Outer rotor permanent magnet motor and unmanned aerial vehicle

Abstract

The utility model relates to an outer rotor permanent magnet motor and an unmanned aerial vehicle, belongs to the technical field of aerospace, and solves the problems in the prior art that the N pole and the S pole need to be magnetized respectively during magnetic steel processing, the processing efficiency is low, uniform air gaps are formed by magnetic steel and a stator iron core, and motor harmonic wave reduction is not facilitated. The utility model comprises a first arc surface, a second arc surface, and a first side surface and a second side surface which are connected with the first arc surface and the second arc surface, the first arc surface and the second arc surface are symmetrically arranged; the first side face and the second side face are symmetrically arranged. According to the utility model, the magnetizing error rate can be reduced, the production efficiency is improved, and the motor harmonic is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to aerospace technology field especially relates to a kind of outer rotor permanent magnet motor and unmanned aerial vehicle. BACKGROUND

[0002] Outer rotor permanent magnet motor is widely used in unmanned aerial vehicle scene.In prior art, on the one hand, the two circular arc surfaces of the magnetic steel of outer rotor permanent magnet motor are concentric, the whole magnetic steel is asymmetric, and it is necessary to distinguish magnetization for N pole and S pole during processing, error is easy to occur, and processing efficiency is relatively low.

[0003] On the other hand, the outer circular arc of the magnetic steel is attached to the rotor yoke, and the inner circular arc and the inner stator core form uniform air gap, which is not conducive to reducing motor harmonic and torque ripple. SUMMARY

[0004] In view of the above analysis, the utility model embodiment aims to provide an outer rotor permanent magnet motor and unmanned aerial vehicle to solve the problem that the magnetic steel processing needs to magnetize N pole and S pole respectively, the processing efficiency is low, and the magnetic steel and the stator core form uniform air gap, which is not conducive to reducing motor harmonic.

[0005] The purpose of the utility model is mainly realized through the following technical solutions:

[0006] The first aspect of the utility model provides an outer rotor permanent magnet motor magnetic steel, which comprises a first circular arc surface and a second circular arc surface, and a first side surface and a second side surface connecting the first circular arc surface and the second circular arc surface.

[0007] The first circular arc surface and the second circular arc surface are symmetrically arranged; the first side surface and the second side surface are symmetrically arranged.

[0008] Further, the first circular arc surface and the second circular arc surface are both outer convex surfaces.

[0009] Further, the first side surface and the second side surface are both planes or arc surfaces.

[0010] The second aspect of the utility model provides an outer rotor permanent magnet motor, which comprises the outer rotor permanent magnet motor magnetic steel.

[0011] Further, it further comprises a rotor yoke; the rotor yoke is circular ring; the rotor yoke has an inner wall surface, and the radius of the inner wall surface is the same as the radius of the first circular arc surface.

[0012] Further, the magnetic steel is uniformly distributed in the circumferential direction with the axis of the motor rotating shaft as the center; the inner wall surface is attached to the first circular arc surface or the second circular arc surface.

[0013] Further, a stator core is further included; the stator core includes stator teeth; the stator teeth are uniformly distributed along a circumferential direction.

[0014] Further, the stator teeth are provided with a third arc surface outside, and a center of the third arc surface overlaps with a center of the rotor yoke.

[0015] Further, the third arc surface is an outward convex arc surface, and a radius of curvature of the third arc surface is same as a radius of curvature of the inner wall surface.

[0016] In a third aspect, the utility model provides an unmanned aerial vehicle which comprises the outer rotor permanent magnet motor.

[0017] Compared with the prior art, the utility model can realize at least one of the following beneficial effects:

[0018] (1) Compared with the prior art, the first arc surface and the second arc surface of the magnetic steel of the utility model are symmetrically arranged, the first side surface and the second side surface are symmetrically arranged, and the whole magnetic steel is a symmetric structure. During processing, the same magnetic steel material can be used for N poles and S poles, only one type of magnetic steel is needed, the management and magnetization of the magnetic steel in the prior art are avoided, the magnetization error rate is reduced, the production process is simplified, and the production efficiency is improved.

[0019] (2) In the outer rotor permanent magnet motor of the utility model, the first arc surface of the magnetic steel is arranged in close contact with the inner wall surface of the rotor yoke, the magnetic field distribution can be optimized, and the magnetic resistance can be effectively reduced.

[0020] (3) Compared with the prior art, in the utility model, the center of the third arc surface overlaps with the center of the rotor yoke, the third arc surface outside the stator tooth and the first arc surface or the second arc surface of the magnetic steel near the stator tooth form an uneven air gap. The uneven air gap is beneficial to reducing motor harmonics, tooth slot torque and torque ripple, improving the precision and quietness of the motor during operation. At the same time, the reduction of harmonics can reduce the motor iron loss and magnetic steel eddy current loss, improve the motor efficiency, and reduce the risk of magnetic steel demagnetization.

[0021] In the utility model, the above-mentioned technical solutions can be combined with each other to realize more preferred combination schemes. Other features and advantages of the utility model will be described in the following content, and some advantages can become apparent from the description or can be understood by implementing the utility model. The purpose and other advantages of the utility model can be realized and obtained through the content specially pointed out in the text and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings are only used for the purpose of showing specific embodiments and are not considered as limiting the utility model, and in the whole drawings, the same reference signs represent the same parts.

[0023] Figure 1 This is a schematic diagram of the structure of the magnets in an external rotor permanent magnet motor according to a specific embodiment;

[0024] Figure 2 This is a schematic diagram of an external rotor permanent magnet motor.

[0025] Figure 3 This is a partially enlarged schematic diagram of the magnets, stator teeth, and air gap of an external rotor permanent magnet motor.

[0026] Figure 4 This is a schematic diagram of the rotor yoke.

[0027] Figure label:

[0028] 1-Magnet, 101-First arc surface, 102-Second arc surface, 103-First side surface, 104-Second side surface, 2-Rotor yoke, 201-Inner wall surface, 3-Stator core, 301-Stator yoke, 302-Stator teeth, 3021-Third arc surface, 4-Air gap. Detailed Implementation

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0030] Example 1

[0031] A specific embodiment of this utility model is as follows: Figure 1 As shown, an external rotor permanent magnet motor magnet is disclosed, including a first arc surface 101 and a second arc surface 102, as well as a first side surface 103 and a second side surface 104 connecting the first arc surface 101 and the second arc surface 102.

[0032] The first arc surface 101 and the second arc surface 102 are symmetrically arranged, and the first side surface 103 and the second side surface 104 are symmetrically arranged.

[0033] When the magnet 1 is installed into the motor, the first arc surface 101 or the second arc surface 102 of the magnet 1 needs to be fitted against the inner wall surface 201 of the rotor yoke 2. Preferably, both the first arc surface 101 and the second arc surface 102 are convex surfaces. Specifically, the radius of the first arc surface 101 or the second arc surface 102 is the same as the radius of the inner wall surface 201 of the rotor yoke 2.

[0034] The first side surface 103 and the second side surface 104 can be curved surfaces or planes. In this embodiment, the first side surface 103 and the second side surface 104 are planes.

[0035] When processing magnet 1, since magnet 1 has a symmetrical structure, only one type of magnet 1 is needed when magnetizing the N pole and the S pole, thus avoiding the need to magnetize the N pole and the S pole of magnet 1 separately.

[0036] Compared to existing technologies, in this embodiment, the first arc surface 101 and the second arc surface 102 of the magnet of the external rotor permanent magnet motor are symmetrical, as are the first side surface 103 and the second side surface 104, making the entire magnet 1 a symmetrical structure. During processing, the same magnet 1 material can be used for both the N and S poles, requiring only one type of magnet 1. This avoids the need for differentiated magnetization management in existing technologies, reduces magnetization error rates, simplifies the production process, and improves production efficiency.

[0037] Example 2

[0038] This embodiment discloses an external rotor permanent magnet motor, such as Figure 2 and Figure 3 As shown, it includes the magnets of the external rotor permanent magnet motor of Embodiment 1.

[0039] Furthermore, it also includes a rotor yoke 2. For example... Figure 4 As shown, the rotor yoke 2 is annular. The rotor yoke 2 has an inner wall surface 201, the radius of which is the same as the radius of the first arc surface 101 of the magnet 1.

[0040] Magnet 1 is evenly arranged on the inner wall surface 201 of rotor yoke 2 along the circumferential direction with the axis of motor shaft as the center. In order to optimize the magnetic field distribution and effectively reduce magnetic resistance, the first arc surface 101 of magnet 1 is fitted to the inner wall surface 201 of rotor yoke 2.

[0041] Furthermore, it also includes a stator core 3. The stator core 3 includes a stator yoke 301 and stator teeth 302.

[0042] The stator yoke 301 is ring-shaped and is used to connect the various stator teeth 302.

[0043] The stator teeth 302 are evenly distributed around the stator yoke 301 along the circumferential direction, with the axis of the stator yoke 301 as the center. The stator teeth 302 are used to support the stator windings, which can make the magnetic field generated by the stator windings more concentrated and enhance the strength and utilization of the magnetic field.

[0044] The stator tooth 302 has a T-shaped structure with a third arc surface 3021 on its outer side. Specifically, the center of the third arc surface 3021 is located on the axis of the stator yoke 301. After being installed in the motor, the center of the third arc surface 3021 overlaps with the center of the rotor yoke 201.

[0045] Since the first arc surface 101 or the second arc surface 102 of the magnetic steel 1 is an outward convex surface, the center of the third arc surface 3021 does not overlap with the center of the first arc surface 101 or the second arc surface 102 of the stator tooth 302. In order to reduce the machining cost of the motor, simplify the structure, and make the motor more convenient to assemble, the third arc surface 3021 is provided as an outward convex arc surface, and the curvature radius of the third arc surface 3021 is the same as the curvature radius of the inner wall surface 201.

[0046] The third arc surface 3021 and the first arc surface 101 or the second arc surface 102 of the stator tooth 302 form an uneven air gap 4 with small middle and gradually increasing sides.

[0047] Compared with the prior art, the third arc surface 3021 on the outer side of the stator tooth 302 and the arc surface of the magnetic steel 1 near the stator tooth 302 form an uneven air gap 4. The uneven air gap 4 is beneficial to reduce the motor harmonics, the cogging torque, and the torque ripple, improve the precision and quietness of the motor during operation. At the same time, the reduction of harmonics can reduce the motor iron loss and the eddy current loss of the magnetic steel 1, improve the motor efficiency, and reduce the demagnetization risk of the magnetic steel 1.

[0048] Embodiment 3

[0049] The embodiment discloses an unmanned aerial vehicle, and the unmanned aerial vehicle comprises the outer rotor permanent magnet motor of embodiment 2.

[0050] Compared with the prior art, the unmanned aerial vehicle has the same advantages as the outer rotor permanent magnet motor magnetic steel and the outer rotor permanent magnet motor, and details are not repeated here.

[0051] The above describes only a preferred specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the utility model, and all should be covered in the protection scope of the utility model.

Claims

1. An external rotor permanent magnet electric machine characterized by, The outer rotor permanent magnet motor comprises a magnetic steel, a rotor yoke (2) and a stator core (3). The magnetic steel (1) comprises a first circular arc surface (101), a second circular arc surface (102), a first side surface (103) and a second side surface (104) connecting the first circular arc surface (101) and the second circular arc surface (102); the first circular arc surface (101) is symmetrically arranged with the second circular arc surface (102); the first side surface (103) and the second side surface (104) are symmetrically arranged; the first circular arc surface (101) and the second circular arc surface (102) are both outward convex surfaces. The rotor yoke (2) is in a circular ring shape; the rotor yoke (2) has an inner wall surface (201); the magnetic steel (1) is uniformly arranged along the circumferential direction with the axis of the motor rotor shaft as the center; the inner wall surface (201) is arranged in close contact with the first circular arc surface (101) or the second circular arc surface (102). The stator core (3) comprises a stator tooth (302); the stator tooth (302) is uniformly distributed along the circumferential direction; the stator tooth (302) has a third circular arc surface (3021) on the outer side; the third circular arc surface (3021) is an outward convex circular arc surface, and the third circular arc surface (3021) and the first circular arc surface (101) or the second circular arc surface (102) form an uneven air gap (4) with a small middle part and gradually increasing sides.

2. The external rotor permanent magnet electric machine of claim 1, wherein, The first side surface (103) and the second side surface (104) are both planar or arc surfaces.

3. The external rotor permanent magnet motor of claim 1, wherein, The radius of the inner wall surface (201) is the same as the radius of the first circular arc surface (101).

4. The external rotor permanent magnet motor of claim 1, wherein, The center of the third circular arc surface (3021) overlaps with the center of the rotor yoke (2).

5. An external rotor permanent magnet electric machine according to claim 4, characterized in that, The curvature radius of the third circular arc surface (3021) is the same as the curvature radius of the inner wall surface (201).

6. A drone, characterized in that, The outer rotor permanent magnet motor comprises any one of claims 1-5.

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