Throttle valve

Abstract

A throttle valve, comprising a valve body, a valve seat, a valve core, a valve stem and a driving assembly. The valve seat is disposed in the valve body and is rotatably connected to the valve core. The valve core is connected to the valve stem. The valve stem extends in its axial direction out of the valve body and is connected to the driving assembly. The driving assembly is used for driving the valve stem to rotate. A transition flow channel provided in the valve core is a diamond-shaped orifice of which four corners are rounded. An upper valve cover is provided on the upper side of the valve body, the valve stem passing through the upper valve cover and being rotatably connected to the upper valve cover. The valve stem and the upper valve cover are sealed by means of a first sealing member and a second sealing member, the first sealing member being disposed over the second sealing member and abutting against the second sealing member. By means of improving a sealing structure and the valve core, the present application improves sealing performance and the accuracy of flow control.

Description

A throttle valve Technical Field

[0001] This invention relates to the field of valve technology, and more particularly to a throttle valve. Background Technology

[0002] A throttle valve is a control device used to regulate the flow rate of fluids. It is widely used in various industrial pipeline systems, including slide valves, needle valves, butterfly valves, and ball valves. Throttling valves control the flow rate and pressure of fluids by changing the opening of the valve orifice, thereby achieving precise control of the fluid system.

[0003] When used as a throttling valve, a ball valve utilizes the specific shape of the transition flow channel on the ball. By rotating the ball, the opening of the transition flow channel is adjusted, achieving precise control of fluid flow. Compared to traditional throttling valves, ball valves have the advantages of simple structure, convenient operation, good sealing performance, high durability, and stable operation in high-pressure, high-temperature, and corrosive environments. Therefore, ball valves are widely used in industrial process control requiring precise flow regulation and high reliability, such as in the petroleum, chemical, water treatment, and power industries. The throttling function achieved by ball valves not only improves the control accuracy of the system but also enhances the overall operating efficiency and safety.

[0004] However, ball valves used in throttling applications still have the following problems:

[0005] (1) In the prior art, the ball valve core usually adopts a circular transition flow channel design; when the valve is opened or closed, the opening of the throttling surface will change rapidly. When this type of valve core is applied to the throttling field, the rotation of the valve core will cause drastic changes in fluid velocity and flow rate. Such drastic changes may affect the smoothness of flow regulation and control accuracy, especially in applications that require precise flow regulation.

[0006] (2) In the prior art, ball valves used in the throttling field usually need to deal with high pressure and corrosive fluids, such as throttling ball valves used in the petroleum industry. This requires the ball valve to have excellent corrosion resistance and high pressure sealing performance, especially in the position of valve stem rotation. At present, the technology for valve stem rotation sealing usually adopts packing seal, that is, sealing packing is arranged around the valve stem. By pressing the packing between the valve stem and the packing gland, a tight sealing layer is formed to prevent media leakage. However, packing seals are subject to wear and corrosion aging, which leads to a decrease in sealing effect. Regular inspection and replacement are required. Moreover, its sealing performance is limited in high pressure, high temperature or corrosive environment. Pressing the packing will increase the valve stem operating force, and frequent operation can also easily cause minor leakage. Summary of the Invention

[0007] The purpose of this invention is to provide a throttle valve to solve the above-mentioned problems.

[0008] This invention is achieved through the following technical solution:

[0009] A throttle valve includes a valve body, a valve seat, a valve core, a valve stem, and a drive assembly. The valve seat is disposed inside the valve body and is rotatably connected to the valve core. The valve core is connected to a valve stem, which extends out of the valve body along its axial direction and is connected to the drive assembly. The drive assembly is used to drive the valve stem to rotate.

[0010] An upper valve cover is provided on the upper side of the valve body. The valve stem passes through the upper valve cover and is rotatably connected to the upper valve cover. The valve stem and the upper valve cover are sealed by a first sealing element and a second sealing element. The first sealing element is located on top of the second sealing element and abuts against the second sealing element. The second sealing element squeezes the first sealing element during the valve opening process.

[0011] In general, the drive assembly drives the valve stem to rotate to control the opening and closing of the throttle valve of the present invention. The rotation of the valve stem drives the valve core to rotate, and the rotation of the valve core drives its transition flow channel to connect with or close the pipes on both sides. The valve seat is used to seal with the rotation of the valve core.

[0012] In the specific configuration, the transition channel of the valve core is a diamond-shaped hole with rounded corners. A tubular first bushing is fitted above the first seal on the valve stem. A pressure plate is also provided on the upper side of the first bushing. The pressure plate is abutted against the first bushing by bolts oriented in the same direction as the valve stem axis. The first bushing is used to compress the first seal, and the pressure plate is used to compress the first bushing. The valve stem is positioned above the valve core, and a balance bar coaxial with the valve stem is provided below the valve core. The balance bar is used to maintain the dynamic balance of the valve stem rotation (existing valve cores typically only include the valve stem portion vertically above the valve core. In high-pressure fluid environments, the valve core is pushed and squeezed by the upstream fluid, causing the valve stem to deflect microscopically. This also results in the valve stem rotation balance capability of existing technologies being weaker than that of the valve stem rotation balance capability provided at both ends of the valve core in this invention).

[0013] Furthermore, the valve body has an internal cavity, in which the valve core is located. A pair of circular openings are laterally arranged through the valve body, used to fix the valve seat and its coaxial pipe and other components. The circular openings communicate with the cavity. A valve seat is located on the side of each circular opening closest to the cavity, and a valve seat sleeve is fitted over the valve seat. The valve seat sleeve is fixed within the circular opening. The valve seat and valve seat sleeve are sealed by a fifth sealing element, which is a flexible sealing ring. A disc spring is also abutted against the valve seat on the side furthest from the cavity. A disc spring plate is also abutted against the disc spring on the side furthest from the cavity. The disc spring is used to push the valve seat to compress the valve core. A pressure plate is located on the side of the disc spring plate furthest from the disc spring. The annular edge of the pressure plate has external threads, which mesh with the corresponding internal threads of the circular openings. The pressure plate fixes all the aforementioned components within the circular openings.

[0014] Furthermore, a bracket is provided above the upper valve cover on the valve body. The bracket is used to rotatably connect the valve stem extending to the outside of the valve body and to fix the drive assembly. The bracket consists of an H-shaped frame and discs fixed with openings on both sides of the H-shaped frame. The two discs are coaxial with the valve stem. The H-shaped frame is made of sheet metal. The discs with openings on both sides are parallel to the middle horizontal plate of the H-shaped frame. The disc at the lower end of the bracket is connected and fixed to the upper valve cover, and the disc at the upper end of the bracket is connected and fixed to the drive assembly.

[0015] Preferably, the second sealing element includes a first rotating element, a second rotating element, and a third fixed element. Each of the first rotating element, the second rotating element, and the third fixed element has a cylindrical body, and all three cylindrical bodies are coaxial with the valve stem. The cylindrical body of the first rotating element is disposed within the cylindrical body of the second rotating element, and the cylindrical body of the second rotating element is rotatably disposed within the third fixed element. The first rotating element is fixed to the valve stem, and the second rotating element is slidably disposed on the first rotating element. The third static component is fixed to the valve body. The outer side of the cylindrical body of the first rotating element is provided with a spline oriented in the same direction as its axis, and the inner side of the cylindrical body of the second rotating element is provided with a spline groove corresponding to the spline. The first rotating element and the second rotating element are slidably connected through the spline and the spline groove. The cylindrical body of the second rotating element... The first and lower ends are respectively provided with a first annular plate and a first slide rail. The first annular plate is perpendicular to the axis of the valve stem. The inner diameter of the first annular plate is the same as the inner diameter of the cylinder of the first rotating component, and its outer diameter is the same as the outer diameter of the cylinder of the third fixing component. The first slide rail is fitted with the second slide rail corresponding to the third fixing component. The lower end of the cylinder of the third fixing component is provided with a second annular plate. The second annular plate is perpendicular to the axis of the valve stem. The inner diameter of the second annular plate is the same as the inner diameter of the cylinder of the first rotating component, and its outer diameter is the same as the outer diameter of the cylinder of the third fixing component. The cylinder of the second rotating component is located on the upper end of the second annular plate. The second annular plate is fitted with the first slide rail corresponding to the first slide rail of the second rotating component. The first slide rail is provided with multiple circumferentially evenly distributed spiral inclined surfaces. The spiral inclined surfaces included in this invention... The valve can be configured with two or three spiral inclined surfaces. In a two-spiral inclined surface configuration, each surface occupies a semi-circular edge, allowing the valve stem to rotate up to 180 degrees without affecting normal operation. In a three-spiral inclined surface configuration, each surface occupies one-third of the circular edge, allowing the valve stem to rotate up to 120 degrees without affecting normal operation. Existing ball valves typically have a rotation range of 0 to 90 degrees, while some ball valves with damping channels have a range of 0 to 110 degrees. Therefore, the aforementioned two configurations ensure the normal rotation and sliding of the second rotating component (when the valve is open, the second rotating component presses against the first seal for compensating sealing; when the valve is closed, the second rotating component is pushed back to its original position by the first seal). However, if only one spiral inclined surface is used (occupying 360 degrees of the circular edge), the second rotating component's sliding... During the process, the bottom fulcrum is biased towards one side of the valve stem axis, resulting in unbalanced sliding forces and increased wear. Using multiple fulcrums would lead to insufficient rotation angle, causing the second rotating component to fall off. Each helical inclined surface is located on the same shaft segment and is symmetrical about the valve stem axis. The helical inclined surfaces are connected end to end on the circumference. This arrangement ensures that the helical inclined surfaces of the second rotating component are connected sequentially on the circumference, rather than being distributed at intervals on the circumference (i.e., localized arrangement). This ensures that the second rotating component has sufficient rotation angle and structural strength when rotating (the radial surfaces are all used to set the first slide rail). The second slide rail adopts the same setting method as the first slide rail, and the second slide rail and the first slide rail fit together. The rotation of the second slide rail supports the first slide rail to slide in the valve stem axis.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. In existing technologies, the valve core of a ball valve is typically designed as a circular transition flow channel. This design causes a rapid change in the opening of the throttling surface when the valve is opened or closed. When this type of valve core is applied to throttling applications, the rotation of the valve core causes drastic changes in fluid velocity and flow rate. These drastic changes affect the smoothness and control accuracy of flow regulation, especially in applications requiring precise flow regulation. Furthermore, excessively drastic changes in the flow rate at the throttling surface can lead to severe erosion and cavitation. To address these issues, the valve core of this invention sets the transition flow channel as a rhomboid hole with rounded corners, while the two opposite sides of the original rhomboid hole are blunt. The vertical angle (aligned with the valve stem orientation) makes the transition flow channel of the valve core flatter on the valve stem shaft (except for the rounded corners, the edges of the transition flow channel are straight edges). This makes the opening change of the throttling surface more linear during the rotation of the valve core driven by the valve stem, making it easier for the valve stem to smoothly and accurately control the change of the throttling surface flow. On the other hand, the change of the throttling surface flow is more stable and closer to linear, and the erosion and cavitation effects of the fluid inside the valve body on the throttling surface-related components are smaller. In high-pressure and corrosive fluid environments, the design of the valve core transition flow channel of this invention can effectively improve the service life of the valve.

[0018] 2. In existing technologies, valve stem rotation sealing typically employs packing (in this invention, the first sealing element) for sealing. This involves arranging packing around the valve stem and pressing it tightly against its circumference to form a tight sealing layer to prevent media leakage. However, packing seals are susceptible to wear and corrosion, leading to a gradual decrease in sealing effectiveness. Furthermore, packing seals have limited sealing performance under high pressure, high temperature, or corrosive environments. The tightness of the packing increases the operating force (torque) of the valve stem, and frequent operation can easily result in minor leaks. To address the problems associated with packing (the first sealing element) for valve stem rotation sealing, this embodiment employs a correspondingly designed second sealing element for resealing (the sealing action is performed according to the valve stem's movement). The second sealing element includes a first rotating element, a second rotating element, and a third fixed element. In this design, the first rotating component, the second rotating component, and the third fixed component all use a cylindrical body as the base. The first rotating component is sleeved and fixed on the valve stem. The second dynamic component is axially slidably disposed on the first rotating component. The third fixed component is fixed on the valve body. The bottom of the second rotating component and the third fixed component are respectively provided with a first slide rail and a second slide rail. When the valve stem rotates (when the transition flow channel is opened to allow fluid to pass through, at which time a large amount of high-pressure corrosive fluid will pass through the transition flow channel, increasing the possibility of leakage at the valve stem position), during the process of the first rotating component driving the second rotating component to rotate, the third fixed component pushes against the second rotating component through the sliding cooperation between the second slide rail and the first slide rail. The upper end of the second rotating component then squeezes the first sealing component to complete the compensation sealing action. Compared with the prior art, this design effectively improves the rotational sealing performance of the valve stem of this invention. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 is a schematic diagram of the throttle valve in the embodiment;

[0021] Figure 2 is a schematic diagram of the internal structure of the embodiment after the valve body is removed;

[0022] Figure 3 is a schematic diagram of the valve stem and valve core structure of the embodiment;

[0023] Figure 4 is a schematic diagram of a cut on one side of the circular port of the throttle valve in the embodiment;

[0024] Figure 5 is a detailed schematic diagram of point A in Figure 4;

[0025] Figure 6 is a detailed schematic diagram of point B in Figure 4;

[0026] Figure 7 is a detailed schematic diagram of point C in Figure 4;

[0027] Figure 8 is a detailed schematic diagram of point D in Figure 4;

[0028] Figure 9 is a cutaway diagram of the throttle valve in the embodiment relative to another view in Figure 4;

[0029] Figure 10 is a detailed schematic diagram of point E in Figure 9;

[0030] Figure 11 is a detailed schematic diagram of point F in Figure 9;

[0031] Figure 12 is a schematic diagram of axial cutting of the second seal;

[0032] Figure 13 is a schematic diagram of radial cutting of the second seal;

[0033] Figure 14 is a schematic diagram of axial cutting of the second seal after the removal of the first rotating part;

[0034] Figure 15 is a schematic diagram of the first rotating component;

[0035] Figure 16 is a schematic diagram of the second rotating component;

[0036] Figure 17 is a schematic diagram of the third fastener structure.

[0037] The reference numerals in the attached drawings represent: 1-valve body, 2-bracket, 3-bottom cover, 4-upper valve cover, 5-valve core, 6-valve stem, 7-pressure plate, 8-transition flow channel, 9-pressure plate, 10-nut disc, 11-first bushing, 12-first seal, 13-second seal, 14-second bushing, 15-third seal, 16-fourth seal, 17-balance bar, 18-valve seat sleeve, 19-disc spring, 20-fifth seal, 21-disc spring plate, 22-valve seat, 23-first rotating component, 24-second rotating component, 25-third fixing component, 26-spline, 27-spline groove, 28-first ring plate, 29-first slide rail, 30-second slide rail, 31-second ring plate. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0039] As shown in Figures 1 to 17, this embodiment relates to a throttle valve, including a valve body 1, a valve seat 22, a valve core 5, a valve stem 6, and a drive assembly. The valve seat 22 is disposed inside the valve body 1 and is rotatably connected to the valve core 5. The valve core 5 is connected to the valve stem 6, which extends out of the valve body 1 along its axial direction and is connected to the drive assembly. The drive assembly is used to drive the valve stem 6 to rotate (in this embodiment, the drive assembly is fixed to the upper part of the valve stem 6, and it can be an automatically controlled drive assembly or a manually controlled drive assembly. As a preferred embodiment, the valve stem 6 in this embodiment adopts an automatically controlled drive assembly).

[0040] In this embodiment, the valve core 5 is a spherical body with a transition channel 8 in the middle. The transition channel 8 is a rhomboid hole (the four corners of the initial rhomboid hole are rounded). A valve stem 6 is provided in the extension direction of the two opposite rounded corners in the transition channel 8 (the two opposite rounded corners correspond to the two opposite obtuse angles of the initial rhomboid, making the transition channel 8 flatter on the axial section of the valve stem 6). The axis of the valve stem 6 coincides with the center of the valve core 5, and the valve stem 6 is vertically arranged on the upper side of the valve body 1. A balance bar 17 is also provided on its lower side, which is used to balance the rotation of the valve stem 6. Valve core 5 is provided with valve seats 22 on both sides. Valve core 5 abuts against valve seats 22. Valve core 5 can rotate relative to valve seats 22 (the rotation of valve core 5 drives the transition flow channel 8 to connect or close with the ends of valve seats 22 on both sides. Pipes are also fixed to the ends of valve seats 22 on both sides. The rotation of valve core 5 connects or closes the transition flow channel 8 with the pipes in valve seats 22). It is worth noting that the diamond-shaped flow channel of the transition flow channel 8 of valve core 5, compared with the circular flow channel of valve core 5 in the prior art, provides a smoother flow change during rotation, enabling more precise throttling control in this embodiment. The prior art valve core 5 adopts a circular flow channel design, which causes drastic changes in the throttling surface during the rotation of valve core 5. The fluid flow rate through the valve pipe changes synchronously with the change of the throttling surface (changing with the degree of drastic change of the throttling surface). This greatly increases the difficulty of using a circular flow channel valve core 5 for throttling control (precision is difficult to control; within a very small rotation angle, the flow rate changes drastically, making it difficult to control the accurate flow rate of the fluid). In contrast, the valve core 5 in this embodiment uses a rhomboid-shaped transition flow channel 8 (except for the four rounded corners, the remaining positions are composed of inclined straight lines). During the rotation of the valve core 5, the change of the throttling surface is more gradual compared to a circular flow channel (the straight edge makes the change in the size of the throttling surface opening more linear), making the valve core 5 in this embodiment more advantageous as a throttling valve.

[0041] The valve body 1 has an internal cavity, and circular openings are coaxially arranged on its left and right sides (the valve stem 6 is vertical, and the circular openings are divided into left and right sides, see Figure 9). Each circular opening connects to the internal cavity of the valve body 1, and a valve seat sleeve 18 (a ring-shaped piece) is coaxially fixed to each circular opening near the internal cavity. The valve seat 22 is coaxially fitted inside the valve seat sleeve 18. A fifth sealing element 20 is provided between the valve seat 22 and the valve seat sleeve 18. The fifth sealing element 20 is a ring-shaped sealing ring fitted outside the valve seat 22. The fifth sealing element 20 is used to seal the gap between the valve seat 22 and the valve seat sleeve 18. Each valve seat 22 also has a butterfly spring 19 abutting against the side away from the internal cavity of the valve body 1. The butterfly spring 19 also has a butterfly spring plate 21 abutting against the side away from the internal cavity of the valve body 1. The butterfly spring plate 21, in conjunction with the butterfly spring, can push the valve seat 22 on the axis of the circular opening of the valve body 1. The valve core 5 is squeezed and sealed to ensure a tight seal between the valve core 5 and the valve seat 22 (the disc spring plate 21 is an annular plate). The disc spring plate 21 is also coaxially provided with a pressure plate 7 on the side away from the disc spring. The pressure plate 7 is an annular plate with external threads on its edge. The circular openings on both sides of the valve body 1 are provided with internal threads on the side away from the internal cavity of the valve body 1. The pressure plate 7 is fixed by engaging the external threads with the internal threads of the circular openings. The pressure plate 7 is used to fix the various components installed in the circular channel of the valve body 1. The valve core 5 is located in the cavity of the valve body 1 and is positioned between two valve seats 22 on both sides. The valve stem 6 is connected to the valve core 5 and is vertically positioned in the valve body 1. The valve body 1 has a bottom cover 3 and an upper valve cover 4 located vertically below and above the valve core 5, respectively. The upper valve cover 4 is rotatably connected to the valve stem 6. (The valve body 1 has openings connecting to the cavity at the middle of its upper and lower ends. The upper opening is sealed by the upper valve cover 4, and the lower opening is sealed by the bottom cover 3. The upper valve cover 4 and the bottom cover 3 are statically sealed to the valve body 1 by a fourth sealing element 16, which is an annular sealing gasket.) The valve stem 6 extends vertically upward along its axis through the upper valve cover 4 to the outside of the valve body 1. It is worth mentioning that the valve stem 6 and the upper valve cover 4 are rotary seals, which are difficult to effectively seal against high-pressure and corrosive fluids over a long period of time. The upper valve cover 4 and the bottom cover 3 are static seals, which are easier to effectively seal against high-pressure and corrosive fluids over a long period of time.

[0042] The upper valve cover 4 is provided with a stuffing box (round hole) corresponding to the valve stem 6. The valve stem 6 and the stuffing box are coaxial. A second seal 13 is provided at a position near the middle cavity of the valve body 1 in the stuffing box. The second seal 13 is coaxially sleeved on the valve stem 6. Above the second seal 13, a first seal 12 (the first seal 12 is a sealing packing) is also abutted and arranged. The first seal 12 is arranged around the valve stem 6. Above the first seal 12, a tubular first bushing 11 is provided. The first bushing 11 is coaxially sleeved on the valve stem 6. The first bushing 11 and the valve stem 6 are sealed by a third seal 15. In the embodiment, the third seal 15 adopts an annular sealing ring. The third seal 15 is provided with two layers, and there is a gap between the two layers of the third seal 15 (one is to prevent the first bushing 11 from contacting the valve stem 6, and long-term contact between different metal materials is likely to cause electrochemical corrosion; the other is to enable the first bushing 11 to be in balanced sliding connection on the valve stem 6). Above the first bushing 11, a pressing plate 9 is also provided. The pressing plate 9 is abutted and fixed on the first bushing 11 by bolts with the same axis orientation as the valve stem 6 (during later maintenance, the pressing plate 9 can be further pressed down by the bolts to strengthen the seal). The pressing plate 9 can drive the first bushing 11 to move axially on the valve stem 6.

[0043] A bracket 2 is fixed on the upper side of the upper valve cover 4. As a preferred embodiment, the bracket 2 in the embodiment is composed of an H-shaped frame and discs fixed to both openings of the H-shaped frame. The H-shaped frame is composed of plates (it is H-shaped in the perspective parallel to the plates). Among them, the discs fixed to both openings are parallel to the middle cross plate of the H-shaped frame. In the horizontal perspective parallel to each plate surface of the H-shaped frame, the bracket 2 is in the shape of a Chinese character 'Ri'. The pressing plate 9 is arranged above the bottom disc of the H-shaped frame. Round holes are provided in both the middle and the edge of the pressing plate 9. The valve stem 6 passes through the round hole in the middle of the pressing plate 9. The round holes at the edge of the pressing plate 9 are connected by vertical bolts (the bolts drive the pressing plate 9 to press downwards, and the first bushing 11 abuts against the pressing plate 9, thereby fixing the pressing plate 9). During the process of later maintenance, when the first seal 12 is not tightly sealed or even leaks, the pressing plate 9 can be further pressed down by the bolts, so that the first seal 12 is subjected to a greater extrusion force, and the first seal 12 can strengthen the rotational seal of the valve stem 6. A threaded shaft section is also provided at a position near the upper end of the valve stem 6. The valve stem 6 of the threaded shaft section passes through the middle cross plate of the bracket 2. Pressure bearings are provided on both the upper and lower sides of the cross plate at the position where the valve stem 6 passes through. The two pressure bearings are fixed by nut plates 10 provided on both the upper and lower sides (the nut plates 10 are meshed and fixed with the threads of the valve stem 6, and the upper and lower two pressure bearings are clamped between the two sides of the cross plate by the nut plates 10). This design ensures the stable balance of the rotational connection between the valve stem 6 and the bracket 2. The upper end of the valve stem 6 is used to connect a driving component. The driving component is fixed on the upper disc of the bracket 2 and is connected to the upper end of the valve stem 6.

[0044] It is worth mentioning that the first seal 12 is a sealing packing, which is sealed by the pressure of the first bushing 11. However, under long-term high pressure and corrosive fluid environment, the first seal 12 will wear and corrode and age, resulting in a weakened sealing effect. It needs to be inspected or replaced regularly (adjusting the bolt to press down the pressure plate 9 to make the first seal 12 tighter can increase the sealing performance). In addition, its sealing performance is limited under high pressure, high temperature or corrosive environment. Excessive tightening of the first seal 12 will also increase the rotation torque of the valve stem 6, making it more difficult to open and close the valve. Especially when the first seal 12 is pressed too tightly, if the valve stem 6 has not been used for a long time and is turned again, the valve stem 6 may not be able to turn. Moreover, frequent rotation of the valve stem 6 can also easily cause a small leak at the sealing position between the first seal 12 and the valve stem 6.

[0045] To address the problem of the first sealing element 12 providing rotational sealing for the valve stem 6, this embodiment provides a second sealing element 13 for compensating sealing (the sealing action is performed according to the movement of the valve stem 6). The second sealing element 13 includes a first rotating element 23, a second rotating element 24, and a third fixing element 25. All three elements—the first rotating element 23, the second rotating element 24, and the third fixing element 25—use a cylindrical body as their base. The first rotating element 23 is coaxially disposed within the second rotating element 24, and the second rotating element 24 is coaxially sleeved within the third fixing element 25. The first rotating element 23 is fixed to the valve stem 6 and rotates synchronously with the valve stem 6 when it rotates. A spline 26 is also provided on the outer side of the cylindrical body of the first rotating element 23, with the spline 26 oriented in the same direction as the axis of the valve stem 6. A spline groove 27 corresponding to the spline 26 is provided on the inner side of the cylindrical body of the second rotating element 24. The first rotating element 23 is slidably disposed within the second rotating element 24 via the spline 26, and the first rotating element 23 can drive the second rotating element 24 to rotate as the valve stem 6 rotates. The top of the cylinder of the second rotating member 24 is provided with a first ring plate 28, which is perpendicular to the axis of the valve stem 6. The inner diameter of the first ring plate 28 is the same as the inner diameter of the cylinder of the first rotating member 23, and the outer diameter of the first ring plate 28 is the same as the outer diameter of the third fixing member 25. The bottom of the cylinder of the second rotating member 24 is also provided with a first slide rail 29, which is used to drive the second rotating member 24 to slide along the axial direction of the valve stem 6 during the rotation of the second rotating member 24 with the valve stem 6. The third fixing member 25 is fixed to the valve body 1, and a second ring plate 31 is provided at its bottom. The inner diameter of the second ring plate 31 is the same as the inner diameter of the cylinder of the first rotating member 23, and the outer diameter of the second ring plate 31 is the same as the outer diameter of the third fixing member 25. The bottom cylinder of the first rotating member 23 is fitted onto the second ring plate 31. The second ring plate 31 is fitted with the first slide rail 29 of the second rotating member 24 and a second slide rail 30 is provided. The second slide rail 30 is used to push the second rotating member 24 to slide along the valve stem 6 axially during the rotation of the second rotating member 24.The first slide rail 29 has two helical inclined surfaces that are symmetrical about the axis of the second rotating member 24. The circumferences of each helical inclined surface are connected end-to-end (the highest point of each helical inclined surface connects to the lowest point of the adjacent helical inclined surface). From the axial perspective of the second rotating member 24, each helical inclined surface occupies half a circle of the cylindrical body of the second rotating member 24, and the two helical inclined surfaces occupy the entire circle of the cylindrical body of the second rotating member 24 (the two helical inclined surfaces occupy the entire radial surface of the cylindrical body). The second slide rail 30 of the third fixing member 25 is fitted to the first slide rail 29, that is, it also has two... In the initial engagement state, the second rotating member 24 and the third fixed member 25 are in a tightly fitted state. When the valve stem 6 rotates, driving the first rotating member 23 to rotate, the first rotating member 23 drives the second rotating member 24 to rotate. During the rotation of the second rotating member 24, the first slide rail 29 of the second rotating member 24, under the sliding push of the second slide rail 30, allows the second rotating member 24 to slide a small distance toward the first sealing member 12. The first ring plate 28 of the second rotating member 24 will then press against the first sealing member 12, completing the compensation seal. It is worth mentioning that in this embodiment, the first slide rail 29 and the second slide rail 30 are composed of helical inclined surfaces evenly distributed at both ends. Each helical inclined surface occupies half of the circumference of the cylinder of the second rotating member 24 radially. This setting is only a preferred embodiment, that is, the first slide rail 29 and the second slide rail 30 can also be three helical inclined surfaces evenly distributed around the circumference. The three helical inclined surfaces are evenly distributed around the circumference and symmetrical (each helical inclined surface occupies one-third of the circumference). The embodiment employs two circumferentially symmetrical helical inclined surfaces. Firstly, this prevents the imbalance that might occur with a single helical inclined surface (a helical inclined surface occupying the entire circumference might, during rotation, cause the fulcrum supporting the second rotating component 24 to shift towards one side of the axis of the first rotating component 23, leading to an imbalance in the sliding forces between the second and first rotating components 24). By using at least two helical inclined surfaces, the second rotating component 24 has at least two circumferentially symmetrical fulcrums on the third fixed component 25, ensuring balance during the axial sliding process of the second rotating component 24. (1) Reduce wear) and (2) Use two or three helical inclined surfaces to prevent the second rotating part 24 from falling back to its original position during the rotation of the valve stem 6 (the rotation angle of a ball valve is usually 90 degrees, and some ball valves can reach 110 degrees, such as ball valves with damping flow channels. Using two or three helical inclined surfaces can ensure that the second rotating part 24 continues to slide in one direction of the valve stem 6 axis when the rotation is less than 120 degrees, thus avoiding the situation where the second rotating part 24 returns to its initial position after the valve stem 6 has rotated to a certain angle).

[0046] Furthermore, the first annular plate 28 vertically above the second rotating member 24 also abuts against the first sealing member 12. The first sealing member 12 is a sealing packing. Generally, the tighter it is compressed, the better its sealing performance. In this embodiment, when the valve stem 6 is rotated to open the valve, the first annular plate 28 of the second rotating member 24 pushes against the first sealing member 12, thereby increasing the sealing performance of the first sealing member 12. The advantage of this design is that it avoids the first sealing member 12 being compressed too tightly, which would increase the static friction of the valve stem 6 and cause the valve stem 6 to become unable to open after a long period of static storage (the first sealing member 12 and the second sealing member 13 are two independent sealing settings, and with the compensating sealing action between the two, the compression degree of the first sealing member 12 can be kept within a reasonable compression pressure range). The specific process of the compensation seal is as follows: during the rotation of the valve stem 6 (the process of opening the valve), the second rotating member 24 pushes against the first sealing member 12 (compressed by the first ring plate 28). After the valve is fully opened, the compression stroke of the second rotating member 24 against the first sealing member 12 reaches its maximum (the second rotating member 24 further compresses the first sealing member 12 to complete the sealing). Therefore, during the rotation of the valve stem 6, the frictional resistance of the first sealing member 12 to the valve stem 6 is variable, rather than a constant resistance value. The frictional resistance of the first sealing member 12 is at its maximum when the compression stroke of the second rotating member 24 is at its maximum (at which point the sealing performance is also the best). Therefore, this design improves the operability of the valve stem 6 rotation and also improves the sealing performance between the valve stem 6 and the upper valve cover 4. After the valve stem 6 rotates back to its initial circumferential position (the rotation of the valve is closed), the second rotating member 24 rotates to its initial circumferential position under the drive of the first rotating member 23. Axially, under the rebound force of the first sealing member 12 (the first sealing member 12 is elastic and has elastic restoring force after compression), it returns to its initial axial position. The second rotating member 24 then returns to its initial position. It is worth mentioning that the valve core 5 used in this embodiment is a diamond-shaped hole with rounded corners (the lateral distance of the opening is longer). During valve opening, fluid easily overflows into the gap between the valve core 5 and the valve body 1. Therefore, the sealing environment faced by the first sealing member 12 in this embodiment when the valve core 5 is open is more stringent than that of the valve core 5 with a circular flow channel design in the prior art (the circular flow channel is similar in shape to the end of the valve seat 22, making it easier to fit and conduct with the valve seat 22, and less likely to overflow into the gap). This embodiment effectively addresses this problem by setting the second sealing member 13 to squeeze the first sealing member 12 during valve opening, thereby increasing the sealing capacity of the first sealing member 12 when the valve is open. In addition, after the valve in the embodiment is closed, the fluid is blocked on one side, and the fluid pressure in the gap between the valve core 5 and the valve body 1 decreases. At this time, the second seal 13 reduces the compression on the first seal 12, ensuring the life of the first seal 12 (if the elastic material is subjected to long-term compression without recovery, its elasticity will decrease and its life will be shortened).

[0047] The balance rod 17 located below the valve core 5 is fitted with a tubular second bushing 14. The second bushing 14 is located in the opening at the lower end of the valve body 1 (the opening at the lower end of the valve body 1 is circular). The second bushing 14 and the balance rod 17 are both sealed in the valve body 1 by the bottom cover 3. The balance rod 17 and the second bushing 14 are rotatably configured, and the valve stem 6 and the upper valve cover 4 are rotatably configured. The rotation of the balance rod 17 and the bottom cover 3 ensures the dynamic balance when the valve stem 6 drives the valve core 5 to rotate. In the prior art, the valve stem 6 is usually only located above the valve core 5. This makes the valve stem 6 unbalanced when dealing with high pressure fluids, resulting in the valve stem 6 being deflected at the microscale. This leads to problems such as valve stem 6 sealing leakage, increased torque, and valve core 5 not closing tightly. It is worth mentioning that the second bushing 14 in the embodiment can be replaced by the second seal 13 (when using the second seal 13, the first ring plate 28 of the second rotating part 24 of the second seal 13 is set downwards, and an elastic sealing ring is set below the second ring plate 31 to adjust the position of the second rotating part 24). The valve in the embodiment is mainly used in the petroleum field. The valve needs to deal with high pressure and corrosive fluids. Under such an environment, the metal contact position between the valve stem 6 and the valve body 1 may be corroded (rusted). This will cause the rotation torque of the valve stem 6 to increase or even prevent it from rotating. After replacing the second bushing 14 with the second seal 13, the rotation of the balance bar 17 will drive the second rotating part 24 to move axially (the first rotating part 23 and the second rotating part 24 rotate with the valve stem 6, and the third fixing part 25 is fixed on the valve body 1). This greatly increases the rotatability between each rotating part and the third fixing part 25 (the relative movement generated by the axial linear movement can effectively remove the static bonding force generated by rust), ensuring the rotational stability of the valve stem 6 (the second seal 13 set above the valve core 5 also has this advantage).

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A throttle valve, comprising a valve body (1), a valve seat (22), a valve core (5), a valve stem (6), and a drive assembly, characterized in that, The valve seat (22) is located inside the valve body (1). The valve seat (22) is rotatably connected to the valve core (5). The valve core (5) is connected to the valve stem (6). The valve stem (6) extends along its axial direction to the outside of the valve body (1) and is connected to the drive assembly. The drive assembly is used to drive the valve stem (6) to rotate. The valve body (1) is provided with an upper valve cover (4) on the upper side. The valve stem (6) passes through the upper valve cover (4) and is rotatably connected to the upper valve cover (4). The valve stem (6) and the upper valve cover (4) are sealed by a first seal (12) and a second seal (13). The first seal (12) is located on the second seal (13). The first seal (12) and the second seal (13) abut against each other. The second seal (13) squeezes the first seal (12) during the opening of the valve.

2. A throttle valve as described in claim 1, characterized in that, The valve core (5) is provided with a through transition channel (8), which is a diamond-shaped hole with rounded corners.

3. A throttle valve as described in claim 1, characterized in that, The valve stem (6) is also fitted with a tubular first bushing (11) above the first seal (12). A pressure plate (9) is also provided on the upper side of the first bushing (11). The pressure plate (9) is mounted on the first bushing (11) by bolts facing the same direction as the valve stem (6). The first bushing (11) is used to squeeze the first seal (12), and the pressure plate (9) is used to squeeze the first bushing (11).

4. A throttle valve as described in claim 1, characterized in that, The valve stem (6) is positioned above the valve core (5), and a balance bar (17) coaxial with the valve stem (6) is positioned below the valve core (5).

5. A throttle valve as described in claim 1, characterized in that, The valve body (1) has a cavity inside, and a pair of circular openings that penetrate the valve body (1) are arranged laterally. The circular openings are connected to the cavity. A valve seat (22) is arranged on the side of each circular opening close to the cavity. A valve seat sleeve (18) is sleeved on the outside of the valve seat (22). The valve seat sleeve (18) is fixed in the circular opening. The valve seat (22) and the valve seat sleeve (18) are sealed by a fifth sealing element (20). A disc spring is also provided on the side of the valve seat (22) away from the cavity. A disc spring plate (21) is also provided on the side of the disc spring (19) away from the cavity. The disc spring is used to push the valve seat (22) to squeeze the valve core (5). A pressure plate (7) is provided on the side of the disc spring plate (21) away from the disc spring. An external thread is provided on the annular edge of the pressure plate (7). The external thread meshes with the internal thread corresponding to the circular opening.

6. A throttle valve as described in claim 1, characterized in that, A bracket (2) is also provided above the upper valve cover (4). The bracket (2) consists of an H-shaped frame and a disc with openings on both sides of the H-shaped frame. The two discs are coaxial with the valve stem (6). The H-shaped frame is made of plate material. The discs with openings on both sides are parallel to the middle horizontal plate of the H-shaped frame. The disc at the lower end of the bracket (2) is connected and fixed to the upper valve cover (4). The disc at the upper end of the bracket (2) is connected and fixed to the drive assembly.

7. A throttle valve as described in claim 1, characterized in that, The second sealing element (13) includes a first rotating element (23), a second rotating element (24) and a third fixing element (25). The first rotating element (23), the second rotating element (24) and the third fixing element (25) are all provided with a cylinder, and the cylinders of the three are coaxial with the valve stem (6). The cylinder of the first rotating element (23) is disposed in the cylinder of the second rotating element (24), and the cylinder of the second rotating element (24) is rotatably disposed in the third fixing element (25). The outer side of the cylinder of the first rotating part (23) is also provided with a spline (26) facing the same axis as it. The inner side of the cylinder of the second rotating part (24) is provided with a spline groove (27) corresponding to the spline (26). The first rotating part (23) and the second rotating part (24) are slidably connected through the spline (26) and the spline groove (27). The upper and lower ends of the cylinder of the second rotating member (24) are respectively provided with a first ring plate (28) and a first slide rail (29). The first ring plate (28) is perpendicular to the axis of the valve stem (6). The inner diameter of the first ring plate (28) is the same as the inner diameter of the cylinder of the first rotating member (23), and its outer diameter is the same as the outer diameter of the cylinder of the third fixing member (25). The first slide rail (29) is matched with the second slide rail (30) corresponding to the third fixing member (25). The lower end of the cylinder of the third fixing member (25) is provided with a second ring plate (31). The second ring plate (31) is perpendicular to the axis of the valve stem (6). The inner diameter of the second ring plate (31) is the same as the inner diameter of the cylinder of the first rotating member (23), and its outer diameter is the same as the outer diameter of the cylinder of the third fixing member (25). The cylinder of the second rotating member (24) is located at the upper end of the second ring plate (31). The second ring plate (31) is provided with a second slide rail (30) that fits into the first slide rail (29) of the second rotating member (24).

8. A throttle valve as described in claim 7, characterized in that, The first slide rail (29) is provided with multiple spiral inclined surfaces evenly distributed around the circumference. Each spiral inclined surface is located on the same shaft segment and is symmetrical about the center of the valve stem (6) axis. Each spiral inclined surface is connected end to end on the circumference.

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