Superconducting magnetic levitation motor and operation method thereof

Abstract

The invention belongs to the technical field of superconducting electricians, and particularly discloses a superconducting magnetic levitation motor and an operation method thereof.The superconducting magnetic levitation motor is characterized in that a magnetic levitation bearing superconducting coil stator is used for pinning a magnetic field of a magnetic levitation bearing permanent magnet rotor linked with the stator at the current position when the stator is cooled to a superconducting state; when the motor and the magnetic suspension bearing permanent magnet rotor move under the action of a load, the magnetic suspension bearing superconducting coil stator is used for sensing shielding current, or the magnetic suspension bearing superconducting coil stator is used for obtaining pumped transmission current to change the total magnetic flux in the magnetic suspension bearing superconducting coil stator; the shielding current and / or the transmission current interact with the magnetic field, so that the motor is subjected to suspension force opposite to the load direction, and when the load is balanced with the suspension force, the motor reaches a magnetic suspension state. The invention provides a superconducting magnetic levitation motor with high power density.

Description

Technical Field

[0001] The present application belongs to the field of superconducting electrical technology, and more specifically, relates to a superconducting magnetic levitation motor and an operating method thereof. Background Art

[0002] Traditional motors are difficult to achieve high speeds due to friction loss and temperature rise of mechanical bearings, and have disadvantages such as high operating noise, low service life and frequent maintenance. With the development of magnetic levitation technology, the use of magnetic levitation bearings instead of mechanical bearings can eliminate the mechanical contact between the stator and rotor of the motor, which is an ideal choice for high-speed and high-efficiency electric drive. The magnetic levitation bearings currently used in motors are mainly divided into three types: permanent magnetic bearings, electromagnetic bearings and superconducting bearings. Permanent magnetic bearings have a simple structure, but cannot guarantee stable suspension in all degrees of freedom and need to be used in conjunction with other bearings; although electromagnetic bearings can achieve stable suspension, they require a complex feedback control system and have disadvantages such as slow dynamic response, large size and limiting the high speed and large capacity of the motor; superconducting bearings use the magnetic flux pinning effect of superconductors to achieve suspension, which is a passive self-stabilizing suspension and provides a new solution for improving motor speed and power quality.

[0003] At present, superconducting magnetic levitation motors are mainly based on high-temperature superconducting bulk bearings, which have the disadvantages of attenuation of suspension force, low effective suspension force, and uncontrollable suspension state. Therefore, it is difficult for existing superconducting magnetic levitation motors to achieve long-term stable operation, and the inherent suspension stiffness of superconducting bulk materials cannot flexibly cope with the situation where the motor carries axial or radial variable loads. In addition, since it is difficult to use an external system for excitation control of high-temperature superconducting bulk materials, for motor systems that use superconducting coils for armature windings or excitation windings, superconducting suspension technology and superconducting drive technology are independent of each other, limiting the upper limit of the development of compact, lightweight and high power density superconducting magnetic levitation motors. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present application is to provide a superconducting magnetic levitation motor and an operating method thereof, aiming to solve the problem of low power density of the existing superconducting magnetic levitation motor due to the independence of superconducting suspension technology and superconducting drive technology.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a superconducting magnetic levitation motor, comprising: a coaxially arranged motor and a magnetic levitation bearing system; the motor comprises a motor stator and a motor rotor; the magnetic levitation bearing system comprises a magnetic levitation bearing superconducting coil stator and a magnetic levitation bearing permanent magnet rotor; the motor rotor is connected to the magnetic levitation bearing permanent magnet rotor; The motor stator is used to generate a rotating magnetic field in the air gap, and the motor rotor rotates under the action of the air gap magnetic field; the magnetic suspension bearing superconducting coil stator is used to pin the magnetic field of the magnetic suspension bearing permanent magnet rotor that is interlinked with itself in the superconducting state; it is also used to obtain the transmission current inside it or to induce the shielding current when the motor rotor is offset under the action of the load; wherein the shielding current and / or the transmission current interacts with the magnetic field of the magnetic suspension bearing permanent magnet rotor, so that the motor is subjected to a suspension force opposite to the load direction, and the motor reaches a magnetic suspension state.

[0006] Further preferably, the motor is a DC motor, an asynchronous motor or a synchronous motor; and the motor winding is a normal conductive winding or a superconducting winding.

[0007] Further preferably, the superconducting coil stator of the magnetic levitation bearing is wound by superconducting wire, the superconducting wire material is NbTi, Nb3Sn, ReBCO, Bi-2223, Bi-2212, MgB2 or iron-based superconductor, and the superconducting coil stator of the magnetic levitation bearing can be an open-loop coil, a closed-loop coil or a combination of the two.

[0008] Further preferably, when the superconducting coil stator of the magnetic bearing is a closed coil, it is used to obtain the transmission current pumped into the wireless excitation system, and the wireless excitation system is used to adjust the transmission current pumped into the superconducting coil stator of the magnetic bearing according to the change of the axial load to limit the axial displacement of the motor.

[0009] Further preferably, the motor further comprises a main shaft; the main shaft is connected to the motor rotor and the permanent magnet rotor of the magnetic suspension bearing, and is used for torque transmission between the motor rotor and the permanent magnet rotor of the magnetic suspension bearing; Or the magnetic bearing rotor and the motor rotor are integrated, the magnetic bearing rotor and the motor rotor are fixed on the same mechanical support, and the power transmission and conversion between the magnetic bearing rotor and the motor rotor are achieved through the magnetic field of the magnetic bearing permanent magnet rotor.

[0010] Further preferably, the superconducting coil stator of the magnetic bearing and the stator winding of the motor share or partially share, and the permanent magnet rotor poles of the magnetic bearing and the rotor poles of the motor share or partially share.

[0011] Further preferably, when the motor adopts a superconducting unipolar DC motor structure, the superconducting magnetic levitation motor comprises: a magnetic levitation bearing superconducting coil stator, a magnetic levitation bearing permanent magnet rotor, a motor rotor, a rotor core and a stator core; the magnetic levitation bearing superconducting coil stator also serves as the motor stator; the motor rotor adopts a superconducting excitation winding, and its magnetic poles are partially shared with the magnetic levitation bearing permanent magnet rotor; the magnetic levitation bearing permanent magnet rotor and the motor rotor share the rotor core; The magnetic poles of the permanent magnet rotor of the magnetic suspension bearing and the motor rotor act together in the air gap to generate a unipolar magnetic field; wherein the unipolar magnetic field forms a closed magnetic circuit along the rotor core; Among them, the current flowing through the superconducting coil stator of the magnetic bearing interacts with the unipolar magnetic field, causing the motor rotor to be subjected to a rotational torque, thereby achieving motor drive; At the same time, magnetic suspension is achieved between the superconducting coil stator of the magnetic suspension bearing and the permanent magnet rotor of the magnetic suspension bearing due to the magnetic flux pinning effect.

[0012] In a second aspect, accordingly, the present application provides a method for operating a superconducting magnetic levitation motor, comprising the following steps: Step S1: cooling the superconducting coil stator of the magnetic suspension bearing to a superconducting state, and the superconducting coil stator of the magnetic suspension bearing pins the magnetic field of the permanent magnet rotor of the magnetic suspension bearing interlinked with itself at the current position; Step S2: When the motor rotor drives the permanent magnet rotor of the magnetic bearing to move under the action of the load, a shielding current is induced in the superconducting coil stator of the magnetic bearing; or pumping a transmission current into the superconducting coil stator of a magnetic bearing; Step S3: the shielding current and / or the transmission current interacts with the magnetic field of the permanent magnet rotor of the magnetic suspension bearing, so that the motor rotor and the permanent magnet rotor of the magnetic suspension bearing are subjected to a suspension force opposite to the load direction. When the load and the suspension force are balanced, the motor reaches a magnetic suspension state; Step S4: Current is passed through the winding of the motor stator to generate a rotating magnetic field in the air gap. The motor rotor is subjected to a rotating torque under the action of the rotating magnetic field, and a high-speed frictionless rotation operating state is established.

[0013] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: The present application provides a superconducting magnetic levitation motor, which is mainly divided into two steps during operation: the first step is that the motor establishes a magnetic levitation state, specifically: when the superconducting coil stator of the magnetic levitation bearing is in a superconducting state, it pins the magnetic field of the permanent magnet rotor of the magnetic levitation bearing that is interlinked with itself; the transmission current is obtained inside the superconducting coil stator of the magnetic levitation bearing, or a shielding current is induced when the motor rotor is offset under the action of a load; the shielding current and / or the transmission current interact with the magnetic field of the permanent magnet rotor of the magnetic levitation bearing, so that the motor is subjected to a suspension force opposite to the load direction, and the motor reaches a magnetic levitation state. In the second step, based on the motor being in a magnetic levitation state, the motor stator is used to generate a rotating magnetic field in the air gap, and the motor rotor rotates under the action of the air gap magnetic field. In the above-mentioned operation method of the superconducting magnetic levitation motor, the magnetic levitation technology can eliminate the friction of the motor and achieve high-speed operation.

[0014] The present application provides a superconducting magnetic levitation motor, in which the magnetic levitation bearing superconducting coil stator and the motor stator, as well as the magnetic levitation bearing permanent magnet rotor and the motor rotor can all be designed in an integrated manner, with the advantages of compact structure and convenient layout. At the same time, this structure no longer relies on a mechanical shaft to transmit power, but directly realizes power transmission and conversion through a magnetic field. In a large-scale distributed drive system, the superconducting magnetic levitation motor can be used as an independent output unit, each unit can be independently controlled and flexibly coordinated to achieve the best output efficiency of energy, and therefore has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a basic structural schematic diagram of a superconducting magnetic levitation motor provided in an embodiment of the present application; FIG2 (a) is a schematic diagram of the magnetic field of the superconducting magnetic levitation motor provided in an embodiment of the present application, which cools the superconducting coil stator of the magnetic levitation bearing to a superconducting state in a horizontal structure; FIG2( b ) is a schematic diagram of a superconducting magnetic levitation motor provided in an embodiment of the present application realizing magnetic levitation operation in a horizontal structure; FIG3 (a) is a schematic diagram of the magnetic field of the superconducting magnetic levitation motor provided in an embodiment of the present application, which cools the superconducting coil stator of the magnetic levitation bearing to a superconducting state in a vertical structure; FIG3( b ) is a schematic diagram of a superconducting magnetic levitation motor provided in an embodiment of the present application realizing magnetic levitation operation in a vertical structure; Figure 4 It is a structural schematic diagram of a superconducting magnetic levitation motor provided in an embodiment of the present application to realize the levitation-motor integration function; Figure 5 It is a schematic diagram of a squirrel-cage asynchronous superconducting magnetic levitation motor system with a horizontal structure provided in an embodiment of the present application; Figure 6 Schematic diagram of a permanent magnet synchronous superconducting magnetic levitation motor system with a vertical structure provided in an embodiment of the present application. The superconducting magnetic levitation bearing used in the motor can be suspended and controlled by a wireless excitation system; Figure 7 It is a schematic diagram of a stator-rotor integrated permanent magnet synchronous superconducting magnetic levitation motor system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] The term "and / or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0018] The terms “first”, “second” and the like in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of the objects.

[0019] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0020] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0021] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0022] like Figure 1As shown, an embodiment of the present application provides a superconducting magnetic levitation motor, including: a motor rotor 1-1, a motor stator 1-2, a magnetic levitation bearing superconducting coil stator 1-3, a cryogenic dewar 1-4, a magnetic levitation bearing superconducting coil stator 1-5, a main shaft 1-6 and a mechanical protection bearing 1-7; wherein the motor body can be various types of DC motors, asynchronous motors and synchronous motors, and the electronic winding can be a conventional winding or a superconducting winding; the magnetic levitation bearing superconducting coil stator 1-3 is wound by a superconducting wire (NbTi, Nb3Sn, ReBCO, Bi-2223, Bi-2212, MgB2 or iron-based superconductor), and the magnetic levitation bearing superconducting coil stator 1-3 can be an open-loop superconducting coil, a closed superconducting coil or a combination of the two. In addition, the magnetic suspension bearing superconducting coil stator 1-3 can work by shielding current or adopt various wireless excitation systems for flux modulation. When wireless excitation is combined with a closed magnetic suspension bearing superconducting coil stator, the motor also has the ability to adjust the current of the magnetic suspension bearing superconducting coil stator 1-3 according to the change of the axial external force to limit the axial displacement; the cryogenic dewar 1-4 is used to cool the magnetic suspension bearing superconducting coil stator 1-3, and the cooling method can be liquid nitrogen, liquid helium or conduction cooling. When the motor winding also adopts a superconducting coil, the dewar adopts an integrated design; the magnetic suspension bearing permanent magnet rotor 1-5 is located in the hollow room temperature cavity of the cryogenic dewar 1-4, coaxially aligned with the magnetic suspension bearing superconducting coil stator, providing the initial background magnetic field required for pinning suspension; the main shaft realizes torque transmission between the motor rotor and the magnetic suspension bearing permanent magnet rotor through a latch structure. When the motor adopts a stator-rotor integrated design, a spindle-free structure can also be adopted; the mechanical protection bearings are arranged at both ends of the superconducting magnetic suspension motor to provide protection when the magnetic suspension bearing superconducting coil stator fails; The motor provided by the present application can work in a horizontal or vertical structure. When working in a horizontal structure, the radial force generated by the interaction between the induced shielding current on the width surface of the superconducting coil stator of the magnetic levitation bearing and the magnetic field of the permanent magnet rotor of the magnetic levitation bearing realizes suspension, and supports the main shaft and the motor rotor to work without contact; Figures 2 (a) and 2 (b) are the working mechanism of the magnetic levitation motor in a horizontal structure. When the superconducting coil stator of the magnetic levitation bearing is cooled to a superconducting state at the position shown in Figure 2 (a), the superconducting coil stator of the magnetic levitation bearing will pin the permanent magnet magnetic field of the permanent magnet rotor of the magnetic levitation bearing that is interlinked with itself at this position; as shown in Figure 2 (b), after the supporting device is removed, the main shaft, the motor rotor and the permanent magnet rotor of the magnetic levitation bearing are suspended under the action of radial load. Down to To maintain the pinning magnetic field unchanged, a shielding current as shown in Figure 2 (b) is induced inside the superconducting coil stator of the magnetic bearing. The shielding current interacts with the magnetic field of the permanent magnet rotor of the magnetic bearing, causing the motor rotor to be subjected to a radial suspension force. F ,when F and When balanced, the motor reaches a state of magnetic suspension, which allows for high-speed, frictionless rotation; When working in a vertical structure, suspension is achieved by the axial force generated by the interaction between the shielding current of the superconducting coil stator length plane of the magnetic suspension bearing and the magnetic field of the permanent magnet rotor of the magnetic suspension bearing. Figures 3 (a) and 3 (b) show the working mechanism of the magnetic suspension motor in a vertical structure. The superconducting coil stator of the magnetic suspension bearing is cooled to a superconducting state at the position shown in Figure 3 (b). After cooling, the support device is removed. The main shaft, the motor rotor and the permanent magnet rotor of the magnetic suspension bearing move downward under the action of the axial load, and the distance is d To maintain the pinning magnetic field unchanged, the superconducting coil stator of the magnetic bearing will induce a shielding current as shown in Figure 3 (b). The shielding current interacts with the magnetic field of the permanent magnet rotor of the magnetic bearing, causing the motor rotor to be subjected to an axial suspension force. F ,when F and When balanced, the motor reaches a state of magnetic suspension, which allows for high-speed, frictionless rotation; If the superconducting bearing coil stator adopts a working mode of closed coil and wireless excitation system flux modulation, the motor satisfies the above working mechanism, and the system can also adjust the stator current of the superconducting coil of the magnetic levitation bearing according to the change of the axial load to limit the axial displacement of the motor rotor; the specific description is as follows: at this time, since the superconducting coil stator of the magnetic levitation bearing forms a closed loop in the circumferential direction, when the motor rotor undergoes axial displacement, the superconducting coil stator of the magnetic levitation bearing will induce a shielding current flowing in the circumferential direction to limit its displacement; the wireless excitation system is used to control the magnetic flux of the closed coil, and from an electrical perspective, a transmission current flowing in the circumferential direction is also generated, so that the active limitation of the axial displacement of the permanent magnet bearing rotor can be achieved. For horizontal structures, the motor relies on the radial stiffness of the bearing to achieve suspension. Therefore, the main function of the wireless excitation system is to enhance the motor's ability to resist changes in axial loads, such as when it is used in electric propulsion systems to adjust the thrust size. For vertical structures, the motor relies on the axial stiffness of the bearing to achieve suspension. The wireless excitation system can not only enhance the motor's ability to resist changes in axial loads after levitation, but also use the transmission current to replace the shielding current to directly achieve the excitation levitation of the motor. Furthermore, by using the transmission current to actively compensate for the shielding current attenuation caused by joint resistance, internal magnetic flux creep of the superconductor, or AC loss, the axial suspension force can be maintained for a long time, thereby achieving long-term stable operation of the motor. Furthermore, by controlling the direction of the transmission current so that it is in the same direction or opposite direction as the original current, the axial suspension force can be adjusted to control the axial suspension position of the motor.

[0023] In addition, when the motor winding adopts superconducting winding, the present application can also realize the multiplexing function of suspension and motor integration, including that the superconducting coil stator of magnetic suspension bearing and the stator winding of motor can be shared or partially shared, and the motor rotor poles and the permanent magnet bearing rotor poles can be shared or partially shared, etc. Figure 4 As a method of implementation, Figure 4 The structure shown is essentially a superconducting unipolar DC motor, including a magnetic suspension bearing superconducting coil stator 4-1, a permanent magnet bearing rotor 4-2, a motor superconducting excitation winding 4-3, a rotor core 4-4 and a stator back iron 4-5; the magnetic suspension bearing superconducting coil stator 4-1 is also the motor stator armature winding; the motor superconducting excitation winding 4-3 and the permanent magnet bearing rotor together provide a unipolar air gap magnetic field; Figure 4 The dotted arrow represents the direction of the closed magnetic circuit of the motor rotor and the superconducting coil stator of the magnetic suspension bearing, and the solid arrow represents the current direction of the superconducting coil stator of the magnetic suspension bearing and the motor armature winding. The excitation winding and the armature winding are perpendicular to each other. Taking the armature winding in the upper left corner as an example, its current direction interacts with the air gap magnetic field, so that the winding is subjected to an outward force perpendicular to the paper surface, and the rotor is subjected to an inward force perpendicular to the paper surface. The motor rotor is subjected to a counterclockwise (looking from left to right) rotation torque as a whole. At the same time, magnetic suspension can be achieved between the superconducting coil stator and the permanent magnet rotor due to the magnetic flux pinning effect. Therefore, under this structure, the superconducting coil stator of the magnetic suspension bearing serves as the stator winding of the motor, and the magnetic pole part of the permanent magnet rotor of the magnetic suspension bearing serves as the magnetic pole of the motor rotor, realizing the suspension-motor integration function.

[0024] Example 1 Figure 5This is an embodiment of the present application, the structure is a squirrel cage type three-phase asynchronous superconducting magnetic levitation motor, and the working mode is horizontal; it includes: a motor stator 5-1, a squirrel cage type motor rotor 5-2, a main shaft 5-3, a magnetic levitation bearing superconducting coil stator 5-4, a low temperature dewar 5-5, a magnetic levitation bearing permanent magnet rotor 5-6, a protective mechanical bearing 5-7, a motor front end cover 5-8, a motor rear end cover 5-9 and a motor casing 5-10; the winding in the motor stator 5-1 is not drawn, and when a three-phase current is passed through the winding, a rotating electromagnetic magnetic field will be generated in the air gap; the squirrel cage type motor rotor 5-2 The cast aluminum winding is adopted, and an induced current is generated inside the winding under the action of the stator magnetic field of the motor. The interaction between the induced current and the magnetic field generates the Lorentz force, which drives the motor to rotate. The main shaft 5-3 is used to transmit torque to the outside world. There is a circulating cryogenic liquid inside the cryogenic dewar 5-5, which is used to cool the superconducting coil, and its inner wall also serves as the skeleton for winding the superconducting double-disc coil. The permanent magnet rotor 5-6 of the magnetic suspension bearing is fixed to the main shaft 5-3 by a pin. The permanent magnet in the rotor 5-6 is arranged in a cross-axial and radial manner so that the magnetic field is concentrated in the outer circumferential direction of the rotor, thereby increasing the magnetic suspension. The strength and gradient of the magnetic field pinned by the superconducting coil stator of the floating bearing; the protective mechanical bearing 5-7 is used to protect the motor when the superconducting coil stator of the magnetic suspension bearing loses its overtime; the front end cover 5-8 of the motor is used to fix the mechanical protection bearing and the superconducting coil stator of the magnetic suspension bearing on one side; the rear end cover 5-9 of the motor is used to fix the mechanical protection bearing and the superconducting coil stator of the magnetic suspension bearing on the other side, and the main shaft 5-3 is led out from the rear end cover 5-9 of the motor to transmit torque to the outside world; the motor housing 5-10 is used to fix the front end cover 5-8, the rear end cover 5-9 and the motor stator 5-1 of the motor; the initial state Under the condition that the motor rotor, main shaft and permanent magnet rotor of magnetic levitation bearing are fixed with external support, after the superconducting coil stator of magnetic levitation bearing is cooled, the motor rotor, main shaft and permanent magnet rotor of magnetic levitation bearing realize contactless suspension as a whole; after the initial suspension is realized, the external support device is removed, and the front and rear end covers embedded with mechanical protection bearings are assembled. At this time, the power supply of the motor stator is turned on, and the motor rotor realizes high-speed operation without contact; based on the advantages of small size, low loss and high force density of superconducting coil stator, the horizontal motor can easily realize high-speed machine power quality, and can be applied to fields such as ship propulsion and cryogenic pumps.

[0025] Example 2 Figure 6Another embodiment provided for the embodiment of the present application is a permanent magnet synchronous superconducting magnetic levitation motor, which works in a vertical manner and includes: a motor stator 6-1, a motor rotor 6-2, a main shaft 6-3, a closed superconducting coil stator 6-4, a low-temperature dewar 6-5, a transformer-rectifier type wireless excitation system 6-6, a permanent magnet rotor 6-7, a protective mechanical bearing 6-8, a motor front end cover 6-9, a motor rear end cover 6-10 and a motor housing 6-11; the winding in the motor stator 6-1 is not drawn, and when a three-phase current is passed through the winding, a rotation is generated in the air gap. The electromagnetic magnetic field is rotated; the surface of the rotor core of the motor rotor 6-2 is embedded with 4 permanent magnets with alternating polarization directions, and its magnetic field interacts with the motor stator current to drive itself to rotate; there is a circulating cryogenic liquid inside the cryogenic dewar 6-5; the transformer-rectifier type wireless excitation system 6-6, when an asymmetric alternating current is passed through its primary side, the secondary side superconducting switch will automatically shut down when the current flowing through itself is greater than the superconducting critical current, thereby realizing the rectification function and pumping direct current into the magnetic suspension bearing superconducting coil stator 6-4; the protection mechanical bearing 6-8 suppresses The motor is prevented from radially swinging when it is working and is protected when the superconducting coil stator 6-4 of the magnetic suspension bearing loses its time; the front end cover 6-9 of the motor is used to fix the mechanical bearing stator and the superconducting bearing stator on one side; the rear end cover 10 of the motor is used to fix the mechanical protection bearing and the superconducting coil stator of the magnetic suspension bearing on the other side, and the main shaft 6-3 is led out from the rear end cover 6-10 of the motor; the motor housing 6-11 is used to fix the front end cover 6-9 of the motor, the rear end cover 6-10 of the motor and the motor stator 6-1; the motor of this embodiment adopts vertical operation, and the bearing suspension force is provided by the closed superconducting coil stator The current flowing in the annular direction inside the stator interacts with the permanent magnet rotor of the magnetic suspension bearing, and the current can be regulated by the transformer-rectifier type wireless excitation system; in the initial state, the motor rotor, the main shaft and the permanent magnet rotor of the magnetic suspension bearing are directly fixed under the support of the protective mechanical bearing; after the closed superconducting coil stator is cooled, the wireless excitation system is used to pump the transmission current into the superconducting coil. When the current increases to a certain extent, the motor rotor, the main shaft and the permanent magnet rotor of the magnetic suspension bearing are suspended. At this time, the protective mechanical bearing no longer provides support and enters the protection state. Compared with the horizontal structure, this embodiment can get rid of the limitation that the shielding current size is difficult to increase. The wireless excitation system can achieve extremely high load capacity and maintain long-term stable operation. Therefore, the motor has broad application prospects in the fields of flywheel energy storage, vertical axis wind power generation and axial propulsion system.

[0026] Example 3 Figure 7Another embodiment of the present application is a stator-rotor integrated superconducting magnetic levitation motor, including: a motor stator 7-1, a motor rotor 7-2, a magnetic levitation bearing superconducting coil stator 7-3, a magnetic levitation bearing permanent magnet rotor 7-4, a cryogenic dewar 7-5 and a rotor frame 7-6; the motor rotor 7-2 is composed of a surface-mounted permanent magnet; the magnetic levitation bearing superconducting coil stator 7-3 and the motor stator 7-1 winding are both assembled inside the cryogenic dewar and cooled by a circulating cryogenic liquid; the magnetic levitation bearing permanent magnet rotor and the motor rotor are both embedded on the rotor frame 7-6 to form an integrated design; after the magnetic levitation bearing superconducting coil stator is cooled, the integrated rotor enters a magnetic levitation state and rotates at high speed driven by the drive motor. In this embodiment, the magnetic levitation bearing superconducting coil stator and the motor stator, as well as the magnetic levitation bearing permanent magnet rotor and the motor rotor are all designed in an integrated manner, which has the advantages of compact structure and convenient layout. At the same time, the structure no longer relies on a mechanical shaft to transmit power, but directly realizes power transmission and conversion through a magnetic field. In a large-scale distributed drive system, this embodiment can be used as an independent output unit, and each unit can be independently controlled and flexibly coordinated to achieve the best energy output efficiency, so it has broad application prospects.

[0027] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0028] In addition, in the present application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0029] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0030] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, verticality, etc. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense, and allow a small amount of deviation, approximation to symmetry, approximation to equality, approximation to parallelism, approximation to verticality, etc. are all possible. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0031] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A superconducting magnetic levitation motor, characterized in that: include: A motor and a magnetic bearing system are coaxially arranged; the motor comprises a motor stator and a motor rotor; the magnetic bearing system comprises a magnetic bearing superconducting coil stator and a magnetic bearing permanent magnet rotor; the motor rotor is connected to the magnetic bearing permanent magnet rotor; The motor stator is used to generate a rotating magnetic field in the air gap, and the motor rotor rotates under the action of the air gap magnetic field; the magnetic suspension bearing superconducting coil stator is used to pin the magnetic field of the magnetic suspension bearing permanent magnet rotor that is interlinked with itself in the superconducting state; it is also used to obtain the transmission current inside it or to induce the shielding current when the motor rotor is offset under the action of the load; wherein the shielding current and / or the transmission current interacts with the magnetic field of the magnetic suspension bearing permanent magnet rotor, so that the motor is subjected to a suspension force opposite to the load direction, and the motor reaches a magnetic suspension state.

2. The superconducting magnetic levitation motor according to claim 1, characterized in that: The motor is a DC motor, an asynchronous motor or a synchronous motor; the motor winding is a normal conductive winding or a superconducting winding.

3. The superconducting magnetic levitation motor according to claim 1, characterized in that: The superconducting coil stator of the magnetic levitation bearing is wound by superconducting wire. The superconducting wire material is NbTi, Nb3Sn, ReBCO, Bi-2223, Bi-2212, MgB2 or iron-based superconductor. The superconducting coil stator of the magnetic levitation bearing is an open-loop coil, a closed-loop coil or a combination of the two.

4. The superconducting magnetic levitation motor according to any one of claims 1 to 3, characterized in that: When the magnetic bearing superconducting coil stator is a closed coil, it is used to obtain the transmission current pumped by the wireless excitation system. The wireless excitation system is used to adjust the transmission current pumped into the magnetic bearing superconducting coil stator according to the change of the axial load to limit the axial displacement of the motor.

5. The superconducting magnetic levitation motor according to any one of claims 1 to 3, characterized in that: The motor also includes a main shaft; the main shaft connects the motor rotor and the permanent magnet rotor of the magnetic suspension bearing, and is used for torque transmission between the motor rotor and the permanent magnet rotor of the magnetic suspension bearing; Or the magnetic bearing rotor and the motor rotor are integrated, the magnetic bearing rotor and the motor rotor are fixed on the same mechanical support, and the power transmission and conversion between the magnetic bearing rotor and the motor rotor are achieved through the magnetic field of the magnetic bearing permanent magnet rotor.

6. The superconducting magnetic levitation motor according to any one of claims 1 to 3, characterized in that: The superconducting coil stator of the magnetic suspension bearing shares or partially shares the stator winding of the motor, and the permanent magnet rotor poles of the magnetic suspension bearing shares or partially shares the rotor poles of the motor.

7. The superconducting magnetic levitation motor according to claim 6, characterized in that: When the motor adopts a superconducting unipolar DC motor structure, the superconducting magnetic levitation motor includes: a magnetic levitation bearing superconducting coil stator, a magnetic levitation bearing permanent magnet rotor, a motor rotor, a rotor core and a stator core; the magnetic levitation bearing superconducting coil stator also serves as the motor stator; the motor rotor adopts a superconducting excitation winding, and its magnetic poles are partially shared with the magnetic levitation bearing permanent magnet rotor; the magnetic levitation bearing permanent magnet rotor and the motor rotor share the rotor core; The magnetic poles of the permanent magnet rotor of the magnetic suspension bearing and the motor rotor act together in the air gap to generate a unipolar magnetic field; wherein the unipolar magnetic field forms a closed magnetic circuit along the rotor core; Among them, the current flowing through the superconducting coil stator of the magnetic bearing interacts with the unipolar magnetic field, causing the motor rotor to be subjected to a rotational torque, thereby achieving motor drive; At the same time, magnetic suspension is achieved between the superconducting coil stator of the magnetic suspension bearing and the permanent magnet rotor of the magnetic suspension bearing due to the magnetic flux pinning effect.

8. An operating method of a superconducting magnetic levitation motor according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: cooling the superconducting coil stator of the magnetic suspension bearing to a superconducting state, and the superconducting coil stator of the magnetic suspension bearing pins the magnetic field of the permanent magnet rotor of the magnetic suspension bearing interlinked with itself at the current position; Step S2: When the motor rotor drives the permanent magnet rotor of the magnetic bearing to move under the action of the load, a shielding current is induced in the superconducting coil stator of the magnetic bearing; or pumping a transmission current into the superconducting coil stator of a magnetic bearing; Step S3: the shielding current and / or the transmission current interacts with the magnetic field of the permanent magnet rotor of the magnetic suspension bearing, so that the motor rotor and the permanent magnet rotor of the magnetic suspension bearing are subjected to a suspension force opposite to the load direction. When the load and the suspension force are balanced, the motor reaches a magnetic suspension state; Step S4: current is passed through the winding of the motor stator to generate a rotating magnetic field in the air gap. The motor rotor is subjected to a rotating torque under the action of the rotating magnetic field, thereby establishing a high-speed frictionless rotation operation state.

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