Motor

Abstract

The present application discloses a motor, the motor comprising: a stator core, comprising a stator yoke and a plurality of stator teeth, the stator yoke is arranged in an annular shape and has an inner circumferential surface, the inner circumferential surface comprises a plurality of arc surfaces and a plurality of straight surfaces arranged alternately and connected in sequence along the circumferential direction, the plurality of stator teeth are connected one-to-one with the plurality of straight surfaces, the wall thickness of the stator yoke at the arc surface is less than the wall thickness at the straight surface; and a rotor, arranged in the stator core, the rotor comprises a rotating shaft and a permanent magnet fixed on the rotating shaft, the permanent magnet comprises a first section and a second section arranged along the axial direction of the rotating shaft, the magnetic poles of the first section and the magnetic poles of the second section are staggered at a preset angle in the circumferential direction of the rotating shaft. Such an arrangement can effectively overcome the problems of poor sinusoidality of magnetic field distribution and serious distortion of air gap magnetic field waveform caused by the traditional stator tooth slot structure.

Description

Technical Field

[0001] The present application relates to the technical field of electric drive devices, and in particular to a motor. Background Art

[0002] The stators of traditional motors, such as micro high-speed and ultra-high-speed motors, all adopt the traditional slotted stator lamination stacking structure, such as Figure 1 As shown in the figure, the stator 30' of the traditional motor has an inner circumference of a circular arc surface. This structure has the following disadvantages: the stator slot structure leads to poor sinusoidal magnetic field distribution, and the air gap magnetic field waveform is seriously distorted, which is mainly manifested as large slot torque and is difficult to eliminate. Based on this, the inherent existence of slot torque will cause the motor to have a series of problems such as a sharp increase in stator iron loss, severe heat generation, large mechanical vibration, high noise, and poor motor structural stability when running at ultra-high speed. At the same time, coupled with Figure 2 After the rotor 20' is matched, the permanent magnet of the rotor 20' adopts a whole-section design, and the harmonics of the air gap magnetic flux density of the motor will be further increased. Utility Model Content

[0003] The main purpose of this application is to propose a motor, which aims to effectively overcome the problems of poor sinusoidal magnetic field distribution and severe distortion of air gap magnetic field waveform caused by the traditional stator slot structure.

[0004] To achieve the above-mentioned purpose, the present application proposes a motor, comprising:

[0005] A stator core, comprising a stator yoke and a plurality of stator teeth, wherein the stator yoke is arranged in an annular shape and has an inner circumferential surface, wherein the inner circumferential surface comprises a plurality of arc surfaces and a plurality of straight surfaces which are alternately arranged and sequentially connected along the circumference thereof, wherein the plurality of stator teeth are connected to the plurality of straight surfaces in a one-to-one correspondence, and wherein the wall thickness of the stator yoke at the arc surface is smaller than the wall thickness at the straight surface; and,

[0006] A rotor is arranged in the stator core, the rotor includes a rotating shaft and a permanent magnet fixed on the rotating shaft, the permanent magnet includes a first section and a second section arranged along the axial direction of the rotating shaft, and the magnetic poles of the first section and the magnetic poles of the second section are staggered by a preset angle in the circumferential direction of the rotating shaft.

[0007] Optionally, the distance from the straight surface to the center of the arc surface is a first distance, and the ratio of the radius of the arc surface to the first distance is greater than or equal to 1.03 and less than or equal to 1.15.

[0008] Optionally, the stator tooth portion comprises a main body section and a flange, one end of the main body section is connected to the straight surface, and the other end of the main body section is laterally protruding and provided with the flange;

[0009] A ratio of a wall thickness of the stator yoke corresponding to the arc surface to a width of the main body segment is greater than or equal to 0.7 and less than or equal to 0.95.

[0010] Optionally, the stator tooth portion comprises a main body section and a flange, one end of the main body section is connected to the straight surface, and the other end of the main body section is laterally protruding and provided with the flange;

[0011] The interval between two adjacent stator teeth forms a tooth slot, and the ratio of the slot width of the tooth slot to the width of the main body segment is greater than or equal to 0.8 and less than or equal to 1.25.

[0012] Optionally, a side of the stator tooth portion facing away from the straight surface is a concave arc surface, and the concave arc surfaces of a plurality of stator teeth portions are concentrically arranged;

[0013] The ratio of the radius of the concave arc surface to the radius of the outer circumference of the stator yoke is greater than or equal to 0.45 and less than or equal to 0.66.

[0014] Optionally, the width of the straight surface is greater than the maximum width of the stator tooth.

[0015] Optionally, the width of the straight surface is greater than the chord length of the arcuate surface.

[0016] Optionally, the arc-shaped surface is recessed outward, and the stator teeth are perpendicular to the straight surface.

[0017] Optionally, the arc surface is an arc surface, the stator tooth portion includes two first side surfaces arranged opposite to each other along the circumference of the stator yoke portion, the two first side surfaces are respectively connected to the straight surface, and the two first side surfaces are both straight surfaces and perpendicular to the straight surface.

[0018] Optionally, the first segment and the second segment respectively have the same number of magnetic pole pairs, and the range of the preset angle is (15° to 30°) / p, where p is the number of magnetic pole pairs of the first segment.

[0019] The technical solution in the embodiment of the present application increases the structural strength of the connection between the stator teeth and the stator yoke. When the coil is wound on the stator teeth, the deviation of the stator teeth caused by the high-frequency wire tension of the winding machine during the winding process can be effectively reduced, and the noise generation can be reduced. The intrinsic vibration frequency of the stator will be greatly improved, which can effectively isolate the stator resonance caused by torque pulsation, so that the harmonic response energy of the stator can be greatly reduced, thereby greatly reducing the noise and vibration of the motor. At the same time, after being matched with the staggered pole structure of the rotor permanent magnet, the stator magnetic circuit path is shorter, the concentration of the rotor magnetic field along the axial distribution is reduced, and the total magnetic flux of the motor will not be reduced, which is conducive to the motor air gap magnetic density distribution showing a sinusoidal wave characteristic, and then the back electromotive force waveform of the motor presents a characteristic close to a sine wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a plan view of the stator core of the motor in the traditional solution;

[0022] Figure 2 It is a schematic diagram of the structure of the rotor and shaft of the motor in the traditional solution;

[0023] Figure 3 It is a schematic diagram of the structure of the stator core of the motor in the embodiment of the present application;

[0024] Figure 4 and Figure 5 They are Figure 3 A schematic plan view of the stator core;

[0025] Figure 6 It is a schematic diagram of the structure after the rotor and the rotating shaft of the motor in the embodiment of the present application are assembled;

[0026] Figure 7 This is a comparison diagram of the back electromotive force waveforms of the technical solution of this application and the traditional solution;

[0027] Figure 8 This is a comparison chart of the output torque pulsation between the technical solution of this application and the traditional solution.

[0028] Description of Figure Numbers:

[0029] Label name Label name Label name 100 Rotor 30 Stator core 32 Stator teeth 10 Shaft 31 stator yoke 321 Body 20 permanent magnet 311 Curved surface 322 Flange 21 Paragraph 1 312 Flat surface 323 First side 22 Paragraph 2 DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] It should be noted that, in the description of this application, if the terms "first", "second", etc. appear, "first" and "second" are only used to facilitate the description of different components or names, and cannot be understood as indicating or implying a sequential relationship, relative importance, or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" appears in the full text, its meaning is that it includes three parallel solutions, taking "A and / or B as an example", including Solution A, or Solution B, or a solution that satisfies both A and B.

[0032] The rotation speed of motors, especially high-speed motors, generally exceeds 30,000 rpm, reaching 100,000 rpm or even 200,000 pm. Many problems in the operation of motors at conventional speeds (generally 3,000 rpm and below), such as torque pulsation, vibration, noise, and efficiency, will be magnified dozens or even hundreds of times under ultra-high-speed operation, which will not only greatly affect the overall operation quality of the motor, but more seriously will bring huge challenges to the stable and reliable operation of the motor and even burn the entire motor drive system. In addition, the biggest challenge of ultra-high-speed motors during operation is the poor waveform of the motor back electromotive force and the large output torque pulsation. The poor waveform of the back electromotive force means that the motor waveform has many harmonic components, which causes serious heating of the motor and the risk of coil burning. The large output torque pulsation means that the motor vibration and noise will be strong, resulting in poor operation quality and poor experience.

[0033] To this end, the present application provides a motor whose main application areas include but are not limited to hair dryers, vacuum cleaners, drone drives, electric ducted motors, electric spindles, etc. Its usage scenarios require the use of high-speed or ultra-high-speed motors and have high requirements for output quality.

[0034] Please refer to Figures 3 to 6The embodiment of the present application proposes a motor, including a rotor 100 and a stator core 30, wherein the rotor 100 is disposed in the stator core 30, and the rotor 100 includes a rotating shaft 10 and a permanent magnet 20, wherein the permanent magnet 20 is fixed on the rotating shaft 10. The permanent magnet 20 includes a first section 21 and a second section 22 disposed along the axial direction of the rotating shaft 10, wherein the magnetic poles of the first section 21 and the magnetic poles of the second section 22 are staggered by a preset angle α in the circumferential direction of the rotating shaft 10. The first section 21 and the second section 22 of the permanent magnet 20 can be disposed in connection or independently. The stator core 30 includes a stator yoke 31 and a plurality of stator teeth 32, wherein the stator yoke 31 is disposed in an annular shape and has an inner circumferential surface, wherein the inner circumferential surface includes a plurality of arc surfaces 311 and a plurality of straight surfaces 312 which are alternately disposed and sequentially connected along the circumferential direction thereof, Figure 4 The arc surface 311 is between the middle dotted lines S1 and S2, and the flat surface 312 is between the dotted lines S2 and S3. The arc surface 311 is recessed outward, and multiple stator teeth 32 are connected to multiple flat surfaces 312 in a one-to-one correspondence. The wall thickness Wq of the stator yoke 31 at the arc surface 311 is smaller than the wall thickness Wa at the flat surface 312.

[0035] The permanent magnet 20 adopts a multi-section design, including at least a first section 21 and a second section 22 arranged along the axial direction of the rotating shaft 10. The first section 21 and the second section 22 are processed separately, so when assembled to the rotating shaft 10, the magnetic poles of the first section 21 and the second section 22 can be staggered at a preset angle along the circumference of the rotating shaft 10 for assembly. The first section 21 and the second section 22 can be fixed to each other to form a whole after processing, or the first section 21 and the second section 22 are only fixed to the rotating shaft 10 respectively.

[0036] N and S distributed along the axial direction of the rotating shaft 10 are regarded as a pair of magnetic poles, which are called a pair of magnetic pole pairs, and N and S are two magnetic poles. The first section 21 and the second section 22 respectively include multiple pairs of magnetic poles of the same number distributed circumferentially around the rotating shaft 10, and, in the circumferential direction of the rotating shaft 10, the magnetic poles at the same end of the first section 21 are distributed alternately, that is, they are distributed in sequence in the manner of N, S, N, S... Similarly, the magnetic poles at the same end of the second section 22 are also distributed alternately. In the embodiment of the present application, the magnetic poles of the first section 21 and the magnetic poles of the second section 22 are staggered at a preset angle in the circumferential direction of the rotating shaft 10, which means that the same pair of magnetic poles in the first section 21 and the second section 22 are not aligned in the axial direction of the rotating shaft 10, but are staggered at a preset angle. For example, taking the NS magnetic pole as an example, the NS magnetic pole of the first section 21 and the NS magnetic pole of the second section 22 only partially overlap in the axial direction of the rotating shaft 10, and the central angle formed by the part of the NS magnetic pole of the first section 21 that exceeds the NS magnetic pole of the second section 22 in the circumferential direction of the rotating shaft 10 is the preset angle α.

[0037] The stator yoke 31 is generally in the form of a circular ring structure, and a plurality of stator teeth 32 are located in the stator yoke 31 and are sequentially arranged along the circumference of the stator yoke 31, and a stator coil is wound around each stator tooth 32. Generally, the stator teeth 32 and the stator yoke 31 are integrally formed, for example, by stamping.

[0038] The arc surface 311 is an arc surface, and a plurality of arc surfaces 311 are concentrically arranged, and the center of the circle is the center of the stator core 30. The straight surface 312 refers to a non-curved structure. Since the arc surface 311 and the straight surface 312 are alternately connected, and the arc surface 311 is concave outward, the wall thickness of the stator yoke 31 at the arc surface 311 is necessarily smaller than the wall thickness at the straight surface 312.

[0039] In the embodiment of the present application, the inside and outside refer to the side close to the rotating shaft 10 as the inside and the side away from the rotating shaft 10 as the outside along the radial direction of the rotating shaft 10 with the rotating shaft 10 as the center.

[0040] The stator adopting this structure is called an SQ stator, and the SQ structure is defined as follows: SQ is the abbreviation of the English words Square and Quoit, the stator teeth 32 and the straight surface 312 of the stator yoke 31 are connected vertically in a square, the S line is a vertical line segment from the center of the arc surface 311 to the straight surface 312, and the length of the S line, that is, the first distance, is the distance from the center of the arc surface 311 to the straight surface 312. The height of the S line can be adjusted as needed to adjust the connection between the stator teeth 32 and the stator yoke 31; the ring formed by the arc surface 311 serves as the inner circle of the stator yoke 31, and the Q line is the diameter of the inner circle of the stator yoke 31 (or the arc formed by the arc surface 311). The size of the Q line can be adjusted as needed to adjust the connection between the stator teeth 32 and the stator yoke 31, and the size adjustment of the two SQ lines can determine the basic magnetic circuit structure and mechanical natural frequency of the motor.

[0041] In the embodiment of the present application, when the SQ stator structure is adopted, since the stator teeth 32 are connected to the thicker and straight position of the stator yoke 31, the connection between the stator teeth 32 and the stator yoke 31 is significantly strengthened, which can bring the following beneficial effects:

[0042] First, the structural strength of the connection between the stator tooth portion 32 and the stator yoke portion 31 is increased. When the coil is wound on the stator tooth portion 32, the deviation of the stator tooth portion 32 caused by the high-frequency wire tension of the winding machine during the winding process can be effectively reduced.

[0043] Second, when the structural strength increases, the intrinsic vibration frequency of the stator will increase significantly, which can effectively isolate the stator resonance caused by torque pulsation and greatly reduce the harmonic response energy of the stator, thereby greatly reducing the noise and vibration of the motor.

[0044] Third, the SQ stator structure is more conducive to winding. When the wire outlet needle of the winding machine is winding on the SQ stator, the wire outlet needle can be perpendicular to the coil at the bottom of the Q wire winding slot. The winding tension is tighter and there is no need to consider the collision between the winding needle and the stator yoke 31. However, in the non-SQ stator structure, since the stator tooth 32 is connected to the arc surface of the stator yoke 31, the two sides of the arc surface are tilted inward to hinder the wire outlet needle. Therefore, when winding the coil, the wire outlet needle must be moved as the number of coil turns increases, otherwise it will cause the wire outlet needle to hit the stator yoke 31. At the same time, this will also cause the winding tension to be insufficient and the winding will be loose, thereby generating additional coil vibration and noise.

[0045] Furthermore, when the SQ stator structure is combined with the staggered pole structure of the permanent magnet 20 of the rotor 100, the stator magnetic circuit path is shorter, the concentration of the magnetic field of the permanent magnet 20 along the axial distribution is reduced, and the total magnetic flux of the motor will not be reduced, which is very beneficial for the air gap magnetic flux distribution of the motor to present a sinusoidal wave characteristic, thereby making the back electromotive force waveform of the motor present a characteristic close to a sine wave, and the beneficial effects brought about are as follows:

[0046] First, increasing the number of segments of the permanent magnet 20 of the rotor 100 can better reduce harmonics, reduce cogging torque, improve motor performance, and reduce the distortion of the motor air gap flux waveform. The distortion rate of the motor back electromotive force waveform also decreases rapidly, and the cogging torque of the motor also decreases rapidly, and the torque pulsation is also greatly reduced. The cogging refers to the interval between two adjacent stator teeth 32.

[0047] Second, since the distortion rate of the motor air gap magnetic flux waveform is very low, the fifth and seventh harmonics of the air gap magnetic field are greatly reduced, and the resulting high-frequency eddy current iron loss (harmonic loss) is also greatly reduced, thereby substantially improving the stator heating and winding heating conditions of the motor, and greatly reducing the temperature rise of the stator core 30 and the winding, which is not only beneficial to the insulation safety of the motor winding, but also can reduce losses and increase efficiency to improve the efficiency of the motor, thereby saving more energy.

[0048] Third, less noise and vibration, lower losses, and better back-EMF waveform will give the motor excellent output quality, more stable control effects, and better user experience.

[0049] Fourth, the production efficiency is high, and a set of molds can be used to produce multiple sections of permanent magnets 20. At the same time, the mold investment cost can be reduced, the difficulty of on-site management of the permanent magnet 20 core materials on site can be reduced, and the management cost can be reduced; furthermore, the difficulty of the motor design stage can be reduced.

[0050] In some embodiments, the distance from the straight surface 312 to the center of the arc surface 311 is a first distance S, and the ratio of the radius Rq of the arc surface 311 to the first distance S is greater than or equal to 1.03 and less than or equal to 1.15. In this embodiment, the straight surface 312 is closer to the center of the arc surface 311, and the arc surface 311 is farther from the center of the arc surface, and the ratio of the two is limited to 1.03-1.15, which not only avoids the stator yoke 31 being too thin at the arc surface 311 to cause insufficient strength, but also avoids the stator yoke 31 being too thick at the straight surface 312 to occupy too much of the internal space of the stator yoke 31. Optionally, the ratio of the radius Rq of the arc surface 311 to the first distance S can be 1.03, 1.05, 1.1 or 1.15.

[0051] The stator tooth portion 32 includes a main body section 321 and a flange 322 . One end of the main body section 321 is connected to the flat surface 312 , and the other end of the main body section 321 is laterally protruding with a flange 322 , which is equivalent to the stator tooth portion 32 forming a T-shaped structure.

[0052] In some embodiments, the ratio of the wall thickness Wq of the stator yoke 31 at the corresponding arc surface 311 to the width Wt of the main section 321 is greater than or equal to 0.7 and less than or equal to 0.95. In this embodiment, the main section 321 serves as a skeleton for winding the coil, so a larger size is adopted to obtain greater strength, thereby avoiding bending and deformation. The position corresponding to the arc surface 311 is a tooth groove, which is used to accommodate the coil or as a avoidance space for the outlet needle. Setting the wall thickness of the stator yoke 31 at the corresponding arc surface 311 to be smaller means that the tooth groove is larger, so it can be more conducive to the avoidance of the outlet needle. Optionally, the ratio of Wq to Wt is 0.7, 0.8, 0.85 or 0.95 or other values.

[0053] It should be noted that the main body segment 321 includes two first side surfaces 323 that are arranged opposite to each other along the circumferential direction of the stator yoke 31 , and the width of the main body segment 321 refers to the distance between the two first side surfaces 323 .

[0054] In some embodiments, the interval between two adjacent stator teeth 32 forms a tooth slot, and the ratio of the slot width Cw of the tooth slot to the width Wt of the main body section 321 is greater than or equal to 0.8 and less than or equal to 1.25. Figure 1For the structure in FIG. 1 , it is obvious that this ratio makes the slot opening of the tooth slot larger, thus facilitating the winding of the coil. At the same time, the slot opening width Cw is relatively harmonious with the width Wt of the main body section 321, and the difference between the two is small. Optionally, the ratio of Cw to Wt is 0.8, 0.9, 0.97, 1.1 or 1.25, etc.

[0055] The side of the stator tooth 32 that faces away from the straight surface 312 is a concave arc surface, and the concave arc surfaces of the multiple stator teeth 32 are concentrically arranged. The ratio of the radius Rr of the concave arc surface to the radius Rs of the outer circumference of the stator yoke 31 is greater than or equal to 0.45 and less than or equal to 0.66. In this way, it can be ensured that the space formed by the multiple concave arc surfaces is more suitable to accommodate the permanent magnet 20 and the rotating shaft 10, and it can also be ensured that the stator has a more suitable outer diameter, and the internal and external structural dimensions are harmonious. Optionally, the ratio of Rr to Rs is 0.45, 0.5 or 0.66, etc.

[0056] In some embodiments, the width of the flat surface 312 is greater than the maximum width of the stator tooth 32. In this way, the orthographic projection of the entire stator tooth 32 on the flat surface 312 falls entirely within the flat surface 312, and when the coil is wound, it can be ensured that the coil can contact the flat surface 312 to achieve positioning.

[0057] In some embodiments, the stator tooth portion 32 is perpendicular to the flat surface 312. Specifically, the stator tooth portion 32 includes two first side surfaces 323 arranged opposite to each other along the circumference of the stator yoke portion, the two first side surfaces 323 are respectively connected to the flat surface 312, and the two first side surfaces 323 are both flat surfaces and perpendicular to the flat surface 312. In this way, the angle between the stator tooth portion 32 and the flat surface 312 is a right angle. When winding on the stator tooth portion 32, the coil can abut against the flat surface 312, which can achieve better contact and positioning of the coil than abutting against the curved surface, thereby facilitating winding.

[0058] In some embodiments, the width of the straight surface 312 is greater than the chord length of the arc surface 311. In this way, the area with a larger wall thickness of the stator yoke 31 accounts for a larger proportion, which can ensure that the entire stator core 30 has a greater strength. In this embodiment, the straight surface 312 has two opposite sides that are relatively distributed along the circumference of the stator yoke 31, and the two opposite sides are respectively connected to an arc surface 311, and the width of the straight surface 312 refers to the distance between the two opposite sides.

[0059] In some embodiments, the first section 21 and the second section 22 have the same number of pole pairs, respectively, and the preset angle α is in the range of (15° to 30°) / p, where p is the number of pole pairs of the first section 21, and 2p is the number of poles of the first section 21. Specifically, the preset angle is greater than or equal to 15° / p and less than or equal to 30° / p. For example, taking the first section 21 including two pairs of poles as an example, each pair of poles occupies half of the first section 21, that is, as a semicircular structure, where P is 2. By using the preset angle in this numerical range, the same poles will not be completely staggered, ensuring that the same poles partially overlap in the axial direction of the rotating shaft 10, and the overlapping area can be avoided, thereby reducing the concentration of the axial distribution of the magnetic field of the permanent magnet 20.

[0060] The first section 21 and the second section 22 may include a plurality of permanent magnets, which are arranged around the rotating shaft 10. Each permanent magnet has a pair of magnetic poles distributed along the axial direction, and the magnetic poles of two adjacent permanent magnets are distributed in opposite directions.

[0061] The effects of the motor of the embodiment of the present application are described in detail below by using a motor of a specific size. The motor outer diameter, i.e., 2Rs, is 17 mm, the lengths of the stator core 30 and the permanent magnet 20 are both 13 mm, the stator core 30 has 6 slots, the permanent magnet 20 includes 2 pairs of magnetic poles, and the rotation speed is 100,000 rpm ultra-high-speed motor. The motor of this size has the following effects:

[0062] First, it can effectively overcome the problems of poor sinusoidal magnetic field distribution and severe air gap magnetic field waveform distortion caused by the traditional stator slot structure, and effectively reduce the distortion rate of the motor back electromotive force waveform. Figure 7 , Figure 7 This is a comparison chart of the back EMF waveforms of the present application and the traditional design. When the traditional design is adopted, the sinusoidality of the motor's back EMF waveform is 81.2%, while after adopting the present application's design, the sinusoidality of the motor's back EMF waveform is 98.8%, and the waveform distortion rate is reduced by 15.7 times year-on-year.

[0063] Secondly, it can effectively reduce the pulsating torque of the motor during operation. Figure 8 , Figure 8 This is a comparison chart of the output torque pulsation of the present application and the traditional solution. When the traditional design solution is adopted, the torque pulsation rate of the motor reaches 51.4%, while after adopting the design of the present application, this parameter is only 2.52%, which is more than 20 times lower than the same period last year.

[0064] Furthermore, the vibration noise of the motor body during operation is greatly reduced. When the traditional design is adopted, the noise of the motor is 69±3dB, while this parameter of the motor of the present application is only 61±3dB, a decrease of 8dB.

[0065] In addition, the vibration noise of the motor body during operation is greatly reduced; when the traditional design is adopted, the efficiency of the motor is 76%, while the parameter of the motor of the present application is 84%, and the efficiency is improved by 8%.

[0066] At the same time, the vibration noise of the motor body is greatly reduced; when the traditional design scheme is adopted, the temperature rise of the motor is 76K, while the parameter of the motor using the present application is only 58K, a decrease of 18K, which is beneficial to the thermal stability of the motor winding and effectively improves the overall life of the motor.

[0067] Furthermore, while effectively solving the problems of the prior art and substantially improving the performance of the motor, the cost of the motor of the present application does not increase, but the stator winding process is simpler and more stable.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A motor, characterized in that: include: A stator core, comprising a stator yoke and a plurality of stator teeth, wherein the stator yoke is arranged in an annular shape and has an inner circumferential surface, wherein the inner circumferential surface comprises a plurality of arc surfaces and a plurality of straight surfaces which are alternately arranged and sequentially connected along the circumference thereof, wherein the plurality of stator teeth are connected to the plurality of straight surfaces in a one-to-one correspondence, and wherein the wall thickness of the stator yoke at the arc surface is smaller than the wall thickness at the straight surface; and, A rotor is arranged in the stator core, the rotor includes a rotating shaft and a permanent magnet fixed on the rotating shaft, the permanent magnet includes a first section and a second section arranged along the axial direction of the rotating shaft, and the magnetic poles of the first section and the magnetic poles of the second section are staggered by a preset angle in the circumferential direction of the rotating shaft.

2. The motor according to claim 1, characterized in that The distance from the straight surface to the center of the arc surface is a first distance, and the ratio of the radius of the arc surface to the first distance is greater than or equal to 1.03 and less than or equal to 1.

15.

3. The motor according to claim 1, characterized in that The stator tooth portion comprises a main body section and a flange, one end of the main body section is connected to the straight surface, and the other end of the main body section is laterally protruding and provided with the flange; A ratio of a wall thickness of the stator yoke corresponding to the arc surface to a width of the main body segment is greater than or equal to 0.7 and less than or equal to 0.

95.

4. The motor according to claim 1, characterized in that The stator tooth portion comprises a main body section and a flange, one end of the main body section is connected to the straight surface, and the other end of the main body section is laterally protruding and provided with the flange; The interval between two adjacent stator teeth forms a tooth slot, and the ratio of the slot width of the tooth slot to the width of the main body segment is greater than or equal to 0.8 and less than or equal to 1.

25.

5. The motor according to claim 1, characterized in that The side of the stator tooth portion facing away from the straight surface is a concave arc surface, and the concave arc surfaces of the plurality of stator teeth portions are concentrically arranged; The ratio of the radius of the concave arc surface to the radius of the outer circumference of the stator yoke is greater than or equal to 0.45 and less than or equal to 0.

66.

6. The motor according to claim 1, characterized in that The width of the straight surface is greater than the maximum width of the stator tooth.

7. The motor according to claim 1, characterized in that The width of the straight surface is greater than the chord length of the arcuate surface.

8. The motor according to claim 1, characterized in that The arc surface is recessed outward, and the stator teeth are perpendicular to the straight surface.

9. The motor according to claim 8, characterized in that The arc surface is an arc surface, the stator tooth portion includes two first side surfaces which are arranged opposite to each other along the circumference of the stator yoke portion, the two first side surfaces are respectively connected to the straight surface, and the two first side surfaces are both straight surfaces and perpendicular to the straight surface.

10. The motor according to any one of claims 1 to 9, characterized in that: The first section and the second section respectively have the same number of magnetic pole pairs, and the range of the preset angle is (15° to 30°) / p, where p is the number of magnetic pole pairs of the first section.

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