Motor rotor and motor

Abstract

The present invention relates to a rotor and a motor. The rotor has an embedded rotor structure and includes: a rotor core, multiple extensions, and multiple magnetic components. The multiple extensions are distributed circumferentially on the rotor core, and each of the multiple magnetic components is arranged between two adjacent extensions. The multiple magnetic components are arranged alternately with north and south poles along the circumference of the rotor core. By setting a relationship between the length of the extension and the thickness of the magnetic components, the problems of large torque pulsation, large motor vibration, and large noise in existing motors are solved. At the same time, the problems of large motor cogging torque, poor operating stability, and large speed fluctuations during low-speed operation are solved. While solving the large motor torque pulsation and large cogging torque, the motor stray losses can be reduced, which is conducive to improving the motor efficiency.

Description

Technical Field

[0001] The present invention relates to the field of electrical appliances, and in particular to a rotor of a motor and a motor. Background Art

[0002] Electric motors are becoming increasingly popular. Permanent magnet motors are widely used in refrigeration compressors due to their simple structure, reliable operation, compact size, light weight, and excellent performance. Based on the position of the magnets on the rotor, permanent magnet motors are generally divided into surface-mounted and embedded-mount types. Surface-mounted permanent magnet motors are further divided into protruding and embedded-mount types based on the rotor magnetic circuit structure. Surface-mounted permanent magnet motors have an extended core in the rotor.

[0003] Surface-embedded permanent magnet motors offer a simple manufacturing process and low manufacturing cost. They can fully utilize the reluctance torque generated by the asymmetry of the rotor magnetic circuit, effectively improving the motor's power density and efficiency. Their dynamic performance is better than that of surface-protruding permanent magnet motors. However, surface-embedded permanent magnet motors exhibit significant torque pulsation and cogging torque. Excessive torque pulsation can affect motor startup and operation, generating significant vibration and noise. Furthermore, high cogging torque is detrimental to drive control stability, particularly affecting the stability of the motor's low-speed operation and high-precision positioning in position control. Therefore, reducing torque pulsation in surface-embedded permanent magnet motors is a key issue that needs to be considered and addressed in motor design.

[0004] Chinese patent document CN104795909A discloses a surface-embedded permanent magnet motor structure for an air compressor, which has a compact structure, high speed, high mechanical strength, and low harmonic loss. This patent focuses on explaining the advantages of the surface-embedded permanent magnet motor, such as using wedge grooves to effectively increase the mechanical strength of the rotor, but does not explain the length of the wedge grooves or the relationship between the wedge groove length and the thickness of the magnetic steel. Summary of the Invention

[0005] In view of this, the present invention provides a rotor and a motor of a motor, which solve the problem of large torque pulsation of existing motors by setting the relationship between the length of the extension part and the thickness of the magnetic part; and / or by setting the shape of the surface of the extension part; and / or by setting grooves on both sides of the extension part and by setting the shape of the grooves.

[0006] Specifically: A rotor of an electric motor, a rotor of an electric motor, comprising: a rotor core, a plurality of magnetic parts, a plurality of protrusions formed on the circumference of the rotor core, the plurality of protrusions radially protruding from the circumferential surface of the rotor core, a magnetic part being provided between every two adjacent protrusions, and the plurality of magnetic parts being arranged alternately in NS poles along the circumference of the rotor core; the cross-section of the top surface (outer surface) of the magnetic part in a cross-section perpendicular to the central axis of the rotor core forms a first arc, and the arc radius of the first arc is R1; the cross-section of the inner surface of the magnetic part in a cross-section perpendicular to the central axis of the rotor core forms a second arc, and the arc radius of the second arc is R2; the thickness of the magnetic part is R1-R2; the cross-section of the top surface of the protrusion of the rotor core in a cross-section perpendicular to the central axis of the rotor core forms a third arc, and the arc radius of the third arc is R3; the length of the protrusion is h, h=R3-R2; wherein, h=(0.3~0.7)*(R1-R2).

[0007] Preferably, the cross-section of the top surface of the rotor core in a cross-section perpendicular to the central axis of the rotor core forms a fourth arc, and the arc radius of the fourth arc is R4; wherein the first arc, the second arc, the third arc and the fourth arc are arranged concentrically, and R4=R2.

[0008] Preferably, h=0.5*(R1-R2).

[0009] Preferably, each of the plurality of magnetic parts occupies a circumferential angle δ in the circumferential direction of the rotor core, and each protrusion occupies a circumferential angle θ in the circumferential direction of the rotor core, wherein δ and θ satisfy the relationship δ+θ=90°.

[0010] Preferably, 1 / 8*δ≤θ≤1 / 2*δ.

[0011] Preferably, θ=18°, δ=72°.

[0012] Preferably, a plurality of protrusions are evenly distributed in the circumferential direction of the rotor core.

[0013] Preferably, the cross section of the top surface of the extension of the rotor core in a cross section perpendicular to the central axis of the rotor core forms multiple arcs.

[0014] Preferably, grooves are formed on both sides of some or all of the plurality of protruding portions.

[0015] Preferably, the rotor is an embedded rotor structure.

[0016] In addition, the present invention also provides a rotor of an electric motor, comprising: a rotor core, a plurality of protruding portions and a plurality of magnetic parts, wherein the plurality of protruding portions are distributed circumferentially of the rotor core, each of the plurality of magnetic parts is arranged between two adjacent protruding portions, and the plurality of magnetic parts are arranged alternately according to N-S poles along the circumference of the rotor core; the protruding portions of the rotor core are in a cross section perpendicular to the central axis of the rotor core, and the cross section of the top surface thereof forms a plurality of line segments.

[0017] Preferably, the multiple line segments are formed in a wavy shape.

[0018] Preferably, each of the multiple line segments is an arc.

[0019] Preferably, the number of segments of the multi-segment line segment is 2-5, and the radius of the arcs of the multi-segment arcs are the same, and the radius is recorded as Rs.

[0020] Preferably, the length of the multiple extensions extending out of the rotor core is denoted as h, where 0≤Rs≤3 / 4*h.

[0021] Preferably, Rs=1 / 2*h.

[0022] Preferably, the center O' of each of the multiple arcs is on a bisector of the width of the extension portion, and the number n of bisectors is determined by the number m of the arc segments of the multiple arcs, satisfying the relationship n=2*m-1.

[0023] Preferably, a plurality of protrusions are evenly distributed in the circumferential direction of the rotor core.

[0024] Preferably, grooves are formed on both sides of some or all of the plurality of protruding portions.

[0025] Preferably, the groove has a cross-sectional shape of a single semicircle, an equilateral triangle, or a double semicircle in a cross-section perpendicular to the central axis of the rotor core.

[0026] In addition, the present invention provides a rotor of a motor, comprising: a rotor core, a plurality of protruding portions, and a plurality of magnetic parts, wherein the plurality of protruding portions are distributed circumferentially on the rotor core, each of the plurality of magnetic parts is arranged between two adjacent protruding portions, and the plurality of magnetic parts are arranged alternately according to NS poles along the circumference of the rotor core; grooves are provided on both sides of some or all of the plurality of protruding portions.

[0027] Preferably, the groove is used to reduce torque ripple of the motor.

[0028] Preferably, the plurality of protruding portions are evenly distributed in the circumferential direction of the rotor core.

[0029] Preferably, the groove has a cross-sectional shape of a single semicircle, an equilateral triangle, or a double semicircle in a cross-section perpendicular to the central axis of the rotor core.

[0030] Preferably, the two side edges of the extension portion are in a cross section perpendicular to the central axis of the rotor core, and the cross section forms a straight line; the cross section of the groove is a single semicircle, and the center of the single semicircle is located at the midpoint of the straight line of the cross section of the two side edges of the extension portion.

[0031] Preferably, the length of the protruding portion protruding from the rotor core is denoted as h, and the radius of a single semicircle is r1, wherein 1 / 8*h≤r1≤3 / 8*h,

[0032] Preferably, r1 = 1 / 2*h.

[0033] Preferably, the two side edges of the extension portion form a straight line in a cross section perpendicular to the central axis of the rotor core; the cross section of the groove is triangular, and the midpoint of the base of the triangle is located at the midpoint of the straight line of the cross section on both sides of the extension portion.

[0034] Preferably, the triangle is an equilateral triangle, and the side length of the equilateral triangle is r2, wherein 1 / 8*h≤r2≤3 / 8*h.

[0035] Preferably, the two side edges of the extension portion are in a cross section perpendicular to the central axis of the rotor core, and the cross section forms a straight line; the cross section shape of the groove is a double semicircle, and the centers of the double semicircles are respectively located at the 1 / 4 point position and the 3 / 4 point position of the cross section straight line on both sides of the extension portion.

[0036] Preferably, the length of the protruding portion protruding from the rotor core is denoted as h, and the radius of the two semicircles is the same, which is denoted as r3, wherein r3=1 / 4*h.

[0037] In addition, the present invention further provides a motor, which includes the rotor of the motor described in the present invention.

[0038] Preferably, the motor is a permanent magnet motor.

[0039] Through the above configuration, the embodiments of the present invention can significantly reduce the torque pulsation of the motor, reduce the motor noise, improve the motor slot torque, improve the motor operation stability, reduce the motor stray loss, and improve the motor efficiency.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings. The drawings described below are only some embodiments of the present disclosure, and it is obvious to those skilled in the art that other drawings can be derived from these drawings without inventive effort.

[0042] Figure 1 A three-dimensional schematic diagram of the rotor of the motor according to the first embodiment of the present invention.

[0043] Figure 2 A three-dimensional schematic diagram of the rotor core according to the first embodiment of the present invention.

[0044] Figure 3 A schematic cross-sectional view of a motor according to a first embodiment of the present invention.

[0045] Figure 4 A schematic cross-sectional view of a rotor core according to a first embodiment of the present invention.

[0046] Figure 5 Schematic diagram comparing torque ripple between a motor using the rotor according to the first embodiment of the present invention and a motor using the prior art.

[0047] Figure 6 A schematic cross-sectional view of a rotor core according to a second embodiment of the present invention.

[0048] Figure 7 Schematic diagram comparing torque pulsation of a motor using the rotor according to the second embodiment of the present invention and a motor using the rotor according to the first embodiment.

[0049] Figure 8 A schematic cross-sectional view of a rotor core according to a third embodiment of the present invention.

[0050] Figure 9 The second cross-sectional schematic diagram of the rotor core according to the third embodiment of the present invention.

[0051] Figure 10 The third schematic cross-sectional view of the rotor core according to the third embodiment of the present invention.

[0052] Figure 11 Schematic diagram comparing torque pulsation between a motor using the rotor according to the third embodiment of the present invention (the groove shape is a single semicircle) and a motor using the prior art.

[0053] Figure 12 Schematic diagram comparing torque ripples of a motor using the rotor according to the third embodiment of the present invention (with the grooves in the shape of equilateral triangles) and a motor using the prior art.

[0054] Figure 13 Schematic diagram comparing torque pulsation of a motor using the rotor of the third embodiment of the present invention (with double semicircular grooves) and a motor of the prior art.

[0055] Wherein: 1- rotor core, 11- through hole, 12- protruding portion, 13- groove, 2- magnetic member, 3- stator, 31- tooth slot;

[0056] A0-the torque pulsation curve of the existing motor, A1-the torque pulsation curve of the motor using the rotor of the motor according to the first embodiment of the present invention; A2-the torque pulsation curve of the motor using the rotor of the motor according to the second embodiment of the present invention; A31-the torque pulsation curve of the motor using the rotor of the motor according to the third embodiment of the present invention (the groove is a single semicircle); A32-the torque pulsation curve of the motor using the rotor of the motor according to the third embodiment of the present invention (the groove is a triangle); A33-the torque pulsation curve of the motor using the rotor of the motor according to the third embodiment of the present invention (the groove is a double semicircle). DETAILED DESCRIPTION

[0057] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the drawings represent like or similar parts, and thus repetitive description thereof will be omitted.

[0058] In addition, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, well-known methods, devices, implementations or operations are not shown or described in detail to avoid blurring various aspects of the present disclosure.

[0059] It should be understood that although the terms first, second, third, etc. may be used herein to describe various structures, these structures should not be limited by these terms. These terms are used to distinguish one structure from another. Thus, the first structure discussed below can be referred to as the second structure without departing from the teachings of the present disclosure. As used herein, the term "and / or" includes any one of the associated listed items and all combinations of one or more of them.

[0060] Those skilled in the art will understand that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present disclosure, and therefore cannot be used to limit the scope of protection of the present disclosure.

[0061] The following is combined with Figure 1-13 The specific embodiments of the present invention are described in detail:

[0062] The rotor (structure) of the motor according to the embodiment of the present invention is an embedded rotor structure. By setting the relationship between the length of the extension 12 and the thickness of the magnetic member 2; and / or by setting the shape of the surface of the extension 12; and / or by setting the grooves 13 on both sides of the extension 12 and by setting the shape of the grooves 13; the motor torque pulsation, motor vibration, and motor noise can be reduced. When the rotor of the motor according to the embodiment of the present invention is used as the rotor of a permanent magnet motor, it can simultaneously reduce the torque of the motor cogging 31, improve the motor operation stability, reduce the low-speed operation speed fluctuation, and facilitate the control of the drive stability. The rotor (structure) according to the embodiment of the present invention also reduces the stray loss of the motor and can improve the motor efficiency to a certain extent.

[0063] Example 1

[0064] like Figure 1-6 As shown, the rotor of the motor of the first embodiment of the present invention is an embedded rotor structure. By setting the relationship between the length of the protruding portion 12 and the thickness of the magnetic component 2, the problems of large torque pulsation, large motor vibration and large noise of the existing motor can be solved; at the same time, the problems of large torque of the motor tooth slot 31, poor operating stability, and large speed fluctuation during low-speed operation can be solved; while solving the large torque pulsation of the motor and the large torque of the tooth slot 31, the motor stray loss can be reduced, which is beneficial to improving the motor efficiency.

[0065] The rotor of the motor according to the embodiment of the present invention includes: a rotor core 1, multiple extensions 12 and multiple magnetic members 2. The multiple extensions 12 are evenly distributed on the circumference of the rotor core 1. Each magnetic member 2 is arranged between two adjacent extensions 12. The multiple magnetic members 2 are arranged alternately in the N-S polarity along the circumference of the rotor core 1. The top surface of the magnetic member 2 in a cross section perpendicular to the central axis of the rotor core 1 forms a first arc, and the arc radius of the first arc is R1. The inner surface of the magnetic member 2 in a cross section perpendicular to the central axis of the rotor core 1 forms a second arc, and the arc radius of the second arc is R2. The thickness of the magnetic member 2 is R1-R2. The top surface of the extension 12 of the rotor core 1 in a cross section perpendicular to the central axis of the rotor core 1 forms a third arc, and the arc radius of the third arc is R3. The length of the extension 12 is h, h=R3-R2; wherein h=(0.3-0.7)*(R1-R2).

[0066] Among them, the magnetic component 2 is preferably a magnetic steel, which can be integrally die-cast by a mold. The rotor of the motor is preferably used as the rotor of a permanent magnet motor, which can solve the problem of excessive cogging torque of the motor. The rotor of the motor includes a rotor core 1, a magnetic steel, and fixing and supporting elements such as bolts or rivets. The rotor core 1 can be laminated by silicon steel sheets with a thickness of 0.25 to 0.5 mm. A through hole 11 is provided on the rotor core 1 for placing fixing and supporting elements such as bolts or rivets. The fixing and supporting elements pass through the through hole 11 and cooperate with nuts or are used to fasten the rotor core 1 by riveting. The protruding parts 12 are evenly spaced on the rotor core 1. The number of the protruding parts 12 is the same as the number of the magnetic steels. The magnetic steels are placed between two adjacent protruding parts 12. The magnetic steels are alternately arranged in a uniform pattern of N and S polarities on the top surface of the rotor core 1 by means of glue bonding or mechanical fixing.

[0067] In the cross-section perpendicular to the central axis of the rotor core 1, the cross-section of its top surface forms a fourth arc, and the arc radius of the fourth arc is R4; among them, the first arc, the second arc, the third arc and the fourth arc are concentrically arranged, and R4 = R2. Preferably, the arc radius R3 satisfies the requirement of R2 < R3 ≤ R1.

[0068] To reduce the torque ripple of the motor, the length h of the protruding part 12 = (0.3 - 0.7)*(R1 - R2), that is, the arc radius R of the top surface of the protruding part 12 satisfies 0.3*R1 + 0.7*R2 ≤ R ≤ 0.7*R1 + 0.3*R2. Preferably, h = 0.5*(R1 - R2), that is, the arc radius R of the top surface of the protruding part 12 = 0.5*R1 + 0.5*R2. At this time, the length of the protruding part 12 of the rotor core 1 is half of the thickness of the magnetic steel.

[0069] The circumferential angle occupied by each magnetic component 2 on the rotor core 1 is δ, and the circumferential angle occupied by each protruding part 12 on the rotor core 1 is θ. Among them, δ and θ satisfy the relationship δ + θ = 90°. In the embodiment of the present invention, to reduce the torque ripple of the motor and make full use of the reluctance torque generated by the rotor magnetic circuit, the angle size of the protruding part 12 needs to satisfy the relationship 1 / 8*δ ≤ θ ≤ 1 / 2*δ. The angle size of the protruding part 12 is preferably θ = 1 / 4*δ. At this time, θ = 18° and δ = 72°.

[0070] Such as Figure 3As shown in the figure, a motor adopts the rotor of the motor of the present invention, which includes a stator 3 and a rotor, wherein the stator 3 is further provided with tooth slots 31, and the tooth slots 31 are used for winding the coil winding. Experiments and simulations show that when the length of the extension portion 12 is h = (0.3 ~ 0.7) * (R1-R2) and / or δ + θ = 90°, 1 / 8 * δ ≤ θ ≤ 1 / 2 * δ, the torque pulsation of the motor can be well reduced. Among them, when the following conditions are met at the same time: h = (0.3 ~ 0.7) * (R1-R2) and δ + θ = 90°, 1 / 8 * δ ≤ θ ≤ 1 / 2 * δ, the torque pulsation is significantly reduced. As shown in the figure Figure 5 As shown in the figure, a schematic diagram of the torque pulsation comparison of a motor using the rotor of the above-mentioned motor and a motor using the rotor of an existing motor is shown. It can be seen from the figure that the torque pulsation of the motor using the rotor of the motor according to the embodiment of the present invention is significantly reduced compared with the torque pulsation of the existing motor; using the rotor of the above-mentioned motor, it can be found through simulation that the motor torque pulsation is significantly reduced compared with the original traditional rotor, and the peak-to-peak value of the motor torque at no-load is reduced from the original 41.4mN*m to 25.8mN*m, and the technical effect is very significant.

[0071] Example 2

[0072] like Figure 1-3 , 6, 7, wherein the second embodiment shows an alternative embodiment, wherein the overall shape of the rotor (structure) is the same as that of the first embodiment Figure 1-3 The structure is the same as shown, the difference is that it uses Figure 6 The cross-sectional shape shown.

[0073] The rotor of the motor of the second embodiment of the present invention is an embedded rotor structure. By setting the surface shape of the extension part 12, the problems of large torque pulsation, large motor vibration and noise in the existing motor can be solved; at the same time, the problems of large torque of the motor tooth slot 31, poor operating stability, and large speed fluctuations during low-speed operation can be solved; while solving the large torque pulsation of the motor and the large torque of the tooth slot 31, the motor stray loss can be reduced, which is beneficial to improving the motor efficiency.

[0074] like Figure 6 As shown, the rotor of the motor of Example 2 includes: a rotor core 1, multiple extensions 12, and multiple magnetic members 2. The multiple extensions 12 are distributed circumferentially of the rotor core 1, each of the multiple magnetic members 2 is disposed between two adjacent extensions 12, and the multiple magnetic members 2 are arranged alternately along the circumference of the rotor core 1 in an N-S polar pattern. The top surface of the extensions 12 of the rotor core 1, within a cross section perpendicular to the central axis of the rotor core 1, forms multiple arcs. Preferably, the multiple extensions 12 are evenly distributed circumferentially of the rotor core 1.

[0075] The motor torque ripple can be further reduced by changing the arc shape of the top surface of the extension portion 12. Changing the arc shape of the top surface of the extension portion 12 to a wavy line can significantly reduce the torque ripple. Preferably, the wavy line on the top surface of the extension portion 12 is a plurality of arc segments with the same radius, which can be 2 to 5 segments, preferably 3 segments.

[0076] The number of the multi-segment arcs is 2-5, and the radii of the multi-segment arcs are the same.

[0077] The center O' of the wavy arc is on the bisector of the width of the extension portion 12. The number n of bisectors is determined by the number m of arc segments, satisfying the relationship n=2*m-1.

[0078] The radius of the wavy line arc is denoted as Rs, which satisfies the relationship 0≤Rs≤3 / 4*h. Preferably, Rs=1 / 2*h.

[0079] The motor of the motor rotor of the present invention is used, wherein the cross-sectional shape of the top surface of the extension portion 12 is set to multiple arc segments. Through simulation, it can be found that the torque pulsation is greatly reduced. The present invention further reduces the torque pulsation by further setting the cross-sectional shape of the top surface of the extension portion 12 to multiple arc segments in the manner of the first embodiment. Figure 7 As shown, the motor torque pulsation is significantly reduced compared with the rotor described in Example 1. The peak-to-peak value of the motor torque at no-load is reduced from the original 25.8mN*m to 14.9mN*m, which further reduces the torque pulsation of the motor, and its technical effect is very significant.

[0080] Example 3

[0081] like Figure 8-13 As shown, the third embodiment shows an alternative embodiment, wherein the overall shape of the rotor structure is the same as that of the first embodiment. Figure 1-3 The structure shown is the same, the difference is that the extension 12 adopts Figure 8-9 The cross-sectional shape shown.

[0082] The rotor of the motor of the third embodiment of the present invention is an embedded rotor structure. By arranging grooves 13 on both sides of the protruding portion 12 and by setting the shape of the grooves 13, the problems of large torque pulsation, large motor vibration and large noise of the existing motor can be solved; at the same time, the problems of large torque of the motor tooth slot 31, poor operating stability, and large speed fluctuations during low-speed operation can be solved; while solving the large torque pulsation of the motor and the large torque of the tooth slot 31, the motor stray loss can be reduced, which is beneficial to improving the motor efficiency.

[0083] like Figure 8-10As shown, the rotor of the motor of embodiment three comprises: a rotor core 1, a plurality of protruding portions 12, and a plurality of magnetic parts 2. The plurality of protruding portions 12 are distributed circumferentially on the rotor core 1, and each of the plurality of magnetic parts 2 is arranged between two adjacent protruding portions 12. The plurality of magnetic parts 2 are arranged alternately according to NS poles along the circumference of the rotor core 1; grooves 13 are provided on both sides of some or all of the plurality of protruding portions 12. Preferably, the grooves 13 are used to reduce the torque pulsation of the motor. Preferably, the plurality of protruding portions 12 are evenly distributed circumferentially on the rotor core 1. The cross-sectional shape of the grooves 13 in the cross section perpendicular to the central axis of the rotor core 1 is a single semicircle, an equilateral triangle, or a double semicircle.

[0084] The two side edges of the extension 12 are in a cross section perpendicular to the central axis of the rotor core 1 , and the cross section forms a straight line; the cross section of the groove 13 is a single semicircle, and the center of the single semicircle is located at the midpoint of the cross section straight line of the two side edges of the extension 12 .

[0085] The length of the extension portion 12 protruding from the rotor core 1 is recorded as h, and the radius of a single semicircle is r1, wherein 1 / 8*h≤r1≤3 / 8*h, wherein r1=1 / 2*h.

[0086] like Figure 8 , as shown in 11, when the semicircular grooves 13 are opened on both sides of the extension portion 12 of the rotor core 1, the motor torque pulsation simulation value is compared with the existing motor torque pulsation simulation value. Figure 11 As shown in the figure, the motor torque ripple is reduced from the original 65.87% to 36.05%, and the torque ripple improvement effect is obvious.

[0087] like Figure 9 As shown in FIG12 , the two sides of the extension 12 form a straight line in a cross section perpendicular to the central axis of the rotor core 1 ; the cross section of the groove 13 is triangular, with the midpoint of the base of the triangle located at the midpoint of the straight lines of the cross section of the extension 12 . The triangle is an equilateral triangle, and the side length of the equilateral triangle is r2, where 1 / 8*h≤r2≤3 / 8*h.

[0088] like Figure 12 As shown, when the extension portion 12 of the rotor core 1 opens an equilateral triangle, the motor torque pulsation simulation value is compared with the original motor torque pulsation simulation value. Figure 12 As shown, the motor torque ripple is reduced from the original 65.87% to 38.79%, and the torque ripple improvement effect is slightly worse than that of the semicircular groove 13.

[0089] like Figure 10As shown in FIG13 , the two sides of the extension 12 form a straight line in a cross section perpendicular to the central axis of the rotor core 1. The cross section of the groove 13 is a double semicircle, with the centers of the double semicircles located at the 1 / 4 and 3 / 4 points of the cross section of the extension 12. The length of the extension 12 protruding from the rotor core 1 is denoted as h. The double semicircles have the same radius, denoted as r3, where r3 = 1 / 4 * h.

[0090] like Figure 13 As shown in FIG. 1 , when the extension portion 12 of the rotor core 1 is provided with double semicircular grooves 13, the motor torque pulsation simulation value is compared with the original motor torque pulsation simulation value. Figure 13 As shown in the figure, the motor torque ripple is reduced from the original 65.87% to 42.68%, and the torque ripple improvement has a good effect.

[0091] In the embodiment of the present invention, Example 1, Example 2, and Example 3, respectively, the length of the extension portion 12, the shape of the top surface of the extension portion 12, and the grooves 13 on both sides of the extension portion 12 are provided to reduce the torque pulsation of the motor. Obviously, any combination of the solutions of Example 1, Example 2, and Example 3 is within the scope of protection of the present invention; for example, on the basis of Example 1, the limitation on the surface shape of Example 2 and / or the limitation on the grooves 13 on both sides of the extension portion 12 of Example 3 can be further adopted; on the basis of Example 2, the limitation on the length of the extension portion 12 and / or the grooves 13 on both sides of the extension portion 12 of Example 1 can be further adopted; on the basis of Example 3, the limitation on the length of the extension portion 12 and / or the surface shape of Example 2 can be further adopted. Through the above further limitations, the technical solutions of the embodiment of the present invention can be further optimized to better reduce the torque pulsation of the motor.

[0092] Beneficial effects:

[0093] The rotor of the motor in the embodiment of the present invention is an embedded rotor structure, which reduces the motor torque pulsation by setting the relationship between the length of the protruding part and the thickness of the magnetic part; and / or by setting the shape of the surface of the protruding part; and / or by setting grooves on both sides of the protruding part and by setting the shape of the grooves; and is beneficial to reducing motor vibration and reducing motor noise; the rotor in the embodiment of the present invention also reduces the motor cogging torque, improves the motor operation stability, reduces the low-speed operation speed fluctuation, and is beneficial to controlling the smoothness of the drive; the rotor structure in the embodiment of the present invention also reduces the motor stray loss and can improve the motor efficiency.

[0094] While the exemplary embodiments of the present disclosure have been specifically illustrated and described above, it should be understood that the present disclosure is not limited to the detailed structures, configurations, or implementations described herein; rather, the present disclosure is intended to encompass various modifications and equivalent configurations within the spirit and scope of the appended claims.

Claims

1. A rotor of a motor, comprising: A rotor core (1) and a plurality of magnetic members (2), characterized in that: a plurality of protruding portions (12) are formed in the circumferential direction of the rotor core (1), and the plurality of protruding portions (12) are arranged to protrude radially from the circumferential surface of the rotor core (1); a magnetic member (2) is provided between each two adjacent protruding portions of the plurality of protruding portions, and the plurality of magnetic members (2) are arranged alternately in the N-S pole direction along the circumferential direction of the rotor core (1); Each magnetic member (2) has a top surface section in a section perpendicular to the central axis of the rotor core (1) forming a first arc, and the radius of the first arc is R1; each magnetic member (2) has an inner surface section in a section perpendicular to the central axis of the rotor core (1) forming a second arc, and the radius of the second arc is R2; the thickness of the magnetic member (2) is R1-R2; Each extension portion (12) of the rotor core (1) has a top surface in a cross section perpendicular to the central axis of the rotor core (1) that forms a plurality of circular arcs, and the radius of each of the plurality of circular arcs is the same; The length of each extension portion (12) is h, where h=(0.3-0.7)*(R1-R2); the radius of each arc in the plurality of arcs is Rs, where 0≤Rs≤3 / 4*h; Grooves (13) are provided on both sides of some or all of the plurality of protruding portions (12).

2. The rotor of the motor according to claim 1, characterized in that: The cross section of the top surface of the rotor core (1) in a cross section perpendicular to the central axis of the rotor core (1) forms a fourth arc, and the radius of the fourth arc is R4; wherein the first arc, the second arc and the fourth arc are arranged concentrically, and R4=R2.

3. The rotor of the motor according to claim 1 or 2, characterized in that: h=0.5*(R1-R2).

4. The rotor of the motor according to claim 1 or 2, characterized in that: Each of the plurality of magnetic parts (2) occupies a circumferential angle δ in the circumferential direction of the rotor core (1), and each protruding portion (12) occupies a circumferential angle θ in the circumferential direction of the rotor core (1), wherein δ and θ satisfy the relationship δ+θ=90°.

5. The rotor of the motor according to claim 4, characterized in that: 1 / 8*δ≤θ≤1 / 2*δ.

6. The rotor of the motor according to claim 5, characterized in that: θ=18°, δ=72°.

7. The rotor of the motor according to any one of claims 1, 2, 5, and 6, characterized in that: The rotor is an embedded rotor structure, a rotor core (1) is evenly distributed with a plurality of protruding portions (12) in the circumferential direction, and each magnetic part (2) of the plurality of magnetic parts (2) is embedded between two adjacent protruding portions (12).

8. A motor, characterized in that: The motor comprises the rotor of the motor according to any one of claims 1 to 7.

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