Halbach type permanent magnet magnetic suspension bearingless motor

Abstract

The invention belongs to the technical field of magnetic suspension motors, and discloses a Halbach type permanent magnet magnetic suspension bearingless motor, which comprises a permanent magnet rotor and a stator, and is characterized in that the stator comprises a first magnet yoke group and an annular second magnet yoke fixed on the first magnet yoke group; driving coil groups for driving the rotor to suspend and rotate are wound on the second magnet yokes; the permanent magnet rotor comprises an upper permanent magnet rotor, a lower permanent magnet rotor and a non-magnetic connecting shaft, the upper permanent magnet rotor and the lower permanent magnet rotor are coaxially arranged up and down, and the non-magnetic connecting shaft is connected between the upper permanent magnet rotor and the lower permanent magnet rotor; the lower permanent magnet rotor is provided with a second annular Halbach array which is formed by arranging second magnet units in a surrounding mode. The first magnet units and the second magnet units are respectively formed by arranging a plurality of magnetic blocks in different magnetizing directions. The motor is simple and compact in structure and smaller in size, and the utilization rate of a magnetic field and the working efficiency of the rotor are effectively guaranteed through the Halbach array arrangement of the rotor.

Description

Technical Field

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

[0002] Due to the combination of the advantages of magnetic levitation technology and bearingless motors, magnetic levitation motors achieve contactless, low-friction, and high-precision operation of the rotor, and thus are widely used in technical fields such as industrial automation, semiconductors, medical health, and smart homes.

[0003] However, in practical applications, current magnetic levitation motors generally have problems such as a relatively complex structure, large volume, and large stator volume in order to reserve sufficient space for the coils of the stator, and low utilization rate of the electromagnetic field of the coils and poor magnetic flux concentration effect. For example, in the magnetic levitation motor with the publication number CN112865609A, as Figure 1 shown, in the stator assembly, both the suspension coil and the drive coil are arranged on the inverted L-shaped second iron core (i.e., the yoke). With such a stator, a large number of coils are installed, the volume is large, and the utilization rate of the electromagnetic field of the coils is low. In addition, the torque and axial stiffness of the traditional permanent magnet rotor used in existing magnetic levitation motors are difficult to improve, the running stability of the rotor at high speeds is insufficient, and the magnetic field utilization rate is low.

[0004] Therefore, the prior art needs to be further improved. Summary of the Invention

[0005] In view of the above problems, the present invention provides a Halbach permanent magnet magnetic levitation bearingless motor, which uses a stator with a more compact structure and better magnetic flux concentration effect in cooperation with an improved permanent magnet rotor, not only significantly improves the space utilization rate of the motor, reduces the manufacturing cost, but also the magnetic field on the outer peripheral surface of the rotor near the stator end is directionally strengthened, and the magnetic field utilization rate of the rotor is high and the running stability is high.

[0006] To solve the above problems existing in the prior art, the present application provides the following technical solutions: A Halbach permanent magnet magnetic levitation bearingless motor, comprising: a permanent magnet rotor and a stator, the stator comprising: a first yoke group composed of a plurality of longitudinally arranged first yokes circumferentially arranged around the permanent magnet rotor, and an annular second yoke vertically fixed on the first yoke group, the second yoke being connected to all the first yokes; drive coil groups for driving the rotor to levitate and rotate are wound on portions of the second yoke located between two adjacent first yokes; The permanent magnet rotor includes an upper permanent magnet rotor, a lower permanent magnet rotor arranged coaxially up and down, and a non-magnetic connecting shaft connected between the two. The upper permanent magnet rotor is provided with a first annular Halbach array in which at least two first magnet units are arranged in a surrounding manner. The lower permanent magnet rotor is provided with a second annular Halbach array in which at least two second magnet units are arranged in a surrounding manner. The first magnet unit and the second magnet unit are respectively composed of more than three magnetic blocks arranged with different magnetization directions.

[0007] Optionally, in the Halbach permanent magnet bearingless motor, the upper permanent magnet rotor and the lower permanent magnet rotor are circular ring structures arranged coaxially up and down and overlapping, and the magnetization directions of the magnets at the axially projected positions where the upper permanent magnet rotor and the lower permanent magnet rotor coincide are the same.

[0008] Optionally, in the Halbach permanent magnet bearingless motor, the first magnet unit is composed of magnet block one, magnet block two, magnet block three, and magnet block four arranged in sequence. Among them, the magnetization mode of magnet block one is radially inward magnetization, the magnetization direction of magnet block three is radially outward magnetization, the magnetization direction of magnet block two is perpendicular to the magnetization direction of magnet block one and points to magnet block three, and the magnetization direction of magnet block four is perpendicular to the magnetization direction of the third magnet block and points to magnet block three; the second magnet unit 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.

[0009] Optionally, in the Halbach permanent magnet bearingless motor, among the four magnetic blocks of the first magnet unit, the adjacent magnetic blocks have complementary structures, and all the magnetic blocks are jointly spliced to form a first annular Halbach array; among the four magnetic blocks of the second magnet unit, the adjacent magnetic blocks have complementary structures, and all the magnetic blocks are jointly spliced to form a second annular Halbach array.

[0010] Optionally, in the Halbach permanent magnet bearingless 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.

[0011] In the motor of the first optional embodiment, each magnetic 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.

[0012] In the motor of the optional second embodiment, each magnetic block of the first magnetic body unit and the second magnetic body unit is a fan-shaped ring column.

[0013] In the motor of the optional third embodiment, the magnetic blocks 1 and 3 of the first magnetic body unit have the same structure, which is an inverted parabola shape or a petal-like shape with the opening facing inwards. The adjacent magnetic blocks 1 and 3 are arranged in a ring-shaped array with their sides connected to form an inner ring of a flower shape. The magnetic blocks 2 and 4 are filled into the gaps between the adjacent magnetic blocks 1 and 3 to jointly form a ring-shaped Halbach array; the structure of the second magnetic body unit is the same as that of the first magnetic body unit.

[0014] Optionally, in the Halbach permanent magnet bearingless motor, the first magnetic body units and the second magnetic body units on the upper permanent magnet rotor and the lower permanent magnet rotor are arranged with overlapping or misaligned positions.

[0015] Optionally, in the Halbach permanent magnet bearingless motor, each 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.

[0016] Optionally, in the Halbach permanent magnet bearingless motor, each drive coil group is a coil that simultaneously provides a rotation magnetic field and a suspension magnetic field for the rotor.

[0017] Optionally, in the Halbach permanent magnet bearingless motor, the second magnetic yoke includes a plurality of second annular laminations stacked on each other along the stacking direction, and the stacking direction is set axially or radially.

[0018] Optionally, in the Halbach permanent magnet bearingless motor, radial arms extend from the upper and lower ends of the axial arm of the first magnetic yoke respectively.

[0019] Optionally, in the Halbach permanent magnet bearingless motor, positioning slot holes for connecting the axial arm of the first magnetic yoke are provided on the second magnetic yoke, and the second magnetic yoke is fixedly connected to the first magnetic yoke through the positioning slot holes.

[0020] Optionally, the Halbach permanent magnet bearingless 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 of the rotor, and the controller is used to regulate the current direction and magnitude of the drive coil group.

[0021] The present invention has the following beneficial effects: 1. The structure of the permanent magnet rotor used in the motor of this application is ingenious. By setting annular Halbach arrays on the upper and lower permanent magnet rotors, 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. This can not only increase the output torque of the motor, but also reduce the cogging torque, thereby reducing torque ripple and helping to improve the running stability and efficiency of the motor.

[0022] 2. The stator structure adopted by the motor of this application is simple and compact, uses a small number of coils, has good magnetic flux collection effect, and can greatly reduce the manufacturing cost and maintenance cost of the motor stator.

[0023] 3. Through the mutual cooperation of the above-mentioned permanent magnet rotor and stator, not only the manufacturing cost of the motor is effectively reduced, the overall motor can be set in a flattened shape, making the overall structure of the motor more compact and the volume smaller. At the same time, through the setting of the Halbach array of the rotor, the magnetic field utilization rate, the working efficiency of the rotor and the running stability are effectively guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an exploded schematic view of the structure of the stator of a magnetic levitation bearingless motor in the prior art; Figure 2 is a three-dimensional structure schematic view of the magnetic levitation bearingless motor of Embodiment 1; The closed-loop route with arrows in the figure represents the main magnetic path; Figure 3 is a three-dimensional view of the stator of the magnetic levitation bearingless motor of Embodiment 1; Figure 4 is a side view of the stator of the magnetic levitation bearingless motor of Embodiment 1; Figure 5 is a longitudinal sectional structure schematic view of the motor applying the stator structure of Embodiment 1; The closed-loop route with arrows in the figure represents the main magnetic path; Figure 6 is a schematic view of the magnetic field line distribution from a top view angle of the upper rotor layer and the lower rotor layer of the magnetic levitation motor of Embodiment 1; A is a top view of the upper rotor, and B is a top view of the lower rotor; Figure 7 is a three-dimensional structure schematic view of the rotor adopted in the motor of Embodiment 1; Figure 8 is a top view structure schematic view of the rotor of Embodiment 1; The arrow represents the magnetization direction; Figure 9 is a top view of the new type permanent magnet rotor of Embodiment 2; The arrow in the figure represents the magnetization direction; Figure 10 is a top view of the new type permanent magnet rotor of Embodiment 3; The arrow in the figure represents the magnetization direction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope 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 thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0026] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill 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 embodiments and are not intended 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 embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Embodiment 1 As Figure 2 shown, this embodiment provides a Halbach permanent magnet bearingless motor, which includes: a permanent magnet rotor 1 and a stator 2. The stator includes: a first yoke group composed of a plurality of longitudinally arranged first yokes 21 circumferentially arranged with the permanent magnet rotor as the center, and an annular second yoke 23 vertically fixed on the first yoke group. The second yoke is connected to all the first yokes; drive coil groups 24 for driving the rotor to levitate and rotate are wound on the portions of the second yoke located between two adjacent first yokes.

[0028] In this embodiment, as Figures 3 - 4 shown, 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 installation position.

[0029] During operation, two closed loops that are symmetrically distributed radially up and down are formed between the second yoke connection part where the main magnetic path coil is located, the upper / lower part of the first yoke on the left and right sides of each drive coil group, and the corresponding radially extending parts. The upper and lower closed main magnetic paths share a part of the magnetic path in the second yoke.

[0030] In this embodiment, the first yoke includes an axially arranged axial arm 21a and radially extending arms 21b that extend radially from the upper and lower ends of the axial arm to the rotor mounting position. The structure of the first yoke is in a similar C-shaped structure.

[0031] Specifically, in this embodiment, the number of the first yokes is 8, and the number of the rotor magnetic poles cooperating with them is 2, 4, or 6, etc.; in other embodiments, the number of the first yokes can also be 6, 10, or more, and the number of the radially extending parts of the rotor can be 2, 4, or 8; 2 or 4.

[0032] 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: a positioning slot hole (not shown in the figure) for the axial arm of the first yoke to penetrate is provided on the second yoke 23, and the second yoke and the first yoke are fixedly connected, such as by bonding, screwing, welding, or riveting and other fixed connection methods.

[0033] In other embodiments, the outer peripheral side wall / inner peripheral side wall of the second yoke is clamped and bonded with the inner side wall / outer side wall of the axial arm of the first yoke, or fixed connection is carried out in other ways.

[0034] The second yoke is composed of a plurality of second annular laminations laminated in the stacking direction, and the stacking direction is axially or radially arranged. 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.

[0035] In this embodiment, the second yoke is formed by a plurality of second annular laminations stacked up and down. The first yoke is formed by stacking a plurality of C-shaped first laminations back and forth.

[0036] In other embodiments, the second yoke is formed by laminating a plurality of annular laminations arranged concentrically inside and outside.

[0037] In this embodiment, each drive coil group includes a suspension coil for the suspension magnetic field of the rotor and a rotation coil for providing a rotating magnetic field for the rotor. 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.

[0038] In other embodiments, each drive coil group is a coil that simultaneously provides a rotating magnetic field and a levitation magnetic field for the rotor. At this time, a single coil provides both the rotating magnetic field and the levitation magnetic field for the permanent magnet rotor. The structure with only one coil is simpler, but it has higher requirements for the control system.

[0039] In this motor, as Figure 7 shown, the permanent magnet rotor in the motor of this embodiment includes an upper permanent magnet rotor 11 and a lower permanent magnet rotor 13 that are coaxially arranged up and down, and a connecting shaft 12 connected between the two. The upper permanent magnet rotor is provided with a first annular Halbach array formed by surrounding and arranging a plurality of first magnet units 11a, and the lower permanent magnet rotor is provided with a second annular Halbach array formed by surrounding and arranging a plurality of second magnet units 13a. The connecting shaft is a non-magnetic cylindrical structure.

[0040] The arrangement of the annular Halbach array of the above rotor causes the magnetic field lines 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, increasing the output torque of the motor, closing and reducing the cogging torque, thereby reducing the torque ripple, and achieving the effect of improving the running stability and efficiency of the motor.

[0041] 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 minimized to the greatest extent, realizing the lightweight of the rotor, reducing the rotor inertia, and thus improving the fast response ability of the motor.

[0042] The upper permanent magnet rotor and the lower permanent magnet rotor are coaxially arranged up and down and overlapped circular ring structures.

[0043] The first magnet unit 11a and the second magnet unit 13a are respectively composed of more than three magnetic blocks arranged with different magnetization directions.

[0044] In this embodiment, as Figure 8 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.

[0045] 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 method 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. Among the four magnet blocks of the second magnet unit, adjacent magnet blocks have complementary structures, and all magnet blocks are jointly spliced to form a second annular Halbach array.

[0046] In other embodiments, the number of magnet blocks constituting the first magnet unit is not limited to 4 in this embodiment, and can also be set to 3, 5, or more.

[0047] 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.

[0048] 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 different from each other.

[0049] 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 overlap. 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.

[0050] 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.

[0051] Specifically, in this embodiment, the number of the first magnetic yokes is 8, and the number of the first magnet unit / second magnet unit of the rotor cooperating with it is four; in other embodiments, the number of the first magnetic yokes can also be 6, 10, or more, and the number of the first magnet unit 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.

[0052] To achieve a stable connection between the connecting shaft and the upper and lower permanent magnet rotors, the connecting shaft and the upper and lower permanent magnet rotors are inserted into each other. One of the achievable ways is as follows: The connecting shaft is a hollow tubular structure with a through hole in the middle. The upper and lower ends of the connecting shaft are respectively provided with a first insertion part, and the central positions of the upper and lower permanent magnet rotors are provided with a second insertion part that is inserted and matched with the first insertion part. On this basis, to strengthen the connection, the first insertion part and the second insertion part are also adhesively bonded or connected by other fixing methods. Optionally, the first insertion part is a plug, and the second insertion part is a socket that is snap-connected with the plug. The installation of this insertion connection method can be pre-installed by insertion, and then the connection strength between the upper and lower permanent magnet rotors and the connecting shaft can be strengthened by other methods. The installation accuracy is higher, avoiding the problem of possible eccentric errors between the upper and lower permanent magnet rotors and the connecting shaft that may occur during the installation of the rotor in Embodiment 1.

[0053] In other implementation manners, in the permanent magnet rotor, the upper end of the connecting shaft is fixedly connected to the lower end surface of the upper permanent magnet rotor, and the lower end of the connecting shaft is fixedly connected to the upper end surface of the lower permanent magnet rotor; the connecting shaft is a hollow tubular structure with a through hole in the middle; the main bodies of the upper and lower permanent magnet rotors are circular, and the centers of the upper and lower permanent magnet rotors are provided with central holes that are aligned with the through hole of the connecting shaft along the penetration.

[0054] The fixed connection of the upper permanent magnet rotor, the lower permanent magnet rotor and the connecting shaft is fixed by one or more of adhesive bonding and ultrasonic welding. Optionally, in the new permanent magnet rotor, adjacent magnetic blocks are directly adhesively bonded for fixed connection.

[0055] The rotation principle of the rotor: As Figure 4 and Figure 6As shown in the figure, at a certain moment, the rotating coils on the two second magnetic yokes 23 that are radially symmetric and not aligned with the radially magnetized magnetic blocks of the rotor are energized simultaneously. The magnetic force lines excited thereby flow counterclockwise to the left side (or clockwise to the right side), respectively, upward along the upper part of the axial arm of the first magnetic yoke to the upper radial arm and simultaneously downward along the lower part of the axial arm of the first magnetic yoke to the lower radial arm, and then successively pass through multiple magnetic blocks of the first magnet unit of the upper permanent magnet rotor / the second magnet unit of the lower permanent magnet rotor corresponding to the radial arm (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 then form a closed magnetic circuit through the second magnetic yokes between the two first magnetic yokes. Since the path of this magnetic circuit at the air gap is not the shortest distance, based on the principle of the shortest magnetic circuit, the rotor will rotate clockwise until the radial arm of the first magnetic yoke is aligned with the magnetic block, so that the magnetic force lines can be closed through the shortest distance. At this time, the rotating coils on the other pair of first magnetic yokes that form a certain angle with this pair of first magnetic yokes work in the same way as above, and pull the rotor to continue rotating clockwise. The rotating coils at the corresponding positions in the stator are energized in sequence according to the above rules, so as to realize the continuous rotation of the rotor. Thus, it can be seen that the suspension and rotation of the reluctance rotor are both realized based on the reluctance principle of the shortest closed path of magnetic flux.

[0056] In other cases, the rotation drive can also be controlled by using two pairs of cross-shaped C-shaped magnetic yokes simultaneously according to the above rules to enhance the rotation driving force.

[0057] In the above scheme, the upper and lower double-layer counterpoint magnetic paths are radially symmetric. During operation, the directions of the upper and lower magnetic paths flowing in the transverse magnetic yoke are the same, so that the cooperation of the upper and lower magnetic paths can be realized. The rotation torque of the rotor can be increased by cooperatively controlling the rotating coils in the upper and lower halves of the stator, and the stability and accuracy of the rotor can be improved.

[0058] The suspension principle of the rotor: As Figure 5 shown, the suspension of the rotor in this embodiment is mainly realized by generating a suction force between the first magnetic yoke and the rotor. When the suspension coils on the second magnetic yokes of the stator are energized and the current magnitude is adjusted so that the pulling force (magnetic resistance torque) received by the rotor axially is equal, the rotor can achieve radial centering suspension. Thus, it can be seen that the axial suspension of the rotor in this embodiment is realized by relying on the reluctance principle of the shortest closed path of magnetic flux. When the rotor has a radial offset, the suspension coil on the side where the air gap of the stator increases will increase the current, so that the attractive force on this side increases to correct the radial offset of the rotor.

[0059] Based on the arrangement of a set of coils on the annular second yoke of the stator described above, not only is the number of coils reduced, and the coils are arranged in the middle of the stator, facilitating the flat design and miniaturization of the stator volume; moreover, this design enables the control of the upper and lower symmetrically arranged short magnetic paths on the adjacent two first yokes by the above-mentioned set of coils, not only making the main magnetic path shorter and the magnetic resistance smaller, but also ensuring the magnetic field intensity and torque. In addition, since the annular second yoke magnetically connects the adjacent first yokes that are independent of each other, the leakage magnetic flux of the first yoke is effectively reduced, and the magnetic field utilization rate is improved.

[0060] In this embodiment, the stator further includes a housing, and the first yoke and the second yoke are arranged inside the housing and fixedly connected to the housing.

[0061] The stator is further provided with: a controller and a sensor that is control-connected to the controller. The sensor is used to detect the radial and axial positions of the rotor, and the controller is used to regulate the current direction and magnitude of the drive coil group. Other structures provided inside the stator can be referred to the prior art and are omitted here.

[0062] Embodiment 2 As Figure 9 shown, this embodiment provides a Halbach permanent magnet type magnetic levitation bearingless motor, which includes a stator and a rotor. The difference from Embodiment 1 lies in the setting of the rotor, and the stator structure is as described in Embodiment 1.

[0063] The rotor includes a longitudinally arranged connecting shaft and an upper permanent magnet rotor and a lower permanent magnet rotor 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, and the lower permanent magnet rotor is provided with a second annular Halbach array surrounded by a plurality of second magnet units. The connecting shaft is a non-magnetic structure, and the connecting shaft is a non-magnetic cylindrical structure ( Figure 8 the connecting shaft in

[0064] 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] 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 method 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.

[0067] In this embodiment, the number of the first magnet unit / second magnet unit is two respectively; in other embodiments, the number of the first magnet unit / second magnet unit can be adjusted as needed, not limited to this embodiment.

[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 rapid 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 Figure 10 shown, this embodiment provides a Halbach permanent magnet type magnetic levitation bearingless motor, which includes a stator and a rotor. The difference from Embodiment 1 lies in the setting of the rotor, and 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 as needed.

[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 circular array to form a flower-shaped inner ring of the circular 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 circular 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 side of the upper permanent magnet rotor / lower permanent magnet rotor close to the outer peripheral surface of the stator, strengthening the magnetic field of the upper permanent magnet rotor 11 and the lower permanent magnet rotor 13 close to the outer peripheral surface of the stator.

[0075] In this embodiment, the number of the first magnet units / the second magnet units is four respectively; in other embodiments, the number of the first magnet units / the second magnet units can be adjusted as needed, not limited to this embodiment.

[0076] 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.

[0077] 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 substitutions or changes can be made according to the technical solutions of the present invention and the concept of the present invention, and all such changes or substitutions should fall within the protection scope of the appended claims of the present invention.

Claims

1. A Halbach permanent magnet magnetic suspension bearingless motor, characterized in that: include: A permanent magnet rotor (1) and a stator (2), the stator comprising: a first magnetic yoke group consisting of a plurality of first magnetic yokes (21) arranged longitudinally and circumferentially with the permanent magnet rotor as the center, and an annular second magnetic yoke (23) vertically fixed to the first magnetic yoke group, the second magnetic yoke being connected to all the first magnetic yokes; a driving coil group (24) for driving the rotor to suspend and rotate is wound around a portion of the second magnetic yoke located between two adjacent first magnetic yokes; The permanent magnet rotor comprises an upper permanent magnet rotor (11), a lower permanent magnet rotor (13) coaxially arranged above and below, and a non-magnetic connecting shaft (12) connected therebetween; the upper permanent magnet rotor is provided with a first annular Halbach array surrounded by at least two first magnet units (11a); the lower permanent magnet rotor is 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) are respectively composed of more than three magnet blocks arranged in different magnetizing directions.

2. According to the Halbach permanent magnet magnetic levitation bearingless motor described in claim 1, the upper permanent magnet rotor and the lower permanent magnet rotor are circular ring structures that are coaxial and overlapping, and the magnetizing directions of the magnets of the upper permanent magnet rotor and the lower permanent magnet rotor that overlap in the axial projection position are the same.

3. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 1 is characterized in that: The first magnet unit (11a) is composed of magnet block 1, magnet block 2, magnet block 3 and magnet block 4 arranged in sequence, wherein the magnetization method of magnet block 1 is radially inward magnetization, the magnetization direction of magnet block 3 is radially 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 (13a) is composed of magnet block 5, magnet block 6, magnet block 7 and magnet block 8 arranged in sequence, wherein the magnetization method of magnet block 5 is radially inward magnetization, the magnetization direction of magnet block 7 is radially 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.

4. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 3 is characterized in that: The adjacent magnetic blocks of the four magnetic blocks of the first magnetic unit have complementary structures, and all the magnetic blocks are spliced ​​together to form a first annular Halbach array; the adjacent magnetic blocks of the four magnetic blocks of the second magnetic unit have complementary structures, and all the magnetic blocks are spliced ​​together to form a second annular Halbach array.

5. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 4 is 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.

6. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 5, 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.

7. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 5, characterized in that: Each magnetic block of the first magnetic unit and the second magnetic unit is a fan-shaped ring column.

8. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 5, 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.

9. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 2, characterized in that: The first magnet unit and the second magnet unit on the upper permanent magnet rotor (11) and the lower permanent magnet rotor (13) are arranged in overlapping or staggered positions.

10. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 1, characterized in that: Each driving coil group includes a suspension coil for providing a rotor suspension magnetic field and a rotating coil for providing a rotating magnetic field for the rotor.

11. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 1, characterized in that: The second magnetic yoke comprises a plurality of second annular laminations which are stacked one on another along a stacking direction, and the stacking direction is axial or radial.

12. The Halbach permanent magnet magnetic suspension bearingless motor according to claim 1, characterized in that: Also includes: A controller and a sensor connected to the controller for control, the sensor is used to detect the radial and axial positions of the rotor, the controller is used to regulate the current direction and magnitude of the drive coil group; the second magnetic yoke is provided with a positioning slot hole for connecting the axial arm of the first magnetic yoke, and the second magnetic yoke is fixedly connected to the first magnetic yoke through the positioning slot hole.

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