Rotor assembly, electric motor and vehicle

Abstract

A rotor assembly (100), an electric motor (2000) and a vehicle. The rotor assembly (100) comprises a rotor body (1) and a plurality of magnetic member groups (2), wherein the rotor body (1) is made of an amorphous material; the rotor body (1) has a plurality of sector regions (11) distributed in the circumferential direction thereof; the sector regions (11) have center lines (L) in the circumferential direction of the rotor body (1); one of the plurality of magnetic member groups (2) is provided in each sector region (11); each magnetic member group (2) can form or generate a magnetic field in the sector region (11) where said magnetic member group (2) is located; and the magnetic fields are asymmetrically distributed along the center lines (L).

Description

Rotor assembly, motor and vehicle

[0001] This application claims priority to Chinese Patent Application No. 202411999024.2, filed on December 31, 2024, and Chinese Patent Application No. 202411720206.1, filed on November 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of vehicle technology, and more particularly to a rotor assembly, an electric motor, and a vehicle. Background Technology

[0003] Electric motors are widely used as drive devices in various fields. In recent years, with the rise of electric vehicles, the importance of drive motors, which propel vehicles, has become self-evident. Summary of the Invention

[0004] In a first aspect, a rotor assembly is provided, including a rotor body and a plurality of magnetic component groups. The rotor body is made of an amorphous material and has a plurality of fan-shaped regions distributed along its circumference, each fan-shaped region having a center line along the circumference of the rotor body.

[0005] Each sector area is equipped with one of multiple magnetic component groups. Each magnetic component group can generate a magnetic field within its sector area, and the magnetic field is asymmetrically distributed along the center line.

[0006] In a second aspect, a rotor assembly is provided, including a rotor body made of amorphous material. The rotor body has multiple fan-shaped regions distributed along its circumference. Each fan-shaped region has a center line along the circumference of the rotor body. A first magnetic component and a second magnetic component are provided in each fan-shaped region. The first magnetic component and the second magnetic component are respectively located on both sides of the center line. The volume of the first magnetic component is greater than or less than the volume of the second magnetic component; or, the coercivity of the first magnetic component is greater than or less than the coercivity of the second magnetic component; or, the remanence of the first magnetic component is greater than or less than the remanence of the second magnetic component; or, in each sector region, the shapes of the first and second magnetic components are asymmetrically distributed relative to the center line; or, in each sector region, the positions of the first and second magnetic components are asymmetrically distributed relative to the center line; or, in each sector region, the orientation of the first and second magnetic components is asymmetrically distributed relative to the center line; or, in each sector region, the first and second magnetic components are of different types; or, in each sector region, a first receiving groove is provided at a position opposite to the first magnetic component, and a second receiving groove is provided at a position opposite to the second magnetic component; the first magnetic component is at least partially contained in the first receiving groove, and the second magnetic component is at least partially contained in the second receiving groove; in each sector region, the first and second receiving grooves are asymmetrically arranged relative to the center line.

[0007] Thirdly, an electric motor is provided, including the rotor assembly described above and a stator assembly disposed around the rotor assembly.

[0008] Fourthly, an electric powertrain is provided, including the aforementioned motor or the aforementioned rotor assembly.

[0009] Fifthly, a vehicle is provided, the vehicle including the rotor assembly described above or the motor described above. Attached Figure Description

[0010] Figure 1 is a structural diagram of a motor rotor according to some embodiments;

[0011] Figure 2 is a structural diagram of a sector-shaped region according to some embodiments;

[0012] Figure 3 is a structural diagram of another sector region according to some embodiments;

[0013] Figure 4 is a comparison diagram of the torque components of an electric motor under different currents according to some embodiments;

[0014] Figure 5A is a magnetic flux density distribution diagram of the motor rotor in a motor A in the related art;

[0015] Figure 5B is a magnetic flux density distribution diagram of the motor rotor in a motor B according to some embodiments;

[0016] Figure 6A is a comparison diagram of the d-axis inductance of motor B and motor A according to some embodiments;

[0017] Figure 6B is a comparison diagram of the q-axis inductance of a motor B and a motor A according to some embodiments;

[0018] Figure 7 shows the magnetization direction of a magnetic material in different shapes according to some embodiments;

[0019] Figure 8 is a schematic diagram of a rotor assembly according to some embodiments;

[0020] Figure 9 is an enlarged view of the sector-shaped region in Figure 8;

[0021] Figure 10 shows the stress simulation diagram of the sector region in Figure 9;

[0022] Figure 11 is a cross-sectional view of a magnet according to some embodiments;

[0023] Figure 12 is a schematic diagram showing the effect of rotor stack diameter ratio on yield of rotor assembly according to some embodiments;

[0024] Figure 13 is a schematic diagram of a rotor assembly provided according to some embodiments;

[0025] Figure 14 is a partial schematic diagram of a motor according to some embodiments;

[0026] Figure 15 is a schematic diagram of a partial module of a motor according to some embodiments;

[0027] Figure 16 is a schematic diagram of a vehicle module according to some embodiments. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this disclosure more apparent and understandable, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The terms "first," "second," etc., used in the specification and claims of this disclosure may explicitly or implicitly include one or more of the features. In the description of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 disclosure and simplifying the description, and are not intended to 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 disclosure.

[0031] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" 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 of two components. Those skilled in the art will understand the meaning of the above terms in this disclosure based on the actual situation.

[0032] Rotor assemblies (such as motor rotors) are an important component of electric motors, which are used in vehicles as drive motors or generators. Conventional rotor assemblies use crystalline materials; however, crystalline materials have high losses, which cannot meet the high-efficiency requirements of vehicle motors.

[0033] To address the aforementioned problems, some embodiments of this disclosure provide a rotor assembly 100, which includes a rotor body 1 made of an amorphous material. Compared to crystalline materials, amorphous materials have disordered atomic arrangement, resulting in low losses. This allows the motor to simultaneously achieve high output efficiency and high output torque, thus meeting the high-efficiency requirements of vehicle motors.

[0034] However, in the rotor assembly 100 provided in some embodiments of this disclosure, after the magnetic component group 2 is disposed on the rotor body 1, the magnetic field of the magnetic component group 2 and the stator assembly 120 are superimposed, and magnetic field superposition will occur in some areas. After the magnetic field superposition in these areas, there is an area with a large magnetic field density, which becomes the magnetic field superposition point. When the magnetic field density at the magnetic field superposition point is large, saturation suppression is likely to occur, which affects the efficiency improvement of the motor.

[0035] Magnetic component group 2 may include multiple magnetic components, which can be permanent magnets or soft magnets. For example, permanent magnets such as steel magnets and ferrites are used as magnetic components, in which case the type of motor is a permanent magnet motor.

[0036] To achieve saturation suppression of the rotor assembly 100 and improve the efficiency of the motor, in some embodiments of this disclosure, the rotor body 1 has a plurality of sector regions 11 distributed along its axial direction, and each sector region 11 has a center line L along the axial direction of the rotor body 1. A magnetic component group 2 is arranged in each sector region 11, and the magnetic component group 2 can form a magnetic field in the sector region 11 in which it is located, and the magnetic field is asymmetrically distributed along the center line L.

[0037] In some embodiments, the number of sector regions 11 corresponds to the number of magnetic poles in the motor. As shown in Figures 1 and 3, when the motor has six poles, the rotor body 1 has six sector regions 11. The center line L of the sector region 11 refers to the straight line that divides the sector region 11 into two equal parts, and this straight line passes through the center of the rotor body 1. In the actual structure, there is a certain interval between two adjacent magnetic poles in the rotor body 1. The middle position of this interval is the boundary of the sector region 11. The boundary of the sector region 11 and the center line L of the sector region 11 can be obtained by measuring the actual dimensions. It is understood that the center line L described in some embodiments of this disclosure refers to a virtual line and is not depicted on the product structure. It is mainly used to assist in judging structural characteristics and does not limit the structure of the product itself.

[0038] In some embodiments, the rotor assembly 100 includes a rotor body 1, which is the main body structure of the rotor assembly 100. The rotor body 1 of the rotor assembly 100 includes a plurality of stacked rotor laminations, the number of which can be selected according to actual needs, and this disclosure does not limit it.

[0039] In some embodiments of this disclosure, as shown in FIG1, the rotor body 1 is an integrally formed circular structure, and the rotor body 1 may be provided with through holes 16 for passing through the rotating shaft. The rotor body 1 has a plurality of fan-shaped regions 11 distributed along its circumference, and the arrangement of each fan-shaped region 11 in the plurality of fan-shaped regions 11 may be the same. Some embodiments of this disclosure are described using only one fan-shaped region 11 as an example.

[0040] In some embodiments of this disclosure, the magnetic field formed by the magnetic component group 2 in the sector region 11 is asymmetrically distributed about the center line L of the sector region 11. In the magnetic field formed by the superposition of the magnetic components group 2 and the magnetic field of the motor stator, the magnetic field density at the superposition point can be reduced, thereby reducing the magnetic flux density saturation region, increasing the reluctance torque, improving the utilization rate of the magnetic body, and thus increasing the output power of the motor.

[0041] In some embodiments, the plurality of magnetic component groups 2 include a first magnetic component 21 and a second magnetic component 22; in each sector region 11, the first magnetic component 21 and the second magnetic component 22 are respectively located on both sides of the center line L, and the magnetic properties of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L.

[0042] In some embodiments of this disclosure, in a single sector region 11, a first magnetic component 21 and a second magnetic component 22 are disposed on both sides of the center line L. The magnetic properties of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L, which facilitates the asymmetrical distribution of the magnetic field generated by the magnetic component group 2 relative to the center line L in its respective sector region 11.

[0043] In some embodiments, the first magnetic component 21 and the second magnetic component 22 are both permanent magnets, so that the first magnetic component 21 and the second magnetic component 22 can always have magnetism, which helps to ensure the operation of the rotor assembly 100 and improve the output torque of the motor.

[0044] For example, each sector region 11 can be provided with a magnetic component group 2. In two adjacent sector regions 11, the first magnetic component 21 of one sector region 11 can be arranged adjacent to the first magnetic component 21 of the other sector region 11, or, in two adjacent sector regions 11, the first magnetic component 21 of one sector region 11 can be arranged adjacent to the second magnetic component 22 of the other sector region 11.

[0045] In some embodiments, in each sector region 11, the first magnetic component 21 and the second magnetic component 22 are disposed on both sides of the center line L. The magnetic properties of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L, so that the magnetic field generated by the magnetic component group 2 in a single sector region 11 is asymmetrically distributed relative to the center line L. As shown in FIG2, the first magnetic component 21 is located on the left side and the second magnetic component 22 is located on the right side. The magnetic field energy on the left side can be greater than or less than the magnetic field energy on the right side.

[0046] In some embodiments, the magnetic properties of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L, that is, the magnetic properties of the first magnetic component 21 and the second magnetic component 22 are different.

[0047] In some embodiments, the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in the same sector region 11 can be arranged asymmetrically with respect to the center line L by considering the position, structure and size of the first magnetic component 21 and the second magnetic component 22.

[0048] In some embodiments, the first magnetic component 21 and the second magnetic component 22 have different magnetic energy products, which can result in different magnetic properties for the first magnetic component 21 and the second magnetic component 22. The first magnetic component 21 and the second magnetic component 22 have different magnetic flux, i.e., different applied currents, which can result in different magnetic properties for the first magnetic component 21 and the second magnetic component 22. The first magnetic component 21 and the second magnetic component 22 have different magnetic fields, which can result in different magnetic properties for the first magnetic component 21 and the second magnetic component 22. The first magnetic component 21 and the second magnetic component 22 have different magnetic induction intensities, i.e., different magnetic flux density, which can result in different magnetic properties for the first magnetic component 21 and the second magnetic component 22. The first magnetic component 21 and the second magnetic component 22 have different magnetomotive forces, i.e., different applied voltages, which can result in different magnetic properties for the first magnetic component 21 and the second magnetic component 22.

[0049] In some embodiments, the fluxmeter can be connected to a single coil or a Helmholtz coil to measure the magnetic flux of the magnet. A magnetic field strength tester can be used to detect the magnetic field of the magnet. In some embodiments, the remanence, coercivity, etc., of the permanent magnet can also be tested using specialized instruments to obtain the magnetic energy product; this disclosure does not limit this approach.

[0050] In some embodiments, the magnetic energy of the first magnetic component 21 or the second magnetic component 22 can be reduced to achieve an asymmetrical distribution of magnetic energy about the center line L. This can increase the ratio of the motor's output torque to the sum of the magnetic energy of the magnetic component group 2, thereby improving the utilization rate of the magnetic energy of the magnetic component group 2. It also facilitates reducing the cost of the rotor assembly 100 by reducing the amount of rare earth elements used in the magnetic component group 2.

[0051] In some embodiments, the magnetic component group 2 accounts for a large proportion of the motor cost. By reducing the amount of magnetic component group 2 used, the effect of reducing the motor cost is more obvious.

[0052] In some embodiments, the magnetic field energy can be the product of the magnetic energy product and the volume, that is, the magnetic field energy of the first magnetic component 21 can be the product of the magnetic energy product and the volume of the first magnetic component 21, and the magnetic field energy of the second magnetic component 22 can be the product of the magnetic energy product and the volume of the second magnetic component 22.

[0053] In some embodiments, the magnetic energy product of the first magnetic component 21 may be greater than or less than (but not equal to) the magnetic energy product of the second magnetic component 22, which can improve the utilization rate of the sum of the magnetic energy products of the magnetic component group 2. Alternatively, the volume of the first magnetic component 21 may be greater than or less than (but not equal to) the volume of the second magnetic component 22, which can improve the utilization rate of the sum of the volumes of the magnetic component group 2.

[0054] In some embodiments, the magnetic energy product can be the product of remanence and coercivity. The magnetic energy product increases with increasing remanence and volume. Remanence (Br), measured in Gauss, is the magnetic flux density remaining after the magnetic field is removed from a saturated state, representing the strength of the magnetic field the magnet can provide. Coercivity (Hc), measured in Oersteds, is the ability of a magnet to resist demagnetization when placed in a reverse magnetic field and the field strength increases to a certain level. Magnetic energy product (BHmax), measured in Gauss-Oersteds, is the magnetic energy produced per unit volume of material, representing the amount of energy a magnet can store.

[0055] In some embodiments, when the coercivity of the first magnetic component 21 and the second magnetic component 22 is the same, and the remanence of the first magnetic component 21 is greater than that of the second magnetic component 22, then the magnetic energy product of the first magnetic component 21 is greater than that of the second magnetic component 22. Similarly, when the remanence of the first magnetic component 21 and the second magnetic component 22 is the same, and the coercivity of the first magnetic component 21 is greater than that of the second magnetic component 22, then the magnetic energy product of the first magnetic component 21 is greater than that of the second magnetic component 22.

[0056] For example, in a single sector region 11, the magnetic energy product of the first magnetic component 21 may be greater than or less than (not equal to) the magnetic energy product of the second magnetic component 22. As shown in FIG2, the first magnetic component 21 may be located on the front side of the rotor assembly 100 in the rotation direction, and the second magnetic component 22 may be located on the rear side of the rotor assembly 100 in the rotation direction; or, as shown in FIG3, the first magnetic component 21 may be located on the rear side of the rotor assembly 100 in the rotation direction, and the second magnetic component 22 may be located on the front side of the rotor assembly 100 in the rotation direction.

[0057] In some embodiments, in each sector region 11, the volume of the first magnetic component 21 is greater than or less than (not equal to) the volume of the second magnetic component 22, so as to ensure that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of the sector region 11.

[0058] In some embodiments, when the volume of the first magnetic component 21 is smaller than the volume of the second magnetic component 22, the volume ratio of the first magnetic component 21 to the second magnetic component 22 is in the range of [75%, 90%]. On the one hand, this can reduce the magnetic field energy of the first magnetic component 21, thereby improving the utilization rate of the magnetic field energy of the first magnetic component 21 and the second magnetic component 22. On the other hand, it can also effectively ensure that the rotor assembly 100 outputs sufficient torque.

[0059] In some embodiments, in each sector region 11, the coercivity of the first magnetic component 21 is greater than or less than (not equal to) the coercivity of the second magnetic component 22, so as to ensure that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of the sector region 11.

[0060] In some embodiments, in each sector region 11, the remanence of the first magnetic component 21 is greater than or less than (not equal to) the remanence of the second magnetic component 22, so as to ensure that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0061] In some embodiments, within the same sector region 11, when the remanence of the first magnetic component 21 and the second magnetic component 22 is the same, the coercivity of the first magnetic component 21 and the second magnetic component 22 can be designed to be different; when the coercivity of the first magnetic component 21 and the second magnetic component 22 is the same, the remanence of the first magnetic component 21 and the second magnetic component 22 can be designed to be different; or, the remanence of the first magnetic component 21 and the second magnetic component 22 can be designed to be different, and the coercivity can also be different, so as to achieve that the magnetic energy product of the first magnetic component 21 and the magnetic energy product of the second magnetic component 22 are different within a single sector region 11.

[0062] In some embodiments, in each sector region 11, the shapes of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L, which facilitates ensuring that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0063] For example, the first magnetic component 21 may be in the shape of a straight plate, while the second magnetic component 22 may be in the shape of an arc; or, the first magnetic component 21 may be in the shape of an arc, while the second magnetic component 22 may be in the shape of a straight plate.

[0064] Alternatively, the thickness of the first magnetic component 21 is greater than or less than (not equal to) the thickness of the second magnetic component 22, or the length of the first magnetic component 21 is greater than or less than (not equal to) the length of the second magnetic component 22, so as to achieve an asymmetrical distribution of the shapes of the first magnetic component 21 and the second magnetic component 22 relative to the center line L in the same sector region 11.

[0065] In some embodiments, in each sector region 11, the positions of the first magnetic component 21 and the second magnetic component 22 are asymmetrically distributed relative to the center line L, so as to ensure that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0066] In some embodiments, the angle between the first magnetic component 21 and the center line L is greater than or equal to the angle between the second magnetic component 22 and the center line L, so as to achieve an asymmetrical arrangement of the first magnetic component 21 and the second magnetic component 22 with respect to the center line L in the same sector region 11.

[0067] In some embodiments, the orientation of the first magnetic component 21 and the second magnetic component 22 in each sector region 11 is asymmetrically distributed relative to the center line L, which facilitates ensuring that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0068] In some embodiments, the magnetism of a permanent magnet primarily derives from its easily magnetized crystal structure. Under the influence of a strong external magnetic field, it acquires extremely high magnetism, and this magnetism persists even after the external magnetic field disappears. Magnetic materials are classified into isotropic magnets and anisotropic magnets. Isotropic magnets exhibit identical magnetic properties in all directions and can attract each other arbitrarily. Anisotropic magnets, on the other hand, have varying magnetic properties in different directions; the direction from which optimal magnetic properties are obtained is called the magnet's orientation direction. Applying a magnetic field along the orientation direction to a permanent magnet and gradually increasing the magnetic field strength until it reaches technical saturation is called magnetization. Figure 7 illustrates the magnetization directions of a permanent magnet in different configurations.

[0069] In some embodiments, the magnetization directions of the first magnetic component 21 and the second magnetic component 22 may be different, so as to achieve an asymmetrical distribution of the magnetic properties of the first magnetic component 21 and the second magnetic component 22 along the center line L of the sector region 11 in which they are located.

[0070] In some embodiments, the types of the first magnetic component 21 and the second magnetic component 22 in each sector region 11 are asymmetrically distributed relative to the center line L, so as to ensure that the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0071] In some embodiments, the first magnetic component 21 and the second magnetic component 22 are of different types, for example, they may be of different categories or different brands.

[0072] In some embodiments, the first magnetic component 21 may be one of rare earth, neodymium iron boron, ferrite, iron nitride, samarium iron nitride, samarium cobalt, or hot-deformed neodymium iron boron, and the second magnetic component 22 may be another of rare earth, neodymium iron boron, ferrite, iron nitride, samarium iron nitride, samarium cobalt, or hot-deformed neodymium iron boron.

[0073] In some embodiments, the first magnetic component 21 may be of grade N48 and the second magnetic component 22 may be of grade N52. Alternatively, the first magnetic component 21 may be of grade N38M and the second magnetic component 22 may be of grade N45M. Or, the first magnetic component 21 may be of grade N38SH and the second magnetic component 22 may be of grade N42SH.

[0074] In some embodiments, in each sector region 11, a first receiving groove 12 is provided at the position opposite to the first magnetic component 21, and a second receiving groove 13 is provided at the position opposite to the second magnetic component 22; the first magnetic component 21 is at least partially received in the first receiving groove 12, and the second magnetic component 22 is at least partially received in the second receiving groove 13.

[0075] In some embodiments of this disclosure, arranging a first receiving groove 12 and a second receiving groove 13 on the rotor body 1 can improve the convenience and reliability of arranging the first magnetic component 21 and the second magnetic component 22.

[0076] In some embodiments, the accommodating space of the first receiving groove 12 is larger than the size of the first magnetic component 21. On the one hand, this facilitates the arrangement of the first magnetic component 21 within the first receiving groove 12; on the other hand, it provides space for slight deformation of the first magnetic component 21. Similarly, the accommodating space of the second receiving groove 13 is larger than the size of the second magnetic component 22, so as to facilitate the arrangement of the second magnetic component 22 within the second receiving groove 13 and to provide space for slight deformation of the second magnetic component 22.

[0077] In some embodiments, the number of first receiving slots 12 may be the same as the number of first magnetic components 21, and one first magnetic component 21 may be arranged in one first receiving slot 12. The number of second receiving slots 13 may be the same as the number of second magnetic components 22, and one second magnetic component 22 may be arranged in one second receiving slot 13.

[0078] In some embodiments, in each sector region 11, the first receiving groove 12 and the second receiving groove 13 are asymmetrically arranged relative to the center line L so that the magnetic resistance is different, and the magnetic properties of the first magnetic component 21 and the second magnetic component 22 are different. Moreover, it is convenient to realize the asymmetrical arrangement of the first magnetic component 21 and the second magnetic component 22 relative to the center line L in the same sector region 11, thereby realizing the asymmetrical distribution of the magnetic field in a single sector region 11 along the circumference of the rotor body 1.

[0079] In some embodiments, the first receiving groove 12 and the second receiving groove 13 can be designed to be asymmetrically arranged with respect to the center line L by considering the design dimensions, shape and arrangement position of the first receiving groove 12 and the second receiving groove 13.

[0080] In some embodiments, the shape of the first receiving groove 12 is adapted to the shape of the first magnetic component 21, and the shape of the second receiving groove 13 is adapted to the shape of the second magnetic component 22.

[0081] In some embodiments, the first receiving groove 12 and the second receiving groove 13 can be combined to form a strip-shaped, V-shaped, or U-shaped structure.

[0082] In some embodiments, the magnetic component group 2 may further include a third magnetic component 23 and a fourth magnetic component 24; in each sector region 11, the third magnetic component 23 and the fourth magnetic component 24 are located on both sides of the center line L, and the magnetic properties of the third magnetic component 23 and the fourth magnetic component 24 are symmetrically or asymmetrically distributed relative to the center line L.

[0083] In some embodiments of this disclosure, the magnetic components in a single sector region 11 can be arranged in two rows. Since the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in the same sector region 11 are asymmetrically distributed relative to the center line L, the magnetic field of the magnetic component group 2 is asymmetrically distributed along the center line L of the sector region 11 in which it is located.

[0084] In some embodiments, in each sector region 11, a first receiving groove 12 is provided at the position opposite to the first magnetic component 21, a second receiving groove 13 is provided at the position opposite to the second magnetic component 22, a third receiving groove 14 is provided at the position opposite to the third magnetic component 23, and a fourth receiving groove 15 is provided at the position opposite to the fourth magnetic component 24; the first magnetic component 21 is at least partially received in the first receiving groove 12, the second magnetic component 22 is at least partially received in the second receiving groove 13, the third magnetic component 23 is at least partially received in the third receiving groove 14, and the fourth magnetic component 24 is at least partially received in the fourth receiving groove 15, which can improve the convenience and reliability of arranging the first magnetic component 21, the second magnetic component 22, the third magnetic component 23, and the fourth magnetic component 24.

[0085] In some embodiments, when the magnetic component assembly 2 includes only the first magnetic component 21 and the second magnetic component 22, the first receiving groove 12 and the second receiving groove 13 can be combined to form an elongated shape, a single U-shape, or a single V-shape. When the magnetic component assembly 2 includes the first magnetic component 21, the second magnetic component 22, the third magnetic component 23, and the fourth magnetic component 24, the first receiving groove 12, the second receiving groove 13, the third receiving groove 14, and the fourth receiving groove 15 can be combined to form any combination of elongated shape, U-shape, and V-shape, such as double U-shape, UV-shape, or double V-shape.

[0086] In some embodiments, in each sector region 11, the first magnetic component 21 and the third magnetic component 23 are located on the same side of the center line L, and the second magnetic component 22 and the fourth magnetic component 24 are located on the same side of the center line L; the minimum distance between the first receiving groove 12 and the third receiving groove 14 is less than or equal to the minimum distance between the second receiving groove 13 and the fourth receiving groove 15, which can improve the problem of output performance degradation caused by magnetic flux density saturation during the heavy load stage of the rotor assembly 100 and increase the output torque of the rotor assembly 100.

[0087] In some embodiments, each magnetic component group 2 includes a fifth magnetic component; in each sector region 11, the fifth magnetic component has a first portion on one side of the center line L and a second portion on the other side of the center line L, and the magnetic properties of the first portion and the second portion are asymmetrically distributed relative to the center line L, which facilitates the asymmetrical distribution of the magnetic field generated by the magnetic component group 2 relative to the center line L of the sector region 11 in which it is located.

[0088] In some embodiments, when the motor is running, the motor torque includes two parts: one part is the permanent magnet torque, i.e., the torque of the rotor assembly 100, and the other part is the reluctance torque. The motor torque is equal to the sum of the permanent magnet torque and the reluctance torque.

[0089] When the motor saturation level is low, the permeability in the magnetic circuit is high; when the motor saturation level is high, the permeability in the magnetic circuit is low. The motor experiences higher saturation during medium-to-high load conditions. In some embodiments, the saturation region of the motor is mainly concentrated in three areas: 1. the yoke of the stator assembly 120; 2. the teeth of the stator assembly 120; and 3. the narrow region between the layers of the rotor assembly 100, specifically the minimum distance between the first receiving slot 12 and the third receiving slot 14, and the minimum distance between the second receiving slot 13 and the fourth receiving slot 15.

[0090] The BH curve is divided into linear and nonlinear regions. The yoke of stator assembly 120 belongs to the linear region, where the magnetic flux density can be less than 1.4T. The narrow region between the teeth of stator assembly 120 and the layers of rotor assembly 100 belongs to the nonlinear region, where the local saturation magnetic flux density is greater than 1.4T.

[0091] Taking the existing motor A and the motor B in some embodiments of this disclosure as examples, in the rotor assembly 100 of motor A, the first magnetic component 21 and the second magnetic component 22 are symmetrically arranged with respect to the center line L in the same sector area. In some embodiments of this disclosure, motor B has the rotor assembly 100 shown in FIG1, that is, the magnetic properties of the first magnetic component 21 and the second magnetic component 22 in the same sector area 11 are asymmetrically arranged with respect to the center line L.

[0092] Compared to motor A, in some embodiments of motor B of this disclosure, the air gap magnetic flux density of rotor assembly 100 in a single sector region 11 is asymmetrically distributed.

[0093] There is an air gap between the stator assembly 120 and the rotor assembly 100, as shown in Figure 4. In motor A, the left and right magnetic fields are the same. The magnetic field superposition point a of the armature and the magnetic components is symmetrically distributed with respect to the center line. The focus of the d-axis magnetic field and the q-axis magnetic field is located at the position indicated by arrow a, that is, the magnetic fields of the armature and the permanent magnet are superimposed. The highest magnetic flux density point of the rotor assembly 100 is located at the position indicated by arrow a in the magnetic circuit. This position is located at the narrowest point between the first receiving slot 12 and the third receiving slot 14, and at the narrowest point between the second receiving slot 13 and the fourth receiving slot 15.

[0094] In some embodiments of motor B of this disclosure, the first magnetic component 21 and the second magnetic component 22 in the same sector region are asymmetrically arranged, resulting in an asymmetrical arrangement of magnetic field energy in a single sector region 11. The air gap magnetic flux density on the left and right sides is different, and the magnetic fields on the left and right sides are different, shifting to one side, as shown in Figure 3. The magnetic flux on the left side is large, and the magnetic flux on the right side is small. Compared with motor A, the saturation degree around the superposition point of the right armature and the first magnetic component 21 can be reduced. Compared with motor A, the saturation degree around point b is less than that around point a, that is, the magnetic flux density saturation area is reduced, the reluctance torque is increased, which makes it easier to ensure that the motor has a larger output torque, so that the output torque of motor B is greater than that of motor A. Moreover, the magnetic circuit saturation of the q-axis is improved, so that the magnetic flux of the q-axis can be increased by 5%, and the highest saturation point is moved forward to the position indicated by arrow b.

[0095] Compared to motor A, in motor B of some embodiments, the superposition point of the left armature magnetic field and the magnetic field of the second magnetic component 22 is moved to the left. In order to further improve the saturation of rotor assembly 100, the minimum distance between the second receiving groove 13 and the fourth receiving groove 15 can be increased, so that the minimum distance between the second receiving groove 13 and the fourth receiving groove 15 is greater than the minimum distance between the first receiving groove 12 and the third receiving groove 14. This can further alleviate the local saturation in rotor assembly 100. As shown in Figures 5A and 5B, the deep saturation region in rotor assembly 100 can be reduced by 30%, and the magnetic flux density of the saturation region along the q-axis path can be less than 2.0T.

[0096] As shown in Figures 6A and 6B, the d-axis and q-axis inductances of the two motors are compared. Blue corresponds to motor A, and red corresponds to motor B of this disclosure. It can be seen from the figures that, compared to motor A, the d-axis and q-axis inductances of motor B in some embodiments of this disclosure are significantly improved, with an improvement rate exceeding 20%. When the motor operates in the medium-to-high load region, the torque content of the magnetic reluctance can be increased.

[0097] As shown in Figure 4, compared to motor A, the current angle corresponding to the peak reluctance torque of motor B in some embodiments of this disclosure is larger.

[0098] In some embodiments, compared to motor A, in motor B of some embodiments of this disclosure, the movement of the local depth saturation point and the increase in the width of the region where the depth saturation point is located alleviate the overall magnetic circuit saturation, increase the magnetic permeability, increase the motor inductance, and improve the magnetic reluctance torque.

[0099] In some embodiments, compared to motor A, motor B in some embodiments of this disclosure alleviates the saturation of the motor, solves the problem of decreased reluctance torque caused by local saturation, and improves the reluctance torque. As shown in Figure 4, on the one hand, it can compensate for the problem of decreased permanent magnet torque, and on the other hand, it can compensate for the problem of decreased motor torque caused by increased current angle. In summary, in some embodiments of this disclosure, while reducing the magnetic energy product of the magnetic component group, the motor torque is not reduced, thereby increasing the ratio of motor torque to the sum of magnetic energy products of the magnetic component group.

[0100] In some embodiments of this disclosure, compared to motor A, the amount of the first magnetic component 21 in motor B is reduced, but the reluctance torque is significantly increased. The sum of the electronic rotor torque and the reluctance torque, i.e., the motor torque, is increased, resulting in a larger current angle. The ratio of the motor torque to the sum of the magnetic energy products of the magnetic component group 2 is increased, thereby improving the utilization rate of the magnetic energy product of the magnetic component group 2. In some embodiments of this disclosure, not only is the motor saturation problem solved, but the amount of the first magnetic component 21 is also reduced, thereby reducing the amount of rare earth elements used and lowering costs.

[0101] The rotor assembly in some embodiments of this disclosure has at least the following advantages:

[0102] In some embodiments of this disclosure, in a single sector region, a first magnetic component group and a second magnetic component group are disposed on both sides of the center line. The magnetic properties of the first magnetic component group and the second magnetic component group are asymmetrically distributed relative to the center line, so that the magnetic field superposition point of the armature and the magnetic component is asymmetrically distributed relative to the center line. This can reduce the saturation around the superposition point, reduce the magnetic flux density saturation area, solve the problem of decreased reluctance torque, and increase the reluctance torque, which can improve the output torque of the motor.

[0103] In related technologies, most rotor magnetic circuit structures of motors used in new energy vehicles are double-V-shaped, which is relatively simple and makes it difficult to further improve performance. Furthermore, when the motor's load exceeds its output capacity, power output saturation occurs, leading to a decrease in the motor's output performance.

[0104] When the magnetic component assembly 2 is installed on the rotor body 1, the magnetic field of the magnetic component assembly 2 and the stator assembly 120 of the motor are superimposed. This superposition results in magnetic field superposition in certain areas. These areas have a high magnetic field density, known as the magnetic field superposition point. When the magnetic field density at this point is high, saturation suppression can easily occur, affecting the efficiency of the motor. In other words, when the motor's load exceeds its output capacity, power output saturation will occur, meaning the motor cannot provide more power output, leading to a decrease in machine performance.

[0105] To address the aforementioned issues, in some embodiments of this disclosure, the magnetic field generated by the magnetic component group 2 within its respective sector region 11 is asymmetrically arranged along the centerline. This results in the magnetic field superposition point of the armature and the magnetic component group being asymmetrically distributed relative to the centerline. Consequently, the saturation level around the superposition point can be reduced, the magnetic flux density saturation region can be decreased, and the technical problem of reduced output performance due to power output saturation can be solved.

[0106] In some embodiments of this disclosure, each sector region 11 is further provided with a first magnetic bridge 33 and a second magnetic bridge 34, which are asymmetrically arranged about the center line L.

[0107] Some embodiments of this disclosure utilize the asymmetrical arrangement of the first magnetic bridge 33 and the second magnetic bridge 34 about the center line L to achieve the asymmetry of the magnetic field about the center line L, thereby solving the technical problem of decreased output performance caused by power output saturation.

[0108] Referring again to Figures 8 and 9, in some embodiments of this disclosure, each magnetic component group 2 includes multiple magnetic components, with a first magnetic bridge 33 and a second magnetic bridge 34 located between two adjacent magnetic components. The width of the first magnetic bridge 33 is not equal to the width of the second magnetic bridge 34. Here, the magnetic bridge width refers to the shortest distance between two adjacent magnetic components.

[0109] In some embodiments of this disclosure, by making the width of the first magnetic bridge 33 unequal to the width of the second magnetic bridge 34, the magnetic field is made asymmetrical along the center line L, thereby making the magnetic field superposition point of the armature and magnetic component group asymmetrically distributed relative to the center line. This can reduce the saturation around the superposition point, reduce the magnetic flux density saturation area, and solve the technical problem of output performance degradation caused by power output saturation.

[0110] In some embodiments of this disclosure, in each sector region 11, the shapes of the first magnetic bridge 33 and the second magnetic bridge 34 are asymmetrical about the center line L. By defining the shapes of the first magnetic bridge 33 and the second magnetic bridge 34, the magnetic field is asymmetrically arranged along the center line L.

[0111] In some embodiments of this disclosure, in each sector region 11, the distance from the first magnetic bridge 33 to the center line L is greater than the distance from the second magnetic bridge 34 to the center line L. By defining the positions of the first magnetic bridge 33 and the second magnetic bridge 34 to the center line L, the magnetic field is asymmetrically arranged along the center line L.

[0112] In some embodiments of this disclosure, the first magnetic bridge 33 and the second magnetic bridge 34 are located on both sides of the center line L, respectively.

[0113] In some embodiments, the rotor body 1 has a shaft side 1110; each magnetic component group 2 includes a first magnetic flux layer 10 and a second magnetic flux layer 20; the first magnetic flux layer 10 is disposed close to the shaft side 1110, and the second magnetic flux layer 20 is radially spaced from the first magnetic flux layer 10 and located on the side of the first magnetic flux layer 10 away from the shaft side 1110. The first magnetic flux layer 10 includes a first magnetic component 102, a second magnetic component 103, and a third magnetic component 104; a first magnetic bridge 33 is located between the first magnetic component 102 and the second magnetic component 103, and a second magnetic bridge 34 is located between the second magnetic component 103 and the third magnetic component 104. The positions of the first magnetic bridge 33 and the second magnetic bridge 34 are defined by defining the first magnetic component 102, the second magnetic component 103, and the third magnetic component 104.

[0114] In some embodiments of this disclosure, the first magnetic element 102 and the third magnetic element 104 are located on opposite sides of the center line L and are asymmetrically arranged about the center line L. By defining the asymmetry of the first magnetic element 102 and the third magnetic element 104 about the center line L, the asymmetry of the first magnetic bridge 33 and the second magnetic bridge 34 is indirectly explained, thereby explaining the asymmetry of the magnetic field.

[0115] In some embodiments of this disclosure, the second magnetic element 103 and the first magnetic element 102 are located on the same side of the center line L, and the second magnetic element 103 and the third magnetic element 104 are asymmetrically arranged about the center line L. By defining the relative positional relationship between the second magnetic element 103 and the center line L, the first magnetic bridge 33 and the second magnetic bridge 34 are asymmetrically arranged about the center line L, thereby making the magnetic field of the second magnetic element 103 asymmetrically arranged about the center line L.

[0116] In some embodiments of this disclosure, a portion of the second magnetic element 103 is located on the same side of the center line L as the first magnetic element 102, and another portion is located on the same side of the center line L as the third magnetic element 104. The second magnetic element 103 is asymmetrically arranged about the center line L. By defining the relative positional relationship between the second magnetic element 103 and the center line L, the first magnetic bridge 33 and the second magnetic bridge 34 are asymmetrically arranged about the center line L, thereby making the magnetic field of the second magnetic element 103 asymmetrically arranged about the center line L.

[0117] The first magnetic component 102 includes a first magnet 501 and a first magnetic slot 71. The second magnetic component 103 includes a second magnet 502 and a second magnetic slot 72. The third magnetic component 104 includes a third magnet 503 and a third magnetic slot 73. The first magnetic slot 71, the second magnetic slot 72, and the third magnetic slot 73 are located within the rotor body 1. The first magnet 501, the second magnet 502, and the third magnet 503 are respectively located within the first magnetic slot 71, the second magnetic slot 72, and the third magnetic slot 73. The first magnetic bridge 33 is located between the first magnetic slot 71 and the second magnetic slot 72, and the second magnetic bridge 34 is located between the second magnetic slot 72 and the third magnetic slot 73. The width of the first magnetic bridge 33 is further equal to the shortest distance between the first magnetic slot 71 and the second magnetic slot 72, and the width of the second magnetic bridge 34 is further equal to the shortest distance between the second magnetic slot 72 and the third magnetic slot 73.

[0118] In some embodiments of this disclosure, the first magnet 501, the second magnet 502, and the third magnet 503 are permanent magnets, so that the first magnet 501, the second magnet 502, and the third magnet 503 can always have magnetism, which facilitates the operation of the rotor assembly 100 of the motor and improves the output torque of the motor.

[0119] In some embodiments of this disclosure, the second magnetic slot 72 is located between the first magnetic slot 71 and the third magnetic slot 73. The first magnetic slot 71 and the third magnetic slot 73 are located on opposite sides of the center line L and are asymmetrically arranged about the center line. By setting the first magnetic slot 71 and the third magnetic slot 73 asymmetrically about the center line, the magnetic fields on both sides of the center line L are different.

[0120] In some embodiments of this disclosure, the second magnetic slot 72 and the first magnetic slot 71 are located on the same side of the center line L; the second magnetic slot 72 and the third magnetic slot 73 are asymmetrically arranged about the center line L. By setting the second magnetic slot 72 and the third magnetic slot 73 asymmetrically about the center line, the magnetic fields on both sides of the center line L are different.

[0121] In some embodiments of this disclosure, at least a portion of the second magnetic slot 72 is located on the same side of the center line L as the first magnetic slot 71; another portion is located on the other side of the center line L as the third magnetic slot 73. The second magnetic slot 72 is symmetrically or asymmetrically arranged about the center line L. Since the second magnetic slot 72 is located between the first magnetic slot 71 and the third magnetic slot 73, even if the first magnetic slot 71 and the third magnetic slot 73 are asymmetrically arranged about the center line L, the symmetry or asymmetry of the second magnetic slot 72 about the center line L can cause the first magnetic bridge 33 and the second magnetic bridge 34 to be asymmetrically arranged about the center line L, thereby causing the magnetic fields on both sides of the center line L to be asymmetrical.

[0122] In some embodiments of this disclosure, the first magnet 501 and the third magnet 503 are located on opposite sides of the center line L and are asymmetrically arranged about the center line L. By setting the first magnet 501 and the third magnet 503 asymmetrically about the center line, the magnetic fields on both sides of the center line L can be made different.

[0123] In some embodiments of this disclosure, the second magnet 502 and the first magnet 501 are located on the same side of the center line L, and the second magnet 502 and the third magnet 503 are asymmetrically arranged about the center line L. By setting the second magnet 502 and the third magnet 503 asymmetrically about the center line L, the magnetic fields on both sides of the center line L can be made different.

[0124] In some embodiments of this disclosure, a portion of the second magnet 502 is located on the same side of the center line L as the first magnet 501, and another portion is located on the same side of the center line L as the third magnet 503; the second magnet 502 is arranged symmetrically or asymmetrically with respect to the center line L. Since the second magnet 502 is located between the first magnet 501 and the third magnet 503, even if the first magnet 501 and the third magnet 503 are asymmetrically arranged with respect to the center line L, the symmetry or asymmetry of the second magnet 502 with respect to the center line L can cause the first magnetic bridge 33 and the second magnetic bridge 34 to be asymmetrically arranged with respect to the center line L, thereby causing the magnetic fields on both sides of the center line L to be asymmetrical.

[0125] In some embodiments of this disclosure, the fourth magnetic element 105 includes a fourth magnetic slot 74 and a fourth magnet 504, and the fifth magnetic element 106 includes a fifth magnetic slot 75 and a fifth magnet 505. The fourth magnetic slot 74 and the fifth magnetic slot 75 are located within the rotor body 1, and the fourth magnet 504 and the fifth magnet 505 are located within the fourth magnetic slot 74 and the fifth magnetic slot 75. The fourth magnetic slot 74 and the fifth magnetic slot 75 are arranged symmetrically or asymmetrically about the center line L; and / or the fourth magnet 504 and the fifth magnet 505 are arranged symmetrically or asymmetrically about the center line L.

[0126] By setting up two layers of magnetic components, the magnets can be fully utilized within the limited space of the rotor body 1, thereby increasing the motor torque without increasing the amount of magnets used.

[0127] By setting the fourth magnetic slot 74 and the fifth magnetic slot 75 asymmetrically about the center line L, or by setting the fourth magnet 504 and the fifth magnet 505 asymmetrically about the center line L, the magnetic fields on both sides of the center line L can be set asymmetrically.

[0128] In some embodiments of this disclosure, the fourth magnetic slot 74 and the first magnetic slot 71 are located on the same side of the center line L, and the fifth magnetic slot 75 and the third magnetic slot 73 are located on the same side of the center line L; the minimum distance from the fourth magnetic slot 74 to the first magnetic slot 71 is greater than or equal to the minimum distance from the fifth magnetic slot 75 to the third magnetic slot 73. This allows the fourth magnetic slot 74 and the first magnetic slot 71 to be asymmetrically arranged compared to the fourth magnetic slot 74 and the first magnetic slot 71.

[0129] Here, in some embodiments of this disclosure, the minimum distance from the fourth magnetic slot 74 to the first magnetic slot 71 is greater than or equal to the minimum distance from the fifth magnetic slot 75 to the third magnetic slot 73. Compared to the minimum distance from the fourth magnetic slot to the first magnetic slot being less than the minimum distance from the fifth magnetic slot to the third magnetic slot, the highest magnetic flux density point in the sector region 11 where the former is located moves to the left compared to the highest magnetic flux density point of the latter. That is, the magnetic flux density point between the fourth magnetic slot 74 and the first magnetic slot 71 moves away from the third magnetic slot 73, and the magnetic flux density point between the fifth magnetic slot 75 and the third magnetic slot 73 moves closer to the second magnetic slot 72. That is, the magnetic flux density point moves towards a wider area between the first magnetic flux layer 10 and the second magnetic flux layer 20. Increasing the magnetic field current width reduces the magnetic flux density and alleviates the magnetic flux density saturation of the rotor assembly. This not only further improves the problem of output performance degradation caused by magnetic flux density saturation during the heavy load stage of the motor rotor assembly 100 and increases the output torque of the motor rotor assembly 100, but also further optimizes the stress distribution of the motor rotor assembly 100 and achieves minimum high-speed equivalent stress.

[0130] In some embodiments of this disclosure, the fourth magnetic slot 74 and the first magnetic slot 71 are located on the same side of the center line L, and the fifth magnetic slot 75 and the third magnetic slot 73 are located on the same side of the center line L; the minimum distance from the fourth magnetic slot 74 to the second magnetic slot 72 is greater than or equal to the minimum distance from the fifth magnetic slot 75 to the third magnetic slot 73.

[0131] Here, in some embodiments of this disclosure, the minimum distance from the fourth magnetic slot 74 to the second magnetic slot 72 is greater than or equal to the minimum distance from the fifth magnetic slot 75 to the third magnetic slot 73. Compared to the minimum distance from the fourth magnetic slot to the second magnetic slot being less than the minimum distance from the fifth magnetic slot to the third magnetic slot, the highest magnetic flux density point in the sector region 11 where the former is located moves to the left compared to the highest magnetic flux density point of the latter. That is, the magnetic flux density point between the fourth magnetic slot 74 and the second magnetic slot 72 moves away from the third magnetic slot 73, and the magnetic flux density point between the fifth magnetic slot 75 and the third magnetic slot 73 moves closer to the second magnetic slot 72. That is, the magnetic flux density point moves towards a wider area between the first magnetic flux layer 10 and the second magnetic flux layer 20. Increasing the magnetic field current width reduces the magnetic flux density and alleviates the magnetic flux density saturation of the rotor assembly. This not only further improves the problem of output performance degradation caused by magnetic flux density saturation during the heavy load stage of the motor rotor assembly 100 and increases the output torque of the motor rotor assembly 100, but also further optimizes the stress distribution of the motor rotor assembly 100 and achieves minimum high-speed equivalent stress.

[0132] The following will use the first magnet 501 and the third magnet 503 as examples to explain in detail the different cases of magnetic field asymmetry on both sides of the pole centerline L. Correspondingly, the cases of asymmetrical arrangement of the second magnet 502 and the third magnet 503 with respect to the pole centerline L are similar.

[0133] In some embodiments, in each sector region 11, the first magnet 501 and the third magnet 503 are disposed on both sides of the center line L. The magnetic properties of the first magnet 501 and the third magnet 503 are asymmetrically distributed relative to the center line L, so that the magnetic field generated by the magnetic component group 2 in a single sector region 11 is asymmetrically distributed relative to the center line L. As shown in FIG9, the first magnet 501 is located on the left side and the third magnet 503 is located on the right side. The magnetic field energy on the left side may be greater than or less than (not equal to) the magnetic field energy on the right side.

[0134] In some embodiments, the magnetic properties of the first magnet 501 and the third magnet 503 are asymmetrically distributed relative to the center line L, that is, the magnetic properties of the first magnet 501 and the third magnet 503 are different.

[0135] In some embodiments, the magnetic properties of the first magnet 501 and the third magnet 503 in the same sector region 11 can be asymmetrically arranged with respect to the center line L by considering the position, structure and size of the first magnet 501 and the third magnet 503.

[0136] In some embodiments, the first magnet 501 and the third magnet 503 have different magnetic energy products, which can result in different magnetic properties for the first magnet 501 and the third magnet 503. The first magnet 501 and the third magnet 503 have different magnetic flux, i.e., different applied currents, which can result in different magnetic properties for the first magnet 501 and the third magnet 503. The first magnet 501 and the third magnet 503 have different magnetic fields, which can result in different magnetic properties for the first magnet 501 and the third magnet 503. The first magnet 501 and the third magnet 503 have different magnetic induction intensities, i.e., different magnetic flux density, which can result in different magnetic properties for the first magnet 501 and the third magnet 503. The first magnet 501 and the third magnet 503 have different magnetomotive forces, i.e., different applied voltages, which can result in different magnetic properties for the first magnet 501 and the third magnet 503. The first magnet 501 and the third magnet 503 have different magnetic reluctances, that is, different applied voltages, which can make the first magnet 501 and the third magnet 503 have different magnetic properties.

[0137] In some embodiments, the fluxmeter can be connected to a single coil or a Helmholtz coil to measure the magnetic flux of the magnet. A magnetic field strength tester can be used to detect the magnetic field of the magnet. In some embodiments, the remanence, coercivity, etc., of the permanent magnet can also be tested using specialized instruments to obtain the magnetic energy product; this disclosure does not limit this approach.

[0138] In some embodiments, the magnetic properties of the first magnet 501 and the third magnet 503 can be asymmetrically distributed about the center line L by reducing the magnetic field energy of the first magnet 501 or the third magnet 503. This can increase the ratio of the motor's output torque to the sum of the magnetic field energy of the magnetic component group 2, thereby improving the utilization rate of the magnetic field energy of the magnetic component group 2. It is also convenient to reduce the cost of the motor's rotor assembly 100 by reducing the amount of rare earth elements used in the magnetic component group 2.

[0139] In some embodiments, the magnetic component group 2 accounts for a large proportion of the motor cost. By reducing the amount of magnetic component group 2 used, the effect of reducing the motor cost is more obvious.

[0140] In some embodiments, the magnetic field energy can be the product of the magnetic energy product and the volume, that is, the magnetic field energy of the first magnet 501 can be the product of the magnetic energy product and the volume of the first magnet 501, and the magnetic field energy of the third magnet 503 can be the product of the magnetic energy product and the volume of the third magnet 503.

[0141] In some embodiments, the magnetic energy product of the first magnet 501 may be greater than or less than (but not equal to) the magnetic energy product of the third magnet 503, which can improve the utilization rate of the sum of the magnetic energy products of the magnetic component group 2. Alternatively, the volume of the first magnet 501 may be greater than or less than (but not equal to) the volume of the third magnet 503, which can improve the utilization rate of the sum of the volumes of the magnetic component group 2.

[0142] In some embodiments, the magnetic energy product can be the product of remanence and coercivity. The magnetic energy product increases with increasing remanence and volume. Remanence (Br), measured in Gauss, is the magnetic flux density remaining after the magnetic field is removed from a saturated state, representing the strength of the magnetic field a magnet can provide. Coercivity (Hc), measured in Oersteds, is the ability of a magnet to resist demagnetization when placed in a reverse magnetic field of sufficient strength. Magnetic energy product (BHmax), measured in Gauss-Oersteds, is the magnetic energy produced per unit volume of material, representing the amount of energy a magnet can store.

[0143] In some embodiments, when the coercivity of the first magnet 501 and the third magnet 503 is the same, and the remanence of the first magnet 501 is greater than that of the third magnet 503, then the magnetic energy product of the first magnet 501 is greater than that of the third magnet 503. Similarly, when the remanence of the first magnet 501 and the third magnet 503 is the same, and the coercivity of the first magnet 501 is greater than that of the third magnet 503, then the magnetic energy product of the first magnet 501 is greater than that of the third magnet 503.

[0144] In some embodiments, within a single sector region 11, the magnetic energy product of the first magnet 501 may be greater than or less than (but not equal to) the magnetic energy product of the third magnet 503, as shown in FIG9. This can be achieved by the first magnet 501 being located at the front of the rotor assembly 100 of the motor in the direction of rotation, and the third magnet 503 being located at the rear of the rotor assembly 100 of the motor in the direction of rotation. Alternatively, the first magnet 501 may be located at the rear of the rotor assembly 100 of the motor in the direction of rotation, and the third magnet 503 may be located at the front of the rotor assembly 100 of the motor in the direction of rotation.

[0145] In some embodiments, in each sector region 11, the volume of the first magnet 501 is greater than or less than (not equal to) the volume of the third magnet 503, so as to ensure that the magnetic properties of the first magnet 501 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the center line L of the sector region 11.

[0146] In some embodiments, in each sector region 11, the coercivity of the first magnet 501 is greater than or less than (not equal to) the coercivity of the third magnet 503, so as to ensure that the magnetic properties of the first magnet 501 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the center line L of the sector region 11.

[0147] In some embodiments, in each sector region 11, the remanence of the first magnet 501 is greater than or less than (not equal to) the remanence of the third magnet 503, so as to ensure that the magnetic properties of the first magnet 501 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the center line L of the sector region 11.

[0148] In some embodiments, within the same sector region 11, when the remanence of the first magnet 501 and the third magnet 503 is the same, the coercivity of the first magnet 501 and the third magnet 503 can be designed to be different; when the coercivity of the first magnet 501 and the third magnet 503 is the same, the remanence of the first magnet 501 and the third magnet 503 can be designed to be different; or, the remanence of the first magnet 501 and the third magnet 503 can be designed to be different, and the coercivity can be different, so as to achieve that the magnetic energy product of the first magnet 501 and the magnetic energy product of the third magnet 503 are different within a single sector region 11.

[0149] For example, the first magnet 501 can be in the shape of a straight plate, while the third magnet 503 can be in the shape of an arc; or, the first magnet 501 can be in the shape of an arc, while the third magnet 503 can be in the shape of a straight plate.

[0150] Alternatively, the thickness of the first magnet 501 is greater than or less than (not equal to) the thickness of the third magnet 503, or the length of the first magnet 501 is greater than or less than (not equal to) the length of the third magnet 503, so as to achieve an asymmetrical distribution of the shapes of the first magnet 501 and the third magnet 503 relative to the center line L in the same sector region 11.

[0151] In some embodiments, the orientation of the first magnet 501 and the third magnet 503 in each sector region 11 is asymmetrically distributed relative to the center line L, which facilitates ensuring that the magnetic properties of the first magnet 501 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0152] In some embodiments, the magnetism of a permanent magnet primarily derives from its easily magnetized crystal structure. Under the influence of a strong external magnetic field, it acquires extremely high magnetism, and this magnetism persists even after the external magnetic field disappears. Magnetic materials are classified into isotropic magnets and anisotropic magnets. Isotropic magnets exhibit identical magnetic properties in all directions and can attract each other arbitrarily. Anisotropic magnets, on the other hand, have varying magnetic properties in different directions; the direction from which optimal magnetic properties are obtained is called the magnet's orientation direction. Applying a magnetic field along the orientation direction to a permanent magnet and gradually increasing the magnetic field strength until it reaches technical saturation is called magnetization. Figure 7 illustrates the magnetization directions of a permanent magnet in different configurations.

[0153] In some embodiments, the types of the first magnet 501 and the third magnet 503 in each sector region 11 are asymmetrically distributed relative to the center line L, which facilitates ensuring that the magnetic properties of the first magnet 501 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the center line L of this sector region 11.

[0154] In some embodiments, the first magnet 501 and the third magnet 503 are of different types, such as different categories or different brands.

[0155] In some embodiments of this disclosure, the first magnetic slot 71, the second magnetic slot 72, the third magnetic slot 73, the fourth magnetic slot 74, and the fifth magnetic slot 75 all include straight segments and arc segments. Furthermore, the axial cross-sectional areas of the first magnetic slot 71, the second magnetic slot 72, the third magnetic slot 73, the fourth magnetic slot 74, and the fifth magnetic slot 75 in the rotor body 1 are respectively larger than the axial cross-sectional areas of the first magnet 501, the second magnet 502, the third magnet 503, the fourth magnet 504, and the fifth magnet 505. The arc segments can adjust the magnetic field distribution, improving the motor's anti-demagnetization capability without increasing the amount of magnets used, saving costs, and having minimal impact on the motor's output performance. The size of the arc segments can be adjusted according to the actual design.

[0156] In some embodiments of this disclosure, the rotor body 1 further includes an outer wall 31, which is located away from the shaft side 1110. The rotor body 1 also includes a third magnetic bridge 35 and a fourth magnetic bridge 36, wherein the third magnetic bridge 35 is located between the first magnetic slot 71 and the outer wall 31, and the fourth magnetic bridge 36 is located between the third magnetic slot 73 and the outer wall 31.

[0157] Please refer to Figure 10, which is a simulation diagram of stress distribution in a sector region 11. As can be seen from Figure 10, the stress of the second magnetic bridge 34 is greater than that of the first magnetic bridge 33, the stress of the first magnetic bridge 33 is greater than that of the fourth magnetic bridge 36, and the stress of the fourth magnetic bridge 36 is greater than that of the third magnetic bridge 35.

[0158] The volume of the third magnet 503 located behind the rotor assembly 100 in the direction of rotation is larger than the volumes of the second magnet 502 and the first magnet 501 located in the direction of rotation of the rotor assembly 100. During rotor assembly 100 rotation (e.g., clockwise), the third magnet 503 generates a leftward centrifugal force, which acts at the location of the second magnetic bridge 34, resulting in higher stress on the second magnetic bridge 34. During rotor assembly 100 rotation in the opposite direction (e.g., counterclockwise), the third magnet 503 generates a rightward centrifugal force, which acts at the location of the fourth magnetic bridge 36. The first magnet 501 generates a leftward centrifugal force, which acts at the location of the third magnetic bridge 35. Because the volume of the third magnet 503 is larger than that of the first magnet 501, the stress on the second magnetic bridge 34 is greater than the stress on the first magnetic bridge 33. Similarly, since the stress of the first magnetic bridge 33 originates from the first magnet 501 and the second magnet 502, the stress of the second magnetic bridge 34 originates from the third magnet 503 and the second magnet 502, and the stress of the third magnetic bridge 35 and the fourth magnetic bridge 36 originates from the first magnet 501 and the third magnet 503, the stress of the second magnetic bridge 34 is greater than the stress of the first magnetic bridge 33, the stress of the first magnetic bridge 33 is greater than the stress of the fourth magnetic bridge 36, and the stress of the fourth magnetic bridge 36 is greater than the stress of the third magnetic bridge 35.

[0159] Therefore, by increasing the width of the magnetic bridge with higher stress (e.g., increasing the width of the first magnetic bridge 33 and the second magnetic bridge 34), a better magnetic bridge ratio can be set to achieve stress distribution, thereby reducing the risk of stress concentration caused by the high-speed rotation of the rotor assembly.

[0160] In some embodiments of this disclosure, the width ratio (magnetic bridge ratio) of the first magnetic bridge 33 and the second magnetic bridge 34 ranges from [0.7, 0.85]. Considering the relatively high stress at the first magnetic bridge 33 and the second magnetic bridge 34, by setting a reasonable width ratio of the first magnetic bridge 33 and the second magnetic bridge 34, the stress at the first magnetic bridge 33 and the second magnetic bridge 34 can be alleviated, stress distribution can be achieved, and the risk of stress concentration caused by the high-speed rotation of the rotor assembly can be reduced.

[0161] In some embodiments of this disclosure, the bridge width ratio (bridge ratio) of the third magnetic bridge 35 and the fourth magnetic bridge 36 is [0.8, 0.95], and the bridge width ratio (bridge ratio) of the fourth magnetic bridge 36 and the second magnetic bridge 34 is in the range of [0.75, 0.85].

[0162] The width of the third magnetic bridge 35 is the shortest distance between the third magnetic slot 73 and the outer wall 31, and the width of the fourth magnetic bridge 36 is the shortest distance between the first magnetic slot 71 and the outer wall 31.

[0163] Since the stress at the second magnetic bridge 34 is greater than the stress at the fourth magnetic bridge 36, and the stress at the fourth magnetic bridge 36 is greater than the stress at the third magnetic bridge 35, by increasing the width of the second magnetic bridge 34 and the fourth magnetic bridge 36 and setting a reasonable magnetic bridge ratio, the stress at the second magnetic bridge 34 and the fourth magnetic bridge 36 can be alleviated, stress distribution can be achieved, and the risk of stress concentration caused by the high-speed rotation of the rotor assembly 100 can be further reduced.

[0164] In some embodiments of this disclosure, the widths of the first magnetic bridge 33, the second magnetic bridge 34, the third magnetic bridge 35, and the fourth magnetic bridge 36 satisfy the following:

[0165] 1.5mm≤L1≤2mm;

[0166] 1.5mm≤L2≤2mm;

[0167] 1mm≤L3≤1.5mm; and

[0168] 1mm≤L4≤1.5mm;

[0169] Among them, L1, L2, L3 and L4 are the widths of the first magnetic bridge 33, the second magnetic bridge 34, the third magnetic bridge 35 and the fourth magnetic bridge 36, respectively.

[0170] Since the stress of the first magnetic bridge 33 and the second magnetic bridge 34 is greater than that of the third magnetic bridge 35 and the fourth magnetic bridge 36, the width of the first magnetic bridge 33 and the second magnetic bridge 34 is greater than that of the third magnetic bridge 35 and the fourth magnetic bridge 36, so as to achieve stress distribution and reduce the problem of high-speed stress concentration in the rotor.

[0171] In some embodiments of this disclosure, in the axial direction of the rotor body 1, the volume V3 of the third magnet 503 located behind the rotor assembly 100 in the rotation direction R is less than the sum of the volumes V1 of the first magnet 501 and the second magnet 502 located at the front of the rotor assembly 100 in the rotation direction R. That is, V3 <V1+V2。

[0172] In some embodiments of this disclosure, V3, V1, and V2 satisfy the condition (V1+V2-V3):(V1+V2)<10%~25%. That is, the volume V3 of the third magnet 503 located behind the rotor assembly 100 in the rotation direction R is less than the sum of the volumes V1 of the first magnet 501 and V2 of the second magnet 502 located in front of the rotor assembly 100 in the rotation direction R by 10%~25%. This facilitates ensuring that the magnetic properties of the first magnet 501 and the second magnet 502 and the third magnet 503 in a single sector region 11 are asymmetrically distributed relative to the centerline L of the sector region 11, thereby improving the problem of decreased output performance due to magnetic flux saturation during the heavy-load phase of the motor rotor assembly 100. Furthermore, the magnetic field energy of the third magnet 503 can be reduced to improve the utilization rate of the magnetic field energy of the first magnet 501, the second magnet 502, and the third magnet 503, and effectively ensure that the motor rotor assembly 100 outputs sufficient torque.

[0173] In some embodiments of this disclosure, the angle α between the extending direction of the fourth magnet 504 and the extending direction of the fifth magnet 505 satisfies: 120° < α < 150°. This can reduce the stress at the locations of the fourth magnetic slot 74 and the fifth magnetic slot 75 to a certain extent.

[0174] In some embodiments of this disclosure, the sum S of the cross-sectional areas S of the fourth magnetic slot 74 and the fifth magnetic slot 75 along the axial direction of the rotor body 1 respectively satisfies: 16mm 2 <S<25mm 2 .

[0175] Due to the poor thermal conductivity of amorphous rotor components, a larger heat dissipation area is required for heat dissipation. However, the stress at the positions of the fourth magnetic slot 74 and the fifth magnetic slot 75 is relatively small. Therefore, the heat dissipation capacity of the motor can be improved by increasing the sum S of the cross-sectional areas of the fourth magnetic slot 74 and the fifth magnetic slot 75, that is, by increasing the cavity area of ​​the fourth magnetic slot 74 and the fifth magnetic slot 75.

[0176] The rotor assembly 100 provided in some embodiments of this disclosure has an asymmetrical magnetic field about the center line L due to the asymmetrical arrangement of its magnetic bridges. Compared with motors with symmetrical magnetic field arrangements in related technologies, the motors in some embodiments of this disclosure, as the local magnetic circuit depth saturation point (magnetic field superposition point) in each sector region 11 moves and the width of the region where the depth saturation point is located (e.g., the region where the first magnetic bridge 33 and the second magnetic bridge 34 are located) increases, the overall magnetic circuit saturation is alleviated, the magnetic permeability is increased, the motor inductance is increased, and the magnetic reluctance torque is improved, so as to solve the technical problem of output performance degradation caused by power output saturation.

[0177] In some embodiments of this disclosure, the rotor body 1 further includes an inner wall 32, which is close to the shaft side 1110; the rotor assembly further includes a through hole 16, which extends axially along the rotor body 1 and is used to receive and fix the shaft, the inner wall 32 being the wall of the through hole 16, and the through hole 16 having a multi-keyway structure.

[0178] Designing the through hole 16 as a multi-keyway structure can improve the stability of torque output during high-speed operation of the rotor assembly 100.

[0179] In some embodiments of this disclosure, the number of magnets included in the rotor assembly 100 is not limited to the first magnet 501, the second magnet 502, the third magnet 503, the fourth magnet 504, and the fifth magnet 505, and may include a greater number of magnets. Providing multiple magnets in each sector region 11 of the rotor assembly 100 can ensure the output performance of the motor.

[0180] In some embodiments of this disclosure, the first magnet 501, the second magnet 502, the third magnet 503, the fourth magnet 504, and the fifth magnet 505 are magnets with permanent magnet properties.

[0181] Please refer to Figure 11. In some embodiments of this disclosure, at least one of the first magnet 501, the second magnet 502, the third magnet 503, the fourth magnet 504, and the fifth magnet 505 includes at least two first sub-magnets 51 and at least one second sub-magnet 52. A second sub-magnet 52 is located between two adjacent first sub-magnets 51. The first sub-magnet 51 is a grain boundary penetration magnet, and the second sub-magnet 52 is a heat-deformable magnet.

[0182] In some embodiments of this disclosure, the first sub-magnet 51 and the second sub-magnet 52 are magnetic steel.

[0183] In some embodiments of this disclosure, the rotor assembly 100 has a plurality of magnets, and the types of magnets are no more than two. An expansion layer (not shown) is formed on the surface of the magnets. During heating, the expansion layer allows the magnets to be interference-fitted with the magnetic slots of the rotor body 1. The magnet (steel) type is not limited to bonded magnets and slotted magnets.

[0184] Grain boundary infiltrating magnets are manufactured using grain boundary infiltrating technology, an advanced magnetic material preparation technique primarily used to improve the performance of neodymium iron boron permanent magnets while reducing the amount of heavy rare earth elements used. This technology involves coating the magnet surface with a thin film containing heavy rare earth elements (such as dysprosium and terbium) and then subjecting it to a high-temperature diffusion process. This allows the heavy rare earth elements to penetrate along the grain boundaries into the magnet's interior, thereby increasing the magnet's coercivity and energy product.

[0185] Hot-deformed magnets are high-performance neodymium iron boron (Nd-Fe-B) permanent magnet materials manufactured through a hot-deformation process. The production process includes rapid quenching, crushing, cold pressing, hot pressing, and hot deformation. During hot deformation, the microstructure of the magnet undergoes significant changes, thereby improving its magnetic properties.

[0186] The maximum torque of a motor refers to the maximum torque value that the motor can output under specific conditions. The maximum torque can vary significantly depending on the motor type and application. With the same rotor body 1, placing thermally deformable magnets (secondary magnets 52) between adjacent grain boundary infiltrated magnets (first sub-magnets 51) can increase the motor's maximum torque, thus compensating for the disadvantage of amorphous motors having lower maximum torque compared to traditional silicon steel motors. Under the same excitation current, the greater the thermal deformation, the greater the motor torque, and the greater the excitation current, the more significant the impact of thermal deformation on the motor torque.

[0187] In some embodiments of this disclosure, the hot-deformed magnets are first prepared using a rapid quenching method, HDDR method, or mechanical alloying method to produce magnetic powder. The magnetic powder is then refined and heat-treated to obtain refined magnetic powder. The magnetic powder is then cold-pressed to obtain a magnet, which is then hot-pressed at a temperature of 550–800°C to allow the grains to grow and rotate, resulting in an isotropic permanent magnet. This permanent magnet is aligned with the cavities of the second layer of magnetic slots (corresponding to the first sub-magnet 51) and the third layer of magnetic slots (corresponding to the first sub-magnet 51). The first sub-magnet 51 and the second sub-magnet 52 are assembled by heating the rotor body (rotor core), first placing a grain boundary penetrating magnet, then placing a hot-deformed magnet, and finally placing another grain boundary penetrating magnet.

[0188] Referring to Figure 12, in some embodiments of this disclosure, the rotor body 1 includes a plurality of rotor laminations (not shown). These laminations are stacked axially on the rotor body 1. The stacking diameter factor of the rotor body 1 is set within the range of [0.19‰, 1.68‰]. The stacking diameter factor of the rotor body 1 refers to the ratio of the thickness of the rotor body 1 in the axial direction to its outer diameter. The outer diameter of the rotor body 1 refers to the distance between the inner wall 32 and the outer wall 31 of the rotor body 1.

[0189] Setting the stacking diameter coefficient of rotor body 1 within the range of [0.19‰, 1.68‰] can ensure that the rotor laminations (amorphous laminations) will not experience problems such as adhesion or warping, thereby improving the yield.

[0190] Please refer to Figure 13. In some embodiments of this disclosure, the rotor assembly 100 further includes a first covering layer 61 and a second covering layer 62. The first covering layer 61 and the second covering layer 62 respectively cover both ends of the rotor body 1 in the axial direction. The first covering layer 61 covers at least one of the first magnetic slot 71, the second magnetic slot 72, the third magnetic slot 73, the fourth magnetic slot 74, and the fifth magnetic slot 75. The second covering layer 62 covers the first magnetic slot 71, the second magnetic slot 72, the third magnetic slot 73, the fourth magnetic slot 74, and the fifth magnetic slot 75, excluding the remaining magnetic slots covered by the first covering layer 61.

[0191] In some embodiments of this disclosure, a first covering layer 61 covers the first magnetic groove 71, the third magnetic groove 73 and the fifth magnetic groove 75, and a second covering layer 62 covers the second magnetic groove 72 and the fourth magnetic groove 74.

[0192] Providing a first covering layer 61 and a second covering layer 62 at both ends of the rotor body 1 can reduce the warping phenomenon during rotor assembly and also improve rotor stiffness.

[0193] In some embodiments of this disclosure, the first covering layer 61 and the second covering layer 62 can be formed by encapsulation with polymer materials or silicon steel sheets.

[0194] Please refer to Figures 14 and 15. Some embodiments of this disclosure also provide an electric motor 2000, which includes a rotor assembly 100 and a stator assembly 120 as described above, with the stator assembly 120 disposed around the rotor assembly 100.

[0195] The stator assembly 120 is the stationary part of the motor, typically composed of a stator core, stator windings, and a frame. Its main function is to generate a rotating magnetic field. The rotor assembly 100 is the rotating part of the motor, typically composed of a rotor core, rotor windings, and a shaft. Its function is to induce an electromotive force in the rotating magnetic field generated by the stator assembly 120 and convert energy through electromagnetic torque. The interaction between the stator assembly 120 and the rotor assembly 100 is fundamental to the operation of the motor. When current flows through the stator windings, a magnetic field is generated in the stator core. This magnetic field attracts or drives the rotor assembly to rotate, thereby realizing the conversion of electrical energy into mechanical energy.

[0196] In some embodiments of this disclosure, the motor 2000 further includes a limit sensor 130, which is positioned relative to the air gap 140 of the stator assembly 120 and the rotor assembly 100. The limit sensor 130 is used to detect whether the outer diameter deformation of the rotor assembly 100 exceeds the standard.

[0197] The air gap 140 between the stator assembly 120 and the rotor assembly 100 refers to the minimum clearance width between the stator assembly and the rotor assembly of the motor. The air gap 140 is a key parameter in motor design, directly affecting the motor's performance, efficiency, and reliability. The existence of the air gap 140 is to ensure that the rotor assembly can rotate freely within the cavity of the stator assembly, while avoiding direct contact between the stator assembly and the rotor assembly, thereby reducing friction and wear.

[0198] In some embodiments of this disclosure, the motor 2000 also includes a housing 150, with the stator assembly 120 and the rotor assembly 100 both located inside the housing 150. A limit sensor 130 is disposed on the housing 150, which can fix the limit sensor 130 while making reasonable use of the space of the motor.

[0199] In some embodiments of this disclosure, the limit sensor 130 is located 2-3 cm below the air gap 140 between the stator assembly 120 and the rotor assembly 100.

[0200] In some embodiments of this disclosure, the limit sensor 130 is a miniature proximity switch limit sensor. Of course, the limit sensor 130 can also be other types of limit sensors.

[0201] The limit sensor 130 uses infrared light to detect whether the outer diameter deformation of the rotor assembly 100 of the motor 2000 exceeds the limit. This is mainly because the rotor body 1 of the rotor assembly 100 is made of amorphous material, and amorphous materials have a low elastic modulus, which may lead to the risk of rotor scorching and dynamic imbalance during high-speed rotation. If the outer diameter of the rotor assembly 100 is detected to exceed the limit (outer diameter exceeds a predetermined value), the operation of the motor 2000 is stopped, which can reduce the risk of rotor scorching and dynamic imbalance during high-speed rotation.

[0202] Referring to Figure 16, this disclosure also provides a vehicle 1000, which includes the motor 2000 as described above or the rotor assembly 100 as described above. That is to say, the rotor assembly provided in some embodiments of this disclosure can be used not only in motors, but also in engines, generator systems, hub motor systems, etc., with diverse application scenarios.

[0203] Some embodiments of this disclosure also disclose an electric powertrain including a rotor assembly, which may be the rotor assembly described above.

[0204] The motors in some embodiments of this disclosure can achieve the same beneficial effects as the rotor assemblies described above, and will not be repeated here. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0205] The embodiments, implementation methods and related technical features disclosed herein can be combined and substituted for each other without conflict.

[0206] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure in any way. Although the descriptions of each embodiment in this disclosure have different focuses, and parts not described in detail in a certain embodiment can be referred to the relevant embodiments in other embodiments, any modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the technical solution content of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A rotor assembly (100), comprising: The rotor body (1) is made of amorphous material. The rotor body (1) has multiple fan-shaped regions (11) distributed along its circumference. Each fan-shaped region (11) has a center line (L) along the axial direction of the rotor body (1). Multiple magnetic component groups (2), one of the multiple magnetic component groups (2) is arranged in each sector region (11), each of the multiple magnetic component groups (2) can form or generate a magnetic field in the sector region (11) where it is located, and the magnetic field is asymmetrically distributed along the center line (L).

2. The rotor assembly (100) according to claim 1, wherein, Each magnetic component group (2) includes a first magnetic component (21) and a second magnetic component (22); In each of the sector regions (11), the first magnetic component (21) and the second magnetic component (22) are located on both sides of the center line (L), and the magnetic properties of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L).

3. The rotor assembly (100) according to claim 2, wherein, In each of the sector regions (11), the volume of the first magnetic component (21) is greater than or less than the volume of the second magnetic component (22).

4. The rotor assembly (100) according to claim 2 or 3, wherein, In each of the sector regions (11), the coercivity of the first magnetic component (21) is greater than or less than the coercivity of the second magnetic component (22).

5. The rotor assembly (100) according to claim 2 or 3, wherein, In each of the sector regions (11), the remanence of the first magnetic component (21) is greater than or less than the remanence of the second magnetic component (22).

6. The rotor assembly (100) according to any one of claims 2 to 5, wherein, In each of the sector regions (11), the shapes of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L).

7. The rotor assembly (100) according to any one of claims 2 to 6, wherein, In each of the sector regions (11), the positions of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L).

8. The rotor assembly (100) according to any one of claims 2 to 7, wherein, In each of the sector regions (11), the orientation of the first magnetic component (21) and the second magnetic component (22) is asymmetrically distributed relative to the center line (L).

9. The rotor assembly (100) according to any one of claims 2 to 8, wherein, In each of the sector regions (11), the first magnetic component (21) and the second magnetic component (22) are of different types.

10. The rotor assembly (100) according to any one of claims 2 to 9, wherein, In each of the sector regions (11), the rotor body (1) is provided with a first receiving groove (12) at the position corresponding to the first magnetic component (21), and a second receiving groove (13) is provided at the position corresponding to the second magnetic component (22); At least a portion of the first magnetic component (21) is housed in the first receiving groove (12), and at least a portion of the second magnetic component (22) is housed in the second receiving groove (13).

11. The rotor assembly (100) according to claim 10, wherein, In each of the sector regions (11), the first receiving groove (12) and the second receiving groove (13) are arranged asymmetrically with respect to the center line (L).

12. The rotor assembly (100) according to any one of claims 2 to 11, wherein, Each magnetic component group (2) further includes a third magnetic component (23) and a fourth magnetic component (24); In each of the sector regions (11), the third magnetic component (23) and the fourth magnetic component (24) are located on both sides of the center line (L), and the magnetic properties of the third magnetic component (23) and the fourth magnetic component (24) are symmetrically or asymmetrically distributed relative to the center line (L).

13. The rotor assembly (100) according to claim 12, wherein, In each of the sector regions (11), a first receiving groove (12) is provided at the position corresponding to the first magnetic component (21) of the rotor body (1), a second receiving groove (13) is provided at the position corresponding to the second magnetic component (22) of the rotor body (1), a third receiving groove (14) is provided at the position corresponding to the third magnetic component (23) of the rotor body (1), and a fourth receiving groove (15) is provided at the position corresponding to the fourth magnetic component (24) of the rotor body (1); At least a portion of the first magnetic component (21) is housed in the first receiving groove (12), at least a portion of the second magnetic component (22) is housed in the second receiving groove (13), at least a portion of the third magnetic component (23) is housed in the third receiving groove (14), and at least a portion of the fourth magnetic component (24) is housed in the fourth receiving groove (15).

14. The rotor assembly (100) according to claim 13, wherein, In each of the sector regions (11), the first magnetic component (21) and the third magnetic component (23) are located on the same side of the center line (L), and the second magnetic component (22) and the fourth magnetic component (24) are located on the same side of the center line (L). The minimum distance between the first receiving groove (12) and the third receiving groove (14) is less than or equal to the minimum distance between the second receiving groove (13) and the fourth receiving groove (15).

15. The rotor assembly (100) according to any one of claims 1 to 14, wherein, Each magnetic component group (2) includes a fifth magnetic component; In each of the sector regions (11), the fifth magnetic component has a first portion on one side of the center line (L) and a second portion on the other side of the center line (L), the magnetic properties of the first portion and the second portion being asymmetrically distributed relative to the center line (L).

16. A rotor assembly (100), comprising: The rotor body (1) is made of amorphous material. The rotor body (1) has a plurality of fan-shaped regions (11) distributed along its circumference. Each fan-shaped region (11) has a center line (L) along the circumference of the rotor body (1). Each fan-shaped region (11) is provided with a first magnetic component (21) and a second magnetic component (22). The first magnetic component (21) and the second magnetic component (22) are respectively located on both sides of the center line (L). The volume of the first magnetic component (21) is greater than or less than the volume of the second magnetic component (22), or, The coercivity of the first magnetic component (21) is greater than or less than the coercivity of the second magnetic component (22), or... The remanence of the first magnetic component (21) is greater than or less than the remanence of the second magnetic component (22), or, In each of the sector regions (11), the shapes of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L), or... The positions of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L), or... The orientations of the first magnetic component (21) and the second magnetic component (22) are asymmetrically distributed relative to the center line (L), or... In each of the sector regions (11), the first magnetic component (21) and the second magnetic component (22) are of different types, or... In each of the sector regions (11), a first receiving groove (12) is provided at the position opposite to the first magnetic component (21) and a second receiving groove (13) is provided at the position opposite to the second magnetic component (22); at least a portion of the first magnetic component (21) is received in the first receiving groove (12) and at least a portion of the second magnetic component (22) is received in the second receiving groove (13); in each of the sector regions (11), the first receiving groove (12) and the second receiving groove (13) are asymmetrically arranged relative to the center line (L).

17. The rotor assembly (100) according to claim 1, wherein, Each sector region (11) is also provided with a first magnetic bridge (33) and a second magnetic bridge (34), which are asymmetrically arranged about the center line (L).

18. The rotor assembly (100) according to claim 17, wherein, Each magnetic component group (2) includes multiple magnetic components, and the first magnetic bridge (33) and the second magnetic bridge (34) are respectively located between two adjacent magnetic components among the multiple magnetic components; The widths of the first magnetic bridge (33) and the second magnetic bridge (34) are not equal, and the width of the magnetic bridge is the shortest distance between the two adjacent magnetic components.

19. The rotor assembly (100) according to claim 17 or 18, wherein, In each of the sector regions (11), the shapes of the first magnetic bridge (33) and the second magnetic bridge (34) are asymmetrical about the center line (L).

20. The rotor assembly (100) according to any one of claims 17 to 19, wherein, In each of the sector regions (11), the distance from the first magnetic bridge (33) to the center line (L) is greater than the distance from the second magnetic bridge (34) to the center line (L).

21. The rotor assembly (100) according to claim 20, wherein, The first magnetic bridge (33) and the second magnetic bridge (34) are located on both sides of the center line (L).

22. The rotor assembly (100) according to any one of claims 17 to 20, wherein, The rotor body (1) has a shaft side (1110); Each magnetic component group (2) includes a first magnetic flux layer (10) and a second magnetic flux layer (20); the first magnetic flux layer (10) is disposed close to the shaft side (1110), and the second magnetic flux layer (20) is disposed radially spaced from the first magnetic flux layer (10) on the rotor body (1), and is located on the side of the first magnetic flux layer (10) away from the shaft side (1110); The first magnetic flux layer (10) includes a first magnetic element (102), a second magnetic element (103) and a third magnetic element (104). The first magnetic bridge (33) is located between the first magnetic element (102) and the second magnetic element (103), and the second magnetic bridge (34) is located between the second magnetic element (103) and the third magnetic element (104).

23. The rotor assembly (100) according to claim 22, wherein, The first magnetic element (102) and the third magnetic element (104) are located on both sides of the center line and are asymmetrically arranged about the center line.

24. The rotor assembly (100) according to claim 23, wherein, The second magnetic element (103) and the first magnetic element (102) are located on the same side of the center line (L); The second magnetic element (103) and the third magnetic element (104) are arranged asymmetrically about the center line (L).

25. The rotor assembly (100) according to claim 23, wherein, The first part of the second magnetic element (103) is located on the same side of the center line (L) as the first magnetic element (102), and the second part of the second magnetic element (103) is located on the same side of the center line (L) as the third magnetic element (104). The first and second portions of the second magnetic element (103) are arranged asymmetrically about the center line (L).

26. The rotor assembly (100) according to any one of claims 22 to 25, wherein, The first magnetic component (102) includes a first magnet (501) and a first magnetic groove (71); The second magnetic component (103) includes a second magnet (502) and a second magnetic groove (72); and The third magnetic component (104) includes a third magnet (503) and a third magnetic groove (73); The first magnetic groove (71), the second magnetic groove (72) and the third magnetic groove (73) are respectively disposed in the rotor body (1), and the first magnet (501), the second magnet (502) and the third magnet (503) are respectively located in the first magnetic groove (71), the second magnetic groove (72) and the third magnetic groove (73); The first magnetic bridge (33) is located between the first magnetic slot (71) and the second magnetic slot (72), and the second magnetic bridge (34) is located between the second magnetic slot (72) and the third magnetic slot (73).

27. The rotor assembly (100) according to claim 26, wherein, The first magnetic groove (71) and the third magnetic groove (73) are located on both sides of the center line (L) and are asymmetrically arranged about the center line (L).

28. The rotor assembly (100) according to claim 27, wherein, The second magnetic groove (72) and the first magnetic groove (71) are located on the same side of the center line (L); The second magnetic groove (72) and the third magnetic groove (73) are arranged asymmetrically about the center line.

29. The rotor assembly of claim 26, wherein, The first part of the second magnetic groove (72) is located on the same side of the center line (L) as the first magnetic groove (71); the second part of the second magnetic groove (72) is located on the other side of the center line (L) as the third magnetic groove (73). The second magnetic groove (72) is arranged symmetrically or asymmetrically about the center line (L).

30. The rotor assembly (100) according to any one of claims 26 to 29, wherein, The first magnet (501) and the third magnet (503) are located on both sides of the center line (L) and are arranged asymmetrically about the center line (L).

31. The rotor assembly (100) according to claim 30, wherein, The second magnet (502) and the first magnet (501) are located on the same side of the center line (L); The second magnet (502) and the third magnet (503) are arranged asymmetrically about the center line (L).

32. The rotor assembly (100) according to claim 30, wherein, The first part of the second magnet (502) is located on the same side of the center line (L) as the first magnet (501), and the second part of the second magnet (502) is located on the same side of the center line (L) as the third magnet (503). The first and second portions of the second magnet (502) are arranged symmetrically or asymmetrically about the center line (L).

33. The rotor assembly (100) according to any one of claims 26 to 32, wherein, The second magnetic flux layer (20) includes a fourth magnetic element (105) and a fifth magnetic element (106). The fourth magnetic element (105) and the first magnetic element (102) are located on the same side of the center line (L), and the fifth magnetic element (106) and the third magnetic element (104) are located on the same side of the center line (L).

34. The rotor assembly (100) according to claim 33, wherein, The fourth magnetic element (105) and the fifth magnetic element (106) are arranged symmetrically or asymmetrically about the center line (L).

35. The rotor assembly (100) according to claim 34, wherein, The fourth magnetic element (105) includes a fourth magnetic groove (74) and a fourth magnet (504), and the fifth magnetic element (106) includes a fifth magnetic groove (75) and a fifth magnet (505); The fourth magnetic slot (74) and the fifth magnetic slot (75) are disposed in the rotor body, and the fourth magnet (504) and the fifth magnet (505) are respectively located in the fourth magnetic slot (74) and the fifth magnetic slot (75); The fourth magnetic slot (74) and the fifth magnetic slot (75) satisfy at least one of the following: the fourth magnetic slot (74) and the fifth magnetic slot (75) are arranged symmetrically or asymmetrically about the center line (L); and the fourth magnet (504) and the fifth magnet (505) are arranged symmetrically or asymmetrically about the center line (L).

36. The rotor assembly (100) according to claim 17, wherein, The fourth magnetic groove (74) and the first magnetic groove (71) are located on the same side of the center line (L), and the fifth magnetic groove (75) and the third magnetic groove (73) are located on the same side of the center line (L); The minimum distance from the fourth magnetic slot (74) to the first magnetic slot (71) is greater than or equal to the minimum distance from the fifth magnetic slot (75) to the third magnetic slot (73).

37. The rotor assembly (100) according to claim 36, wherein, The minimum distance from the fourth magnetic slot (74) to the second magnetic slot (72) is greater than or equal to the minimum distance from the fifth magnetic slot (75) to the third magnetic slot (73).

38. The rotor assembly (100) according to any one of claims 26 to 37, wherein, The width ratio of the first magnetic bridge (33) and the second magnetic bridge (34) ranges from [0.7, 0.85].

39. The rotor assembly (100) according to claim 38, wherein, The rotor body also includes an outer wall (31) located away from the shaft side; the rotor body (1) also includes: A third magnetic bridge (35) is located between the first magnetic groove (71) and the outer wall (31); and The fourth magnetic bridge (36) is located between the third magnetic groove (73) and the outer wall (31); Wherein, the third magnetic bridge (35) and the fourth magnetic bridge (36) satisfy at least one of the following: The width ratio of the third magnetic bridge (35) and the fourth magnetic bridge (36) ranges from [0.8, 0.95]; and The width ratio of the fourth magnetic bridge (36) and the second magnetic bridge (34) ranges from [0.75, 0.85].

40. The rotor assembly (100) according to claim 39, wherein, The widths of the first magnetic bridge (33), the second magnetic bridge (34), the third magnetic bridge (35), and the fourth magnetic bridge (36) satisfy the following: 1.5mm≤L1≤2mm; 1.5mm≤L2≤2mm; 1mm≤L3≤1.5mm; and 1mm≤L4≤1.5mm; wherein L1, L2, L3, and L4 are the widths of the first magnetic bridge (33), the second magnetic bridge (34), the third magnetic bridge (35), and the fourth magnetic bridge (36), respectively.

41. The rotor assembly (100) according to any one of claims 26 to 40, wherein, In the axial direction of the rotor body (1), the volume of the third magnet (503) located at the rear side of the rotor assembly (100) in the rotation direction is smaller than the sum of the volumes of the first magnet (501) and the second magnet (502) located at the front side of the rotor assembly (100) in the rotation direction.

42. The rotor assembly (100) according to claim 41, wherein, The volume V3 of the third magnet (503), the volume V1 of the first magnet (501), and the volume V2 of the second magnet (502) satisfy the following: (V1+V2-V3): (V1+V2) < any value in [10%, 25%].

43. The rotor assembly (100) according to any one of claims 35 to 42, wherein, The angle between the extension direction of the fourth magnet (504) and the extension direction of the fifth magnet (505) is in the range of [120°, 150°].

44. The rotor assembly (100) according to claim 35 or 36, wherein, The sum of the cross-sectional areas of the fourth magnetic slot (74) and the fifth magnetic slot (75) perpendicular to the axial direction of the rotor body is [16mm]. 2 25mm 2 Any value in ].

45. The rotor assembly (100) according to any one of claims 26 to 44, wherein, At least one of the first magnet (501), the second magnet (502) and the third magnet (503) includes at least two first sub-magnets and at least one second sub-magnet, wherein one of the at least two second sub-magnets is located between two adjacent first sub-magnets.

46. ​​The rotor assembly (100) according to claim 45, wherein, The first sub-magnet is a grain boundary penetrating magnet, and the second sub-magnet is a heat-deformation magnet.

47. The rotor assembly (100) according to any one of claims 35 to 46, further comprising: First covering layer (61); and Second covering layer (62); The first covering layer (61) and the second covering layer (62) are respectively located on the axial direction of the rotor body (1) and cover both ends of the rotor body (1); The first covering layer (61) covers at least one of the first magnetic groove (71), the second magnetic groove (72), the third magnetic groove (73), the fourth magnetic groove (74), and the fifth magnetic groove (75); The second covering layer (62) covers the first magnetic groove (71), the second magnetic groove (72), the third magnetic groove (73), the fourth magnetic groove (74) and the fifth magnetic groove (75), excluding the remaining magnetic grooves covered by the first covering layer (61).

48. The rotor assembly (100) according to any one of claims 25 to 47, wherein, The rotor body (1) also includes an inner wall (32) which is close to the shaft side (1110); The rotor assembly (100) further includes a through hole (16) extending axially along the rotor body (1) and used to receive and fix the rotating shaft; The inner wall (32) is the wall of the through hole (16), and the through hole (16) has a multi-keyway structure.

49. The rotor assembly (100) according to any one of claims 17 to 48, wherein, The stacking diameter coefficient of the rotor body (1) is set in the range of [0.19‰, 1.68‰]. The stacking diameter coefficient of the rotor body (1) refers to the ratio of the thickness of the rotor body (1) in the axial direction to the outer diameter of the rotor body (1).

50. An electric motor, comprising: The rotor assembly according to any one of claims 1 to 49.

51. The motor according to claim 50, further comprising: A stator assembly (120) is arranged around the rotor assembly.

52. The motor according to claim 51, further comprising: The limit sensor (130) is positioned relative to the air gap of the stator assembly (120) and the rotor assembly (100); The limit sensor (130) is configured to detect whether the outer diameter deformation of the rotor assembly (100) exceeds the standard.

53. The motor according to claim 52, further comprising a housing (150), wherein the stator assembly (120) and the rotor assembly (100) are located within the housing (150); in, The limit sensor (130) is mounted on the housing.

54. The rotor assembly according to any one of claims 1 to 49, wherein, The rotor assembly is used in the electric powertrain.

55. A vehicle comprising: The rotor assembly according to any one of claims 1 to 49, or the motor according to any one of claims 50 to 54.

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