Axial magnetic flux magnetic field modulation permanent magnet motor with double layers of magnetic conductive blocks

Abstract

The invention relates to the field of motor magnetic field modulation, in particular to an axial magnetic flux magnetic field modulation permanent magnet motor with double layers of magnetic conductive blocks, which comprises a motor body, a stator and a rotor are arranged in the motor body, and a fixed modulation ring and a movable modulation ring which are coaxially arranged along the axial direction are arranged between the stator and the rotor. An axial air gap is formed between the movable modulation ring and the rotor to form a single-stator, double-modulation-ring and single-rotor structure; according to the motor, the double-layer modulation ring composed of the fixed modulation ring and the movable modulation ring is adopted, the internal magnetic field intensity is adjusted by adjusting the positions of the magnetic conductive blocks on the movable modulation ring, the magnetic field intensity can be flexibly adjusted within a certain range according to different operation conditions and performance requirements, and therefore the performance of the motor is optimized, and the service life of the motor is prolonged. And therefore, the device can adapt to wider working conditions and load requirements.

Description

Technical Field

[0001] The invention relates to the field of motor magnetic field modulation, in particular to an axial magnetic flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks. Background Art

[0002] Axial flux motors, also known as disc motors, have some incomparable advantages over radial flux motors, such as better cooling and regulation, high power density, compact structure, small size, and large radius to axial length ratio. Therefore, they are very suitable for some applications that have special requirements on motor size and shape. They have great development and application prospects in large torque applications and high-performance servo systems. Due to the rapid development of processing technology and the development of high-performance permanent magnet materials, permanent magnet disc motors have developed rapidly and have been widely used in many life and industrial applications 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 modulated pole structure in traditional permanent magnet motors. Based on the magnetic field modulation principle and utilizing the special harmonic effect, the magnetic field of the stator armature winding with low pole pair number and high speed is modulated to obtain a harmonic magnetic field component that can match the magnetic field of the permanent magnet with high pole pair number and low speed, so as to improve the torque density and adapt to low-speed and high-torque applications.

[0004] At present, permanent magnet motors mainly adjust the motor magnetic field by adjusting the magnetomotive force and the magnetic circuit reluctance. However, the method of adjusting the magnetomotive force requires adding additional excitation windings, which increases copper loss and thus reduces the efficiency of the motor, or increases the risk of demagnetization faced by permanent magnets. The method of adjusting the magnetic circuit reluctance requires a more complex mechanical structure, which reduces the reliability of the motor operation. For this reason, we propose an axial flux magnetic field modulation permanent magnet motor with a double-layer magnetic conductive block. Summary of the invention

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

[0006] To achieve the above object, an axial magnetic flux magnetic field modulation permanent magnet motor with a double-layer magnetic conductive block comprises a motor body, wherein a stator and a rotor are arranged inside the motor body, a fixed modulation ring and a movable modulation ring are arranged coaxially along the axial direction between the stator and the rotor, and an axial air gap is arranged between the movable modulation ring and the rotor, forming a single-stator double-modulation ring single-rotor structure;

[0007] The fixed modulation ring and the movable modulation ring both include a magnetic conductive block and an annular non-magnetic conductive ring, and a plurality of the magnetic conductive blocks are fixedly installed on the outer side of the annular non-magnetic conductive 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, the two groups of magnetic conductive blocks on the fixed modulation ring and the movable modulation ring are axially offset to form a magnetic field path through the rotation of the movable modulation ring, thereby adjusting the coupling degree of the permanent magnetic field between the stator and the rotor.

[0010] Further: the stator includes a stator core and a stator armature winding, an axial stator yoke and a plurality of axial stator teeth uniformly distributed on the axial stator yoke along the circumferential direction are arranged on one side of the stator core, and the stator armature winding is wound on the axial stator teeth across the slots.

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

[0012] Furthermore: the number of magnetic 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 magnet.

[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 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.

[0014] Furthermore: the rotor permanent magnet adopts alternating pole axial magnetization or Halbach type magnetization.

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

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[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. The internal magnetic field strength is adjusted by adjusting the position of the magnetic conductive block on the movable modulation ring. The magnetic field strength can be flexibly adjusted within a certain range according to different operating conditions and performance requirements, thereby optimizing the motor performance and enabling it to adapt to a wider range of working conditions and load requirements;

[0018] 2. Different from the traditional magnetic field regulation method by adjusting the magnetomotive force or magnetic circuit reluctance, it does not need to increase the excitation winding, reduce the risk of permanent magnet demagnetization, or set up complex auxiliary mechanical devices, which simplifies the motor structure, reduces the motor cost, and increases the reliability of motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0021] Figure 3 Schematic diagram of the stator in the present invention;

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

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

[0024] Figure 6 It is a schematic diagram of the combination of the fixed modulation ring and the movable modulation ring in the weak magnetic state of the motor in the present invention;

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

[0026] Figure 8 It is a schematic diagram of the distribution of magnetic conductive blocks on the fixed modulation ring and the movable modulation ring on the inner side of the stator and rotor in the weak magnetic 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 conductive block; 2-2, annular non-magnetic conductive ring; 1-1, stator core; 1-2, stator armature winding; 4-1, rotor core; 4-2, rotor permanent magnet. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-8 , the figure shows a preferred embodiment of the present invention, an axial magnetic flux magnetic field modulation permanent magnet motor with double-layer magnetic conductive blocks, comprising 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 axial direction 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] The fixed modulation ring 2 and the movable modulation ring 3 both include a magnetic conductive block 2-1 and an annular non-magnetic conductive ring 2-2. A plurality of magnetic conductive blocks 2-1 are fixedly mounted on the outside of the annular non-magnetic conductive ring 2-2 along the circumferential direction, wherein the annular non-magnetic conductive ring is made of a low magnetic permeability material. Figure 5 As shown, the fixed modulation ring 2 and the movable modulation ring 3 are both composed of magnetic conductive blocks 2-1 uniformly connected to the annular non-magnetic conductive ring 2-2 along the circumferential direction. Figure 5 , 6 , 7 and 8 only show a structural scheme in which the magnetic blocks 2-1 are evenly connected to the annular non-magnetic ring 2-2 along the circumferential direction. It can also be connected through an outer low magnetic permeability material, or a low magnetic permeability material such as epoxy resin is cast between the magnetic blocks 2-1. The cross-section of the magnetic blocks 2-1 in the vertical axis 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, the two groups of magnetic conductive blocks 2-1 on the fixed modulation ring 2 and the movable modulation ring 3 are axially offset by the rotation of the movable modulation ring 3 to form a magnetic field path, thereby adjusting the coupling degree of the permanent magnetic field between the stator 1 and the rotor 4.

[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 strength can be flexibly adjusted within a certain range according to different operating conditions and performance requirements.

[0034] Specifically, the stator 1 includes a stator core 1-1 and a stator armature winding 1-2. An axial stator yoke and a plurality of axial stator teeth uniformly distributed on the axial stator yoke along the circumferential direction are arranged on one side of the stator core 1-1. The stator armature winding 1-2 is wound on the axial stator teeth across the slots.

[0035] It should be added that the stator core 1-1 is made of silicon steel sheets or laminated thin steel plates. Silicon steel sheets have good magnetic conductivity, which can effectively reduce eddy current losses and improve efficiency. Insulating materials are set outside the stator armature winding 1-2 to prevent short circuit.

[0036] Preferably, the rotor 4 includes a rotor core 4-1 and a rotor permanent magnet 4-2, and the rotor permanent magnet 4-2 is evenly distributed on the rotor core 4-1 along the circumferential direction; when current flows through the stator 1, a rotating magnetic field is generated in space. After being modulated by the double-layer modulation rings 2 and 3, this rotating magnetic field interacts with the magnetic field generated by the rotor permanent magnet 4-2 in the air gap, 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 has high flexibility and adaptability. By adjusting the relative position of the magnetic block 2-1, the magnetic field strength can be flexibly adjusted within a certain range according to different operating conditions and performance requirements, thereby optimizing the motor performance and enabling 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 terms "vertical", "up", "down", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0045] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly stipulated and limited, the terms "set", "installed", "connected" and "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 a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0046] The above content is a further detailed description of the present invention in combination with specific implementation methods. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the scope of protection 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 coaxially arranged 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), and 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 the 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 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); 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 arranged on one side of the stator core (1-1); and the stator armature winding (1-2) is wound on the axial stator teeth across slots.

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), and the rotor permanent magnets (4-2) are evenly distributed on the rotor iron core (4-1) along the 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 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 2, 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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