阅读说明：本技术 一种接力器及压力波动调节阀 (Servomotor and pressure fluctuation adjusting valve ) 是由 唐学林 张凌 吴国鸿 朱江会 李小芹 彭致功 于 2021-08-02 设计创作，主要内容包括：本发明涉及一种接力器以及压力波动调节阀,包括：缸体、上盖、下盖以及安装在所述缸体内的若干个固定叶片和活动叶片,所述缸体、上盖和下盖之间形成圆柱筒状的密封腔体；旋转轴,所述旋转轴位于所述缸体的中心位置处,所述旋转轴的顶端与所述上盖密封转动连接,底端与所述下盖之间密封转动连接；若干个所述固定叶片将所述密封腔体分隔为相同数量的密封工作腔；若干个所述活动叶片并将对应的所述密封工作腔分隔为密封高压腔和密封低压腔,每个所述密封高压腔和密封低压腔的底部均开设有进水孔。所述压力波动调节阀通过所述接力器的设置能够调节阀门打开和关闭的速度,进而有效消减管路的水压振荡和冲击。(The invention relates to a servomotor and a pressure fluctuation regulating valve, comprising: the device comprises a cylinder body, an upper cover, a lower cover, and a plurality of fixed blades and movable blades which are arranged in the cylinder body, wherein a cylindrical sealed cavity is formed among the cylinder body, the upper cover and the lower cover; the rotating shaft is positioned at the center of the cylinder body, the top end of the rotating shaft is in sealed and rotating connection with the upper cover, and the bottom end of the rotating shaft is in sealed and rotating connection with the lower cover; the fixed blades divide the sealed cavity into a same number of sealed working cavities; the movable blades divide the corresponding sealed working cavity into a sealed high-pressure cavity and a sealed low-pressure cavity, and water inlet holes are formed in the bottoms of the sealed high-pressure cavity and the sealed low-pressure cavity. The pressure fluctuation adjusting valve can adjust the opening and closing speed of the valve through the arrangement of the servomotor, and further effectively reduces water pressure oscillation and impact of a pipeline.)

1. A servomotor, comprising:

the cylinder body, the upper cover and the lower cover form a cylindrical sealed cavity;

the rotating shaft is positioned at the center of the cylinder body, the top end of the rotating shaft is in sealed and rotating connection with the upper cover, the bottom end of the rotating shaft penetrates out of the bottom of the lower cover to form an extending part, and the bottom of the rotating shaft is in sealed and rotating connection with the lower cover;

the fixed blades are uniformly distributed along the circumferential direction of the cylinder body, one end of each fixed blade is fixedly installed on the inner wall of the cylinder body, the other end of each fixed blade extends to the center of the cylinder body along the radial direction, and the fixed blades divide the sealed cavity into the sealed working cavities with the same number;

a plurality of movable vane, a plurality of movable vane is along circumference evenly distributed, a plurality of movable vane and a plurality of sealed working chamber one-to-one, every movable vane's one end is all fixed on the rotation axis, the other end is to corresponding along radial direction sealed working intracavity extends, and will correspond sealed working chamber separates for sealed high-pressure chamber and sealed low-pressure chamber, every the inlet opening has all been seted up to the bottom in sealed high-pressure chamber and sealed low-pressure chamber.

2. The servomotor according to claim 1, wherein at least one of the fixed blades has a damping hole formed therein.

3. The servomotor according to claim 1, wherein one end of the fixed blade close to the inner wall of the cylinder body protrudes to both sides to form a protrusion.

4. The servomotor according to claim 1, wherein a driving gear is fixedly mounted to a bottom of the extension shaft.

5. The servomotor according to claim 1, wherein one end of each of the movable blades is sealingly fixed to the rotary shaft, and the other end of each of the movable blades extends in a radial direction into the corresponding sealed working chamber and is in sealed rotational contact with the inner wall of the cylinder body, and the top and bottom of each of the movable blades are in sealed rotational contact with the upper cover and the lower cover, respectively.

6. The servomotor according to claim 4, wherein the top, bottom and end of each movable blade are provided with a sealing groove along the length direction, and a sealing member is pressed in the sealing groove and is in sealing contact with the inner wall of the cylinder body, the upper cover and the lower cover.

7. The servomotor of claim 6, wherein the seal comprises a seal ring and a plastic seal bead pressed over the seal ring.

8. A pressure fluctuation adjusting valve is characterized by comprising a valve and the servomotor of any one of claims 1 to 7 mounted on the valve, wherein the valve comprises a valve body, a valve core and a valve rod, the valve core and the valve rod are mounted in the valve body, the valve rod rotates to drive the valve core to rotate so as to close or open the valve, and the extension shaft is connected with the valve rod through a gear transmission device;

each sealed high-pressure cavity on the servomotor is communicated with the water inlet end of the main pipeline of the valve through a first bypass pipe, each sealed low-pressure cavity on the servomotor is communicated with the water outlet end of the main pipeline of the valve through a second bypass pipe, and each first bypass pipe and each second bypass pipe are provided with regulating valves.

9. The pressure fluctuation regulating valve according to claim 8, wherein a water filter is installed at a connection portion between each of the first and second bypass pipes and the main line.

10. The pressure fluctuation regulating valve of claim 8, wherein the gear assembly is submerged in a tank.

Technical Field

The invention relates to the field of water supply pipeline equipment, in particular to a servomotor and a pressure fluctuation regulating valve.

Background

In the water supply pipeline, when the pump is stopped due to the opening and closing of the water pump or the power failure, pressure fluctuation can be generated in the pipeline system, the pressure fluctuation is overlarge, the safe and stable operation of the pipeline system can be seriously influenced, and even the elements of the water supply system are damaged. At present, a check valve is mostly adopted in a pipeline to prevent a water hammer of a pump from stopping, due to the one-way conductivity of the check valve, originally, water flowing at a high speed is suddenly cut off, the pressure at the outlet of the check valve is rapidly reduced to be negative pressure, negative pressure wave impact is formed on the check valve and the pipeline until the inertia of water flow is counteracted, the water flow flows backwards to form high pressure wave impact on the check valve and the pipeline, the instantaneous pressure can reach more than twice of the normal working pressure, and the alternate impact of the negative pressure wave and the high pressure wave is extremely large in damage to the check valve and the pipeline. Therefore, it is necessary to use a ball valve or butterfly valve to prevent a water hammer from stopping the pump.

In addition, the control modes of the butterfly valve and the ball valve can be divided into manual, electric, pneumatic, hydraulic and other modes. The manual operation mode has high labor intensity and low efficiency for opening and closing the valves with medium and large specifications. The operation structure of electric, pneumatic, hydraulic control and other control modes is relatively complex, and the cost is high.

How to combine the pressure energy of the pipeline itself with a ball valve or a butterfly valve to form a pressure fluctuation regulating valve which has a small and exquisite and simple structure and is convenient to install and use to eliminate the water hammer impact is a technical problem to be solved urgently in the field.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a relay and a pressure fluctuation control valve for reducing pressure fluctuation caused by starting or stopping a pump in a piping system, thereby protecting the entire water supply system.

In order to achieve the purpose, the invention adopts the following technical scheme:

a servomotor, comprising:

the cylinder body, the upper cover and the lower cover form a cylindrical sealed cavity;

the rotating shaft is positioned at the center of the cylinder body, the top end of the rotating shaft is in sealed and rotating connection with the upper cover, the bottom end of the rotating shaft penetrates out of the bottom of the lower cover to form an extending part, and the bottom of the rotating shaft is in sealed and rotating connection with the lower cover;

the fixed blades are uniformly distributed along the circumferential direction of the cylinder body, one end of each fixed blade is fixedly installed on the inner wall of the cylinder body, the other end of each fixed blade extends to the center of the cylinder body along the radial direction, and the fixed blades divide the sealed cavity into the sealed working cavities with the same number;

a plurality of movable vane, a plurality of movable vane is along circumference evenly distributed, a plurality of movable vane and a plurality of workspace one-to-one, every movable vane's one end is all fixed on the rotation axis, the other end is to corresponding along radial direction sealed work intracavity extends, and will correspond sealed work chamber separates for sealed high-pressure chamber and sealed low-pressure chamber, every the inlet opening has all been seted up to the bottom in sealed high-pressure chamber and sealed low-pressure chamber.

Furthermore, at least one fixed blade is provided with a damping hole.

Furthermore, one end of the fixed blade close to the inner wall of the cylinder body protrudes to two sides to form a bulge.

Furthermore, a driving gear is fixedly mounted at the bottom of the extension shaft.

Furthermore, one end of each movable blade is fixed on the rotating shaft in a sealing mode, the other end of each movable blade extends into the corresponding sealing working cavity along the radial direction and is in sealing rotary contact with the inner wall of the cylinder body, and the top and the bottom of each movable blade are in sealing rotary contact with the upper cover and the lower cover respectively.

Furthermore, the top, the bottom and the end part of each movable blade are provided with sealing grooves along the length direction, sealing elements are pressed in the sealing grooves, and the sealing elements are in sealing contact with the inner wall of the cylinder body, the upper cover and the lower cover.

Further, the sealing element comprises a sealing ring and a plastic sealing strip pressed on the sealing ring.

A pressure fluctuation adjusting valve comprises a valve and a servomotor arranged on the valve, wherein the valve comprises a valve body, a valve core and a valve rod, the valve core and the valve rod are arranged in the valve body, the valve rod rotates to drive the valve core to rotate, so that the valve is closed or opened, and an extension shaft is connected with the valve rod through a gear transmission device;

each sealed high-pressure cavity on the servomotor is communicated with the water inlet end of the main pipeline of the valve through a first bypass pipe, each sealed low-pressure cavity on the servomotor is communicated with the water outlet end of the main pipeline of the valve through a second bypass pipe, and each first bypass pipe and each second bypass pipe are provided with regulating valves.

Furthermore, a water filter is arranged at the connecting part between each first bypass pipe and each second bypass pipe and the main pipeline.

Further, the gear assembly is submerged in the oil tank.

Due to the adoption of the technical scheme, the invention has the following advantages:

(1) the number of the fixed blades of the servomotor is set to be Z, the number of the movable blades of the servomotor is also Z, the sealing cavity is divided into 2Z working cavities by the Z fixed blades and the Z movable blades, a water injection hole is formed in the bottom of each working cavity and is connected with a corresponding bypass pipe, so that liquid in the cavities is ensured to be injected and discharged, each bypass pipe is suitable for different pipeline pressures, each bypass pipe is provided with an adjusting valve, the pressure of the liquid, which is connected into the servomotor cylinder, is controlled by the opening degree of the adjusting valve, the opening and closing speed of the valve is controlled, and the water hammer pressure impact in a pipeline system is further controlled, so that the reduction of the water hammer pressure impact of the pipeline system is realized by the pressure energy of the pipeline and the valve;

(2) because each high-pressure cavity and each low-pressure cavity are communicated with the main pipe of the valve through a bypass pipe, each bypass pipe is provided with an adjusting valve, the number of the actually utilized working cavities can be controlled through the switch of the adjusting valve, and the torque of the servomotor rotor can be further controlled, the servomotor can keep the water pressure in the servomotor cavity stable by closing the adjusting valve of the bypass pipe to realize the locking of the valve at any position within the range of 0-90 degrees, thereby controlling the opening and closing speed of the valve and further controlling the water hammer pressure impact in a pipeline system;

(3) the damping holes are formed in the fixed blade, so that the valve can be opened slowly and then opened quickly and closed quickly and then closed slowly, the peak value of water hammer pressure is reduced, and pressure oscillation after the valve is completely closed is obviously reduced.

Drawings

FIG. 1 is a schematic diagram of a pressure fluctuation regulating valve according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the operation of the pressure fluctuation control valve;

FIG. 3 is a schematic structural diagram of the servomotor;

FIG. 4 is a schematic view of the internal structure of the servomotor with the upper cover removed;

description of reference numerals:

1-valve, 2-servomotor, 3-oil tank, 4-second by-pass pipe, 5-first by-pass pipe, 6-regulating valve, 7-filter, 8-driving gear, 9-driven gear, 11-valve body, 12-valve core, 13-valve rod, 21-cylinder body, 22-upper cover, 23-lower cover, 24-movable blade, 25-fixed blade, 26-rotating shaft, 27-damping hole, 251-bulge, 28-sealed high pressure cavity and 29-sealed low pressure cavity.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the system or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used to define elements only for convenience in distinguishing between the elements, and unless otherwise stated have no special meaning and are not to be construed as indicating or implying any relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1, a pressure fluctuation regulating valve provided for an embodiment of the present invention includes a valve 1 and a servomotor 2 mounted on the valve 1. The servomotor 2 is used for opening or closing the valve 1 and adjusting the flow of water flow, so that the pressure impact of water hammer on a pipeline is reduced. Further, when the valve is opened, the servomotor 2 can realize that the valve 1 is opened slowly and then quickly; when the valve is closed, the valve 1 can be closed quickly and then closed slowly, and water hammer pressure impact generated when the pump is started or stopped is further reduced, so that damage to a pipeline system is reduced.

As shown in fig. 2, the valve 1 may be an existing ball valve or a butterfly valve. The valve comprises a valve body 11, and a valve core 12 and a valve rod 13 which are arranged in the valve body 11. The bottom of the valve rod 13 is connected with the valve core 12, the valve core 12 is driven to rotate by rotating the valve rod 13, and the valve core 12 rotates to enable the two ends of the main pipe to be communicated or disconnected, so that the valve 1 is opened and closed. The left end of the main pipe is a water inlet end, and the right end of the main pipe is a water outlet end. The servomotor 2 is in transmission connection with the valve rod 13 through a gear, and the opening and closing speed of the valve core 12 is controlled through the servomotor 2.

Referring to fig. 3 and 4, the servomotor 2 includes a cylinder 21, an upper cover 22, a lower cover 23, and a plurality of fixed blades 25, a plurality of movable blades 24, and a rotating shaft 26 installed in the cylinder 21. The cylinder body 21 is a cylindrical cylinder body, the top end and the bottom end of the cylinder body 21 are respectively connected with the upper cover 22 and the lower cover 23 in a sealing mode, and a cylindrical sealing cavity is formed among the cylinder body 21, the upper cover 22 and the lower cover 23.

Preferably, high-hardness oil-resistant rubber sealing rings are adopted for sealing connection between the cylinder body 21 and the upper cover 22 and the lower cover 23, specifically, annular grooves may be formed in the top and the bottom of the cylinder body 21 along the circumferential direction, the high-hardness oil-resistant rubber sealing rings are pressed in the annular grooves, and then the cylinder body 21 and the upper cover 22 and the lower cover are fixedly connected into a whole through bolts.

As another embodiment, the cylinder body, the upper cover and the lower cover may be integrally formed.

The rotating shaft 26 is located at the center of the cylinder body 21, the top end of the rotating shaft 26 is connected with the upper cover 22 in a sealing and rotating manner, the bottom end of the rotating shaft passes through the bottom of the lower cover 23 to form an extending part, and the bottom of the rotating shaft 26 is connected with the lower cover 23 in a sealing and rotating manner. The rotating shaft 26 and the upper cover 22 and the lower cover 23 can also be in sealed and rotatable connection by adopting high-hardness oil-resistant rubber sealing rings. Specifically, the upper cover 22 and the lower cover 23 may be respectively provided with a through hole rotatably matched with the rotating shaft 26, an annular groove is formed in the inner wall of each through hole, an annular high-hardness oil-resistant rubber sealing ring is pressed in the annular groove, and the sealing ring is connected with the rotating shaft 26 in a sealing and rotating manner.

A plurality of fixed blade 25 along the circumference direction evenly distributed of cylinder body 21, every the equal fixed mounting in one end of blade is in on the inner wall of cylinder body 21, the other end along radial direction to the center of cylinder body 21 extends, and with sealed rotation contact between the rotation axis 26, fixed blade 25's top and bottom respectively with sealed fixed connection between upper cover 22 and the lower cover 23, a plurality of fixed blade 25 will sealed cavity separates for the sealed working chamber of the same quantity.

The fixed blade 25 may be connected to the cylinder 21, the upper cover 22, and the lower cover 23 by screws, or may be connected to the cylinder 21, the upper cover 22, and the lower cover 23 by welding. When a screw is used for connection, the screw is sealed by a lead gasket or a red copper gasket. For a large valve, the servomotor blade bears large pressure, the fixed blade 25 can be directly welded on the cylinder body 21, and the fixed blade 25 and the cylinder cover are still fixed by screws.

As other embodiments, the fixed blade 25, the cylinder 21, the upper cover 22, and the lower cover 23 may be integrally formed. When the fixed blade 25 needs to be replaced or disassembled for some occasions, the bolt connection mode is preferably adopted.

The fixed blades 25 and the rotating shaft 26 can be pressed by adopting high-hardness oil-resistant rubber to form a rotating contact seal.

A plurality of movable vane 24 is along rotation axis 26's circumference evenly distributed, a plurality of movable vane 24 and a plurality of sealed working chamber one-to-one, every movable vane 24's one end is all fixed on rotation axis 26, the other end along radial direction to corresponding sealed working intracavity extends, and with sealed contact, every between the inner wall of cylinder body 21 movable vane 24's top and bottom respectively with sealed rotating contact, every between upper cover 22 and the lower cover 23 movable vane 24 will correspond sealed working chamber separates for sealed high-pressure chamber 28 and sealed low-pressure chamber 29. The bottom of each of the high-pressure sealed cavity 28 and the low-pressure sealed cavity 29 is provided with a water inlet (not shown in the figure) and is communicated with the main pipe of the valve 1 through the water inlet. Each sealed high-pressure cavity 28 is communicated with the water inlet end of the main pipe through a first bypass pipe 5, each sealed low-pressure cavity 29 is communicated with the water outlet end of the main pipe through a second bypass pipe 4, and each first bypass pipe 5 and each second bypass pipe 4 are provided with a regulating valve 6.

The top, the bottom and the end of each movable blade 24 are provided with a sealing groove along the length direction, and a sealing element is pressed in the sealing groove and is in sealing contact with the inner wall of the cylinder body 21, the upper cover 22 and the lower cover 23 through the sealing element. The sealing element comprises a sealing ring and a plastic sealing strip pressed on the sealing ring. The sealing ring is preferably an O-shaped sealing ring, and the O-shaped sealing ring can be made of polyurethane elastomer.

When the water pump is started, water at the water inlet end of the main pipe enters the sealed high-pressure cavity 28 through the first bypass pipe 5, the movable blade is pushed to rotate towards a first direction, so that the rotating shaft 26 is driven to rotate, the rotating shaft 26 rotates and drives the valve rod 13 and the valve core 12 to rotate through the transmission of a gear transmission device between the rotating shaft 26 and the valve rod 13, and the valve 1 is opened;

when the water pump is turned off, the water in the sealed high-pressure cavity 28 is discharged through the first bypass pipe 5, meanwhile, the pressure at the water outlet end of the main pipe rises, the regulating valves on all the second bypass pipes 4 connected with the sealed low-pressure cavity 29 are opened, and the water flow enters the sealed low-pressure cavity 29 of the servomotor through the outlet second bypass pipes 4 to push the movable blades to enable the rotating shaft 26 to rotate reversely, so that the valve 1 is turned off.

Therefore, the invention can control the closing of the pressure fluctuation adjusting valve and adjust the water flow by the design of the servomotor 2, thereby reducing the pressure fluctuation generated by starting or stopping the pump in the pipeline system and protecting the whole water supply system.

The design of the parameters of the servomotor in the invention comprises the following steps:

1. since the above-mentioned fixed blades 25 have substantially the same structural dimensions as the movable blades 24, the structural dimensions of the blades are designed:

because the main parameters of the servomotor 2 depend on the working torque of the valve 1, firstly, the operating torque of the servomotor 2 is determined according to the working torque of the valve 1, the operating torque of the servomotor 2 is equal to the working torque of the valve 1, and a balance equation (1) is established:

wherein M is₀-an operating torque of the servomotor 2, said operating torque of the servomotor 2 being equal to the working torque of the valve; different opening degrees of the alpha-valve;

p (alpha) -pressure values corresponding to different opening degrees of the valve; r-servomotor radius, i.e., the distance from the center of the rotating shaft 26 to the edge of the cylinder; z is the number of working zones; d₁-cylinder internal diameter; d₂-the diameter of the rotating shaft; p_min-a minimum working pressure; according to the formulas (1) and (2), the working area of the servomotor blade is as follows:

b-blade width; h-leaf height;

calculating the thickness of the blade according to the step (3), wherein the thickness of the blade determines the strength of the blade, and the thickness can be approximately calculated according to the water head connected into the servomotor cavity:

s, blade thickness; h, connecting a water head; a-material coefficient related to the material, generally taking the value of 4.3-4.6;

2. calculating the maximum stroke and the number of working cavities of the servomotor 2:

the number of the fixed blades 25 of the servomotor 2 is equal to the number of the working areas of the servomotor 2, and the more the fixed blades 25 are arranged, the more the working areas are, the smaller the stroke range of the servomotor 2 is. The maximum stroke, i.e. the maximum rotation angle of the servomotor 2 is as follows:

the number of the fixed blades 25 of the servomotor 2 can be preliminarily determined according to different moments of the valve 1. The stroke of the servomotor 2 is related to the stroke of the valve 1, and the maximum stroke of the ball valve is usually about 85 °, so the minimum value of the number Z of the fixed blades 25 of the servomotor 2 is 4. Further considering the sealing and friction loss, the value range of Z is 4-6. Namely, the maximum stroke of the servomotor 2 is 85 to 55 degrees. The number Z of the working cavities can be selected according to different valve types and sizes on the premise of meeting the strength requirement.

3. Calculating a gear ratio i of a gear transmission

The stroke of the servomotor rotating shaft 26 is kept consistent with the stroke of the valve 1 through gear transmission. A pair of gears which are meshed with each other are arranged on the rotating shaft of the servomotor 2 and the valve rod 13, the two gears are respectively arranged on the rotating shaft 26 of the servomotor and the valve rod 13 through key connection, and the transmission ratio i of the gear of the rotating shaft 26 of the servomotor to the gear of the valve rod 13 is as follows:

in addition, in the invention, each bypass pipe is provided with the regulating valve 6 so as to be suitable for different pipeline pressures, and the opening degree of the regulating valve 6 is used for controlling the pressure in the connection servomotor cylinder 21. The switch of the adjusting valve 6 can control the number of the actually utilized working chambers, can further control the torque of the servomotor rotor, and controls the opening and closing speed of the valve, thereby reducing the water hammer pressure impact on the pipeline.

As shown in fig. 3 and 4, in order to further reduce pressure oscillation in the pipeline and peak water hammer pressure when starting and stopping the pump, damping holes 27 are further opened on at least part of the fixed blades 25 of the servomotor 2.

When the valve is opened, the valve can be opened slowly and then quickly, and specifically comprises the following steps:

when the pump is started, the pressure in front of the valve rises, the regulating valve on the first bypass pipe 5 connected with the high-pressure cavity with the damping hole is opened, water enters the high-pressure cavity with the damping hole of the servomotor 2 through the first bypass pipe 5, and the movable blade 24 is pushed to rotate at a slow speed, so that the rotating shaft 26 rotates slowly, and slow opening is realized. And then, opening the regulating valve on the inlet first bypass pipe 5 connected with the high-pressure cavity without the damping hole, so that water enters the high-pressure cavity which is not communicated before, the water pressure in the cavity is increased, the rotating speed of the rotating shaft 26 is increased, and the quick opening of the valve is further realized.

When closing the valve, can realize closing slowly after fast closing earlier, specifically do:

when the pump is stopped, the pre-valve pressure drops and the water sealing the high pressure chamber 28 is drained through the inlet first bypass pipe 5. As the pressure behind the valve rises, the regulating valves of all the outlet second bypass pipes 4 connected with the sealed low-pressure cavity 29 are opened, water flows into the sealed low-pressure cavity 29 of the servomotor through the outlet second bypass pipes 4, and the movable blades 24 are pushed to rotate fast and reversely, so that fast closing is realized. The regulating valve on the outlet second bypass 4, which is connected to the low-pressure chamber without damping orifice, is then closed, at which point only the sealed low-pressure chamber 29 with damping orifice is in operation, thus achieving a slow closing of the valve.

According to the invention, the damping holes 27 are arranged on part of the fixed blades 25, so that the sealed high-pressure cavity 28 and the sealed low-pressure cavity 29 are respectively provided with the sealed high-pressure cavity with the damping holes 27 and the high-pressure cavity without the damping holes, and the sealed low-pressure cavity with the damping holes and the low-pressure cavity without the damping holes, when the working cavity with the damping holes 27 works, the damping holes 27 have a certain pressure relief effect, and simultaneously, water in the high-pressure cavity flows to the low-pressure cavity adjacent to the high-pressure cavity through the damping holes 27 to further play a role of speed reduction, so that the valve can be opened slowly and then opened quickly, and closed quickly and slowly firstly, when the ball valve is closed, a two-stage valve closing rule of firstly closing quickly and then slowly is adopted, the peak value of water hammer pressure is reduced, and pressure oscillation after the valve is completely closed is obviously reduced.

To further realize the different two-stage valve closing law of first-speed and second-speed, the number of the fixed blades with the damping holes 27 can be controlled under the condition that the number of the fixed blades is certain. The fixed blades 25 with the damping holes 27 are different in number, and the servomotor 2 is different in rotation speed when the number of the working chambers of the access system is different in the process of slow opening and slow closing of the valve.

Among them, in consideration of the force balance of the servomotor 2, it is preferable to arrange the damping holes 27 on the symmetrical fixed blades 25

Furthermore, the root of the fixed blade 25 of the servomotor 2, i.e. the part contacting the inner wall surface of the cylinder 21, is provided with a projection 251 for preventing the movable blade 24 from completely attaching to the fixed blade 25, so that water can conveniently enter the cavity.

Further, the damping hole 27 is a thin-walled small hole when the ratio of the hole length to the diameter is less than 0.5, and the damping characteristic is best, but the processing is difficult, and therefore, the ratio of the hole length to the diameter of the damping hole 27 is generally less than 4. The number of the damping holes 27 in each of the fixed blades 25 is 6 to 12, and the larger the number of the damping holes 27 is, the larger the resistance is, and the slower the rotational speed is.

The water filter is arranged at the connection part of the main pipeline and the bypass pipe, so that water entering the cylinder body 21 of the servomotor 2 does not contain impurities, the friction resistance is reduced, and the cylinder body 21 of the booster is protected.

In the invention, the stroke of the rotating shaft 26 of the servomotor 2 is kept consistent with the stroke of the valve through gear transmission, a pair of gears which are meshed with each other are arranged on the rotating shaft 26 of the servomotor and the valve rod 13, and the two gears are respectively arranged on the rotating shaft 26 of the servomotor and the valve rod 13 through key connection. Particularly, the maximum stroke of the servomotor is different due to different numbers of blades, but the maximum opening degree of the valve can be finally realized.

In the process of gear transmission, in order to realize the functions of lubrication and heat dissipation, an oil tank 3 is arranged below the servomotor 2, and the two gears are immersed in the oil tank.

According to the invention, the opening and closing speeds of the valve are controlled by arranging the plurality of working chambers, so that the water hammer pressure is reduced. Further, the damping holes 27 are formed in the fixed blades, so that the valve 1 is opened slowly and then opened quickly and closed quickly and then closed slowly, when the ball valve is closed, a two-stage valve closing rule of closing quickly and slowly is adopted, the peak value of water hammer pressure is reduced, and the pressure oscillation after the valve 1 is completely closed is obviously reduced.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.