Rotor assembly, motor and vehicle

Abstract

The invention discloses a rotor assembly, a motor and a vehicle, and the rotor assembly comprises a rotor iron core which is provided with magnetic steel grooves; and the magnetic steel is located in the magnetic steel groove, and only the surface, facing the radial inner side of the rotor iron core, of the two surfaces in the thickness direction of the magnetic steel is provided with an expansion coating. According to the rotor assembly provided by the invention, the expanded expansion coating fills the gap between the magnetic steel and the magnetic steel groove to ensure that the magnetic steel is firmly and reliably fixed in the magnetic steel groove, so that the vibration caused by the looseness or displacement of the magnetic steel is eliminated, the dynamic balance is effectively improved, the noise vibration is reduced, and the reliability of the rotor assembly is improved; and therefore, the motor applying the rotor assembly can still keep excellent stability and durability under long-time and high-load operation conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a rotor assembly, a motor and a vehicle. Background Art

[0002] The rotor is an important part of the motor. However, in the prior art, when the motor runs at a high speed, the magnetic steel on the rotor tends to loosen easily, which not only affects the dynamic balance of the motor, but also causes problems such as vibration and noise. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a rotor assembly, which ensures that the magnets are firmly and reliably fixed in the magnet slots, thereby eliminating vibration caused by loosening or displacement of the magnets, thereby effectively improving dynamic balance and reducing noise and vibration.

[0004] The present invention also provides a motor, comprising the above-mentioned rotor assembly.

[0005] The present invention also provides a vehicle, comprising the above-mentioned motor.

[0006] According to an embodiment of the present invention, a rotor assembly includes: a rotor core having a magnetic steel slot; a magnetic steel located in the magnetic steel slot, and of the two surfaces of the magnetic steel in the thickness direction, only the surface facing the radial inner side of the rotor core has an expansion coating.

[0007] According to the rotor assembly of the embodiment of the present invention, the rotor core has magnetic steel slots, and the magnetic steels are respectively located in the magnetic steel slots. Among the two surfaces in the thickness direction of the magnetic steel, only the surface facing the radial inner side of the rotor core has an expansion coating, so that the expanded expansion coating fills the gap between the magnetic steel and the magnetic steel slot, ensuring that the magnetic steel is firmly and reliably fixed in the magnetic steel slot, thereby eliminating the vibration caused by loosening or displacement of the magnetic steel, and then effectively improving the dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly, so as to achieve that the motor using the rotor assembly can still maintain excellent stability and durability under long-term and high-load operation conditions.

[0008] In some embodiments of the present invention, along the thickness direction of the magnetic steel, the thickness of the expansion coating is 20 μm-350 μm.

[0009] In some embodiments of the present invention, when the expansion coating is in a pre-cured state, the ratio of the area of ​​the expansion coating region on the surface of the magnetic steel having the expansion coating to the total area of ​​the surface of the magnetic steel having the expansion coating is 0.32-0.73.

[0010] In some embodiments of the present invention, the expansion coating is located in a middle region of the surface facing the radial inner side of the rotor core between the two surfaces of the magnetic steel in the thickness direction.

[0011] In some embodiments of the present invention, the expansion coating has a pre-cured state and a cured state. In the pre-cured state, the expansion coating is spaced apart from the inner wall of the magnetic steel slot. In the cured state, the expansion coating abuts against the inner wall of the magnetic steel slot.

[0012] In some embodiments of the present invention, along the thickness direction of the magnetic steel, the thickness of the expansion coating in the cured state is more than four times the thickness of the expansion coating in the pre-cured state.

[0013] In some embodiments of the present invention, the rotor core includes a plurality of magnetic pole portions arranged along the circumferential direction of the rotor core, each of the magnetic pole portions has the same number and shape of magnetic steel slots, and the magnetic steel is a plurality of magnetic steel slots corresponding one-to-one to the plurality of magnetic steel slots.

[0014] In some embodiments of the present invention, the ratio of the number of the magnetic pole portions to the number of the magnetic steel slots on each of the magnetic pole portions is 0.5-5.33, wherein the number of the magnetic pole portions is at least 4 and the number of the magnetic steel slots is at least 1.

[0015] In some embodiments of the present invention, the intumescent coating comprises, by weight percentage, 2%-35% of an intumescent agent, 20%-65% of a polymer binder, 2%-20% of an additive, and the balance of a diluent.

[0016] In some embodiments of the present invention, the expansion agent is expandable microspheres, an inorganic foaming agent or an organic foaming agent.

[0017] In some embodiments of the present invention, the expanded microspheres include an outer shell and an inner core located in the outer shell, the outer shell is a thermoplastic polymer, and the boiling point of the inner core is 60°-170°.

[0018] In some embodiments of the present invention, the inner core is a hydrocarbon and includes at least one of ethane, propane, isobutane, n-pentane, isopentane, isooctane, butane, pentane or heptane.

[0019] In some embodiments of the present invention, the polymer binder includes at least one of a water-based thermoplastic resin, a water-based thermosetting resin and a hot-melt filling resin; and / or the additive includes at least one of a film-forming aid, a curing agent, a dispersant, a leveling agent, a defoaming agent, a filler, a coupling agent, a thickener and a colorant.

[0020] A motor according to an embodiment of the present invention includes the above-mentioned rotor assembly.

[0021] According to the motor of the embodiment of the present invention, a rotor assembly is provided, the rotor core has a magnetic steel slot, the magnetic steel is located in the magnetic steel slot, and of the two surfaces in the thickness direction of the magnetic steel, only the surface facing the radial inner side of the rotor core is provided with an expansion coating, so that the expanded expansion coating fills the gap between the magnetic steel and the magnetic steel slot, ensuring that the magnetic steel is firmly and reliably fixed in the magnetic steel slot, thereby eliminating vibration caused by loosening or displacement of the magnetic steel, thereby effectively improving dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly, thereby achieving the motor being able to maintain excellent stability and durability under long-term and high-load operation conditions.

[0022] A vehicle according to an embodiment of the present invention includes the above-mentioned motor.

[0023] According to the vehicle of the embodiment of the present invention, a motor is provided, the rotor core of the motor has a magnetic steel slot, the magnetic steel is located in the magnetic steel slot, and of the two surfaces in the thickness direction of the magnetic steel, only the surface facing the radial inner side of the rotor core is provided with an expansion coating, so that the expanded expansion coating fills the gap between the magnetic steel and the magnetic steel slot, ensuring that the magnetic steel is firmly and reliably fixed in the magnetic steel slot, thereby eliminating vibration caused by loosening or displacement of the magnetic steel, and further effectively improving dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly, thereby achieving the motor can still maintain excellent stability and durability under long-term and high-load operation conditions, thereby improving the performance of the vehicle.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 is a schematic top view of a magnetic pole portion according to a first embodiment of the present invention;

[0027] Figure 2 is a schematic top view of a magnetic pole portion according to a second embodiment of the present invention;

[0028] Figure 3 is a schematic top view of a magnetic pole portion according to a third embodiment of the present invention;

[0029] Figure 4 is a schematic top view of a magnetic pole portion according to a fourth embodiment of the present invention;

[0030] Figure 5 is a schematic top view of a magnetic pole portion according to a fifth embodiment of the present invention;

[0031] Figure 6is a schematic top view of a magnetic pole portion according to a sixth embodiment of the present invention;

[0032] Figure 7 is a schematic top view of a rotor assembly according to an embodiment of the present invention;

[0033] Figure 8 is a schematic side view of a magnetic steel and an expansion coating according to an embodiment of the present invention;

[0034] Fig. 9 is a tensile force test curve of an expansion coating disposed toward the radial inner surface of the rotor core on one of the two surfaces in the thickness direction of the magnetic steel according to an embodiment of the present invention;

[0035] Fig.10 It is a compression force test curve of the expansion coating provided on the two surfaces in the thickness direction of the magnetic steel toward the radial outer side surface of the rotor core in the prior art.

[0036] Reference numerals:

[0037] 100. Rotor assembly;

[0038] 1. rotor core; 11. magnetic pole portion; 111. magnetic steel slot;

[0039] 2. Magnetic steel;

[0040] 3. Expansion coating. DETAILED DESCRIPTION

[0041] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The rotor assembly 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0045] like Figure 1-Figure 7 As shown, the rotor assembly 100 according to an embodiment of the present invention comprises a rotor core 1 and a magnetic steel 2. The rotor core 1 has a magnetic steel slot 111, the magnetic steel 2 is located in the magnetic steel slot 111, and of the two surfaces of the magnetic steel 2 in the thickness direction, only the surface facing the radial inner side of the rotor core 1 has an expansion coating 3.

[0046] It can be understood that the expansion coating 3 has the characteristics of single high-temperature expansion and solidification of the expansion effect after cooling. Therefore, when the rotor assembly 100 is running at high speed, the expanded expansion coating 3 fills the gap between the magnetic steel 2 and the magnetic steel slot 111, so that the magnetic steel 2 is firmly fixed in the magnetic steel slot 111, thereby eliminating the vibration caused by the loosening or displacement of the magnetic steel 2, thereby effectively improving the dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly 100, thereby achieving that the motor using the rotor assembly 100 can still maintain excellent stability and durability under long-term and high-load operation conditions.

[0047] At the same time, the expanded coating 3 is an elastomer compared to the magnetic steel 2, which can change the contact between the magnetic steel 2 and the magnetic steel slot 111 from hard contact to flexible contact, thereby increasing elastic damping, further improving mechanical vibration and transmission path, and improving the dynamic balance of the rotor assembly 100 from the source, thereby improving vibration noise.

[0048] In addition, the rotor assembly 100 includes a plurality of rotor segments arranged along the axial direction of the rotor assembly 100, each of which has a magnetic steel slot 111 and a magnetic steel 2. Compared with the expansion coating provided on both surfaces in the thickness direction of the magnetic steel, after expansion, the expansion coating is easy to overflow from the magnetic steel slot, resulting in the expansion coating size in the axial direction of the rotor assembly being larger than the size of the rotor segment, thereby affecting the inter-laminated fit of adjacent rotor segments and affecting the dynamic balance. In the present application, only the surface facing the radial inner side of the rotor core 1 among the two surfaces in the thickness direction of the magnetic steel 2 has the expansion coating 3, while achieving the magnetic steel 2 firmly fixed in the magnetic steel slot 111, effectively avoiding the expansion coating 3 from easily overflowing from the magnetic steel slot 111, ensuring the close fit of adjacent rotor segments, and improving the reliability of the rotor assembly 100. Moreover, only the surface facing the radial inner side of the rotor core 1 among the two surfaces in the thickness direction of the magnetic steel 2 has the expansion coating 3, which can effectively reduce the amount of the expansion coating 3 and reduce the cost of the rotor assembly 100.

[0049] When the rotor assembly 100 is running at high speed, the surface of the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner side of the rotor core 1 has an expansion coating 3 that is subjected to tensile force, while the surface of the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner side of the rotor core 1 has an expansion coating 3 that is subjected to compressive force.

[0050] According to the inventor's experiments, Fig. 9 The figure shows the tensile force test curve of the expansion coating 3 disposed on the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner surface of the rotor core 1. When the rotor assembly 100 is running at 18,000 to 30,000 revolutions, the expansion coating 3 on the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner surface of the rotor core 1 is subjected to a tensile force between 30N and 150N. Therefore, it can be seen that the present application can withstand the tensile force when the rotor assembly 100 is running by disposing the expansion coating 3 on the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner surface of the rotor core 1, thereby ensuring the effect of filling the gap between the magnetic steel 2 and the magnetic steel slot 111, so as to improve the dynamic balance;

[0051] like Fig.10 The figure shows the compression force test curve of the expansion coating disposed on the radially outer surface of the rotor core 1 in the two surfaces in the thickness direction of the magnetic steel. The surface in the radially inner side of the rotor core in the two surfaces in the thickness direction of the magnetic steel has the expansion coating subjected to a compression force between 1800N and 2500N. Therefore, it can be seen that the compression force that the expansion coating disposed on the radially outer surface of the rotor core in the two surfaces in the thickness direction of the magnetic steel can withstand is much smaller than the compression force on the expansion coating when the rotor assembly is running. The expansion coating will be flattened, resulting in the failure of the gap fixation, and the magnetic steel cannot be fixed in the magnetic guide slot.

[0052] In summary, the present application ensures that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111 by only providing the expansion coating 3 on the radially inner surface of the rotor core 1 among the two surfaces of the magnetic steel 2 in the thickness direction.

[0053] Optionally, the rotor core 1 uses high magnetic permeability silicon steel sheets, high strength silicon steel sheets or amorphous composite materials. It is understandable that high magnetic permeability silicon steel sheets have higher magnetic permeability, which effectively improves the output power and efficiency of the motor; high strength silicon steel sheets can withstand greater mechanical stress, effectively improving the overall mechanical strength and durability of the motor; amorphous composite materials have high resistivity and light weight, which improves the efficiency of the motor while achieving lightweight. Therefore, the rotor core 1 can use high magnetic permeability silicon steel sheets, high strength silicon steel sheets or amorphous composite materials according to different motor requirements.

[0054] Optionally, the expansion coating 3 is formed on the surface of the magnetic steel 2 by at least one of spraying, printing and painting.

[0055] According to the rotor assembly 100 of the embodiment of the present invention, the rotor core 1 has a magnetic steel slot 111, and the magnetic steel 2 is located in the magnetic steel slot 111. Among the two surfaces of the magnetic steel 2 in the thickness direction, only the surface facing the radial inner side of the rotor core 1 has an expansion coating 3, so that the expanded expansion coating 3 fills the gap between the magnetic steel 2 and the magnetic steel slot 111, ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111, thereby eliminating the vibration caused by the loosening or displacement of the magnetic steel 2, and then effectively improving the dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly 100, so as to achieve that the motor using the rotor assembly 100 can still maintain excellent stability and durability under long-term and high-load operation conditions.

[0056] In some embodiments of the present invention, along the thickness direction of the magnetic steel 2 , the thickness of the expansion coating 3 is 20 μm-350 μm.

[0057] It is understandable that if the thickness of the expansion coating 3 is too thin along the thickness direction of the magnetic steel 2, the expansion coating 3 will not be able to fill the gap between the magnetic steel 2 and the inner wall of the magnetic steel slot 111 after expansion, so that the magnetic steel 2 cannot be firmly fixed, and the magnetic steel 2 will still shake when rotating, resulting in poor dynamic balance; while if the thickness of the expansion coating 3 is too thick along the thickness direction of the magnetic steel 2, it will increase the difficulty of assembling the magnetic steel 2 into the magnetic steel slot 111, increase the material cost, and weaken the magnetic force and thus reduce the pressing force of the magnetic steel 2. If the pressing force is too small, the impact resistance of the magnetic steel 2 will be reduced, and it is easy to shake or fall out of the magnetic steel slot 111. Therefore, along the thickness direction of the magnetic steel 2, by limiting the thickness of the expansion coating 3 to 20μm-350μm, it is effectively ensured that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111, and the dynamic balance is improved.

[0058] It should be noted that, along the thickness direction of the magnetic steel 2, the thickness of the expansion coating 3 can be 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, 220μm, 230μm, 250μm, 270μm, 290μm, 300μm, 320μm or 350μm.

[0059] In some embodiments of the present invention, Figure 8 As shown, when the expansion coating 3 is in the pre-cured state, the ratio of the area of ​​the surface of the magnetic steel 2 having the expansion coating 3 to the total area of ​​the surface of the magnetic steel 2 having the expansion coating 3 is 0.32-0.73.

[0060] It is understandable that if the area of ​​the region where the expansion coating 3 is arranged on the surface of the magnetic steel 2 with the expansion coating 3 accounts for too large a total area of ​​the surface of the magnetic steel 2 with the expansion coating 3, the expanded expansion coating 3 will overflow from the magnetic steel slot 111 after expansion; and if the area of ​​the region where the expansion coating 3 is arranged on the surface of the magnetic steel 2 with the expansion coating 3 accounts for too small a total area of ​​the surface of the magnetic steel 2 with the expansion coating 3, the pressing force of the magnetic steel 2 will be reduced, and it is impossible to ensure that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111. Therefore, by limiting the ratio of the area of ​​the region where the expansion coating 3 is arranged on the surface of the magnetic steel 2 with the expansion coating 3 to the total area of ​​the surface of the magnetic steel 2 with the expansion coating 3 to 0.32-0.73, while ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111, the expanded expansion coating 3 is effectively prevented from overflowing from the magnetic steel slot 111 after expansion, thereby improving the reliability of the rotor assembly 100.

[0061] It should be noted that, when the expansion coating 3 is in the pre-cured state, the ratio of the area of ​​the surface of the magnetic steel 2 having the expansion coating 3 to the total area of ​​the surface of the magnetic steel 2 having the expansion coating 3 can be 0.32, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7 or 0.73.

[0062] In some embodiments of the present invention, Figure 8As shown, the expansion coating 3 is located in the middle area of ​​the two surfaces in the thickness direction of the magnetic steel 2, which are facing the radial inner side of the rotor core 1. It can be understood that the rotor core 1 is composed of a plurality of rotor punchings stacked along the axial direction of the rotor assembly 100, and the expansion coating 3 is located in the middle area of ​​the two surfaces in the thickness direction of the magnetic steel 2, which are facing the radial inner side of the rotor core 1, so that the expansion coating 3 after expansion can fill the gap between the uppermost and lowermost rotor punchings and the magnetic steel 2 in the axial direction of the rotor assembly 100, further ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111.

[0063] In some embodiments of the present invention, the expansion coating 3 has a pre-curing state and a curing state. In the pre-curing state, the expansion coating 3 is spaced apart from the inner wall of the magnetic steel slot 111, and in the curing state, the expansion coating 3 is in contact with the inner wall of the magnetic steel slot 111. It can be understood that in the pre-curing state, the expansion coating 3 is fixed on the surface of the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner side of the rotor core 1, and the expansion coating 3 is spaced apart from the inner wall of the magnetic steel slot 111, so that the expansion coating 3 can be assembled into the corresponding magnetic steel slot 111 with the magnetic steel 2. At the same time, in the curing stage, the expansion coating 3 expands at high temperature and the expansion effect is cured after cooling, so that the expanded expansion coating 3 is in contact with the inner wall of the magnetic steel slot 111, filling the gap between the magnetic steel 2 and the magnetic steel slot 111, thereby ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111.

[0064] In some embodiments of the present invention, along the thickness direction of the magnetic steel 2, the thickness of the expansion coating 3 in the solidified state is more than four times the thickness of the expansion coating 3 in the pre-solidified state. Thus, through such an arrangement, it is ensured that the expansion coating 3 after expansion fills the gap between the magnetic steel 2 and the magnetic steel slot 111, and further ensures that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111.

[0065] In some embodiments of the present invention, Figure 7 As shown, the rotor core 1 includes a plurality of magnetic poles 11 arranged along the circumferential direction of the rotor core 1, each magnetic pole 11 has magnetic steel slots 111 of the same number and shape, and the magnetic steels 2 are multiple and correspond to the multiple magnetic steel slots 111. Thus, such an arrangement ensures that the magnetic field strength generated by each magnetic pole 11 is consistent, thereby improving the operating efficiency and stability of the rotor assembly 100 and reducing the vibration and noise caused by the uneven magnetic field. At the same time, the magnetic steel slot 111 of each magnetic pole 11 has a magnetic steel 2, and of the two surfaces of the magnetic steel 2 in the thickness direction, only the surface facing the radial inner side of the rotor core 1 has an expansion coating 3, so as to ensure that each magnetic steel 2 is firmly and reliably fixed in the corresponding magnetic steel slot 111.

[0066] Specifically, the magnetic pole portions 11 are multiple and an even number, for example, the number of the magnetic pole portions 11 is four, six, eight, ten or twelve. It can be understood that the magnetic pole portions 11 appear in pairs. For example, when the number of the magnetic pole portions 11 is six, the number of pole pairs P of the rotor core 1 is three pairs (refer to Figure 7 ), when the number of magnetic pole portions 11 is ten, the number of pole pairs P of the rotor core 1 is five pairs.

[0067] In some embodiments of the present invention, the ratio of the number of magnetic pole portions 11 to the number of magnetic steel slots 111 on each magnetic pole portion 11 is 0.5-5.33, wherein the number of magnetic pole portions 11 is at least 4, and the number of magnetic steel slots 111 is at least 1. Thus, through such a configuration, the rotor assembly 100 can change the number of magnetic pole portions 11 and magnetic steel slots 111 according to different application scenarios and requirements to meet different performance requirements.

[0068] For example, when the number of magnetic pole portions 11 is 16 and the number of magnetic steel slots 111 on each magnetic pole portion 11 is 3, the ratio of the number of magnetic pole portions 11 to the number of magnetic steel slots 111 on each magnetic pole portion 11 is 5.33; or, when the number of magnetic pole portions 11 is 4 and the number of magnetic steel slots 111 on each magnetic pole portion 11 is 8, the ratio of the number of magnetic pole portions 11 to the number of magnetic steel slots 111 on each magnetic pole portion 11 is 0.5; or, when the number of magnetic pole portions 11 is 6 and the number of magnetic steel slots 111 on each magnetic pole portion 11 is 3, the ratio of the number of magnetic pole portions 11 to the number of magnetic steel slots 111 on each magnetic pole portion 11 is 2 (refer to Figure 7 ).

[0069] In some embodiments of the present invention, Figure 1-Figure 7 As shown, in the cross section perpendicular to the axis of the rotor core 1, the shape of the plurality of magnetic steel slots 111 can be at least one of a "-" shape, a "V" shape, a "U" shape and a "W" shape. Thus, through such an arrangement, the rotor assembly 100 can select the shape of the magnetic steel slots 111 according to different application scenarios and needs to meet different performance requirements. At the same time, of the two surfaces in the thickness direction of the magnetic steel 2 in the magnetic steel slot 111 of each magnetic pole portion 11, only the surface facing the radial inner side of the rotor core 1 has an expansion coating 3 to ensure that each magnetic steel 2 is firmly and reliably fixed in the corresponding magnetic steel slot 111.

[0070] For example, Figure 1 As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1, the shape of the magnetic steel slot 111 is a "-" shape plus a "V" shape; or, Figure 2 As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1, the shape of the magnetic steel slot 111 is a "-" shape plus a "U" shape; or, Figure 3As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1, the shape of the magnetic steel slot 111 is a "V" shape plus a "V" shape; or, Figure 4 As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1, the shape of the magnetic steel slot 111 is a "V" shape plus a "V" shape plus a "V" shape; or, Figure 5 As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1, the shape of the magnetic steel slot 111 is a "U" shape plus a "U" shape; or, Figure 6 As shown, in a cross section of one of the magnetic pole portions 11 perpendicular to the axis of the rotor core 1 , the shape of the magnetic steel slot 111 is a “U” shape plus a “V” shape.

[0071] In some embodiments of the present invention, the expansion coating 3 includes 2%-35% of expansion agent, 20%-65% of polymer binder, 2%-20% of additives and the balance of diluents by weight percentage. It can be understood that the expansion agent is the main component to achieve the characteristics of the expansion coating 3 having a single high-temperature expansion and the expansion effect solidification after cooling, the polymer binder is used to achieve the fixation of the expansion agent and other additives, and the additives can further improve the comprehensive performance of the expansion coating 3, so that the expansion coating 3 is suitable for various complex environments. Therefore, by setting that the expansion coating 3 includes 2%-35% of expansion agent, 20%-65% of polymer binder, 2%-20% of additives and the balance of diluents by weight percentage, the expansion coating 3 can be achieved to have the characteristics of a single high-temperature expansion and the expansion effect solidification after cooling, so as to ensure that the expanded expansion coating 3 fills the gap between the magnetic steel 2 and the magnetic steel slot 111.

[0072] It should be noted that the diluent is water.

[0073] In some embodiments of the present invention, the expansion agent is expandable microspheres, an inorganic foaming agent or an organic foaming agent.

[0074] It can be understood that the expanded microsphere is a thermoplastic hollow polymer microsphere, which is composed of a thermoplastic polymer shell and an enclosed liquid alkane gas. When heated, the gas pressure in the shell increases and the thermoplastic shell softens, thereby significantly increasing the volume of the expanded microsphere. When cooled, the shell of the expanded microsphere hardens again and the volume is fixed, thereby achieving the characteristics of the expanded coating 3 having a single high-temperature expansion and the expansion effect solidifying after cooling.

[0075] Inorganic foaming agents produce chemical reactions at high temperatures to release gases, which gather inside the material, causing the volume to expand rapidly, thereby achieving the characteristics of the expansion coating 3 having a single high-temperature expansion and the expansion effect solidifying after cooling. In addition, inorganic foaming agents have the advantages of safety, endothermic decomposition, and good nucleation effect.

[0076] The organic foaming agent produces a chemical reaction at high temperature to release gas, and the gas gathers inside the material, causing the volume to expand rapidly, thereby achieving the characteristics of the expansion coating 3 having a single high-temperature expansion and the expansion effect solidifying after cooling. In addition, the organic foaming agent can quickly decompose and release gas after being heated, and has a high foaming rate and less residue after foaming, thereby achieving a good foaming effect.

[0077] Therefore, the expansion agent can be expansion microspheres, inorganic foaming agents or organic foaming agents according to different needs.

[0078] In some embodiments of the present invention, the expanded microspheres include an outer shell and an inner core located in the outer shell, the outer shell is a thermoplastic polymer, and the boiling point of the inner core is 60°-170°. It can be understood that the expansion coating 3 has a pre-cured state and a cured state. In the pre-cured state, the expansion coating 3 is fixed on the surface of the two surfaces in the thickness direction of the magnetic steel 2 facing the radial inner side of the rotor core 1. Therefore, by limiting the boiling point of the inner core to a minimum of 60°, the expansion coating 3 is fixed on the surface of the magnetic steel 2 without expansion, so that the expansion coating 3 can be assembled into the corresponding magnetic steel slot 111 along with the magnetic steel 2.

[0079] During the curing stage and when heated, the inner core expands and the thermoplastic shell softens, thereby significantly increasing the volume of the expanded microspheres. When cooled, the shell of the expanded microspheres hardens again and the volume is fixed, thereby achieving the characteristics of the expansion coating 3 having a single high-temperature expansion and the expansion effect solidifying after cooling, so that the expanded expansion coating 3 abuts against the inner wall of the magnetic steel slot 111. At the same time, it is necessary to limit the boiling point of the inner core to no more than the maximum operating temperature of the rotor core 1 and the magnetic steel 2 itself to avoid failure of the rotor core 1 and the magnetic steel 2 due to excessively high heating expansion temperature. Therefore, the boiling point of the inner core is limited to a maximum of 170°.

[0080] In some embodiments of the present invention, the inner core is a hydrocarbon, and includes at least one of ethane, propane, isobutane, n-pentane, isopentane, isooctane, butane, pentane or heptane. Thus, when the expandable microspheres are heated, the hydrocarbon begins to vaporize through such a limitation, and a large amount of gas is generated in the shell, thereby achieving the expansion of the expandable coating 3.

[0081] In some embodiments of the present invention, the polymer binder includes at least one of a water-based thermoplastic resin, a water-based thermosetting resin, and a hot-melt filling resin. It is understood that the water-based thermoplastic resin has the properties of softening by heat and hardening by cooling, the water-based thermosetting resin has high strength and adhesion after curing, and the hot-melt filling resin can be quickly cured after heating and can fill the gap. Therefore, the polymer binder can be selected according to the needs of the expansion coating 3, including at least one of a water-based thermoplastic resin, a water-based thermosetting resin, and a hot-melt filling resin.

[0082] In some embodiments of the present invention, the additive includes at least one of a film-forming aid, a curing agent, a dispersant, a leveling agent, a defoaming agent, a filler, a coupling agent, a thickener, and a colorant. It is understood that the film-forming aid can promote the plastic flow and elastic deformation of the polymer compound to improve the agglomeration performance, the curing agent accelerates the curing process of the expansion coating 3, the dispersant can reduce the viscosity of the coating, the leveling agent can improve the flatness of the expansion coating 3, the defoaming agent is used to eliminate the foam generated during the production and construction of the expansion coating 3, the filler is used to increase the thickness and flexibility of the expansion coating 3, the coupling agent can improve the adhesion, durability and toughness of the expansion coating 3, the thickener can increase the viscosity of the expansion coating 3, and the colorant can change the color effect of the expansion coating 3. Therefore, the additive can be selected according to the needs of the expansion coating 3, including at least one of a film-forming aid, a curing agent, a dispersant, a leveling agent, a defoaming agent, a filler, a coupling agent, a thickener, and a colorant.

[0083] In summary, by limiting the expansion agent, polymer adhesive and additives constituting the expansion coating 3, the expansion multiple and temperature of the expansion coating 3 can meet the required requirements. Compared with the low expansion coefficient materials in the prior art, it can not only simplify the assembly process, but also avoid assembly tolerances due to excessive thickness of the expansion coating 3, and effectively reduce the dosage, which is conducive to cost reduction.

[0084] The following describes a motor according to an embodiment of the present invention.

[0085] The motor according to the embodiment of the present invention includes a rotor assembly 100 .

[0086] According to the motor of the embodiment of the present invention, a rotor assembly 100 is provided, the rotor core 1 has a magnetic steel slot 111, the magnetic steel 2 is located in the magnetic steel slot 111, and the expansion coating 3 is provided on only the surface facing the radial inner side of the rotor core 1 of the two surfaces in the thickness direction of the magnetic steel 2, so that the expanded expansion coating 3 fills the gap between the magnetic steel 2 and the magnetic steel slot 111, ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111, thereby eliminating the vibration caused by the loosening or displacement of the magnetic steel 2, thereby effectively improving the dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly 100, thereby achieving the motor can still maintain excellent stability and durability under long-term and high-load operation conditions.

[0087] Next, a vehicle according to an embodiment of the present invention will be described.

[0088] A vehicle according to an embodiment of the present invention includes a motor.

[0089] According to the vehicle of the embodiment of the present invention, a motor is provided, the rotor core 1 of the motor has a magnetic steel slot 111, the magnetic steel 2 is located in the magnetic steel slot 111, and the expansion coating 3 is provided on only the surface facing the radial inner side of the rotor core 1 of the two surfaces in the thickness direction of the magnetic steel 2, so that the expanded expansion coating 3 fills the gap between the magnetic steel 2 and the magnetic steel slot 111, ensuring that the magnetic steel 2 is firmly and reliably fixed in the magnetic steel slot 111, thereby eliminating the vibration caused by the loosening or displacement of the magnetic steel 2, and then effectively improving the dynamic balance, reducing noise and vibration, and improving the reliability of the rotor assembly 100, so as to achieve that the motor can still maintain excellent stability and durability under long-term and high-load operation conditions, thereby improving the performance of the vehicle.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A rotor assembly, characterized in that: include: A rotor core (1), wherein the rotor core (1) has a magnetic steel slot (111); A magnetic steel (2), the magnetic steel (2) being located in the magnetic steel slot (111), and having an expansion coating (3) on only the surface facing the radial inner side of the rotor core (1) of the two surfaces in the thickness direction of the magnetic steel (2).

2. The rotor assembly according to claim 1, characterized in that: Along the thickness direction of the magnetic steel (2), the thickness of the expansion coating (3) is 20 μm-350 μm.

3. The rotor assembly according to claim 1, characterized in that: When the expansion coating (3) is in a pre-cured state, the ratio of the area of ​​the surface of the magnetic steel (2) having the expansion coating (3) where the expansion coating (3) is arranged to the total area of ​​the surface of the magnetic steel (2) having the expansion coating (3) is 0.32-0.

73.

4. The rotor assembly according to claim 1, characterized in that: The expansion coating (3) is located in the middle area of ​​the surface facing the radial inner side of the rotor core (1) between the two surfaces in the thickness direction of the magnetic steel (2).

5. The rotor assembly according to claim 1, characterized in that: The expansion coating (3) has a pre-curing state and a curing state. In the pre-curing state, the expansion coating (3) is separated from the inner wall of the magnetic steel groove (111). In the curing state, the expansion coating (3) abuts against the inner wall of the magnetic steel groove (111).

6. The rotor assembly according to claim 5, characterized in that Along the thickness direction of the magnetic steel (2), the thickness of the expansion coating (3) in the cured state is more than four times the thickness of the expansion coating (3) in the pre-cured state.

7. The rotor assembly according to claim 1, characterized in that The rotor core (1) comprises a plurality of magnetic pole portions (11) arranged in a circumferential direction of the rotor core (1), each of the magnetic pole portions (11) having magnetic steel slots (111) of the same number and shape, and the magnetic steel (2) is a plurality of magnetic steel slots (111) corresponding one-to-one to the plurality of magnetic steel slots (111).

8. The rotor assembly according to claim 7, characterized in that The ratio of the number of the magnetic pole portions (11) to the number of the magnetic steel slots (111) on each of the magnetic pole portions (11) is 0.5-5.33, wherein the number of the magnetic pole portions (11) is at least 4 and the number of the magnetic steel slots (111) is at least 1.

9. The rotor assembly according to claim 1, characterized in that: The expansion coating (3) comprises, by weight percentage, 2%-35% of an expansion agent, 20%-65% of a polymer binder, 2%-20% of an additive, and the balance of a diluent.

10. The rotor assembly according to claim 9, characterized in that The expansion agent is expansion microspheres, inorganic foaming agent or organic foaming agent.

11. The rotor assembly according to claim 10, characterized in that The expanded microsphere comprises an outer shell and an inner core located in the outer shell, the outer shell is a thermoplastic polymer, and the boiling point of the inner core is 60°-170°.

12. The rotor assembly according to claim 11, characterized in that The inner core is a hydrocarbon and includes at least one of ethane, propane, isobutane, n-pentane, isopentane, isooctane, butane, pentane or heptane.

13. The rotor assembly according to claim 9, characterized in that The polymer binder includes at least one of a water-based thermoplastic resin, a water-based thermosetting resin, and a hot-melt filling resin; And / or, the additive includes at least one of a film-forming aid, a curing agent, a dispersant, a leveling agent, a defoaming agent, a filler, a coupling agent, a thickener and a colorant.

14. A motor, characterized in that: Comprising a rotor assembly (100) according to any one of claims 1-13.

15. A vehicle, characterized in that: Comprising an electric machine according to claim 14.

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