阅读说明：本技术 电机和家用电器 (Motor and household appliance ) 是由 邵非非 李文瑞 李虎 李伟 于 2020-11-09 设计创作，主要内容包括：本发明提出了一种电机和家用电器,其中,电机包括：定子,定子上具有通孔,定子上设置有多个定子齿；绕组,设于两个相邻的定子齿之间；转子,设于通孔内,与定子之间形成气隙,转子包括多个扇形部,定子齿与扇形部相对设置,其中,以垂直于定子的轴线的方向对定子进行截面,在截面上,一个定子齿朝向转子的一侧的轮廓线,依次包括第一直线段、第一圆弧段和第二直线段。本发明提出的电机,在转子转动时,气隙磁场中主要产生径向电磁力的谐波磁密通过自耦合及相互耦合起到削弱作用,进而避免了产生径向电磁力的主要谐波磁密在同方向上进行叠加作用,降低电机定子和转子所受的径向电磁力,进而降低电机的径向电磁噪音。(The invention provides a motor and a household appliance, wherein the motor comprises: the stator is provided with a through hole and a plurality of stator teeth; the winding is arranged between two adjacent stator teeth; the rotor is arranged in the through hole and forms an air gap with the stator, the rotor comprises a plurality of fan-shaped parts, the stator teeth are arranged opposite to the fan-shaped parts, the stator is provided with a section in the direction perpendicular to the axis of the stator, and one contour line of one side of one stator tooth facing the rotor on the section sequentially comprises a first straight line section, a first circular arc section and a second straight line section. According to the motor provided by the invention, when the rotor rotates, the harmonic flux density mainly generating radial electromagnetic force in the air gap magnetic field plays a weakening role through self-coupling and mutual coupling, so that the main harmonic flux density generating the radial electromagnetic force is prevented from being superposed in the same direction, the radial electromagnetic force borne by the stator and the rotor of the motor is reduced, and the radial electromagnetic noise of the motor is further reduced.)

1. An electric machine, comprising:

the stator is provided with a through hole and is provided with a plurality of stator teeth;

the winding is arranged between two adjacent stator teeth;

the rotor is arranged in the through hole, an air gap is formed between the rotor and the stator, the rotor comprises a plurality of fan-shaped parts, the stator teeth are arranged opposite to the fan-shaped parts,

the stator is provided with a first straight line section, a first circular arc section and a second straight line section, wherein the stator is provided with a section in the direction perpendicular to the axis of the stator, and on the section, one of the stator teeth faces the contour line of one side of the rotor and sequentially comprises the first straight line section, the first circular arc section and the second straight line section.

2. The electric machine of claim 1,

with the perpendicular to the direction of the axis of rotor is right the rotor carries out the cross-section, on the cross-section, the scallop orientation the contour line of one side of stator includes in proper order: the second circular arc section, third circular arc section and fourth circular arc section, the third circular arc section with the fourth circular arc section is the decentraction.

3. The electric machine of claim 2,

the first straight line section and the second straight line section on the same stator tooth are symmetrically arranged by taking the center line of the first circular arc section as a symmetry axis;

the range of the mechanical angle between the center lines of the first straight line segment and the first circular arc segment is 86.5 degrees to 92 degrees.

4. The electric machine of claim 3,

the rotor also comprises a shaft sleeve, and the sector part is arranged on the shaft sleeve;

the third arc section is concentric with the shaft sleeve;

the radius of the third circular arc section is larger than that of the second circular arc section;

the radius of the third circular arc section is larger than that of the fourth circular arc section;

the second arc segment and the fourth arc segment on the same sector are symmetrically arranged by taking the central line of the third arc segment as a symmetry axis.

5. The electric machine of claim 4,

the centre of a circle of third circular arc section with distance between the centre of a circle of fourth circular arc section is first distance, the value range of the numerical value of first distance does, 3 times the numerical value of the electrical angle of third circular arc section divides with utmost point groove least common multiple, and add 10.5, to 3 times the numerical value of the electrical angle of third circular arc section divides with utmost point groove least common multiple, and 12.5 is added again, wherein, the unit of first distance is the millimeter, the unit of the electrical angle of third circular arc section is the degree.

6. The electric machine of claim 5,

the minimum width value of an air gap between the first circular arc section and the third circular arc section is a first air gap width, and the maximum width value of an air gap between the first straight line section or the second straight line section and the second circular arc section or the fourth circular arc section is a second air gap width;

the second air gap width is greater than or equal to 1.9 times of the first air gap width and less than or equal to 3.2 times of the first air gap width.

7. The electric machine according to any of the claims 2 to 6,

the numerical value of the electrical angle of the second arc section is greater than 0 and smaller than the numerical value of the minimum common multiple of the pole slots multiplied by the fundamental wave winding coefficient multiplied by the number of pole pairs, and the unit of the electrical angle of the second arc section is degree.

8. The electric machine according to any of claims 1 to 6,

an opening distance between two adjacent sectors is bro, the bro satisfies:

0.9×Dro×sin[π÷(2×LCM)]≤bro≤1.1×Dro×sin[π÷(2×LCM)]，

wherein Dro is the radius of the rotor and LCM is the pole slot least common multiple.

9. The electric machine of claim 8,

the opening distance between two adjacent stator teeth is a second distance;

the opening distance between two adjacent sectors is a third distance;

wherein the second distance is greater than or equal to 0.48 times the third distance and less than or equal to 0.79 times the third distance.

10. The electric machine of claim 4,

a connecting part is arranged between the fan-shaped part and the shaft sleeve,

the ratio of the width of the connecting part to the diameter of the rotor is more than or equal to 0.006 time of the diameter of the rotor and less than 0.019 time of the diameter of the rotor.

11. A household appliance, characterized in that it comprises:

an electric machine as claimed in any one of claims 1 to 10.

Technical Field

The invention relates to the field of motors, in particular to a motor and a household appliance.

Background

In the related art, compared with a surface-mounted permanent magnet brushless direct current motor with a unit motor of 2 poles and 3 slots, the built-in permanent magnet brushless direct current motor has the advantages of high power density, simple structure, good manufacturability, low cost and the like, but the high power density easily generates obvious 2-frequency and 4-frequency radial vibration noise.

Disclosure of Invention

The present invention is directed to solving at least one of the problems in the art or improving the art.

To this end, a first aspect of the invention proposes an electric machine.

A second aspect of the invention proposes a household appliance.

In view of this, according to a first aspect of the present invention, there is provided a motor comprising: the stator is provided with a through hole and a plurality of stator teeth; the winding is arranged between two adjacent stator teeth; the rotor is arranged in the through hole and forms an air gap with the stator, the rotor comprises a plurality of fan-shaped parts, the stator teeth are arranged opposite to the fan-shaped parts, the stator is provided with a section in the direction perpendicular to the axis of the stator, and one contour line of one side of one stator tooth facing the rotor on the section sequentially comprises a first straight line section, a first circular arc section and a second straight line section.

The motor provided by the invention is characterized in that a winding is arranged between two adjacent stator teeth of a stator, a magnetic part is arranged between two adjacent fan-shaped parts of a rotor, and the magnetic part generates magnetic density in an air gap and further interacts with the magnetic density generated when the winding is electrified to drive the rotor to rotate. And a gap, namely an air gap, is required between the rotor and the stator so as to ensure the normal rotation of the rotor.

In addition, the profile of the stator teeth and the profile of the rotor sector facing the stator teeth generate radial electromagnetic force on the stator and the rotor by self-coupling and mutual coupling action of fundamental flux density and other higher harmonic flux density (collectively referred to as harmonic flux density) caused in the air gap.

The stator is further sectioned in the direction perpendicular to the axis of the stator, and on the section, the outline of one side, facing the rotor, of the stator tooth is provided with a first straight line section, a first circular arc section and a second straight line section which are connected in sequence, namely the width of an air gap is changed, the width of the whole air gap is changed, and the magnetic density of the air gap is further changed. When the rotor rotates, the harmonic flux density of radial electromagnetic force mainly generated in the air gap magnetic field plays a role in weakening through self-coupling and mutual coupling, so that the main harmonic flux density generating the radial electromagnetic force is prevented from being superposed in the same direction, the radial electromagnetic force borne by the motor stator and the rotor is reduced, and the radial electromagnetic noise of the motor is reduced.

In addition, according to the motor in the above technical solution provided by the present invention, the following additional technical features may also be provided:

in the above technical solution, further, the rotor is sectioned in a direction perpendicular to an axis of the rotor, and a contour line of a side of the sector facing the stator in the section sequentially includes: the first arc section is concentric with the second arc section, and the second arc section is concentric with the third arc section.

In this technical scheme, carry out the cross-section to the rotor with the direction of the axis of perpendicular to stator, on the cross-section, set up the profile of the fan-shaped portion of rotor towards stator one side into second circular arc section, third circular arc section and the fourth circular arc section that connects gradually, further change the width of air gap. And then when the rotor rotates, because including first straightway and second straightway on the stator tooth, and the sector has three circular arc section of decentraction, consequently, the change of whole air gap is bigger, and it is more obvious to the harmonic flux density weakening that mainly produces radial electromagnetic force, and then has avoided producing the main harmonic flux density of radial electromagnetic force and has carried out the superposition effect in the equidirectional, reduces the radial electromagnetic force that stator and rotor received, and then reduces the radial electromagnetic noise of motor.

In any of the above technical solutions, further, the first straight line segment and the second straight line segment on the same stator tooth are symmetrically arranged with the center line of the first arc segment as a symmetry axis; the range of the mechanical angle between the center lines of the first straight line segment and the first circular arc segment is 86.5 degrees to 92 degrees.

In the technical scheme, a first straight line section and a second straight line section on the same stator tooth are symmetrically arranged by taking the center line of a first circular arc section as a symmetry axis, and the value range of the mechanical angle between the center lines of the first straight line section and the first circular arc section is set to be 86.5-92 degrees, namely the value range of the mechanical angle between the center lines of the second straight line section and the first circular arc section is set to be 86.5-92 degrees. The shape of the air gap can be limited by limiting the mechanical angles of the central lines of the first straight line section, the second straight line section and the first circular arc section, so that the change of the air gap is in a more gentle range, the cliff-like change is avoided, the change of the magnetic density of the whole air gap is smoother, the sine performance is better, the cliff-like change is avoided, the radial electromagnetic force is increased, and the effect of reducing the vibration of the motor stator and the rotor is ensured.

In any of the above technical solutions, further, the rotor further includes a shaft sleeve, and the sector is disposed on the shaft sleeve; the third arc section is concentric with the shaft sleeve; the radius of the third circular arc section is larger than that of the second circular arc section; the radius of the third circular arc section is larger than that of the fourth circular arc section; the second arc section and the fourth arc section on the same sector are symmetrically arranged by taking the central line of the third arc section as a symmetry axis.

In the technical scheme, the third arc segment is concentric with the shaft sleeve of the rotor, that is, when the rotor rotates, the third arc segment rotates around the circle center of the third arc segment, that is, the third arc segment does not cause the change of the air gap. The second arc section and the fourth arc section are not concentric with the shaft sleeve, so that air gap change can be caused during rotation, the second arc section and the fourth arc section can be greatly changed when the second arc section and the fourth arc section are combined with profile change of stator teeth, intermittent continuous change is formed, harmonic flux density which mainly generates radial electromagnetic force is obviously weakened, the main harmonic flux density which generates the radial electromagnetic force is prevented from being superposed in the same direction, and the radial electromagnetic force is reduced.

In any of the above technical solutions, further, a distance between a center of the third arc segment and a center of the fourth arc segment is a first distance, a numeric value of the first distance ranges from 3 times of the electrical angle of the second arc segment divided by the least common multiple of the polar trough, to which 10.5 to 3 times of the electrical angle of the second arc segment divided by the least common multiple of the polar trough, to which 12.5 times of the electrical angle of the third arc segment is added, wherein a unit of the first distance is millimeter, and a unit of the electrical angle of the third arc segment is degree.

In this technical scheme, because the second arc segment and the fourth arc segment are symmetrical about the center line of the third arc segment, the distance between the center of the third arc segment and the center of the fourth arc segment is equal to the distance between the center of the third arc segment and the center of the second arc segment, and both are the first distance. The numerical value of the electrical angle of the second circular arc section that sets up the numerical value of first distance at 3 times divides the minimum common multiple of utmost point groove, and the numerical value of the electrical angle of the second circular arc section that adds 10.5 to 3 times divides the minimum common multiple of utmost point groove, and again between 12.5, and then make first distance accord with the condition of this motor, inject the air gap situation of change between second circular arc section, fourth circular arc section and the stator promptly for air gap etc. are favorable to this motor. And due to the limitation of the air gap, the counter electromotive force distortion rate of the motor can be reduced, the tangential torque pulsation of the motor is reduced, the tangential electromagnetic noise of the motor is reduced, and the amplitude of the counter electromotive force of the motor is increased, so that the performance of the motor is improved.

In any of the above technical solutions, further, a minimum width value of an air gap between the first arc segment and the third arc segment is a first air gap width, and a maximum width value of an air gap between the first straight line segment or the second straight line segment and the second arc segment or the fourth arc segment is a second air gap width; the second air gap width is larger than or equal to 1.9 times of the first air gap width and smaller than or equal to 3.2 times of the first air gap width.

In the technical scheme, the first arc segment is opposite to the third arc segment, and has the minimum width of the air gap, which is referred to as the width of the first air gap. The first straight line segment is opposite to the second circular arc segment, and the second circular arc segment and the fourth circular arc segment are symmetrical relative to the center of the third circular arc segment because the first straight line segment and the second straight line segment are opposite to each other and are lower than the center line of the first circular arc segment. Therefore, the distribution of the air gap between the first straight line segment and the second circular arc segment, the distribution of the air gap between the first straight line segment and the fourth circular arc segment, the distribution of the air gap between the second straight line segment and the second circular arc segment, and the distribution of the air gap between the second straight line segment and the fourth circular arc segment are all the same, and the maximum width of the air gap is referred to as a second air gap width. And further setting the second air gap width to be more than or equal to 1.9 times of the first air gap width and less than or equal to 3.2 times of the first air gap width, namely setting the maximum value of the air gap width between the stator and the rotor to be 1.9 times to 3.2 times of the minimum value. Further limiting the variation range of the air gap flux density, reducing the strength of harmonic flux density interaction and further weakening radial electromagnetic force.

In any of the above technical solutions, further, a numerical value of an electrical angle of the second arc segment is greater than 0 and smaller than a numerical value of a least common multiple of the pole slots multiplied by a fundamental wave winding coefficient multiplied by a pole pair number, where a unit of the electrical angle of the second arc segment is degree.

In this solution, the electrical angle is equal to the mechanical angle multiplied by the pole pair number. That is to say, the electrical angle can directly reflect mechanical angle, be about to the electrical angle of second circular arc section and the numerical value of the minimum common multiple of pole slot, fundamental wave winding coefficient and the number of pole pairs of this motor are correlated with, and then the air gap between second circular arc section and the stator that obtains accords with the fundamental wave winding state of this motor, and, the situation of change of such air gap, can reduce the back electromotive force distortion rate, reduce motor tangential torque pulsation, thereby reduce the radial electromagnetic noise of motor, and, promote the amplitude of motor back electromotive force, thereby promote the performance of motor.

In any of the above technical solutions, further, the opening distance between two adjacent sectors is bro, bro satisfies: 0.9 XDro x sin [ pi/L (2 XLCM) ] < bro < 1.1 XDro x sin [ pi/L (2 XLCM) ], wherein Dro is the radius of the rotor and LCM is the smallest common multiple of the polar trough.

In this solution, the opening distance between two adjacent sectors is bro: 0.9 XDro x sin [ pi/phi (2 XLCM) ] < bro < 1.1 XDro x sin [ pi/phi (2 XLCM) ], and further relates the opening distance between two adjacent sectors to the rotor radius of the motor, so as to obtain the opening distance between two adjacent sectors according to the motor, namely, limit the cogging torque to a lower range, reduce the tangential torque pulsation of the motor, and further reduce the radial electromagnetic noise of the motor.

In any of the above technical solutions, further, an opening distance between two adjacent stator teeth is a second distance; the opening distance between two adjacent sectors is a third distance; wherein the second distance is greater than or equal to 0.48 times the third distance and less than or equal to 0.79 times the third distance.

In the technical scheme, the opening distance between the stator teeth and the opening distance between the fan-shaped parts are limited, so that the opening distance between the stator teeth and the opening distance between the fan-shaped parts are in a certain range, the cogging torque is limited in a lower range, the tangential torque pulsation of the motor is reduced, and the tangential electromagnetic noise of the motor is reduced.

In any of the above technical solutions, further, there is a connection portion between the sector and the shaft sleeve, and a ratio of a width of the connection portion to a diameter of the rotor is greater than 0.006 times the diameter of the rotor and less than 0.019 times the diameter of the rotor.

In this embodiment, combine the diameter of rotor, set up the width of connecting portion between sector and the axle sleeve, and then improve the joint strength between sector and the axle sleeve, improve rotor structural strength, reduce the self-cross-linked magnetic leakage of permanent magnet, improve motor back electromotive force amplitude, and then, improve the motor performance.

According to a second aspect of the invention, the invention proposes a household appliance comprising: the motor according to any one of the above aspects.

The household appliance provided by the invention comprises the motor provided by any one of the above technical solutions, so that all the beneficial effects of the motor provided by any one of the above technical solutions are achieved, and the description is omitted.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a motor according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a motor according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a rotor in the motor according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a rotor in the motor according to an embodiment of the present invention;

fig. 5 is a schematic structural view of a stator tooth in the motor according to an embodiment of the present invention;

figure 6 shows a schematic view of a sector in an electrical machine according to an embodiment of the invention;

FIG. 7 is a MAP graph illustrating a ratio of a second gap width to a first gap width and a 4 octave radial electromagnetic force in an electric machine, according to an embodiment of the present invention;

FIG. 8 is a MAP graph illustrating the ratio of the second gap width to the first gap width and the sum of 4-times flux density vectors for an electric machine according to an embodiment of the present invention;

FIG. 9 is a MAP graph illustrating a ratio of a second gap width to a first gap width and a 2 octave radial electromagnetic force in an electric machine provided in accordance with an embodiment of the present invention;

FIG. 10 is a MAP graph illustrating the ratio of the second gap width to the first gap width and the sum of the 2-times flux density vectors for an electric machine provided in accordance with an embodiment of the present invention;

FIG. 11 is a diagram illustrating a method for optimizing electromagnetic force and corresponding counter-potential fundamental amplitude in the related art;

fig. 12 is a schematic diagram illustrating an electrical angle and a back electromotive force distortion rate of a third arc segment in the motor according to an embodiment of the present invention;

fig. 13 is a schematic diagram illustrating a distance between a center of the second arc segment and a third arc segment and a back electromotive force distortion rate in the motor according to an embodiment of the present invention;

FIG. 14 is a schematic diagram illustrating the electrical angle and back emf fundamental assignments of a third arc segment in a motor provided by one embodiment of the present invention;

fig. 15 is a schematic diagram illustrating the distance between the center of the second arc segment and the third arc segment and the back-emf fundamental value in the motor according to an embodiment of the present invention.

Wherein, the correspondence between the reference numbers and the part names in fig. 1 to 6 is:

the magnetic component comprises a 100 motor, a 110 stator, 112 stator teeth, 114 a first straight line segment, 116 a first arc segment, 118 a second straight line segment, 120 a rotor, 122 a fan-shaped part, 124 a second arc segment, 126 a third arc segment, 128 a fourth arc segment, 130 shaft sleeves, 132 connecting parts, 140 windings and 150 magnetic components.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A motor provided according to some embodiments of the present invention is described below with reference to fig. 1 to 15.

Example 1

As shown in fig. 1, 2 and 5, the present invention provides a motor 100 including: stator 110, rotor 120, and windings 140.

Wherein, the stator 110 is provided with a through hole, the rotor 120 is arranged in the through hole, the stator 110 is provided with a plurality of stator teeth 112 facing the rotor 120, a winding 140 is arranged between two adjacent stator teeth 112, the rotor 120 is provided with a plurality of sectors 122 facing the stator 110, and an air gap is provided between the stator 110 and the rotor 120 to ensure the free rotation of the rotor 120.

The stator 110 is sectioned in a direction perpendicular to the axis of the stator 110, and in the section, the profiles of a plurality of stator teeth 112 are the same, and one side of the stator teeth 112 facing the rotor 120 includes a first straight line segment 114, a first circular arc segment 116 and a second straight line segment 118 which are connected in sequence.

In the motor 100 provided by the invention, the winding 140 is arranged between two adjacent stator teeth 112 of the stator 110, the magnetic member 150 is arranged between two adjacent fan-shaped parts 122 of the rotor 120, the magnetic member 150 generates magnetic density in an air gap, and the generated magnetic density interacts with the winding 140 to drive the rotor 120 to rotate. A gap, i.e., an air gap, must be provided between the rotor 120 and the stator 110 to ensure the normal rotation of the rotor 120.

The profile of the stator teeth 112 and the profile of the opposing rotor segment 122 cause a fundamental flux density and other higher harmonic flux densities (collectively referred to as harmonic flux densities) in the air gap to generate radial electromagnetic forces on the stator 110 and the rotor 120 through self-coupling and mutual coupling.

Furthermore, the invention performs the cross section of the stator 110 in the direction perpendicular to the axis of the stator 110, and on the cross section, the outline of the stator teeth 112 of the stator 110 facing to the rotor 120 is set as a first straight line segment 114, a first circular arc segment and a second straight line segment 118 which are connected in sequence, namely, the width of the air gap is changed, the width of the whole air gap is changed, and further, the magnetic density of the air gap is changed. When the rotor 120 rotates, the air gap flux densities at various positions are dynamic, and when the rotor rotates, the harmonic flux densities mainly generating the radial electromagnetic force weaken through self-coupling and mutual coupling, so that the main harmonic flux densities generating the radial electromagnetic force are prevented from being superposed in the same direction, the radial electromagnetic force applied to the stator 110 and the rotor 120 is reduced, and the noise of the motor 100 is reduced.

Specifically, the magnetic member 150 is disposed between two adjacent sectors 122.

The sector 122 is a sector.

Example 2:

as shown in fig. 1, 2, 3, 4, and 6, in addition to embodiment 1, the rotor 120 is further sectioned in a direction perpendicular to the axis of the rotor 120, and in the section, the profile of the sector 122 facing the stator 110 includes a second arc segment 124, a third arc segment 126, and a fourth arc segment 128 in this order.

The centers of the third arc segment 126 and the second arc segment 124 are not at the same point, and the centers of the third arc segment 126 and the fourth arc segment 128 are not at the same point, i.e., the center O of the third arc segment 126₁And the center O of the fourth arc segment 128₂Different.

In this embodiment, the rotor 120 is sectioned in a direction perpendicular to the axis of the stator 110, and in the section, the profile of the sector 122 of the rotor 120 toward the stator 110 side is provided as a second circular arc segment, a third circular arc segment, and a fourth circular arc segment that are connected in this order, further changing the width of the air gap. Further, when the rotor 120 rotates, the stator teeth 112 include the first straight line segment 114 and the second straight line segment 118, and the sector 122 has three non-concentric circular arc segments. Therefore, the change of the whole air gap is larger, the harmonic flux density mainly generating the radial electromagnetic force is weakened more obviously, the main harmonic flux density generating the radial electromagnetic force is prevented from being superimposed in the same direction, the radial electromagnetic force applied to the stator 110 and the rotor 120 is reduced, and the radial electromagnetic noise of the motor 100 is reduced.

Example 3:

as shown in fig. 1, 2, and 5, in embodiment 2, the stator 110 is further sectioned in a direction perpendicular to the axis of the stator 110, and in the section, the first straight line segment 114 and the second straight line segment 118 located on the same stator tooth 112 are axisymmetric with respect to the center line of the first circular arc segment 116 as a symmetry axis.

The mechanical angle β between the center lines of the first straight line segment 114 and the first circular arc segment 116 is in the range of 86.5 ° to 92 °, which is an angle of the opening toward the rotor 120. The mechanical angle between the second straight line segment 118 and the center line of the first circular arc segment 116 is the same, and for simplicity, the mechanical angle between the second straight line segment 118 and the center line of the first circular arc segment 116 is also denoted by β.

In this embodiment, the first straight line segment 114 and the second straight line segment 118 on the same stator tooth 112 are symmetrically arranged with the center line of the first circular arc segment 116 as a symmetry axis, and the range of the mechanical angle β between the center lines of the first straight line segment 114 and the first circular arc segment 116 is set to 86.5 ° to 92 °, that is, the range of the mechanical angle β between the center lines of the second straight line segment 118 and the first circular arc segment 116 is set to 86.5 ° to 92 °. The mechanical angle β between the center lines of the first straight line segment 114, the second straight line segment 118 and the first circular arc segment 116 is limited to limit the shape of the air gap, so that the change of the air gap is within a relatively gentle range, thereby avoiding the occurrence of cliff-like changes, further making the change of the magnetic density of the whole air gap smoother, weakening the harmonic magnetic density mainly generating radial electromagnetic force more obviously, further avoiding the superposition of the main harmonic magnetic density generating radial electromagnetic force in the same direction, avoiding the occurrence of cliff-like changes to increase the radial electromagnetic force, and ensuring the effect of reducing the radial vibration of the motor stator 110 and the rotor 120

Example 4:

as shown in fig. 1, 2, 3 and 4, in addition to embodiment 2 or embodiment 3, the rotor 120 further includes a bushing 130, and the sector 122 is disposed on the bushing 130.

The third arc segment 126 is concentric with the shaft sleeve 130, the radius of the third arc segment 126 is greater than that of the second arc segment 124, the radius of the third arc segment 126 is greater than that of the fourth arc segment 128, and the second arc segment 124 and the fourth arc segment 128 on the same sector 122 are in an axisymmetrical state with the center line of the third arc segment 126 as a symmetry axis.

In this embodiment, the third arc segment 126 is concentric with the bushing 130 of the rotor 120, that is, the third arc segment 126 rotates around the center of the rotor 120, i.e., the third arc segment 126 does not cause the change of the air gap by itself. The second arc segment 124 and the fourth arc segment 128 are not concentric with the shaft sleeve 130, and therefore when the stator 110 rotates, the air gap changes, and when the stator 110 is combined with the profile change of the stator teeth 112, the second arc segment 124 and the fourth arc segment 128 are greatly changed, so that intermittent change is formed, the harmonic magnetic density mainly generating radial electromagnetic force is obviously weakened, the main harmonic magnetic density generating radial electromagnetic force is prevented from being superimposed in the same direction, and the radial electromagnetic force is reduced.

Example 5:

as shown in fig. 3 and 4, in addition to any one of embodiments 2 to 4, a center O of the third arc segment 126 is further provided₁And the center O of the fourth arc segment 128₂The first distance Ra.

The value of the first distance Ra ranges from 3 times the electrical angle α of the second arc segment 124 divided by the pole-slot least common multiple LCM, to which 10.5 to 3 times the electrical angle α of the second arc segment 124 divided by the pole-slot least common multiple LCM, to which 12.5 times the electrical angle α of the second arc segment 124 (specifically, the least common multiple of the pole number and the slot number in the motor 100 coefficient, for example, the least common multiple of the pole-slot and the slot number of the 8-pole 12-slot is 24). I.e., 10.5+3 × α/LCM < Ra <12.5+3 × α/LCM. Wherein the first distance Ra is in millimeters and the electrical angle α of the third arc segment is in degrees.

In this embodiment, since the second arc segment 124 and the fourth arc segment 128 are symmetrical about the center line of the third arc segment 126, the distance between the center of the third arc segment 126 and the center of the fourth arc segment 128 is equal to the distance between the center of the third arc segment 126 and the center of the second arc segment 124, and is the first distance Ra. The numerical value of the electrical angle α of the second arc segment 124 that sets up the numerical value of first distance Ra at 3 times divides the pole slot least common multiple LCM, and the numerical value of the electrical angle α of the second arc segment 124 that adds 10.5 to 3 times divides the pole slot least common multiple LCM, and between 12.5, and then make first distance Ra accord with the condition of this motor 100, inject the air gap change condition between second arc segment 124, fourth arc segment 128 and the stator 110 promptly, make air gap etc. be favorable to this motor 100. In addition, due to the limitation of the air gap, the counter potential distortion rate of the motor 100 can be reduced, the tangential torque pulsation of the motor can be reduced, and the amplitude of the counter potential of the motor 100 can be increased, so that the performance of the motor 100 can be improved, and the cost of the motor can be reduced.

Specifically, as shown in fig. 14 and 15, the electrical angle α of the second arc segment 124 and the center O of the third arc segment 126 are set₁And the center O of the fourth arc segment 128₂The first distance Ra satisfies 10.5+3 x alpha/LCM<Ra<In the 12.5+3 × α/LCM relationship, i.e., in fig. 14 and 15, the dashed solid circles are connected, so that the back electromotive force amplitude and the distortion rate are in the better state under the condition of integrating the frequency-2 and frequency-4 electromagnetic forces, and the overall performance is better than other ratio ranges.

Example 6:

as shown in fig. 2, in addition to any one of embodiments 2 to 5, further, the minimum width value of the air gap between the first circular arc segment 116 and the third circular arc segment 126 is a first air gap width δ min, and the maximum width value of the air gap between the first straight line segment 114 or the second straight line segment 118 and the second circular arc segment 124 or the fourth circular arc segment 128 is a second air gap width δ max.

The second air gap width delta max is larger than or equal to 1.9 times of the first air gap width delta min and smaller than or equal to 3.2 times of the first air gap width delta min. That is, delta max/delta min is more than or equal to 1.9 and less than or equal to 3.2.

In this embodiment, the first arc segment 116 is opposite the third arc segment 126 and has a minimum width of the air gap, which is referred to as a first air gap width δ min. The first straight line segment 114 is opposite to the second circular arc segment 124, and since the first straight line segment 114 and the second straight line segment are symmetrical with respect to the center line of the first circular arc segment 116, the second circular arc segment 124 and the fourth circular arc segment 128 are symmetrical with respect to the center line of the third circular arc segment 126. Therefore, the distribution of the air gap between the first straight line segment 114 and the second circular arc segment 124, the distribution of the air gap between the first straight line segment 114 and the fourth circular arc segment 128, the distribution of the air gap between the second straight line segment 118 and the second circular arc segment 124, and the distribution of the air gap between the second straight line segment 118 and the fourth circular arc segment 128 are all the same, and the maximum width having the air gap therein is referred to as a second air gap width. Further, the second air gap width δ max is set to be 1.9 times or more the first air gap width δ min and 3.2 times or less the first air gap width δ min, that is, the maximum value of the air gap width between the stator 110 and the rotor 120 is 1.9 times to 3.2 times the minimum value. Further limiting the variation range of the air gap flux density, reducing the strength of the harmonic flux density and further weakening the radial electromagnetic force.

Specifically, as shown in fig. 7, by defining the angle of two segments of trimming lines and the maximum and minimum air gap ratio of the trimmed motor 100, the radial vibration noise generated by the large 4-octave radial electromagnetic force caused by the interaction of 1 to 5 harmonic flux densities in the air gap flux density can be effectively attenuated.

Fig. 8 is a MAP of the corresponding sum of the flux densities of the major harmonics producing 4-fold frequencies (ignoring other relatively small higher harmonic interactions) for different stator 110 parameters of the above-described embodiment, where the sum of the flux densities of the major harmonics is:

as can be seen from fig. 8: the value of the flux density vector sum of the main harmonic waves generating the 4-frequency multiplication is continuously changed along with the change of the combination of the beta angle and the delta max/delta min, and the value of the flux density vector sum of the 4-frequency multiplication harmonic waves is in a better range when 86.5 degrees < beta <92 degrees and 1.9-delta max/delta min < 3.2 from the contour line in the MAP. Further, for convenience of displaying the numerical values in the figures, the flux density vector sums are each enlarged by 1000 times.

Similarly, the magnetic density with the time frequency difference of 2 generated by the harmonic magnetic density self-coupling and mutual coupling in the air gap magnetic density is the root cause for generating 2 frequency multiplication radial force; in order to reduce 2-frequency-doubled radial electromagnetic force caused by self coupling and mutual coupling of harmonic flux density (including fundamental flux density).

The invention weakens the vector sum of the harmonic flux density generating 2 times frequency by limiting the trimming straight line and the air gap at the inner edge of the stator 110 in principle, thereby effectively reducing the radial electromagnetic force of the 2 times frequency.

Fig. 9 is a graph of the generated 2-times frequency radial electromagnetic force MAP corresponding to different stator 110 parameters calculated by the present invention. As can be seen from fig. 9: by limiting the angle of two sections of trimming straight lines and the ratio of the second air gap width to the first air gap width of the trimmed motor 100, the larger 2-time frequency radial electromagnetic force caused by the interaction of 1-time harmonic flux density and 3-time harmonic flux density in the air gap flux density can be effectively weakened.

Fig. 10 is a MAP of the corresponding sum of the flux densities of the major harmonics generating the frequency 2 when the inner edges of the stator teeth 112 of the above embodiment take different parameters (ignoring other relatively small higher harmonic interactions), where the sum of the flux densities of the major harmonics is:

as can be seen from fig. 10: the value of the flux density vector sum of the main harmonic for generating 2-frequency multiplication is continuously changed along with the combination of beta and delta max/delta min, and the MAP graph shows that when the angle is 84 degrees < beta <92 degrees and the angle is 1.4-delta max/delta min is less than or equal to 3.2, the value of the flux density vector sum of the 2-frequency multiplication harmonic is in a better range. Also, for convenience in displaying the figures, the flux density vector sums are each magnified 1000 times.

By combining 4-frequency multiplication and 2-frequency multiplication radial electromagnetic force, it can be seen that the following requirements should be met in the beta range: 86.5 degrees < beta <92 degrees, and the range of delta max/delta min should be satisfied, namely 1.9-3.2-1.2, 2 frequency multiplication radial electromagnetic force and 4 frequency multiplication radial electromagnetic force, and 2 frequency multiplication magnetic density adaptive vector and 4 frequency multiplication magnetic density adaptive vector can be in a better state.

Specifically, the value of the selected scheme β in the present embodiment may be 86 °, 87 °, 88 °, 89 °, or the like; the ratio of δ max/δ min is 2, 2.05, 2.12, 2.18, 2.54, 2.9, 3.12, etc., and at β 87 °, δ max/δ min 2.12, the corresponding 4-and 2-fold radial forces are 1756N/m, respectively²And 15852N/m²。

Example 7:

as shown in fig. 4, on the basis of any one of embodiments 2 to 6, further, the value of the electrical angle α of the second circular arc segment 124 is greater than 0 and smaller than the value of the product of the pole slot least common multiple LCM and the fundamental wave winding 140 coefficient Kw1 and the pole pair number p.

In this embodiment, the electrical angle is equal to the mechanical angle multiplied by the pole pair number. That is to say, the electrical angle may directly reflect the mechanical angle, that is, the electrical angle α of the second arc segment 124 is associated with the values of the minimum common multiple LCM of the pole slot of the motor 100, the coefficient Kw1 of the fundamental wave winding 140, and the number p of the pole pairs, so that the obtained air gap between the second arc segment 124 and the stator 110 conforms to the state of the fundamental wave winding 140 of the motor 100, and the change condition of the air gap can reduce the back electromotive force distortion rate, reduce the tangential torque ripple of the motor 100, reduce the tangential electromagnetic noise of the motor 100, and improve the amplitude of the back electromotive force of the motor 100, thereby improving the performance of the motor 100.

Specifically, fig. 12 and 13 show the no-load back electromotive force and the distortion rate variation corresponding to different fan-shaped profiles of the rotor 120.

The sector part of the rotor 120 consists of a third arc section 126 concentric with a shaft sleeve 130 and a second arc section 124 and a fourth arc section 128 which are bilaterally symmetrical relative to the third arc section 126 and are not concentric with the shaft sleeve 130; the electrical angle corresponding to the third arc segment 126 is α, and the center O of the third arc segment 126₁And a center O of the second arc segment 124 or the third arc segment 126₂Is Ra, and fig. 12 and 13 show the back-emf distortion rate for different values of alpha and Ra.

When the frequency multiplication 2 and the frequency multiplication 4 are ensured to be smaller, when the electrical angle alpha corresponding to the first arc of the sector part of the rotor 120 meets the condition that the electrical angle alpha is larger than 0 degrees and smaller than the product of the least common multiple LCM of the pole slot, the coefficient Kw1 of the fundamental wave winding 140 and the pole pair number p, namely: 0< α < Kw1 × LCM (3p, 2p) × p, the back-emf waveform is better sinusoidal and the distortion rate is generally smaller.

And, at the third arc segment 126O₁And a center O of the second arc segment 124 or the fourth arc segment 128₂Is Ra satisfies the following formula: 10.5+3 × alpha/LCM<Ra<12.5+3×α/LCM。

In FIGS. 12 and 13, the filled circles indicate that the 2-octave radial force range is 16000 to 17000N/m²4 radial direction of frequency multiplicationForce 1650 to 1850N/m²Point (2) of (c). When α and Ra satisfy the above equation, the 4-and 2-times radial forces of the motor 100 are both in the radial force range represented by the solid circle and are substantially the same, and a dotted line fitted to the solid circle in fig. 12 and 13 is shown, even in the state where the back electromotive distortion rate satisfies the above equation. And further, the same radial force of 2-frequency multiplication and 4-frequency multiplication can be ensured, the distortion rate can be lower, the tangential torque pulsation of the motor 100 is reduced, the tangential electromagnetic noise of the motor 100 is reduced, the operation efficiency is improved, and the research and development period is shortened.

Further, when the radial electromagnetic force and the distortion rate of the motor 100 are low, the motor 100 should have a lower cogging torque, so as to further reduce the tangential torque ripple of the motor 100 and reduce the tangential electromagnetic noise of the motor 100.

Example 8:

in addition to any one of embodiment 2 to embodiment 7, an opening distance between two adjacent sectors 122 is further bro.

bro satisfies the following conditions: 0.9 XDro x sin [ pi/L (2 XLCM) ] < bro < 1.1 XDro x sin [ pi/L (2 XLCM) ], wherein Dro is the radius of the rotor 120 and LCM is the polar cell least common multiple (polar cell common factor).

In this embodiment, an opening distance of bro between two adjacent sectors 122 satisfies: 0.9 XDro x sin [ pi/phi (2 XLCM) ] < bro < 1.1 XDro x sin [ pi/phi (2 XLCM) ], and further, the opening distance between two adjacent sectors 122 is related to the radius of the rotor 120 of the motor 100, so that the opening distance between two adjacent sectors 122 conforming to the motor 100 is obtained, namely, the cogging torque is limited to a lower range, the tangential torque pulsation of the motor 100 can be effectively reduced, and the tangential electromagnetic noise of the motor 100 is reduced.

Specifically, the width between two adjacent stator teeth 112, i.e. the width of the slot of the stator 110, is 2mm to 3mm, and may be 2.2mm, 2.4mm, 2.6mm, 2.8 mm; the width of two adjacent sectors 122, i.e. the width of the rotor 120 slot, is between 3mm and 4mm, which may be 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9 mm. Specifically, the stator 110 slot width is 2.6mm and the rotor 120 slot width is 3.8 mm.

Example 9:

as shown in fig. 4, on the basis of any one of embodiments 2 to 8, further, the opening distance between two adjacent stator teeth 112 is the second distance bso; the opening distance between two adjacent sectors 122 is a third distance bro.

The second distance bso is greater than or equal to 0.48 times the third distance bro and less than or equal to 0.79 times the third distance bro. Namely, 0.48 multiplied by bro is not less than bso is not less than 0.79 multiplied by bro.

In this embodiment, by limiting the opening distance between the stator teeth 112 and the opening distance between the sectors 122, and further limiting the opening distance between the stator teeth 112 and the opening distance between the sectors 122 within a certain range, the cogging torque is further limited to a lower range, and the torque ripple of the motor 100 is reduced, thereby reducing the tangential vibration noise of the motor 100. Specifically, the slot widths of the stator 110 and the rotor 120 affect the cogging torque of the motor 100, and the larger the cogging torque is, the smaller the load of the motor 100 is, the larger the torque ripple is, and the larger the noise is. The small cogging torque peak value is taken as an optimization target, the scheme that different stator 110 notches are matched with different rotor 120 notch widths is calculated through a genetic algorithm, when the rotor 120 notch bro and the stator 110 notch bso respectively meet the following formula, the cogging torque is better, the torque pulsation is lower, the structural strength of the rotor 120 side can be improved by limiting the relation between the width of a connecting bridge (an inner magnetic bridge) and the outer diameter of the rotor 120, the self-interlinkage magnetic leakage of a permanent magnet is reduced, the back electromotive force of the motor 100 is improved, the power density of the motor 100 is further improved, and the cost of the motor 100 is reduced.

Example 10:

as shown in fig. 1, 2, 3 and 4, in addition to any one of embodiments 2 to 9, further, the sector 122 and the shaft sleeve 130 are connected by the connecting portion 132, and a ratio of the width bd of the connecting portion 132 to the diameter Dro of the rotor 120 is greater than 0.006 times the diameter Dro of the rotor 120 and less than 0.019 times the diameter Dro of the rotor 120. Namely, 0.006 × Dro < bd/Dro <0.019 × Dro.

In this embodiment, the width of the connection portion 132 between the sector 122 and the shaft sleeve 130 is set in combination with the diameter of the rotor 120, so as to improve the connection strength between the sector 122 and the shaft sleeve 130, improve the structural strength of the rotor 120, reduce the self-link leakage flux of the permanent magnet, improve the power density of the motor, and reduce the cost of the motor 100.

Example 11

Referring to fig. 1 to 6, which are schematic cross-sectional views of an embodiment of a motor 100 provided in the present invention, a rotor 120 is nested in a stator 110. The stator 110 includes a stator 110 yoke, 3p stator teeth 112, and 3p stator 110 slots circumferentially spaced adjacent to the stator teeth 112, the stator 110 slots having windings 140 disposed therein. The sectors of the rotor 120 are connected to the shaft sleeve 130 by connection portions 132, in particular connection bridges, in which magnetic members 150, in particular permanent magnets, are placed.

FIGS. 2-4 are schematic diagrams of various parameters of the present invention; respectively as follows: the minimum circumferential distance between two adjacent stator teeth 112 is the slot bso of the stator 110, the included angle β between the first straight line or the second straight line of the inner edge trimming of the stator 110 and the center line of the stator teeth 112 (i.e. the center line of the first circular arc section 116), the minimum radial distance between the midpoint of the first circular arc section 116 of the stator 110 and the midpoint of the third circular arc section 126 of the sector of the rotor 120 forms a minimum air gap, i.e. a first air gap width: δ min, the minimum distance between the first straight line segment 114 or the second straight line segment 118 of the stator 110 and the third arc segment 126 or the fourth arc segment 128 of the sector forms the maximum air gap, i.e. the second air gap width: δ max. The electrical angle α corresponding to the third arc segment 126 of the rotor 120 sector and the center O of the third arc segment 126₁And a center O of the second arc segment 124 or the fourth arc segment 128₂Is equal to (3). The minimum circumferential distance between the outer edges of the sectors of the adjacent rotors 120 is the notch bro of the rotor 120, and the diameter of the third circular arc section 126 of the rotor 120 is the outer diameter of the rotor 120: dro, the connecting bridge has a circumferential width bd.

According to the principle of the electromagnetic field of the motor 100, the air-gap flux-density interaction with a time difference of 4 times in the air-gap magnetic field is the root cause of generating 4 times of frequency radial electromagnetic force. In order to reduce 4-frequency-multiplication radial electromagnetic force caused by harmonic flux density interaction in an air gap magnetic field, the invention improves the inner edge profile of the stator teeth 112, and a large amount of analysis and tests are carried out after the improvement, so that the motor 100 provided by the invention is finally verified to have better performance.

As shown in fig. 7, by defining the angles of the two trimming straight lines and the maximum and minimum air gap ratios of the trimmed motor 100, the radial vibration noise generated by the large 4-fold frequency radial electromagnetic force caused by the interaction of the 1 to 5 harmonic magnetic densities in the air gap magnetic density can be effectively attenuated.

Fig. 8 is a MAP of the corresponding sum of the flux densities of the major harmonics producing 4-fold frequencies (ignoring other relatively small higher harmonic interactions) for different stator 110 parameters of the above-described embodiment, where the sum of the flux densities of the major harmonics is:

as can be seen from fig. 8: the value of the flux density vector sum of the main harmonic waves generating the 4-frequency multiplication is continuously changed along with the change of the combination of the beta angle and the delta max/delta min, and the value of the flux density vector sum of the 4-frequency multiplication harmonic waves is in a better range when 86.5 degrees < beta <92 degrees and 1.9-delta max/delta min < 3.2 from the contour line in the MAP. Further, for convenience of displaying the numerical values in the figures, the flux density vector sums are each enlarged by 1000 times.

Similarly, the air-gap flux density interaction with the time order difference of 2 in the air-gap magnetic field is the root cause for generating 2 frequency multiplication radial electromagnetic force. In order to reduce 2-frequency-doubled radial electromagnetic force caused by harmonic flux density interaction in the air gap magnetic field.

The invention weakens the vector sum of the harmonic flux density mainly generating 2-frequency multiplication in principle by limiting the trimming straight line and the air gap at the inner edge of the stator 110, thereby effectively reducing the 2-frequency multiplication radial electromagnetic force and reducing the radial electromagnetic noise of the motor.

Fig. 9 is a graph of the generated 2-times frequency radial electromagnetic force MAP corresponding to different stator 110 parameters calculated by the present invention. As can be seen from fig. 9: by limiting the angle of two sections of trimming straight lines and the ratio of the second air gap width to the first air gap width of the trimmed motor 100, the larger 2-time frequency radial electromagnetic force caused by the interaction of 1-time harmonic flux density and 3-time harmonic flux density in the air gap flux density can be effectively weakened.

Fig. 10 is a MAP of the corresponding sum of the flux densities of the major harmonics generating the frequency 2 when the inner edges of the stator teeth 112 of the above embodiment take different parameters (ignoring other relatively small higher harmonic interactions), where the sum of the flux densities of the major harmonics is:

as can be seen from fig. 10: the value of the flux density vector sum of the main harmonic for generating 2-frequency multiplication is continuously changed along with the combination of beta and delta max/delta min, and the MAP graph shows that when the angle is 84 degrees < beta <92 degrees and the angle is 1.4-delta max/delta min is less than or equal to 3.2, the value of the flux density vector sum of the 2-frequency multiplication harmonic is in a better range. Also, for convenience in displaying the figures, the flux density vector sums are each magnified 1000 times.

By combining 4-frequency multiplication and 2-frequency multiplication radial electromagnetic force, it can be seen that the following requirements should be met in the beta range: 86.5 degrees < beta <92 degrees, and the range of delta max/delta min should be satisfied, namely 1.9-3.2-1.2, 2 frequency multiplication radial electromagnetic force and 4 frequency multiplication radial electromagnetic force, and 2 frequency multiplication magnetic density adaptive vector and 4 frequency multiplication magnetic density adaptive vector can be in a better state.

Specifically, the value of the selected scheme β in the present embodiment may be 86 °, 87 °, 88 °, 89 °, or the like; the ratio of δ max/δ min is 2, 2.05, 2.12, 2.18, 2.54, 2.9, 3.12, etc., and at β 87 °, δ max/δ min 2.12, the corresponding 4-and 2-fold radial forces are 1756N/m, respectively²And 15852N/m²。

The size of the air gap along the radial direction determines the flux density distribution and flux transfer efficiency between the rotor 120 and the stator 110 according to the electromagnetic principles of the motor 100. The smaller the radial dimension of the air gap δ, the smaller the air gap reluctance. The larger the radial dimension of the air gap δ, the larger the corresponding air gap reluctance. An excessive air gap reluctance leads to a decrease in magnetic flux density in the air gap δ, which in turn leads to a decrease in magnetic flux involved in the electromechanical energy conversion, a decrease in back electromotive force, and an increase in the amount of copper wire used in the motor 100, thereby increasing the cost of the motor 100. A reasonable air gap delta is therefore an important factor in balancing cost and noise of the motor 100.

Further, fig. 11 is a view showing an increased air gap in the related artThe 4-frequency radial force weakening method is shown in fig. 11, wherein the 4-frequency radial force and the back electromotive force amplitude are shown along with the radial length delta of the air gap of the rotor sector. In FIG. 11, the 4-frequency multiplication radial force density is 2311N/m²Compared with the motor 100 provided by the invention, when the density of the 4-frequency-doubled radial force is the same, the counter potential fundamental wave amplitude is 527V, the motor 100 provided by the invention can ensure that the counter potential is improved by 18% compared with the counter potential obtained by the method in the related technology when the density of the 4-frequency-doubled radial force is the same, and the performance of the motor 100 is stronger.

The above design method achieves the purpose of reducing 4-frequency and 2-frequency radial force caused by harmonic flux density interaction in the air gap magnetic field of the motor 100 under the condition of ensuring counter potential of the motor 100 by limiting the inner edge profile of the stator teeth 112 and the radial length delta of the air gap.

The sine of the no-load back emf of motor 100 affects the tangential torque ripple of motor 100, with higher back emf sine having less parasitic harmonic currents and lower tangential torque ripple. The distribution of the air gap flux density determines the sine of the no-load back emf, and the spline curve of the stator and rotor 120 relative to the profile determines the air gap flux density. And carrying out parametric scanning optimization on the outer edge of the sector of the rotor 120 so as to improve the sine degree of the no-load counter electromotive force of the motor 100, reduce the distortion rate of the motor, reduce the tangential torque pulsation of the motor 100 and reduce the tangential electromagnetic noise of the motor 100.

Fig. 12 and 13 show the variation of the no-load back-emf distortion rate for different rotor 120 sector profiles.

The sector part of the rotor 120 consists of a third arc section 126 concentric with a shaft sleeve 130 and a second arc section 124 and a fourth arc section 128 which are bilaterally symmetrical relative to the third arc section 126 and are not concentric with the shaft sleeve 130; the electrical angle corresponding to the third arc segment 126 is α, and the center O of the third arc segment 126₁And a center O of the second arc segment 124 or the third arc segment 126₂Is Ra, and fig. 12 and 13 show the back-emf distortion rate for different values of alpha and Ra.

When the frequency multiplication 2 and the frequency multiplication 4 are ensured to be smaller, when the electrical angle alpha corresponding to the first arc of the sector part of the rotor 120 meets the condition that the electrical angle alpha is larger than 0 degrees and smaller than the product of the least common multiple LCM of the pole slot, the coefficient Kw1 of the fundamental wave winding 140 and the pole pair number p, namely: 0< α < Kw1 × LCM (3p, 2p) × p, the back-emf distortion rate is generally small.

And, at the third arc segment 126O₁And a center O of the second arc segment 124 or the fourth arc segment 128₂Is Ra satisfies the following formula: 10.5+3 × alpha/LCM<Ra<12.5+3×α/LCM。

In FIGS. 12 and 13, the filled circles indicate that the 2-octave radial force range is 16000N/m²To 17000N/m²4 frequency multiplication radial force 1650N/m²To 1850N/m²Point (2) of (c). When α and Ra satisfy the above expression, the 4-and 2-times radial forces of the motor 100 are substantially the same, and a dotted line fitted with a solid circle in fig. 12 and 13 even in a state of the back electromotive force distortion rate when α and Ra satisfy the above expression. And further, the method can ensure that the radial force of the frequency multiplication 2 is the same as that of the frequency multiplication 4, can ensure lower distortion rate and lower tangential torque pulsation, and can also improve the operation efficiency and shorten the research and development period.

Further, when the radial electromagnetic force and the distortion rate of the motor 100 are low, the motor 100 should have a lower cogging torque, so as to further reduce the tangential torque ripple of the motor 100 and reduce the tangential electromagnetic noise of the motor 100.

Fig. 14 and 15 are fundamental back emf magnitudes corresponding to fig. 12 and 13, respectively; the solid circle in the figure represents that the range of 2 times of frequency radial force is 16000N/m²To 17000N/m²4 frequency multiplication radial force 1650N/m²To 1850N/m²The point of (2) is a point connected by a broken line in the figure, and is a point satisfying the relationship between α and Ra in the present invention.

Specifically, the electrical angle α of the second circular arc segment 124 may be 55 °, 56 °, 57 °, 60 °, Ra 18.5mm, 19mm, 22 mm; the distortion rate is controlled to be about 1.0 percent, and the corresponding 4-frequency multiplication radial force and 2-frequency multiplication radial force are 1756N/m respectively²And 15852N/m²Left and right.

Further, the magnitude of the cogging torque of the motor 100 also affects the tangential torque ripple of the motor 100, and the smaller the cogging torque, the lower the tangential torque ripple. The slot widths of the stator 110 and the rotor 120 affect the cogging torque of the motor 100, and the larger the cogging torque is, the smaller the load of the motor 100 is, the larger the torque ripple is, and the larger the noise is. The scheme that different stator 110 notches are matched with different rotor 120 notch widths is calculated through a genetic algorithm by taking a smaller cogging torque peak value as an optimization target, when the rotor 120 notch bro and the stator 110 notch bso respectively satisfy the following formulas, cogging torque is better, the structural strength of the rotor 120 side can be improved by limiting the relation between the width of a connecting bridge (inner magnetic bridge) and the outer diameter of the rotor 120, the flux leakage of an automatic link of a permanent magnet is reduced, and the efficiency of the motor 100 is improved.

Namely 0.9 XDro xsin [ pi/divided (2 XLCM) ] < bro < 1.1 XDro xsin [ pi/divided (2 XLCM) ];

0.48×bro≤bso≤0.79×bro；

specifically, the stator 110 slot width is 2.6mm and the rotor 120 slot width is 3.8 mm.

The width bd of the connection bridge between the shaft sleeve 130 and the rotor 120 and the outer diameter Dr of the rotor 120 should satisfy 0.006 × Dro < bd/Dro <0.0118 × Dro, and by defining the relationship between the width of the connection bridge (inner magnetic bridge) and the outer diameter of the rotor 120, the structural strength of the rotor 120 side can be improved, the self-interlinkage leakage flux of the permanent magnet can be reduced, and the efficiency of the motor 100 can be improved.

The width bd of the shaft sleeve 130 and the connecting bridge selected in the embodiment is 0.8 mm.

Example 12

The present invention provides a household appliance, comprising: the motor 100 according to any of the above embodiments.

The motor 100 provided by the present invention includes the motor 100 provided in any of the above embodiments, and therefore, all the advantages of the motor 100 provided in any of the above embodiments are provided, which is not described herein.

Specifically, the home appliance is a washing machine, and the motor 100 is used to be connected to a tub or a washing tub of the washing machine.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.