Single degree of freedom magnetic levitation shaftless pump pushing structure

Abstract

The application relates to a single-degree-of-freedom magnetic suspension shaftless channel pump pushing structure, belonging to the field of engineering technology, which comprises a stator pump body and a magnetic suspension rotor impeller. The stator pump body is provided with a pair of axial magnetization stator magnetic steel rings, a hollow cup winding and a pair of annular induction coils; the magnetic suspension rotor impeller is provided with a pair of axial magnetization rotor magnetic steel rings, multi-pole radial magnetization magnetic steel, a wound induction silicon steel ring and a magnetic suspension channel impeller. The axial magnetization stator magnetic steel rings and the axial magnetization rotor magnetic steel rings correspond to each other in the axial direction, form repulsion magnetic circuits, and realize passive stabilization of radial displacement and deflection; the annular induction coils are used for detecting axial displacement by acting on the wound induction silicon steel ring; the hollow cup winding is used for simultaneously realizing axial active suspension control and torque driving, and drives the magnetic suspension channel impeller to rotate to form thrust. The structure has the advantages of good sealing performance, strong pressure resistance and compact structure, and is suitable for liquid driving scenes in special environments such as deep-sea submersibles, super-clean water pumps and high-pressure water gun pump heads.

Description

Technical Field

[0001] This invention belongs to the field of engineering technology, specifically relating to a single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure. Background Technology

[0002] A magnetically levitated shaftless ducted pump is a propulsion or pumping device that combines magnetic levitation technology, electric motor drive technology, and ducted impeller propulsion technology. By simultaneously establishing a driving magnetic field and a levitation magnetic field in the stator, the rotor can be levitated and rotated without mechanical contact, thereby driving the ducted impeller to generate propulsive force or pumping pressure. Because it eliminates the traditional shaft and bearing structure, this type of device has advantages such as low wear, low noise, fewer sealing interfaces, and suitability for hydraulic drive applications in special environments such as deep seas, deep lakes, or high-pressure sealed oil tanks.

[0003] Existing magnetic levitation drive devices mostly employ multi-degree-of-freedom active control schemes, typically requiring multiple displacement sensors and power drive units. This results in complex system structures, strong control coupling, and high manufacturing costs. For underwater propulsion or high-pressure pumping scenarios, the equipment is also affected by vibration, temperature variations, and high-pressure sealing constraints. Conventional external displacement sensors are prone to drift or measurement inaccuracies, and traditional dynamic sealing shaft structures struggle to balance long-term sealing reliability with low-friction operation. Therefore, it is necessary to provide a single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure with a simplified structure, high integration of sensing and drive, and suitability for static sealing and pressure-resistant environments. Summary of the Invention

[0004] The purpose of this invention is to provide a single-degree-of-freedom magnetic levitation shaftless duct pump pusher structure to solve the problems of existing magnetic levitation pump pusher devices having multiple degrees of freedom in control, easy sensitivity of sensing links to environmental interference, complex systems, and being unsuitable for high-pressure static sealing applications.

[0005] The present invention adopts the following technical solution:

[0006] A single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure includes a hollow cylindrical stator pump body and a magnetic levitation rotor impeller coaxially disposed within the stator pump body;

[0007] The stator pump body includes a stator pump housing cavity and a stator pump housing end cover. The stator pump housing cavity has an annular cavity, and the lower end of the stator pump housing cavity is sealed to the stator pump housing end cover. An annular hollow cup winding is fixed to the upper part of the annular cavity, and a pair of axially magnetized stator magnet rings are fixed to both sides of the hollow cup winding. A pair of annular induction coils are fixed at intervals to the lower part of the annular cavity. The two annular induction coils are wound in opposite directions and connected in series at the same end. The annular cavity is filled with potting material.

[0008] The magnetic levitation rotor impeller includes an inner rotor shaft coaxially disposed within the stator pump body. A pair of axially magnetized rotor magnet rings, which are aligned with the axial position of the axially magnetized stator magnet rings, a multi-pole radially magnetized magnet aligned with the axial position of the hollow cup winding, and a wound induction silicon steel ring located on the axial center plane of a pair of annular induction coils are fixed on the outer peripheral wall of the inner rotor shaft. A magnetically levitated duct impeller is fixed at the lower end of the inner rotor shaft.

[0009] The pair of axially magnetized stator magnetic rings and the pair of axially magnetized rotor magnetic rings form a repulsive magnetic circuit, thereby passively stabilizing and controlling the radial displacement and yaw of the magnetic levitation rotor impeller; the two ring-shaped induction coils generate differential voltage signals when the winding induction silicon steel rings produce axial displacement, in order to obtain the axial displacement of the magnetic levitation rotor impeller; the hollow cup winding forms a driving magnetic field and a rotating magnetic field, thereby providing the magnetic levitation rotor impeller with axial active control force and driving torque around the central axis.

[0010] The present invention also provides a magnetic levitation pumping method based on the aforementioned single-degree-of-freedom magnetic levitation shaftless duct pumping structure, the method comprising:

[0011] First, the pump push structure is placed in a preset starting position, a set of known axial displacements are applied to the magnetic levitation rotor impeller, differential voltage signals are collected synchronously, and the sensitivity coefficient is obtained.

[0012] Subsequently, the hollow cup winding generates a rotating magnetic field under the action of the three-phase drive current. This rotating magnetic field interacts with the multipole radial magnetized magnet to generate a torque that drives the multipole radial magnetized magnet to rotate around the central axis. The multipole radial magnetized magnet drives the magnetic levitation duct impeller to rotate through the inner shaft of the rotor, which in turn drives the fluid to flow axially and forms a propulsive force.

[0013] During operation, when the magnetic levitation rotor impeller undergoes axial displacement, the wound induction silicon steel ring interacts with the two annular induction coils, causing the two annular induction coils to generate a differential voltage signal corresponding to the axial displacement. The axial displacement of the magnetic levitation rotor impeller is calculated based on the sensitivity coefficient and the differential voltage signal. Then, zero-sequence current is injected into the hollow cup winding based on the axial displacement. Under the action of the zero-sequence current, the hollow cup winding generates an axial electromagnetic force, stabilizing the magnetic levitation rotor impeller at the predetermined axial equilibrium position.

[0014] Meanwhile, the pair of axially magnetized stator magnetic steel rings and the pair of axially magnetized rotor magnetic steel rings repel each other. When the magnetic levitation rotor impeller undergoes radial displacement or deflection, a radial restoring force or restoring torque is generated between the pair of axially magnetized stator magnetic steel rings and the pair of axially magnetized rotor magnetic steel rings, thereby realizing the passive magnetic levitation control of the magnetic levitation rotor impeller.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] 1. An array of components, including an axially magnetized stator magnet ring, an axially magnetized rotor magnet ring, multi-pole radially magnetized magnets, a wound induction silicon steel ring, a hollow cup winding, and a ring induction coil, is assembled. The relative positions of each component are rigorously designed, enabling the pump push structure to function as both a suspension support and a rotary drive. Specifically, the axially magnetized stator and rotor magnet rings, through axially corresponding repulsive magnetic circuits, self-correct the radial displacement and deflection of the magnetic levitation rotor impeller. The ring induction coil is used to detect axial displacement in real time, injecting zero-sequence current into the hollow cup winding to generate axial electromagnetic force to actively adjust the axial position of the magnetic levitation rotor impeller. Simultaneously, the hollow cup winding generates a rotating magnetic field under the action of three-phase drive current, forming an electromagnetic torque that drives the multi-pole radially magnetized magnets to rotate, thereby driving the magnetic levitation rotor impeller to rotate. Through the coordinated operation of these components, a compact magnetic levitation bearingless single-axis motor is constructed.

[0017] 2. The magnetic levitation ducted impeller and shaftless drive structure are adopted, and there is no mechanical contact between the rotor and the stator. This eliminates the wear, noise and temperature rise problems caused by mechanical contact in traditional bearings, significantly reduces operating power consumption and maintenance requirements, and helps to improve service life and overall efficiency.

[0018] 3. The stator pump body adopts a statically sealed potting cavity structure, eliminating the need for dynamic seals. This effectively prevents high-pressure media penetration, achieving high-pressure sealing and overall pressure resistance, making it suitable for use in deep-sea or high-pressure fluid environments.

[0019] 4. By symmetrically arranging the ring-shaped induction coil about the center plane of the wound induction silicon steel ring, a compact differential axial displacement detection structure is formed, which can reduce the impact of vibration and temperature changes on the stability of displacement measurement and significantly improve detection accuracy and environmental adaptability.

[0020] 5. The hollow cup winding simultaneously undertakes torque output and axial control functions, integrating the two electrical functions of drive and suspension into the same winding structure. There is no need to configure an additional axial winding or independent suspension coil, which helps to reduce system size, reduce control complexity and compress drive costs. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the structure of a single-degree-of-freedom magnetically levitated shaftless ducted pump provided in an embodiment of the present invention. The markings in the diagram are as follows: 1-Stator pump body; 10-Stator pump housing cavity; 11-Upper axially magnetized stator magnet ring; 12-Magnet support end cover assembly; 13-Hollow cup winding; 14-Magnet support base; 15-Lower axially magnetized stator magnet ring; 160-Upper annular induction coil; 161-Lower annular induction coil; 17-Coil support body; 18-Stator pump housing end cover; 19-Aerospace waterproof socket; 2-Magnetic levitation rotor impeller; 20-Rotor inner shaft; 21-Rotor end locking ring; 22-Upper axially magnetized rotor magnet ring; 23-Upper magnet support component; 24-Multi-pole radially magnetized magnet; 25-Lower magnet support component; 26-Lower axially magnetized rotor magnet ring; 27-Wound induction silicon steel ring; 28-Magnetic levitation ducted impeller.

[0022] Figure 2 This is a schematic diagram of the stator pump housing cavity, stator pump housing end cover, and aviation waterproof socket provided in an embodiment of the present invention. The markings in the figure are as follows: 100 - upper end ground contact protection ring; 101 - upper side fixing groove; 102 - lower side fixing groove; 103 - inner side sealing groove; 104 - outer side sealing groove; 105 - sealing threaded hole at the end of the pump housing cavity; 106 - lower end ground contact protection ring; 107 - threaded hole of the waterproof socket at the end of the pump housing cavity; 108 - sealing through hole of the pump housing end cover.

[0023] Figure 3 This is a side view of the axial displacement sensing system structure provided in an embodiment of the present invention. Labeling in the figure: 160 - upper annular induction coil; 161 - lower annular induction coil; 27 - wound induction silicon steel ring.

[0024] Figure 4 This is a schematic diagram of the magnetic levitation and rotation control system provided in an embodiment of the present invention. The markings in the diagram are as follows: 11-Upper magnet ring; 13-Hollow cup winding; 15-Lower magnet ring; 22-Upper axially magnetized rotor magnet ring; 24-Multi-pole radially magnetized magnet; 26-Lower axially magnetized rotor magnet ring.

[0025] Figure 5 This is a schematic diagram of a hollow cup winding structure provided in an embodiment of the present invention. The markings in the diagram are as follows: 131 - upper end of the hollow cup winding; 132 - middle section of the hollow cup winding; 133 - lower end of the hollow cup winding.

[0026] Figure 6This is a schematic diagram of the magnetic levitation rotor impeller structure provided in an embodiment of the present invention. The markings in the diagram are as follows: 20-Inner rotor shaft; 21-Rotor end locking ring; 22-Upper axial magnetized rotor magnet ring; 23-Upper magnet support; 24-Multi-pole radial magnetized magnet; 25-Lower magnet support; 26-Lower axial magnetized rotor magnet ring; 27-Wound induction silicon steel ring; 28-Magnetic levitation duct impeller; 200-Threaded hole at the end of the inner rotor shaft; 210-Through hole for the screw of the locking ring at the end of the rotor; 201-Lower rotor shaft positioning ring; 202-Threaded hole for the impeller on the inner rotor shaft; 280-Through hole for the screw of the impeller; 281-Impeller blade.

[0027] Figure 7 This is a schematic diagram of a magnetic levitation ducted impeller structure provided in an embodiment of the present invention. The markings in the diagram are as follows: 280 - rotor impeller screw through hole; 281 - rotor impeller blade. Detailed Implementation

[0028] The following is in conjunction with the appendix Figures 1 to 7 The specific embodiments of the present invention will be described in detail below.

[0029] The following description, in conjunction with preferred embodiments, further illustrates the structural composition, assembly relationship, and working process of the present invention. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0030] like Figure 1 and Figure 2 As shown, the single-degree-of-freedom magnetic levitation shaftless ducted pump push structure of this embodiment consists of a stator pump body 1 and a magnetic levitation rotor impeller 2. The stator pump body 1 is a hollow cylindrical static sealing component, and the magnetic levitation rotor impeller is located at the center of the stator pump body 1. The two are arranged coaxially along the axial direction and maintain a preset radial gap, so as to complete the levitation and rotation in a state of no mechanical contact. The upper end (one end along the positive direction of the Z-axis) of the pump push structure is the inlet end, and the lower end (one end along the negative direction of the Z-axis) is the outlet end.

[0031] The stator pump body 1 includes a stator pump housing consisting of a stator pump housing cavity 10 and a stator pump housing end cover 18, as well as internal components of the stator pump housing. The stator pump housing cavity 10 has an annular cavity with an open lower end. The lower end of the annular cavity is inserted into the stator pump housing end cover 18, thereby forming a closed cavity through static sealing. This replaces the dynamic seal bearing structure required in traditional propellers and eliminates the leakage risk caused by the rotating dynamic seal.

[0032] Inside the annular cavity, from top to bottom, there are a magnet support end cap assembly 12 and a magnet support base 14. The upper part of the magnet support end cap assembly 12 and the upper part of the magnet support base 14 are both left with gaps between them and the inner wall of the annular cavity. The lower part of the magnet support end cap assembly 12 and the lower part of the magnet support base 14 are both interference fit with the inner wall of the annular cavity.

[0033] An upper axially magnetized stator magnet ring 11 is fixed in the gap between the upper part of the magnet support end cap assembly 12 and the inner wall of the annular cavity. A hollow cup winding 13 and a lower axially magnetized stator magnet ring 15 are fixed in the gap between the upper part of the magnet support base 14 and the inner wall of the annular cavity. The lower axially magnetized stator magnet ring 15 is located below the hollow cup winding 13. The upper axially magnetized stator magnet ring 11, the hollow cup winding 13, and the lower axially magnetized stator magnet ring 15 are all annular and are all interference-fitted with the inner wall of the annular cavity. The hollow cup winding 13 is used to generate a magnetic field and drive the magnetic levitation rotor impeller 2 to rotate around its axis and move axially. The upper axially magnetized stator magnet ring 11 and the lower axially magnetized stator magnet ring 15 are placed on both sides of the axial direction of the hollow cup winding 13 to generate axial magnetic levitation force by interacting with the magnetic field generated by the upper end 131 and the lower end 133 of the hollow cup winding.

[0034] The lower diameter of the magnetic steel support base 14 is reduced. The lower outer peripheral wall of the magnetic steel support base 14 is sequentially press-fitted with an upper annular induction coil 160, a coil support body 17, and a lower annular induction coil 161 from top to bottom. The coil support body 17 is used to fix the upper annular induction coil 160 and the lower annular induction coil 161 axially. The upper annular induction coil 160 and the lower annular induction coil 161 are preferably connected in a series differential manner (i.e., the two annular induction coils are wound in opposite directions and their corresponding ends are connected in series, and the output signal is the voltage difference between the two ends), which is used to detect the axial displacement of the magnetic levitation rotor impeller 2 in real time and output a differential voltage signal. The upper end of the stator pump housing 10 has a waterproof socket threaded hole 107 at the end of the pump housing. The aviation waterproof socket 19 is fixedly connected to the stator pump housing 10 through the waterproof socket threaded hole 107 at the end of the pump housing. The hollow cup winding 13, the upper annular induction coil 160 and the lower annular induction coil 161 are all led out through the aviation waterproof socket 19 and connected to the external power supply and control system, thereby realizing effective communication and energy transmission in high hydraulic environments such as deep sea.

[0035] The magnet support base 14 serves two purposes: firstly, it provides mounting support for the hollow cup winding 13, the lower axially magnetized stator magnet ring 15, the upper annular induction coil 160, the coil support body 17, and the lower annular induction coil 161; secondly, it ensures precise coaxial positioning between the components.

[0036] like Figure 2As shown, the upper end of the inner peripheral wall of the stator pump body 1 is provided with an upper end contact protection ring 100, and the lower end of the inner peripheral wall is provided with a lower end contact protection ring 106. The upper end contact protection ring 100 and the lower end contact protection ring 106 are used to realize the axial positioning of the magnetic levitation rotor impeller 2 and ensure the axial assembly accuracy. The upper part of the outer peripheral wall of the stator pump housing cavity 10 is provided with an annular upper side fixing groove 101, and the lower part is provided with an annular lower side fixing groove 102. The upper side fixing groove 101 and the lower side fixing groove 102 are used to install positioning rings or cooperate with external mounting brackets to fix the axial position of the stator pump body 1. The stator pump housing end cover 18 has an annular inner sealing groove 103 on its inner peripheral wall and an annular outer sealing groove 104 on the lower end of the inner peripheral wall of the stator pump housing cavity 10. The inner sealing groove 103 and the outer sealing groove 104 are used to place an annular sealing ring to achieve the sealing of the closed cavity formed by the stator pump housing cavity 10 and the stator pump housing end cover 18. The stator pump housing cavity 10 is provided with a pump housing cavity end sealing threaded hole 105 at the lower end, and the stator pump housing end cover 18 is provided with a pump housing end cover sealing through hole 108 at the corresponding position. The stator pump housing cavity 10 and the stator pump housing end cover 18 are connected by a threaded seal through the pump housing cavity end sealing threaded hole 105 and the pump housing end cover sealing through hole 108. After installing the components in the annular cavity inside the stator pump housing cavity 10, high-hardness epoxy resin is injected into the annular cavity to improve the insulation performance, sealing performance and pressure resistance of the stator pump body, ensuring that the pump body can withstand a static water pressure of at least 50 MPa.

[0037] like Figure 1 and Figure 6 As shown, the magnetic levitation rotor impeller 2 is positioned between the upper end ground contact protection ring 100 and the lower end ground contact protection ring 106. The magnetic levitation rotor impeller 2 includes an inner rotor shaft 20, a rotor end locking ring 21, an upper axial magnetized rotor magnet ring 22, an upper magnet support member 23, a multi-pole radial magnetized magnet 24, a lower magnet support member 25, a lower axial magnetized rotor magnet ring 26, a wound induction silicon steel ring 27, and a magnetically levitated duct impeller 28. The inner rotor shaft 20 serves as the assembly base for the magnetic levitation rotor impeller 2. The inner rotor shaft 20 is coaxially positioned at the center of the stator pump body 1, with a gap between it and the inner peripheral wall to accommodate other components.

[0038] The outer circumferential wall of the inner rotor shaft 20 is sequentially press-fitted with an upper axially magnetized rotor magnet ring 22, a multi-pole radially magnetized magnet 24, a lower axially magnetized rotor magnet ring 26, and a wound induction silicon steel ring 27 from top to bottom. The upper axially magnetized rotor magnet ring 22 and the upper axially magnetized stator magnet ring 11 are in the same axial position, and the lower axially magnetized rotor magnet ring 26 and the lower axially magnetized stator magnet ring 15 are in the same axial position. That is, the axially magnetized stator magnet ring and the axially magnetized rotor magnet ring form an axially corresponding repulsive magnetic circuit. Therefore, when the magnetic levitation rotor impeller 2 deviates along the X-axis or Y-axis, a radial restoring force is generated between the paired axially magnetized stator magnet ring and the axially magnetized rotor magnet ring, thereby achieving passive magnetic levitation control of the magnetic levitation rotor impeller 2 along the X-axis and Y-axis. When the magnetic levitation rotor impeller 2 wobbles around the X-axis or Y-axis, a restoring torque is generated between the paired axially magnetized stator magnet ring and the axially magnetized rotor magnet ring, thereby achieving passive magnetic levitation control of the magnetic levitation rotor impeller 2 around the X-axis and Y-axis. Thus, this embodiment only requires active control of the axial degree of freedom to constitute a single-degree-of-freedom active magnetic levitation system.

[0039] The multipole radially magnetized magnet 24 is composed of multiple magnets spliced ​​together to form a ring, and each magnet is alternately magnetized along the radial direction. The multipole radial magnetized magnet 24 and the hollow cup winding 13 are located in the same axial position, so the magnetic field generated by the hollow cup winding 13 interacts with the multipole radial magnetized magnet 24 to generate an axial electromagnetic force along the Z-axis and a driving torque around the Z-axis, realizing active magnetic levitation control and pump push control. The upper magnet support 23 is set between the upper axial magnetized rotor magnet ring 22 and the multipole radial magnetized magnet 24, and the lower magnet support 25 is set between the multipole radial magnetized magnet 24 and the lower axial magnetized rotor magnet ring 26. Both the upper magnet support 23 and the lower magnet support 25 are annular and are interference-fitted with the inner shaft 20 of the rotor. The upper magnet support 23 and the lower magnet support 25 are used to realize the axial positioning of the upper axial magnetized rotor magnet ring 22, the multipole radial magnetized magnet 24, and the lower axial magnetized rotor magnet ring 26, ensuring axial assembly accuracy.

[0040] like Figure 3The wound induction silicon steel ring 27 is located axially at the center between the upper annular induction coil 160 and the lower annular induction coil 161 (i.e., the upper annular induction coil 160 and the lower annular induction coil 161 are symmetrically installed about the center plane of the wound induction silicon steel ring 27). When the magnetic levitation rotor impeller 2 is in the axial equilibrium position, the electromagnetic coupling between the wound induction silicon steel ring 27 and the upper annular induction coil 160 and the lower annular induction coil 161 is basically consistent, and the differential output is close to zero. When the magnetic levitation rotor impeller 2 is displaced along the Z-axis, the coupling between the wound induction silicon steel ring 27 and the upper annular induction coil 160 and the lower annular induction coil 161 changes in the opposite direction, thereby forming a differential voltage signal corresponding to the axial displacement and transmitting it to the external power supply and control system. The external power supply and control system can obtain the axial displacement of the magnetic levitation rotor impeller based on this differential voltage signal. :

[0041] ;

[0042] In the formula, The voltage output by the upper ring induction coil 160 is... The voltage output by the lower ring induction coil 161; To determine the sensitivity coefficient, a known axial displacement is applied to the magnetic levitation rotor impeller 2 before each use, and differential voltage signals are simultaneously acquired. The sensitivity coefficient is then obtained by fitting the displacement-differential voltage signals. .

[0043] The magnetically levitated impeller 28 is fixed to the lower end of the inner shaft 20 of the rotor, and generates axial thrust as the inner shaft 20 rotates. Figure 7 The magnetic levitation duct impeller 28 includes a rotor impeller housing and rotor impeller blades 281 inside it. The rotor impeller housing is provided with rotor impeller screw through holes 280, and screw holes are provided at corresponding positions on the inner peripheral wall of the rotor inner shaft 20, thereby realizing the fixation of the magnetic levitation duct impeller 28 and the rotor inner shaft 20.

[0044] The inner shaft 20 of the rotor is provided with rotor end locking rings 21 at both ends. The rotor end locking rings 21 are fixed to the outer peripheral wall of the inner shaft 20 of the rotor to realize the axial pressing and anti-loosening positioning of the components on the outer peripheral wall of the inner shaft 20 of the magnetic levitation rotor impeller 2.

[0045] like Figure 4 and Figure 5As shown, the hollow cup winding 13 consists of three independent windings, each with the same winding direction. Each independent winding is arranged cyclically in the circumferential direction according to the phase sequence A, B, and C, with the number of cycles equal to the number of pole pairs in the hollow cup winding. The number of pole pairs is an integer greater than or equal to 2 (e.g., 2, 3, 4, 5, etc.). Each independent winding has the same spatial configuration, being either a saddle-shaped winding or a racetrack-shaped winding. Each independent winding includes a middle section extending linearly along the axial direction, and upper and lower ends located at both ends of the middle section. The upper and lower ends are used to achieve electrical connection of the middle section and are configured as arcs or rhombuses. The middle sections of each independent winding collectively constitute the middle section 132 of the hollow cup winding, the upper ends of each independent winding collectively constitute the upper end 131 of the hollow cup winding, and the lower ends of each independent winding collectively constitute the lower end 133 of the hollow cup winding.

[0046] The hollow cup winding 13 is preferably a three-phase Y-connection structure, with the same end of each independent winding connected as the three-phase neutral point, and the other end of each independent winding connected to the external current injection terminal; the three-phase neutral point is actively led out from the hollow cup winding through an independent lead, which is used to introduce zero-sequence current in addition to the three-phase drive current, and the zero-sequence current has the same direction in the three-phase independent windings A, B, and C.

[0047] Through the above structure, the upper end 131 and lower end 133 of the hollow cup winding form different spatial current vector distributions with the middle section 132 of the hollow cup winding. Under the action of the three-phase drive current, the three-phase currents of the middle section 132 of the hollow cup winding are arranged cyclically in spatial ABC phase sequence. The currents of each phase alternate with time, generating a rotating magnetic field along the circumferential direction, which interacts with the multi-pole radial magnetized magnet 24 to drive the multi-pole radial magnetized magnet 2 to drive the magnetic levitation rotor impeller 2 to rotate around the Z-axis. Under the action of the zero-sequence current, the currents located on the same radial side in the regions of the upper end 131 and lower end 133 of the hollow cup winding have the same direction, thereby generating a superimposed and enhanced axial magnetic field in the axial direction, which interacts with the upper axial magnetized rotor magnet ring 22 and the lower axial magnetized rotor magnet ring 26 to generate an adjustable axial electromagnetic force. By simultaneously controlling the three-phase alternating current and the neutral point zero-sequence current through an external power supply and control system, torque control and axial levitation control can be realized respectively.

[0048] The magnetic levitation pumping principle of the single-degree-of-freedom magnetic levitation shaftless ducted pumping structure provided in this embodiment is as follows:

[0049] The assembled single-degree-of-freedom magnetic levitation shaftless pump pusher structure is placed at a preset starting position in the deep sea, deep lake, or high-pressure sealed oil tank. A set of known axial displacements is applied to the magnetic levitation rotor impeller 2, and differential voltage signals are simultaneously acquired. The sensitivity coefficient is obtained by fitting the displacement-differential voltage signals.

[0050] Subsequently, the hollow cup winding intermediate section 132 generates a rotating magnetic field under the action of the three-phase drive current. This rotating magnetic field interacts with the multipole radial magnetized magnet 24, generating a torque that drives the multipole radial magnetized magnet 24 to rotate around the Z-axis. The multipole radial magnetized magnet 24 drives the rotor inner shaft 20 to rotate, which in turn drives the magnetic levitation duct impeller 28 to rotate, pushing the fluid to flow axially and forming propulsion force or pumping pressure.

[0051] During operation, when the magnetic levitation rotor impeller 2 undergoes axial displacement, the coupling between the wound induction silicon steel ring 27 and the upper annular induction coil 160 and the lower annular induction coil 161 changes in opposite directions. The upper annular induction coil 160 and the lower annular induction coil 161 generate a differential voltage signal corresponding to the axial displacement and transmit it to the external power supply and control system through the aviation waterproof socket 19. The external power supply and control system first calculates the axial displacement of the magnetic levitation rotor impeller 2 based on the sensitivity coefficient and the differential voltage signal, and then injects zero-sequence current into the hollow cup winding 13 based on the axial displacement. The axial electromagnetic force generated by the hollow cup winding 13 under the action of the zero-sequence current stabilizes the magnetic levitation rotor impeller 2 at the predetermined axial equilibrium position.

[0052] Meanwhile, the upper axially magnetized stator magnetic ring 11 and the upper axially magnetized rotor magnetic ring 22, and the lower axially magnetized stator magnetic ring 15 and the lower axially magnetized rotor magnetic ring 26 repel each other. When the magnetic levitation rotor impeller 2 deviates along the X-axis or Y-axis, a radial restoring force is generated between the paired axially magnetized stator magnetic rings and the axially magnetized rotor magnetic rings, thereby realizing the passive magnetic levitation control of the magnetic levitation rotor impeller 2 along the X-axis and Y-axis. When the magnetic levitation rotor impeller 2 wobbles around the X-axis or Y-axis, a restoring torque is generated between the paired axially magnetized stator magnetic rings and the axially magnetized rotor magnetic rings, thereby realizing the passive magnetic levitation control of the magnetic levitation rotor impeller 2 around the X-axis and Y-axis.

[0053] In summary, this invention, by rationally setting the relative positions of the axially magnetized stator magnet ring, the axially magnetized rotor magnet ring, the multi-pole radially magnetized magnet 24, the wound induction silicon steel ring 27, the hollow cup winding 13, and the ring induction coil, utilizes the repulsive magnetic circuit formed by the axially magnetized stator magnet ring and the axially magnetized rotor magnet ring to self-correct the radial displacement and deflection of the magnetic levitation rotor impeller 2. Based on the real-time displacement detected by the ring induction coil, zero-sequence current is injected into the hollow cup winding 13 to generate an axial electromagnetic force that adjusts the axial position of the magnetic levitation rotor impeller 2. The rotating magnetic field generated by the hollow cup winding 13 under the action of the three-phase drive current drives the multi-pole radially magnetized magnet 24 to rotate, thereby driving the magnetic levitation rotor impeller 2 to rotate. The components work together in a compact structure, achieving simultaneous drive and levitation control without the need for additional axial windings or independent levitation coils, offering the dual advantages of simplified control logic and controllable cost.

[0054] This embodiment is only one of the preferred embodiments of the present invention. Without departing from the concept of the present invention, equivalent substitutions or conventional adjustments to the magnet size, number of winding turns, number of pole pairs, number of impeller blades, and pump casing structure should all fall within the protection scope of the present invention.

Claims

1. A single-degree-of-freedom magnetically levitated shaftless ducted pump pusher structure, characterized in that, It includes a hollow cylindrical stator pump body and a magnetic levitation rotor impeller coaxially disposed within the stator pump body; The stator pump body includes a stator pump housing cavity and a stator pump housing end cover. The stator pump housing cavity has an annular cavity, and the lower end of the stator pump housing cavity is sealed to the stator pump housing end cover. An annular hollow cup winding is fixed to the upper part of the annular cavity, and a pair of axially magnetized stator magnet rings are fixed to both sides of the hollow cup winding. A pair of annular induction coils are fixed at intervals to the lower part of the annular cavity. The two annular induction coils are wound in opposite directions and connected in series at the same end. The annular cavity is filled with potting material. The magnetic levitation rotor impeller includes an inner rotor shaft coaxially disposed within the stator pump body. A pair of axially magnetized rotor magnet rings, which are aligned with the axial position of the axially magnetized stator magnet rings, a multi-pole radially magnetized magnet aligned with the axial position of the hollow cup winding, and a wound induction silicon steel ring located on the axial center plane of a pair of annular induction coils are fixed on the outer peripheral wall of the inner rotor shaft. A magnetically levitated duct impeller is fixed at the lower end of the inner rotor shaft. The pair of axially magnetized stator magnetic rings and the pair of axially magnetized rotor magnetic rings form a repulsive magnetic circuit, thereby passively stabilizing and controlling the radial displacement and yaw of the magnetic levitation rotor impeller; the two ring-shaped induction coils generate differential voltage signals when the winding induction silicon steel rings produce axial displacement, in order to obtain the axial displacement of the magnetic levitation rotor impeller; the hollow cup winding forms a driving magnetic field and a rotating magnetic field, thereby providing the magnetic levitation rotor impeller with axial active control force and driving torque around the central axis.

2. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The hollow cup winding consists of three independent windings, each with the same winding direction. Each independent winding is arranged cyclically in the ABC phase sequence in the circumferential direction, and the number of cycles is equal to the number of pole pairs of the hollow cup winding. The hollow cup winding has a three-phase Y-connection structure, with the same end of each independent winding connected as the three-phase neutral point. The three-phase neutral point is led out from the hollow cup winding through an independent lead to the external circuit. This independent lead is used to introduce zero-sequence current in addition to the three-phase drive current.

3. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 2, characterized in that, Each of the independent windings has the same spatial configuration, which is either a saddle-shaped winding or a racetrack-shaped winding; each independent winding includes a middle section extending in a straight line along the axial direction, and an upper end and a lower end located at both ends of the middle section. The upper end and the lower end are used to realize the electrical connection of the middle section, and the configuration is arc-shaped or rhomboid. The middle sections of each independent winding are used together to generate a rotating magnetic field under the action of three-phase drive current. This rotating magnetic field interacts with the multi-pole radially magnetized magnets to generate a driving torque around the central axis, thereby driving the inner shaft of the rotor to rotate, which in turn drives the magnetically levitated duct impeller to rotate, pushing the fluid to flow axially and forming propulsion force or pumping pressure. The upper and lower ends of each independent winding are used to form a driving magnetic field under the action of zero-sequence current and interact with the pair of axially magnetized rotor magnet rings to generate axial electromagnetic force.

4. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The axial displacement of the magnetic levitation rotor impeller is obtained by calibrating and converting the differential voltage output by the two ring induction coils, and the conversion factor is the sensitivity coefficient. The sensitivity coefficient is determined by calibration before each use: a known axial displacement is applied to the magnetic levitation rotor impeller, and the differential voltage signals output by the two ring induction coils are collected simultaneously. The sensitivity coefficient is obtained by fitting the displacement-differential voltage signals.

5. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The upper end of the stator pump body is equipped with an aviation waterproof socket. The hollow cup winding, the upper ring induction coil and the lower ring induction coil are all led out through the aviation waterproof socket and connected to the external power supply and control system. The differential voltage signal, drive current and control electrical signal are transmitted through the aviation waterproof socket, thereby realizing energy transmission and signal communication in a sealed state.

6. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The joint between the stator pump housing cavity and the stator pump housing end cover is provided with a sealing groove and screw connection structure to form a statically sealed pump body without dynamic seal; the potting material is sufficient to enable the stator pump body to withstand a static water pressure of at least 50 MPa.

7. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The annular cavity is further equipped with a magnet support end cap assembly, a magnet support base, and a coil support body, which provide installation support and coaxial positioning functions. The magnet support end cap assembly is interference-fitted to the upper part of the inner wall of the annular cavity, and the magnet support base is interference-fitted to the lower part of the inner wall of the annular cavity. A gap is left between the upper part of the magnet support end cap assembly and the inner wall of the annular cavity, and a gap is left between the upper part of the magnet support base and the inner wall of the annular cavity. The gaps are used to install the hollow cup winding and a pair of axially magnetized stator magnet rings. The lower diameter of the magnet support base is reduced, and the coil support body and two annular induction coils are interference-fitted to the lower outer peripheral wall of the magnet support base, with the two annular induction coils separated by the coil support body. The outer peripheral wall of the inner shaft of the rotor is also provided with an upper magnet support and a lower magnet support; the upper magnet support and the lower magnet support are respectively disposed between the multi-pole radial magnetized magnet and a pair of axial magnetized rotor magnet rings on both sides, and the upper magnet support and the lower magnet support are used to fix the pair of axial magnetized rotor magnet rings and the multi-pole radial magnetized magnet.

8. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The stator pump body has rotor end locking rings at both ends of its inner peripheral wall.

9. The single-degree-of-freedom magnetic levitation shaftless ducted pump pusher structure according to claim 1, characterized in that, The multi-pole radially magnetized magnet comprises multiple magnets spliced ​​into a ring, with each magnet being alternately magnetized along the radial direction.

10. A magnetic levitation pumping method based on the single-degree-of-freedom magnetic levitation shaftless ducted pumping structure as described in claim 2, characterized in that, The method includes: First, the pump push structure is placed in a preset starting position, a set of known axial displacements are applied to the magnetic levitation rotor impeller, differential voltage signals are collected synchronously, and the sensitivity coefficient is obtained. Subsequently, the hollow cup winding generates a rotating magnetic field under the action of the three-phase drive current. This rotating magnetic field interacts with the multipole radial magnetized magnet to generate a torque that drives the multipole radial magnetized magnet to rotate around the central axis. The multipole radial magnetized magnet drives the magnetic levitation duct impeller to rotate through the inner shaft of the rotor, which in turn drives the fluid to flow axially and forms a propulsive force. During operation, when the magnetic levitation rotor impeller undergoes axial displacement, the wound induction silicon steel ring interacts with the two annular induction coils, causing the two annular induction coils to generate a differential voltage signal corresponding to the axial displacement. The axial displacement of the magnetic levitation rotor impeller is calculated based on the sensitivity coefficient and the differential voltage signal. Then, zero-sequence current is injected into the hollow cup winding based on the axial displacement. Under the action of the zero-sequence current, the hollow cup winding generates an axial electromagnetic force, stabilizing the magnetic levitation rotor impeller at the predetermined axial equilibrium position. Meanwhile, the pair of axially magnetized stator magnetic steel rings and the pair of axially magnetized rotor magnetic steel rings repel each other. When the magnetic levitation rotor impeller undergoes radial displacement or deflection, a radial restoring force or restoring torque is generated between the pair of axially magnetized stator magnetic steel rings and the pair of axially magnetized rotor magnetic steel rings, thereby realizing the passive magnetic levitation control of the magnetic levitation rotor impeller.

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