Motor and household appliance

Abstract

The utility model discloses a motor and a household electrical appliance, the motor comprises a rotor assembly and a stator assembly, the rotor assembly comprises a plurality of outer iron core units and a plurality of permanent magnets, the projection of the outer contour of each outer iron core unit comprises a second arc-shaped section, a first arc-shaped section and a fifth arc-shaped section which are connected in sequence on a projection plane perpendicular to a rotation axis, in the direction away from the first arc-shaped section, the distance between the second arc-shaped section and the rotating axis is decreased progressively, and the distance between the fifth arc-shaped section and the rotating axis is decreased progressively; the stator core comprises a plurality of stator units arranged in the circumferential direction, each stator unit comprises a yoke part, a tooth part and a shoe part, the yoke parts and the shoe parts are connected to the two radial ends of the teeth respectively, the radial outer wall faces and the radial inner wall faces of the yoke parts are parallel planes, every two adjacent yoke parts are connected, and a winding groove is defined between every two adjacent stator units. A groove opening of the winding groove is defined between every two adjacent shoe parts. The motor provided by the utility model can reduce harmonic components in an air-gap magnetic field, and reduce vibration and noise.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical equipment, in particular to a motor and a household appliance. Background Art

[0002] For clothes processing devices, such as washing machines, clothes dryers, etc., the motors installed inside them are the core components of the clothes processing devices, and the performance of the motors plays a key role in the performance of the clothes processing devices. In the related art, generally speaking, the motors in the clothes processing devices run at a high speed. Due to the existence of stator slots and the large air gap magnetic field harmonics between the stator and the rotor, the stator and the rotor vibrate greatly during the high-speed operation of the motor, which will generate large noise and affect the performance of the motor. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a motor capable of reducing the harmonic components in the air gap magnetic field, and reducing vibration and noise.

[0004] The utility model also provides a household appliance with the motor.

[0005] According to the first aspect of the utility model, the motor includes a rotor assembly, which rotates around a rotation axis. The rotor assembly includes a plurality of outer core units and a plurality of permanent magnets. The plurality of outer core units are arranged at intervals along the circumference of the rotor assembly. An installation groove is defined between two adjacent outer core units. The plurality of permanent magnets are correspondingly installed in the plurality of installation grooves. On a projection plane perpendicular to the rotation axis, the projection of the outer contour of the outer core unit includes a second arc segment, a first arc segment and a fifth arc segment connected in sequence. In a direction away from the first arc segment, the second arc segment is aligned with the rotor assembly. The distance between the fifth arc segment and the moving axis decreases, and the distance between the fifth arc segment and the rotating axis decreases; a stator assembly, including a stator core, which is arranged around the outer circumference of the rotor assembly, and the stator core includes a plurality of stator units arranged along the circumferential direction, and the stator unit includes a yoke, a tooth portion and a boot portion, the yoke portion and the boot portion are respectively connected to the radial ends of the tooth portion, the radial outer wall surface and the radial inner wall surface of the yoke portion are parallel planes, two adjacent yoke portions are connected, a winding groove is defined between two adjacent stator units, and a notch of the winding groove is defined between two adjacent boot portions.

[0006] The motor according to the embodiment of the first aspect of the utility model has at least the following beneficial effects: by setting the projection of the outer contour of the outer core unit of the rotor assembly to include a second arc segment, a first arc segment and a fifth arc segment connected in sequence, and along the direction away from the first arc segment, the distance between the second arc segment and the rotation axis decreases, and the distance between the fifth arc segment and the rotation axis decreases, so that the radial distance of the air gap between the rotor assembly and the stator assembly is close to a sinusoidal distribution in the circumferential direction of the rotor assembly, so that the waveform of the air gap magnetic flux distribution is close to a sinusoidal waveform, which is beneficial to reducing the harmonic components in the air gap magnetic field, reducing the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the distortion rate of the back electromotive force waveform, thereby improving the performance of the motor.

[0007] According to some embodiments of the present invention, the second arc segment and the fifth arc segment are symmetrically arranged.

[0008] According to some embodiments of the present invention, along the circumferential direction, in units of mm, the minimum width of the notch is W 1 , the central angle corresponding to the first arc segment is θ 1 , the central angle of the second arc segment is θ 2 , satisfying: 0.615≤W 1 *θ 1 / θ 2 ≤2.

[0009] According to some embodiments of the present invention, the minimum width W of the notch is 1 The central angle θ corresponding to the second arc segment 2 Satisfy: 0.0405≤W 1 / θ 2 ≤0.1.

[0010] According to some embodiments of the present invention, the central angle θ corresponding to the first arc segment 1 The central angle θ corresponding to the second arc segment 2 Satisfies: 0.41≤θ 1 / θ 2 ≤0.572.

[0011] According to some embodiments of the present invention, along the circumferential direction, the boot portion is protruding toward both sides of the tooth portion, and the minimum width of the boot portion along the circumferential direction is W. 2 , satisfying: 0.088≤W 1 / W 2 ≤0.234.

[0012] According to some embodiments of the present utility model, on a projection plane perpendicular to the rotation axis, the projection of the inner contour of the boot includes a third arc segment and a fourth line segment respectively connected to both ends of the third arc segment, and the distance between the fourth line segment and the rotation axis increases in a direction away from the third arc segment.

[0013] According to some embodiments of the present invention, there is an air gap between the outer peripheral wall of the rotor assembly and the inner peripheral wall of the stator assembly, and the minimum distance of the air gap along the direction perpendicular to the rotation axis is L 1 , the maximum distance of the air gap is L 2 , satisfying: 0.107≤L 1 / L 2 ≤0.25.

[0014] According to some embodiments of the present invention, the number of the outer core units is N, and the maximum outer diameter of the rotor assembly is D. 3 , satisfying: 0.01≤L 1 *N / (π*D 3 )≤0.025.

[0015] According to some embodiments of the present invention, the minimum distance L of the air gap 1 Meet: 0.3mm≤L 1 ≤0.6mm.

[0016] According to some embodiments of the utility model, the outer core unit is provided with a magnetic barrier hole. On a projection plane perpendicular to the rotation axis, the projection of the magnetic barrier hole is in the shape of an elongated strip and has a length direction. The two ends of the magnetic barrier hole along the length direction are respectively facing the mounting slot and the outer contour of the outer core unit.

[0017] According to some embodiments of the present invention, the number of the magnetic barrier holes of each outer core unit is two, the two magnetic barrier holes are symmetrically arranged about the first symmetry center line of the outer core unit, and the angle between the two magnetic barrier holes is θ 3 , satisfying: 0.033≤W 1 / θ 3 ≤0.14.

[0018] According to some embodiments of the present invention, the minimum width W of the notch is 1 , the central angle θ corresponding to the first arc segment 1 and the angle θ between the two magnetic barrier holes 3 Satisfy: 0.49≤W 1 *θ 1 / θ 3 ≤5.58.

[0019] According to some embodiments of the present invention, the distance between two wall surfaces of the permanent magnet that are away from each other along the circumferential direction decreases from the middle of the permanent magnet to both ends of the permanent magnet along the radial direction.

[0020] According to some embodiments of the present invention, the maximum outer diameter of the stator assembly is D 1 , the minimum inner diameter of the stator assembly is D 2 , satisfying: 0.58≤D 2 / D 1 ≤0.625.

[0021] According to some embodiments of the utility model, the outer core unit includes a second limiting protrusion, which is located at one end of the mounting slot away from the rotation axis, and the second limiting protrusion includes a fixing portion, which is located at one end of the second limiting protrusion away from the mounting slot and protrudes along the circumferential direction.

[0022] According to some embodiments of the present invention, the rotor assembly further includes a first overmolded part, which covers the outer core unit and the permanent magnet, and the stator assembly further includes a second overmolded part, which covers the stator core.

[0023] The household appliance according to the embodiment of the second aspect of the utility model comprises the motor according to the embodiment of the first aspect of the utility model.

[0024] The household appliance according to the embodiment of the second aspect of the utility model has at least the following beneficial effects: since the household appliance adopts the above-mentioned motor, by setting the projection of the outer contour of the outer core unit of the rotor assembly to include a second arc segment, a first arc segment and a fifth arc segment connected in sequence, and along the direction away from the first arc segment, the distance between the second arc segment and the rotation axis decreases, and the distance between the fifth arc segment and the rotation axis decreases, so that the radial distance of the air gap between the rotor assembly and the stator assembly is close to a sinusoidal distribution in the circumferential direction of the rotor assembly, so that the waveform of the air gap magnetic density distribution is close to a sinusoidal waveform, which is beneficial to reducing the harmonic components in the air gap magnetic field, reducing the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the distortion rate of the back electromotive force waveform, thereby improving the performance of the motor.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 It is an axial schematic diagram of a motor in one embodiment of the utility model;

[0028] Figure 2 yes Figure 1 A in the enlarged view;

[0029] Figure 3 It is an axial schematic diagram of a rotor core in one embodiment of the utility model;

[0030] Figure 4 yes Figure 3 The enlarged view of point B in the figure;

[0031] Figure 5 It is an axial schematic diagram of a stator core in one embodiment of the utility model;

[0032] Figure 6 yes Figure 5 The enlarged view of point C in the figure;

[0033] Figure 7 It is a schematic diagram of a stator core in an embodiment of the utility model unfolded into a straight strip;

[0034] Figure 8 It is a partial axial schematic diagram of an outer core unit in another embodiment of the utility model;

[0035] Fig. 9 It is a columnar schematic diagram comparing the radial acceleration of the technical solution of the utility model with the prior art solution.

[0036] Reference numerals:

[0037] Rotor assembly 100; outer core unit 110; first wall surface 111; first arc segment 1111; second arc segment 1112; fifth arc segment 1113; magnetic barrier hole 112; second position-limiting protrusion 113; through hole 114; fixing portion 115; permanent magnet 120; mounting groove 130; second wall surface 131; third wall surface 132; air gap 140; inner core 150; shaft hole 151; first position-limiting protrusion 152;

[0038] stator core 200; stator unit 220; tooth portion 221; boot portion 222; fourth wall surface 2221; third arc segment 2222; fourth line segment 2223; fifth wall surface 2224; sixth wall surface 2225; winding groove 230; notch 231; yoke portion 240; rivet portion 250;

[0039] First reference point K; first symmetry center line Z 1 ; Second symmetry center line Z 2 ; The first reference circle P 1 ; Second reference circle P 2 . DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0043] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model based on the specific content of the technical solution.

[0044] For clothing processing devices, such as washing machines, clothes dryers, etc., the motors installed inside them are the core components of the clothing processing devices. The performance of the motors plays a key role in the performance of the clothing processing devices. At present, the requirements for the performance and cost performance of the motors are gradually increasing. In the related art, generally speaking, the motors in clothing processing devices have a relatively high operating speed. Due to the existence of stator slots, the motors have torque pulsations, and the air gap magnetic field harmonics between the stator and the rotor are relatively large. Some of the harmonics will cause noise, and some of the harmonics will cause the back electromotive force waveform to be distorted. During the high-speed operation of the motor, the vibrations of the stator and the rotor are relatively large, which will generate relatively large noise and affect the performance of the motor.

[0045] For this purpose, refer to Figures 1 to 9 As shown, a first aspect of the present invention provides a motor which is applied to household appliances such as washing machines, clothes dryers, etc., and drives the drum of the washing machine or clothes dryer to rotate by the motor.

[0046] Reference Figure 1 and Figure 2As shown, it can be understood that the motor includes a rotor assembly 100 and a stator assembly. In this embodiment, the motor is an inner rotor motor, that is, the stator assembly is arranged around the outer periphery of the rotor assembly 100, or in other words, the stator assembly has an inner cavity, and the rotor assembly 100 is accommodated in the inner cavity. In addition, the rotor assembly 100 can rotate relative to the stator assembly, and the central axis of the rotor assembly 100 itself is the rotation axis.

[0047] Reference Figure 1 and Figure 3 As shown, it can be understood that the rotor assembly 100 includes a rotor core. Specifically, in terms of composition, the rotor core is composed of a plurality of rotor punchings arranged in a corresponding stacked manner along the direction of the rotation axis. Generally speaking, the structural form of each rotor punching is the same, which is convenient for processing, reduces the number of molds, and reduces production costs. The rotor punching generally includes an annular punching monomer and a plurality of fan-shaped punching monomers, the fan-shaped punching monomer is connected to the outer periphery of the annular punching monomer, and the plurality of fan-shaped punching monomers are arranged at equal intervals along the circumference of the annular punching monomer, and the annular punching monomer and the plurality of fan-shaped punching monomers are an integrated structure. The circumferential direction is the direction around the rotation axis.

[0048] Reference Figure 1 and Figure 3 As shown, it can be understood that, from the overall structure, the rotor core includes an inner core 150 and a plurality of outer core units 110, wherein the inner core 150 corresponds to the annular punching monomer of the rotor punching, and the outer core unit 110 corresponds to the fan-shaped punching monomer of the rotor punching. Specifically, the outer core unit 110 is connected to the outer periphery of the inner core 150, and the plurality of outer core units 110 are arranged at equal intervals along the circumference of the inner core 150. The inner core 150 is provided with an axial hole 151 that passes through the direction of the rotation axis, and the rotating shaft of the motor is passed through the axial hole 151 and fixedly connected to the rotor core, for example, the rotating shaft of the motor and the rotor core are interference fit. On the projection plane perpendicular to the rotation axis, the projection of the outer core unit 110 is roughly fan-shaped, and the projection of the inner core 150 is roughly annular.

[0049] Reference Figure 1 and Figure 3 As shown, it can be understood that the rotor assembly 100 also includes a plurality of permanent magnets 120. Specifically, a mounting slot 130 is defined between two adjacent outer core units 110 and the inner core 150. It is easy to understand that the number of mounting slots 130, the number of permanent magnets 120 and the number of outer core units 110 are equal. In this embodiment, the number of mounting slots 130, the number of permanent magnets 120 and the number of outer core units 110 are all eight. The mounting slot 130 passes through the rotor core along the direction of the rotation axis. A plurality of permanent magnets 120 are correspondingly accommodated in a plurality of mounting slots 130, thereby realizing the installation of the permanent magnets 120 into the rotor core.

[0050] Reference Figure 1 and Figure 4 As shown, it can be understood that in order to improve the structural strength of the rotor assembly 100, the rotor assembly 100 also includes a first overmolded component, which covers the outer core unit 110 and the permanent magnet 120. Specifically, each outer core unit 110 is also provided with a through hole 114, and the through hole 114 passes through the rotor core along the direction of the rotation axis. The first overmolded component fills the through hole 114 and the gap between the permanent magnet 120 and the inner wall of the mounting groove 130. At the same time, the first overmolded component covers the wall surfaces at both ends of the permanent magnet 120 along the direction of the rotation axis, so that the rotor assembly 100 is more integrated, has high structural strength, and is more reliable, thereby avoiding loosening of the permanent magnet 120 and reducing magnetic leakage.

[0051] Reference Figure 1 and Figure 4 As shown, it can be understood that the inner core 150 includes a first limiting protrusion 152, which is located on the outer peripheral wall of the inner core 150 and protrudes toward the center of the mounting groove 130, and the first limiting protrusion 152 corresponds to the mounting groove 130. In addition, each outer core unit 110 includes two second limiting protrusions 113, which are located at the outer end of the outer core unit 110 and protrude toward the outer core unit 110 along the circumference of the rotor core. That is, the second limiting protrusion 113 is located at one end of the mounting groove 130 away from the rotation axis, and the outer ends of the mounting groove 130 on both sides of the circumference of the rotor core are provided with the second limiting protrusion 113. Here, "outside" refers to the direction away from the rotation axis, and the opposite direction is "inside". The permanent magnet 120 is installed in the installation groove 130, and the first limit portion and the second limit portion respectively abut against the two ends of the permanent magnet 120 along the radial direction of the rotor core, where the radial direction is the direction perpendicular to the rotation axis, so that the permanent magnet 120 is installed firmly, avoiding the permanent magnet 120 from loosening during the rotation of the rotor assembly 100, which may cause the permanent magnet 120 to demagnetize or generate vibration, noise and other disadvantages, which is beneficial to improving the performance of the motor.

[0052] Reference Figure 2 and Figure 4As shown, it can be understood that the second limiting protrusion 113 includes a fixing portion 115, and the fixing portion 115 is located at the outer end of the second limiting protrusion 113, that is, the fixing portion 115 is located at the end of the second limiting protrusion 113 away from the mounting groove 130, and the fixing portion 115 is protruded along the circumference of the rotor core, that is, in the two second limiting protrusions 113 located on both sides of the mounting groove 130 along the circumference of the rotor core, the two fixing portions 115 are protruded in opposite directions. Generally speaking, the first overmolded part of the rotor assembly 100 will fill the space between the two second limiting protrusions 113 located on both sides of the mounting groove 130 along the circumference of the rotor core, thereby, the fixing portion 115 is inserted or embedded in the first overmolded part, and plays a fixing role on the first overmolded part. During the rotation of the rotor assembly 100, the risk of the first overmolded part being separated from the rotor core under the action of centrifugal force is reduced, so that the structure of the first overmolded part is more stable.

[0053] Reference Figure 5 and Figure 7 As shown, it can be understood that the stator assembly includes a stator core 200 and a winding. Specifically, the stator core 200 includes a plurality of stator units 220, and the plurality of stator units 220 are connected in sequence and arranged in a ring shape, so that the ring structure surrounded by the plurality of stator units 220 forms an inner cavity capable of accommodating the rotor assembly 100.

[0054] Reference Figure 5 and Figure 6As shown, it can be understood that in the stator core 200, a plurality of stator units 220 are arranged at equal intervals along the circumference of the stator core 200, and winding slots 230 are defined between two adjacent stator units 220. Each winding slot 230 penetrates the stator core 200 along the direction of the rotation axis, and the number of winding slots 230 is equal to the number of stator units 220. The stator unit 220 includes a yoke 240, a tooth 221 and a shoe 222. The tooth 221 is arranged along the radial direction of the stator core 200, one end of the tooth 221 is connected to the yoke 240, and the shoe 222 is connected to the other end of the tooth 221, that is, the yoke 240 is located at the end of the tooth 221 away from the rotation axis, and the shoe 222 is located at the end of the tooth 221 close to the rotation axis. Two adjacent yokes 240 are connected, and are partially connected. For example, only the outer ends of the two yokes 240 are adjacent, so that the two adjacent stator units 220 can swing relative to each other. The radial outer wall surface and the radial inner wall surface of the yoke 240 are parallel planes. Therefore, multiple stator units 220 can be unfolded into straight strips or surrounded in a ring shape. In other words, the stator core 200 is a block structure. Along the circumference of the stator core 200, the boot 222 protrudes toward both sides of the tooth 221. Therefore, a notch 231 connected to the winding slot 230 is formed between the two adjacent boots 222, and the notch 231 faces the rotor assembly 100. The winding is wound around the tooth 221. When winding, the winding nozzle extends into the winding slot 230 through the notch 231 for winding, which is convenient for operation.

[0055] Of course, in other embodiments, in two adjacent stator units 220, the two yokes 240 can be connected by means of a shaft pin and a pin hole, which can also enable the two adjacent stator units 220 to swing relative to each other, and multiple stator units 220 can be unfolded into straight strips or arranged in a ring shape, which will not be repeated here.

[0056] Reference Figure 5 and Figure 7 As shown, it can be understood that, in terms of composition, the stator core 200 is also composed of a plurality of stator punchings arranged in a corresponding stacked manner along the direction of the rotation axis. Since the stator core 200 is a block structure and can be unfolded into a straight strip, when producing the stator core 200, a straight stator punching can be first processed, and then a plurality of straight stator punchings can be stacked and fixed in sequence, and then formed into a ring to obtain the stator core 200. Straight stator punchings are conducive to optimizing the arrangement method on the sheet material, so as to make full use of the sheet material, reduce waste, improve the utilization rate of the sheet material, and reduce production costs.

[0057] Reference Figure 5 and Figure 6As shown, it can be understood that in order to improve the structural strength of the stator core 200, in each stator punching sheet, the part corresponding to each yoke 240 and the part corresponding to each tooth 221 are provided with a rivet portion 250, and the two adjacent stator punching sheets are connected and fixed by the rivet portion 250, thereby increasing the overall structural strength of the stator core 200 and making the structure more reliable.

[0058] Reference Figure 5 and Figure 7 As shown, it can be understood that in each stator unit 220, the wall surface of the yoke 240 on one side facing away from the stator unit 220 is a plane, that is, the outer wall surface of the yoke 240 is a plane, and when multiple stator units 220 are unfolded into a straight strip, the outer wall surfaces of multiple yokes 240 are on the same plane. Therefore, when punching stator punching sheets, the wall surfaces on the stator punching sheets corresponding to the outer wall surfaces of multiple yokes 240 are on the same plane, so that the arrangement method on the sheet can be further optimized to make full use of the sheet, reduce waste, improve the utilization rate of the sheet, and reduce production costs.

[0059] Reference Figure 5 As shown, it can be understood that after the multiple stator units 220 surround the annular stator core 200, the projection of the outer peripheral wall of the stator core 200 on the projection plane perpendicular to the rotation axis is a regular polygon. In this embodiment, the stator core 200 includes twelve stator units 220, and the projection of the outer peripheral wall of the stator core 200 is a regular dodecagon.

[0060] Reference Figure 1 and Figure 2 As shown, it can be understood that the inner circumferential wall of the stator assembly and the outer circumferential wall of the rotor assembly 100 are arranged at intervals and an air gap 140 is formed between the two. Generally speaking, the stator assembly includes a second overmolding member, which is coated on the stator core 200 to increase the overall structural stability of the stator assembly, but the second overmolding member does not cover the inner circumferential wall of the stator core 200, that is, the inner circumferential wall of the stator core 200 is the inner circumferential wall of the stator assembly. Similarly, the first overmolding member on the rotor assembly 100 does not cover the outer circumferential wall of the rotor core, and the outer circumferential wall of the rotor core is the outer circumferential wall of the rotor assembly 100. In other words, the air gap 140 is located between the inner circumferential wall of the stator core 200 and the outer circumferential wall of the rotor core.

[0061] Reference Figure 2 and Figure 6 As shown, it can be understood that the two opposite walls defining two adjacent boots 222 are the fifth wall 2224 and the sixth wall 2225, that is, the fifth wall 2224 and the sixth wall 2225 are two inner walls of the slot 231 arranged oppositely in the circumferential direction of the stator core. The minimum width of the slot 231 is defined as W 1In this embodiment, the fifth wall surface 2224 and the sixth wall surface 2225 are parallel, and the vertical distance between the fifth wall surface 2224 and the sixth wall surface 2225 is the minimum width W of the notch 231. 1 , measure W 1 When the width of the slot 231 is 2224, the measurement can be performed by directly clamping the fifth wall 2224 and the sixth wall 2225 with a vernier caliper. 1 The unit is mm.

[0062] In other embodiments, if the fifth wall 2224 and the sixth wall 2225 are not parallel, the measurement can be performed by using a vernier caliper at the point where the distance between the fifth wall 2224 and the sixth wall 2225 is the smallest.

[0063] Reference Figure 4 As shown, it can be understood that the outer wall of the outer core unit 110 is defined as the first wall surface 111, that is, the first wall surface 111 is the wall surface of the outer core unit 110 on the side away from the rotation axis, that is, the first wall surface 111 is the outer contour of the outer core unit 110, and the first wall surface 111 is also a part of the outer peripheral wall of the rotor core. On the projection plane perpendicular to the rotation axis, the projection of the rotation axis is defined as the first reference point K, and the projection of the first wall surface 111 includes the second arc segment 1112, the first arc segment 1111 and the fifth arc segment 1113 connected in sequence. The outer core unit 110 has a first symmetry center line Z arranged along the radial direction of the rotor core. 1 , and the first symmetry center line Z 1 Passing through the first reference point K. The first arc segment 1111 and the first symmetric center line Z 1 Intersect and about the first symmetric center line Z 1 The second arc segment 1112 is symmetrically arranged, and extends along the circumference of the rotor core and in a direction away from the first arc segment 1111. Similarly, the fifth arc segment 1113 extends along the circumference of the rotor core and in a direction away from the first arc segment 1111. The second arc segment 1112 and the fifth arc segment 1113 are symmetrically arranged about the first symmetrical center line Z. 1 Symmetrical arrangement, that is, the projection of the first wall surface 111 is about the first symmetry center line Z 1 symmetry.

[0064] Reference Figure 3 and Figure 4As shown, it can be understood that, in this embodiment, the first arc segment 1111 is an arc segment, and the center of the reference circle where the first arc segment 1111 is located coincides with the first reference point K. The second arc segment 1112 and the fifth arc segment 1113 are also arc segments, and the center of the reference circle where the second arc segment 1112 is located deviates from the first reference point K. Similarly, the center of the reference circle where the fifth arc segment 1113 is located deviates from the first reference point K. In the direction away from the first arc segment 1111, the distance between the second arc segment 1112 and the first reference point K decreases. Define the circle with the center at the first reference point K and the maximum outer diameter of the rotor core as the diameter as the first reference circle P 1 Generally speaking, the maximum outer diameter of the rotor core is twice the maximum distance between the first arc segment 1111 and the first reference point K, that is, the first reference circle P 1 The radius is the maximum distance between the first arc segment 1111 and the first reference point K. In this embodiment, the reference circle where the first arc segment 1111 is located is the first reference circle P 1 That is, the second arc segment 1112 and the fifth arc segment 1113 are biased toward the first reference circle P 1 The inner side of the stator assembly 100, so that the radial distance of the air gap 140 between the stator assembly and the rotor assembly 100 at the second arc segment 1112 and the fifth arc segment 1113 is away from the first symmetry center line Z 1 The direction increases, that is, it is close to the first symmetry center line Z 1 The radial distance of the air gap 140 is large, far away from the first symmetry center line Z 1 The radial distance of the air gap 140 is small. In the circumferential direction of the rotor assembly 100, the radial distance of the air gap 140 is close to a sine distribution, so that the waveform of the air gap magnetic flux distribution is close to a sine waveform, which is beneficial to reduce the harmonic components in the air gap magnetic field, reduce the effect of the harmonic magnetic field, and thus reduce vibration and noise.

[0065] At the same time, since the stator core 200 adopts a block structure, the structural rigidity of the stator core 200 is relatively poor compared to the rigidity of the integral annular structure. During the operation of the motor, the poor structural rigidity of the stator core 200 will cause vibration and noise. Therefore, by setting the first wall surface 111 to be a second arc segment 1112, a first arc segment 1111 and a fifth arc segment 1113 connected in sequence on a projection surface perpendicular to the rotation axis, and the second arc segment 1112 and the fifth arc segment 1113 are symmetrically arranged, so that the waveform of the air gap magnetic flux distribution is close to a sine waveform, which is conducive to reducing the harmonic components in the air gap magnetic field and reducing the effect of the harmonic magnetic field, and further can improve the vibration and noise problems caused by the poor structural rigidity of the stator core 200, thereby reducing vibration and noise.

[0066] Of course, in other embodiments, the second arc segment 1112 and the fifth arc segment 1113 may be asymmetric, which can reduce the noise generated by resonance or excitation.

[0067] An embodiment in which the second arc segment 1112 and the fifth arc segment 1113 are symmetrically arranged will be described in detail below. The structure of the fifth arc segment 1113 may refer to the structure of the second arc segment 1112 .

[0068] Reference Figure 3 and Figure 4 As shown, it can be understood that the central angle corresponding to the first arc segment 1111 is defined as θ 1 , the central angle of the second arc segment 1112 is θ 2 . Measure θ 1 and θ 2 When the first arc segment 1111 is 1111, the first arc segment 1111 is 1111. The first arc segment 1111 is 1111. 1 The central angle θ corresponding to the second arc segment 1112 2 The unit is °.

[0069] Reference Figures 2 to 4 As shown, it can be understood that the minimum width W of the notch 231 1 , the central angle θ corresponding to the first arc segment 1111 1 The central angle θ corresponding to the second arc segment 1112 2 Satisfy: 0.615≤W 1 *θ 1 / θ 2 ≤2. Among them, θ 1 / θ 2 It can be understood that the relationship between the length and curvature of the first arc segment 1111 and the second arc segment 1112 is limited, which corresponds to the sinusoidal degree of the waveform of the air gap magnetic flux distribution. Since the radial distance of the air gap 140 from the stator unit 220 to the slot 231 will suddenly change, the air gap magnetic flux will suddenly change, resulting in a sense of frustration in the rotor assembly 100, a large pulsation of the tooth slot torque, and a large vibration and noise. Therefore, W 1 *θ 1 / θ 2 The value represented by is within a relatively small range, that is, not greater than 2. On the one hand, the minimum width of the slot 231 will not be too large, which is beneficial to reducing the cogging torque pulsation; on the other hand, θ 1 / θ 2 The value of will not be too large, that is, it can be understood as θ 1 The value of is small, θ 2The value of is larger, so that in the circumferential direction of the rotor assembly 100, the radial distance of the air gap 140 is closer to the sinusoidal distribution, so that the waveform of the air gap magnetic density distribution is closer to the sinusoidal waveform, which is beneficial to reduce the harmonic components in the air gap magnetic field, reduce the effect of the harmonic magnetic field, and thus reduce vibration and noise, and reduce the back-electromotive force waveform distortion rate.

[0070] It is understandable that, since the slot 231 is too small, the magnetic flux lines of the magnetic field formed by part of the permanent magnet 120 will be closed at the slot 231, and will not pass through the winding, resulting in magnetic leakage, and the magnetic field of the permanent magnet 120 cannot be fully utilized, resulting in low output torque and output efficiency of the motor. And when the radial distance of the air gap 140 is too large, the air gap magnetic flux density will be too weak, and the magnetic field of the permanent magnet 120 cannot be fully utilized, which will also cause low output torque and output efficiency of the motor. Therefore, W 1 *θ 1 / θ 2 The minimum value represented is 0.615, which can avoid leakage due to the minimum width of the slot 231 being too small, and can avoid the air gap magnetic flux density at this position being too weak due to the maximum radial distance of the air gap 140 being too large, thereby ensuring full utilization of the magnetic field of the permanent magnet 120, ensuring the output torque and output efficiency of the motor, and improving the performance of the motor. Therefore, 0.615≤W 1 *θ 1 / θ 2 ≤2, for example W 1 *θ 1 / θ 2 The values ​​represented are 0.7, 1.0, 1.5 or 1.8, etc., which reduce leakage flux and cogging torque pulsation while ensuring that the output torque and output efficiency of the motor meet the set requirements, making the waveform of the air gap magnetic flux distribution closer to a sinusoidal waveform, which is beneficial to reducing the harmonic components in the air gap magnetic field, reducing the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the distortion rate of the back-EMF waveform.

[0071] Reference Fig. 9 As shown, Base is the existing technical solution, the new solution is the technical solution of the utility model, and the radial acceleration is used to indicate the magnitude of vibration. The larger the radial acceleration, the larger the vibration. Conversely, the smaller the radial acceleration, the smaller the vibration. The figure shows the comparison of radial accelerations of the existing technical solution and the present technical solution at different frequencies. It can be seen from the figure that, except for the radial acceleration of the present technical solution being greater than the radial acceleration of the existing technical solution at 24 rpm, at other frequencies, the radial acceleration of the present technical solution is smaller than the radial acceleration of the existing technical solution, and the total radial acceleration of the present technical solution is smaller than the total radial acceleration of the existing technical solution. Therefore, the present technical solution can significantly reduce vibration and thus reduce noise.

[0072] Reference Figure 5 and Figure 7 As shown, it can be understood that, since the stator core 200 is a block structure and is surrounded by straight strips into a ring. It is easy to understand that for the straight stator core 200, the minimum distance between the two adjacent boots 222 is larger, that is, the minimum width of the notch 231 at this time is larger, on the one hand, it is convenient for the winding nozzle to extend into the winding slot 230 through the notch 231 for winding operation, the movement space of the winding nozzle is larger, easy to operate, and more wires can be wound, which is conducive to improving the slot full rate and improving the performance of the motor; on the other hand, since the minimum distance between the two adjacent boots 222 is larger at this time, the difficulty of blanking the stator punching sheet can be reduced, the dimensional accuracy is high, and it is easy to process. After the winding operation is completed, the straight stator core 200 can be surrounded into a ring, that is, a ring-shaped stator assembly is obtained, which is convenient for production, and at this time, since there is no need to consider the difficulty of winding operation and processing difficulty, a notch 231 with a smaller width can be formed, which is conducive to reducing the tooth slot torque pulsation, reducing vibration and noise.

[0073] Reference Figure 2 and Figure 3 As shown, it can be understood that the minimum width W of the notch 231 1 The central angle θ corresponding to the second arc segment 1112 2 Satisfy: 0.0405≤W 1 / θ 2 ≤0.1, that is, the minimum width of the slot 231 and the length and curvature of the second arc segment 1112 are further limited, so that the minimum width of the slot 231 and the length and curvature of the second arc segment 1112 are within a reasonable range. The length and curvature of the second arc segment 1112 affect the sinusoidality of the waveform of the air gap magnetic flux distribution. 1 / θ 2 If the value represented is too small, the minimum width of the slot 231 is too small, which will cause magnetic leakage. If the maximum radial distance of the air gap 140 is too large, the air gap magnetic flux density at this position will be too weak, and the output torque and output efficiency of the motor will be low. 1 / θ 2 The value represented is too large, and the minimum width of the slot 231 is too large, which will cause the cogging torque pulsation to be too large, and the waveform of the air gap magnetic flux distribution deviates from the sine waveform, the harmonic component in the air gap magnetic field is large, the vibration and noise are large, and the back EMF waveform distortion rate is large. Therefore, 0.0405≤W 1 / θ 2 ≤0.1, e.g. W 1 / θ 2The values ​​represented are 0.05, 0.07, 0.08 or 0.09, etc., which further reduce leakage flux and reduce cogging torque pulsation while ensuring that the output torque and output efficiency of the motor meet the set requirements, so that the waveform of the air gap magnetic flux distribution is closer to a sinusoidal waveform, which is beneficial to reduce the harmonic components in the air gap magnetic field, reduce the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the distortion rate of the back-EMF waveform.

[0074] Reference Figure 3 As shown, it can be understood that the angle between the two ends of the first arc segment 1111 and the line connecting the first reference point K (that is, the central angle of the first arc segment 1111) θ 1 The round angle θ corresponding to the second arc segment 1112 2 Satisfies: 0.41≤θ 1 / θ 2 ≤0.572. In other words, the sinusoidal degree of the waveform of the air gap magnetic flux distribution is further limited. 1 / θ 2 If the value of is too small, the maximum radial distance of the air gap 140 will be too large, which will cause the air gap magnetic flux density at this position to be too weak, and the output torque and output efficiency of the motor will be low; when θ 1 / θ 2 The value of is too large, the waveform of the air gap magnetic density distribution deviates from the sine waveform, the harmonic component in the air gap magnetic field is large, the vibration and noise are large, and the back EMF waveform distortion rate is large. Therefore, make 0.41≤θ 1 / θ 2 ≤0.572, for example, θ 1 / θ 2 The values ​​represented are 0.5, 0.52, 0.55 or 0.56, etc., which can further reduce the cogging torque pulsation and make the waveform of the air gap magnetic flux distribution closer to a sinusoidal waveform while ensuring that the output torque and output efficiency of the motor meet the set requirements, which is beneficial to reducing the harmonic components in the air gap magnetic field and the effect of the harmonic magnetic field, thereby reducing vibration and noise and reducing the distortion rate of the back-EMF waveform.

[0075] Reference Figure 6 As shown, it can be understood that along the circumference of the stator core 200, the minimum width of the boot portion 222 is defined as W 2 Along the circumferential direction of the stator core 200, the boot portion 222 has a seventh wall surface and an eighth wall surface that are separated from each other, and the minimum distance between the seventh wall surface and the eighth wall surface is W. 2 . Measure W 2 When the seventh wall surface is the smallest, the measurement can be performed by using a vernier caliper at the position where the distance between the seventh wall surface and the eighth wall surface is the smallest. In this embodiment, the minimum width of the boot portion 222, that is, the minimum distance W between the seventh wall surface and the eighth wall surface, is 2is the minimum distance between the end of the seventh wall surface close to the rotation axis and the end of the eighth wall surface close to the rotation axis. It can also be understood that, on the projection plane perpendicular to the rotation axis, W 2 is the distance between the end of the projection of the seventh wall surface close to the first reference point K and the end of the eighth wall surface close to the first reference point K. The minimum width W of the boot portion 222 2 The unit is mm.

[0076] Reference Figure 2 and Figure 6 As shown, it can be understood that the minimum width W of the notch 231 1 and the minimum width of the boot 222 is W 2 Satisfy: 0.088≤W 1 / W 2 ≤0.234. It is easy to understand that the minimum width W of the notch 231 1 and the minimum width of the boot 222 is W 2 Inversely proportional, that is, the minimum width of the boot portion 222 is W 2 The smaller the minimum width W of the notch 231 is, 1 The larger the width, the smaller the minimum width of the boot 222 is. 2 The larger the minimum width W of the notch 231 is, 1 The smaller. When W 1 / W 2 If the value of is too small, the minimum width of the slot 231 will be too small, which will cause magnetic leakage, resulting in low output torque and output efficiency of the motor. 1 / W 2 If the value of is too large, on the one hand, the minimum width of the slot 231 is too large, the tooth torque pulsation is too large, and the vibration and noise are large; on the other hand, the minimum width of the shoe 222 is too small, and the area of ​​the shoe 222 for receiving the magnetic flux is too small, and the magnetic field of the permanent magnet 120 cannot be fully utilized, which also causes the output torque and output efficiency of the motor to be low. Therefore, 0.088≤W 1 / W 2 ≤0.234, for example, W 1 / W 2 =0.1, W 1 / W 2 =0.15 or W 1 / W 2 =0.2, etc., while ensuring that the output torque and output efficiency of the motor meet the set requirements, the leakage flux is further reduced, and the cogging torque pulsation can be reduced, thereby reducing vibration and noise.

[0077] Reference Figure 6As shown, it can be understood that, along the radial direction of the stator core 200, the side of the boot 222 facing the rotation axis has a fourth wall 2221, that is, the fourth wall 2221 is the wall of the stator unit 220 facing the rotor core, that is, the fourth wall 2221 is the inner contour of the boot 222, and the fourth wall 2221 is also a part of the inner circumferential wall of the stator core 200. On the projection plane perpendicular to the rotation axis, the projection of the fourth wall 2221 includes a third arc segment 2222 and two fourth line segments 2223, and the stator unit 220 has a second symmetric center line Z arranged along the radial direction of the stator core 200. 2 , and the second symmetry center line Z 2 The third arc segment 2222 and the second symmetric center line Z 2 Intersect and about the second symmetric center line Z 2 The two fourth line segments 2223 are symmetrically arranged, and the two fourth line segments 2223 are respectively connected to the two ends of the third arc segment 2222 along the circumferential direction of the stator core 200, and the fourth line segment 2223 extends along the circumferential direction of the stator core 200 and in a direction away from the third arc segment 2222. The two fourth line segments 2223 are symmetrical about the second symmetrical center line Z. 2 Symmetrical arrangement.

[0078] Reference Figure 5 and Figure 6 As shown, it can be understood that, in this embodiment, the third arc segment 2222 is an arc segment, and the center of the reference circle where the third arc segment 2222 is located coincides with the first reference point K. The fourth line segment 2223 is a straight line segment, and the distance between the fourth line segment 2223 and the first reference point K increases in the direction away from the third arc segment 2222. The circle with the center at the first reference point K and the minimum inner diameter of the stator core 200 as the diameter is defined as the second reference circle P 2 Generally speaking, the minimum inner diameter of the stator core 200 is twice the minimum distance between the third arc segment 2222 and the first reference point K, that is, the second reference circle P 2 The radius is the minimum distance between the third arc segment 2222 and the first reference point K. In this embodiment, the reference circle where the third arc segment 2222 is located is the second reference circle P 2 That is, the fourth line segment 2223 deviates toward the second reference circle P 2 Generally speaking, the third arc segment 2222 and the second arc segment 1112 are arranged opposite to each other in the radial direction of the stator core 200. Therefore, the radial distance of the air gap 140 at the second arc segment 1112 is along the direction away from the first symmetry center line Z. 1The direction increases, and the distance further increases, so that in the circumferential direction of the rotor assembly 100, the radial distance of the air gap 140 is closer to the sinusoidal distribution, so that the waveform of the air gap magnetic density distribution is closer to the sinusoidal waveform, which is beneficial to reduce the harmonic components in the air gap magnetic field, reduce the effect of the harmonic magnetic field, and thus reduce vibration and noise, and reduce the back-electromotive force waveform distortion rate.

[0079] Reference Figure 2 As shown, it can be understood that, due to the first reference circle P 1 The center of the second reference circle P 2 The center of the circle coincides with the first reference point K. Generally speaking, the first arc segment 1111 and the third arc segment 2222 are arranged relative to each other in the radial direction of the rotor core. Therefore, in the circumferential direction of the rotor assembly 100, the radial distance of the air gap 140 at the first arc segment 1111 is equal at all places, that is, the air gap 140 at the first arc segment 1111 is a uniform air gap 140, and the radial distance of the air gap 140 at the first arc segment 1111 is the smallest. Therefore, in the circumferential direction of the rotor assembly 100, the range in which the radial distance of the air gap 140 is the smallest is relatively large, which is conducive to the magnetic field generated by the permanent magnet 120 to pass through the air gap 140 more, expanding the range with a larger air gap magnetic density, so as to make full use of the magnetic field of the permanent magnet 120, thereby improving the output efficiency and output torque of the motor and improving the performance of the motor.

[0080] Reference Figure 2 As shown, it can be understood that along the radial direction of the rotor core, the minimum distance of the air gap 140 is defined as L 1 , the maximum distance of the air gap 140 is L 2 .L 1 and L 2 The unit is mm. It is easy to understand that, on the projection plane perpendicular to the rotation axis, the radial distance between the first arc segment 1111 and the third arc segment 2222 is the minimum distance L of the air gap 140. 1 The distance between the end of the second arc segment 1112 away from the first arc segment 1111 and the end of the fourth line segment 2223 away from the third arc segment 2222 is the maximum distance L of the air gap 140. 2 The minimum distance L of the air gap 140 1 The maximum distance L from the air gap 140 2 Satisfy: 0.107≤L 1 / L 2 ≤0.25.L 1 / L 2 The ratio of is reflected in the sine degree of the radial distance distribution of the air gap 140 in the circumferential direction of the rotor assembly 100, that is, the sine degree of the waveform of the air gap magnetic flux distribution. 1 / L 2The value of is too small, the minimum distance of the air gap 140 is too small, and during the rotation of the rotor assembly 100, the rotor core and the stator core 200 are easily scratched and generate noise, and the maximum distance of the air gap 140 is too large, resulting in the air gap magnetic flux density at this position being too weak, and the output torque and output efficiency of the motor are low. 1 / L 2 The value of is too large, the waveform of the air gap magnetic density distribution deviates from the sinusoidal distribution, the harmonic component in the air gap magnetic field is large, the vibration and noise are large, and the back EMF waveform distortion rate is large. Therefore, make 0.107≤L 1 / L 2 ≤0.25, for example, L 1 / L 2 =0.15, L 1 / L 2 =0.18, L 1 / L 2 =0.2 or L 1 / L 2 =0.23, etc., under the premise of ensuring that the output torque and output efficiency of the motor meet the set requirements, the rotor core and the stator core are prevented from scratching each other by 200, so that the waveform of the air gap magnetic flux distribution is closer to a sine waveform, which is beneficial to reduce the harmonic components in the air gap magnetic field, reduce the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the back-EMF waveform distortion rate.

[0081] Reference Figure 2 and Figure 3 As shown, it can be understood that the number of outer core units 110 is defined as N, and the maximum outer diameter of the rotor assembly 100 is defined as D 3 , that is, the first reference circle P 1 The diameter is D 3 , satisfying: 0.01≤L 1 *N / (π*D 3 )≤0.025. Generally speaking, the number N of the outer core units 110 is a certain value, and the maximum outer diameter of the rotor assembly 100 is a certain value, that is, the minimum distance of the air gap 140 is set according to the maximum outer diameter of the rotor assembly 100. Therefore, 0.01≤L 1 *N / (π*D 3 )≤0.025, for example, L 1 *N / (π*D 3 )=0.015、L 1 *N / (π*D 3 )=0.018 or L 1 *N / (π*D 3)=0.02, etc., can avoid the drawback that the rotor core and the stator core 200 scrape and generate noise due to the minimum distance of the air gap 140 being too small, and at the same time, can avoid the output torque and output efficiency of the motor being low due to the air gap magnetic density being too weak due to the minimum distance of the air gap 140 being too large. Therefore, under the premise of ensuring that the output torque and output efficiency of the motor meet the set requirements, the rotor core and the stator core 200 can be prevented from scraping and generating noise. At the same time, the minimum distance L of the air gap 140 is 1 Meet: 0.3mm≤L 1 ≤0.6mm, for example L 1 =0.3mm, L 1 =0.4mm or L 1 =0.5mm, etc., will not be repeated here.

[0082] Reference Figure 4 As shown, it can be understood that the magnetic resistance of the iron core is smaller than that of the air. In order to further optimize the magnetic field distribution of the permanent magnet 120, each outer core unit 110 is provided with a magnetic barrier hole 112, and the magnetic barrier hole 112 passes through the outer core unit 110 along the direction of the rotation axis. On the projection plane perpendicular to the rotation axis, the magnetic barrier hole 112 is located at the first symmetry center line Z 1 On one side, the projection of the magnetic barrier hole 112 is an elongated hole and has a center line arranged along the length direction, and the two ends of the magnetic barrier hole 112 along the center line are respectively facing the mounting groove 130 and the first wall surface 111, that is, the center line of the magnetic barrier hole 112 is symmetrical to the first center line Z 1 Therefore, when the magnetic field generated by the permanent magnet 120 is directed to the air gap 140 through the outer core unit 110, the magnetic field of the permanent magnet 120 does not pass through the magnetic barrier hole 112. It can also be understood that the magnetic barrier hole 112 shunts the magnetic field on the outer core unit 110 and directs the magnetic field toward the first symmetry center line Z. 1 The positions are concentrated, thereby optimizing the magnetic field distribution on the outer core unit 110, making the waveform of the air gap magnetic density distribution closer to a sine waveform, which is beneficial to reducing the harmonic components in the air gap magnetic field, reducing the effect of the harmonic magnetic field, thereby reducing vibration and noise, and reducing the distortion rate of the back-EMF waveform, thereby improving the back-EMF waveform.

[0083] Reference Figure 4 and Figure 8 As shown, it can be understood that, in this embodiment, each outer core unit 110 is provided with two magnetic barrier holes 112, and the two magnetic barrier holes 112 are about the first symmetric center line Z 1 The two magnetic barrier holes 112 are arranged symmetrically, and are perpendicular to the first symmetry center line Z. 1 The distance in the direction of decreases from the rotation axis to the outside of the rotor core. The angle between the center lines of the two magnetic barrier holes 112 is defined as θ 3 ,θ3 The unit is °. The minimum width W of the notch 231 1 The angle θ between the center lines of the two magnetic barrier holes 112 3 Satisfy: 0.033≤W 1 / θ 3 ≤0.14. That is, the value of the included angle between the center lines of the two magnetic barrier holes 112 is set according to the minimum width of the slot 231. 1 Under the premise of determining the value of 1 / θ 3 ≤0.14, e.g. W 1 / θ 3 The represented values ​​are 0.04, 0.06, 0.08, 0.1 or 0.12, etc., which can prevent the angle between the center line of the two magnetic barrier holes 112 and the magnetic field direction on the outer core unit 110 from being too large, thereby optimizing the magnetic field distribution on the outer core unit 110 and making the waveform of the air gap magnetic flux distribution closer to a sine waveform.

[0084] Reference Figures 2 to 4 As shown, it can be understood that the minimum width W of the notch 231 1 , the angle between the two ends of the first arc segment 1111 and the line connecting the first reference point K (ie, the central angle of the first arc segment 1111) θ 1 The angle θ between the center lines of the two magnetic barrier holes 112 3 Satisfy: 0.49≤W 1 *θ 1 / θ 3 ≤5.58. That is, the included angle of the center lines of the two magnetic barrier holes 112 is further limited, according to the minimum width of the slot 231 and the center angle θ corresponding to the first arc segment 1111 1 The value of more accurately sets the value of the angle between the center lines of the two magnetic barrier holes 112, and the minimum width W of the slot 231 1 The central angle θ corresponding to the first arc segment 1111 1 Under the premise of determining the value of 1 *θ 1 / θ 3 ≤5.58, for example, W 1 *θ 1 / θ 3 The represented value is 0.5, 0.9, 1.5, 2 or 3, etc., to further optimize the value range of the angle between the center lines of the two magnetic barrier holes 112, so that the direction of the center lines of the two magnetic barrier holes 112 is closer to the direction of the magnetic field on the outer core unit 110, thereby further optimizing the magnetic field distribution on the outer core unit 110, so that the waveform of the air gap magnetic flux distribution is closer to a sine waveform.

[0085] It is understandable that in order to increase the output torque of the motor, it is generally achieved by increasing the magnetic field of the permanent magnet 120. Therefore, it is necessary to increase the thickness of the permanent magnet 120, that is, it is necessary to increase the width of the installation slot 130 in the circumferential direction of the rotor core. If the width of the installation slot 130 in the circumferential direction of the rotor core is too large, there will be interference between two adjacent installation slots 130 close to the end of the rotation axis, and the permanent magnet 120 cannot be installed.

[0086] For this purpose, refer to Figure 4 As shown, it can be understood that, along the circumference of the rotor core, the mounting groove 130 has a second wall surface 131 and a third wall surface 132 arranged opposite to each other, and the second wall surface 131 and the third wall surface 132 are respectively recessed in opposite directions, that is, the second wall surface 131 and the third wall surface 132 are respectively recessed in opposite directions toward the mounting groove 130 along the circumference of the rotor core. On the projection surface perpendicular to the rotation axis, the projections of the second wall surface 131 and the third wall surface 132 can be arc segments, broken line segments or curve segments, that is, in the radial direction of the rotor core, the mounting groove 130 is wide in the middle and narrow at both ends. Correspondingly, on the projection surface perpendicular to the rotation axis, the outer contour of the permanent magnet 120 matches the inner contour of the mounting groove 130. That is, from the middle of the permanent magnet 120 to the two ends of the permanent magnet 120 in the radial direction, the distance between the two walls of the permanent magnet 120 that are opposite to each other along the circumference decreases, and the permanent magnet 120 is wide in the middle and narrow at both ends. Therefore, the maximum width of the mounting groove 130 in the circumferential direction of the rotor core can be increased, that is, the maximum width of the permanent magnet 120 is increased, the magnetic field generated by the permanent magnet 120 is enhanced, the torque density is improved, and the output torque of the motor is improved. At the same time, the width of the mounting groove 130 close to the rotation axis is not too large to avoid interference, and the structure is reasonable and conducive to ensuring the structural strength of the rotor core.

[0087] In other embodiments, or, from the direction of the stator assembly toward the rotation axis, that is, from the outside to the inside, the distance between the second wall surface 131 and the third wall surface 132 in the circumferential direction of the rotor core decreases, and the second wall surface 131 and the third wall surface 132 are both planes, that is, in the radial direction of the rotor core, the installation slot 130 is wide on the outside and narrow on the inside, that is, on the projection plane perpendicular to the rotation axis, the projection of the installation slot 130 is trapezoidal. Therefore, the maximum width of the permanent magnet 120 can also be increased, the magnetic field generated by the permanent magnet 120 can be enhanced, and the width of the installation slot 130 at one end close to the rotation axis will not be too large to avoid interference.

[0088] Reference Figure 5 As shown, it can be understood that the maximum outer diameter of the stator assembly is defined as D 1 , the minimum inner diameter of the stator assembly is D 2It is easy to understand that the maximum outer diameter of the stator assembly is the maximum outer diameter of the stator core 200, and the minimum inner diameter of the stator assembly is the minimum inner diameter of the stator core 200. In this embodiment, the maximum outer diameter of the stator core 200 is the diameter of the circumscribed circle of the projection of the outer peripheral wall of the stator core 200 which is a regular polygon on the projection plane perpendicular to the rotation axis, and the minimum inner diameter of the stator core 200 is the second reference circle P 2 The maximum outer diameter of the stator assembly is D 1 and the minimum inner diameter D of the stator assembly 2 The unit is mm, satisfying: 0.58≤D 2 / D 1 ≤0.625. Generally speaking, in order to meet the installation requirements of the motor, the outer diameter of the stator core 200 is a certain value. Under the premise that the maximum radial distance of the air gap 140 remains unchanged, D 2 / D 1 The value of is not less than 0.58, which can increase the minimum inner diameter of the stator core 200, and then increase the maximum outer diameter of the rotor core. Therefore, a larger installation slot 130 can be set on the rotor core to install a thicker permanent magnet 120, thereby increasing the magnetic field generated by the permanent magnet 120, improving the torque density, and helping to improve the output torque of the motor. At the same time, D 2 / D 1 The value of is not more than 0.625, which can avoid the minimum inner diameter of the stator core 200 being too large and causing the radial width of the yoke 240 to be too small, thereby avoiding the problem of reduced structural strength of the stator core 200 and the disadvantage of easy occurrence of magnetic flux saturation at the yoke 240, thereby improving the reliability of motor operation. At the same time, it can avoid the space of the winding slot 230 being too small to affect the winding size, which is conducive to ensuring that the performance of the motor meets the set requirements.

[0089] The household appliance of the second embodiment of the utility model comprises the motor of the first embodiment of the utility model. The household appliance may be a washing machine, a dryer, etc. In the washing machine or the dryer, the drum of the washing machine or the dryer is driven to rotate by the motor.

[0090] Since the household appliance adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0091] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A motor, characterized in that include: A rotor assembly, rotating around a rotation axis, the rotor assembly comprising a plurality of outer core units and a plurality of permanent magnets, the plurality of outer core units being arranged at intervals along the circumference of the rotor assembly, a mounting groove being defined between two adjacent outer core units, the plurality of permanent magnets being correspondingly mounted in the plurality of mounting grooves, the projection of the outer contour of the core unit on a projection plane perpendicular to the rotation axis comprising a second arc segment, a first arc segment and a fifth arc segment connected in sequence, the distance between the second arc segment and the rotation axis decreasing in a direction away from the first arc segment, and the distance between the fifth arc segment and the rotation axis decreasing in a direction away from the first arc segment; A stator assembly comprises a stator core, which is arranged around the outer circumference of the rotor assembly. The stator core comprises a plurality of stator units arranged along the circumferential direction. The stator units comprise a yoke, a tooth and a shoe. The yoke and the shoe are respectively connected to the radial ends of the tooth. The radial outer wall surface and the radial inner wall surface of the yoke are parallel planes. Two adjacent yokes are connected, a winding groove is defined between two adjacent stator units, and a notch of the winding groove is defined between two adjacent shoe portions.

2. The motor according to claim 1, characterized in that: The second arc segment and the fifth arc segment are arranged symmetrically.

3. The motor according to claim 2, characterized in that: Along the circumferential direction, in units of mm, the minimum width of the notch is W1, the center angle corresponding to the first arc segment is θ1, and the center angle corresponding to the second arc segment is θ2, satisfying: 0.615≤W1*θ1 / θ2≤2.

4. The motor according to claim 3, characterized in that: The minimum width W1 of the notch and the central angle θ2 corresponding to the second arc segment satisfy: 0.0405≤W1 / θ2≤0.

1.

5. The motor according to claim 3, characterized in that: The center angle θ1 corresponding to the first arc segment and the center angle θ2 corresponding to the second arc segment satisfy: 0.41≤θ1 / θ2≤0.

572.

6. The motor according to claim 3, characterized in that: Along the circumferential direction, the boot portion is protruded toward both sides of the tooth portion, and the minimum width of the boot portion along the circumferential direction is W2, satisfying: 0.088≤W1 / W2≤0.

234.

7. The motor according to claim 6, characterized in that: On the projection plane perpendicular to the rotation axis, the projection of the inner contour of the boot includes a third arc segment and a fourth line segment respectively connected to both ends of the third arc segment, and the distance between the fourth line segment and the rotation axis increases in a direction away from the third arc segment.

8. The motor according to claim 1, characterized in that: An air gap is provided between the outer circumferential wall of the rotor assembly and the inner circumferential wall of the stator assembly. Along a direction perpendicular to the rotation axis, the minimum distance of the air gap is L1, and the maximum distance of the air gap is L2, satisfying: 0.107≤L1 / L2≤0.

25.

9. The motor according to claim 8, characterized in that: The number of the outer core units is N, and the maximum outer diameter of the rotor assembly is D3, satisfying: 0.01≤L1*N / (π*D3)≤0.

025.

10. The motor according to claim 8, characterized in that: The minimum distance L1 of the air gap satisfies: 0.3 mm ≤ L1 ≤ 0.6 mm.

11. The motor according to claim 1, characterized in that: The outer core unit is provided with a magnetic barrier hole. On a projection plane perpendicular to the rotation axis, the projection of the magnetic barrier hole is in the shape of an elongated strip and has a length direction. The two ends of the magnetic barrier hole along the length direction respectively face the mounting slot and the outer contour of the outer core unit.

12. The motor according to claim 11, characterized in that: The number of the magnetic barrier holes of each outer core unit is two, the two magnetic barrier holes are symmetrically arranged about the first symmetry center line of the outer core unit, and the included angle of the two magnetic barrier holes is θ3, satisfying: 0.033≤W1 / θ3≤0.

14.

13. The motor according to claim 12, characterized in that: The minimum width W1 of the notch, the central angle θ1 corresponding to the first arc segment and the included angle θ3 of the two magnetic barrier holes satisfy: 0.49≤W1*θ1 / θ3≤5.

58.

14. The motor according to claim 1, characterized in that: From the middle of the permanent magnet to both ends of the permanent magnet in the radial direction, the distance between the two wall surfaces of the permanent magnet that are away from each other in the circumferential direction decreases gradually.

15. The motor according to claim 1 or 14, characterized in that: The maximum outer diameter of the stator assembly is D1, and the minimum inner diameter of the stator assembly is D2, satisfying: 0.58≤D2 / D1≤0.

625.

16. The motor according to claim 1, characterized in that: The outer core unit includes a second limiting protrusion, which is located at one end of the mounting slot away from the rotation axis. The second limiting protrusion includes a fixing portion, which is located at one end of the second limiting protrusion away from the mounting slot and protrudes along the circumferential direction.

17. The motor according to claim 1, characterized in that: The rotor assembly further includes a first overmolded component, which covers the outer core unit and the permanent magnet. The stator assembly further includes a second overmolded component, which covers the stator core.

18. A household appliance, characterized in that Comprising a motor as claimed in any one of claims 1 to 17.

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