Rotor assembly and motor

Abstract

The utility model discloses a rotor assembly and a motor, and relates to the technical field of motors, the rotor assembly comprises a rotor yoke, a plurality of radial magnetic shoes and a plurality of circumferential magnetic shoes, and the rotor yoke is configured to be annular and rotates around a rotation axis; the plurality of radial magnetic shoes are connected to the inner side of the rotor yoke and configured to be magnetized in the radial direction of the rotating axis, and the plurality of radial magnetic shoes are arranged at intervals in the circumferential direction of the rotating axis; the plurality of circumferential magnetic shoes are connected to the inner side of the rotor yoke and configured to be magnetized in the circumferential direction of the rotating axis, and the plurality of circumferential magnetic shoes are located between every two adjacent radial magnetic shoes respectively; one side surface, facing the rotating axis, of each radial magnetic shoe comprises a first arc surface, and a first surface and a second surface which are connected to the two sides of the first arc surface in the circumferential direction, the distance between the first surface and the rotating axis is gradually increased in the direction away from the first arc surface, and the distance between the second surface and the rotating axis is gradually increased in the direction away from the first arc surface. The rotor assembly of the utility model can enhance the electromagnetic performance and improve the mute effect.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor assembly and a motor. Background Technology

[0002] Permanent magnet synchronous motors have high power density and torque density, and are widely used in electrical appliances such as air conditioners. Traditional external rotor motors have problems such as poor magnet concentration and high harmonic content in their permanent magnet arrays, which affect the power density of the motor and lead to electromagnetic vibration and noise issues. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a rotor assembly that can enhance electromagnetic performance and improve noise reduction.

[0004] This utility model also proposes a motor having the above-mentioned rotor assembly.

[0005] A rotor assembly according to a first aspect of the present invention includes: a rotor yoke configured in an annular shape and rotating about a rotation axis; a plurality of radial magnets connected to the inner side of the rotor yoke and configured to be radially magnetized along the rotation axis, the plurality of radial magnets being arranged circumferentially spaced along the rotation axis; and a plurality of circumferential magnets connected to the inner side of the rotor yoke and configured to be circumferentially magnetized along the rotation axis, the plurality of circumferential magnets being located between two adjacent radial magnets; wherein, the radial magnets have a side facing the rotation axis including a first arcuate surface and a first surface and a second surface connected to both sides of the first arcuate surface circumferentially, the distance between the first surface and the rotation axis increasing in a direction away from the first arcuate surface, and the distance between the second surface and the rotation axis increasing in a direction away from the first arcuate surface.

[0006] The rotor assembly according to the embodiments of the present invention has at least the following beneficial effects:

[0007] By placing circumferential magnetic tiles between two adjacent radial magnetic tiles, the magnetic lines of force of the radial and circumferential magnetic tiles facing the air gap are superimposed, increasing the magnetic lines of force on the rotor assembly facing the air gap and enhancing the magnetic concentration effect, thereby strengthening the magnetic field on the rotor assembly facing the air gap. Conversely, the magnetic lines of force of the radial and circumferential magnetic tiles facing the rotor yoke cancel each other out, weakening the magnetic field at the rotor yoke and reducing the magnetic saturation of the rotor yoke. This ensures smooth magnetic flux flow within the rotor yoke, thereby improving the electromagnetic performance and efficiency of the motor. Simultaneously, the side of the radial magnetic tile facing the air gap is designed with a structure consisting of a first surface, a first arc surface, and a second surface connected sequentially along the circumference. This optimizes the air gap structure and allows the magnetic flux of the radial magnetic tiles to better concentrate along the radial centerline towards the first arc surface, making the air gap magnetic field more sinusoidal. This improves the magnetic field and magnetic flux density, further enhancing the electromagnetic performance of the motor. Furthermore, it helps reduce harmonic components in the air gap magnetic field, lowers back electromotive force harmonics, and thus reduces vibration and noise during motor operation, improving the motor's quietness.

[0008] According to some embodiments of this utility model, the minimum width of the circumferential magnetic tile is L1, the minimum width of the radial magnetic tile is L2, the maximum distance between the side of the radial magnetic tile facing the rotor yoke and the rotation axis is D / 2, and the number of pole pairs of the motor is p, satisfying: 0.82≤(L1+L2)*2p / (π*D)≤0.99.

[0009] According to some embodiments of this utility model, the minimum width L1 of the circumferential magnetic tile and the minimum width L2 of the radial magnetic tile satisfy: 0.22≤L1 / L2≤0.4.

[0010] According to some embodiments of the present invention, the first surface and the second surface are arranged symmetrically along the radial center line of the first arc surface.

[0011] According to some embodiments of the present invention, the radial magnetic tile has a second arc surface on one side facing the rotor yoke. The second arc surface and the first arc surface are concentric. The angle of the central angle corresponding to the first arc surface is α1, and the angle of the central angle corresponding to the second arc surface is α2, satisfying: 0.35≤α1 / α2≤0.85.

[0012] According to some embodiments of the present invention, the thickness of the radial magnetic tile along the radial center line of the first arc surface is L5, and the radius of the first arc surface is R1, satisfying: 0.1≤L5 / R1≤0.15.

[0013] According to some embodiments of the present invention, the cross-section of the circumferential magnetic tile is square, the width of the circumferential magnetic tile is L1, and the radial thickness of the circumferential magnetic tile is L3, satisfying: 0.65≤L1 / L3≤1.36.

[0014] According to some embodiments of this utility model, the radius of the first arc surface is R1, the maximum distance between the side of the radial magnetic tile facing the rotor yoke and the rotation axis is D / 2, and the number of pole pairs of the motor is p, satisfying: 0.155≤2p*L1*L3 / (π*D 2 / 4-π*R1 2 ) ≤0.245.

[0015] According to some embodiments of the present invention, the side of the radial magnetic tile facing the rotor yoke is configured as a second arc surface that fits against the inner side of the rotor yoke, the thickness of the rotor yoke along the radial center line of the first arc surface is L4, and the thickness of the radial magnetic tile along the radial center line of the first arc surface is L5, satisfying: 0.2≤L4 / L5≤0.5.

[0016] The motor according to a second aspect of the present invention includes a stator assembly and a rotor assembly according to a first aspect of the present invention, wherein the rotor assembly is sleeved on the outside of the stator assembly.

[0017] The motor according to the second aspect embodiment of the present invention has at least the following beneficial effects:

[0018] The rotor assembly adopting the first aspect embodiment has a circumferential magnetic tile between two adjacent radial magnetic tiles. The magnetic lines of force of the radial and circumferential magnetic tiles facing the air gap are superimposed, increasing the magnetic lines of force on the air gap side of the rotor assembly and enhancing the magnetic concentration effect, thereby strengthening the magnetic field on the air gap side of the rotor assembly. Meanwhile, the magnetic lines of force of the radial and circumferential magnetic tiles facing the rotor yoke cancel each other out, weakening the magnetic field at the rotor yoke and reducing the magnetic saturation of the rotor yoke. This ensures smooth magnetic flux flow in the rotor yoke, thereby improving the electromagnetic performance and efficiency of the motor. Simultaneously, the side of the radial magnetic tile facing the air gap is configured as a structure with a first surface, a first arc surface, and a second surface connected sequentially along the circumference. This optimizes the air gap structure and allows the magnetic flux of the radial magnetic tile to better concentrate along the radial centerline towards the first arc surface, making the air gap magnetic field more sinusoidal, improving the magnetic field and magnetic flux density state, further enhancing the electromagnetic performance of the motor, and helping to reduce harmonic components in the air gap magnetic field, reducing back electromotive force harmonics, thereby reducing vibration and noise during motor operation and improving the motor's quietness.

[0019] According to some embodiments of the present invention, the radius of the largest circumscribed circle of the outer side wall of the stator assembly is R2, and the radius of the first arc surface is R1, satisfying: 0.4mm≤R1-R2≤1.1mm.

[0020] Additional aspects and advantages of this 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. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is an axial schematic diagram of the motor in one embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the magnetic field lines distribution of radial and circumferential magnetic tiles in one embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the assembly of radial and circumferential magnetic tiles in one embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a radial magnetic tile in one embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the assembly of the rotor yoke and radial magnetic tiles in one embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the assembly of the rotor yoke with the radial and circumferential magnetic tiles in one embodiment of the present invention;

[0028] Figure 7 for Figure 6 Enlarged view of point A in the middle;

[0029] Figure 8 A bar chart comparing the back EMF amplitude of the first harmonic in one embodiment of the present invention with that in the prior art.

[0030] Figure 9 This is a bar chart comparing the back EMF amplitude of other harmonics in one embodiment of the present invention with that of the prior art.

[0031] Icon labels:

[0032] Rotor yoke 100;

[0033] Radial magnetic tile 200; first arc surface 210; first surface 220; second surface 230; second arc surface 240; first magnetic field 250;

[0034] Circumferential magnetic tile 300; Second magnetic field 310;

[0035] Stator core 400; stator teeth 410; air gap 420;

[0036] Rotation axis Z1; radial centerline Z2. Detailed Implementation

[0037] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0038] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] In the description of this utility model, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or their sequential relationship.

[0040] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0041] Reference Figures 1 to 7 As shown, this utility model embodiment provides a rotor assembly applied in a motor.

[0042] Reference Figure 1 As shown, it can be understood that, generally speaking, the motor also includes a stator assembly. Specifically, the stator assembly includes a stator core 400 and multiple windings. The stator core 400 includes multiple stator teeth 410 arranged in a divergent pattern, and the multiple windings are respectively wound around the multiple stator teeth 410. The rotor assembly is annular, fitted around the outer periphery of the stator assembly, and can rotate about the rotation axis Z1; that is, the motor is an external rotor motor. It is easy to understand that an air gap 420 is formed between the inner sidewall of the rotor assembly and the outer sidewall of the stator core 400. Generally speaking, the inner side is the side facing the rotation axis Z1 of the rotor assembly, and the side away from the rotation axis Z1 of the rotor assembly is the outer side.

[0043] Reference Figure 1As shown, the rotor assembly includes a rotor yoke 100, multiple radial magnetic tiles 200, and multiple circumferential magnetic tiles 300. Specifically, the rotor yoke 100 is annular and has a central axis, and the rotor yoke 100 rotates around the central axis, that is, the central axis of the rotor yoke 100 is the rotation axis Z1. The rotor yoke 100 may be composed of multiple magnetic sheets, which are annular thin sheets, and the multiple magnetic sheets are stacked along the thickness direction of the magnetic sheets to form the rotor yoke 100.

[0044] It is understood that in other embodiments, the rotor yoke 100 may also be formed by winding strip steel plates into a ring, or by directly cutting steel pipes, or by stacking or winding silicon steel sheets.

[0045] It is understandable that the material of the rotor yoke 100 can be SPCC (i.e., generally cold-rolled carbon steel sheet and steel strip), silicon steel, powder metallurgy and other magnetic materials.

[0046] It is understandable that the circumferential direction of the rotor yoke 100 is the same as the circumferential direction of the rotation axis Z1 of the rotor yoke 100, and the radial direction of the rotor yoke 100 is the same as the radial direction of the rotation axis Z1 of the rotor yoke 100.

[0047] It is understandable that the magnetization direction is the direction of the magnetic field lines formed by the corresponding magnetic tile. In other words, the magnetization direction is the direction from the S pole through the interior of the magnetic tile to the N pole.

[0048] Reference Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, it can be understood that multiple radial magnetic tiles 200 and multiple circumferential magnetic tiles 300 are disposed on the inner side of the rotor yoke 100. Specifically, the radial magnetic tiles 200 are fixedly connected to the inner circumferential wall of the rotor yoke 100, for example, the radial magnetic tiles 200 are adhered to the inner circumferential wall of the rotor yoke 100, and multiple radial magnetic tiles 200 are arranged at equal intervals along the circumference of the rotor yoke 100. The radial magnetic tiles 200 are configured to be magnetized radially along the rotor yoke 100, that is, the magnetization direction of the radial magnetic tiles 200 is radial along the rotor yoke 100. In other words, one side of the radial magnetic tile 200 along the radial direction of the rotor yoke 100, either the outer or inner side, is the N pole, and the other side is the S pole. The magnetization directions of two adjacent radial magnetic tiles 200 are opposite. That is, among two adjacent radial magnetic tiles 200, one radial magnetic tile 200 is magnetized outward along the radial direction of the rotor yoke 100, and the other radial magnetic tile 200 is magnetized inward along the radial direction of the rotor yoke 100.

[0049] Reference Figure 1 , Figure 6 and Figure 7As shown, it can be understood that the number of circumferential magnetic tiles 300 is equal to the number of radial magnetic tiles 200. Multiple circumferential magnetic tiles 300 are arranged at circumferential intervals along the rotor yoke 100, and each circumferential magnetic tile 300 is located between two adjacent radial magnetic tiles 200. That is, one circumferential magnetic tile 300 is connected between every two adjacent radial magnetic tiles 200. The circumferential magnetic tiles 300 can be in contact with the inner circumferential wall of the rotor yoke 100, or a gap can be left between the circumferential magnetic tiles 300 and the inner circumferential wall of the rotor yoke 100.

[0050] It is understandable that each radial magnet 200 and each circumferential magnet 300 are fixedly connected to the rotor yoke 100 by adhesive. The use of adhesive bonding results in a small gap between the radial magnet 200 and the circumferential magnet 300 and the rotor yoke 100, which has little impact on performance.

[0051] Reference Figure 1 As shown, it can be understood that in this embodiment, the number of circumferential magnetic tiles 300 and the number of radial magnetic tiles 200 are both 14. Of course, the number of circumferential magnetic tiles 300 and the number of radial magnetic tiles 200 can both be 12, 16, etc.

[0052] Reference Figure 1 , Figure 6 and Figure 7 As shown, it can be understood that, generally speaking, the circumferential magnetic tile 300 abuts against the two radial magnetic tiles 200 arranged adjacent to the circumferential magnetic tile 300 on the two opposite sides of the rotor yoke 100, so as to make full use of the circumferential space inside the rotor yoke 100, increase the amount of magnetic tiles, and improve the electromagnetic performance of the motor.

[0053] Reference Figure 2 As shown, it can be understood that the circumferential magnetic tile 300 is configured to be magnetized circumferentially along the rotor yoke 100, that is, the magnetization direction of the circumferential magnetic tile 300 is along the circumference of the rotor yoke 100. In other words, one side of the circumferential magnetic tile 300 on each side opposite to the other along the circumference of the rotor yoke 100 is the N pole, and the other side is the S pole. The magnetization directions of two adjacent circumferential magnetic tiles 300 are opposite; that is, of two adjacent circumferential magnetic tiles 300, one is magnetized clockwise along the circumference of the rotor yoke 100, and the other is magnetized counterclockwise along the circumference of the rotor yoke 100.

[0054] Reference Figure 2As shown, it can be understood that the magnetization direction of the magnetic tiles is explained in detail using two adjacent radial magnetic tiles 200 and the circumferential magnetic tile 300 located between them as examples. Specifically, among the two adjacent radial magnetic tiles 200, the magnetization direction of one radial magnetic tile 200 is radially outward along the rotor yoke 100, and the magnetization direction of the other radial magnetic tile 200 is radially inward along the rotor yoke 100. The magnetization direction of the circumferential magnetic tile 300 located between the two radial magnetic tiles 200 is that the radial magnetic tile 200 magnetized radially outward along the circumference of the rotor yoke 100 points to the radial magnetic tile 300 magnetized radially inward.

[0055] Reference Figure 2 As shown, for ease of explanation, the relative positions of the magnetic tiles in the figure are described using a left-right direction. Two radial magnetic tiles 200 are arranged at intervals along the left-right direction, and a circumferential magnetic tile 300 is located between the two radial magnetic tiles 200. Specifically, the magnetization direction of the radial magnetic tile 200 on the left is radially inward along the rotor yoke 100, the magnetization direction of the magnetic tile on the right is radially outward along the rotor yoke 100, and the magnetization direction of the circumferential magnetic tile 300 located between the two radial magnetic tiles 200 is from right to left.

[0056] Continue to refer to Figure 2 The air gap 420 is located inside the radial magnetic tiles 200 and the circumferential magnetic tiles 300, while the rotor yoke 100 is located outside the radial magnetic tiles 200 and the circumferential magnetic tiles 300. In the first magnetic field 250 formed by the two radial magnetic tiles 200, the direction of the magnetic field lines on the side of the air gap 420 is from left to right, and the direction of the magnetic field lines on the side of the rotor yoke 100 is from right to left. In the second magnetic field 310 formed by the circumferential magnetic tiles 300, the direction of the magnetic field lines on the side of the air gap 420 is from left to right, and the direction of the magnetic field lines on the side of the rotor yoke 100 is also from left to right. Therefore, by setting a circumferential magnetic tile 300 between two adjacent radial magnetic tiles 200, the magnetic lines of force of the radial magnetic tile 200 and the circumferential magnetic tile 300 toward the air gap 420 are superimposed, which increases the magnetic lines of force of the rotor assembly toward the air gap 420 and enhances the magnetic concentration effect, thereby strengthening the magnetic field of the rotor assembly toward the air gap 420. Meanwhile, the magnetic lines of force of the radial magnetic tile 200 and the circumferential magnetic tile 300 toward the rotor yoke 100 cancel each other out, thereby weakening the magnetic field at the rotor yoke 100, thereby reducing the magnetic saturation of the rotor yoke 100, ensuring that the magnetic flux flows smoothly in the rotor yoke 100, and thus improving the electromagnetic performance and efficiency of the motor.

[0057] Reference Figure 1 and Figure 4As shown, it can be understood that the radial magnetic tile 200, facing the rotation axis Z1 (i.e., the inner side or the side facing the air gap 420), includes a first arc surface 210, a first surface 220, and a second surface 230. The first surface 220 and the second surface 230 are respectively connected to both sides of the first arc surface 210 along the circumference of the rotor yoke 100. The first surface 220 and the second surface 230 can be planes, arc surfaces, or other curved surfaces. The distance between the first surface 220 and the rotation axis Z1 of the rotor assembly increases along the circumference of the rotor yoke 100 and away from the first arc surface 210. Similarly, the distance between the second surface 230 and the rotation axis Z1 of the rotor assembly increases along the circumference of the rotor yoke 100 and away from the first arc surface 210. In other words, the radial width of the air gap 420 between the first surface 220 and the outer wall of the stator core 400 increases along the circumference of the rotor yoke 100 and away from the first arc surface 210. Similarly, the radial dimension of the air gap 420 between the second surface 230 and the outer wall of the stator core 400 increases along the circumference of the rotor yoke 100 and away from the first arc surface 210.

[0058] Therefore, by setting the side of the radial magnetic tile 200 facing the air gap 420 to a structure in which the first surface 220, the first arc surface 210, and the second surface 230 are sequentially connected along the circumference of the rotor yoke 100, the radial dimension of the air gap 420 is made non-uniform, thereby optimizing the structure of the air gap 420. This allows the magnetic flux of the radial magnetic tile 200 to be better concentrated along the radial center line Z2 of the first arc surface 210 along the radial direction of the rotor yoke 100, making the air gap magnetic field more sinusoidal, improving the magnetic field and magnetic density state, further improving the electromagnetic performance of the motor, and helping to reduce the harmonic components in the air gap magnetic field, reduce the back electromotive force harmonics, thereby reducing the vibration and noise during motor operation and improving the motor's quietness.

[0059] It is easy to understand that the radial center line Z2 of the first arc surface 210 is the line connecting the midpoint of the arc of the first arc surface 210 on the cross section perpendicular to the rotation axis Z1 of the rotor assembly and the point on the cross section perpendicular to the rotation axis Z1 of the rotor assembly.

[0060] Reference Figure 1 and Figure 4As shown, it can be understood that the first surface 220 and the second surface 230 are symmetrically arranged along the radial center line Z2 of the first arc surface 210. That is, on a cross-section perpendicular to the rotation axis Z1 of the rotor assembly, the line segments corresponding to the first surface 220 and the second surface 230 are symmetrically arranged about the radial center line Z2 of the first arc surface 210. This ensures that the air gap magnetic flux density is symmetrically distributed about the radial center line Z2 of the first arc surface 210, avoiding the drawback of additional harmonic content in the air gap 420 due to asymmetrical distribution of the air gap magnetic flux density. This effectively reduces vibration and noise during motor operation, improving the motor's quietness.

[0061] Reference Figure 8 and Figure 9 As shown in the figures, it can be understood that the two figures show a comparison of the magnitude of the back EMF in each order of harmonics between this embodiment and the prior art, wherein the magnitude of the back EMF reflects the harmonic content.

[0062] Depend on Figure 8 It can be seen that the back EMF amplitude of the 9th harmonic in this embodiment is greater than the back EMF amplitude of the 1st harmonic in the prior art solution. Therefore, the electromagnetic performance of the motor in this embodiment is better than that of the motor in the prior art solution.

[0063] Depend on Figure 9 It can be seen that the back EMF amplitude of the 5th harmonic in this embodiment is significantly smaller than that of the 5th harmonic in the prior art; the back EMF amplitude of the 7th harmonic in this embodiment is significantly smaller than that of the 7th harmonic in the prior art; the back EMF amplitude of the 9th harmonic in this embodiment is significantly smaller than that of the 9th harmonic in the prior art; the back EMF amplitude of the 9th harmonic in this embodiment is significantly smaller than that of the 11th harmonic in the prior art; the back EMF amplitude of the 9th harmonic in this embodiment is significantly smaller than that of the 13th harmonic in the prior art; and the back EMF amplitude of the 15th harmonic in this embodiment is significantly smaller than that of the 15th harmonic in the prior art. In other words, apart from the first harmonic, the back EMF amplitude of the other harmonics in this embodiment is significantly smaller than that of the corresponding harmonics in the prior art. That is, the harmonic content of the other harmonics in this embodiment is significantly smaller than that of the corresponding harmonics in the prior art. Therefore, the motor in this embodiment has lower noise and better quietness.

[0064] Reference Figure 3As shown, it can be understood that the minimum width of the circumferential magnetic tile 300 is defined as L1, and the minimum width of the radial magnetic tile 200 is defined as L2. The minimum width L1 of the circumferential magnetic tile 300 is the minimum distance between the two opposite sides of the circumferential magnetic tile 300 along the rotor yoke 100. Generally speaking, the distance between the two opposite sides of the circumferential magnetic tile 300 along the rotor yoke 100 that are closest to the rotation axis Z1 of the rotor assembly is the smallest. Similarly, the minimum width L2 of the radial magnetic tile 200 is the minimum distance between the two opposite sides of the radial magnetic tile 200 along the rotor yoke 100 that are closest to the rotation axis Z1 of the rotor assembly.

[0065] Reference Figure 1 As shown, it can be understood that the maximum distance between the side of the radial magnetic tile 200 facing the rotor yoke 100 and the rotation axis Z1 of the rotor assembly is defined as D / 2, where D can be understood as the diameter of the largest circumcircle of the outer side wall of the radial magnetic tile 200.

[0066] Reference Figure 1 and Figure 3As shown, it can be understood that the minimum width L1 of the circumferential magnetic tile 300, the minimum width L2 of the radial magnetic tile 200, and D / 2 satisfy: 0.82≤(L1+L2)*2p / (π*D)≤0.99, where p is the number of pole pairs of the motor, and in this embodiment, p=7. It is easy to understand that the value of (L1+L2)*2p is approximately the perimeter of the polygon formed by the inner surfaces of all radial magnetic tiles 200 and all circumferential magnetic tiles 300 on a section perpendicular to the rotation axis Z1 of the rotor assembly. (L1+L2)*2p / (π*D) reflects the radial space between this polygon and the largest circumcircle of the outer wall of the radial magnetic tile 200 along the rotor yoke 100. Given a fixed diameter D of the maximum circumscribed circle of the outermost wall of the radial magnet 200, a smaller value of (L1+L2)*2p / (π*D) results in a larger radial space between the polygon and the maximum circumscribed circle of the outermost wall of the radial magnet 200 along the rotor yoke 100. This leads to a larger total number of radial magnets 200 and circumferential magnets 300, which in turn reduces magnet utilization and motor performance. Conversely, a larger value of (L1+L2)*2p / (π*D) results in a smaller radial space between the polygon and the maximum circumscribed circle of the outermost wall of the radial magnet 200 along the rotor yoke 100. This leads to a smaller total number of radial magnets 200 and circumferential magnets 300, resulting in lower air gap magnetic flux density and also degrading motor performance. Therefore, by ensuring that 0.82≤(L1+L2)*2p / (π*D)≤0.99, for example, the value of (L1+L2)*2p / (π*D) is 0.82, 0.88, 0.92, 0.95 or 0.99, the total amount of radial magnetic tiles 200 and circumferential magnetic tiles 300 is kept within a reasonable range to obtain a larger air gap magnetic flux density and improve the performance of the motor.

[0067] Reference Figure 1 As shown, it can be understood that the diameter D of the maximum circumscribed circle of the outermost sidewall of the radial magnet 200 satisfies: 95mm ≤ D ≤ 100mm. Therefore, limiting the diameter of the maximum circumscribed circle of the outermost sidewall of the radial magnet 200 can, to a certain extent, limit the outer diameter of the rotor assembly, thereby ensuring that the overall structural dimensions of the motor meet design and manufacturing requirements and maintain the motor's compact size. For example, D can be 95mm, 98mm, 99mm, or 100mm, etc. The specific value of D can be reasonably set according to actual design and processing needs.

[0068] Reference Figure 3As shown, it can be understood that the minimum width L1 of the circumferential magnetic tile 300 and the minimum width L2 of the radial magnetic tile 200 also satisfy: 0.22≤L1 / L2≤0.4. That is, it defines the ratio between the minimum widths of the circumferential magnetic tile 300 and the radial magnetic tile 200 in the circumferential direction of the rotor yoke 100. Given that the thickness dimensions of the circumferential magnetic tile 300 and the radial magnetic tile 200 along the radial direction of the rotor yoke 100 are determined, if L1 / L2 < 0.22, the minimum width of the circumferential magnetic tile 300 is too small and the minimum width of the radial magnetic tile 200 is too large. The magnetic field lines of the circumferential magnetic tile 300 facing the rotor yoke 100 have a small canceling effect on the magnetic field lines of the radial magnetic tile 200 facing the rotor yoke 100. The magnetic field weakening effect at the rotor yoke 100 is not obvious, resulting in a high degree of magnetic saturation of the rotor yoke 100 and a weakening of the magnetic focusing effect on the air gap 420 side, which affects the performance of the motor. If L1 / L2 > 0.4, the minimum width of the circumferential magnetic tile 300 is too large and the minimum width of the radial magnetic tile 200 is too small. The amount of radial magnetic poles used is reduced. As the main part of the magnetic poles of the motor, the reduction in the amount of radial magnetic poles used by the radial magnetic tile 200 will lead to a reduction in the magnetic flux flowing through the stator assembly, and a decrease in the electromagnetic performance of the motor. Therefore, 0.22≤L1 / L2≤0.4 is made, for example, the value of L1 / L2 is 0.22, 0.28, 0.3, 0.35 or 0.4, etc., to optimize the ratio between the minimum widths of the circumferential magnetic tile 300 and the radial magnetic tile 200 in the circumferential direction of the rotor yoke 100, that is, to optimize the ratio of the amount of circumferential magnetic tile 300 and radial magnetic tile 200, so as to enhance the magnetic focusing effect on the air gap 420 side, reduce the magnetic saturation of the rotor yoke 100, and thus improve the electromagnetic performance of the motor.

[0069] Reference Figure 4 and Figure 5 As shown, it can be understood that the radial magnetic tile 200 has a second arc surface 240 on its side facing the rotor yoke 100, that is, the outer side of the radial magnetic tile 200 includes the second arc surface 240. The second arc surface 240 is concentric with the first arc surface 210. Generally, the center of the first arc surface 210 and the center of the second arc surface 240 are located on the rotation axis Z1 of the rotor assembly. The angle of the central angle corresponding to the first arc surface 210 is defined as α1, and the angle of the central angle corresponding to the second arc surface 240 is defined as α2. That is, α1 is the angle between the two ends of the arc corresponding to the first arc surface 210 on the cross section perpendicular to the rotation axis Z1 of the rotor assembly and the center of the circle. Similarly, α2 is the angle between the two ends of the arc corresponding to the second arc surface 240 on the cross section perpendicular to the rotation axis Z1 of the rotor assembly and the center of the circle. It satisfies: 0.35≤α1 / α2≤0.85.

[0070] Reference Figure 4As shown, it can be understood that in this embodiment, the side (i.e., the inner side) of the radial magnetic tile 200 facing the air gap 420 is configured as a structure in which the first surface 220, the first arc surface 210, and the second surface 230 are sequentially connected along the circumference of the rotor yoke 100. This is equivalent to the inner side of the radial magnetic tile 200 having chamfered corners at both ends along the circumference of the rotor yoke 100. Chamfering removes part of the structure of the radial magnetic tile 200. If the chamfer is too large, the magnetic flux density of the radial magnetic tile 200 will be too small, resulting in a significant decrease in motor performance. If the chamfer is too small, the magnetic focusing effect of the radial magnetic tile 200 will be poor, the sinusoidal degree of the air gap magnetic flux density will be small, the harmonic components in the air gap magnetic field will be large, and the noise will increase.

[0071] Therefore, by ensuring that 0.35≤α1 / α2≤0.85, for example, the value of α1 / α2 is 0.35, 0.4, 0.5, 0.75, or 0.85, and by limiting the ratio between the angles of the central angles corresponding to the first arc surface 210 and the second arc surface 240, the angle of the central angle corresponding to the first arc surface 210 is kept within a reasonable range. That is, the size of the chamfer at both ends of the inner side of the radial magnetic tile 200 is kept within a reasonable range. This not only enhances the magnetic focusing effect of the radial magnetic tile 200, making the air gap magnetic flux density more sinusoidal, reducing the harmonic components in the air gap magnetic field, and reducing noise, but also ensures that the magnetic flux density of the radial magnetic tile 200 is not too small, thus avoiding a significant decrease in motor performance due to the reduction in the magnetic flux density of the radial magnetic tile 200.

[0072] Reference Figure 4 As shown, it can be understood that the thickness of the radial magnetic tile 200 along the radial center line Z2 of the first arc surface 210 is defined as L5, and the radius of the first arc surface 210 is R1. Here, L5 is the distance between the first arc surface 210 and the second arc surface 240 on the radial center line Z2 of the first arc surface 210, and R1 is the radius of the circle containing the arc shape corresponding to the first arc surface 210 on the cross-section perpendicular to the rotation axis Z1 of the rotor assembly.

[0073] Reference Figure 4As shown, it can be understood that the thickness L5 of the radial magnet 200 along the radial center line Z2 of the first arc surface 210 and the radius R1 of the first arc surface 210 satisfy: 0.1≤L5 / R1≤0.15. L5 reflects the amount of radial magnet 200 used to a certain extent. Under the premise that the radial distance of the air gap 420 is determined, R1 can reflect the maximum outer diameter of the stator assembly, and thus reflect the amount of winding used in the stator assembly to a certain extent. If L5 / R1<0.1, the amount of radial magnet 200 used is too small, the amount of winding used is too large, and the copper loss and iron loss are large; if L5 / R1>0.15, the amount of radial magnet 200 used is too large, the amount of winding used is too small, and the efficiency of the motor decreases. Therefore, by setting 0.1≤L5 / R1≤0.15, for example, the value of L5 / R1 is 0.1, 0.12, 0.13, 0.14 or 0.15, the ratio of the amount of radial magnet 200 to the amount of winding is kept within a reasonable range, so as to reduce copper loss and iron loss and improve motor efficiency.

[0074] Reference Figure 3 As shown, it can be understood that the cross-section of the circumferential magnetic tile 300 is square, that is, the outline of the circumferential magnetic tile 300 on the section perpendicular to the rotation axis Z1 of the rotor assembly is square, such as a rectangle or a square. The width of the circumferential magnetic tile 300 is equal everywhere, that is, the width of the circumferential magnetic tile 300 is L1. The radial thickness of the circumferential magnetic tile 300 is defined as L3, which is the distance between the two radially opposite sides of the circumferential magnetic tile 300 along the rotor yoke 100. The width L1 and the radial thickness L3 of the circumferential magnetic tile 300 satisfy: 0.65≤L1 / L3≤1.36. It is easy to understand that if the width and radial thickness of the circumferential magnetic tile 300 are too small, its magnetic flux focusing effect on the air gap 420 side and its magnetic flux cancellation effect on the rotor yoke 100 side will not be fully utilized. If the width of the circumferential magnetic tile 300 is too large, it will occupy the space of the radial magnetic tile 200 in the circumferential direction of the rotor yoke 100, resulting in a decrease in the electromagnetic performance of the motor. If the radial thickness of the circumferential magnetic tile 300 is too large, it will be detrimental to installation. Therefore, setting the ratio between the width and radial thickness of the circumferential magnetic tile 300 within a reasonable range, for example, with L1 / L3 values ​​of 0.65, 0.7, 0.9, 1.2, or 1.36, can fully utilize the magnetic flux focusing effect of the circumferential magnetic tile 300 on the air gap 420 side and its magnetic flux cancellation effect on the rotor yoke 100 side, while meeting installation requirements, thereby improving the electromagnetic performance of the motor.

[0075] It is understood that in other embodiments, the cross-section of the circumferential magnetic tile 300 may also be of other shapes. For example, the two opposite sides of the circumferential magnetic tile 300 along the rotor yoke 100 may be flat and parallel arcs. The inner and outer sides of the circumferential magnetic tile 300 may also be arc surfaces or other curved surfaces, inclined surfaces, etc. No further specific limitations are imposed here.

[0076] Reference Figure 1 , Figure 3 and Figure 4 As shown, it can be understood that in this embodiment, the width L1 and radial thickness L3 of the circumferential magnetic tile 300, the radius R1 of the first arc surface 210, the maximum distance D / 2 between the side of the radial magnetic tile 200 facing the rotor yoke 100 and the rotation axis Z1 of the rotor assembly, and the number of pole pairs p of the motor also satisfy the following: 0.155≤2p*L1*L3 / (π*D 2 / 4-π*R1 2 ) ≤0.245.

[0077] Reference Figure 1 , Figure 3 and Figure 4 As shown, it can be understood that 2p*L1*L3 can be interpreted as the sum of the cross-sectional areas of all circumferential magnetic tiles 300, reflecting the total amount of circumferential magnetic tiles 300 used. π*D 2 / 4-π*R1 2 This can be understood as the area of ​​the annulus formed by the circles corresponding to the arcs of the first arc surface 210 and the second arc surface 240 of the radial magnet 200 on the cross section perpendicular to the rotation axis Z1 of the rotor assembly. This area, to a certain extent, reflects the sum of the total quantity of the circumferential magnet 300 and the radial magnet 200. Therefore, by setting 0.155≤2p*L1*L3 / (π*D) 2 / 4-π*R1 2 ) ≤0.245, for example, 2p*L1*L3 / (π*D 2 / 4-π*R1 2 The value of ) is 0.155, 0.16, 0.19, 0.21 or 0.245, etc., so that the total amount of circumferential magnetic tiles 300 is within a suitable range as a proportion of the total amount of circumferential magnetic tiles 300 and radial magnetic tiles 200. This can give full play to the magnetic concentration effect of circumferential magnetic tiles 300 on the air gap 420 side and the magnetic flux cancellation effect on the rotor yoke 100 side, thereby helping to improve the electromagnetic performance of the motor.

[0078] Reference Figure 5 As shown, it can be understood that the second arc surface 240 of the radial magnet 200 is attached to the inner side of the rotor yoke 100 to improve the installation stability of the radial magnet 200. The thickness of the rotor yoke 100 along the radial center line Z2 of the first arc surface 210 is defined as L4. L4 is the distance between the outer wall surface and the inner wall surface of the rotor yoke 100 on the radial center line Z2 of the first arc surface 210. L4 can reflect the amount of material used in the rotor yoke 100 to a certain extent.

[0079] Reference Figure 5As shown, it can be understood that the thickness L4 of the rotor yoke 100 along the radial center line Z2 of the first arc surface 210 and the thickness L5 of the radial magnet 200 along the radial center line Z2 of the first arc surface 210 satisfy: 0.2≤L4 / L5≤0.5. Here, L5 can reflect the amount of radial magnet 200 used to a certain extent. If L4 / L5<0.2, the material usage of the rotor yoke 100 is too small, and the amount of radial magnet 200 used is too large, leading to magnetic saturation of the rotor yoke 100 and a decrease in the utilization rate of the radial magnet 200, thus reducing the electromagnetic performance of the motor. If L4 / L5>0.5, the material usage of the rotor yoke 100 is too large, and the amount of radial magnet 200 used is too small, resulting in a low magnetic flux density of the radial magnet 200 and a decrease in the utilization rate of the rotor yoke 100, which also leads to a decrease in the electromagnetic performance of the motor. Therefore, by ensuring that 0.2 ≤ L4 / L5 ≤ 0.5, for example, the value of L4 / L5 is 0.2, 0.25, 0.35, 0.4, or 0.5, the ratio between the material usage of the rotor yoke 100 and the radial magnet 200 is optimized to reduce the magnetic saturation of the rotor yoke 100 and ensure the magnetic flux density of the radial magnet 200, thereby improving the utilization rate of the radial magnet 200 and the rotor yoke 100 and thus enhancing the electromagnetic performance of the motor.

[0080] The motor of the second aspect of the present invention includes a stator assembly and a rotor assembly of the first aspect of the present invention, wherein the rotor assembly is sleeved on the outer periphery of the stator assembly.

[0081] Since the motor of this utility model adopts all the technical solutions of the rotor assembly of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0082] Reference Figure 1 As shown, it can be understood that the radius of the largest circumscribed circle of the outer wall of the stator assembly is defined as R2, which is the radius of the largest circumscribed circle of the outer wall surface of the stator core 400 (i.e., the side surface of the stator teeth 410 facing away from the rotation axis Z1 of the rotor assembly). The radius R2 of the largest circumscribed circle of the outer wall of the stator assembly and the radius R1 of the first arc surface 210 satisfy: 0.4mm ≤ R1 - R2 ≤ 1.1mm.

[0083] Reference Figure 1As shown, R1-R2 can be understood as the radial width of the air gap 420. If R1-R2 < 0.4mm, meaning the radial width of the air gap 420 is less than 0.4mm, the radial width of the air gap 420 is too small. On the one hand, this results in high assembly precision requirements between the rotor and stator assemblies, poor manufacturability, and on the other hand, it can cause rubbing between the rotor and stator assemblies during motor operation, leading to wear on the magnets and stator core 400, as well as generating significant noise and reducing motor reliability. If R1-R2 > 1.1mm, the radial width of the air gap 420 is too large, leading to a decrease in air gap magnetic flux density and a decline in the motor's electromagnetic performance. Therefore, ensuring that 0.4mm ≤ R1-R2 ≤ 1.1mm, for example, with R1-R2 values ​​of 0.4, 0.65, 0.8, 1, or 1.1, ensures good electromagnetic performance of the motor, improves manufacturability, and avoids noise and reliability issues caused by rubbing.

[0084] It should be noted that, in the embodiments of this utility model, "fixed connection" can be interpreted as a connection in a manner in which the two parts cannot be displaced relative to each other.

[0085] It should be noted that in the embodiments of this utility model, the term "roughly parallel" can be interpreted as parallel, nearly parallel, or having a certain preset angle; "roughly perpendicular" can be interpreted as perpendicular, nearly perpendicular, or having a certain preset angle.

[0086] Since the motor of this utility model adopts all the technical solutions of the rotor assembly of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0087] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A rotor assembly, used in a motor, characterized in that, include: The rotor yoke is configured in a ring shape and rotates about the axis of rotation. Multiple radial magnetic tiles are connected to the inner side of the rotor yoke and configured to be radially magnetized along the rotation axis, and the multiple radial magnetic tiles are arranged circumferentially spaced along the rotation axis. Multiple circumferential magnetic tiles are connected to the inner side of the rotor yoke and configured to be circumferentially magnetized along the rotation axis, with the multiple circumferential magnetic tiles respectively located between two adjacent radial magnetic tiles; The radial magnetic tile has a side facing the rotation axis, including a first arc surface and a first surface and a second surface connected to the first arc surface on both sides in the circumferential direction. The distance between the first surface and the rotation axis increases in the direction away from the first arc surface, and the distance between the second surface and the rotation axis increases in the direction away from the first arc surface.

2. The rotor assembly according to claim 1, characterized in that: The minimum width of the circumferential magnetic tile is L1, the minimum width of the radial magnetic tile is L2, the maximum distance between the side of the radial magnetic tile facing the rotor yoke and the rotation axis is D / 2, and the number of pole pairs of the motor is p, satisfying: 0.82≤(L1+L2)*2p / (π*D)≤0.

99.

3. The rotor assembly according to claim 1, characterized in that: The minimum width L1 of the circumferential magnetic tile and the minimum width L2 of the radial magnetic tile satisfy: 0.22≤L1 / L2≤0.

4.

4. The rotor assembly according to claim 1, characterized in that: The first surface and the second surface are arranged symmetrically along the radial centerline of the first arc surface.

5. The rotor assembly according to claim 1 or 4, characterized in that: The radial magnetic tile has a second arc surface on one side facing the rotor yoke. The second arc surface and the first arc surface are concentric. The angle of the central angle corresponding to the first arc surface is α1, and the angle of the central angle corresponding to the second arc surface is α2, satisfying: 0.35≤α1 / α2≤0.

85.

6. The rotor assembly according to claim 1 or 4, characterized in that: The thickness of the radial magnetic tile along the radial center line of the first arc surface is L5, and the radius of the first arc surface is R1, satisfying: 0.1≤L5 / R1≤0.

15.

7. The rotor assembly according to claim 1, characterized in that: The circumferential magnetic tile has a square cross-section, a width of L1, and a radial thickness of L3, satisfying the condition: 0.65≤L1 / L3≤1.

36.

8. The rotor assembly according to claim 7, characterized in that: The radius of the first arc surface is R1, the maximum distance between the radial magnetic tile facing the rotor yoke and the rotation axis is D / 2, and the number of pole pairs of the motor is p, satisfying: 0.155≤2p*L1*L3 / (π*D) 2 / 4-π*R1 2 ) ≤0.

245.

9. The rotor assembly according to claim 1, characterized in that: The radial magnetic tile is configured on the side facing the rotor yoke as a second arc surface that fits against the inner side of the rotor yoke. The thickness of the rotor yoke along the radial center line of the first arc surface is L4, and the thickness of the radial magnetic tile along the radial center line of the first arc surface is L5, satisfying: 0.2≤L4 / L5≤0.

5.

10. An electric motor, characterized in that: It includes a stator assembly and a rotor assembly as described in any one of claims 1 to 9, wherein the rotor assembly is sleeved on the outside of the stator assembly.

11. The motor according to claim 10, characterized in that: The radius of the largest circumscribed circle of the outer side wall of the stator assembly is R2, and the radius of the first arc surface is R1, satisfying: 0.4mm≤R1-R2≤1.1mm.

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