Rotor assembly, electric machine and household appliance

Abstract

The application provides a rotor assembly, a motor and a household appliance, the rotor assembly is used for the motor, the motor comprises a stator assembly, the stator assembly is located on one side of the rotor assembly in the axial direction, and the rotor assembly comprises a rotor core, a plurality of magnetic pole groups are arranged on the rotor core in a circumferential direction of the rotor core, the polarities of two adjacent magnetic pole groups in the circumferential direction are opposite, the magnetic pole groups are arranged in a stepped shape in a radial direction of the rotor core, so that the magnetic pole groups comprise at least two layers of stepped portions distributed in the radial direction, wherein the stepped portions are magnetic conductors or permanent magnets, in the plurality of magnetic pole groups, the stepped portions located in the same layer in the radial direction constitute a magnetic material group, and in at least one magnetic material group, any two adjacent stepped portions located in two magnetic pole groups are one magnetic conductor and the other permanent magnet. The rotor assembly provided by the application improves the space utilization rate of the rotor core and reduces the manufacturing cost.

Description

[0001] This application claims priority to Chinese Patent Application No. 202510453536.7, filed on April 10, 2025, entitled "Rotor Assembly, Motor and Household Appliance", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of household appliance technology, and more specifically, to a rotor assembly, a motor, and a household appliance. Background Technology

[0003] In related technologies, for the rotor assembly of axial flux motors, the permanent magnets are usually fan-shaped, circular, or single rectangular. Fan-shaped permanent magnets have a higher utilization rate, but the manufacturing process is complex and the cost is high. Circular and rectangular permanent magnets are simple to manufacture, but the projected area of ​​the permanent magnet on the stator core is small, which will reduce the space utilization rate of the rotor core and lose some motor performance. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, a first aspect of the present invention provides a rotor assembly.

[0006] A second aspect of the invention also provides an electric motor.

[0007] A third aspect of the present invention also provides a household appliance.

[0008] In view of the above, a first aspect of the present invention provides a rotor assembly for use in an electric motor, the electric motor including a stator assembly located on one side of the rotor assembly along the axial direction, the rotor assembly including: a rotor core; a plurality of magnetic pole groups spaced apart along the circumferential direction of the rotor core, the polarities of two adjacent magnetic pole groups being opposite along the circumferential direction; the magnetic pole groups being arranged in a stepped shape in the radial direction of the rotor core, such that the magnetic pole groups include at least two layers of stepped portions distributed along the radial direction; wherein the stepped portions are magnetic conductors or permanent magnets, in the plurality of magnetic pole groups, the stepped portions located in the same layer along the radial direction constitute a magnetic material group, in at least one magnetic material group, one of any two adjacent stepped portions located in two magnetic pole groups is a magnetic conductor, and the other is a permanent magnet.

[0009] The rotor assembly provided by this invention includes a rotor core and multiple magnetic pole groups. The multiple magnetic pole groups are arranged circumferentially around the rotor core so that adjacent magnetic pole groups form magnetic poles with opposite polarities. The magnetic pole groups are arranged in a stepped shape in the radial direction of the rotor core, such that the magnetic pole groups include at least two layers of stepped portions distributed in the radial direction. This arrangement increases the axial projection area of ​​the magnetic pole groups on the stator assembly, improves the space utilization of the rotor core, significantly improves the torque output capability of the motor, and enhances the performance of the motor. In this system, multiple magnetic pole groups are formed by stepped portions on the same layer along the radial direction, which constitute a magnetic material group. Each magnetic pole group has at least two magnetic material groups. In at least one magnetic material group, one of any two adjacent stepped portions located in the two magnetic pole groups is a magnetic conductor, and the other is a permanent magnet. In this way, in at least one magnetic material group, the magnetic conductor and the permanent magnet are arranged alternately along the circumferential direction of the rotor core. Thus, in at least one magnetic material group, the permanent magnet can magnetize the magnetic conductor, so that the magnetic conductor and the permanent magnet on the same layer form a pair of magnetic poles. This improves the efficiency of the motor, reduces manufacturing costs, and the magnetic conductor, as a soft magnetic material with a low temperature coefficient, can compensate for the demagnetization effect of the permanent magnet caused by temperature rise. It can maintain the stability of the magnetic circuit in high-temperature environments and improve the reliability of the system.

[0010] It should be noted that the stepped portions located on the same layer along the radial direction constitute a magnetic material group. For example, in any magnetic pole group, from the radial inner side to the radial outer side, the stepped portion located on the first layer is the first-layer stepped portion, the stepped portion located on the second layer is the second-layer stepped portion, the first-layer stepped portions of multiple magnetic pole groups are stepped portions located on the same layer and constitute a magnetic material group, the second-layer stepped portions of multiple magnetic pole groups are stepped portions located on the same layer and constitute another magnetic material group, and so on. The third-layer stepped portions of multiple magnetic pole groups are stepped portions located on the same layer, and the arrangement of the remaining layers is the same, which will not be repeated here.

[0011] It should be noted that the magnetic pole group is arranged in a stepped shape in the radial direction of the rotor core, thereby forming at least two layers of stepped portions distributed radially, with the stepped portions as the boundary. In other words, the magnetic pole group includes at least two layers of stepped portions, which are distributed in the radial direction of the rotor core, and the at least two layers of stepped portions have a height difference along the axial direction, or the at least two layers of stepped portions bulge outward in one direction clockwise and / or counterclockwise in the circumferential direction of the rotor core, so that the at least two layers of stepped portions form a stepped shape, that is, the magnetic pole group is stepped.

[0012] It should be noted that the stepped section is either a magnetic conductor or a permanent magnet. That is, among all the stepped sections of all magnetic pole groups, some stepped sections are magnetic conductors, while others are permanent magnets.

[0013] Understandably, the stator assembly is located on one side of the rotor assembly along its axial direction. Through the principle of axial magnetic flux coupling, the rotor and stator assemblies are separated, eliminating the need for a connecting shaft to transmit power between the parts connected to the rotor and stator assemblies. This design also reduces the axial thickness and overall weight of both the stator and rotor assemblies, thus contributing to a reduction in the overall height and weight of the appliance, facilitating storage and transportation. Users can easily store the parts with the stator and rotor assemblies separately, improving convenience. Furthermore, by separating the stator and rotor assemblies through axial magnetic flux coupling, the elimination of a connecting shaft for power transmission and the need for couplings between the shafts reduces motor noise during operation.

[0014] Optionally, the rotor assembly and the stator assembly are spaced apart along the axial direction of the rotor assembly.

[0015] Optionally, the axis of the rotor assembly is parallel to the axis of the stator assembly in the axial direction.

[0016] Optionally, the axis of the rotor assembly coincides with the axis of the stator assembly in the axial direction.

[0017] In some embodiments, optionally, in any magnetic pole group, the ends of two adjacent stepped portions in the radial direction are staggered in the circumferential direction to make the magnetic pole group have a stepped shape; or in any magnetic pole group, one of two adjacent stepped portions in the radial direction protrudes axially from the other to make the magnetic pole group have a stepped shape.

[0018] In this embodiment, in any magnetic pole group, the ends of two radially adjacent stepped portions are staggered in the circumferential direction, so that the end of one stepped portion protrudes beyond the end of the other stepped portion, thereby making the magnetic pole group have a stepped shape; or, in any magnetic pole group, one of two radially adjacent stepped portions protrudes axially beyond the other, thereby making the two radially adjacent stepped portions have a height difference in the axial direction, thereby making the magnetic pole group have a stepped shape.

[0019] It should be noted that in any magnetic pole group, the ends of two adjacent stepped sections in the radial direction are misaligned in the circumferential direction. This includes two adjacent stepped sections in the radial direction having the same length and their ends being misaligned in the circumferential direction, and also includes two adjacent stepped sections in the radial direction having different lengths and their ends being misaligned in the axial direction.

[0020] In some embodiments, optionally, in any two radially adjacent stepped portions of a magnetic pole group, the length of the inner stepped portion in the circumferential direction is less than the length of the outer stepped portion in the circumferential direction; wherein, the inner stepped portion is the stepped portion near the axis of the rotor core, and the outer stepped portion is the stepped portion near the sidewall of the rotor core.

[0021] In this embodiment, in any two radially adjacent stepped portions of a magnetic pole group, the circumferential length of the inner stepped portion is shorter than that of the outer stepped portion. This increases the overall coverage area of ​​the magnetic pole group on the stator assembly, improving the main magnetic flux utilization rate, while also ensuring the gap between two adjacent stepped portions in different magnetic pole groups, thus guaranteeing magnetic field reliability. Simultaneously, the shortened circumferential length of the inner stepped portion weakens the magnetic field strength gradient in the axial region near the rotor core; the circumferential extension of the outer stepped portion expands the magnetic field coverage range at the air gap edge.

[0022] In some embodiments, optionally, in any two radially adjacent stepped portions of a magnetic pole group, the two ends of the outer stepped portion in the circumferential direction protrude outward from the inner stepped portion in the circumferential direction.

[0023] In this embodiment, in any two radially adjacent stepped portions of a magnetic pole group, the two ends of the outer stepped portion protrude circumferentially from the inner stepped portion, that is, the two ends of the outer stepped portion extend beyond the two ends of the inner stepped portion circumferentially, so that the circumferential ends of multiple stepped portions in the magnetic pole group are trapezoidal structures, which improves torque density and running stability while enhancing the magnetic field anti-saturation capability under high-speed conditions.

[0024] In some embodiments, optionally, in any two adjacent magnetic pole groups along the circumferential direction: all the stepped portions of one magnetic pole group are permanent magnets, and in all the stepped portions of the other magnetic pole group, at least one layer of the stepped portion is a permanent magnet and at least one layer of the stepped portion is a magnetic conductor, or all the stepped portions of the other magnetic pole group are magnetic conductors; or all the stepped portions of any magnetic pole group include at least one permanent magnet and at least one magnetic conductor, so that the arrangement of the stepped portions in any magnetic material group is: along the circumferential direction, the magnetic conductors and permanent magnets are arranged alternately.

[0025] In this embodiment, any two adjacent magnetic pole groups along the circumferential direction can have various combinations of permanent magnets and magnetic conductors. The different numbers or arrangements of magnetic conductors and permanent magnets in each combination allow the motor to have multiple power outputs, thus adapting to different operating conditions. For example, in any two adjacent magnetic pole groups along the circumferential direction, all the stepped portions of one pole group are permanent magnets, while in the other pole group, at least one stepped portion is a magnetic conductor and at least one stepped portion is a permanent magnet. This results in one pole group consisting entirely of permanent magnets, and the other containing both permanent magnets and magnetic conductors, reducing manufacturing costs while still achieving higher power outputs. Alternatively, in any two adjacent magnetic pole groups along the circumferential direction, all the stepped portions of one pole group are permanent magnets, and all the stepped portions of the other pole group are magnetic conductors. This allows magnetic conductors and permanent magnets to be alternately arranged circumferentially. Or, in two adjacent pole groups, each pole group is provided with both magnetic conductors and permanent magnets, thereby achieving adaptation to different power operating conditions.

[0026] In some embodiments, optionally, in any magnetic pole group, if two adjacent stepped portions in the radial direction are both permanent magnets, the adjacent permanent magnets are either a separate structure or an integral structure; if two adjacent stepped portions in the radial direction are both magnetic conductors, the adjacent magnetic conductors are either a separate structure or an integral structure.

[0027] In this embodiment, when two adjacent stepped sections along the radial direction are both permanent magnets, the adjacent permanent magnets are separate structures. This eliminates the need for complex shape design for individual stepped sections, avoids increasing manufacturing costs, and allows the dimensions of the stepped sections to be adjusted for different stator components. Furthermore, in each pole group, different grades of stepped sections can be selected to flexibly adjust the magnetic flux, resulting in greater design freedom. Alternatively, when two adjacent stepped sections along the radial direction are both permanent magnets, the adjacent permanent magnets are a single-piece structure to reduce assembly steps and difficulty. In any pole group, when two adjacent stepped sections along the radial direction are both magnetic conductors, the adjacent magnetic conductors are separate structures to facilitate individual design of the magnetic conductors, forming a trapezoidal structure and reducing manufacturing costs. Alternatively, in any pole group, when two adjacent stepped sections along the radial direction are both magnetic conductors, the adjacent magnetic conductors are a single-piece structure to reduce the difficulty of demolding the magnetic conductors.

[0028] In some embodiments, optionally, in any magnetic pole group, if two adjacent stepped portions in the radial direction are both permanent magnets, the adjacent permanent magnets are split structures and are attached to each other; and / or if the magnetic pole group includes at least one permanent magnet and at least one magnetic conductor, the adjacent permanent magnets and magnetic conductors in the radial direction are spaced apart to form a magnetic isolation bridge.

[0029] In this embodiment, when the magnetic pole group includes multiple permanent magnets, the radially adjacent permanent magnets are fitted together, which can eliminate the air gap magnetic resistance between adjacent stepped portions, allowing the magnetic fields of the multilayer permanent magnets to be efficiently superimposed radially, further suppressing spatial harmonics, thereby achieving a synergistic improvement in high torque density and low vibration noise. Optionally, when the magnetic pole group includes at least one permanent magnet and at least one magnetic conductor, the radially adjacent permanent magnets and magnetic conductors are spaced apart to form a magnetic isolation bridge, thereby reducing the leakage magnetic flux between the radially adjacent permanent magnets and magnetic conductors, improving magnetic flux utilization, and thus increasing the torque of the motor.

[0030] In some embodiments, optionally, in any magnetic pole group, the magnetic pole centerlines of two radially adjacent stepped portions are staggered along the circumferential direction of the rotor core.

[0031] In this embodiment, in any magnetic pole group, the magnetic pole center lines of two adjacent stepped sections along the radial direction are misaligned along the circumferential direction of the rotor core, so that the torque formed by the two adjacent stepped sections is misaligned along the circumferential direction, and the magnetic pole phase difference generated by the misalignment makes the magnetic flux absorption process of adjacent stator teeth asynchronous, weakening the peak value of the tooth cogging torque, thereby achieving the effects of reducing harmonics, improving the back electromotive force of the motor, reducing the tooth cogging torque of the motor, and reducing vibration and noise.

[0032] In some embodiments, optionally, in any magnetic pole group, the circumferential misalignment of the magnetic pole centerlines of two radially adjacent stepped sections along the rotor core is the target misalignment, and the target misalignment is the same for any two adjacent magnetic pole groups along the circumferential direction.

[0033] In this embodiment, the target misalignment of the magnetic pole centerlines of any two adjacent magnetic pole groups is the same, so that the peak value of the cogging torque is weakened in the same way, thereby achieving the effect of improving back electromotive force and reducing vibration noise.

[0034] It should be noted that the target misalignment amount is set according to the actual situation.

[0035] In some embodiments, the permanent magnet is optionally attached to the axial surface of the rotor core; and / or the magnetic conductor is disposed on one side of the rotor core along the axial direction and is integral with the rotor core.

[0036] In this embodiment, a permanent magnet is attached to the axial surface of the rotor core. The surface-mounted permanent magnet directly couples with the air gap magnetic field, increasing the magnetic flux density. Optionally, a magnetic conductor is disposed on one side of the rotor core along the axial direction and is integrally formed with the rotor core. That is, the magnetic conductor is part of the rotor core, allowing the magnetic conductor and the rotor core to be integrally formed, thereby reducing manufacturing and assembly costs.

[0037] According to a second aspect of the invention, an electric motor is also provided, comprising: a stator assembly; and a rotor assembly as described in any of the preceding claims, the stator assembly being located on one side of the axial direction of the rotor assembly, the stator assembly being capable of driving the rotor assembly to rotate.

[0038] The motor provided in the second aspect of the present invention, because it includes the rotor assembly proposed in any of the above embodiments, has all the beneficial effects of the rotor assembly. The stator assembly is located on one side of the rotor assembly along its axial direction. Through the principle of axial magnetic flux coupling, the rotor assembly and stator assembly are separated, so that the parts connected to the rotor assembly and the parts connected to the stator assembly do not need to be connected by a connecting shaft to transmit power. At the same time, this arrangement can reduce the axial thickness of the stator assembly and the rotor assembly, as well as the overall weight, thereby helping to reduce the overall height and weight of the household appliance, facilitating its storage and transportation. When storing, the user can separately store the part with the stator assembly and the part with the rotor assembly, improving the convenience of storage and carrying.

[0039] Optionally, the stator assembly includes a stator core and a winding. The stator core includes a wire frame, teeth, and a yoke. The winding is wound on the wire frame, the wire frame is sleeved on the teeth, the teeth are disposed on the yoke, and the teeth and yoke are welded together to form the stator assembly.

[0040] Optionally, the teeth are arranged in a stepped shape along the radial direction of the stator assembly, and the windings are arranged in a stepped shape along the radial direction of the stator assembly.

[0041] Optionally, the tooth portion includes a first tooth portion and a second tooth portion along the radial direction of the stator assembly, wherein the first tooth portion is located on the side of the second tooth portion near the axis of the rotor assembly, and the ends of the first tooth portion and the ends of the second tooth portion are offset along the circumferential direction of the stator assembly.

[0042] Optionally, along the circumferential direction of the stator assembly, the end of the second tooth protrudes beyond the end of the first tooth.

[0043] Optionally, along the circumferential direction of the stator assembly, both ends of the second tooth protrude beyond the ends of the first tooth.

[0044] Optionally, the yoke is provided with a trapezoidal groove, and the teeth are engaged in the trapezoidal groove.

[0045] Optionally, the wire frame is provided with a hollow groove, and the wire frame is fitted onto the toothed part through the hollow groove.

[0046] According to a third aspect of the invention, a household appliance is also provided, comprising: a rotor assembly as described in any of the above embodiments; or a motor as described in the above embodiments.

[0047] The household appliance provided in the third aspect of the present invention, having the rotor assembly or motor proposed in any of the above embodiments, has all the beneficial effects of the rotor assembly or motor.

[0048] In some embodiments, the household appliance may optionally include any one of a food processor, a rice cooker, and a fan.

[0049] In this embodiment, the household appliance can be any of a food processor, a rice cooker, and a fan, allowing for the separation of the rotor assembly from the stator assembly via an axial flux motor, facilitating disassembly and cleaning of the food processor, rice cooker, and fan. Simultaneously, the axial flux motor eliminates the need for a connecting shaft between the rotor and stator assemblies, preventing leaks from the food processor and rice cooker.

[0050] In some embodiments, optionally, when the household appliance includes a food processor, the food processor includes: a base assembly, a stator assembly disposed on the base assembly; a cup assembly that can be mounted on the base assembly; and a processing unit located on the cup assembly, the processing unit including a rotating shaft, a rotor assembly located on the cup assembly and sleeved on the rotating shaft, the stator assembly being capable of driving the rotor assembly to rotate, thereby causing the processing unit to rotate.

[0051] In this embodiment, when the household appliance includes a food processor, the food processor includes a base assembly, a cup assembly, and a processing unit. The rotor assembly is located on the cup assembly, and the stator assembly is located on the base assembly. The cup assembly can be placed on the base assembly. Through the interaction between the stator assembly and the rotor assembly, the processing unit is rotated, thereby processing the food inside the cup assembly. This avoids leakage from the cup assembly. At the same time, this arrangement also facilitates the disassembly and cleaning of the cup assembly, as well as the separate storage of the cup assembly and the base assembly.

[0052] Understandably, the stator assembly is located on the base assembly, and the rotor assembly is located on the cup assembly. The rotor assembly is connected to the processing unit. Under the interaction of the magnetic fields of the stator and rotor assemblies, the rotor assembly can rotate, thereby driving the processing unit to rotate and processing the food inside the cup assembly. The rotor assembly is located on one side of the stator assembly along its axial direction. Through the principle of axial magnetic flux coupling, the rotor and stator assemblies are separated. This also reduces the thickness and weight of the motor along its axial direction, thus reducing the overall height and weight of the food processor and facilitating its storage and transportation. Furthermore, by separating the stator and rotor assemblies through axial magnetic flux coupling, there is no need for a connecting shaft passing through the cup assembly to transmit power, improving the sealing performance of the cup assembly. It also eliminates the need for a coupling to connect the drive shafts, thereby reducing noise during operation.

[0053] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0055] Figure 1 One of the schematic diagrams of a rotor assembly according to an embodiment of the present invention is shown;

[0056] Figure 2 A second schematic diagram of the rotor assembly according to an embodiment of the present invention is shown;

[0057] Figure 3 A third schematic diagram of the rotor assembly according to an embodiment of the present invention is shown;

[0058] Figure 4 A fourth schematic diagram of the rotor assembly according to an embodiment of the present invention is shown;

[0059] Figure 5 Fifth schematic diagram of the rotor assembly according to an embodiment of the present invention is shown;

[0060] Figure 6 A sixth schematic diagram of the structure of a rotor assembly according to an embodiment of the present invention is shown;

[0061] Figure 7 A comparison diagram of permanent magnet flux generated by permanent magnets of different shapes is shown;

[0062] Figure 8 A comparison diagram of permanent magnet flux linkages when permanent magnets in different layers act individually is shown.

[0063] Figure 9 A schematic diagram of the structure of a motor according to an embodiment of the present invention is shown;

[0064] Figure 10 One of the structural schematic diagrams of a stator assembly according to an embodiment of the present invention is shown;

[0065] Figure 11 A second schematic diagram of the stator assembly according to an embodiment of the present invention is shown;

[0066] Figure 12 A third schematic diagram of the structure of a stator assembly according to an embodiment of the present invention is shown;

[0067] Figure 13 The fourth schematic diagram of the stator assembly according to an embodiment of the present invention is shown;

[0068] Figure 14 The fifth schematic diagram shows the structure of a stator assembly according to an embodiment of the present invention;

[0069] Figure 15 A schematic diagram of the structure of a household appliance according to an embodiment of the present invention is shown;

[0070] Figure 16 One schematic diagram of a motor according to an embodiment of the present invention is shown;

[0071] Figure 17 A second schematic diagram of a motor according to an embodiment of the present invention is shown;

[0072] Figure 18 A schematic diagram of the winding structure of a stator assembly according to an embodiment of the present invention is shown;

[0073] Figure 19 A schematic diagram of the winding and wire frame structure of a stator assembly according to an embodiment of the present invention is shown;

[0074] Figure 20 One of the structural schematic diagrams of a stator assembly portion according to an embodiment of the present invention is shown;

[0075] Figure 21 A second schematic diagram of the stator assembly portion according to an embodiment of the present invention is shown;

[0076] Figure 22 The third schematic diagram shows the structure of a stator assembly portion according to an embodiment of the present invention;

[0077] Figure 23 A schematic diagram of the stator assembly portion according to an embodiment of the present invention is shown.

[0078] in, Figures 1 to 23 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0079] 1. Rotor assembly, 10. Rotor core, 12. Magnetic pole group, 120. Step section, 1200. Permanent magnet, 1202. Magnetic conductor, 14. Magnetic isolation bridge, 2. Stator assembly, 20. Tooth section, 202. First tooth section, 204. Second tooth section, 22. Winding, 24. Wire frame, 240. Hollow slot, 26. Yoke section, 3. Base assembly, 4. Cup body assembly, 5. Processing section, 50. Rotary shaft. Detailed Implementation

[0080] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0081] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0082] The following reference Figures 1 to 23 The present invention describes a rotor assembly 1, a motor, and a household appliance according to some embodiments thereof.

[0083] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 9 As shown, according to an embodiment of the present invention, a rotor assembly 1 is provided for use in a motor. The motor includes a stator assembly 2, which is located on one side of the axial direction of the rotor assembly 1. The rotor assembly 1 includes: a rotor core 10; a plurality of magnetic pole groups 12, which are spaced apart along the circumferential direction of the rotor core 10, and the polarities of two adjacent magnetic pole groups 12 along the circumferential direction are opposite; in the radial direction of the rotor core 10, the magnetic pole groups 12 are arranged in a stepped shape, such that the magnetic pole group 12 includes at least two layers of stepped portions 120 distributed in the radial direction; wherein the stepped portions 120 are magnetic conductors 1202 or permanent magnets 1200. In the plurality of magnetic pole groups 12, the stepped portions 120 located in the same layer along the radial direction constitute a magnetic material group. In at least one magnetic material group, one of any two adjacent stepped portions 120 located in two magnetic pole groups 12 is a magnetic conductor 1202 and the other is a permanent magnet 1200.

[0084] The rotor assembly provided by the present invention includes a rotor core 10 and a plurality of magnetic pole groups 12. The plurality of magnetic pole groups 12 are arranged circumferentially around the rotor core 10 such that adjacent magnetic pole groups 12 form magnetic poles with opposite polarities. The magnetic pole groups 12 are arranged in a stepped shape in the radial direction of the rotor core 10, such that the magnetic pole group 12 includes at least two layers of stepped portions 120, which are distributed in the radial direction. This arrangement increases the axial projection area of ​​the magnetic pole groups 12 on the stator assembly 2, improves the space utilization of the rotor core 10, significantly improves the torque output capability of the motor, and improves the performance of the motor. In this configuration, among the multiple magnetic pole groups 12, the stepped portions 120 located on the same layer along the radial direction constitute a magnetic material group. The multiple magnetic pole groups 12 have at least two magnetic material groups. In at least one magnetic material group, one of any two adjacent stepped portions 120 located in the two magnetic pole groups 12 is a magnetic conductor 1202, and the other is a permanent magnet 1200. This is such that in at least one magnetic material group, the magnetic conductor 1202 and the permanent magnet 1200 are arranged alternately along the circumferential direction of the rotor core 10. In this way, in at least one magnetic material group, the permanent magnet 1200 can magnetize the magnetic conductor 1202, so that the magnetic conductor 1202 and the permanent magnet 1200 on the same layer constitute a pair of magnetic poles, thereby improving the efficiency of the motor and reducing the manufacturing cost. Furthermore, the magnetic conductor 1202, as a soft magnetic material with a low temperature coefficient, can compensate for the demagnetization effect of the permanent magnet 1200 caused by temperature rise, and can maintain the stability of the magnetic circuit in high-temperature environments, thereby improving the reliability of the system.

[0085] It should be noted that the stepped portions 120 located on the same layer along the radial direction constitute a magnetic material group. For example, in any magnetic pole group 12, from the radial inner side to the radial outer side, the stepped portion 120 located on the first layer is the first-layer stepped portion, the stepped portion 120 located on the second layer is the second-layer stepped portion, and the first-layer stepped portions of multiple magnetic pole groups 12 are stepped portions 120 located on the same layer, constituting one magnetic material group. The second-layer stepped portions of multiple magnetic pole groups 12 are stepped portions 120 located on the same layer, constituting another magnetic material group, and so on. The third-layer stepped portions of multiple magnetic pole groups 12 are stepped portions 120 located on the same layer, and the arrangement of the remaining layers is the same, which will not be described again here. Figure 1 As shown, the magnetic pole group 12 includes two stepped portions 120. The outermost stepped portions 120 of all the magnetic pole groups 12 constitute a magnetic material group, and the innermost stepped portions 120 of all the magnetic pole groups 12 constitute a magnetic material group.

[0086] It should be noted that the magnetic pole group 12 is arranged in a stepped shape in the radial direction of the rotor core 10, thereby forming at least two layers of stepped portions 120 distributed radially, with the stepped portion as the boundary. In other words, the magnetic pole group 12 includes at least two layers of stepped portions 120, which are distributed in the radial direction of the rotor core 10, and the at least two layers of stepped portions 120 have a height difference along the axial direction, or the at least two layers of stepped portions 120 protrude from one side in a clockwise and / or counterclockwise direction in the circumferential direction of the rotor core 10, so that the at least two layers of stepped portions 120 form a stepped shape, that is, the magnetic pole group 12 is stepped.

[0087] It should be noted that the stepped portion 120 is either a magnetic conductor 1202 or a permanent magnet 1200. That is, among all the stepped portions 120 of all the magnetic pole groups 12, some stepped portions 120 are magnetic conductors 1202, and others are permanent magnets 1200.

[0088] Understandably, the stator assembly 2 is located on one side of the rotor assembly 1 along its axial direction. Through the principle of axial magnetic flux coupling, the rotor assembly 1 and stator assembly 2 are separated. This eliminates the need for a connecting shaft to transmit power between the parts connected to rotor assembly 1 and stator assembly 2. Furthermore, this arrangement reduces the axial thickness of both the stator assembly 2 and rotor assembly 1, as well as the overall weight, thus contributing to a reduction in the overall height and weight of the appliance. This facilitates storage and transportation, allowing users to separately store the parts with stator assembly 2 and rotor assembly 1, improving convenience. Additionally, by separating the stator assembly 2 and rotor assembly 1 through axial magnetic flux coupling, a connecting shaft for power transmission and a coupling for connecting the shafts are eliminated, thereby reducing motor noise during operation.

[0089] Optionally, the rotor assembly 1 and the stator assembly 2 are spaced apart along the axial direction of the rotor assembly 1.

[0090] Optionally, the axis of rotor assembly 1 is parallel to the axis of stator assembly 2 in the axial direction.

[0091] Optionally, the axis of rotor assembly 1 coincides with the axis of stator assembly 2 in the axial direction.

[0092] In some embodiments, optionally, in any magnetic pole group 12, the ends of two adjacent stepped portions 120 in the radial direction are staggered in the circumferential direction so that the magnetic pole group 12 is arranged in a stepped shape; or in any magnetic pole group 12, one of two adjacent stepped portions 120 in the radial direction protrudes axially from the other so that the magnetic pole group 12 is arranged in a stepped shape.

[0093] In this embodiment, in any magnetic pole group 12, the ends of two radially adjacent stepped portions 120 are misaligned in the circumferential direction, so that the end of one stepped portion 120 protrudes beyond the end of the other stepped portion 120, thereby making the magnetic pole group 12 have a stepped shape; or, in any magnetic pole group 12, one of two radially adjacent stepped portions 120 protrudes axially beyond the other, thereby making the two radially adjacent stepped portions 120 have a height difference in the axial direction, thereby making the magnetic pole group 12 have a stepped shape.

[0094] It should be noted that in any magnetic pole group 12, the ends of two adjacent stepped portions 120 in the radial direction are misaligned in the circumferential direction. This includes two adjacent stepped portions 120 in the radial direction having the same length and their ends being misaligned in the circumferential direction, and also includes two adjacent stepped portions 120 in the radial direction having different lengths and their ends being misaligned in the axial direction.

[0095] like Figures 1 to 6 As shown, in some embodiments, optionally, in any two radially adjacent stepped portions 120 of any magnetic pole group 12, the length of the inner stepped portion 120 in the circumferential direction is less than the length of the outer stepped portion 120 in the circumferential direction; wherein, the inner stepped portion 120 is the stepped portion 120 close to the axis of the rotor core 10, and the outer stepped portion 120 is the stepped portion 120 close to the sidewall of the rotor core 10.

[0096] In this embodiment, among two radially adjacent stepped portions 120 of any magnetic pole group 12, the circumferential length of the inner stepped portion 120 is shorter than that of the outer stepped portion 120. This increases the overall coverage area of ​​the magnetic pole group 12 on the stator assembly 2, improving the utilization rate of the main magnetic flux, while also ensuring the gap between two circumferentially adjacent stepped portions 120 of different magnetic pole groups 12, thus guaranteeing magnetic field reliability. Simultaneously, the shortened circumferential length of the inner stepped portion 120 weakens the magnetic field strength gradient near the axial region of the rotor core 10; the circumferential extension of the outer stepped portion 120 expands the magnetic field coverage range at the air gap edge.

[0097] Optionally, in any two adjacent magnetic pole groups 12, the stepped portions 120 located on the same layer are arranged opposite each other in the circumferential direction. For example, in two adjacent magnetic pole groups 12, the outermost stepped portion 120 in one magnetic pole group 12 is arranged opposite to the outermost stepped portion 120 in the other magnetic pole group 12 in the circumferential direction.

[0098] like Figures 1 to 6 As shown, in some embodiments, optionally, in any two radially adjacent stepped portions 120 of any magnetic pole group 12, the two ends of the outer stepped portion 120 in the circumferential direction protrude from the inner stepped portion 120 in the circumferential direction.

[0099] In this embodiment, in any two radially adjacent stepped portions 120 of any magnetic pole group 12, the two ends of the outer stepped portion 120 in the circumferential direction protrude beyond the two ends of the inner stepped portion 120 in the circumferential direction, that is, the two ends of the outer stepped portion 120 both extend beyond the two ends of the inner stepped portion 120 in the circumferential direction, so that the two ends of the multiple stepped portions 120 in the magnetic pole group 12 are all trapezoidal structures in the circumferential direction, which improves the torque density and running stability while enhancing the magnetic field anti-saturation capability under high-speed conditions.

[0100] Optionally, the permanent magnet 1200 is a bar magnet.

[0101] In some embodiments, optionally, in any two adjacent magnetic pole groups 12 along the circumferential direction: all the stepped portions 120 of one magnetic pole group 12 are permanent magnets 1200, and in all the stepped portions 120 of the other magnetic pole group 12, at least one layer of the stepped portion 120 is a permanent magnet 1200 and at least one layer of the stepped portion 120 is a magnetic conductor 1202, or all the stepped portions 120 of the other magnetic pole group 12 are magnetic conductors 1202; or all the stepped portions 120 of any magnetic pole group 12 include at least one permanent magnet 1200 and at least one magnetic conductor 1202, so that the arrangement of the stepped portions 120 in any magnetic material group is: along the circumferential direction, the magnetic conductor 1202 and the permanent magnet 1200 are arranged alternately.

[0102] In this embodiment, any two adjacent magnetic pole groups 12 along the circumferential direction can have multiple combinations of permanent magnets 1200 and magnetic conductors 1202. The different numbers or arrangements of the magnetic conductors 1202 and permanent magnets 1200 in each combination allow the motor to have various power outputs, thus adapting to different operating conditions. For example, as... Figure 1 , Figure 2 , Figure 5 , Figure 6 and Figure 9 As shown, in any two adjacent magnetic pole groups 12 along the circumferential direction, all the stepped portions 120 of one magnetic pole group 12 are permanent magnets 1200, and in the other magnetic pole group 12, at least one stepped portion 120 is a magnetic conductor 1202, and at least one stepped portion 120 is a permanent magnet 1200. This makes one set of magnetic pole groups 12 consist entirely of permanent magnets 1200, while the other set has both permanent magnets 1200 and magnetic conductors 1202, reducing manufacturing costs while satisfying higher power requirements. Or as... Figure 3 and Figure 9 As shown, in any two adjacent magnetic pole groups 12 along the circumferential direction, all the stepped portions 120 of one magnetic pole group 12 are permanent magnets 1200, and all the stepped portions 120 of the other magnetic pole group 12 are magnetic conductors 1202, such that the magnetic conductors 1202 and the permanent magnets 1200 are alternately arranged along the circumferential direction, or as shown in the diagram. Figure 4 and Figure 9 As shown, in two adjacent magnetic pole groups 12, each magnetic pole group 12 is provided with a magnetic conductor 1202 and a permanent magnet 1200, thereby realizing the adaptation to different power conditions.

[0103] Optionally, the multiple magnetic pole groups 12 are divided into two types, with one of the two adjacent magnetic pole groups 12 belonging to one type and the other magnetic pole group 12 belonging to the other type. In the multiple magnetic pole groups 12, the step portion 120 of the same type of magnetic pole group 12 has the same shape, structure and material.

[0104] Optionally, the number of stepped portions 120 in each magnetic pole group 12 can be two, three, four, or five, etc.

[0105] In some embodiments, optionally, in any magnetic pole group 12, if two adjacent stepped portions 120 in the radial direction are both permanent magnets 1200, the adjacent permanent magnets 1200 are either separate structures or integral structures; in any magnetic pole group 12, if two adjacent stepped portions 120 in the radial direction are both magnetic conductors 1202, the adjacent magnetic conductors 1202 are either separate structures or integral structures.

[0106] In this embodiment, when two radially adjacent stepped sections 120 are both permanent magnets 1200, the adjacent permanent magnets 1200 are a separate structure. This eliminates the need for complex shape design for individual stepped sections 120, avoids increasing manufacturing costs, and allows the dimensions of the stepped sections 120 to be adjusted for different stator components 2. Furthermore, in each pole group 12, different grades of stepped sections 120 can be selected to flexibly adjust the magnetic flux, resulting in greater design freedom. Alternatively, when two radially adjacent stepped sections 120 are both permanent magnets 1200, the adjacent permanent magnets 1200 are a single integrated structure, reducing assembly steps and simplifying assembly. In any magnetic pole group 12, if two adjacent stepped portions 120 in the radial direction are both magnetic conductors 1202, the adjacent magnetic conductors 1202 are of a split structure, so that the magnetic conductors 1202 can be designed separately, so that the adjacent magnetic conductors 1202 form a trapezoidal structure and reduce manufacturing costs; or, in any magnetic pole group 12, if two adjacent stepped portions 120 in the radial direction are both magnetic conductors 1202, the adjacent magnetic conductors 1202 are of an integral structure, so as to reduce the demolding difficulty of the magnetic conductors 1202.

[0107] Optionally, when the adjacent permanent magnets 1200 are in a split structure, the permanent magnets 1200 are rectangular in shape.

[0108] like Figure 1 , Figure 2 and Figure 4 As shown, in some embodiments, optionally, in any magnetic pole group 12, when two adjacent stepped portions 120 in the radial direction are both permanent magnets 1200, the adjacent permanent magnets 1200 are split structures and are attached to each other; and / or when the magnetic pole group 12 includes at least one permanent magnet 1200 and at least one magnetic conductor 1202, the permanent magnets 1200 and magnetic conductors 1202 in the radial direction are spaced apart to form a magnetic isolation bridge 14.

[0109] In this embodiment, when the magnetic pole group 12 includes multiple permanent magnets 1200, the radially adjacent permanent magnets 1200 are in close contact, which can eliminate the air gap magnetic resistance between adjacent stepped portions 120, allowing the magnetic fields of the multilayer permanent magnets 1200 to be efficiently superimposed radially, further suppressing spatial harmonics, thereby achieving a synergistic improvement in high torque density and low vibration noise. Optionally, when the magnetic pole group 12 includes at least one permanent magnet 1200 and at least one magnetic conductor 1202, the radially adjacent permanent magnets 1200 and magnetic conductors 1202 are spaced apart to form a magnetic isolation bridge 14, thereby reducing the leakage magnetic field between the radially adjacent permanent magnets 1200 and magnetic conductors 1202, improving magnetic flux utilization, and thus increasing the torque of the motor.

[0110] like Figure 6 and Figure 9 As shown, in some embodiments, optionally, in any magnetic pole group 12, the magnetic pole center lines of two radially adjacent stepped portions 120 are staggered along the circumferential direction of the rotor core 10.

[0111] In this embodiment, in any magnetic pole group 12, the magnetic pole center lines of two radially adjacent stepped portions 120 are misaligned along the circumferential direction of the rotor core 10, so that the torque formed by the two adjacent stepped portions 120 is misaligned along the circumferential direction, and the magnetic pole phase difference generated by the misalignment makes the magnetic flux absorption process of adjacent stator teeth asynchronous, weakening the peak value of the tooth cogging torque, thereby achieving the effects of reducing resonant waves, improving the back electromotive force of the motor, reducing the tooth cogging torque of the motor, and reducing vibration noise.

[0112] Specifically, such as Figure 6 and Figure 9 As shown, the magnetic pole center line of the outer stepped portion 120 is d1, and the magnetic pole center line of the inner stepped portion 120 is d2. The offset distance between d1 and d2 is D, and the value of D can be set according to the actual situation.

[0113] In some embodiments, optionally, in any magnetic pole group 12, the circumferential misalignment of the magnetic pole center lines of two radially adjacent stepped portions 120 along the rotor core 10 is the target misalignment, and the target misalignment is the same for any two adjacent magnetic pole groups 12 in the circumferential direction.

[0114] In this embodiment, the target misalignment of the center lines of any two adjacent magnetic pole groups 12 is the same, so that the peak value of the cogging torque is weakened in the same way, thereby achieving the effect of improving the back electromotive force and reducing vibration noise.

[0115] It should be noted that the target misalignment amount is set according to the actual situation.

[0116] In some embodiments, the permanent magnet 1200 is optionally attached to the axial surface of the rotor core 10; and / or the magnetic conductor 1202 is disposed on one side of the rotor core 10 along the axial direction and is integral with the rotor core 10.

[0117] In this embodiment, the permanent magnet 1200 is attached to the axial surface of the rotor core 10. The surface-mount permanent magnet 1200 directly couples with the air gap magnetic field, thereby increasing the magnetic flux density. Optionally, the magnetic conductor 1202 is disposed on one side of the rotor core 10 along the axial direction and is integrally formed with the rotor core 10. That is, the magnetic conductor 1202 is part of the rotor core 10, so that the magnetic conductor 1202 and the rotor core 10 can be integrally formed, thereby reducing manufacturing and assembly costs.

[0118] like Figure 9 As shown, according to one embodiment of the present invention, an electric motor is also provided, comprising: a stator assembly 2; and a rotor assembly 1 as described in any of the preceding claims, wherein the stator assembly 2 is located on one side of the axial direction of the rotor assembly 1, and the stator assembly 2 is capable of driving the rotor assembly 1 to rotate.

[0119] The motor provided by this invention, because it includes the rotor assembly 1 proposed in any of the above embodiments, has all the beneficial effects of the rotor assembly 1. The stator assembly 2 is located on one side of the rotor assembly 1 along its axial direction. Through the principle of axial magnetic flux coupling, the rotor assembly 1 and the stator assembly 2 are separated, so that the part connected to the rotor assembly 1 and the part connected to the stator assembly 2 do not need to be connected by a connecting shaft to transmit power. At the same time, this arrangement can also reduce the axial thickness of the stator assembly 2 and the rotor assembly 1, as well as the overall weight, thereby helping to reduce the overall height and weight of the household appliance, facilitating its storage and transportation. When storing, the user can separately store the part with the stator assembly 2 and the part with the rotor assembly 1, improving the convenience of storage and carrying.

[0120] Alternatively, the shape of the tooth 20 can be as follows: Figure 10 The sector shown, as Figure 11 The coiled rectangle shown is as follows: Figure 12 The overlapping rectangles shown are as follows: Figure 13 The trapezoid shown is, for example Figure 14 The stepped shape shown.

[0121] Optionally, such as Figure 18 , Figure 19 , Figure 20 , Figure 21 , Figure 22 and Figure 23 As shown, the stator assembly 2 includes a stator core and a winding 22. The stator core includes a wire frame 24, a toothed portion 20, and a yoke 26. The winding 22 is wound on the wire frame 24. The wire frame 24 is sleeved on the toothed portion 20. The toothed portion 20 is disposed on the yoke 26. The toothed portion 20 and the yoke 26 are welded together to form the stator assembly 2.

[0122] Optionally, such as Figure 18 and Figure 20 As shown, the toothed portion 20 is arranged in a stepped shape along the radial direction of the stator assembly 2, and the winding 22 is arranged in a stepped shape along the radial direction of the stator assembly 2.

[0123] Optionally, such as Figure 20 and Figure 23 As shown, the tooth portion 20 includes a first tooth portion 202 and a second tooth portion 204 along the radial direction of the stator assembly 2. The first tooth portion 202 is located on the side of the second tooth portion 204 close to the axis of the stator assembly 2. The ends of the first tooth portion 202 and the ends of the second tooth portion 204 are offset along the circumferential direction of the stator assembly 2.

[0124] Optionally, along the circumferential direction of the stator assembly 2, the end of the second tooth 204 protrudes beyond the end of the first tooth 202.

[0125] Optionally, along the circumferential direction of the stator assembly 2, both ends of the second tooth 204 protrude from the ends of the first tooth 202.

[0126] Optionally, the yoke 26 is provided with a trapezoidal groove, and the tooth 20 is engaged in the trapezoidal groove.

[0127] Optionally, such as Figure 19 and Figure 20 As shown, the wire frame 24 is provided with a hollow groove 240, and the wire frame 24 is sleeved on the toothed part 20 through the hollow groove 240.

[0128] Optionally, such as Figure 16 and Figure 17 As shown, the magnetic field lines between the stator assembly 2 and the rotor assembly 1 point from the N pole of the stator assembly 2 to the S pole of the rotor assembly 1 along the axial direction of the rotor assembly 1, and from the N pole of the rotor assembly 1 to the S pole of the stator assembly 2; the magnetic field lines inside the stator assembly 2 point from the S pole of the stator assembly 2 to the N pole of the stator assembly 2 along the circumference of the stator assembly 2, and the magnetic field lines inside the rotor assembly 1 point from the S pole of the rotor assembly 1 to the N pole of the rotor assembly 1 along the circumference of the rotor assembly 1.

[0129] In this embodiment, when the motor is turned on, the magnetic field lines inside the stator assembly 2 move circumferentially from the S pole to the N pole of the stator assembly 2, causing the magnetic field of the stator assembly 2 to rotate circumferentially. The N pole of the stator assembly 2 generates a repulsive force on the N pole of the rotor assembly 1, and the S pole of the stator assembly 2 generates an attractive force on the N pole of the rotor assembly 1. The S pole of the stator assembly 2 generates a repulsive force on the S pole of the rotor assembly 1, and the N pole of the stator assembly 2 generates an attractive force on the S pole of the rotor assembly 1. The electromagnetic forces acting on the N and S poles of the rotor assembly 1 along the axial direction of the rotor assembly 1 cancel each other out, and the resultant force is in the circumferential direction. The electromagnetic force of the stator assembly 2 causes the rotor assembly 1 to rotate in the same direction when the magnetic field of the stator assembly 2 rotates circumferentially. Thus, the rotor assembly 1 rotates under the action of the stator assembly 2. The rotation of the rotor assembly 1 causes the processing unit 5 connected to the rotor assembly 1 to rotate. In addition, the axial magnetic flux of the motor is achieved through the magnetic field distribution of the stator assembly 2 and the rotor assembly 1. This allows the stator assembly 2 and the rotor assembly 1 to be separated axially. When storing the motor, the part with the stator assembly 2 and the part with the rotor assembly 1 can be stored separately, improving the convenience of storage and carrying.

[0130] It can be understood that the magnetic poles of adjacent magnetic pole groups 12 include N poles and S poles, that is, the magnetic pole of one of the adjacent magnetic pole groups 12 is the N pole and the magnetic pole of the other is the S pole.

[0131] According to one embodiment of the present invention, a household appliance is also provided, comprising: a rotor assembly 1 as described in any of the above embodiments; or a motor as described in the above embodiments.

[0132] The household appliance provided by the present invention, having the rotor assembly 1 or motor proposed in any of the above embodiments, has all the beneficial effects of the rotor assembly 1 or motor.

[0133] In some embodiments, the household appliance may optionally include any one of a food processor, a rice cooker, and a fan.

[0134] In this embodiment, the household appliance can be any of a food processor, a rice cooker, and a fan, so that the part connected to the rotor assembly 1 and the part connected to the stator assembly 2 can be separated by an axial flux motor, facilitating the disassembly and cleaning of the food processor, rice cooker, and fan. At the same time, the axial flux motor does not require a connecting shaft to connect the rotor assembly 1 and the stator assembly 2, thus preventing leakage from the food processor and rice cooker.

[0135] like Figure 15As shown, in some embodiments, optionally, when the household appliance includes a food processor, the food processor includes: a base assembly 3, a stator assembly 2 disposed on the base assembly 3; a cup assembly 4, which can be mounted on the base assembly 3; and a processing unit 5 located on the cup assembly 4. The processing unit 5 includes a rotating shaft 50, a rotor assembly 1 located on the cup assembly 4 and sleeved on the rotating shaft 50, and the stator assembly 2 can drive the rotor assembly 1 to rotate, thereby causing the processing unit 5 to rotate.

[0136] In this embodiment, when the household appliance includes a food processor, the food processor includes a base assembly 3, a cup assembly 4, and a processing unit 5. The rotor assembly 1 is disposed on the cup assembly 4, and the stator assembly 2 is disposed on the base assembly 3. The cup assembly 4 can be placed on the base assembly. Through the interaction between the stator assembly 2 and the rotor assembly 1, the processing unit 5 is rotated, thereby processing the food inside the cup assembly 4. This can prevent leakage from the cup assembly 4. At the same time, this arrangement can also facilitate the disassembly and cleaning of the cup assembly 4, as well as the separate storage of the cup assembly 4 and the base assembly 3.

[0137] Understandably, the stator assembly 2 is located on the base assembly 3, and the rotor assembly 1 is located on the cup assembly 4. The rotor assembly 1 is connected to the processing unit 5. Under the interaction of the magnetic fields of the stator assembly 2 and the rotor assembly 1, the rotor assembly 1 can rotate, thereby driving the processing unit 5 to rotate and process the food inside the cup assembly 4. The rotor assembly 1 is located on one side of the stator assembly 2 along its axial direction. Through the principle of axial magnetic flux coupling, the rotor assembly 1 and the stator assembly 2 are separated. This also reduces the thickness and weight of the motor along its axial direction, thus reducing the overall height and weight of the food processor and facilitating its storage and transportation. Furthermore, by separating the stator assembly 2 and the rotor assembly 1 through the principle of axial magnetic flux coupling, there is no need for a connecting shaft to pass through the cup assembly 4 for power transmission, improving the sealing performance of the cup assembly 4. It also eliminates the need for a coupling to connect the drive shafts, thereby reducing the noise during the operation of the food processor.

[0138] Optionally, the processing unit 5 includes a blade or a stirring rod. When the stator assembly 2 is energized, the stator assembly 2 can drive the rotor assembly 1 to rotate through a magnetic field. When the rotor assembly 1 rotates, it drives the rotating shaft 50 of the processing unit 5 to rotate, thereby causing the processing unit 5 to rotate to process the food inside the cup assembly 4.

[0139] Optionally, the cup assembly 4 includes: a cup body, which includes a first cavity and a second cavity, a portion of the cutter being disposed in the first cavity and another portion being disposed in the second cavity, a rotor assembly 1 being disposed in the second cavity and connected to the cutter; and a bottom cover, which covers the end of the second cavity away from the first cavity.

[0140] In this embodiment, the cup assembly 4 includes a cup body and a bottom cover. A blade is disposed within the cup body, dividing the cup body into a first cavity and a second cavity. The first cavity is used to hold food ingredients, and the second cavity is used to hold components on the cup assembly 4. The bottom cover seals the end of the second cavity opposite to the first cavity, thus protecting the components within the second cavity. Part of the blade is disposed within the first cavity, and the other part is disposed within the second cavity and connected to a rotor assembly 1 within the second cavity. The rotor assembly 1 then drives the blade to rotate, allowing the blade to process the food ingredients within the first cavity.

[0141] Optionally, the household appliance includes a rice cooker, which includes a first pot body, a second pot body, and a processing unit 5. The second pot body is disposed inside the first pot body, and at least a portion of the processing unit 5 extends into the second pot body. A stator assembly 2 is disposed in the first pot body, and a rotor assembly 1 is disposed in the second pot body and connected to the processing unit 5. When the stator assembly 2 drives the rotor assembly 1 to rotate, the rotor assembly 1 drives the processing unit 5 to rotate.

[0142] In this embodiment, when the household appliance includes a rice cooker, the rice cooker includes a first pot body and a second pot body. The second pot body is disposed inside the first pot body, and at least a portion of the processing unit 5 extends into the second pot body. The rotor assembly 1 drives the processing unit 5 to rotate, thereby stirring the food in the second pot body, which improves the uniformity of heating of the food in the second pot body and also prevents the food from burning.

[0143] Optionally, the processing unit 5 includes a stirring rod or a blade.

[0144] Optionally, the household appliance includes a fan, which includes a fan base, a fan head, and a processing unit 5. The fan head can be mounted on the fan base, and the processing unit 5 includes fan blades. The fan blades are disposed on the fan head and can rotate relative to the fan head. The stator assembly 2 is disposed on the fan base, and the rotor assembly 1 is disposed on the fan head and connected to the fan blades. When the stator assembly 2 drives the rotor assembly 1 to rotate, the rotor assembly 1 drives the fan blades to rotate.

[0145] In this embodiment, when the household appliance includes a fan, the fan head and the fan base can be separated, which facilitates cleaning of the fan head. At the same time, when the fan head is installed in the fan base, the stator assembly 2 in the fan base drives the rotor assembly 1 in the fan head to rotate, and the rotor assembly 1 drives the fan blades to rotate, thereby realizing the air delivery function.

[0146] According to one embodiment of this application, in order to balance the requirements of cost, motor performance and design efficiency, this application proposes a general-purpose alternating pole combination magnetic pole, which can adapt to different stator core tooth shapes 20, thereby reducing the cost caused by the complexity of magnet manufacturing process, and can improve the utilization rate of permanent magnet 1200 and realize the flexible design of permanent magnet flux linkage.

[0147] Optionally, the permanent magnet 1200 includes a first permanent magnet (e.g., an outer permanent magnet 1200) and a second permanent magnet (e.g., an inner permanent magnet 1200). The first magnetic pole group 12 includes a first permanent magnet and a second permanent magnet, and the second magnetic pole group 12 includes a first permanent magnet and a magnetic conductor 1202. In the first magnetic pole group 12, the first and second permanent magnets are bonded together to form a stepped structure. The two permanent magnets 1200 are combined to form permanent magnet poles. The first permanent magnet of the second magnetic pole group 12... A stepped structure is also formed between the magnet and the iron core pole. In addition, a magnetic isolation bridge 14 is provided between the first permanent magnet and the iron core pole (e.g., the magnetic conductor 1202) in the magnetic pole group 12. The magnetic isolation bridge 14 is used to weaken the leakage magnetic field between the first permanent magnet and the iron core pole. The three parts of the first permanent magnet, the iron core pole and the magnetic isolation bridge 14 form a hybrid pole (that is, a hybrid magnetic pole with both permanent magnet 1200 and magnetic conductor 1202). The iron core pole is integrated with the rotor iron core 10, and the polarity of the permanent magnet pole and the hybrid pole are opposite. Compared to the single rectangular permanent magnets in the prior art, the stepped permanent magnet 1200 is easier to adjust in size according to the specific structure of the stator core teeth, which helps to increase the contact area between the stator teeth and the permanent magnet 1200, thereby improving the utilization rate of the permanent magnet 1200 and thus increasing the torque density of the motor. At the same time, different grades of permanent magnet 1200 can be selected and combined according to the different ratios of permanent magnet flux provided by the first permanent magnet and the second permanent magnet, which provides greater design freedom.

[0148] Figures 10 to 14 The structure of the teeth 20 of several stator cores is shown. For teeth 20 with different shapes, the size of the first permanent magnet and the second permanent magnet can be optimized to improve the utilization rate of the permanent magnet, thereby improving the torque density of the motor.

[0149] Taking the fan-shaped toothed section 20 as an example, such as Figure 7 As shown, permanent magnet chains generated by permanent magnets of different shapes under the fan-shaped teeth 20 are given. The shapes of the permanent magnets are fan-shaped, circular, single rectangle and stepped.

[0150] Depend on Figure 7 It can be seen that the sector-shaped permanent magnet has the largest projected area on the stator core, so it produces the largest permanent magnet flux linkage. The permanent magnet flux linkage produced by the stepped combination of magnetic poles is second only to that of the sector-shaped permanent magnet. The permanent magnet flux linkage produced by the circular and rectangular permanent magnets is basically the same.

[0151] Optionally, since the magnetic circuits of the magnetic fields generated by the first permanent magnet and the second permanent magnet do not interfere with each other, the permanent magnet flux generated by the first permanent magnet and the second permanent magnet can be analyzed separately.

[0152] Figure 8The diagram shows the permanent magnet flux generated when the first permanent magnet (e.g., the outer permanent magnet 1200) and the second permanent magnet (e.g., the inner permanent magnet 1200) act alone. It can be seen that the proportion of permanent magnet flux provided by the two is different. Therefore, different grades of permanent magnet 1200 can be used to flexibly design the permanent magnet 1200 flux. Table 1 shows the permanent magnet flux under different combinations of permanent magnet 1200 grades. Since the permanent magnet generated by the first permanent magnet has a higher proportion of permanent magnet flux, the change of its grade has a greater impact on the permanent magnet flux. The change of the second permanent magnet has a smaller impact on the permanent magnet flux. Therefore, the grade of permanent magnet 1200 can be selected according to the actual application.

[0153] Table 1

[0154]

[0155] This application uses a stepped combination of magnetic poles, which does not increase the cost of the manufacturing process of the magnets, and allows for adjustment of the size of each permanent magnet 1200 to adapt to different stator structures. In addition, different grades of permanent magnets 1200 can be selected for combination to flexibly adjust the permanent magnet chain, resulting in greater design freedom.

[0156] Optionally, such as Figures 1 to 6 As shown, different alternating pole combination magnetic pole schemes can be adopted according to the power scenarios of actual applications.

[0157] Optionally, such as Figure 5 As shown in the figure, each magnetic pole group 12 has a three-layer stepped portion 120 (including a permanent magnet 1200 and a magnetic conductor 1202). L1, L2 and L3 represent the circumferential lengths of the three-layer stepped portion 120, and H1, H2 and H3 represent the widths of the three-layer stepped portion 120, wherein L1 > L2 > L3, and optionally, H1 > H2 > H3.

[0158] Optionally, such as Figure 6 As shown, the back electromotive force of the motor can be improved and the cogging torque of the motor can be reduced by deflecting the magnetic poles.

[0159] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installed," "connected," "linked," and "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "linked" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0160] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0161] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotor assembly, characterized in that, The rotor assembly is used in a motor, the motor including a stator assembly located on one side of the rotor assembly along its axial direction, the rotor assembly comprising: Rotor core; Multiple magnetic pole groups are spaced apart on the rotor core along the circumferential direction, and the polarities of two adjacent magnetic pole groups along the circumferential direction are opposite. In the radial direction of the rotor core, the magnetic pole group is arranged in a stepped shape, so that the magnetic pole group includes at least two layers of stepped portions distributed along the radial direction; Wherein, the stepped portion is a magnetic conductor or a permanent magnet. In the plurality of magnetic pole groups, the stepped portions located in the same layer along the radial direction constitute a magnetic material group. In at least one of the magnetic material groups, one of any two adjacent stepped portions located in two magnetic pole groups is the magnetic conductor, and the other is the permanent magnet.

2. The rotor assembly according to claim 1, characterized in that, In any of the aforementioned magnetic pole groups, the ends of two adjacent stepped portions along the radial direction are staggered along the circumferential direction, so that the magnetic pole groups are arranged in a stepped shape; or In any of the magnetic pole groups, one of the two adjacent stepped portions along the radial direction protrudes from the other along the axial direction, so that the magnetic pole groups are arranged in a stepped shape.

3. The rotor assembly according to claim 2, characterized in that, In any of the two adjacent stepped portions along the radial direction of any magnetic pole group, the length of the inner stepped portion along the circumferential direction is less than the length of the outer stepped portion along the circumferential direction. The inner stepped portion is the stepped portion near the axis of the rotor core, and the outer stepped portion is the stepped portion near the side wall of the rotor core.

4. The rotor assembly according to claim 3, characterized in that, In any one of the two adjacent stepped portions along the radial direction of the magnetic pole group, the two ends of the outer stepped portion along the circumferential direction respectively protrude from the inner stepped portion along the circumferential direction.

5. The rotor assembly according to claim 1, characterized in that, In any two adjacent sets of magnetic poles along the circumferential direction: In one magnetic pole group, all the stepped portions are permanent magnets; in another magnetic pole group, at least one layer of the stepped portions is a permanent magnet, and at least one layer of the stepped portions is a magnetic conductor; or in another magnetic pole group, all the stepped portions are magnetic conductors. All the stepped portions in any magnetic pole group include at least one permanent magnet and at least one magnetic conductor, such that the arrangement of the stepped portions in any magnetic material group is such that the magnetic conductor and the permanent magnet are arranged alternately along the circumferential direction.

6. The rotor assembly according to claim 5, characterized in that, In any of the magnetic pole groups, if two adjacent stepped portions along the radial direction are both permanent magnets, the adjacent permanent magnets are either a split structure or an integral structure. In any of the magnetic pole groups, if two adjacent stepped portions along the radial direction are both magnetic conductors, the adjacent magnetic conductors are either separate structures or integral structures.

7. The rotor assembly according to claim 6, characterized in that, In any of the aforementioned magnetic pole groups, where two adjacent stepped sections along the radial direction are both permanent magnets, the adjacent permanent magnets are of a separate structure and are fitted together; and / or In the case where the magnetic pole group includes at least one of the permanent magnets and at least one of the magnetic conductors, the permanent magnets and magnetic conductors that are adjacent in the radial direction are spaced apart to form a magnetic isolation bridge.

8. The rotor assembly according to any one of claims 1 to 7, characterized in that, In any of the magnetic pole groups, the center lines of the magnetic poles of two radially adjacent stepped portions are staggered along the circumferential direction of the rotor core.

9. The rotor assembly according to claim 8, characterized in that, In any of the magnetic pole groups, the circumferential misalignment of the magnetic pole centerlines of two adjacent stepped sections along the radial direction along the rotor core is the target misalignment, and the target misalignment is the same for any two adjacent magnetic pole groups along the circumferential direction.

10. The rotor assembly according to any one of claims 1 to 7, characterized in that, The permanent magnet is attached to the axial surface of the rotor core; and / or The magnetic conductor is located on one side of the rotor core along its axial direction and is an integral part of the rotor core.

11. An electric motor, characterized in that, include: Stator assembly; and The rotor assembly as claimed in any one of claims 1 to 10, wherein the stator assembly is located on one side of the axial direction of the rotor assembly and the stator assembly is capable of driving the rotor assembly to rotate.

12. A household appliance, characterized in that, include: The rotor assembly as described in any one of claims 1 to 10; or The motor as described in claim 11.

13. The household appliance according to claim 12, characterized in that, The household appliances include any one of a food processor, a rice cooker, and a fan.

14. The household appliance according to claim 13, characterized in that, In the case where the household appliance includes the food processor, the food processor includes: A base assembly, wherein the stator assembly is disposed on the base assembly; A cup assembly that can be mounted on the base assembly; The processing unit is located on the cup assembly. The processing unit includes a rotating shaft. The rotor assembly is located on the cup assembly and sleeved on the rotating shaft. The stator assembly can drive the rotor assembly to rotate, so that the processing unit rotates.

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