Rotor suspension driving structure, suspension driving method and motor

Abstract

The invention discloses a rotor suspension driving structure and method and a motor, and belongs to the technical field of magnetic suspension drive.The rotor suspension driving structure comprises a rotor suspension assembly and a rotor rotation driving assembly which are arranged on the two radial sides of a rotor, and working air gaps are formed between the rotor suspension assembly and the rotor rotation driving assembly and the rotor; the rotor is made of diamagnetic materials, the rotor suspension assembly below the rotor adopts a permanent magnet array and can be arranged in an Opposite or Halbach mode, passive and stable suspension support is provided for the rotor through magnetic repulsive force, the ratio of the suspension force to the gravity of the rotor is increased along with reduction of the scale, the miniature design of the bearing can be achieved, meanwhile, extra space is not occupied, and the bearing is more compact in structure and more compact in structure. And the size requirement of the motor can be further reduced.

Description

A rotor suspension drive structure, suspension drive method and motor Technical Field

[0001] This invention relates to the field of micro motor technology, specifically to a rotor suspension drive structure, a suspension drive method, and a motor. Background Technology

[0002] Micro-electro-mechanical systems (MEMS) integrate micromechanical and microelectronic functions and are widely used in high-tech industries such as microelectronics, aerospace, sensors, and actuators. With the continuous development of MEMS technology, micro motors have become the core equipment for energy conversion, functional drive, and precision control in MEMS systems, and they play a dual role in precision drive and control in key fields such as microrobots, microsatellites, and biomedicine.

[0003] Prior to this invention, research on rotor suspension in the field of magnetic levitation drive mainly focused on hybrid suspension bearings, which have a relatively complex structure and require separate suspension bearings for support. The magnetic bearing has a small working surface, while the rotor that needs to be suspended has a large gravity, resulting in an increase in the volume of the corresponding suspension bearing, making it difficult to achieve miniaturization of the magnetic levitation motor. Summary of the Invention

[0004] Technical objective: To address the shortcomings of existing magnetic levitation structures, this invention discloses a rotor levitation drive structure, a levitation drive method, and a motor.

[0005] Technical Solution: To achieve the above technical objectives, the present invention adopts the following technical solution: a rotor suspension drive structure, comprising a rotor suspension assembly and a rotor rotation drive assembly disposed opposite to each other on both sides of the rotor along the radial direction of the rotor, forming a working air gap between the rotor and the corresponding rotor suspension assembly and rotor rotation drive assembly; the rotor suspension assembly is disposed below the rotor to provide suspension support for the rotor, and the rotor rotation drive assembly generates an excitation magnetic field that drives the rotor to rotate; the rotor is made of antimagnetic material.

[0006] Preferably, the rotor suspension component of the present invention is a permanent magnet array; the permanent magnet array adopts an "Opposite" arrangement, which is a tile-shaped array composed of N identical sector magnetic poles, where N is a natural number greater than 2. Each sector magnetic pole is magnetized radially and the magnetization intensity is equal. The sector magnetic poles are arranged alternately in two directions: inward radiation and outward radiation. Alternatively, a "Halbach" arrangement can be adopted, in which the sector magnetic poles are arranged sequentially in the directions of outward radiation, counterclockwise circumferential, inward radiation, and clockwise circumferential.

[0007] Preferably, the rotor of the present invention is made of antimagnetic pyrolytic graphite. The rotor includes a suspension body for levitation in cooperation with the rotor suspension assembly and a rotating body disposed at both ends of the suspension body for cooperation with the excitation magnetic field generated by the rotor rotation drive assembly. The length of the suspension body is greater than the axial length of the rotor suspension assembly and the rotor rotation drive assembly. The rotating body is fixed at the end of the suspension body and has several salient poles protruding in the radial direction. It rotates by interacting with the excitation magnetic field through the salient poles.

[0008] Preferably, the rotor rotation drive assembly of the present invention includes a stator base plate, the stator base plate having a semi-circular cross-section, the diameter of the stator base plate matching the diameter of the rotating body, a stator core corresponding to the salient pole of the rotating body being disposed on the inner wall of the stator base plate, a toothed unit having a stator core winding wound on the stator core, the stator core winding being connected to a three-phase AC power supply, and generating an excitation magnetic field rotating in the rotor plane after being energized.

[0009] Preferably, the present invention has twelve sets of salient poles, which are evenly distributed along the circumferential direction of the suspension body. The number of toothed units is half that of the salient poles, and the angle of each toothed unit is between the corresponding angles of adjacent salient poles.

[0010] Preferably, the present invention has 5 sets of sector-shaped magnetic poles, which are arranged in a semi-circle below the rotor. The magnetization directions of adjacent sector-shaped magnetic poles are opposite, and the ends of the sector-shaped magnetic poles are directly attracted and fixed.

[0011] This invention discloses a rotor suspension drive method. Using the above-mentioned rotor suspension drive structure, the rotor suspension component cooperates with the rotor's suspension body below the rotor to provide a suspension force for the rotor, counteracting the rotor's gravity, thus suspending the rotor and leaving a working air gap between the rotor suspension component and the rotor rotation drive component. The rotor rotation drive component cooperates with the rotating bodies at both ends of the rotor, and generates a planar rotation excitation magnetic field to drive the rotating bodies to rotate, thereby causing the entire rotor to rotate.

[0012] Preferably, in the rotor rotation drive assembly of the present invention, a three-phase alternating current is passed through the stator core winding on the toothed unit to generate a three-phase rotating planar magnetic field; when the rotor is driven to rotate, the salient poles on the rotating body resist the magnetic field to achieve rotor rotation.

[0013] The present invention also discloses an electric motor that uses the above-described rotor suspension drive structure to drive the rotor rotation.

[0014] Beneficial effects: The rotor suspension drive structure, suspension drive method and motor disclosed in this invention have the following beneficial effects: 1. The antimagnetic suspension force of the rotor suspension component of this invention is positively correlated with the rotor weight and the rotor surface area. Therefore, under the scale effect, the ratio of suspension force to rotor weight increases as the scale decreases, which can realize the miniaturization design of the bearing, without occupying additional space, and can further reduce the size requirements of the motor.

[0015] 2. In this invention, a permanent magnet array is used to levitate and support the rotor. The antimagnetic levitation of the rotor is not limited by Earnshaw's theorem, which means that it can achieve stable levitation at room temperature, passively and statically, without the need for external energy input. This greatly simplifies the structure and cost of the micro rotor system. During continuous operation, it has the advantages of low energy consumption, low heat generation, compact structure and high space utilization.

[0016] 3. The sector-shaped magnetic poles of the permanent magnet array of the present invention adopt the arrangement of "Opposite" or "Halbach". Except for the direction of rotor suspension support, the forces in other directions cancel each other out. Through this sector-shaped magnetic pole arrangement, the stable suspension support of the rotor can be guaranteed.

[0017] 4. This invention utilizes salient poles made of antimagnetic material in conjunction with a planar rotating magnetic field. The corresponding rotating magnetic field driving method, while ensuring sufficient driving force, has minimal coupling impact on the rotor's suspension stability and stiffness characteristics. The stator core can be integrated and arranged to fit the rotor's shape. Without introducing traditional space-consuming drive devices, this invention achieves non-contact driving of the suspended rotor, which is beneficial for overall miniaturization and modularization, while also facilitating maintenance, replacement, assembly, and debugging. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 is an overall structural diagram of the drive mechanism of the present invention; Figure 2 is a structural diagram of the rotor suspension assembly of the present invention; Figure 3 is a structural diagram of the rotor rotation drive assembly of the present invention; Figure 4 is a schematic diagram of the three-dimensional antimagnetic force on the rotor of the present invention; wherein, 1-rotor, 2-rotor suspension assembly, 3-rotor rotation drive assembly, 4-fan-shaped magnetic pole, 5-suspended body, 6-rotating body, 7-salient pole, 8-stator core, 9-stator core winding, 10-tooth unit, 11-stator substrate. Detailed Implementation

[0020] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are set forth herein. Each embodiment and example is provided by way of explanation of the apparatus, composition, and materials of the present disclosure, and not as a limitation. Rather, the following description provides convenient illustrations for implementing exemplary embodiments of the present disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the teachings of the present disclosure without departing from the scope or spirit of the present disclosure. Embodiments

[0021] As shown in Figure 1, the rotor suspension drive structure provided by the present invention mainly includes a rotor 1, a rotor suspension assembly 2, and a rotor rotation drive assembly 3. The rotor suspension assembly 2 and the rotor rotation drive assembly 3 are arranged opposite each other on both sides of the rotor 1 along its radial direction. A working air gap is formed between the rotor 1 and the corresponding rotor suspension assembly 2 and rotor rotation drive assembly 3 to ensure that the rotor has no contact and low friction during suspension and rotation.

[0022] The rotor suspension assembly 2 is positioned below the rotor 1, providing a stable suspension support force for the rotor 1. This suspension support force counteracts the rotor's gravity, allowing the rotor to remain stably suspended in the working air gap. The rotor rotation drive assembly 3 generates an excitation magnetic field capable of driving the rotor to rotate around its axis through the action of the magnetic field. In this embodiment, the rotor 1 is made of a diamagnetic material, such as diamagnetic pyrolytic graphite. The diamagnetic material can generate a stable repulsive force with the permanent magnetic field, thereby achieving passive, passive, and stable suspension without the need for additional active control circuitry.

[0023] As shown in Figure 2, the rotor suspension assembly 2 of the present invention preferably employs a permanent magnet array. This permanent magnet array can adopt two typical arrangement forms: the first is an "Opposite" arrangement, which is a tile-shaped array composed of N (N is a natural number greater than 2) identical sector-shaped magnetic poles 4. The magnetization direction of each sector-shaped magnetic pole 4 is a radial direction (i.e., along the radial direction), and the magnetization intensity is equal. The magnetization directions of adjacent sector-shaped magnetic poles 4 are opposite, i.e., they are arranged alternately in inward and outward radial directions, thereby forming a strong gradient magnetic field above the rotor and generating an upward levitation force. The second is a "Halbach" arrangement, in which the magnetic field enhancement direction is more concentrated. Specifically, the magnetization directions of the sector-shaped magnetic poles 4 are arranged sequentially in the order of outward radiation, counterclockwise circumferential direction, inward radiation, and clockwise circumferential direction, which can more efficiently provide levitation force for the rotor.

[0024] For the rotor suspension assembly 2, in a preferred embodiment, the number of sector magnetic poles 4 is set to five groups. The five groups of sector magnetic poles 4 are arranged together in a semi-circle (covering an area of ​​approximately 180 degrees) and positioned directly below the rotor 1. The magnetization directions of adjacent sector magnetic poles 4 are opposite (one inward and one outward). The side ends of these sector magnetic poles 4 can be directly fixed by magnetic attraction, facilitating assembly. This semi-circular arrangement is sufficient to provide vertical (upward) levitation force, while maintaining a compact structure and ensuring force balance in all directions except the support direction.

[0025] Figure 4 illustrates the variation of the antimagnetic force on rotor 1 in an "Opposite" type radially magnetized tile-shaped permanent magnet array along the x, y, and z vector directions. The z-direction is the rotor axis, the y-direction is the rotor's levitation height, and the x-direction is the horizontal direction perpendicular to the y and z directions, forming a three-dimensional coordinate system. Similar to a passive antimagnetic levitation system, in the y-vector direction, the antimagnetic force decreases inversely with increasing levitation height, increasing closer to the surface of the permanent magnet array. In the x-vector direction, when the rotor deviates from the center, it is also subject to an antimagnetic restoring force, causing it to spontaneously stabilize at the origin. However, in the z-vector direction, there is no stable levitation point for the rotor; therefore, except for the z-vector direction (axial direction), rotor 1 can stably levitate in other degrees of freedom. Example

[0026] Based on Embodiment 1, as shown in Figures 1 and 2, the specific structure of the rotor 1 of the present invention can be further optimized. The rotor 1 uses antimagnetic pyrolytic graphite material and includes two parts: a suspension body 5 and a rotating body 6. The suspension body 5 is a cylindrical main body, and its length (axial dimension) is greater than the axial length of the rotor suspension assembly 2 and the rotor rotation drive assembly 3, with a difference of 0 to +5 mm, ensuring that the suspension surface remains covered during rotor rotation and minor axial displacement. The lower part of the suspension body 5 corresponds to the permanent magnet array of the rotor suspension assembly 2, achieving stable suspension through the repulsive force generated by antimagnetism.

[0027] The rotating body 6 is fixedly connected to both ends of the suspension body 5 and protrudes radially to form several salient poles 7. The salient poles 7 are preferably integrally formed or fixedly connected using the same antimagnetic material as the suspension body 5. The function of the rotating body 6 is to interact with the excitation magnetic field generated by the rotor rotation drive assembly 3. When the excitation magnetic field changes, the salient poles 7, due to their antimagnetism, tend to "resist" the change in the magnetic field, thus being driven in the rotating magnetic field and causing the entire rotor to rotate.

[0028] The rotor structure and permanent magnet arrangement of this invention increase the levitation area without occupying additional axial space, which helps to further reduce the size of the motor and ensure stable rotor levitation. Example

[0029] As shown in Figure 3, the specific structure of the rotor rotation drive assembly 3 of the present invention includes a stator base plate 11. The stator base plate 11 has a semi-circular cross-section, and its inner diameter matches the outer diameter of the rotating body 6, with a uniform working air gap between them. A stator core 8 is disposed on the inner wall of the stator base plate 11. The stator core 8 adopts a ring structure and has several toothed units 10. The toothed units 10 are made of stacked silicon steel sheets with high magnetic permeability, and stator core windings 9 are wound on them. All stator core windings 9 are connected to a three-phase AC power supply. When a symmetrical three-phase alternating current is applied, an excitation magnetic field rotating in the rotor plane is generated.

[0030] To optimize the driving effect, the number of salient poles 7 on the rotating body 6 is designed to be twelve groups, evenly distributed along the circumference. The number of toothed units 10 on the stator core is designed to be half the number of salient poles 7, i.e., six groups. These six groups of toothed units 10 are evenly distributed circumferentially, and the circumferential angular position of each toothed unit 10 is exactly at the midpoint between two adjacent salient poles 7 on the rotating body. This "pole number matching" relationship can generate a stable rotating reluctance torque, enabling the rotor to start smoothly and rotate stably. Example

[0031] This invention also provides a rotor suspension driving method using any of the above-described rotor suspension drive structures, with the following specific steps: The rotor 1 is placed above the rotor suspension assembly 2. Since the rotor 1 is made of a diamagnetic material, the static gradient magnetic field generated by the permanent magnet array will induce a reverse magnetization intensity in the suspension body 5 at the bottom of the rotor, thereby generating a repulsive force (i.e., levitation force) opposite to the direction of gravity. When this levitation force balances with the rotor's own gravity, the rotor will be stably suspended, maintaining a certain working air gap between itself and the rotor suspension assembly 2 below and the rotor rotation drive assemblies 3 on both sides.

[0032] A symmetrical three-phase alternating current is introduced into the stator core winding 9 of the rotor rotation drive assembly 3. This current generates a rotating magnetic field (i.e., a planar rotating excitation magnetic field) with a constant amplitude and a continuously changing direction along the circumference in the air gap formed by the stator core and the salient pole 7 of the rotor rotating body 6. The salient pole 7 of the rotating body 6 is made of a diamagnetic material, which resists changes in the external magnetic field. When the rotating magnetic field passes over the salient pole 7, the salient pole 7 tends to "follow" the rotating magnetic field in order to maintain its internal magnetic field, i.e., it generates reluctance torque. Under the continuous action of this torque, the rotating body 6 will rotate synchronously with the rotating magnetic field, thereby driving the entire rotor 1 to rotate around its axis. Example

[0033] This invention also provides an electric motor that employs a rotor suspension drive structure as its core drive and support component. This significantly reduces the motor's size and allows for wide application in microelectromechanical systems (MEMS).

[0034] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0035] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A rotor suspension drive structure, characterized in that, The rotor (1) includes a rotor suspension assembly (2) and a rotor rotation drive assembly (3) arranged opposite each other on both sides of the rotor (1) in the radial direction, forming a working air gap between the rotor (1) and the corresponding rotor suspension assembly (2) and rotor rotation drive assembly (3); the rotor suspension assembly (2) is arranged below the rotor (1) to provide suspension support for the rotor (1), and the rotor rotation drive assembly (3) generates an excitation magnetic field that drives the rotor to rotate; the rotor (1) is made of antimagnetic material.

2. The rotor suspension drive structure according to claim 1, characterized in that, The rotor suspension component (2) is a permanent magnet array; the permanent magnet array adopts the "Opposite" arrangement, which is a tile-shaped array composed of N identical fan-shaped magnetic poles (4), where N is a natural number greater than 2. The magnetization direction of each fan-shaped magnetic pole (4) is radial magnetization and the magnetization intensity is equal. The magnetization direction of the fan-shaped magnetic poles (4) is arranged alternately in two directions: inward radiation and outward radiation, or in the "Halbach" arrangement, where the magnetization direction of the fan-shaped magnetic poles (4) is arranged sequentially in the directions of outward radiation, counterclockwise circumferential, inward radiation, and clockwise circumferential.

3. The rotor suspension drive structure according to claim 2, characterized in that, The rotor (1) is made of antimagnetic pyrolytic graphite. The rotor (1) includes a suspension body (5) for suspending in conjunction with the rotor suspension assembly (2) and a rotating body (6) set at both ends of the suspension body (5) for cooperating with the excitation magnetic field generated by the rotor rotation drive assembly (3). The length of the suspension body (5) is greater than the axial length of the rotor suspension assembly (2) and the rotor rotation drive assembly (3). The rotating body (6) is fixed at the end of the suspension body (5) and has several convex poles (7) protruding in the radial direction. It rotates by interacting with the excitation magnetic field through the convex poles (7).

4. The rotor suspension drive structure according to claim 3, characterized in that, The rotor rotation drive assembly (3) includes a stator base plate (11), the stator base plate (11) has a semi-circular cross section, the diameter of the stator base plate (11) matches the diameter of the rotating body (6), a stator core (8) corresponding to the salient pole (7) of the rotating body is provided on the inner wall of the stator base plate (11), and a toothed unit (10) with a stator core winding (9) is provided on the stator core (8). The stator core winding (9) is connected to a three-phase AC power supply, and generates an excitation magnetic field that rotates in the rotor plane after being energized.

5. The rotor suspension drive structure according to claim 4, characterized in that, The number of salient poles (7) is twelve, which are evenly distributed along the circumference of the suspension body. The number of toothed units (10) is half that of the salient poles, and the angle of each toothed unit is between the corresponding angles of the adjacent salient poles.

6. The rotor suspension drive structure according to claim 2, characterized in that, The number of the sector magnetic poles (4) is 5 sets. The 5 sets of sector magnetic poles are arranged in a semi-circle below the rotor (1). The magnetization directions of adjacent sector magnetic poles (4) are opposite, and the ends of the sector magnetic poles (4) are directly attracted and fixed.

7. A rotor suspension drive method, using the rotor suspension drive structure according to any one of claims 1-6, characterized in that, The rotor suspension assembly, located below the rotor, works in conjunction with the rotor's suspension body to provide a levitation force for the rotor, counteracting the rotor's gravity and suspending it. A working air gap is maintained between the rotor suspension assembly and the rotor rotation drive assembly. The rotor rotation drive assembly works in conjunction with the rotating bodies at both ends of the rotor. The rotor rotation drive assembly generates a planar rotational excitation magnetic field, driving the rotating bodies to rotate and causing the entire rotor to rotate.

8. The rotor suspension drive method according to claim 7, characterized in that, Three-phase alternating current is passed through the stator core windings on the toothed unit of the rotor rotation drive assembly to generate a three-phase rotating planar magnetic field; when the rotor is driven to rotate, the salient poles on the rotating body resist the magnetic field to achieve rotor rotation.

9. An electric motor, characterized in that, The rotor rotation is driven by the rotor suspension drive structure according to any one of claims 1-6.

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