channel is formed inside, including an inlet end and an outlet end. The valve shaft 20 is rotatably and vertically mounted inside the valve body 1. The ball core 9 has a hemispherical structure and is driven by the valve shaft 20 to realize the opening and closing of the valve. The track valve cover 25 is fixedly mounted on the upper part of the valve body 1 and is used to enclose and guide the movement of the valve shaft 20.

[0028] A guide assembly is provided between the valve shaft 20 and the track valve cover 25. This guide assembly guides the valve shaft 20 to perform a combined lifting and rotating motion. Specifically, a guide shaft 21 is transversely arranged through the valve shaft 20, with both ends of the guide shaft 21 extending out of the side wall of the valve shaft 20. A rolling sleeve 22 is fitted at each extended end of the guide shaft 21. Correspondingly, a guide rail 29 is formed on the side wall of the track valve cover 25. The guide rail 29 is a closed track groove that penetrates the side wall of the track valve cover 25. The rolling sleeve 22 is embedded in the guide rail 29 and can slide along it. As a preferred embodiment, there are two guide shafts 21 and rolling sleeves 22, symmetrically distributed along the axial direction of the valve shaft 20, forming a double guide shaft structure. Correspondingly, there are also two guide rails 29, symmetrically arranged on both sides of the track valve cover 25.

[0029] The guide rail 29 has a specially designed trajectory shape. Its lower section is a vertical straight track groove, and its upper section is a spiral track groove extending in an "S" shape around the outer wall of the track valve cover 25. When the valve shaft 20 is driven to rise and fall by an external force, the rolling sleeve 22 first slides in the vertical straight track groove, causing the valve shaft 20 to only move in a straight line. When the rolling sleeve 22 enters the "S"-shaped spiral track groove, under the guidance of the track groove, the rolling sleeve 22 is forced to move along the spiral trajectory, thereby driving the valve shaft 20 to generate a rotational motion around its own axis while continuing to rise and fall.

[0030] The upper end of the ball core 9 is provided with a guide hole 31, and the slider pin 10 is disposed on the side wall of the guide hole 31. The lower end of the ball core 9 is supported in the valve body 1 by a trunnion 2 in a swinging and rotating manner. In this embodiment, a trunnion 2 with a spherical support protrusion at the upper end is selected as a spherical support member, so that the ball core 9 can only swing and rotate around the trunnion 2. The lower end of the valve shaft 20 is provided with a curved track 30. The cross-section of the curved track 30 is a non-circular cross-section, which is used for sliding engagement with the slider pin 10. The shape of the curved track 30 matches its function, with its upper section being arc-shaped and its lower section being straight. After assembly, the curved track 30 is inserted into the guide hole 31, and the two slider pins 10 are clamped on the side of the curved track 30 to achieve rolling contact. When the valve shaft 20 performs a compound motion defined by the guide assembly, the curved track 30 at its lower end moves accordingly. Since the slider pin 10 is constrained in the guide hole 31, the movement trajectory of the curved track 30 forces the slider pin 10 in the guide hole 31 to move, thereby driving the ball core 9 to swing and rotate around the trunnion 2.

[0031] A valve seat assembly is provided at the inlet end of the valve body 1 to seal with the ball core 9. This valve seat assembly, from the inside out, includes a sealing ring 7, a sealing sleeve 5 mounted on the outside of the sealing ring 7, and a sealing ring 3 threadedly connected to the inlet end of the valve body 1. A sealing graphite ring 6 is provided between the sealing sleeve 5 and the sealing ring 7 to achieve a static seal between them. A spring 4 is provided between the sealing ring 3 and the sealing sleeve 5, with the spring 4 sleeved on the outside of the sealing sleeve 5, one end abutting against the sealing ring 3 and the other end abutting against the sealing sleeve 5. The spring 4 constitutes an elastic compensation mechanism to automatically compensate for the wear of the sealing ring 7. When the sealing ring 7 wears due to long-term use, the spring 4 releases its preload, pushing the sealing sleeve 5 and the sealing ring 7 towards the ball core 9, thereby automatically compensating for the wear and ensuring that the sealing pressure is always maintained within a reasonable range.

[0032] A scraper 8 is detachably mounted on the sealing ring 7. The scraper 8 is annular, and its inner edge maintains elastic contact with the spherical surface of the ball core 9 during the opening and closing of the valve. When the ball core 9 rotates, the scraper 8 can scrape off particles, scale, and other impurities adhering to the spherical surface of the ball core 9, preventing impurities from entering the sealing surface and causing scratches.

[0033] To prevent media leakage along the valve shaft 20, a packing seal structure is provided between the valve shaft 20 and the track valve cover 25. A sealing chamber structure is formed on the lower inner side wall of the track valve cover 25. Multiple graphite rings are vertically stacked within the sealing chamber, forming a graphite packing assembly 14, which is fitted onto the outer wall of the valve shaft 20. A sealing bushing 32 is press-fitted onto the uppermost graphite ring. Symmetrical gland mounting grooves are formed on the side wall of the track valve cover 25 above the sealing chamber structure. The two ends of the packing gland 16 are engaged within these grooves, with its middle portion fitted onto the valve shaft 20. By pressing the packing gland 16 downwards, the sealing bushing 32 and the graphite packing assembly 14 are compressed, causing radial expansion and thus ensuring a tight seal between the valve shaft 20 and the track valve cover 25.

[0034] An injection hole 34 is provided on the side wall of the track valve cover 25. A one-way valve plug 33 is installed on the injection hole 34. The one-way valve plug 33 is assembled to the injection hole 34 by a threaded connection. This injection structure can realize online injection of glue during valve operation. By replenishing the sealant into the stuffing box, the sealing performance of the packing is maintained, thereby significantly extending the service life of the packing.

[0035] To eliminate the rigid impact at the end of the valve opening stroke, a buffer mechanism is provided above the vertical straight track groove of the guide rail 29. Buffer chambers are symmetrically formed inside the side wall of the valve cover 25 above the vertical straight track groove. Within each buffer chamber, a buffer screw 26, a buffer spring 24, and a buffer stop 23 are installed sequentially from top to bottom. The lower end of the buffer stop 23 extends out of the buffer chamber and inserts into the guide rail 29. Its lower end face has a guide slope that matches the shape of the upper side wall of the guide rail 29 at that location. When the valve shaft 20 rises to near the end of its stroke, the rolling sleeve 22 on the guide shaft 21 approaches the uppermost end of the vertical straight track groove. At this point, the rolling sleeve 22 first contacts the guide slope of the buffer stop 23, pushing the buffer stop 23 upward to compress the buffer spring 24. During this process, the compression reaction force of the buffer spring 24 absorbs the inertial kinetic energy of the moving parts, achieving smooth buffering. By adjusting the screw depth of the buffer screw 26, the preload of the buffer spring 24 can be changed, thereby adjusting the buffering effect.

[0036] The present invention also includes an anti-blowout structure, which includes an angled outer conical annular platform 35 located at the lower end of the valve shaft 20 and an angled inner conical annular groove 36 located at the lower end of the track valve cover 25. The outer wall of the angled outer conical annular platform 35 matches the inner wall of the angled inner conical annular groove 36. The cone angle of the angled outer conical annular platform 35 and the angled inner conical annular groove 36 is preferably 45°. The anti-blowout structure prevents the medium pressure from axially pushing the valve shaft 20 out of the valve through structural limiting. It is a mandatory safety structure for high-pressure / safe conditions. When the valve shaft 20 performs a "rising + rotating" compound motion, when it moves to the highest point along the "S" spiral track by the guide shaft 21, the angled outer conical annular platform 35 on the valve shaft 20 and the angled inner conical annular groove 36 at the lower end of the track valve cover 25 are tightly engaged, which plays the role of preventing blowout and providing a line seal.

[0037] The upper end of the valve shaft 20 is fixedly connected to the connecting sleeve 27 via a cylindrical pin 15. A bearing 28 is inlaid inside the connecting sleeve 27, and the upper end of the valve shaft 20 passes through the inner hole of the bearing 28. The upper end of the connecting sleeve 27 is connected to the telescopic rod of the linear actuator. When the linear actuator pushes the connecting sleeve 27 to perform linear motion, due to the presence of the bearing 28, the connecting sleeve 27 can drive the valve shaft 20 to move up and down synchronously, but it will not interfere with the rotational motion of the valve shaft 20 under the action of the guide rail 29.

[0038] The track valve cover 25 is fixedly installed on the upper end of the valve body 1 by double-ended bolts 13, flat washers 11, and fixing nuts 12. The packing gland 16 is tightened and fixed to the track valve cover 25 by hinge bolts 18, washers 17, and nuts 19. The connection method of hinge bolts 18 facilitates the quick installation and removal of the packing gland 16, making it convenient to adjust the packing tightness or replace the packing during on-site maintenance.

[0039] The following describes the method of using the cantilevered ball valve of the present invention.

[0040] like Figure 4 As shown, when the valve is in the closed state, the valve shaft 20 is located at the lower limit position, the guide shaft 21 and the rolling sleeve 22 are located at the bottom of the vertical straight track groove at the bottom of the guide rail 29, and the ball core 9 is tightly fitted with the valve seat assembly under the pressure of the valve shaft 20, and the valve is in the closed state.

[0041] When the valve needs to be opened, the linear actuator pushes the connecting sleeve 27 upward, causing the valve shaft 20 to rise synchronously. In the initial opening phase, the rolling sleeve 22 rises linearly along the vertical straight track groove, while the valve shaft 20 only moves upward. At this time, the curved track 30 at the lower end of the valve shaft 20 drives the ball core 9 to swing around the trunnion 2 and then disengage from the valve seat, creating a gap between the ball core 9 and the sealing ring 7 and scraper 8 to prevent friction on the sealing surfaces. When the rolling sleeve 22 rises to the top of the vertical straight track groove and enters the "S"-shaped spiral track groove, the rolling sleeve 22 contacts the buffer stop 23, compressing the buffer spring 24 to absorb inertial impact. Then, guided by the spiral track groove, the rolling sleeve 22 begins to move along the spiral trajectory, thereby driving the valve shaft 20 to rotate while continuing to rise. The rotational movement of the valve shaft 20, through the cooperation of its lower curved track 30 and the slider pin 10, drives the ball core 9 to rotate around the trunnion 2, gradually opening the fluid passage. The valve is fully opened when the valve shaft 20 rises to near the end of its stroke.

[0042] When the valve needs to be closed, the linear actuator moves in the reverse direction, pulling the connecting sleeve 27 downward, causing the valve shaft 20 to descend synchronously and rotate in the opposite direction. First, the rolling sleeve 22 enters the vertical straight track groove from the "S"-shaped spiral track groove. The valve shaft 20 rotates in the opposite direction and descends, driving the ball core 9 to rotate in the opposite direction, gradually closing the fluid passage. Subsequently, the rolling sleeve 22 enters the vertical straight track groove's linear descent section. The valve shaft 20 only performs a linear descent motion, pressing the ball core 9 back onto the sealing ring 7 through the curved track 30. At the same time, the scraper 8 moves relative to the spherical surface of the ball core 9, scraping away impurities adhering to the spherical surface, achieving a reliable seal. At this point, the valve returns to the closed state.

[0043] Through the above operations, the valve can be opened and closed smoothly without disassembling it. The self-cleaning function of the scraper 8 and the automatic compensation function of the spring 4 can effectively extend the service life of the valve under complex working conditions.

[0044] Product test data are shown in Table 1.

[0045] Table 1 - Extreme Operating Condition Test Data for Cantilevered Orbital Ball Valve

[0046] Experimental description: 1. Test medium: Inert gas (nitrogen) is used for high temperature test, and clean water is used for low temperature and high pressure differential test.

[0047] 2. Test equipment: High temperature test furnace (accuracy ±5℃), low temperature test chamber (accuracy ±1℃), high frequency opening and closing table, high voltage test table (accuracy ±0.01MPa).

[0048] 3. Test environment: Standard atmospheric environment (temperature 23±2℃, humidity 50±5%RH).

[0049] 4. Cantilevered orbital ball valve (DN150) conforms to API 6D-2022 and GB / T 12237-2022; all tests meet the requirements of API 6D-2022 and GB / T 12237-2022 standards, and the test data are true and valid.

[0050] 5. Test results show that the cantilevered ball valve can withstand a maximum high temperature of 1400℃ and a maximum low temperature of -196℃. It operates stably under high frequency and high pressure differential conditions, and the performance of the ball, valve seat and guide structure all meet the design and standard requirements.

[0051] The core conclusion of the test is that, through extreme working condition tests, the valve's maximum high temperature, maximum low temperature and high frequency resistance were determined by the tests, and the ball, valve seat and guide rail structure operated stably.

[0052] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A cantilevered ball valve, comprising a valve body (1), a valve shaft (20) rotatably mounted within the valve body (1), and a hemispherical ball core (9) driven by the valve shaft (20), characterized in that, It also includes a guide assembly, which is disposed between the valve shaft (20) and the track valve cover (25) to guide the valve shaft (20) to perform lifting and rotating movements; the guide assembly includes a guide shaft (21) that passes through the valve shaft (20) and a rolling bushing (22) sleeved on the end of the guide shaft (21); the outer wall of the track valve cover (25) is provided with a guide rail (29) that slides with the rolling bushing (22), and the guide rail (29) is a closed track groove used to convert the linear motion of the valve shaft (20) into rotational motion; The upper end of the ball core (9) is provided with a guide hole (31), and a slider pin (10) is provided on the side wall of the guide hole (31). The lower end of the valve shaft (20) is provided with a curved track (30), which is inserted into the guide hole (31) and slides in contact with the slider pin (10). The lower end of the ball core (9) is supported in the valve body (1) by a trunnion (2) in a swinging and rotating manner, so as to realize the movement of the ball core (9) and the rotation of the valve shaft (20) when it is raised, lowered and rotated.

2. The cantilevered ball valve according to claim 1, characterized in that, The lower part of the guide rail (29) is a vertical straight track groove, and the upper part is a spiral track groove. The guide rail (29) and the rolling bushing (22) are set in two and are symmetrically distributed along the axial direction of the valve shaft (20).

3. The cantilevered ball valve according to claim 1, characterized in that, The upper end of the curved track (30) is arc-shaped, the lower end is straight, and its cross-section is non-circular; the cross-sectional shape of the curved track (30) matches that of the guide hole (31).

4. The cantilevered ball valve according to claim 1, characterized in that, The valve body (1) is provided with a valve seat assembly that seals with the ball core (9). The valve seat assembly is installed at the inlet end of the valve body (1). A sealing ring (7) is provided at the contact end between the valve seat assembly and the ball core (9). A scraper (8) is detachably installed on the sealing ring (7). The inner edge of the scraper (8) makes elastic contact with the spherical surface of the ball core (9) during the opening and closing of the valve to scrape off the attached impurities.

5. The cantilevered ball valve according to claim 4, characterized in that, The valve seat assembly also includes a sealing ring (3), a spring (4), a sealing sleeve (5), and a sealing graphite ring (6). The sealing sleeve (5) is installed on the outside of the sealing ring (7), and a sealing graphite ring (6) is provided between the sealing sleeve (5) and the sealing ring (7). The sealing ring (3) is installed on the outside of the sealing sleeve (5) and is detachably connected to the inlet end of the valve body (1). A spring (4) is provided between the sealing ring (3) and the sealing sleeve (5).

6. The cantilevered orbital ball valve according to claim 1, characterized in that, A packing seal structure is provided between the valve shaft (20) and the track valve cover (25). The packing seal structure includes a graphite packing assembly (14) disposed inside the track valve cover (25) and a packing gland (16) that presses the graphite packing assembly (14). The graphite packing assembly (14) includes three or more graphite rings. A sealing chamber structure is opened on the lower inner side wall of the track valve cover (25). The graphite rings are vertically stacked in the sealing chamber structure and fitted onto the outer wall of the valve shaft (20). A sealing bushing (32) is press-fitted onto the uppermost graphite ring. A pressure cap mounting groove is symmetrically opened on the side wall of the track valve cover (25) above the sealing chamber structure. The two ends of the packing pressure cap (16) are set in the pressure cap mounting groove and the middle part of the packing pressure cap (16) is fitted onto the valve shaft (20). The packing pressure cap (16) can seal and press the sealing bushing (32).

7. The cantilevered ball valve according to claim 6, characterized in that, An injection hole (34) is made on the side wall of the track valve cover (25), and a one-way valve plug (33) is installed on the injection hole (34).

8. The cantilevered ball valve according to claim 1, characterized in that, The upper end of the valve shaft (20) is connected to the linear actuator via a connecting sleeve (27); a bearing (28) is provided inside the connecting sleeve (27), and the upper end of the valve shaft (20) passes through the bearing (28) so that the linear actuator can drive the valve shaft (20) to achieve a combined motion of lifting and rotating through linear motion.

9. The cantilevered orbital ball valve according to claim 2, characterized in that, A buffer mechanism is provided above the vertical straight track groove of the guide rail (29). The buffer mechanism includes a buffer block (23), a buffer spring (24), and a buffer top screw (26). Buffer chambers are symmetrically opened in the side wall of the track valve cover (25) above the vertical straight track groove. The buffer top screw (26), the buffer spring (24), and the buffer block (23) are installed in the buffer chambers from top to bottom. The lower end of the buffer block (23) extends out of the buffer chamber and is inserted into the guide rail (29).

10. The cantilevered orbital ball valve according to claim 1, characterized in that, It also includes an anti-blowout structure, which includes an oblique outer conical annular platform (35) located at the lower end of the valve shaft (20) and an oblique inner conical annular groove (36) located at the lower end of the track valve cover (25). The outer wall of the oblique outer conical annular platform (35) matches the inner wall of the oblique inner conical annular groove (36).

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