A high-speed multi-stage centrifugal pump supported by an air film

Abstract

The present invention relates to a high-speed multi-stage centrifugal pump supported by an air film, which achieves efficient liquid transportation through a unique design. When the motor in the driving mechanism is energized, the power is smoothly transmitted to the pump shaft through the coupling, driving the multi-stage impeller to rotate at high speed. The liquid flows in from the water inlet at the bottom of the pump body, obtains velocity energy under the action of the centrifugal force of the impeller, and is then converted into pressure energy through the multi-stage guide vanes to achieve efficient transportation. The gas chamber in the stator of the air bearing stores gas, and an air film is formed through the multi-stage convergence nozzle to support the pump shaft, reduce friction resistance, and adapt to high speed. The rubidium magnet in the rotor sleeve interacts with the magnetic fluid chamber to enhance the seal and assist in regulation. Mechanical seals and oil seals prevent liquid leakage and protect the air bearing. The overflow chamber and overflow trough regulate the pressure in the pump, the water inlet filter intercepts impurities, and strengthens the pull rod to stabilize the structure. The present invention effectively solves the problems faced by traditional centrifugal pumps at high speeds, and has the advantages of high efficiency, stability, and long life.

Description

Technical Field

[0001] The present invention relates to the field of multi-stage centrifugal pumps, in particular to an air film supported high-speed multi-stage centrifugal pump. Background Art

[0002] Multistage centrifugal pumps are widely used in industrial and civilian applications, primarily for conveying liquids. Due to their high efficiency, stability, and reliability, they are widely used in industries such as petrochemicals, power generation, water supply, and drainage. Cost control is a key objective in industrial production. Reducing the number of guide vanes and impellers to reduce costs is a common approach for multistage centrifugal pumps. However, this inevitably reduces the number of pump stages, which in turn affects pump pressure output. To maintain adequate pump pressure while reducing the number of stages, increasing motor speed becomes necessary, often reaching tens of thousands of rpm.

[0003] During high-speed operation of centrifugal pumps, vibration becomes a key technical bottleneck affecting their performance, lifespan, and safety. First, under ultra-high-speed conditions, the rotor is prone to severe centrifugal imbalance due to machining errors, installation deviations, or uneven moments of inertia, leading to periodic excitation. High-speed rotation exponentially amplifies tiny disturbances through centrifugal force, causing axial and radial displacement and a vibration amplification effect. This is particularly true at the rotor ends, where the structural stiffness boundary effects make them more prone to concentrated vibration zones, which in turn continuously impact the support system.

[0004] To reduce frictional losses and avoid the wear and heat accumulation caused by mechanical contact, non-contact support structures have become the mainstream solution. Air film bearings (including static and dynamic pressure types) offer excellent damping performance and low starting friction, making them a promising approach. However, at high speeds, the air bearing is a separate component that supports the rotor as an additional module. This can easily lead to assembly errors and dynamic imbalance relative to the pump body, especially at high speeds, which can exacerbate vibration. On the one hand, the air film has limited load-bearing capacity and stiffness, making it susceptible to uneven film thickness under external disturbances (such as pressure fluctuations, unstable air intake, and ambient thermal changes). On the other hand, the instability of the gas flow can cause the film layer to rupture, leading to transient contact, increased vibration, and even equipment damage.

[0005] These problems seriously restrict the efficient and stable operation of multi-stage centrifugal pumps at high speeds and urgently need to be solved by innovative technologies. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In view of the deficiencies of the prior art, the present invention aims to provide a high-speed multi-stage centrifugal pump supported by an air film, which solves the problems existing in the prior art. The present invention integrates the structure of the air bearing directly into the interior of the pump body bracket to form a support system that is integrated with the pump body, which has the significant effects of reducing assembly errors, improving structural coaxiality, and enhancing dynamic stability. Unlike the traditional method of installing the air bearing as an independent module on the outside of the pump body, the integrated design of the present invention avoids the mechanical deviation and structural discontinuity caused by the intermediate connection interface, which significantly improves the rotational accuracy and stiffness of the rotor at high speeds. This design effectively solves the common technical problems of traditional air bearings in high-speed centrifugal pumps, such as difficulty in ensuring coaxiality, complex assembly, and easy excitation of vibration during operation.

[0008] At the same time, through the precisely designed partial pressure air cavity and main air cavity and the annular, multi-stage contraction nozzle structure, it is ensured that the jet airflow can evenly and stably form a high-rigidity air film, effectively supporting the stable suspension of the rotor at high speeds, and reducing air film vibration and fluid disturbances. In addition, the present invention embeds permanent magnets inside the rotor, and sets magnetic poles in the form of an annular Halbach magnetic array inside the bracket, and cooperates with the conductive lining to achieve passive magnetic damping by utilizing the eddy current effect, thereby further enhancing the magnetic suspension support and vibration suppression effect. In this way, through the organic combination of air film support with magnetic suspension and magnetic damping technology, the present invention not only greatly improves the operating stability and energy efficiency of the centrifugal pump at high speeds, but also effectively reduces equipment wear and maintenance costs, significantly extends the service life of the equipment, and provides a solid technical guarantee for the efficient, stable and low-noise operation of the centrifugal pump.

[0009] (2) Technical solution

[0010] To achieve the above-mentioned object, the present invention provides the following technical solution: an air film supported high-speed multi-stage centrifugal pump, comprising a bracket, a drive mechanism and a pump body being fixed to the upper and lower ends of the bracket, a pressure-dividing air cavity and a main air cavity being provided inside the bracket, a nozzle being provided through the inner wall of the main air cavity, and a rotor being sleeved on the inner side of the main air cavity.

[0011] Preferably, the nozzle is distributed in an annular shape along the wall of the main air cavity, and the nozzle as a whole has a symmetrical conical structure, and is provided with three levels of gradually contracting conical sections, with each level having a contraction angle of 5°-10°, and a throttle hole is provided at the end of the nozzle;

[0012] Preferably, a permanent magnet is embedded in the rotor, and multiple groups of magnetic poles are embedded in the bracket, arranged in a ring-shaped Halbach magnetic array. The magnetic poles are arranged at the steps at the upper and lower ends of the rotor, and the outer edges of the magnetic poles are provided with conductive linings.

[0013] Preferably, an air valve and an air channel are provided on the side of the bracket, and the air channel is connected to the pressure-dividing air cavity.

[0014] Preferably, the upper and lower ends of the pressure-dividing air cavity and the main air cavity are arc-shaped, and grids are arranged in arrays at the upper and lower ends of the connection between the pressure-dividing air cavity and the main air cavity.

[0015] Preferably, an overflow cavity is provided at the inner bottom of the bracket, and an overflow trough is provided at the bottom of the overflow cavity.

[0016] Preferably, the driving mechanism includes a motor, a coupling is fixed to the end of the output shaft of the motor, and a pump shaft is fixed to the lower end of the coupling.

[0017] Preferably, the rotor and the pump shaft are interference fit.

[0018] Preferably, the pump body includes a guide vane fixed to the lower end of the bracket and an impeller mounted on the pump shaft, and a water inlet is provided at the bottom of the pump body.

[0019] Preferably, an oil seal is provided at the contact point between the upper end of the overflow chamber and the pump shaft.

[0020] Preferably, a mechanical seal is fixed to the outer edge of the pump shaft, and the mechanical seal is clamped between the bracket and the impeller.

[0021] Preferably, a reinforcing rod is fixed between the bracket and the water inlet.

[0022] (3) Beneficial effects

[0023] The object of the present invention is to provide a high-speed multi-stage centrifugal pump supported by an air film. The present application achieves high coaxiality and structural compactness of the rotor and the bracket by directly integrating the stator of the traditional air bearing into the interior of the pump body, significantly reducing the unbalanced vibration caused by assembly errors. At the same time, the optimized design of the partial pressure air cavity and the main air cavity, combined with the precise arrangement of the annular and multi-stage convergence nozzles, enables the jet airflow to uniformly and stably form a high-rigidity air film, effectively supporting the stable suspension of the rotor at high speeds, reducing the vibration risk caused by air film fluctuations and fluid disturbances; in addition, the present application utilizes the synergistic effect of the permanent magnets embedded in the rotor and the magnetic poles arranged in a magnetic array in the bracket to form a strong magnetic suspension support at the upper and lower ends of the rotor, which not only shares the supporting load of the air bearing, but also realizes the eddy current damping effect by arranging a conductive lining at the outer edge of the magnetic pole, automatically absorbing and suppressing the rotor vibration, thereby further reducing the resonance phenomenon and noise level;

[0024] Secondly, the Halbach magnetic array and the air film injection area form a structural spatial overlap. When the rotor rotates, the alternating magnetic field and the high-speed shear air film flow field couple with each other, generating a magnetohydrodynamic (MHD) effect in the localized micro-conductive air film. This effect limits the expansion of the perturbed vortices within the air film at the microscale, constraining the micro-vortex structure through the Lorentz force, thereby significantly enhancing the stability and continuity of the air film support and improving the system's anti-disturbance capability under high-speed operation. It demonstrates a nonlinear stability effect under the multi-field coupling of structure, magnetic field, and fluid, and has technical advantages over traditional air bearings or independent magnetic levitation structures.

[0025] To sum up, the structure of this application combines the advantages of air film support, magnetic levitation and magnetic damping technology, greatly improving the operating stability and energy efficiency of the centrifugal pump under high-speed conditions, reducing mechanical wear and maintenance costs, and extending the service life of the equipment, providing a solid technical guarantee for efficient, stable and low-noise operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an overall schematic diagram of the present invention.

[0027] Figure 2 It is a cross-sectional view of the entire invention.

[0028] Figure 3 for Figure 2 Axonometric view at point A in the overall section.

[0029] Figure 4 for Figure 2 An enlarged view of point B in the overall cross-section.

[0030] Figure 5 It is a cross-sectional view of the bracket and the driving mechanism in the present invention.

[0031] Figure 6 for Figure 5 Enlarged view of point C in the cross-sectional view of the bracket and drive mechanism.

[0032] Figure 7 It is a half-section view of the bracket in the present invention.

[0033] Figure 8 for Figure 7 An enlarged view of point D in the half-section view of the bracket.

[0034] Figure 9 Schematic diagram of the arrangement of magnetic poles in the present invention.

[0035] In the figure: 1- bracket, 2- driving mechanism, 3- pump body, 11- partial pressure air cavity, 12- main air cavity, 13- nozzle, 14- rotor, 15- throttle hole, 16- magnetic pole, 17- conductive lining, 18- air valve, 19- air duct, 20- grille, 111- overflow cavity, 112- water outlet, 141- permanent magnet, 21- motor, 22- coupling, 23- pump shaft, 24- mechanical seal, 25- oil seal, 31- guide vane, 32- impeller, 33- water inlet, 34- reinforcing rod. DETAILED DESCRIPTION

[0036] The following is a summary of the examples of the present invention. Figures 1-9 A clear and complete description of the technical solutions in the embodiments of the present invention is provided. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] The present invention provides a technical solution: a high-speed, multi-stage, air-film-supported centrifugal pump comprising a bracket 1, with a drive mechanism 2 and a pump body 3 fixed to the upper and lower ends of the bracket 1, respectively. The bracket 1 serves as the basic support structure for the entire centrifugal pump, connecting and securing the other major components. The drive mechanism 2 and pump body 3 are fixed to their upper and lower ends, respectively, ensuring the relative stability of these two key components. This ensures the integrity and stability of the entire centrifugal pump during operation, preventing component sway or displacement from affecting the pump's normal operation. The drive mechanism 2 provides the power source for the centrifugal pump, ensuring proper pump operation. The motor 21 in the drive mechanism generates rotational power, which is transmitted via the output shaft to the coupling 22. The coupling 22 then smoothly transmits the motor power to the pump shaft 23, driving the pump shaft to rotate and providing rotational power for the impeller 32 within the pump body 3, enabling the centrifugal pump to perform its liquid delivery function. The pump body 3 is the core component that enables liquid delivery. An overflow chamber 111, located within the bracket 1, primarily serves to buffer and regulate pressure. During the operation of a centrifugal pump, unstable liquid flow or pressure fluctuations may occur. The overflow chamber can accommodate excess liquid, preventing excessive pressure in the pump and ensuring safe operation. When the pressure in the pump is too high, some liquid can flow into the overflow chamber. When the pressure drops, the liquid in the overflow chamber can flow back into the pump's working flow path, maintaining stable operation.

[0038] The interior of the bracket 1 is provided with a pressure-dividing air chamber 11 and a main air chamber 12. A nozzle 13 is provided through the inner wall of the main air chamber 12, and a rotor 14 is sleeved on the inner side of the main air chamber 12. The pressure-dividing air chamber 11 mainly plays the role of regulating and distributing the gas pressure. During the operation of a high-speed multi-stage centrifugal pump, the pressure of the gas source fluctuates or is unstable. The pressure-dividing air chamber can perform preliminary regulation and buffering on the incoming gas pressure, adjusting the gas pressure to an appropriate range, and providing stable gas with appropriate pressure to the subsequent main air chamber. The main air chamber 12 is the main storage and transportation space for gas. It receives gas with adjusted pressure and flow from the pressure-dividing air chamber, stores it in a centralized manner, and then transports it to the area where an air film needs to be formed through the nozzle on the inner wall. The main air chamber can further stabilize the gas pressure, so that the gas maintains a relatively stable pressure state before reaching the nozzle, thereby ensuring that the gas ejected from the nozzle has stable parameters, which is conducive to the formation of a uniform and stable air film.

[0039] The upper and lower ends of the pressure-dividing air cavity 11 and the main air cavity 12 are arc-shaped, and a grid 20 is arranged in an array at the upper and lower ends of the connection between the pressure-dividing air cavity 11 and the main air cavity 12. The pressure-dividing air cavity 11 receives the gas input from the air duct 19, and the arc-shaped structure in the cavity slows down the impact of the airflow, so that the gas is evenly distributed and initially pressurized before entering the main air cavity 12. The arc-shaped design can avoid the formation of dead corners in the airflow in the cavity, ensuring that the air supply pressure of each nozzle 13 in the main air cavity 12 is consistent. The grid 20 array at the connection between the pressure-dividing air cavity 11 and the main air cavity 12 can evenly guide the gas in the pressure-dividing air cavity 11 to the main air cavity 12, avoid airflow turbulence, and ensure the stability of the air supply from the nozzle 13.

[0040] The nozzles 13 are arranged in a circular pattern along the wall of the main air chamber 12. They have a symmetrical conical structure with three gradually converging sections, each with a converging angle of 5°-10°. A throttle orifice 15 is located at the distal end of the nozzle 13. This unique structural design allows the gas flow rate to increase continuously as the flow path gradually contracts as it passes through the nozzle. This multi-stage contraction achieves multiple accelerations of the gas, ultimately ejecting it at a higher velocity. The nozzles, arranged in a circular pattern along the wall of the main air chamber, spray gas evenly around the rotor, forming a uniform and stable air film between the rotor and stator. This air film supports and lubricates the rotor, reducing friction and wear between the rotor and stator, lowering energy loss, and improving pump efficiency and reliability. The throttle orifice 15, located at the distal end of the nozzle, further controls the flow of the accelerated gas. By limiting the area through which the gas can flow, the orifice precisely regulates the gas flow rate, ensuring that the correct amount of gas enters the air film area, thus preventing excessive or insufficient gas flow from affecting the stability and performance of the air film. The orifice also stabilizes the gas pressure. When gas passes through the orifice, a certain pressure drop occurs, which stabilizes the gas pressure and promotes the formation of a stable air film.

[0041] A permanent magnet 141 is embedded in the rotor 14, and multiple groups of magnetic poles 16 are embedded in the bracket 1, arranged in a ring-shaped Halbach magnetic array. The magnetic poles 16 are set at the steps at the upper and lower ends of the rotor 14, and a conductive lining 17 is set on the outer edge of the magnetic poles 16.

[0042] First, because the upper and lower ends of the rotor are more prone to vibration and displacement deviation due to geometric structure and dynamic load, traditional air film support may be insufficient in these areas. To this end, the present invention arranges magnetic poles 16 at the upper and lower steps of the rotor. These magnetic poles are arranged in a Halbach magnetic array, such as Figure 9 As shown, by continuously rotating the magnetic pole arrangement 90°, the magnetic field is significantly enhanced in the area facing the rotor interior (working side) and weakened in the opposite direction. This high-intensity magnetic field works synergistically with the permanent magnets 141 within the rotor to provide additional magnetic levitation support for the rotor, effectively supplementing and strengthening the effectiveness of the existing air film support system.

[0043] Secondly, the enhanced magnetic levitation support not only shares some of the load generated by high-speed operation and reduces the pressure on the air film, but also automatically pulls the rotor back to a stable operating position through the "self-centering" effect of the magnetic field when the rotor vibrates or deflects, further suppressing vibration. In other words, the interaction between the magnetic poles and permanent magnets forms a non-contact auxiliary support mechanism, which builds an additional support "barrier" in the upper and lower end areas of the rotor to counteract the instability caused by vibration, thereby improving the dynamic rigidity and stability of the entire system.

[0044] Finally, the conductive lining 17 positioned at the outer edge of the magnetic poles 16 further enhances the magnetic damping effect. When the rotor rotates or vibrates at high speed, the changes in the magnetic field generate eddy currents in the conductive lining. These eddy currents, in turn, generate a magnetic field in the opposite direction of the rotor's motion, creating a damping force that effectively absorbs vibration energy and reduces resonance. This passive magnetic damping, without requiring additional energy, rapidly responds to rotor disturbances and suppresses vibration. It is particularly effective in the upper and lower rotor ends, where vibration is more easily excited. The conductive lining 17 is made of a non-magnetic metal such as copper or aluminum. The principle is that when the rotor vibrates in a magnetic field, the changes in the magnetic field generate eddy currents in nearby conductors (the conductive lining). These eddy currents form a magnetic field in the opposite direction. According to Lenz's law, this opposing magnetic field exerts a braking force on the rotor's motion, thereby providing electromagnetic damping.

[0045] The side of the bracket 1 is equipped with an air valve 18 and an air channel 19, which connects to the pressure-dividing air chamber 11. The air valve 18 acts as a switch for gas to enter the system. By adjusting the valve opening, the flow of gas entering the pressure-dividing air chamber 11 is controlled, thereby adjusting the air pressure within the main air chamber 12 and ensuring the stability of the air film between the rotor 14 and the stator. The air channel 19 and the pressure-dividing air chamber 11 work together to dynamically adjust the air supply pressure of the main air chamber 12 to meet the requirements of air film support under different speeds or loads.

[0046] The pump body 3 comprises multi-stage guide vanes 31 fixed to the lower end of the support 1 and a multi-stage impeller 32 mounted on the pump shaft 23. A water inlet 33 is provided at the bottom of the pump body 3. The guide vanes, mounted at the lower end of the support 1, primarily direct the liquid passing through the impeller 32 and convert its energy. As the liquid gains kinetic energy through the impeller, the guide vanes adjust the liquid's flow direction, allowing it to flow more smoothly. They also convert some of the liquid's kinetic energy into pressure energy, increasing the liquid's pressure and enhancing the pump's delivery capacity. The impeller 32 is mounted on the pump shaft 23 and rotates at high speed as the shaft rotates. During its rotation, the impeller performs work on the liquid, imparting energy to the liquid and generating centrifugal force, which propels the liquid from the center of the impeller to its edge, achieving both suction and discharge. The multi-stage impeller further increases the pump's head and flow rate, meeting the demands of various operating conditions. The water inlet 33, located at the bottom of the pump body 3, serves as the channel through which the centrifugal pump draws in the liquid to be delivered. The liquid enters the pump body through the water inlet, then passes through the multi-stage impeller and guide vanes, and is finally transported to where it is needed.

[0047] An overflow trough is provided at the bottom of the overflow chamber 111. When the pressure in the pump is too high or the liquid flow rate is too large, excess liquid can be discharged from the overflow chamber through the overflow trough, preventing excessive accumulation of liquid in the overflow chamber and causing excessive pressure. This ensures that the overflow chamber can properly perform its buffering and pressure regulation functions, protecting the safe and stable operation of the centrifugal pump.

[0048] A mechanical seal 24 is fixed to the outer edge of the pump shaft 23, and the mechanical seal 24 is clamped between the bracket 1 and the impeller 32. An oil seal 25 is provided at the contact point between the upper end of the overflow chamber 111 and the pump shaft 23. The mechanical seal 24 is installed on the outer edge of the pump shaft 23 and is clamped between the bracket 1 and the impeller 32. It is a key component to prevent leakage of liquid in the pump. When the high-speed multi-stage centrifugal pump is running, the pump shaft rotates at high speed and the liquid in the pump has a high pressure. The mechanical seal forms an effective seal between the rotating pump shaft and the stationary bracket and impeller through the tight fit between the dynamic and static rings and the action of the auxiliary seals. The oil seal 25 is provided at the contact point between the upper end of the overflow chamber 111 and the pump shaft 23. It is mainly used to prevent the liquid in the pump from entering the overflow chamber 111, and at the same time prevent the gas or impurities that may exist in the overflow chamber from reversely entering the working area of the pump body.

[0049] A reinforcing rod 34 is fixed between the bracket 1 and the water inlet 33. The reinforcing rod 34 is connected between the bracket 1 and the water inlet 33, and mainly serves to enhance the stability of the pump body structure. During the operation of a high-speed multi-stage centrifugal pump, the pump body is subjected to various forces such as the impact and vibration of the liquid and the inertial force generated by its own high-speed operation. The reinforcing rod transmits these forces in a dispersed manner by rigidly connecting the bracket and the water inlet, effectively enhancing the strength and stability of the overall structure of the pump body, preventing structural deformation and damage caused by uneven force or vibration, and ensuring that the relative positions of the various components of the pump are stable under long-term high-load operation, thereby ensuring the normal working performance of the pump.

[0050] MHD stabilization mechanism caused by spatial coupling between Halbach magnetic array and air film shear zone:

[0051] 1. Structural foundation:

[0052] The spatial overlap zone is formed in this application: an annular Halbach magnetic array is embedded in the upper and lower steps of the rotor. This magnetic array has the characteristics of magnetic flux concentration and inward and outward orientation. Correspondingly, a multi-stage annular conical nozzle is set on the inner wall of the main air cavity inside the pump body. The nozzle airflow outlet faces the outer edge of the rotor end, which is also the location of the magnetic array. Therefore, when the rotor is in operation, the area with drastic changes in magnetic flux density and the high-speed shear airflow area spatially overlap. This structural layout forms a physical "multi-field strength coupling zone" with the simultaneous presence of: strong gradient changes in magnetic induction intensity (Halbach array characteristics); boundary shear layer formed by high-speed gas flow (nozzle air film); and time-varying magnetic field under high-speed rotation.

[0053] 2. Interaction between magnetic disturbance and fluid shear under high-speed rotation:

[0054] When the rotor runs at high speed, the permanent magnets embedded in the rotor rotate at high speed, forming a rapidly changing alternating magnetic field in the magnetic pole region. Due to the Halbach structure, the magnetic field is highly concentrated on one side (towards the air film). When the rotor rotates, this alternating magnetic field generates magnetic disturbances in the air film area formed by the nozzle ejection. The high-speed airflow ejected from the nozzle forms a thin air film (thickness of about 10 to 50 μm) near the rotor surface. This air film is in a shear flow state and has a certain local micro-vortex structure. At this time, the alternating magnetic field penetrates this tiny shear flow area and interacts with the vortex or ion components therein.

[0055] 3. Magnetic field confinement mechanism of microvortices

[0056] Although air itself has extremely low electrical conductivity, under conditions of high-speed shear flow and high local temperature rise, the air film exhibits extremely weak electrical conductivity. According to the basic principles of magnetohydrodynamics (MHD), when a conductive fluid moves in a magnetic field, it induces eddy currents, which in turn generate a magnetic field that interacts with the original magnetic field to generate the Lorentz force.

[0057] For the situation in this device, this effect is mainly manifested as the "suppression" effect of the magnetic field on the micro-vortex, that is, the Lorentz force hinders the expansion and turning of the conductive vortex, thereby stabilizing the boundary layer flow state and slowing down the development of the disturbance.

[0058] In other words, although the conductivity within the air film is weak, the magnetic disturbance is sufficiently intense and highly concentrated in space, which exerts a "constraint field" effect on the vortex disturbance or micro-instability zone in the air film.

[0059] 4. Results: Mechanisms for enhancing the stability of air film support

[0060] The effect of the magnetic field on the air film disturbance is ultimately manifested in the following ways: first, at the microscopic level, irregular disturbances or vortex collapses at the air film boundary are suppressed, thus avoiding a local decrease in the thickness of the air film; second, at the macroscopic level, the continuity and stability of the air film can be extended, allowing the rotor to be more stably lifted by the air film; a flexible coupling mechanism is formed between the air film support and the magnetic levitation support. When one side is disturbed and drops, the stabilization mechanism of the other side begins to take effect, playing a role of automatic buffering and mutual compensation.

[0061] The working principle of the present invention can be specifically divided into the following stages:

[0062] 1. Power Transmission and Impeller Rotation: After the motor 21 in the drive mechanism is started, it drives the coupling 22 to rotate via the output shaft. The coupling 22 then transmits power to the pump shaft 23. Due to the interference fit between the rotor 14 and the pump shaft 23, the pump shaft 23 drives the rotor 14 to rotate together. At the same time, the impeller 32 mounted on the pump shaft 23 also rotates with the pump shaft 23. The rotation of the impeller 32 creates centrifugal force within the pump body 3, which throws the liquid entering through the water inlet 33 toward the outer edge of the impeller 32, thus achieving liquid delivery.

[0063] 2. Magnetic Levitation and Damping: Permanent magnets 141 embedded within rotor 14 interact with magnetic poles 16 arranged in a circular Halbach magnetic array within bracket 1, generating a magnetic levitation force that allows rotor 14 to levitate within main air cavity 12 and rotate at high speed. When rotor 14 vibrates due to various factors, the changing magnetic field generated by permanent magnets 141 generates eddy currents in conductive liner 17 at the outer edge of magnetic poles 16. The magnetic field generated by these eddy currents interacts with the magnetic field of permanent magnets 141, generating eddy current damping force, which dampens rotor 14 vibration and improves system stability through the magnetic damping effect.

[0064] 3. Gas assistance and partial pressure: External gas enters the air passage 19 through the air valve 18, and then enters the partial pressure air chamber 11. The grids 20 arranged in an array at the upper and lower ends of the connection between the partial pressure air chamber 11 and the main air chamber 12 allow the gas to enter the main air chamber 12 evenly from the partial pressure air chamber 11. The nozzles 13 distributed in a ring shape on the inner wall of the main air chamber 12 eject the gas at a specific angle. Since the nozzle 13 has a symmetrical conical structure and has three levels of gradually contracting conical sections, each level has a contraction angle of 5°-10°, and there is a throttle hole 15 at the end section, the ejected gas forms a high-speed airflow, which acts on the rotor 14, providing support and stabilization for the rotor 14, while also helping to cool and lubricate the rotor 14.

[0065] 4. Sealing and Protection: A mechanical seal 24 fixed to the outer edge of the pump shaft 23 is clamped between the bracket 1 and the impeller 32 to prevent liquid leakage from the pump body 3. The overflow chamber 111 is used to collect any leaked liquid. An oil seal 25, located at the contact point between the upper end of the overflow chamber 111 and the pump shaft 23, further prevents liquid leakage along the pump shaft 23, providing sealing and protection to ensure normal operation of the system.

[0066] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-speed multi-stage centrifugal pump supported by an air film, comprising a bracket (1), wherein a driving mechanism (2) and a pump body (3) are fixed to the upper and lower ends of the bracket (1), respectively, and characterized in that: The bracket (1) is provided with a pressure-dividing air cavity (11) and a main air cavity (12) inside. A nozzle (13) is provided through the inner wall of the main air cavity (12). A rotor (14) is sleeved on the inner side of the main air cavity (12). The nozzle (13) is distributed in an annular shape along the wall of the main air cavity (12). The nozzle (13) is a symmetrical conical structure as a whole and is provided with three levels of gradually contracting conical sections. The contraction angle of each level is 5°-10°. The end section of the nozzle (13) is provided with a throttle hole (15); A permanent magnet (141) is embedded in the rotor (14), and a plurality of groups of magnetic poles (16) are embedded in the bracket (1), and are arranged in a ring-shaped Halbach magnetic array. Each group of magnetic poles (16) is rotated 90 degrees relative to the previous group. The magnetic poles (16) are arranged at the upper and lower steps of the rotor (14), and the outer edges of the magnetic poles (16) are provided with conductive linings (17).

2. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: An air valve (18) and an air channel (19) are provided on the side of the bracket (1), and the air channel (19) is connected to the pressure-dividing air cavity (11).

3. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: The upper and lower ends of the pressure-dividing air cavity (11) and the main air cavity (12) are arc-shaped, and grids (20) are arranged in arrays at the upper and lower ends of the connection between the pressure-dividing air cavity (11) and the main air cavity (12).

4. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: An overflow cavity (111) is provided at the inner bottom of the bracket (1).

5. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: The driving mechanism (2) comprises a motor (21), a coupling (22) is fixed to the end of the output shaft of the motor (21), and a pump shaft (23) is fixed to the lower end of the coupling (22).

6. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: The rotor (14) and the pump shaft (23) are interference fit.

7. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: The pump body (3) includes a guide vane (31) fixed to the lower end of the bracket (1) and an impeller (32) mounted on the pump shaft (23). A water inlet (33) is provided at the bottom of the pump body (3), and a reinforcing rod (34) is provided on the side of the pump body (3).

8. The high-speed multi-stage centrifugal pump supported by an air film according to claim 4, characterized in that: An oil seal (25) is provided at the contact point between the upper end of the overflow chamber (111) and the pump shaft (23).

9. The high-speed multi-stage centrifugal pump supported by an air film according to claim 5, characterized in that: A mechanical seal (24) is fixed to the outer edge of the pump shaft (23), and the mechanical seal (24) is clamped between the bracket (1) and the impeller (32).

10. The high-speed multi-stage centrifugal pump supported by an air film according to claim 1, characterized in that: A water outlet (112) is provided on the side of the bracket (1).

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