Quantitative plunger pump

Abstract

The utility model provides a quantitative plunger pump which comprises a pump body arranged in the vertical direction. The suction valve and the pump body are integrally arranged, and the suction valve is located at the end, deviating from the ground in the vertical direction, of the pump body; the discharge valve and the suction valve are integrally arranged, and the discharge valve and the suction valve are arranged side by side; the sealing assemblies are respectively positioned in the suction valve and the discharge valve and are used for blocking the suction valve and the discharge valve; the conveying assembly is connected with the interior of the pump body, a fluid cavity is formed, fluid conveying is used for conveying fluid, and leakage of the fluid in the suction and discharge process is prevented through the structure.

Description

Technical Field

[0001] This application relates to the field of pumps, and more particularly to a fixed displacement plunger pump. Background Technology

[0002] A fixed displacement piston pump is a machine used to transport or pressurize fluids. It is mainly used to transport fluids such as water, oil, acids and alkalis, emulsions, suspensions, and liquid metals. The fixed displacement piston pump employs a precision piston and sealing structure to ensure extremely high metering accuracy during operation, making it widely applicable in situations requiring precise flow control.

[0003] In existing technologies, there are certain gaps between the plunger and the cylinder block, and between the cylinder block and the end cap. If these gaps are too large, or if uneven gaps are caused by insufficient machining precision, the risk of leakage will increase.

[0004] Therefore, a leak-proof metering plunger pump is needed. Utility Model Content

[0005] In view of this, it is necessary to provide a leak-proof metering plunger pump to solve the above problems.

[0006] Embodiments of this application provide a metering plunger pump, comprising:

[0007] The pump body is installed vertically.

[0008] A valve assembly, integrally formed with the pump body and located at one end of the pump body vertically away from the ground, the valve assembly comprising:

[0009] The suction valve is integrally formed with the pump body and is located at the end of the pump body that is vertically away from the ground.

[0010] The discharge valve is integrally formed with the suction valve and is arranged side by side with the suction valve;

[0011] A sealing assembly, located inside the suction valve and the discharge valve respectively, is used to block the suction valve and the discharge valve;

[0012] The delivery assembly is connected to the inside of the pump body and forms a fluid chamber for delivering fluid.

[0013] In at least one embodiment of this application, the suction valve includes:

[0014] The suction inlet is located at one end away from the pump body;

[0015] A first placement chamber is connected to the suction port, and the sealing assembly is located in the first placement chamber;

[0016] The suction tube has one end connected to the end of the first placement cavity opposite to the suction port, and the other end connected to the fluid chamber.

[0017] In at least one embodiment of this application, the discharge valve includes:

[0018] The discharge port is located at the end opposite to the pump body;

[0019] A second placement cavity is connected to the outlet, and the sealing assembly is located in the second placement cavity;

[0020] The discharge tube has one end connected to the end of the second placement cavity opposite to the discharge port, and the other end connected to the fluid chamber.

[0021] In at least one embodiment of this application, the sealing assembly includes:

[0022] A first seal, located in the first placement cavity, is used to block the suction port;

[0023] The second seal, located in the second placement cavity, is used to block the discharge tube.

[0024] In at least one embodiment of this application, the suction valve further includes:

[0025] The first limiting rod is located and passes through the first placement cavity, and is located below the first seal;

[0026] During inhalation, the first seal abuts against the first limiting rod, and the inhalation port, the first placement cavity, the inhalation tube, and the fluid chamber are connected.

[0027] During discharge, the first seal abuts against the suction port.

[0028] In at least one embodiment of this application, the discharge valve further includes:

[0029] The second limiting rod is located and passes through the second placement cavity, and is located above the second seal and abuts against the second seal;

[0030] During inhalation, the second seal abuts against the discharge tube;

[0031] During discharge, the second seal abuts against the second limiting rod, and the discharge port, the second placement cavity, the discharge pipe and the fluid chamber are connected.

[0032] In at least one embodiment of this application, the diameter of the first seal is set to A1, the diameter of the first placement cavity is set to B1, and the diameter of the suction port is set to C1, satisfying the following relationship:

[0033] A1 < B1;

[0034] A1 > C1.

[0035] In at least one embodiment of this application, the diameter of the second seal is set to A2, the diameter of the second placement cavity is set to B2, and the diameter of the discharge pipe is set to C2, satisfying the following relationship:

[0036] A1 < B2;

[0037] A2 > C2.

[0038] In at least one embodiment of this application, the delivery component includes:

[0039] The base is set vertically on the ground, and the end facing away from the ground is connected to the pump body;

[0040] The transmission component connects to the drive motor to obtain driving force.

[0041] In at least one embodiment of this application, the conveying assembly further includes:

[0042] The pushing component has one end connected to the transmission component and pushes it in the vertical direction;

[0043] A flow control distribution component, connected to the other end of the pusher, is located within the pump body and fits tightly against the pump body to form a sealed fluid chamber. The flow control distribution component is used to control the flow direction and flow rate of the fluid.

[0044] The aforementioned quantitative plunger pump integrates the valve assembly with the pump body and is equipped with a sealing component to block the interior of the valve, thereby reducing fluid leakage in the suction and discharge valves. Attached Figure Description

[0045] Figure 1 This is a perspective view of the metering plunger pump described in this application;

[0046] Figure 2 This is a top view of the metering plunger pump described in this application;

[0047] Figure 3 This is a front view of the metering plunger pump described in this application;

[0048] Figure 4 for Figure 3 Cross-sectional view of BB in the middle;

[0049] Figure 5 for Figure 3 Cross-sectional view of CC in China;

[0050] Figure 6 for Figure 2A cross-sectional view of the AA valve and a schematic diagram showing the sealing assembly located within the valve assembly when fluid is being drawn in.

[0051] Figure 7 for Figure 2 A cross-sectional view of the AA valve and a schematic diagram showing the sealing assembly located within the valve assembly during fluid discharge.

[0052] Figure 8 A front view of the metering plunger pump described in this application, excluding the base;

[0053] Explanation of main component symbols

[0054] 100. Metering plunger pump; 10. Pump body; 1134. Fluid chamber; 20. Valve assembly; 21. Suction valve; 211. Suction port; 212. First placement chamber; 213. Suction pipe; 214. First limit rod; 22. Discharge valve; 221. Discharge port; 222. Second placement chamber; 223. Discharge pipe; 224. Second limit rod; 23. Sealing assembly; 231. First seal; 232. Second seal; 30. Conveying assembly; 31. Base; 32. Transmission component; 33. Pushing component; 34. Flow control distribution component; F1. Vertical direction. Detailed Implementation

[0055] The embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0056] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0057] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0058] Please see Figures 1-8This application provides a quantitative plunger pump 100, comprising: a pump body 10, a valve assembly 20, a sealing assembly 23, and a delivery assembly 30. The pump body 10 is arranged vertically along a direction F1, and its interior is a fluid chamber 1134. The valve assembly 20 is integrally formed with the pump body 10 and is located at the end of the pump body 10 facing away from the ground along the vertical direction F1. The valve assembly 20 includes: a suction valve 21 and a discharge valve 22. The suction valve 21 is integrally formed with the pump body 10 and is located at the end of the pump body 10 facing away from the ground along the vertical direction F1. The discharge valve 22 is integrally formed with the suction valve 21 and is arranged side-by-side with the suction valve 21. The sealing assembly 23 is located inside both the suction valve 21 and the discharge valve 22, and is used to block the suction valve 21 and the discharge valve 22. The delivery assembly 30 is connected to the pump body 10 and is used to deliver fluid.

[0059] Specifically, when the quantitative plunger pump 100 is turned on, the delivery component 30, through its connection with the drive motor, moves in the vertical direction F1 to draw in and discharge fluid;

[0060] During the fluid intake process, when the delivery component 30 moves downward, a negative pressure is generated in the fluid chamber 1134 formed by the pump body 10 and the delivery component 30. Since the suction valve 21 is connected to the fluid chamber 1134, the sealing component 23 in the suction valve 21 is opened, and the fluid at the suction port 211 is drawn into the pump body 10.

[0061] During the fluid discharge process, as the conveying component 30 moves downward, the volume of the fluid chamber 1134 decreases, and the water source is pushed by pressure, flowing out through the discharge port 221. This reciprocating motion causes the water inlet and outlet processes to alternate, thereby achieving liquid pressurization and conveying.

[0062] The pump body 10 is the main structural component of the fixed displacement plunger pump 100, and it is vertically arranged. The internal fluid chamber 1134 is used to contain and transport fluid. The vertical arrangement reduces the footprint of the fixed displacement plunger pump 100. It provides a flow path for the fluid and ensures smooth fluid transport within the pump. The pump body 10 is made of suitable materials (such as stainless steel, cast iron, etc.), and the internal fluid chamber 1134 is designed to have sufficient strength and corrosion resistance. It is suitable for applications requiring vertical fluid transport, such as high-rise building water supply systems and chemical processes.

[0063] Valve assembly 20 is a key component for controlling the flow of fluid into and out of pump body 10. It is integrally formed with pump body 10 and located on top of pump body 10. It ensures that the fluid flows along a predetermined path.

[0064] The valve assembly 20 is designed as an integral part of the pump body 10, and precision machining ensures the sealing performance between the valve assembly 20 and the pump body 10. This design is suitable for applications requiring precise control of fluid flow into and out of the pump body 10, such as precision metering systems and chemical production equipment.

[0065] The suction valve 21 is a valve that controls the flow of fluid into the pump body 10. It is integrally formed with the pump body 10 and located on the top of the pump body 10. It controls the flow of fluid from the outside into the pump body 10 and prevents reverse flow.

[0066] The suction valve 21 is designed to fit tightly into the pump body 10, and a tight seal is ensured by the sealing assembly 23. This design is suitable for applications requiring prevention of fluid backflow, such as liquid metering systems and water supply equipment.

[0067] The discharge valve 22 is a valve that controls the discharge of fluid from the pump body 10. It is integrally formed with the suction valve 21 and arranged side by side. It controls the discharge of fluid from the pump body 10 and prevents backflow. The structure of the discharge valve 22 is designed to be integrally formed with the suction valve 21, and a sealing component 23 ensures a tight seal. It is suitable for applications requiring precise control of fluid discharge, such as chemical reactors and liquid transfer systems.

[0068] The sealing assembly 23 is a key component ensuring the valve's sealing performance, located inside both the suction valve 21 and the discharge valve 22. It prevents fluid leakage and guarantees the valve's sealing performance. Appropriate sealing materials (such as rubber, PTFE, etc.) are selected, and the structure of the sealing assembly 23 is designed to effectively seal the valve. It is suitable for applications requiring high sealing performance, such as high-pressure transmission systems and corrosive liquid transmission systems.

[0069] The delivery assembly 30 is the drive unit of the fixed displacement plunger pump 100, connected to the pump body 10, and used to deliver fluid. It propels the fluid through mechanical motion within the pump body 10. The structure of the delivery assembly 30 is designed to effectively connect with the pump body 10 and transmit driving force to the pump body 10 via a transmission mechanism. It is suitable for applications requiring efficient fluid delivery, such as industrial production lines and liquid transport systems.

[0070] The pump body 10 and valve assembly 20 are integrally molded to ensure structural stability and sealing. The valve assembly 20 is located on top of the pump body 10 for easy control of fluid inflow and outflow.

[0071] The intake valve 21 and the discharge valve 22 are arranged side by side, which simplifies the structural design and facilitates installation and maintenance.

[0072] The sealing components 23 are located inside the suction valve 21 and the discharge valve 22, respectively. Through precision machining and appropriate material selection, the sealing performance of the valves is guaranteed.

[0073] The delivery assembly 30 is mechanically connected to the pump body 10, transmitting driving force to the pump body 10 to drive fluid flow.

[0074] The 100 fixed displacement piston pump is suitable for applications requiring precise control of fluid flow, such as production lines in the chemical, pharmaceutical, and food industries. It is also suitable for applications requiring high-pressure fluid delivery, such as hydraulic systems and fuel delivery systems.

[0075] In a specific implementation example, the suction valve 21 includes: a suction port 211, a first placement chamber 212, and a suction pipe 213. The suction port 211 is located at the end opposite to the pump body 10. The first placement chamber 212 communicates with the suction port 211, and the sealing assembly 23 is located in the first placement chamber 212. One end of the suction pipe 213 is connected to the end of the first placement chamber 212 opposite to the suction port 211, and the other end is connected to the fluid chamber 1134.

[0076] Specifically, the suction port 211 is located at the end of the pump body 10 facing away from the ground, and is used to introduce the fluid to be pumped. This design ensures that the fluid can easily enter the interior of the pump body 10.

[0077] The first placement chamber 212 communicates with the suction port 211 and houses the sealing assembly 23. This chamber provides a space to accommodate the sealing assembly 23 and maintains a sealed connection with the suction port 211 to prevent leakage during pump operation.

[0078] One end of the suction tube 213 is connected to the end of the first placement chamber 212 opposite to the suction port 211, and the other end is connected to the fluid chamber 1134. The function of this tube is to guide the fluid introduced from the suction port 211 into the main fluid chamber 1134, thereby preparing the fluid to be delivered.

[0079] The suction port 211 is tightly connected to the first placement chamber 212 and the suction pipe 213 to ensure that the fluid can smoothly enter the pump body 10 during the suction stage, and the sealing component 23 prevents the fluid from leaking during the discharge process.

[0080] In a specific implementation example, the discharge valve 22 includes: a discharge port 221, a second placement chamber 222, and a discharge pipe 223. The discharge port 221 is located at the end opposite to the pump body 10. The second placement chamber 222 communicates with the discharge port 221. The sealing assembly 23 is located in the second placement chamber 222. One end of the discharge pipe 223 is connected to the end of the second placement chamber 222 opposite to the discharge port 221, and the other end is connected to the fluid chamber 1134.

[0081] Specifically, the outlet 221 is located at the end of the pump body 10 facing away from the ground, and is used to discharge the fluid processed by the pump. This design ensures that the pump can effectively deliver fluid to the target location or system.

[0082] The second placement chamber 222 communicates with the outlet 221 and also houses the sealing assembly 23. This chamber functions similarly to the first placement chamber 212 in the suction valve 21, providing a space to accommodate the sealing assembly 23 and maintaining a sealed connection with the outlet 221 to prevent leakage when the pump draws in fluid.

[0083] One end of the discharge pipe 223 is connected to the end of the second placement chamber 222 opposite to the discharge port 221, and the other end is connected to the fluid chamber 1134. The function of this pipe is to effectively discharge the fluid processed by the discharge valve 22 from the inside of the pump body 10, ensuring the smoothness and reliability of fluid delivery.

[0084] The outlet 221 is tightly connected to the second placement chamber 222 and the discharge pipe 223 to ensure that the fluid processed by the pump body 10 can be discharged smoothly and effectively from the inside of the pump body 10 during the discharge stage. At the same time, the sealing component 23 prevents leakage during the suction process.

[0085] In a specific implementation example, the sealing assembly 23 includes: a first seal 231 and a second seal 232. The first seal 231 is located in the first placement cavity 212 and is used to block the suction port 211. The second seal 232 is located in the second placement cavity 222 and is used to block the discharge pipe 223.

[0086] Specifically, the first seal 231 is located in the first placement chamber 212 of the suction valve 21, and its function is to block the suction port 211 to prevent leakage when the fluid is discharged. This seal is typically tightly fitted to the structure of the suction valve 21 to ensure that the suction port 211 is effectively sealed when the fluid is discharged.

[0087] The second seal 232 is located in the second placement chamber 222 of the discharge valve 22. Its function is to block the discharge pipe 223 to prevent leakage when fluid is drawn in. This seal fits tightly with the structure of the discharge valve 22 to ensure that the discharge pipe 223 can be effectively sealed when fluid is drawn in.

[0088] These seals are tightly installed in the suction valve 21 and discharge valve 22 through their respective placement chambers and connected to their respective through pipes. Their design and installation ensure that the flow direction of the fluid is effectively controlled and leakage is prevented during the operation of the pump body 10, whether in the suction or discharge phase, thereby guaranteeing the pump's operating efficiency and safety.

[0089] In a specific implementation example, the suction valve 21 further includes a first limiting rod 214. The first limiting rod 214 is located within and passes through the first placement cavity 212, and is positioned below the first seal 231. During suction, the first seal 231 abuts against the first limiting rod 214, and the suction port 211, the first placement cavity 212, the suction tube 213, and the fluid chamber 1134 are connected. During discharge, the first seal 231 abuts against the suction port 211.

[0090] Specifically, the first limiting rod 214 is located and passes through the first placement cavity 212 of the suction valve 21, and is located below the first seal 231. Its function is to provide limiting and guiding functions when the pump is working. Specifically, when the pump is sucking in fluid, a negative pressure is generated, and the first sealing assembly 23 moves downward according to the negative pressure state until the first seal 231 abuts against the first limiting rod 214, while ensuring the communication between the suction port 211, the first placement cavity 212, the suction pipe 213 and the fluid chamber 1134, ensuring that the fluid can be smoothly sucked into the pump body 10.

[0091] When the pump discharges fluid, the volume of the fluid chamber 1134 decreases, pushing the fluid upward. The fluid flows through the first placement chamber 212 of the first seal 231, pushing the first seal 231 upward until the first seal 231 comes into contact with the suction port 211, closing the suction port 211 and preventing fluid from leaking from the suction valve 21 when discharging fluid.

[0092] In a specific implementation example, the discharge valve 22 further includes a second limiting rod 224, which is located and passes through the second placement cavity 222. The second limiting rod 224 is positioned above the second seal 232 and abuts against the second seal 232. During suction, the second seal 232 abuts against the discharge pipe 223. During discharge, the second seal 232 abuts against the second limiting rod 224. The discharge port 221, the second placement cavity 222, the discharge pipe 223, and the fluid chamber 1134 are connected.

[0093] Specifically, the function of the second limit switch is to provide a limit and guide for the discharge valve 22 when the pump is working.

[0094] When the pump discharges fluid, the volume of the fluid chamber 1134 decreases, pushing the fluid upward. The fluid flows through the second placement cavity 222 of the second seal 232, pushing the second seal 232 upward until the second seal 232 abuts against the second limit rod 224, ensuring the connectivity between the outlet 221, the second placement cavity 222, the discharge pipe 223 and the fluid chamber 1134, so that the fluid can be smoothly discharged from the inside of the pump body 10.

[0095] When the pump draws in fluid, a negative pressure is generated. The second seal moves downward according to the negative pressure state until the second seal 232 comes into contact with the discharge pipe 223, preventing fluid from leaking from the discharge valve 22 when it is drawn in.

[0096] In a specific implementation example, the diameter of the first seal 231 is set to A1, the diameter of the first placement cavity 212 is set to B1, and the diameter of the suction port 211 is set to C1, satisfying the following relationship:

[0097] A1 < B1;

[0098] A1 > C1.

[0099] Specifically, the diameter A1 of the seal must be smaller than the diameter of the placement cavity B1. This ensures that the seal can move and seal effectively within the placement cavity, preventing fluid leakage during pump operation.

[0100] The suction port 211 is the channel through which fluid enters the pump body 10. Its diameter C1 should be smaller than the diameter A1 of the first seal 231 to ensure that the first seal 231 can effectively block the suction port 211 and prevent unnecessary fluid leakage during pump operation.

[0101] The first seal 231 forms a tight seal with the inner wall of the first placement cavity 212B1 through its smaller diameter A1, ensuring that the suction port 211 can be effectively sealed during pump suction operation. At the same time, the diameter A1 of the first seal 231 is larger than the diameter C1 of the suction port 211, which ensures that the first seal 231 can completely seal the suction port 211 during the discharge of fluid by the suction valve 21, preventing fluid leakage.

[0102] In a specific implementation example, the diameter of the second seal 232 is set to A2, the diameter of the second placement cavity 222 is set to B2, and the diameter of the discharge pipe 223 is set to C2, satisfying the following relationship:

[0103] A1 < B2;

[0104] A2 > C2.

[0105] Specifically, the second seal 232 forms a tight seal with the inner wall of the second placement cavity 222B2 through its appropriate diameter A2, ensuring effective sealing of the discharge port 221 during pump discharge operation. Simultaneously, the diameter A2 of the second seal 232 is larger than the diameter C2 of the discharge pipe 223, ensuring that the second seal 232 completely seals the discharge pipe 223 during the suction process of the discharge valve 22, preventing fluid leakage.

[0106] In a specific implementation example, the conveying assembly 30 includes a base 31 and a transmission component 32. The base 31 is disposed on the ground in a vertical direction F1, and the end of the base 31 facing away from the ground is connected to the pump body 10. The transmission component 32 is connected to a drive motor and receives driving force.

[0107] Specifically, the base 31 is an important component of the fixed displacement plunger pump 100. It is set vertically on the ground along the direction F1, and the end facing away from the ground is connected to the pump body 10. The function of the base 31 is to provide support and stability for the pump as a whole, and at the same time, it serves as a support for the pump body 10, so that the pump can be safely fixed on the ground and is not easy to move or shake.

[0108] The transmission component 32 is a part connected to the drive motor and is used to obtain driving force. It is responsible for transmitting the power provided by the drive motor to the internal components of the pump body 10. Under normal circumstances, the transmission component 32 converts the rotational motion of the motor into the reciprocating motion required by the plunger pump through mechanical transmission (such as gear transmission, belt transmission, etc.), thereby driving the fluid transport.

[0109] In a specific implementation example, the conveying assembly 30 further includes a pusher 33 and a flow control distributor 34. One end of the pusher 33 is connected to the transmission member 32, and the pusher 33 pushes in the vertical direction F1. The flow control distributor 34 is connected to the other end of the pusher 33, and the flow control distributor 34 is located inside the pump body 10 and is tightly fitted to the pump body 10 to form a closed fluid chamber 1134. The flow control distributor 34 is used to control the flow direction and flow rate of the fluid.

[0110] Specifically, one end of the pusher 33 is connected to the transmission component 32 and pushes vertically in the direction of F1. The main function of the pusher 33 is to convert the power transmitted from the transmission component 32 into the linear motion required by the plunger pump, thereby driving the fluid transport. The motion of the pusher 33 is generally reciprocating motion, and through its connection with the transmission component 32, it converts rotational motion into linear motion.

[0111] The flow control distributor 34 is connected to the other end of the pusher 33, located inside the pump body 10, and fits tightly against the pump body 10 to form a closed fluid chamber 1134. The function of the flow control distributor 34 is to control the direction and flow rate of the fluid, ensuring that the fluid flows within the pump along the designed path, and to adjust the flow rate of the fluid as needed. This component is a key part for achieving precise control and efficient fluid delivery.

[0112] The above description is merely an embodiment of this application. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this application, but these improvements all fall within the protection scope of this application.

Claims

1. A dosing piston pump, characterized in that The utility model relates to a pump body, vertical direction is set up, valve group, with pump body integral setting and located pump body vertical direction ground one end of deviating, valve group includes: Suction valve, with pump body integral setting and located pump body vertical direction ground one end of deviating, Discharge valve, with suction valve integral setting and with suction valve side by side setting, Sealing assembly, respectively located suction valve and discharge valve inside, are used for plugging suction valve and discharge valve, Conveying assembly, with pump body inside connection and form fluid chamber, convey fluid is used for conveying fluid. Suction valve includes: Suction inlet, open in one end of deviating pump body, 2. The positive displacement piston pump of claim 1, wherein, First placement cavity, with suction inlet communication, sealing assembly is located first placement cavity, Suction pipe, one end with first placement cavity deviating suction inlet one end communication, other end with fluid chamber communication. Discharge valve includes: Discharge outlet, open in one end of deviating pump body, 3. The positive displacement piston pump of claim 2, wherein, Second placement cavity, with discharge outlet communication, sealing assembly is located second placement cavity, Discharge pipe, one end with second placement cavity deviating discharge outlet one end communication, other end with fluid chamber communication. Sealing assembly includes: First sealing piece, located first placement cavity, is used for plugging suction inlet, 4. The positive displacement piston pump of claim 3, wherein, Second sealing piece, located second placement cavity, is used for plugging discharge pipe. Suction valve still includes: First limit rod, located and passes through first placement cavity inside, and located first sealing piece below, 5. The positive displacement piston pump of claim 4, wherein, When suction, first sealing piece with first limit rod abutment, suction inlet, first placement cavity, suction pipe and fluid chamber communication, When discharge, first sealing piece with suction inlet abutment. Discharge valve still includes: Second limit rod, located and passes through second placement cavity inside, and located second sealing piece above, and with second sealing piece abutment, 6. The positive displacement piston pump of claim 4, wherein, When suction, second sealing piece with discharge pipe abutment, When discharge, second sealing piece with second limit rod abutment, discharge outlet, second placement cavity, discharge pipe and fluid chamber communication. The diameter of the first sealing piece is A1, the diameter of the first placement cavity is B1, and the diameter of the suction inlet is C1, which satisfy the relationship: A1 7. The positive displacement piston pump of claim 4 wherein, A1 The diameter of the second sealing piece is A2, the diameter of the second placement cavity is B2, and the diameter of the discharge pipe is C2, which satisfy the relationship: A1 8. The positive displacement piston pump of claim 4, wherein, A2 The conveying assembly includes: Base, vertical direction is set up on ground, and one end of deviating ground is connected with pump body, 9. The positive displacement piston pump of claim 1 wherein, Transmission part, with drive motor connection, obtains driving force. The conveying assembly further includes: Pushing part, one end is connected with transmission part, and pushes along vertical direction, 10. The positive displacement piston pump of claim 9, wherein, Flow control distribution part, with the other end of pushing part connection, is located in pump body and is closely attached with pump body to form sealed fluid chamber, and the flow control distribution part is used for controlling the flow direction and flow of fluid. ​ ​

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