Rotor, stator, motor and household appliance

Abstract

The invention provides a rotor, a stator, a motor and a household electrical appliance, the rotor is used for the motor, the motor comprises the stator, the stator is provided with an inner circumferential wall surrounding the rotor, the rotor is arranged in the stator, the rotor can rotate around a rotation axis, and the rotor comprises a first iron core unit and a second iron core unit; the first iron core unit can define a first air gap together with the inner peripheral wall, and the first air gap has a first magnetic flux density curve; the second iron core unit can define a second air gap together with the inner peripheral wall, and the second air gap has a second magnetic flux density curve; wherein the first magnetic flux density curve does not coincide with the second magnetic flux density curve. The rotor provided by the invention has various iron core unit air gap structures, can be correspondingly adapted to different harmonic waves, can effectively suppress various harmonic waves, and gives full play to the magnetic conductance modulation effect, thereby facilitating improvement of motor efficiency, reduction of tangential electromagnetic force harmonic waves and reduction of vibration noise.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a rotor, a stator, a motor and a household appliance. Background Art

[0002] Permanent magnet synchronous motors have high power density and torque density and are widely used in the field of household appliances. To meet the current needs of household appliances, motors have high power density and low noise performance requirements. One of the factors that affect motor performance is the harmonics generated during motor operation. The main source of harmonics is the cogging torque caused by the slot structure between the rotor and the stator. The cogging torque will cause torque pulsation of the permanent magnet motor, which will lead to speed fluctuations and reduce motor efficiency. Torque pulsation will also cause additional vibration and noise in the motor.

[0003] At present, one method to reduce the torque pulsation of the motor is to design the outer contour of the rotor or the inner contour of the stator as an irregular outer contour wall surface to form an uneven air gap between the stator and the rotor of the motor. The uneven air gap can make the air gap flux density distribution waveform under the magnet correspond to the harmonic waveform of the torque pulsation, which is beneficial to reduce the cogging torque. However, the stator / rotor of the related technology often only adopts one irregular outer contour structure in each core unit. With the diversification of the stator / rotor structure design, the single type of stator / rotor uneven surface structure cannot effectively suppress specific harmonic waveforms. For example, the stator / rotor has a variety of slot structures, so that a variety of harmonic waveforms will be generated during the operation of the motor; or the torque pulsation has a more complex harmonic waveform, and the irregular wall surface of the stator / rotor unit of a single form cannot adapt to the changing period of the harmonic waveform. Therefore, it is currently necessary to seek a diversified stator / rotor unit contour structure to effectively suppress the complex harmonic waveform of the motor. Summary of the invention

[0004] The main purpose of the present invention is to provide a rotor, a stator, a motor and a household appliance, which can effectively suppress multiple harmonics.

[0005] To achieve the above objectives, the embodiment of the first aspect of the present invention adopts the following technical solutions:

[0006] A rotor is used for a motor, the motor comprises a stator, the stator has an inner peripheral wall arranged around the rotor, the rotor is arranged in the stator, and the rotor can rotate around a rotation axis, the rotor comprises a first iron core unit and a second iron core unit;

[0007] The first core unit can define a first air gap together with the inner peripheral wall, and the first air gap has a first magnetic flux density curve;

[0008] The second core unit can define a second air gap together with the inner peripheral wall, and the second air gap has a second magnetic flux density curve;

[0009] The first magnetic flux density curve does not overlap with the second magnetic flux density curve.

[0010] In some embodiments, the first core unit has a first wall surface facing the inner circumferential wall, and the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection; the second core unit has a second wall surface facing the inner circumferential wall, and the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection; the shape of the first projection is different from the shape of the second projection, and / or the size of the first projection is different from the size of the second projection.

[0011] In some embodiments, the first core unit has a first wall surface facing the inner circumferential wall, the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection, and the first projection is curved; and / or, the second core unit has a second wall surface facing the inner circumferential wall, the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection, and the second projection is curved.

[0012] In some embodiments, the first core unit has a first wall surface facing the inner circumferential wall, the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection, the first projection includes a first arc and a second arc, the first arc corresponds to a first center, the second arc corresponds to a second center, and the first center does not coincide with the second center;

[0013] and / or,

[0014] The second core unit has a second wall surface facing the inner circumferential wall, and the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection. The second projection includes a third arc and a fourth arc. The third arc corresponds to a third center, and the fourth arc corresponds to a fourth center. The third center and the fourth center do not coincide.

[0015] In some embodiments, along the radial direction of the rotor, a minimum dimension L1 between the rotor and the inner circumferential wall satisfies: 0.2 mm ≤ L1 ≤ 0.5 mm.

[0016] In some embodiments, along the radial direction of the rotor, a minimum dimension L1 between the rotor and the inner circumferential wall and a maximum dimension L2 between the rotor and the inner circumferential wall satisfy: 0.15≤L1 / L2≤0.75.

[0017] In some embodiments, the first core unit and the second core unit are spaced apart from each other, and the rotor further includes a cladding layer, which fills a gap between the first core unit and the second core unit.

[0018] In some embodiments, the rotor further includes a permanent magnet, a receiving space is defined between the first core unit and the second core unit, the permanent magnet is disposed in the receiving space, and the coating layer is coated on one end of the permanent magnet radially away from the rotation axis of the rotor.

[0019] In some embodiments, the rotor includes a plurality of core units arranged adjacent to each other in the circumferential direction around the rotation axis, the shape and structure of each core unit are the same as the first core unit or the second core unit, and each core unit is arranged in a ring array with the rotation axis as the central axis.

[0020] In some embodiments, the rotor includes a plurality of core units arranged adjacent to each other in a circumferential direction around a rotation axis; each core unit is disconnected from each other, or the rotor also includes a first magnetic bridge, the first magnetic bridge is located on a side of each core unit close to the rotation axis, and the first magnetic bridge is used to connect at least two core units, or the rotor also includes a second magnetic bridge, the second magnetic bridge is located on a side of each core unit away from the rotation axis, and the second magnetic bridge is used to connect at least two core units.

[0021] The embodiment of the second aspect of the present invention further provides a stator for a motor, the motor comprising a rotor, the rotor having an outer peripheral wall arranged around the stator, the rotor being arranged in the stator, and the stator comprising a third core unit and a fourth core unit;

[0022] The third core unit can define a third air gap together with the outer peripheral wall, and the third air gap has a third magnetic flux density curve;

[0023] The fourth core unit can define a fourth air gap together with the outer peripheral wall, and the fourth air gap has a fourth magnetic flux density curve;

[0024] The third magnetic flux density curve does not overlap with the fourth magnetic flux density curve.

[0025] An embodiment of the third aspect of the present invention further provides a motor, comprising the stator of any one of the embodiments of the second aspect above, and a rotor.

[0026] An embodiment of the fourth aspect of the present invention further provides a motor, comprising the rotor of any one of the embodiments of the first aspect above, and a stator.

[0027] The embodiment of the fifth aspect of the present invention further provides a household appliance, comprising the motor of the embodiment of the fourth aspect.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The rotor of the present invention has a first core unit and a second core unit, and the two can respectively define a first air gap and a second air gap together with the inner circumferential wall of the stator, and the magnetic flux density of the air gap at various positions along the circumferential direction of the rotation axis can have a certain change trend, and the change trend can be expressed as a magnetic flux density curve. The two air gaps have different magnetic flux density curves, and the difference in magnetic flux density curves can reflect that the first core unit and the second core unit have different outer wall structures. The different magnetic flux density curves (or different air gap structures) between the core units of different rotors can correspond to the harmonics generated by the air gap at various positions along the circumferential direction of the rotation axis. Through the different magnetic flux density curves between the rotor units, multiple harmonic waveforms can be further suppressed. Therefore, the rotor of the present invention has multiple core unit air gap structures, which can be adapted to different harmonics, and can effectively suppress multiple harmonics, give full play to the magnetic permeability modulation effect, thereby helping to improve the efficiency of the motor, reduce the tangential electromagnetic force harmonics, and reduce vibration noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 A schematic side view of a rotor and a stator combined in a first embodiment of the present invention;

[0032] Figure 2 for Figure 1 A local enlarged schematic diagram of the middle A;

[0033] Figure 3 is a schematic diagram of a first magnetic flux density curve in a first rectangular coordinate system according to a first embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of a second magnetic flux density curve in a second rectangular coordinate system according to the first embodiment of the present invention;

[0035] Figure 5 A side view schematic diagram of a first core unit and a second core unit combined in a first embodiment of the present invention;

[0036] Figure 6 A side view schematic diagram of a first core unit and a second core unit combined in a second embodiment of the present invention;

[0037] Figure 7A side view schematic diagram of a first core unit and a second core unit combined in a third embodiment of the present invention;

[0038] Figure 8 A side schematic diagram of a first core unit provided in a first embodiment of the present invention;

[0039] Fig. 9 A side view schematic diagram of a first core unit provided in a second embodiment of the present invention;

[0040] Fig.10 A side view schematic diagram of a first core unit and a second core unit combined in a third embodiment of the present invention;

[0041] Fig.11 A schematic side view of a rotor provided in a fourth embodiment of the present invention;

[0042] Fig.12 A schematic side view of a rotor provided in a fifth embodiment of the present invention;

[0043] Fig.13 A schematic side view of a rotor provided in a sixth embodiment of the present invention;

[0044] Fig.14 A schematic side view of a stator and a rotor after being combined is provided in an embodiment of the second aspect of the present invention;

[0045] Fig.15 for Fig.14 A partial enlarged view of point B in the middle.

[0046] Description of Figure Numbers:

[0047] 100-rotor;

[0048] 110 - first core unit; 111 - first wall surface; 112 - first projection; 1121 - first arc; 1122 - second arc;

[0049] 120 - second core unit; 121 - second wall surface; 122 - second projection;

[0050] 130- first air gap;

[0051] 140 - second air gap;

[0052] 150-cladding layer;

[0053] 160-Permanent magnet;

[0054] 170-first magnetic bridge;

[0055] 180-second magnetic bridge;

[0056] 200(300)-stator;

[0057] 210-inner peripheral wall;

[0058] 310-third core unit;

[0059] 320- fourth core unit;

[0060] 330- third air gap;

[0061] 340- fourth air gap;

[0062] 400 - rotor; 410 - outer peripheral wall.

[0063] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0064] 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.

[0065] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0066] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or", "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0067] Permanent magnet synchronous motors are prone to torque pulsation during operation, which will reduce motor efficiency and generate additional vibration and noise. At present, one method to reduce motor torque pulsation is to design the outer contour of the rotor or the inner contour of the stator as an irregular outer contour wall surface to form an uneven air gap between the stator and rotor of the motor. The uneven air gap can make the air gap flux density distribution waveform under the magnet correspond to the harmonic waveform of the torque pulsation, which is beneficial to reduce the cogging torque. However, the stator / rotor of the related art often only adopts one irregular outer contour structure in each core unit. With the diversification of the stator / rotor structure design, the single type of stator / rotor uneven surface structure cannot effectively suppress specific harmonic waveforms. For example, the stator / rotor has a variety of slot structures, so that a variety of harmonic waveforms will be generated during the operation of the motor; or the torque pulsation has a more complex harmonic waveform, and the irregular wall surface of the stator / rotor unit of a single form cannot adapt to the changing period of the harmonic waveform. Therefore, it is currently necessary to seek a diversified stator / rotor unit contour structure to effectively suppress the complex harmonic waveform of the motor.

[0068] In view of this, see Figure 1-Figure 13 In the embodiment of the first aspect of the present invention, a rotor 100 is provided for a motor, wherein the motor comprises a stator 200, wherein the stator 200 has an inner circumferential wall 210 disposed around the rotor 100, the rotor 100 is disposed inside the stator 200, and the rotor 100 can rotate around a rotation axis. In different embodiments of the above-mentioned rotor 100, the rotor 100 can be a rotor core composed of a plurality of core units, or a rotor assembly composed of a rotor core and other components such as a rotating shaft; and the stator 200 is similar. It can be understood that the rotor 100 can be disposed relatively to the stator 200, the stator 200 can have an inner circumferential wall 210, and the inner circumferential wall 210 can define a placement cavity, the rotor 100 can be located inside the stator 200 (placed in the placement cavity), and rotate around the rotation axis relative to the stator 200. It should be noted that in some embodiments, the inner circumferential wall 210 of the above-mentioned stator 200 can be a continuously extended wall defining an annular cavity; see Figure 1 In other embodiments, the inner circumferential wall 210 may also be defined by a plurality of spaced inner wall surfaces, that is, the inner circumferential wall 210 may be disconnected between the core units of the stator 200 .

[0069] See also Figure 1-Figure 2, the rotor 100 includes a first core unit 110 and a second core unit 120. In some embodiments, the rotor core may include a plurality of core units arranged around the rotation axis of the rotor core, and each core unit may include the first core unit 110 and the second core unit 120 described above. The first core unit 110 and the second core unit 120 may be arranged adjacent to each other along the circumference of the rotation axis. The following defines the direction of "the circumference of the rotation axis" as follows: when viewed in a direction parallel to the rotation axis, the circumference of the rotation axis is the clockwise direction.

[0070] See also Figure 2 , the first core unit 110 can define a first air gap 130 together with the inner peripheral wall 210. Correspondingly, the second core unit 120 can define a second air gap 140 together with the inner peripheral wall 210. It can be understood that the first air gap 130 can be represented as the wall surface of the first core unit 110 facing the inner peripheral wall 210 and the gap space between the inner peripheral wall 210, and correspondingly, the second air gap 140 can be represented as the wall surface of the second core unit 120 facing the inner peripheral wall 210 and the gap space between the inner peripheral wall 210. In some embodiments, when the permanent magnet motor is working, a permanent magnet 160 is provided in the rotor 100, and the permanent magnet 160 can make the first air gap 130 and the second air gap 140 have a certain magnetic field and a corresponding air gap magnetic flux density. The corresponding spatial arrangement of the air gap and the size of the air gap will affect the magnetic flux density. Therefore, the magnetic flux density of the air gap is related to the structure of the air gap, and the magnetic flux density at each location will vary with the different corresponding air gap structures at that location. Based on this, the first air gap 130 has a first magnetic flux density curve, and the second air gap 140 has a second magnetic flux density curve.

[0071] See also Figure 3 , the following definition of "the first air gap 130 has a first magnetic flux density curve" is given as follows: the first magnetic flux density curve can be expressed in a first rectangular coordinate system, the horizontal axis of the rectangular coordinate system is used to represent various positions of the first air gap 130 along the circumferential direction of the rotation axis, the vertical axis is used to represent the first magnetic flux density, and the value of 0 on the horizontal axis can represent an end position of the first air gap 130 along the circumferential direction of the rotation axis. The first magnetic flux density of the first air gap 130 at various positions along the circumferential direction of the rotation axis has a certain change trend, and the change trend as a whole is reflected in the coordinate system as the first magnetic flux density curve. Therefore, in the first rectangular coordinate system, any point on the first magnetic flux density curve is expressed as the first magnetic flux density of the first air gap 130 corresponding to the position of the first air gap 130 corresponding to the horizontal axis coordinate value of the point.

[0072] Accordingly, see Figure 4, the following definition of "the second air gap 140 has a second magnetic flux density curve" is given as follows: the second magnetic flux density curve can be expressed in a second rectangular coordinate system, wherein the horizontal axis of the rectangular coordinate system is used to represent various positions of the second air gap 140 along the circumferential direction of the rotation axis, the vertical axis is used to represent the second magnetic flux density, and the value of 0 on the horizontal axis can represent an end position of the second air gap 140 along the circumferential direction of the rotation axis. The second magnetic flux density of the second air gap 140 at various positions along the circumferential direction of the rotation axis has a certain change trend, and the change trend as a whole is reflected in the coordinate system as a second magnetic flux density curve. Therefore, in the second rectangular coordinate system, any point on the second magnetic flux density curve is expressed as the corresponding second magnetic flux density of the second air gap 140 at the position of the second air gap 140 corresponding to the horizontal axis coordinate value of the point.

[0073] It should be noted that the first magnetic flux density curve and the second magnetic flux density curve of the present invention only represent the changing trend of the magnetic flux density in the coordinate system. Therefore, the first magnetic flux density curve and the second magnetic flux density curve can be composed of curve segments or straight line segments, or can be composed of straight line segments as a whole.

[0074] The above-mentioned first magnetic flux density curve does not overlap with the second magnetic flux density curve. It should be noted that the above-mentioned non-overlap means incomplete overlap (ignoring the incomplete overlap caused by error factors). And the comparison method for the non-overlap of magnetic flux density curves is: remove the rectangular coordinate system and only compare the curve graphs of the first magnetic flux density curve and the second magnetic flux density curve. Therefore, the first magnetic flux density curve and the second magnetic flux density curve have different shapes. It can be seen that the first core unit 110 and the second core unit 120 can have different structural designs to form the above-mentioned non-overlapping magnetic flux density curves. For details, see Figure 1-Figure 2 The first core unit 110 and the second core unit 120 may have different outer wall shapes.

[0075] Explanation of different outer wall shapes. For example, in one embodiment, the above different outer wall shapes can be outer wall shapes of different structures, see Figure 5 Specifically, in this embodiment, along the direction parallel to the rotation axis, the outer wall projection of the first core unit 110 may be composed of a first arc segment; the outer wall projection of the second core unit 120 may be composed of: a second arc segment, a third arc segment, and a straight line segment. In this embodiment, the outer wall shapes of the first core unit 110 and the second core unit 120 are different. In another embodiment, the above-mentioned different outer wall shapes can be outer wall shapes of the same composition. For details, see Figure 6 or Figure 7In this embodiment, the projection of the outer wall surface of the first core unit 110 may be composed of: a first arc segment and a second arc segment that are concentrically arranged, and a third arc segment that is non-concentrically arranged relative to the first arc segment and the second arc segment; the projection of the outer wall surface of the second core unit 120 may be composed of: the above-mentioned first arc segment and the second arc segment, and a fourth arc segment that is non-concentrically arranged relative to the first arc segment and the second arc segment, wherein the third arc segment is non-concentric with the fourth arc segment. In this embodiment, the first core unit 110 and the second core unit 120 both have three arc segments, which are still considered to be different outer wall surface shapes, and have non-overlapping first magnetic flux density curves and second magnetic flux density curves.

[0076] According to the combination of the above embodiments, it can be concluded that in some embodiments, the rotor 100 of the present invention has a first core unit 110 and a second core unit 120, and the two can respectively define a first air gap 130 and a second air gap 140 together with the inner circumferential wall 210 of the stator 200, and the magnetic flux density of the air gap at various positions along the circumferential direction of the rotation axis can have a certain change trend, and the change trend can be expressed as a magnetic flux density curve. The two air gaps have different magnetic flux density curves, and the difference in magnetic flux density curves can reflect that the first core unit 110 and the second core unit 120 have different outer wall structures. The different magnetic flux density curves (or different air gap structures) between the core units of different rotors 100 can correspond to the harmonics generated by the air gap at various positions along the circumferential direction of the rotation axis. Through the different magnetic flux density curves between the units of each rotor 100, multiple harmonic waveforms can be further suppressed. Therefore, the rotor 100 of the present invention has a variety of core unit air gap structures, which can adapt to different harmonics and effectively suppress multiple harmonics, giving full play to the magnetic conductivity modulation effect, thereby helping to improve motor efficiency, reduce tangential electromagnetic force harmonics, and reduce vibration noise.

[0077] In some embodiments, the first core unit 110 may have an irregular outer wall surface, and similarly, the second core unit 120 may also have an irregular outer wall surface, so that this embodiment can suppress harmonics within the circumferential rotation range of a single core unit and reduce the interference of tangential electromagnetic forces.

[0078] It is understandable that the first core unit 110 and the second core unit 120 have different outer wall structures to form different air gap structures between the core units. In order to make the first air gap 130 or the second air gap 140 have an uneven air gap within the range of the first core unit 110 or the second core unit 120, and give full play to the harmonic suppression effect of the uneven air gap within a single core unit, the composition of the core unit wall can be designed accordingly. For details, see Figure 8In some embodiments, the first core unit 110 may have a first wall surface 111 facing the inner peripheral wall. It can be understood that the first wall surface 111 is the wall surface of the first core unit 110 facing the inner peripheral wall, and the first wall surface 111 can define the first air gap 130 together with the inner peripheral wall 210. The orthographic projection of the first wall surface 111 on a plane perpendicular to the rotation axis is the first projection 112. In other words, the first projection 112 can be understood as the projection profile formed by the first wall surface 111 when observed in a direction parallel to the rotation axis. Correspondingly, in some embodiments, the second core unit 120 may have a second wall surface 121 facing the inner peripheral wall. Correspondingly, the second wall surface 121 can be understood as the wall surface of the second core unit 120 facing the inner peripheral wall, and the second wall surface 121 can define the second air gap 140 together with the inner peripheral wall 210. The orthographic projection of the second wall surface 121 on a plane perpendicular to the rotation axis is the second projection 122. For the related description of the second projection 122 , reference may be made to the first projection 112 .

[0079] For the specific shapes of the first projection 112 and the second projection 122, in some embodiments, the first projection 112 may be composed of straight line segments, and / or the second projection 122 may be composed of straight line segments. In order to make the magnetic flux density curve smoother, so that the suppression effect of the uneven air gap on harmonics is more stable and it is not easy to generate additional harmonics, see Figure 5-Figure 9 In some embodiments, the first projection 112 may be in a curved shape, and / or the second projection 122 may be in a curved shape. The above-mentioned curved shape may be understood as defining the shape of the first projection 112 having at least one curved segment, or the second projection 122 having at least one curved segment. In different embodiments, the first projection 112 may include at least one curved segment and at least one straight segment, or the first projection 112 may be composed entirely of curved segments, and the above description is the same for the second projection 122. The first projection 112 / the second projection 122 being in a curved shape may make the corresponding magnetic flux density curve smoother and reduce harmonic fluctuations.

[0080] It should be noted that the specific shapes and change trends of the first projection 112 and the second projection 122 need to correspond to the harmonic change trend during the actual operation of the motor, so the specific outer wall design of the first core unit 110 or the second core unit 120 needs to refer to the motor selection and test data. Exemplarily, the present invention provides some outer wall structure forms of the core unit as a reference.

[0081] For the first projection 112 and the second projection 122, in some embodiments, the different air gap structures between the core units can be specifically reflected as different projection sizes or shapes of the core unit walls. Figure 5-Figure 7In some embodiments, the shape of the first projection may be different from the shape of the second projection, and / or the size of the first projection may be different from the size of the second projection.

[0082] For the outer wall composition of the core unit. Figure 8 In some embodiments, the first core unit 110 has a first wall surface 111 facing the inner circumferential wall, and the orthographic projection of the first wall surface 111 on a plane perpendicular to the rotation axis is a first projection 112. For the first wall surface 111 and the first projection 112, reference may be made to the above-mentioned related descriptions. The first projection 112 may include a first arc 1121 and a second arc 1122. It is understandable that the first arc 1121 and the second arc 1122 may correspond to the shape constituting the first projection 112. Therefore, in different embodiments, the first projection 112 may be composed only of the first arc 1121 and the second arc 1122, or the first projection 112 may also be composed of the first arc 1121, the second arc 1122 and other line segments (including straight line segments and curve segments). For example, see Figure 8 In some embodiments, the first projection 112 may be composed of two first arcs 1121 located at two sides and a second arc 1122 located between the first two. The first arc 1121 may be arranged concentrically with the third arc. Fig. 9 In other embodiments, the first projection 112 may be composed of a first arc 1121 and a second arc 1122. For the above-mentioned arc segment setting, the first arc 1121 corresponds to a first center, and the second arc 1122 corresponds to a second center. It can be understood that the first center is the center used to form the first arc 1121, and the first arc 1121 uniquely corresponds to one first center, and the same is true for the second center. In some embodiments, the first projection 112 may also be composed of more arc segments or straight line segments.

[0083] For the settings of the first and second center of the circle. Figure 8 or Fig. 9 , in some embodiments, the first center of the circle and the second center of the circle may not coincide with each other. In other words, the positional limitations of the first center of the circle and the second center of the circle can be understood as the non-concentric arrangement of the first center of the circle and the second center of the circle. By arranging at least two arc segments on the outer wall of the core unit, and arranging the two arc segments non-concentrically, the two arc segments on the first projection 112 or the second projection 122 can form different air gap structures with the inner circumferential wall 210, respectively, so that the core unit has an uneven air gap structure. In the process of the rotor 100 rotating relative to the stator 200 and passing through the two arc segments in the circumferential direction, the size of the air gap at various circumferential positions along the axis of rotation can have a certain change trend (for example, the air gap gradually increases or gradually decreases), so that the air gap can more effectively suppress motor harmonics.

[0084] Accordingly, in some embodiments, the second core unit 120 has a second wall surface 121 facing the inner circumferential wall, and the orthographic projection of the second wall surface 121 on a plane perpendicular to the rotation axis is a second projection 122. The second projection 122 may include a third arc and a fourth arc. The third arc corresponds to a third center, and the fourth arc corresponds to a fourth center. Accordingly, in some embodiments, the third center and the fourth center may not coincide. In addition, the configuration and definition of the second wall surface 121, the second projection 122, the third arc, and the fourth arc may refer to the above-mentioned description of the first wall surface 111 and its arc segment.

[0085] Regarding the trend of wall structure changes along the circumferential direction of the core unit. Taking the first core unit 110 as an example, in some embodiments, during the process of the first air gap 130 from one end position to another end position along the circumference of the rotation axis, the first air gap 130 formed by each point on the first wall 111 can gradually increase, or gradually decrease, or first increase and then decrease, or first decrease and then increase. It can be understood that the above-mentioned air gap change trend can correspond to the actual motor harmonics generated, and can play a role in reducing the harmonic rate of the motor back-electromotive force and improving the motor efficiency. It should be noted that along the circumference of the rotation axis, the size of the air gap at each point at various positions of the rotor 100 can be jointly defined by the core unit wall corresponding to the point and the inner circumferential wall 210.

[0086] Next, the design of the first air gap 130 and the second air gap 140 is further optimized. In order to reduce the vibration noise of the motor and optimize the magnetic field in the air gap space, the air gap magnetic resistance can be made to be similar to a sine distribution. The air gap magnetic resistance is related to the air gap size and the outer wall surface of the rotor 100, so the outer contour of the rotor core also needs to be optimized.

[0087] Through experiments and analysis, it is found that when the minimum size of the air gap is within a certain range, it can more accurately ensure that the motor has higher efficiency, less harmonic content, and lower magnetic field distortion rate. Figure 2 In some embodiments, along the radial direction of the rotor 100, the minimum dimension L1 of the rotor 100 from the inner peripheral wall 210 satisfies: 0.2mm≤L1≤0.5mm. It can be understood that the minimum dimension of the rotor 100 from the inner peripheral wall 210 is the distance between the rotor 100 and the inner peripheral wall 210 in the radial direction. For the first core unit 110, the minimum dimension from the inner peripheral wall 210 is the distance between the first wall surface 111 and the inner peripheral wall 210 in the radial direction. Exemplarily, in some embodiments, the minimum dimension L1 of the rotor 100 from the inner peripheral wall 210 can be one of 0.2mm, 0.3mm, 0.4mm, and 0.5mm.

[0088] See also Figure 1, Figure 8 or Fig. 9 The rotor 100 may have an annular structure and the rotor 100 may rotate around a rotation axis. Therefore, the radial direction of the rotor 100 may be understood as a direction perpendicular to the rotation axis.

[0089] In addition, since the air gap reluctance can be similar to a sine distribution, the maximum and minimum values ​​of the air gap can correspond to the extreme values ​​of the air gap reluctance distribution waveform. Furthermore, through experiments and analysis, it is found that when the minimum size of the air gap and the maximum size of the air gap are within a certain numerical range, it can more accurately ensure that the motor efficiency is high, the harmonic content is low, and the magnetic field distortion rate is low. For details, see Figure 2 In some embodiments, along the radial direction of the rotor 100, the minimum dimension L1 of the rotor 100 from the inner circumferential wall 210 and the maximum dimension L2 of the rotor 100 from the inner circumferential wall 210 satisfy: 0.15≤L1 / L2≤0.75. It should be noted that the above L1 / L2 can be understood as the minimum dimension of the air gap between the rotor 100 and the stator 200 and the maximum dimension of the air gap, not limited to the first air gap 130 or the second air gap 140. Exemplarily, in some embodiments, the ratio L1 / L2 of the minimum dimension L1 of the rotor 100 from the inner circumferential wall 210 and the maximum dimension L2 of the rotor 100 from the inner circumferential wall 210 can be one of 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.75.

[0090] It can be understood that, in some embodiments, the minimum dimension L1 or the maximum dimension L2 can be the distance from a point on the first core unit 110 or the second core unit 120 to the inner circumferential wall 210 along the radial direction of the rotor 100. It should be noted that the minimum dimension L1 and the maximum dimension L2 in the above embodiments are not limited to the comparison within the range of the first core unit 110 and the second core unit 120. In the embodiment where the rotor 100 further includes other core units, the above dimensions can also be the distance from a point on the other core units to the inner circumferential wall 210.

[0091] For the arrangement of the core units in the rotor 100. Figure 1-Figure 2In some embodiments, the first core unit 110 and the second core unit 120 can be arranged at intervals. In some embodiments, the first core unit 110 and the second core unit 120 can be disconnected from each other to form the above-mentioned interval arrangement form; in other embodiments, the first core unit 110 and the second core unit 120 can be two parts of the rotor 100 as a whole, and the two can be partially connected and partially form an interval. It can be understood that in this embodiment, the gap between the first core unit 110 and the second core unit 120 can be used to separate the core units. Further, in some embodiments, the gap between the first core unit 110 and the second core unit 120 can be used to place the permanent magnet 160 to adapt to the working performance requirements of the rotor 100 corresponding to the motor.

[0092] See also Fig.10 In some embodiments, the rotor 100 may further include a coating layer 150. In some embodiments, the coating layer 150 may be a plastic body filled on the surface of the rotor 100 or inside the rotor 100, and the plastic body may be used to connect the units inside the rotor 100 or connect the rotor 100 with other components. In other embodiments, the coating layer 150 may be a filler connected to the wall of the rotor 100, and the filler may be used to connect or fill the gap between the core units. In order to achieve a better coating effect without affecting the overall performance of the motor, the material of the coating layer 150 may be an insulating material, such as plastic, rubber, etc.

[0093] For the above embodiment, the rotor 100 includes the coating layer 150. Fig.10 In some embodiments, the rotor 100 may further include a permanent magnet 160. An accommodation space may be defined between the first core unit 110 and the second core unit 120. The permanent magnet 160 may be disposed in the accommodation space. The accommodation space may be defined by two side wall surfaces of the first core unit 110 and the second core unit 120 that are respectively opposite to each other in the circumferential direction. The coating 150 may be coated on one end of the permanent magnet 160 that is radially away from the axis of rotation of the rotor 100. It is understandable that, in the present embodiment, the coating 150 at least coats the side of the permanent magnet 160 that faces the stator 200, thereby reducing the influence of the exposed portion of the permanent magnet 160 on the overall magnetic field and magnetic flux density of the motor.

[0094] For the above embodiment, the first core unit 110 and the second core unit 120 are arranged at intervals, with a gap formed therebetween. Fig.10In order to improve the overall connectivity of the rotor 100, the coating layer 150 can fill the gap between the first core unit 110 and the second core unit 120. Further, the coating layer 150 can be connected to one end of the first core unit 110, or connected to one end of the second core unit 120. It can be understood that the above-mentioned setting of the coating layer 150 can fill the gap between the core units, thereby improving the integrity of the rotor 100 and reducing the leakage magnetic phenomenon and other interference caused by the gap. On the other hand, based on the improvement of the air gap structure of the present invention, the coating layer 150 can further affect the magnetic flux density curve corresponding to the air gap change between the first core unit 110 and the second core unit 120. Specifically, the gap between the coating layer 150 and the inner peripheral wall 210 can make the air gap change from the first core unit 110 to the second core unit 120 smoother, thereby reducing the harmonics caused by the sudden change of the air gap structure. The gap between the coating layer 150 and the inner peripheral wall 210 corresponds to a coating magnetic flux density curve, which corresponds to the description of the magnetic flux density curve in the rectangular coordinate system. The coating magnetic flux density curve can be connected to one end of the first magnetic flux density curve and one end of the second magnetic flux density curve in the coordinate system. The coating magnetic flux density curve can adapt to the change trend of the first magnetic flux density curve and the second magnetic flux density curve, and is located between the first magnetic flux density curve and the second magnetic flux density curve, so that the rotor 100 can form a relatively continuous and smooth magnetic flux density curve within the rotation range from the first core unit 110 to the second core unit 120, so as to reduce the sudden change of magnetic flux density at the gap of the core unit, and can correspondingly reduce the harmonics at the gap.

[0095] See also Fig.11 In some embodiments, the rotor 100 may include a plurality of core units arranged adjacent to each other in the circumferential direction around the rotation axis. The shape and structure of each core unit may be the same as the first core unit 110 or the second core unit 120, and each core unit is arranged in a ring array with the rotation axis as the central axis. It can be understood that the above-mentioned multiple core units can together form the overall ring shape of the rotor 100. Therefore, for embodiments in which the rotor 100 also includes other core units, the description and definition of the first core unit 110 or the second core unit 120 in the above-mentioned embodiments can also be further applied to other core units.

[0096] Corresponding to the above embodiment in which the rotor 100 includes a plurality of core units arranged adjacent to each other in the circumferential direction around the rotation axis, the core units of the rotor 100 may have different arrangements. Fig.11 In the embodiment of the first aspect of the distribution of the core units, the core units can be disconnected from each other. Fig.12In the embodiment of the second aspect of the distribution of each core unit, the rotor 100 may further include a first magnetic bridge 170, and the first magnetic bridge 170 is located on a side of each core unit close to the rotation axis, and the first magnetic bridge 170 is used to connect at least two core units. It can be understood that in this embodiment, the first magnetic bridge 170 is used to connect each core unit, and a plurality of first magnetic bridges 170 may be provided to connect more than two core units. Therefore, in some embodiments, the material of the first magnetic bridge 170 may be plastic, rubber or other insulating materials, so that the first magnetic bridge 170 plays a role of magnetic isolation, thereby reducing the magnetic field interference between the core units. In addition, see Fig.13 In the embodiment of the third aspect of the distribution of each core unit, the rotor 100 may further include a second magnetic bridge 180, which is located on the side of each core unit away from the rotation axis, and the second magnetic bridge 180 is used to connect at least two core units. It can be understood that the second magnetic bridge 180 is similar to the first magnetic bridge 170 described above, with the difference that the first magnetic bridge 170 is located on the side of each core unit close to the rotation axis (which can be understood as the inner area formed by the surrounding core unit), while the second magnetic bridge 180 is located on the side of each core unit away from the rotation axis (which can be understood as the outer wall area of ​​the surrounding core unit). Therefore, the setting method of the second magnetic bridge 180 can refer to the first magnetic bridge 170 described above.

[0097] See also Figure 14-15The embodiment of the second aspect of the present invention further provides a stator 300 for a motor, the motor comprising a rotor 400, the rotor 400 having an outer peripheral wall 410 arranged around the stator 300, and the rotor 400 being arranged in the stator 300. The stator 300 comprises a third core unit 310 and a fourth core unit 320. The third core unit 310 can define a third air gap 330 together with the outer peripheral wall 410. The third air gap 330 has a third magnetic flux density curve. The fourth core unit 320 can define a fourth air gap 340 together with the outer peripheral wall 410. The fourth air gap 340 has a fourth magnetic flux density curve. Among them, the third magnetic flux density curve does not overlap with the fourth magnetic flux density curve. It can be understood that the above-mentioned setting of the stator 300 is similar to the setting of the rotor 400 in the embodiment of the first aspect of the present invention, except that the air gap and structural definition of the rotor 100 in the embodiment of the first aspect correspond to the stator 300 in the embodiment of the second aspect. It can be understood that the third core unit 310 in this embodiment can correspond to the first core unit 110, the fourth core unit 320 can correspond to the second core unit 120, the third air gap 330 and the third magnetic flux density can correspond to the first air gap 130 and the first magnetic flux density, respectively, and the fourth air gap 340 and the fourth magnetic flux density can correspond to the second air gap 140 and the second magnetic flux density, respectively. Therefore, for the stator 300 and its rotor unit settings and related definitions in this embodiment, reference can be made to the relevant description of the rotor 100 provided in the embodiment of the first aspect, which will not be repeated here.

[0098] The embodiment of the third aspect of the present invention further provides a motor, including the rotor 100 of the embodiment of the first aspect of the present invention, and the stator 200. It should be noted that the embodiment of this aspect does not limit the form of the stator, so in some embodiments, the embodiment of this aspect may include the stator 300 of the embodiment of the second aspect above, that is, in this embodiment, the rotor 100 and the stator 300 both have at least two core units with different air gap structures, and the stator / rotor are both relatively provided with irregular outer wall surfaces, which can increase the combination diversity of the stator outer contour and the rotor outer contour, and further give full play to the magnetic permeability tempering effect of the uneven air gap.

[0099] An embodiment of the third aspect of the present invention further provides a motor, comprising the stator of the embodiment of the second aspect above, and a rotor.

[0100] An embodiment of the fourth aspect of the present invention further provides a motor, comprising the rotor of the embodiment of the first aspect of the present invention, and a stator.

[0101] The embodiment of the fifth aspect of the present invention further provides a household appliance, comprising the motor of the embodiment of the fourth aspect.

[0102] Other contents related to the motor of the third aspect, the motor of the fourth aspect and the household appliance of the fifth aspect can be found in the prior art and will not be described in detail here.

[0103] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A rotor for a motor, the motor comprising a stator, the stator having an inner peripheral wall arranged around the rotor, the rotor being arranged in the stator, and the rotor being rotatable around a rotation axis, characterized in that: The rotor comprises: A first core unit, capable of defining a first air gap together with the inner peripheral wall, wherein the first air gap has a first magnetic flux density curve; A second core unit, capable of defining a second air gap together with the inner peripheral wall, wherein the second air gap has a second magnetic flux density curve; The first magnetic flux density curve does not overlap with the second magnetic flux density curve.

2. The rotor according to claim 1, characterized in that The first core unit has a first wall surface facing the inner circumferential wall, and the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection. The second core unit has a second wall surface facing the inner circumferential wall, and the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection. The shape of the first projection is different from the shape of the second projection, and / or the size of the first projection is different from the size of the second projection.

3. The rotor according to claim 1, characterized in that The first core unit has a first wall surface facing the inner peripheral wall, the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection, and the first projection is in a curved shape; and / or, The second core unit has a second wall surface facing the inner peripheral wall, the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection, and the second projection is in a curved shape.

4. The rotor according to claim 1, characterized in that The first core unit has a first wall surface facing the inner circumferential wall, the orthographic projection of the first wall surface on a plane perpendicular to the rotation axis is a first projection, the first projection includes a first arc and a second arc, the first arc corresponds to a first center, the second arc corresponds to a second center, and the first center does not coincide with the second center; and / or, The second core unit has a second wall surface facing the inner circumferential wall, and the orthographic projection of the second wall surface on a plane perpendicular to the rotation axis is a second projection. The second projection includes a third arc and a fourth arc. The third arc corresponds to a third center, and the fourth arc corresponds to a fourth center, and the third center does not coincide with the fourth center.

5. The rotor according to claim 1, characterized in that Along the radial direction of the rotor, a minimum dimension L1 of the rotor from the inner circumferential wall satisfies: 0.2 mm ≤ L1 ≤ 0.5 mm.

6. The rotor according to claim 1, characterized in that Along the radial direction of the rotor, a minimum dimension L1 of the rotor from the inner circumferential wall and a maximum dimension L2 of the rotor from the inner circumferential wall satisfy: 0.15≤L1 / L2≤0.

75.

7. The rotor according to claim 1, characterized in that The first core unit and the second core unit are arranged at intervals, and the rotor further includes a coating layer, and the coating layer fills a gap between the first core unit and the second core unit.

8. The rotor according to claim 7, characterized in that The rotor further includes a permanent magnet. An accommodation space is defined between the first core unit and the second core unit. The permanent magnet is disposed in the accommodation space. The coating layer coats one end of the permanent magnet away from the rotation axis along the radial direction of the rotor.

9. The rotor according to claim 1, characterized in that The rotor includes a plurality of core units arranged adjacent to each other in the circumferential direction around the rotation axis. The shape and structure of each core unit are the same as the first core unit or the second core unit. Each core unit is arranged in a ring array with the rotation axis as the central axis.

10. The rotor according to claim 1, characterized in that The rotor comprises a plurality of core units arranged adjacent to each other in the circumferential direction around the rotation axis; The core units are disconnected from each other. or, The rotor further comprises a first magnetic bridge, the first magnetic bridge being located on a side of each of the core units close to the rotation axis, and the first magnetic bridge being used to connect at least two of the core units. or, The rotor further includes a second magnetic bridge, which is located on a side of each of the core units away from the rotation axis, and is used to connect at least two of the core units.

11. A stator for a motor, the motor comprising a rotor, the rotor having an outer peripheral wall arranged around the stator, the rotor being arranged in the stator, characterized in that: The stator comprises: A third core unit, capable of defining a third air gap together with the outer peripheral wall, wherein the third air gap has a third magnetic flux density curve; a fourth core unit, capable of defining a fourth air gap together with the outer peripheral wall, wherein the fourth air gap has a fourth magnetic flux density curve; The third magnetic flux density curve does not overlap with the fourth magnetic flux density curve.

12. A motor, characterized in that: include: The stator of claim 11; and Rotor.

13. A motor, characterized in that: include: A rotor as claimed in any one of claims 1 to 10; and stator.

14. A household appliance, characterized in that: include: The motor as claimed in claim 13.

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