Patent Description:
A disc-type motor is also referred to as an axial flux permanent magnet machine (axial flux permanent magnet machine, AFPMM). The disc-type motor has advantages such as a compact structure, high torque density, high efficiency, and high power density. The disc-type motor may be used in an electric vehicle, a renewable energy system, an energy storage system, an industrial device, and the like.

For a conventional surface-mounted disc-type motor structure, with an increase of an operating frequency of a rotor, eddy current loss of a conventional surface-mounted permanent magnet rotor structure significantly increases. This degrades performance of the motor. In addition, a reluctance torque component of the rotor is small, and power rapidly decreases at a high speed.

For a conventional built-in disc-type motor structure, during preparation of a disc-type motor, a silicon steel sheet is wound into an integrated ring rotor core, and then magnetic steel is embedded in the rotor core. However, when the silicon steel sheet is wound into the integrated ring rotor core, both an inner ring wall and an outer ring wall of the rotor core are in an Archimedes' involute shape instead of a circular shape. As a result, the inner ring wall and the outer ring wall of the rotor core cannot effectively fit with another mechanical part of a rotor of the motor, and a connection between the inner ring wall of the magnetic steel and a motor shaft is unreliable. This affects structural strength of the disc-type motor.

Document <CIT> discloses a rotor used for an axial gap permanent magnet motor in which a stator and the rotor are oppositely arranged having a gap between the stator and the rotor in a direction parallel to a rotary shaft, comprising: a plurality of permanent magnets that are magnetized in a rotary shaft direction respectively and arranged along a circumferential direction of the rotary shaft to form field magnetic poles; a plurality of soft magnetic material segments each of which is provided so as to cover at least a stator-facing surface in each of the permanent magnets to form a permanent magnet/soft magnetic material composite part including the permanent magnet and the soft magnetic material segment; and a disc-shaped non-magnetic moulded frame that is moulded so as to cover a periphery of the permanent magnet/soft magnetic material composite parts while leaving at least the stator-facing surfaces of the soft magnetic material segments as exposed surfaces, wherein the permanent magnet/soft magnetic material composite parts are integrated with the disc-shaped non-magnetic moulded frame by moulding of the disc-shaped non-magnetic moulded frame.

Document <CIT> discloses a rotor for an axial flux motor comprising an iron core including a plurality of side surfaces thereof and a plurality of permanent magnets facing each of the plurality of side surfaces so as to open the facing surfaces and surround the iron core, and the plurality of permanent magnets are the iron cores.

Embodiments of this application provide a rotor, a disc-type motor, a motor-driven system, and a vehicle, to improve structural strength. All embodiments and aspects in the following paragraphs of the description (from §<NUM> - §<NUM>) relate to the present invention.

According to a first aspect, an embodiment of this application provides a rotor, applied to a disc-type motor, and including: a fastening sleeve, including 2P accommodation grooves provided along a circumferential direction of the fastening sleeve, where P is an integer greater than or equal to <NUM>; and a magnetic field concentration structure, including 2P composite magnetic field concentration components, where each composite magnetic field concentration component is fixedly accommodated in a corresponding accommodation groove, and the composite magnetic field concentration component includes a permanent magnet structure and a soft magnet structure that are embedded in each other.

The composite magnetic field concentration component includes the permanent magnet structure and the soft magnet structure that are embedded in each other, and the soft magnet structure can implement effective magnetic conduction. The magnetic field concentration structure can effectively reduce eddy current loss. This helps increase an output torque of the rotor and reduce torque fluctuation, so that performance of the rotor is improved.

The magnetic field concentration structure is obtained by splicing the 2P composite magnetic field concentration components along the circumferential direction of the fastening sleeve, but not an integrated structure obtained through winding. In this way, outer walls of the composite magnetic field concentration components can well fit with inner walls of the accommodation grooves. This improves stability of a connection between the magnetic field concentration structure and the fastening sleeve (or another mechanical part of the rotor, for example, a rotating shaft), so that strength of the rotor is improved.

The composite magnetic field concentration component can be considered as a part of an overall ring structure. During preparation of the magnetic field concentration structure, a silicon steel sheet does not need to be wound into an integrated ring structure, and an inner ring wall and an outer ring wall of the rotor do not need to be fine-processed to ensure coaxiality of the rotor. Therefore, difficulty in preparation and assembly of the magnetic field concentration structure is reduced.

The fastening sleeve is made of a non-magnetic-conducting and non-electrical-conducting material. The magnetic field concentration structure is fastened to the fastening sleeve. The fastening sleeve can reduce magnetic leakage of the rotor, so that the output torque of the rotor is increased.

According to the first aspect, the permanent magnet structure includes an intermediate axial permanent magnet unit and a side permanent magnet unit distributed on one side or two sides of the intermediate axial permanent magnet unit along an axial direction of the rotor. The intermediate axial permanent magnet unit and each side permanent magnet unit jointly form first accommodation space. The soft magnet structure is embedded in the first accommodation space.

A built-in permanent magnet structure is implemented by arranging permanent magnets in a magnetic field concentration manner, in combination with a special rotor core structure. Compared with a surface-mounted permanent magnet rotor, the motor achieves significant salience effects and has an advantage of generating a large reluctance torque, so that the output torque of the rotor is increased. Each pair of magnetic poles is obtained by splicing a plurality of pieces of soft magnetic materials and permanent magnetic materials, and a process is simple. The composite magnetic field concentration structure is obtained by combining permanent magnets with different shapes and magnetization manners, and a large saliency ratio is set. In a magnetic circuit, the soft magnetic materials, the permanent magnets, and a stator form a complete magnetic loop, so that main flux is increased, and magnetic leakage is reduced. This implements magnetic concentration, and improves air-gap flux density. In addition, a built-in permanent magnet structure is implemented, so that the motor achieves significant salience effects, flux-weakening performance is high, and a reluctance torque is large.

According to the first aspect, the side permanent magnet unit includes an inner permanent magnet element and two outer permanent magnet elements. Both the intermediate axial permanent magnet unit and the inner permanent magnet element are located between the two outer permanent magnet elements along a circumferential direction of the rotor. The inner permanent magnet element and the intermediate axial permanent magnet unit are disposed at a spacing along the axial direction of the rotor. The intermediate axial permanent magnet unit, the inner permanent magnet element, and the two outer permanent magnet elements jointly enclose the first accommodation space. The soft magnet structure includes a first soft magnet, and the first soft magnet is embedded in the first accommodation space. According to the first aspect, in a possible implementation, the inner permanent magnet element includes a side axial permanent magnet and two inner permanent magnets. The side axial permanent magnet is connected between the two inner permanent magnets along the circumferential direction of the rotor. A surface, backing the intermediate axial permanent magnet unit, of the side axial permanent magnet and the two inner permanent magnets jointly enclose second accommodation space. The soft magnet structure further includes a second soft magnet, and the second soft magnet is embedded in the second accommodation space.

According to the first aspect, in a possible implementation, the accommodation groove is a through groove that penetrates the fastening sleeve along the axial direction of the rotor, there are two side permanent magnet units, and the two side permanent magnet units are respectively located on two sides of the intermediate axial permanent magnet unit along the axial direction of the rotor.

According to the first aspect, in a possible implementation, the two side permanent magnet units located on the two sides of the intermediate axial permanent magnet unit are symmetrical with respect to the intermediate axial permanent magnet unit along the axial direction of the rotor. This helps improve stability of the output torque of the rotor.

According to the first aspect, in a possible implementation, the fastening sleeve further includes 2P interlayers. Each interlayer is located in the accommodation groove and is configured to divide the accommodation groove into a first accommodation sub-groove and a second accommodation sub-groove along the axial direction of the rotor. Each composite magnetic field concentration component includes a first magnetic part and a second magnetic part. The first magnetic part is fixedly accommodated in the first accommodation sub-groove, and the second magnetic part is fixedly accommodated in the second accommodation sub-groove. The first magnetic part and the second magnetic part each include a permanent magnet structure and a soft magnet structure that are embedded in each other. Along the axial direction of the rotor, the interlayer is located between an intermediate axial permanent magnet unit of the first magnetic part and an intermediate axial permanent magnet unit of the second magnetic part, a side permanent magnet unit of the first magnetic part is located on a side, backing the interlayer, of the intermediate axial permanent magnet unit of the first magnetic part, and a side permanent magnet unit of the second magnetic part is located on a side, backing the interlayer, of the intermediate axial permanent magnet unit of the second magnetic part. The interlayers are disposed. This helps improve overall strength of the fastening sleeve, and improve reliability of the rotor and the disc-type motor.

According to the first aspect, in a possible implementation, a structure of the first magnetic part and a structure of the second magnetic part are symmetrical with respect to the interlayer along the axial direction of the rotor. This helps improve stability of the output torque of the rotor.

According to the first aspect, in a possible implementation, the fastening sleeve includes an inner ring, an outer ring, and 2P ribs. The outer ring is sleeved on the inner ring. The 2P ribs are fastened between the inner ring and the outer ring. The 2P ribs are provided at spacings along the circumferential direction of the fastening sleeve. Every two adjacent ribs, the inner ring, and the outer ring jointly enclose the accommodation groove.

The fastening sleeve includes the inner ring, the outer ring, and the 2P ribs. This implements a simple structure of the fastening sleeve, and facilitates preparation of the fastening sleeve. According to the first aspect, in a possible implementation, each rib includes a positioning rod and a limiting rib that protrudes from a side surface of the positioning rod that faces the accommodation groove, and the limiting rib is configured to limit a position of the composite magnetic field concentration component.

The positioning rod is configured to limit a position when the composite magnetic field concentration component is assembled in a corresponding accommodation groove. This improves assembly convenience for assembling the composite magnetic field concentration component on the fastening sleeve, and improves assembly efficiency and assembly precision of the rotor. The limiting rib is configured to limit movement of the composite magnetic field concentration component along the axial direction of the rotor. This improves stability of positions of the composite magnetic field concentration component and the fastening sleeve, so that stability and reliability of the rotor are improved.

According to the first aspect, in a possible implementation, each composite magnetic field concentration component is provided with a limiting groove, and the limiting rib is accommodated in the limiting groove. The accommodation groove is a through groove that penetrates the fastening sleeve, so as to facilitate preparation of the fastening sleeve.

According to the first aspect, in a possible implementation, the fastening sleeve is further provided with a cooling channel for circulating a cooling medium.

Because the cooling medium can be circulated on the fastening sleeve, heat dissipation performance of the rotor is improved, so that reliability of the rotor is improved.

According to a second aspect, an embodiment of this application further provides a disc-type motor, including two stators, the rotor according to the first aspect, a rotating shaft, and a housing. The rotor is located between the two stators along an axial direction of the disc-type motor. The rotating shaft penetrates the two stators and the rotor. The rotating shaft is connected to the rotor to rotate along with the rotor. The housing is sleeved on the two stators, the rotor, and the rotating shaft.

The magnetic field concentration structure of the rotor is obtained by splicing the 2P composite magnetic field concentration components along the circumferential direction of the fastening sleeve, but not an integrated structure obtained through winding. In this way, outer walls of the composite magnetic field concentration components can well fit with inner walls of the accommodation grooves. This improves stability of a connection between the magnetic field concentration structure and the fastening sleeve (or another mechanical part of the rotor, for example, a rotating shaft), so that strength of the rotor is improved, and structural strength and stability of the disc-type motor are improved.

According to a third aspect, an embodiment of this application further provides a motor-driven system, including the disc-type motor according to the second aspect, a controller, and a battery. The controller is electrically connected to the disc-type motor, and the battery is electrically connected to the disc-type motor.

According to a fourth aspect, an embodiment of this application further provides a vehicle, including the motor-driven system according to the third aspect and a frame. The motor-driven system is mounted on the frame.

<FIG> is a schematic diagram of an application scenario of a vehicle <NUM> according to an embodiment of this application. The vehicle <NUM> may be one of an electric vehicle (Electric Vehicle, EV for short), a pure electric vehicle/battery electric vehicle (Pure Electric Vehicle/Battery Electric Vehicle, PEV/BEV for short), a hybrid electric vehicle (Hybrid Electric Vehicle, HEV for short), a range extended electric vehicle (Range Extended Electric Vehicle, REEV for short), a plug-in hybrid electric vehicle (Plug-in Hybrid Electric Vehicle, PHEV for short), and a new energy vehicle (New Energy Vehicle).

The vehicle <NUM> includes a frame <NUM> and a motor-driven system <NUM>. The motor-driven system <NUM> is mounted on the frame <NUM>. As a structural framework of the vehicle <NUM>, the frame <NUM> is configured to support, fasten, and connect various systems, and carry load inside the vehicle <NUM> and load that comes from an external environment.

The motor-driven system <NUM> is a system that includes a series of components and that is configured to produce a driving force and transfer the driving force to a road surface. As shown in <FIG>, the motor-driven system <NUM> may include a disc-type motor <NUM>, a controller <NUM>, and a battery <NUM>. The controller <NUM> is electrically connected to the disc-type motor <NUM>, and is configured to control operation of the disc-type motor <NUM>. The battery <NUM> is electrically connected to the disc-type motor <NUM>, and the battery <NUM> is configured to provide electric energy for the disc-type motor <NUM>. The motor-driven system <NUM> may further include a gearbox <NUM>. The gearbox <NUM> is configured to connect to the disc-type motor <NUM>, to adjust a speed of the vehicle <NUM>.

The vehicle <NUM> further includes a wheel <NUM> disposed on the frame <NUM>. A rotating shaft of the disc-type motor <NUM> is connected to the wheel <NUM> through a transmission component. In this way, the rotating shaft of the disc-type motor <NUM> outputs a driving force, and the transmission component transfers the driving force to the wheel <NUM>, so that the wheel <NUM> rotates. The wheel <NUM> includes front wheels and rear wheels. In this embodiment of this application, the motor-driven system <NUM> may include one or two disc-type motors <NUM>. When there is one disc-type motor <NUM>, the disc-type motor <NUM> is connected to two front wheels or two rear wheels through a transmission component. When there are two disc-type motors <NUM>, one disc-type motor is connected to two front wheels through a transmission component, and the other disc-type motor is connected to two rear wheels through another transmission component.

As shown in <FIG>, and <FIG>, an embodiment of this application provides a disc-type motor <NUM>, including a stator <NUM>, a rotor <NUM>, a rotating shaft <NUM>, and a housing <NUM>. The stator <NUM> and the rotor <NUM> are arranged along an axial direction of the disc-type motor <NUM>. The rotating shaft <NUM> penetrates the stator <NUM> and the rotor <NUM>. The rotating shaft <NUM> is connected to the rotor <NUM> to rotate along with rotor <NUM>. The housing <NUM> is sleeved on the stator <NUM>, the rotor <NUM>, and the rotating shaft <NUM> to protect the stator <NUM> and the rotor <NUM>. The rotating shaft <NUM> rotatably penetrates the housing <NUM> and is connected to a wheel through a transmission component.

In some embodiments of this application, there are two stators <NUM> and one rotor <NUM>, that is, the disc-type motor <NUM> has a dual-stator single-rotor structure. Because the disc-type motor <NUM> has the dual-stator single-rotor structure, compared with a single-stator single-rotor structure, an electromagnetic torque applied to the rotor <NUM> increases, so that overall torque density and power density of the disc-type motor <NUM> are improved. The rotor <NUM> is located between the two stators <NUM> along the axial direction of the disc-type motor <NUM>. The stator <NUM> includes a stator body <NUM> and a winding <NUM> that surrounds the stator body <NUM>. After the winding <NUM> is energized, a rotating magnetic field applied to the rotor <NUM> may be generated, so that the rotor <NUM> rotates relative to the stator <NUM>. The winding <NUM> may be a concentrated winding.

The housing <NUM> includes a first housing <NUM>, a second housing <NUM>, and a third housing <NUM>. The first housing <NUM> is sleeved on the stator <NUM> and the rotor <NUM>. Along the axial direction of the disc-type motor <NUM>, the second housing <NUM> is fastened to a first end of the first housing <NUM>, the third housing <NUM> is fastened to a second end of the first housing <NUM>, and the second housing <NUM> and the third housing <NUM> are disposed opposite to each other. The first housing <NUM>, the second housing <NUM>, and the third housing <NUM> jointly enclose accommodation space for accommodating the stator <NUM> and the rotor <NUM>. One of the two stators <NUM> that is close to the second housing <NUM> is fastened to the second housing <NUM>, and the other of the two stators <NUM> that is close to the third housing <NUM> is fastened to the third housing <NUM>. Because the rotor <NUM> of the disc-type motor <NUM> is located between the two stators <NUM>, the stator <NUM> may be directly fastened to the second housing <NUM> or the third housing <NUM>. This facilitates assembly and disassembly of the rotor <NUM>.

In some implementations of this application, the stator <NUM> may be fastened to the second housing <NUM> or the third housing <NUM> through clamping. It can be understood that a manner of fastening the stator <NUM> to the second housing <NUM> or the third housing <NUM> is not limited in this application.

The first housing <NUM>, the second housing <NUM>, and the third housing <NUM> are disposed separately. This facilitates assembly and maintenance of the disc-type motor <NUM>. A first through hole <NUM> is provided on the second housing <NUM>, and one end of the rotating shaft <NUM> penetrates the first through hole <NUM>. A second through hole <NUM> is provided on the third housing <NUM>, and the rotating shaft <NUM> penetrates the second through hole <NUM>.

The disc-type motor <NUM> further includes a connector <NUM>, a first bearing <NUM>, a second bearing <NUM>, and a position detector <NUM>. The connector <NUM> is disposed on the second housing <NUM> and is located on a side of the second housing <NUM> that faces the third housing <NUM>. The first bearing <NUM> is mounted on the connector <NUM>, and one end of the rotating shaft <NUM> penetrates the first bearing <NUM>, so that the rotating shaft <NUM> is rotatably connected to the second housing <NUM>. The second bearing <NUM> is mounted on the third housing <NUM>, and one end of the rotating shaft <NUM> penetrates the second bearing <NUM>, so that the rotating shaft <NUM> is rotatably connected to the third housing <NUM>. The position detector <NUM> is fastened to the second housing <NUM>, and the rotating shaft <NUM> rotatably penetrates the position detector <NUM>. The position detector <NUM> is configured to detect a position of the rotor <NUM>.

In another embodiment of this application, as shown in <FIG>, the stator <NUM> includes a stator body <NUM> and a winding <NUM> that surrounds the stator body <NUM>, where the winding <NUM> may alternatively be a distributed winding.

In some embodiments of this application, the rotor <NUM> is a built-in magnetized permanent magnet rotor. As shown in <FIG>, and <FIG>, the rotor <NUM> includes a fastening sleeve <NUM> and a magnetic field concentration structure <NUM> fastened to the fastening sleeve <NUM>. The fastening sleeve <NUM> includes 2P accommodation grooves <NUM> provided along a circumferential direction of the fastening sleeve <NUM>, where P is an integer greater than or equal to <NUM>. The magnetic field concentration structure <NUM> includes 2P composite magnetic field concentration components <NUM>. Each composite magnetic field concentration component <NUM> is fixedly accommodated in a corresponding accommodation groove <NUM>. Each composite magnetic field concentration component <NUM> includes a permanent magnet structure <NUM> and a soft magnet structure <NUM> that are embedded in each other. The soft magnet structure <NUM> is made of a soft magnetic composite (soft magnetic composite, SMC) material, or the soft magnet structure <NUM> may be made of another magnetic conducting material. In this embodiment of this application, the soft magnet structure <NUM> is made of the SMC material, and the permanent magnet structure <NUM> is made of a magnetic steel material. Polarities of adjacent composite magnetic field concentration components <NUM> are different.

The accommodation groove <NUM> is roughly presented as fan-shaped space. In some implementations of this application, the accommodation groove <NUM> is a through groove that penetrates the fastening sleeve <NUM> along an axial direction of the rotor <NUM>, to facilitate preparation of the fastening sleeve <NUM>.

The composite magnetic field concentration component <NUM> is roughly in a fan-shaped structure, and the composite magnetic field concentration component <NUM> adapts to the accommodation groove <NUM>. Each composite magnetic field concentration component <NUM> further includes an inner wall <NUM> and an outer wall <NUM> that are opposite to each other along a radial direction of the rotor <NUM>. On a cross section perpendicular to the axial direction of the rotor <NUM>, a contour of the inner wall <NUM> is in an arc shape, and a contour of the outer wall <NUM> is in an arc shape. Along the circumferential direction of the fastening sleeve <NUM>, the 2P composite magnetic field concentration components <NUM> are spliced into the magnetic field concentration structure <NUM> in a ring structure. Inner walls <NUM> of the 2P composite magnetic field concentration components <NUM> are spliced into an inner ring wall of the magnetic field concentration structure <NUM>, and outer walls <NUM> of the 2P composite magnetic field concentration components <NUM> are spliced into an outer ring wall of the magnetic field concentration structure <NUM>.

In a conventional technology, during preparation of a disc-type motor, a silicon steel sheet is wound into an integrated ring rotor core, and then magnetic steel is embedded in the rotor core. However, when the silicon steel sheet is wound into the integrated ring rotor core, both an inner ring wall and an outer ring wall of the rotor core are in an Archimedes' involute shape instead of an arc shape. As a result, the inner ring wall and the outer ring wall of the rotor core further need to be fine-processed (for example, fine-ground) to ensure coaxiality of the rotor, so that the rotor core can fit with another mechanical part of the rotor (for example, a fastening sleeve of the rotor).

The magnetic field concentration structure <NUM> is obtained by splicing the 2P composite magnetic field concentration components <NUM> along the circumferential direction of the fastening sleeve <NUM>, but not an integrated structure obtained through winding. In this way, the inner walls <NUM> and the outer walls <NUM> of the composite magnetic field concentration components <NUM> can well fit with side walls of the accommodation grooves <NUM>. This improves stability of a connection between the magnetic field concentration structure <NUM> and the fastening sleeve <NUM> (or another mechanical part of the rotor, for example, the rotating shaft), so that strength of the rotor <NUM> is improved. A silicon steel sheet does not need to be wound into an integrated ring structure, and an inner ring wall and an outer ring wall of the rotor do not need to be fine-processed to ensure coaxiality of the rotor. Therefore, difficulty in preparation and assembly of the magnetic field concentration structure <NUM> is reduced.

The fastening sleeve <NUM> is made of a non-magnetic-conducting and non-electrical-conducting high-strength material. The magnetic field concentration structure <NUM> is fastened to the fastening sleeve <NUM>. The fastening sleeve <NUM> can reduce magnetic leakage of the rotor <NUM>, so that an output torque of the rotor <NUM> is increased.

The fastening sleeve <NUM> is roughly in a ring shape. Refer to both <FIG> and <FIG>. The fastening sleeve <NUM> includes an inner ring <NUM>, an outer ring <NUM>, and 2P ribs <NUM>. The inner ring <NUM> is configured to limit movement of the composite magnetic field concentration component <NUM> toward the inside of the fastening sleeve <NUM> along a radial direction of the fastening sleeve <NUM> (that is, movement in a direction from the outer ring <NUM> to the inner ring <NUM>). The outer ring <NUM> is sleeved on the inner ring <NUM>, and the outer ring <NUM> is configured to limit movement of the composite magnetic field concentration component <NUM> toward the outside of the fastening sleeve <NUM> along the radial direction of the fastening sleeve <NUM> (that is, movement in a direction from the inner ring <NUM> to the outer ring <NUM>). The 2P ribs <NUM> are fastened between the inner ring <NUM> and the outer ring <NUM>. The 2P ribs are provided at spacings along the circumferential direction of the fastening sleeve <NUM>. Every two adjacent ribs <NUM>, the inner ring <NUM>, and the outer ring <NUM> jointly enclose an accommodation groove <NUM>. In other words, the fastening sleeve <NUM> includes 2P accommodation grooves <NUM> provided along the circumferential direction of the fastening sleeve <NUM>.

The rib <NUM> extends along the radial direction of the fastening sleeve <NUM>. In this application, the radial direction is a diameter direction. Each rib <NUM> includes a positioning rod <NUM> and a limiting rib <NUM> that protrudes from a side surface of the positioning rod <NUM> that faces the accommodation groove <NUM>. The positioning rod <NUM> is configured to limit a position when the composite magnetic field concentration component <NUM> is assembled in a corresponding accommodation groove <NUM>. This improves assembly convenience for assembling the composite magnetic field concentration component <NUM> on the fastening sleeve <NUM>, and also improves assembly efficiency and assembly precision of the rotor <NUM>. The limiting rib <NUM> is configured to limit movement of the composite magnetic field concentration component <NUM> along the axial direction of the rotor <NUM>, to improve stability of positions of the composite magnetic field concentration component <NUM> and the fastening sleeve <NUM>, so that stability and reliability of the rotor <NUM> are improved.

The fastening sleeve <NUM> is further provided with a cooling channel <NUM> for circulating a cooling medium (for example, cooling oil). In some implementations of this application, there are 2P cooling channels <NUM>. One opening of the cooling channel <NUM> is located on a side, backing the inner ring <NUM>, of the outer ring <NUM>, and one opening of the cooling channel <NUM> is located on a side, backing the outer ring <NUM>, of the inner ring <NUM>. The cooling channel <NUM> extends along the positioning rod <NUM>, to transfer the cooling medium from the outer ring <NUM> to the side of the inner ring <NUM>. In another implementation of this application, a quantity of cooling channels <NUM> is not limited. The cooling channel <NUM> is provided with a plurality of interconnected sub-channels. The sub-channels may be provided on the inner ring <NUM>, the outer ring <NUM>, and the rib <NUM>. Because the cooling medium can be circulated on the fastening sleeve <NUM>, heat dissipation performance of the rotor <NUM> is improved, so that reliability of the rotor <NUM> is improved.

Each composite magnetic field concentration component <NUM> is fixedly accommodated in a corresponding accommodation groove <NUM>. As shown in <FIG>, and <FIG>, for ease of differentiation, the permanent magnet structure <NUM> in <FIG> is indicated by a gray area, and the permanent magnet structure <NUM> includes an intermediate axial permanent magnet unit <NUM> and two side permanent magnet units <NUM>. Along the axial direction of the rotor <NUM>, the intermediate axial permanent magnet unit <NUM> is located between the two side permanent magnet units <NUM>. In some implementations of this application, the two side permanent magnet units <NUM> located on two sides of the intermediate axial permanent magnet unit <NUM> are symmetrical with respect to the intermediate axial permanent magnet unit <NUM> along the axial direction of the rotor <NUM>. This helps improve stability of the output torque of the rotor <NUM>. In another implementation of this application, the two side permanent magnet units <NUM> located on the two sides of the intermediate axial permanent magnet unit <NUM> may not be symmetrical with respect to the intermediate axial permanent magnet unit <NUM>. The intermediate axial permanent magnet unit <NUM> and each side permanent magnet unit <NUM> jointly form accommodation space <NUM> for embedding the soft magnet structure <NUM>.

Each side permanent magnet unit <NUM> includes an inner permanent magnet element <NUM> and two outer permanent magnet elements <NUM>. The accommodation space <NUM> includes first accommodation space <NUM> and second accommodation space <NUM>.

Along the axial direction of the rotor <NUM>, the inner permanent magnet element <NUM> and the intermediate axial permanent magnet unit <NUM> are disposed at a spacing. The outer permanent magnet element <NUM> is perpendicular to the intermediate axial permanent magnet unit <NUM>. Along the axial direction of the rotor <NUM>, the intermediate axial permanent magnet unit <NUM> is located between inner permanent magnet elements <NUM> of the two side permanent magnet units <NUM>. Along a circumferential direction of the rotor <NUM>, both the intermediate axial permanent magnet unit <NUM> and the inner permanent magnet element <NUM> are located between the two outer permanent magnet elements <NUM>. The intermediate axial permanent magnet unit <NUM>, the inner permanent magnet element <NUM>, and the two outer permanent magnet elements <NUM> jointly enclose the first accommodation space <NUM>. The first accommodation space <NUM> is used to accommodate the soft magnet structure <NUM>. In another implementation of this application, the outer permanent magnet element <NUM> may not be perpendicular to the intermediate axial permanent magnet unit <NUM>.

Each inner permanent magnet element <NUM> includes a side axial permanent magnet <NUM> and two inner permanent magnets <NUM>. In each inner permanent magnet element <NUM>, the side axial permanent magnet <NUM> is fastened between the two inner permanent magnets <NUM> along the circumferential direction of the rotor <NUM>. In other words, along the circumferential direction of the rotor <NUM>, a first end of the side axial permanent magnet <NUM> is fastened to one inner permanent magnet <NUM>, and a second end of the side axial permanent magnet <NUM> is fastened to the other inner permanent magnet <NUM>. The side axial permanent magnet <NUM> is perpendicular to the inner permanent magnet <NUM>. In some other implementations of this application, the side axial permanent magnet <NUM> may not be perpendicular to the inner permanent magnet <NUM>.

A surface, backing the intermediate axial permanent magnet unit <NUM>, of the side axial permanent magnet <NUM> and the two inner permanent magnets <NUM> jointly enclose the second accommodation space <NUM>. The second accommodation space <NUM> is used for embedding the soft magnet structure <NUM>. In some implementations of this application, the inner permanent magnet <NUM> is perpendicular to the side axial permanent magnet <NUM>. In some other implementations of this application, the inner permanent magnet <NUM> may not be perpendicular to the side axial permanent magnet <NUM>.

In each composite magnetic field concentration component <NUM>, along the circumferential direction of the rotor <NUM>, outer permanent magnet elements <NUM>, located at a same end of an intermediate axial permanent magnet unit <NUM>, of two side permanent magnet units <NUM> and the intermediate axial permanent magnet unit <NUM> jointly enclose a limiting groove <NUM>. The limiting rib <NUM> is accommodated in the limiting groove <NUM>, so that the composite magnetic field concentration component <NUM> cannot move along the axial direction of the rotor <NUM>. This improves stability of the composite magnetic field concentration component <NUM> on the fastening sleeve <NUM>.

The soft magnet structure <NUM> includes two first soft magnets <NUM> and two second soft magnets <NUM>. Each first soft magnet <NUM> is embedded in corresponding first accommodation space <NUM>, and each second soft magnet <NUM> is embedded in second accommodation space <NUM>.

The intermediate axial permanent magnet unit <NUM>, the outer permanent magnet element <NUM>, the side axial permanent magnet <NUM>, the two inner permanent magnets <NUM>, the two first soft magnets <NUM>, and the two second soft magnets <NUM> may all be directly molded through compression. Then the intermediate axial permanent magnet unit <NUM>, the outer permanent magnet element <NUM>, the side axial permanent magnet <NUM>, and the two inner permanent magnets <NUM> constitute the composite magnetic field concentration component <NUM>. This helps reduce difficulty in preparation and assembly of the composite magnetic field concentration component <NUM> and the rotor <NUM>.

As shown in <FIG>, it is assumed that a radian of the intermediate axial permanent magnet unit <NUM> is a1° and a radian of the side axial permanent magnet <NUM> is a2°. As shown in <FIG>, a radian of the outer permanent magnet element <NUM> is b1°, and a radian of the inner permanent magnet <NUM> is b2°. In every two adjacent composite magnetic field concentration components <NUM>, along the circumferential direction of the rotor <NUM>, radians of two inner permanent magnets <NUM> of every two adjacent composite magnetic field concentration components <NUM> is c1°, and a radian between an outer permanent magnet element <NUM> on a first side of a first composite magnetic field concentration component <NUM> and an outer permanent magnet element <NUM> on a second side of a second composite magnetic field concentration component <NUM> is c2°.

As shown in <FIG>, a thickness of the side axial permanent magnet <NUM> along the axial direction of the rotor <NUM> is L1, and a thickness of the intermediate axial permanent magnet unit <NUM> along the axial direction of the rotor <NUM> is L2. A thickness of the inner permanent magnet <NUM> along the axial direction of the rotor <NUM> is d1, and a thickness of the outer permanent magnet element <NUM> along the axial direction of the rotor <NUM> is d2. A thickness of the second soft magnet <NUM> located in the second accommodation space <NUM> along the axial direction of the rotor <NUM> is e1. A thickness of a part, located between the side axial permanent magnet <NUM> and the intermediate axial permanent magnet unit <NUM>, of the first soft magnet <NUM> along the axial direction of the rotor <NUM> is e2. The parameters a1°, a2°, b1°, b2°, c1°, c2°, L1, L2, e1, and e2 may be set according to a requirement. Because there are many optimizable parameters, the rotor <NUM> can be optimized to a great extent, and a design is more flexible. Value ranges of the parameters are determined, and results such as usage of permanent magnets, an output torque, and direct-axis and quadrature-axis inductances in various parameter combinations may be obtained.

Every two adjacent composite magnetic field concentration components <NUM> constitute a pair of magnetic poles (namely, a complete magnetic loop N-S), where one composite magnetic field concentration component <NUM> is an N pole, the other composite magnetic field concentration component <NUM> is an S pole, and magnetization directions at a same pole are the same. <FIG> is a diagram of magnetic circuits in magnetization directions of permanent magnet structures at one pair of magnetic poles.

The rotor <NUM> is in a magnetic field concentration structure, and the side permanent magnet unit <NUM> is further disposed on a side of the intermediate axial permanent magnet unit <NUM>, so that a waveform of air-gap flux density of the disc-type motor <NUM> is close to a sine wave, an output torque can be increased, and torque fluctuation can be reduced. A peak value of air-gap flux density of a surface-mounted disc-type motor with same specifications is approximately <NUM> T (as shown in <FIG>). In comparison, a peak value of air-gap flux density of the disc-type motor <NUM> provided in this implementation of this application can reach <NUM> T (as shown in <FIG>).

A quantity of axial permanent magnets (including the intermediate axial permanent magnet unit <NUM> and the side axial permanent magnet <NUM>) is N (N is an odd number), and magnetization directions at a same pole are the same. Along the axial direction of the rotor <NUM>, axial permanent magnets are symmetrically distributed along the limiting rib <NUM> of the fastening sleeve <NUM>. A soft magnetic composite material is provided between the axial permanent magnets, and an axial permanent magnet closer to the intermediate axial permanent magnet unit <NUM> has a larger radian, that is, a(N - <NUM>)/a1 > <NUM>.

A quantity of soft magnets (including the first soft magnet <NUM> and the second soft magnet <NUM>) is N± <NUM> (N is the quantity of axial permanent magnets), and the soft magnets are embedded between the axial permanent magnets.

In another implementation of this application, as shown in <FIG>, the inner permanent magnet <NUM> may be omitted, the intermediate axial permanent magnet unit <NUM> is perpendicular to the outer permanent magnet element <NUM>, and the side axial permanent magnet <NUM> is roughly parallel to the intermediate axial permanent magnet unit <NUM>.

In another implementation of this application, as shown in <FIG>, the outer permanent magnet element <NUM> is not perpendicular to the intermediate axial permanent magnet unit <NUM>, and two outer permanent magnet elements <NUM> at a same end of one intermediate axial permanent magnet unit <NUM> are fastened to each other along the circumferential direction of the rotor. The limiting groove may be omitted. The inner permanent magnet <NUM> and the side axial permanent magnet <NUM> obliquely intersect with each other, and an obtuse angle is formed between the inner permanent magnet <NUM> and the side axial permanent magnet <NUM>.

In another implementation of this application, as shown in <FIG>, the outer permanent magnet element <NUM> may be omitted, the side axial permanent magnet <NUM> is roughly perpendicular to the inner permanent magnet <NUM>, and the side axial permanent magnet <NUM> is roughly parallel to the intermediate axial permanent magnet unit <NUM>.

In another implementation of this application, as shown in <FIG>, the side permanent magnet unit <NUM> may be omitted, and the outer permanent magnet element <NUM> is roughly perpendicular to the intermediate axial permanent magnet unit <NUM>.

In another implementation of this application, as shown in <FIG>, both the outer permanent magnet element <NUM> and the inner permanent magnet <NUM> may be omitted, and the intermediate axial permanent magnet unit <NUM> is located between the two side axial permanent magnets <NUM> along the axial direction of the rotor.

In another implementation of this application, as shown in <FIG>, the accommodation groove <NUM> is not a through groove that penetrates the fastening sleeve <NUM> along the axial direction of the rotor, the fastening sleeve <NUM> further includes 2P interlayers <NUM>, each interlayer <NUM> is fastened to two adjacent ribs <NUM>, and each interlayer <NUM> is accommodated in a corresponding accommodation groove <NUM> to divide the accommodation groove <NUM> into a first accommodation sub-groove <NUM> and a second accommodation sub-groove (not shown in the figure) along the axial direction of the rotor. It should be noted that the first accommodation sub-groove <NUM> and the second accommodation sub-groove are respectively formed on two sides of the interlayer <NUM> along the axial direction of the rotor.

With reference to <FIG>, each composite magnetic field concentration component <NUM> includes a first magnetic part <NUM> and a second magnetic part <NUM>, the first magnetic part <NUM> is fixedly accommodated in the first accommodation sub-groove <NUM>, the second magnetic part <NUM> is fixedly accommodated in the second accommodation sub-groove, and the first magnetic part and the second magnetic part each include a permanent magnet structure and a soft magnet structure that are embedded in each other. The permanent magnet structure includes an intermediate axial permanent magnet unit <NUM> and a side permanent magnet unit <NUM>. The intermediate axial permanent magnet unit <NUM> and the side permanent magnet unit <NUM> are arranged along the axial direction of the rotor. The interlayer <NUM> is located between an intermediate axial permanent magnet unit <NUM> of the first magnetic part <NUM> and an intermediate axial permanent magnet unit <NUM> of the second magnetic part <NUM>. Along the axial direction of the rotor, a side permanent magnet unit <NUM> of the first magnetic part <NUM> is located on a side, backing the interlayer <NUM>, of the intermediate axial permanent magnet unit <NUM> of the first magnetic part <NUM>, and a side permanent magnet unit <NUM> of the second magnetic part <NUM> is located on a side, backing the interlayer <NUM>, of the intermediate axial permanent magnet unit <NUM> of the second magnetic part <NUM>. A structure of the first magnetic part <NUM> and a structure of the second magnetic part <NUM> are symmetrical with respect to the interlayer <NUM> along the axial direction of the rotor <NUM>. This helps improve stability of the output torque of the rotor. In another implementation of this application, a structure of the first magnetic part <NUM> and a structure of the second magnetic part <NUM> may not be symmetric with respect to the interlayer <NUM>. The intermediate axial permanent magnet unit <NUM> and the side permanent magnet unit <NUM> jointly form first accommodation space <NUM> for embedding a part of the soft magnet structure.

The side permanent magnet unit <NUM> further includes an inner permanent magnet element <NUM> and two outer permanent magnet elements <NUM>. A surface, backing the intermediate axial permanent magnet unit <NUM>, of the side axial permanent magnet <NUM> and the two inner permanent magnets <NUM> jointly enclose second accommodation space <NUM> for embedding a part of the soft magnet structure.

In the foregoing embodiments, two layers are equivalently obtained through division along an axial direction of the fastening sleeve <NUM>, and each layer includes 2P accommodation sub-grooves. A magnetic part including a permanent magnet structure and a soft magnet structure may be fastened in the accommodation sub-groove through bonding, and then integral potting is performed. The fastening sleeve <NUM> further includes 2P interlayers <NUM>. This can improve overall strength of the fastening sleeve <NUM>, and improve reliability of the rotor and the disc-type motor.

It can be understood that structures of the permanent magnet structure and the soft magnet structure are not limited in this application, provided that the permanent magnet structure and the soft magnet structure are embedded in each other.

In this application, a built-in permanent magnet structure is implemented by arranging permanent magnets in a magnetic field concentration manner, in combination with a special rotor core structure. Compared with a surface-mounted permanent magnet rotor, the motor achieves significant salience effects and has an advantage of generating a large reluctance torque, so that the output torque of the rotor is increased. Each pair of magnetic poles is obtained by splicing a plurality of pieces of soft magnetic materials and permanent magnetic materials, and a process is simple. The composite magnetic field concentration structure is obtained by combining permanent magnets with different shapes and magnetization manners, and a large saliency ratio is set. In a magnetic circuit, the soft magnetic materials, the permanent magnets, and a stator form a complete magnetic loop, so that main flux is increased, and magnetic leakage is reduced. This implements magnetic concentration, and improves air-gap flux density. In addition, a built-in permanent magnet structure is implemented, so that the motor achieves significant salience effects, flux-weakening performance is high, and a reluctance torque is large.

It should be understood that expressions such as "include" and "may include" used in this application may indicate existence of a disclosed function, operation, or constituent element, but not limit one or more additional functions, operations, or constituent elements. In this application, terms such as "include" and/or "have" may be construed as indicating a particular feature, quantity, operation, constituent element, or component, or a combination thereof, but shall not be construed as excluding existence or possible addition of one or more other features, quantities, operations, constituent elements, or components, or combinations thereof.

In addition, in this application, the expression "and/or" includes any and all combinations of terms listed in association. For example, the expression "A and/or B" may include A, may include B, or may include both A and B.

In this application, an expression including ordinal numbers such as "first" and "second" may modify elements. However, the elements are not limited by the expression. For example, the expression does not limit an order and/or importance of the elements. The expression is merely intended to distinguish one element from another element. For example, first user equipment and second user equipment indicate different user equipment, although both the first user equipment and the second user equipment are user equipment. Similarly, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may also be referred to as a first element.

When a component is described as being "connected to" another component, it should be understood that the component may be directly connected to the another component, or there may be another component between the component and the another component. In addition, when a component is described as being "directly connected to" another component, it should be understood that there is no component between the component and the another component.

Claim 1:
A rotor (<NUM>) for an axial flux permanent magnet machine (<NUM>), the rotor comprising:
a fastening sleeve (<NUM>), comprising 2P accommodation grooves provided along a circumferential direction of the fastening sleeve, wherein P is an integer greater than or equal to <NUM>; and
a magnetic field concentration structure (<NUM>), comprising 2P composite magnetic field concentration components, wherein each composite magnetic field concentration component is fixedly accommodated in a corresponding accommodation groove (<NUM>), and the composite magnetic field concentration component comprises a permanent magnet structure (<NUM>) and a soft magnet structure (<NUM>) that are embedded in each other, wherein the permanent magnet structure comprises an intermediate axial permanent magnet unit (<NUM>) and a side permanent magnet unit (<NUM>) distributed on one side or two sides of the intermediate axial permanent magnet unit along an axial direction of the rotor; and
the intermediate axial permanent magnet unit and the side permanent magnet unit jointly form a first accommodation space (<NUM>), and the soft magnet structure is embedded in the first accommodation space,
characterized in that
the side permanent magnet unit comprises an inner permanent magnet element (<NUM>) and two outer permanent magnet elements (<NUM>);
both the intermediate axial permanent magnet unit and the inner permanent magnet element are located between the two outer permanent magnet elements along a circumferential direction of the rotor, and the inner permanent magnet element and the intermediate axial permanent magnet unit are disposed at a spacing along the axial direction of the rotor; and
the intermediate axial permanent magnet unit, the inner permanent magnet element, and the two outer permanent magnet elements jointly enclose the first accommodation space, the soft magnet structure comprises a first soft magnet (<NUM>), and the first soft magnet is embedded in the first accommodation space.