Axial flux motor rotor, motor and hovercar

Abstract

The invention provides an axial magnetic flux motor rotor, a motor and a hovercar, the axial magnetic flux motor rotor comprises an annular magnet fixing part and a preset number of permanent magnet groups, the magnet fixing part is uniformly provided with a preset number of magnet mounting grooves, and the permanent magnet groups are embedded and fixed in the magnet mounting grooves. The magnetic poles of two adjacent permanent magnet groups face opposite directions; the permanent magnet group comprises three permanent magnets which are arranged in sequence, the tangent planes of the three permanent magnets along the first direction are fan-shaped, the magnetic densities of the two permanent magnets on the two sides are the same, and the magnetic densities of the two permanent magnets on the two sides are smaller than the magnetic density of the permanent magnet in the middle. According to the rotor, the torque can be increased, the torque pulsation can be reduced, and the stability can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of permanent magnet synchronous motors, and in particular to an axial flux motor rotor, a motor and a flying car. Background Art

[0002] The axial flux motor has high torque density, light weight and small volume. It is hailed as the next generation of drive technology and has been widely used in the field of flying cars.

[0003] The axial flux motor used in flying cars has extremely high requirements for torque density and stability, but existing axial flux motors cannot meet these requirements. Summary of the invention

[0004] In view of this, the present application provides an axial flux motor rotor, a motor and a flying car to solve the above-mentioned technical problems.

[0005] In the first aspect, an embodiment of the present application provides an axial flux motor rotor, comprising a ring-shaped magnet fixing portion and a preset number of permanent magnet groups, wherein a preset number of magnet mounting grooves are evenly arranged on the magnet fixing portion, and the permanent magnet groups are embedded and fixed in the magnet mounting grooves, and the magnetic poles of two adjacent permanent magnet groups are in opposite directions; the permanent magnet group comprises three permanent magnets arranged in sequence, and the cross-section of the three permanent magnets along the first direction is fan-shaped, wherein the magnetic density of the two permanent magnets on both sides is the same, and the magnetic density of the two permanent magnets on both sides is smaller than the magnetic density of the middle permanent magnet.

[0006] Furthermore, the three permanent magnets are made of the same material, and the areas of the cross-sections of the three permanent magnets along the first direction are the same; the thicknesses of the two permanent magnets on both sides along the second direction are the same, and the thicknesses of the permanent magnets on both sides along the second direction are smaller than the thickness of the middle permanent magnet along the second direction.

[0007] Furthermore, the two permanent magnets on both sides are made of the same material, and the magnetic energy product of the two permanent magnets on both sides is smaller than the magnetic energy product of the permanent magnet in the middle.

[0008] Furthermore, the two permanent magnets on both sides are ferrite, and the middle permanent magnet is neodymium iron boron.

[0009] Further, the thickness of the two permanent magnets on both sides along the second direction is less than or equal to the thickness of the middle permanent magnet along the second direction.

[0010] Furthermore, the relationship between the thickness of the three permanent magnets along the second direction and the area of ​​the cross section along the first direction and the magnetic flux density of the magnet group satisfies:

[0011] The magnetomotive force F of the three permanent magnets PM1 ,F PM2 ,FPM3 for:

[0012]

[0013] The reluctance R of the three permanent magnets PM1 R PM2 R PM3 for:

[0014]

[0015] Among them, B r1 ,B r2 and B r3 is the remanence of the three permanent magnets, μ r1 , μ r2 and μ r3 is the relative magnetic permeability of the three permanent magnets, μ0 is the magnetic permeability of vacuum, h PM1 ,h PM2 and h PM3 S is the thickness of the three permanent magnets along the second direction; PM1 , S PM2 and S PM3 is the area of ​​the cross section of the three permanent magnets along the first direction;

[0016] Calculate the magnetic flux Φ of the three permanent magnets according to Kirchhoff's law g1 , Φ g2 and Φ g3 :

[0017] F PM1 -F PM2 =R PM1 Φ g1 -R PM2 Φ g2

[0018] F PM2 -F PM3 =R PM2 Φ g2 -R PM3 Φ g3

[0019] F PM3 =R PM3 Φ g3 +R g (Φ g1 +Φ g2 +Φ g3 )

[0020] Among them, R g is the air gap reluctance;

[0021] The magnetic induction intensities h1, h2 and h3 of the three permanent magnets are:

[0022]

[0023] Then the fundamental wave component a1 of the magnetic flux density of the magnet group is:

[0024]

[0025] Wherein, T is the electrical period; θ1 is the first electrical angle, θ2 is the second electrical angle, and θ3 is the third electrical angle;

[0026] The harmonic component a of the magnetic flux density of the magnet group n for

[0027]

[0028] Where n≥3, n is an odd number;

[0029] Then the magnetic flux density B of the magnet group is:

[0030]

[0031] Among them, ω0 is the frequency of the fundamental wave.

[0032] In a second aspect, an embodiment of the present application provides an axial flux motor, comprising: a stator, and also comprising: an axial flux motor rotor of an embodiment of the present application.

[0033] In a third aspect, an embodiment of the present application provides a flying car, including: an axial flux motor of an embodiment of the present application.

[0034] The rotor of the present application can increase the torque, reduce the torque pulsation, and improve stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of an axial flux motor rotor provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the thickness of three permanent magnets provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of an equivalent magnetic circuit model provided in an embodiment of the present application;

[0039] Figure 4A schematic diagram of the magnetic flux density of a single permanent magnet provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the magnetic flux density of three permanent magnets provided in an embodiment of the present application.

[0041] Figure ID:

[0042] 101: magnet fixing part; 102: permanent magnet group; 103: magnet mounting groove. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0045] First, the design concept of the embodiments of the present application is briefly introduced.

[0046] In order to meet the high requirements of flying cars on the torque density and stability of axial flux motors, the present application provides an axial flux motor rotor, including a ring-shaped magnet fixing portion and a preset number of permanent magnet groups, the magnet fixing portion is evenly provided with a preset number of magnet mounting grooves, the permanent magnet groups are embedded and fixed in the magnet mounting grooves, and the magnetic poles of two adjacent permanent magnet groups are in opposite directions; the permanent magnet group includes three permanent magnets arranged in sequence, and the cross-section of the three permanent magnets along the first direction is fan-shaped, wherein the magnetic density of the two permanent magnets on both sides is the same, and the magnetic density of the two permanent magnets on both sides is smaller than the magnetic density of the permanent magnet in the middle.

[0047] Compared with the prior art, the advantages of the present invention are:

[0048] 1. The air gap flux density of the axial flux motor of the present application is changed from a square wave to an irregular rectangular wave. The air gap flux density is subjected to Fourier decomposition to obtain the expressions of the fundamental wave and each harmonic and structure; the amplitude of the fundamental wave becomes larger, thereby increasing the torque; the sinusoidal degree is improved, which can reduce the harmonic amplitude, reduce the size of the torque pulsation, and improve stability.

[0049] 2. The axial flux motor rotor of the present application uses part of low-cost ferrite to replace neodymium iron boron, which can effectively reduce costs.

[0050] After introducing the application scenarios and design concepts of the embodiments of the present application, the technical solutions provided by the embodiments of the present application are described below.

[0051] like Figure 1 As shown, the present application provides an axial flux motor rotor, including a ring-shaped magnet fixing portion 101 and a preset number of permanent magnet groups 102, wherein a preset number of magnet mounting grooves 103 are evenly arranged on the magnet fixing portion, and the permanent magnet groups 102 are embedded and fixed in the magnet mounting grooves 103, and the magnetic poles of two adjacent permanent magnet groups are in opposite directions; the permanent magnet group includes three permanent magnets arranged in sequence, and the cross-section of the three permanent magnets along the first direction is fan-shaped, wherein the magnetic density of the two permanent magnets on both sides is the same, and the magnetic density of the two permanent magnets on both sides is smaller than the magnetic density of the middle permanent magnet.

[0052] The number of permanent magnet groups is an even number, which may be 6, 8 or 12, etc.

[0053] In some embodiments, the three permanent magnets are made of the same material, and the areas of the cross-sections of the three permanent magnets along the first direction are the same; the thicknesses of the two permanent magnets on both sides along the second direction are the same, and the thicknesses of the permanent magnets on both sides along the second direction are smaller than the thickness of the middle permanent magnet along the second direction.

[0054] In some embodiments, the two permanent magnets on both sides are made of the same material, and the magnetic energy product of the two permanent magnets on both sides is smaller than the magnetic energy product of the permanent magnet in the middle.

[0055] In some embodiments, the two permanent magnets on both sides are ferrite, and the middle permanent magnet is neodymium iron boron.

[0056] In some embodiments, the thickness of the two permanent magnets on both sides along the second direction is less than or equal to the thickness of the middle permanent magnet along the second direction.

[0057] In some embodiments, the relationship between the thickness of the three permanent magnets along the second direction and the area of ​​the cross section along the first direction and the magnetic flux density of the magnet group satisfies:

[0058] The magnetomotive force F of the three permanent magnets PM1 ,F PM2 ,F PM3 for:

[0059]

[0060] The reluctance R of the three permanent magnets PM1 R PM2 R PM3for:

[0061]

[0062] Among them, B r1 ,B r2 and B r3 is the remanence of the three permanent magnets, μ r1 , μ r2 and μ r3 is the relative magnetic permeability of the three permanent magnets, μ0 is the magnetic permeability of vacuum, h PM1 ,h PM2 and h PM3 is the thickness of the three permanent magnets along the second direction, such as Figure 2 As shown; S PM1 , S PM2 and S PM3 is the area of ​​the cross section of the three permanent magnets along the first direction;

[0063] like Figure 3 As shown, the magnetic flux Φ of the three permanent magnets is calculated according to Kirchhoff's law g1 , Φ g2 and Φ g3 :

[0064] F PM1 -F PM2 =R PM1 Φ g1 -R PM2 Φ g2

[0065] F PM2 -F PM3 =R PM2 Φ g2 -R PM3 Φ g3

[0066] F PM3 =R PM3 Φ g3 +R g (Φ g1 +Φ g2 +Φ g3 )

[0067] Among them, R g is the air gap reluctance;

[0068] The magnetic induction intensities h1, h2 and h3 of the three permanent magnets are:

[0069]

[0070] Then the fundamental wave component a1 of the magnetic flux density of the magnet group is:

[0071]

[0072] Wherein, T is the electrical period; θ1 is the first electrical angle, θ2 is the second electrical angle, and θ3 is the third electrical angle;

[0073] The magnetic density of a single permanent magnet is Figure 4 As shown, the magnetic density of the magnet group composed of three permanent magnets provided in the embodiment of the present application is as follows Figure 5 shown.

[0074] The harmonic component a of the magnetic flux density of the magnet group n for

[0075]

[0076] Where n≥3, n is an odd number;

[0077] Then the magnetic flux density B of the magnet group is:

[0078]

[0079] Among them, ω0 is the frequency of the fundamental wave.

[0080] In addition, for a magnet group, the mechanical angle corresponding to the first magnet in the clockwise direction is The mechanical angle between the first magnet and the second magnet is The mechanical angles corresponding to the first magnet, the second magnet, and the third magnet are Then the first electrical angle θ1 is:

[0081]

[0082] Where, p is the number of motor pole pairs;

[0083] The second electrical angle θ2 is:

[0084]

[0085] The third electrical angle θ3 is:

[0086]

[0087] Based on the same inventive concept, an embodiment of the present application provides an axial flux motor, including: a stator, and also including: the axial flux motor rotor.

[0088] Based on the same inventive concept, an embodiment of the present application provides a flying car, including: an axial flux motor.

[0089] In addition, although illustrative embodiments are described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., combinations of schemes across various embodiments), adjustments, or variations based on the present disclosure. The elements in the claims are to be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the continuation of this application. In addition, the steps of the disclosed methods may be modified in any way, including by reordering steps or inserting or deleting steps. Therefore, it is intended that the description be viewed merely as an example, with the true scope being represented by the following claims and their full range of equivalents.

[0090] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more aspects thereof) can be used in combination with each other. After reading the above description, other embodiments may be used by a person of ordinary skill in the art, for example. Moreover, in the above detailed description, various features may be combined together to simplify the present disclosure. This should not be interpreted as intending that the disclosed features that are not requested for protection are essential to any claim. Therefore, the following claims are incorporated into the specific implementation as examples or embodiments, wherein each claim itself is a separate embodiment, and it can be expected that these embodiments can be combined with each other in various combinations or permutations. The scope of the present invention should be determined with reference to the attached claims and the full scope of equivalents given by these claims.

Claims

1. An axial flux motor rotor, comprising a ring-shaped magnet fixing portion and a preset number of permanent magnet groups, characterized in that: A preset number of magnet mounting grooves are evenly arranged on the magnet fixing part, and the permanent magnet group is embedded and fixed in the magnet mounting groove, and the magnetic poles of two adjacent permanent magnet groups are in opposite directions; the permanent magnet group includes three permanent magnets arranged in sequence, and the cross-section of the three permanent magnets along the first direction is fan-shaped, wherein the magnetic density of the two permanent magnets on both sides is the same, and the magnetic density of the two permanent magnets on both sides is smaller than the magnetic density of the permanent magnet in the middle.

2. The axial flux motor rotor according to claim 1, characterized in that: The three permanent magnets are made of the same material, and the areas of the cross-sections of the three permanent magnets along the first direction are the same; the thicknesses of the two permanent magnets on both sides along the second direction are the same, and the thicknesses of the permanent magnets on both sides along the second direction are smaller than the thickness of the middle permanent magnet along the second direction.

3. The axial flux motor rotor according to claim 1, characterized in that: The two permanent magnets on both sides are made of the same material, and the magnetic energy product of the two permanent magnets on both sides is smaller than the magnetic energy product of the permanent magnet in the middle.

4. The axial flux motor rotor according to claim 3, characterized in that: The two permanent magnets on both sides are ferrite, and the middle permanent magnet is neodymium iron boron.

5. The axial flux motor rotor according to claim 3 or 4, characterized in that: The thickness of the two permanent magnets on the two sides along the second direction is less than or equal to the thickness of the middle permanent magnet along the second direction.

6. The axial flux motor rotor according to claim 5, characterized in that: The relationship between the thickness of the three permanent magnets along the second direction and the area of ​​the section along the first direction and the magnetic flux density of the magnet group satisfies: The magnetomotive force F of the three permanent magnets PM1 ,F PM2 ,F PM3 for: The reluctance R of the three permanent magnets PM1 R PM2 R PM3 for: Among them, B r1 ,B r2 and B r3 is the remanence of the three permanent magnets, μ r1 , μ r2 and μ r3 is the relative magnetic permeability of the three permanent magnets, μ0 is the magnetic permeability of vacuum, h PM1 ,h PM2 and h PM3 S is the thickness of the three permanent magnets along the second direction; PM1 , S PM2 and S PM3 is the area of ​​the cross section of the three permanent magnets along the first direction; Calculate the magnetic flux Φ of the three permanent magnets according to Kirchhoff's law g1 , Φ g2 and Φ g3 : F PM1 -F PM2 =R PM1 F g1 -R PM2 F g2 F PM2 -F PM3 =R PM2 F g2 -R PM3 F g3 F PM3 =R PM3 F g3 +R g (F g1 +F g2 +F g3 ) Among them, R g is the air gap reluctance; The magnetic induction intensities h1, h2 and h3 of the three permanent magnets are: Then the fundamental wave component a1 of the magnetic flux density of the magnet group is: Wherein, T is the electrical period; θ1 is the first electrical angle, θ2 is the second electrical angle, and θ3 is the third electrical angle; The harmonic component a of the magnetic flux density of the magnet group n for Where n≥3, n is an odd number; Then the magnetic flux density B of the magnet group is: Among them, ω0 is the frequency of the fundamental wave.

7. An axial flux motor, comprising: The stator is characterized in that it also includes: the axial flux motor rotor described in any one of claims 1-6.

8. A flying car, characterized in that: include: The axial flux motor as claimed in claim 7.

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