A valve slider gear crank actuator

Abstract

This utility model discloses a valve slider-type gear crank actuator. The actuator body includes a rotating shaft arm and a screw. A swinging part extends from the rotating shaft arm, and the swinging part is hinged to a connecting rod. The other end of the connecting rod is hinged to a threaded slider sleeve fitted on the screw. This slider-type gear crank mechanism is applied to a butterfly valve, ensuring that during the closing process, when the handwheel rotates the screw at a constant speed, the torque output speed characteristics perfectly match the butterfly valve's opening and closing process, which requires a fast initial closing followed by a slow closing. This mechanism provides high torque, prevents rapid valve plate closure, reduces pressure fluctuations, minimizes water hammer, protects the system, extends valve life, and is energy-efficient and economical.

Description

Technical Field

[0001] This utility model relates to the technical field of valve actuators, specifically to a valve slider-type gear crank actuator. Background Technology

[0002] In conventional worm gear actuators, because the outer edge of the worm wheel is always tangent to the worm, the input torque at the worm end is constant, resulting in a constant torque transmitted from the worm to the worm wheel, and consequently, a uniform and constant rotational speed of the worm wheel. Therefore, conventional worm gear actuators, when used in rotary valves, such as butterfly valves, have the following drawbacks: (1) The constant torque output characteristic of the worm gear and the valve opening and closing torque characteristic curve are not synchronized: When a valve is opened, the torque required is not constant from 0 degrees to 90 degrees; it gradually decreases as the opening degree increases. The torque is at its maximum when the valve is opened to 0 degrees, gradually decreases during the opening process, and reaches its minimum when the valve is fully open. Conversely, during the closing process, the torque gradually increases as the opening degree decreases. This results in the traditional worm gear actuator and some rotary valves not being able to synchronize the output torque of the actuator with the torque characteristic curve required by the valve, leading to unstable switching process and uneconomical actuator selection. (2) The constant output speed of the worm gear is prone to water hammer, pressure fluctuations and turbulence during valve closing, and the speed characteristics do not match the flow characteristics: During the closing process of a butterfly valve, the rotation speed of the worm gear is constant. However, during the closing process, the pressure fluctuation inside the valve is small and there is no obvious turbulence when the valve is in the 90°-20° stroke. When closing to the last 20°-0°, the valve pressure difference will suddenly increase, the pressure fluctuation will be large, there will be obvious turbulence, water hammer will occur, and the valve life will be reduced. Utility Model Content

[0003] In view of the prior art, the technical solution adopted by this utility model is as follows: a valve slider gear crank actuator, including an actuator body fixedly installed with the valve, the actuator body including a rotating shaft arm and a screw, a handwheel connected to the screw, a swinging part extending and fixed on the rotating shaft arm, a hinge hole provided on the swinging part, a screw sleeve slider also sleeved on the screw, a connecting rod hinged on the screw sleeve slider, and the other end of the connecting rod hinged to the swinging part by a pin.

[0004] As a further feature of the above solution, a positioning ring is also fitted on the threaded portion of the screw for the screw sleeve slider, and a limiting screw for radially locking the screw passes through the positioning ring.

[0005] As a further feature of the above scheme, a box cover is also fixed to the actuator body by bolts, and a limiting hole cover is provided on the actuator body relative to the positioning ring.

[0006] As a further feature of the above solution, a pointer cover is provided on the box cover directly opposite the axis of the rotating arm. The pointer cover has a scale and is made of transparent material. A pointer mark is also provided on the rotating arm.

[0007] As a further feature of the above solution, the actuator body is provided with a front end cover and a rear end cover.

[0008] As a further provision of the above scheme, a bearing is also provided between the screw and the actuator body, and the screw rotates circumferentially within the actuator body by means of two bearings.

[0009] Beneficial effects: When the slider-type gear crank mechanism of this utility model is applied to a butterfly valve, it ensures that during the closing process, while the handwheel rotates the screw at a constant speed, the rotation speed of the connecting rod is not constant; that is, the rotation speed of the connecting rod gradually decreases. In other words, the butterfly valve requires more time to close in the latter half than in the first half. When the butterfly valve closes to the final 20°-0°, the closing speed of the butterfly plate is the slowest, requiring more time. Coincidentally, during this stage, the valve pressure differential suddenly increases, resulting in large pressure fluctuations, necessitating a slow closing to eliminate water hammer.

[0010] The torque output speed characteristics perfectly match the butterfly valve's opening and closing process, which requires a rapid initial closing followed by a slow final closing. When closing to 0°, the butterfly plate closes more slowly, achieving the effect of rapid initial closing followed by a slow, gradual closure. This effectively eliminates pressure fluctuations, turbulence, and protects the valve. This mechanism provides high torque and prevents rapid valve closure, reducing pressure fluctuations, minimizing water hammer, protecting the system, extending valve life, and offering energy savings. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the actuator structure in this embodiment.

[0012] Figure 2 This is a schematic diagram of the side structure of the actuator in this embodiment.

[0013] Figure 3 This is a schematic diagram of the internal transverse cross-sectional structure of the actuator in this embodiment.

[0014] Figure 4 This is a schematic diagram of the internal longitudinal cross-sectional structure of the actuator in this embodiment.

[0015] Figure 5 This is a schematic diagram of the slider-type gear crank actuator in this embodiment.

[0016] Figure 6 This is a schematic diagram showing the torque comparison curves of a conventional worm gear mechanism in the opening and closing of a butterfly valve.

[0017] Reference numerals in the attached diagram: 1. Actuator body; 2. Rotary shaft arm; 3. Connecting rod; 4. Pin; 5. Screw; 6. Screw sleeve slider; 7. Positioning ring; 8. Bearing; 9. Rear end cover; 10. Locking bolt; 11. Limiting screw; 12. Limiting hole cover; 13. Front end cover; 14. Handwheel; 15. Box cover; 16. Bolt; 17. Pointer cover. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments and features described in these embodiments can be combined with each other.

[0019] like Figure 1-6 The present invention discloses a valve slider-type gear crank actuator, comprising an actuator body 1 fixedly mounted to a valve. The actuator body 1 includes a rotating shaft arm 2 and a screw 5. A handwheel 14 is connected to the screw 5. A swinging part 21 extends and is fixedly mounted on the rotating shaft arm 2. A hinge hole 22 is provided on the swinging part 21. A threaded sleeve slider 6 is also fitted onto the screw 5. A connecting rod 3 is hinged to the threaded sleeve slider 6. The other end of the connecting rod 3 is hinged to the swinging part 21 via a pin 4. Figure 3 As shown, in this embodiment, the rotating arm 2 has a certain central offset relative to the screw 5. This change causes the driving force of the screw sleeve slider 6 on the swing part 21 and the rotating arm 2 to change the rotation of the rotating arm 2 at different times. As described above, when the actuator of this embodiment is in use, it drives the handwheel 14 exposed on the outside of the actuator body 1 to rotate. The rotating handwheel 14 drives the screw 5, which is circumferentially fixed and linked inside the actuator body 1, to rotate. The screw 5 is axially limited by the bearings 8 on both sides and does not rotate. The bearing 8 generates axial displacement and smoothly rotates circumferentially. The threaded part on the bearing 8 rotates, and the threaded sleeve slider 6, which is threadedly engaged with it, moves along the front and back axial direction of the screw 5 as the screw 5 rotates in both directions. At the same time, during the axial movement of the threaded sleeve slider 6, the connecting rod 3, which is hinged to the threaded sleeve slider 6, drives the swing part 21, which is also hinged to the other end, to swing. This causes the rotating shaft arm 2 to rotate, thereby realizing the movement of the valve plate driven by the valve stem, which is circumferentially fixedly connected to the rotating shaft arm 2, and realizing the opening and closing degree control of the valve.

[0020] Based on the pressure difference changes during valve opening and closing within the pipeline and the torque fluctuations required to satisfy these changes, such as Figure 5 and Figure 6As shown, the slider-type gear crank actuator of this embodiment, when applied to a butterfly valve, is more in line with the torque characteristics required for the opening and closing of the butterfly valve plate compared to the conventional worm gear structure of the prior art. The speed characteristics of the torque output process are perfectly matched with the characteristics of the butterfly valve's opening and closing process, which requires fast closing in the first stage and slow closing in the second stage. This better adapts to the usage requirements of the butterfly valve and makes the opening and closing of the butterfly valve's medium channel smoother and more stable.

[0021] As a further feature of the above scheme, a positioning ring 7 is also fitted on the threaded portion of the screw 5 for the screw sleeve slider 6. A limiting screw 11 for radially locking the screw 5 is provided through the positioning ring 7. This design allows the opening and closing angle of the valve plate to be adjusted by 90±5° by making the relative position of the positioning ring 7 and its locking position relative to the screw 5 adjustable, thereby achieving continuous maintenance of valve sealing. In the event of valve not closing tightly after long-term use, better sealing can be achieved by adjusting the valve closing angle.

[0022] As a further feature of the above scheme, a box cover 15 is also fixed to the actuator body 1 by bolts 16, and a limiting hole cover 12 is provided on the actuator body 1 relative to the positioning ring 7.

[0023] As a further feature of the above solution, a pointer cover 17 is provided on the box cover 15, which is directly opposite the axis of the rotating arm 2. The pointer cover 17 is provided with a scale and is made of transparent material. The rotating arm 2 is also provided with a pointer mark.

[0024] As a further feature of the above scheme, the actuator body 1 is provided with a front end cover 13 and a rear end cover 9 fixed by a locking bolt 10.

[0025] As a further provision of the above scheme, a bearing 8 is provided between the screw 5 and the actuator body 1, and the screw 5 rotates circumferentially within the actuator body 1 by providing two bearings 8.

[0026] As described above, the actuator structure of this utility model utilizes a slider-type gear-crank mechanism, resulting in a curved output torque characteristic. Compared to the linear characteristic of a worm gear, this curve better reflects the characteristic of a valve gradually decreasing torque as the opening angle increases. In this embodiment, the characteristic curve of the actuator and the torque characteristic curve required by the valve decrease almost synchronously during the valve opening process. The slider-type gear mechanism fundamentally solves the two major drawbacks of traditional worm gear mechanisms applied to butterfly valves, offering the following advantages: (1) During the opening and closing process, the output torque of the slider gear mechanism and the torque required for valve opening and closing are synchronously changed with the angle and basically matched. The opening and closing process is smoother and more stable. It is more economical and reasonable to choose the slider gear mechanism.

[0027] (2) During the closing process of the butterfly valve, the connecting rod of the slider-type gear crank mechanism rotates at a constant speed when the handwheel rotates the screw. The rotation speed of the connecting rod is not constant, that is, the rotation speed of the connecting rod gradually decreases. In other words, the second half of the butterfly valve closing process takes more time than the first half. When the butterfly valve is closed to the last 20°-0°, the butterfly plate closes the slowest and the required time increases. It is precisely at this stage that the valve pressure difference will suddenly increase and the pressure fluctuation will be large, so it is necessary to close slowly to eliminate water hammer.

[0028] The torque output speed characteristics of the slider gear mechanism perfectly match the characteristics of the butterfly valve's opening and closing process, which requires a fast closing in the first stage and a slow closing in the second stage.

[0029] When the slider-type gear mechanism closes to 20°-0°, the butterfly plate closes more slowly, achieving a rapid closing in the initial stage and a slow closing in the final stage. This effectively eliminates pressure fluctuations, eliminates turbulence, and protects the valve. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of this invention and its equivalents, this invention also intends to include these modifications and variations.

Claims

1. A valve slider gear crank actuator comprising an actuator body (1) fixedly mounted with a valve, characterized in that: The actuator body (1) includes a rotating shaft arm (2) and a screw (5). A handwheel (14) is connected to the screw (5). A swing part (21) extends and is fixed on the rotating shaft arm (2). A hinge hole (22) is provided on the swing part (21). A screw sleeve slider (6) is also sleeved on the screw (5). A connecting rod (3) is hinged on the screw sleeve slider (6). The other end of the connecting rod (3) is hinged to the swing part (21) through a pin (4).

2. A valve slider gear crank actuator according to claim 1, characterized in that: The threaded portion of the screw (5) for the screw sleeve slider (6) is also fitted with a positioning ring (7), and a limiting screw (11) for the radial locking screw (5) is provided through the positioning ring (7).

3. A valve slider gear crank mechanism according to claim 1, wherein: The actuator body (1) is also fixed with a box cover (15) by bolts (16), and the actuator body (1) is provided with a limiting hole cover (12) relative to the positioning ring (7).

4. A valve slider gear crank mechanism according to claim 3, wherein: The cover (15) is provided with a pointer cover (17) facing the axis of the rotating arm (2). The pointer cover (17) is provided with a scale and is made of transparent material. The rotating arm (2) is also provided with a pointer mark.

5. A valve slider gear crank mechanism according to claim 1, wherein: The actuator body (1) is provided with a front end cover (13) and a rear end cover (9).

6. A valve slider gear crank mechanism according to claim 1, wherein: A bearing (8) is provided between the screw (5) and the actuator body (1), and the screw (5) rotates circumferentially within the actuator body (1) by setting two bearings (8).

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