Rotor assembly, motor and electrical equipment

Abstract

The invention discloses a rotor assembly, a motor and electrical equipment, the rotor assembly comprises a rotor yoke part, a first permanent magnet, a second permanent magnet and a third permanent magnet, the first permanent magnet is arranged on the inner circumference of the rotor yoke part, and along the radial direction of the rotor yoke part, one side, close to the rotation axis of the rotor yoke part, of the first permanent magnet is an S pole; one side, deviating from the rotating axis, of the first permanent magnet is an N pole; the second permanent magnets are arranged on the inner circumference of the rotor yoke part, the second permanent magnets and the first permanent magnets are arranged at intervals in the circumferential direction of the rotor yoke part, in the radial direction, the sides, close to the rotating axis of the rotor yoke part, of the second permanent magnets are N poles, and the sides, away from the rotating axis, of the second permanent magnets are S poles; the third permanent magnets are arranged on the inner periphery of the rotor yoke part and located between the first permanent magnets and the second permanent magnets, and the magnetizing direction of the third permanent magnets is from the first permanent magnets to the second permanent magnets. The rotor assembly can reduce magnetic leakage and improve the utilization rate of the permanent magnets, thereby improving the performance of the motor.

Description

Technical Field

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

[0002] Permanent magnet motors (PMMs) have become the mainstream motor type in the market, offering advantages such as simple structure, high power density, a wide high-efficiency range, and high torque density. They are widely used in modern industrial systems. However, in related technologies, because adjacent permanent magnets in PMMs are either bonded together or separated only by a magnetic bridge, the permanent magnets suffer from severe magnetic flux leakage. This is particularly severe at the circumferential ends of the rotor assembly, resulting in low utilization of the permanent magnets and affecting motor performance. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a rotor assembly that can reduce magnetic leakage, increase the utilization rate of permanent magnets, and thus improve the performance of the motor.

[0004] The present invention also provides a motor having the rotor assembly and an electrical device having the motor.

[0005] According to an embodiment of the first aspect of the present invention, a rotor assembly includes a rotor yoke; a first permanent magnet is arranged on the inner circumference of the rotor yoke, and along the radial direction of the rotor yoke, the side of the first permanent magnet close to the rotation axis of the rotor yoke is an S pole, and the side of the first permanent magnet away from the rotation axis is an N pole; a second permanent magnet is arranged on the inner circumference of the rotor yoke, and the second permanent magnet and the first permanent magnet are arranged at intervals along the circumferential direction of the rotor yoke, and along the radial direction, the side of the second permanent magnet close to the rotation axis of the rotor yoke is an N pole, and the side of the second permanent magnet away from the rotation axis is an S pole; a third permanent magnet is arranged on the inner circumference of the rotor yoke and is located between the first permanent magnet and the second permanent magnet, and the magnetization direction of the third permanent magnet is from the first permanent magnet to the second permanent magnet.

[0006] According to the rotor assembly of the embodiment of the first aspect of the present invention, there are at least the following beneficial effects: by arranging a third permanent magnet between the first permanent magnet and the second permanent magnet, and the magnetization direction of the third permanent magnet is from the first permanent magnet to the second permanent magnet, the magnetic field of the third permanent magnet can be used to enhance the guidance of the magnetic lines of force from the first permanent magnet to the second permanent magnet, thereby reducing the leakage magnetic field of the first permanent magnet and the second permanent magnet along the circumferential end of the rotor yoke. At the same time, it is beneficial to reduce the saturation degree of the magnetic circuit in the rotor yoke, thereby improving the utilization rate of the first permanent magnet and the second permanent magnet, enhancing the magnetic field, and improving the torque, working efficiency and other performance of the motor.

[0007] According to some embodiments of the present invention, the first permanent magnet has a center line of symmetry, which intersects and is perpendicular to the rotation axis, and the magnetization direction of the first permanent magnet is parallel to the center line of symmetry; or, the opposite direction of the magnetization direction of the first permanent magnet points to the rotation axis; or, the opposite direction of the magnetization direction of the first permanent magnet points to a first reference point, the first reference point is located on the center line of symmetry, and the first reference point is located between the first permanent magnet and the rotation axis.

[0008] According to some embodiments of the present invention, the second permanent magnet has a symmetric center line, which intersects and is perpendicular to the rotation axis, and the magnetization direction of the second permanent magnet is parallel to the symmetric center line; or, the magnetization direction of the second permanent magnet points to the rotation axis; or, the magnetization direction of the second permanent magnet points to a second reference point, the second reference point is located on the symmetric center line, and the second reference point is located between the second permanent magnet and the rotation axis.

[0009] According to some embodiments of the present invention, the third permanent magnet has a symmetry center line, the symmetry center line intersects with and is perpendicular to the rotation axis, and the magnetization direction of the third permanent magnet is perpendicular to the symmetry center line.

[0010] According to some embodiments of the present invention, along the radial direction of the rotor yoke, the maximum thickness of the first permanent magnet is T1, the maximum thickness of the second permanent magnet is T2, and the maximum thickness of the third permanent magnet is T3, satisfying: T3>T1, T3>T2.

[0011] According to some embodiments of the present invention, a third mounting groove is provided on the wall surface of the rotor yoke facing the rotation axis, the third permanent magnet is partially accommodated in the third mounting groove, and the first permanent magnet and the second permanent magnet respectively contact the two sides of the third permanent magnet along the circumference of the rotor yoke.

[0012] According to some embodiments of the present invention, the first permanent magnet has a first wall surface facing the rotation axis, the second permanent magnet has a second wall surface facing the rotation axis, and the third permanent magnet has a third wall surface facing the rotation axis. Along the circumference of the rotor yoke, both ends of the third wall surface are connected to the first wall surface and the second wall surface respectively.

[0013] According to some embodiments of the present invention, a first mounting groove, a second mounting groove, and a third mounting groove are provided on the wall surface of the rotor yoke facing the rotation axis, and the first mounting groove, the third mounting groove, and the second mounting groove are arranged in sequence along the circumference of the rotor yoke, the first permanent magnet is installed in the first mounting groove, the second permanent magnet is installed in the second mounting groove, and the third permanent magnet is installed in the third mounting groove.

[0014] According to some embodiments of the present invention, the third mounting groove has a third width along the circumference of the rotor yoke, and the third width decreases along the radial direction of the rotor yoke and toward the rotation axis.

[0015] According to some embodiments of the present invention, along the circumference of the rotor yoke, the first mounting groove has a first width, the second mounting groove has a second width, and along the radial direction of the rotor yoke and toward the rotation axis, the first width and the second width both decrease.

[0016] According to some embodiments of the present invention, the first permanent magnet has a first wall facing the rotation axis, the second permanent magnet has a second wall facing the rotation axis, and the third permanent magnet has a third wall facing the rotation axis. The rotor yoke includes a first isolation portion and a second isolation portion, the first isolation portion is located between the first mounting slot and the third mounting slot, the first isolation portion has a fourth wall facing the rotation axis, the second isolation portion is located between the second mounting slot and the third mounting slot, and the second isolation portion has a fifth wall facing the rotation axis. On a projection plane perpendicular to the rotation axis, the projection of the first wall, the projection of the second wall, the projection of the third wall, the projection of the fourth wall, and the projection of the fifth wall form a first reference circle, and the center of the first reference circle coincides with the rotation axis.

[0017] According to some embodiments of the present invention, along the circumference of the rotor yoke, the first permanent magnet has a sixth wall surface and a seventh wall surface facing away from each other, and the maximum distance between the sixth wall surface and the seventh wall surface is W1; the second permanent magnet has an eighth wall surface and a ninth wall surface facing away from each other, and the maximum distance between the eighth wall surface and the ninth wall surface is W2; the third permanent magnet has a tenth wall surface and an eleventh wall surface facing away from each other, and the maximum distance between the tenth wall surface and the eleventh wall surface is W3, satisfying: W3<W1, W3<W2.

[0018] The motor according to the second embodiment of the present invention includes a stator assembly and a rotor assembly according to the first embodiment of the present invention, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

[0019] The motor according to the embodiment of the second aspect of the present invention has at least the following beneficial effects: since the motor adopts the above-mentioned rotor assembly, by arranging the third permanent magnet between the first permanent magnet and the second permanent magnet, and the magnetization direction of the third permanent magnet is from the first permanent magnet to the second permanent magnet, the magnetic field of the third permanent magnet can be used to enhance the guidance of the magnetic lines of force from the first permanent magnet to the second permanent magnet, thereby reducing the leakage of the first permanent magnet and the second permanent magnet at the circumferential ends of the rotor yoke. At the same time, it is beneficial to reduce the degree of magnetic circuit saturation in the rotor yoke, thereby improving the utilization rate of the first permanent magnet and the second permanent magnet, enhancing the magnetic field, and improving the torque, working efficiency and other performance of the motor.

[0020] An electrical device according to an embodiment of the third aspect of the present invention includes the motor according to the embodiment of the second aspect of the present invention.

[0021] The electrical equipment according to the embodiment of the third aspect of the present invention has at least the following beneficial effects: since the electrical equipment adopts the above-mentioned motor, by arranging the third permanent magnet between the first permanent magnet and the second permanent magnet, and the magnetization direction of the third permanent magnet is from the first permanent magnet to the second permanent magnet, the magnetic field of the third permanent magnet can be used to enhance the guidance of the magnetic lines of force from the first permanent magnet to the second permanent magnet, thereby reducing the leakage of the first permanent magnet and the second permanent magnet along the circumferential end of the rotor yoke. At the same time, it is beneficial to reduce the saturation degree of the magnetic circuit in the rotor yoke, thereby improving the utilization rate of the first permanent magnet and the second permanent magnet, enhancing the magnetic field, and improving the torque, working efficiency and other performance of the motor.

[0022] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0024] Figure 1 is a cross-sectional view of a rotor assembly in one embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A cross-sectional view of the rotor yoke in FIG.

[0026] Figure 3 is a cross-sectional view of a first permanent magnet according to an embodiment of the present invention;

[0027] Figure 4 is a cross-sectional view of a second permanent magnet according to an embodiment of the present invention;

[0028] Figure 5 is a cross-sectional view of a third permanent magnet in an embodiment of the present invention;

[0029] Figure 6 is a cross-sectional view of a rotor assembly in another embodiment of the present invention;

[0030] Figure 7 yes Figure 6 A cross-sectional view of the rotor yoke in FIG.

[0031] Figure 8 is a cross-sectional view of a motor in one embodiment of the present invention;

[0032] Figure 9 is a cross-sectional view of a motor in another embodiment of the present invention;

[0033] Figure 10 is a cross-sectional view of a first permanent magnet in another embodiment of the present invention;

[0034] Figure 11 is a cross-sectional view of a first permanent magnet in another embodiment of the present invention.

[0035] Reference numerals:

[0036] Rotor yoke 100; first mounting groove 110; second mounting groove 120; third mounting groove 130; first isolation portion 140; fourth wall 141; second isolation portion 150; fifth wall 151; first reference circle 160;

[0037] First permanent magnet 200; first wall 210; twelfth wall 220; sixth wall 230; seventh wall 240;

[0038] The second permanent magnet 300; the second wall 310; the thirteenth wall 320; the eighth wall 330; and the ninth wall 340;

[0039] The third permanent magnet 400; the third wall 410; the fourteenth wall 420; the tenth wall 430; and the eleventh wall 440;

[0040] Stator assembly 500; stator teeth 510; air gap 520;

[0041] Axis of rotation Z; first reference point Q. DETAILED DESCRIPTION

[0042] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0043] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0044] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0045] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense. Technical personnel in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0046] Because the two adjacent permanent magnets in the rotor assembly of a permanent magnet motor fit together or are separated from each other only by a magnetic isolation bridge, the permanent magnets suffer from a serious magnetic leakage problem, especially at the two ends of the permanent magnets along the circumference of the rotor assembly, where the magnetic leakage problem is more serious. For example, at the end position of the permanent magnet, after the magnetic lines of force are emitted from the north pole, they are directly directed to the south pole of the permanent magnet itself through the magnetic isolation bridge, forming a closed magnetic circuit. Alternatively, the magnetic lines of force are directed from the north pole of the first permanent magnet through the magnetic isolation bridge to the south pole of the adjacent second permanent magnet, and from the north pole of the second permanent magnet through the magnetic isolation bridge to the south pole of the first permanent magnet, forming a closed magnetic circuit. Alternatively, the magnetic lines of force are directly directed from the north pole of the first permanent magnet to the south pole of the adjacent second permanent magnet, and from the north pole of the second permanent magnet to the south pole of the first permanent magnet, forming a closed magnetic circuit. In the above-mentioned magnetic lines of force, no one passes through the stator assembly, thus causing magnetic leakage, affecting the magnetic field distribution and magnetic field strength between the rotor assembly and the stator assembly, and at the same time resulting in low utilization of the permanent magnets, affecting the performance of the motor.

[0047] For this purpose, refer to Figures 1 to 11 As shown, a first embodiment of the present invention provides a rotor assembly for use in a motor of an electrical device, such as a fan, an air conditioner compressor, a refrigerator compressor, a drum washing machine, etc. The motor is an outer rotor motor. Specifically, the motor further includes a stator assembly 500 , and the rotor assembly is wound around the outer circumference of the stator assembly 500 .

[0048] The structure of the rotor assembly is described in detail below by taking the rotor assembly of an outer rotor motor as an example.

[0049] Reference Figure 8 and Figure 9 As shown, it can be understood that the motor includes a stator assembly 500 and a rotor assembly, wherein the stator assembly 500 includes a stator core and windings. The stator core includes a plurality of stator teeth 510 arranged in a divergent pattern, and the windings are wound around the stator teeth 510. The rotor assembly includes a rotor yoke 100, which is generally annular and has an iron core structure. The rotor yoke 100 is wound around the outer circumference of the stator core and can rotate relative to the stator core. The rotation axis Z of the rotor yoke 100 is the rotation axis Z of the rotor assembly and is also the central axis of the rotor yoke 100. At the same time, the central axis of the stator core coincides with the rotation axis Z of the rotor yoke 100.

[0050] Reference Figure 1 、 Figure 8 and Figure 9 As shown, it can be understood that the rotor assembly also includes a plurality of main permanent magnets (i.e., the first permanent magnet 200 or the second permanent magnet 300) and a plurality of secondary permanent magnets (i.e., the third permanent magnet 400). The number of main permanent magnets is equal to the number of secondary permanent magnets. In this embodiment, the rotor assembly includes ten main permanent magnets and ten secondary permanent magnets. Specifically, the main permanent magnets and the secondary permanent magnets are both installed on the inner periphery of the rotor yoke 100, that is, the main permanent magnets and the secondary permanent magnets are both located on the side of the rotor yoke 100 facing the stator core. Generally speaking, an air gap 520 is formed between the main permanent magnets and the secondary permanent magnets and the outer peripheral wall of the stator core. The inner side here refers to the side facing the rotation axis Z of the rotor yoke 100, and the opposite side is the outer side.

[0051] Reference Figure 1 As shown, it can be understood that multiple main permanent magnets are arranged at equal intervals along the inner circumference of the rotor yoke 100. The circumferential direction of the rotor yoke 100 is the direction around the rotation axis Z of the rotor yoke 100. Each secondary permanent magnet is located between two adjacent main permanent magnets. The main permanent magnets are magnetized in a radial direction along the rotor yoke 100, with the magnetization directions of two adjacent main permanent magnets opposite. The main permanent magnets serve as the magnetic poles of the rotor assembly. The secondary permanent magnets are magnetized in a tangential direction along the rotor yoke 100, with the magnetization directions of two adjacent secondary permanent magnets opposite. Furthermore, the magnetization direction of each secondary permanent magnet is the same as the direction of the magnetic field formed between the two adjacent main permanent magnets. The magnetization direction here refers to the direction of the magnetic field lines of the magnetic field formed by the corresponding permanent magnet, that is, the direction from the south pole through the interior of the permanent magnet to the north pole of the corresponding permanent magnet.

[0052] Reference Figure 1 and Figure 2As shown, it can be understood that the main permanent magnet and the auxiliary permanent magnet can be bonded to the inner circumferential wall of the rotor yoke 100 , or the main permanent magnet and the auxiliary permanent magnet can be installed in the installation groove provided on the inner circumferential wall of the rotor yoke 100 .

[0053] The following describes in detail two adjacent main permanent magnets and the auxiliary permanent magnet therebetween as an example.

[0054] Reference Figure 1 As shown, it can be understood that two adjacent main permanent magnets are defined as the first permanent magnet 200 and the second permanent magnet 300 , and the auxiliary permanent magnet between the first permanent magnet 200 and the second permanent magnet 300 is defined as the third permanent magnet 400 .

[0055] Reference Figure 1 and Figure 8 As shown, it can be understood that the inner side of the first permanent magnet 200 is the S pole and the outer side is the N pole, and the magnetization direction of the first permanent magnet 200 is from the S pole of the first permanent magnet 200 through the interior of the first permanent magnet 200 to the N pole of the first permanent magnet 200. The inner side of the second permanent magnet 300 is the N pole and the outer side is the S pole, and the magnetization direction of the second permanent magnet 300 is from the S pole of the second permanent magnet 300 through the interior of the second permanent magnet 300 to the N pole of the second permanent magnet 300, and the magnetization direction of the second permanent magnet 300 is opposite to that of the first permanent magnet 200. Therefore, under the action of the magnetic fields of the first permanent magnet 200 and the second permanent magnet 300, a magnetic field is formed between the rotor assembly and the stator assembly 500. The direction of the magnetic lines of force of the magnetic field is from the N pole of the first permanent magnet 200 through the rotor yoke 100, the S pole of the second permanent magnet 300, the second permanent magnet 300, the N pole of the second permanent magnet 300, the air gap 520, the stator assembly 500, the air gap 520, the S pole of the first permanent magnet 200, the first permanent magnet 200 and back to the N pole of the first permanent magnet 200. The magnetic lines of force are a closed loop, and the magnetic field corresponding to the direction of the magnetic lines of force is the effective magnetic field of the motor.

[0056] Reference Figure 3 As shown, it can be understood that the first permanent magnet 200 has a symmetric centerline. Generally speaking, the first permanent magnet 200 has an axisymmetric structure. The first permanent magnet 200 is symmetrically arranged about its own symmetric centerline. The symmetric centerline of the first permanent magnet 200 intersects and is perpendicular to the rotation axis Z of the rotor yoke 100. The magnetization direction of the first permanent magnet 200 is parallel to the symmetric centerline of the first permanent magnet 200.

[0057] Reference Figure 10 As shown, in other embodiments, the opposite direction of the magnetization direction of the first permanent magnet 200 points to the rotation axis Z, that is, the reverse extension line of the magnetization direction of the first permanent magnet 200 intersects the rotation axis Z.

[0058] Reference Figure 11 As shown, in other embodiments, the opposite direction of the magnetization direction of the first permanent magnet 200 points to the first reference point Q, wherein the first reference point Q is located on the symmetry center line of the first permanent magnet 200 and between the first permanent magnet 200 and the rotation axis Z, that is, the reverse extension line of the magnetization direction of the first permanent magnet 200 intersects with the first reference point Q.

[0059] It is understandable that the magnetization direction of the second permanent magnet 300 can refer to the magnetization direction of the first permanent magnet 200, as long as the magnetization direction of the second permanent magnet 300 is opposite to the magnetization direction of the first permanent magnet 200, which will not be repeated here.

[0060] Reference Figure 1 As shown, it can be understood that the side of the third permanent magnet 400 facing the first permanent magnet 200 is the S pole, and the side facing the second permanent magnet 300 is the N pole, and the magnetization direction of the third permanent magnet 400 is from the S pole of the third permanent magnet 400 through the inside of the third permanent magnet 400 to the N pole of the third permanent magnet 400, that is, the magnetization direction of the third permanent magnet 400 is from the first permanent magnet 200 to the second permanent magnet 300 along the circumferential direction of the rotor yoke 100.

[0061] Therefore, under the action of the magnetic field of the third permanent magnet 400, the direction of the magnetic field lines of the leakage magnetic flux can be adjusted to point from the N pole of the first permanent magnet 200 to the S pole of the second permanent magnet 300, and will not directly return to the S pole of the first permanent magnet 200 through the rotor yoke 100 to form a closed loop, or will not return to the S pole of the first permanent magnet 200 through the second permanent magnet 300, the N pole of the second permanent magnet 300 and the rotor yoke 100 in sequence to form a closed loop, but will be connected to the effective magnetic field of the motor. The magnetic lines of force are aligned in direction and form a closed loop. In other words, the magnetic field of the third permanent magnet 400 is used to enhance the guidance of the magnetic lines of force directed from the first permanent magnet 200 to the second permanent magnet 300. This allows the previously leaked magnetic lines of force to be added to the effective magnetic field of the motor, thereby reducing magnetic leakage from the circumferential ends of the first and second permanent magnets 200 and 300 along the rotor yoke 100, improving the utilization of the first and second permanent magnets 200 and 300, and thereby enhancing the effective magnetic field of the motor. Furthermore, the magnetic lines of force directed from the north pole of the first permanent magnet 200 to the south pole of the second permanent magnet 300 can pass through the third permanent magnet 400, which helps reduce the degree of magnetic circuit saturation in the rotor yoke 100, further improving the utilization of the first and second permanent magnets 200 and 300, and enhancing the magnetic field, thereby improving the motor's torque, operating efficiency, and other performance.

[0062] Reference Figure 1As shown, it can be understood that the third permanent magnet 400 has a symmetrical centerline. Generally speaking, the third permanent magnet 400 has an axisymmetric structure and is symmetrically arranged about the symmetrical centerline. The symmetrical centerline of the third permanent magnet 400 intersects and is perpendicular to the rotation axis Z of the rotor yoke 100. The magnetization direction of the third permanent magnet 400 is perpendicular to the symmetrical centerline of the third permanent magnet 400. Therefore, the magnetization direction of the third permanent magnet 400 is the same as and parallel to the direction of the magnetic field between the first permanent magnet 200 and the second permanent magnet 300. This is more conducive to enhancing the guidance of the magnetic lines of force from the first permanent magnet 200 to the second permanent magnet 300, reducing magnetic leakage, and enhancing the effective magnetic field of the motor.

[0063] Reference Figure 1 and Figure 3 As shown, it can be understood that on a projection plane perpendicular to the rotation axis Z of the rotor yoke 100, the projections of the first permanent magnet 200, the second permanent magnet 300, and the third permanent magnet 400 are all quadrilaterals. Along the radial direction of the rotor yoke 100, the first permanent magnet 200 has a first wall 210 and a twelfth wall 220 that are separated from each other. The first wall 210 faces the rotation axis Z of the rotor yoke 100, while the twelfth wall 220 faces away from the rotation axis Z of the rotor yoke 100. The maximum distance between the first wall 210 and the twelfth wall 220 is the maximum thickness T1 of the first permanent magnet 200. To measure T1, a vernier caliper can be used to directly clamp onto the first wall 210 and the twelfth wall 220 and measure the dimension at the position where the distance between the first wall 210 and the twelfth wall 220 is the greatest.

[0064] Reference Figure 1 and Figure 4 As shown, it can be understood that along the radial direction of the rotor yoke 100, the second permanent magnet 300 has a second wall 310 and a thirteenth wall 320 that are separated from each other, wherein the second wall 310 faces the rotation axis Z of the rotor yoke 100, and the thirteenth wall 320 faces away from the rotation axis Z of the rotor yoke 100. The maximum distance between the second wall 310 and the thirteenth wall 320 is the maximum thickness T2 of the second permanent magnet 300. When measuring T2, a vernier caliper can be used to directly clamp the second wall 310 and the thirteenth wall 320 and measure the dimension at the position where the distance between the second wall 310 and the thirteenth wall 320 is the largest. Generally speaking, the shape of the first permanent magnet 200 is the same as that of the second permanent magnet 300, and T1 = T2.

[0065] Reference Figure 1 and Figure 5As shown, it can be understood that, along the radial direction of the rotor yoke 100, the third permanent magnet 400 has a third wall 410 and a fourteenth wall 420 that are separated from each other. The third wall 410 faces the rotation axis Z of the rotor yoke 100, while the fourteenth wall 420 faces away from the rotation axis Z of the rotor yoke 100. The maximum distance between the third wall 410 and the fourteenth wall 420 is the maximum thickness T3 of the third permanent magnet 400. To measure T3, a vernier caliper is used to directly clamp onto the third wall 410 and the fourteenth wall 420 and measure the dimension at the position where the distance between the third wall 410 and the fourteenth wall 420 is the greatest. The following conditions are satisfied: T3>T1, T3>T2, i.e., the maximum thickness of the third permanent magnet 400 is greater than the maximum thickness of the first permanent magnet 200, and the maximum thickness of the third permanent magnet 400 is greater than the maximum thickness of the second permanent magnet 300. Therefore, along the circumference of the rotor yoke 100, the two opposite wall surfaces of the third permanent magnet 400 can respectively cover the maximum thickness range of the first permanent magnet 200 and the second permanent magnet 300, thereby increasing the range of the third permanent magnet 400 guiding the magnetic lines of force from the first permanent magnet 200 to the second permanent magnet 300, which is beneficial to further reduce leakage magnetic flux and increase the effective magnetic field of the motor.

[0066] Reference Figure 1 and Figure 2 As shown, it can be understood that the rotor yoke 100 is provided with a third mounting slot 130. Specifically, the third mounting slot 130 is located on the side of the rotor yoke 100 facing the rotation axis Z of the rotor yoke 100. That is, the third mounting slot 130 is provided on the inner circumferential wall of the rotor yoke 100. The third mounting slot 130 passes through the rotor yoke 100 along the direction of the rotation axis Z of the rotor yoke 100, and the opening of the third mounting slot 130 faces the rotation axis Z of the rotor yoke 100. The number of third mounting slots 130 is equal to the number of secondary permanent magnets. The end of the third permanent magnet 400 facing away from the rotation axis Z of the rotor yoke 100 is accommodated in the third mounting slot 130. That is, the third permanent magnet 400 is partially accommodated in the third mounting slot 130, and the end of the third permanent magnet 400 closer to the rotation axis Z of the rotor yoke 100 protrudes inwardly from the inner circumferential wall of the rotor yoke 100.

[0067] Reference Figure 1As shown, it can be understood that the first permanent magnet 200 and the second permanent magnet 300 respectively contact the two sides of the third permanent magnet 400 along the circumferential direction of the rotor yoke 100. Therefore, in the entire rotor assembly, after a plurality of secondary permanent magnets (i.e., the third permanent magnets 400) are installed on the rotor yoke 100, an installation space for installing the main permanent magnet (i.e., the first permanent magnet 200 or the second permanent magnet 300) is formed between each two adjacent secondary permanent magnets (i.e., the third permanent magnets 400). The main permanent magnets are accommodated in the installation space, thereby simplifying the structure of the rotor yoke 100 and facilitating production. In addition, the main permanent magnets respectively contact the two adjacent secondary permanent magnets along the circumferential direction of the rotor yoke 100. Therefore, when assembling the rotor assembly, the secondary permanent magnet is first installed in the third mounting groove 130 of the rotor yoke 100, and the secondary permanent magnet is positioned through the third mounting groove 130. Then, the main permanent magnet is installed between the two adjacent secondary permanent magnets, and the main permanent magnet is positioned through the two adjacent secondary permanent magnets to facilitate assembly.

[0068] Reference Figure 1 As shown, it can be understood that along the circumference of the rotor yoke 100, the ends of the third wall 410 are respectively connected to the first wall 210 and the second wall 310. That is, the first wall 210, the third wall 410, and the second wall 310 are sequentially connected along the circumference of the rotor yoke 100 and form a portion of the inner circumferential wall of the rotor assembly. The walls of the multiple main permanent magnets (i.e., the first permanent magnet 200 or the second permanent magnet 300) and the multiple secondary permanent magnets (i.e., the third permanent magnet 400) facing the rotation axis Z of the rotor yoke 100 are sequentially connected to form the inner circumferential wall of the rotor assembly, making the inner circumferential wall of the rotor assembly a continuous wall surface to ensure the balance and stability of the rotor assembly during rotation. Specifically, the first wall 210, the second wall 310, and the third wall 410 can be planes. In this case, the projection of the inner circumferential wall of the rotor assembly on a projection plane perpendicular to the rotation axis Z of the rotor yoke 100 is a polygon.

[0069] Of course, in other embodiments, the first wall 210, the second wall 310 and the third wall 410 can be arc surfaces, and on the projection surface perpendicular to the rotation axis Z of the rotor yoke 100, the first wall 210, the second wall 310 and the third wall 410 are on the same reference circle with the center located on the rotation axis Z of the rotor yoke 100. Therefore, on the projection surface perpendicular to the rotation axis Z of the rotor yoke 100, the projection of the inner circumferential wall of the rotor assembly is a circle.

[0070] Therefore, T3>T1, T3>T2 are satisfied, so that the third permanent magnet 400 can be pre-installed in the rotor yoke 100, and the third permanent magnet 400 is used as the positioning and installation reference for the first permanent magnet 200 and the second permanent magnet 300, which facilitates the installation of the first permanent magnet 200 and the second permanent magnet 300, that is, the auxiliary permanent magnet is used as the positioning and installation reference for the main permanent magnet; at the same time, after the main permanent magnet and the auxiliary permanent magnet are installed, the inner circumferential wall of the rotor assembly can be made into a continuous wall surface to ensure the balance and stability of the rotor assembly during rotation.

[0071] Reference Figure 6 and Figure 7 As shown, it will be understood that in other embodiments, the rotor yoke 100 is provided with a first mounting groove 110, a second mounting groove 120, and a third mounting groove 130. The first mounting groove 110, the second mounting groove 120, and the third mounting groove 130 are all provided on the inner circumferential wall of the rotor yoke 100, and the first mounting groove 110, the third mounting groove 130, and the second mounting groove 120 are sequentially spaced apart along the circumferential direction of the rotor yoke 100. Similarly, the first mounting groove 110, the second mounting groove 120, and the third mounting groove 130 all penetrate the rotor yoke 100 in the direction of the rotation axis Z of the rotor yoke 100, and the openings of the first mounting groove 110, the second mounting groove 120, and the third mounting groove 130 all face the rotation axis Z of the rotor yoke 100. The number of first mounting slots 110 and second mounting slots 120 is equal, and the sum of the number of first mounting slots 110 and second mounting slots 120 equals the number of main permanent magnets. The number of third mounting slots 130 is equal to the number of secondary permanent magnets. The first permanent magnet 200 is accommodated in the first mounting slot 110, the second permanent magnet 300 is accommodated in the second mounting slot 120, and the third permanent magnet 400 is accommodated in the third mounting slot 130. Therefore, in the entire rotor assembly, the secondary permanent magnet is mounted in the third mounting slot 130, and the main permanent magnet is mounted in the first mounting slot 110 and second mounting slot 120, respectively. When assembling the rotor assembly, the main permanent magnet is positioned using the first mounting slot 110 and second mounting slot 120, while the secondary permanent magnet is positioned using the third mounting slot 130. In other words, the installation and positioning of the main and secondary permanent magnets are independent of each other, which helps simplify the assembly process and reduce assembly errors.

[0072] Reference Figure 6 and Figure 7As shown, it can be understood that since the first mounting slot 110, the third mounting slot 130, and the second mounting slot 120 are sequentially spaced apart along the circumference of the rotor yoke 100, the rotor yoke 100 is formed with a first insulating portion 140 and a second insulating portion 150. The first insulating portion 140 is formed between the first mounting slot 110 and the third mounting slot 130, and the second insulating portion 150 is formed between the second mounting slot 120 and the third mounting slot 130. Throughout the rotor yoke 100, the number of first insulating portions 140 and second insulating portions 150 is equal, and the number of first insulating portions 140 and third mounting slots 130 is equal. The first insulating portion 140 has a fourth wall surface 141 facing the rotation axis Z of the rotor yoke 100, and the second insulating portion 150 has a fifth wall surface 151 facing the rotation axis Z of the rotor yoke 100. The first wall 210, the fourth wall 141, the third wall 410, the fifth wall 151, and the second wall 310 are sequentially butted together along the circumference of the rotor yoke 100 to form a portion of the inner circumferential wall of the rotor assembly. The walls of the plurality of main permanent magnets (i.e., the first permanent magnet 200 or the second permanent magnet 300), the plurality of secondary permanent magnets (i.e., the third permanent magnet 400), the plurality of first partitions 140, and the plurality of second partitions 150 that face the rotation axis Z of the rotor yoke 100 are sequentially butted together to form the inner circumferential wall of the rotor assembly, forming a continuous wall surface to ensure the balance and stability of the rotor assembly during rotation.

[0073] Reference Figure 6 As shown, it can be understood that the first wall surface 210, the second wall surface 310, the third wall surface 410, the fourth wall surface 141, and the fifth wall surface 151 are all arcuate surfaces. On the projection plane perpendicular to the rotation axis Z of the rotor yoke 100, the projections of the first wall surface 210, the second wall surface 310, the third wall surface 410, the fourth wall surface 141, and the fifth wall surface 151 form a first reference circle 160, and the center of the first reference circle 160 coincides with the rotation axis Z of the rotor yoke 100. Therefore, on the projection plane perpendicular to the rotation axis Z of the rotor yoke 100, the projection of the inner circumferential wall of the rotor assembly is a circle.

[0074] Of course, in other embodiments, the first wall 210, the second wall 310, the third wall 410, the fourth wall 141 and the fifth wall 151 can be planes. In this case, the projection of the inner circumferential wall of the rotor assembly on the projection plane perpendicular to the rotation axis Z of the rotor yoke 100 is a polygon.

[0075] Reference Figure 2 and Figure 7As shown, it can be understood that along the circumference of the rotor yoke 100, the first mounting slot 110 has a first width W4, which is the distance between two opposite groove walls of the first mounting slot 110 arranged along the circumference of the rotor yoke 100. Similarly, the second mounting slot 120 has a second width W5, which is the distance between two opposite groove walls of the second mounting slot 120 arranged along the circumference of the rotor yoke 100. The third mounting slot 130 has a third width W6, which is the distance between two opposite groove walls of the third mounting slot 130 arranged along the circumference of the rotor yoke 100. In the radial direction of the rotor yoke 100 and toward the rotation axis Z of the rotor yoke 100, that is, from the outside to the inside of the rotor yoke 100, the first width W4, the second width W5, and the third width W6 all decrease. That is, the width of the first mounting groove 110 at the notch is smaller than the width at the bottom of the groove. Similarly, the width of the second mounting groove 120 at the notch is smaller than the width at the bottom of the groove, and the width of the third mounting groove 130 at the notch is smaller than the width at the bottom of the groove. Therefore, when installing the first permanent magnet 200, the second permanent magnet 300 and the third permanent magnet 400, the first permanent magnet 200 is inserted into the first mounting groove 110 along the direction of the rotation axis Z of the rotor yoke 100, the second permanent magnet 300 is inserted into the second mounting groove 120 along the direction of the rotation axis Z of the rotor yoke 100, and the third permanent magnet 400 is inserted into the third mounting groove 130 along the direction of the rotation axis Z of the rotor yoke 100. Thus, the first mounting groove 110 can limit the first permanent magnet 200 from escaping from the rotor yoke 100 toward the inner side of the rotor yoke 100 and prevent the first permanent magnet 200 from escaping from the rotor yoke 100. The magnet 200 is loose. Similarly, the second mounting groove 120 can limit the second permanent magnet 300 from detaching from the rotor yoke 100 toward the inner side of the rotor yoke 100, and the third mounting groove 130 can limit the third permanent magnet 400 from detaching from the rotor yoke 100 toward the inner side of the rotor yoke 100, and can prevent the second permanent magnet 300 and the third permanent magnet 400 from loosening, thereby improving the installation stability of the first permanent magnet 200, the second permanent magnet 300 and the third permanent magnet 400, that is, improving the installation stability of the main permanent magnet and the auxiliary permanent magnet, ensuring the stability of the rotor assembly during rotation and helping to reduce noise.

[0076] Reference Figure 3As shown, it can be understood that along the circumference of the rotor yoke 100, the first permanent magnet 200 has a sixth wall surface 230 and a seventh wall surface 240 that are separated from each other. The maximum distance between the sixth wall surface 230 and the seventh wall surface 240 is W1, that is, the maximum width of the first permanent magnet 200 is W1. When measuring W1, a vernier caliper is used to directly clamp the sixth wall surface 230 and the seventh wall surface 240 and measure the size at the position where the distance between the sixth wall surface 230 and the seventh wall surface 240 is the largest. In this embodiment, the maximum width W1 of the first permanent magnet 200 is the distance from the intersection of the sixth wall surface 230 and the twelfth wall surface 220 to the intersection of the seventh wall surface 240 and the twelfth wall surface 220.

[0077] Reference Figure 4 As shown, it can be understood that along the circumference of the rotor yoke 100, the second permanent magnet 300 has an eighth wall 330 and a ninth wall 340 that are separated from each other. The maximum distance between the eighth wall 330 and the ninth wall 340 is W2, that is, the maximum width of the second permanent magnet 300 is W2. When measuring W2, a vernier caliper is used to directly clamp the eighth wall 330 and the ninth wall 340 and measure the size at the position where the distance between the eighth wall 330 and the ninth wall 340 is the largest. In this embodiment, the maximum width W2 of the second permanent magnet 300 is the distance from the intersection of the eighth wall 330 and the thirteenth wall 320 to the intersection of the ninth wall 340 and the thirteenth wall 320. Generally speaking, W1 = W2.

[0078] Reference Figure 5 As shown, it can be understood that along the circumference of the rotor yoke 100, the third permanent magnet 400 has a tenth wall surface 430 and an eleventh wall surface 440 that are separated from each other. The maximum distance between the tenth wall surface 430 and the eleventh wall surface 440 is W3, that is, the maximum width of the third permanent magnet 400 is W3. When measuring W3, a vernier caliper is directly clamped on the tenth wall surface 430 and the eleventh wall surface 440 and the dimension at the position where the distance between the tenth wall surface 430 and the eleventh wall surface 440 is the largest. In this embodiment, the maximum width W3 of the third permanent magnet 400 is the distance from the intersection of the tenth wall surface 430 and the fourteenth wall surface 420 to the intersection of the eleventh wall surface 440 and the fourteenth wall surface 420.

[0079] Reference Figures 3 to 5As shown, it can be understood that the maximum width W1 of the first permanent magnet 200, the maximum width W2 of the second permanent magnet 300, and the maximum width W3 of the third permanent magnet 400 satisfy the following conditions: W3 < W1, W3 < W2. In other words, the maximum width of the third permanent magnet 400 is smaller than the maximum width of the first permanent magnet 200, and the maximum width of the third permanent magnet 400 is smaller than the maximum width of the second permanent magnet 300. This results in a smaller width for the third permanent magnet 400. In other words, a smaller auxiliary permanent magnet is used to reduce the space occupied by the auxiliary permanent magnet, thereby increasing the installation space of the main permanent magnet. This increases the width of the main permanent magnet, strengthens the strength of the effective magnetic field, and thus increases the torque of the motor.

[0080] The motor according to the second embodiment of the present invention includes a stator assembly 500 and a rotor assembly according to the first embodiment of the present invention, wherein the rotor assembly is wound around the outer circumference of the stator assembly 500 .

[0081] Since the motor adopts all the technical solutions of the rotor assembly of the above embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above embodiment.

[0082] The electrical equipment of the third embodiment of the present invention includes the motor of the second embodiment of the present invention. The electrical equipment can be a fan, an air-conditioning compressor, a refrigerator compressor, a drum washing machine, etc.

[0083] Since the electrical device adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above embodiment.

[0084] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A rotor assembly, characterized in that: include: rotor yoke; a first permanent magnet disposed on the inner periphery of the rotor yoke, wherein along the radial direction of the rotor yoke, a side of the first permanent magnet close to the rotation axis of the rotor yoke is an S pole, and a side of the first permanent magnet away from the rotation axis is an N pole; a second permanent magnet disposed on the inner circumference of the rotor yoke, the second permanent magnet and the first permanent magnet being spaced apart from each other in the circumferential direction of the rotor yoke, wherein along the radial direction, the side of the second permanent magnet closer to the rotation axis of the rotor yoke is an N pole, and the side of the second permanent magnet facing away from the rotation axis is an S pole; The third permanent magnet is arranged on the inner periphery of the rotor yoke and located between the first permanent magnet and the second permanent magnet. The magnetization direction of the third permanent magnet is from the first permanent magnet to the second permanent magnet.

2. The rotor assembly according to claim 1, wherein: The first permanent magnet has a symmetric center line, the symmetric center line intersects and is perpendicular to the rotation axis, and the magnetization direction of the first permanent magnet is parallel to the symmetric center line; Alternatively, the opposite direction of the magnetization direction of the first permanent magnet points to the rotation axis; Alternatively, the opposite direction of the magnetization direction of the first permanent magnet points to a first reference point, the first reference point is located on the symmetry center line, and the first reference point is located between the first permanent magnet and the rotation axis.

3. The rotor assembly according to claim 1, wherein: The second permanent magnet has a symmetric center line, the symmetric center line intersects and is perpendicular to the rotation axis, and the magnetization direction of the second permanent magnet is parallel to the symmetric center line; Alternatively, the magnetization direction of the second permanent magnet points to the rotation axis; Alternatively, the magnetization direction of the second permanent magnet points to a second reference point, the second reference point is located on the symmetry center line, and the second reference point is located between the second permanent magnet and the rotation axis.

4. The rotor assembly according to claim 1, wherein: The third permanent magnet has a symmetry center line, which intersects and is perpendicular to the rotation axis, and the magnetization direction of the third permanent magnet is perpendicular to the symmetry center line.

5. The rotor assembly according to claim 1, wherein: Along the radial direction of the rotor yoke, the maximum thickness of the first permanent magnet is T1, the maximum thickness of the second permanent magnet is T2, and the maximum thickness of the third permanent magnet is T3, satisfying: T3>T1, T3>T2.

6. The rotor assembly according to claim 5, characterized in that: The rotor yoke has a wall facing the rotation axis with a third mounting groove, the third permanent magnet is partially accommodated in the third mounting groove, and the first permanent magnet and the second permanent magnet respectively contact two sides of the third permanent magnet along the circumference of the rotor yoke.

7. The rotor assembly according to claim 6, wherein: The first permanent magnet has a first wall surface facing the rotation axis, the second permanent magnet has a second wall surface facing the rotation axis, and the third permanent magnet has a third wall surface facing the rotation axis. Along the circumference of the rotor yoke, the two ends of the third wall surface are respectively connected to the first wall surface and the second wall surface.

8. The rotor assembly according to claim 5, wherein: The wall surface of the rotor yoke facing the rotation axis is provided with a first mounting groove, a second mounting groove and a third mounting groove. The first mounting groove, the third mounting groove and the second mounting groove are arranged in sequence along the circumference of the rotor yoke. The first permanent magnet is installed in the first mounting groove, the second permanent magnet is installed in the second mounting groove, and the third permanent magnet is installed in the third mounting groove.

9. The rotor assembly according to claim 6 or 8, characterized in that: The third mounting groove has a third width along the circumferential direction of the rotor yoke, and the third width decreases gradually along the radial direction of the rotor yoke and toward the rotation axis.

10. The rotor assembly according to claim 8, wherein: Along the circumference of the rotor yoke, the first installation slot has a first width, and the second installation slot has a second width. Along the radial direction of the rotor yoke and toward the rotation axis, the first width and the second width both decrease gradually.

11. The rotor assembly according to claim 8, wherein: The first permanent magnet has a first wall facing the rotation axis, the second permanent magnet has a second wall facing the rotation axis, and the third permanent magnet has a third wall facing the rotation axis. The rotor yoke includes a first isolating portion and a second isolating portion. The first isolating portion is located between the first mounting groove and the third mounting groove. The first isolating portion has a fourth wall facing the rotation axis. The second isolating portion is located between the second mounting groove and the third mounting groove. The second isolating portion has a fifth wall facing the rotation axis. On a projection plane perpendicular to the rotation axis, the projection of the first wall, the projection of the second wall, the projection of the third wall, the projection of the fourth wall, and the projection of the fifth wall form a first reference circle. The center of the first reference circle coincides with the rotation axis.

12. The rotor assembly according to claim 1, wherein: Along the circumference of the rotor yoke, the first permanent magnet has a sixth wall surface and a seventh wall surface facing away from each other, and the maximum distance between the sixth wall surface and the seventh wall surface is W1; the second permanent magnet has an eighth wall surface and a ninth wall surface facing away from each other, and the maximum distance between the eighth wall surface and the ninth wall surface is W2; the third permanent magnet has a tenth wall surface and an eleventh wall surface facing away from each other, and the maximum distance between the tenth wall surface and the eleventh wall surface is W3, satisfying: W3<W1, W3<W2.

13. A motor, characterized in that include: stator assembly; The rotor assembly according to any one of claims 1 to 12, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

14. Electrical equipment, characterized in that Comprising the motor as claimed in claim 13.

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