Low-resistance fluid end structure of plunger pump

Abstract

The invention relates to the technical field of plunger pumps, in particular to a low-resistance fluid end structure of a plunger pump, which comprises a pump head serving as a mounting foundation of the fluid end structure; the plunger is hermetically arranged in the pump head in a reciprocating sliding manner; the suction valve is arranged in the pump head and is used for controlling fluid to flow in when the plunger reciprocates; the discharge valve is arranged in the pump head and is used for controlling the fluid to flow out when the plunger reciprocates; wherein the suction valve, the discharge valve and the plunger are coaxially arranged; the plunger pump has the beneficial effects that the suction valve, the discharge valve and the plunger are coaxially arranged, turning of a fluid flowing path is reduced, turning of the fluid flowing path is reduced, resistance loss is reduced, the energy utilization efficiency is improved, turbulence and cavitation phenomena are reduced, and the service life of the plunger pump is prolonged. Therefore, the service life is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of plunger pumps, and specifically relates to a low-resistance hydraulic end structure for a plunger pump. Background Technology

[0002] As a typical positive displacement fluid machine, the plunger pump is widely used in many industrial fields such as petrochemicals, mining and metallurgy, engineering machinery, and hydraulic transmission due to its high-pressure output, stable flow rate, and wide range of adaptable media. The hydraulic end structure is the core module for the plunger pump to realize the functions of fluid intake, pressurization, and discharge. Its flow channel design and valve group layout directly determine the pressure loss, working efficiency, and operational stability of the plunger pump.

[0003] In existing technologies, the mainstream structural design of the hydraulic end of a plunger pump typically adopts a T-shaped layout: the reciprocating axis of the plunger is perpendicular to the mounting axes of the suction valve and discharge valve, and the plunger chamber (working chamber) is connected to the suction valve chamber and discharge valve chamber respectively through right-angle flow channels. During the working cycle of the plunger pump, when the plunger extends outward, the volume of the working chamber increases, creating a negative pressure. Fluid flows in through the inlet and needs to be turned through the right-angle flow channel before entering the working chamber. When the plunger compresses inward, the volume of the working chamber decreases, and the high-pressure fluid needs to be turned again through the right-angle flow channel before flowing into the outlet through the discharge valve and being discharged.

[0004] This T-shaped hydraulic end structure has obvious technical defects: First, the turning of the fluid in the right-angle flow channel when pumped out will generate significant local resistance loss, causing the pump output pressure to decrease and reducing energy utilization efficiency. The negative impact of pressure loss is more prominent, especially under high pressure and high flow conditions. Second, the fluid is prone to turbulence and eddies during the turning process in the right-angle flow channel, which aggravates the erosion and wear of the inner wall of the flow channel, and increases the probability of cavitation, thus shortening the service life of the hydraulic end.

[0005] To address these issues, attempts have been made to reduce resistance by optimizing the roughness of the flow channel inner wall and using streamlined valve seats. However, such improvements only alleviate pressure loss locally and do not fundamentally eliminate the drawbacks caused by fluid diversion. The reason for this is that existing technologies have consistently failed to overcome the structural limitation of "non-coaxial plunger and valve assembly," making it impossible to achieve straight fluid flow within the hydraulic end.

[0006] Therefore, a low-resistance hydraulic end structure for a plunger pump is needed to overcome the aforementioned problems. Summary of the Invention

[0007] To address the aforementioned problems, embodiments of the present invention provide a low-resistance hydraulic end structure for a plunger pump, thereby achieving the objective of resolving the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention employs the following technical solution: a low-resistance hydraulic end structure for a plunger pump, comprising: a pump head serving as the mounting base for the hydraulic end structure; a plunger reciprocally sliding and sealingly disposed inside the pump head; an intake valve disposed inside the pump head for controlling fluid inflow during plunger reciprocating motion; and an exhaust valve disposed inside the pump head for controlling fluid outflow during plunger reciprocating motion; wherein the intake valve and the exhaust valve are coaxially arranged with the plunger.

[0009] As a further improvement to the above technical solution:

[0010] The suction valve includes: a valve sleeve, which is fixedly connected inside the pump head and serves as the mounting base for the suction valve; and a valve core, which is elastically slidably disposed inside the valve sleeve by a spring; wherein the valve core is disposed on the outer periphery of the plunger and can slide along its axial direction.

[0011] The inner hole of the valve core and the outer surface of the plunger are sealed by a gap seal or a lip seal ring.

[0012] The discharge valve includes: valve sleeve two, which is fixedly connected inside the pump head and serves as the mounting base for the discharge valve; and valve core two, which is elastically slidably disposed inside valve sleeve two by spring two.

[0013] The pump head has an internal cavity that communicates with the inlet and outlet; the cavity is divided into an inlet chamber, a working chamber and an outlet chamber by an inlet valve and an outlet valve.

[0014] The working chamber, discharge chamber, and liquid outlet are coaxially arranged to form a linear fluid discharge path.

[0015] The pump head includes: a main body, serving as the mounting base for the pump head; a base block, disposed inside the pump head, with one end used to connect to the mounting base of the plunger, and forming an intake chamber connected to the inlet; an isolation cylinder, disposed between the intake valve and the discharge valve, forming a working chamber; and a fixed end, fixedly connected to the end of the pump head, forming an outlet and a discharge chamber connected to each other.

[0016] Both the intake valve and the discharge valve are one-way valves.

[0017] The beneficial effects of the embodiments of the present invention are as follows: This application reduces the detours in the fluid flow path by coaxially arranging the intake valve and discharge valve with the plunger. This reduces resistance loss, improves energy utilization efficiency, reduces turbulence and cavitation, and thus extends service life. Attached Figure Description

[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] In the diagram: 1. Pump head; 2. Plunger; 3. Suction valve; 4. Discharge valve; 5. Inlet; 6. Outlet; 7. Suction chamber; 8. Working chamber; 9. Discharge chamber; 11. Main body; 12. Base block; 13. Isolation cylinder; 14. Fixed end; 31. Valve sleeve 1; 32. Valve core 1; 33. Spring 1; 41. Valve sleeve two; 42. Valve core two; 43. Spring two. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0021] See Figure 1 This invention discloses a low-resistance hydraulic end structure for a plunger pump, comprising: a pump head 1, serving as the mounting base for the hydraulic end structure; a plunger 2, reciprocally sliding and sealingly disposed inside the pump head 1; a suction valve 3, disposed inside the pump head 1, used to control fluid inflow during the reciprocating motion of the plunger 2; and a discharge valve 4, disposed inside the pump head 1, used to control fluid outflow during the reciprocating motion of the plunger 2; the suction valve 3 and the discharge valve 4 are coaxially disposed with the plunger 2.

[0022] For ease of understanding, the following explains some key terms in this embodiment: Pump head 1 is the main component of the hydraulic end structure. It forms fluid channels and chambers inside and provides installation and support for other components. The structural design of pump head 1 directly affects the flow characteristics of the fluid and the strength of the entire hydraulic end structure.

[0023] The plunger 2 is the core working component of the plunger pump. It reciprocates linearly inside the pump head 1, changing the volume of the working chamber 8 to achieve the intake, compression, and discharge of fluid. The motion accuracy and sealing performance of the plunger 2 affect the pump's efficiency and lifespan.

[0024] The suction valve 3 is a one-way valve. Its function is to allow fluid to flow from the inlet 5 into the working chamber 8 when the plunger 2 extends outward (suction stroke), and to close when the plunger 2 compresses inward (discharge stroke) to prevent fluid backflow.

[0025] The discharge valve 4 is also a one-way valve. Its function is to allow the compressed fluid to be discharged from the working chamber 8 to the outlet 6 when the plunger 2 compresses inward (discharge stroke), and to close when the plunger 2 extends outward (suction stroke) to prevent high-pressure fluid backflow.

[0026] Coaxial arrangement means that the central axes of the suction valve 3, discharge valve 4, and plunger 2 coincide or are parallel and located on the same straight line. This layout aims to optimize the fluid path, reduce fluid detours, and thus reduce flow resistance.

[0027] This embodiment provides a low-resistance hydraulic end structure for a plunger pump. The core of this structure lies in optimizing the fluid path to reduce flow resistance.

[0028] The hydraulic end structure includes a pump head 1, which serves as the mounting base for the entire hydraulic end structure. The pump head 1 has reserved mounting space for the plunger 2, suction valve 3, and discharge valve 4, as well as fluid passages.

[0029] The plunger 2 is reciprocatingly sliding and sealingly disposed inside the pump head 1. The plunger 2 is typically a cylindrical rod-shaped structure, with one end connected to an external drive mechanism and the other end extending into the working chamber inside the pump head 1. The sliding seal between the plunger 2 and the inner wall of the pump head 1 can be achieved in various ways. For example, a traditional packing seal structure can be used, which prevents fluid leakage by compressing the packing ring; or, elastic seals such as O-rings or U-rings can be used, installed in corresponding grooves in the plunger 2 or the pump head 1 to provide a dynamic seal.

[0030] The suction valve 3 is located inside the pump head 1 and is used to control the inflow of fluid during the reciprocating motion of the plunger 2. The function of the suction valve 3 is to ensure that the fluid smoothly enters the working chamber during the suction stroke and to effectively close during the discharge stroke. The discharge valve 4 is also located inside the pump head 1 and is used to control the outflow of fluid during the reciprocating motion of the plunger 2. The function of the discharge valve 4 is to ensure that the high-pressure fluid smoothly leaves the working chamber during the discharge stroke and to effectively close during the suction stroke.

[0031] In this application, the suction valve 3 and the discharge valve 4 are coaxially arranged with the plunger 2. That is, the central axes of the suction valve 3, the discharge valve 4 and the plunger 2 are aligned in space, so that when the fluid enters the working chamber through the suction valve 3 and leaves the working chamber through the discharge valve 4, its main flow direction is aligned with the axial movement direction of the plunger 2.

[0032] The hydraulic end structure of the plunger pump in this embodiment effectively eliminates the local resistance loss caused by multiple fluid turns in the traditional T-shaped layout by coaxially arranging the suction valve 3 and discharge valve 4 with the plunger 2. As a result, the fluid achieves straight-line flow within the hydraulic end, significantly reducing flow resistance and improving the pump's energy utilization efficiency and output pressure. Simultaneously, it avoids turbulence, eddies, and cavitation, extending the service life of the hydraulic end components and enhancing the pump's operational stability.

[0033] This application further proposes that the suction valve 3 includes a valve sleeve 31, a valve core 32, and a spring 33. Specifically, the valve sleeve 31 is fixedly connected inside the pump head 1, serving as the mounting base for the suction valve 3. The valve sleeve 31 is typically cylindrical or annular in shape and is fixedly connected to the pump head 1 to ensure stable installation of the suction valve 3 inside the pump head 1. An internal channel is formed to accommodate the valve core 32 and provide sliding guidance for it. The material of the valve sleeve 31 is typically selected from corrosion-resistant and wear-resistant metals to adapt to fluid media and high-pressure operating environments.

[0034] Valve core 32 is elastically slidably disposed inside valve sleeve 31 via spring 33. Valve core 32 is the core opening and closing component of suction valve 3. Spring 33 provides preload to valve core 32, ensuring that suction valve 3 remains closed in the non-operating state and providing the necessary reset force in the operating state. Spring 33 is typically a helical compression spring, and its stiffness, preload, and maximum compression must be precisely designed based on parameters such as pump operating pressure, flow rate, and response speed. The material of spring 33 should have good fatigue strength and corrosion resistance, such as stainless steel or a special alloy.

[0035] The valve core 32 is sleeved on the outer periphery of the plunger 2 and can slide along its axial direction. This structure is the key to this embodiment. During the reciprocating motion of the plunger 2, the valve core 32 can slide along the axial direction of the plunger 2. The material of the valve core 32 needs to have good wear resistance, corrosion resistance, and low density to ensure rapid response and long service life.

[0036] Through the above technical solution, the suction valve 3 is designed to include a valve sleeve 31, a valve core 32, and a spring 33. The valve core 32 is fitted around the outer periphery of the plunger 2 and can slide along its axial direction, effectively achieving the coaxial arrangement of the plunger 2 and the suction valve 3. Simultaneously, the coaxial arrangement of the valve core 32 directly fitted around the outer periphery of the plunger 2 allows the fluid to directly enter the working chamber 8 along the axial direction of the plunger 2 through the annular channel formed around the outer periphery of the valve core 32 during the suction stroke. This significantly shortens the fluid path, reduces fluid turning and cross-sectional changes, thereby significantly reducing the local resistance of the fluid during the suction process and improving the pump's suction efficiency and volumetric efficiency. Furthermore, this compact coaxial fitting structure achieves a higher degree of integration between the suction valve 3 and the plunger 2, simplifies the overall structure of the hydraulic end, facilitates the lightweight and miniaturized design of the pump, and also simplifies assembly and maintenance.

[0037] This application further proposes that the inner hole of valve core 32 and the outer circular surface of plunger 2 be sealed by a gap seal or a lip seal ring.

[0038] Specifically, when using a gap seal, a very small, precisely controlled gap is maintained between the inner bore of valve core 32 and the outer surface of plunger 2. This sealing method relies on the resistance generated when fluid flows through the tiny gap to limit leakage, while avoiding direct contact friction between components. When using a lip seal, one or more lip seals are installed in the inner bore of valve core 32, with their lips in close contact with the outer surface of plunger 2. Lip seals are typically made of elastic materials such as rubber or polytetrafluoroethylene (PTFE), and their design allows the lips to further press against the surface of plunger 2 under fluid pressure, thereby forming a reliable seal.

[0039] This application further discloses the specific structure of the discharge valve 4, which includes a valve sleeve 41, a valve core 42, and a spring 43. Specifically, the valve sleeve 41 of the discharge valve 4 is fixedly connected inside the pump head 1, serving as the mounting base for the discharge valve 4. The function of the valve sleeve 41 is to provide a stable installation environment and a precise fluid passage for the discharge valve 4, ensuring that the valve core 42 can be accurately guided and sealed within it.

[0040] Valve core 42 is elastically slidably disposed inside valve sleeve 41 via spring 43. Valve core 42 is the core opening and closing element of discharge valve 4, controlling the flow of fluid by axial sliding within valve sleeve 41. The design of valve core 42 typically includes a sealing surface that mates with a valve seat inside valve sleeve 41 to achieve a reliable seal in the closed state. Spring 43 provides preload to valve core 42, keeping it closed in the absence of differential pressure or at low differential pressure, and allowing valve core 42 to open when the fluid pressure reaches a set value. The elastic characteristics of spring 43 (such as stiffness and pre-compression) are key parameters ensuring the response speed and closing reliability of discharge valve 4. Spring 43 is typically a helical compression spring made of an elastic material, such as spring steel, to ensure its stability and fatigue life during long-term operation.

[0041] This application further proposes that the pump head 1 has a cavity inside that communicates with the inlet 5 and the outlet 6; the cavity is divided into an inlet chamber 7, a working chamber 8 and an outlet chamber 9 by an inlet valve 3 and an outlet valve 4.

[0042] Pump head 1 is designed with a cavity. This cavity is the physical path for fluid flow inside pump head 1, and its shape and volume directly affect the fluid delivery efficiency. Inlet 5 and outlet 6 are the interfaces for connecting pump head 1 to external fluid pipelines, ensuring that fluid can enter the cavity of pump head 1 from the outside and be discharged from the cavity to the outside after being pumped.

[0043] The suction valve 3 and discharge valve 4 not only control the unidirectional flow of fluid, but also structurally divide the internal cavity of the pump head 1 into three functional areas: the suction chamber 7, the working chamber 8, and the discharge chamber 9. The suction chamber 7 is typically directly connected to the inlet 5 and is responsible for receiving fluid flowing in from the outside. The working chamber 8 is the area where the plunger 2 reciprocates; its volume changes periodically with the movement of the plunger 2, making it the core area for fluid intake and discharge. The discharge chamber 9 is connected to the outlet 6 and is responsible for collecting the fluid discharged from the working chamber 8 and transporting it to the outside. This separation ensures the orderly flow of fluid in the pumping cycle, avoiding mixing and backflow of fluid at different stages, which is crucial for achieving efficient pump operation.

[0044] Through the above technical solution, a cavity connected to the inlet 5 and outlet 6 is set inside the pump head 1. This cavity is clearly divided into an inlet chamber 7, a working chamber 8, and an outlet chamber 9 using a suction valve 3 and a discharge valve 4, thus clearly defining the flow path of the fluid inside the pump head 1. This structured design effectively avoids disordered flow, eddies, or dead zones during pumping, significantly reducing the flow resistance inside the pump head 1. The fluid can efficiently enter the inlet chamber 7 from the inlet 5 along a preset, low-resistance path, enter the working chamber 8 through the suction valve 3, enter the outlet chamber 9 through the discharge valve 4, and finally exit from the outlet 6. This precise chamber division and fluid path optimization not only improves the pump's suction and discharge efficiency and volumetric efficiency but also makes the pump operation more stable and reliable, effectively solving the problems of high fluid resistance and low efficiency.

[0045] Simultaneously, the working chamber 8, the discharge chamber 9, and the outlet 6 are coaxially arranged to form a linear fluid discharge path. "Coaxial arrangement" means that the central axes of the working chamber 8, the discharge chamber 9, and the outlet 6 are spatially coincident or located on the same straight line. This design is the basis for constructing a low-resistance fluid discharge path, ensuring that the fluid does not undergo abrupt changes in direction during discharge, thereby fundamentally reducing energy loss caused by changes in flow direction.

[0046] "Forming a linear fluid discharge path" means that as the fluid flows from the working chamber 8 through the discharge chamber 9 and finally out of the outlet 6, its main flow direction remains highly consistent, without significant bends or abrupt changes in direction. In addition to the aforementioned coaxial arrangement, to further optimize fluid flow, the walls of the channels connecting the working chamber 8, discharge chamber 9, and outlet 6 can be smoothed, avoiding sudden changes in cross-section or sharp angles. For example, using smooth transitions or tapered transition sections to connect cavities of different diameters minimizes friction and eddies within the channels, ensuring smooth fluid discharge with minimal resistance.

[0047] The above technical solution arranges the working chamber 8, discharge chamber 9, and outlet 6 coaxially, forming a linear fluid discharge path. As the fluid flows from the working chamber 8, through the discharge chamber 9, and finally out of the outlet 6, its flow direction remains highly consistent, avoiding additional resistance caused by changes in direction within the internal structure. This linear fluid path significantly reduces flow resistance within the hydraulic end structure, minimizing energy loss and thus improving the volumetric and mechanical efficiency of the plunger pump. Simultaneously, it reduces turbulence and pressure fluctuations during discharge, contributing to improved pump operational stability and extended component lifespan.

[0048] This application further proposes that the pump head 1 includes a main body 11, a base block 12, an isolation cylinder 13, and a fixed end 14.

[0049] The main body 11 serves as the mounting base for the pump head 1 and is the core load-bearing component of the entire hydraulic end structure, providing structural support and mounting interfaces for other internal components. The main body 11 is typically made of high-strength, corrosion-resistant materials through integral molding or precision machining, and its interior has pre-drilled mating surfaces or threaded connection structures for mounting the base block 12, the isolation cylinder 13, and the fixed end 14. Its design must comprehensively consider overall strength, sealing performance, and connection requirements with other external components.

[0050] The base block 12 is disposed inside the pump head 1, with one end used to connect to the mounting base of the plunger 2. Internally, it forms a suction chamber 7 that communicates with the inlet 5. The base block 12 can be a separate machined component, installed inside the main body 11 via threads, flanges, or other fixing methods. Its internal channels are precisely designed to ensure that fluid from the inlet 5 can smoothly enter the suction chamber 7. One end of the base block 12 is typically designed with a connection structure that matches the mounting base of the plunger 2 (e.g., a plunger mount). To ensure sealing, appropriate sealing structures, such as O-rings or gaskets, are provided between the base block 12 and the main body 11, and between the base block 12 and the mounting base of the plunger 2.

[0051] An isolation cylinder 13 is positioned between the suction valve 3 and the discharge valve 4, forming a working chamber 8 inside. The isolation cylinder 13 is typically a precision-machined cylindrical component. It is fixed inside the main body 11 by press-fitting, threaded connection, or welding, and fits tightly with corresponding parts of the suction valve 3 and discharge valve 4 to form a sealed working chamber 8. The length and inner diameter of the isolation cylinder 13 determine the volume of the working chamber 8, thus affecting the pump's displacement. The selection of its material must consider wear resistance, corrosion resistance, and fluid compatibility.

[0052] The fixed end 14 is fixedly connected to the end of the pump head 1, and internally forms a connected outlet 6 and discharge chamber 9. The fixed end 14 is typically tightly connected to the end of the body 11 by means of threads, flanges, or clamps, ensuring good sealing. Its internal structure contains one or more fluid channels for connecting the discharge chamber 9 and the outlet 6, forming a linear fluid discharge path. The material selection for the fixed end 14 is similar to that of the body 11, requiring sufficient strength and corrosion resistance.

[0053] By subdividing the pump head 1 into modular components such as the main body 11, base block 12, isolation cylinder 13, and fixed end 14, the formation of the internal chambers and fluid channels of the pump head 1 becomes more precise and controllable. This modular design greatly simplifies the manufacturing and assembly process, allowing each component to be machined independently, ensuring the dimensional accuracy of the suction chamber 7, working chamber 8, and discharge chamber 9, as well as the connection accuracy with the inlet 5 and outlet 6. Simultaneously, this structure facilitates the precise installation and coaxial alignment of the suction valve 3, discharge valve 4, and plunger 2, effectively ensuring the linearity of the fluid discharge path, thereby significantly reducing fluid resistance and improving the pump's efficiency and reliability.

[0054] This application further proposes that both the suction valve 3 and the discharge valve 4 are one-way valves. Designing the suction valve 3 and discharge valve 4 as one-way valves ensures that the fluid always flows in a predetermined direction during pumping, effectively preventing backflow during the suction and discharge strokes. Specifically, during the suction stroke of the plunger 2, the suction valve 3 automatically opens as a one-way valve, allowing the fluid to smoothly enter the working chamber, while the discharge valve 4 remains closed as a one-way valve, preventing the discharged fluid from flowing back. During the discharge stroke of the plunger 2, the discharge valve 4 automatically opens as a one-way valve to discharge the fluid, while the suction valve 3 remains closed as a one-way valve, preventing the fluid from flowing back into the suction line. This design significantly improves the pump's volumetric efficiency and overall operating efficiency, reduces energy loss, and lowers fluid pulsation, thereby enhancing the operational stability and reliability of the plunger pump.

[0055] The above technical solution will be explained in detail below with a more specific example: The hydraulic end structure includes a pump head 1, which serves as the mounting base for the entire hydraulic end structure. Inside the pump head 1, a plunger 2 is disposed, capable of reciprocating sliding and forming a sliding seal with the interior of the pump head 1. Furthermore, a suction valve 3 and a discharge valve 4 are also disposed inside the pump head 1. The suction valve 3 controls the inflow of fluid during the reciprocating motion of the plunger 2, while the discharge valve 4 controls the outflow of fluid during the reciprocating motion of the plunger 2. A key structural feature is that the suction valve 3 and the discharge valve 4 are coaxially arranged with the plunger 2.

[0056] When plunger 2 moves backward (away from the discharge direction) inside pump head 1, the volume of working chamber 8 increases, creating a negative pressure. At this time, suction valve 3 opens. Suction valve 3 consists of valve sleeve 31 and valve core 32, where valve sleeve 31 is fixedly connected inside pump head 1, and valve core 32 is elastically slidably disposed inside valve sleeve 31 by spring 33. Valve core 32 is sleeved on the outer circumference of plunger 2 and can slide along the axial direction of plunger 2. The inner hole of valve core 32 and the outer circular surface of plunger 2 are sealed by a gap seal or lip seal ring, ensuring effective sealing of fluid during suction.

[0057] The pump head 1 has an internal cavity that communicates with the inlet 5 and the outlet 6. This cavity is divided into an inlet chamber 7, a working chamber 8, and an outlet chamber 9 by an inlet valve 3 and an outlet valve 4. Specifically, the pump head 1 includes a main body 11, a base block 12, an isolation cylinder 13, and a fixed end 14. The base block 12 is located inside the pump head 1, and its interior forms the inlet chamber 7, which communicates with the inlet 5. The isolation cylinder 13 is located between the inlet valve 3 and the outlet valve 4, and its interior forms the working chamber 8.

[0058] During the suction stroke, external fluid enters the suction chamber 7 through the inlet 5. Since the suction valve 3 is coaxially aligned with the plunger 2, the fluid flows directly from the suction chamber 7 through the open suction valve 3, along the axis of the plunger 2, into the working chamber 8. The entire fluid path is linear, without any abrupt change in direction. The suction valve 3 acts as a one-way valve, ensuring that fluid can only flow into the working chamber 8 during the suction stroke.

[0059] When plunger 2 moves forward (towards the discharge direction) inside pump head 1, the volume of working chamber 8 decreases, compressing the internal fluid and creating high pressure. At this time, suction valve 3 closes and discharge valve 4 opens. Discharge valve 4 consists of valve sleeve 41 and valve core 42, wherein valve sleeve 41 is fixedly connected inside pump head 1, and valve core 42 is elastically slidably disposed inside valve sleeve 41 by spring 43.

[0060] The fixed end 14 is fixedly connected to the end of the pump head 1, and its interior forms a connected liquid outlet 6 and discharge chamber 9. The working chamber 8, discharge chamber 9 and liquid outlet 6 are coaxially arranged to form a linear fluid discharge path.

[0061] During the discharge stroke, the high-pressure fluid in the working chamber 8 pushes the discharge valve 4 to open. The fluid flows directly into the discharge chamber 9 along the axial direction of the plunger 2 through the discharge valve 4, and is finally discharged through the outlet 6. The entire discharge path is also linear, and the fluid does not experience a sharp change in direction. The discharge valve 4 acts as a one-way valve, ensuring that the fluid can only flow out of the working chamber 8 during the discharge stroke.

[0062] Compared to existing technologies, the hydraulic end structure in this example achieves straight-line fluid flow during both intake and discharge processes by coaxially aligning the intake valve 3 and discharge valve 4 with the plunger 2. In existing T-shaped layouts, the fluid needs to deflect within the right-angle flow channel during pumping out, resulting in local resistance losses, a decrease in pump head output pressure, and the formation of turbulence and eddies, exacerbating erosion and wear on the channel wall and increasing the probability of cavitation. The structure in this example eliminates the abrupt deflection of the fluid within the hydraulic end, thus avoiding local resistance losses caused by deflection. The fluid flows along a straight path, reducing the formation of turbulence and eddies, and lowering the probability of erosion and wear on the channel wall and cavitation. This coaxial, linear flow channel design reduces the flow resistance within the hydraulic end, improving fluid transfer efficiency and extending the service life of the hydraulic end structure.

[0063] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0064] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0065] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A low-resistance hydraulic end structure for a plunger pump, characterized in that, include: Pump head (1) serves as the mounting base for the hydraulic end structure; The plunger (2) is reciprocally sliding and sealed inside the pump head (1); The suction valve (3), located inside the pump head (1), is used to control the fluid inflow during the reciprocating motion of the plunger (2); and The discharge valve (4) is located inside the pump head (1) and is used to control the flow of fluid when the plunger (2) reciprocates. The suction valve (3) and discharge valve (4) are coaxially arranged with the plunger (2).

2. The low-resistance hydraulic end structure of the plunger pump according to claim 1, characterized in that, The suction valve (3) includes: Valve sleeve 1 (31) is fixedly connected inside the pump head (1) and serves as the mounting base for the suction valve (3); and Valve core 1 (32) is elastically slidably disposed inside valve sleeve 1 (31) by means of spring 1 (33); The valve core (32) is sleeved on the outer periphery of the plunger (2) and can slide along its axial direction.

3. The low-resistance hydraulic end structure of the plunger pump according to claim 2, characterized in that, The inner hole of the valve core (32) and the outer surface of the plunger (2) are sealed by a gap seal or a lip seal ring.

4. The low-resistance hydraulic end structure of the plunger pump according to claim 1, characterized in that, The discharge valve (4) includes: Valve sleeve 2 (41) is fixedly connected inside the pump head (1) and serves as the mounting base for the discharge valve (4); and Valve core 2 (42) is elastically slidably disposed inside valve sleeve 2 (41) by spring 2 (43).

5. The low-resistance hydraulic end structure of the plunger pump according to claim 1, characterized in that, The pump head (1) has a cavity inside that communicates with the inlet (5) and outlet (6); the cavity is divided into an inlet chamber (7), a working chamber (8) and an outlet chamber (9) by an inlet valve (3) and an outlet valve (4).

6. The low-resistance hydraulic end structure of the plunger pump according to claim 5, characterized in that, The working chamber (8), the discharge chamber (9) and the liquid outlet (6) are arranged coaxially to form a linear fluid discharge path.

7. The low-resistance hydraulic end structure of the plunger pump according to claim 6, characterized in that, The pump head (1) includes: The main body (11) serves as the mounting base for the pump head (1); The base block (12) is set inside the pump head (1), with one end used to connect the mounting base of the plunger (2), and the interior forms a suction chamber (7) that communicates with the liquid inlet (5). An isolation cylinder (13) is disposed between the suction valve (3) and the discharge valve (4), and forms a working chamber (8) inside; and The fixed end (14) is fixedly connected to the end of the pump head (1), and forms a liquid outlet (6) and a discharge chamber (9) that are connected inside.

8. The low-resistance hydraulic end structure of the plunger pump according to claim 1, characterized in that, Both the intake valve (3) and the discharge valve (4) are one-way valves.

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