A multistage horizontal centrifugal pump

Abstract

This invention relates to the field of multistage horizontal centrifugal pump technology, and discloses a multistage horizontal centrifugal pump, comprising: a drive motor, the output end of which is fixedly connected to one end of a pump shaft, and the other end of the pump shaft is fixedly connected to a multistage centrifugal pump component; a positioning mechanism is also provided on the pump shaft, and the positioning mechanism is rotatably connected to the pump shaft; a balancing mechanism, including a driven component and a hydraulic component, the driven component being located between the positioning mechanism and the drive motor, one end of the driven component being connected to the pump shaft, and the other end of the driven component being fixedly connected to the hydraulic component; and a feedback mechanism, including a thrust component, an amplification component, and a sealing component, the thrust component being located between the positioning mechanism and the multistage centrifugal pump component, the thrust component and the amplification component being connected through the sealing component, the amplification component being rotatably connected to the hydraulic component, and the thrust component being connected to the hydraulic component through a pipeline. This application improves adaptability under various operating conditions and reduces pump shaft axial movement.

Description

Technical Field

[0001] This invention relates to the field of multistage horizontal centrifugal pump technology, and more particularly to a multistage horizontal centrifugal pump. Background Technology

[0002] A multistage horizontal centrifugal pump is a rotary power pump that connects multiple centrifugal impellers in series on the same pump shaft and employs a horizontal structure design. Its core design concept is to use a "cascade" approach, allowing the fluid to pass sequentially through each impeller and guide vane stage. The pressure (head) increases with each stage, ultimately achieving an outlet pressure significantly higher than that of a single-stage centrifugal pump within a single pump body. It is a key piece of equipment for achieving high-head delivery of various clean or slightly contaminated liquids, and its operation is based on the principle of centrifugal force. The motor drives the pump shaft to rotate, causing all impellers to rotate synchronously. The fluid enters from the pump's suction end, flows into the first-stage impeller, and gains kinetic and pressure energy in the high-speed rotation of the impeller. It then flows into the fixed guide vanes, where some of the kinetic energy is effectively converted into pressure energy, guiding the fluid to the next stage impeller at the optimal angle. This process is repeated stage by stage until the fluid exits from the last stage guide vane, achieving the final high-pressure output through the outlet section.

[0003] Existing multistage horizontal centrifugal pumps, with all impellers arranged in the same direction and typically featuring backward-curved blades and asymmetrical front and rear cover plates, generate a cumulative axial force pointing towards the pump's suction end during operation. If not effectively balanced, this force can cause the entire rotor assembly (shaft and impeller) to move towards the suction end, leading to friction and collision between the impeller and the pump casing, resulting in catastrophic damage. The industry has long used two passive mechanical balancing devices: balancing discs and balancing drums, or combinations of both. However, the adjustment of the balancing disc relies on the physical movement of the rotor. When sudden changes in operating conditions (such as pump start-up, pump shutdown, or rapid valve opening and closing) cause a rapid and instantaneous change in axial force, the rotor needs to shift first to adjust the clearance and balance pressure. This physical feedback process inevitably involves mechanical lag. Before adjustment is complete, the rotor has already experienced severe axial movement ("shaft slippage"), impacting the mechanical seal and bearings. The balancing disc's operation relies on an "optimal leakage clearance," but this clearance itself is a friction pair that continuously wears during operation. As wear intensifies, leakage increases, reducing the efficiency of pressure build-up in the balancing chamber and gradually worsening the balancing effect. This performance degradation is irreversible unless the entire balancing system is replaced after shutdown. This means that the pump's operational reliability naturally decreases with increasing operating time, especially during the startup phase when the balancing pressure has not yet been established, the balancing disc is almost ineffective, and the rotor will momentarily surge towards the suction end. Although the design relies on the thrust bearing to withstand brief impacts, repeated occurrences over a long period will also increase bearing wear. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-stage horizontal centrifugal pump to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a multi-stage horizontal centrifugal pump, comprising:

[0006] A drive motor is provided, the output end of which is fixedly connected to one end of the pump shaft, and the other end of the pump shaft is fixedly connected to a multi-stage centrifugal pump component. A positioning mechanism is also provided on the pump shaft, and the positioning mechanism is rotatably connected to the pump shaft.

[0007] The balancing mechanism includes a driven component and a hydraulic component. The driven component is located between the positioning mechanism and the drive motor. One end of the driven component is connected to the pump shaft, and the other end of the driven component is fixedly connected to the hydraulic component.

[0008] The feedback mechanism includes a thrust component, an amplification component, and a sealing component. The thrust component is located between the positioning mechanism and the multi-stage centrifugal pump component. The thrust component and the amplification component are connected through the sealing component. The amplification component is rotatably connected to the hydraulic component. The thrust component is connected to the hydraulic component through a pipeline.

[0009] Furthermore, the multi-stage centrifugal pump component includes a centrifugal pump housing, impellers, an outlet, and an inlet. The pump shaft extends through the centrifugal pump housing. Several impellers are provided, located inside the centrifugal pump housing and fixedly connected to the pump shaft. The centrifugal pump housing is provided with an outlet and an inlet.

[0010] Furthermore, the positioning mechanism includes a main bearing, a secondary bearing, a positioning housing, a sealing side plate, a cooling inlet, and a cooling outlet. The positioning housing is sleeved on the pump shaft. Both the main bearing and the secondary bearing are rotatably connected to the pump shaft, and both the main bearing and the secondary bearing are located inside the positioning housing. The main bearing is located near the impeller, and the secondary bearing is located near the drive motor. Both sides of the positioning housing are bolted together by the sealing side plate. The positioning housing has the cooling inlet and the cooling outlet.

[0011] Furthermore, the driven component includes a first bevel gear, a driven rod, a second bevel gear, a third bevel gear, and a fourth bevel gear. The first bevel gear is fixedly connected to the pump shaft. The driven rod is perpendicular to the pump shaft. The driven rod meshes with the first bevel gear through the second bevel gear. The driven rod is also provided with a third bevel gear. The second bevel gear and the third bevel gear are respectively located at both ends of the driven rod. The fourth bevel gear is located on the hydraulic component and meshes with the third bevel gear.

[0012] Furthermore, the hydraulic component includes a hydraulic housing, a hydraulic outlet, a hydraulic inlet, a hydraulic shaft, a piston, a follower rod, and a sloping plate. The hydraulic housing has a hydraulic inlet and a hydraulic outlet. A plurality of pistons are slidably connected inside the hydraulic housing. One end of the plurality of pistons is connected to the sloping plate. The follower rod is fixedly connected to the sloping plate. A fourth bevel gear is also fixedly connected to the follower rod. The hydraulic shaft is rotatably connected to one end of the follower rod.

[0013] Furthermore, the thrust component includes a balance chamber, a thrust ring, a shoulder, a stop washer, and an inner groove. The balance chamber is rotatably connected to the pump shaft. The thrust ring is disposed within the balance chamber and is located on the pump shaft between the sealing side plate and the centrifugal pump housing. The thrust ring is interference-fitted with the pump shaft. A shoulder is also fixedly connected to the pump shaft. The shoulder is located between the sealing side plate and the thrust ring and abuts against the thrust ring. The stop washer is located on the side away from the shoulder and abuts against the thrust ring. The stop washer is used to prevent the thrust ring from loosening. An inner groove is formed on the outer wall of the thrust ring in an annular shape.

[0014] Furthermore, the amplification component includes a short arm, a long arm, an annular contact, a rotating disk, a pilot-operated relief valve, and an amplification rod. One end of the short arm is fixedly connected to the annular contact, which is located in the recessed groove and rotatably connected to the thrust ring. The other end of the short arm is rotatably connected to the long arm. The long arm is fixedly connected to the amplification rod, which is connected to the rotating disk. The rotating disk is fixedly connected to the pressure regulating handwheel of the pilot-operated relief valve, and the pilot-operated relief valve is connected to the hydraulic outlet through the pipeline.

[0015] Furthermore, the sealing component includes a rotary shaft lip seal and a rolling bearing. A rolling bearing is provided at the connection between the balance chamber and the short arm, and a rotary shaft lip seal is connected to the outside of the rolling bearing.

[0016] This invention discloses the following technical effects: By establishing a feedback mechanism and a balancing mechanism, a continuous and automatic adjustment loop is constructed. The thrust component senses the axial displacement change of the rotor in real time and immediately transmits this mechanical signal to the hydraulic component through an amplification component. The hydraulic component then responds, actively and steplessly adjusting the hydraulic pressure acting on the balancing chamber, thereby generating a reverse thrust that matches the changing axial force. This active control structure based on real-time feedback ensures that the axial force can be canceled out under any operating condition, controlling the axial position fluctuation of the rotor within a small range and achieving dynamic balancing accuracy. Through an independent hydraulic loop, the key control elements in this loop do not rely on precise dynamic and static fit clearances to establish pressure; therefore, its balancing performance will not degrade over time, eliminating the need for... The performance degradation caused by wear of the balancing device and the risk of sudden "shaft slippage" are mitigated by improving the inherent reliability of the equipment, extending the stable operation cycle, and reducing the reliance on frequent maintenance and inspection. Through the hydraulic balancing circuit, the internal fluid flow is mainly used to transmit pressure and control signals. When a stable balance is achieved, there is no need for a large, continuous leakage flow to maintain pressure, thereby reducing internal diversion losses for balancing purposes and allowing more input energy to be used to pressurize the main process liquid, improving energy utilization efficiency. During pump operation, the entire mechanism can automatically identify and compensate for changes in axial force regardless of the cause or timing. This enables the pump to maintain excellent axial stability under various operating conditions throughout the entire process from start-up and shutdown to flow regulation, expanding its range of efficient and safe operation. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is an overall schematic diagram of a multi-stage horizontal centrifugal pump provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the multi-stage horizontal centrifugal pump provided in an embodiment of the present invention from another perspective;

[0020] Figure 3 A cross-sectional view of the hydraulic components in a multi-stage horizontal centrifugal pump provided in an embodiment of the present invention;

[0021] Figure 4 This is a cross-sectional view of the multistage centrifugal pump component in a multistage horizontal centrifugal pump provided in an embodiment of the present invention.

[0022] In the diagram: 1. Drive motor; 2. Pump shaft; 3. Balancing mechanism; 310. Driven component; 3101. First bevel gear; 3102. Driven rod; 3103. Second bevel gear; 3104. Third bevel gear; 3105. Fourth bevel gear; 320. Hydraulic component; 3201. Hydraulic housing; 3202. Hydraulic outlet; 3203. Hydraulic inlet; 3204. Hydraulic shaft; 3205. Piston; 3206. Follower rod; 3207. Inclined plate; 4. Feedback mechanism; 410. Thrust component; 4101. Balancing chamber; 4102. Push... 4103, Force ring; 4104, Retaining washer; 420, Inner groove; 420, Amplifying component; 4201, Short arm; 4202, Long arm; 4203, Annular contact; 4204, Rotary disc; 4205, Pilot-operated relief valve; 4206, Amplifying rod; 5, Multistage centrifugal pump components; 501, Centrifugal pump housing; 502, Impeller; 503, Liquid outlet; 504, Liquid inlet; 6, Positioning mechanism; 601, Main bearing; 602, Auxiliary bearing; 603, Positioning housing; 604, Sealing side plate; 605, Cooling inlet; 606, Cooling outlet. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] In some embodiments of this application, see Figures 1-4 As shown, a multi-stage horizontal centrifugal pump includes:

[0027] The drive motor 1 has its output end fixedly connected to one end of the pump shaft 2, and the other end of the pump shaft 2 is fixedly connected to the multi-stage centrifugal pump component 5. The pump shaft 2 is also provided with a positioning mechanism 6, which is rotatably connected to the pump shaft 2.

[0028] The balancing mechanism 3 includes a driven component 310 and a hydraulic component 320. The driven component 310 is located between the positioning mechanism 6 and the drive motor 1. One end of the driven component 310 is connected to the pump shaft 2, and the other end of the driven component is fixedly connected to the hydraulic component 320.

[0029] Feedback mechanism 4 includes a thrust component 410, an amplification component 420, and a sealing component. The thrust component 410 is located between the positioning mechanism 6 and the multi-stage centrifugal pump component 5. The thrust component 410 and the amplification component 420 are connected through the sealing component. The amplification component 420 is rotatably connected to the hydraulic component 320. The thrust component 410 is connected to the hydraulic component 320 through a pipeline.

[0030] Specifically, when the drive motor 1 drives the pump shaft 2 to rotate, the pump shaft 2 drives the multi-stage centrifugal pump component 5 to operate. At this time, the driven component 310 rotates synchronously with the pump shaft 2, thereby driving the hydraulic component 320 to deliver high-pressure medium to the thrust component 410. At this time, the pressure inside the thrust component 410 begins to rise, thereby generating an axial force on the rotor. The thrust generated by the thrust component 410 is used to overcome the axial force of the rotor and counteract the problem of pump shaft 2 axial movement caused by the change in the head of the multi-stage centrifugal pump. For example, when the operating conditions change, the axial force will increase, and the rotor will tend to move towards the suction end. At this time, the movement of the rotor towards the suction end will drive the thrust component 410 to shift, which in turn will drive the amplification component 420 to rotate. The rotation of the amplification component 420 increases the set pressure of the thrust component 410. When the set pressure increases, the pressure in the pipeline from the outlet of the hydraulic component 320 to the thrust component 410 is forced to increase to reach a new, higher equilibrium point. When the rotor returns to the equilibrium position, the thrust component 410 and the amplification component 420 return to their original positions, and the set pressure in the pipeline stops changing. If the axial force decreases, the process is reversed. Therefore, through the cooperation of the thrust component 410 and the amplification component 420, the axial displacement of the pump shaft 2 can be obtained, thereby increasing the pressure in the thrust component 410 to achieve balance and prevent damage to the pump shaft 2 caused by axial movement. The short arm 4201 covers the sealing component, so it is not shown in the figure.

[0031] Understandably, traditional multistage pumps generally rely on devices such as balance discs or balance drums, and their working principle is passive compensation. That is, only after axial force has occurred and caused physical movement of the rotor does a new balance attempt to be established by changing the clearance or other mechanical means, which has inherent response delay and adjustment lag. This embodiment constructs a continuous, adaptive dynamic adjustment closed loop through a unique mechanism design. When the axial force of the pump shaft 2 shows a changing trend, the thrust component 410 can instantly sense its minute displacement and transmit this mechanical signal to the hydraulic control part through the amplification component 420. The hydraulic component 320 then responds and actively adjusts the hydraulic pressure output to the thrust component 410, thereby generating a reverse thrust that matches the changing axial force in real time. This active control mechanism based on instantaneous feedback ensures that the axial force can be canceled out under any operating condition, controls the axial position fluctuation of the rotor within an extremely small range, fundamentally eliminates the occurrence of harmful movement, and achieves unprecedented operational stability. The effectiveness of traditional balancing devices relies heavily on precise dynamic-static fit clearances. These clearances inevitably increase gradually during operation due to friction, leading to a continuous decline in balancing efficiency and increased leakage. This not only reduces efficiency but also poses a risk of serious accidents due to sudden failure. The balancing function of this embodiment no longer relies on such vulnerable friction pairs. Its core force balance is achieved through an independent hydraulic and feedback mechanism 4 composed of robust mechanical components. The key components in this mechanism do not depend on precise dynamic-static clearances to operate, therefore their performance does not degrade over time. This improves the inherent reliability and long-term consistency of equipment operation, extends the stable operating cycle without intervention, reduces reliance on frequent maintenance checks, and eliminates the risk of catastrophic failure due to sudden damage to the balancing device. To achieve the balancing function, traditional devices must be designed with a path that allows continuous leakage of high-pressure fluid. This leaking fluid does not perform useful work and directly constitutes a constant energy loss for the pump, leading to reduced overall operating efficiency. The hydraulic balancing circuit used in this embodiment primarily serves pressure transmission and control signal generation, resulting in a more optimized design. Once a steady state is reached, there is no need to rely on a large, continuous leakage flow to maintain the balancing pressure, thereby reducing internal diversion losses for balancing purposes. This allows more input energy to be used for effective pressurization of the main process fluid, improving energy utilization efficiency and economy. In practical applications, pumps often need to operate at different flow rates and pressures according to process requirements, causing the axial force to change dynamically. Traditional devices suffer significant reductions in balancing effectiveness and may even exacerbate vibration when deviating from their design operating conditions. The advantage of this embodiment lies in its feedback mechanism, which is not optimized for a specific operating point. Regardless of changes in axial force due to flow rate variations, inlet pressure fluctuations, or any other reason, the entire mechanism can automatically identify and immediately initiate a compensation procedure.This enables the pump to maintain excellent axial stability under various operating conditions throughout the entire process, from startup and shutdown to significant load changes, thus expanding its range of safe and stable operation and demonstrating stronger process adaptability.

[0032] In some embodiments of this application, the multi-stage centrifugal pump component 5 includes a centrifugal pump housing 501, an impeller 502, an outlet 503, and an inlet 504. The pump shaft 2 extends into the centrifugal pump housing 501. Several impellers 502 are provided, and the several impellers 502 are located inside the centrifugal pump housing 501 and are fixedly connected to the pump shaft 2. The centrifugal pump housing 501 is provided with an outlet 503 and an inlet 504.

[0033] In some embodiments of this application, the positioning mechanism 6 includes a main bearing 601, a secondary bearing 602, a positioning housing 603, a sealing side plate 604, a cooling inlet 605, and a cooling outlet 606. The positioning housing 603 is sleeved on the pump shaft 2. Both the main bearing 601 and the secondary bearing 602 are rotatably connected to the pump shaft 2, and both the main bearing 601 and the secondary bearing 602 are located inside the positioning housing 603. The main bearing 601 is located on the side closer to the impeller 502, and the secondary bearing 602 is located on the side closer to the drive motor 1. Both sides of the positioning housing 603 are bolted together by the sealing side plate 604. The positioning housing 603 is provided with a cooling inlet 605 and a cooling outlet 606.

[0034] Specifically, when the pump shaft 2 starts to rotate, it drives several impellers 502 in multiple stages to rotate, thereby transporting fluid from the inlet 504 to the outlet 503. When the pump shaft 2 rotates, the main bearing 601 and the auxiliary bearing 602 rotate synchronously. A positioning housing 603 is provided outside the bearing. The positioning housing 603 is sealed by a sealing side plate 604, and coolant is introduced into it through a cooling inlet 605.

[0035] Understandably, the long rotor of a multistage pump is prone to vibration at high speeds, and its stability hinges on reliable and precise radial positioning. The architecture, with the main bearing 601 and auxiliary bearing 602 arranged in pairs and housed within a rigid positioning housing 603, provides a solid and unified support foundation for the pump shaft 2, constraining the radial movement of the rotor and enhancing the rigidity of the rotor system. This suppresses vibrations that may be caused by rotor deflection or external forces. The shorter bearing span and integrated housing ensure high concentricity of the support points, making the rotation trajectory of the pump shaft 2 more precise and stable. This lays a solid foundation for the pump's smooth, low-vibration, and low-noise operation, while also reducing dynamic interference to precision components such as the mechanical seal. Bearings generate significant frictional heat during high-speed operation. If this heat cannot be dissipated in time, it can lead to deterioration of the lubricating oil, annealing of the bearing metal, and ultimately, lubrication failure, shaft seizure, or even burnout. By integrating independent cooling channels (cooling inlet 605 and cooling outlet 606) into the positioning housing 603, the direct benefit is the ability to perform forced and active heat exchange on the bearing housing. The cooling medium continuously removes the heat generated during bearing operation, maintaining the bearing's operating temperature within the ideal range. This not only prevents lubrication failure and metal fatigue caused by overheating but also significantly slows down the aging rate of the bearing, lubricating oil, and their own seals, thereby comprehensively extending the service life and reliability of the entire bearing assembly and related components. Proper bearing operation depends on clean and sufficient lubrication. Traditional open or simply sealed bearing housings pose a risk of grease being thrown out or lubricating oil leakage, and are also difficult to completely prevent the intrusion of external contaminants such as moisture and dust. By using sealing side plates 604 on both sides and fastening them to the positioning housing 603 with bolts, a highly sealed clean chamber is constructed. This improves the sealing integrity of the bearing chamber, reliably sealing the lubricating medium inside while completely isolating external contaminants. This not only reduces lubricant consumption and avoids environmental pollution from leaks but, more importantly, provides the bearing with a long-term stable clean working environment, reducing abrasive wear and premature damage caused by contamination.

[0036] In some embodiments of this application, the driven component 310 includes a first bevel gear 3101, a driven rod 3102, a second bevel gear 3103, a third bevel gear 3104, and a fourth bevel gear 3105. The first bevel gear 3101 is fixedly connected to the pump shaft 2. The driven rod 3102 is perpendicular to the pump shaft 2. The driven rod 3102 meshes with the first bevel gear 3101 through the second bevel gear 3103. The driven rod 3102 is also provided with a third bevel gear 3104. The second bevel gear 3103 and the third bevel gear 3104 are located at the two ends of the driven rod 3102, respectively. The fourth bevel gear 3105 is located on the hydraulic component 320 and meshes with the third bevel gear 3104.

[0037] In some embodiments of this application, the hydraulic component 320 includes a hydraulic housing 3201, a hydraulic outlet 3202, a hydraulic inlet 3203, a hydraulic shaft 3204, a piston 3205, a follower rod 3206, and a sloping plate 3207. The hydraulic housing 3201 has a hydraulic inlet 3203 and a hydraulic outlet 3202. A plurality of pistons 3205 are slidably connected inside the hydraulic housing 3201. One end of the plurality of pistons 3205 is connected to the sloping plate 3207. The follower rod 3206 is fixedly connected to the sloping plate 3207. A fourth bevel gear 3105 is also fixedly connected to the follower rod 3206. The hydraulic shaft 3204 is rotatably connected to one end of the follower rod 3206.

[0038] Specifically, when the pump shaft 2 rotates, it drives the first bevel gear 3101 to rotate, which in turn drives the second bevel gear 3103 to rotate, which in turn drives the driven rod 3102 to rotate. The rotation of the driven rod 3102 drives the third bevel gear 3104 to rotate, which in turn drives the fourth bevel gear 3105 to rotate. The fourth bevel gear 3105 is connected to the hydraulic component 320, which drives the inclined plate 3207 to move, which in turn drives the piston 3205 to move, thereby realizing the delivery of high-pressure medium to the thrust component 410. The hydraulic outlet 3202 is connected to an independent high-pressure medium storage device, which delivers the high-pressure medium from the hydraulic inlet 3203 to the hydraulic outlet 3202, and then delivers it to the thrust component 410 through the pipeline.

[0039] Understandably, the vertical transmission of power from the main pump shaft 2 to the hydraulic component 320 is achieved through a bevel gear set. The fixed connection between the first bevel gear 3101 and the pump shaft 2 ensures that the source of power extraction is strictly synchronized with the main operating component. The meshing bevel gear pair forms a robust mechanical power transmission chain with a stable and precise transmission relationship, free from slippage or delay. This rigid connection ensures that the output flow and pressure of the hydraulic component 320 maintain a constant proportional relationship with the pump main shaft speed, providing a stable and reliable power foundation that is completely synchronized with the pump's operating conditions for subsequent hydraulic control, eliminating control errors introduced by unstable power sources. The hydraulic component 320 adopts a swashplate-type axial piston 3205 pump design, which is a highly efficient and mature hydraulic power component. Its core advantage lies in the ingenious conversion of rotational motion into the reciprocating motion of the piston 3205 through the swashplate 3207, thereby generating high-pressure fluid. It achieves continuous output of high-pressure media within a limited space, resulting in high power density. Compared to other types of pumps, it boasts higher efficiency and less pressure pulsation, providing smooth and powerful hydraulic power to meet the instantaneous demands of the balancing system for high-pressure media, ensuring rapid and forceful establishment of reverse thrust. The entire hydraulic system's power is derived entirely from the rotational kinetic energy of the pump spindle itself, without relying on external motors, hydraulic stations, or other independent power sources. This coaxial drive design achieves internal energy circulation and self-sufficiency, simplifying the overall system structure and avoiding the risk of balancing system failure due to external power source malfunction. It makes the axial force balancing system a highly integrated and self-driving subsystem, enhancing the overall pump unit's integration and operational autonomy. Because power transmission is purely mechanical and direct, the response speed of hydraulic component 320 is completely synchronized with changes in pump spindle speed. When pump operating conditions change, causing speed variations, the output capacity of hydraulic component 320 changes instantly, without waiting for external control signals or speed adjustments from external power sources. This inherent linkage characteristic ensures the immediacy of hydraulic power supply, providing a crucial prerequisite for the feedback mechanism 4 to achieve rapid pressure regulation and dynamic axial force balance, thus guaranteeing the response speed of the entire active balancing system from the source. The swashplate piston 3205 pump has excellent high-speed performance and a wide pressure adaptability range. Its output characteristics can well match the working requirements of multi-stage pumps at different speeds and heads. Whether the pump is operating at high speed and full load or low speed and partial load, this hydraulic component 320 can provide hydraulic power of corresponding strength, ensuring the effectiveness of the balancing system across the entire operating range, avoiding the decline or fluctuation of balancing performance caused by insufficient or excessive hydraulic power, and enhancing the pump's adaptability to complex and variable operating conditions.

[0040] In some embodiments of this application, the thrust component 410 includes a balance chamber 4101, a thrust ring 4102, a shoulder, a stop washer 4103, and an inner groove 4104. The balance chamber 4101 is rotatably connected to the pump shaft 2. The thrust ring 4102 is disposed in the balance chamber 4101. The thrust ring 4102 is located on the pump shaft 2 between the sealing side plate 604 and the centrifugal pump housing 501, and the thrust ring 4102 is interference-fitted with the pump shaft 2. A shoulder is also fixedly connected to the pump shaft 2. The shoulder is located between the sealing side plate 604 and the thrust ring 4102 and abuts against the thrust ring 4102. The stop washer 4103 is located on the side away from the shoulder and abuts against the thrust ring 4102. The stop washer 4103 is used to prevent the thrust ring 4102 from loosening. The outer wall of the thrust ring 4102 is provided with an inner groove in annular shape.

[0041] In some embodiments of this application, the amplifying component 420 includes a short arm 4201, a long arm 4202, an annular contact 4203, a rotating disk 4204, a pilot-operated relief valve 4205, and an amplifying rod 4206. One end of the short arm 4201 is fixedly connected to the annular contact 4203, which is located in the recessed groove 4104 and rotatably connected to the thrust ring 4102. The other end of the short arm 4201 is rotatably connected to the long arm 4202. The long arm 4202 is fixedly connected to the amplifying rod 4206, which is connected to the rotating disk 4204. The rotating disk 4204 is fixedly connected to the pressure regulating handwheel of the pilot-operated relief valve 4205, which is connected to the hydraulic outlet 3202 through a pipeline.

[0042] In some embodiments of this application, the sealing component includes a rotary shaft lip seal and a rolling bearing. A rolling bearing is provided at the connection between the balance cavity 4101 and the short arm 4201, and a rotary shaft lip seal is connected to the outside of the rolling bearing.

[0043] Specifically, the balance chamber 4101 is connected to the hydraulic component 320 via a pipeline. Shoulders and retaining washers 4103 are provided on both sides of the thrust ring 4102, allowing the thrust ring 4102 to be clamped in the middle. Therefore, when the thrust ring 4102 undergoes axial displacement, its annular contact 4203 displaces synchronously, causing the short arm 4201 to rotate. This, in turn, drives the long arm 4202 to rotate in the opposite direction. Because the long arm 4202 is longer than the short arm 4201, its minute displacement is amplified. When the long arm 4202 rotates, it drives the... The large rod 4206 moves laterally, which in turn causes the rotating disk 4204 to rotate, which in turn causes the pressure regulating handwheel on the pilot-operated relief valve 4205 to rotate, changing its pressure. One end of the pipeline is connected to the balance chamber 4101, and the pilot-operated relief valve 4205 is set in the middle of the pipeline, which is then connected to the hydraulic component 320. Since the short arm 4201 extends out of the balance chamber 4101, the connection between the short arm 4201 and the balance chamber 4101 is sealed by a rotary shaft lip seal and a rolling bearing without affecting its operation.

[0044] Understandably, the thrust ring 4102, through a combination of interference fit, shoulder positioning, and locking washer 4103, forms a rigid whole with the pump shaft 2, achieving absolutely synchronous movement. This connection eliminates axial or circumferential backlash, ensuring that any minute axial displacement of the pump shaft 2 can be transmitted to the thrust ring 4102 accurately, without delay, and without distortion. The annular groove 4104 on its outer wall, in conjunction with the annular contact 4203, provides a precise reference surface for the transmission of displacement signals. This results in extremely high fidelity of the displacement sensing source signal, laying the most solid foundation for the accuracy of the entire closed-loop control system and avoiding control inaccuracies caused by lag or errors in the signal acquisition stage. The amplification component 420 uses the lever principle (short arm 4201 and long arm 4202) combined with the subsequent transmission mechanism to convert the axial displacement of the thrust ring 4102 into the angular displacement of the pressure regulating handwheel of the pilot-operated relief valve 4205. This purely mechanical amplification method requires no external power source and has a robust and reliable structure. It converts physical changes into effective valve operation, improving the resolution of minute displacements and the system's control sensitivity. This amplification capability enables the system to respond effectively to extremely subtle changes in axial force, thereby achieving extremely smooth and precise axial position control, stabilizing the rotor at the ideal equilibrium point. The pilot-operated relief valve 4205, as the core of hydraulic pressure setting, typically requires manual adjustment with high precision. This embodiment uses a mechanical amplification mechanism to ultimately convert the axial displacement signal into the rotational motion of the pressure regulating handwheel, achieving purely mechanical automatic adjustment of the relief valve's set pressure. This not only reduces reliance on manual intervention but, more importantly, achieves continuous, stepless, and automated pressure setting, with response speed and precision far exceeding manual operation. It perfectly integrates a control element requiring precise operation into the automatic control closed loop, improving the system's automation level and response performance. The sealing component adopts a combination of a rotary shaft lip seal and a rolling bearing, solving the dynamic sealing problem when the short-arm 4201 fulcrum shaft penetrates the wall of the high-pressure balance chamber 4101. The rolling bearing effectively supports radial force, ensuring flexible and unhindered lever oscillation and minimizing frictional torque. The outer rotating shaft lip seal reliably seals high-pressure media, preventing leakage. This combined design ensures sealing reliability while reducing frictional resistance of moving parts, preventing the absorption of weak displacement signals or control lag due to excessive sealing friction, thus guaranteeing the accuracy of feedback signal transmission and system sensitivity. The fixing method of the thrust ring 4102 assembly (shoulder, retaining washer 4103) prevents potential loosening, ensuring the stability of the measurement reference during long-term operation. This reduces the risk of measurement error accumulation, control point drift, and even system failure due to loose mechanical connections or joint wear, enhancing the long-term stability and reliability of the system.

[0045] In summary, the beneficial effects of this invention are as follows: Through the feedback mechanism 4 and the balancing mechanism 3, a continuous and automatic adjustment loop is constructed. The thrust component 410 senses the axial displacement change of the rotor in real time and immediately transmits this mechanical signal to the hydraulic component 320 through the amplification component 420. The hydraulic component 320 then responds, actively and steplessly adjusting the hydraulic pressure acting on the balancing chamber 4101, thereby generating a reverse thrust that matches the changing axial force. This active control structure based on real-time feedback ensures that the axial force can be canceled under any operating condition, controlling the axial position fluctuation of the rotor within a small range and achieving dynamic balancing accuracy. Through an independent hydraulic loop, the key control elements in this loop do not rely on precise dynamic and static fit clearances to establish pressure; therefore, its balancing performance does not decrease with operating time. Over time, this design eliminates performance degradation and the risk of sudden "shaft slippage" caused by wear of the balancing device, improving the inherent reliability of equipment operation, extending the stable operation cycle, and reducing reliance on frequent maintenance and inspection. Through the hydraulic balancing circuit, the internal fluid flow is mainly used to transmit pressure and control signals. When a stable balance is achieved, there is no need for a large, continuous leakage flow to maintain pressure, thereby reducing internal diversion losses for balancing purposes. This allows more input energy to be used to pressurize the main process fluid, improving energy utilization efficiency. During pump operation, regardless of the cause or timing of changes in axial force, the entire mechanism can automatically identify and compensate for these changes. This enables the pump to maintain excellent axial stability under various operating conditions throughout the entire process from start-up and shutdown to flow regulation, expanding its range of efficient and safe operation.

[0046] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0047] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multi-stage horizontal centrifugal pump, characterized in that, include: The drive motor (1) has its output end fixedly connected to one end of the pump shaft (2), and the other end of the pump shaft (2) is fixedly connected to the multi-stage centrifugal pump component (5). The pump shaft (2) is also provided with a positioning mechanism (6), which is rotatably connected to the pump shaft (2). The balancing mechanism (3) includes a driven component (310) and a hydraulic component (320). The driven component (310) is located between the positioning mechanism (6) and the drive motor (1). One end of the driven component (310) is connected to the pump shaft (2), and the other end of the driven component (310) is fixedly connected to the hydraulic component (320). The feedback mechanism (4) includes a thrust component (410), an amplification component (420), and a sealing component. The thrust component (410) is located between the positioning mechanism (6) and the multi-stage centrifugal pump component (5). The thrust component (410) and the amplification component (420) are connected through the sealing component. The amplification component (420) is rotatably connected to the hydraulic component (320). The thrust component (410) is connected to the hydraulic component (320) through a pipeline. The multi-stage centrifugal pump component (5) includes a centrifugal pump housing (501), an impeller (502), an outlet (503) and an inlet (504), and the pump shaft (2) extends through the centrifugal pump housing (501); The positioning mechanism (6) includes a main bearing (601), a secondary bearing (602), a positioning housing (603), a sealing side plate (604), a cooling inlet (605), and a cooling outlet (606). Both sides of the positioning housing (603) are bolted to the sealing side plate (604). The thrust component (410) includes a balance chamber (4101), a thrust ring (4102), a shoulder, a retaining washer (4103), and an inner groove (4104). The balance chamber (4101) is rotatably connected to the pump shaft (2). The thrust ring (4102) is disposed in the balance chamber (4101). The thrust ring (4102) is located on the pump shaft (2) between the sealing side plate (604) and the centrifugal pump housing (501). The pump shaft (2) is interference-fitted with the pump shaft (2), and a shoulder is fixedly connected to the pump shaft (2). The shoulder is located between the sealing side plate (604) and the thrust ring (4102) and abuts against the thrust ring (4102). The stop washer (4103) is located away from the shoulder and abuts against the thrust ring (4102). The stop washer (4103) is used to prevent the thrust ring (4102) from loosening. The outer wall of the thrust ring (4102) is provided with an inner groove in annular shape. The amplifying component (420) includes a short arm (4201), a long arm (4202), an annular contact (4203), a rotating disk (4204), a pilot-operated overflow valve (4205), and an amplifying rod (4206). One end of the short arm (4201) is fixedly connected to the annular contact (4203). The annular contact (4203) is located within the recessed groove (4104) and is rotatably connected to the thrust ring (4102). The other end of the short arm (4201) is rotatably connected to the long arm (4202). The long arm (4202) is fixedly connected to an amplifying rod (4206). The amplifying rod (4206) is connected to the rotating disk (4204). The rotating disk (4204) is fixedly connected to the pressure regulating handwheel of the pilot-operated relief valve (4205). The pilot-operated relief valve (4205) is connected to the hydraulic outlet (3202) through the pipeline.

2. The multi-stage horizontal centrifugal pump according to claim 1, characterized in that, The impeller (502) is provided in a plurality of manner, and the plurality of impellers (502) are located inside the centrifugal pump housing (501) and are fixedly connected to the pump shaft (2). The centrifugal pump housing (501) is provided with an outlet (503) and an inlet (504).

3. The multi-stage horizontal centrifugal pump according to claim 2, characterized in that, The positioning housing (603) is sleeved on the pump shaft (2). The main bearing (601) and the auxiliary bearing (602) are rotatably connected to the pump shaft (2). The main bearing (601) and the auxiliary bearing (602) are both located inside the positioning housing (603). The main bearing (601) is located near the impeller (502), and the auxiliary bearing (602) is located near the drive motor (1). The positioning housing (603) is provided with the cooling inlet (605) and the cooling outlet (606).

4. The multi-stage horizontal centrifugal pump according to claim 3, characterized in that, The driven component (310) includes a first bevel gear (3101), a driven rod (3102), a second bevel gear (3103), a third bevel gear (3104), and a fourth bevel gear (3105). The first bevel gear (3101) is fixedly connected to the pump shaft (2). The driven rod (3102) is perpendicular to the pump shaft (2). The driven rod (3102) meshes with the first bevel gear (3101) through the second bevel gear (3103). The driven rod (3102) is also provided with a third bevel gear (3104). The second bevel gear (3103) and the third bevel gear (3104) are located at the two ends of the driven rod (3102), respectively. The fourth bevel gear (3105) is located on the hydraulic component (320) and meshes with the third bevel gear (3104).

5. The multi-stage horizontal centrifugal pump according to claim 4, characterized in that, The hydraulic component (320) includes a hydraulic housing (3201), a hydraulic outlet (3202), a hydraulic inlet (3203), a hydraulic shaft (3204), a piston (3205), a follower rod (3206), and a sloping plate (3207). The hydraulic housing (3201) has a hydraulic inlet (3203) and a hydraulic outlet (3202). Several pistons (3205) are slidably connected inside the hydraulic housing (3201). One end of each piston (3205) is connected to the sloping plate (3207). The follower rod (3206) is fixedly connected to the sloping plate (3207). A fourth bevel gear (3105) is also fixedly connected to the follower rod (3206). The hydraulic shaft (3204) is rotatably connected to one end of the follower rod (3206).

6. The multi-stage horizontal centrifugal pump according to claim 5, characterized in that, The sealing component includes a rotary shaft lip seal and a rolling bearing. A rolling bearing is provided at the connection between the balance chamber (4101) and the short arm (4201), and a rotary shaft lip seal is connected to the outside of the rolling bearing.

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