CN204145121U - External rotor electric machine - Google Patents

Abstract

The utility model discloses an external rotor motor, comprising: a stator and an annular rotor, the rotor is covered on the stator, the rotor includes a support part and multiple sets of permanent magnet groups, and the multiple sets of permanent magnet groups are respectively fixed on the inner peripheral wall of the support part , multiple sets of permanent magnet groups are arranged sequentially in the circumferential direction of the rotor, and each set of permanent magnet groups includes a plurality of permanent magnets distributed sequentially in the axial direction of the rotor. On the same circumferential surface, the permanent magnet groups in each set The magnetism of multiple permanent magnets is the same, and the magnetism of the permanent magnet groups of two adjacent groups is different, wherein the angle between the center of any two adjacent permanent magnets in each group of permanent magnets and the center of the rotor is Skew angle α, α>0. According to the outer rotor motor of the utility model, the amplitude of the cogging torque can be effectively reduced and the number of cycles of the cogging torque waveform can be changed, thereby reducing the vibration and noise of the outer rotor motor.

Description

Outer rotor motor

technical field

The utility model relates to the driving field, in particular to an outer rotor motor.

Background technique

In the related art, the cogging torque of the external rotor motor is large, so the torque fluctuation caused by the cogging torque increases accordingly, which in turn brings about relatively large vibration and noise.

Utility model content

The utility model aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to provide an external rotor motor, which reduces the amplitude of the cogging torque and changes the number of cycles of the cogging torque waveform.

According to the utility model, the outer rotor motor comprises: a stator; an annular rotor, the rotor is sheathed on the stator, and the rotor includes a supporting part and multiple sets of permanent magnet groups, and the multiple sets of permanent magnet groups are respectively fixed on On the inner peripheral wall of the support part, the plurality of sets of permanent magnet groups are arranged sequentially in the circumferential direction of the rotor, and each set of permanent magnet groups includes a plurality of permanent magnet groups distributed sequentially in the axial direction of the rotor. Permanent magnets, on the same circumferential surface, the magnetic properties of the plurality of permanent magnets in each permanent magnet group are the same, and the magnetic properties of the permanent magnet groups in two adjacent groups are different, wherein each permanent magnet group The included angle between the centers of any two adjacent permanent magnets and the center of the rotor is a deflection angle α, α>0.

According to the outer rotor motor of the present utility model, a plurality of sets of permanent magnet groups distributed at intervals in the circumferential direction are provided, and each set of permanent magnet groups includes a plurality of permanent magnets distributed sequentially in the axial direction, and any permanent magnet group in each set The phases of the magnetic poles of two adjacent permanent magnets are staggered along the circumferential direction of the rotor with a deflection angle α, which can effectively reduce the cogging torque amplitude and change the number of cycles of the cogging torque waveform, reducing the external rotor Motor vibration and noise.

In addition, according to the utility model, the above-mentioned outer rotor motor can also have the following additional technical features:

Preferably, the value range of the deflection angle α is: 2°≤α≤15°.

According to some embodiments of the present invention, each permanent magnet group includes two permanent magnets, the axial lengths of the two permanent magnets in each permanent magnet group are the same, and the two permanent magnets in different groups The deflection angles between the two permanent magnets are equal.

According to other embodiments of the present invention, each set of permanent magnet groups includes N permanent magnets, where N is an even number and said N is greater than 2, and any two adjacent permanent magnet groups of each set The axial lengths of the permanent magnets are different, and all the deflection angles α in the plurality of permanent magnet groups are equal.

According to some further embodiments of the present invention, each set of permanent magnet groups includes N permanent magnets, where N is an odd number and said N is greater than 2, and each set of N permanent magnet groups The axial lengths of the magnets are the same, any two adjacent permanent magnets in each set of permanent magnet groups form a pair, and the skew between the pairs of permanent magnets in the multiple sets of permanent magnet groups The angle α is not the same.

In some embodiments of the present invention, each set of permanent magnets includes N permanent magnets, where N<7.

According to some specific embodiments of the present utility model, the support portion is formed in a substantially "U" shape.

Optionally, each of the permanent magnets is pasted on the inner peripheral wall of the support part by an adhesive.

In some embodiments of the present invention, the stator is formed by stacking a plurality of stator punching pieces sequentially along the axial direction of the rotor.

Description of drawings

Fig. 1 is a schematic diagram of an outer rotor motor according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of an outer rotor motor according to another embodiment of the present invention;

Fig. 3 is a schematic diagram of an outer rotor motor according to yet another embodiment of the present invention;

Fig. 4 is a side view of an outer rotor motor according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of comparing the torque characteristics of the outer rotor motor shown in Fig. 1 and the related art outer rotor motor, where T1 is the cogging torque waveform of the related art outer rotor motor, and T2 is the outer rotor shown in Fig. 1 Motor cogging torque waveform;

Fig. 6 is a schematic diagram comparing the torque characteristics of the outer rotor motor shown in Fig. 2 and the related art outer rotor motor, where T1 is the cogging torque waveform of the related art outer rotor motor, and T2 is the outer rotor shown in Fig. 2 Motor cogging torque waveform;

Fig. 7 is a schematic diagram of comparing the torque characteristics of the outer rotor motor shown in Fig. 3 and the related art outer rotor motor, where T1 is the cogging torque waveform of the related art outer rotor motor, and T2 is the outer rotor shown in Fig. 3 Motor cogging torque waveform.

Reference signs:

Outer rotor motor 100,

Stator 1, tooth slot 10,

The rotor 2, the supporting part 20, the permanent magnet group 21, the permanent magnet 210,

The first connection 3 and the second connection 4 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" The orientation or positional relationship indicated by , "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying the referred device Or elements must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present utility model, "plurality" means two or more, unless otherwise specifically defined.

In this utility model, unless otherwise specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection, or integration; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

The outer rotor motor 100 according to the embodiment of the present utility model will be described in detail below with reference to FIGS. 1-7 .

As shown in FIGS. 1-4 , an outer rotor motor 100 according to an embodiment of the present invention includes: a stator 1 and an annular rotor 2 , wherein the stator 1 is provided with a plurality of slots 10 for winding coil windings. The cogging torque is a torque generated in the circumferential direction by the interaction between the magnetic field of the permanent magnet 210 of the rotor 2 and the cogging 10 of the stator 1 .

The rotor 2 is sheathed on the stator 1, and the rotor 2 includes a supporting part 20 and multiple sets of permanent magnet groups 21. It should be noted that the material of the supporting part 20 is a magnetically permeable material, and the purpose of using the magnetically permeable material for the supporting part 20 is to provide The magnetic field provides the loop. Specifically, the supporting part 20 may be a monolithic type, a laminated type, or the like. In the examples of FIGS. 1-3 of the present invention, the support portion 20 is formed in a substantially "U" shape.

Multiple groups of permanent magnet groups 21 are respectively fixed on the inner peripheral wall of the support portion 20. In other words, multiple groups of permanent magnet groups 21 are located on the outer peripheral wall of the stator 1, between the center of the outer rotor motor 100 and the outer peripheral wall of the outer rotor motor 100. Direction, the rotor 2, the permanent magnet group 21 and the supporting part 20 are arranged in sequence.

Multiple groups of permanent magnet groups 21 are arranged sequentially in the circumferential direction of the rotor 2, and each group of permanent magnet groups 21 includes a plurality of permanent magnets 210 distributed sequentially in the axial direction of the rotor 2, that is to say, each group of permanent magnet groups 21 is divided into multiple sections in the axial direction of the rotor 2 , it can be understood that the number of permanent magnets 210 in different sets of permanent magnet sets 21 should be the same. In a specific example of the present invention, in order to reduce the processing difficulty of the rotor 2 , each set of permanent magnet groups 21 includes N permanent magnets 210 , where N<7.

On the same circumferential surface, the magnetism of a plurality of permanent magnets 210 in each group of permanent magnet groups 21 is the same, and the magnetic properties of the permanent magnet groups 21 of two adjacent groups are different, wherein any adjacent two permanent magnet groups in each group of permanent magnet groups 21 The included angle between the center of the permanent magnet 210 and the center of the rotor 2 is the deflection angle α, α>0, that is to say, any two adjacent permanent magnets 210 in each set of permanent magnet groups 21 There is a deflection angle α between the line connecting the center of one of the permanent magnets 210 to the center of the rotor 2 and the line connecting the center of the other permanent magnet 210 to the center of the rotor 2 . In other words, the phases of the magnetic poles of two axially adjacent permanent magnets 210 of the same level in each set of permanent magnet groups 21 are distributed on the inner peripheral wall of the support portion 20 along the circumferential direction of the rotor 2 with an offset angle α.

Any adjacent two permanent magnets 210 in each group of permanent magnet groups 21 form a pair, so each group of permanent magnet groups 21 includes at least one pair of permanent magnets 210, and the center of one of the permanent magnets 210 in each pair of permanent magnets 210 is aligned with The connecting line of the center of the rotor 2 is the first connecting line 3, the connecting line between the center of the other permanent magnet 210 and the center of the rotor 2 is the second connecting line 4, and there is a connection between the first connecting line 3 and the second connecting line 4. The included angle is a deflection angle α, in other words, there is a deflection angle α between each pair of permanent magnets 210 .

It can be understood that the deflection angles α of the multiple pairs of permanent magnets 210 in the multiple sets of permanent magnet groups 21 can be the same or different. The magnitude of the deflection angle α of each pair of permanent magnets 210 affects the reduction magnitude of the cogging torque and the number of cycles of the cogging torque waveform. In a preferred example of the present utility model, the value range of the skew angle α is: 2°≤α≤15°, so as to ensure that the maximum value of the cogging torque can be reduced to the minimum and make the waveform of the cogging torque The number of cycles is optimal.

According to the outer rotor motor 100 of the embodiment of the present utility model, a plurality of sets of permanent magnet groups 21 distributed at intervals in the circumferential direction are provided, and each set of permanent magnet groups 21 includes a plurality of permanent magnets 210 distributed sequentially in the axial direction, and each set The phases of the magnetic poles of any two adjacent permanent magnets 210 in the permanent magnet group 21 are staggered along the circumferential direction of the rotor 2 with a deflection angle α, so that the amplitude of the cogging torque can be effectively reduced and the cogging torque can be changed. The number of cycles of the waveform can reduce the vibration and noise of the outer rotor motor 100 .

In some specific examples of the present utility model, when each set of permanent magnet groups 21 includes two permanent magnets 210 and the deflection angle α of the two permanent magnets 210 is 10°, the cogging of the outer rotor motor 100 of the present utility model The maximum value of the torque is reduced by 63% compared with the maximum value of the cogging torque of the external rotor motor of the related art, and the number of cycles of the cogging torque waveform is increased.

The rotor 2 according to three specific embodiments of the present invention will be described in detail below with reference to FIGS. 1-7 .

Example 1:

In this embodiment, as shown in Figure 1, each group of permanent magnet groups 21 includes two permanent magnets 210, and the axial lengths of the two permanent magnets 210 of each group of permanent magnet groups 21 are the same, and the two permanent magnets of different groups The skew angle between 210 is equal. In other words, each group of permanent magnet groups 21 has two segments along the axial direction of the rotor 2, and the two permanent magnets 210 in each group of permanent magnet groups 21 are deflected along the equiaxial length of the circumferential direction, and many pairs of permanent magnets The deflection angles α of the magnets 210 are equal.

As shown in Figure 5, compared with the outer rotor motor 100 in the related art, the cogging torque of the outer rotor motor 100 adopting the rotor 2 of this embodiment is significantly larger. decreases and the number of cycles of the cogging torque waveform increases.

Example 2:

As shown in Figure 2, in this embodiment, each group of permanent magnet groups 21 includes three permanent magnets 210, and the axial lengths of the three permanent magnets 210 of each group of permanent magnet groups 21 are the same, and in each group of permanent magnet groups 21 Any two adjacent permanent magnet groups 21 form a pair, that is, each group of permanent magnet groups 21 includes two pairs of permanent magnets 210, and the deflection angle α between the two pairs of permanent magnets 210 in each group of permanent magnet groups 21 is not the same , and the deflection angle α between any two pairs of permanent magnets 210 in different sets of permanent magnet groups 21 is not the same, in short, the deflection angle between multiple pairs of permanent magnets 210 in multiple groups of permanent magnet groups 21 α is not the same.

In other words, each group of permanent magnet groups 21 is divided into three segments along the axial direction of the rotor 2, and any two adjacent permanent magnets 210 in each group of permanent magnet groups 21 are deflected equiaxially along the circumferential direction, And the deflection angles α of any two pairs of permanent magnets 210 are different.

As shown in Figure 6, compared with the outer rotor motor 100 in the related art, the cogging torque of the outer rotor motor 100 adopting the rotor 2 of this embodiment is significantly larger. decreases and the number of cycles of the cogging torque waveform does not change.

It can be understood that, in this embodiment, the number of permanent magnets 210 in each permanent magnet group 21 is Can not be limited to three, for example also can be odd numbers such as 5, 7, in other words, each group of permanent magnet groups 21 includes N permanent magnets 210, N is an odd number and N is greater than 2, the N of each group of permanent magnet groups 21 The axial lengths of the permanent magnets 210 are the same, any two adjacent permanent magnets 210 in each group of permanent magnet groups 21 form a pair, and the deflection angle α between the pairs of permanent magnets 210 in multiple groups of permanent magnet groups 21 Are not the same.

Example 3:

As shown in Figure 3, in this embodiment, each group of permanent magnet groups 21 includes four permanent magnets 210, and any adjacent two permanent magnet groups 21 in each group of permanent magnet groups 21 form a pair, that is, each permanent magnet group 21 The magnet group 21 includes three pairs of permanent magnets 210, the axial lengths of any two adjacent permanent magnets 210 in each group of permanent magnet groups 21 are different, and all the deflection angles α in the multiple groups of permanent magnet groups 21 are equal, All the deflection angles α being equal means that the deflection angles α of any two pairs of permanent magnets 210 in the plurality of sets of permanent magnet groups 21 are equal.

In other words, each group of permanent magnet groups 21 has four segments in the axial direction of the rotor 2, and any two adjacent permanent magnets 210 in each group of permanent magnet groups 21 are skewed unevenly along the axial length of the circumferential direction. , and the deflection angles α of two pairs of axially adjacent permanent magnets 210 of the same level are the same, and the deflection angles α of any two pairs of permanent magnets 210 are the same.

As shown in Figure 7, compared with the outer rotor motor 100 in the related art, the cogging torque of the outer rotor motor 100 adopting the rotor 2 of this embodiment is significantly larger. decreases and the number of cycles of the cogging torque waveform decreases.

It can be understood that, in this embodiment, on the premise that the magnitude of the cogging torque is greatly reduced and the number of periods of the cogging torque waveform is reduced, the number of permanent magnets 210 in each permanent magnet group 21 may be different. limited to three, such as 6, 8 and other even numbers, in other words, each group of permanent magnet groups 21 includes N permanent magnets 210, N is an even number and N is greater than 2, any adjacent permanent magnet groups 21 of each group The axial lengths of the two permanent magnets 210 are different, and all the deflection angles α in the multiple sets of permanent magnet groups 21 are equal.

In a specific embodiment of the present utility model, each permanent magnet 210 is pasted on the inner peripheral wall of the supporting part 20 by an adhesive, and in order to ensure sufficient bonding strength, an adhesive layer of a certain thickness must be provided. Therefore, it is ensured that the permanent magnet 210 will not be shifted or dropped due to the high-speed rotation of the rotor 2 , and the reliability of the outer rotor motor 100 is improved. In a specific example of the present invention, high-strength glue can be used to glue the permanent magnet 210, and the glue strength requirement is determined according to the shape and size of the rotor 2 and the materials used. It can be understood that each permanent magnet 210 can also be fixed on the inner peripheral wall of the supporting part 20 by other fixing methods, such as using a retaining spring.

According to a specific embodiment of the present invention, the stator 1 is composed of a plurality of stator punches stacked in sequence along the axial direction of the rotor 2, that is to say, the stator 1 is composed of the same stator punches, and the stator punches are stacked along the axial direction. sheet to the desired height. Specifically, each stator punch can be a silicon steel sheet. In a specific example of the present invention, each stator punch is a silicon steel sheet with a thickness of 0.35mm or 0.5mm or other thinner ones, which reduces the iron loss of the motor.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first feature and the second feature through an intermediary indirect contact. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structures, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and should not be construed as limitations of the present invention, and those skilled in the art are within the scope of the present invention. Variations, modifications, substitutions and variations can be made to the above-described embodiments.

Claims (9)

1. An external rotor motor, characterized in that, comprising: stator; An annular rotor, the rotor is sheathed on the stator, the rotor includes a support part and multiple sets of permanent magnet groups, the multiple sets of permanent magnet groups are respectively fixed on the inner peripheral wall of the support part, the multiple sets The permanent magnet groups are arranged sequentially in the circumferential direction of the rotor, and each group of permanent magnet groups includes a plurality of permanent magnets distributed sequentially in the axial direction of the rotor. On the same circumferential surface, each group of permanent magnets The magnetic properties of the plurality of permanent magnets in the permanent magnet group are the same, and the magnetic properties of the permanent magnet groups in two adjacent groups are different, wherein the center of any adjacent two permanent magnets in each group of permanent magnet groups is connected to all the permanent magnet groups. The included angle between the lines connecting the centers of the rotors is a deflection angle α, α>0. 2. The external rotor motor according to claim 1, characterized in that, the value range of the deflection angle α is: 2°≤α≤15°. 3. The outer rotor motor according to claim 1, wherein each set of permanent magnet groups includes two permanent magnets, and the axial length of the two permanent magnets of each set of permanent magnet groups is Likewise, the skew angles between the two permanent magnets of different groups are equal. 4. The external rotor motor according to claim 1, characterized in that, each set of permanent magnet groups includes N permanent magnets, wherein N is an even number and said N is greater than 2, and each set of permanent magnets The axial lengths of any two adjacent permanent magnets in the group are different, and all the deflection angles α in the plurality of permanent magnet groups are equal. 5. The external rotor motor according to claim 1, characterized in that, each set of permanent magnet groups includes N permanent magnets, and said N is an odd number and said N is greater than 2, and each set of said permanent magnets The axial lengths of the N permanent magnets in the group are the same, any two adjacent permanent magnets in each group of permanent magnets form a pair, and multiple pairs of the permanent magnets in the plurality of permanent magnet groups The deflection angle α is different between the permanent magnets. 6. The external rotor motor according to any one of claims 1-2, 4-5, characterized in that each permanent magnet group includes N permanent magnets, where N<7. 7. The outer rotor electric machine according to claim 1, wherein the support portion is formed in a substantially "U" shape. 8 . The external rotor motor according to claim 1 , wherein each of the permanent magnets is pasted on the inner peripheral wall of the supporting part by an adhesive. 9 . The external rotor motor according to claim 1 , wherein the stator is formed by sequentially stacking a plurality of stator punches along the axial direction of the rotor. 10 .