Rotor core, motor rotor, motor, and automobile

Abstract

The present application provides a rotor core (1), a motor rotor, a motor, and an automobile. A rotor shaft cavity (11), a plurality of first cooling channels (12), and a plurality of first rotor slots (13) are formed in the rotor core (1); the rotor shaft cavity (11), the first cooling channels (12), and the first rotor slots (13) pass through the rotor core (1) in the axial direction of the rotor core (1); the plurality of first rotor slots (13) and the plurality of first cooling channels (12) are distributed at intervals in the circumferential direction of the rotor core (1), separately; all the first cooling channels (12) are located between the rotor shaft cavity (11) and the first rotor slots (13); and all the first rotor slots (13) are communicated with the first cooling channels (12). By means of the arrangement, a cooling medium flowing in the first cooling channels is in direct contact with permanent magnets in the first rotor slots for heat exchange so as to cool the permanent magnets, thereby preventing the risk of demagnetization of the permanent magnets caused by excessive temperature.

Description

Rotor core, motor rotor, motor and automobile

[0001] This application claims priority to Chinese Patent Application No. CN202410577897.8, filed on May 10, 2024, entitled "Rotor Core, Motor Rotor, Motor and Automobile", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of motor technology, and in particular to a rotor core, a motor rotor, a motor, and an automobile. Background Technology

[0003] With the rapid development of electric vehicles, the requirements for the speed and power density of automotive drive motors are becoming increasingly stringent. Traditional built-in permanent magnet synchronous motors experience increased rotor losses and severe heat generation at high speeds due to deep magnet weakening, necessitating cooling to achieve high power density.

[0004] In motors using related technologies, the cooling medium for the rotor typically comes from the shaft. The heat source is close to the rotor surface, while the cooling medium is far from the heat source, resulting in poor cooling performance. This can easily increase the risk of demagnetization of the permanent magnets and affect the motor's performance. Summary of the Invention

[0005] This application provides a rotor core, a motor rotor, a motor, and an automobile, which can improve the cooling effect on the motor rotor.

[0006] Specifically, the following technical solutions are included:

[0007] In a first aspect, embodiments of this application provide a rotor core, the rotor core having a rotor shaft cavity, a plurality of first cooling channels and a plurality of first rotor slots, the rotor shaft cavity, the first cooling channels and the first rotor slots all penetrating the rotor core along the axial direction of the rotor core, the plurality of first rotor slots and the plurality of first cooling channels being distributed at intervals along the circumference of the rotor core, each of the first cooling channels being located between the rotor shaft cavity and the first rotor slot, and each of the first rotor slots being connected to the first cooling channel.

[0008] This configuration allows the coolant flowing in the first cooling channel to directly contact and exchange heat with the first permanent magnet in the first rotor slot, thereby cooling the first permanent magnet and preventing it from demagnetizing due to excessive temperature, which helps improve the performance of the motor.

[0009] In an optional embodiment, the rotor core includes first and second magnetic poles of opposite polarity that are alternately distributed along its circumference, and a first rotor slot is provided between every two adjacent first and second magnetic poles.

[0010] The rotor core is also provided with a plurality of spaced second rotor slots, and each of the first magnetic poles and the second magnetic poles is provided with two second rotor slots arranged in a V-shape.

[0011] This configuration makes full use of the rotor core space, improves the space utilization rate of the rotor core, and makes it easier to achieve high power density in the motor. At the same time, it improves the air gap magnetic flux density waveform, which helps to improve motor performance.

[0012] In an optional embodiment, a connection is constructed between every two adjacent first cooling channels, and each connection is located in the first magnetic pole, or each connection is located in the second magnetic pole.

[0013] This design avoids the formation of magnetic paths between adjacent first and second magnetic poles, which can cause magnetic leakage. It reduces magnetic leakage in the motor rotor, prevents motor efficiency from decreasing and temperature from rising too high, and helps improve the stability and reliability of the motor.

[0014] In an optional embodiment, air slots are provided at both ends of each of the second rotor slots in the extension direction.

[0015] This configuration improves the magnetic circuit structure and reduces the leakage flux formed by the second permanent magnet in the second rotor slot.

[0016] In an optional embodiment, the widths of the two air slots in each of the second rotor slots gradually decrease toward the side opposite to each other.

[0017] This design improves the magnetic circuit structure and also limits the movement of the second permanent magnet in the second rotor slot, preventing it from moving along the extension direction of the second rotor slot and affecting its installation strength.

[0018] In an optional embodiment, each of the first magnetic pole and the second magnetic pole is provided with a second cooling channel, the second cooling channel passing through the rotor core along the axial direction of the rotor core, the second cooling channel being disposed on the side of the second rotor slot away from the rotor shaft cavity and located between two adjacent second rotor slots.

[0019] With this configuration, the cooling medium flows axially along the rotor core in the second cooling channel to cool the rotor core and simultaneously cool the second permanent magnet in the second rotor slot, preventing the risk of demagnetization of the second permanent magnet due to excessive temperature.

[0020] In an optional embodiment, the rotor core is further provided with a third cooling channel communicating with the first cooling channel. The third cooling channel is located on the side of the first cooling channel near the second rotor slot, and the sidewall of the third cooling channel protrudes outward relative to the sidewall of the first cooling channel toward the side where the second rotor slot is located.

[0021] This design not only cools the rotor core and the second permanent magnet, but also features a simple and reliable structure that is easy to manufacture.

[0022] Secondly, embodiments of this application provide a motor rotor, the motor rotor including a rotor shaft, a first permanent magnet and a rotor core provided in any embodiment of the first aspect, the rotor shaft being inserted into a rotor shaft cavity, and the first permanent magnet being embedded in a first rotor slot.

[0023] Thirdly, embodiments of this application also provide an electric motor, including the motor rotor provided in the second aspect embodiment.

[0024] Fourthly, embodiments of this application also provide an automobile, including the motor provided in the third aspect embodiment.

[0025] The beneficial effects of the technical solution provided in this application embodiment include at least the following: by setting each first cooling channel to be located between the rotor shaft cavity and the first rotor slot, and each first rotor slot to be connected to the first cooling channel, the cooling medium flowing in the first cooling channel directly contacts the permanent magnet in the first rotor slot and exchanges heat, thereby cooling the permanent magnet and preventing the permanent magnet from demagnetizing due to excessive temperature, which helps to improve the performance of the motor. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 is a schematic diagram of the rotor core structure provided in some embodiments of this application;

[0028] Figure 2 is a schematic diagram of the rotor core provided in some other embodiments of this application.

[0029] The reference numerals in the figure are as follows: 1-Rotor core; 11-Rotor shaft cavity; 12-First cooling channel; 13-First rotor slot; 14-First magnetic pole; 15-Second magnetic pole; 16-Second rotor slot; 161-Air slot; 17-Second cooling channel; 18-Third cooling channel; 19-Connecting part; 100-First permanent magnet; 200-Second permanent magnet. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0031] The directional terms used in the embodiments of this application, such as "up," "down," and "side," are generally based on the relative positions shown in Figure 1. These directional terms are used merely to more clearly describe the relationships between structures, not to describe absolute positions. When the product is placed in different orientations, the positions may change; for example, "up" and "down" may be interchanged.

[0032] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art.

[0033] To make the technical solutions and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0034] As mentioned in the background section, in motors of the relevant technology, the permanent magnets of the rotor may demagnetize due to long-term operation in a high-temperature environment. Therefore, it is necessary to adopt forced heat dissipation measures to remove the heat from the permanent magnet synchronous motor.

[0035] To improve motor performance, related technologies provide cooling systems for cooling rotors. In these systems, the cooling medium for the motor rotor typically comes from the rotor shaft. The cooling medium is introduced from the rotor shaft to cool the rotor. However, the heat source is close to the rotor surface, while the cooling medium is far from the heat source, resulting in poor cooling effect. This can easily increase the risk of demagnetization of permanent magnets and affect motor performance.

[0036] According to various embodiments of this application, a rotor core 1 is provided.

[0037] As shown in Figures 1 and 2, the rotor core 1 provided in this embodiment of the application has a rotor shaft cavity 11, a plurality of first cooling channels 12 and a plurality of first rotor slots 13. The rotor shaft cavity 11, the first cooling channels 12 and the first rotor slots 13 all penetrate the rotor core 1 along the axial direction of the rotor core 1. The plurality of first rotor slots 13 and the plurality of first cooling channels 12 are distributed at intervals along the circumference of the rotor core 1. Each first cooling channel 12 is located between the rotor shaft cavity 11 and the first rotor slot 13, and each first rotor slot 13 is connected to the first cooling channel 12.

[0038] The rotor shaft cavity 11 of the rotor core 1 is used to accommodate the rotor shaft, the first cooling channel 12 is used to supply cooling medium such as cooling oil, and the first rotor slot 13 is used to accommodate the first permanent magnet 100.

[0039] In some embodiments, the rotor core 1 is cylindrical, the central axis of the rotor shaft cavity 11 is collinear with the central axis of the rotor core 1, the first rotor slot 13 is located on the side of the outer wall of the rotor core 1, and the first cooling channel 12 is located at the end of the first rotor slot 13 near the rotor shaft cavity 11.

[0040] In some embodiments, as shown in FIG1, the first rotor slot 13 extends radially along the rotor core 1, and the cross-sectional profile of the first rotor slot 13 is approximately rectangular. The embedded first permanent magnet 100 is embedded in the first rotor slot 13, and the shape and size of the first rotor slot 13 are adapted to the shape and size of the first permanent magnet 100.

[0041] It is understandable that the aforementioned "cross section" is a cross section obtained by cutting with a plane perpendicular to the central axis of the rotor core 1.

[0042] The shape of the first rotor slot 13 is adapted to the shape of the first permanent magnet 100, meaning that the shape of the first rotor slot 13 is the same as the shape of the first permanent magnet 100. For example, the first rotor slot 13 is a rectangular slot and the first permanent magnet 100 is a rectangular block. The size of the first rotor slot 13 is adapted to the size of the first permanent magnet 100, meaning that the size of the first rotor slot 13 is the same as the size of the first permanent magnet 100, or the size of the first rotor slot 13 is slightly larger than the size of the first permanent magnet 100, so that the first permanent magnet 100 can be embedded in the first rotor slot 13.

[0043] Furthermore, multiple first rotor slots 13 are evenly distributed around the central axis of the rotor core 1, as shown in Figures 1 and 2. There are a total of eight first rotor slots 13, which are evenly spaced around the circumference of the rotor core 1.

[0044] By setting the first rotor slot 13 to extend radially along the rotor core 1, the magnetic flux in the rotor core 1 can be strengthened, which helps to improve the power density of the motor.

[0045] In some embodiments, the cross-sectional profile of the first cooling channel 12 is arc-shaped, and a plurality of first cooling channels 12 are distributed around the central axis of the rotor core 1 along the circumference of the rotor core 1 to form a near-circular annular groove.

[0046] Each first cooling channel 12 is connected to at least one first rotor slot 13. For example, as shown in Figures 1 and 2, there are four first cooling channels 12 in total, and each first cooling channel 12 is connected to two first rotor slots 13. This ensures that each first rotor slot 13 is connected to the first cooling channel 12, and also allows the first permanent magnet 100 in the two first rotor slots 13 to be cooled simultaneously when the cooling medium is introduced into each first cooling channel 12.

[0047] When the cooling medium is introduced into the first cooling channel 12, the cooling medium in the first cooling channel 12 flows along the axial direction of the rotor core 1 and directly contacts the end face of the first permanent magnet 100 near the rotor shaft cavity 11, thereby directly exchanging heat with the first permanent magnet 100 and carrying away the heat generated on the rotor core 1 and the first permanent magnet 100. Compared with the cooling system in related technologies, it has a better cooling effect and is conducive to solving the rotor heating problem caused by high speed and high power density of motor.

[0048] The rotor core 1 provided in this application embodiment is configured such that each first cooling channel 12 is located between the rotor shaft cavity 11 and the first rotor slot 13, and each first rotor slot 13 is connected to the first cooling channel 12. This allows the coolant flowing in the first cooling channel 12 to directly contact and exchange heat with the first permanent magnet 100 in the first rotor slot 13, thereby cooling the first permanent magnet 100 and preventing the risk of demagnetization due to excessive temperature. This helps to improve the performance of the motor.

[0049] In a further embodiment, the rotor core 1 includes first magnetic poles 14 and second magnetic poles 15 of opposite polarity that are alternately distributed along its circumference, and a first rotor slot 13 is provided between every two adjacent first magnetic poles 14 and second magnetic poles 15; the rotor core 1 also has a plurality of spaced second rotor slots 16, and each magnetic pole has two second rotor slots 16 arranged in a V-shape.

[0050] In some embodiments, the rotor core 1 has eight magnetic poles, with four first magnetic poles 14 and four second magnetic poles 15. The first magnetic pole 14 is the N pole and the second magnetic pole 15 is the S pole. The first magnetic poles 14 and the second magnetic poles 15 are evenly distributed alternately along the circumference of the rotor core 1, and each first rotor slot 13 is located between adjacent first magnetic poles 14 and second magnetic poles 15.

[0051] In some embodiments, as shown in Figures 1 and 2, each first magnetic pole 14 and each second magnetic pole 15 are provided with two second rotor slots 16. The two second rotor slots 16 are inclined to each other, and the distance between the two second rotor slots 16 gradually increases from the inside to the outside along the radial direction of the rotor core 1. The two second rotor slots 16 form a slot group arranged in a "V" shape. The eight slot groups are evenly distributed along the circumference of the rotor core 1, so that each magnetic pole has a set of slot groups, and each slot group is located between two adjacent first rotor slots 13.

[0052] Specifically, a second permanent magnet 200 is embedded in the second rotor slot 16. The rotor core 1 has both a first rotor slot 13 extending radially and a second rotor slot 16 arranged in a "V" shape. This makes full use of the space of the rotor core 1, improves the space utilization rate of the rotor core 1, and makes it easier to achieve high power density of the motor. At the same time, it improves the air gap magnetic flux density waveform, which helps to improve the performance of the motor.

[0053] In a further embodiment, a connecting portion 19 is constructed between every two adjacent first cooling channels 12, and each connecting portion 19 is located in a first magnetic pole 14, or each connecting portion 19 is located in a second magnetic pole 15.

[0054] Specifically, the interval between every two adjacent first cooling channels 12 in the rotor core 1 constitutes a connection portion 19. All connection portions 19 are located in the same magnetic pole. For example, all connection portions 19 are located in the second magnetic pole 15, or all connection portions 19 are located in the first magnetic pole 14.

[0055] For example, as shown in Figures 1 and 2, there are four first cooling channels 12. The four first cooling channels 12 are evenly distributed around the central axis of the rotor core 1 along the circumference of the rotor core 1, forming four connecting parts 19. Each second magnetic pole 15 has a connecting part 19.

[0056] In this embodiment, by setting each connecting part 19 to be located in the first magnetic pole 14 or each connecting part 19 to be located in the second magnetic pole 15, magnetic path is avoided between adjacent first magnetic poles 14 and second magnetic poles 15, which would cause magnetic leakage. This reduces the magnetic leakage of the motor rotor, avoids motor efficiency decline and excessive temperature rise, and helps to improve the stability and reliability of the motor.

[0057] In a further embodiment, air slots 161 are provided at both ends of each second rotor slot 16 in the extending direction.

[0058] As shown in Figures 1 and 2, each of the second rotor slots 16 has an air slot 161 at both ends, and the air slot 161 passes through the rotor core 1 along the axial direction of the rotor core 1.

[0059] In this embodiment, by providing an air slot 161, the magnetic circuit structure can be improved, and the leakage flux formed by the second permanent magnet 200 in the second rotor slot 16 can be reduced.

[0060] Furthermore, the width of the two air slots 161 of each second rotor slot 16 gradually decreases toward the side away from each other.

[0061] For example, the air slots 161 are semi-circular, triangular, semi-elliptical, etc., and the width of each air slot 161 gradually decreases along the direction from the center of the second rotor slot 16 to the end.

[0062] As shown in Figures 1 and 2, the cross-sectional profile of the air slot 161 is triangular. Each air slot 161 gradually narrows towards the direction away from the opposite side of the air slot 161. While improving the magnetic circuit structure, it also plays a certain limiting role for the second permanent magnet 200 in the second rotor slot 16, preventing the second permanent magnet 200 from moving along the extension direction of the second rotor slot 16 and affecting the installation strength of the second permanent magnet 200.

[0063] In one embodiment, each first magnetic pole 14 and second magnetic pole 15 is provided with a second cooling channel 17. The second cooling channel 17 extends through the rotor core 1 along the axial direction of the rotor core 1. The second cooling channel 17 is located on the side of the second rotor slot 16 away from the rotor shaft cavity 11 and between two adjacent second rotor slots 16.

[0064] As shown in Figure 1, there are eight second cooling channels 17, with one second cooling channel 17 in each of the first magnetic poles 14 and the second magnetic poles 15.

[0065] The second cooling channel 17 is located near the outer wall of the rotor core 1 and between the two second rotor slots 16 of the magnetic pole. The second cooling channel 17 is used to supply the flow of cooling medium. The cooling medium flows along the axial direction of the rotor core 1 in the second cooling channel 17 to cool the rotor core 1 and indirectly cool the second permanent magnet 200 in the second rotor slot 16 to prevent the second permanent magnet 200 from demagnetizing due to excessive temperature.

[0066] Optionally, the second cooling channel 17 is connected to the two second rotor slots 16 in the magnetic pole respectively, so that the cooling medium flowing in the second cooling channel 17 can directly contact the second permanent magnet 200 in the second rotor slot 16, thereby improving the cooling effect on the second permanent magnet 200.

[0067] Optionally, each of the first magnetic pole 14 and the second magnetic pole 15 is provided with a plurality of second cooling channels 17 to improve the cooling effect on the rotor core 1 and the second permanent magnet 200.

[0068] Optionally, the cross-sectional profile of the second cooling channel 17 may be circular, elliptical, rectangular, or other polygonal, and this application does not impose specific limitations. For example, as shown in FIG1, the cross-sectional profile of the second cooling channel 17 is circular.

[0069] Optionally, the second cooling channel 17 is disposed on the side of the two second rotor slots 16 in the magnetic pole near the rotor shaft cavity 11.

[0070] In one embodiment, the rotor core 1 is further provided with a third cooling channel 18 that communicates with the first cooling channel 12. The third cooling channel 18 is located on the side of the first cooling channel 12 that is close to the second rotor slot 16, and the sidewall of the third cooling channel 18 protrudes outward relative to the sidewall of the first cooling channel 12 toward the side where the second rotor slot 16 is located.

[0071] As shown in Figure 2, the third cooling channel 18 is located in the middle of the first cooling channel 12 and between two adjacent first rotor slots 13. The third cooling channel 18 protrudes towards the two second rotor slots 16 of the magnetic pole. The cross-sectional outline of the third cooling channel 18 can be fan-shaped, rectangular, triangular, circular, elliptical or other shapes. This application does not make specific limitations. For example, as shown in Figure 2, the sidewall of the third cooling channel 18 is arc-shaped and protrudes towards the side where the second rotor slot 16 is located.

[0072] The third cooling channel 18 is used to supply the flow of cooling medium. The cooling medium flows along the axial direction of the rotor core 1 in the third cooling channel 18 to cool the rotor core 1. At the same time, it indirectly cools the second permanent magnet 200 in the second rotor slot 16 to prevent the second permanent magnet 200 from demagnetizing due to excessive temperature.

[0073] By setting a third cooling channel 18 connected to the first cooling channel 12, not only can the rotor core 1 and the second permanent magnet 200 be cooled, but the structure is also simple, reliable, and easy to process and manufacture.

[0074] This application embodiment also provides a motor rotor, which includes a rotor shaft, a first permanent magnet 100 and a rotor core 1 provided in any of the above embodiments. The rotor shaft is inserted into the rotor shaft cavity 11, and the first permanent magnet 100 is embedded in the first rotor slot 13.

[0075] In some embodiments, as shown in FIG1, the first rotor slot 13 extends radially along the rotor core 1, and the cross-sectional profile of the first rotor slot 13 is approximately rectangular. The embedded first permanent magnet 100 is embedded in the first rotor slot 13, and the shape and size of the first rotor slot 13 are adapted to the shape and size of the first permanent magnet 100.

[0076] By setting the first rotor slot 13 to extend radially along the rotor core 1, and the first permanent magnet 100 embedded in the first rotor slot 13, the magnetic flux in the rotor core 1 can be enhanced, which helps to improve the power density of the motor.

[0077] The motor rotor provided in this application embodiment has each first cooling channel 12 located between the rotor shaft cavity 11 and the first rotor slot 13, and each first rotor slot 13 connected to the first cooling channel 12. This allows the coolant flowing in the first cooling channel 12 to directly contact and exchange heat with the first permanent magnet 100 in the first rotor slot 13, thereby cooling the first permanent magnet 100 and preventing the risk of demagnetization due to excessive temperature. This helps to improve the performance of the motor.

[0078] In a further embodiment, the rotor core 1 includes first magnetic poles 14 and second magnetic poles 15 of opposite polarity that are alternately distributed along its circumference, and a first rotor slot 13 is provided between every two adjacent first magnetic poles 14 and second magnetic poles 15; the rotor core 1 also has a plurality of spaced second rotor slots 16, and each magnetic pole has two second rotor slots 16 arranged in a V-shape.

[0079] Specifically, a second permanent magnet 200 is embedded in the second rotor slot 16. The rotor core 1 has both a first rotor slot 13 extending radially and a second rotor slot 16 arranged in a "V" shape. This makes full use of the space of the rotor core 1, improves the space utilization rate of the rotor core 1, and makes it easier to achieve high power density of the motor. At the same time, it improves the air gap magnetic flux density waveform, which helps to improve the performance of the motor.

[0080] This application also provides a motor, including the motor rotor provided in any of the above embodiments.

[0081] This application also provides a vehicle, including the motor provided in the above embodiments. Exemplarily, the vehicle is a new energy vehicle such as an electric vehicle or a hybrid vehicle.

[0082] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0083] It should be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0084] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0085] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0086] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A rotor core (1), wherein, The rotor core (1) has a rotor shaft cavity (11), a plurality of first cooling channels (12) and a plurality of first rotor slots (13). The rotor shaft cavity (11), the first cooling channels (12) and the first rotor slots (13) all penetrate the rotor core (1) along the axial direction. The plurality of first rotor slots (13) and the plurality of first cooling channels (12) are distributed at intervals along the circumference of the rotor core (1). Each first cooling channel (12) is located between the rotor shaft cavity (11) and the first rotor slot (13), and each first rotor slot (13) is connected to the first cooling channel (12).

2. The rotor core (1) according to claim 1, wherein, The rotor core (1) includes a first magnetic pole (14) and a second magnetic pole (15) with opposite polarities that are alternately distributed along its circumference, and a first rotor slot (13) is provided between every two adjacent first magnetic poles (14) and second magnetic poles (15). The rotor core (1) is also provided with a plurality of spaced second rotor slots (16), and each of the first magnetic pole (14) and the second magnetic pole (15) is provided with two second rotor slots (16) arranged in a V-shape.

3. The rotor core (1) according to claim 2, wherein, A connection (19) is constructed between every two adjacent first cooling channels (12), and each connection (19) is located in the first magnetic pole (14), or each connection (19) is located in the second magnetic pole (15).

4. The rotor core (1) according to claim 2 or 3, wherein, Each of the second rotor slots (16) has an air slot (161) at both ends in the extending direction.

5. The rotor core (1) according to claim 4, wherein, The width of the two air slots (161) of each second rotor slot (16) gradually decreases toward the side away from each other.

6. The rotor core (1) according to any one of claims 2 to 5, wherein, Each of the first magnetic pole (14) and the second magnetic pole (15) is provided with a second cooling channel (17). The second cooling channel (17) passes through the rotor core (1) along the axial direction of the rotor core (1). The second cooling channel (17) is located on the side of the second rotor slot (16) away from the rotor shaft cavity (11) and between two adjacent second rotor slots (16).

7. The rotor core (1) according to any one of claims 2 to 6, wherein, The rotor core (1) is also provided with a third cooling channel (18) that communicates with the first cooling channel (12). The third cooling channel (18) is located on the side of the first cooling channel (12) near the second rotor slot (16). The sidewall of the third cooling channel (18) protrudes outward relative to the sidewall of the first cooling channel (12) toward the side where the second rotor slot (16) is located.

8. An electric motor rotor, wherein, The motor rotor includes a rotor shaft, a first permanent magnet (100) and a rotor core (1) as described in any one of claims 1 to 7. The rotor shaft is inserted into the rotor shaft cavity (11), and the first permanent magnet (100) is embedded in the first rotor slot (13).

9. An electric motor, wherein, The motor includes the motor rotor as described in claim 8.

10. A type of automobile, wherein, The vehicle includes the motor as described in claim 9.

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