Permanent magnet rotor and magnetic suspension motor using same

Abstract

The utility model belongs to the technical field of magnetic suspension motors, and discloses a permanent magnet rotor and a magnetic suspension motor applying the permanent magnet rotor, the permanent magnet rotor comprises a permanent magnet connecting ring, and an upper permanent magnet rotor and a lower permanent magnet rotor which are arranged at two ends of the permanent magnet connecting ring, the lower permanent magnet rotor is formed by alternately arranging a plurality of radially magnetized second sector rings in a surrounding manner, the magnetizing directions of the adjacent first sector rings or second sector rings are opposite, and the permanent magnet connecting ring is formed by axially magnetizing a plurality of axially magnetized third sector rings with opposite magnetizing directions in a surrounding manner; the main magnetic circuit is axially distributed along the three aligned sector rings on the upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor. The permanent magnet rotor is simple in structure and high in magnetic field density, and the main magnetic circuit is axially oriented along the three sector rings which are axially aligned, so that the magnetic fields at the two ends of the rotor are enhanced, the torque, the axial rigidity and the demagnetization resistance of the rotor are improved, and the service life of the rotor is remarkably prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of magnetic suspension motor, especially to a permanent magnet rotor and a magnetic suspension motor using the same. BACKGROUND

[0002] The magnetic suspension bearingless motor is a motor combining rotation driving and shaft self-bearing suspension functions. It not only overcomes many limitations of traditional motors, but also has a series of advantages such as compact structure, easy miniaturization, high critical speed, large output power, no need for additional DC bias magnetic field, and small power consumption. Since there is no mechanical contact between the rotor and the stator, noise and wear during operation are reduced, pollution is less, energy consumption of the motor is less, and operation efficiency and precision are higher. The magnetic suspension bearingless motor is now widely used in various fields such as semiconductors, health care, smart home, and industrial automation.

[0003] The existing magnetic suspension bearingless motor mainly consists of a rotor and a stator providing driving force for the rotor. According to the type of the rotor used, it is divided into reluctance type and permanent magnet type. The existing reluctance type and permanent magnet type. Although the reluctance type rotor has no demagnetization problem and high reliability, it generally has problems of insufficient rotor torque and axial stiffness, and low motor operation efficiency.

[0004] The torque and axial stiffness of the existing permanent magnet type rotor are relatively higher, but on the one hand it is easy to demagnetize, and most of them are short shaft rotors, which are not suitable for long shaft rotors. The existing permanent magnet long shaft permanent magnet rotor generally has insufficient driving force and operation stability.

[0005] Therefore, the existing technology needs to be further improved. SUMMARY

[0006] In view of the above problems, the utility model provides a permanent magnet rotor and a magnetic suspension motor using the same. The above-mentioned permanent magnet rotor has simple structure, oriented magnetic field, and strong operation stability and anti-demagnetization ability.

[0007] In the first aspect, the application provides a permanent magnet rotor, which includes a longitudinally arranged permanent magnet connecting ring and an upper permanent magnet rotor and a lower permanent magnet rotor vertically arranged at both ends of the permanent magnet connecting ring. The upper permanent magnet rotor is composed of a plurality of first sector rings with radial magnetization arranged alternately in a ring. The lower permanent magnet rotor is composed of a plurality of second sector rings with radial magnetization arranged alternately in a ring. The magnetization directions of adjacent first sector rings or second sector rings are opposite. The permanent magnet connecting ring is composed of a plurality of third sector rings with axial magnetization and opposite magnetization directions arranged in a ring. The main magnetic circuit is axially parallel to the three sector rings aligned on the upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor.

[0008] The upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor are provided with permanent magnets with the same magnetization direction as the main magnetic circuit along the flow direction of the main magnetic circuit.

[0009] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring, and the local part of the second sector ring are provided with permanent magnets.

[0010] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring, and the second sector ring are permanent magnets as a whole.

[0011] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring, and the second sector ring have the same width.

[0012] Optionally, in the permanent magnet rotor, the number of the first sector ring and the third sector ring, and the second sector ring is at least four.

[0013] Optionally, in the permanent magnet rotor, the permanent magnet connecting ring is a hollow tubular structure, a through hole is arranged in the middle part, and the upper and lower ends of the permanent magnet connecting ring are respectively provided with first plug-in parts, and the central positions of the upper permanent magnet rotor and the lower permanent magnet rotor are provided with second plug-in parts for plug-in cooperation with the first plug-in parts.

[0014] Optionally, in the permanent magnet rotor, the upper end of the permanent magnet connecting ring is fixedly connected to the lower end face of the upper permanent magnet rotor, and the lower end of the permanent magnet connecting ring is fixedly connected to the upper end face of the lower permanent magnet rotor; the permanent magnet connecting ring is a hollow tubular structure, and a through hole is arranged in the middle part; the main bodies of the upper permanent magnet rotor and the lower permanent magnet rotor are circular, and the centers of the upper permanent magnet rotor and the lower permanent magnet rotor are provided with a center hole aligned with the through hole of the permanent magnet connecting ring.

[0015] Optionally, in the permanent magnet rotor, the fixed connection of the upper permanent magnet rotor, the lower permanent magnet rotor and the permanent magnet connecting ring is one or more of the following: adhesion, ultrasonic welding.

[0016] In a second aspect, the application also provides a magnetic levitation motor, comprising a stator and the aforementioned permanent magnet rotor arranged at the center position of the stator.

[0017] Optionally, in the magnetic levitation motor, the stator comprises a plurality of first magnetic yokes arranged in a ring around the outer periphery of the rotor, and coils for driving the rotor to levitate and rotate are arranged in the middle part of the first magnetic yokes; the first magnetic yoke comprises: an axially arranged axial arm and a radial arm horizontally extending towards the upper permanent magnet rotor or the lower permanent magnet rotor at both ends of the axial arm; the upper permanent magnet rotor, the permanent magnet connecting ring, the lower permanent magnet rotor and the first magnetic yoke form a closed loop magnetic circuit in communication.

[0018] The utility model has the following beneficial effects:

[0019] The permanent magnet rotor provided by the utility model has simple structure, high magnetic field density, and the main magnetic circuit is axially and directionally distributed along the three fan-shaped rings of the upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor, so that the magnetic field of the upper and lower ends of the rotor is strengthened, the torque and the axial supporting force of the rotor are improved, and in addition, the rotor has strong anti-demagnetization capacity and significantly prolonged service life. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the permanent magnet rotor of the embodiment 1;

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure of the magnetic suspension motor mounted with the permanent magnet rotor of the embodiment 2;

[0022] Figure 3 It is a schematic diagram of the rotation principle of the magnetic suspension motor of the embodiment 2; A is a top view of the upper permanent magnet rotor, and B is a top view of the lower permanent magnet rotor;

[0023] Figure 4 It is a schematic diagram of the suspension principle of the magnetic suspension motor of the embodiment 2; the closed curve with an arrow represents the main magnetic circuit;

[0024] Figure 5 It is a schematic diagram of the cross-sectional structure of one embodiment of the permanent magnet rotor of the embodiment 1;

[0025] Figure 6 It is a schematic diagram of the cross-sectional structure of another embodiment of the permanent magnet rotor of the embodiment 1. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intermediate elements can exist therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element or one or more intermediate elements can exist therebetween. The terms used in the specification indicate the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0027] Unless otherwise defined, all technical and scientific terms used in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. The use of the terms "and / or" includes a combination of one or more of the associated listed items. In addition, any feature described in relation to one embodiment of the present application can be used in combination with features of any other embodiment of the present application described herein, unless otherwise stated.

[0028] Embodiment 1

[0029] The embodiment provides a permanent magnet rotor, which comprises a longitudinally arranged permanent magnet connecting ring 12 and an upper permanent magnet rotor 11 and a lower permanent magnet rotor 13 vertically arranged at both ends of the permanent magnet connecting ring. The upper permanent magnet rotor is composed of a plurality of first sector rings 111 which are alternately arranged in a radial magnetization manner. The lower permanent magnet rotor is composed of a plurality of second sector rings 131 which are alternately arranged in a radial magnetization manner. The magnetization directions of adjacent first sector rings or second sector rings are opposite. The permanent magnet connecting ring is composed of a plurality of third sector rings 121 which are alternately arranged in an axial magnetization manner and have opposite magnetization directions. The main magnetic circuit is axially parallel to the three sector rings which are aligned along the upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor.

[0030] The upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor are provided with permanent magnets which are consistent with the magnetization direction of the main magnetic circuit along the flowing direction of the main magnetic circuit.

[0031] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring and the second sector ring are partially provided with permanent magnets.

[0032] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring and the second sector ring are entirely permanent magnets.

[0033] Optionally, in the permanent magnet rotor, the first sector ring and the third sector ring and the second sector ring have the same width.

[0034] In the embodiment, the number of the first sector ring and the third sector ring and the second sector ring is four. The four first sector rings have the same size and are spliced into the annular upper permanent magnet rotor. The four second sector rings have the same size and are spliced into the annular lower permanent magnet rotor.

[0035] In other embodiments, the number of the first sector ring and the third sector ring and the second sector ring can be six or eight, which can be adjusted as required.

[0036] In other variant embodiments, the inner and outer diameters of the first sector rings which constitute the upper permanent magnet rotor are consistent, but the arc lengths are different. The arc lengths of the opposite group of first sector rings are consistent.

[0037] Preferably, the widths of the first sector ring, the third sector ring and the second sector ring which are overlapped in the up-down position are consistent.

[0038] In this embodiment, in order to realize the stable connection of the permanent magnet connecting ring with the upper permanent magnet rotor and the lower permanent magnet rotor, the following settings are made:

[0039] As shown in Figure 5 The permanent magnet connecting ring is a hollow tubular structure, a through hole 121 is arranged in the middle part, and a first plug-in part 142 is arranged at the upper and lower ends of the permanent magnet connecting ring. The central positions of the upper permanent magnet rotor and the lower permanent magnet rotor are provided with a second plug-in part for plug-in cooperation with the first plug-in part.

[0040] On this basis, in order to strengthen the connection, the first plug-in part and the second plug-in part are further bonded or fixedly connected in other ways.

[0041] Alternatively, the first plug-in part is a plug, and the second plug-in part is a jack for clamping the plug. The installation of this plug-in connection mode can be pre-installed through plug-in, and then the connection strength of the upper and lower permanent magnet rotors and the permanent magnet connecting ring can be further strengthened through other ways. The installation precision is higher, and the problem of eccentric error of the upper and lower permanent magnet rotors and the permanent magnet connecting ring in the installation process of the rotor of embodiment 1 can be avoided.

[0042] The fixed connection of the upper permanent magnet rotor, the lower permanent magnet rotor and the permanent magnet connecting ring is one or more of bonding, ultrasonic welding or clamping.

[0043] As shown in Figure 6 In the permanent magnet rotor of other embodiments, the upper end of the permanent magnet connecting ring is fixedly connected to the lower end face of the upper permanent magnet rotor, and the lower end of the permanent magnet connecting ring is fixedly connected to the upper end face of the lower permanent magnet rotor. The permanent magnet connecting ring is a hollow tubular structure, and a through hole 121 is arranged in the middle part. The main bodies of the upper permanent magnet rotor and the lower permanent magnet rotor are circular, and the centers of the upper permanent magnet rotor and the lower permanent magnet rotor are arranged along the center hole 141 aligned with the through hole of the permanent magnet connecting ring.

[0044] The permanent magnet rotor of this embodiment has the advantages of simple structure, high magnetic field density, and axial directional distribution of the main magnetic circuit along the three sector rings of the upper permanent magnet rotor, the permanent magnet connecting ring and the lower permanent magnet rotor. The magnetic field layout arranged in this way strengthens the magnetic field at the upper and lower ends of the rotor, improves the torque and axial support force of the rotor, and has strong anti-demagnetization ability, which significantly prolongs the service life of the rotor.

[0045] Embodiment 2

[0046] This embodiment provides a magnetic suspension motor, which comprises a stator and the aforementioned permanent magnet rotor arranged at the central position of the stator. The permanent magnet rotor adopts the scheme of embodiment 1.

[0047] AsFigure 2 As shown in the drawings, in the magnetic suspension motor of the embodiment, the stator 2 comprises a plurality of first magnetic yokes 21 distributed annularly around the outer periphery of the rotor, and coils 22 for driving the rotor to suspend and rotate are arranged in the middle of the first magnetic yokes. The first magnetic yoke comprises: an axial arm arranged longitudinally, and radial arms horizontally extending towards the upper permanent magnet rotor or the lower permanent magnet rotor respectively at both ends of the axial arm, and the first magnetic yoke is in a C shape.

[0048] The axial projections of the upper permanent magnet rotor and the lower permanent magnet rotor overlap, the upper permanent magnet rotor 11 and the upper horizontal extension of the first magnetic yoke are substantially in the same plane, the lower permanent magnet rotor 13 of the rotor and the lower horizontal extension of the C-shaped first magnetic yoke are substantially in the same plane, and the first fan ring of the upper permanent magnet rotor, the third fan ring of the permanent magnet connecting ring, the second fan ring of the lower permanent magnet rotor and the first magnetic yoke form a closed loop magnetic circuit.

[0049] As shown in the drawings, the working principle of the reluctance motor is as follows: Figure 3

[0050] Rotary principle: At a certain moment, the rotary coils of the two first magnetic yokes which are radially symmetrical to each other and not paired with the first magnetic yokes / second magnetic yokes of the rotor are not energized at the same time, and the magnetic lines of force flowing simultaneously in the axial direction upwards or downwards are excited, which are closed through the first magnetic yoke radial arm, the first fan ring of the upper permanent magnet rotor, the third fan ring of the permanent magnet connecting ring, the second fan ring of the lower permanent magnet rotor, and the first magnetic yoke lower radial arm, forming two closed magnetic circuits distributed on the left and right. Since the path of the magnetic circuit at the air gap is not the shortest distance, the rotor will rotate counterclockwise to make the magnetic lines of force closed through the shortest distance. When the pair of first magnetic yokes and the first fan ring / second fan ring of the permanent magnet of the rotor pulled by them are paired, the rotary coils on the other pair of first magnetic yokes which are 90° away from the pair of first magnetic yokes work in the same way as described above, and the rotor rotates counterclockwise again. The rotary coils are energized in turn according to this rule, thereby realizing the continuous rotation of the rotor. Meanwhile, rotary drive can also use two pairs of first magnetic yokes crossed at right angles to control through the above rules to enhance the rotary driving force.

[0051] Suspension principle: As shown in the drawings, when the suspension coils on the first magnetic yokes are energized and the current is adjusted to make the pulling force (magnetic force) on the rotor in the axial direction equal, the rotor can be radially centered and suspended. At a certain moment, when the rotor is radially offset, the suspension coils on the side where the air gap increases will increase the current, so that the attractive force on that side increases to correct the radial offset. As can be seen, the two degrees of freedom of the rotor of the motor of the embodiment in the radial direction are actively controlled, and the degree of freedom in the axial direction is passively controlled. Figure 4

[0052] The magnetic suspension motor of the embodiment has simple structure, high magnetic field density and magnetic field strength, high stability of rotor operation, large driving force, and long service life of the rotor.​​

[0053] The device embodiments described above are only illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs.

[0054] It can be understood that, for those skilled in the art, equivalent replacements or changes can be made according to the technical scheme of the present application and the concept of the present application, and all these changes or replacements shall belong to the protection scope of the claims attached to the present application.

Claims

1. A permanent magnet rotor, characterized by, The permanent magnet connecting ring (12) is longitudinally arranged, and the upper permanent magnet rotor (11) and the lower permanent magnet rotor (13) are vertically arranged at both ends of the permanent magnet connecting ring.

2. The permanent magnet rotor of claim 1, wherein The first sector ring and the third sector ring, and the second sector ring are locally provided with permanent magnets.

3. The permanent magnet rotor of claim 1, wherein, The first sector ring and the third sector ring, and the second sector ring are permanent magnets as a whole.

4. The permanent magnet rotor of claim 1, wherein, The first sector ring and the third sector ring, and the second sector ring have the same width.

5. A permanent magnet rotor according to claim 4, characterised in that, The number of the first sector ring and the third sector ring, and the second sector ring is at least four.

6. A permanent magnet rotor according to claim 5, characterised in that, The permanent magnet connecting ring is a hollow tubular structure, and the upper end and the lower end of the permanent magnet connecting ring are respectively provided with a first plug-in part, and the central positions of the upper permanent magnet rotor and the lower permanent magnet rotor are provided with a second plug-in part for plug-in cooperation with the first plug-in part.

7. The permanent magnet rotor of claim 5, wherein, The upper end of the permanent magnet connecting ring is fixedly connected to the lower end surface of the upper permanent magnet rotor, and the lower end of the permanent magnet connecting ring is fixedly connected to the upper end surface of the lower permanent magnet rotor; the permanent magnet connecting ring is a hollow tubular structure; the main bodies of the upper permanent magnet rotor and the lower permanent magnet rotor are circular, and the central holes of the upper permanent magnet rotor and the lower permanent magnet rotor are aligned with the through hole of the permanent magnet connecting ring.

8. The permanent magnet rotor of claim 1, wherein, The fixed connection of the upper permanent magnet rotor, the lower permanent magnet rotor and the permanent magnet connecting ring is one or more of adhesion, ultrasonic welding and clamping.

9. A magnetic levitation motor, characterized by The permanent magnet rotor comprises: The stator (2) comprises a plurality of first magnetic yokes (21) arranged in a ring around the outer periphery of the rotor, and a coil (22) arranged in the middle of the first magnetic yoke to drive the rotor to float and rotate, wherein the first magnetic yoke comprises an axial arm arranged longitudinally and a radial arm extending horizontally towards the upper permanent magnet rotor or the lower permanent magnet rotor at both ends of the axial arm, and the upper permanent magnet rotor, the permanent magnet connecting ring, the lower permanent magnet rotor and the first magnetic yoke form a closed loop magnetic circuit in communication.

10. The magnetic levitation motor of claim 9, wherein, ​

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