Rotor, electric motor, powertrain and vehicle

Abstract

Provided in the embodiments of the present application are a rotor, an electric motor, a powertrain and a vehicle. The rotor comprises: a rotor core and a plurality of magnetic poles distributed at intervals in the circumferential direction of the rotor core, wherein the magnetic poles include a first magnetic pole and a second magnetic pole adjacent to each other, the coercive force of at least one permanent magnet in the first magnetic pole being different from the coercive force of permanent magnets in the second magnetic pole. In the embodiments of the present application, the overall magnetic stability of the rotor can be improved, preventing the risk of demagnetization, and thereby facilitating improvement to the operational reliability of the electric motor.

Description

A rotor, an electric motor, a powertrain, and a vehicle

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent applications filed on October 22, 2024, with application number 202411481160.2 and titled "A Rotor, Motor, Powertrain and Vehicle"; applications filed on October 22, 2024, with application number 202411482130.3 and titled "A Rotor, Motor, Powertrain and Vehicle"; and applications filed on October 22, 2024, with application number 202411483685.X and titled "A Rotor, Motor, Powertrain and Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of electric motor technology, specifically relating to a rotor, electric motor, powertrain, and vehicle. Background Technology

[0004] Permanent magnet motors are widely used in automotive, air conditioning, and other technological fields due to their high efficiency, high power density, and good mechanical properties. The motor rotor consists of a rotor core and a magnetic structure housed within it. By changing the magnetization state of the magnetic structure, the motor can be adapted to different operating conditions.

[0005] In related technologies, the magnetic structure of the rotor typically uses permanent magnets with low coercivity, whose magnetization state is easily altered, allowing the motor to adapt to different operating conditions and achieve efficient operation across all operating ranges. However, permanent magnets with low coercivity are susceptible to demagnetization, affecting the motor's operational reliability. Summary of the Invention

[0006] This application aims to provide a rotor, motor, powertrain, and vehicle to solve the problem that the magnetic structure of existing rotors has the risk of demagnetization, which affects the reliability of motor operation.

[0007] To solve the above-mentioned technical problems, this application is implemented as follows:

[0008] This application discloses a rotor, the rotor comprising:

[0009] The rotor core and multiple magnetic poles distributed circumferentially along the rotor core; the magnetic poles include adjacent first magnetic poles and second magnetic poles, wherein the coercivity of at least one permanent magnet in the first magnetic pole is different from the coercivity of the permanent magnet in the second magnetic pole.

[0010] In some embodiments, the first magnetic pole is provided with a first permanent magnet group, and the second magnetic pole is provided with a second permanent magnet group, wherein the coercivity of the first permanent magnet group is less than that of the second permanent magnet group.

[0011] In some embodiments, the first permanent magnet group and the second permanent magnet group are both one layer, and the coercivity of at least one permanent magnet in the first permanent magnet group is less than the coercivity of the permanent magnet in the second permanent magnet group.

[0012] In some embodiments, the first permanent magnet group includes multiple layers of first permanent magnet units, which are arranged radially spaced along the rotor core; at least one layer of first permanent magnet unit includes at least one first permanent magnet and / or at least one composite permanent magnet, which is composed of a first permanent magnet and a second permanent magnet, wherein the coercivity of the first permanent magnet is less than that of the second permanent magnet.

[0013] In some embodiments, the first permanent magnet group further includes a second permanent magnet, the second permanent magnet being arranged radially spaced from the first permanent magnet along the rotor core, and / or the second permanent magnet being arranged radially spaced from the composite permanent magnet along the rotor core.

[0014] In some embodiments, the first permanent magnet group includes a first permanent magnet and a second permanent magnet, wherein the second permanent magnet is adapted to be arranged close to the gap between the rotor and the stator, and the first permanent magnet is adapted to be arranged away from the gap.

[0015] In some embodiments, the first permanent magnet group includes a composite permanent magnet and a second permanent magnet, wherein the composite permanent magnet is disposed on the radially outer side of the rotor core, or the composite permanent magnet is disposed on the radially inner side of the rotor core.

[0016] In some embodiments, the composite permanent magnet constitutes a series magnetic circuit structure or a parallel magnetic circuit structure.

[0017] In some embodiments, the first permanent magnet group further includes a second permanent magnet, the second permanent magnet being spaced apart from the first permanent magnet along the circumferential direction of the rotor core, and / or the second permanent magnet being spaced apart from the composite permanent magnet along the circumferential direction of the rotor core.

[0018] In some embodiments, the first permanent magnet group further includes a plurality of second permanent magnets, the second permanent magnets being arranged at radial and circumferential intervals with the first permanent magnets along the rotor core, and / or the second permanent magnets being arranged at radial and circumferential intervals with the composite permanent magnets along the rotor core.

[0019] In some embodiments, the first permanent magnet and the second permanent magnet in the composite permanent magnet are arranged sequentially along the radial direction of the rotor core. The first permanent magnet is adapted to be arranged away from the air gap between the rotor and the stator, and the second permanent magnet is adapted to be arranged close to the air gap.

[0020] In some embodiments, the second permanent magnet group includes multiple layers of second permanent magnet units, which are arranged radially spaced along the rotor core, and each layer of second permanent magnet units includes at least one third permanent magnet.

[0021] In some embodiments, the permanent magnets in each layer of the second permanent magnet unit are third permanent magnets.

[0022] In some embodiments, the coercivity of the third permanent magnet is greater than or equal to the coercivity of the second permanent magnet.

[0023] In some embodiments, the first permanent magnet group has a first magnetic pole centerline, the second permanent magnet group has a second magnetic pole centerline, the first permanent magnet group is symmetrically arranged about the first magnetic pole centerline, and the second permanent magnet group is symmetrically arranged about the second magnetic pole centerline.

[0024] In some embodiments, the magnetic pole includes at least one permanent magnet, wherein the permanent magnet is at least one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, and Iron Nitride permanent magnet.

[0025] In some embodiments, the first magnetic pole and the second magnetic pole are alternately arranged along the circumference of the rotor core, with the first magnetic pole being one of the positive and negative poles and the second magnetic pole being the other of the positive and negative poles.

[0026] In some embodiments, the rotor core is provided with a mounting groove, and the permanent magnet in the magnetic pole is disposed in the mounting groove.

[0027] In some embodiments, a permanent magnet in at least one magnetic pole is placed in a mounting slot.

[0028] In some embodiments, there are multiple mounting slots, which form a preset shape. The preset shape includes one or more of the following: straight, arc, V, U, and W.

[0029] In some embodiments, the magnetic pole further includes at least one auxiliary slot, and the rotor core has a peripheral wall on which the auxiliary slot is disposed.

[0030] In some embodiments, the rotor core includes a plurality of core units, which are arranged sequentially along the axial direction of the rotor core.

[0031] In some embodiments, there is an offset angle between two adjacent core units along the circumference of the rotor core, and the magnetic poles on two adjacent core units are arranged in the same way, and / or the magnetic poles on two adjacent core units are arranged in different ways.

[0032] This application discloses another type of rotor, which includes a rotor core and a plurality of magnetic poles distributed circumferentially along the rotor core; the magnetic poles include at least one composite permanent magnet, which is a series magnetic circuit structure composed of a first permanent magnet and a second permanent magnet with different coercivity.

[0033] In some embodiments, the first permanent magnet and the second permanent magnet are arranged sequentially along the radial direction of the rotor core.

[0034] In some embodiments, the coercivity of the first permanent magnet is greater than that of the second permanent magnet, the first permanent magnet is adapted to be arranged close to the air gap between the rotor and the stator, and the second permanent magnet is adapted to be arranged away from the air gap.

[0035] In some embodiments, the thickness of the first permanent magnet in the radial direction accounts for 0.05-0.9% of the thickness of the composite permanent magnet in the radial direction.

[0036] In some embodiments, the magnetic poles further include a first permanent magnet and / or a second permanent magnet, wherein the first permanent magnet and the composite permanent magnet are arranged along the radial direction of the rotor core, and / or the second permanent magnet and the composite permanent magnet are arranged along the radial direction of the rotor core.

[0037] In some embodiments, the first permanent magnet or the second permanent magnet is any one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, or Iron Nitride permanent magnet.

[0038] In some embodiments, the magnetic poles include a multilayer permanent magnet assembly arranged in the radial direction of the rotor core, and at least one permanent magnet assembly includes at least one composite permanent magnet.

[0039] In some embodiments, the permanent magnets in at least one layer of permanent magnet assembly are all composite permanent magnets.

[0040] In some embodiments, each layer of permanent magnets includes at least one composite permanent magnet.

[0041] In some embodiments, the permanent magnets in each layer of permanent magnets are composite permanent magnets.

[0042] In some embodiments, the multilayer permanent magnet group includes at least a first permanent magnet group and a second permanent magnet group. The first permanent magnet group is adapted to be arranged close to the air gap between the rotor and the stator, and the second permanent magnet group is adapted to be arranged away from the air gap. The first permanent magnet group includes a first permanent magnet and / or a second permanent magnet, and the second permanent magnet group includes at least one composite permanent magnet.

[0043] In some embodiments, the permanent magnets in each layer of permanent magnet assembly are arranged symmetrically about the magnetic pole centerline.

[0044] In some embodiments, the composite permanent magnet includes at least one of ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets.

[0045] In some embodiments, the permanent magnet in the magnetic pole includes a composite permanent magnet, or a combination of at least one of a first permanent magnet and a second permanent magnet with a composite permanent magnet, and the rotor core is provided with a mounting groove, in which the permanent magnet in the magnetic pole is disposed.

[0046] In some embodiments, a permanent magnet in at least one magnetic pole is placed in a mounting slot.

[0047] In some embodiments, there are multiple permanent magnets in the magnetic poles and multiple mounting slots. The multiple mounting slots form a preset shape, which includes one or more of the following: straight, arc, V, U, and W.

[0048] In some embodiments, the magnetic pole further includes at least one auxiliary slot, and the rotor core has a peripheral wall on which the auxiliary slot is disposed.

[0049] In some embodiments, the rotor core includes a plurality of core units, which are arranged sequentially along the axial direction of the rotor core.

[0050] In some embodiments, there is an offset angle between two adjacent core units along the circumference of the rotor core, wherein the magnetic poles on the two adjacent core units are arranged in the same way, and / or the magnetic poles on the two adjacent core units are arranged in different ways.

[0051] This application discloses yet another rotor, including a rotor core and a plurality of magnetic poles, the plurality of magnetic poles being distributed at intervals along the circumference of the rotor core;

[0052] The magnetic pole includes a first magnetic part and a second magnetic part, which are asymmetrically arranged about the center line of the magnetic pole; wherein...

[0053] The coercivity of the first magnetic part is different from that of the second magnetic part.

[0054] In some embodiments, the coercivity of the first magnetic part is less than the coercivity of the second magnetic part; wherein...

[0055] The first magnetic part is adapted to be disposed on the side of the magnetic pole facing the forward rotation direction of the motor, and the second magnetic part is adapted to be disposed on the side of the magnetic pole facing the reverse rotation direction of the motor.

[0056] In some embodiments, the first magnetic part includes a fifth permanent magnet and / or a first composite permanent magnet, the first composite permanent magnet including a fifth permanent magnet and a sixth permanent magnet, and the coercivity of the fifth permanent magnet is less than that of the sixth permanent magnet.

[0057] In some embodiments, the first magnetic part includes multiple layers of fifth permanent magnet units, which are arranged radially spaced along the rotor core, and at least one layer of permanent magnet units is provided with at least one fifth permanent magnet and / or at least one first composite permanent magnet.

[0058] In some embodiments, the first magnetic part further includes a sixth permanent magnet, which is arranged radially spaced from the fifth permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged radially spaced from the first composite permanent magnet along the rotor core.

[0059] In some embodiments, the sixth permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

[0060] In some embodiments, the first magnetic part further includes a sixth permanent magnet, which is arranged circumferentially with the fifth permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged circumferentially with the first composite permanent magnet along the rotor core.

[0061] In some embodiments, the first magnetic part further includes a plurality of sixth permanent magnets, the sixth permanent magnets being arranged at intervals with the fifth permanent magnets along the radial and circumferential directions of the rotor core, and / or the sixth permanent magnets being arranged at intervals with the first composite permanent magnets along the radial and circumferential directions of the rotor core.

[0062] In some embodiments, the first composite permanent magnet constitutes a series magnetic circuit structure or a parallel magnetic circuit structure.

[0063] In some embodiments, the first magnetic part includes a first composite permanent magnet, wherein a fifth permanent magnet and a sixth permanent magnet in the first composite permanent magnet are alternately arranged along the radial direction of the rotor core to form a series magnetic circuit structure.

[0064] In some embodiments, the first magnetic part includes a first composite permanent magnet, wherein a fifth permanent magnet and a sixth permanent magnet in the first composite permanent magnet are alternately arranged along the circumference of the rotor core to form a parallel magnetic circuit structure.

[0065] In some embodiments, the first composite permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

[0066] In some embodiments, the second magnetic part includes a seventh permanent magnet and / or a second composite permanent magnet, the second composite permanent magnet including a seventh permanent magnet and an eighth permanent magnet, wherein the coercivity of the seventh permanent magnet is greater than that of the eighth permanent magnet.

[0067] In some embodiments, the second magnetic part includes multiple layers of sixth permanent magnet units, which are arranged radially spaced along the rotor core, and at least one layer of sixth permanent magnet units is provided with at least one seventh permanent magnet and / or at least one second composite permanent magnet.

[0068] In some embodiments, the second magnetic part further includes an eighth permanent magnet, which is arranged radially spaced from the seventh permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged radially spaced from the second composite permanent magnet along the rotor core.

[0069] In some embodiments, the seventh permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

[0070] In some embodiments, the second magnetic part further includes an eighth permanent magnet, which is arranged circumferentially with the seventh permanent magnet along the rotor core, and / or the eighth permanent magnet is arranged circumferentially with the second composite permanent magnet along the rotor core.

[0071] In some embodiments, the second magnetic part further includes a plurality of eighth permanent magnets, the eighth permanent magnets being arranged at radial and circumferential intervals with the seventh permanent magnets along the rotor core, and / or the eighth permanent magnets being arranged at radial and circumferential intervals with the second composite permanent magnets along the rotor core.

[0072] In some embodiments, the second magnetic part includes a second composite permanent magnet, which constitutes a series magnetic circuit structure or a parallel magnetic circuit structure.

[0073] In some embodiments, the second magnetic part includes a second composite permanent magnet, wherein the seventh and eighth permanent magnets of the second composite permanent magnet are alternately arranged along the radial direction of the rotor core to form a series magnetic circuit structure.

[0074] In some embodiments, the second magnetic part includes a second composite permanent magnet, and the seventh and eighth permanent magnets of the second composite permanent magnet are alternately arranged along the circumference of the rotor core to form a parallel magnetic circuit structure.

[0075] In some embodiments, the second composite permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

[0076] In some embodiments, the coercivity of the seventh permanent magnet is greater than or equal to the coercivity of the sixth permanent magnet.

[0077] In some embodiments, the coercivity of the eighth permanent magnet is less than or equal to the coercivity of the sixth permanent magnet.

[0078] In some embodiments, the coercivity of the seventh permanent magnet is equal to that of the sixth permanent magnet, and / or the coercivity of the eighth permanent magnet is equal to that of the fifth permanent magnet.

[0079] In some embodiments, both the first magnetic part and the second magnetic part include at least one permanent magnet, wherein the permanent magnet is at least one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, and Iron Nitride permanent magnet.

[0080] In some embodiments, the rotor core is provided with a first mounting slot group and a second mounting slot group symmetrically distributed about the magnetic pole center line, and a first magnetic part and a second magnetic part are respectively disposed in the first mounting slot group and the second mounting slot group.

[0081] In some embodiments, both the first mounting slot group and the second mounting slot group include at least one mounting slot, and the mounting slots of the first mounting slot group and the second mounting slot group form a preset shape in the circumferential direction of the rotor core.

[0082] In some embodiments, the preset shape includes one or more of the following: arc shape, straight line shape, V shape, U shape, and W shape.

[0083] In some embodiments, the rotor core includes a plurality of core units, which are arranged sequentially along the axial direction of the rotor core.

[0084] In some embodiments, there is an offset angle between two adjacent core units along the circumferential direction, wherein the magnetic poles on the two adjacent core units are arranged in the same way, or the magnetic poles on the two adjacent core units are arranged in different ways.

[0085] This application discloses an electric motor, a stator, and a rotor of any of the above; the stator is disposed on the radial inner side and / or radial outer side of the rotor.

[0086] In some embodiments, the first permanent magnet in the composite permanent magnet is arranged close to the air gap between the rotor and the stator, and the second permanent magnet is arranged away from the air gap. The coercivity of the first permanent magnet is greater than that of the second permanent magnet.

[0087] In some embodiments, the magnetic poles include multi-layer permanent magnet groups arranged along the radial direction of the rotor core, wherein the permanent magnets in each layer of the permanent magnet group are composite permanent magnets.

[0088] In some embodiments, the magnetic pole includes a multilayer permanent magnet group arranged in the radial direction of the rotor core. The multilayer permanent magnet group includes at least a first permanent magnet group and a second permanent magnet group. The first permanent magnet group is arranged close to the air gap between the stator and the rotor, and the second permanent magnet group is arranged away from the air gap. The first permanent magnet group includes a first permanent magnet and / or a second permanent magnet, and the second permanent magnet group includes at least one composite permanent magnet.

[0089] In some embodiments, the motor further includes a motor controller electrically connected to the stator winding of the stator. The motor controller is used to output an instantaneous pulse current to cause the stator winding to generate a magnetic field acting on the rotor to change the magnetic flux through the rotor.

[0090] In some embodiments, the motor has a forward rotation direction and a reverse rotation direction, a first magnetic part is disposed on the side of the motor facing the forward rotation direction, and a second magnetic part is disposed on the side of the motor facing the reverse rotation direction.

[0091] This application discloses a powertrain, including the aforementioned electric motor.

[0092] This application discloses a vehicle, which includes the aforementioned electric motor or the aforementioned powertrain.

[0093] In some embodiments of this application, since the coercivity of at least one permanent magnet in the first magnetic pole is different from that of the permanent magnet in the second magnetic pole, i.e., the magnetization states of the permanent magnets in the first and second magnetic poles are different, the magnetization state of the permanent magnet with lower coercivity is more easily changed during motor operation than that of the permanent magnet with higher coercivity. This allows the motor to adapt to different operating conditions in a timely manner, achieving efficient operation across the entire operating range. Conversely, the magnetization state of the permanent magnet with higher coercivity is less prone to change, thereby improving the overall load magnetic stability of the rotor, avoiding the risk of demagnetization, and improving the operational reliability of the motor.

[0094] In some embodiments of this application, the permanent magnet of the magnetic pole includes at least one composite permanent magnet, which is a series magnetic circuit structure composed of a first permanent magnet and a second permanent magnet with different coercivity. Since the first and second permanent magnets have different coercivity, i.e., different magnetization states, the magnetization state of the permanent magnet with lower coercivity is more easily changed during motor operation, thereby adjusting the air gap flux. Simultaneously, the magnetization state of the permanent magnet with higher coercivity is less easily changed, thus improving the overall magnetic stability of the magnetic pole, avoiding demagnetization phenomena outside of design conditions, and improving the operational reliability of the motor.

[0095] In some embodiments of this application, the rotor's magnetic poles include two asymmetrical first and second magnetic parts with different coercivity, meaning the first and second magnetic parts have different magnetization states. During motor operation, the magnetization state of the magnetic part with lower coercivity is more easily changed than that of the magnetic part with higher coercivity. This allows the motor to adapt to different operating conditions promptly, achieving efficient operation across the entire motor's operating range. Conversely, the magnetization state of the magnetic part with higher coercivity is less prone to change, thereby improving the rotor's overall load-stabilizing magnetic capability, avoiding the risk of demagnetization, and enhancing the motor's operational reliability.

[0096] Additional aspects and advantages of this application 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 this application. Attached Figure Description

[0097] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0098] Figure 1 is a schematic diagram of the structure of the motor in some embodiments of this application;

[0099] Figure 2 is a cross-sectional view of the motor in some embodiments of this application;

[0100] Figure 3 is a schematic diagram of the skew pole rotor in some embodiments of this application;

[0101] Figure 4 is a schematic diagram of the straight pole rotor in some embodiments of this application;

[0102] Figure 5 is a schematic diagram of the rotor structure in the first embodiment of this application;

[0103] Figure 6 is a top view of the core unit in the first embodiment of this application;

[0104] Figure 7 is a top view of the rotor in the first embodiment of this application;

[0105] Figure 8 is a schematic diagram of the magnetization direction of the permanent magnets on the rotor in the first embodiment of this application;

[0106] Figure 9 is a schematic diagram of the simulation results of the magnetic field lines of the permanent magnet on the rotor in the first embodiment of this application;

[0107] Figure 10 is a cross-sectional view of the motor in the first embodiment of this application;

[0108] Figure 11 is a cross-sectional view of the motor in the second embodiment of this application;

[0109] Figure 12 is a cross-sectional view of the motor in the third embodiment of this application;

[0110] Figure 13 is a cross-sectional view of the motor in the fourth embodiment of this application;

[0111] Figure 14 is a cross-sectional view of the motor in the fifth embodiment of this application;

[0112] Figure 15 is a cross-sectional view of the motor in the sixth embodiment of this application;

[0113] Figure 16 is a cross-sectional view of the motor in the seventh embodiment of this application;

[0114] Figure 17 is a top view of a core unit in the eighth embodiment of this application;

[0115] Figure 18 is a cross-sectional view of the motor in the eighth embodiment of this application;

[0116] Figure 19 is a cross-sectional view of the motor in the ninth embodiment of this application;

[0117] Figure 20 is a cross-sectional view of the motor in the ninth embodiment of this application;

[0118] Figure 21 is a cross-sectional view of the motor in the tenth embodiment of this application;

[0119] Figure 22 is a cross-sectional view of the motor in the eleventh embodiment of this application;

[0120] Figure 23 is a cross-sectional view of the motor in the twelfth embodiment of this application;

[0121] Figure 24 is a schematic diagram of the direct axis and quadrature axis of the permanent magnet of the motor in some embodiments of this application;

[0122] Figure 25 is a schematic diagram of the magnetic field lines of the direct-axis current of the motor in some embodiments of this application;

[0123] Figure 26 is a schematic diagram of the magnetic field lines of the quadrature-axis current of the motor in some embodiments of this application;

[0124] Figure 27 is a schematic diagram of the simulation results of the magnetic field lines of the permanent magnet in some embodiments of this application;

[0125] Figure 28 is a schematic diagram of the magnetic field line simulation results of the direct-axis current in some embodiments of this application;

[0126] Figure 29 is a schematic diagram of the magnetic field line simulation results of the quadrature axis current in some embodiments of this application;

[0127] Figure 30 is a magnetic density cloud diagram of the second permanent magnet being 100% fully magnetized in some embodiments of this application;

[0128] Figure 31 is a magnetic density cloud diagram of the second permanent magnet being 30% magnetized in some embodiments of this application;

[0129] Figure 32 is a comparison of the no-load back EMF and electric angle of the second permanent magnet in two states as shown in Figures 30 and 31.

[0130] Figure 33 is a torque-speed curve of the motor described in some embodiments of this application;

[0131] Figure 34 is a torque-speed curve of the high-efficiency region of the motor described in some embodiments of this application;

[0132] Figure 35 is a schematic diagram of the rotor structure in the thirteenth embodiment of this application.

[0133] Figure 36 is a top view of the rotor in the thirteenth embodiment of this application;

[0134] Figure 37 is a schematic diagram of a magnetic pole structure in a core unit in the thirteenth embodiment of this application;

[0135] Figure 38 is a schematic diagram of the magnetic pole slant arrangement of multiple core units in the thirteenth embodiment of this application;

[0136] Figure 39 is a cross-sectional view of the motor in the thirteenth embodiment of this application;

[0137] Figure 40 is a cross-sectional view of the motor in the fourteenth embodiment of this application;

[0138] Figure 41 is a cross-sectional view of the motor in the fifteenth embodiment of this application;

[0139] Figure 42 is a cross-sectional view of the motor in the sixteenth embodiment of this application;

[0140] Figure 43 is a cross-sectional view of the motor in the seventeenth embodiment of this application;

[0141] Figure 44 is a cross-sectional view of the motor in the eighteenth embodiment of this application;

[0142] Figure 45 is a cross-sectional view of the motor in the nineteenth embodiment of this application;

[0143] Figure 46 is a contour plot of the demagnetization rate of the permanent magnet in a conventional variable flux motor;

[0144] Figure 47 is a cloud map of the demagnetization rate of the permanent magnet of the motor in the thirteenth embodiment of this application.

[0145] Reference numerals: 1. Rotor core; 10. Core unit; 11. Mounting slot; 111. First mounting slot group; 112. Second mounting slot group; 12. Auxiliary slot; 13. Weight reduction hole; 2. Magnetic pole; 20-First magnetic pole; 200. First permanent magnet group; 201. First permanent magnet; 202. Composite permanent magnet; 203. Second permanent magnet; 21-Second magnetic pole; 211. Second permanent magnet group; 212. First permanent magnet group; 212. Second permanent magnet group; 213. Second permanent magnet group; 214. Second permanent magnet group; 215. Second permanent magnet group; 216. Second permanent magnet group; 217. Second permanent magnet group; 218. Second permanent magnet group; 219. Second permanent magnet group; 200. Second permanent magnet group; 201. First permanent magnet group; 202. Second 3 permanent magnets; 30 stator; 31 stator core; 4 baffle; 5 shaft; 61-first magnetic part; 611-fifth permanent magnet; 612-sixth permanent magnet; 613-first composite permanent magnet; 614-first permanent magnet unit; 62-second magnetic part; 621-seventh permanent magnet; 622-eighth permanent magnet; 623-second composite permanent magnet; 624-second permanent magnet unit. Detailed Implementation

[0146] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated 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 application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0147] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0148] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "axial", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0149] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0150] A permanent magnet variable flux motor is a type of motor that uses permanent magnets to generate a main magnetic field and can adjust the magnetic flux according to operating requirements. In such a motor design, the permanent magnets typically include low-coercivity permanent magnets. The magnetization state of low-coercivity permanent magnets is easily changed, so they are mainly used for magnetization adjustment. That is, by applying a short-duration pulse current to the armature winding of the motor, the resulting direct-axis pulse magnetic field can change the magnetization state of the low-coercivity permanent magnets, making the magnetic flux in the motor's air gap adjustable. This allows the motor to adapt to different operating conditions in a timely manner, achieving efficient operation across all operating conditions.

[0151] Normally, the magnetization state of low-coercivity permanent magnets only needs to be adjusted when magnetic adjustment is required. For operating conditions where magnetic adjustment is not required, it is not desirable for the magnetic field generated by the armature winding to change the magnetization state of the permanent magnets. Therefore, under motor load conditions, i.e., when current is flowing through the armature winding, the permanent magnets need to have load-stabilizing magnetic capability and must not exhibit unintended demagnetization.

[0152] Based on the above analysis, some embodiments of this application disclose a rotor. By improving the magnetic pole structure in the rotor, the magnetic stability capability of the magnetic poles can be enhanced, thereby improving the performance of the motor.

[0153] The rotors provided in some embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation details.

[0154] This application provides a rotor in some embodiments, including a rotor core 1 and a plurality of magnetic poles 2 spaced circumferentially along the rotor core 1. Referring to Figures 5 to 9, a schematic diagram of the rotor core 1 provided in some embodiments of this application is shown. As shown in Figure 5, the portion circled in dashed lines represents a magnetic pole 2. The plurality of magnetic poles 2 are spaced circumferentially along the rotor core 1. As shown in Figure 7, one portion circled in dashed lines represents a first magnetic pole 20, and another portion circled in dashed lines represents a second magnetic pole 21. In some embodiments of this application, the rotor core 1 is provided with eight magnetic poles 2, including four first magnetic poles and four second magnetic poles. In practical applications, the number of magnetic poles 2 can be arbitrary. The magnetic poles 2 include permanent magnets, which can generate a constant magnetic field to provide a basis for generating torque in the motor. The rotor core 1 uses magnetically conductive materials, commonly including silicon steel sheets, silicon steel sheets, amorphous & nanocrystalline alloys, iron-cobalt materials, and other magnetically conductive materials. The magnetic pole 2 includes an adjacent first magnetic pole 20 and a second magnetic pole 21, wherein the coercivity of at least one permanent magnet in the first magnetic pole 20 is different from the coercivity of the permanent magnet in the second magnetic pole 21.

[0155] For ease of understanding, Figure 7 uses a dashed arrow to indicate the center line of a magnetic pole 2, which is the direct axis (d1 axis and d2 axis) of the magnetic pole 2. Another dashed arrow indicates the axis of symmetry of two adjacent magnetic poles 2, which is the quadrature axis (q axis) of the core unit 10. Specifically, the rotor is used in a permanent magnet motor, which usually also includes a stator 3. The stator 3 is equipped with a stator winding 31. When current is applied to the stator winding 31, it generates an alternating magnetic field. This alternating magnetic field interacts with the constant magnetic field generated by the permanent magnet in the magnetic pole 2 and generates torque. In order to improve the control effect of the current in the motor, the three-phase alternating current can be decomposed into two DC components, the direct axis current and the quadrature axis current, through coordinate transformation for control. The direct axis current refers to the current component flowing through the stator winding 31 of the motor that can generate a magnetic field in the same or opposite direction as the magnetic field generated by the permanent magnet. The quadrature axis current refers to the current component in the stator winding 31 that generates a magnetic field perpendicular to the magnetic field generated by the permanent magnet. The magnetic field generated by the permanent magnet in pole 2 is a direct-axis magnetic field, and the magnetic field generated by the direct-axis current is also a direct-axis magnetic field. When the direction of the magnetic field generated by the direct-axis current is opposite to the direction of the magnetic field generated by the permanent magnet, the magnetic field generated by the direct-axis current will change the magnetization state of the permanent magnet, which may cause the permanent magnet to undergo unintended demagnetization. In addition, during actual load operation, in addition to the direct-axis magnetic field, there is also a quadrature-axis magnetic field generated by the quadrature-axis current. That is, the quadrature-axis and direct-axis magnetic fields are coupled to each other. Furthermore, the distance of the permanent magnet at different positions on pole 2 from the air gap is not equal, and the degree of influence of the magnetic field of the stator winding 31 on the permanent magnet is different, which may also cause non-uniform magnetization or demagnetization of the permanent magnet.

[0156] In some embodiments of this application, referring to Figure 8, the direction indicated by the hollow arrow is the magnetization direction of the magnetic pole 2. In a single magnetic pole 2, the magnetization direction extends approximately radially along the rotor. Referring to Figure 9, a schematic diagram of the simulation results of the magnetic field lines generated individually by the permanent magnets in adjacent first magnetic poles 20 and second magnetic poles 21 is shown. The black arrow in Figure 9 indicates the direction of the magnetic field lines of the permanent magnets in adjacent first magnetic poles 20 and second magnetic poles 21. As shown in Figures 8 and 9, the magnetic field lines generated by the permanent magnets in the first magnetic pole 20 pass through the magnetic field lines generated by the permanent magnets in the second magnetic pole 21. The permanent magnets in the first magnetic pole 20 and the second magnetic pole 21 form a series magnetic circuit. The magnetization directions of the permanent magnets in the same magnetic pole 2 are the same, while the magnetization directions of the permanent magnets in the first magnetic pole 20 and the second magnetic pole 21 are opposite. In some embodiments of this application, since the coercivity of at least one permanent magnet in the first magnetic pole 20 is different from that of the permanent magnet in the second magnetic pole 21, that is, the magnetization states of the permanent magnets in the first magnetic pole 20 and the second magnetic pole 21 are different, the magnetization state of the permanent magnet with lower coercivity is more easily changed during motor operation than that of the permanent magnet with higher coercivity. This allows the motor to adapt to different operating conditions in a timely manner, achieving efficient operation across all operating conditions. Conversely, the magnetization state of the permanent magnet with higher coercivity is less prone to change, thereby improving the overall load magnetic stability of the rotor, avoiding the risk of demagnetization, and improving the operational reliability of the motor.

[0157] In some embodiments, the first magnetic pole 20 is provided with a first permanent magnet group 200, and the second magnetic pole 21 is provided with a second permanent magnet group 211, wherein the coercivity of the first permanent magnet group 200 is less than the coercivity of the second permanent magnet group 211.

[0158] Specifically, both the first permanent magnet group 200 and the second permanent magnet group 211 include multiple permanent magnets. The coercivity of the first permanent magnet group 200 refers to the combined and superimposed coercivity of the permanent magnets in the first permanent magnet group 200, while the coercivity of the first permanent magnet 201 refers to the combined and superimposed coercivity of the permanent magnets in the second permanent magnet group 211. The coercivity of the first permanent magnet group 200 is less than that of the second permanent magnet group 211. At least one permanent magnet in the first permanent magnet group 200 is a low-coercivity permanent magnet, and at least one permanent magnet in the second permanent magnet group 211 is a high-coercivity permanent magnet. The permanent magnets in the first permanent magnet group 200 and the permanent magnets in the second permanent magnet group 211 are connected in series. In this way, since the coercivity of the first permanent magnet group 200 is less than that of the second permanent magnet group 211, the magnetization state of the permanent magnet with lower coercivity is easier to change than that of the permanent magnet with higher coercivity. The magnetization state of the permanent magnet with higher coercivity is not easily changed, thereby improving the overall load stabilization capability of the rotor, avoiding the risk of demagnetization, and improving the operational reliability of the motor.

[0159] It should be noted that during rotor rotation, both the rotor core 1 and the permanent magnets are subjected to significant centrifugal force. When the inter-pole magnetic bridge is thin, this centrifugal force may cause deformation or even breakage of the magnetic bridge, reducing the reliability of the permanent magnet motor. In this case, to prevent deformation or breakage of the magnetic bridge, the rotor speed must be reduced, leading to a decrease in motor performance. However, in some embodiments of this application, by designing the coercivity of the permanent magnets in adjacent magnetic poles 2, the goal of improving the rotor's load magnetic stability can be achieved. Therefore, in some embodiments of this application, it is not necessary to achieve the improvement of magnetic stability through the cooperation of two adjacent magnetic poles 2. The spacing between two adjacent magnetic poles 2 along the circumference of the rotor core 1 can be set to be larger, so that the inter-pole magnetic bridge of the rotor core 1 is larger, ensuring the reliability of the motor even when the motor rotates at high speed, thus improving motor performance.

[0160] In some embodiments, the first permanent magnet group 200 and the second permanent magnet group 211 are both one layer, and the coercivity of at least one permanent magnet in the first permanent magnet group 200 is less than the coercivity of the permanent magnet in the second permanent magnet group 211.

[0161] Specifically, the first permanent magnet group 200 and the second permanent magnet group 211 can be single-layered. Both the single-layered first permanent magnet group 200 and the single-layered permanent magnet group 211 can include at least one permanent magnet. The at least one permanent magnet of the single-layered first permanent magnet group 200 can be a low coercivity permanent magnet, and / or a composite permanent magnet composed of a high coercivity permanent magnet and a low coercivity permanent magnet. The at least one permanent magnet of the second permanent magnet group 211 is a high coercivity permanent magnet. In practical applications, by setting the first permanent magnet group 200 and the second permanent magnet group 211 as single-layer permanent magnets, the design of single-layer permanent magnets is relatively simple, reducing the complexity of the internal structure of the motor and making manufacturing and assembly simpler. By making the coercivity of at least one permanent magnet in the single-layer first permanent magnet group 200 less than that of the permanent magnet in the single-layer second permanent magnet group 211, the magnetization state of the permanent magnet with lower coercivity is easier to change than that of the permanent magnet with higher coercivity, while the magnetization state of the permanent magnet with higher coercivity is not easily changed. This can improve the overall load magnetic stability capability of the rotor set with single-layer permanent magnets, which is beneficial to improving the operational reliability of the single-layer motor.

[0162] It should be noted that the number of the first permanent magnet group 200 and the second permanent magnet group 211 in a single layer can be one or two, etc., and can be selected according to actual needs. This application does not make a specific limitation on this.

[0163] In some other embodiments, the first permanent magnet group 200 includes multiple layers of first permanent magnet units, which are arranged radially spaced along the rotor core 1; at least one layer of first permanent magnet unit includes at least one first permanent magnet 201 and / or at least one composite permanent magnet 202, the composite permanent magnet 202 is composed of the first permanent magnet 201 and the second permanent magnet 203, and the coercivity of the first permanent magnet 201 is less than the coercivity of the second permanent magnet 203.

[0164] Specifically, the first permanent magnet group 200 may include multiple layers of first permanent magnet units. Each first permanent magnet unit includes permanent magnets in the same layer arranged radially along the rotor core 1 in the first magnetic pole 20. Each layer of the first permanent magnet unit includes at least one permanent magnet. The permanent magnets in at least one layer of the first permanent magnet unit include at least one first permanent magnet 201 and / or at least one composite permanent magnet 202. The first permanent magnet 201 is a single, individually arranged permanent magnet, and the composite permanent magnet 202 is a combination of first permanent magnets 201 and second permanent magnets 203.

[0165] It should be noted that in some embodiments of this application, the division between the first permanent magnet 201 and the second permanent magnet 203 is based on their coercivity. Specifically, the first permanent magnet 201 is the permanent magnet with the lower coercivity among the first permanent magnet 201 and the second permanent magnet 203, and the second permanent magnet 203 is the permanent magnet with the higher coercivity among the first permanent magnet 201 and the second permanent magnet 203. The first permanent magnet 201 in the separately configured first permanent magnet 201 and the first permanent magnet 201 in the composite permanent magnet 202 can have the same or different coercivity. Since the coercivity of the first permanent magnet 201 is less than that of the second permanent magnet 203, by setting either the first permanent magnet 201 or the composite permanent magnet 202 in the first permanent magnet group 200, the arrangement of permanent magnets in the first permanent magnet group 200 becomes more flexible, and the coercivity in the first permanent magnet group 200 can be more easily adjusted according to the needs of different motors.

[0166] In practical applications, multiple first permanent magnet units are set in the first permanent magnet group 200, and each permanent magnet unit includes at least one permanent magnet. This increases the number of permanent magnets, allowing them to better fill the space of the magnetic poles 2, resulting in a more uniform magnetic flux density. Furthermore, this reduces the size of the permanent magnets. Compared to large permanent magnets, smaller permanent magnets can disperse the centrifugal force experienced during rotation, thereby improving the mechanical strength and lifespan of the motor. Smaller permanent magnets also have better heat dissipation, improving the overall thermal stability of the motor.

[0167] In some embodiments, the first permanent magnet group 200 further includes a second permanent magnet 203, wherein the second permanent magnet 203 and the first permanent magnet 201 are arranged radially spaced apart along the rotor core 1, and / or the second permanent magnet 203 and the composite permanent magnet 202 are arranged radially spaced apart along the rotor core 1.

[0168] As mentioned above, the second permanent magnet 203 is a high-coercivity permanent magnet, the first permanent magnet 201 is a low-coercivity permanent magnet, and the composite permanent magnet 202 is composed of the second permanent magnet 203 and the first permanent magnet 201. By setting the second permanent magnet 203 in the first magnetic pole 20, the magnetic stability of the first magnetic pole 20 can be improved, and the configuration flexibility of the permanent magnets in the first magnetic pole 20 can be enhanced.

[0169] In some embodiments of this application, as shown in Figures 11 and 14, the first magnetic pole 20 includes a second permanent magnet 203 and a composite permanent magnet 202. In this way, while achieving magnetic adjustment, the overall antimagnetic demagnetization performance of the first magnetic pole 20 can be further improved, avoiding irreversible demagnetization that is not designed or expected, which is beneficial to improving the operational reliability of the motor.

[0170] In some other embodiments of this application, as shown in FIG10, the first magnetic pole 20 includes a second permanent magnet 203 and a first permanent magnet 201. Compared with the method of setting a composite permanent magnet 202, since only one type of permanent magnet is set in a mounting slot, the assembly process can be simplified, thereby improving production efficiency.

[0171] It should be noted that in the multi-layer first permanent magnet unit, the combination of the first permanent magnet 201, the composite permanent magnet 202 and the second permanent magnet 203 can be selected according to the actual situation. For example, as shown in Figure 10, the first permanent magnet unit has two layers, with the first permanent magnet 201 set in one layer and the second permanent magnet 203 set in the other layer. As shown in Figure 11, the composite permanent magnet 202 is set in one layer and the second permanent magnet 203 is set in the other layer.

[0172] Furthermore, the first permanent magnet assembly 200 includes a first permanent magnet 201 and a second permanent magnet 203, the second permanent magnet 203 being adapted to be arranged close to the gap between the rotor and the stator 3.

[0173] As before, the second permanent magnet 203 is a high coercivity permanent magnet. The second permanent magnet 203 is arranged close to the gap between the rotor and the stator 3, as shown in Figures 10-13 and 15-16. The gap between the rotor and the stator 3 forms the air gap of the rotor. This arrangement can reduce the risk of demagnetization of the permanent magnet unit near the air gap side and ensure the reliability and operating efficiency of the permanent magnet motor.

[0174] The gap between the rotor and stator 3 forms the rotor's air gap. This arrangement reduces the risk of demagnetization of the first permanent magnet unit near the air gap, ensuring the reliability and operating efficiency of the permanent magnet motor. It should be noted that, as shown in Figures 10 to 16, the gap formed between the radially outer side of the rotor and the radially inner side of the stator 3 is the motor's air gap. Near this air gap, the permanent magnet is not only subjected to a strong magnetic field from the stator winding 31, but may also experience additional stress due to mechanical vibration and temperature changes during motor operation. These factors combined make the permanent magnet near the air gap more prone to demagnetization. Therefore, placing the second permanent magnet 203, with greater coercivity, near the air gap reduces the risk of demagnetization of the permanent magnet near the air gap, minimizing unintended or unplanned irreversible demagnetization and ensuring the reliability and operating efficiency of the motor.

[0175] Furthermore, the first permanent magnet group 200 includes a composite permanent magnet 202 and a second permanent magnet 203. The composite permanent magnet 202 is disposed on the radial outer side of the rotor core 1, or the composite permanent magnet 202 is disposed on the radial inner side of the rotor core 1.

[0176] Specifically, as shown in Figure 11, in the first permanent magnet group 200, the composite permanent magnet 202 can be set on the radial inner side of the rotor core 1. As shown in Figure 14, the composite permanent magnet 202 can also be set on the radial outer side of the rotor core 1. In practical applications, by flexibly setting the setting position of the first magnetic pole 20 of the composite permanent magnet 202, the flexibility is higher, the applicability is wider, and the application scenarios of the rotor are enriched.

[0177] In some embodiments, the composite permanent magnet 202 forms a series magnetic circuit structure, or the composite permanent magnet 202 forms a parallel magnetic circuit structure.

[0178] As shown in Figure 11, the first permanent magnet 201 and the second permanent magnet 203 in the composite permanent magnet 202 are alternately arranged along the radial direction of the rotor core 1, that is, the first permanent magnet 201 and the second permanent magnet 203 are arranged along the magnetization direction to form a series magnetic circuit structure.

[0179] In other embodiments of this application, the first permanent magnet 201 and the second permanent magnet 203 in the composite permanent magnet 202 are alternately arranged along the circumference of the rotor core 1, that is, the first permanent magnet 201 and the second permanent magnet 203 are arranged approximately perpendicular to the magnetization direction to form a parallel magnetic circuit structure.

[0180] As described above, some embodiments of this application provide multiple arrangement methods for the composite permanent magnet 202, which are more flexible, have wider applicability, and enrich the application scenarios of the rotor.

[0181] In some embodiments, the first permanent magnet group 200 further includes a second permanent magnet 203, wherein the second permanent magnet 203 and the first permanent magnet 201 are arranged circumferentially apart along the rotor core 1, and / or the second permanent magnet 203 and the composite permanent magnet 202 are arranged circumferentially apart along the rotor core 1.

[0182] In order to ensure the improvement of the magnetic stability of the first magnetic pole 20, a second permanent magnet 203 with higher coercivity can be set in the first magnetic pole 20. Since the first magnetic pole 20 can be set with a first permanent magnet 201, a second permanent magnet 203 or a composite permanent magnet 202, and the second permanent magnet 203 and the first permanent magnet 201 are arranged circumferentially to the rotor core 1, and / or the second permanent magnet 203 and the composite permanent magnet 202 are arranged circumferentially to the rotor core 1, the arrangement flexibility of the permanent magnets in the first magnetic pole 20 can be improved, and the adjustment of the coercivity after their superposition is also more flexible.

[0183] The first permanent magnet group 200 also includes a plurality of second permanent magnets 203. The second permanent magnets 203 and the first permanent magnets 201 are arranged at intervals along the radial and circumferential directions of the rotor core 1, and / or the second permanent magnets 203 and the composite permanent magnets 202 are arranged at intervals along the radial and circumferential directions of the rotor core 1. This improves the flexibility of the permanent magnet arrangement. Specifically, a first permanent magnet unit may include second permanent magnets 203 and first permanent magnets 201, or second permanent magnets 203 and composite permanent magnets 202, or simultaneously include second permanent magnets 203, first permanent magnets 201 and composite permanent magnets 202, wherein the first permanent magnets 201, second permanent magnets 203 and composite permanent magnets 202 are arranged at intervals along the circumferential direction of the rotor core 1.

[0184] Furthermore, the first permanent magnet 201 and the second permanent magnet 203 in the composite permanent magnet 202 are arranged sequentially along the radial direction of the rotor core 1, thus forming a series magnetic circuit structure. The first permanent magnet 201 is suitable for being arranged away from the air gap between the rotor and the stator 3, and the second permanent magnet 203 is suitable for being arranged close to the air gap.

[0185] As mentioned above, the first permanent magnet 201 is a low-coercivity permanent magnet, and the second permanent magnet 203 is a high-coercivity permanent magnet. In the motor, there is an air gap between the stator 3 and the rotor. Near the air gap, the permanent magnet is not only subjected to a strong magnetic field from the stator winding 31, but may also bear additional stress due to mechanical vibration and temperature changes during motor operation. These factors combined make the permanent magnet near the air gap more prone to demagnetization. In some embodiments of this application, by placing the second permanent magnet 203 in the composite permanent magnet 202 on the side near the air gap, the high-coercivity permanent magnet can effectively resist magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations, and other factors during motor operation. This allows the motor to maintain a stable magnetic field output even under harsh operating conditions, extending the motor's service life and reliability.

[0186] Furthermore, in some embodiments, the first permanent magnet group 200 includes a second permanent magnet 203 and a composite permanent magnet 202. The second permanent magnet 203 is disposed near the air gap side, and the second permanent magnet 203 in the composite permanent magnet 202 is also disposed near the air gap side. Compared with the scheme in which the first permanent magnet group 200 includes a second permanent magnet 203 and a first permanent magnet 201, it can further effectively resist magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations and other factors during motor operation, so that the motor can maintain a stable magnetic field output even under harsh working conditions, thus extending the service life and reliability of the motor.

[0187] In some embodiments, the second permanent magnet group 211 includes multiple layers of second permanent magnet units, which are arranged radially spaced along the rotor core 1, and each layer of second permanent magnet units includes at least one third permanent magnet 212.

[0188] Specifically, the second permanent magnet unit includes a third permanent magnet 212 located in the same radial layer of the rotor core, as shown in Figures 8 and 9. The multi-layered first and second permanent magnet units are arranged radially along the rotor core 1. Specifically, the corresponding first permanent magnet 201 and / or composite permanent magnet 202 are arranged with the second permanent magnet 203 along the magnetization direction, forming a series magnetic circuit structure. Multiple third permanent magnets 212 are arranged along the magnetization direction, forming a series magnetic circuit structure for the multi-layered second permanent magnet units. Furthermore, as mentioned earlier, the first permanent magnet unit also forms a series magnetic circuit with the second permanent magnet unit. In other words, in some embodiments of this application, the series magnetic circuit includes two types: one is a first series magnetic circuit formed by a low-coercivity first permanent magnet 201 or a composite permanent magnet 202 and a high-coercivity second permanent magnet 203 under the same magnetic pole 2 but in different layers; the other is a second series magnetic circuit formed by the low-coercivity first permanent magnet 201 or a composite permanent magnet 202 and multiple layers of high-coercivity third permanent magnets 212 in the second permanent magnet unit under its adjacent magnetic pole 2. In this way, the two series magnetic circuits, with high-coercivity permanent magnets and low-coercivity permanent magnets connected in series, improve the operating point and uniformity of the low-coercivity permanent magnets; under load, if the magnetic flux generated by the stator winding 31 passes through the low-coercivity permanent magnets, it must pass through the remaining high-coercivity permanent magnets, so that all permanent magnets have strong magnetic stability capabilities, further improving the stability and controllability of the rotor magnetic field, enabling the motor to maintain excellent performance under various operating conditions and improving the reliability of the motor.

[0189] In practical applications, by setting multiple second permanent magnet units in the second permanent magnet group 211, each permanent magnet unit includes at least one permanent magnet, the number of permanent magnets is further increased, so that multiple permanent magnets can better fill the space of the magnetic pole 2, making the magnetic flux density more uniform.

[0190] Furthermore, the coercivity of the third permanent magnet 212 is greater than or equal to the coercivity of the second permanent magnet 203.

[0191] As mentioned earlier, the second permanent magnet 203 is a high-coercivity permanent magnet, and the coercivity of the third permanent magnet 212 is greater than or equal to that of the second permanent magnet 203, meaning the third permanent magnet 212 is also a high-coercivity permanent magnet. As shown in Figures 8 and 9, the multi-layer first permanent magnet unit and the multi-layer second permanent magnet unit are arranged radially along the rotor core 1. The first permanent magnet 201 and / or the composite permanent magnet 202 are arranged along the magnetization direction, and the multiple third permanent magnets 212 are also arranged along the magnetization direction. The magnetic lines of force of the first permanent magnet 201 and / or the composite permanent magnet 202 in the first permanent magnet group 200 pass through the multi-layer third permanent magnets 212 in the second permanent magnet group 211, forming a series magnetic circuit structure. In practical applications, since the third permanent magnet 212 is a high-coercivity permanent magnet, the multi-layer third permanent magnets 212 can further improve the rotor's magnetic stability, thereby improving the reliability of the motor.

[0192] Furthermore, the permanent magnets in each layer of the second permanent magnet unit are all third permanent magnets 212.

[0193] As mentioned above, the third permanent magnet is a high coercivity permanent magnet. As shown in Figures 10-16, the permanent magnets in each layer of the second permanent magnet unit are all high coercivity permanent magnets. This can increase the number of high coercivity permanent magnets in the second magnetic pole 21, thereby avoiding the reduction in the magnetic stability of the first magnetic pole 20 caused by the fact that various types of permanent magnets, such as permanent magnets in parallel magnetic circuits, can be set in the first magnetic pole 20. This further improves the magnetic stability of the rotor and enhances the reliability of the motor.

[0194] In some embodiments, the first permanent magnet group 200 has a first magnetic pole centerline, the second permanent magnet group 211 has a second magnetic pole centerline, the first permanent magnet group 200 is symmetrical about the first magnetic pole centerline, and the second permanent magnet group 211 is symmetrical about the second magnetic pole centerline.

[0195] Specifically, as shown in Figure 7, the dashed lines represent the first magnetic pole center line d1 and the second magnetic pole line d2. The permanent magnets in each layer of the first permanent magnet group 200 are symmetrical about the first magnetic pole center line, and the permanent magnets in each layer of the second permanent magnet group 211 are also symmetrically arranged about the magnetic pole center line. This symmetrical arrangement of permanent magnets generates a more uniform magnetic field distribution. Because the magnetic field lines are uniformly distributed on both sides of the magnetic pole center line, this helps reduce the non-uniformity of magnetic flux, thereby reducing electromagnetic noise and vibration. Furthermore, a uniform magnetic field distribution means that the motor can utilize magnetic energy more effectively during operation, reducing energy loss. This helps improve the overall efficiency of the motor, enabling it to maintain high performance under various operating conditions.

[0196] In some embodiments, the magnetic pole 2 includes at least one permanent magnet, wherein the permanent magnet is at least one selected from ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets. The permanent magnet may include, but is not limited to, ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets, etc., and those skilled in the art can flexibly combine them according to actual needs. In practical applications, the difference in coercivity of each permanent magnet can be achieved by using permanent magnets of the same material but different grades, or by using permanent magnets of different materials. In practical applications, those skilled in the art can flexibly design and combine them according to the level of coercivity.

[0197] In some embodiments, the first magnetic pole 20 and the second magnetic pole 21 are alternately arranged along the circumference of the rotor core 1, and the magnetic pole 2 of the first magnetic pole 20 is one of the positive pole and the negative pole, and the magnetic pole 2 of the second magnetic pole 21 is the other of the positive pole and the negative pole.

[0198] Specifically, the first magnetic pole 20 and the second magnetic pole 21 are spaced apart circumferentially along the rotor core 1. The magnetic pole 2 corresponding to the first magnetic pole 20 is one of the positive (N) pole and the negative (S) pole, and the magnetic pole 21 is the other of the positive (N) pole and the negative (S) pole. That is, by making the permanent magnets in adjacent magnetic poles 2 have opposite magnetic poles, an alternating pole structure is formed. Compared with traditional permanent magnet motors, this design can effectively reduce the amount of permanent magnet material used while maintaining the integrity of the magnetic circuit, significantly reducing manufacturing costs. Furthermore, by making the coercivity of the permanent magnets in the first magnetic pole 20 and the second magnetic pole 21 in the alternating poles different, the magnetic stability of the rotor in the alternating pole motor is improved, thereby improving the operational reliability of the alternating pole motor.

[0199] In some embodiments, the rotor core 1 is provided with at least one mounting groove 11, and the magnetic pole 2 includes at least one first permanent magnet 201, at least one second permanent magnet 203 and / or at least one composite permanent magnet 202. The mounting groove 11 is used to place the first permanent magnet 201 or the second permanent magnet 203 or the composite permanent magnet 202.

[0200] Specifically, the mounting slot 11 is set on the rotor core 1 and can extend along the circumference and axial direction of the rotor core 1. The permanent magnets in the magnetic pole 2 can be placed in the mounting slot 11. In practical applications, the mounting slot 11 can accurately set the position and direction of the permanent magnets, ensuring that each permanent magnet is installed in the optimal design position, improving the consistency of the magnetic circuit and the overall performance of the motor, and reducing the problem of uneven magnetic field caused by installation errors.

[0201] The rotor core 1 has multiple mounting slots 11, each containing at least one permanent magnet. As shown in Figures 7-16, the mounting slots 11 are arranged circumferentially around the rotor core 1 and can form preset shapes, including one or more of the following: straight, arc, V, U, and W shapes. This allows the permanent magnets in the mounting slots 11 to also be positioned in preset shapes within the magnetic poles 2. In practical applications, different shapes of mounting slots 11 can guide the magnetic field generated by the permanent magnets to be distributed as needed. For example, arc-shaped slots can conform to the circular motion path inside the motor, optimizing the continuity of the rotating magnetic field, while V-shaped or U-shaped slots can concentrate magnetic field lines, enhance local magnetic flux density, and improve the output torque and efficiency of the motor. Furthermore, slots of various shapes can adapt to the needs of different motor designs. For instance, straight slots are suitable for linear motors or motors with simplified structures, while W-shaped slots may be used in advanced motor designs requiring complex magnetic field control. This flexibility allows motor designs to better fit actual application scenarios.

[0202] The following examples illustrate several embodiments provided in this application:

[0203] Example 1:

[0204] As shown in Figure 10, the mounting slots 11 for the permanent magnets are in the form of a "double V": "outer small V + inner large V". In the mounting slots 11 corresponding to the first permanent magnet group 200, both mounting slots 11 of the outer large V are equipped with a first permanent magnet 201 with low coercivity, and both mounting slots 11 of the small V are equipped with a second permanent magnet 203 with high coercivity. In the mounting slots 11 corresponding to the second permanent magnet group 211, both the mounting slots 11 of the outer small V and the inner large V are equipped with a third permanent magnet 212 with high coercivity.

[0205] Example 2:

[0206] As shown in Figure 11, the mounting slots 11 for the permanent magnets are in the form of a "double V": "outer small V + inner large V". In the mounting slots 11 corresponding to the first permanent magnet group 200, both large V slots 11 are equipped with composite permanent magnets 202. The composite permanent magnets 202 are a series magnetic circuit structure formed by a high-coercivity second permanent magnet 203 and a low-coercivity first permanent magnet 201 along the radial direction of the rotor core 1. Each of the two small V slots 11 is equipped with a high-coercivity second permanent magnet 203. In the mounting slots 11 corresponding to the second permanent magnet group 211, both the outer small V and inner large V slots 11 are equipped with high-coercivity third permanent magnets 212.

[0207] Example 3:

[0208] As shown in Figure 12, the mounting slots 11 for the permanent magnets are in the form of a "one + V" configuration: an outer "one" groove and an inner "V" groove. In the mounting slots 11 corresponding to the first permanent magnet group 200, a second permanent magnet 203 with high coercivity is installed in one of the "one" grooves, while a first permanent magnet 201 with low coercivity is installed in each of the two "V" grooves. In the mounting slots 11 corresponding to the second permanent magnet group 211, a third permanent magnet 212 with high coercivity is installed in both the outer "one" groove and the inner "V" groove.

[0209] Example 4:

[0210] As shown in Figure 13, the permanent magnet mounting slot 11 is in the form of a "one + V": "outer layer discrete one-line + inner layer large V". In the mounting slot 11 corresponding to the first permanent magnet group 200, a second permanent magnet 203 with high coercivity is set in the two mounting slots 11 of the one-line, and a first permanent magnet 201 with low coercivity is set in each of the two mounting slots 11 of the large V. In the mounting slot 11 corresponding to the second permanent magnet group 211, a third permanent magnet 212 with high coercivity is set in the mounting slots 11 of both the outer discrete one-line and the inner large V.

[0211] Example 5:

[0212] As shown in Figure 14, the permanent magnet mounting slot 11 is in the form of a "one + V" configuration: "outer layer one-line + inner layer large V". In the mounting slot 11 corresponding to the first permanent magnet group 200, a composite permanent magnet 202 is installed in the one-line mounting slot 11. The composite permanent magnet 202 is a series magnetic circuit structure formed by a high-coercivity second permanent magnet 203 and a low-coercivity first permanent magnet 201 along the radial direction of the rotor core 1. A high-coercivity second permanent magnet 203 is installed in each of the two large V mounting slots 11. In the mounting slot 11 corresponding to the second permanent magnet group 211, a high-coercivity third permanent magnet 212 is installed in both the outer one-line and inner large V mounting slots 11.

[0213] Example 6:

[0214] As shown in Figure 15, the permanent magnet mounting slot 11 is in the form of "I+V+U": "outer layer I-shaped + middle layer small V-shaped + inner layer large U-shaped". In the mounting slot 11 corresponding to the first permanent magnet group 200, a second permanent magnet 203 with high coercivity is set in the I-shaped and V-shaped mounting slots 11, and a first permanent magnet 201 with low coercivity is set in each of the three mounting slots 11 of the large U-shaped slot. In the mounting slot 11 corresponding to the second permanent magnet group 211, a third permanent magnet 212 with high coercivity is set in the mounting slots 11 of the outer I-shaped, middle small V-shaped, and inner large U-shaped slots.

[0215] Example 7:

[0216] As shown in Figure 16, the permanent magnet mounting slot 11 is in the form of "I+V+U"+"I+U": In the mounting slot 11 corresponding to the first permanent magnet group 200, a second permanent magnet 203 with high coercivity is set in the I-shaped and V-shaped mounting slots 11, and a first permanent magnet 201 with low coercivity is set in each of the three mounting slots 11 of the large U. In the mounting slot 11 corresponding to the second permanent magnet group 211, a third permanent magnet 212 with high coercivity is set in the outer I-shaped and inner large U-shaped mounting slots 11.

[0217] It should be noted that the above embodiments are merely examples. In actual applications, the arrangement of permanent magnets may not be limited to the above embodiments. Technicians may design them according to actual needs, and this application does not impose any specific limitations on them.

[0218] Furthermore, as in Embodiments 1 to 5, the permanent magnet includes two layers that are generally distributed radially along the rotor core 1; as in Embodiment 6, the permanent magnet includes three layers that are generally distributed radially along the rotor core 1; and as in Embodiment 7, the permanent magnet includes both three layers that are generally distributed radially along the rotor core 1 and two layers that are generally distributed radially along the rotor core 1. This application does not specifically limit these aspects.

[0219] In some embodiments, the magnetic pole 2 further includes at least one auxiliary slot 12, and the rotor core 1 has a peripheral wall, on which the auxiliary slot 12 is disposed.

[0220] Specifically, the rotor core 1 has a peripheral wall, and auxiliary slots 12 are disposed on the peripheral wall. Each magnetic pole 2 is provided with an auxiliary slot 12. The auxiliary slots 12 are recessed inward in the radial direction of the rotor core 1 and extend in the axial direction. The auxiliary slots 12 help to achieve the mass balance of the rotor core 1, adjust the rotor's center of gravity, reduce harmonics and losses during rotation, and address NVH (Noise, Vibration and Harshness) issues, thereby improving the smoothness and lifespan of the motor operation. Furthermore, there can be multiple auxiliary slots 12, which are distributed at intervals along the circumference of the rotor core 1, further reducing harmonics and losses during rotation and addressing NVH issues.

[0221] In addition, the rotor core 1 is provided with multiple weight-reducing holes 13, which are arranged axially and circumferentially along the rotor core 1. This application does not specifically limit the shape, position, or number of the weight-reducing holes 13. The weight-reducing holes 13 can reduce the overall mass of the rotor core 1, thereby reducing inertia and enabling the rotor to respond to control signals more quickly, improving the dynamic performance of the motor. The reduced mass of the rotor core 1 also reduces the weight of the motor, which is beneficial for motor lightweighting and miniaturization. Furthermore, due to the reduced mass, the heat generated by the motor during operation is also reduced accordingly, helping to lower the motor's temperature rise and extend its service life.

[0222] In some embodiments, the rotor core 1 includes a plurality of core units 10, which are arranged sequentially along the axial direction of the rotor core 1.

[0223] In some embodiments of this application, by setting multiple core units 10, the rotor core 1 can be designed in segments, which can not only reduce magnetic leakage loss and improve motor efficiency, but also reduce processing difficulty and improve production efficiency.

[0224] In some embodiments, there is an offset angle between two adjacent core units 10 along the circumference of the rotor core 1, wherein the magnetic poles 2 on the two adjacent core units 10 are arranged in the same way, and / or the magnetic poles 2 on the two adjacent core units 10 are arranged in different ways.

[0225] Specifically, as shown in Figure 3, a schematic diagram of a skewed-pole rotor provided in some embodiments of this application is illustrated. Two adjacent core units 10 are offset along the axial direction, meaning the rotor core 1 has a skewed-pole structure. This skewed-pole structure allows the rotor core 1 to alter the distribution of the air gap magnetic field, making the magnetic field more spatially uniform or distributed according to specific requirements. When the skew angle is different, the distribution of the air gap magnetic flux density also changes significantly. Furthermore, the skewed-pole structure also has higher starting torque, lower vibration and noise levels, and can withstand greater loads and maintain more stable speeds.

[0226] The arrangement of magnetic poles 2 in two adjacent core units 10 refers to the arrangement of permanent magnets in magnetic poles 2. This arrangement can be the same or different, and can be flexibly set according to actual needs. This application does not make specific limitations on this.

[0227] In some other embodiments of this application, as shown in FIG4, a schematic diagram of a direct-pole rotor provided in some embodiments of this application is illustrated. Two adjacent core units 10 have an axial offset angle of 0°, meaning the rotor core 1 is a direct-pole structure. The direct-pole rotor core 1 has a relatively simple structural design, and the magnetic poles 2 of each rotor unit are tightly fitted, resulting in a uniform distribution of the air gap magnetic field along the motor axial direction. In summary, the rotor provided in some embodiments of this application has at least the following advantages:

[0228] In some embodiments of this application, since the coercivity of at least one permanent magnet in the first magnetic pole 20 is different from that of the permanent magnet in the second magnetic pole 21, that is, the magnetization states of the permanent magnets in the first magnetic pole 20 and the second magnetic pole 21 are different, the magnetization state of the permanent magnet with lower coercivity is more easily changed during motor operation than that of the permanent magnet with higher coercivity. This allows the motor to adapt to different operating conditions in a timely manner, achieving efficient operation across all operating conditions. Conversely, the magnetization state of the permanent magnet with higher coercivity is less prone to change, thereby improving the overall load magnetic stability of the rotor, avoiding the risk of demagnetization, and improving the operational reliability of the motor. Some embodiments of this application provide another rotor. Referring to Figures 6 and 17, a structural schematic diagram of the core unit 10 provided in some embodiments of this application is shown. The rotor includes: a rotor core 1 and a plurality of magnetic poles 2 distributed circumferentially along the rotor core 1. The magnetic poles 2 include at least one composite permanent magnet 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 and a second permanent magnet 203 with different coercivity.

[0229] Specifically, referring to Figure 24, which shows schematic diagrams of the direct and quadrature axes of the permanent magnets of the motor in some embodiments of this application; for ease of understanding, a dashed arrow in Figure 24 indicates the center line of a magnetic pole 2, that is, the direct axis (d-axis) of the magnetic pole 2, and another dashed arrow indicates the axis of symmetry of two adjacent magnetic poles 2, that is, the quadrature axis (q-axis) of the core unit 10. The direction of the hollow arrow in Figure 24 is the magnetization direction of the composite permanent magnet 202. In a single magnetic pole 2, the magnetization direction extends approximately radially along the rotor. Referring to Figure 25, which shows schematic diagrams of the magnetic field lines of the direct axis current of the motor in some embodiments of this application; multiple black arrows in Figure 25 indicate the direction of the magnetic field lines generated by the d-axis current in the stator winding 31. Referring to Figure 16, which shows schematic diagrams of the magnetic field lines of the quadrature axis current in the stator winding 31 in some embodiments of this application; multiple black arrows in Figure 26 indicate the direction of the magnetic field lines generated by the q-axis current in the stator winding 31. Figure 27 shows a schematic diagram of the simulation results of the magnetic field lines generated by the permanent magnet in the magnetic pole alone. Figure 28 shows a schematic diagram of the simulation results of the magnetic field lines generated by the q-axis current in the stator winding 31 alone. Figure 29 shows a schematic diagram of the simulation results of the magnetic field lines generated by the d-axis current in the stator winding 31 alone.

[0230] During the operation of the motor under load, an alternating current is passed through the stator winding 31 of the permanent magnet motor. Taking a three-phase motor as an example, the A / B / C three-phase windings will be circulated with an alternating current that is 120 electrical degrees out of phase. This alternating current will generate an alternating magnetic field. This alternating magnetic field interacts with the constant magnetic field generated by the permanent magnet and generates torque. In order to improve the control effect of the current in the motor, the three-phase alternating current is decomposed into two DC components, the direct-axis current and the quadrature-axis current, through coordinate transformation for control. The direct-axis current refers to the current component that flows through the stator winding 31 of the motor and can generate a magnetic field in the same or opposite direction as the magnetic field generated by the permanent magnet. The quadrature-axis current refers to the current component that generates a magnetic field in the stator winding 31 that is perpendicular to the magnetic field generated by the permanent magnet. The magnetic field generated by the permanent magnet in magnetic pole 2 is a direct-axis magnetic field (as shown in Figure 27), and the magnetic field generated by the direct-axis current is also a direct-axis magnetic field (as shown in Figure 29). When the direction of the magnetic field generated by the direct-axis current (as shown in Figure 29) is opposite to the direction of the magnetic field generated by the permanent magnet (as shown in Figure 27), the magnetic field generated by the direct-axis current will change the magnetization state of the permanent magnet, which may cause the permanent magnet to undergo unintended demagnetization. In addition, as shown in Figures 26 and 28, in actual load operation, in addition to the direct-axis magnetic field, there is also a quadrature-axis magnetic field generated by the quadrature-axis current (as shown in Figure 28). That is, the quadrature-axis and direct-axis magnetic fields are coupled to each other, and the distance of the permanent magnet at different positions on magnetic pole 2 from the air gap is not equal. The degree of influence of the magnetic field of the stator winding 31 on the permanent magnet is different, which may also cause the permanent magnet to undergo non-uniform magnetization or demagnetization.

[0231] Specifically, the rotor core 1 uses magnetically conductive materials, commonly including silicon steel sheets, silicon steel sheets, amorphous & nanocrystalline alloys, iron-cobalt materials, and other magnetically conductive materials.

[0232] As shown in Figure 17, the part circled by the dashed circle is a magnetic pole 2. Multiple magnetic poles 2 are arranged circumferentially on the rotor core 1. Each magnetic pole 2 includes at least one composite permanent magnet 202. The composite permanent magnet 202 is arranged inside the rotor core 1. As shown in Figure 24, the first permanent magnet 201 and the second permanent magnet 203 in the composite permanent magnet 202 are arranged sequentially along the magnetization direction to form a series magnetic circuit. The magnetization direction of the composite permanent magnet 202 in the same magnetic pole 2 is the same, and the magnetization direction of the composite permanent magnet 202 in two adjacent magnetic poles 2 is opposite.

[0233] The magnetic pole 2 includes at least one composite permanent magnet 202. The composite permanent magnet 202 is formed by connecting two first permanent magnets 201 and second permanent magnets 203 with different coercivities in series along the magnetization direction. Different coercivities mean that the coercivity of the first permanent magnet 201 is greater than that of the second permanent magnet 203, or vice versa. In some embodiments of this application, since the permanent magnet of the magnetic pole 2 includes the composite permanent magnet 202, which includes first permanent magnets 201 and second permanent magnets 203 with different coercivities, the magnetization states of the first permanent magnets 201 and second permanent magnets 203 are different. Thus, during the operation of the motor, the magnetization state of the permanent magnet with lower coercivity is easily changed, thereby achieving adjustment of the air gap flux. At the same time, the magnetization state of permanent magnets with high coercivity is not easily changed, which improves the magnetic stability of composite permanent magnet 202, thereby improving the overall magnetic stability of magnetic pole 2, avoiding demagnetization phenomena that are not designed, and helping to improve the operational reliability of the motor.

[0234] In some embodiments, the first permanent magnet 201 and the second permanent magnet 203 are arranged sequentially along the radial direction of the rotor core 1.

[0235] Specifically, the magnetization direction extends roughly along the radial direction of the rotor core 1. The first permanent magnet 201 and the second permanent magnet 203 have the same magnetization direction. The first permanent magnet 201 and the second permanent magnet 203 are sequentially attached in the radial direction, so that the first permanent magnet 201 and the second permanent magnet 203 are connected in series to form a series magnetic circuit. In some embodiments of this application, since the composite permanent magnet 202 is composed of two types of permanent magnets in the magnetization direction, compared with a single type of coercive force solid permanent magnet, it can cut off the permanent magnet eddy current path, thereby reducing magnetic field loss and temperature, and further increasing the output capacity and efficiency of the motor.

[0236] In some embodiments, the coercivity of the first permanent magnet 201 is greater than that of the second permanent magnet 203. The first permanent magnet 201 is adapted to be arranged close to the air gap between the rotor and the stator 3, and the second permanent magnet 203 is adapted to be arranged away from the air gap.

[0237] Specifically, the first permanent magnet 201 is a high coercivity permanent magnet, and the second permanent magnet 203 is a low coercivity permanent magnet. The first permanent magnet 201 is located on the outer side near the air gap, and the second permanent magnet 203 is located on the inner side away from the rotor core 1.

[0238] It should be noted that in the motor, there is an air gap between the stator 3 and the rotor. Near this air gap, the permanent magnet is not only subjected to a strong magnetic field from the stator winding 31, but may also experience additional stress due to mechanical vibrations and temperature changes during motor operation. These factors combined make the permanent magnet near the air gap more prone to demagnetization. In this embodiment, by placing the first permanent magnet 201 in the composite permanent magnet 202 near the air gap, the high-coercivity permanent magnet can effectively resist magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations, and other factors during motor operation. This allows the motor to maintain a stable magnetic field output even under harsh operating conditions, extending the motor's service life and reliability. The low-coercivity permanent magnet is located away from the air gap, and its magnetization state is relatively easy to change. This facilitates dynamic flux adjustment of the motor under different load conditions, thereby maximizing energy efficiency.

[0239] In some embodiments, the thickness of the first permanent magnet 201 along the radial direction of the rotor core 1 accounts for 0.05-0.9% of the thickness of the composite permanent magnet 202 along the radial direction.

[0240] Specifically, the radial thickness of the composite permanent magnet 202 is the sum of the radial thicknesses of the first permanent magnet 201 and the second permanent magnet 203. The first permanent magnet 201 is a high-coercivity permanent magnet, and the second permanent magnet 203 is a low-coercivity permanent magnet. By adjusting the thickness ratio of the high-coercivity permanent magnet, the magnetic field distribution inside the motor can be finely adjusted, ensuring that sufficient excitation magnetic field is provided while maintaining good flux regulation capability. The ratio range of 0.05-0.9 gives designers high flexibility to balance the magnetic stability characteristics of the high-coercivity permanent magnet and the dynamic adjustment capability of the low-coercivity permanent magnet according to the needs of different application scenarios. A thinner first permanent magnet 201 (close to 0.05) can make the motor more responsive under rapidly changing operating conditions, while a ratio close to 0.9 can improve the stability and durability of the motor in harsh environments.

[0241] In some embodiments, the magnetic pole 2 further includes a first permanent magnet 201 and / or a second permanent magnet 203, wherein the first permanent magnet 201 and the composite permanent magnet 202 are arranged along the radial direction of the rotor core 1, and / or the second permanent magnet 203 and the composite permanent magnet 202 are arranged sequentially along the radial direction of the rotor core 1.

[0242] It should be noted that in some embodiments of this application, the division between the first permanent magnet 201 and the second permanent magnet 203 is based on their coercivity. That is, the first permanent magnet 201 is the permanent magnet with higher coercivity among the first permanent magnet 201 and the second permanent magnet 203, and the second permanent magnet 203 is the permanent magnet with lower coercivity among the first permanent magnet 201 and the second permanent magnet 203. The first permanent magnet 201 alone and the first permanent magnet 201 in the composite permanent magnet 202 can have the same or different coercivity. Similarly, the second permanent magnet 203 alone and the second permanent magnet 203 in the composite permanent magnet 202 can have the same or different coercivity. For example, as shown in FIG3, the magnetic pole 2 can be provided with a composite permanent magnet 202 and a second permanent magnet 203. The composite permanent magnet 202, the first permanent magnet 201 and / or the second permanent magnet 203 form a series magnetic circuit structure in the radial direction of the rotor core 1.

[0243] It should be noted that the radial arrangement of the first permanent magnet 201 and / or the second permanent magnet 203, as well as the composite permanent magnet 202, can be specifically set according to actual needs. In some embodiments, the high coercivity first permanent magnet 201 is arranged on the side near the air gap between the rotor and the stator 3, and the first permanent magnet 201 in the composite permanent magnet 202 is also arranged on the side near the air gap. In this way, the multi-layer high coercivity permanent magnets can further effectively resist magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations, and other factors during motor operation, so that the motor can maintain a stable magnetic field output even under harsh operating conditions, extending the service life and reliability of the motor. In practical applications, since the coercivity of the first permanent magnet 201 is greater than that of the second permanent magnet 203, by setting the first permanent magnet 201 and / or the second permanent magnet 203, as well as the composite permanent magnet 202 in the magnetic pole 2, the arrangement of permanent magnets in the magnetic pole 2 becomes more flexible, and the coercivity in the magnetic pole 2 can be more easily adjusted according to the needs of different motors.

[0244] In some embodiments of this application, as shown in FIG23, the magnetic pole 2 includes a second permanent magnet 203 and a composite permanent magnet 202. In this way, while achieving magnetic adjustment, the overall anti-magnetic demagnetization performance of the magnetic pole can be further improved, avoiding irreversible demagnetization that is not designed or expected, which is beneficial to improving the operational reliability of the motor.

[0245] In some embodiments of this application, the magnetic pole 2 includes a first permanent magnet 201 and a composite permanent magnet 202. In this way, when the coercivity of the composite permanent magnet 202 is low, the coercivity of the magnetic pole 2 can be increased by the first permanent magnet, thereby improving the magnetic stability of the magnetic pole 2 and increasing the flexibility of the permanent magnet in the magnetic pole 2.

[0246] In some embodiments of this application, the magnetic pole 2 includes a first permanent magnet 201, a second permanent magnet 203, and a composite permanent magnet 202. This allows for a more flexible arrangement of the permanent magnets in the magnetic pole 2, and the coercivity in the magnetic pole 2 can be more easily adjusted according to the needs of different motors.

[0247] In some embodiments, the magnetic pole 2 includes a multilayer permanent magnet assembly arranged in the radial direction of the rotor core 1, and at least one layer of the permanent magnet assembly includes at least one composite permanent magnet 202.

[0248] In practical applications, multiple layers of permanent magnet groups are set in the magnetic pole 2. Each permanent magnet group includes at least one composite permanent magnet 202. This increases the number of permanent magnets, allowing multiple permanent magnets to better fill the space of the magnetic pole, resulting in a more uniform magnetic flux density. Furthermore, this reduces the size of the permanent magnets. Compared to large permanent magnets, smaller permanent magnets can disperse the centrifugal force experienced during rotation, thereby improving the mechanical strength and lifespan of the motor. Smaller permanent magnets also have better heat dissipation, improving the overall thermal stability of the motor. By setting at least one layer of composite permanent magnets 202, regions with different magnetization states can be created within the permanent magnet group. The second permanent magnet 203 in the composite permanent magnet 202, whose magnetization state is easily changed, can achieve magnetization adjustment, while the first permanent magnet 201 in the composite permanent magnet 202, whose magnetization state is not easily changed, can achieve magnetization stabilization. Therefore, the permanent magnet group 23 possesses both good magnetization adjustment and magnetization stabilization capabilities.

[0249] It should be noted that the specific number of permanent magnets in each layer of permanent magnet assembly can be flexibly set according to actual needs, and this application does not impose specific limitations on this.

[0250] In some embodiments, the permanent magnets in at least one layer of permanent magnet group are all composite permanent magnets 202.

[0251] Specifically, each layer of permanent magnet assembly includes multiple permanent magnets, and at least one layer of permanent magnet assembly contains multiple permanent magnets that are composite permanent magnets 202. Because the composite permanent magnets 202 are composed of a combination of high-coercivity and low-coercivity permanent magnets, they can achieve stronger resistance to external magnetic field interference and fine adjustment of the internal magnetic field. In practical applications, at least one layer of permanent magnet assembly contains only composite permanent magnets 202, allowing the arrangement, quantity, or even the composition ratio of each composite permanent magnet 202 within the same layer to meet specific magnetic field performance targets according to the specific needs of different areas, thereby improving the flexibility of magnetic circuit design in the motor.

[0252] It should be noted that when the rotor rotates, both the permanent magnets in the rotor core 1 and the magnetic poles 2 are subjected to significant centrifugal force. When the magnetic bridge between the magnetic poles 2 is thin, this centrifugal force may cause deformation or even breakage of the magnetic bridge, reducing the reliability of the permanent magnet motor. In this case, to prevent deformation or breakage of the magnetic bridge, the rotor assembly speed must be reduced, leading to a decrease in motor performance. However, in some embodiments of this application, the goal of improving the rotor load magnetic stability can be achieved by designing the coercivity of a single permanent magnet in a single magnetic pole 2. Therefore, in some embodiments of this application, it is not necessary to achieve the improvement of magnetic stability through the cooperation of two adjacent permanent magnet groups. The distance between two adjacent permanent magnet groups along the radial direction of the core unit 10 can be set to be larger, so that the magnetic bridge between the permanent magnet groups of the core unit 10 is larger, ensuring the reliability of the motor even when the motor rotates at high speed, and improving the motor performance.

[0253] In some embodiments, each permanent magnet assembly includes at least one composite permanent magnet 202.

[0254] Specifically, in each layer of permanent magnets, at least one of the multiple permanent magnet groups is a composite permanent magnet 202. Thus, each layer contains a composite permanent magnet 202, meaning that the entire magnetic pole 2 possesses the magnetic stabilization effect provided by the composite permanent magnet 202 in the radial direction. This enhances the stability and controllability of the entire rotor magnetic field, enabling the motor to maintain excellent performance under various operating conditions.

[0255] In some embodiments, the permanent magnets in each layer of permanent magnets are composite permanent magnets 202.

[0256] As shown in Figures 18-22, in some embodiments of this application, since the permanent magnets in each layer of permanent magnet group are all composite permanent magnets 202, if the magnetic flux generated by the stator winding 31 passes through the low coercivity permanent magnet in the composite permanent magnet 202, it must pass through the high coercivity permanent magnet part of each composite permanent magnet 202. Thus, all permanent magnets have strong magnetic stability, which further improves the stability and controllability of the rotor magnetic field, enabling the motor to maintain excellent performance under various operating conditions and improving the reliability of the motor.

[0257] In some embodiments, the multilayer permanent magnet group includes at least a first permanent magnet group 200 and a second permanent magnet group 211. The first permanent magnet group 200 is adapted to be arranged close to the air gap between the rotor and the stator 3, and the second permanent magnet group 211 is adapted to be arranged away from the air gap. The first permanent magnet group 200 includes a first permanent magnet 201 and / or a second permanent magnet 203, and the second permanent magnet group 211 includes at least one composite permanent magnet 202.

[0258] Specifically, both the first permanent magnet group 200 and the second permanent magnet group 211 include multiple permanent magnets. The permanent magnets in the first permanent magnet group 200 can be the first permanent magnet 201 and / or the second permanent magnet 203, while the permanent magnets in the second permanent magnet group 211 are all composite permanent magnets 202. This allows for more precise control of the magnetic field distribution inside the motor, forming a more complex magnetic field gradient, improving the motor's working efficiency. Furthermore, by providing multiple arrangement methods for the permanent magnets in the multi-layer permanent magnet group, the flexibility is higher, the applicability is wider, and the application scenarios of the rotor are enriched.

[0259] In some embodiments, the permanent magnet in the first permanent magnet group 200 is a first permanent magnet 201, and the permanent magnet in the second permanent magnet group 211 is a composite permanent magnet 202. In this case, the first permanent magnet group 200 is located close to the air gap, and the second permanent magnet group 211 is located away from the air gap. This is in contrast to when the permanent magnet in the first permanent magnet group 200 is a second permanent magnet 203 (a low-coercivity permanent magnet), and the permanent magnet in the second permanent magnet group 211 is a composite permanent magnet 202. In this case, the first permanent magnet group 200 is located close to the air gap. In this design, the second permanent magnet group 211 is positioned away from the air gap, while the first permanent magnet 201 with high coercivity is positioned on the side close to the air gap between the rotor and stator 3. The first permanent magnet 201 in the composite permanent magnet 202 is also positioned on the side close to the air gap. In this way, the multi-layer high coercivity permanent magnets can further and effectively resist magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations and other factors during motor operation. This allows the motor to maintain a stable magnetic field output even under harsh operating conditions, thus extending the service life and reliability of the motor.

[0260] In some embodiments, the permanent magnets in each layer of permanent magnet assembly are arranged symmetrically about the magnetic pole centerline.

[0261] As shown in Figure 17, the dashed line represents the center line d of the magnetic poles. The permanent magnets in each layer of the permanent magnet assembly are symmetrically arranged about the center line of magnetic pole 2. This symmetrical arrangement generates a more uniform magnetic field distribution. Because the magnetic field lines are evenly distributed on both sides of the center line of magnetic pole 2, this helps reduce the non-uniformity of magnetic flux, thereby reducing electromagnetic noise and vibration. Furthermore, a uniform magnetic field distribution means that the motor can utilize magnetic energy more effectively during operation, reducing energy loss. This helps improve the overall efficiency of the motor, enabling it to maintain high performance under various operating conditions.

[0262] It should be noted that the number of permanent magnets in each layer of permanent magnet group can be 1, 2, 3, etc., and can be selected according to the actual situation. When the number of permanent magnets is even, the permanent magnets are respectively set on both sides of the center line of magnetic pole 2 (as shown in Figure 17). When the number of permanent magnets is odd, the two parts of a permanent magnet are respectively set on both sides of the center line of magnetic pole 2, and the other permanent magnets are set on both sides of this permanent magnet (as shown in Figure 23).

[0263] In some embodiments, the composite permanent magnet 202 may include, but is not limited to, ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets. Further, when the permanent magnet in the magnetic pole also includes a first permanent magnet 201 and / or a second permanent magnet 203, the first permanent magnet 201 or the second permanent magnet 203 may include, but is not limited to, ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets. Those skilled in the art can flexibly combine them according to actual needs. In practical applications, differences in the coercivity of permanent magnets can be achieved using permanent magnets of the same material but different grades, or using permanent magnets of different materials. In practical applications, those skilled in the art can flexibly design and combine them according to the level of coercivity.

[0264] In some embodiments, the permanent magnet in the magnetic pole 2 includes a composite permanent magnet 202, or a combination of at least one of a first permanent magnet 201, a second permanent magnet 203 and a composite permanent magnet 202. The rotor core 1 is provided with a mounting groove 11, and the permanent magnet in the magnetic pole 2 is disposed in the mounting groove 11.

[0265] Specifically, the mounting slot 11 is set on the rotor core 1 and can extend along the circumference and axial direction of the rotor core 1. The permanent magnets in the magnetic pole 2 can be placed in the mounting slot 11. The mounting slot 11 can accurately set the position and direction of the permanent magnets, ensuring that each permanent magnet is installed in the optimal design position, improving the consistency of the magnetic circuit and the overall performance of the motor, and reducing the problem of uneven magnetic field caused by installation errors.

[0266] Furthermore, at least one permanent magnet in the magnetic pole 2 is placed in a mounting slot 11.

[0267] Specifically, one permanent magnet of the magnetic pole 2 can be placed in a mounting slot 11, or multiple permanent magnets can be placed there. In this way, the number of permanent magnets set in a mounting slot can be selected according to actual needs, so that the permanent magnets in the magnetic pole 2 can more flexibly adapt to the shape of the mounting slot 11.

[0268] In some embodiments, there are multiple permanent magnets in the magnetic pole 2 and multiple mounting slots 11. The multiple mounting slots 11 form a preset shape, which includes one or more of the following: straight, arc, V, U, and W.

[0269] This application does not limit the number of mounting slots 11, and those skilled in the art can adjust it according to actual needs. Multiple mounting slots 11 form a mounting slot unit, and one mounting slot unit corresponds to one magnetic pole 2. It can be understood that the number of mounting slot units is consistent with the number of magnetic poles 2. In some embodiments, a single rotor core 1 is provided with 8 mounting slot units, and correspondingly, there are 8 magnetic poles 2. The permanent magnet of one magnetic pole 2 is installed in one mounting slot 11 unit.

[0270] Specifically, a magnetic pole 2 includes multiple permanent magnets, among which a composite permanent magnet 202 is included, or a combination of at least one of a first permanent magnet 201 and a second permanent magnet 203 with the composite permanent magnet 202 is also included. Multiple mounting slots 11 are provided on the rotor core, and at least one permanent magnet is placed in each mounting slot 11.

[0271] As shown in Figures 18-23, multiple mounting slots 11 are arranged circumferentially in the rotor core 1 and can form preset shapes, including one or more of the following: straight, arc, V, U, and W shapes. This allows the permanent magnets set in the mounting slots 11 to also be positioned in preset shapes within the magnetic poles 2. In practical applications, mounting slots 11 of different shapes can guide the magnetic field generated by the permanent magnets to be distributed as needed. For example, arc-shaped slots can conform to the circular motion path inside the motor, optimizing the continuity of the rotating magnetic field, while V-shaped or U-shaped slots can concentrate magnetic field lines, enhance local magnetic flux density, and improve the output torque and efficiency of the motor. Furthermore, slots of various shapes adapt to the needs of different motor designs. For example, straight slots are suitable for linear motors or motors with simplified structures, while W-shaped slots may be used in advanced motor designs requiring complex magnetic field control. This flexibility allows motor designs to better fit actual application scenarios.

[0272] The following examples illustrate several embodiments provided in this application:

[0273] Example 8:

[0274] As shown in Figure 18, the mounting slot 11 is in the form of a "double V": "outer small V + inner discrete large V". Each of the two mounting slots 11 of the small V is provided with a composite permanent magnet 202, and each of the two mounting slots 11 of the inner discrete large V is provided with two composite permanent magnets 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 with high coercivity and a second permanent magnet 203 with low coercivity. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0275] Example 9:

[0276] As shown in Figure 19, the mounting slot 11 is in the form of "double V": "outer small V + inner large V". Each of the two mounting slots 11 of the small V is provided with a composite permanent magnet 202, and each of the two mounting slots 11 of the large V is provided with a composite permanent magnet 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 with high coercivity and a second permanent magnet 203 with low coercivity. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0277] Example 10:

[0278] As shown in Figure 20, the mounting slot 11 is in the form of "V+U": "outer small V + inner large U". Each of the two mounting slots 11 of the small V is provided with a composite permanent magnet 202, and each of the three mounting slots 11 of the large U is provided with a composite permanent magnet 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 with high coercivity and a second permanent magnet 203 with low coercivity. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0279] Example 11:

[0280] As shown in Figure 21, the mounting slot 11 is in the form of "I + V": "outer layer discrete I + inner layer V". Each of the two mounting slots 11 of the outer layer discrete I is provided with a composite permanent magnet 202, and each of the two mounting slots 11 of the large V is provided with two composite permanent magnets 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 with high coercivity and a second permanent magnet 203 with low coercivity. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0281] Example 12:

[0282] As shown in Figure 12, the mounting slot 11 is in the form of "I + V": "outer layer I + inner layer large V". Each of the two mounting slots 11 of the outer layer I is provided with a composite permanent magnet 202, and each of the two mounting slots 11 of the large V is provided with a composite permanent magnet 202. The composite permanent magnet 202 is a series magnetic circuit structure composed of a first permanent magnet 201 with high coercivity and a second permanent magnet 203 with low coercivity. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0283] Example 13:

[0284] As shown in Figure 23, the mounting slot 11 is in the form of "I+V+U": "Outer layer I-shaped + middle layer small V + inner layer large U": a low coercivity second permanent magnet 203 is set in one mounting slot 11 of the I-shaped type, a low coercivity second permanent magnet 203 is set in each of the two mounting slots 11 of the small V, and a composite permanent magnet 202 is set in each of the three mounting slots 11 of the large U. The composite permanent magnet 202 is a series magnetic circuit structure composed of a high coercivity first permanent magnet 201 and a low coercivity second permanent magnet 203. The first permanent magnet 201 is set close to the air gap, and the second permanent magnet 203 is set away from the air gap.

[0285] It should be noted that the above embodiments are merely examples. In actual applications, the arrangement of the mounting slot 11 may not be limited to the above embodiments. Technicians may design it according to actual needs, and this application does not impose any specific limitations on it.

[0286] In some embodiments, the magnetic pole 2 further includes at least one auxiliary slot 12, and the rotor core 1 has a peripheral wall, on which the auxiliary slot 12 is disposed.

[0287] Specifically, the rotor core 1 has a peripheral wall, and auxiliary slots 12 are disposed on the peripheral wall. Each magnetic pole 2 is provided with an auxiliary slot 12. The auxiliary slots 12 are recessed inward in the radial direction of the rotor core 1 and extend in the axial direction. The auxiliary slots 12 help to achieve the mass balance of the rotor core 1, adjust the rotor's center of gravity, reduce harmonics and losses during rotation, and address NVH issues (vibration, noise, and acoustic roughness), thereby improving the smoothness and lifespan of the motor. Furthermore, there can be multiple auxiliary slots 12, which are distributed at intervals along the circumference of the rotor core 1, further reducing harmonics and losses during rotation and addressing NVH issues (vibration, noise, and acoustic roughness).

[0288] In addition, the rotor core 1 is provided with multiple weight-reducing holes 13, which are arranged axially and circumferentially along the rotor core 1. This application does not specifically limit the shape, position, or number of the weight-reducing holes 13. The weight-reducing holes 13 can reduce the overall mass of the rotor core 1, thereby reducing inertia and enabling the rotor to respond to control signals more quickly, improving the dynamic performance of the motor. The reduced mass of the rotor core 1 also reduces the weight of the motor, which is beneficial for motor lightweighting and miniaturization. Furthermore, due to the reduced mass, the heat generated by the motor during operation is also reduced accordingly, helping to lower the motor's temperature rise and extend its service life.

[0289] In some embodiments, the rotor core 1 includes a plurality of core units 10, which are arranged sequentially along the axial direction of the rotor core 1.

[0290] In some embodiments of this application, by setting multiple core units 10, the rotor core 1 can be designed in segments, which can not only reduce magnetic leakage loss and improve motor efficiency, but also reduce processing difficulty and improve production efficiency.

[0291] In some embodiments, there is an offset angle between two adjacent core units 10 along the circumference of the rotor core, wherein the magnetic poles 2 on the two adjacent core units 10 are arranged in the same way, and / or the magnetic poles 2 on the two adjacent core units 10 are arranged in different ways.

[0292] Specifically, as shown in Figure 3, a schematic diagram of the skewed-pole rotor structure is illustrated in some embodiments of this application. Two adjacent core units 10 are offset along the axial direction, meaning the rotor core 1 has a skewed-pole structure. This skewed-pole structure allows the rotor core 1 to alter the distribution of the air gap magnetic field, making the magnetic field more spatially uniform or distributed according to specific requirements. When the skew angle is different, the distribution of the air gap magnetic flux density also changes significantly. Furthermore, the skewed-pole structure also has higher starting torque, lower vibration and noise levels, and can withstand greater loads and maintain more stable speeds.

[0293] The arrangement of magnetic poles 2 in two adjacent core units 10 refers to the arrangement of permanent magnets in magnetic poles 2. This arrangement can be the same or different, and can be flexibly set according to actual needs. Some embodiments of this application do not specifically limit this.

[0294] In some embodiments of this application, as shown in FIG4, a schematic diagram of a direct-pole rotor structure is shown in some embodiments of this application; the two adjacent iron core units 10 have an offset angle of 0° along the circumference of the rotor iron core 1, that is, the rotor iron core 1 is a direct-pole structure. The rotor iron core 1 structure of the direct-pole structure is relatively simple in design, and the magnetic poles 2 of each unit rotor are closely attached, and the air gap magnetic field distribution in the motor axial direction shows a uniform variation law.

[0295] In summary, the rotors provided in some embodiments of this application have at least the following advantages:

[0296] In some embodiments of this application, the permanent magnet of the magnetic pole 2 includes a composite permanent magnet 202, which comprises a first permanent magnet 201 and a second permanent magnet 203 with different coercivities. Since the coercivities of the first permanent magnet 201 and the second permanent magnet 203 are different, their magnetization states are also different. Thus, during motor operation, the magnetization state of the permanent magnet with lower coercivity is more easily changed, thereby adjusting the air gap flux. Simultaneously, the magnetization state of the permanent magnet with higher coercivity is less easily changed, improving the magnetic stability of the composite permanent magnet 202, thereby enhancing the overall magnetic stability of the magnetic pole 2, preventing demagnetization under unintended conditions, and improving the operational reliability of the motor.

[0297] This application provides another type of rotor, including a rotor core 1 and multiple magnetic poles 2. Referring to Figures 35, 6, and 36-38, a schematic diagram of the rotor core 1 provided in some embodiments of this application is shown. As shown in Figure 35, the dotted circle represents a magnetic pole 2, and the multiple magnetic poles 2 are distributed circumferentially around the rotor core 1. In some embodiments of this application, the rotor core 1 has eight magnetic poles 2. In practical applications, the number of magnetic poles 2 can be arbitrary. The magnetic poles 2 include permanent magnets, which can generate a constant magnetic field to provide a basis for generating torque in the motor. The rotor core 1 uses magnetically conductive materials, commonly including silicon steel sheets, silicon steel sheets, amorphous & nanocrystalline alloys, and iron-cobalt materials. Symmetrical or asymmetrical auxiliary slots can be formed on the surface of the rotor core 1 near the air gap to further reduce harmonics, losses, and NVH issues.

[0298] Specifically, the rotor is used in a permanent magnet motor, which typically also includes a stator 3. The stator 3 has stator windings 31. When current is applied to the stator windings 31, an alternating magnetic field is generated. This alternating magnetic field interacts with the constant magnetic field generated by the permanent magnets in the magnetic poles 2, producing torque. The rotor rotates under the influence of this torque. During the rotation of the rotor under the influence of torque, the rotor core 1 has a forward rotation direction and a reverse rotation direction. It should be noted that the forward and reverse rotation directions are artificially defined in the embodiments of this application. Since the rotors provided in some embodiments of this application are typically used in drive motors and generators, in some embodiments of this application, the forward rotation direction corresponds to the forward direction of a vehicle in a drive motor, or the rotation direction of an engine in a generator, and the reverse rotation direction is the opposite of the forward rotation direction.

[0299] In some embodiments of this application, the magnetic pole 2 includes two magnetic parts located on both sides of the magnetic pole center line, namely a first magnetic part 61 and a second magnetic part 62. The first magnetic part 61 and the second magnetic part 62 are asymmetrically arranged about the magnetic pole center line, and the coercivity of the first magnetic part 61 is different from that of the second magnetic part 62.

[0300] It should be noted that, as shown in Figure 35, the d-axis indicated by the dashed arrow is the magnetic pole centerline described in some embodiments of this application. In some embodiments of this application, both the first magnetic part 61 and the second magnetic part 62 may include at least one permanent magnet. When the first magnetic part 61 and the second magnetic part 62 each include multiple permanent magnets, the permanent magnets in the first magnetic part 61 and the second magnetic part 62 each have a combined coercivity. The coercivity of the first magnetic part 61 refers to the combined coercivity of the permanent magnets in the first magnetic part 61, and the coercivity of the second magnetic part 62 refers to the combined coercivity of the permanent magnets in the second magnetic part 62.

[0301] In some embodiments of this application, the first magnetic part 61 and the second magnetic part 62 are asymmetrically arranged about the magnetic pole center line, including the following three cases: First, the permanent magnets distributed on both sides with the magnetic pole center line as the axis of symmetry are arranged differently; second, the permanent magnets distributed on both sides with the magnetic pole center line as the axis of symmetry are arranged in the same way, but the coercivity is different; third, the arrangement of the permanent magnets distributed on both sides with the magnetic pole center line as the axis of symmetry and the coercivity are both different. This application does not make specific limitations on this, as long as the coercivity of the first magnetic part 61 and the coercivity of the second magnetic part 62 are different.

[0302] Understandably, the first magnetic section 61 and the second magnetic section 62 have different coercivities, meaning their magnetization states are different. During motor operation, the magnetization state of the magnetic section with lower coercivity is more easily changed than that of the magnetic section with higher coercivity. This allows the motor to adapt to different operating conditions quickly, achieving efficient operation across the entire motor's operating range. Conversely, the magnetization state of the magnetic section with higher coercivity is less prone to change, thus improving the rotor's overall load-stabilizing capability, avoiding the risk of demagnetization, and enhancing the motor's operational reliability.

[0303] In some embodiments of this application, the rotor core 1 is provided with a first mounting slot group 111 and a second mounting slot group 112 symmetrically distributed about the magnetic pole centerline. The first magnetic part 61 and the second magnetic part 62 are respectively disposed in the first mounting slot group 111 and the second mounting slot group 112. Further, both the first mounting slot group 111 and the second mounting slot group 112 include at least one mounting slot 11, wherein the mounting slot 11 is used to set a permanent magnet. A single permanent magnet can be set in a mounting slot 11, or multiple permanent magnets can be set in a single mounting slot. This application does not specifically limit this. The mounting slots of the first mounting slot group 111 and the second mounting slot group 112 form a preset shape in the circumferential direction of the rotor core 1. The preset shape includes one or more of the following: arc shape, straight line shape, V shape, U shape, and W shape.

[0304] Furthermore, the positions of the first mounting slot group 111 and the second mounting slot group 112 on the rotor core 1 can be set symmetrically about the magnetic pole centerline, making it easier to achieve precise alignment and positioning of the rotor during assembly and reducing assembly errors. In rotating equipment such as motors, the symmetrical arrangement of the two magnetic parts also helps to reduce unbalanced forces and vibrations, lowering the risk of equipment failure and damage.

[0305] In some embodiments, the coercivity of the first magnetic part 61 is less than that of the second magnetic part 62, wherein the first magnetic part 61 is adapted to be disposed on the side of the magnetic pole 2 facing the forward rotation direction of the motor, and the second magnetic part 62 is adapted to be disposed on the side of the magnetic pole 2 facing the reverse rotation direction of the motor.

[0306] Specifically, both the first magnetic part 61 and the second magnetic part 62 may include multiple permanent magnets. These permanent magnets may include, but are not limited to, ferrite permanent magnets, AlNiCo permanent magnets, NdFeB permanent magnets, Samarium Cobalt permanent magnets, and Iron Nitride permanent magnets. Those skilled in the art can flexibly combine them according to actual needs. In practical applications, the difference in coercivity between the first magnetic part 61 and the second magnetic part 62 can be achieved using permanent magnets of the same material but different grades, or using permanent magnets of different materials. In practical applications, those skilled in the art can flexibly design and combine them according to the level of coercivity.

[0307] It should be noted that during the operation of the motor, for this type of motor with built-in permanent magnets, the current in the armature winding cannot be a pure direct-axis current or a pure quadrature-axis current under actual load. In reality, it is a current containing both quadrature-axis and direct-axis components under maximum torque-to-current ratio (MTPA) control and field weakening control. This results in different operating points and magnetization levels of the two permanent magnets in each magnetic pole 2, making the magnetic part on the side facing the reverse direction more prone to undesigned demagnetization.

[0308] Figure 46 shows the demagnetization rate cloud diagram of the permanent magnet of a conventional variable flux motor. In Figure 46, the reverse direction of the rotor core 1 is clockwise, and the forward direction is counterclockwise. As can be seen from the results in Figure 46, under normal operating conditions (without magnet adjustment), the magnetic part facing the reverse direction of this conventional variable flux motor has a higher demagnetization rate. As shown in Figure 18, this is a demagnetization rate cloud diagram of the permanent magnet of the motor in the first embodiment of this application. Similarly, in Figure 47, the reverse rotation direction of the rotor core 1 is clockwise, and the forward rotation direction is counterclockwise. As can be seen from the results in Figure 47, the demagnetization rate of the magnetic part facing the reverse rotation direction of the motor provided in the thirteenth embodiment of this application is much lower than that of the magnetic part in Figure 47. Moreover, in this motor, the difference between the demagnetization rate of the magnetic part facing the reverse rotation direction and the demagnetization rate of the magnetic part facing the forward rotation direction is smaller. Therefore, this application effectively improves the load stabilization capability of the magnetic pole 2 in the rotor, improves the uniformity of the demagnetization rate between the two magnetic parts in the magnetic pole 2, improves the stabilization capability of the rotor, and enhances the reliability and stability of the variable flux motor system.

[0309] It should be noted that during rotor rotation, both the rotor core 1 and the permanent magnets are subjected to significant centrifugal force. When the inter-pole magnetic bridge is thin, this centrifugal force may cause deformation or even breakage of the magnetic bridge, reducing the reliability of the permanent magnet motor. In this case, to prevent deformation or breakage of the magnetic bridge, the rotor speed must be reduced, leading to a decrease in motor performance. However, in the embodiments of this application, by designing the coercivity of the two magnetic parts in a single magnetic pole 2, the goal of improving the rotor's load magnetic stability can be achieved. Therefore, in some embodiments of this application, it is not necessary to achieve the improvement of magnetic stability through the cooperation of two adjacent magnetic poles 2. The spacing between two adjacent magnetic poles 2 along the circumference of the rotor core 1 can be set to be larger, so that the inter-pole magnetic bridge of the rotor core 1 is larger, ensuring the reliability of the motor even when the motor rotates at high speed, thus improving motor performance.

[0310] In addition, since the magnetic bridge between adjacent magnetic poles 2 is thicker in some embodiments of this application, the cross-axis (q-axis in Figure 35) inductance is increased, and the reluctance torque is further increased, thereby reducing the output torque of the motor.

[0311] Optionally, the first magnetic part 61 includes a fifth permanent magnet 611 and / or a first composite permanent magnet 616, wherein the first composite permanent magnet 616 includes the fifth permanent magnet 611 and a sixth permanent magnet 612, and the coercivity of the fifth permanent magnet 611 is less than that of the sixth permanent magnet 612.

[0312] As mentioned above, the permanent magnets in the first magnetic part 61 and the second magnetic part 62 are both disposed in the mounting groove. In some embodiments of this application, the first magnetic part 61 includes a fifth permanent magnet 611 and / or a first composite permanent magnet 616. This means that in a mounting groove, a fifth permanent magnet 611 can be disposed alone, or a first composite permanent magnet 616 can be disposed. The first composite permanent magnet 616 includes a fifth permanent magnet 611 and a sixth permanent magnet 612 with different coercivity.

[0313] It should be noted that in some embodiments of this application, the division between the fifth permanent magnet 611 and the sixth permanent magnet 612 is based on their coercivity. That is, the fifth permanent magnet 611 is the permanent magnet with lower coercivity among the fifth permanent magnet 611 and the sixth permanent magnet 612, and the sixth permanent magnet 612 is the permanent magnet with higher coercivity among the fifth permanent magnet 611 and the sixth permanent magnet 612. The fifth permanent magnet 611 provided separately and the fifth permanent magnet 611 in the first composite permanent magnet 616 can have the same or different coercivity. Furthermore, in the first composite permanent magnet 616, the number of fifth permanent magnets 611 and the number of sixth permanent magnets 612 are not limited and can be any number of more than one. For example, as shown in FIG39, in the first magnetic part 61, a first composite permanent magnet 616 is provided in a mounting groove away from the stator 3. The first composite permanent magnet 616 includes one fifth permanent magnet 611 and two sixth permanent magnets 612.

[0314] Understandably, since the coercivity of the fifth permanent magnet 611 is less than that of the sixth permanent magnet 612, by setting the fifth permanent magnet 611 or the first composite permanent magnet 616 in the first magnetic part 61, the arrangement of permanent magnets in the first magnetic part 61 becomes more flexible, and the coercivity in the first magnetic part 61 can be more easily adjusted according to the needs of different motors.

[0315] In some embodiments, the first magnetic part 61 includes multiple layers of first permanent magnet units 614, which are arranged radially spaced along the rotor core 1. At least one layer of first permanent magnet units 614 is provided with at least one fifth permanent magnet 611 and / or at least one first composite permanent magnet 616. Specifically, at least one layer of first permanent magnet units 614 is provided with one or more fifth permanent magnets 611, or at least one layer of first permanent magnet units 614 is provided with one or more first composite permanent magnets 616, or at least one layer of first permanent magnet units 614 is provided with both fifth permanent magnets 611 and first composite permanent magnets 616. That is, the first permanent magnet unit 614 can be a single low-coercivity permanent magnet, or it can be a first composite permanent magnet 616 composed of a low-coercivity permanent magnet and a high-coercivity permanent magnet.

[0316] It should be noted that, in some embodiments of this application, the first mounting slot group 111 for setting the first magnetic part 61 may include multiple layers of mounting slots arranged radially at intervals along the rotor core 1. At least one layer of mounting slots may include one mounting slot for setting the fifth permanent magnet 611 or the first composite permanent magnet 616, or it may include multiple mounting slots for setting the fifth permanent magnet 611 and the first composite permanent magnet 616 respectively. It is understood that, in order to ensure a high coercivity of the second magnetic part 62 facing the reverse rotation direction, a composite permanent magnet including the fifth permanent magnet 611 and the sixth permanent magnet 612, i.e., a combination of a low-coercivity permanent magnet and a high-coercivity permanent magnet, can be provided in the first magnetic part 61 facing the forward rotation direction.

[0317] In practical applications, multiple permanent magnet units are arranged in the magnetic section, each unit including at least one permanent magnet. This increases the number of permanent magnets, allowing them to better fill the space of the magnetic poles 2, resulting in a more uniform magnetic flux density. Furthermore, this reduces the size of the permanent magnets. Compared to large permanent magnets, smaller permanent magnets can better distribute the centrifugal force experienced during rotation, thereby improving the mechanical strength and lifespan of the motor. Smaller permanent magnets also offer better heat dissipation, enhancing the overall thermal stability of the motor.

[0318] In some embodiments, the first magnetic part 61 further includes a sixth permanent magnet 612, which is arranged radially spaced from the fifth permanent magnet 611 along the rotor core 1, and / or the sixth permanent magnet 612 is arranged radially spaced from the first composite permanent magnet 616 along the rotor core 1. It should be noted that the sixth permanent magnet 612 here is a high-coercivity permanent magnet separately disposed in a mounting slot.

[0319] As mentioned above, the coercivity of the sixth permanent magnet 612 is greater than that of the fifth permanent magnet 611. By setting the sixth permanent magnet 612 in the first magnetic part 61, the difference in coercivity between the first magnetic part 61 and the second magnetic part 62 can be reduced when the coercivity of the first magnetic part 61 is lower. This improves the magnetic stability of the first magnetic part 61 and enhances the flexibility of the permanent magnet configuration in the first magnetic part 61.

[0320] In some optional embodiments of this application, as shown in Figures 39 to 44, the first magnet part includes a first composite permanent magnet 616 and a sixth permanent magnet 612. In this way, while achieving magnetization, the overall antimagnetic demagnetization performance of the first magnetic part 61 can be further improved, avoiding irreversible demagnetization that is not designed or expected, which is beneficial to improving the operational reliability of the motor.

[0321] In some embodiments of this application, as shown in FIG45, the first magnet part includes a fifth permanent magnet 611 and a sixth permanent magnet 612. Compared with the method of setting a first composite permanent magnet 616, since only one type of permanent magnet is set in a mounting slot in this method, the assembly process can be simplified, thereby improving production efficiency.

[0322] Furthermore, the sixth permanent magnet 612 is adapted to be arranged close to the gap between the rotor and the stator 3, wherein the gap between the rotor and the stator 3 forms the air gap of the rotor. This arrangement can reduce the risk of demagnetization of the permanent magnet unit close to the air gap side, and ensure the reliability and operating efficiency of the permanent magnet motor.

[0323] It should be noted that, as shown in Figures 39 to 45, the gap formed between the radially outer side of the rotor and the radially inner side of the stator 3 is the air gap of the motor. Near this air gap, the permanent magnets are not only subjected to a strong magnetic field from the stator windings 31, but may also experience additional stress due to mechanical vibrations and temperature changes during motor operation. These factors combined make the permanent magnets near the air gap more prone to demagnetization. Therefore, placing the sixth permanent magnet 612, which has greater coercivity, closer to the air gap can reduce the risk of demagnetization of permanent magnets located near the air gap, minimize unintended or unplanned irreversible demagnetization, and ensure the reliability and efficiency of motor operation.

[0324] In some embodiments, the first magnetic part 61 further includes a sixth permanent magnet 612, which is arranged circumferentially with the fifth permanent magnet 611, and / or the sixth permanent magnet 612 is arranged circumferentially with the first composite permanent magnet 616.

[0325] In order to ensure that the coercivity of the second magnetic part 62 is greater than that of the first magnetic part 61, a fifth permanent magnet 611 with lower coercivity can be provided in the first magnetic part 61. When the difference in coercivity between the first magnetic part 61 and the second magnetic part 62 is large, a sixth permanent magnet 612 can be provided in the first magnetic part 61. Since the first magnetic part 61 can be provided with a fifth permanent magnet 611, a sixth permanent magnet 612, or a first composite permanent magnet 616, the arrangement flexibility of the permanent magnets in the first magnetic part 61 is improved, and the adjustment of the coercivity after their combination and superposition is also more flexible.

[0326] In some embodiments, the first magnetic part 61 further includes a plurality of sixth permanent magnets 612, the sixth permanent magnets 612 and the fifth permanent magnets 611 being arranged at intervals along the radial and circumferential directions of the rotor core 1, and / or, the sixth permanent magnets 612 and the first composite permanent magnets 616 being arranged at intervals along the radial and circumferential directions of the rotor core 1, thereby improving the flexibility of the permanent magnet arrangement. Specifically, the second permanent magnet unit 624 may include a sixth permanent magnet 612 and a fifth permanent magnet 611, or a sixth permanent magnet 612 and a first composite permanent magnet 616, or simultaneously a sixth permanent magnet 612, a fifth permanent magnet 611, and a first composite permanent magnet 616. The fifth permanent magnet 611, the sixth permanent magnet 612, and the first composite permanent magnet 616 are spaced apart in the circumferential direction of the rotor core 1. In addition, the multiple layers of first composite permanent magnets 616 spaced apart radially along the rotor core 1 may each contain any one of the fifth permanent magnet 611, the sixth permanent magnet 612, or the first composite permanent magnet 616. This application does not make any specific limitation in this regard.

[0327] In some embodiments, the first composite permanent magnet 616 is adapted to be arranged close to the gap between the rotor and the stator 3, which is the air gap of the motor. As shown in FIG43, the first magnetic part 61 includes multiple layers of first permanent magnet units 614, each containing a first composite permanent magnet 616. As shown in FIG44, the first magnetic part 61 includes multiple layers of first permanent magnet units 614, one layer being a first composite permanent magnet 616 and another layer being a sixth permanent magnet 612. Arranging the first composite permanent magnet 616 close to the air gap, compared to arranging the fifth permanent magnet 611 close to the air gap, reduces the risk of demagnetization of the rotor on the air gap side, thus ensuring the rotor's magnetic stability on the air gap side.

[0328] In some embodiments, the first composite permanent magnet 616 constitutes a series magnetic circuit structure or a parallel magnetic circuit structure. It should be noted that in this embodiment, a momentary pulse current (direct-axis current) is applied to the stator winding 31 to generate a magnetic field that rotates synchronously with the rotor, thereby changing the magnetization state of the low-coercivity permanent magnets on the rotor, thus changing the magnitude of the air gap magnetic flux and achieving real-time online magnetic adjustment. Referring to Figure 36, a schematic diagram of the magnetic field lines generated by the direct-axis current is shown. As shown, the arrows indicate the magnetization direction of the magnetic pole 2. In a single magnetic pole 2, the magnetization direction extends approximately radially along the rotor core 1. The first magnetic part 61 and the second magnetic part 62 on both sides of the magnetic pole centerline each generate a magnetic field line and form a parallel magnetic circuit structure. When the first magnetic part 61 and the second magnetic part 62 are provided with multi-layer permanent magnet units, the magnetic field lines of the first magnetic part 61 simultaneously pass through the multi-layer permanent magnet units, so that the multi-layer permanent magnet units form a series magnetic circuit structure.

[0329] Furthermore, in some embodiments of this application, as shown in Figures 42 to 45, the first magnetic part 61 includes a first composite permanent magnet 616, in which the fifth permanent magnet 611 and the sixth permanent magnet 612 are alternately arranged along the radial direction of the rotor core 1, that is, the fifth permanent magnet 611 and the sixth permanent magnet 612 are arranged along the magnetization direction to form a series magnetic circuit structure.

[0330] In some embodiments of this application, as shown in Figures 39 to 41, the first magnetic part 61 includes a first composite permanent magnet 616. The fifth permanent magnet 611 and the sixth permanent magnet 612 in the first composite permanent magnet 616 are alternately arranged along the circumference of the rotor core 1, that is, the fifth permanent magnet 611 and the sixth permanent magnet 612 are arranged approximately perpendicular to the magnetization direction to form a parallel magnetic circuit structure.

[0331] As described above, this application provides multiple arrangement methods for the first composite permanent magnet 616, which offers greater flexibility, wider applicability, and enriches the application scenarios of the rotor.

[0332] In some embodiments, the second magnetic part 62 includes a seventh permanent magnet 621 and / or a first composite permanent magnet 623, wherein the first composite permanent magnet 623 includes the seventh permanent magnet 621 and an eighth permanent magnet 622, and the coercivity of the seventh permanent magnet 621 is greater than that of the eighth permanent magnet 622.

[0333] As mentioned above, the permanent magnets in the first magnetic part 61 and the second magnetic part 62 are both disposed in the mounting groove. In some embodiments of this application, the second magnetic part 62 includes a seventh permanent magnet 621 and / or a first composite permanent magnet 623. This means that in a mounting groove, a seventh permanent magnet 621 can be disposed alone, or a first composite permanent magnet 623 can be disposed. The first composite permanent magnet 623 includes a seventh permanent magnet 621 and an eighth permanent magnet 622 with different coercivity.

[0334] It should be noted that in some embodiments of this application, the division between the seventh permanent magnet 621 and the eighth permanent magnet 622 is based on their coercivity. That is, the seventh permanent magnet 621 is the permanent magnet with higher coercivity between the seventh permanent magnet 621 and the eighth permanent magnet 622, and the eighth permanent magnet 622 is the permanent magnet with lower coercivity between the seventh permanent magnet 621 and the eighth permanent magnet 622. The seventh permanent magnet 621 in the separately provided seventh permanent magnet 621 and the seventh permanent magnet 621 in the first composite permanent magnet 623 can have the same or different coercivity. Furthermore, in the first composite permanent magnet 623, the number of seventh permanent magnets 621 and the number of eighth permanent magnets 622 are not limited and can be any number of more than one. For example, as shown in FIG39, in the second magnetic part 62, a first composite permanent magnet 623 is provided in a mounting groove away from the stator 3. The first composite permanent magnet 623 includes a seventh permanent magnet 621 and an eighth permanent magnet 622.

[0335] Understandably, since the coercivity of the seventh permanent magnet 621 is greater than that of the eighth permanent magnet 622, by setting the seventh permanent magnet 621 or the first composite permanent magnet 623 in the second magnetic part 62, the arrangement of permanent magnets in the second magnetic part 62 becomes more flexible, and the coercivity in the second magnetic part 62 can be more easily adjusted according to the needs of different motors.

[0336] In some embodiments, the second magnetic part 62 includes multiple layers of second permanent magnet units 624, which are arranged radially spaced along the rotor core 1. At least one layer of second permanent magnet units 624 is provided with at least one seventh permanent magnet 621 and / or at least one first composite permanent magnet 623.

[0337] It should be noted that, in some embodiments of this application, the second mounting slot group 112 for setting the second magnetic part 62 may include multiple layers of mounting slots arranged radially at intervals along the rotor core 1. At least one layer of mounting slots may include one mounting slot for setting a seventh permanent magnet 621 or a first composite permanent magnet 623, or multiple mounting slots may be included for setting the seventh permanent magnet 621 and the first composite permanent magnet 623 respectively. It is understood that, in order to ensure a high coercivity of the second magnetic part 62 facing the reverse direction, a seventh permanent magnet 621 can be set in the second magnetic part 62 facing the forward direction. Furthermore, by setting a first composite permanent magnet 623 including the seventh permanent magnet 621 and the eighth permanent magnet 622—that is, a combination of a low-coercivity permanent magnet and a high-coercivity permanent magnet—the flexibility of adjusting the coercivity of the second magnetic part 62 is improved.

[0338] In some embodiments, the second magnetic part 62 further includes an eighth permanent magnet 622, which is arranged radially spaced from the seventh permanent magnet 621 along the rotor core 1, and / or the eighth permanent magnet 622 is arranged radially spaced from the first composite permanent magnet 623 along the rotor core 1.

[0339] As mentioned above, the coercivity of the eighth permanent magnet 622 is less than that of the seventh permanent magnet 621. By providing the eighth permanent magnet 622 in the second magnetic part 62, the configuration flexibility of the permanent magnets in the second magnetic part 62 can be improved, as can the flexibility of adjusting the coercivity of the second magnetic part 62.

[0340] In some embodiments of this application, as shown in FIG45, the second magnetic part 62 includes a seventh permanent magnet 621 and an eighth permanent magnet 622. In this way, while ensuring the overall antimagnetic demagnetization performance of the second magnetic part 62, the configuration flexibility of the permanent magnets in the second magnetic part 62 is improved. At the same time, since only one type of permanent magnet is set in a mounting slot under this arrangement, the assembly process can be simplified, thereby improving production efficiency.

[0341] It should be noted that, in some embodiments of this application, while ensuring that the coercivity of the second magnetic part 62 is greater than that of the first magnetic part 61, the second magnetic part 62 may also include an eighth permanent magnet 622 and a first composite permanent magnet 623.

[0342] Furthermore, the seventh permanent magnet 621 is adapted to be arranged close to the gap between the rotor and the stator 3, wherein the gap between the rotor and the stator 3 forms the air gap of the rotor. This arrangement can reduce the risk of demagnetization of the permanent magnet unit close to the air gap side, and ensure the reliability and operating efficiency of the permanent magnet motor.

[0343] Similar to the arrangement of the first magnetic part 61, in the second magnetic part 62, the seventh permanent magnet 621 with greater coercivity is arranged close to the air gap. This can reduce the risk of demagnetization of the permanent magnet arranged close to the air gap side, reduce irreversible demagnetization that is not designed or expected, and ensure the reliability and efficiency of motor operation.

[0344] In some embodiments, the second magnetic part 62 further includes an eighth permanent magnet 622, which is arranged circumferentially with the seventh permanent magnet 621 along the rotor core 1, and / or the eighth permanent magnet 622 is arranged circumferentially with the first composite permanent magnet 623 along the rotor core 1.

[0345] To ensure that the coercivity of the second magnetic section 62 is greater than that of the first magnetic section 61, a seventh permanent magnet 621 with higher coercivity can be provided in the second magnetic section 62. When the difference in coercivity between the second magnetic section 62 and the first magnetic section 61 is large, an eighth permanent magnet 622 can be provided in the second magnetic section 62 to expand the rotor's applicability. Since the second magnetic section 62 can be equipped with a seventh permanent magnet 621, an eighth permanent magnet 622, or a first composite permanent magnet 623, the arrangement flexibility of the permanent magnets in the second magnetic section 62 is improved, and the adjustment of the coercivity after their combined superposition is also more flexible.

[0346] In some embodiments, the second magnetic part 62 further includes a plurality of eighth permanent magnets 622, the eighth permanent magnets 622 and the seventh permanent magnets 621 being arranged at intervals along the radial and circumferential directions of the rotor core 1, and / or, the eighth permanent magnets 622 and the first composite permanent magnets 623 being arranged at intervals along the radial and circumferential directions of the rotor core 1, thereby improving the flexibility of the permanent magnet arrangement. Specifically, the second permanent magnet unit 624 may include an eighth permanent magnet 622 and a seventh permanent magnet 621, or an eighth permanent magnet 622 and a first composite permanent magnet 623, or simultaneously an eighth permanent magnet 622, a seventh permanent magnet 621, and a first composite permanent magnet 623. The seventh permanent magnet 621, the eighth permanent magnet 622, and the first composite permanent magnet 623 are spaced apart in the circumferential direction of the rotor core 1. In addition, the multiple layers of first composite permanent magnets 623 arranged radially spaced along the rotor core 1 may each be provided with any one of the seventh permanent magnet 621, the eighth permanent magnet 622, or the first composite permanent magnet 623. This application does not make any specific limitation in this regard.

[0347] In some embodiments, the first composite permanent magnet 623 is adapted to be arranged close to the gap between the rotor and the stator 3, which is the air gap of the motor. As shown in Figures 43 and 44, the second magnetic part 62 includes multiple layers of second permanent magnet units 624, one layer of which is the first composite permanent magnet 623, and another layer is a seventh permanent magnet 621. Arranging the first composite permanent magnet 623 close to the air gap, compared to arranging the eighth permanent magnet 622 close to the air gap, reduces the risk of demagnetization of the rotor on the air gap side, thus ensuring the rotor's magnetic stability on the air gap side.

[0348] In some embodiments, the first composite permanent magnet 623 constitutes a series magnetic circuit structure or a parallel magnetic circuit structure.

[0349] Furthermore, in some embodiments of this application, as shown in FIG39, the second magnetic part 62 includes a first composite permanent magnet 623, wherein the seventh permanent magnet 621 and the eighth permanent magnet 622 in the first composite permanent magnet 623 are alternately arranged along the radial direction of the rotor core 1, that is, the seventh permanent magnet 621 and the eighth permanent magnet 622 are arranged along the magnetization direction to form a series magnetic circuit structure.

[0350] In some embodiments of this application, as shown in FIG40, the second magnetic part 62 includes a first composite permanent magnet 623. The seventh permanent magnet 621 and the eighth permanent magnet 622 in the first composite permanent magnet 623 are alternately arranged along the circumference of the rotor core 1, that is, the seventh permanent magnet 621 and the eighth permanent magnet 622 are arranged approximately perpendicular to the magnetization direction to form a parallel magnetic circuit structure.

[0351] As described above, this application provides multiple arrangement methods for the first composite permanent magnet 623, which offers greater flexibility, wider applicability, and enriches the application scenarios of the rotor.

[0352] In some embodiments, the coercivity of the seventh permanent magnet 621 is greater than or equal to the coercivity of the sixth permanent magnet 612. Specifically, both the sixth permanent magnet 612 and the seventh permanent magnet 621 are located close to the air gap. The fact that the coercivity of the seventh permanent magnet 621 is greater than or equal to the coercivity of the sixth permanent magnet 612 can ensure that the rotor has a stronger magnetic stabilization capability on the side of the second magnetic part 62 near the air gap, thereby reducing the risk of demagnetization of the second magnetic part 62.

[0353] In some embodiments, the coercivity of the eighth permanent magnet 622 is less than or equal to the coercivity of the sixth permanent magnet 612. Specifically, the sixth permanent magnet 612 is disposed close to the air gap, and the eighth permanent magnet 622 is disposed away from the air gap. The coercivity of the eighth permanent magnet 622 is less than or equal to the coercivity of the sixth permanent magnet 612, which can ensure that the rotor has a stronger magnetic stabilization capability on the side of the first magnetic part 61 close to the air gap, and reduce the risk of demagnetization of the first magnetic part 61.

[0354] In some embodiments, the coercivity of the seventh permanent magnet 621 is equal to that of the sixth permanent magnet 612, and / or the coercivity of the eighth permanent magnet 622 is equal to that of the fifth permanent magnet 611, so as to improve the flexibility of the arrangement of permanent magnets between the first magnetic part 61 and the second magnetic part 62.

[0355] In specific applications, the rotor core 1 includes multiple laminations stacked along the axial direction. The laminations are manufactured through processes such as stamping and cutting, and the multiple laminations are stacked to form the rotor core 1. Mounting holes are provided on the laminations according to the design position of the magnetic components. After the multiple laminations are stacked as a whole, a mounting groove for mounting the magnetic components is formed.

[0356] Specifically, as shown in Figures 43 and 44, in some embodiments, among the multiple permanent magnets in a magnetic pole 2, the permanent magnets near the air gap are disposed in a mounting groove. In the embodiment shown in Figure 45, among the multiple permanent magnets in a magnetic pole 2, the permanent magnets near the air gap and the permanent magnets away from the air gap are respectively disposed in a mounting groove. It should be noted that when one or more mounting grooves are located on both sides of the magnetic pole centerline, the permanent magnets disposed in the mounting groove facing the reverse rotation direction along the magnetic pole centerline belong to the second magnetic part 62, and the permanent magnets disposed in the mounting groove facing the forward rotation direction belong to the first magnetic part 61.

[0357] In addition, the rotor core 1 is provided with weight-reduction holes 13. This application does not specifically limit the shape, position, or number of weight-reduction holes 13. The weight-reduction holes 13 can reduce the overall mass of the rotor, thereby reducing inertia and enabling the rotor to respond to control signals more quickly, thus improving the dynamic performance of the motor. The reduction in the mass of the rotor core 1 also helps to achieve the miniaturization and weight reduction of the motor, which is particularly important for applications that require space saving or weight reduction. Due to the reduction in mass, the heat generated by the motor during operation will also be reduced accordingly, which helps to reduce the temperature rise of the motor and extend its service life.

[0358] In some embodiments of this application, the rotor core 1 includes multiple core units, which are arranged sequentially along the axial direction of the rotor core 1. By setting multiple core units, i.e., designing the rotor core 1 in segments, not only can magnetic leakage loss be reduced and motor efficiency improved, but also processing difficulty can be reduced and production efficiency improved.

[0359] In practical applications, the core unit typically uses magnetically conductive materials, including but not limited to silicon steel sheets, silicon steel sheets, amorphous & nanocrystalline alloys, and iron-cobalt materials. It should be noted that this application does not limit the number of core units; those skilled in the art can adjust the number according to actual needs.

[0360] In some embodiments, the rotor has a skewed pole structure, meaning that there is a circumferential offset angle between two adjacent core units. By controlling the circumferential offset angle between two adjacent core units, the magnetic field distribution of the motor can be optimized, reducing torque fluctuations during motor operation and thus improving the motor's operational reliability. Furthermore, the skewed pole structure also has higher starting torque, lower vibration and noise levels, and can withstand larger loads and maintain more stable speeds. The magnetic poles 2 on two adjacent core units can be arranged in the same way, or in different ways, thereby increasing the flexibility of the rotor core 1 configuration.

[0361] It should be noted that the rotor can also be a straight-pole structure, that is, multiple rotor cores 1 are offset by 0° along the circumferential direction. Among them, the rotor structure design of the straight-pole structure is relatively simple, and the magnetic poles 2 of each unit rotor are closely attached, and the air gap magnetic field distribution in the axial direction of the motor shows a uniform variation pattern.

[0362] The following examples are based on several embodiments provided in this application:

[0363] Example 13:

[0364] As shown in Figure 39, the permanent magnet mounting slot is in the form of a "double V": "outer small V + inner large V". Both mounting slots of the small V are equipped with high coercivity permanent magnets. The first magnetic part 61 of the large V is a parallel magnetic circuit composite permanent magnet, which includes high coercivity permanent magnets on both sides and low coercivity permanent magnets in the middle. The second magnetic part 62 is a series magnetic circuit composite permanent magnet, which includes high coercivity permanent magnets near the air gap and low coercivity permanent magnets away from the air gap.

[0365] Example 14:

[0366] As shown in Figure 40, the permanent magnet mounting slot is in the form of a "double V": "outer small V + inner large V". Both mounting slots of the small V are equipped with high coercivity permanent magnets. The first magnetic part 61 and the second magnetic part 62 of the large V are both parallel magnetic circuit composite permanent magnets. The first magnetic part 61 includes high coercivity permanent magnets on both sides and low coercivity permanent magnets in the middle. The second magnetic part 62 includes an alternating high coercivity permanent magnet and a low coercivity permanent magnet.

[0367] Example 15:

[0368] As shown in Figure 41, the permanent magnet mounting slot is in the form of a "double V": "outer small V + inner large V". Both mounting slots of the small V are equipped with high coercivity permanent magnets. The first magnetic part 61 of the large V is a parallel magnetic circuit composite permanent magnet, which includes high coercivity permanent magnets on both sides and low coercivity permanent magnets in the middle. The second magnetic part 62 is a high coercivity permanent magnet.

[0369] Example 16:

[0370] As shown in Figure 42, the permanent magnet mounting slot is in the form of a "double V": "outer small V + inner large V". Both mounting slots of the small V are equipped with high coercivity permanent magnets. The first magnetic part 61 of the large V is a series magnetic circuit composite permanent magnet, which includes a high coercivity permanent magnet placed near the air gap and a low coercivity permanent magnet placed away from the air gap. The second magnetic part 62 of the large V is a high coercivity permanent magnet.

[0371] Example 17:

[0372] As shown in Figure 43, the permanent magnet mounting slot is in the form of "I + V": "outer layer I + inner layer large V". The permanent magnet in the outer layer I mounting slot is divided into a first magnetic part 61 and a second magnetic part 62 by the magnetic pole center line. The first magnetic part 61 and the second magnetic part 62 are both series magnetic circuit composite permanent magnets, and include a high coercivity permanent magnet placed near the air gap and a low coercivity permanent magnet placed away from the air gap. The first magnetic part 61 of the large V is a series magnetic circuit composite permanent magnet, and includes a high coercivity permanent magnet placed near the air gap and a low coercivity permanent magnet placed away from the air gap. The second magnetic part 62 of the large V is a high coercivity permanent magnet.

[0373] Example 18:

[0374] As shown in Figure 44, the permanent magnet mounting slot is in the form of "I+V": "outer layer I-shaped + inner layer large V". The permanent magnets in the outer layer I-shaped mounting slot are divided into the first magnetic part 61 and the second magnetic part 62 by the magnetic pole center line. The first magnetic part 61 and the second magnetic part 62 are both composite permanent magnets with series magnetic circuits, and include a high coercivity permanent magnet placed near the air gap and a low coercivity permanent magnet placed away from the air gap. The first magnetic part 61 of the large V is a low coercivity permanent magnet, and the second magnetic part 62 of the large V is a high coercivity permanent magnet.

[0375] Example 19:

[0376] As shown in Figure 45, the permanent magnet mounting slot is in the form of "I+V+U": "outer layer I-shaped + middle layer small V-shaped + inner layer large U-shaped". The permanent magnets in the outer layer I-shaped and inner layer U-shaped mounting slots are divided into the first magnetic part 61 and the second magnetic part 62 by the magnetic pole center line. In the outer layer I-shaped slot, the first magnetic part 61 and the second magnetic part 62 are both high coercivity permanent magnets. In the large V-shaped slot, the first magnetic part 61 is a low coercivity permanent magnet, and the second magnetic part 62 is a high coercivity permanent magnet. In the large U-shaped slot, the first magnetic part 61 consists of low coercivity permanent magnets connected in parallel, and the second magnetic part 62 consists of low coercivity permanent magnets and high coercivity permanent magnets connected in parallel.

[0377] It should be noted that the above embodiments are merely examples. In actual applications, the arrangement of permanent magnets may not be limited to the above embodiments. Technicians may design them according to actual needs, and this application does not impose any specific limitations on them.

[0378] Furthermore, as in Embodiments 13 to 19, the permanent magnet comprises two layers that are generally distributed radially along the rotor core 1; as in Embodiment 7, the permanent magnet comprises three layers that are generally distributed radially along the rotor core 1. This application does not specifically limit these aspects.

[0379] In summary, the rotors provided in some embodiments of this application have at least the following advantages:

[0380] In some embodiments of this application, the magnetic poles on the rotor core include two asymmetrical first and second magnetic parts with different coercivities. Since the magnetization state of a permanent magnet with lower coercivity is easier to change than that of a permanent magnet with higher coercivity, the magnetization degree of the magnetic part with lower coercivity can be changed under conditions requiring magnetic adjustment, thereby achieving adjustment of the air gap flux. When the coercivities of the two magnetic parts of the rotor poles are the same, the demagnetization rate of the magnetic part facing the reverse direction is much greater than that of the magnetic part facing the forward direction. Compared to this type of rotor, the rotor provided in this application embodiment increases the coercivity of the magnetic part facing the reverse direction, thereby reducing the demagnetization rate of this magnetic part, making the overall demagnetization rate of the magnetic poles more uniform, and improving the rotor's load magnetic stability capability.

[0381] In addition, the rotors provided by some embodiments of this application can also achieve the following beneficial effects:

[0382] First, it achieves magnetic field regulation function, combining the advantages of constant torque region and constant power region, effectively expanding the constant power operation region and high efficiency region while ensuring high torque density and power density.

[0383] Second, introducing additional degrees of freedom in magnetization helps reduce the dependence on the armature direct-axis weak magnetic current in the medium- and high-speed regions, thereby reducing the risk of irreversible demagnetization of the permanent magnet.

[0384] Third, it enables effective adjustment of the permanent magnet magnetic field, allowing real-time control of the motor's no-load back EMF and voltage. For example, in the low-speed region, adjusting the magnet can increase the no-load back EMF (i.e., permanent magnet flux linkage), thereby increasing the torque and power performance in the low-speed region. In the high-speed region, adjusting the magnet can reduce the no-load back EMF in real time, which can not only reduce core losses, widen the constant power region, and increase the peak torque / power in the high-speed region, but also prevent the inverter from being damaged by overvoltage, adding a layer of protection to the electric drive system.

[0385] Fourth, it helps to improve the high-efficiency range of the motor and achieve a high degree of matching between the high-efficiency range of the motor and the operating point of the new energy vehicle, thereby reducing power consumption and improving economy.

[0386] Fifth, by applying an instantaneous pulsed magnetic adjustment current (direct-axis current) to the stator winding 31, a magnetic adjustment magnetic field rotating synchronously with the rotor is generated. This changes the magnetization state of the low-coercivity permanent magnets on the rotor, thereby altering the air gap flux and achieving real-time online magnetic adjustment. Because it is an instantaneous pulsed current, the magnetic adjustment loss is very low, improving motor efficiency. While achieving effective and flexible adjustment of the air gap magnetic field of the permanent magnet motor, it effectively improves the stable operation capability of all permanent magnets under all operating conditions, as well as the torque output capability, thereby achieving efficient and stable operation of the permanent magnet motor across the entire operating range and effectively improving the overall vehicle power and economy.

[0387] As shown in Figures 1-4, some embodiments of this application also disclose an electric motor, including a stator 3 and a rotor of any of the above-mentioned types; the stator 3 is disposed on the radial inner side and / or radial outer side of the rotor.

[0388] Specifically, the stator 3 includes a stator core 30 and a stator winding 31. The stator winding 31 is mounted on the stator core 30 and is used to pass three-phase alternating current and generate an alternating magnetic field. This alternating magnetic field interacts with the constant magnetic field generated by the permanent magnets in the magnetic poles 2 and generates torque, causing the rotor to rotate under the torque. The stator winding 31 in this application can be any feasible winding form, such as distributed winding or concentrated winding. Among them, distributed winding, due to its more uniform current distribution, can reduce harmonic generation, reduce motor noise and vibration, and improve motor operating efficiency, and can be regarded as a preferred winding form.

[0389] Stator 3 is located on the radial outer side of the rotor, and the corresponding motor is an inner rotor motor. Stator 3 is located on the radial inner side of the rotor, and the corresponding motor is an outer rotor motor.

[0390] It should be noted that the accompanying drawings of some embodiments of this application only show the case where the stator 3 is disposed on the radially outer side (i.e., the inner rotor) of the core unit 10. In actual applications, the stator 3 can also be disposed on the radially inner side (i.e., the outer rotor) of the core unit 10. This is not limited here, and those skilled in the art can make adjustments according to actual needs.

[0391] In addition, the motor also includes a rotating shaft 5 and a baffle 4. The rotor and stator 3 are sleeved on the rotating shaft 5. The baffle 4 is arranged on both sides of the rotor that are axially opposite each other. The baffle 4 is used to limit the movement of the rotor along the axial direction to prevent the unit rotor from being separated from the rotating shaft 5 by centrifugal force during rotation.

[0392] Because the rotors in some embodiments of this application possess both excellent magnetic adjustment and magnetic stabilization capabilities, the motor can operate stably and reliably under all operating conditions. It should be noted that in some embodiments of this application, the rotor structure is the same as that of any of the rotors described above, and its beneficial effects are similar; therefore, further details will not be elaborated upon here.

[0393] In some embodiments, the magnetic pole 2 includes a multilayer permanent magnet group arranged in the radial direction of the rotor core 1, and the permanent magnet in each layer of the permanent magnet group is a composite permanent magnet 202.

[0394] In this embodiment, since the permanent magnets in each layer of permanent magnet group are all composite permanent magnets 202, if the magnetic flux generated by the stator winding 31 passes through the low coercivity permanent magnet in the composite permanent magnet 202, it must pass through the high coercivity permanent magnet part of each permanent magnet. Thus, all permanent magnets have strong magnetic stability, which further improves the stability and controllability of the rotor magnetic field, enabling the motor to maintain excellent performance under various operating conditions.

[0395] In some embodiments, the magnetic pole 2 includes a multilayer permanent magnet group arranged in the radial direction of the rotor core 1. The multilayer permanent magnet group includes at least a first permanent magnet group 200 and a second permanent magnet group 211. The first permanent magnet group 200 is arranged close to the air gap between the stator 3 and the rotor, and the second permanent magnet group 211 is arranged away from the air gap. The first permanent magnet group 200 includes a first permanent magnet 221 or a second permanent magnet 222, and the second permanent magnet group 211 includes at least one composite permanent magnet 202.

[0396] Specifically, the permanent magnets in the first permanent magnet group 200 can be the first permanent magnet 201 and / or the second permanent magnet 203, while the permanent magnets in the second permanent magnet group 211 are all composite permanent magnets 202. This allows for more precise control of the magnetic field distribution inside the motor, creating more complex magnetic field gradients, improving motor efficiency, and providing multiple arrangement methods for permanent magnets in multi-layer permanent magnet groups. This offers greater flexibility, wider applicability, and enriches the rotor's application scenarios.

[0397] In one embodiment, the permanent magnet in the first permanent magnet group 200 is a first permanent magnet 201, and the permanent magnet in the second permanent magnet group 211 is a composite permanent magnet 202. In this case, the first permanent magnet group 200 is located close to the air gap, and the second permanent magnet group 211 is located away from the air gap. Compared with the scheme where the permanent magnet in the first permanent magnet group 200 is a second permanent magnet 203, and the permanent magnet in the second permanent magnet group 211 is a composite permanent magnet 202, in which case the first permanent magnet group 200 is located close to the air gap and the second permanent magnet group 211 is located away from the air gap, the risk of demagnetization of the rotor on the air gap side can be reduced, so as to ensure the rotor's magnetic stability capability on the air gap side.

[0398] The first permanent magnet 201 with high coercivity is set on the side near the air gap between the rotor and the stator 3. The first permanent magnet 201 in the composite permanent magnet 202 is also set on the side near the air gap. In this way, the multi-layer high coercivity permanent magnet can further effectively resist the magnetization reversal or demagnetization caused by external electromagnetic interference, temperature fluctuations and other factors during motor operation. This allows the motor to maintain a stable magnetic field output even under harsh working conditions, thus extending the service life and reliability of the motor.

[0399] In some embodiments of this application, the motor further includes a motor controller, which is electrically connected to the stator winding 31 of the stator 3. The motor controller is used to output an instantaneous pulse current to generate a magnetic field acting on the magnetic structure by the stator winding 31, so as to change the air gap flux of the second magnetic part.

[0400] In some embodiments of this application, by setting a motor controller, the motor controller can apply an instantaneous pulse current to the stator winding 31 so that the stator winding 31 generates a magnetic field acting on the magnetic structure, thereby changing the magnetization state of the second magnetic part with a smaller coercivity, and thus changing the size of the air gap magnetic flux, thereby realizing real-time online magnetic adjustment.

[0401] In some embodiments, the motor controller can apply an instantaneous pulse current to the stator winding 31 to generate a magnetic field acting on the magnetic pole 2 on the rotor, thereby changing the magnetization state of the permanent magnet with low coercivity in the magnetic pole 2, and thus changing the size of the air gap flux to achieve online magnetic adjustment.

[0402] It should be noted that the motor controller used to output instantaneous pulse current and the motor controller used to output operating current can be shared or set separately. Using instantaneous pulse current (direct-axis current) can reduce magnetization losses and improve motor efficiency. Furthermore, by introducing additional magnetization freedom, it is beneficial to reduce the dependence on armature direct-axis weakening current in the medium and high-speed range, thereby reducing the risk of irreversible demagnetization of the permanent magnet. Specifically, by effectively adjusting the air gap flux, the no-load back EMF and voltage of the motor can be controlled in real time. For example, in the low-speed range, magnetization can increase the no-load back EMF (i.e., permanent magnet flux linkage), thereby increasing the torque performance and power in the low-speed range. In the high-speed range, magnetization can reduce the no-load back EMF in real time, which not only reduces core losses, widens the constant power range, and increases peak torque / power in the high-speed range, but also avoids inverter overvoltage damage to power devices, adding a layer of protection to the electric drive system.

[0403] Specifically, referring to Figures 30 and 31, a low-coercivity permanent magnet can achieve 100% complete magnetization and 30% incomplete magnetization under the action of an instantaneous pulse current. As can be seen from Figures 30 and 31, the magnetic flux generated by the permanent magnet varies with the magnetization state, thereby enabling the adjustment of the air gap flux. Figure 33 shows the speed-torque curves of a conventional permanent magnet motor, an existing variable flux motor, and the motor of this application in some embodiments of this application. Figure 32 shows a schematic diagram of the electrical angle-back EMF curves of a low-coercivity permanent magnet in a 100% magnetization state and a 30% magnetization state. As shown in Figure 32, the no-load back EMF and voltage of the motor can be controlled in real time by effectively adjusting the air gap flux. As shown in Figure 33, in the low-speed region, Figures 32 and 33 show that adjusting the magnet can increase the no-load back EMF (i.e., permanent magnet flux linkage), thereby increasing the torque and power performance of the motor in the low-speed region. In the high-speed region, Figures 32 and 33 show that adjusting the magnet can reduce the no-load back EMF in real time, which can not only reduce core losses, widen the constant power region, and increase the peak torque / power in the high-speed region, but also prevent the inverter from being damaged by overvoltage, adding a layer of protection to the electric drive system. As shown in Figure 34, the speed-torque curves of a traditional permanent magnet motor, an existing variable flux motor, and the motor of this application in the high-efficiency region are shown in some embodiments of this application. The high-efficiency region curve is a similar circular schematic diagram to that in Figure 24. As shown in Figure 34, the motor provided by this application is beneficial to improving the high-efficiency region of the motor and achieving a high degree of matching between the high-efficiency region of the motor and the operating point of the new energy vehicle, thereby reducing power consumption and improving economy.

[0404] Some embodiments of this application also provide a powertrain including the motor of any of the above embodiments. Because the motors of some embodiments of this application possess both good magnetic adjustment and magnetic stabilization capabilities, the motors can operate stably and reliably under all operating conditions, and can be highly matched to the vehicle's operating point, thereby reducing energy consumption and improving economy.

[0405] It should be noted that the powertrain can be a pure electric powertrain, a hybrid powertrain, or other types, and it can be equipped with any drive architecture, such as centralized drive, four-wheel drive, two-wheel drive, wheel-side drive, etc.

[0406] Some embodiments of this application also provide a vehicle, including the motor or powertrain described above. The motor or powertrain provided in this application can be applied to all new energy electric vehicles, including hybrid, pure electric, and range-extended electric vehicles, and can also be mounted on any drive architecture, including centralized drive, four-wheel drive, two-wheel drive, and wheel-side drive.

[0407] In some embodiments of this application, the structure of the motor or powertrain is the same as that of the motor or powertrain in any of the above embodiments, and its beneficial effects are similar, so they will not be described in detail here.

[0408] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0409] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor, wherein, The rotor includes: The rotor core and a plurality of magnetic poles spaced apart circumferentially along the rotor core; the magnetic poles include adjacent first magnetic poles and second magnetic poles, wherein the coercivity of at least one permanent magnet in the first magnetic pole is different from the coercivity of the permanent magnet in the second magnetic pole.

2. The rotor according to claim 1, wherein, The first magnetic pole is provided with a first permanent magnet group, and the second magnetic pole is provided with a second permanent magnet group. The coercivity of the first permanent magnet group is less than that of the second permanent magnet group.

3. The rotor according to claim 2, wherein, Both the first permanent magnet group and the second permanent magnet group are single layers, and the coercivity of at least one permanent magnet in the first permanent magnet group is less than the coercivity of the permanent magnet in the second permanent magnet group.

4. The rotor according to claim 2, wherein, The first permanent magnet group includes multiple layers of first permanent magnet units, which are arranged radially at intervals along the rotor core; at least one layer of the first permanent magnet unit includes at least one first permanent magnet and / or at least one composite permanent magnet, wherein the composite permanent magnet is composed of a first permanent magnet and a second permanent magnet, and the coercivity of the first permanent magnet is less than that of the second permanent magnet.

5. The rotor according to claim 4, wherein, The first permanent magnet group further includes a second permanent magnet, which is arranged radially spaced from the first permanent magnet along the rotor core, and / or the second permanent magnet is arranged radially spaced from the composite permanent magnet along the rotor core.

6. The rotor according to claim 5, wherein, The first permanent magnet assembly includes a first permanent magnet and a second permanent magnet, wherein the second permanent magnet is adapted to be arranged close to the gap between the rotor and the stator, and the first permanent magnet is adapted to be arranged away from the gap.

7. The rotor according to claim 5, wherein, The first permanent magnet group includes the composite permanent magnet and the second permanent magnet. The composite permanent magnet is disposed on the radial outer side of the rotor core, or the composite permanent magnet is disposed on the radial inner side of the rotor core.

8. The rotor according to claim 4, wherein, The composite permanent magnets form a series magnetic circuit structure or a parallel magnetic circuit structure.

9. The rotor according to claim 4, wherein, The first permanent magnet group further includes a second permanent magnet, which is arranged circumferentially with the first permanent magnet along the rotor core, and / or the second permanent magnet is arranged circumferentially with the composite permanent magnet along the rotor core.

10. The rotor according to claim 4, wherein the first permanent magnet group further includes a plurality of second permanent magnets, the second permanent magnets and the first permanent magnets being arranged at radial and circumferential intervals along the rotor core, and / or the second permanent magnets and the composite permanent magnets being arranged at radial and circumferential intervals along the rotor core.

11. The rotor according to claim 4, wherein, The first permanent magnet and the second permanent magnet in the composite permanent magnet are arranged sequentially along the radial direction of the rotor core. The first permanent magnet is adapted to be arranged away from the air gap between the rotor and the stator, and the second permanent magnet is adapted to be arranged close to the air gap.

12. The rotor according to any one of claims 4-11, wherein, The second permanent magnet assembly includes multiple layers of second permanent magnet units, which are arranged radially along the rotor core. Each layer of the second permanent magnet unit includes at least one third permanent magnet.

13. The rotor according to claim 12, wherein, The permanent magnets in each layer of the second permanent magnet unit are the third permanent magnets.

14. The rotor according to claim 12, wherein, The coercivity of the third permanent magnet is greater than or equal to that of the second permanent magnet.

15. The rotor according to any one of claims 2-14, wherein, The first permanent magnet group has a first magnetic pole center line, and the second permanent magnet group has a second magnetic pole center line. The first permanent magnet group is symmetrically arranged about the first magnetic pole center line, and the second permanent magnet group is symmetrically arranged about the second magnetic pole center line.

16. The rotor according to any one of claims 1-15, wherein, The magnetic pole includes at least one permanent magnet, wherein the permanent magnet is at least one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, and Iron Nitride permanent magnet.

17. The rotor according to any one of claims 1-15, wherein, The first magnetic pole and the second magnetic pole are alternately arranged along the circumference of the rotor core, with the first magnetic pole being one of the positive and negative poles and the second magnetic pole being the other of the positive and negative poles.

18. The rotor according to any one of claims 1-15, wherein, The rotor core is provided with a mounting groove, and the permanent magnet in the magnetic pole is disposed in the mounting groove.

19. The rotor according to claim 18, wherein, At least one permanent magnet of the magnetic pole is placed in one of the mounting slots.

20. The rotor according to claim 18, wherein, The mounting slots are multiple, and the multiple mounting slots form a preset shape. The preset shape includes one or more of the following: straight, arc, V, U, and W.

21. The rotor according to any one of claims 1-15, wherein, The magnetic pole also includes at least one auxiliary slot, and the rotor core has a peripheral wall, on which the auxiliary slot is disposed.

22. The rotor according to any one of claims 1-15, wherein, The rotor core includes multiple core units, which are arranged sequentially along the axial direction of the rotor core.

23. The rotor according to claim 22, wherein, There is an offset angle between two adjacent core units along the circumference of the rotor core, and the magnetic poles on two adjacent core units are arranged in the same way, and / or the magnetic poles on two adjacent core units are arranged in different ways.

24. A rotor, wherein, The rotor includes: a rotor core and a plurality of magnetic poles distributed circumferentially along the rotor core; the magnetic poles include at least one composite permanent magnet, the composite permanent magnet being a series magnetic circuit structure composed of a first permanent magnet and a second permanent magnet with different coercivity.

25. The rotor according to claim 24, wherein, The first permanent magnet and the second permanent magnet are arranged sequentially along the radial direction of the rotor core.

26. The rotor according to claim 25, wherein, The coercivity of the first permanent magnet is greater than that of the second permanent magnet. The first permanent magnet is adapted to be arranged close to the air gap between the rotor and the stator, and the second permanent magnet is adapted to be arranged away from the air gap.

27. The rotor according to claim 25, wherein, The thickness of the first permanent magnet along the radial direction is 0.05-0.9 times the thickness of the composite permanent magnet along the radial direction.

28. The rotor according to claim 24, wherein, The magnetic pole further includes the first permanent magnet and / or the second permanent magnet, wherein the first permanent magnet and the composite permanent magnet are arranged along the radial direction of the rotor core, and / or the second permanent magnet and the composite permanent magnet are arranged along the radial direction of the rotor core.

29. The rotor according to claim 28, wherein, The first permanent magnet or the second permanent magnet is any one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, or Iron Nitride permanent magnet.

30. The rotor according to claim 24, wherein, The magnetic poles include a multi-layer permanent magnet assembly arranged along the radial direction of the rotor core, and at least one layer of the permanent magnet assembly includes at least one of the composite permanent magnets.

31. The rotor according to claim 30, wherein, At least one layer of the permanent magnet group consists of the composite permanent magnet.

32. The rotor according to claim 30, wherein, Each layer of the permanent magnet assembly includes at least one of the composite permanent magnets.

33. The rotor according to claim 30, wherein, The permanent magnets in each layer of the permanent magnet assembly are composite permanent magnets.

34. The rotor according to claim 30, wherein, The multilayer permanent magnet group includes at least a first permanent magnet group and a second permanent magnet group. The first permanent magnet group is adapted to be arranged close to the air gap between the rotor and the stator, and the second permanent magnet group is adapted to be arranged away from the air gap. The first permanent magnet group includes the first permanent magnet and / or the second permanent magnet, and the second permanent magnet group includes at least one of the composite permanent magnets.

35. The rotor according to claim 30, wherein, The permanent magnets in each layer of the permanent magnet assembly are arranged symmetrically about the center line of the magnetic poles.

36. The rotor according to any one of claims 24-35, wherein, The composite permanent magnet includes at least one of the following: ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, and Iron Nitride permanent magnet.

37. The rotor according to any one of claims 24-35, wherein, The permanent magnet in the magnetic pole includes the composite permanent magnet, or a combination of at least one of the first permanent magnet and the second permanent magnet with the composite permanent magnet. The rotor core is provided with a mounting groove, and the permanent magnet in the magnetic pole is disposed in the mounting groove.

38. The rotor according to claim 37, wherein, At least one permanent magnet of the magnetic pole is placed in one of the mounting slots.

39. The rotor according to claim 37, wherein, The magnetic pole contains multiple permanent magnets, and there are multiple mounting slots. The multiple mounting slots form a preset shape, which includes one or more of the following: straight, arc, V, U, and W.

40. The rotor according to any one of claims 24-35, wherein, The magnetic pole also includes at least one auxiliary slot, and the rotor core has a peripheral wall, on which the auxiliary slot is disposed.

41. The rotor according to any one of claims 24-40, wherein, The rotor core includes multiple core units, which are arranged sequentially along the axial direction of the rotor core.

42. The rotor according to claim 41, wherein, There is an offset angle between two adjacent core units along the circumference of the rotor core, and the magnetic poles on two adjacent core units are arranged in the same way, and / or the magnetic poles on two adjacent core units are arranged in different ways.

43. A rotor, wherein, It includes a rotor core and multiple magnetic poles, wherein the multiple magnetic poles are distributed at circumferential intervals along the rotor core; The magnetic pole includes a first magnetic portion and a second magnetic portion, wherein the first magnetic portion and the second magnetic portion are asymmetrically arranged about the center line of the magnetic pole; wherein... The coercivity of the first magnetic part is different from that of the second magnetic part.

44. The rotor according to claim 43, wherein, The coercivity of the first magnetic part is less than that of the second magnetic part; wherein... The first magnetic part is adapted to be disposed on the side of the magnetic pole facing the forward rotation direction of the motor, and the second magnetic part is adapted to be disposed on the side of the magnetic pole facing the reverse rotation direction of the motor.

45. The rotor according to claim 44, wherein, The first magnetic part includes a fifth permanent magnet and / or a first composite permanent magnet. The first composite permanent magnet includes the fifth permanent magnet and a sixth permanent magnet, and the coercivity of the fifth permanent magnet is less than that of the sixth permanent magnet.

46. ​​The rotor according to claim 45, wherein, The first magnetic part includes multiple layers of fifth permanent magnet units, which are arranged radially spaced along the rotor core. At least one layer of the fifth permanent magnet unit is provided with at least one fifth permanent magnet and / or at least one first composite permanent magnet.

47. The rotor according to claim 45, wherein, The first magnetic part further includes the sixth permanent magnet, which is arranged radially spaced from the fifth permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged radially spaced from the first composite permanent magnet along the rotor core.

48. The rotor according to claim 47, wherein, The sixth permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

49. The rotor according to claim 45, wherein, The first magnetic part further includes the sixth permanent magnet, which is arranged circumferentially with the fifth permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged circumferentially with the first composite permanent magnet along the rotor core.

50. The rotor according to claim 45, wherein, The first magnetic part further includes a plurality of the sixth permanent magnets, which are arranged at intervals with the fifth permanent magnets along the radial and circumferential directions of the rotor core, and / or, the sixth permanent magnets are arranged at intervals with the first composite permanent magnet along the radial and circumferential directions of the rotor core.

51. The rotor according to claim 45, wherein, The first composite permanent magnet forms a series magnetic circuit structure or a parallel magnetic circuit structure.

52. The rotor according to claim 45, wherein, The first magnetic part includes the first composite permanent magnet, wherein the fifth permanent magnet and the sixth permanent magnet in the first composite permanent magnet are alternately arranged along the radial direction of the rotor core to form a series magnetic circuit structure.

53. The rotor according to claim 45, wherein, The first magnetic part includes the first composite permanent magnet, wherein the fifth permanent magnet and the sixth permanent magnet in the first composite permanent magnet are alternately arranged along the circumference of the rotor core to form a parallel magnetic circuit structure.

54. The rotor according to claim 45, wherein, The first composite permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

55. The rotor according to any one of claims 45 to 54, wherein, The second magnetic part includes a seventh permanent magnet and / or a second composite permanent magnet. The second composite permanent magnet includes the seventh permanent magnet and an eighth permanent magnet, and the coercivity of the seventh permanent magnet is greater than that of the eighth permanent magnet.

56. The rotor according to claim 55, wherein, The second magnetic part includes multiple layers of sixth permanent magnet units, which are arranged radially spaced along the rotor core. At least one layer of the sixth permanent magnet units is provided with at least one seventh permanent magnet and / or at least one second composite permanent magnet.

57. The rotor according to claim 55, wherein, The second magnetic part further includes the eighth permanent magnet, which is arranged radially spaced from the seventh permanent magnet along the rotor core, and / or the sixth permanent magnet is arranged radially spaced from the second composite permanent magnet along the rotor core.

58. The rotor according to claim 57, wherein, The seventh permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

59. The rotor according to claim 55, wherein, The second magnetic part further includes the eighth permanent magnet, which is arranged circumferentially with the seventh permanent magnet along the rotor core, and / or the eighth permanent magnet is arranged circumferentially with the second composite permanent magnet along the rotor core.

60. The rotor according to claim 55, wherein, The second magnetic part further includes a plurality of the eighth permanent magnets, which are arranged at intervals with the seventh permanent magnets along the radial and circumferential directions of the rotor core, and / or, the eighth permanent magnets and the second composite permanent magnets are arranged at intervals along the radial and circumferential directions of the rotor core.

61. The rotor according to claim 55, wherein, The second magnetic part includes the second composite permanent magnet, which forms a series magnetic circuit structure or a parallel magnetic circuit structure.

62. The rotor according to claim 55, wherein, The second magnetic part includes the second composite permanent magnet, wherein the seventh and eighth permanent magnets of the second composite permanent magnet are alternately arranged along the radial direction of the rotor core to form a series magnetic circuit structure.

63. The rotor according to claim 55, wherein, The second magnetic part includes the second composite permanent magnet, and the seventh and eighth permanent magnets of the second composite permanent magnet are alternately arranged along the circumference of the rotor core to form a parallel magnetic circuit structure.

64. The rotor according to claim 55, wherein, The second composite permanent magnet is adapted to be arranged close to the gap between the rotor and the stator.

65. The rotor according to claim 56, wherein, The coercivity of the seventh permanent magnet is greater than or equal to that of the sixth permanent magnet.

66. The rotor according to claim 65, wherein, The coercivity of the eighth permanent magnet is less than or equal to the coercivity of the sixth permanent magnet.

67. The rotor according to claim 66, wherein, The coercivity of the seventh permanent magnet is equal to that of the sixth permanent magnet, and / or the coercivity of the eighth permanent magnet is equal to that of the fifth permanent magnet.

68. The rotor according to claim 43 or 44, wherein, Both the first magnetic part and the second magnetic part include at least one permanent magnet, wherein the permanent magnet is at least one of ferrite permanent magnet, AlNiCo permanent magnet, NdFeB permanent magnet, Samarium Cobalt permanent magnet, and Iron Nitride permanent magnet.

69. The rotor according to claim 43 or 44, wherein, The rotor core is provided with a first mounting slot group and a second mounting slot group symmetrically distributed about the center line of the magnetic poles, and the first magnetic part and the second magnetic part are respectively disposed in the first mounting slot group and the second mounting slot group.

70. The rotor according to claim 69, wherein, Both the first mounting slot group and the second mounting slot group include at least one mounting slot, and the mounting slots of the first mounting slot group and the second mounting slot group form a preset shape in the circumferential direction of the rotor core.

71. The rotor according to claim 70, wherein, The preset shape includes one or more of the following: arc shape, straight line shape, V shape, U shape, and W shape.

72. The rotor according to claim 43 or 44, wherein, The rotor core includes multiple core units, which are arranged sequentially along the axial direction of the rotor core.

73. The rotor according to claim 72, wherein, There is a circumferential offset angle between two adjacent core units, wherein the magnetic poles on the two adjacent core units are arranged in the same way, or the magnetic poles on the two adjacent core units are arranged in different ways.

74. An electric motor, wherein, include: The stator and the rotor according to any one of claims 1-73; The stator is disposed on the radial inner side and / or radial outer side of the rotor.

75. The motor according to claim 74, wherein, The motor also includes a motor controller, which is electrically connected to the stator winding of the stator. The motor controller is used to output an instantaneous pulse current to cause the stator winding to generate a magnetic field acting on the rotor, thereby changing the magnetic flux through the rotor.

76. A powertrain, wherein, Includes the motor described in claim 74 or 75.

77. A vehicle, wherein, include: The motor as described in claim 74 or 75, or the powertrain as described in claim 76.

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