Asynchronous motor and motor rotor thereof, powertrain, and electric vehicle

Abstract

The present application provides a motor rotor of an asynchronous motor in which both ends of guide bars are skewed in a same direction, an asynchronous motor, and an electric vehicle. The motor rotor comprises a rotor core and a rotor squirrel cage. The rotor squirrel cage comprises two end rings and a plurality of guide bars. The two end rings are fixed to both ends of the rotor core in the axial direction of the motor rotor. The plurality of guide bars are fixed to the interior of the rotor core. Each guide bar comprises a first section, a second section, and a third section. The first section, the second section, and the third section are sequentially connected in the axial direction of the motor rotor. The second section is parallel to the axial direction of the motor rotor, the first section and the third section intersect with the axial direction of the motor rotor, and the first section and the third section are skewed from the second section toward a same side in the circumferential direction of the motor rotor. By means of designing the first section and the third section of each guide bar into a V-shaped structure and designing the second section for transition, the amplitude of a radial electromagnetic force can be reduced, a torsional mode excited by an axially-uneven electromagnetic force can be eliminated, the manufacturing quality of the motor rotor can be improved, and the NVH performance of an entire vehicle can be improved.

Description

Asynchronous motor and motor rotor, powertrain and electric vehicle

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 14, 2023, with application number 202311722778.9 and application name “Asynchronous motor and its motor rotor, powertrain and electric vehicle”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of motor rotors, and in particular to an asynchronous motor and its motor rotor, a powertrain, and an electric vehicle. Background Art

[0003] Asynchronous motor rotors typically use straight or V-shaped bars. While straight bars can reduce radial electromagnetic force amplitude, they also create uneven axial electromagnetic force distribution, which can excite stator torsional modal resonance. The V-shaped bars also have a large intersection angle, causing sudden changes in the direction of the molten aluminum flow during casting, which can easily create air holes and complicate casting quality. Summary of the Invention

[0004] The present application provides an asynchronous motor and a motor rotor thereof, a powertrain, and an electric vehicle.

[0005] In a first aspect, embodiments of the present application provide a rotor for an asynchronous motor, the rotor comprising a rotor core and a rotor cage, the rotor cage comprising two end rings and a plurality of guide bars, the two end rings being fixed to the rotor core at both ends along the axial direction of the motor rotor, and the plurality of guide bars being fixed within the rotor core. Each guide bar comprises a first segment, a second segment, and a third segment, the first, second, and third segments being sequentially connected along the axial direction of the motor rotor, the second segment being parallel to the axial direction of the motor rotor, the first segment and the third segment intersecting the axial direction of the motor rotor, and the first and third segments being deflected toward the same side from the second segment along the circumferential direction of the motor rotor.

[0006] The shape of the conductor bars affects the performance of asynchronous motors and is a key performance indicator for evaluating asynchronous motor systems, directly impacting the overall vehicle driving experience. Radial electromagnetic force is a key excitation source for the vibrations generated by asynchronous motors. Excessive radial electromagnetic force can lead to performance degradation. This radial electromagnetic force resonates with the stator modal resonance, and even a small excitation can cause a sharp increase in vibration and noise. If the conductor bars are generally parallel to the motor axis, the radial electromagnetic force amplitude is large, making it more likely to excite stator modal resonance. If the conductor bars are generally straight and intersect the motor axis, the radial electromagnetic force amplitude can be effectively reduced. However, the electromagnetic force is unevenly distributed axially, which can excite stator torsional modal resonance. If the conductor bars are V-shaped, while this can alleviate the uneven axial electromagnetic force distribution, the angle at the intersection of the grooves in the rotor core is large, resulting in a sudden change in the direction of the molten aluminum flow during casting, which can easily cause air holes and complicate casting quality.

[0007] In an embodiment of the present application, each guide bar includes a first section, a second section, and a third section. The first section, the second section, and the third section are connected in sequence along the axial direction of the motor rotor. The second section is parallel to the axial direction of the motor rotor. The first section and the third section intersect with the axial direction of the motor rotor. The first section and the third section are deflected toward the same side from the second section along the circumferential direction of the motor rotor. This also helps reduce the amplitude of the radial electromagnetic force of the motor rotor and eliminates torsional modes excited by axial unevenness of the electromagnetic force, thereby improving the NVH performance of the entire vehicle. The first and third sections of the guide bar are deflected toward the same side from the second section along the circumferential direction of the motor rotor. Compared to a guide bar without a second section and directly connected to form the first and third sections, the second section in the embodiment of the present application can reduce the angle between adjacent sections, which helps reduce the probability of manufacturing quality problems during the formation of the guide bar of the rotor cage and improve the casting quality of the motor rotor.

[0008] In one embodiment, the two end rings and the plurality of guide bars are integrally die-cast, the two end rings are integrally die-cast at both ends of the rotor core, and the plurality of guide bars are integrally die-cast inside the rotor core.

[0009] In an embodiment of the present application, two end rings and multiple guide bars are die-cast as one body, and the process is simple. The two end rings are respectively connected to the two ends of the multiple guide bars. The two end rings are die-cast as one body at the two ends of the rotor core, which is conducive to axial demolding from the motor rotor after the two end rings are formed. The multiple guide bars are die-cast as one body in the rotor core, so that the guide bars fully occupy the guide bar slots in the rotor core, thereby improving the slot fill rate and thus improving the performance of the rotor core.

[0010] In one embodiment, in each conductor bar, the angle between either the first or third section and the second section is smaller than the angle between the first and third sections. In this embodiment of the present application, this helps reduce the angle of material flow at the junction of the second section with the first and third sections during the die-casting process, reduces porosity in the conductor bar, improves manufacturability and casting quality, and thereby reduces radial electromagnetic forces, avoids torsional modes, and facilitates the production of high-quality motor rotors.

[0011] In one embodiment, in each conductive bar, the angle between the first and second segments is equal to the angle between the third and second segments. In this embodiment, the deflection angles of the first and third segments are made equal, ensuring uniformity of the conductive bar. This helps uniformly reduce radial electromagnetic forces, avoid torsional modes, and facilitate the production of high-quality motor rotors.

[0012] In one embodiment, in each guide bar, the end surface of the first section facing the second section is aligned with the end surface of the second section facing the first section, and the end surface of the second section facing the third section is aligned with the end surface of the third section facing the second section. In this embodiment of the present application, the area of ​​the location where the first section or the third section connects with the second section is made the same. This avoids a smooth transition of material between the first section or the third section and the second section at the connection location, prevents the generation of air holes in the material during the formation of the first, second, and third sections, and helps improve casting quality.

[0013] In one embodiment, in each conductor bar, along the axial direction of the motor rotor, at least one of the first and third sections is longer than the second section. In this embodiment, the conductor bar portion parallel to the axial direction of the motor rotor is reduced, and the second section is shorter, which helps reduce radial electromagnetic forces.

[0014] In one embodiment, the first and third sections of each conductor bar are of equal length, resulting in a uniform distribution of the conductor bars in the rotor cage. This helps to uniformly reduce the radial electromagnetic force of the entire rotor axial direction, avoid torsional modal resonance, and improve the casting quality of the rotor core.

[0015] In one embodiment, the rotor core includes a first sub-core, a second sub-core, and a third sub-core. The first sub-core, the second sub-core, and the third sub-core are arranged adjacent to each other in the axial direction of the motor rotor. The first sub-core, the second sub-core, and the third sub-core each include a plurality of first guide slots, a plurality of second guide slots, and a plurality of third guide slots. A second guide slot is used to accommodate the second segment of a guide bar, and a first guide slot and a third guide slot are used to accommodate the first segment and the third segment of a guide bar, respectively. Each second guide slot extends through the second sub-core along the axial direction of the motor rotor. Each first guide slot and each third guide slot extend through the first sub-core and the third sub-core, respectively, in a direction intersecting the axial direction of the motor rotor. A first guide slot and a third guide slot deviate from a second guide slot toward the same side along the circumferential direction of the motor rotor.

[0016] In an embodiment of the present application, a first guide groove, a second guide groove, and a third guide groove arranged adjacent to each other in the axial direction of the motor rotor are respectively used to accommodate the first section, the second section, and the third section of the same guide bar, thereby facilitating the first section, the second section, and the third section of the same guide bar to be connected in sequence along the axial direction of the motor rotor, thereby facilitating the die-casting of the guide bar.

[0017] In an embodiment of the present application, each second guide slot extends through the second sub-core axially along the motor rotor, facilitating connection between the second guide slot and the first guide slot of the first sub-core and the third guide slot of the third sub-core, thereby facilitating the second section formed by die-casting to be parallel to the motor axial direction. Each first guide slot and each third guide slot intersect axially along the motor rotor, thereby causing the first section of each guide bar and the third section of each guide bar to intersect axially along the motor rotor. This formation of guide bars facilitates reducing the radial electromagnetic force amplitude of the motor rotor and eliminating torsional modes excited by axially uneven electromagnetic forces, thereby improving vehicle performance. A first guide slot and a third guide slot deviate to the same side from a second guide slot along the circumference of the motor rotor, while a second guide slot extends through the second sub-core axially along the motor rotor, thereby forming a concave skew groove on the rotor core. This facilitates a more uniform distribution of the electromagnetic force of the motor rotor axially along the motor rotor, thereby reducing stator torsional mode resonance. A second guide groove can transitionally connect the connection between a first guide groove and a third guide groove, thereby helping to reduce the minimum angle formed by the direct connection between a first guide groove and a third guide groove, thereby helping to avoid large-angle sudden changes in the flow direction of the aluminum liquid during the casting process, reducing the pores generated in the guide bar, and improving the manufacturability and casting quality of the motor rotor.

[0018] In one embodiment, the first sub-core includes at least two first core punchings, which are stacked axially along the motor rotor. Each first core punching includes a plurality of first guide bar holes, each of which extends axially through the first core punching along the motor rotor. The first guide bar holes of each of the at least two first core punchings are staggered clockwise to form a first guide slot.

[0019] In an embodiment of the present application, each first guide bar hole extends through the first core punching sheet along the axial direction of the motor rotor, thereby facilitating interconnection between the first guide bar holes of at least two first core punching sheets to form a first guide slot, thereby facilitating formation of multiple first guide slots within the first sub-core to accommodate the first segments of multiple guide bars. In an embodiment of the present application, the first guide bar holes of each of the at least two first core punching sheets are staggered clockwise to form a first guide slot, which facilitates the first guide slot formed in the first sub-core to intersect with the axial direction of the motor rotor, thereby facilitating the first segments of the multiple guide bars accommodated in the multiple first guide slots to intersect with the axial direction of the motor rotor, thereby facilitating reduction of the radial electromagnetic force amplitude of the motor rotor.

[0020] In one embodiment, the first guide bar holes in each adjacent two first core punchings have the same staggered angle. In this embodiment of the present application, the first guide bar holes in each adjacent two first core punchings have the same staggered angle. This facilitates smoother and more regular channels in the first guide grooves when forming the first guide grooves in the first sub-core, thereby facilitating smoother flow of molten aluminum in the first sections of the plurality of guide bars during the casting process, reducing the generation of air holes in the first guide grooves, and thereby facilitating the formation of smoother and more regular guide bars, thereby improving casting quality.

[0021] In one embodiment, a first guide bar hole of a first core punch adjacent to the second sub-core in at least two first core punches is aligned with a second guide groove of the second sub-core along the axial direction of the motor rotor. In an embodiment of the present application, a first guide bar hole of a first core punch adjacent to the second sub-core is aligned with a second guide groove of the second sub-core along the axial direction of the motor rotor, thereby facilitating that a first guide groove formed by the first guide bar holes of at least two first core punches is connected to a second guide groove of the second sub-core. The alignment along the axial direction of the motor rotor facilitates smoother connection between the first guide groove and the second guide groove, facilitates smoother flow of molten aluminum from the connection during the casting process, reduces the generation of pores, and facilitates improved casting quality.

[0022] In one embodiment, the third sub-core includes at least two third core punchings, which are stacked axially along the motor rotor. Each third core punching includes a plurality of third guide bar holes, each of which extends axially through the third core punching along the motor rotor. The third guide bar holes in each of the at least two third core punchings are staggered counterclockwise to form a third guide slot.

[0023] In the embodiment of the present application, each third guide bar hole extends through the third core punching sheet along the axial direction of the motor rotor, thereby facilitating interconnection between the third guide bar holes of at least two third core punching sheets to form a third guide slot, thereby facilitating formation of multiple third guide slots within the third sub-core to accommodate the third segments of the multiple guide bars. In the embodiment of the present application, the third guide bar holes of each of the at least two third core punching sheets are staggered counterclockwise to form a third guide slot, which facilitates the third guide slot formed in the third sub-core to intersect with the axial direction of the motor rotor, thereby facilitating the third segments of the multiple guide bars accommodated in the multiple third guide slots to intersect with the axial direction of the motor rotor, thereby facilitating reduction of the radial electromagnetic force amplitude of the motor rotor.

[0024] In one embodiment, the third guide bar holes in each two adjacent third core punchings have the same staggered angle. In this embodiment of the present application, the third guide bar holes in each two adjacent third core punchings have the same staggered angle. This facilitates smoother and more regular channels in the third guide slots when forming the third guide slots in the third sub-core, thereby facilitating smoother flow of molten aluminum in the third sections of the multiple guide bars during the casting process, reducing the generation of air holes in the third guide slots, and thereby facilitating the formation of smoother and more regular guide bars, thereby improving casting quality.

[0025] In one embodiment, a third guide bar hole of a third core punching adjacent to the second sub-core among the at least two third core punchings is aligned with a second guide slot of the second sub-core along the axial direction of the motor rotor.

[0026] In an embodiment of the present application, a third guide bar hole of a third core punching sheet adjacent to the second sub-core is aligned with a second guide groove of the second sub-core along the axial direction of the motor rotor, thereby facilitating a third guide groove formed by the third guide bar holes of at least two third core punching sheets to be connected with a second guide groove of the second sub-core. The axial alignment along the motor rotor facilitates smoother connection between the third guide groove and the second guide groove, facilitates smoother flow of molten aluminum from the connection during the casting process, reduces the generation of pores, and facilitates improved casting quality.

[0027] In one embodiment, the staggered angle of the first guide bar holes in each adjacent two first core punching sheets is the same as the staggered angle of the third guide bar holes in each adjacent two third core punching sheets.

[0028] In an embodiment of the present application, the first guide bar hole in the first core punching sheet is used to form a first guide groove, and the third guide bar hole in the third core punching sheet is used to form a third guide groove. The first guide groove accommodates the first section of the guide bar, and the third guide groove accommodates the third section of the guide bar. The staggered angle of the first guide bar holes in each two adjacent first core punching sheets is the same as the staggered angle of the third guide bar holes in each two adjacent third core punching sheets, which is beneficial for a first guide groove and a third guide groove to deflect from a second guide groove to the same side at the same angle along the circumference of the motor rotor, thereby facilitating a first section of a guide bar and a third section of a guide bar to deflect from a second section of a guide bar to the same side at the same angle along the circumference of the motor rotor, which is beneficial for reducing the radial electromagnetic force amplitude of the motor rotor, and is also beneficial for eliminating the torsional mode excited by the axial unevenness of the electromagnetic force caused by the unidirectional inclined guide groove, thereby improving the NVH performance of the entire vehicle.

[0029] In one embodiment, along the axial direction of the motor rotor, projections of the first guide bar hole in the first core punching sheet and the third guide bar hole in the third core punching sheet, which are at the same distance from the second sub-core, overlap.

[0030] In an embodiment of the present application, the thickness of the first core punching sheet and the third core punching sheet are the same, the number of first core punching sheets contained in the first sub-core is the same as the number of third core punching sheets contained in the third sub-core, and along the axial direction of the motor rotor, the projections of the first guide bar hole of the first core punching sheet and the third guide bar hole of the third core punching sheet at the same distance from the second sub-core coincide with each other, which is conducive to making the arrangement of the first guide groove and the third guide groove regular, and is also conducive to making the arrangement of the first section and the third section of the guide bar regular, that is, the motor rotor is axially symmetrical along the neutral plane of the motor rotor, which is conducive to the regularity of the overall structure of the motor rotor, and is also conducive to eliminating the torsional mode excited by the axial unevenness of the electromagnetic force caused by the unidirectional inclined guide groove, thereby improving the NVH performance of the whole vehicle.

[0031] In one embodiment, the second sub-core includes at least two second core punchings, which are stacked axially along the motor rotor. Each second core punching includes a plurality of second guide bar holes, each of which extends axially through the second core punching along the motor rotor. The second guide bar holes in each of the at least two second core punchings are aligned axially along the motor rotor to form a second guide slot.

[0032] In an embodiment of the present application, a second guide bar hole in each of at least two second core punchings is aligned along the axial direction of the motor rotor to form a second guide slot, which facilitates the second guide slot formed by the second sub-core to be parallel to the axial direction of the motor rotor, and further facilitates the second sections of the plurality of guide bars accommodated in the plurality of second guide slots to be parallel to the axial direction of the motor rotor. A second guide slot is respectively connected to a first guide slot and a third guide slot, and a first guide slot and a third guide slot are deflected to the same side from a second guide slot along the circumference of the motor rotor, that is, a second guide slot has a transition effect, which can reduce the angle between a first guide slot and a third guide slot, thereby effectively reducing the radial electromagnetic force amplitude of the motor rotor, eliminating the torsional mode excited by the axial non-uniformity of the electromagnetic force, and avoiding large-angle sudden changes in the flow direction of the molten aluminum during the casting process, reducing the generation of pores, and improving the manufacturability and casting quality of the motor rotor.

[0033] In one embodiment, the angle between the arrangement direction of the first guide bar holes of all first core punchings and the arrangement direction of the third guide bar holes of all third core punchings is smaller than the angle between the arrangement direction of the first guide bar holes of all first core punchings and the third guide bar holes of all third core punchings. The angle between the arrangement direction of the first guide bar holes of all first core punchings and the arrangement direction of the second guide bar holes of all second core punchings is smaller than the angle between the arrangement direction of the first guide bar holes of all first core punchings and the third guide bar holes of all third core punchings.

[0034] In an embodiment of the present application, the first guide bar hole is used to form a first guide groove, which is used to accommodate the first section of the guide bar; the second guide bar hole is used to form a second guide groove, which is used to accommodate the second section of the guide bar; and the third guide bar hole is used to form a third guide groove, which is used to accommodate the third section of the guide bar. The arrangement of the first guide bar hole, the second guide bar hole, and the third guide bar hole in the manner of the embodiment of the present application is conducive to improving the connection arrangement of a first guide groove, a second guide groove, and a third guide groove, thereby facilitating the reduction of the angle of the aluminum liquid flow direction at the connection between the first guide groove and the second guide groove during the die-casting process, reducing the generation of pores, improving manufacturability and casting quality, and thereby reducing radial electromagnetic force, avoiding torsional modes, and facilitating the production of high-quality motor rotors.

[0035] In one embodiment, the second sub-core includes a motor shaft hole, multiple oil guide channels, and multiple radial oil channels. The oil guide channels and radial oil channels are used to carry oil. The motor shaft hole is used to accommodate the motor shaft. Each oil guide channel connects the internal oil channels of the first and third sub-cores. Each radial oil hole connects the internal oil channel of the motor shaft to an oil guide channel. The motor shaft hole, the multiple oil guide channels, and the multiple second guide grooves are sequentially spaced apart along the radial direction of the motor rotor. Each radial oil channel extends radially along the motor rotor and is arranged between the motor shaft hole and an oil guide channel.

[0036] In an embodiment of the present application, the radial oil passage extends radially along the motor rotor, which facilitates the flow of cooling oil from the internal oil passage of the motor shaft into the oil guide passage along the radial direction of the motor rotor through the radial oil holes and radial oil passages to cool the motor rotor when the motor rotates, thereby reducing power loss. The radial oil passage is provided in the second sub-core. Since the guide bars in the second sub-core are parallel to the second section of the motor rotor axis, and the multiple second oil guide holes forming the second section are aligned along the motor rotor axis, the radial oil holes in each second core punching can be more accurately aligned along the motor rotor axis. Compared to providing the radial oil holes in the first or third core punching, since the first or third core punching needs to be staggered, it is difficult to ensure that the radial oil holes in the first or third core punching are connected, which increases the difficulty of connecting the radial oil holes and the difficulty of arrangement.

[0037] In a second aspect, an embodiment of the present application provides an asynchronous motor, comprising a motor housing, a motor stator, a motor shaft, and a motor rotor as described above, wherein the motor housing is configured to house and secure the motor stator, the motor stator is configured to house the motor rotor, and the motor rotor is configured to house and secure the motor shaft. In the present application, the first and third sections of the guide bars of the motor rotor are deflected toward the same side relative to the second section along the circumferential direction of the motor rotor, thereby reducing the probability of manufacturing quality problems occurring during the formation of the guide bars of the rotor cage, improving the casting quality of the motor rotor, and reducing the radial electromagnetic force amplitude, thereby improving the NVH performance of the vehicle. Furthermore, the motor housing can eliminate torsional modes excited by axial non-uniformity of the electromagnetic force, thereby improving the performance and casting quality of the asynchronous motor.

[0038] In a third aspect, embodiments of the present application provide a powertrain comprising a reducer and an asynchronous motor as described in any of the above embodiments, wherein the motor shaft of the asynchronous motor is drivingly connected to the input shaft of the reducer, and the output shaft of the reducer is drivingly connected to the wheels of the electric vehicle. The asynchronous motor of the present application improves the performance and casting quality of the asynchronous motor, thereby improving the quality of the powertrain, by deflecting the first and third segments of the guide bars of the motor rotor toward the same side relative to the second segment along the circumferential direction of the motor rotor.

[0039] Fourthly, embodiments of the present application provide an electric vehicle comprising a vehicle body, wheels, a reducer, and a powertrain as described above, wherein the vehicle body is used to secure the powertrain, and the powertrain is used to drive the wheels. The asynchronous motor in the powertrain of the present application improves the performance and casting quality of the asynchronous motor by deflecting the first and third sections of the motor rotor's guide bars toward the same side along the circumference of the motor rotor relative to the second section, thereby improving the NVH performance of the entire electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0041] FIG1 is a schematic structural diagram of an electric vehicle provided in one embodiment of the present application;

[0042] FIG2 is a schematic structural diagram of a powertrain according to an embodiment of the present application;

[0043] FIG3 is a schematic structural diagram of a motor rotor provided in one embodiment of the present application;

[0044] FIG4 is a schematic structural diagram of a rotor core provided in one embodiment of the present application;

[0045] FIG5 is a schematic structural diagram of a rotor cage provided in one embodiment of the present application;

[0046] FIG6 is a schematic structural diagram of a first guide groove, a second guide groove, and a third guide groove provided in one embodiment of the present application;

[0047] FIG7 is a schematic structural diagram of a rotor cage provided in one embodiment of the present application;

[0048] FIG8 is a schematic structural diagram of a first core punching sheet provided in one embodiment of the present application;

[0049] FIG9 is a schematic structural diagram of three adjacent first core punching sheets provided in one embodiment of the present application;

[0050] FIG10 is a schematic structural diagram of a third core punching sheet provided in one embodiment of the present application;

[0051] FIG11 is a schematic structural diagram of three adjacent third core punching sheets provided in one embodiment of the present application;

[0052] FIG12 is a schematic structural diagram of a second core punching sheet provided in one embodiment of the present application;

[0053] FIG13 is a cross-sectional view of a motor rotor provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0055] As used herein, the terms "first," "second," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more.

[0056] In addition, in this article, directional terms such as "upper" and "lower" are defined relative to the orientation of the structure schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the structure.

[0057] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of this application are explained and described below.

[0058] Parallel: The parallelism defined in the embodiments of the present application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, which allows for situations where the absolute parallelism is not caused by factors such as assembly tolerance, design tolerance, and the influence of structural flatness.

[0059] Vertical: The vertical defined in the embodiments of the present application is not limited to an absolute vertical intersection relationship (an angle of 90 degrees). It allows for non-absolute vertical intersection relationships caused by factors such as assembly tolerance, design tolerance, and the influence of structural flatness. It 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.

[0060] Misalignment: Misalignment as defined in the embodiments of the present application refers to the overlapping of the projections of two adjacent core punchings along the axial direction of the motor.

[0061] Alignment: Alignment as defined in the embodiments of the present application means that the projections of two adjacent core punchings along the axial direction of the motor completely overlap.

[0062] NVH: It is the abbreviation of Noise, Vibration and Harshness, which refers to noise, vibration and harshness.

[0063] To improve the performance and casting quality of an asynchronous motor, an embodiment of the present application provides a motor rotor for an asynchronous motor. The motor rotor includes a rotor core and a rotor cage. The rotor cage includes two end rings and a plurality of guide bars. The two end rings are fixed to the two ends of the rotor core along the axial direction of the motor rotor, and the plurality of guide bars are fixed to the interior of the rotor core. Each guide bar includes a first section, a second section, and a third section. The first, second, and third sections are sequentially connected along the axial direction of the motor rotor. The second section is parallel to the axial direction of the motor rotor. The first and third sections intersect with the axial direction of the motor rotor. The first and third sections deflect from the second section to the same side along the circumferential direction of the motor rotor. The embodiment of the present application reduces the angle between the first and third sections of each guide bar by designing a second section parallel to the axial direction of the motor in the guide bar. This helps reduce the probability of manufacturing quality problems during the formation of the guide bars of the rotor cage and improves the casting quality of the motor rotor. At the same time, the first and third sections of the guide bar deflect from the second section to the same side along the circumferential direction of the motor rotor. This also helps reduce the radial electromagnetic force amplitude, thereby improving the NVH performance of the vehicle and eliminating torsional modes excited by axial uneven electromagnetic force.

[0064] The motor rotor provided in the embodiment of the present application is applied to an asynchronous motor, and the asynchronous motor is applied to an electric vehicle to improve the overall performance of the electric vehicle.

[0065] Please refer to Figure 1, which is a schematic diagram of the structure of an electric vehicle 1 provided in one embodiment of the present application. In this embodiment, the electric vehicle 1 includes a vehicle body 2, a powertrain 3, a battery pack 4, and wheels 5. The powertrain 3 and battery pack 4 are fixed to the vehicle body 2. The powertrain 3 is used to receive power from the battery pack 4 and to drive the wheels 5.

[0066] In the embodiment of the present application, the battery pack 4 may also be referred to as a power battery.

[0067] In the embodiment of the present application, the vehicle body 2 may also be referred to as a vehicle frame.

[0068] In the embodiment of the present application, the electric vehicle 1 refers to a wheeled device driven or towed by a power device.

[0069] Please refer to Figures 2 and 3. Figure 2 is a schematic diagram of the structure of a powertrain 3 provided in one embodiment of the present application, and Figure 3 is a schematic diagram of the structure of a motor rotor 100 provided in one embodiment of the present application. In one embodiment, the powertrain 3 includes a motor 10 and a reducer 20. The motor 10 includes a motor shaft 130 (shown in Figure 3), a motor stator (not shown), and the motor rotor 100. The reducer 20 includes a gear assembly (not shown), an input shaft (not shown), and an output shaft (not shown). The input shaft receives power transmitted from the motor shaft 130 of the motor 10 and transmits the power to the output shaft via the gear assembly. The gear assembly can be configured as needed and may be a single-speed reduction gear assembly, a two-speed reduction gear assembly, or a multi-speed reduction gear assembly. The motor rotor 100 is fixedly mounted on the motor shaft 130. After receiving AC power, the motor stator drives the motor rotor 100 to rotate, thereby driving the motor shaft 130 to rotate. The motor shaft 130 of the motor 10 is configured to be in transmission connection with the reducer input shaft. It should be noted that the motor shaft 130 in Figure 3 is a schematic representation of the position of the motor shaft 130.

[0070] In the embodiment of the present application, the motor 10 and the reducer 20 are arranged along the motor axis, and the motor shaft 130 of the motor 10 is fixed to the input shaft of the reducer 20. In the embodiment of the present application, the motor 10 is an asynchronous motor 10.

[0071] Continuing with Figures 2 and 3 , in one embodiment, the powertrain 3 further includes a motor controller 30, which is fixed to the vehicle body 2. The motor controller 30 is configured to receive direct current (DC) power from the battery pack 4, convert the DC power into AC power, and transmit the power to the asynchronous motor 10. The asynchronous motor 10 is in driving connection with the reducer 20. The asynchronous motor 10 is configured to receive AC power, convert the electrical energy into mechanical energy, and transmit the mechanical energy to the reducer 20. The reducer 20 is in driving connection with the wheels 5, transmitting power to the wheels 5 to drive the wheels 5 to rotate.

[0072] In one embodiment, the powertrain 3 includes an integrated housing that includes at least two of the following: a motor housing cavity, a reducer housing cavity, and a motor controller housing cavity. The motor housing cavity accommodates the motor rotor, motor stator, and motor shaft; the reducer housing cavity accommodates the gear assembly, input shaft, intermediate shaft, and output shaft of the reducer 20; and the motor controller housing cavity accommodates components such as the power module, circuit board, and busbar capacitors of the motor controller. The integrated housing makes the powertrain 3 more integrated and compact, making it suitable for electric vehicles with smaller installation spaces.

[0073] In one embodiment, the asynchronous motor 10 , the reducer 20 and the motor controller 30 in the power assembly 3 may also be split, and there is no common part in the housings of the asynchronous motor 10 , the reducer 20 and the motor controller 30 .

[0074] Please continue to refer to Figures 2 and 3. In one embodiment, the asynchronous motor 10 includes a motor housing (not shown), a motor stator, a motor rotor 100 and a motor shaft 130. The motor housing is used to sleeve and fix the motor stator, and the motor stator can generate a magnetic field after current is passed through it. The motor rotor 100 is sleeved and fixed on the motor shaft 130 and can rotate relative to the motor stator. There is an air gap between the motor rotor 100 and the motor stator. When the asynchronous motor 10 is working, the force exerted by the motor stator on the motor rotor 100 causes the motor rotor 100 to rotate relative to the motor stator. When the motor rotor 100 rotates, it can drive the motor shaft 130 to rotate, and the asynchronous motor 10 outputs power through the motor shaft 130.

[0075] The motor rotor 100 provided in an embodiment of the present application will be described in detail below.

[0076] Please refer to Figures 3, 4, and 5. Figure 4 is a schematic diagram of the structure of a rotor core 110 provided in an embodiment of the present application, and Figure 5 is a schematic diagram of the structure of a rotor cage 120 provided in an embodiment of the present application. This embodiment of the present application provides a motor rotor 100 for an asynchronous motor. The motor rotor 100 includes a rotor core 110 (as shown in Figure 4) and a rotor cage 120 (as shown in Figure 5). The rotor cage 120 includes two end rings 121 and a plurality of conductive bars 122. The two end rings 121 are fixed to both ends of the rotor core 110 along the rotor axial direction O, and the plurality of conductive bars 122 are fixed to the interior of the rotor core 110. Each conductive bar 122 includes a first section 123, a second section 124, and a third section 125. The first section 123, the second section 124, and the third section 125 are sequentially connected along the motor rotor axial direction O (as shown in FIG5 ). The second section 124 is parallel to the motor rotor axial direction O. The first section 123 and the third section 125 intersect at the motor rotor axial direction O. The first section 123 and the third section 125 deflect toward the same side from the second section 124 along the motor rotor circumferential direction C.

[0077] In the embodiment of the present application, the motor rotor 100 is fixedly mounted on the motor shaft 130. The motor stator drives the motor rotor 100 to rotate after receiving alternating current, thereby driving the motor shaft 130 to rotate. When the current supplied by the motor controller 30 reaches the motor stator, the coils of the motor stator generate a magnetic field, which interacts with the rotor cage 120 in the motor rotor 100, generating an electromagnetic force, thereby driving the motor rotor 100 to rotate. The rotor cage 120 is located within the rotor core 110. The two end rings 121 and multiple conductive bars 122 of the rotor cage 120 are formed by high-temperature aluminum hydraulic casting and are all conductive. The interaction between the motor rotor 100 and the motor stator generates current, which is transmitted in the rotor cage 120 and generates a magnetic field. The ends of the multiple conductive bars 122 of the rotor cage 120 are respectively connected to the two end rings 121.

[0078] The shape of the guide bar 122 will affect the NVH performance of the motor. NVH is a key performance indicator for evaluating the motor system and directly affects the driving experience of the entire vehicle. Radial electromagnetic force is an important excitation source for the vibration generated by the drive motor. Excessive radial electromagnetic force will lead to deterioration of NVH performance. The radial electromagnetic force resonates with the stator modal, and even a small excitation will cause a sharp deterioration of vibration and noise. If the shape of the guide bar 122 used is generally parallel to the motor axis, the radial electromagnetic force amplitude is large, which is more likely to excite stator modal resonance. If the shape of the guide bar 122 used is generally straight and intersects with the motor axis, the radial electromagnetic force amplitude can be effectively reduced, but the electromagnetic force is unevenly distributed along the axial direction, which will excite stator torsional modal resonance. If the shape of the guide bar 122 used is V-shaped, although it can alleviate the problem of uneven axial distribution of electromagnetic force, the angle at the junction of the V-grooves in the rotor core 110 is large, and the flow direction of the molten aluminum changes suddenly during the casting process, which is easy to produce air holes and the casting quality is difficult to guarantee.

[0079] In the embodiment of the present application, each guide bar 122 includes a first section 123, a second section 124 and a third section 125. The first section 123, the second section 124 and the third section 125 are connected in sequence along the axial direction O of the motor rotor. The second section 124 is parallel to the axial direction O of the motor rotor. The first section 123 and the third section 125 both intersect at the axial direction O of the motor rotor. The first section 123 and the third section 125 are deflected to the same side from the second section 124 along the circumferential direction C of the motor rotor, which is also beneficial to reducing the radial electromagnetic force amplitude of the motor rotor 100. At the same time, it can also eliminate the torsional mode excited by the axial unevenness of the electromagnetic force, thereby improving the NVH performance of the entire vehicle. The first section 123 and the third section 125 of the guide bar 122 are deflected toward the same side from the second section 124 along the circumferential direction C of the motor rotor. Compared to a case where there is no second section 124 and the first section 123 and the third section 125 are directly connected to form a V-shaped guide bar, the second section 124 in the embodiment of the present application can reduce the angle between adjacent sections, thereby reducing the probability of manufacturing quality problems occurring during the formation of the guide bar 122 of the rotor cage 120 and improving the casting quality of the motor rotor 100. The term "same-side deflection" as defined in the embodiment of the present application refers to deflection along the circumferential direction C of the motor rotor and on the same side of the motor rotor's axial direction, i.e., the first section 123 and the third section 125 are located on the same side of the second section 124 along the motor rotor's axial direction C.

[0080] 4 and 5 , in one embodiment, the two end rings 121 and the plurality of guide bars 122 are integrally die-cast. The two end rings 121 are integrally die-cast at both ends of the rotor core 110 , and the plurality of guide bars 122 are integrally die-cast inside the rotor core 110 .

[0081] In the embodiment of the present application, the two end rings 121 and the plurality of guide bars 122 are integrally die-cast, and the process is simple. The two end rings 121 are respectively connected to the two ends of the plurality of guide bars 122. The two end rings 121 are integrally die-cast at the two ends of the rotor core 110, which is conducive to demolding from the axial direction O of the motor rotor after the two end rings 121 are formed. The plurality of guide bars 122 are integrally die-cast in the rotor core 110, so that the guide bars 122 fully occupy the guide bar slots in the rotor core 110, thereby improving the slot fill rate and thereby improving the performance of the rotor core 110.

[0082] In one embodiment, the rotor cage 120 is formed on the rotor core 110 by aluminum hydraulic casting. That is, the two end rings 121 and the plurality of conductive bars 122 are made of aluminum. The motor in the embodiment of the present application is an asynchronous motor 10. The asynchronous motor 10 refers to a motor rotor 100 whose rotational speed is less than the rotational speed of the rotating magnetic field of the motor stator. The motor rotor of the asynchronous motor has an aluminum conductor. After the stator winding is energized, a rotating magnetic field is generated in the air gap between the motor stator and the motor rotor 100. The motor rotor 100 cuts through the magnetic field to generate an induced electromotive force. Since the motor rotor 100 is in a short-circuit state, a rotor current is generated. The rotor current interacts with the air gap magnetic field to generate an electromagnetic torque, thereby driving the motor rotor 100 to rotate.

[0083] Continuing with Figures 4 and 5 , in one embodiment, the rotor core 110 includes a first sub-core 110a, a second sub-core 110b, and a third sub-core 110c. The first sub-core 110a, the second sub-core 110b, and the third sub-core 110c are sequentially arranged adjacent to each other along the rotor axial direction O of the motor. The first sub-core 110a, the second sub-core 110b, and the third sub-core 110c each include a plurality of first guide slots 114, a plurality of second guide slots 115, and a plurality of third guide slots 116. A second guide slot 115a is configured to accommodate a second segment 124a of a conductive bar 122, and a first guide slot 114a and a third guide slot 116a are configured to accommodate a first segment 123a of a conductive bar 122 and a third segment 125a of a conductive bar 122, respectively. Each second guide slot 115 extends through the second sub-core 110b along the rotor axial direction O of the motor. Each first guide slot 114 and each third guide slot 116 respectively penetrates the first sub-core 110a and the third sub-core 110c along a direction intersecting the axial direction O of the motor rotor. A first guide slot 114a and a third guide slot 116a deviate from a second guide slot 115a toward the same side along the circumferential direction C of the motor rotor.

[0084] In the embodiment of the present application, the first sub-core 110a, the second sub-core 110b and the third sub-core 110c are arranged adjacent to each other in sequence along the axial direction O of the motor rotor. The first sub-core 110a, the second sub-core 110b and the third sub-core 110c respectively include a plurality of first guide grooves 114, a plurality of second guide grooves 115 and a plurality of third guide grooves 116. A first guide groove 114a, a second guide groove 115a and a third guide groove 116a arranged adjacent to each other in sequence along the axial direction O of the motor rotor are respectively used to accommodate the first segment 123a, the second segment 124a and the third segment 125a of the same guide bar 122, thereby facilitating the first segment 123a, the second segment 124a and the third segment 125a of the same guide bar 122 to be connected in sequence along the axial direction O of the motor rotor, thereby facilitating the die-casting of the guide bar 122.

[0085] In the embodiment of the present application, each second guide slot 115 extends through the second sub-core 110b along the motor rotor axial direction O. This facilitates communication between the second guide slot 115 and the first guide slot 114 of the first sub-core 110a and the third guide slot 116 of the third sub-core 110c, and facilitates the die-cast second segment 124 being parallel to the motor axial direction O. Each first guide slot 114 and each third guide slot 116 intersect with the motor rotor axial direction O, thereby causing the first segment 123 of each guide bar 122 and the third segment 125 of each guide bar 122 to intersect with the motor rotor axial direction O. The resulting guide bars 122 can reduce the radial electromagnetic force amplitude of the motor rotor 100, eliminate torsional modes excited by axially non-uniform electromagnetic force, and thus improve the NVH performance of the vehicle. A first guide slot 114a and a third guide slot 116a deflect toward the same side from a second guide slot 115a along the circumferential direction C of the motor rotor. The second guide slot 115a extends through the second sub-core 110b along the motor rotor axial direction O. This allows the first guide slot 114a and the third guide slot 116a to form a concave skew groove on the rotor core 110. This facilitates more even distribution of the electromagnetic force of the motor rotor 100 along the motor rotor axial direction O and reduces stator torsional modal resonance. The second guide slot 115a provides a transitional connection between the first guide slot 114a and the third guide slot 116a, thereby reducing the minimum angle formed by the direct connection between the first guide slot 114a and the third guide slot 116a. This helps avoid sudden changes in the flow direction of the molten aluminum during the casting process, reduces the formation of air holes within the guide bars, and improves the manufacturability and casting quality of the motor rotor 100.

[0086] Please continue to refer to Figures 4, 5, and 6. Figure 6 is a schematic diagram of the structure of a first guide groove 114a, a second guide groove 115a, and a third guide groove 116a according to an embodiment of the present application. In one embodiment, the angle between any one of the first guide groove 114a and the third guide groove 116a and the second guide groove 115a is smaller than the angle between the first guide groove 114a and the third guide groove 116a.

[0087] In the embodiment of the present application, a first guide groove 114a is used to accommodate a first section 123a of a guide bar 122, a second guide groove 115a is used to accommodate a second section 124a of a guide bar 122, and a third guide groove 116a is used to accommodate a third section 125a of a guide bar 122. A first guide groove 114a is connected to one end of a second guide groove 115a, and a third guide groove 116a is connected to the other end of a second guide groove 115a. The angle between any one of the first guide groove 114a and the third guide groove 116a and the second guide groove 115a is recorded as α, and the angle between the first guide groove 114a and the third guide groove 116a is recorded as β, α<β (as shown in Figure 6). α is smaller, which is beneficial to reducing the angle of change of the flow direction of the aluminum liquid during die casting at the connection between the first guide groove 114a and the second guide groove 115a during die casting, reducing the pores generated by the guide bar 122, improving the manufacturability and casting quality, and thus reducing the radial electromagnetic force, avoiding the torsional mode, and facilitating the acquisition of a high-quality motor rotor 100.

[0088] 6 , in one embodiment, the ratio of the angle between any one of a first guide groove 114 a and a third guide groove 116 a and a second guide groove 115 a to the angle between the first guide groove 114 a and the third guide groove 116 a is 0.5.

[0089] In the embodiment of the present application, the angle between any one of a first guide groove 114a and a third guide groove 116a and a second guide groove 115a is α, and the angle between a first guide groove 114a and a third guide groove 116a is β, α=0.5β, α is small, that is, the setting of a second guide groove 115a reduces the minimum angle of the connection between a first guide groove 114a and a third guide groove 116a by half, which is beneficial to avoid a large-angle sudden change in the flow direction of the aluminum liquid during the casting process, reduce the generation of pores, and improve the casting quality.

[0090] Please refer to Figures 4, 5, and 7. Figure 7 is a schematic diagram of the structure of a rotor cage 120 according to an embodiment of the present application. In one embodiment, the angle between either the first segment 123a of a conductor bar 122 or the third segment 125a of a conductor bar 122 and the second segment 124a of the conductor bar 122 is smaller than the angle between the first segment 123a of a conductor bar 122 and the third segment 125a of the conductor bar 122. In this embodiment of the present application, in each conductor bar 122, the angle between either the first segment 123 or the third segment 125 and the second segment 124 is smaller than the angle between the first segment 123 and the third segment 125.

[0091] In the embodiment of the present application, the first section 123a of a conductive bar 122 is formed in a first guide groove 114a of the first sub-core 110a, the second section 124a of a conductive bar 122 is formed in a second guide groove 115a of the second sub-core 110b, and the third section 125a of a conductive bar 122 is formed in the first third guide groove 116a of the third sub-core 110c. The first section 123a of a conductive bar 122 is connected to one end of the second section 124a of a conductive bar 122, and the third section 125a of a conductive bar 122 is connected to the other end of the second section 124a of a conductive bar 122. The angle between the first section 123a of a guide bar 122 and any one of the third sections 125a of a guide bar 122 and the second section 124a of a guide bar 122 is recorded as α1, and the angle between the first section 123a of a guide bar 122 and the third section 125a of a guide bar 122 is recorded as β1, α1<β1, which is beneficial to reducing the angle of the flow direction of the aluminum liquid at the connection between the first guide groove 114 and the second guide groove 115 during the die-casting process, reducing the pores generated by the guide bar 122, improving the manufacturability and casting quality, and thereby reducing the radial electromagnetic force, avoiding the torsional mode, and facilitating the acquisition of a high-quality motor rotor 100.

[0092] 4 , 5 and 7 , in one embodiment, a ratio of an angle between the first segment 123 a of a conductive bar 122 and the third segment 125 a of a conductive bar 122 and the second segment 124 a of a conductive bar 122 to an angle between the first segment 123 a of a conductive bar 122 and the third segment 125 a of a conductive bar 122 is 0.5.

[0093] In the embodiment of the present application, the angle between the first segment 123a of a guide bar 122 and any one of the third segments 125a of a guide bar 122 and the second segment 124a of a guide bar 122 is denoted as α1, and the angle between the first segment 123a of a guide bar 122 and any one of the third segments 125a of a guide bar 122 is denoted as β1. α1 = 0.5β1. A smaller α1 is beneficial for improving the connection and arrangement of the first guide groove 114a, the second guide groove 115a, and the third guide groove 116a. This arrangement helps avoid large angle changes in the flow direction of the molten aluminum during the casting process, reduces the generation of pores, and improves casting quality. In the embodiment of the present application, in each guide bar 122, the ratio of the angle between any one of the first segment 123 and the third segment 125 and the second segment 124a of the guide bar 122 to the angle between the first segment 123a of the guide bar 122 and the third segment 125a of the guide bar 122 is 0.5.

[0094] In one embodiment, in each conductive bar 122, the angle between the first segment 123 and the second segment 124 is equal to the angle between the third segment 125 and the second segment 124. This ensures that the deflection angles of the first segment 123 and the third segment 125 are the same, ensuring uniformity of the conductive bar 122, facilitating uniform reduction of radial electromagnetic forces, avoiding torsional modes, and facilitating the production of a high-quality motor rotor 100.

[0095] Please refer to Figures 4, 5, 8 and 9. Figure 8 is a schematic structural diagram of a first core punching sheet 111 provided in an embodiment of the present application, and Figure 9 is a schematic structural diagram of three adjacent first core punching sheets 111 provided in an embodiment of the present application. In one embodiment, the first sub-core 110a (as shown in Figure 4) includes at least two first core punching sheets 111 (as shown in Figure 8), and the at least two first core punching sheets 111 are stacked along the axial direction O of the motor rotor. Each first core punching sheet 111 includes a plurality of first guide bar holes 111a (as shown in Figure 8), and each first guide bar hole 111a passes through the first core punching sheet 111 along the axial direction O of the motor rotor. Among them, the first guide bar holes 111c of each of the at least two first core punching sheets 111 are staggered in sequence along the clockwise direction S to form a first guide slot 114a (as shown in Figure 4).

[0096] In an embodiment of the present application, at least two first core punching sheets 111 are stacked along the axial direction O of the motor rotor by riveting or welding to form a first sub-core 110a. Each first core punching sheet 111 includes a plurality of first guide bar holes 111a. Each first guide bar hole 111a passes through the first core punching sheet 111 along the axial direction O of the motor rotor, thereby facilitating the mutual connection between the first guide bar holes 111a of at least two first core punching sheets 111 to form a first guide groove 114, thereby facilitating the formation of a plurality of first guide grooves 114 in the first sub-core 110a to accommodate the first sections 123 of a plurality of guide bars 122 (as shown in Figure 5).

[0097] In an embodiment of the present application, a first guide bar hole 111c of each of at least two first core punching sheets 111 is staggered in sequence along the clockwise direction S to form a first guide groove 114a (as shown in Figure 9), which is conducive to the first guide groove 114 formed by the first sub-core 110a intersecting with the axial direction O of the motor rotor, and further conducive to the first sections 123 of the multiple guide bars 122 accommodated in the multiple first guide grooves 114 intersecting with the axial direction O of the motor rotor, which is conducive to reducing the radial electromagnetic force amplitude of the motor rotor 100.

[0098] Please continue to refer to Figures 4, 5, 8 and 9. In one embodiment, the staggered angles of the first guide bar holes 111a in every two adjacent first core punching sheets 111 are the same.

[0099] In the embodiment of the present application, the first guide bar holes 111a of each two adjacent first core punching sheets 111 are staggered at the same angle, which is beneficial for forming the first guide slot 114 (as shown in FIG. 4 ) in the first sub-core 110a. The passage of the first guide slot 114 is smoother and more regular, thereby facilitating smoother flow of the molten aluminum during the casting process of the first sections 123 of the plurality of guide bars 122 (as shown in FIG. 5 ), reducing the generation of air holes in the first guide slot 114, thereby facilitating the formation of smoother and more regular guide bars 122 and improving casting quality. As shown in FIG. 9 , the clockwise staggered angle of the middle first core punching sheet 111 relative to the left first core punching sheet 111 is equal to the clockwise staggered angle of the right first core punching sheet 111 relative to the middle first core punching sheet 111. In one embodiment, when stacking the three first core punches 111 shown in Figure 9, the left, middle and right three first core punches 111 in Figure 9 can be stacked in sequence, and the rightmost first core punch 111 is closer to the second sub-core 110b than the leftmost first core punch 111.

[0100] 4 and 8 , in one embodiment, a first guide bar hole 111 c of a first core punching sheet 111 adjacent to the second sub-core 110 b among the at least two first core punching sheets 111 is aligned with a second guide slot 115 a of the second sub-core 110 b along the axial direction O of the motor rotor.

[0101] In an embodiment of the present application, a first guide bar hole 111c of a first core punching sheet 111 adjacent to the second sub-core 110b is aligned with a second guide groove 115a of the second sub-core 110b along the axial direction O of the motor rotor, thereby facilitating that a first guide groove 114a formed by the first guide bar holes 111a of at least two first core punching sheets 111 is connected to a second guide groove 115a of the second sub-core 110b. The alignment along the axial direction O of the motor rotor is conducive to making the connection between the first guide groove 114 and the second guide groove 115 smoother, which is conducive to smoother flow of molten aluminum from the connection during the casting process, reducing the generation of air holes, and improving the casting quality.

[0102] In one embodiment, in each guide bar 122, the end surface of the first segment 123 facing the second segment 124 is aligned with the end surface of the second segment 124 facing the first segment 123. This ensures that the area of ​​the connection between the first segment 123 and the second segment 124 is the same, thereby preventing a smooth transition of materials between the first segment 123 and the second segment 124 at the connection point, and reducing the generation of air holes in the material during the formation of the first segment 123 and the second segment 124, thereby improving casting quality.

[0103] In one embodiment, in each guide bar 122, the end surface of the second segment 124 facing the third segment 125 is aligned with the end surface of the third segment 125 facing the second segment 124. This ensures that the areas of the connection between the third segment 125 and the second segment 124 are the same, thereby preventing a smooth transition of materials between the third segment 125 and the second segment 124 at the connection point, and reducing the generation of pores in the material during the formation of the third segment 125 and the second segment 124, thereby improving casting quality.

[0104] Please refer to Figures 4, 5, 10, and 11. Figure 10 is a schematic diagram of the structure of a third core punching 113 provided in an embodiment of the present application, and Figure 11 is a schematic diagram of the structure of three adjacent third core punchings 113 provided in an embodiment of the present application. In one embodiment, the third sub-core 110c includes at least two third core punchings 113, which are stacked along the axial direction O of the motor rotor. Each third core punching 113 includes a plurality of third guide bar holes 113a (as shown in Figure 10), and each third guide bar hole 113a passes through the third core punching 113 along the axial direction O of the motor rotor. Among them, the third guide bar holes 113c of each of the at least two third core punchings 113 are staggered in sequence along the counterclockwise direction N to form a third guide slot 116a.

[0105] In an embodiment of the present application, at least two third core punching sheets 113 are stacked along the axial direction O of the motor rotor by riveting or welding to form a third sub-core 110c. Each third core punching sheet 113 includes a plurality of third guide bar holes 113a. Each third guide bar hole 113a passes through the third core punching sheet 113 along the axial direction O of the motor rotor, thereby facilitating the mutual connection between the third guide bar holes 113a of at least two third core punching sheets 113 to form a third guide groove 116, thereby facilitating the formation of multiple third guide grooves 116 in the third sub-core 110c to accommodate the third sections 125 of multiple guide bars 122 (as shown in Figure 5).

[0106] In an embodiment of the present application, a third guide bar hole 113c of each of at least two third core punching sheets 113 is staggered in sequence counterclockwise N to form a third guide groove 116a (as shown in Figure 11), which is conducive to the third guide groove 116 formed by the third sub-core 110c intersecting with the axial direction O of the motor rotor, and further conducive to the third sections 125 of the multiple guide bars 122 accommodated in the multiple third guide grooves 116 intersecting with the axial direction O of the motor rotor, which is conducive to reducing the radial electromagnetic force amplitude of the motor rotor 100.

[0107] Please continue to refer to Figures 4, 5, 10 and 11. In one embodiment, the staggered angles of the third guide bar holes 113a in every two adjacent third core punching sheets 113 are the same.

[0108] In the embodiment of the present application, the third guide bar holes 113a of each two adjacent third core punching sheets 113 are staggered at the same angle, which facilitates smoother and more regular channels of the third guide slots 116 when forming the third sub-core 110c. This facilitates smoother flow of molten aluminum in the third sections 125 of the plurality of guide bars 122 during the casting process, reduces the generation of air holes in the third guide slots 116, and facilitates the formation of smoother and more regular guide bars 122, thereby improving casting quality. As shown in FIG11 , the counterclockwise staggered angle of the middle third core punching sheet 113 relative to the left third core punching sheet 113 is equal to the counterclockwise staggered angle of the right third core punching sheet 113 relative to the middle third core punching sheet 113. In one embodiment, when stacking the three third core punches 113 shown in Figure 11, the left, middle and right third core punches 113 in Figure 11 can be stacked in sequence, and the leftmost third core punch 113 is closer to the second sub-core 110b than the rightmost third core punch 113.

[0109] It should be noted that the counterclockwise direction indicated in Figure 11 and the clockwise direction indicated in Figure 9 are relative directions. When the motor rotor is viewed from different directions, the direction shown in Figure 11 may also be a clockwise direction, and the direction shown in Figure 9 may also be a counterclockwise direction. When the motor rotor is viewed from the same direction, the third guide bar hole 113a and the first guide bar hole 111a are staggered in opposite directions.

[0110] 4 and 10 , in one embodiment, a third guide bar hole 113 c of a third core punching sheet 113 adjacent to the second sub-core 110 b among the at least two third core punching sheets 113 is aligned with a second guide slot 115 a of the second sub-core 110 b along the axial direction O of the motor rotor.

[0111] In an embodiment of the present application, a third guide bar hole 113c of a third core punching sheet 113 adjacent to the second sub-core 110b is aligned with a second guide groove 115a of the second sub-core 110b along the axial direction O of the motor rotor, thereby facilitating that a third guide groove 116a formed by the third guide bar holes 113a of at least two third core punching sheets 113 is connected to a second guide groove 115a of the second sub-core 110b. The alignment along the axial direction O of the motor rotor is conducive to making the connection between the third guide groove 116 and the second guide groove 115 smoother, which is conducive to smoother flow of molten aluminum from the connection during the casting process, reducing the generation of air holes, and improving the casting quality.

[0112] 8 , 9 , 10 and 11 , in one embodiment, the staggered angle of the first guide bar holes 111 a in each adjacent two first core punching sheets 111 is the same as the staggered angle of the third guide bar holes 113 a in each adjacent two third core punching sheets 113 .

[0113] In the embodiment of the present application, the first guide bar hole 111a in the first core punching sheet 111 is used to form a first guide groove 114, and the third guide bar hole 113a in the third core punching sheet 113 is used to form a third guide groove 116 (as shown in FIG4 ). The first guide groove 114 accommodates the first section 123 of the guide bar 122, and the third guide groove 116 accommodates the third section 125 of the guide bar 122 (as shown in FIG5 ). The staggered angle of the first guide bar holes 111a in each adjacent two first core punching sheets 111 and the staggered angle of the third guide bar holes 113a in each adjacent two third core punching sheets 113 are The same (as shown in Figures 9 and 11) is beneficial for a first guide groove 114a and a third guide groove 116a to have the same angle of deflection from a second guide groove 115a to the same side along the circumferential direction C of the motor rotor, thereby benefiting a first section 123a of a guide bar and a third section 125a of a guide bar to have the same angle of deflection from a second section 124a of a guide bar along the circumferential direction C of the motor rotor, which is beneficial for reducing the radial electromagnetic force amplitude of the motor rotor 100, and is also beneficial for eliminating the torsional mode excited by the axial unevenness of the electromagnetic force caused by the unidirectional oblique guide groove, thereby improving the NVH performance of the entire vehicle.

[0114] 4 , 8 and 10 , in one embodiment, along the motor rotor axial direction O, the projections of the first guide bar hole 111a in the first core punching sheet 111 and the third guide bar hole 113a in the third core punching sheet 113 at the same distance from the second sub-core 110b overlap.

[0115] In the embodiment of the present application, the thickness of the first core punching sheet 111 and the third core punching sheet 113 are the same, the number of first core punching sheets 111 included in the first sub-core 110a is the same as the number of third core punching sheets 113 included in the third sub-core 110c, and along the axial direction O of the motor rotor, the projections of the first guide bar hole 111a of the first core punching sheet 111 and the third guide bar hole 113a of the third core punching sheet 113, which are at the same distance from the second sub-core 110b, coincide with each other, which is conducive to making the first guide groove 114 and the third guide groove 116 arranged regularly, and is also conducive to making the first section 123 and the third section 125 of the guide bar 122 arranged regularly, that is, the motor rotor 100 is axially symmetrical along the neutral plane of the motor rotor 100, which is conducive to the regularity of the overall structure of the motor rotor 100, and is also conducive to eliminating the torsional mode excited by the axial unevenness of the electromagnetic force caused by the unidirectional inclined guide groove, thereby improving the NVH performance of the vehicle.

[0116] Please refer to Figures 4, 5, and 12. Figure 12 is a schematic structural diagram of a second core punching sheet 112 provided in one embodiment of the present application. In one embodiment, the second sub-core 110b includes at least two second core punching sheets 112, which are stacked along the motor rotor axial direction O. Each second core punching sheet 112 includes a plurality of second guide bar holes 112a, and each second guide bar hole 112a extends through the second core punching sheet 112 along the motor rotor axial direction O. Among them, a second guide bar hole 112d (as shown in Figure 12) of each of the at least two second core punching sheets 112 is aligned along the motor rotor axial direction O to form a second guide slot 115a (as shown in Figure 4).

[0117] In an embodiment of the present application, at least two second core punching sheets 112 are stacked along the axial direction O of the motor rotor by riveting or welding to form a second sub-core 110b, and each second core punching sheet 112 includes a plurality of second guide bar holes 112a, and each second guide bar hole 112a passes through the second core punching sheet 112 along the axial direction O of the motor rotor, thereby facilitating the second guide bar holes 112a of at least two second core punching sheets 112 to be connected to each other to form a second guide groove 115, thereby facilitating the formation of a plurality of second guide grooves 115 in the second sub-core 110b to accommodate the second sections 124 of the plurality of guide bars 122 (as shown in Figure 5).

[0118] In the embodiment of the present application, a second guide bar hole 112d of each of the at least two second core punching sheets 112 is aligned along the axial direction O of the motor rotor to form a second guide groove 115a, which is conducive to the second guide groove 115 formed by the second sub-core 110b being parallel to the axial direction O of the motor rotor, and further conducive to the second sections 124 of the multiple guide bars 122 accommodated in the multiple second guide grooves 115 being parallel to the axial direction O of the motor rotor. A second guide groove 115a is respectively connected to a first guide groove 114a and a third guide groove 116a, and a first guide groove 114a and a third guide groove 116a are deflected from a second guide groove 115a to the same side along the circumferential direction C of the motor rotor, that is, a second guide groove 115a has a transition effect, which can reduce the angle between a first guide groove 114a and a third guide groove 116a, so that the motor rotor 100 can effectively reduce the radial electromagnetic force amplitude, eliminate the torsional mode excited by the axial unevenness of the electromagnetic force, avoid large-angle sudden changes in the flow direction of the molten aluminum during the casting process, reduce the generation of pores, and improve the manufacturability and casting quality of the motor rotor 100.

[0119] Referring to Figures 4 and 5, in one embodiment, the angle between the arrangement direction of the first guide bar holes 111a of all first core punching sheets 111 and the arrangement direction of the third guide bar holes 113a of all third core punching sheets 113 is smaller than the angle between the arrangement direction of the first guide bar holes 111a of all first core punching sheets 111 and the third guide bar holes 113a of all third core punching sheets 113. The angle between the arrangement direction of the first guide bar holes 111a of all first core punching sheets 111 and the arrangement direction of the second guide bar holes 112a of all second core punching sheets 112 is smaller than the angle between the arrangement direction of the first guide bar holes 111a of all first core punching sheets 111 and the third guide bar holes 113a of all third core punching sheets 113.

[0120] In the embodiment of the present application, the first guide bar hole 111a is used to form a first guide groove 114, and the first guide groove 114 is used to accommodate the first section 123 of the guide bar 122. The second guide bar hole 112a is used to form a second guide groove 115, and the second guide groove 115 is used to accommodate the second section 124 of the guide bar 122 (as shown in Figure 5). The third guide bar hole 113a is used to form a third guide groove 116, and the third guide groove 116 is used to accommodate the third section 125 of the guide bar 122 (as shown in Figure 5). The first guide bar hole 111a, the second guide bar hole 112a, and the third guide bar hole 113a are arranged in the manner of the embodiment of the present application, which is conducive to improving the connection arrangement of a first guide groove 114a, a second guide groove 115a, and a third guide groove 116a, thereby helping to reduce the angle of the flow direction of the aluminum liquid at the connection between the first guide groove 114 and the second guide groove 115 during the die-casting process, reduce the generation of air holes, improve manufacturability and casting quality, and further achieve the reduction of radial electromagnetic force and avoidance of torsional mode, which is conducive to obtaining a high-quality motor rotor 100.

[0121] Continuing to refer to FIG4 , FIG5 and FIG6 , in one embodiment, the ratio of the angle between the arrangement direction of the first guide bar holes 111a of all first core punchings 111 and the arrangement direction of the third guide bar holes 113a of all third core punchings 113 to the angle between the arrangement direction of the first guide bar holes 111a of all first core punchings 111 and the third guide bar holes 113a of all third core punchings 113 is equal to 0.5. The ratio of the angle between the arrangement direction of the first guide bar holes 111a of all first core punchings 111 and the arrangement direction of the second guide bar holes 112a of all second core punchings 112 to the angle between the arrangement direction of the first guide bar holes 111a of all first core punchings 111 and the third guide bar holes 113a of all third core punchings 113 is equal to 0.5.

[0122] In the embodiment of the present application, it is beneficial to improve the connection arrangement of a first guide groove 114a, a second guide groove 115a, and a third guide groove 116a (as shown in Figures 4 and 6). This arrangement is beneficial to avoiding large-angle sudden changes in the flow direction of the aluminum liquid during the casting process, reducing the generation of pores, and improving the casting quality of the motor rotor 100.

[0123] 4 and 5 , in one embodiment, the number of the first core punching sheets 111 of the first sub-core 110 a is greater than the number of the second core punching sheets 112 of the second sub-core 110 b .

[0124] In the embodiment of the present application, the thickness of the punching sheets of the first sub-core 110a is the same as the thickness of the second sub-core punching sheets 112, and the number of first core punching sheets 111 of the first sub-core 110a is greater than the number of punching sheets of the second sub-core 110b. That is, along the motor rotor axial direction O, the thickness of the first sub-core 110a is greater than the thickness of the second sub-core 110b. The first guide bar holes 111a of the first core punching sheets 111 form the first guide slots 114, and the second guide bar holes 112a of the second core punching sheets 112 form the second guide slots 115. That is, along the motor rotor axial direction O, the length of the first guide slots 114 is greater than the length of the second guide slots 115. The first guide groove 114 is used to accommodate the first section 123 of the guide bar 122, and the second guide groove 115 is used to accommodate the second section 124 of the guide bar 122. In other words, along the axial direction O of the motor rotor, the length of the first section 123 of the guide bar 122 is greater than the length of the second section 124 of the guide bar 122 (as shown in FIG. 5 ). This reduces the portion of the guide bar parallel to the axial direction O of the motor rotor, and the length of the second section 124 is short, which is beneficial to reducing the radial electromagnetic force.

[0125] In the embodiment of the present application, the second guide slot 115 formed in the second sub-core 110b is parallel to the axial direction O of the motor rotor, and the second section 124 of the conductive bar 122 accommodated in the second guide slot 115 is parallel to the axial direction O of the motor rotor. If the second section 124 of the conductive bar 122 is long in the rotor core 110, that is, the thickness of the second sub-core 110b in the rotor core 110 along the axial direction O of the motor rotor is thick, the electromagnetic force amplitude of the motor rotor 100 may be too high, which may easily excite stator modal resonance.

[0126] Continuing to refer to FIG. 4 and FIG. 5 , in one embodiment, the number of the third core punching sheets 113 of the third sub-core 110 c is greater than the number of the second core punching sheets 112 of the second sub-core 110 b .

[0127] In the embodiment of the present application, the thickness of the third sub-core 110c punching sheet is the same as the thickness of the second sub-core punching sheet 112, and the number of first core punching sheets 111 in the third sub-core 110c is greater than the number of punching sheets in the second sub-core 110b. This means that along the motor rotor axial direction O, the thickness of the third sub-core 110c is greater than the thickness of the second sub-core 110b. The third guide bar hole 113a of the third core punching sheet 113 forms a third guide slot 116, and the second guide bar hole 112a of the second core punching sheet 112 forms a second guide slot 115. This means that along the motor rotor axial direction O, the length of the third guide slot 116 is greater than the length of the second guide slot 115. The third guide groove 116 is used to accommodate the third section 125 of the guide bar 122, and the second guide groove 115 is used to accommodate the second section 124 of the guide bar 122. In other words, along the axial direction O of the motor rotor, the length of the third section 125 of the guide bar 122 is greater than the length of the second section 124 of the guide bar 122, thereby reducing the portion of the guide bar parallel to the axial direction O of the motor rotor. The length of the second section 124 is short, which is beneficial to reducing the radial electromagnetic force.

[0128] In one embodiment, the first sub-core 110a and the third sub-core 110c are of equal length. In one embodiment, the first guide slot 114 and the third guide slot 116 are of equal length. In one embodiment, in each conductive bar 122, the length of the first segment 123 is equal to the length of the third segment 125. This ensures a uniform distribution of the rotor cage, which helps reduce radial electromagnetic forces, avoid torsional modal resonance, and improve the casting quality of the rotor core.

[0129] Referring to Figures 4, 12, and 13, Figure 13 is a cross-sectional view of a motor rotor 100 according to an embodiment of the present application. In one embodiment, the second sub-core 110b includes a motor shaft hole 131, multiple oil guide channels 117b (as shown in Figure 4), and multiple radial oil channels 118 (as shown in Figure 12). The oil guide channels 117b and the radial oil channels 118 are used to pass oil. The motor shaft hole 131 is used to accommodate the motor shaft 130. Each oil guide channel 117b is used to connect the internal oil channels of the first sub-core 110a and the third sub-core 110c. Each radial oil hole 112c is used to connect the internal oil channel 132 of the motor shaft 130 (as shown in Figure 13) and an oil guide channel 117b. The motor shaft hole 131, the multiple oil guide channels 117b, and the multiple second guide grooves 115 are sequentially arranged along the radial direction R of the motor rotor. Each radial oil passage 118 extends along the radial direction R of the motor rotor. Each radial oil passage 118 is arranged between the motor shaft hole 131 and one oil guide channel 117 b.

[0130] In the embodiment of the present application, the motor shaft hole 131 is used to accommodate the motor shaft 130, and the motor rotor 100 is fixed to the motor shaft 130. The second sub-core 110b includes at least two second core punchings 112, each of which includes a plurality of second oil guide holes 112b. At least one second core punching 112 includes a plurality of radial oil holes 112c. The plurality of second oil guide holes 112b of at least two second core punchings 112 are superimposed to form a plurality of oil guide channels 117b within the second sub-core 110b. The plurality of radial oil holes 112c are superimposed to form a plurality of radial oil passages 118. Each radial oil hole 112c is used to connect the internal oil passage 132 of the motor shaft 130 with one of the second oil guide holes 112b. Multiple oil guide channels 117b and multiple radial oil channels 118 are used to transport cooling oil from the internal oil channel 132 of the motor shaft 130 to cool the motor rotor 100. The cooling oil flows in sequence from the internal oil channel 132 of the motor shaft, the motor shaft oil outlet 133 (as shown in Figure 13), the radial oil holes 112c of the second sub-core 110b, and the radial oil channels 118 into the oil guide channels 117b of the second sub-core 110b. The oil guide channels 117b of the second sub-core 110b are parallel to the axial direction O of the motor rotor, which is conducive to the communication between the internal oil channel 132 of the motor shaft 130 and the oil guide channels 117b through the radial oil channels 118.

[0131] In the embodiment of the present application, along the radial direction R of the motor rotor, the motor shaft hole 131, the plurality of oil guide channels 117b, and the plurality of second guide grooves 115 (as shown in FIG4 ) are sequentially arranged at intervals. This facilitates the regular arrangement of the motor shaft hole 131, the plurality of second oil guide channels 112b, and the plurality of second guide bar holes 112a (as shown in FIG13 ) on the second core punching 112, and facilitates the processing and manufacturing of the second core punching 112. This facilitates the motor shaft hole 131 to accommodate the motor shaft 130, the plurality of oil guide channels 117b to conduct oil, and the plurality of second guide grooves 115 to accommodate the second sections 124 of the plurality of guide bars 122 (as shown in FIG5 ) without interfering with each other, thereby ensuring the normal operation of the motor rotor 100. Furthermore, along the radial direction R of the motor rotor, the plurality of oil guide channels 117b are located between the motor shaft hole 131 and the plurality of second guide grooves 115, which facilitates the cooling oil flowing through the oil guide channels 117b to better cool the interior of the rotor core 110.

[0132] In the embodiment of the present application, each radial oil passage 118 extends along the radial direction R of the motor rotor, and each radial oil passage 118 is arranged between the motor shaft hole 131 and an oil guide channel 117b, that is, each radial oil hole 112c extends along the radial direction R of the motor rotor, and each radial oil hole 112c is arranged between the motor shaft hole 131 and a second oil guide hole 112b. The radial oil passage 118 extends along the radial direction R of the motor rotor, which is beneficial for the cooling oil to flow from the internal oil passage 132 of the motor shaft 130 into the oil guide channel 117b along the direction of the centrifugal force of the rotation of the motor rotor 100 when the asynchronous motor 10 rotates, so as to cool the motor rotor 100 through the radial oil holes 112c and the radial oil passage 118, thereby reducing power loss.

[0133] In the embodiment of the present application, since the second guide slots 115 in the second sub-core 110b are parallel to the motor axial direction O, the second core punchings 112 are sequentially aligned along the motor axial direction O. Disposing the radial oil holes 112c in the second core punchings 112 allows all radial oil holes 112c in the second sub-core 110b to be aligned along the motor axial direction O, simplifying the manufacturing process. Compared to disposing the radial oil holes 112c in the first core punching 111 or the third core punching 113, since the first core punching 111 or the third core punching 113 need to be staggered, it is difficult to ensure that the radial oil holes 112c in the first core punching 111 or the third core punching 113 are connected, which increases the difficulty of connecting and arranging the radial oil holes 112c.

[0134] Continuing with FIG13 , in one embodiment, the motor shaft 130 further includes a bearing lubrication hole 134 and a bearing mounting position 135 . The bearing lubrication hole 134 is used to lubricate the motor bearing (not shown), and the bearing mounting position 135 is used to mount the motor bearing. Along the motor rotor axial direction O, the bearing mounting position 135 , the bearing lubrication hole 134 , and the rotor core 110 are sequentially spaced apart. The bearing lubrication hole 134 extends in a direction that intersects the motor rotor axial direction O. The inlet of the bearing lubrication hole 134 is connected to and communicates with the motor shaft hole 131 . Along the motor rotor axial direction O, the bearing mounting position 135 , the outlet of the bearing lubrication hole 134 , and the inlet of the bearing lubrication hole 134 are sequentially spaced apart, so that the bearing lubrication hole 134 sprays oil toward the motor bearing to cool the motor bearing.

[0135] In one embodiment, the inner diameter of the bearing lubrication hole 134 is smaller than the inner diameter of the motor shaft oil outlet hole 133, so that most of the cooling oil enters the rotor core 110 for cooling. In one embodiment, the number of bearing lubrication holes 134 is greater than or equal to 2, achieving more uniform cooling and lubrication of the motor bearings.

[0136] In one embodiment, the motor shaft hole 131 penetrates the motor shaft 130 along the motor rotor axis O, so that cooling oil is supplied to the input shaft of the reducer 20 through the motor shaft hole 131 to cool the gear set, bearings, and shaft of the reducer 20. In one embodiment, as shown in FIG13 , the motor shaft hole 131 may not penetrate the motor shaft 130.

[0137] Referring to FIG. 4 , FIG. 8 , FIG. 10 and FIG. 12 , in one embodiment, the first core punching sheet 111 includes a plurality of first oil guide holes 111 b , and the third core punching sheet 113 includes a plurality of third oil guide holes 113 b .

[0138] In the embodiment of the present application, the multiple first oil guide holes 111b of at least two first core punching sheets 111 are superimposed to form multiple oil guide channels 117a in the first sub-core 110a (as shown in FIG4 ), and the multiple third oil guide holes 113b of at least two third core punching sheets 113 are superimposed to form multiple oil guide channels 117c in the third sub-core 110c. The multiple oil guide channels 117c in the first sub-core 110a, the second sub-core 110b, and the third sub-core 110c are 17a, 117b, and 117c (as shown in FIG4 ) are interconnected to form an oil guide channel 117 in the iron core of the motor rotor 100, and the cooling oil flows in sequence from the multiple radial oil channels 118 (as shown in FIG12 ) of the second sub-core 110b and the multiple oil guide channels 117b of the second sub-core 110b, and then flows into the multiple oil guide channels 117a and 117c in the first sub-core 110a and the third sub-core 110c, respectively, for cooling the rotor core 110.

[0139] Referring to Figures 8, 10 and 12, in one embodiment, along the radial direction R of the motor rotor, the distances between the first oil guide hole 111b, the second oil guide hole 112b, the third oil guide hole 113b and the motor shaft hole 131 are respectively smaller than the distances between the first guide bar hole 111a, the second guide bar hole 112a, the third guide bar hole 113a and the motor shaft hole 131.

[0140] In the embodiment of the present application, along the radial direction R of the motor rotor, the first oil guide hole 111b is arranged between the motor shaft hole 131 and the first guide bar hole 111a, the second oil guide hole 112b is arranged between the motor shaft hole 131 and the second guide bar hole 112a, and the third oil guide hole 113b is arranged between the motor shaft hole 131 and the third guide bar hole 113a, which is conducive to the cooling oil in the oil guide channel 117 being able to simultaneously cool the first guide groove 114, the second guide groove 115, and the third guide groove. 116, the guide bar 122, and the motor shaft 130 are cooled. At the same time, the first guide bar hole 111a, the second guide bar hole 112a, and the third guide bar hole 113a are arranged closer to the outer peripheral surface of the rotor core 110, which is convenient for the integral die-casting of the two end rings 121 and the multiple guide bars 122 of the rotor squirrel cage 120. The circumference close to the outer peripheral surface is longer, which is conducive to forming a larger number of first guide bar holes 111a, second guide bar holes 112a, and third guide bar holes 113a.

[0141] Please continue to refer to Figures 8, 10 and 12. In one embodiment, along the circumferential direction C of the motor rotor, the maximum length of each first oil guide hole 111b of the first core punching sheet 111 is greater than the maximum length of each first guide bar hole 111a, the maximum length of each second oil guide hole 112b of the second core punching sheet 112 is greater than the maximum length of each second guide bar hole 112a, and the maximum length of each third oil guide hole 113b of the third core punching sheet 113 is greater than the maximum length of each third guide bar hole 113a.

[0142] In the embodiment of the present application, along the circumferential direction C of the motor rotor, the maximum lengths of the first oil guide hole 111b, the second oil guide hole 112b, and the third oil guide hole 113b are relatively large, which is beneficial to ensuring that the first oil guide holes 111b of the two adjacent first core punchings 111 can be connected when they are staggered, and is beneficial to ensuring that the third oil guide holes 113b of the two adjacent third core punchings 113 can be connected when they are staggered.

[0143] In the embodiment of the present application, along the circumferential direction C of the motor rotor, the maximum lengths of the first oil guide hole 111b, the second oil guide hole 112b, and the third oil guide hole 113b are relatively large, which is beneficial to increasing the contact area between the cooling oil and the rotor core 110 and improving the cooling effect on the rotor core 110.

[0144] Please refer to Figures 8, 10 and 12. In one embodiment, multiple first oil guide holes 111b, multiple second oil guide holes 112b, and multiple third oil guide holes 113b are respectively arranged at intervals along the circumferential direction C of the motor rotor, and multiple first guide bar holes 111a, multiple second guide bar holes 112a, and multiple third guide bar holes 113a are respectively arranged at intervals along the circumferential direction C of the motor rotor. In the embodiment of the present application, it is beneficial to the regular arrangement of the openings on the first core punching sheet 111, the second core punching sheet 112, and the third core punching sheet 113, and it is also beneficial to the processing and manufacturing of the first core punching sheet 111, the second core punching sheet 112, and the third core punching sheet 113.

[0145] Referring to Figures 4, 8, 10, and 12, in one embodiment, along the circumferential direction C of the motor rotor, the distance between two adjacent first oil guide holes 111b is greater than the distance between two adjacent first guide bar holes 111a, the distance between two adjacent second oil guide holes 112b is greater than the distance between two adjacent second guide bar holes 112a, and the distance between two adjacent third oil guide holes 113b is greater than the distance between two adjacent third guide bar holes 113a. Along the circumferential direction C of the motor rotor, the number of first oil guide holes 111b is less than the number of first guide bar holes 111a, the number of second oil guide holes 112b is less than the number of second guide bar holes 112a, and the number of third oil guide holes 113b is less than the number of third guide bar holes 113a. In this embodiment of the present application, the arrangement of the oil guide channels 117 within the iron core of the motor rotor 100 (as shown in Figure 4) is reduced, which helps to strengthen the rotor core 110.

[0146] In one embodiment, the first guide slots 114 of the first sub-core 110a, the second guide slots 115 of the second sub-core 110b, and the third guide slots 116 of the third sub-core 110c can also be formed directly by machining. For example, multiple core punchings are stacked and then machined to form the first guide slots 114, the second guide slots 115, and the third guide slots 116. For example, the first guide slots 114, the second guide slots 115, and the third guide slots 116 can be formed on a single core. Forming the first guide bar holes 111a in each first core punching 111 simplifies the process compared to directly machining the first guide slots 114 in the first sub-core 110a. The same applies to the second guide slots 115 of the second sub-core 110b and the third guide slots 116 of the third sub-core 110c.

[0147] In one embodiment, the asynchronous motor 10 of the present application can also be applied to small asynchronous motor businesses, for example, refrigerators, washing machines, air conditioners and small industrial asynchronous motor rotors.

[0148] The above is a detailed introduction to the asynchronous motor and its motor rotor, powertrain and electric vehicle provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and embodiments of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there may be changes in the specific embodiments and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A motor rotor of an asynchronous motor, characterized in that: The motor rotor comprises a rotor core and a rotor cage, wherein the rotor cage comprises two end rings and a plurality of guide bars, wherein the two end rings are fixed to the two ends of the rotor core along the axial direction of the motor rotor, and the plurality of guide bars are fixed to the inside of the rotor core, wherein: Each of the conductive bars comprises a first section, a second section and a third section, wherein the first section, the second section and the third section are sequentially connected along the axial direction of the motor rotor, the second section is parallel to the axial direction of the motor rotor, the first section and the third section of each conductive bar intersect in the axial direction of the motor rotor, and the first section and the third section are deflected to the same side from the second section along the circumferential direction of the motor rotor.

2. The motor rotor according to claim 1, characterized in that: The two end rings and the plurality of guide bars are integrally die-cast, the two end rings are integrally die-cast at both ends of the rotor core, and the plurality of guide bars are integrally die-cast inside the rotor core.

3. The motor rotor according to claim 1 or 2, characterized in that: In each of the conductive bars, an angle between the second segment and any one of the first segment and the third segment is smaller than an angle between the first segment and the third segment.

4. The motor rotor according to any one of claims 1 to 3, characterized in that: In each of the conductive bars, an angle between the first segment and the second segment is equal to an angle between the third segment and the second segment.

5. The motor rotor according to any one of claims 1 to 4, characterized in that: In each of the conductive bars, an end surface of the first segment facing the second segment is aligned with an end surface of the second segment facing the first segment, and an end surface of the second segment facing the third segment is aligned with an end surface of the third segment facing the second segment.

6. The motor rotor according to any one of claims 1 to 5, characterized in that: In each of the conductive bars, along the axial direction of the motor rotor, a length of at least one of the first segment and the third segment is greater than a length of the second segment.

7. The motor rotor according to any one of claims 1 to 6, characterized in that: In each of the conductive bars, the first section and the third section are equal in length.

8. The motor rotor according to any one of claims 1 to 7, characterized in that: The rotor core comprises a first sub-core, a second sub-core and a third sub-core, wherein the first sub-core, the second sub-core and the third sub-core are arranged adjacent to each other in sequence along the axial direction of the motor rotor, the first sub-core, the second sub-core and the third sub-core respectively comprise a plurality of first guide grooves, a plurality of second guide grooves and a plurality of third guide grooves, one of the second guide grooves is used to accommodate the second section of one of the guide bars, and one of the first guide grooves and one of the third guide grooves are respectively used to accommodate the first section and the third section of one of the guide bars, wherein: Each of the second guide grooves penetrates the second sub-core along the axial direction of the motor rotor; Each of the first guide grooves and each of the third guide grooves respectively penetrates the first sub-core and the third sub-core along a direction intersecting the axial direction of the motor rotor, and the first guide groove and the third guide groove deflect toward the same side from the second guide groove along the circumferential direction of the motor rotor.

9. The motor rotor according to claim 8, characterized in that: The first sub-core includes at least two first core punching sheets, the at least two first core punching sheets are stacked along the axial direction of the motor rotor, each of the first core punching sheets includes a plurality of first guide bar holes, and each of the first guide bar holes penetrates the first core punching sheet along the axial direction of the motor rotor, wherein: The first guide bar holes of each of the at least two first core punching sheets are staggered in sequence in a clockwise direction to form a first guide groove.

10. The motor rotor according to claim 9, characterized in that: The staggered angles of the first guide bar holes in every two adjacent first core punching sheets are the same.

11. The motor rotor according to claim 8, characterized in that: The third sub-core includes at least two third core punching sheets, the at least two third core punching sheets are stacked along the axial direction of the motor rotor, each of the third core punching sheets includes a plurality of third guide bar holes, and each of the third guide bar holes penetrates the third core punching sheet along the axial direction of the motor rotor, wherein: The third guide bar holes of each of the at least two third core punching sheets are staggered in sequence counterclockwise to form a third guide groove.

12. The motor rotor according to claim 8, characterized in that: The second sub-core comprises at least two second core punching sheets, the at least two second core punching sheets are stacked along the axial direction of the motor rotor, each of the second core punching sheets comprises a plurality of second guide bar holes, each of the second guide bar holes penetrates the second core punching sheet along the axial direction of the motor rotor, wherein: One of the second guide bar holes of each of the at least two second core punching sheets is aligned along the axial direction of the motor rotor to form a second guide groove.

13. The motor rotor according to claim 8, characterized in that: The second sub-core comprises a motor shaft hole, a plurality of oil guide channels and a plurality of radial oil channels, wherein the oil guide channels and the radial oil channels are used for passing oil, the motor shaft hole is used for accommodating the motor shaft, each of the oil guide channels is used for connecting the internal oil channels of the first sub-core and the third sub-core, and each of the radial oil holes is used for connecting the internal oil channel of the motor shaft and one of the oil guide channels, wherein: Along the radial direction of the motor rotor, the motor shaft hole, the plurality of oil guide channels and the plurality of second guide grooves are sequentially arranged at intervals; Each of the radial oil passages extends radially along the motor rotor, and each of the radial oil passages is arranged between the motor shaft hole and one of the oil guide channels.

14. An asynchronous motor, characterized in that: The asynchronous motor comprises a motor housing, a motor stator, a motor shaft and a motor rotor as described in any one of claims 1 to 13, wherein the motor housing is used to sleeve and fix the motor stator, the motor stator is used to sleeve on the motor rotor, and the motor rotor is used to sleeve on and fix on the motor shaft.

15. A powertrain, characterized in that: The power assembly includes a reducer and an asynchronous motor as claimed in claim 14, wherein the motor shaft of the asynchronous motor is used for driving connection with the input shaft of the reducer, and the output shaft of the reducer is used for driving connection with the wheels of the electric vehicle.

16. An electric vehicle, characterized in that: The electric vehicle comprises a body, wheels, a reducer and the power assembly as claimed in claim 15, wherein the body is used to fix the power assembly, and the power assembly is used to drive the wheels.

Images