Motor rotor with magnetic steel having multiple coatings, motor, power assembly and vehicle

Abstract

The invention provides a motor rotor with magnetic steel having a plurality of coatings, a motor, a power assembly and a vehicle, the motor rotor comprises a rotor core, a plurality of magnetic steel, a plurality of fixed coatings and a plurality of protective coatings, the rotor core comprises a plurality of magnetic steel grooves, the magnetic steel grooves penetrate through the rotor core along the axial direction of the rotor core, and each magnetic steel groove is used for accommodating one or more magnetic steel. One magnetic steel comprises two first surfaces parallel to the axial direction of the rotor iron core, the two first surfaces are oppositely arranged, and the distance between one first surface and the inner wall of one magnetic steel groove is larger than the distance between the other first surface and the inner wall of one magnetic steel groove; a gap between one first surface and the inner wall of one magnetic steel groove is used for accommodating a fixed coating, and a gap between the other first surface and the inner wall of one magnetic steel groove is used for accommodating a protective coating. The magnetic steel is fixed by the fixed coating, so that the risk of damage of the protective coating is reduced, and the magnetic steel and the rotor core can be well isolated by the fixed coating and the protective coating.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and particularly to a motor rotor, a motor, a power assembly, and a vehicle in which a permanent magnet has multiple coatings. Background Art

[0002] In a permanent magnet motor, the motor rotor includes a rotor core and permanent magnets, and the permanent magnets are fixedly installed in the magnet slots of the rotor core. In order to reduce the eddy current loss of the motor rotor, insulation isolation is usually required between the permanent magnets and the rotor core. In the prior art, the insulation between the permanent magnets and the rotor core is poor, and the insulation layer between the permanent magnets and the rotor core is easily damaged, reducing the output performance of the motor. Summary of the Invention

[0003] The present application provides a motor rotor, a motor, a power assembly, and a vehicle in which a permanent magnet has multiple coatings.

[0004] In a first aspect, the present application provides a motor rotor in which a permanent magnet has multiple coatings. The motor rotor includes a rotor core, a plurality of permanent magnets, a plurality of fixing coatings, and a plurality of protective coatings. The rotor core includes a plurality of magnet slots that axially penetrate the rotor core along the axis of the rotor core. Each magnet slot is used to accommodate one or more of the permanent magnets. A permanent magnet includes two first surfaces parallel to the axis of the rotor core, and the two first surfaces are arranged opposite to each other. The distance between one of the first surfaces and the inner wall of a magnet slot is greater than the distance between the other first surface and the inner wall of the one magnet slot. The gap between the one first surface and the inner wall of the one magnet slot is used to accommodate one of the fixing coatings, and the gap between the other first surface and the inner wall of the one magnet slot is used to accommodate one of the protective coatings.

[0005] In an embodiment of the present application, the permanent magnet is fixed by a fixing coating, reducing the risk of damage to the protective coating and improving the insulation isolation between the permanent magnet and the rotor core. A fixing coating and a protective coating are arranged opposite to each other on both sides of a permanent magnet. The fixing coating can also be used to isolate the permanent magnet and the inner wall of the magnet slot, so that both first surfaces of the permanent magnet can maintain good insulation with the rotor core.

[0006] In addition, in the present application, the distance between one of the first surfaces and the inner wall of a magnet slot is large, so that the thickness of the fixing coating along the arrangement direction of the two first surfaces can be set to be large, improving the reliability of the fixation between the permanent magnet and the inner wall of the magnet slot. And since the protective coating is mainly used to isolate the permanent magnet and the inner wall of the magnet slot, the gap between the other first surface and the inner wall of the one magnet slot is small in the present application, enabling good isolation between the permanent magnet and the inner wall of the magnet slot and being beneficial to reducing the equivalent air gap length of the magnetic circuit, thereby improving the output performance of the motor.

[0007] In one embodiment, the one fixed coating includes two first side surfaces. Along the arrangement direction of the two first surfaces, the two first side surfaces face away from each other, and the two first side surfaces are respectively in contact with the one first surface and the inner wall of the one magnet groove. In the embodiment of the present application, the two first side surfaces of the fixed coating are respectively in contact with the one first surface and the inner wall of the one magnet groove, which is beneficial to fixing the magnet and the rotor core by the fixed coating.

[0008] In one embodiment, one of the first side surfaces of the one fixed coating is fixed to the one first surface. In the embodiment of the present application, the fixed coating is fixed to the magnet, which is beneficial to the assembly of the fixed coating and the magnet and the fixation in the magnet groove. And the fixed coating is fixed to the one first surface, and the fixed coating can isolate the one first surface from the air, improving the anti-corrosion performance of the magnet.

[0009] In one embodiment, the one protective coating includes two second side surfaces. Along the arrangement direction of the two first surfaces, the two second side surfaces face away from each other, and the two second side surfaces are respectively in contact with the other first surface and the inner wall of the one magnet groove. In the embodiment of the present application, the two second side surfaces of the protective coating are respectively in contact with the other first surface and the inner wall of the one magnet groove, which is beneficial to cooperate with the fixed coating to fix the magnet and the rotor core. And the protective coating is in contact with the other first surface, and the protective coating can protect the magnet, reducing the risk of magnet oxidation. The protective coating is in contact with the inner wall of the one magnet groove, which is beneficial to reducing the distance between the other first surface and the inner wall of the one magnet groove, thereby reducing the equivalent air gap of the magnetic circuit.

[0010] In one embodiment, one of the second side surfaces of the one protective coating is fixed to the other first surface. In the embodiment of the present application, the protective coating is fixed to the magnet, which is beneficial to the assembly of the protective coating and the magnet and the fixation in the magnet groove. And the protective coating is fixed to the other first surface, and the protective coating can isolate the other first surface from the air, improving the anti-corrosion performance of the magnet.

[0011] In one embodiment, the orthographic projection area of the one fixed coating on the one first surface along the arrangement direction of the two first surfaces is less than or equal to the orthographic projection area of the one protective coating on the one first surface along the arrangement direction of the two first surfaces.

[0012] In the embodiments of the present application, the fixing coating is mainly used to fix the permanent magnet. Even if the orthographic projection area of the fixing coating on the first surface is small, it can still play a good fixing role. Since the fixing coating is arranged between a first surface and the inner wall of a magnet groove, a first surface is spaced from the inner wall of the magnet groove, so that insulation isolation can be achieved between a first surface and the rotor core. And because the fixing coating does not completely cover a first surface, the gap between a first surface and the inner wall of a magnet groove can be used for circulating the coolant to facilitate cooling of the permanent magnet. In addition, since the thickness of a protective coating is small, in the embodiments of the present application, the orthographic projection area of a protective coating on a first surface is set to be large, which is beneficial to realizing effective isolation between another first surface of the permanent magnet and the inner wall of a magnet groove. When a protective coating is coated on another first surface, the protective coating covers a large range of another first surface, so that the protective coating can effectively protect the permanent magnet.

[0013] In one embodiment, the fixing coating includes a foaming coating. The foaming coating can expand when heated, and the expansion effect can be cured after cooling. By using the expansibility of the foaming coating, the foamed foaming coating fills the gap between the permanent magnet and the inner wall of the magnet groove, so that the permanent magnet is tightly combined with the inner wall of the magnet groove, thereby achieving the purpose of fixing the permanent magnet. In the embodiments of the present application, using the foaming coating as the fixing coating has a simple process and the permanent magnet can be reliably fixed.

[0014] In one embodiment, the protective coating includes an epoxy coating. The epoxy coating has poor conductivity and has an insulating effect. In the embodiments of the present application, using the epoxy coating as the protective coating can better achieve insulation isolation between the permanent magnet and the rotor core. When the epoxy coating is coated on another first surface of the permanent magnet, the epoxy coating can play a good protective role for the permanent magnet and improve the anti-corrosion performance of the permanent magnet.

[0015] In one embodiment, along the radial direction of the rotor core, the minimum distance between the fixing coating and the outer peripheral surface of the rotor core is greater than the minimum distance between the protective coating and the outer peripheral surface of the rotor core. In the embodiments of the present application, the motor stator is sleeved on the outer peripheral surface of the rotor core. Since the distance between a first surface and the inner wall of the magnet groove is large and the magnetic permeability of the fixing coating is low, the fixing coating is arranged far from the motor stator, which is beneficial to reducing the magnetic resistance of the motor rotor to improve the output performance of the motor.

[0016] In one embodiment, the permanent magnet includes two second surfaces parallel to the axial direction of the rotor core. The two second surfaces are arranged opposite to each other, and the second surface intersects with the first surface. The distance between the first surface and the inner wall of the magnet groove is less than the distance between any one of the second surfaces and the inner wall of the magnet groove.

[0017] In an embodiment of the present application, the distance between a first surface and the inner wall of a magnet groove is less than the distance between a second surface and the inner wall of the magnet groove, such that the fixing coating arranged between a first surface and the inner wall of the magnet groove can play a role in fixing the magnet, and the thickness of the fixing coating will not be too large to cause waste of the fixing coating. When the arrangement directions of the two first surfaces are parallel to the arrangement direction of the magnetic south pole and the magnetic north pole of the magnet, the distance between a first surface and the inner wall of the magnet groove is small, which is beneficial to reducing the equivalent air gap of the magnetic circuit. The distance between the other first surface and the inner wall of the magnet groove is less than the distance between the second surface and the inner wall of the magnet groove, which is also beneficial to reducing the equivalent air gap of the magnetic circuit. In addition, the distance between the second surface and the inner wall of the magnet groove is large, and the second surface and the magnet groove can be insulated and isolated by air, which is beneficial to reducing costs.

[0018] In one embodiment, the orthographic projection area of the fixing coating on the first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the second surfaces. The larger orthographic projection area of the fixing coating on the first surface enables the fixing coating to fix the magnet more firmly in the magnet groove. And when the fixing coating is applied to the first surface, the larger projection area of the fixing coating enables the fixing coating to more completely cover the first surface, which can play a better protective role for the magnet.

[0019] In one embodiment, the orthographic projection area of the protective coating on the first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the second surfaces. The larger orthographic projection area of the protective coating on the first surface enables the protective coating to effectively isolate the magnet from the rotor core. And when the protective coating is applied to the other first surface, the larger projection area of the protective coating enables the protective coating to more completely cover the other first surface, which can play a better protective role for the magnet.

[0020] In one embodiment, the gap between one of the second surfaces and the inner wall of the one magnet slot is used to accommodate one of the protective coatings. One of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot is spaced apart from the inner wall of the one magnet slot and in contact with one of the second surfaces. In the embodiment of the present application, one of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot is in contact with one of the second surfaces. One of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot can protect the magnet and improve the anti-corrosion performance of the magnet. One of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot is spaced apart from the inner wall of the one magnet slot. The gap between one of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot and the inner wall of the one magnet slot can be used to circulate the coolant to facilitate the heat dissipation of the magnet.

[0021] In one embodiment, the thickness of one of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot is less than the thickness of the one fixing coating and less than or equal to the thickness of the one protective coating. In the embodiment of the present application, since the distance between one of the second surfaces and the inner wall of the one magnet slot is large, air insulation can be achieved between one of the second surfaces and the inner wall of the one magnet slot. The relatively small thickness of one of the protective coatings accommodated in the gap between one of the second surfaces and the inner wall of the one magnet slot can save costs.

[0022] In one embodiment, the one magnet includes two third surfaces perpendicular to the axial direction of the rotor core. The third surfaces intersect with the first surface. The orthographic projection area of the one fixing coating on the one first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the third surfaces. The relatively large orthographic projection area of the fixing coating on one of the first surfaces enables the fixing coating to fix the magnet more firmly in the magnet slot. And when the fixing coating is applied to one of the first surfaces, the relatively large projection area of the fixing coating enables the fixing coating to more completely cover one of the first surfaces and can provide better protection for the magnet.

[0023] In one embodiment, the orthographic projection area of the one protective coating on the one first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the third surfaces. The relatively large orthographic projection area of the protective coating on one of the first surfaces enables the protective coating to effectively isolate the magnet from the rotor core. And when the protective coating is applied to the other first surface, the relatively large projection area of the protective coating enables the protective coating to more completely cover the other first surface and can provide better protection for the magnet.

[0024] In one embodiment, one of the protective coatings is fixed to one of the third surfaces. A protective coating is in contact with a third surface, and the protective coating fixed to the third surface can protect the magnet steel and improve the anti-corrosion performance of the magnet steel.

[0025] In one embodiment, the thickness of one of the protective coatings fixed to the one third surface is less than the thickness of the one fixing coating and less than or equal to the thickness of the one protective coating. In the embodiment of the present application, since the third surface does not contact the inner wall of the magnet steel groove, there is no need for insulation isolation between the third surface and the rotor core, and the smaller thickness of the one protective coating fixed to the one third surface can save costs.

[0026] In a second aspect, the present application provides a motor, the motor includes a motor shaft and the motor rotor as described above, and the rotor core of the motor rotor is sleeved and fixed to the motor shaft.

[0027] In a third aspect, the present application provides a power assembly, the power assembly includes a speed reducer and the motor as described above, and the input shaft of the speed reducer is used for driving connection with the motor shaft of the motor.

[0028] In a fourth aspect, the present application provides an electric vehicle, the electric vehicle includes wheels, a battery pack and the motor as described above or includes the power assembly as described above, and the motor or the power assembly is used for receiving power supply from the power battery and driving the wheels. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be described below.

[0030] Figure 1 Schematic diagram of an electric vehicle provided by an embodiment of the present application.

[0031] Figure 2 Schematic diagram of a power assembly provided by an embodiment of the present application.

[0032] Figure 3 Schematic diagram of a motor rotor provided by an embodiment of the present application.

[0033] Figure 4 Schematic diagram of a magnet steel groove, a magnet steel, a fixing coating and a protective coating provided by an embodiment of the present application.

[0034] Figure 5 Schematic diagram of a magnet steel groove and a magnet steel provided by an embodiment of the present application.

[0035] Figure 6A perspective view of a magnet, a fixing coating, and a protective coating provided by an embodiment of the present application.

[0036] Figure 7 A perspective view of a magnet, a fixing coating, and a protective coating provided by an embodiment of the present application.

[0037] Figure 8 A perspective view of a magnet, a fixing coating, and a protective coating provided by an embodiment of the present application.

[0038] Figure 9 A schematic diagram of a magnet groove, a magnet, a fixing coating, and multiple protective coatings provided by an embodiment of the present application.

[0039] Figure 10 A perspective view of a magnet and multiple coatings provided by an embodiment of the present application. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0041] In this article, terms such as "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0042] In addition, in this article, orientation terms such as "upper" and "lower" are defined relative to the orientation of the structural schematic placement in the accompanying drawings. It should be understood that these directional terms are relative concepts, and they are used for relative description and clarification, and they may change accordingly with the change of the orientation where the structure is placed.

[0043] For ease of understanding, the relevant technical terms involved in the embodiments of the present application will be explained and described first below.

[0044] Parallel: The parallel defined in the embodiments of the present application is not limited to absolute parallelism. The definition of this parallel can be understood as substantially parallel, allowing for situations where it is not absolutely parallel due to factors such as assembly tolerances, design tolerances, and the influence of structural flatness.

[0045] Vertical: The verticality defined in the embodiments of the present application is not limited to an absolute vertical intersection relationship (angle of 90 degrees). It allows for a relationship that is not absolutely vertical due to factors such as assembly tolerance, design tolerance, and influence of structural flatness. It also allows for errors in a small angle range. For example, the assembly error range of 80 to 100 degrees can be understood as a vertical relationship.

[0046] See also Figure 1 , Figure 1 Schematic diagram of an electric vehicle provided in one embodiment of the present application. The electric vehicle includes a battery pack 3, wheels 2 and a powertrain 1. The powertrain 1 and the battery pack 3 are installed on the frame of the electric vehicle, and the powertrain 1 is used to receive power from the battery pack 3 and drive the wheels 2 to rotate.

[0047] Among them, electric vehicles include two-wheeled, three-wheeled or four-wheeled vehicles. The electric vehicle can be one of a pure electric vehicle (Pure Electric Vehicle / Battery Electric Vehicle, PEV / BEV), a hybrid electric vehicle (Hybrid Electric Vehicle, HEV), a range extended electric vehicle (Range Extended Electric Vehicle, REEV), a plug-in hybrid electric vehicle (Plug-in Hybrid Electric Vehicle, PHEV), and a new energy vehicle (New Energy Vehicle). In one embodiment, the electric vehicle is a means of transportation. Exemplarily, the electric vehicle is one of a commercial vehicle, a passenger car, a motorcycle, a flying car, and a train. In one embodiment, the electric vehicle is an industrial vehicle or an engineering vehicle. Exemplarily, the electric vehicle is one of a forklift, a trailer, a tractor, an excavator, a bulldozer, and a crane. In one embodiment, the vehicle can be an electric car or a fuel car. In one embodiment, the electric vehicle can also be agricultural equipment (such as a lawn mower, a harvester, etc.), amusement equipment, a toy vehicle, etc.

[0048] In one embodiment, an electric vehicle may include one or more powertrains 1 .

[0049] See also Figure 2 , Figure 2 A schematic diagram of a powertrain 1 provided in accordance with an embodiment of the present application. The powertrain 1 includes a reducer 5 and a motor 4. The motor 4 includes a motor shaft, which is used for driving connection with the input shaft of the reducer 5. The rotation of the motor shaft can drive the input shaft of the reducer 5 to rotate, so that the power output by the motor 4 is transmitted to the input shaft of the reducer 5. The axial direction of the input shaft of the reducer 5 is parallel to the axial direction of the motor 4. The gear set of the reducer 5 can change the transmission ratio between the motor 4 and the wheel 2.

[0050] In one embodiment, the speed reducer 5 further includes a differential 6 (as Figure 2 shown). The differential 6 is drivingly connected to the gear set of the speed reducer 5. The half shafts 7 of the differential 6 are fixedly connected to the wheels 2. The speed reducer 5 receives the power transmitted by the motor shaft through the gear set of the speed reducer 5 and delivers the power to the half shafts 7 through the differential 6 to drive the wheels 2 to rotate. The differential 6 realizes differential rotation of the two half shafts 7 of the differential 6 through the planetary gear set of the differential 6.

[0051] In one embodiment, the power assembly 1 may include one motor 4 or one speed reducer 5. In one embodiment, the power assembly 1 may include multiple motors 4 or multiple speed reducers 5. Exemplarily, the power assembly 1 may be a dual-drive assembly.

[0052] In one embodiment, the motor 4 includes a motor shaft, a motor rotor 10 and a motor stator. Among them, the motor rotor 10 includes a rotor core 300 and a plurality of permanent magnets 100. The rotor core 300 is sleeved and fixed on the outer surface of the motor shaft. The plurality of permanent magnets 100 are received in the magnet slots 310 of the rotor core 300. The permanent magnets 100 are also referred to as permanent magnetic bodies. The permanent magnets 100 are used to generate the magnetic field of the motor rotor 10. The motor stator includes a stator core and a stator winding. The stator core is sleeved on the motor rotor 10 and is spaced apart from the outer surface of the motor rotor 10. The motor winding is installed and fixed in the winding slots of the motor stator.

[0053] In one embodiment, the power assembly 1 further includes a motor controller. The motor controller is connected to the battery pack 3 and the motor winding. The motor controller is configured to receive the direct current output by the battery pack 3 and convert the direct current output by the battery pack 3 into alternating current and then transmit it to the motor winding. The rotating magnetic field generated after the motor winding receives the alternating current interacts with the plurality of permanent magnets 100. The interaction of the electromagnetic field causes the motor rotor 10 to rotate, thereby driving the motor shaft to rotate.

[0054] To reduce the eddy current loss of the motor rotor 10, insulation isolation is usually required between the permanent magnet 100 and the rotor core 300. Generally, the surface of the permanent magnet 100 can be insulated by coating an insulating coating on the surface of the permanent magnet 100. However, when the permanent magnet 100 is fixed in the magnet slot 310 of the rotor core 300, the insulating coating is prone to breakage. In particular, when the permanent magnet 100 is fixed in the magnet slot 310 of the rotor core 300 by means of riveting, spring pressing, etc., the insulating coating on the surface of the permanent magnet 100 is prone to breakage, resulting in a reduction in the insulation isolation performance between the permanent magnet 100 and the rotor core 300. In the present application, there are multiple coatings between the permanent magnet 100 and the inner wall of the magnet slot 310. When the permanent magnet 100 is installed and fixed in the magnet slot 310, the multiple coatings between the permanent magnet 100 and the inner wall of the magnet slot 310 are not easily broken, and there is good insulation isolation performance between the permanent magnet 100 and the rotor core 300, which is beneficial to improving the performance of the motor 4.

[0055] The motor rotor 10 in the present application will be introduced in detail below.

[0056] Please refer to Figure 3 、 Figure 4 and Figure 5 。 Figure 3 It is a schematic diagram of the motor rotor 10 provided by an embodiment of the present application. Figure 4 It is a schematic diagram of a magnet slot 310, a permanent magnet 100, a fixing coating 210 and a protective coating 220 provided by an embodiment of the present application. Figure 5 It is a schematic diagram of a magnet slot 310 and a permanent magnet 100 provided by an embodiment of the present application. The present application provides a motor rotor 10 in which the permanent magnet 100 has multiple coatings. The motor rotor 10 includes a rotor core 300, a plurality of permanent magnets 100, a plurality of fixing coatings 210 and a plurality of protective coatings 220. The rotor core 300 includes a plurality of magnet slots 310, and the magnet slots 310 axially penetrate the rotor core 300 along the axial direction of the rotor core 300. Each magnet slot 310 is used to accommodate one or more permanent magnets 100. A permanent magnet 100 includes two first surfaces 110 parallel to the axial direction of the rotor core 300, and the two first surfaces 110 are arranged opposite to each other. The distance between one first surface 110 and the inner wall of a magnet slot 310 is greater than the distance between the other first surface 110 and the inner wall of a magnet slot 310. The gap between one first surface 110 and the inner wall of a magnet slot 310 is used to accommodate a fixing coating 210, and the gap between the other first surface 110 and the inner wall of a magnet slot 310 is used to accommodate a protective coating 220.

[0057] Wherein, the axial direction of the rotor core 300 is parallel to the axial direction of the motor shaft. In one embodiment, the axial direction of the rotor core 300 is parallel to the length direction of the permanent magnet 100.

[0058] The permanent magnet 100 is received in the permanent magnet groove 310. The two first surfaces 110 of the permanent magnet 100 are parallel to each other, and the plane where the first surfaces 110 are located is parallel to the axial direction of the rotor core 300. The arrangement direction of the two first surfaces 110 is perpendicular to the plane where the first surfaces 110 are located. The permanent magnet groove 310 includes two first groove walls arranged opposite to each other along the arrangement direction of the two first surfaces 110. One first surface 110 is spaced from one first groove wall, and the distance between one first surface 110 and one first groove wall is Figure 5 L1 in Figure 5 The distance between the other first surface and the other first groove wall is L2 in

[0059] One fixing coating 210 is arranged between one first surface 110 and one first groove wall. The fixing coating 210 is used to fix the permanent magnet 100 in the permanent magnet groove 310. The fixing coating 210 has insulation properties, and the fixing coating 210 can isolate the permanent magnet 100 from one first groove wall, reducing the eddy current loss between the permanent magnet 100 and the rotor core 300.

[0060] One protective coating 220 is arranged between the other first surface 110 and the other first groove wall. The protective coating 220 has insulation properties, and the protective coating 220 can isolate the permanent magnet 100 from the other first groove wall, reducing the eddy current loss between the permanent magnet 100 and the rotor core 300.

[0061] In the embodiment of the present application, the permanent magnet 100 is fixed by the fixing coating 210, reducing the risk of damage to the protective coating 220 and improving the insulation isolation between the permanent magnet 100 and the rotor core 300. One fixing coating 210 and one protective coating 220 are arranged opposite to each other on both sides of one permanent magnet 100, and the fixing coating 210 can also be used to isolate the permanent magnet 100 and the inner wall of the permanent magnet groove 310, so that both first surfaces 110 of the permanent magnet 100 can maintain good insulation with the rotor core 300.

[0062] In addition, in the present application, the distance between one first surface 110 and one first groove wall is relatively large, so that the thickness of the fixing coating 210 along the arrangement direction of the two first surfaces 110 can be set relatively large, improving the reliability of the fixation between the permanent magnet 100 and the inner wall of the permanent magnet groove 310. And since the protective coating 220 is mainly used to isolate the permanent magnet 100 and the inner wall of the permanent magnet groove 310, the gap between the other first surface 110 and the inner wall of one permanent magnet groove 310 is relatively small in the present application, enabling better isolation between the permanent magnet 100 and the inner wall of the permanent magnet groove 310, and being beneficial to reducing the equivalent air gap length of the magnetic circuit and improving the output performance of the motor 4.

[0063] In one embodiment, the fixing coating 210 includes an expanded state and a contracted state. When the fixing coating 210 is arranged along the arrangement direction of the two first surfaces 110 and is in the expanded state, the thickness of the fixing coating 210 is greater than the thickness of the fixing coating 210 in the contracted state. Among them, the thickness of the fixing coating 210 in the contracted state is smaller, so that when the magnet 100 is installed in the magnet groove 310, the protective coating 220 is not easily damaged by friction with the magnet or the inner wall of the magnet groove 310. After the magnet 100 is placed in the magnet groove 310, the fixing coating 210 is changed from the contracted state to the expanded state. The thickness of the fixing coating 210 in the expanded state is larger, so that the fixing coating 210 fills the gap between one first surface 110 of the magnet 100 and the inner wall of the magnet groove 310, thereby fixing the magnet 100 in the magnet groove 310.

[0064] In the embodiment of the present application, the expansion characteristic of the fixing coating 210 is used to fix the magnet 100. The process is simple and the structure is reliable. Moreover, both the fixing coating 210 and the protective coating 220 are not easily damaged, which helps to achieve better isolation between the magnet 100 and the inner wall of the magnet groove 310. In addition, since the fixing coating 210 fixes the magnet 100 along the arrangement direction of the two first surfaces 110, if there is no protective coating 220 between the other first surface 110 and the other first groove wall, the other first surface 110 needs to abut against the other first groove wall to fix the magnet 100. The demand for insulation isolation between the other first surface 110 and the other first groove wall is relatively large. In the present application, the protective coating 220 is arranged between the other first surface 110 and the other first groove wall, which can effectively isolate the magnet 100 from the rotor core 300.

[0065] It should be noted that for the motor rotor 10, the motor 4, and the electric vehicle provided by the present application, the magnet 100 is fixed in the magnet groove 310 of the rotor core 300. At this time, the fixing coating 210 is in the expanded state. Unless otherwise specified below, the structure and position characteristics of the fixing coating 210 are the structure and position characteristics of the fixing coating 210 in the expanded state.

[0066] In one embodiment, the fixing coating 210 includes a foaming coating. The foaming coating can expand when heated, and the expansion effect can be cured after cooling. The expansibility of the foaming coating is used to make the foamed foaming coating fill the gap between the magnet 100 and the inner wall of the magnet groove 310, so that the magnet 100 and the inner wall of the magnet groove 310 are closely combined, thereby achieving the purpose of fixing the magnet 100. In the embodiment of the present application, the foaming coating is used as the fixing coating 210, and the process is simple, and the magnet 100 can be reliably fixed.

[0067] In one embodiment, the foaming coating includes at least one of a dry powder foaming coating, a glue foaming coating, and a foaming tape.

[0068] In one embodiment, the protective coating 220 includes an epoxy coating. The epoxy coating has poor conductivity and has an insulating effect. In the embodiment of the present application, the epoxy coating is used as the protective coating 220, which can better achieve insulation isolation between the magnetic steel 100 and the rotor core 300. When the epoxy coating is applied to the other first surface 110 of the magnetic steel 100, the epoxy coating can play a good protective role on the magnetic steel 100 and improve the anti-corrosion performance of the magnetic steel 100.

[0069] In one embodiment, the epoxy coating includes at least one of an electrophoretic epoxy coating, a spray epoxy coating, an aluminum epoxy coating, and a copper-nickel epoxy coating.

[0070] In one embodiment, the thickness of the fixed coating 210 along the arrangement direction of the two first surfaces 110 is greater than the thickness of the protective coating 220. Figure 4 d1 in the figure, the thickness of the protective coating 220 is Figure 4 In the embodiment of the present application, the fixed coating 210 has a relatively large thickness, which is conducive to the fixed coating 210 firmly fixing the magnetic steel 100 in the magnetic steel slot 310. The protective coating 220 has a relatively small thickness, which reduces the total size of the protective coating 220 and the magnetic steel 100 along the arrangement direction of the two first surfaces 110, and helps to reduce the equivalent air gap length of the magnetic circuit.

[0071] In one embodiment, the ratio of the thickness of the fixed coating 210 to the thickness of the protective coating 220 along the arrangement direction of the two first surfaces 110 is greater than 1 and less than or equal to 1000. The thickness of the fixed coating 210 and the thickness of the protective coating 220 affect the isolation between the magnetic steel 100 and the rotor core 300 and the reliability of the fixation. In the embodiment of the present application, the ratio of the thickness of the fixed coating 210 to the thickness of the protective coating 220 is greater than 1 and less than or equal to 1000, which is conducive to the fixed coating 210 firmly fixing the magnetic steel 100 in the magnetic steel slot 310 of the rotor core 300, and is conducive to the fixed coating 210 and the protective coating 220 to effectively isolate the two first surfaces 110 of the magnetic steel 100 from the rotor core 300.

[0072] Exemplarily, the ratio of the thickness of the fixing coating 210 to the thickness of the protective coating 220 fixed along the arrangement direction of the two first surfaces 110 is 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000.

[0073] In one embodiment, the thickness range of the fixing coating 210 is 0.01 mm to 5 mm. The thickness of the fixing coating 210 referred to in the embodiments of the present application is the thickness of the fixing coating 210 in the expanded state after the fixing coating 210 in the shrunk state foams. Exemplarily, the thickness of the fixing coating 210 can be 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm or 5 mm. In the embodiments of the present application, when the thickness of the fixing coating 210 is within the range of 0.01 mm to 5 mm, it helps the fixing coating 210 to firmly fix the magnet 100 in the magnet groove 310 of the rotor core 300.

[0074] In one embodiment, the thickness range of the protective coating 220 is 5 μm to 30 μm. Exemplarily, the thickness of the protective coating 220 can be 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm or 30 μm. In the embodiments of the present application, when the thickness of the protective coating 220 is within the range of 5 μm to 30 μm, it helps the protective coating 220 to isolate the magnet 100 from the rotor core 300, and since the thickness of the protective coating 220 is small, it helps to reduce the equivalent air-gap length of the magnetic circuit.

[0075] Please refer to Figure 6 , Figure 6A three-dimensional view of a magnet 100, a fixing coating 210, and a protective coating 220 provided in an embodiment of the present application. In one embodiment, the projection of a fixing coating 210 along the arrangement direction of the two first surfaces 110 covers one first surface 110. Among them, the orthographic projection area of a fixing coating 210 along the arrangement direction of the two first surfaces 110 on one first surface 110 is equal to the area of one first surface 110. The larger projection area of the fixing coating 210 is beneficial to stably fixing the magnet 100 and effectively isolating one first surface 110 from one first groove wall.

[0076] In one embodiment, the projection of a protective coating 220 along the arrangement direction of the two first surfaces 110 covers the other first surface 110. Among them, the orthographic projection area of a protective coating 220 along the arrangement direction of the two first surfaces 110 on the other first surface 110 is equal to the area of the other first surface 110. The larger projection area of the fixing coating 210 is beneficial to stably fixing the magnet 100 and effectively isolating the other first surface 110 from the other first groove wall.

[0077] In one embodiment, the orthographic projection area of a fixing coating 210 along the arrangement direction of the two first surfaces 110 on one first surface 110 is less than or equal to the orthographic projection area of a protective coating 220 along the arrangement direction of the two first surfaces 110 on one first surface 110. Among them, the fixing coating 210 is mainly used to fix the magnet 100, and a relatively small orthographic projection area of the fixing coating 210 on the first surface 110 can also play a good fixing role. Since the fixing coating 210 is arranged between one first surface 110 and one first groove wall, one first surface 110 is spaced from one first groove wall, so that insulation isolation can be achieved between one first surface 110 and the rotor core 300. And because the fixing coating 210 does not completely cover one first surface 110, the gap between one first surface 110 and one first groove wall can be used for circulating coolant to facilitate cooling of the magnet 100.

[0078] In addition, since the thickness of a protective coating 220 is small, in the embodiment of the present application, setting the orthographic projection area of a protective coating 220 on one first surface 110 to be large is beneficial to effectively isolating the other first surface 110 of the magnet 100 from the other first groove wall. When a protective coating 220 is coated on the other first surface 110, the protective coating 220 covers a larger range of the other first surface 110, so that the protective coating 220 can effectively protect the magnet 100.

[0079] In one embodiment, the ratio of the orthographic projection area of a fixing coating 210 on one first surface 110 along the arrangement direction of the two first surfaces 110 to the orthographic projection area of a protective coating 220 on one first surface 110 along the arrangement direction of the two first surfaces 110 is less than or equal to 1 and greater than or equal to 0.1. The projection areas of a fixing coating 210 and a protective coating 220 affect the isolation and fixing reliability between the magnet 100 and the rotor core 300. In the embodiments of the present application, the ratio of the projection area of a fixing coating 210 to the projection area of a protective coating 220 is less than or equal to 1 and greater than or equal to 0.1, which is beneficial to firmly fixing the magnet 100 in the magnet slot 310 of the rotor core 300 by a fixing coating 210 and reducing costs. Additionally, it is also beneficial for a fixing coating 210 and a protective coating 220 to effectively isolate the two first surfaces 110 of the magnet 100 from the rotor core 300.

[0080] In one embodiment, the ratio of the orthographic projection area of a fixing coating 210 on one first surface 110 along the arrangement direction of the two first surfaces 110 to the orthographic projection area of a protective coating 220 on one first surface 110 along the arrangement direction of the two first surfaces 110 can be 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.1.

[0081] Please refer to Figure 7 , Figure 7 which is a three-dimensional view of a magnet 100, a fixing coating 210, and a protective coating 220 provided in an embodiment of the present application. In one embodiment, a fixing coating 210 includes a plurality of sub-coatings spaced apart from each other. Exemplarily, the plurality of sub-coatings are arranged at intervals along the axial direction of the rotor core 300. Along the arrangement direction of the two first surfaces 110, the projections of the plurality of sub-coatings do not overlap each other. In the embodiments of the present application, the gap between two adjacent sub-coatings can be used for circulating coolant, facilitating the heat dissipation of the magnet 100.

[0082] Please refer to Figure 8 , Figure 8 which is a three-dimensional view of a magnet 100, a fixing coating 210, and a protective coating 220 provided in an embodiment of the present application. In one embodiment, a fixing coating 210 includes multiple columns of sub-coatings, and the multiple columns of sub-coatings are arranged at intervals along the width direction of the magnet 100. Each column of sub-coatings includes at least two sub-coatings. The at least two sub-coatings are arranged at intervals along the axial direction of the rotor core 300. Among them, the width direction of the magnet 100 is perpendicular to the axial direction of the rotor core 300 and perpendicular to the arrangement direction of the two first surfaces 110.

[0083] In one embodiment, when the fixed coating 210 is in a contracted state, the fixed coating 210 includes a plurality of spaced-apart sub-coatings. Among them, when the plurality of sub-coatings are in a contracted state, the orthographic projection area on one of the first surfaces 110 along the arrangement direction of the two first surfaces 110 is smaller than the orthographic projection area on one of the first surfaces 110 along the arrangement direction of the two first surfaces 110 when the plurality of sub-coatings are in an expanded state. In one embodiment, after the plurality of sub-coatings in the contracted state are foamed, the plurality of sub-coatings are connected to each other. So that the fixed coating 210 in the expanded state can continuously cover one of the first surfaces 110, and the fixed coating 210 can provide better protection for one of the first surfaces 110.

[0084] In the embodiments of the present application, the fixed coating 210 in the contracted state includes a plurality of spaced-apart sub-coatings, which is beneficial to the full foaming of the fixed coating 210 in the contracted state into the fixed coating 210 in the expanded state. And the gap between two adjacent sub-coatings in the contracted state can be used for foaming, reducing the occurrence of the situation where the fixed coating 210 foams outside the gap between one of the first surfaces 110 and one of the first groove walls.

[0085] In one embodiment, the ratio of the distance between two adjacent sub-coatings in the contracted state to the thickness of the sub-coating in the contracted state is greater than or equal to 0.1 and less than or equal to 50. In the embodiments of the present application, the distance between adjacent sub-coatings in the contracted state is within a suitable range, which is beneficial to the foaming of the fixed coating 210 for better fixing of the magnet 100. And it can reduce the occurrence of the overflow of the fixed coating 210.

[0086] In one embodiment, the range of the distance between two adjacent sub-coatings in the contracted state is 0.5 mm to 500 mm. Exemplarily, the distance between two adjacent sub-coatings in the contracted state can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 300 mm, 400 mm or 500 mm.

[0087] In one embodiment, the range of the thickness of the sub-coating in the contracted state is 0.01 mm to 2 mm. Exemplarily, the thickness of the sub-coating in the contracted state can be 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm.

[0088] In one embodiment, a fixed coating 210 includes two first side surfaces which face away from each other along the arrangement direction of two first surfaces 110, and the two first side surfaces are respectively in contact with a first surface 110 and the inner wall of a magnet groove 310. Among them, the two first side surfaces of the fixed coating 210 are the two side surfaces with the largest areas among the six surfaces of the fixed coating 210. In the embodiment of the present application, the two first side surfaces of the fixed coating 210 are respectively in contact with a first surface 110 and a first groove wall, which is beneficial to fixing the magnet 100 and the rotor core 300 by the fixed coating 210.

[0089] In one embodiment, the arrangement direction of the two first surfaces 110 is parallel to the arrangement direction of the magnetic south pole and the magnetic north pole of the magnet 100. The two first side surfaces of the fixed coating 210 are respectively in contact with a first surface 110 and a first groove wall, which is beneficial to reducing the distance between a first surface 110 and a first groove wall, thereby reducing the equivalent air gap of the magnetic circuit.

[0090] In one embodiment, at least one of an epoxy coating and a phosphating coating is further included between a fixed coating 210 and a first surface 110. Among them, the phosphating coating includes at least one of a zinc-based phosphating coating, an iron-based phosphating coating, a manganese-based phosphating coating, a binary phosphating coating, a ternary phosphating coating, and a multi-component phosphating coating. In one implementation manner, a first surface 110 is coated with a phosphating coating, and the two first side surfaces of a fixed coating 210 are respectively in contact with the phosphating coating and the inner wall of a magnet groove 310. The phosphating coating can be used to protect the magnet 100 and improve the bonding force between a fixed coating 210 and a first surface 110.

[0091] In one implementation manner, the thickness range of the phosphating coating is 3 μm to 5 μm. Exemplarily, the thickness of the phosphating coating can be 3 μm, 3.2 μm, 3.4 μm, 3.8 μm, 4 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm, or 5 μm. When the thickness of the phosphating coating is within an appropriate range, it is beneficial for the phosphating coating to adhere to the surface of the magnet 100.

[0092] In one implementation manner, a first surface 110 is coated with an epoxy coating, and the two first side surfaces of a fixed coating 210 are respectively in contact with the epoxy coating and the inner wall of a magnet groove 310. Compared with the fixed coating 210, the epoxy coating has stronger anti-corrosion ability. Adding an epoxy coating between the fixed coating 210 and the magnet 100 can play a better protective role for the magnet 100 and effectively improve the anti-corrosion performance of the magnet 100.

[0093] In one embodiment, the thickness of the epoxy coating arranged between a fixed coating 210 and a first surface 110 along the arrangement direction of the two first surfaces 110 is less than or equal to the thickness of a protective coating 220 and less than the thickness of a fixed coating 210. In the embodiments of the present application, since there are two coatings such as an epoxy coating and a fixed coating 210 arranged between a first surface 110 and a first groove wall, insulation isolation can be achieved between a first surface 110 and a first groove wall through a fixed coating 210. The smaller thickness of the epoxy coating arranged between a fixed coating 210 and a first surface 110 can save costs.

[0094] In one embodiment, an epoxy coating and a phosphating coating are further included between a fixed coating 210 and a first surface 110, and a fixed coating 210, an epoxy coating, a phosphating coating, and a first surface 110 are arranged in sequence. Two coatings are applied to a first surface 110, which greatly improves the anti-corrosion performance of the magnet 100. Moreover, the phosphating coating has good infiltration performance. The phosphating coating is arranged between an epoxy coating and a first surface 110, which can improve the bonding force between the epoxy coating and the magnet 100.

[0095] Please refer to Figure 3 and Figure 4 In one embodiment, a first side surface of a fixed coating 210 is fixed to a first surface 110. Among them, another first side surface of a fixed coating 210 abuts against a first groove wall. Before foaming, the fixed coating 210 can be first coated on a first surface 110 of the magnet 100, and then the magnet 100 is placed in the magnet groove 310 and heated to cause the fixed coating 210 to expand to fix the magnet 100. In the embodiments of the present application, the fixed coating 210 is fixed to the magnet 100, which is beneficial to the assembly of the fixed coating 210 and the magnet 100 and the fixation in the magnet groove 310. Moreover, the fixed coating 210 is fixed to a first surface 110, and the fixed coating 210 can isolate the first surface 110 from the air, improving the anti-corrosion performance of the magnet 100.

[0096] In one embodiment, another first side surface of a fixed coating 210 is fixed to the inner wall of the magnet groove 310. Among them, a first side surface of a fixed coating 210 can abut against a first surface 110. Before foaming, the fixed coating 210 can be first coated on a first groove wall of the magnet groove 310, and then the magnet 100 is placed in the magnet groove 310 and heated to cause the fixed coating 210 to expand to fix the magnet 100.

[0097] In one embodiment, a protective coating 220 includes two second side surfaces. Along the arrangement direction of the two first surfaces 110, the two second side surfaces face away from each other, and the two second side surfaces are respectively in contact with another first surface 110 and the inner wall of a magnet groove 310. Among them, the two second side surfaces of the protective coating 220 are the two side surfaces with the largest area among the six surfaces of the protective coating 220. In the embodiment of the present application, the two second side surfaces of the protective coating 220 are respectively in contact with another first surface 110 and another first groove wall, which is beneficial to cooperate with the fixing coating 210 to fix the magnet 100 and the rotor core 300. And the protective coating 220 is in contact with another first surface 110, and the protective coating 220 can protect the magnet 100 and reduce the risk of oxidation of the magnet 100. The protective coating 220 is in contact with another first groove wall, which is beneficial to reduce the distance between another first surface 110 and another first groove wall, thereby reducing the equivalent air gap of the magnetic circuit.

[0098] In one embodiment, a phosphating coating is further included between a protective coating 220 and another first surface 110. Another first surface 110 is coated with two coatings, and the anti-corrosion performance of the magnet 100 is greatly improved. And the phosphating coating has good infiltration performance. The phosphating coating is arranged between a protective coating 220 and another first surface 110, which can improve the bonding force between the protective coating 220 and the magnet 100.

[0099] In one embodiment, one second side surface of a protective coating 220 is fixed to another first surface 110. Among them, the other second side surface abuts against another first groove wall. The protective coating 220 can be first coated on another first surface 110 of the magnet 100, and then the protective coating 220 and the magnet 100 are installed and fixed in the magnet groove 310 together. In the embodiment of the present application, the protective coating 220 is fixed to the magnet 100, which is beneficial to the assembly of the protective coating 220 and the magnet 100 and the fixation in the magnet groove 310. And the protective coating 220 is fixed to another first surface 110, and the protective coating 220 can isolate another first surface 110 from the air, improving the anti-corrosion performance of the magnet 100.

[0100] In one embodiment, the other second side surface of a protective coating 220 is fixed to the inner wall of the magnet groove 310. Among them, one second side surface of a protective coating 220 can abut against another first surface 110. The protective coating 220 can be first coated on another first groove wall, and then the magnet 100 is installed and fixed in the magnet groove 310. The protective coating 220 is located between another first surface 110 and another first groove wall, and can isolate another first surface 110 and another first groove.

[0101] Please refer to Figure 3, in one embodiment, the minimum distance between a fixed coating 210 and the outer peripheral surface of the rotor core 300 in the radial direction of the rotor core 300 is greater than the minimum distance between a protective coating 220 and the outer peripheral surface of the rotor core 300. Among them, the minimum distance between a first surface 110 and the outer peripheral surface of the rotor core 300 in the radial direction of the rotor core 300 is greater than the minimum distance between another first surface 110 and the outer peripheral surface of the rotor core 300. Among them, the radial direction of the rotor core 300 is perpendicular to the axial direction of the rotor core 300. In the embodiment of the present application, the motor stator is sleeved on the outer peripheral surface of the rotor core 300. Since the distance between a first surface 110 and the groove wall of the magnet slot 310 is large and the magnetic permeability of the fixed coating 210 is low, and the fixed coating 210 is arranged far from the motor stator, it is beneficial to reduce the magnetic resistance of the motor rotor 10 to improve the output performance of the motor 4.

[0102] Please refer to Figure 4 and Figure 5 , in one embodiment, a magnet 100 includes two second surfaces 120 parallel to the axial direction of the rotor core 300. The two second surfaces 120 are arranged oppositely, and the second surface 120 intersects with the first surface 110. The distance between a first surface 110 and the inner wall of a magnet slot 310 is less than the distance between any one of the second surfaces 120 and the inner wall of a magnet slot 310. Among them, the two second surfaces 120 of the magnet 100 are parallel to each other, and the plane where the second surface 120 is located is parallel to the axial direction of the rotor core 300. The arrangement direction of the two second surfaces 120 is perpendicular to the plane where the second surface 120 is located and perpendicular to the arrangement direction of the two first surfaces 110.

[0103] The magnet slot 310 includes two second groove walls arranged oppositely along the arrangement direction of the two second surfaces 120. The two second surfaces 120 are respectively spaced from the two second groove walls. Along the arrangement direction of the two second surfaces 120, the distance between a first surface 110 and the inner wall of a magnet slot 310 is less than the distance between a second surface 120 and a second groove wall and less than the distance between the other second surface 120 and the other second groove wall.

[0104] In the embodiments of the present application, the distance between a first surface 110 and the inner wall of a magnet groove 310 is less than the distance between a second surface 120 and the inner wall of a magnet groove 310, so that the fixing coating 210 arranged between a first surface 110 and a first groove wall can play a role in fixing the magnet 100, and the thickness of the fixing coating 210 will not be too large to cause waste of the fixing coating 210. When the arrangement directions of the two first surfaces 110 are parallel to the arrangement direction of the magnetic south pole and the magnetic north pole of the magnet 100, the distance between a first surface 110 and a first groove wall is small, which is beneficial to reducing the equivalent air gap of the magnetic circuit. The distance between the other first surface 110 and the other first groove wall is less than the distance between the second surface 120 and the inner wall of a magnet groove 310, which is also beneficial to reducing the equivalent air gap of the magnetic circuit. In addition, the distance between the second surface 120 and the inner wall of the magnet groove 310 is large, and the second surface 120 and the magnet groove 310 can be insulated and isolated by air, which is beneficial to reducing costs.

[0105] Please refer to Figure 4 and Figure 6 In an embodiment, the area of the first surface 110 is larger than the area of the second surface 120. The area of the first surface 110 is large, and the fixing coating 210 is arranged between a first surface 110 and the groove wall of the magnet groove 310. The fixing coating 210 has a large contact area with a first surface 110, so that the magnet 100 can be fixed in the magnet groove 310 more stably. The areas of the two first surfaces 110 are large, and the insulation requirements between the two first surfaces 110 and the rotor core 300 are greater. A fixing coating 210 and a protective coating 220 are arranged between the two first surfaces 110 and the inner wall of the magnet groove 310, which can effectively isolate the magnet 100 from the rotor core 300.

[0106] In an embodiment, the orthographic projection area of a fixing coating 210 along the arrangement direction of the two first surfaces 110 on a first surface 110 is larger than the area of any second surface 120. The orthographic projection area of the fixing coating 210 on a first surface 110 is large, so that the fixing coating 210 can fix the magnet 100 more firmly in the magnet groove 310. And when the fixing coating 210 is coated on a first surface 110, the projection area of the fixing coating 210 is large, so that the fixing coating 210 can more completely cover a first surface 110 and can play a better protective role for the magnet 100.

[0107] Please refer to Figure 4 and Figure 6, in one embodiment, the positive projection area of a protective coating 220 on one first surface 110 along the arrangement direction of the two first surfaces 110 is larger than the area of any one of the second surfaces 120. The relatively large positive projection area of the protective coating 220 on one first surface 110 enables the protective coating 220 to effectively isolate the magnet 100 from the rotor core 300. Moreover, when the protective coating 220 is coated on the other first surface 110, the projection area of the protective coating 220 is relatively large, enabling the protective coating 220 to more completely cover the other first surface 110, which can provide better protection for the magnet 100.

[0108] Combined Figure 5 and Figure 9 , in one embodiment, the gap between a second surface 120 and the inner wall of a magnet groove 310 is used to accommodate a protective coating 220. A protective coating 220 accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 is spaced from the inner wall of the magnet groove 310 and is in contact with a second surface 120. For the sake of convenient description, a protective coating 220 arranged between a second surface 120 and the inner wall of a magnet groove 310 is defined as the protective coating 220a. The protective coating 220a includes two sides facing away from each other along the arrangement direction of the two second surfaces 120. One side of the protective coating 220a is in contact with a second surface 120. Exemplarily, one side of the protective coating 220a can be fixed to a second surface 120. The other side of the protective coating 220a is spaced from a second groove wall.

[0109] In the embodiment of the present application, the protective coating 220a is in contact with a second surface 120. The protective coating 220a can protect the magnet 100 and improve the anti-corrosion performance of the magnet 100. The protective coating 220a is spaced from a second groove wall, and the gap between the protective coating 220a and the second groove wall can be used for circulating a coolant to facilitate heat dissipation of the magnet 100.

[0110] In one embodiment, the gap between a second surface 120 and the inner wall of a magnet groove 310 can also be used to accommodate a phosphating coating. A phosphating coating is spaced from the inner wall of the magnet groove 310 and is in contact with a second surface 120. The phosphating coating can also play a certain anti-corrosion role. Moreover, compared with an epoxy coating, the price of the phosphating coating is lower. Coating a second surface 120 with a phosphating coating can reduce costs.

[0111] In one embodiment, the gap between a second surface 120 and the inner wall of a magnet groove 310 is used to accommodate a protective coating 220a and a phosphating coating. Among them, the phosphating coating is arranged between a second surface 120 and a protective coating 220a. A protective coating 220a is spaced from the inner wall of a magnet groove 310 and is in contact with a phosphating coating. In the embodiment of the present application, a phosphating coating and a protective coating 220a are sequentially coated on a second surface 120, and the anti-corrosion performance of the magnet 100 is greatly improved. Moreover, the phosphating coating has good wetting performance. The phosphating coating is arranged between a protective coating 220a and a second surface 120, which can improve the bonding force between the protective coating 220a and the magnet 100.

[0112] In one embodiment, the thickness of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 is less than the thickness of a fixing coating 210 and less than or equal to the thickness of a protective coating 220. Among them, the thickness of a protective coating 220a refers to the thickness of the protective coating 220a along the arrangement direction of two second surfaces 120. The thickness of a fixing coating 210 refers to the thickness of the fixing coating 210 along the arrangement direction of two first surfaces 110. The said protective coating 220 refers to a protective coating 220 arranged between another first surface 110 and another first groove wall. The thickness of a protective coating 220 refers to the thickness of a protective coating 220 along the arrangement direction of two first surfaces 110.

[0113] In the embodiment of the present application, since the distance between a second surface 120 and a second groove wall is relatively large, air insulation can be carried out between a second surface 120 and a second groove wall. The relatively small thickness of a protective coating 220a can save costs.

[0114] In one embodiment, the ratio of the thickness of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 to the thickness of a fixing coating 210 is less than 1 and greater than or equal to 0.001. The thickness of the protective coating 220a is relatively small, which can save the manufacturing cost of the motor rotor 10.

[0115] In one embodiment, the ratio of the thickness of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 to the thickness of a fixing coating 210 can be 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.05, 0.01, 0.009, 0.005 or 0.001.

[0116] In one embodiment, the ratio of the thickness of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 to the thickness of a protective coating 220 is less than or equal to 1 and greater than or equal to 0.001. In the embodiments of the present application, a protective coating 220 arranged between another first surface 110 and another first groove wall is used to isolate the another first surface 110 from the rotor core 300, and a certain thickness of the protective coating 220 is required to ensure the isolation performance of the magnet 100. Since the protective coating 220a is isolated from a second groove wall, the gap between the protective coating 220a and the second groove wall can effectively isolate the second surface 120 from the rotor core 300. The protective coating 220a mainly serves to protect the second surface 120, and the smaller thickness of the protective coating 220a can save the manufacturing cost of the motor rotor 10.

[0117] In one embodiment, the ratio of the thickness of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310 to the thickness of a protective coating 220 is 1, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.009, 0.005 or 0.001.

[0118] Combined with Figure 5 and Figure 9 , in one embodiment, the gap between another second surface 120 and the inner wall of a magnet groove 310 is used to accommodate a protective coating 220. For the structure and positional relationship of a protective coating 220 accommodated in the gap between another second surface 120 and the inner wall of a magnet groove 310, reference may be made to the above-mentioned structure and positional relationship of a protective coating 220a accommodated in the gap between a second surface 120 and the inner wall of a magnet groove 310, which will not be elaborated here.

[0119] Please refer to Figure 10 , Figure 10A perspective view of a magnet 100 and multiple coatings provided by an embodiment of the present application. In one embodiment, a magnet 100 includes two third surfaces 130 perpendicular to the axial direction of the rotor core 300, and the third surfaces 130 intersect with the first surfaces 110. Among them, the magnet 100 is a cube, and the magnet 100 includes six surfaces. Two first surfaces 110 and two second surfaces 120 of the magnet 100 are received in the magnet groove 310 and are parallel to the axial direction of the rotor core 300. The two third surfaces 130 of the magnet 100 are parallel to each other, and the plane where the third surfaces 130 are located is perpendicular to the axial direction of the rotor core 300 and perpendicular to the second surfaces 120. The arrangement direction of the two third surfaces 130 is perpendicular to the plane where the third surfaces 130 are located and perpendicular to the arrangement direction of the two first surfaces 110.

[0120] Please refer to Figure 10 , in one embodiment, the area of the first surface 110 is larger than the area of the third surface 130. The area of the first surface 110 is larger, and the fixing coating 210 is arranged between one first surface 110 and the groove wall of the magnet groove 310. The fixing coating 210 has a larger contact area with one first surface 110, so that the magnet 100 can be fixed in the magnet groove 310 more stably. The areas of the two first surfaces 110 are larger, and the insulation requirement between the two first surfaces 110 and the rotor core 300 is greater. The fixing coating 210 and the protective coating 220 are arranged between the two first surfaces 110 and the inner wall of the magnet groove 310, which can effectively isolate the magnet 100 from the rotor core 300.

[0121] In one embodiment, the area of the second surface 120 is larger than the area of the third surface 130.

[0122] Please refer to Figure 10 , in one embodiment, the orthographic projection area of a fixing coating 210 along the arrangement direction of the two first surfaces 110 on one first surface 110 is larger than the area of any one third surface 130. The orthographic projection area of the fixing coating 210 on one first surface 110 is larger, so that the fixing coating 210 can fix the magnet 100 more firmly in the magnet groove 310. And when the fixing coating 210 is coated on one first surface 110, the projection area of the fixing coating 210 is larger, so that the fixing coating 210 can more completely cover one first surface 110, which can play a better protection role for the magnet 100.

[0123] Please refer to Figure 10, in one embodiment, a protective coating 220 has a positive projection area on one of the first surfaces 110 that is larger than the area of any one of the third surfaces 130 along the arrangement direction of the two first surfaces 110. The relatively large positive projection area of the protective coating 220 on one of the first surfaces 110 enables the protective coating 220 to effectively isolate the magnet 100 from the rotor core 300. Moreover, when the protective coating 220 is coated on the other first surface 110, the projection area of the protective coating 220 is relatively large, such that the protective coating 220 can more completely cover the other first surface 110, providing better protection for the magnet 100.

[0124] In one embodiment, a protective coating 220 is fixed to one of the third surfaces 130. For the sake of convenient description, the protective coating 220 fixed to one of the third surfaces 130 is defined as the protective coating 220b. In the embodiment of the present application, the protective coating 220b is in contact with one of the third surfaces 130, and the protective coating 220b can protect the magnet 100, improving the anti-corrosion performance of the magnet 100.

[0125] In one embodiment, one of the third surfaces 130 can also be used to fix a phosphating coating. The phosphating coating can also play a certain anti-corrosion role. Moreover, compared with the epoxy coating, the price of the phosphating coating is lower. Coating one of the third surfaces 130 with the phosphating coating can reduce costs.

[0126] In one embodiment, one of the third surfaces 130 is used to fix a protective coating 220b and a phosphating coating. Among them, the phosphating coating is arranged between one of the third surfaces 130 and a protective coating 220b. In the embodiment of the present application, one of the third surfaces 130 is sequentially coated with a phosphating coating and a protective coating 220b, greatly improving the anti-corrosion performance of the magnet 100. Moreover, the phosphating coating has good infiltration performance. The phosphating coating is arranged between a protective coating 220b and one of the third surfaces 130, which can improve the bonding force between the protective coating 220b and the magnet 100.

[0127] In one embodiment, the thickness of a protective coating 220 fixed to one of the third surfaces 130 is less than the thickness of a fixing coating 210 and less than or equal to the thickness of a protective coating 220. The thickness of the protective coating 220b is the thickness of the protective coating 220b along the arrangement direction of the two third surfaces 130. The thickness of a fixing coating 210 refers to the thickness of the fixing coating 210 along the arrangement direction of the two first surfaces 110. The said protective coating 220 refers to a protective coating 220 arranged between the other first surface 110 and the other first groove wall. The thickness of a protective coating 220 is the thickness of the protective coating 220 along the arrangement direction of the two first surfaces 110.

[0128] In the embodiments of the present application, since the third surface 130 does not contact the inner wall of the magnet slot 310, there is no need for insulation isolation between the third surface 130 and the rotor core 300, and the relatively small thickness of a protective coating 220b can save costs.

[0129] In one embodiment, the ratio of the thickness of a protective coating 220 fixed to a third surface 130 to the thickness of a fixing coating 210 is less than 1 and greater than or equal to 0.001. The relatively small thickness of the protective coating 220b can save the manufacturing cost of the motor rotor 10.

[0130] In one embodiment, the ratio of the thickness of a protective coating 220 fixed to a third surface 130 to the thickness of a protective coating 220 is less than or equal to 1 and greater than or equal to 0.001. In the embodiments of the present application, the protective coating 220b mainly serves to protect a third surface 130, and the relatively small thickness of the protective coating 220b can save the manufacturing cost of the motor rotor 10.

[0131] In one embodiment, another third surface 130 is used to accommodate a protective coating 220. For the structure and positional relationship of a protective coating 220 fixed to another third surface 130, reference may be made to the above-mentioned structure and positional relationship of a protective coating 220a fixed to a third surface 130, which will not be elaborated herein.

[0132] The motor rotor, motor, powertrain, and vehicle with multiple coatings on the magnet provided by the embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate the principles and embodiments of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in specific embodiments and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A motor rotor with a magnet having multiple coatings, characterized in that, The motor rotor includes a rotor core, a plurality of permanent magnets, a plurality of fixing coatings, and a plurality of protective coatings. The rotor core includes a plurality of magnet slots that axially penetrate the rotor core along the axial direction of the rotor core. Each magnet slot is used to accommodate one or more of the permanent magnets, where: One of the permanent magnets includes two first surfaces parallel to the axial direction of the rotor core. The two first surfaces are arranged oppositely. The distance between one of the first surfaces and the inner wall of one of the magnet slots is greater than the distance between the other first surface and the inner wall of the one magnet slot. The gap between the one first surface and the inner wall of the one magnet slot is used to accommodate one of the fixing coatings, and the gap between the other first surface and the inner wall of the one magnet slot is used to accommodate one of the protective coatings.

2. The motor rotor according to claim 1, characterized in that, One of the fixing coatings includes two first side surfaces. The two first side surfaces face away from each other along the arrangement direction of the two first surfaces. The two first side surfaces are respectively in contact with the one first surface and the inner wall of the one magnet slot. One of the protective coatings includes two second side surfaces. The two second side surfaces face away from each other along the arrangement direction of the two first surfaces. The two second side surfaces are respectively in contact with the other first surface and the inner wall of the one magnet slot.

3. The motor rotor according to claim 2, wherein One of the first side surfaces of the one fixing coating is fixed to the one first surface, and one of the second side surfaces of the one protective coating is fixed to the other first surface.

4. The motor rotor according to claim 2 or 3, characterized in that The orthographic projection area of the one fixing coating on the one first surface along the arrangement direction of the two first surfaces is less than or equal to the orthographic projection area of the one protective coating on the one first surface along the arrangement direction of the two first surfaces.

5. The motor rotor according to any one of claims 1-4, characterized in that, The one fixing coating includes a foaming coating, and the one protective coating includes an epoxy coating.

6. The motor rotor according to any one of claims 1-5, characterized in that, The minimum distance between the one fixing coating and the outer peripheral surface of the rotor core along the radial direction of the rotor core is greater than the minimum distance between the one protective coating and the outer peripheral surface of the rotor core.

7. The motor rotor according to any one of claims 1-6, characterized in that, One of the permanent magnets includes two second surfaces parallel to the axial direction of the rotor core. The two second surfaces are arranged oppositely. The second surfaces intersect with the first surfaces, where: The distance between the one first surface and the inner wall of the one magnet slot is less than the distance between any one of the second surfaces and the inner wall of the one magnet slot.

8. The motor rotor according to claim 7, wherein The orthographic projection area of the one fixing coating on the one first surface along the arrangement direction of the two first surfaces is greater than the area of any one of the second surfaces, and the orthographic projection area of the one protective coating on the one first surface along the arrangement direction of the two first surfaces is greater than the area of any one of the second surfaces.

9. The motor rotor according to claim 7 or 8, characterized in that, The gap between one of the second surfaces and the inner wall of the one magnet slot is used to accommodate one of the protective coatings, where: One of the protective coatings accommodated in the gap between the one second surface and the inner wall of the one magnet slot is spaced from the inner wall of the one magnet slot and is in contact with the one second surface.

10. The motor rotor according to claim 9, characterized in that, The thickness of one of the protective coatings accommodated in the gap between the one second surface and the inner wall of the one magnet groove is less than the thickness of the one fixing coating and less than or equal to the thickness of the one protective coating.

11. The motor rotor according to any one of claims 1-10, characterized in that, The one magnet includes two third surfaces perpendicular to the axial direction of the rotor core, the third surfaces intersect with the first surface, the orthographic projection area of the one fixing coating on the one first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the third surfaces, and the orthographic projection area of the one protective coating on the one first surface along the arrangement direction of the two first surfaces is larger than the area of any one of the third surfaces.

12. The motor rotor according to claim 11, characterized in that, One of the protective coatings is fixed to one of the third surfaces, wherein: The thickness of the one protective coating fixed to the one third surface is less than the thickness of the one fixing coating and less than or equal to the thickness of the one protective coating.

13. A motor, characterized in that, The motor includes a motor shaft and a motor rotor as claimed in any one of claims 1 - 12, and the rotor core of the motor rotor is sleeved and fixed on the motor shaft.

14. A powertrain, characterized in that, The power assembly includes a speed reducer and a motor as claimed in claim 13, and the input shaft of the speed reducer is used for drivingly connecting with the motor shaft of the motor.

15. An electric vehicle, characterized in that, The electric vehicle includes wheels, a battery pack and a motor as claimed in claim 13 or includes a power assembly as claimed in claim 14, and the motor or the power assembly is used for receiving the power supply from the power battery and driving the wheels.

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