An axial flow plug valve

Abstract

The present invention relates to an axial flow plug valve, which comprises a valve body, a cone arranged inside the valve body, a sleeve sleeved outside the cone, a driving and transmission mechanism for driving the sleeve to open and close the valve through linear and rotational motions, and a limiting mechanism. The cone is provided with a plurality of water outlets evenly and symmetrically along the circumferential direction. Compared with the prior art, the present invention has the advantages of durability, high cost performance, small torque, small driving force, flow regulation and pressure regulation, collision and energy dissipation, anti-vibration and cavitation resistance, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of valve design and manufacturing, and in particular, to an axial flow plug valve. Background Art

[0002] The control valves used for flow regulation or energy dissipation in water systems mainly include linear stroke sleeve valves and rotary plug valves (rotary valve). However, both types of valves have various disadvantages, specifically as follows:

[0003] 1. Sleeve valve: Although the fluid is in an axial flow pattern, with good flow state and strong cavitation resistance, and there is almost no pressure-bearing torque when closed, there is a frictional torque during the movement of the sleeve gate. Especially over time, the friction force increases significantly due to water corrosion and scaling on the inner wall of the sleeve, and in severe cases, the valve may fail.

[0004] 2. Plug valve: Although the structure is simple, the flow state is not in an axial flow pattern, the cavitation phenomenon is relatively large when the pressure difference is large, and the friction force and torque are huge during opening and closing. Although some designs have a lifting mechanism for the plug body during the opening and closing process to reduce the torque, the structure is complex or remote control cannot be achieved. At the same time, it is very difficult to manufacture large-diameter valves. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide an axial flow plug valve.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] An axial flow plug valve includes a valve body, a cone arranged inside the valve body, a sleeve sleeved outside the cone, a driving and transmission mechanism for driving the sleeve to realize the opening and closing of the valve through linear and rotational movements, and a limiting mechanism. The cone is evenly and symmetrically provided with a plurality of water outlets along the circumferential direction.

[0008] The cone is a frustum-shaped cylinder with a closed bottom, which is fixedly connected to the flange at the outlet end of the valve body. The shape of the sleeve matches that of the cone, and a ring-shaped rubber seal is provided between the sleeve and the cone.

[0009] A lining ring for realizing the sliding and rotational positioning of the sleeve is provided between the sleeve and the inner wall of the valve body.

[0010] The described drive transmission mechanism includes an actuator, a transmission shaft, a linkage shaft, a small bevel gear, a large bevel gear meshing with the small bevel gear, a T-shaped screw rod, and a spline sleeve, which are fixed on the top small flange of the valve body. The upper end of the transmission shaft is in transmission connection with the actuator, and the lower end is in transmission connection with the small bevel gear through the linkage shaft. The inner end of the T-shaped screw rod passes through the center of the cross beam of the sleeve and is fixedly connected. The large bevel gear is in transmission connection with the T-shaped screw rod through screw threads to drive the sleeve to move linearly. The spline sleeve and the large bevel gear form an integral body and are rotationally connected to the cross beam through a limiting mechanism.

[0011] A gland with a half-ring fixed on the outside is also provided on the top small flange of the valve body to position the transmission shaft to prevent it from moving up and down, and a bushing for guiding the transmission shaft is provided at the neck of the small flange.

[0012] The lower end of the transmission shaft is in transmission connection with the upper end of the linkage shaft through a connecting sleeve with an inner square and an outer circle.

[0013] A hemispherical flow deflector and a support frame are also provided inside the valve body, which are fixed at the bottom of the cone. The linkage shaft is arranged on the horizontal fixing plate of the support frame. The spline sleeve and the large bevel gear are connected to the support frame through bearings. The cross beam of the sleeve is located in the space between the bottom of the cone and the support frame.

[0014] The limiting mechanism includes a Z-shaped fork rotatably arranged on the cross beam of the sleeve through a central rotating shaft, a tension spring connecting the outer end of the fork and the cross beam to provide tension, and a limiting unit fixed at the bottom of the cone. The inner end of the fork realizes the rotational transmission connection between the cross beam and the large bevel gear by extending into the spline sleeve.

[0015] The limiting unit includes an angular stroke close limiting pile, a linear stroke limiting pile, and an angular stroke open limiting pile, which are respectively fixed at the bottom of the cone and arranged in sequence along the circumference. The length of the linear stroke limiting pile is lower than that of the angular stroke close limiting pile. The position of the angular stroke close limiting pile is the rotational closing valve position, and the angular stroke open limiting pile is the rotational opening valve position. When the cross beam moves linearly, it is limited between the angular stroke close limiting pile and the linear stroke limiting pile.

[0016] The operation process of this axial flow globe valve is specifically as follows:

[0017] When the valve is opened, the actuator starts to rotate forward. It drives the large bevel gear to rotate successively through the transmission shaft, linkage shaft, and small bevel gear. At this time, the inner end of the fork does not extend into the spline sleeve. The large bevel gear drives the T-shaped screw through transmission, causing the T-shaped screw to drive the crossbeam of the sleeve to move linearly. The inner surface of the sleeve and the outer surface of the cone gradually separate to form a gap, reducing the valve opening torque. When the crossbeam moves linearly from the straight valve closing position to the straight valve opening position, the crossbeam disengages from the straight stroke limit post. At this time, under the action of the tension of the tension spring, the inner end of the fork extends into the spline sleeve, causing the crossbeam and the large bevel gear to form a transmission unit for rotational motion until the crossbeam rotates to the rotary valve opening position, and the axial flow plug valve is in the fully open state;

[0018] When the valve is closed, the actuator starts to rotate reversely. It drives the large bevel gear to rotate successively through the transmission shaft, linkage shaft, and small bevel gear. At this time, the inner end of the fork is located in the spline sleeve. The transmission unit formed by the crossbeam and the large bevel gear performs rotational motion until the crossbeam rotates to the rotary valve closing position. The outer end of the fork contacts the angular stroke closing limit post, causing the inner end to disengage from the spline sleeve. After the crossbeam and the large bevel gear are separated from the transmission, the large bevel gear continues to rotate, driving the T-shaped screw and the crossbeam to move linearly from the straight valve opening position to the straight valve closing position. After the inner surface of the sleeve and the outer surface of the cone are gradually and completely fitted, the axial flow plug valve is in the fully closed state.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] First, in the valve structure of the present invention, both the cone and the sleeve are inclined. When opening the valve, the sleeve first moves linearly and then rotates. When closing the valve, the sleeve first rotates and then moves linearly. The linear movement during valve opening creates a gap between the sleeve and the cone, greatly reducing the valve opening torque, achieving a clever zero-friction rotation, and significantly extending the service life of the valve.

[0021] Second, the present invention only requires one actuator to achieve linear and rotational motions. Compared with the existing plug valves that require one actuator for linear motion and one actuator for rotational motion respectively, it can effectively reduce costs and space, reduce the structural complexity, and facilitate use and maintenance.

[0022] Third, the present invention adopts an axial flow design. The water flows into the valve body in an axial arc. The flow channel in the valve body is axisymmetric, and the fluid will not generate turbulence. No matter where the sleeve moves, the water flow cross-section in the valve cavity is annular and contracts at the axis at the outlet, thereby achieving the best anti-cavitation effect and avoiding the damage to the valve body and pipeline caused by cavitation that may occur due to throttling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1a It is the front view sectional view of the axial flow plug valve in the valve opening state.

[0024] Figure 1b isFigure 1a The D-D sectional view in

[0025] Figure 1c is Figure 1a The partial enlarged view of part I in

[0026] Figure 1d is Figure 1a The partial enlarged view of part II in

[0027] Figure 2 a is the front sectional view of the axial flow plug valve in the valve-closed state.

[0028] Figure 2 b is Figure 2 The F-F sectional view in a.

[0029] Figure 2 c is Figure 2 The partial enlarged view of part III in a.

[0030] Figure 2 d is Figure 2 The partial enlarged view of part IV in a.

[0031] Figure 2 e is Figure 2 The C-C sectional view in b (the crossbeam is in the limited state).

[0032] Figure 2 f is Figure 2 The C-C sectional view in b (the crossbeam is in the disengaged state).

[0033] Figure 3 The flow state schematic diagram of an axial flow plug valve provided by the present invention.

[0034] Figure 4 The flow regulation working condition schematic diagram of an axial flow plug valve provided by the present invention

[0035] Figure 5 The pressure regulation working condition schematic diagram of an axial flow plug valve provided by the present invention

[0036] Explanation of the marks in the figure:

[0037] 1. Valve body, 2. Cone, 3. Sleeve, 4. Gasket, 5. Actuator, 6. gland, 7. Half-ring, 8. Bush, 9. Transmission shaft, 10. Connecting sleeve, 11. Flow guide cover, 12. Linking shaft, 13. Small bevel gear, 14. T-shaped screw rod, 15. Large bevel gear, 16. Spline sleeve, 17. Support frame, 18. Pull spring, 19. Fork. Specific embodiments

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Embodiment:

[0040] As shown in Figure 1, the present invention provides an axial plug valve, which is composed of a valve body 1, a cone 2, a sleeve 3, a gasket 4, an actuator 5, a gland 6, a split ring 7, a bushing 8, a transmission shaft 9, a connecting sleeve 10, a deflector 11, a linkage shaft 12, a pinion gear 13, a T-shaped screw 14, a bull gear 15, a spline sleeve 16, a support frame 17, a tension spring 18, a fork 19, etc.

[0041] The cone 2 is fixed on the flange at the outlet end of the valve body 1. The sleeve 3 is sleeved outside the cone 2 and is externally connected to the gasket 4. The cone 2 and the sleeve 3 are sealed by an annular rubber ring. The gasket 4 is fixed inside the valve body 1 and serves as a sliding and rotating positioning component for the sleeve 3. The actuator 5 and the gland 6 are fixed on the small flange at the top of the valve body 1. The outside of the split ring 7 is fixed to the gland 6, and the inside positions the transmission shaft 9 to prevent it from moving up and down. The bushing 8 is fixed to the neck of the small flange of the valve body 1 and serves as a guide for the transmission shaft 9. The upper end of the transmission shaft 9 is connected to the actuator 5, and the lower end is jointly driven with the linkage shaft 12 through a connecting sleeve 10 with a square inside and a round outside. The connecting sleeve 10 is used to connect the square opening at the lower end of the transmission shaft 9 and the square opening at the upper end of the linkage shaft 12. The deflector 11 is fixed to the bottom plate of the cone 2 with screws and is used for guiding the flow and protecting the driving device. The square opening at the upper end of the linkage shaft 12 is jointly driven with the connecting sleeve 10 and the transmission shaft 9. The lower end is key-connected to the pinion gear 13 and is arranged on the fixing plate at the horizontal position of the support frame 17 to rotate along the vertical axis. The T-shaped screw 14 is fixed at the center of the cross beam of the sleeve 3 and passes through the spline sleeve 16 and is in screw thread fit with the center of the bull gear 15. The bull gear 15 and the spline sleeve 16 are fixed at the horizontal position of the support frame 17. The support frame 17 is fixed at the edge of the bottom plane of the cone 2 and maintains a vertical position.

[0042] The tension spring 18 is fixed to the cross beam. The central rotating shaft of the fork 19 is arranged on the cross beam of the sleeve 3. One end is connected to the tension spring 18, and the other end is located in the square hole at the center of the cross beam of the sleeve 3 and slides into the groove of the spline sleeve 16 during the conversion from linear motion to rotational motion. Among them, Figure 2 the cross beam in e is a part of the sleeve 3. In addition, the angular stroke closing limit post and the linear stroke limit post are both parts of the cone 2, that is, the sleeve 3 is a movable part and the cone 2 is a fixed part.

[0043] The operation process of this plug valve is as follows:

[0044] When opening the valve, the actuator 5 starts, and the torque is transmitted from the transmission shaft 9, the connecting sleeve 10, the linkage shaft 12, the pinion gear 13, the bull gear 15, and the T-shaped screw 14 to the sleeve 3, and the sleeve 3 first starts to move linearly. The cross beam moves linearly from the linear closing valve position to the linear opening valve position (as shown in Figure 2 e and 2f), at this time, the sleeve 3 is respectively from Figure 2 the III position inFigure 2 The IV position of d moves to Figure 1c the I position of Figure 1d and the II position of Figure 1b . The shift fork 19 is pulled up by the tension spring 18 at the outer end of the Z shape because it disengages from the angular stroke closing limit stake, and the inner end is pulled into the spline sleeve 16, so that the sleeve 3 is fixed and locked with the spline sleeve 16. The sleeve 3 completes the first linear displacement, basically disengaging the sleeve 3 from the contact with the cone 2, preparing for greatly reducing the frictional torque for the subsequent rotational movement. Then, it continues to rotate with low friction to open the valve until it reaches the angular stroke opening limit (position B) shown in Figure 3 section D-D. When the sleeve 3 is fully open, that is, the crossbeam rotates from position A to position B to complete the second rotational displacement, i.e., the fully open action. The whole process is that the crossbeam first moves linearly from the linear valve closing position to the linear valve opening position, and then rotates from position A to position B to complete the valve opening stroke. As

[0045] shown, the water flow of this axial flow plug valve flows into the valve body along an axial arc. The flow channel in the valve body 1 is axisymmetric, and the fluid will not generate turbulence. No matter where the sleeve 3 moves, the water flow section in the valve cavity is annular and contracts at the axis at the outlet, so as to achieve the best anti-cavitation effect and avoid the damage to the valve body and pipeline caused by cavitation that may occur due to throttling. Figure 1c the I position of Figure 1d and the II position of Figure 2 moves to the III position of c and Figure 2 the IV position of d to complete the valve closing action. The whole process is that the crossbeam first rotates from position B to position A, and then moves linearly from the linear valve opening position to the linear valve closing position to complete the valve closing stroke.

[0046] The working conditions of applying this plug valve are as follows:

[0047] As one of the flow or pressure control elements, the axial flow plug valve is mainly used in the pipeline network systems of water conservancy, hydropower, thermal power and municipal water supply pipelines. According to its installation position, it can be divided into the pipe type and the end discharge type. When the pressure difference is high, in order to avoid the harmful noise and vibration generated during the energy dissipation in the valve or in the pipe, on the premise that the on-site conditions permit, the axial flow plug valve should be arranged at the end of the pipeline to eliminate the energy outside the valve body. For the flow or pressure regulation working condition, the axial flow plug valve should be arranged as the pipe type, which can be used to regulate the flow and pressure of the downstream low water level. As Figure 4 shown, when used for flow regulation, the water volume of the upstream high water level reservoir flows to the downstream low water level pool under the action of gravity flow. The flow meter at the back end of the valve is used to send the flow signal to the PLC control system for judgment. When the flow exceeds the limit, the actuator is instructed to close the flow, and when the flow is too small, the actuator is instructed to open the flow, so as to accurately control the flow at the back end. As Figure 5 shown, when used for pressure reduction regulation, the water volume of the upstream high water level reservoir flows to the user under the action of gravity flow. The pressure sensor at the back end of the valve is used to send the pressure signal to the PLC control system for judgment. When the pressure exceeds the limit, the actuator is instructed to open the sleeve 3, and when the pressure difference is too small, the actuator is instructed to close the sleeve 3, so as to accurately control the pressure at the back end.

Claims

1. An axial flow plug valve, characterized in that, It includes a valve body (1), a cone (2) arranged inside the valve body (1), a sleeve (3) sleeved outside the cone (2), a driving and transmission mechanism for driving the sleeve (3) to open and close the valve through linear and rotational motions, and a limiting mechanism. The cone (2) is evenly and symmetrically provided with a plurality of water outlets in the circumferential direction; A gasket (4) for realizing the sliding and rotational positioning of the sleeve (3) is arranged between the sleeve (3) and the inner wall of the valve body (1); The driving and transmission mechanism includes an actuator (5) fixed on the top small flange of the valve body (1), a transmission shaft (9), a linkage shaft (12), a small bevel gear (13), a large bevel gear (15) meshing with the small bevel gear (13), a T-shaped screw rod (14), and a spline sleeve (16). The upper end of the transmission shaft (9) is in transmission connection with the actuator (5), and the lower end is in transmission connection with the small bevel gear (13) through the linkage shaft (12). The inner end of the T-shaped screw rod (14) passes through the center of the cross beam of the sleeve (3) and is fixedly connected. The large bevel gear (15) is in transmission connection with the T-shaped screw rod (14) through screw threads to drive the sleeve (3) to perform a linear motion. The spline sleeve (16) and the large bevel gear (15) form a whole and realize the rotational transmission connection with the cross beam through the limiting mechanism; The limiting mechanism includes a Z-shaped fork (19) rotatably arranged on the cross beam of the sleeve (3) through a central rotating shaft, a tension spring (18) connecting the outer end of the fork (19) and the cross beam and used to provide tension, and a limiting unit fixed at the bottom of the cone (2). The inner end of the fork (19) realizes the rotational transmission connection between the cross beam and the large bevel gear (15) by extending into the spline sleeve (16); The limiting unit includes an angular stroke close limiting pile, a linear stroke limiting pile, and an angular stroke open limiting pile which are respectively fixed at the bottom of the cone (2) and arranged in sequence in the circumferential direction. The length of the linear stroke limiting pile is lower than that of the angular stroke close limiting pile. The position where the angular stroke close limiting pile is located is the rotational closing valve position, and the angular stroke open limiting pile is the rotational opening valve position. When the cross beam performs a linear motion, it is limited between the angular stroke close limiting pile and the linear stroke limiting pile.

2. The axial flow cock valve according to claim 1, characterized in that, The cone (2) is a frustum-shaped cylinder with a closed bottom, which is fixedly connected to the flange at the outlet end of the valve body (1). The shape of the sleeve (3) matches that of the cone (2), and a ring-shaped rubber seal is provided between the sleeve (3) and the cone (2).

3. The axial flow cock valve according to claim 1, characterized in that, A gland (6) with a half-ring (7) fixed on the outside is also arranged on the top small flange of the valve body (1) to position the transmission shaft (9) to prevent it from moving up and down, and a bushing (8) for guiding the transmission shaft (9) is arranged at the neck of the small flange.

4. An axial flow plug valve according to claim 1, characterized in that, The lower end of the transmission shaft (9) is in transmission connection with the upper end of the linkage shaft (12) through an inner-square and outer-round connecting sleeve (10).

5. An axial flow plug valve according to claim 1, characterized in that, Inside the described valve body (1), there is also a hemispherical flow deflector (11) fixed at the bottom of the cone (2) and a support frame (17). The linkage shaft (12) is arranged on the horizontal fixed plate of the support frame (17). The spline sleeve (16) and the large bevel gear (15) are connected to the support frame (17) through bearings. The cross beam of the sleeve (3) is located in the space between the bottom of the cone (2) and the support frame (17).

6. An axial flow plug valve according to claim 1, characterized in that, The operation process of this axial flow plug valve is specifically as follows: (1) When the valve is opened, the actuator (5) starts to rotate forward. Sequentially, through the transmission shaft (9), the linkage shaft (12), and the small bevel gear (13), it drives the large bevel gear (15) to rotate. At this time, the inner end of the fork (19) does not extend into the spline sleeve (16). The transmission between the large bevel gear (15) and the T-shaped screw (14) causes the T-shaped screw (14) to drive the cross beam of the sleeve (3) to perform a linear motion. The inner surface of the sleeve (3) and the outer surface of the cone (2) gradually separate to form a gap, so as to reduce the valve opening torque. When the cross beam moves linearly from the linear valve closing position to the linear valve opening position, the cross beam disengages from the linear stroke limit post. At this time, under the action of the tension of the tension spring (18), the inner end of the fork (19) extends into the spline sleeve (16), making the cross beam and the large bevel gear (15) form a transmission unit to perform a rotational motion until the cross beam rotates to the rotational valve opening position, and this axial flow plug valve is in the fully open state; (2) When the valve is closed, the actuator (5) starts to rotate reversely. Sequentially, through the transmission shaft (9), the linkage shaft (12), and the small bevel gear (13), it drives the large bevel gear (15) to rotate. At this time, the inner end of the fork (19) is located inside the spline sleeve (16). The transmission unit formed by the cross beam and the large bevel gear (15) performs a rotational motion until the cross beam rotates to the rotational valve closing position. The outer end of the fork (19) contacts the angular stroke closing limit post, causing the inner end to disengage from the spline sleeve (16). After the transmission between the cross beam and the large bevel gear (15) is separated, the large bevel gear (15) continues to rotate, driving the T-shaped screw (14) and the cross beam to linearly move from the linear valve opening position to the linear valve closing position. After the inner surface of the sleeve (3) and the outer surface of the cone (2) are gradually and completely fitted, this axial flow plug valve is in the fully closed state.

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