Modular multi-stage impeller liquid pump

Abstract

The utility model relates to the field of multistage pump, concretely relates to a modular multistage impeller liquid pump. Including the pump shell that extends along the axial direction, the pump shell forms continuous pressure boundary, one end is equipped with the liquid inlet, the other end is equipped with the liquid outlet, and the inner wall of pump shell limits the through flow channel, a plurality of power units are arranged in the flow channel along the axial direction of pump shell, each power unit includes the stator fixedly sleeved in the inside of pump shell, the rotatable rotor installed in the inside of stator, the rotor shaft coaxial connection with rotor and the impeller fixed on the rotor shaft, and the gap between the inner wall of pump shell and the outer edge of impeller is communicated and forms the through flow channel between each power unit. The structure is through the continuous flow channel formed by pump shell and the modular power unit layout, realizes the step -by -step pressurization of liquid, and facilitates the assembly, maintenance and modular control of pump body.

Description

Technical Field

[0001] This utility model relates to the field of multistage pumps, specifically to a modular multistage impeller liquid pump. Background Technology

[0002] Centrifugal pumps are fluid machines that use high-speed rotating impellers to convert the energy of liquids. They are commonly used in cryogenic media transportation, petrochemicals, and natural gas liquefaction. Existing multistage centrifugal pumps generally adopt a structure with a single motor driving a long drive shaft. Multiple impellers are installed on the axially arranged drive shaft. The liquid enters each impeller in turn and is pressurized step by step, thereby obtaining a head higher than that of a single-stage pump.

[0003] After entering the center of the first-stage impeller from the pump inlet, the liquid is thrown to the outer periphery by the rotating impeller and gains energy. It then enters the diffuser section or guide vane channel inside the pump casing to decelerate and pressurize before flowing to the inlet of the next-stage impeller. Through multiple stages of repetition, continuous pressure superposition is achieved.

[0004] However, when there are many impeller stages, the length of the drive shaft and its supporting components (couplings, bearing supports, interstage seals, etc.) increases significantly, making the overall structure more complex. The shaft system is also limited by machining accuracy, coaxiality, critical speed, and vibration control, increasing the difficulty of design and manufacturing. In addition, each impeller stage is driven by the same motor at a fixed speed, but the flow and pressure conditions of different stages differ, resulting in inconsistent efficiency among stages, limiting overall energy efficiency, and making it impossible to independently adjust the operating status of a single stage. Utility Model Content

[0005] To address the problems of traditional multistage centrifugal pumps, such as reliance on a single long drive shaft, complex structure, high manufacturing difficulty, and the inability to independently adjust each impeller stage, a modular multistage impeller liquid pump is proposed. This invention arranges multiple independent power units within the same pump casing, enabling each impeller stage to achieve progressive energy enhancement within the same continuous flow channel, thus replacing the traditional long drive shaft transmission structure.

[0006] A modular multistage impeller liquid pump, comprising: The pump casing is a cylindrical structure extending along the axial direction, forming a continuous pressure boundary. One end is provided with an inlet and the other end with an outlet. A flow channel that penetrates the pump housing and is defined by its inner wall; Multiple power units are installed at intervals along the axial direction of the pump casing within the flow channel, and each of the multiple power units includes: The stator is fixedly sleeved inside the pump casing; The rotor is rotatably mounted inside the stator; The rotor shaft is coaxially connected to the rotor and extends axially along the pump casing; The impeller is fixedly mounted on the rotor shaft and located in the flow channel.

[0007] Preferably, each power unit has a guide plate at its front end, which is fixedly connected to the pump casing and arranged around the rotor shaft.

[0008] Preferably, an annular gap is formed between the inner wall of the pump casing and the outer edge of the impeller, and multiple power units are connected through this annular gap to form a through internal flow channel.

[0009] Preferably, the pump housing is an integral structure.

[0010] Preferably, the pump casing is formed by welding or threading multiple casing segments together.

[0011] Preferably, each power unit is provided with an independent electrical connection port.

[0012] Preferably, an impeller is mounted at at least one end of the rotor shaft, and the impeller is fixedly arranged in a direction perpendicular to the rotor shaft.

[0013] This invention, by arranging multiple independent power units axially within the same pump casing, eliminates the reliance on traditional long drive shaft transmission structures for multi-stage pressurization, thereby bringing the following beneficial effects: This invention avoids the manufacturing bottleneck caused by a long drive shaft. Traditional multistage centrifugal pumps use a single long drive shaft to connect multiple impellers in series, requiring multiple bearing supports, couplings, and interstage seals, resulting in a complex structure and high requirements for coaxiality and machining accuracy. This invention uses multiple independent power units, each individually fixed inside the pump casing, eliminating the long drive shaft and related components. This significantly simplifies the overall pump structure and reduces manufacturing and assembly difficulty.

[0014] Modular power unit design. Multiple power units are complete, independent modules that can be installed separately in the continuous flow channel defined by the pump casing, achieving standardized and modular assembly. Compared to traditional long drive shaft driven structures, this invention facilitates unit-level replacement or maintenance, improving the maintainability and engineering adaptability of the entire machine.

[0015] Reduce vibration and alignment issues. Since each power unit has its own stator, rotor, and rotor shaft unit, and there is no mechanical transmission relationship between power units, the traditional long-distance shaft alignment arrangement is no longer required. This fundamentally avoids the problems of long drive shaft structures being susceptible to vibration, critical speed, deflection, and other factors, thus improving operational stability.

[0016] Improved operating efficiency. Multiple modular power units can independently control output power, ensuring all impellers operate at their optimal state, thus avoiding the problem of inconsistent operating efficiency despite uniform impeller speeds in traditional technologies.

[0017] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of a liquid pump, a utility model of a pump.

[0019] Explanation of reference numerals in the attached figures 1-Pump casing, 1a-Inlet, 1b-Outlet; 2-Power unit, 2a-Stator, 2b-Rotor, 2c-Rotor shaft, 2d-Impeller; 3-Flow channel; 4-Guide plate. Detailed Implementation

[0020] The specific embodiments of this utility model are described in detail below. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this utility model. In this utility model, unless otherwise stated, "inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.

[0021] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. The core of the multi-stage centrifugal pump power unit arrangement structure of the present invention lies in the fact that each stage impeller is respectively mounted on an independent power unit, each power unit has a built-in independent motor that directly drives the corresponding stage impeller through a short shaft, and the segmented pump casings are connected in series to form a multi-stage pressurization process. This structure can expand the number of stages as needed, and the speed of each power unit can be adjusted independently through a control system to achieve an independently optimizable multi-stage pump operation mode.

[0022] Overall structure introduction (see attached document) Figure 1 ): This invention relates to a multi-stage impeller 2d liquid pump, the purpose of which is to achieve progressive liquid pressurization within a single pump body, while simultaneously solving the problems of complex structure, large vibration of long drive shafts, and mismatch of operating conditions between stages in existing multi-stage pumps. In the prior art, multi-stage pumps typically employ a single long drive shaft carrying multiple 2d impellers, or achieve high pumping capacity by directly connecting multiple pumps in series. However, these solutions suffer from high manufacturing difficulty, uncontrollable vibration of long drive shafts, poor matching of operating conditions between stages, and insufficient structural flexibility, resulting in complex pump body manufacturing, insufficient operational stability, and inconvenient maintenance.

[0023] The liquid pump of this invention mainly includes a pump casing 1, multiple power units 2, and a flow guiding structure. Its overall technical solution is as follows: the pump casing 1 is an axially extending cylindrical structure used to form the overall pressure boundary of the pump. One end has an inlet 1a, and the other end has an outlet 1b. The pump casing 1 can be an integral structure, formed by casting, welding, or machining to create a continuous closed cylinder. Alternatively, it can be formed by splicing multiple casing sections to create a single pressure boundary, ensuring that the liquid forms a continuous flow channel 3 inside the pump body, while providing space and support for the installation of the power unit 2 modules. The design of the pump casing 1 must consider mechanical strength and sealing performance to withstand the pressure after liquid pressurization and the axial and radial forces generated by the rotation of the impeller 2d. Suitable materials, such as carbon steel, stainless steel, or alloy steel, can be selected according to the conveying medium and operating conditions.

[0024] Multiple power units 2 are axially spaced inside the pump casing 1. Each power unit 2 independently includes a stator 2a, a rotor 2b, a rotor shaft 2c, and an impeller 2d. The stator 2a is a cylindrical structure fixed inside the pump casing 1, providing rotation space and mechanical support for the rotor 2b. The rotor 2b is disposed within the stator 2a, and the rotor shaft 2c extends axially along the pump casing 1, transmitting power to the impeller 2d. Impellers 2d can be installed at both ends of the rotor shaft 2c, or only at one end. The impeller 2d is arranged perpendicular to the rotor shaft 2c and is used for centrifugal pressurization of liquids. Compared to existing multi-stage pumps with long drive shafts, the power units 2 of this invention are arranged independently with short shafts, which helps reduce shaft vibration and mechanical stress, and allows for flexible adjustment of the number of power units 2 to match different operating conditions.

[0025] Each impeller 2d is equipped with a guide plate 4 at its front end to guide the liquid flowing into the suction inlet of the impeller 2d to the central area of ​​the impeller 2d disk, ensuring that the liquid enters the blade area of ​​the impeller 2d uniformly. The liquid thrown out by the impeller 2d forms an annular flow channel 3 along the inner wall of the pump casing 1, flows to the guide plate 4 at the front end of the next stage power unit 2, and re-enters the next stage impeller 2d, realizing the gradual pressurization of the liquid. The continuous flow channel 3 inside the pump is formed by the pump casing 1 and the guide structure, eliminating the need for independent inlet and outlet and connecting pipelines required in traditional multi-pump series connection, thus ensuring the continuity and stability of the liquid flow.

[0026] Each power unit 2 has the same structure and can be modularly installed inside the pump casing 1. The number of power units 2 can be increased or decreased according to actual needs. Each power unit 2 can be connected to an independent drive power supply or control module to independently adjust the speed or output power for different impeller 2d operating conditions, thereby optimizing the overall pump operating conditions.

[0027] In summary, this invention achieves staged liquid pressurization by connecting independent power units 2 in series within a single pump casing 1, and forming a continuous liquid path with guide plates 4 and annular flow channels 3. Compared with existing multi-stage long drive shaft pumps or pump series solutions, this solution is significantly different in terms of compact structure, modular layout, continuous liquid flow, and independent power control. It solves problems such as complex manufacturing, difficult vibration control, and mismatch between stage operating conditions in existing technologies, providing a reliable engineering solution for high-head, high-flow-rate liquid transportation.

[0028] Pump body and pump casing: The pump body of this invention consists of a pump casing 1 extending axially. The pump casing 1 has a cylindrical structure, forming a continuous pressure boundary. One end is provided with an inlet 1a, and the other end is provided with an outlet 1b, providing a complete flow path for the liquid from the pump inlet to the outlet. The pump casing 1 can be integrally machined to form a single cylindrical body, or it can be formed by welding, threaded connection, or flange connection of multiple casing sections to form an integral pressure boundary.

[0029] The pump casing 1 has an axially extending flow channel 3 inside, providing installation space for multiple power units. The pump casing 1 can be equipped with a support or guide to fix the stator 2a and the guide plate 4 of the power unit, ensuring the stable positioning of the power unit 2 in the axial and radial directions, while ensuring the continuity of the fluid channel.

[0030] The pump body features a compact overall structure and a modular layout that facilitates assembly and maintenance. By selecting either an integral or segmented pump casing 1 structure, the manufacturing difficulty and pump body length can be adjusted according to different operating conditions. The pump casing 1 can be made of metal to meet structural strength and pressure resistance requirements.

[0031] An annular gap is formed between the inner wall of the pump casing 1 and the outer edge of the impeller of the power unit, enabling liquid communication between the various power units 2 and ensuring the fluid pressurization sequence of the multi-stage impellers 2d. The exterior of the pump casing 1 can provide an interface or support structure for the installation of the electrical control module, providing a foundation for subsequent modular electrical installation.

[0032] Power Unit 2: In this embodiment, the power units 2 are arranged axially along the pump casing 1 within the continuous internal flow channels 3 defined by the pump casing 1. Each power unit 2 is installed inside the pump casing 1 as an independent modular structural unit. The power units 2 maintain a consistent structural form, including components such as a stator 2a, a rotor 2b, a rotor shaft 2c, and an impeller 2d fixedly connected to the rotor shaft 2c. The power units 2 are connected to each other through the flow channels 3 inside the pump casing 1, allowing the liquid to pass through each power unit 2 sequentially and be pressurized stage by stage.

[0033] The stator 2a is cylindrical in shape and is fixed to the inner wall of the pump casing 1 by welding, fasteners, and other structures. This ensures that the stator 2a maintains a stable spatial position during pump operation and prevents axial or radial displacement caused by vibration. The inner cavity of the stator 2a is used to accommodate the rotor 2b, allowing the rotor 2b to rotate within it and generate driving force.

[0034] The rotor 2b is disposed inside the stator 2a, can rotate freely relative to the stator 2a, and is fixedly connected to the rotor shaft 2c. The rotor shaft 2c extends axially along the pump casing 1 and serves as the main component for power transmission between multiple power units 2.

[0035] The impeller 2d is fixedly installed at the end or both ends of the rotor shaft 2c, and its specific position can be adjusted according to the fluid dynamics design. When the liquid passes through the power unit 2, it first enters the suction port of the impeller 2d. The centrifugal force generated by the rotation of the impeller 2d throws the liquid towards the annular flow channel 3 formed on the inner wall of the pump casing 1, and then into the inlet of the next stage power unit 2. In this invention, a guide plate 4 is provided at the inlet position of each impeller 2d to stabilize the liquid flow direction and ensure that the liquid can be guided to the central area of ​​the impeller 2d, thereby ensuring the efficiency and stability of subsequent pressurization.

[0036] Because this invention employs multiple power units 2 arranged in segments along the axial direction of the pump casing 1, with a designed distance between each power unit 2, each stage of the power unit 2 can operate independently, forming a continuous multi-stage pressurization structure as a whole. Unlike traditional multi-stage pumps where multiple impellers 2d share the same long rotor shaft 2c and are driven by a single motor, the power units 2 of this invention can implement a distributed drive scheme according to requirements. That is, each module can be connected to an independent drive power supply or control unit, thereby allowing for individual adjustment of the power output of different stages under specific operating conditions, improving the controllability and stability of the overall system.

[0037] To adapt to the continuous flow channel 3 structure of the pump casing 1, each power unit 2 in this embodiment has a standardized shape, allowing it to be directly inserted or embedded in the corresponding installation position within the pump casing 1, forming a modular installation method. This modular structural design makes the assembly, testing, and replacement of the power unit 2 more convenient, and also allows for flexible adjustment of the number of power units 2 during production according to the required head, enabling rapid customization of pump performance.

[0038] Through the above structural layout, the power unit 2 of the present invention achieves distributed arrangement, step-by-step pressurization and modular installation within a unified pump casing 1, ensuring that after the liquid enters through the inlet 1a, it can pass through each power unit 2 in sequence and finally be output from the outlet 1b.

[0039] Flow guiding structure and flow channel 3: In this embodiment, in order to achieve a stable transition of liquid between multiple power units 2, a guide plate 4 is provided inside the pump casing 1, and a continuous annular flow channel 3 is formed on the inner wall of the pump casing 1, so that the liquid enters each stage of impeller 2d in sequence and is pressurized step by step.

[0040] A guide vane 4 is installed at the front end of each impeller 2d to guide the liquid from the previous power unit 2 to the central region of the impeller 2d's suction inlet. The guide vane 4 can be a conical or arc-shaped converging structure to maintain a stable flow state before the liquid enters the impeller 2d, reducing flow deviation and eddies, and improving suction efficiency. For a power unit 2 with double-ended impellers 2d, guide vanes 4 can be installed on both sides to ensure suction requirements in different directions.

[0041] As the impeller 2d rotates, it throws the liquid from the suction port toward the outer edge of the impeller 2d and directly guides it into the annular flow channel 3 on the inner wall of the pump casing 1. This annular flow channel 3 is naturally defined by the internal cavity of the pump casing 1 and extends continuously along the axial direction of the pump casing 1, allowing multiple power units 2 to share the same continuous flow channel 3. The liquid flows axially forward in the annular flow channel 3, enters the guide plate 4 area of ​​the next power unit 2, and is once again guided into the center of the impeller 2d.

[0042] The flow channel 3 structure of this invention differs from the segmented switching method achieved by guide vanes or diffusers in traditional multi-stage centrifugal pumps. By allowing multiple power units 2 to work together in a continuous pump casing 1 flow channel 3, this invention reduces energy loss points and makes the liquid path of multi-stage pressurization more compact and linear. The structure of the guide plate 4 can be independently optimized for each stage of operation, adapting to the arrangement of the modular power units 2, further improving the transition stability of the liquid between stages and the overall efficiency.

[0043] Power Unit 2 Control and Modular Design: The multi-stage impeller 2d liquid pump of this embodiment adopts a modular power unit 2 design. Each power unit 2 is structurally independent and can be installed as a standardized component in the axial position of the pump casing 1. The power units 2 maintain consistency in size, stator 2a structure, rotor 2b structure, and impeller 2d arrangement, allowing them to be freely added or removed as needed to adapt to different head or flow requirements. This invention does not rely on the traditional long main shaft drive method, but instead achieves stepwise pressurization by having multiple power units 2 act sequentially on the liquid within the same pump casing 1.

[0044] To accommodate the varying operating conditions of different power units 2, each power unit 2 can be connected to an independent drive power source or an independent control module. The control module can adjust the output power, speed, or start / stop status of each power unit 2 individually, ensuring that each impeller 2d operates within its optimal suction pressure and load range. Since the inlet pressure increases with each stage, independent control prevents any single power unit 2 from affecting the overall pump operation due to suction overload or cavitation, thus enhancing the pump's stability under different operating conditions.

[0045] The modular power unit 2 is fixed inside the pump casing 1 through a standardized interface, and its electrical connections, cooling methods, and installation positions can all be arranged according to a unified standard. Since there is no mechanical axial connection between the power units 2, this invention avoids the processing difficulties and vibration transmission problems of traditional long spindle structures, making the overall pump structure more compact and reliable.

[0046] Through modular layout and hierarchical control, the present invention can flexibly adjust the number of power units 2 according to on-site requirements, realize the rapid configuration of multi-stage pressurization capabilities, and ensure that each power unit 2 can maintain a matched working state at different levels, thereby significantly improving system efficiency and operational reliability.

[0047] Implementation results: This invention achieves a compact and linear multi-stage lifting effect by arranging multiple power units 2 in series within a single pump casing 1, allowing the liquid to be pressurized step-by-step through multiple impellers 2d in the same continuous flow channel 3. Compared with the traditional method of relying on a long main shaft to arrange multiple impellers 2d, this invention avoids the difficulties caused by long drive shaft machining, coaxiality control, and shaft vibration, significantly improving the overall stability of the machine.

[0048] Because power unit 2 adopts a modular structure, all units maintain consistency in geometric dimensions, stator 2a form, and impeller 2d installation method, allowing the number of pump stages to be flexibly increased or decreased as needed. When a higher head is required, only the number of power units 2 needs to be increased; when power reduction or maintenance is required, a single power unit 2 can be disassembled and installed, improving the equipment's scalability and maintainability.

[0049] Multiple power units 2 operate independently, enabling each stage of impeller 2d to adjust its power and speed according to its corresponding inlet pressure and flow conditions, thus making the step-by-step pressurization process more matched. In the lower stage where the negative pressure is higher, the speed can be increased to improve the suction capacity, while in the higher stage, the output can be reduced to reduce overpressure loss, significantly improving overall operating efficiency and reducing the risks of cavitation and abnormal loads.

[0050] Relying on the continuous flow channel 3 formed by the guide plate 4 and the inner wall of the pump casing 1, the liquid switches smoothly between different power units 2 without significant energy loss points. The guide structure allows the liquid to enter each stage of the impeller 2d in a stable direction, reducing eddies and impacts and improving the continuity of the pressurization process. The overall pump body forms a single pressure boundary, avoiding the sealing, assembly, and strength problems of traditional interstage connections, making the structure simpler and more reliable.

[0051] In summary, this invention achieves a comprehensive effect of structural simplification, efficiency improvement, and stability under high head requirements through modular power unit 2, continuous flow channel 3, and independent control strategy, and has good engineering application value.

Claims

1. A modular multi-stage impeller liquid pump, characterized in that, include: The pump casing (1) has a cylindrical structure that extends along the axial direction, forming a continuous pressure boundary. One end of the casing is provided with an inlet (1a) and the other end is provided with an outlet (1b). A flow channel (3) that penetrates the pump housing (1) and is defined by its inner wall; Multiple power units (2) are installed axially spaced within the flow channel (3) of the pump housing (1), and each of the multiple power units (2) comprises: The stator (2a) is fixedly sleeved inside the pump casing (1); The rotor (2b) is rotatably mounted inside the stator (2a); The rotor shaft (2c) is coaxially connected to the rotor (2b) and extends along the axial direction of the pump casing (1); The impeller (2d) is fixedly mounted on the rotor shaft (2c) and located in the flow channel (3).

2. The modular multi-stage impeller liquid pump according to claim 1, characterized in that, Each power unit (2) has a guide plate (4) at its front end, which is fixedly connected to the pump casing (1) and arranged around the rotor shaft (2c).

3. The modular multi-stage impeller liquid pump according to claim 1, characterized in that, An annular gap is formed between the inner wall of the pump casing (1) and the outer edge of the impeller (2d), and multiple power units (2) are connected through this annular gap to form a through internal flow channel (3).

4. The modular multi-stage impeller liquid pump according to claim 1, characterized in that, The pump casing (1) is an integral structure.

5. The modular multi-stage impeller liquid pump according to claim 1, characterized in that, The pump casing (1) is formed by welding or threading multiple casing segments together.

6. The modular multistage impeller liquid pump according to claim 1, characterized in that, Each power unit (2) is equipped with an independent electrical connection port.

7. The modular multistage impeller liquid pump according to claim 1, characterized in that, An impeller (2d) is mounted on at least one end of the rotor shaft (2c), and the impeller (2d) is fixedly arranged in a direction perpendicular to the rotor shaft (2c).

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