Axial flux motor
By designing a non-uniform air gap between the rotor and stator in an axial flux motor, the problem of harmonics affecting performance was solved, resulting in improved efficiency and performance.
Patent Information
- Application Number
- CN202423321852.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing axial flux motors suffer from harmonic distortion affecting performance and require improvement.
The air gap between the rotor and stator is designed as an uneven structure that gradually widens from the center to both sides of the circumference. By adjusting the surface shape of the iron core block and the magnet, an uneven air gap is formed, which improves the back electromotive force waveform and reduces the harmonic content.
It improves the efficiency of the axial flux motor, reduces cogging torque and torque ripple, and improves overall performance.
Smart Images
Figure CN223729516U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electric machines, in particular to an axial flux electric machine. BACKGROUND
[0002] Electric machines can be divided into radial flux electric machines and axial flux electric machines. Axial flux electric machines are widely concerned due to their compact structure, large torque density and short axial length, and are particularly suitable for occasions where the axial size is limited. However, there are still many problems in the current axial flux electric machines that need to be improved, for example, the current axial flux electric machines have many harmonics which affect the performance and there is still room for improvement. CONTENT OF THE UTILITY MODEL
[0003] The present application aims to at least partly solve one of the problems in the related art. To this end, the present application provides an axial flux electric machine.
[0004] To achieve the above-mentioned purpose, the present application discloses an axial flux electric machine, which comprises:
[0005] a rotor comprising a plurality of magnets arranged in a ring shape and alternately arranged; and
[0006] a stator arranged in the axial direction of the rotor, the stator comprising a stator core, the stator core comprising a plurality of core blocks arranged in a ring shape and alternately arranged, an air gap being formed between the core blocks and the magnets, the air gap gradually widening from the center to the two sides in the circumferential direction.
[0007] In some embodiments of the present application, a first virtual plane is defined to pass through the central axis of the axial flux electric machine and bisect the core blocks and the magnets, and the air gap is symmetrical about the first virtual plane.
[0008] In some embodiments of the present application, along the axial direction of the axial flux electric machine, the minimum width of the air gap is L1, and the maximum width of the air gap is L2, and L2>2*L1 is satisfied.
[0009] In some embodiments of the present application, the surface of the core block facing the magnet is convexly arranged towards the magnet.
[0010] In some embodiments of the present application, the surface of the core block facing the magnet is convexly arranged towards the magnet in an arc shape.
[0011] In some embodiments of the present application, the surface of the magnet facing the core block is a plane.
[0012] In some embodiments of the present application, the surface of the magnet facing the core block is convexly arranged towards the core block.
[0013] In some embodiments of the present application, the surface of the magnet facing the core block is arc-shaped.
[0014] In some embodiments of the present application, the surface of the core block facing the magnet is planar.
[0015] In some embodiments of the present application, the core block is molded from a soft magnetic composite material.
[0016] In some embodiments of the present application, the stator is provided with the rotor on each of the axial sides, and the stator and the rotor on one side form the air gap, and the stator and the rotor on the other side form the air gap.
[0017] The technical solution of the present application designs the air gap between the core block and the magnet to gradually widen from the center to the two sides in the circumferential direction, thereby forming a non-uniform air gap, which is conducive to improving the back electromotive force waveform of the axial flux motor, reducing the harmonic content, improving the efficiency of the axial flux motor, reducing the cogging torque and torque ripple, and thereby improving the performance.
[0018] Other advantages of the present application will be partially given in the following description, partially will become apparent from the following description, or will be understood by practicing the present application. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.
[0020] Figure 1 Axial flux motor schematic diagram in some embodiments;
[0021] Figure 2 Axial flux motor exploded view in some embodiments;
[0022] Figure 3 Stator core schematic diagram in some embodiments;
[0023] Figure 4 Rotor schematic diagram in some embodiments;
[0024] Figure 5 Core block schematic diagram in some embodiments;
[0025] Figure 6 Axial flux motor partial structure schematic diagram (showing L1, L2) in some embodiments;
[0026] Figure 7 Fig. 1 is a schematic diagram of partial structure of an axial flux motor in some embodiments (showing a first virtual plane);
[0027] Figure 8 Fig. 2 is a schematic diagram of partial structure of an axial flux motor in some embodiments, in some other embodiments;
[0028] Figure 9 Fig. 3 is a waveform diagram of back electromotive force of an axial flux motor (uniform air gap, horizontal axis: time, vertical axis: back electromotive force);
[0029] Figure 10 Fig. 4 is a waveform diagram of back electromotive force of an axial flux motor (non-uniform air gap, horizontal axis: time, vertical axis: back electromotive force).
[0030] Brief Description of the Drawings:
[0031] Fig. 1 is a schematic diagram of partial structure of an axial flux motor in some embodiments (showing a first virtual plane);
[0032] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.
[0035] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0036] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features indicated or implicitly indicating the number of technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the present application.
[0037] The first aspect of the present application discloses an axial flux motor 3000, which combines Figures 1 to 6 As shown in the figure, in some embodiments, the axial flux motor 3000 includes a rotor 2000 and a stator 1000, the stator 1000 is arranged in the axial direction of the rotor 2000, the rotor 2000 includes a plurality of magnets 2100, the plurality of magnets 2100 are arranged in a ring shape, the stator 1000 includes a stator core 1100, the stator core 1100 includes a plurality of core blocks 1110, the plurality of core blocks 1110 are arranged in a ring shape, wherein the core blocks 1110 and the magnets 2100 form an air gap 3100, the air gap 3100 gradually widens from the center to the two sides of the circumference.
[0038] By designing the air gap 3100 to gradually widen from the center to the two sides of the circumference, the air gap 3100 becomes non-uniform, which is beneficial to improve the back electromotive force waveform of the axial flux motor 3000, thereby reducing the harmonic content, improving the efficiency and performance of the axial flux motor 3000.
[0039] Specifically, the rotor 2000 and the stator 1000 are arranged in sequence along the axial direction, the rotor 2000 is located in the axial direction of the stator 1000, the stator 1000 is located in the axial direction of the rotor 2000, and the rotor 2000 and the stator 1000 are coaxially arranged. The so-called rotor 2000 is the part of the axial flux motor 3000 that can rotate during work, and the so-called stator 1000 is the part of the axial flux motor 3000 that is fixed during work.
[0040] The rotor 2000 comprises a magnet 2100, and generally comprises a support disc 2200, the magnet 2100 is fixed on the support disc 2200, the magnet 2100 is fixed on the support disc 2200 in various ways, such as by bonding, integral molding or other ways, the magnet 2100 is made of various materials, such as a rare earth permanent magnet material, a ferrite permanent magnet material or other composite materials, in the embodiment, the number of magnets 2100 is multiple, multiple means two or more, the multiple magnets 2100 are arranged in a ring shape, the number of magnets 2100 on a single rotor 2000 in the drawing is 18.
[0041] The stator 1000 comprises a stator core 1100, the stator core 1100 comprises a core block 1110, the number of core blocks 1110 is multiple, multiple means two or more, the number of core blocks 1110 in the stator 1000 in the drawing is 18, the multiple core blocks 1110 are arranged in a ring shape, and each core block 1110 is wound with a corresponding enameled wire (not shown in the drawing). The core block 1110 comprises a tooth portion 1111 and a shoe portion 1112, the axial two sides of the tooth portion 1111 are respectively provided with the shoe portion 1112 (here, the axial direction is the axial direction of the axial flux motor 3000, and the radial direction is perpendicular to the axial direction), the shoe portion 1112 is larger than the tooth portion 1111, and the enameled wire is wound on the tooth portion 1111 and is blocked by the shoe portions 1112 on the axial two sides.
[0042] The core block 1110 and the magnet 2100 form an air gap 3100, which ensures that the rotation of the rotor 2000 does not interfere with the stator 1000, in the embodiment, the air gap 3100 is gradually widened from the center to the circumferential two sides. It can be understood that the circumferential direction here refers to the circumferential direction of the stator 1000, that is, the circumferential direction of the axial flux motor 3000, which surrounds the central axis (axial direction) of the axial flux motor 3000. By such arrangement, the center of the air gap 3100 is relatively narrow, and the circumferential two sides of the air gap 3100 are relatively wide, the air gap 3100 forms a non-uniform structural feature, which is beneficial to improve the back electromotive force waveform of the axial flux motor 3000, reduce the harmonic content, improve the efficiency of the axial flux motor 3000, reduce the cogging torque and torque ripple, and thus improve the performance.
[0043] In the embodiment, since the stator core 1100 is arranged by a plurality of core blocks 1110, each core block 1110 can form an uneven air gap 3100 with the corresponding magnet 2100, which is beneficial to reduce the harmonic content of the axial flux motor 3000. Since the stator core 1100 includes a plurality of core blocks 1110 arranged at intervals, and the number of magnets 2100 is also a plurality, each core block 1110 or each magnet 2100 can be processed to form a corresponding uneven air gap 3100, thereby reducing the processing difficulty.
[0044] The core block 1110 and the magnet 2100 can be matched to form an uneven air gap 3100 in the following manner, for example, in combination with Figure 6 and Figure 7 In some embodiments, the surface of the core block 1110 facing the magnet 2100 is convex towards the magnet 2100. Since the air gap 3100 gradually widens from the center to the two sides in the circumferential direction, the middle position of the surface of the core block 1110 facing the magnet 2100 needs to be more convex than the peripheral position of the surface of the core block 1110 facing the magnet 2100, so that the air gap 3100 forms a structure feature that the center is relatively narrow and the two sides in the circumferential direction are relatively wide. Moreover, the surface of the core block 1110 facing the magnet 2100 being convex towards the magnet 2100 is beneficial to increase the heat dissipation area, thereby facilitating heat dissipation of the stator core 1100.
[0045] In combination with Figure 6 and Figure 7 In some embodiments, the surface of the core block 1110 facing the magnet 2100 is arc-shaped convex towards the magnet 2100. By such a setting, it is beneficial to correct the back EMF waveform of the axial flux motor 3000, so that the waveform is smoother and the mutation is inhibited, further reducing the harmonic energy.
[0046] In combination with Figure 6 and Figure 7 In some embodiments, the surface of the magnet 2100 facing the core block 1110 is a plane. When the surface of the core block 1110 facing the magnet 2100 is convex towards the magnet 2100 so that the air gap 3100 forms a structure feature that the center is relatively narrow and the two sides in the circumferential direction are relatively wide, the surface of the magnet 2100 facing the core block 1110 is a plane, which is beneficial to reduce the difficulty of structural design. In the related art, the air gap 3100 is uniform and is composed of two parallel planes, while in the embodiment, the air gap 3100 is uneven. Under the premise of achieving the same effect, only one factor (the surface of the core block 1110 facing the magnet 2100 is convex towards the magnet 2100) is changed, which is beneficial to reduce the design difficulty.
[0047] The iron core block 1110 and the magnet 2100 can also be matched to form the uneven air gap 3100 in the following manner, in combination with Figure 8 As shown in the drawings, in some embodiments, the surface of the magnet 2100 facing the iron core block 1110 is convexly arranged towards the iron core block 1110. Since the air gap 3100 gradually widens from the center to the two sides in the circumferential direction, the middle position of the surface of the magnet 2100 facing the iron core block 1110 needs to be more convexly arranged relative to the peripheral position of the surface of the magnet 2100 facing the iron core block 1110, so as to make the air gap 3100 form a structure feature of a relatively narrow center and relatively wide circumferential two sides.
[0048] In combination with Figure 8 As shown in the drawings, in some embodiments, the surface of the magnet 2100 facing the iron core block 1110 is arranged in an arc shape towards the iron core block 1110. By arranging in this way, it is beneficial to correct the back EMF waveform of the axial flux motor 3000, so that the waveform is smoother and the mutation is inhibited, further reducing harmonic energy.
[0049] In combination with Figure 8 As shown in the drawings, in some embodiments, the surface of the iron core block 1110 facing the magnet 2100 is a plane. When the surface of the magnet 2100 facing the iron core block 1110 is convexly arranged towards the iron core block 1110 to make the air gap 3100 form a structure feature of a relatively narrow center and relatively wide circumferential two sides, the surface of the iron core block 1110 facing the magnet 2100 is a plane, which is beneficial to reduce the difficulty of structural design. In the related art, the air gap 3100 is uniform and is composed of two parallel planes. In this embodiment, the air gap 3100 is uneven. Under the premise of achieving the same effect, only one factor (the surface of the magnet 2100 facing the iron core block 1110 is convexly arranged towards the iron core block 1110) is changed, which is beneficial to reduce the design difficulty.
[0050] Of course, in some embodiments, the surface of the iron core block 1110 facing the magnet 2100 can also be convexly arranged towards the magnet 2100, and the surface of the magnet 2100 facing the iron core block 1110 is convexly arranged towards the iron core block 1110. By arranging in this way, the air gap 3100 can also form a structure feature of a relatively narrow center and relatively wide circumferential two sides, but this scheme is more complex than improving only the iron core block 1110 or changing only the magnet 2100.
[0051] In combination with Figure 6As shown, in some embodiments, the minimum width of the air gap 3100 is L1 along the axial direction of the axial flux motor 3000, and the maximum width of the air gap 3100 is L2, and L2>2*L1 is satisfied. Since the air gap 3100 gradually widens from the center to the circumferential sides, the minimum width L1 of the air gap 3100 is located at the middle position of the air gap 3100, and the maximum width L2 of the air gap 3100 is located at the circumferential side position. By optimizing the size of the air gap 3100, the back EMF waveform is closer to a sine wave, and the harmonic energy is further reduced.
[0052] In combination Figure 7 As shown, in some embodiments, a first virtual plane 3200 is defined to pass through the central axis of the axial flux motor 3000 and to bisect the core block 1110 and the magnet 2100, and the air gap 3100 is symmetrically arranged about the first virtual plane 3200.
[0053] Specifically, the first virtual plane 3200 passes through the central axis of the axial flux motor 3000 and extends along the radial direction of the axial flux motor 3000, and the first virtual plane 3200 passes through the corresponding core block 1110 and magnet 2100, and the first virtual plane 3200 bisects the corresponding core block 1110 and magnet 2100 into two halves. At this time, the first virtual plane 3200 also bisects the corresponding air gap 3100 into two halves, and the air gap 3100 is symmetrically arranged about the first virtual plane 3200. By such an arrangement, the harmonic is further reduced, the back EMF waveform is further corrected, the cogging torque and torque ripple are reduced, and the motor efficiency is further improved.
[0054] For example, the surface of the core block 1110 facing the magnet 2100 is arranged to be arc-shaped and convex toward the magnet 2100, and the surface of the magnet 2100 facing the core block 1110 is planar. At this time, the air gap 3100 is symmetrically arranged about the first virtual plane 3200, and the position of the first virtual plane 3200 passing through the air gap 3100 corresponds to the minimum width L1 of the air gap 3100, and the circumferential sides of the air gap 3100 correspond to the maximum width L2 of the air gap 3100. By capturing the back EMF waveform with an oscilloscope, the waveform is closer to a sine wave (corresponding to Figure 10 The motor speed is 1200 rpm, and the effective value of the back EMF is 50. In the comparative example, the surface of the core block 1110 facing the magnet 2100 and the surface of the magnet 2100 facing the core block 1110 are both planar. The results are shown in Figure 9 The motor speed is 1200 rpm, and the effective value of the back EMF is 55.
[0055] In some embodiments, the core block 1110 is molded by a soft magnetic composite material, also known as soft magnetic composite material, which is a composite material with soft magnetic function composed of soft magnetic ferrite and polymer matrix. Through molding processing, relatively complex structure shape processing can be completed.
[0056] In combination Figures 1 to 8 As shown in the drawings, in some embodiments, the axial two sides of the stator 1000 are respectively provided with the rotors 2000, the stator 1000 and one side of the rotors 2000 form the air gap 3100, and the stator 1000 and the other side of the rotors 2000 form the air gap 3100. In this embodiment, the axial flux motor 3000 is in the form of double-rotor single-stator, the stator 1000 and one side of the rotors 2000 can form a non-uniform air gap 3100, and the other side of the rotors 2000 can also form a non-uniform air gap 3100. By forming a non-uniform air gap 3100 on the axial two sides of the stator 1000, the harmonic content is greatly reduced, and the performance of the axial flux motor 3000 in the form of double-rotor single-stator is improved.
[0057] The above description is only the preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.
Claims
1. An axial flux electric machine (3000) characterized by, The axial flux motor (3000) comprises: a rotor (2000) comprising a plurality of magnets (2100) arranged in a ring shape; a stator (1000) arranged axially to the rotor (2000), the stator (1000) comprising a stator core (1100) comprising a plurality of core blocks (1110) arranged in a ring shape, an air gap (3100) being formed between the core blocks (1110) and the magnets (2100), the air gap (3100) gradually widening from the center to the two sides in the circumferential direction.
2. The axial flux motor (3000) of claim 1, wherein, A first virtual plane (3200) is defined to pass through the central axis of the axial flux motor (3000) and bisect the core blocks (1110) and the magnets (2100), the air gap (3100) being symmetrical about the first virtual plane (3200); And / or, along the axial direction of the axial flux motor (3000), the minimum width of the air gap (3100) is L1, and the maximum width of the air gap (3100) is L2, satisfying L2>2*L1.
3. The axial flux motor (3000) of claim 1, wherein, The surface of the core block (1110) facing the magnet (2100) is convex towards the magnet (2100).
4. The axial flux motor (3000) of claim 3, wherein, The surface of the core block (1110) facing the magnet (2100) is convexly arranged in an arc shape towards the magnet (2100).
5. The axial flux motor (3000) of claim 3, wherein, The surface of the magnet (2100) facing the core block (1110) is a plane.
6. The axial flux motor (3000) of claim 1, wherein, The surface of the magnet (2100) facing the core block (1110) is convex towards the core block (1110).
7. The axial flux motor (3000) of claim 6, wherein, The surface of the magnet (2100) facing the core block (1110) is convexly arranged in an arc shape towards the core block (1110).
8. The axial flux motor (3000) of claim 6, wherein, The surface of the core block (1110) facing the magnet (2100) is a plane.
9. The axial flux motor (3000) of any one of claims 1 to 8, characterized in that, The core block (1110) is molded from a soft magnetic composite material.
10. The axial flux motor (3000) of any one of claims 1 to 8, characterized in that, The axial direction of the stator (1000) is provided with the rotor (2000) on both sides, the air gap (3100) is formed between the stator (1000) and the rotor (2000) on one side, and the air gap (3100) is formed between the stator (1000) and the rotor (2000) on the other side.