An Axial Flux Field Modulated Permanent Magnet Machine with Double-Layer Magnetic Conductive Blocks

Abstract

The present invention relates to the field of motor magnetic field modulation, and specifically to an axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conduction blocks, including a motor body. Inside the motor body, a stator and a rotor are provided. Between the stator and the rotor, a fixed modulation ring and a movable modulation ring are coaxially arranged along the axial direction. An axial air gap is provided between the movable modulation ring and the rotor, forming a single stator, double modulation ring, and single rotor structure. The motor of the present invention adopts a double-layer modulation ring composed of a fixed modulation ring and a movable modulation ring. By adjusting the position of the magnetic conduction blocks on the movable modulation ring, the internal magnetic field intensity can be adjusted. According to different operating conditions and performance requirements, the magnetic field intensity can be flexibly adjusted within a certain range, thereby optimizing the motor performance and enabling it to adapt to a wider range of working conditions and load requirements.

Description

Technical Field

[0001] The present invention relates to the field of motor magnetic field modulation, and specifically to an axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conduction blocks. Background Technique

[0002] Axial flux motors, also known as disk motors, have some advantages that radial flux motors cannot match, such as better cooling regulation, high power density, compact structure, small volume, and a large ratio of radius to axial length. Therefore, they are very suitable for some application scenarios with special requirements for motor size and shape, and have great development and application prospects in high-torque application scenarios and high-performance servo systems. Due to the rapid progress of processing technology and the development of high-performance permanent magnet materials, permanent disk motors have developed rapidly and have been widely used in many life and industrial application scenarios such as robots, electric vehicles, and centrifuges.

[0003] Since the concept of magnetic field modulation permanent magnet gears was proposed and widely studied, permanent magnet magnetic field modulation motors have introduced a modulation pole structure into traditional permanent magnet motors. According to the magnetic field modulation principle, using special harmonic effects, the magnetic field of the stator armature winding with low pole pairs and high speed is modulated to obtain a harmonic magnetic field component that can match the magnetic field of the permanent magnets with high pole pairs and low speed, so as to improve the torque density and adapt to low-speed and high-torque application scenarios.

[0004] At present, permanent magnet motors mainly adjust the motor magnetic field by two methods: adjusting the magnetomotive force and the magnetic reluctance of the magnetic circuit. However, the method of adjusting the magnetomotive force requires adding an additional excitation winding, resulting in an increase in copper loss and thus a decrease in the efficiency of the motor, or an increase in the risk of demagnetization faced by the permanent magnets. And the method of adjusting the magnetic reluctance of the magnetic circuit requires a more complex mechanical structure, reducing the reliability of the motor operation. For this reason, we propose an axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conduction blocks. Summary of the Invention

[0005] The purpose of the present invention is to provide an axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conduction blocks to solve the problems raised in the above background technique.

[0006] To achieve the above purpose, an axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conduction blocks includes a motor body. Inside the motor body, a stator and a rotor are provided. Between the stator and the rotor, a fixed modulation ring and a movable modulation ring are coaxially arranged along the axis. An axial air gap is provided between the movable modulation ring and the rotor, forming a single-stator, double-modulation-ring, single-rotor structure.

[0007] Both the fixed modulation ring and the movable modulation ring include magnetic conduction blocks and annular non-magnetic conduction rings. A plurality of the magnetic conduction blocks are fixedly installed on the outer side of the annular non-magnetic conduction ring along the circumferential direction.

[0008] The difference between the fixed modulation ring and the movable modulation ring is that the fixed modulation ring is fixedly installed between the stator and the rotor, and the movable modulation ring is movably connected between the stator and the rotor;

[0009] Between the fixed modulation ring and the movable modulation ring, by rotating the movable modulation ring, two sets of magnetic conduction blocks on the fixed modulation ring and the movable modulation ring are axially staggered to form a magnetic field path, so as to adjust the coupling degree of the permanent magnetic field between the stator and the rotor.

[0010] Furthermore: The stator includes a stator core and a stator armature winding. One side of the stator core is provided with an axial stator yoke and a number of axial stator teeth evenly distributed on the axial stator yoke in the circumferential direction. The stator armature winding is wound across slots on the axial stator teeth.

[0011] Furthermore: The rotor includes a rotor core and rotor permanent magnets, and the rotor permanent magnets are evenly distributed on the rotor core in the circumferential direction.

[0012] Furthermore: The number of magnetic conduction blocks on the fixed modulation ring and the movable modulation ring is equal to the sum of the number of pole pairs of the stator armature winding and the rotor permanent magnets.

[0013] Furthermore: After the magnetic field generated by the stator armature winding is modulated by the fixed modulation ring and the movable modulation ring, the number of pole pairs of the spatial harmonics of the generated modulated magnetic field is the same as the number of pole pairs of the permanent magnetic field generated by the rotor permanent magnets.

[0014] Furthermore: The rotor permanent magnets adopt an alternating pole axial magnetization or a Halbach type magnetization method.

[0015] Furthermore: The annular non-magnetic conductive ring is made of a material with low magnetic permeability.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. In the present invention, the motor of the present invention adopts a double-layer modulation ring composed of a fixed modulation ring and a movable modulation ring. By adjusting the position of the magnetic conduction blocks on the movable modulation ring, the internal magnetic field intensity can be adjusted. According to different operating conditions and performance requirements, the magnetic field intensity can be flexibly adjusted within a certain range, so as to optimize the motor performance and enable it to adapt to a wider range of working conditions and load requirements;

[0018] 2. Different from the traditional magnetic field adjustment methods by adjusting the magnetomotive force or the magnetic resistance of the magnetic circuit, there is no need to increase the excitation winding, reduce the risk of permanent magnet demagnetization, nor set up complex auxiliary mechanical devices, which simplifies the motor structure, reduces the motor cost, and increases the reliability of the motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front elevation schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a disassembled schematic diagram of the stator, fixed modulation ring, movable modulation ring and rotor in the present invention;

[0021] Figure 3 This is a schematic diagram of the stator in the present invention;

[0022] Figure 4 This is a schematic diagram of the rotor structure in the present invention;

[0023] Figure 5 This is a schematic diagram of the combined form of the fixed modulation ring and the movable modulation ring in the normal state of the motor in the present invention;

[0024] Figure 6 This is a schematic diagram of the combined form of the fixed modulation ring and the movable modulation ring in the field-weakening state of the motor in the present invention;

[0025] Figure 7 This is a schematic diagram of the distribution of magnetic conduction blocks on the fixed modulation ring and the movable modulation ring on the inner sides of the stator and the rotor in the normal state of the motor in the present invention;

[0026] Figure 8 This is a schematic diagram of the distribution form of magnetic conduction blocks on the fixed modulation ring and the movable modulation ring on the inner sides of the stator and the rotor in the field-weakening state of the motor in the present invention.

[0027] In the figure: 1. Stator; 2. Fixed modulation ring; 3. Movable modulation ring; 4. Rotor; 2-1. Magnetic conduction block; 2-2. Ring-shaped non-magnetic conduction ring; 1-1. Stator iron core; 1-2. Stator armature winding; 4-1. Rotor iron core; 4-2. Rotor permanent magnet. Specific embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Please refer to Figure 1-8 , the figure is a preferred embodiment of the present invention, an axial-flux field-modulated permanent magnet motor with double-layer magnetic conduction blocks, including a motor body. A stator 1 and a rotor 4 are arranged inside the motor body. A fixed modulation ring 2 and a movable modulation ring 3 are arranged coaxially along the axis between the stator 1 and the rotor 4. An axial air gap is arranged between the movable modulation ring 3 and the rotor 4, forming a single-stator double-modulation-ring single-rotor structure;

[0030] Both the fixed modulation ring 2 and the movable modulation ring 3 include magnetic conductive blocks 2-1 and annular non-magnetic conductive rings 2-2. A number of magnetic conductive blocks 2-1 are fixedly installed on the outer side of the annular non-magnetic conductive ring 2-2 along the circumferential direction. Among them, the annular non-magnetic conductive ring is made of a material with a low magnetic permeability; as Figure 5 shown, both the fixed modulation ring 2 and the movable modulation ring 3 are formed by magnetic conductive blocks 2-1 being evenly connected to the annular non-magnetic conductive ring 2-2 along the circumferential direction, Figure 5 , 6 , 7 and 8 only show one structural scheme in which the magnetic conductive blocks 2-1 are evenly connected to the annular non-magnetic conductive ring 2-2 along the circumferential direction. It can also be connected by a material with a low magnetic permeability on the outside, or poured with a material with a low magnetic permeability such as epoxy resin between the magnetic conductive blocks 2-1. The cross-section of the magnetic conductive blocks 2-1 in the vertical axial direction is a parallel or fan-shaped structure.

[0031] The difference between the fixed modulation ring 2 and the movable modulation ring 3 is that the fixed modulation ring 2 is fixedly installed between the stator 1 and the rotor 4, and the movable modulation ring 3 is movably connected between the stator 1 and the rotor 4;

[0032] Between the fixed modulation ring 2 and the movable modulation ring 3, by rotating the movable modulation ring 3, two groups of magnetic conductive blocks 2-1 on the fixed modulation ring 2 and the movable modulation ring 3 are axially staggered to form a magnetic field path, and the coupling degree of the permanent magnetic field between the stator 1 and the rotor 4 is adjusted.

[0033] In this way, by adjusting the relative positions of the two groups of magnetic conductive blocks 2-1 between the fixed modulation ring 2 and the movable modulation ring 3, the magnetic field intensity can be flexibly adjusted within a certain range according to different operating conditions and performance requirements.

[0034] Specifically, the stator 1 includes a stator iron core 1-1 and a stator armature winding 1-2. On one side of the stator iron core 1-1, there is an axial stator yoke and a number of axial stator teeth evenly distributed on the axial stator yoke along the circumferential direction. The stator armature winding 1-2 is wound across the slots on the axial stator teeth.

[0035] It should be added that the material of the stator iron core 1-1 is silicon steel sheet or laminated by thin steel plates. The silicon steel sheet has good magnetic conductivity, can effectively reduce eddy current loss and improve efficiency; an insulating material is arranged outside the stator armature winding 1-2 to prevent short circuit.

[0036] Preferably, the rotor 4 includes a rotor iron core 4-1 and rotor permanent magnets 4-2. The rotor permanent magnets 4-2 are evenly distributed on the rotor iron core 4-1 along the circumferential direction; when current flows through the stator 1, a rotating magnetic field will be generated in space. This rotating magnetic field interacts with the magnetic field generated by the rotor permanent magnets 4-2 in the air gap after being modulated by the double-layer modulation rings 2 and 3, generating a torque to drive the motor to operate.

[0037] Among them, the number of magnetic blocks 2-1 on the fixed modulation ring 2 and the movable modulation ring 3 is equal to the sum of the pole pairs of the stator armature winding 1-2 and the rotor permanent magnet 4-2. If the pole pair number of the stator armature winding 1-2 is P1 and the pole pair number of the rotor permanent magnet 4-2 is P2, then the number of magnetic blocks 2-1 on a single modulation ring is N=P1+P2.

[0038] It should be added that after the magnetic field generated by the stator armature winding 1-2 is modulated by the fixed modulation ring 2 and the movable modulation ring 3, the number of spatial harmonic pole pairs of the modulated magnetic field generated is the same as the number of permanent magnetic field pole pairs generated by the rotor permanent magnet 4-2.

[0039] Optionally, the rotor permanent magnet 4 - 2 adopts alternating pole axial magnetization or Halbach type magnetization method, wherein the Halbach type magnetization method has a magnetic field concentration effect, which helps to improve the air gap flux density of the motor.

[0040] In this embodiment, when the motor is working in a normal working state, the position of the movable modulation ring 3 is as follows: Figure 5 As shown, at this time, the magnetic blocks 2-1 on the fixed modulation ring 2 and the movable modulation ring 3 completely overlap in the axial direction, and the magnetic field generated by the stator armature winding 1-2 is modulated by the modulation ring composed of the fixed modulation ring 2 and the movable modulation ring 3. The number of pole pairs of the generated spatial harmonics matches the number of pole pairs of the rotor permanent magnet 4-2, so that the stator 1 and the rotor 4 can perform stable energy transfer.

[0041] When the magnetic field strength inside the motor needs to be adjusted, the position of the movable modulation ring 3 is as follows: Figure 6 As shown, at this time, the magnetic blocks 2-1 on the fixed modulation ring 2 and the movable modulation ring 3 are staggered in the axial direction to form a magnetic field path, which weakens the modulation effect of the two modulation rings and reduces the degree of coupling of the magnetic field generated by the stator armature winding 1-2 to the permanent magnetic field generated by the rotor permanent magnet 4-2, thereby making the motor work in a weak magnetic state.

[0042] It should be noted that the axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks of the present invention has the advantages of high power density and compact structure of axial motors; at the same time, the magnetic field modulation principle is used to improve the torque density to cope with low-speed and high-torque applications. Structurally, the motor of the present invention adopts a double-layer modulation ring composed of a fixed modulation ring 2 and a movable modulation ring 3. The position of the movable modulation ring 3 is adjusted to adjust the magnetic field strength inside the motor, and the weak magnetic operation of the motor is achieved with a simple structure. The motor of the present invention provides a simpler and more cost-effective solution through its double-layer modulation ring design. This design does not require additional excitation windings, thereby reducing the risk of demagnetization of permanent magnets; it also eliminates complex auxiliary mechanical devices, making the motor structure simpler, which not only reduces manufacturing costs, but also improves the reliability of motor operation.

[0043] In addition, this design also has high flexibility and adaptability. By adjusting the relative positions of the magnetic conduction blocks 2-1, the magnetic field intensity can be flexibly adjusted within a certain range according to different operating conditions and performance requirements, so as to optimize the motor performance and enable it to adapt to a wider range of working conditions and load requirements.

[0044] Finally, it should be noted that: in the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0045] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] The above content is a further detailed description of the present invention in combination with specific embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope determined by the claims submitted for the present invention.

Claims

1. An axial flux magnetic field modulation permanent magnet motor with a double-layer magnetic conductive block, comprising a motor body, wherein a stator (1) and a rotor (4) are arranged inside the motor body, characterized in that: A fixed modulation ring (2) and a movable modulation ring (3) are arranged coaxially along the axial direction between the stator (1) and the rotor (4), and an axial air gap is provided between the movable modulation ring (3) and the rotor (4), forming a single-stator, double-modulation-ring, single-rotor structure; The fixed modulation ring (2) and the movable modulation ring (3) both comprise a magnetic conductive block (2-1) and an annular non-magnetic conductive ring (2-2), wherein a plurality of the magnetic conductive blocks (2-1) are fixedly mounted on the outside of the annular non-magnetic conductive ring (2-2) along a circumferential direction; The difference between the fixed modulation ring (2) and the movable modulation ring (3) is that the fixed modulation ring (2) is fixedly mounted between the stator (1) and the rotor (4), and the movable modulation ring (3) is movably connected between the stator (1) and the rotor (4); Between the fixed modulation ring (2) and the movable modulation ring (3), the two groups of magnetic conductive blocks (2-1) on the fixed modulation ring (2) and the movable modulation ring (3) are axially offset to form a magnetic field path through the rotation of the movable modulation ring (3), thereby adjusting the coupling degree of the permanent magnetic field between the stator (1) and the rotor (4).

2. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 1 is characterized in that: The stator (1) comprises a stator core (1-1) and a stator armature winding (1-2); an axial stator yoke and a plurality of axial stator teeth evenly distributed on the axial stator yoke along a circumferential direction are provided on one side of the stator core (1-1); and the stator armature winding (1-2) is wound across slots on the axial stator teeth.

3. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 1 is characterized in that: The rotor (4) comprises a rotor iron core (4-1) and rotor permanent magnets (4-2), wherein the rotor permanent magnets (4-2) are evenly distributed on the rotor iron core (4-1) along a circumferential direction.

4. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 1, characterized in that: The number of magnetic conductive blocks (2-1) on the fixed modulation ring (2) and the movable modulation ring (3) is equal to the sum of the number of pole pairs of the stator armature winding (1-2) and the rotor permanent magnet (4-2).

5. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 4, characterized in that: After the magnetic field generated by the stator armature winding (1-2) is modulated by the fixed modulation ring (2) and the movable modulation ring (3), the number of spatial harmonic pole pairs of the modulated magnetic field generated is the same as the number of permanent magnetic field pole pairs generated by the rotor permanent magnet (4-2).

6. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 3, characterized in that: The rotor (4) adopts an alternating pole axial magnetization or a Halbach type magnetization method.

7. The axial flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks according to claim 1, characterized in that: The annular non-magnetic conductive ring (2-2) is made of a low magnetic permeability material.

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