Halbach permanent magnet type magnetic suspension motor

Abstract

The invention belongs to the technical field of magnetic suspension motors, and discloses a Halbach permanent magnet type magnetic suspension motor, a rotor of the Halbach permanent magnet type magnetic suspension motor comprises an upper permanent magnet rotor, a lower permanent magnet rotor and a connecting shaft connected between the upper permanent magnet rotor and the lower permanent magnet rotor, the upper permanent magnet rotor is provided with a first annular Halbach array surrounded by first magnet units, and the lower permanent magnet rotor is provided with a second annular Halbach array. The lower permanent magnet rotor is provided with a second annular Halbach array formed by arranging second magnet units in a surrounding manner; each of the first magnet units and the second magnet units is formed by arranging more than three magnetic blocks with different magnetizing directions; the connecting shaft is of a non-magnetic conductive structure; the stator comprises a first magnet yoke group and an annular second magnet yoke fixedly arranged in the middle of the first magnet yoke group; and a first driving coil group for driving the rotor to suspend and rotate is wound on the axial arm of the first magnet yoke. The magnetic suspension motor is simple in structure and good in magnetic collection effect, the peripheral surface magnetic field of the rotor close to the stator end is directionally strengthened, and the magnetic field utilization rate and the operation stability of the rotor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation motors, and particularly to a Halbach permanent magnet type magnetic levitation motor. Background Art

[0002] Magnetic levitation motors are divided into bearing magnetic levitation motors and shaftless magnetic levitation motors. The levitation force of bearing magnetic levitation motors is provided by separate electromagnetic bearings. Compared with traditional motors, shaftless magnetic levitation motors use stator windings and permanent magnet rotors to achieve active levitation control, no longer requiring additional magnetic levitation bearings. And because there is no mechanical contact between the rotor and the stator, the noise and wear during operation are small, and the pollution is also less. Therefore, it is developed and applied to high-speed and high-power application scenarios.

[0003] However, in practical applications, based on its traditional structural design, existing magnetic levitation motors generally have problems such as low magnetic field utilization rate, difficulty in improving the torque and axial stiffness of permanent magnet rotors, and insufficient operating stability of permanent magnet rotors at high speeds.

[0004] Therefore, the existing technology needs to be further improved. Summary of the Invention

[0005] In view of the above problems, the present invention provides a Halbach permanent magnet type magnetic levitation motor. The structure of this magnetic levitation motor is simple and has a good magnetic focusing effect. Through the annular Halbach array on the rotor, the magnetic field on the outer peripheral surface near the stator end of the rotor is directionally strengthened, improving the magnetic field utilization rate and operating stability of the rotor.

[0006] To solve the above problems, the present application provides the following technical solutions: A Halbach permanent magnet type magnetic levitation motor includes a mover and a stator. The rotor includes an upper permanent magnet rotor, a lower permanent magnet rotor coaxially arranged up and down, and a connecting shaft connected between the two. The upper permanent magnet rotor is provided with a first annular Halbach array surrounded by at least two first magnet units, and the lower permanent magnet rotor is provided with a second annular Halbach array surrounded by at least two second magnet units. The first magnet unit and the second magnet unit are respectively arranged by more than three magnetic blocks with different magnetization directions; the connecting shaft is a non-magnetic conducting structure; The stator includes: a first magnetic yoke group and a ring-shaped second magnetic yoke fixedly arranged in the middle of the first magnetic yoke group. The first magnetic yoke group is composed of a plurality of longitudinally arranged first magnetic yokes arranged in a circumferential pattern centered on the rotor. The second magnetic yoke is fixedly connected to all the first magnetic yokes; the first magnetic yoke includes a longitudinally arranged axial arm and a radial arm extending radially from at least one end of the axial arm towards the rotor. A first driving coil group for driving the rotor to levitate and rotate is wound on the axial arm of the first magnetic yoke; the central axis of the ring-shaped second magnetic yoke is set to coincide with the central axis of the rotor.

[0007] Optionally, in the Halbach permanent magnet type magnetic levitation motor, the second yoke is vertically connected to the axial arm of the first yoke; the second yoke is vertically connected to the middle position of the first yoke; radial arms extend from the upper and lower ends of the axial arm of the first yoke respectively.

[0008] In an optional implementation manner, in the Halbach permanent magnet type magnetic levitation motor, each first drive coil group is a coil that simultaneously provides a rotating magnetic field and a levitation magnetic field for the rotor, and the first drive coil group is arranged above and / or below the second yoke. In another optional implementation manner, in the Halbach permanent magnet type magnetic levitation motor, each first drive coil group includes a levitation coil for the rotor's levitation magnetic field and a rotating coil for providing a rotating magnetic field for the rotor; Each group of first drive coil groups is arranged above and / or below the second yoke, or the levitation coil and the rotating coil of each group of drive coils are respectively arranged at one position above or below the second yoke.

[0009] On the above basis, further preferably, in the Halbach permanent magnet type magnetic levitation motor, a second drive coil group for adjusting the levitation and rotation states of the rotor is wound on the part of the second yoke located between two adjacent first yokes.

[0010] Optionally, in the Halbach permanent magnet type magnetic levitation motor, each group of second drive coil groups includes two coils, a levitation coil for the rotor's levitation magnetic field and a rotating coil for providing a rotating magnetic field for the rotor; or each group of second drive coil groups is a single coil.

[0011] Optionally, in the Halbach permanent magnet type magnetic levitation motor, the upper permanent magnet rotor and the lower permanent magnet rotor are circular ring structures that are coaxially arranged up and down and overlap, and the magnetization directions of the magnets at the axially projected positions of the upper permanent magnet rotor and the lower permanent magnet rotor are the same or opposite.

[0012] Optionally, in the Halbach permanent magnet type magnetic levitation motor, in the first magnet unit, the structures of magnet block one, magnet block two, magnet block three, and magnet block four are different from each other, or two of magnet block one, magnet block two, magnet block three, and magnet block four have the same structure; in the second magnet unit, the structures of magnet block five, magnet block six, magnet block seven, and magnet block eight are different from each other, or two of magnet block five, magnet block six, magnet block seven, and magnet block eight have the same structure.

[0013] The structures of adjacent magnet blocks in the first magnet unit or the second magnet unit are complementary, and all the magnet blocks are jointly spliced to form a first annular Halbach array; Optionally, in the Halbach permanent magnet type magnetic levitation motor, the first magnet unit is composed of magnet block 1, magnet block 2, magnet block 3, and magnet block 4 arranged in sequence. Among them, the magnetization method of magnet block 1 is radial inward magnetization, the magnetization direction of magnet block 3 is radial outward magnetization, the magnetization direction of magnet block 2 is perpendicular to the magnetization direction of magnet block 1 and points to magnet block 3, and the magnetization direction of magnet block 4 is perpendicular to the magnetization direction of the third magnet block and points to magnet block 3; The second magnet unit is composed of magnet block 5, magnet block 6, magnet block 7, and magnet block 8 arranged in sequence. Among them, the magnetization method of magnet block 5 is radial inward magnetization, the magnetization direction of magnet block 7 is radial outward magnetization, the magnetization direction of magnet block 6 is perpendicular to the magnetization direction of magnet block 5 and points to magnet block 7, and the magnetization direction of magnet block 8 is perpendicular to the magnetization direction of magnet block 7 and points to magnet block 7.

[0014] On the above basis, in the first further optional embodiment, each magnet block of the first magnet unit and the second magnet unit is a quasi-triangular prism, and the inner or outer side surface of the quasi-triangular prism facing the rotor axis is an arc surface.

[0015] On the above basis, in the second further optional embodiment, each magnet block of the first magnet unit and the second magnet unit is a fan-shaped ring column.

[0016] On the above basis, in the third further optional embodiment, magnet block 1 and magnet block 3 of the first magnet unit have the same structure, which is an inverted parabolic shape or a quasi-petal shape with an opening inward. Adjacent magnet block 1 and magnet block 3 are arranged in a ring-shaped array of a flower shape with their two sides connected in a ring, and magnet block 2 and magnet block 4 are filled into the gaps between adjacent magnet block 1 and magnet block 3 to jointly form a ring-shaped Halbach array; the structure of the second magnet unit is the same as that of the first magnet unit.

[0017] Optionally, in the rotor of the Halbach permanent magnet type magnetic levitation motor, the first magnets and the second magnets on the upper permanent magnet rotor and the lower permanent magnet rotor are arranged with overlapping or misaligned positions.

[0018] The present invention has the following beneficial effects: 1. The structural design of the novel permanent magnet rotor provided by the present invention is ingenious. By arranging a ring-shaped Halbach array on the upper permanent magnet rotor and the lower permanent magnet rotor, the magnetic field on the outer peripheral surface near the stator end of the rotor is directionally strengthened, the magnetic field of the rotor is optimized, and the magnetic field utilization rate of the permanent magnet material is improved. It can not only increase the output torque of the motor but also reduce the cogging torque, thereby reducing the torque ripple and contributing to improving the running stability and running efficiency of the motor.

[0019] In the permanent magnet rotor, the annular Halbach array permanent magnet array can eliminate the magnetic conductive backplane in a motor with a traditional multi-pole magnet rotor due to its unique magnetic field distribution and does not rely on the magnetic conductivity of the connecting shaft. Therefore, on the premise of ensuring the structural stability of the rotor, the thickness and specifications of the connecting shaft can be minimized to the greatest extent, achieving the light weight of the rotor, reducing the rotor inertia, and thus improving the rapid response ability of the motor.

[0020] 2. In the magnetic levitation motor, the stator with an annular second magnetic yoke optimizes the main magnetic circuit through cooperation with the permanent magnet rotor. On the one hand, the main magnetic circuit becomes shorter. On the other hand, there are closed-loop main magnetic circuits symmetrically distributed up and down in the motor. Through the regulation of these two main magnetic circuits by two sets of drive coil groups, independent control of the upper and lower parts of the rotor can be achieved, facilitating the precise regulation of the axial position offset, radial offset, and tilt angle of the rotor, and realizing the transformation of the tilt angle and suspension control of the rotor from passive control to active control, thereby greatly improving the operation stability of the rotor. Due to the high stability of the rotor driven by this stator, the torque of the rotor can be significantly increased, with the torque of the rotor increased by at least more than 10%.

[0021] 3. The stator of the magnetic levitation motor can achieve multi-dimensional regulation methods through the cooperation of the first drive coil group and the second drive coil group, making the regulation of the rotor more flexible and variable, effectively improving the control accuracy and stability. Brief Description of the Drawings

[0022] Figure 1 Schematic perspective view of the Halbach permanent magnet motor of Embodiment 1; Figure 2 Schematic perspective view of the rotor in the motor of Embodiment 1; Figure 3 Top view of the permanent magnet rotor of Embodiment 1; the arrows in the figure represent the magnetization direction; Figure 4 Schematic perspective view of the stator in the motor of Embodiment 1; Figure 5 Schematic longitudinal sectional structure view of the magnetic levitation motor of Embodiment 1; the arrowed lines represent magnetic force lines; Figure 6 Schematic diagram of the magnetic force line distribution from the top view angle of the upper permanent magnet rotor layer and the lower permanent magnet rotor layer of the magnetic levitation motor of Embodiment 1; Figure 7 Top view of the new permanent magnet rotor of Embodiment 2; the arrows in the figure represent the magnetization direction; Figure 8 Schematic perspective view of the motor applying the new permanent magnet rotor of Embodiment 2; the connecting shaft part in the figure is omitted; Figure 9Schematic top view structure of the novel permanent magnet rotor of Embodiment 3; Figure 10 Schematic three-dimensional structure of the motor of Embodiment 3; Figure 11 A, B, C, and D in the figure are schematic diagrams of four different implementation manners of the stator of the magnetic levitation motor of Embodiment 4; the closed-loop route with arrows in the figure represents the main magnetic circuit; Figure 12 Schematic stator structure of the motor of Embodiment 5; Figure 13 Another implementation manner of the motor in Embodiment 1. Specific implementation manners

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "vertical", "horizontal", "left", "right", "upper", "lower", "inner", "outer", "bottom", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in this specification in the description of the present invention are only for the purpose of describing specific implementation manners and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items. In addition, the technical features involved in different implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] Embodiment 1 As Figure 1As shown in the figure, this embodiment provides a Halbach permanent magnet type magnetic levitation motor, which includes a rotor 1 and a stator 2. Among them, the rotor includes an upper permanent magnet rotor 11, a lower permanent magnet rotor 13 arranged coaxially up and down, and a connecting shaft 12 fixedly connected between the two.

[0026] The upper permanent magnet rotor is provided with a first annular Halbach array surrounded by a plurality of first magnet units 11a, and the lower permanent magnet rotor is provided with a second annular Halbach array surrounded by a plurality of second magnet units 13a. The first magnet unit 11a and the second magnet unit 13a are respectively composed of more than three magnetic blocks arranged in different magnetization directions; the connecting shaft is a non-magnetic structure, and the connecting shaft is a non-magnetic cylindrical structure.

[0027] The arrangement of the annular Halbach array of the above rotor causes the magnetic lines of force on the outer peripheral surface side of the upper permanent magnet rotor / lower permanent magnet rotor close to the stator to be concentrated, that is, the magnetic fields of the upper permanent magnet rotor 11 and the lower permanent magnet rotor 13 close to the outer peripheral surface of the stator are strengthened, thereby greatly improving the magnetic field utilization rate, thereby increasing the output torque of the motor, and closing and reducing the cogging torque, thereby reducing the torque ripple, so as to improve the running stability and efficiency of the motor.

[0028] In the permanent magnet rotor, due to the unique magnetic field distribution of the annular Halbach array permanent magnet array, the magnetic conductive backplane in the motor using a multi-pole permanent magnet rotor in the traditional way can be omitted, and it does not depend on the magnetic conductivity of the connecting shaft. Therefore, on the premise of ensuring the structural stability of the rotor, the thickness and specifications of the connecting shaft can be reduced to the greatest extent, the rotor is lightened, the rotor inertia is reduced, and the rapid response ability of the motor is improved.

[0029] The upper permanent magnet rotor and the lower permanent magnet rotor are circular ring structures arranged coaxially up and down and overlapping.

[0030] The first magnet unit 11a and the second magnet unit 13a are respectively composed of more than three magnetic blocks arranged in different magnetization directions.

[0031] In this embodiment, as Figure 2 shown, the first magnet unit 11a is composed of four magnetic blocks, namely magnetic block one, magnetic block two, magnetic block three and magnetic block four, arranged in sequence. Among them, the magnetization method of magnetic block one is radial inward magnetization, the magnetization direction of magnetic block three is radial outward magnetization, the magnetization direction of magnetic block two is perpendicular to the magnetization direction of magnetic block one and points to magnetic block three, and the magnetization direction of magnetic block four is perpendicular to the magnetization direction of the third magnetic block and points to magnetic block three. The adjacent magnetic blocks in the four magnetic blocks of the first magnet unit are complementary in structure, and all the magnetic blocks are jointly spliced to form the first annular Halbach array. The radial magnetization refers to pointing to or away from the axis along the radius direction of the rotor.

[0032] The second magnet unit 13a is composed of magnet block five, magnet block six, magnet block seven, and magnet block eight arranged in sequence. Among them, the magnetization mode of magnet block five is radially inward magnetization, the magnetization direction of magnet block seven is radially outward magnetization, the magnetization direction of magnet block six is perpendicular to the magnetization direction of magnet block five and points to magnet block seven, and the magnetization direction of magnet block eight is perpendicular to the magnetization direction of magnet block seven and points to magnet block seven. Among the four magnet blocks of the second magnet unit, the adjacent magnet blocks have complementary structures, and all the magnet blocks are jointly spliced to form a second annular Halbach array.

[0033] In other embodiments, the number of magnet blocks forming the first magnet unit is not limited to 4 in this embodiment, and can also be set to 3, 5, or more.

[0034] In this embodiment, magnet block one and magnet block three have the same structure, and magnet block two and magnet block four have the same structure; correspondingly, magnet block five and magnet block seven have the same structure, and magnet block six and magnet block eight have the same structure.

[0035] In other embodiments, the structures of magnet block one, magnet block two, magnet block three, and magnet block four are all different, and in the second magnet unit, the structures of magnet block five, magnet block six, magnet block seven, and magnet block eight are all different from each other.

[0036] In this embodiment, the upper permanent magnet rotor and the lower permanent magnet rotor are circular ring structures that are coaxially arranged up and down and overlapped. Each magnet block of the first magnet unit and the second magnet unit is a quasi-triangular prism, and the inner or outer side surface of the quasi-triangular prism facing the rotor axis is an arc surface.

[0037] In other embodiments, there may be other deformations in the shapes of adjacent magnet blocks. These deformation schemes all fall within the protection scope of this application.

[0038] The fixed connection of the upper permanent magnet rotor, the lower permanent magnet rotor, and the connecting shaft is one or more of the existing fixed connection methods such as bonding, ultrasonic welding, and clamping.

[0039] In this embodiment, as Figure 1 and 4 shown, the stator includes: a first magnetic yoke group and an annular second magnetic yoke 23 fixedly arranged in the middle of the first magnetic yoke group. The first magnetic yoke group is composed of a plurality of longitudinally arranged first magnetic yokes 21 arranged in a circumferential pattern centered on the rotor. The second magnetic yoke is fixedly connected to all the first magnetic yokes; the first magnetic yoke includes a longitudinally arranged axial arm 21a and a radial arm 21b extending radially from at least one end of the axial arm towards the rotor. A first drive coil group 22 for driving the rotor to levitate and rotate is wound around the axial arm of the first magnetic yoke; the central axis of the annular second magnetic yoke is set to coincide with the central axis of the rotor.

[0040] During operation, two closed loops are formed between the second yoke where the main magnetic path coil is located, the upper / lower parts of the first yoke on the left and right sides of each drive coil group, and the corresponding upper permanent magnet rotor / lower permanent magnet rotor, which are symmetrically distributed in the up-down radial direction. The upper and lower closed main magnetic paths share a partial magnetic path in the second yoke.

[0041] In other embodiments, the position of the second yoke can be set at a position slightly above or below the middle of the axial arm of the first yoke and can be adjusted as needed. These deformation schemes all fall within the scope of protection of this application. This scheme can improve the adverse effects caused by the offset of the rotor center of gravity due to the load, such as rotor tilt. This is because the magnetic path at the offset end of the second yoke is shorter, the magnetic resistance is smaller, and the relative output force is larger, which can effectively balance the influence caused by the center of gravity offset.

[0042] In the stator of this embodiment, the first yoke includes an axially arranged axial arm 21a and a radially extending radial arm 21b from at least one end of the axial arm. The first drive coil group 22 for driving the rotor to levitate and rotate is wound around the axial arm of the first yoke.

[0043] The second yoke 23 is vertically connected to the axial arm of the first yoke; the center of the annular second yoke is set to coincide with the rotor center axis of the rotor. In this embodiment, further, the second yoke 23 is vertically connected to the middle of the axial arm of the first yoke, so that the stator is symmetrically arranged up and down with the second yoke as the central axis.

[0044] In this embodiment, the first yoke includes an axially arranged axial arm 21a and radially extending radial arms 21b respectively extending from the upper and lower ends of the axial arm to the rotor radius. The structure of this first yoke is in a similar C-shaped structure, and the first drive coil group 22 for driving the rotor to levitate and rotate is wound around the axial arm of the first yoke.

[0045] Specifically, in this embodiment, the number of the first yokes is 8, and the number of the first magnet units / second magnet units of the rotor cooperating with them is 4; in other embodiments, the number of the first yokes can also be 6, 10 or more, and the number of the first magnet units of the rotor can be 1, 2 or 4, 1 or 2, as long as the pole-slot matching of the permanent magnet motor is satisfied.

[0046] In this embodiment, in order to facilitate the installation of the second yoke and its connection with the first yoke and ensure that the magnetic lines of force can be connected between the second yoke and the adjacent first yoke, the following settings are made: The second yoke 23 is provided with a positioning hole for the axial arm of the first yoke to pass through, and the second yoke and the first yoke are fixedly connected, such as by bonding, screwing, welding or riveting and other fixed connection methods.

[0047] In other embodiments, the outer peripheral side wall / inner peripheral side wall of the second yoke is clamped and bonded to the inner side wall / outer side wall portion of the axial arm of the first yoke, or fixedly connected in other ways.

[0048] The second yoke is composed of a plurality of second annular laminations stacked on each other along the stacking direction, and the stacking direction is set axially or radially. The first yoke is formed by laminating a plurality of first laminations along the stacking direction. The laminations can be made of silicon steel sheets.

[0049] In this embodiment, specifically, the second yoke is formed by stacking a plurality of second annular laminations vertically. The first yoke is formed by stacking a plurality of C-shaped first laminations front and back. In other embodiments, the second yoke is formed by stacking a plurality of annular laminations arranged concentrically inside and outside.

[0050] In this embodiment, as Figure 3 shown, each first drive coil group includes a suspension coil 22a for the suspension magnetic field of the rotor and a rotation coil 22b for providing a rotation magnetic field for the rotor. In this embodiment, a set of the above-mentioned first drive coil groups 22 are respectively arranged above and below the second yoke. This method uses more coils, but has lower requirements for the control system. The suspension and rotation of the rotor can be independently controlled by controlling the suspension coil or the rotation coil respectively, and the control flexibility is higher.

[0051] At present, due to the independent setting of the traditional longitudinally arranged yokes (or coil cores), during operation, in addition to forming a closed main magnetic circuit between the energized yoke and the corresponding rotor magnetic poles, the yoke will also release unused magnetic flux lines in the lateral direction other than the main magnetic circuit direction, resulting in a large amount of magnetic flux leakage and low magnetic field utilization rate.

[0052] In the stator of the motor in this embodiment, since the annular second yoke connects the magnetic circuits between the independent annularly distributed first yokes, during operation, the magnetic flux leakage to the side in each originally independent first yoke can form other magnetic circuits through the connected annular yoke and be fully utilized, thereby improving the magnetic flux collection effect of the stator, increasing the utilization rate of the magnetic field, and further improving the working efficiency of the rotor.

[0053] On this basis, since the stator of this embodiment is symmetrically distributed up and down with the second yoke as the symmetry center, during operation, there are closed-loop main magnetic circuits symmetrically distributed up and down in the stator. These two main magnetic circuits are respectively controlled by two sets of first drive coil groups 22 distributed up and down, thereby realizing the separate control of the rotation and suspension torques of the upper and lower parts of the rotor, and improving the controllability and stability of the rotor.

[0054] The working principle will be described below by taking the main magnetic circuit of the upper half of the motor stator as an example. The main magnetic circuit of the lower half of the stator is symmetrically arranged with that of the upper half, so it is omitted here.

[0055] Rotation principle: As Figure 6 shown, at a certain moment, the rotating coils on the two first magnetic yokes 21 that are radially symmetric and not aligned with the rotor magnets are energized simultaneously, exciting magnetic force lines that flow upward (or downward) along the axis at the same time. The main magnetic force lines respectively pass through a first magnetic yoke, multiple magnets of the first magnet unit of the upper permanent magnet rotor / the second magnet unit of the lower permanent magnet rotor (forming a U-shaped magnetic circuit with an outward opening), the first magnetic yoke corresponding to the other end of the U-shaped magnetic circuit, and a closed-loop magnetic circuit is formed between the second magnetic yoke connection parts located between these two first magnetic yokes, forming two shorter closed main magnetic circuits distributed left and right in the upper part of the stator.

[0056] The flowing directions of the upper and lower layer magnetic circuits in the transverse magnetic yoke are the same, enabling the coordinated cooperation of the upper and lower magnetic circuits. The rotational torque of the rotor can be increased by coordinately controlling the rotating coils of the upper half and the lower half of the stator, improving the stability and accuracy of the rotor.

[0057] Levitation principle: As Figure 5 shown, the levitation of the rotor in this embodiment is mainly achieved by generating magnetic force between the first magnetic yoke and the rotor. When the levitation coils on the first magnetic yokes of the stator are energized and the current magnitude is adjusted so that the axial pulling forces on the rotor are equal, the rotor can achieve radial centered levitation. When the bottom of the rotor undergoes radial displacement, the levitation coils on the side with an increased air gap in the lower part of the stator will increase the current, increasing the attraction force on this side to correct the radial displacement of the bottom of the rotor.

[0058] In other embodiments, the first magnets and the second magnets on the upper permanent magnet rotor 11 and the lower permanent magnet rotor 13 located on the same main magnetic circuit are vertically offset and magnetized in the same direction. For example, the corresponding first magnets and second magnets on the upper permanent magnet rotor 11 and the lower permanent magnet rotor 13 are vertically offset by 45°. This way of vertically offsetting the upper and lower permanent magnet rotors can make the rotor transition more smoothly during rotation and have smaller torque fluctuations. The distribution of the main magnetic circuit of this scheme is basically the same as that of the main magnetic circuit with the upper and lower permanent magnet rotors overlapping and magnetized in the same direction.

[0059] In still other embodiments, the magnetization directions of the magnets where the upper permanent magnet rotor and the lower permanent magnet rotor overlap in the axial projection position are opposite. This rotor can be assembled and operated with a stator configured with an annular second magnetic yoke or without a second magnetic yoke.

[0060] In this case, as Figure 13As shown, the distribution of the main magnetic circuit in the motor is different from that of this embodiment. Specifically, when the rotating coils of the two first magnetic yokes that are radially symmetric are energized simultaneously, two sets of longitudinally distributed main magnetic force lines will be excited simultaneously. Each set of main magnetic force lines respectively passes through the upper radial arm of the first magnetic yoke A, the first magnet unit of the upper permanent magnet rotor (forming a U-shaped magnetic circuit), and then flows into the upper radial arm of another adjacent first magnetic yoke B, then axially downward to its lower radial arm, the corresponding second magnet unit of the lower permanent magnet rotor (forming a U-shaped magnetic circuit), and finally flows back to the initial first magnetic yoke A to complete the closed loop of the main magnetic circuit, forming two relatively large closed magnetic circuits that penetrate the upper and lower parts of the stator and are distributed left and right. Its suspension and rotation working principles are basically similar to those of this embodiment and will not be elaborated here.

[0061] The stator of the motor further includes: a controller and a sensor that is control-connected to the controller. The sensor is used to detect the radial and axial positions and postures of the rotor, and the controller is used to regulate the current directions and magnitudes of the first drive coil group and the second drive coil group.

[0062] For other structures provided inside the motor, refer to the prior art.

[0063] Embodiment 2 As Figures 7 - 8 As shown, this embodiment provides a composite magnetic levitation motor, which includes a stator and a rotor. The difference from Embodiment 1 lies in the setting of the rotor. For the stator structure, refer to Embodiment 1.

[0064] The rotor includes a longitudinally arranged connecting shaft and upper permanent magnet rotors 11 and lower permanent magnet rotors 13 vertically arranged at both ends of the connecting shaft. The upper permanent magnet rotor is provided with a first annular Halbach array formed by a plurality of first magnet units 11a arranged in a surrounding manner, and the lower permanent magnet rotor is provided with a second annular Halbach array formed by a plurality of second magnet units 13a arranged in a surrounding manner. The connecting shaft is a non-magnetic structure, and the connecting shaft is a non-magnetic cylindrical structure ( Figure 8 the connecting shaft in [] is omitted).

[0065] In this embodiment, the upper permanent magnet rotor is composed of two first magnet units, and the lower permanent magnet rotor is composed of two second magnet units. In other embodiments, the number of the first magnet units on the upper permanent magnet rotor and the second magnet units on the lower permanent magnet rotor can be increased as needed.

[0066] In this embodiment, each magnetic block of the first magnet unit and the second magnet unit is a fan-shaped ring column. The first magnet unit 11a is composed of four magnetic blocks, namely magnetic block one, magnetic block two, magnetic block three, and magnetic block four, which are arranged in sequence. Among them, the magnetization direction of magnetic block one is radially inward, the magnetization direction of magnetic block three is radially outward, the magnetization direction of magnetic block two is perpendicular to the magnetization direction of magnetic block one and points to magnetic block three, and the magnetization direction of magnetic block four is perpendicular to the magnetization direction of the third magnetic block and points to magnetic block three.

[0067] The second magnet unit is composed of magnet blocks five, six, seven, and eight arranged in sequence in a sector-ring cylindrical shape. Among them, the magnetization mode of magnet block five is radial inward magnetization, the magnetization direction of magnet block seven is radial outward magnetization, the magnetization direction of magnet block six is perpendicular to the magnetization direction of magnet block five and points to magnet block seven, and the magnetization direction of magnet block eight is perpendicular to the magnetization direction of magnet block seven and points to magnet block seven.

[0068] In order to reduce production costs and simplify the structure, the magnet blocks in the magnet unit can be set as four magnet blocks with the same shape but different magnetization directions. In order to facilitate the distinction of various magnet blocks and quick installation, each magnet block is provided with a clamping portion for cooperating with adjacent magnet blocks on the connection surface, and the structures or positions of the clamping portions at different positions are designed differently.

[0069] The suspension principle and rotation principle of the motor in this embodiment are the same as those in Embodiment 1, and will not be elaborated here.

[0070] Embodiment 3 As Figures 9 - 10 shown, this embodiment provides a composite magnetic levitation motor, which includes a stator and a rotor. The difference from Embodiment 1 lies in the setting of the rotor. The stator structure can be seen in Embodiment 1.

[0071] The rotor includes a longitudinally arranged connecting shaft and upper permanent magnet rotor 11 and lower permanent magnet rotor 13 vertically arranged at both ends of the connecting shaft. The upper permanent magnet rotor is provided with a first annular Halbach array surrounded by a plurality of first magnet units 11a, and the lower permanent magnet rotor is provided with a second annular Halbach array surrounded by a plurality of second magnet units 13a. The connecting shaft is a non-magnetic cylindrical structure.

[0072] In this embodiment, the upper permanent magnet rotor is composed of four first magnet units, and the lower permanent magnet rotor is composed of four second magnet units. In other embodiments, the number of the first magnet units on the upper permanent magnet rotor and the second magnet units on the lower permanent magnet rotor can be adjusted according to needs.

[0073] As Figure 9 shown, in this embodiment, magnet block one and magnet block three of the first magnet unit have the same structure, which is an inverted parabolic shape or a petal-like shape with an opening inward. Adjacent magnet block one and magnet block three are connected side by side in a ring-shaped array to form a flower-shaped inner ring of the ring-shaped array, and magnet block two and magnet block four are filled into the gaps between adjacent magnet block one and magnet block three to jointly form a ring-shaped Halbach array; the structure of the second magnet unit is the same as that of the first magnet unit.

[0074] The above settings concentrate the magnetic field lines on the outer peripheral surface side of the upper permanent magnet rotor / lower permanent magnet rotor close to the stator, and strengthen the magnetic field on the outer peripheral surface of the upper permanent magnet rotor 11 and the lower permanent magnet rotor 13 close to the stator.

[0075] The suspension principle and rotation principle of the motor in this embodiment are the same as those in Embodiment 1, and will not be elaborated here.

[0076] Embodiment 4 This embodiment provides a magnetic levitation motor, which is different from Embodiment 1 in the improvement of the stator structure. Specifically, in the stator, only one first drive coil group 22 is wound on each first yoke 21, and this group of first drive coil groups 22 is located above or below the second yoke, as Figure 11 shown.

[0077] In the first implementation manner, as Figure 11 A and Figure 11 B shown, each first drive coil group 22 of the first drive coil group includes a suspension coil 22a for the rotor suspension magnetic field and a rotation coil 22b for providing a rotation magnetic field for the rotor, and the first drive coil group is located above or below the second yoke. This method uses more coils, but has lower requirements for the control system. The suspension and rotation of the rotor can be independently controlled by controlling the suspension coil or the rotation coil respectively, and the control flexibility is higher.

[0078] In the second implementation manner, as Figure 11 C shown, the first drive coil group 22 is a coil that simultaneously provides a rotation magnetic field and a suspension magnetic field for the rotor, and is arranged above or below the second yoke. In this setting, by controlling the coil on the first yoke, the rotation magnetic field and the suspension magnetic field provided by the stator for the rotor are adjusted simultaneously. This setting can simplify the coil arrangement and reduce the use cost of the coil, but has higher requirements for the control system of the stator.

[0079] In the third implementation manner, as Figure 11 D shown, the suspension coil 22a and the rotation coil 22b of each group of first drive coil groups are respectively arranged above and below the second yoke. Specifically, the suspension coil 22a is arranged at the position of each first yoke above the second yoke, and the rotation coil 22b is arranged at the position of each first yoke below the second yoke. In other cases, the positions of the suspension coil 22a and the rotation coil 22b are reversed. For other structural settings of the motor in this embodiment, refer to Embodiment 1.

[0080] In this embodiment, the suspension of the rotor is controlled by the suspension coil located above the second yoke, and the rotation of the rotor is controlled by the rotation coil located below the second yoke. Such an arrangement can reduce the difficulty of controlling the suspension and rotation of the rotor. Since the suspension coil 22a and the rotation coil 22b of the first drive coil group are respectively arranged in the upper half and the lower half of the stator, the main suspension magnetic path and the main rotation magnetic path are respectively distributed in the upper half or the lower half of the stator. The working principle of the stator driving the mover to rotate and suspend is also referred to in Embodiment 1.

[0081] For the rotor structure of the motor in this embodiment and other structures of the stator, refer to Embodiment 1. Since the first drive coil group 22 in this embodiment is only arranged in the upper half or the lower half of the stator, its main magnetic path is only distributed in the upper half or the lower half, and the control method is not as flexible as that in Embodiment 1. The working principle of the stator driving the mover to rotate and suspend is referred to in Embodiment 1.

[0082] Embodiment 5 (Stator Scheme 12) This embodiment provides a magnetic levitation motor obtained by improving the stator structure on the basis of Embodiments 1 to 4. For the structure of the rotor of the motor in this embodiment, refer to any of the foregoing embodiments.

[0083] As Figure 12 shown, the stator of this embodiment includes: the aforementioned first yoke group and the annular second yoke 23 fixedly arranged on the first yoke group, and the second yoke is connected to all the first yokes. The second yoke 23 is vertically connected to the middle of the axial arm of the first yoke. The center of the annular second yoke is set to coincide with the rotor center axis of the rotor. In this embodiment, the first yoke includes the axially arranged axial arm 21a and the radial arms 21b respectively extending radially from the upper and lower ends of the axial arm to the rotor. The structure of the first yoke is in a similar C-shaped structure, and the first drive coil group 22 for driving the suspension and rotation of the rotor is wound on the axial arm of the first yoke. In this embodiment, each first drive coil group includes a suspension coil for the suspension magnetic field of the rotor and a rotation coil for providing a rotation magnetic field for the rotor.

[0084] On this basis, the improvement of the stator in this embodiment lies in that: a second drive coil group 24 for assisting in driving the suspension and rotation of the rotor is wound on the part (i.e., the connecting part) of the second yoke 23 located between two adjacent first yokes 21.

[0085] During operation, the first drive coil group 22 wound on the axial arm of the first yoke provides the main driving force for the suspension and rotation of the rotor, while the second drive coil group 24 arranged on the second yoke 23 plays an auxiliary adjustment role according to the state of the rotor, and is used to improve the control accuracy and stability of the rotor.

[0086] The specific principle is as follows: At a certain moment, such as when the rotor as a whole undergoes radial offset, in addition to adjusting the current of the first driving coil, the current of the second driving coil on the side with a larger stator air gap can also be increased, so that the auxiliary magnetic circuit generated by the second driving coil is in the same direction as the magnetic circuit of the first driving coil, strengthening the original magnetic field; thereby increasing the attraction force on this side to correct the radial offset of the rotor at this position.

[0087] Alternatively, the current of the second driving coil on the side with a smaller stator air gap can also be decreased, so that the auxiliary magnetic circuit generated by the second driving coil is opposite to the magnetic circuit of the first driving coil, reducing the original magnetic field at this position, thereby the radial offset of the rotor at this position.

[0088] In another case, when the rotor as a whole undergoes axial offset (such as dropping), by increasing the current of the corresponding second driving coil, the axial suction force of the stator on the rotor is increased, so that the rotor moves upward to correct its axial offset and improve the axial stiffness.

[0089] For other settings of the stator in this embodiment, reference can be made to Embodiment 1.

[0090] In other embodiments of the motor, the second driving coil group 24 on the second yoke can also provide the main driving force for the suspension and levitation of the rotor, and the first driving coil groups 22 distributed up and down on the axial arms of the first yoke are respectively used to independently and precisely assist in adjusting the upper and lower states of the rotor, significantly improving the stability and control accuracy of the rotor.

[0091] In the case where the stability of the rotor is significantly improved, the stator can carry a larger working current, which can significantly increase the torque of the rotor.

[0092] It can be seen that due to the existence of two different driving coil groups in the motor of this embodiment, there are various adjustment methods for the stator, the control of the rotor is more flexible, variable, with more control dimensions, and the control accuracy and stability of the rotor are higher.

[0093] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. It can be understood that for those of ordinary skill in the art, equivalent replacements or changes can be made according to the technical solution of the present invention and the concept of the present invention, and all such changes or replacements should fall within the protection scope of the appended claims of the present invention.

Claims

1. A Halbach permanent magnet levitation motor, comprising a mover (1) and a stator (2), characterized in that: The rotor comprises an upper permanent magnet rotor (11), a lower permanent magnet rotor (13) and a connecting shaft (12) connected therebetween, the upper permanent magnet rotor being provided with a first annular Halbach array surrounded by at least two first magnet units (11a), the lower permanent magnet rotor being provided with a second annular Halbach array surrounded by at least two second magnet units (13a), the first magnet unit (11a) and the second magnet unit (13a) respectively being composed of more than three magnet blocks arranged in different magnetizing directions; and the connecting shaft being a non-magnetic conductive structure; The stator comprises: a first yoke group and an annular second yoke (23) fixedly arranged in the middle of the first yoke group, the first yoke group comprising a plurality of first yokes (21) arranged longitudinally and arranged in a circumferential manner with the rotor as the center, the second yoke being fixedly connected to all the first yokes; the first yoke comprises an axial arm (21a) arranged longitudinally and a radial arm (21b) extending radially from at least one end of the axial arm toward the rotor, the axial arm of the first yoke being wound with a first drive coil group (22) for driving the rotor to suspend and rotate; the central axis of the annular second yoke is arranged to coincide with the central axis of the rotor.

2. The Halbach permanent magnet levitation motor according to claim 1 is characterized in that: The second magnetic yoke (23) is vertically connected to the axial arm of the first magnetic yoke; the second magnetic yoke is vertically connected to the middle position of the first magnetic yoke; radial arms (21b) are respectively extended from the upper and lower ends of the axial arm of the first magnetic yoke.

3. The Halbach permanent magnet levitation motor according to claim 2 is characterized in that: Each first drive coil group is a coil that simultaneously provides a rotating magnetic field and a suspension magnetic field for the rotor, and the first drive coil group (22) is arranged above the second magnetic yoke and / or below the second magnetic yoke.

4. The Halbach permanent magnet levitation motor according to claim 2 is characterized in that: Each first driving coil group includes a suspension coil (22a) for providing a rotor suspension magnetic field and a rotating coil (22b) for providing a rotating magnetic field for the rotor; Each group of first drive coils (22) is arranged above the second magnetic yoke and / or below the second magnetic yoke, or the suspension coil (22a) and the rotation coil (22b) of each group of drive coils are arranged at a position above or below the second magnetic yoke.

5. The Halbach permanent magnet levitation motor according to claim 3 or 4, characterized in that: A second drive coil group (24) for adjusting the suspension and rotation state of the rotor is wound around a portion of the second magnetic yoke located between two adjacent first magnetic yokes.

6. The Halbach permanent magnet levitation motor according to claim 5, characterized in that: Each group of second drive coil groups (24) comprises two coils, a suspension coil for the rotor suspension magnetic field and a rotation coil for providing a rotating magnetic field for the rotor; or each group of second drive coil groups comprises one coil.

7. The Halbach permanent magnet levitation motor according to any one of claims 1 to 6, characterized in that: The upper permanent magnet rotor and the lower permanent magnet rotor are coaxial and overlapped annular structures, and the magnetizing directions of the magnets of the upper permanent magnet rotor and the lower permanent magnet rotor that overlap in axial projection positions are the same or opposite.

8. The Halbach permanent magnet levitation motor according to claim 7, characterized in that: In the first magnet unit, the structures of magnet block one, magnet block two, magnet block three and magnet block four are different from each other, or two of the structures of magnet block one, magnet block two, magnet block three and magnet block four are the same; in the second magnet unit, the structures of magnet block five, magnet block six, magnet block seven and magnet block eight are different from each other, or two of the structures of magnet block five, magnet block six, magnet block seven and magnet block eight are the same.

9. The Halbach permanent magnet levitation motor according to claim 8, characterized in that: The first magnet unit (11a) is composed of a first magnet block, a second magnet block, a third magnet block and a fourth magnet block arranged in sequence, wherein the magnetization method of the first magnet block is radially inward magnetization, the magnetization direction of the third magnet block is radially outward magnetization, the magnetization direction of the second magnet block is perpendicular to the magnetization direction of the first magnet block and points to the third magnet block, and the magnetization direction of the fourth magnet block is perpendicular to the magnetization direction of the third magnet block and points to the third magnet block; The second magnet unit (13a) is composed of magnet block five, magnet block six, magnet block seven and magnet block eight arranged in sequence, wherein the magnetization method of magnet block five is radially inward magnetization, the magnetization direction of magnet block seven is radially outward magnetization, the magnetization direction of magnet block six is ​​perpendicular to the magnetization direction of magnet block five and points to magnet block seven, and the magnetization direction of magnet block eight is perpendicular to the magnetization direction of magnet block seven and points to magnet block seven.

10. The Halbach permanent magnet levitation motor according to claim 9, characterized in that: Each magnetic block of the first magnet unit and the second magnet unit is a triangular prism-like prism, and the inner side surface or the outer side surface of the triangular prism-like prism facing the rotor axis is a curved surface.

11. The Halbach permanent magnet levitation motor according to claim 9, characterized in that: Each magnetic block of the first magnetic unit and the second magnetic unit is a fan-shaped ring column.

12. The Halbach permanent magnet levitation motor according to claim 9, characterized in that: The first magnet unit has the same structure of magnetic block 1 and magnetic block 3, which are inverted parabolic or petal-like shapes with openings facing inwards. The adjacent magnetic blocks 1 and 3 are connected on both sides and arranged in a ring to form a flower-shaped inner ring of a ring array. The magnetic blocks 2 and 4 are filled in the gaps between the adjacent magnetic blocks 1 and 3, together forming a ring-shaped Halbach array. The structure of the second magnet unit is consistent with that of the first magnet unit.

13. The Halbach permanent magnet levitation motor according to any one of claims 1 to 12, characterized in that: The first magnet and the second magnet on the upper permanent magnet rotor (11) and the lower permanent magnet rotor (13) are arranged in overlapping or staggered positions.

14. The Halbach permanent magnet levitation motor according to claim 9, characterized in that: Also includes: A controller and a sensor connected to the controller for control, wherein the sensor is used to detect the radial and axial positions of the rotor, and the controller is used to adjust the current direction and magnitude of the driving coil group.

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