Built-in disc motor, power assembly and electric vehicle

Abstract

The application provides an in-built disc type motor, a power assembly and an electric vehicle. The in-built disc type motor comprises an in-built rotor. A plurality of first magnets of the in-built rotor are arranged along the circumferential direction of the in-built rotor and are inserted into a rotor core of the in-built rotor along the radial direction of the in-built rotor. The first magnet is inserted into a first end surface of the rotor core along the radial direction of the in-built rotor from the outer circumferential surface of the rotor core, and the first end surface is a plane, thereby reducing the magnetic steel loss amount of the first end surface, reducing the production cost, simplifying the processing technology, the second end surface opposite to the first end surface along the radial direction of the in-built rotor is an arc surface, thereby ensuring that the first magnet has sufficient filling rate in the rotor core, being beneficial to reducing the torque fluctuation of the in-built rotor, improving the reliability of the in-built rotor, and ensuring that the work of the in-built rotor can be normally performed. The scheme can improve the magnetic steel utilization rate while ensuring that the work of the in-built rotor is not affected, and reduce the production cost.

Description

Technical Field

[0001] This application relates to the field of electric vehicle technology, and in particular to a built-in disc motor, powertrain, and electric vehicle. Background Technology

[0002] Built-in disc motors have attracted attention due to their advantages such as compact structure, high torque density, and high efficiency. The built-in rotor of a built-in disc motor includes multiple magnets inserted radially into the rotor core. Both end faces of the magnets along the radial direction of the built-in rotor are arc surfaces. However, the raw materials for the magnets are generally rectangular, requiring the inner and outer sides of the rectangular magnets to be cut to form the two arc surfaces. This results in significant waste of magnet material, low magnet utilization, and high production costs for built-in rotors. Summary of the Invention

[0003] This application provides a built-in disc motor, powertrain, and electric vehicle to improve the utilization rate of magnets and reduce production costs.

[0004] In a first aspect, this application provides an internal disc motor, which includes an internal rotor. A plurality of first magnets of the internal rotor are arranged at circumferential intervals along the internal rotor and inserted radially into the rotor core of the internal rotor. The first end face of the first magnet inserted radially from the outer circumferential surface of the rotor core into the rotor core is a plane, and the second end face of the first magnet opposite the first end face radially to the internal rotor is an arc surface.

[0005] In this embodiment, during the manufacturing process of the built-in rotor, the first magnet is formed by machining magnetic steel. The incoming magnetic steel is typically rectangular in shape. The first magnet is inserted radially from the outer circumference of the rotor core into the first end face of the rotor core, which is a plane. This eliminates the need for cutting when forming the first end face of the incoming magnetic steel, reducing magnetic steel loss, improving magnetic steel utilization, and lowering production costs. It also simplifies the machining process of the first end face.

[0006] In this embodiment, the second end face of the first magnet, which is opposite to the first end face along the radial direction of the built-in rotor, is an arc surface. This allows the first magnet to better fit the outer circumference of the rotor core, enabling the first magnet to occupy more space within the rotor core and resulting in a higher magnet filling rate in the rotor core. This, in turn, helps ensure the normal operation of the rotor core.

[0007] Typically, the first magnet has two curved end faces along the radial direction of the built-in rotor. However, the incoming magnet material is rectangular with two flat end faces. This requires cutting the inner and outer sides of the incoming magnet material to form the two curved end faces, resulting in significant material loss and high production costs. In contrast, the first magnet in this application has a flat first end face and a curved second end face. Only the outer side of the incoming magnet material needs to be cut to form the curved surface, reducing magnet loss, increasing magnet utilization, and lowering production costs.

[0008] In this embodiment, by setting the first end face of the first magnet to a plane, the loss of magnet steel forming the first end face is reduced, production costs are lowered, and the processing technology is simplified. Furthermore, setting the second end face to an arc surface ensures sufficient filling rate of the first magnet within the rotor core. This helps to minimize torque fluctuations in the built-in rotor, improves its reliability, and ensures normal operation. Thus, it is possible to improve magnet steel utilization and reduce production costs while ensuring the operation of the built-in rotor is not affected.

[0009] In one embodiment, the first end face is configured to form two right angles with the two sides of the first magnet distributed circumferentially along the built-in rotor.

[0010] In this embodiment, the first end face forms two right angles with the two sides of the first magnet distributed circumferentially along the built-in rotor. This allows the two sides of the first magnet to retain the shape of the incoming magnet material without cutting or trimming, thereby further improving the utilization rate of the magnet material and reducing production costs. Reducing cutting also simplifies the processing technology of the first magnet.

[0011] In one embodiment, along the arrangement direction of the first end face and the second end face, the distance between the second end face and the first end face gradually decreases from the midpoint of the second end face along the circumferential direction of the built-in rotor to both sides.

[0012] In this embodiment, along the arrangement direction of the first end face and the second end face, the distance between the second end face and the first end face gradually decreases from the midpoint of the second end face along the circumference of the built-in rotor to both sides. This makes the arc surface of the second end face of the first magnet more compatible with the arc shape of the outer circumference of the rotor core. This results in a smaller volume of incoming magnet material being cut during the processing of the second end face of the first magnet, leading to higher utilization of the magnet and reducing production costs.

[0013] In one embodiment, along the arrangement direction of the first end face and the second end face, the distance between the two ends of the second end face and the first end face along the circumferential direction of the built-in rotor is equal.

[0014] In this embodiment, along the arrangement direction of the first and second end faces, the distance between the two ends of the second end face and the first end face along the circumferential direction of the built-in rotor is equal. This results in a smaller cutting volume of the incoming magnet material during the formation of the first magnet, leading to higher utilization of the magnet material and reducing production costs. Furthermore, it allows for a higher filling rate after the first magnet is inserted into the rotor core, resulting in smaller torque fluctuations in the built-in rotor and improved reliability.

[0015] In one embodiment, the built-in rotor further includes a plurality of second magnets, each second magnet being arranged radially inside a first magnet. Each second magnet includes a third end face and a fourth end face arranged radially opposite to each other on the built-in rotor, the fourth end face being closer to the first end face than the third end face. The fourth end face is parallel to the first end face.

[0016] In this embodiment, each second magnet is arranged radially inside a first magnet along the inner side of the built-in rotor. The fourth end face is closer to the first end face than the third end face, and the fourth end face is parallel to the first end face. This allows the fourth end face of the second magnet to better fit with the first end face of the first magnet, resulting in a higher filling rate of the second and first magnets within the rotor core. This helps to reduce torque fluctuations in the built-in rotor and improve its reliability. It also helps to increase the stability of the first and second magnets within the rotor core during rotor rotation.

[0017] In this embodiment, the fourth end face is parallel to the first end face, and the first end face is a plane, so that the fourth end face is also a plane. This allows the incoming magnet material to be formed into the fourth end face of the second magnet without cutting, which is beneficial to improving the utilization rate of the magnet, reducing production costs, and simplifying the process.

[0018] In one embodiment, the fourth end face is used to form two right angles with the two sides of the second magnet distributed circumferentially along the built-in rotor.

[0019] In this embodiment, the fourth end face is used to form two right angles with the two sides of the second magnet distributed circumferentially along the built-in rotor, so that the incoming magnet material can form the fourth end face of the second magnet and the two sides distributed circumferentially along the built-in rotor without cutting, which makes the utilization rate of the incoming magnet material high, which is conducive to reducing production costs and simplifying the production process.

[0020] In one embodiment, the third end face is parallel to the fourth end face.

[0021] In this embodiment, the third end face is parallel to the fourth end face, and the fourth end face is planar, making the third end face also planar. This eliminates the need for cutting the third end face of the incoming magnet to form the second magnet, thus eliminating the need for cutting during the formation of the second magnet. This results in high overall utilization of the magnet during the manufacturing of the built-in rotor, which helps reduce production costs. Furthermore, it eliminates the need for additional processing of the second magnet, simplifying the manufacturing process of the built-in rotor.

[0022] In one embodiment, the line connecting the first end face and the third end face at the same end along the circumference of the built-in rotor is parallel to the radial direction of the built-in rotor.

[0023] In this embodiment, the line connecting the first end face and the third end face along the same end of the circumference of the built-in rotor is parallel to the radial direction of the built-in rotor. This makes the magnet filling rate in the rotor core higher after the first magnet and the second magnet are inserted into the rotor core, which helps to reduce the torque fluctuation of the built-in rotor and improve the reliability of the built-in rotor.

[0024] In one embodiment, along the arrangement direction of the first end face and the second end face, the sum of the lengths of the first magnet and the second magnet is less than or equal to half the difference between the outer diameter of the outer circumferential surface and the inner diameter of the inner circumferential surface of the rotor core.

[0025] In one embodiment, the built-in rotor further includes a plurality of first rectangular magnets, with two first rectangular magnets arranged on either side of the first magnet along the circumference of the built-in rotor. The length of the first rectangular magnet is greater than the distance between the two ends of the second end face along the circumference of the built-in rotor and the first end face along the arrangement direction of the first and second end faces, and one end of the first rectangular magnet facing the axis of the built-in rotor protrudes from the first end face.

[0026] In this embodiment of the application, two first rectangular magnets are arranged on both sides of the first magnet along the circumference of the built-in rotor, so that the two first rectangular magnets can increase the magnet filling rate in the rotor core of the built-in rotor, which is beneficial to reduce the torque fluctuation of the built-in rotor and improve the reliability of the built-in rotor.

[0027] In this embodiment, the first magnet is missing magnets on both sides of the magnetic steel slot inside the rotor core because the first end face is flat. Along the arrangement direction of the first end face and the second end face, the length of the first rectangular magnet is greater than the distance between the two ends of the second end face and the first end face along the circumference of the built-in rotor. This allows the first rectangular magnet to compensate for and increase the magnetic steel filling rate inside the rotor core, thereby optimizing the magnetic field distribution, increasing the air gap magnetic field strength, reducing torque fluctuations, and improving the overall efficiency of the built-in disc motor.

[0028] In this embodiment, one end of the first rectangular magnet facing the axis of the built-in rotor protrudes from the first end face, which makes it easier for the first rectangular magnet to fill the two sides of the shorter side of the first magnet in the rotor core along the radial direction of the built-in rotor. This results in a high magnet filling rate in the rotor core, which can optimize the magnetic field distribution, increase the magnetic flux density, reduce torque fluctuation, improve the reliability of the built-in rotor, and improve the overall efficiency of the built-in disc motor.

[0029] In one embodiment, along the direction perpendicular to the arrangement direction of the first and second end faces, the width of the first rectangular magnet is greater than or equal to 2 mm and less than or equal to 5 mm. This ensures that the first rectangular magnet can both compensate for and increase the magnet filling rate in the rotor core without making the volume too large, and that the magnet slots have sufficient space to accommodate the first magnet.

[0030] In one embodiment, the built-in rotor further includes a plurality of second rectangular magnets, with two second rectangular magnets arranged on either side of the second magnet along the circumference of the built-in rotor. The length of the second rectangular magnet along the radial direction of the built-in rotor is less than the distance between the third and fourth end faces.

[0031] In this embodiment, two second rectangular magnets are arranged on both sides of the second magnet along the circumference of the built-in rotor. Because the fourth end face of the second magnet is flat, the magnets on both sides of the magnetic steel slot in the rotor core used to accommodate the second magnet are missing. This allows the two second rectangular magnets to compensate for and increase the magnetic steel filling rate in the rotor core of the built-in rotor, optimize the magnetic field distribution, increase the magnetic flux density, reduce torque fluctuation, improve the reliability of the built-in rotor, and improve the overall efficiency of the built-in disc motor.

[0032] In this embodiment, the length of the second rectangular magnet along the radial direction of the built-in rotor is less than the distance between the third end face and the fourth end face. This allows for optimization of the magnetic field distribution by filling the two sides of the second rectangular magnet, increasing the magnetic flux density, reducing torque fluctuations, and reducing the use of magnetic steel material to form the second rectangular magnet, thus saving materials and reducing production costs.

[0033] In one embodiment, the width of the second rectangular magnet is greater than or equal to 2 mm and less than or equal to 2 mm along a direction perpendicular to the arrangement direction of the first and second end faces. This ensures that the second rectangular magnet can both compensate for and increase the magnet filling rate in the rotor core without making the volume too large, and that the magnet slots have sufficient space to accommodate the second magnet.

[0034] In one embodiment, one end of the second rectangular magnet facing the axis of the built-in rotor is flush with the third end face, and the other end of the second rectangular magnet away from the axis of the built-in rotor is spaced apart from the first end face.

[0035] In this embodiment, one end of the second rectangular magnet facing the axis of the built-in rotor is flush with the third end face, which reduces the magnetic leakage at both ends of the third end face of the second rectangular magnet, allowing more of the magnetic field to be directed to the air gap between the built-in rotor and the stator, thereby increasing the main magnetic flux density and output torque.

[0036] In this embodiment, one end of the second rectangular magnet facing the axis of the built-in rotor is flush with the third end face. The length of the second rectangular magnet along the radial direction of the built-in rotor is less than the distance between the third end face and the fourth end face. The fourth end face of the second magnet is adjacent to the first end face of the first magnet, so that the other end of the second rectangular magnet away from the axis of the built-in rotor is spaced apart from the first end face.

[0037] In one embodiment, one end of the second rectangular magnet facing the axis of the built-in rotor protrudes from the third end face, and this end is flush with the inner circumferential surface of the rotor core. This reduces magnetic leakage at both ends of the third end face of the second rectangular magnet, allowing more of the magnetic field to be directed into the air gap between the built-in rotor and the stator, thereby increasing the main magnetic flux density and output torque.

[0038] In one embodiment, the second rectangular magnet has the same shape as the first rectangular magnet.

[0039] In this embodiment, the first rectangular magnet and the second rectangular magnet can use the same specification of magnet material, which standardizes the magnets and reduces the types of magnets used in the built-in rotor, thus helping to reduce production costs.

[0040] In one embodiment, the built-in rotor further includes a third magnet, which is stacked at intervals on the first magnet along the axial direction of the built-in rotor. The length of the third magnet along the circumferential direction of the built-in rotor is less than the length of the first magnet. The third magnet has a fifth end face and a sixth end face arranged opposite each other along the radial direction of the built-in rotor, with the fifth end face being closer to the axis of the built-in rotor than the sixth end face. The fifth end face is parallel to the first end face.

[0041] In this embodiment, the third magnet is stacked on top of the first magnet at intervals along the axial direction of the built-in rotor. The length of the third magnet along the circumferential direction of the built-in rotor is less than the length of the first magnet. This allows the third magnet to be used to gather the magnetic lines of force in the built-in rotor, thereby enhancing the strength of the magnets in the built-in rotor, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0042] In this embodiment, the fifth and sixth end faces of the third magnet are arranged radially opposite to each other along the built-in rotor. The fifth end face is closer to the axis of the built-in rotor than the sixth end face. The first end face is planar, and the fifth end face is parallel to the first end face, making the fifth end face of the third magnet also planar. This eliminates the need to cut the incoming magnet material to form the fifth end face, which helps improve the utilization rate of the magnet and reduce production costs. Furthermore, the fifth end face of the third magnet can be flush with the first end face of the first magnet along the axial direction of the built-in rotor, allowing the third magnet to better concentrate the magnetic lines of force generated by the first magnet.

[0043] In one embodiment, the length difference between the first magnet and the third magnet is greater than or equal to 4 mm along a direction perpendicular to the arrangement direction of the first and second end faces. This allows the third magnet to be used to gather the magnetic lines of force in the built-in rotor, thereby enhancing the strength of the magnets in the built-in rotor, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0044] In one embodiment, the built-in rotor further includes a fourth magnet, which is stacked at intervals on the second magnet along the axial direction of the built-in rotor. The length of the fourth magnet is less than the length of the second magnet along the circumferential direction of the built-in rotor. The fourth magnet has a seventh end face and an eighth end face that are arranged opposite each other in the radial direction of the built-in rotor. The seventh end face is closer to the axis of the built-in rotor than the eighth end face. The eighth end face is parallel to the fifth end face.

[0045] In this embodiment, the fourth magnet is stacked on top of the second magnet at intervals along the axial direction of the built-in rotor. Along the circumference of the built-in rotor, the length of the fourth magnet is less than the length of the second magnet, so that the fourth magnet can be used to gather the magnetic lines of force in the built-in rotor, thereby enhancing the strength of the magnets in the built-in rotor, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0046] In this embodiment, the seventh and eighth end faces of the fourth magnet are arranged radially opposite to each other along the built-in rotor. The seventh end face is closer to the axis of the built-in rotor than the eighth end face. The eighth end face is parallel to the fifth end face, and the fifth end face is parallel to the first end face, making the eighth end face planar. This eliminates the need to cut the incoming magnet material to form the eighth end face, which helps to improve the utilization rate of the magnet and reduce production costs.

[0047] In one embodiment, the length difference between the second magnet and the fourth magnet is greater than or equal to 4 mm along a direction perpendicular to the arrangement direction of the first and second end faces. This allows the fourth magnet to be used to gather the magnetic lines of force in the built-in rotor, thereby enhancing the strength of the magnets in the built-in rotor, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0048] In one embodiment, the first magnet, the second magnet, the first rectangular magnet, and the second rectangular magnet are high-coercivity magnets, while the third magnet and the fourth magnet are low-coercivity magnets. This helps reduce magnetic leakage, enhances the magnetic field strength, reduces eddy current losses, and improves the reliability of the built-in rotor.

[0049] In one embodiment, the first magnet, the second magnet, the third magnet, and the fourth magnet are made of four different types of magnets, while the first rectangular magnet and the second rectangular magnet are made of the same type of magnet. This means that the built-in rotor in this embodiment only needs to use one type of magnet, which helps to reduce production costs.

[0050] In one embodiment, the combination of a first magnet, a second magnet, a third magnet, a fourth magnet, a first rectangular magnet, and a second rectangular magnet, compared to using a combination of magnets with two curved end faces arranged radially along the built-in rotor, can increase the utilization rate of the magnets by more than 15%. It can also improve the strength of the magnets and prevent the risk of cracking in the magnetic bridge.

[0051] In one embodiment, the first magnet, second magnet, third magnet, fourth magnet, first rectangular magnet, and second rectangular magnet are integrated into a single structure. This simplifies the assembly of the built-in rotor and also enhances its structural strength and stability.

[0052] In one embodiment, the first magnet, the second magnet, the first rectangular magnet, the second rectangular magnet, the third magnet, and the fourth magnet can be segmented into at least two sub-magnets along the radial direction or the circumferential direction of the built-in rotor. Segmenting the magnets helps reduce eddy current losses on the magnet surface and reduces torque ripple in the built-in rotor. It also simplifies the magnet manufacturing process.

[0053] In one embodiment, the first magnet, second magnet, third magnet, fourth magnet, first rectangular magnet, and second rectangular magnet are of a split structure, which can be divided into two sub-magnets along the arrangement direction of the first and second end faces. The two sub-magnets of the second magnet, fourth magnet, first rectangular magnet, and second rectangular magnet are of the same shape and size. One sub-magnet of the first magnet near the axis of the built-in rotor is rectangular, and the other sub-magnet away from the axis of the built-in rotor has two opposite end faces arranged radially along the built-in rotor, one of which is a plane and the other is an arc surface; the arc surface forms the second end face of the first magnet. Similarly, one sub-magnet of the third magnet near the axis of the built-in rotor is rectangular, and the other sub-magnet away from the axis of the built-in rotor has two opposite end faces arranged radially along the built-in rotor, one of which is a plane and the other is an arc surface; the arc surface forms the sixth end face of the third magnet. Segmenting the magnets helps reduce eddy current losses on the magnet surface and reduces torque ripple in the built-in rotor.

[0054] In one embodiment, the first, second, third, and fourth magnets are circumferentially separated into two sub-magnets along the built-in rotor. The two sub-magnets are identical in shape and size. The length of one sub-magnet of the first magnet, along the arrangement direction of the first and second end faces, gradually decreases from the end closer to the other sub-magnet to the end farther away. This segmentation of the magnets helps reduce eddy current losses on the magnet surface and thus reduces torque ripple in the built-in rotor.

[0055] In one embodiment, the rotor core includes a plurality of first magnet slots and a plurality of second magnet slots. The plurality of first magnet slots and the plurality of second magnet slots are arranged at intervals along the circumference of the built-in rotor. Each first magnet slot and a second magnet slot are arranged adjacent to and communicate with each other along the radial direction of the built-in rotor. The first magnet slots penetrate the outer circumferential surface of the rotor core, and the second magnet slots penetrate the inner circumferential surface of the rotor core. The first magnet slots are used to accommodate a first magnet and a first rectangular magnet, and the second magnet slots are used to accommodate a second magnet and a second rectangular magnet.

[0056] In one embodiment, the minimum spacing between two adjacent second magnet slots along the circumference of the built-in rotor is greater than or equal to 2 mm. This helps ensure sufficient structural strength of the rotor core and improves the reliability of the built-in rotor.

[0057] In one embodiment, the rotor core further includes a plurality of third magnet slots and a plurality of fourth magnet slots. The plurality of third magnet slots and the plurality of fourth magnet slots are arranged at intervals along the circumference of the built-in rotor. Each third magnet slot is radially adjacent to and communicates with one fourth magnet slot along the radial direction of the built-in rotor. The third magnet slots penetrate the outer circumferential surface of the rotor core, and the fourth magnet slots penetrate the inner circumferential surface of the rotor core. The third magnet slots are used to accommodate third magnets, and the fourth magnet slots are used to accommodate fourth magnets. Along the axial direction of the built-in rotor, the third magnet slots are spaced apart from the first magnet slots, and the fourth magnet slots are spaced apart from the second magnet slots. Along the circumferential direction of the built-in rotor, the third magnet slots are spaced apart from the first rectangular magnets, and the fourth magnet slots are spaced apart from the second rectangular magnets.

[0058] In one embodiment, the rotor core further includes a plurality of first reinforcing ribs. The first reinforcing ribs extend radially along the built-in rotor within the first magnet slot and the second magnet slot. The first reinforcing ribs are used to improve the structural strength of the rotor core, reduce the deformation of the rotor core after winding, and improve the reliability of the built-in rotor. The first reinforcing ribs can also be used to separate the first magnet and the second magnet along the circumference of the built-in rotor, so that the first magnet and the second magnet are segmented. The segmentation of the magnets helps to reduce eddy current losses on the surface of the magnets and reduce torque fluctuations.

[0059] In one embodiment, the number of first reinforcing ribs in the first magnet slot and the second magnet slot is one. This allows the first magnet and the second magnet to be arranged in segments, which helps to reduce eddy current losses on the magnet surface and reduces torque fluctuations in the built-in rotor.

[0060] In another embodiment, the number of first reinforcing ribs in the first and second magnet slots is two or more. This allows the first and second magnets to be arranged in multiple segments, which helps reduce eddy current losses on the magnet surface and reduces torque fluctuations in the built-in rotor.

[0061] In one embodiment, the width of the first reinforcing rib along the circumference of the built-in rotor is less than or equal to 3 mm. This ensures that the first reinforcing rib improves the structural strength of the rotor core without excessively occupying the space of the magnet slots within the rotor core, and also helps to concentrate the magnetic lines of force of the first and second magnets.

[0062] In one embodiment, the rotor core further includes a plurality of second reinforcing ribs. The second reinforcing ribs extend radially along the built-in rotor within the third and fourth magnet slots. The second reinforcing ribs are used to enhance the structural strength of the rotor core. The second reinforcing ribs can also be used to separate the third and fourth magnets circumferentially along the built-in rotor, so that the third and fourth magnets are segmented. The segmentation of the magnets helps to reduce eddy current losses on the surface of the magnets and reduce torque fluctuations.

[0063] In one embodiment, the width of the second reinforcing rib is greater than or equal to 0 along the circumferential direction of the built-in rotor. This ensures that the second reinforcing rib enhances the structural strength of the rotor core 220 without excessively occupying the space of the magnet slots within the rotor core.

[0064] In one embodiment, the number of second reinforcing ribs within the third magnet slot is one or more. This allows the third and fourth magnets to be arranged in segments, which helps reduce eddy current losses on the magnet surface and thus reduces torque fluctuations in the built-in rotor. It also helps improve the structural strength of the rotor core.

[0065] In one embodiment, the first magnet slot includes a first reinforcing rib, while the third magnet slot has no second reinforcing rib. This simplifies the machining process of the rotor core.

[0066] In one embodiment, the rotor core includes multiple partial arcs located on the outer side of the end face of the rotor core along the axial direction of the built-in rotor and along the circumferential direction of the built-in rotor. A portion of the partial arcs are arranged between the first and third magnet slots, while another portion is arranged between the second and fourth magnet slots. These partial arcs can reduce torque ripple and leakage flux in the built-in rotor, optimize its NVH performance, and improve output torque.

[0067] In one embodiment, the localized arc trimming is semi-cylindrical, with a circular cross-section diameter greater than or equal to 3 mm. This localized arc trimming reduces torque ripple and leakage flux in the built-in rotor, optimizes the NVH performance of the built-in rotor, and increases output torque.

[0068] In one embodiment, the rotor core includes a plurality of magnetic leakage holes that penetrate the rotor core radially along the built-in rotor. A portion of the magnetic leakage holes are arranged axially between the first and second reinforcing ribs of the built-in rotor, while another portion are arranged circumferentially between two adjacent first magnet slots of the built-in rotor. The magnetic leakage holes can reduce torque ripple and magnetic leakage in the built-in rotor, optimize its NVH performance, and improve output torque.

[0069] In one embodiment, the diameter of the magnetic flux leakage orifice is greater than or equal to 0. This allows the orifice to reduce torque ripple and magnetic flux leakage in the built-in rotor, optimize the NVH performance of the built-in rotor, and improve output torque.

[0070] In one embodiment, the rotor core includes a plurality of core fixing holes, which are arranged at intervals with the first magnet slot and the second magnet slot along the circumference of the built-in rotor. The core fixing holes penetrate the rotor core along the axial direction of the built-in rotor, so that the rotor core can be fixed to the sheath of the built-in rotor, thereby realizing the installation and fixing of the rotor core.

[0071] Secondly, this application provides a powertrain including a reducer and a built-in disc motor as described in the first aspect, wherein the motor shaft of the built-in disc motor is driven to the input shaft of the reducer.

[0072] In the built-in disc motor of this application embodiment, by setting the first end face of the first magnet to a plane, the loss of magnet steel forming the first end face is reduced, production costs are lowered, and the processing technology is simplified. Furthermore, by setting the second end face to an arc surface, sufficient filling rate of the first magnet within the rotor core is ensured. This helps to minimize torque fluctuations in the built-in rotor, improves its reliability, and ensures normal operation. Thus, while ensuring the operation of the built-in rotor is not affected, magnet steel utilization is increased and production costs are reduced, thereby lowering the production cost of the powertrain.

[0073] Thirdly, this application provides an electric vehicle, which includes a frame and a powertrain as described in the second aspect, the powertrain being used to receive electrical energy provided by a power battery to drive the wheels.

[0074] The powertrain in this embodiment includes a built-in disc motor. The built-in disc motor reduces magnet loss by making the first end face of the first magnet flat, thereby lowering production costs and simplifying the manufacturing process. Furthermore, it makes the second end face curved, ensuring sufficient filling of the first magnet within the rotor core. This helps minimize torque fluctuations in the built-in rotor, improving its reliability and ensuring normal operation. Therefore, it is possible to improve magnet utilization and reduce production costs while ensuring the operation of the built-in rotor is not affected, thus lowering the production costs of the powertrain and electric vehicle. Attached Figure Description

[0075] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0076] Figure 1 This is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0077] Figure 2 This is a schematic diagram of a powertrain provided in an embodiment of this application;

[0078] Figure 3 This is a schematic diagram of a built-in disc motor provided in an embodiment of this application;

[0079] Figure 4 This is a schematic diagram of a built-in rotor provided in an embodiment of this application;

[0080] Figure 5 yes Figure 4 An exploded view of the built-in rotor in the image;

[0081] Figure 6 This is another schematic diagram of the built-in rotor provided in the embodiments of this application;

[0082] Figure 7 This is another schematic diagram of the built-in rotor provided in the embodiments of this application;

[0083] Figure 8 yes Figure 7 An exploded view of a centrally located rotor;

[0084] Figure 9 This is a schematic diagram of a first magnet, a second magnet, a first rectangular magnet, and a second rectangular magnet provided in an embodiment of this application;

[0085] Figure 10 This is a schematic diagram of a first magnet formed from incoming magnetic steel provided in an embodiment of this application;

[0086] Figure 11This is another schematic diagram of the built-in rotor provided in the embodiments of this application;

[0087] Figure 12 This is another schematic diagram of the rotor core provided in the embodiments of this application;

[0088] Figure 13 This is another schematic diagram of the built-in rotor provided in the embodiments of this application;

[0089] Figure 14 This is another schematic diagram of the rotor core provided in the embodiments of this application;

[0090] Figure 15 This is another schematic diagram of the built-in rotor provided in the embodiments of this application;

[0091] Figure 16 This is another schematic diagram of the rotor core provided in the embodiments of this application;

[0092] Figure 17 This is another schematic diagram of the rotor core provided in the embodiments of this application. Detailed Implementation

[0093] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0094] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0095] NVH is an abbreviation for Noise, Vibration, and Harshness, which refers to noise, vibration, and acoustic roughness.

[0096] This application provides an internal disc motor including an internal rotor, a plurality of first magnets of the internal rotor arranged at circumferential intervals along the internal rotor and inserted into the rotor core of the internal rotor radially. The first end face of the first magnet inserted into the rotor core from the outer circumferential surface of the rotor core radially is flat, and the second end face of the first magnet opposite the first end face radially to the internal rotor is arc-shaped.

[0097] By setting the first end face of the first magnet to a flat plane, the loss of magnet steel forming the first end face is reduced, production costs are lowered, and the processing technology is simplified. Furthermore, setting the second end face to an arc surface ensures sufficient filling rate of the first magnet within the rotor core. This helps to minimize torque fluctuations in the built-in rotor, improves its reliability, and ensures normal operation. Thus, it is possible to improve magnet utilization and reduce production costs while ensuring the operation of the built-in rotor is not affected.

[0098] Figure 1 This is a schematic diagram of an electric vehicle 1 provided in an embodiment of this application.

[0099] In one embodiment, the electric vehicle 1 includes a frame 10, a powertrain 20, a power battery 30, and wheels 40. Wherein, as... Figure 1 As shown, the powertrain 20 and the power battery 30 are fixed to the frame 10. The powertrain 20 receives power from the power battery 30 and drives the wheels 40. In this embodiment, the electric vehicle 1 refers to a wheeled device driven or towed by a power unit.

[0100] Figure 2 This is a schematic diagram of a powertrain 20 provided in an embodiment of this application. Figure 3 This is a schematic diagram of a built-in disc motor 21 provided in an embodiment of this application.

[0101] In one embodiment, such as Figure 2 and Figure 3 As shown, the powertrain 20 includes a disc motor 21 and a reducer 22. The disc motor 21 includes a motor shaft 100, a rotor 200, and a stator 300. The stator 300 is mounted on and rotatably connected to the motor shaft 100. The rotor 200 is fixedly sleeved on the motor shaft 100. After receiving AC power, the stator 300 drives the rotor 200 to rotate, thereby driving the motor shaft 100 to rotate. The stator 300 is rotatably connected to the motor shaft 100, allowing the motor shaft 100 to rotate relative to the stator 300. The reducer 22 includes a gear assembly (not shown), an input shaft (not shown), and an output shaft (not shown). The input shaft receives the power transmitted from the motor shaft 100 of the disc motor 21 and transmits the power to the output shaft through the gear assembly. The output shaft is drive-connected to the half-shaft of the wheel 40, driving the wheel 40 to rotate. The disc motor 21 is a built-in disc motor 21.

[0102] In one embodiment, such as Figure 3 As shown, the stator 300 and rotor 200 are arranged along the axial direction O of the motor shaft 100.

[0103] In one embodiment, such as Figure 3 As shown, the built-in disc motor 21 includes a stator 300 and a rotor 200.

[0104] In another embodiment, the built-in disc motor 21 includes a stator 300 and two rotors 200, the two rotors 200 being arranged on both sides of the stator 300 along the axial direction O of the motor shaft 100.

[0105] In another embodiment, the built-in disc motor 21 includes a plurality of stators 300 and a plurality of rotors 200, the rotors 200 and stators 300 being arranged alternately along the axial direction O of the motor shaft 100. For example, the built-in disc motor 21 includes three rotors 200 and two stators 300.

[0106] In one embodiment, the rotor 200 of the built-in disc motor 21 is a built-in rotor 200.

[0107] In one embodiment, such as Figure 2 As shown, the powertrain 20 also includes a motor controller 23, which receives DC power from the power battery 30 and converts it into AC power to drive the built-in disc motor 21.

[0108] In one embodiment, the built-in disc motor 21 is connected to the engine drive as a generator.

[0109] Currently, the magnets of the built-in rotor have two curved ends along the radial direction of the built-in rotor. However, the magnets are usually rectangular, so the inner and outer sides of the rectangular magnets need to be cut to form curved surfaces, which results in a lot of waste of magnet materials and high production costs.

[0110] This embodiment of the application reduces magnet loss by making the first end face of the first magnet planar, thereby lowering production costs and simplifying the processing. Furthermore, by making the second end face curved, it ensures sufficient filling of the first magnet within the rotor core. This helps to minimize torque fluctuations in the built-in rotor, improving its reliability and ensuring normal operation. Thus, it is possible to improve magnet utilization and reduce production costs while ensuring the operation of the built-in rotor is not affected.

[0111] The built-in disc motor 21 provided in the embodiments of this application will be described in detail below.

[0112] Figure 4 This is a schematic diagram of a built-in rotor 200 provided in an embodiment of this application. Figure 5 yes Figure 4 An exploded view of the built-in rotor 200 in the middle. Figure 6 This is another schematic diagram of the built-in rotor 200 provided in the embodiments of this application. Figure 7 This is another schematic diagram of the built-in rotor 200 provided in the embodiments of this application. Figure 8yes Figure 7 An exploded view of a built-in rotor 200. Figure 9 This is a schematic diagram of a first magnet 210, a second magnet 230, a first rectangular magnet 240, and a second rectangular magnet 250 provided in an embodiment of this application. Figure 10 This is a schematic diagram of a first magnet 210a formed from incoming magnetic steel provided in an embodiment of this application.

[0113] In one embodiment, such as Figures 3 to 5 As shown, the built-in disc motor 21 includes a built-in rotor 200, a plurality of first magnets 210 of the built-in rotor 200 are arranged at intervals along the circumferential direction C of the built-in rotor 200 and inserted into the rotor core 220 of the built-in rotor 200 along the radial direction R of the built-in rotor 200. Wherein, as... Figures 5 to 9 As shown, the first magnet 210 is inserted from the outer peripheral surface 221 of the rotor core 220 along the radial direction R of the built-in rotor 200. The first end face 211 of the rotor core 220 is a plane, and the second end face 212 of the first magnet 210 opposite to the first end face 211 along the radial direction R of the built-in rotor 200 is an arc surface.

[0114] In this embodiment, during the manufacturing process of the built-in rotor 200, the first magnet 210 is formed by machining magnetic steel. The incoming magnetic steel is typically rectangular in shape. The first magnet 210 is inserted into the first end face 211 of the rotor core 220 from the outer peripheral surface 221 along the radial direction R of the built-in rotor 200. This makes the first end face 211 of the rotor core 220 planar, eliminating the need for cutting when forming the first end face 211 from the incoming magnetic steel. This reduces magnetic steel loss, increases magnetic steel utilization, and lowers production costs. It also simplifies the machining process of the first end face 211.

[0115] In this embodiment, the second end face 212 of the first magnet 210, which is opposite to the first end face 211 along the radial R of the built-in rotor 200, is an arc surface. This allows the first magnet 210 to better fit the outer peripheral surface 221 of the rotor core 220, enabling the first magnet 210 to occupy more space within the rotor core 220 and resulting in a higher magnet filling rate in the rotor core 220. This, in turn, helps ensure the normal operation of the rotor core 220.

[0116] Under normal circumstances, such as Figure 10 As shown, the first magnet 210a has two curved end faces 211a and 212a along the radial direction R of the built-in rotor 200. However, the incoming magnet material is rectangular, with both end faces being flat. Therefore, the inner and outer sides of the incoming magnet material need to be cut to form the two curved end faces 211a and 212a. This results in significant material loss and high production costs. Figure 9As shown, the first magnet 210 in this application has a first end face 211 that is flat and a second end face 212 that is curved. Only the outer side of the incoming magnet needs to be cut to form a curved surface, which can reduce magnet loss, improve magnet utilization, and reduce production costs.

[0117] In this embodiment, by setting the first end face 211 of the first magnet 210 as a plane, the loss of magnet steel forming the first end face 211 is reduced, production costs are lowered, and the processing technology is simplified. Furthermore, by setting the second end face 212 as an arc surface, sufficient filling rate of the first magnet 210 within the rotor core 220 is ensured. This helps to minimize torque fluctuations in the built-in rotor 200, improves the reliability of the built-in rotor 200, and ensures normal operation of the built-in rotor 200. Thus, it is possible to improve magnet steel utilization and reduce production costs while ensuring that the operation of the built-in rotor 200 is not affected.

[0118] In one embodiment, such as Figure 4 As shown, the rotor core 220 is formed by winding silicon steel sheets. The silicon steel sheets are punched with slots at different intervals to accommodate magnets, and then wound to form the rotor core 220.

[0119] In one embodiment, such as Figure 8 and Figure 9 As shown, the first end face 211 is used to form two right angles with the two side faces 213 and 214 of the first magnet 210 distributed along the circumferential C of the built-in rotor 200.

[0120] In this embodiment, the first end face 211 forms two right angles with the two side faces 213 and 214 of the first magnet 210 distributed along the circumferential direction C of the built-in rotor 200. This allows the two side faces 213 and 214 of the first magnet 210 to directly retain the shape of the incoming magnet material without cutting, thereby further improving the utilization rate of the magnet material and reducing production costs. Reducing cutting also simplifies the processing technology of the first magnet 210.

[0121] In one embodiment, such as Figure 8 and Figure 9 As shown, along the arrangement direction A of the first end face 211 and the second end face 212, the distance between the second end face 212 and the first end face 211 gradually decreases from the midpoint of the second end face 212 along the circumferential direction C of the built-in rotor 200 towards both sides.

[0122] In this embodiment, along the arrangement direction A of the first end face 211 and the second end face 212, the distance between the second end face 212 and the first end face 211 gradually decreases from the midpoint of the second end face 212 along the circumferential direction C of the built-in rotor 200 to both sides. This makes the arc surface of the second end face 212 of the first magnet 210 more compatible with the arc shape of the outer circumferential surface 221 of the rotor core 220. This results in a smaller volume of incoming magnet material being cut during the processing of the second end face 212 of the first magnet 210, thus increasing the utilization rate of the magnet and helping to reduce production costs.

[0123] In one embodiment, such as Figure 9 As shown, along the arrangement direction A of the first end face 211 and the second end face 212, the distance between the two ends 2121 and 2122 of the second end face 212 along the circumferential direction C of the built-in rotor 200 and the first end face 211 is equal.

[0124] In the embodiments of this application, such as Figure 4 and Figure 9 As shown, along the arrangement direction A of the first end face 211 and the second end face 212, the distances between the two ends 2121 and 2122 of the second end face 212 along the circumferential direction C of the built-in rotor 200 and the first end face 211 are denoted as D1 and D2, respectively, where D1 = D2. This results in a smaller cutting volume of the incoming magnet material during the formation of the first magnet 210, leading to higher utilization of the magnet material and reducing production costs. It also allows for a higher filling rate after the first magnet 210 is inserted into the rotor core 220, which helps to reduce torque fluctuations in the built-in rotor 200 and improves its reliability.

[0125] In one embodiment, such as Figure 8 and Figure 9 As shown, the built-in rotor 200 also includes a plurality of second magnets 230. Each second magnet 230 is arranged along the radial direction R of the built-in rotor 200 inside a first magnet 210. The second magnet 230 includes a third end face 231 and a fourth end face 232 arranged opposite to each other along the radial direction R of the built-in rotor 200. The fourth end face 232 is closer to the first end face 211 than the third end face 231. The fourth end face 232 is parallel to the first end face 211.

[0126] In the embodiments of this application, such as Figure 4 , Figure 8 and Figure 9As shown, each second magnet 230 is arranged radially R along the built-in rotor 200 inside a first magnet 210. The fourth end face 232 is closer to the first end face 211 than the third end face 231, and the fourth end face 232 is parallel to the first end face 211. This allows the fourth end face 232 of the second magnet 230 to better fit with the first end face 211 of the first magnet 210, resulting in a higher filling rate of the second magnet 230 and the first magnet 210 within the rotor core 220. This helps to reduce torque fluctuations in the built-in rotor 200 and improves its reliability. It also helps to increase the stability of the first magnet 210 and the second magnet 230 within the rotor core 220 during the rotation of the built-in rotor 200.

[0127] In this embodiment, the fourth end face 232 is parallel to the first end face 211. The first end face 211 is a plane, so that the fourth end face 232 is also a plane. This allows the incoming magnet material to be formed into the fourth end face 232 of the second magnet 230 without cutting, which is beneficial to improve the utilization rate of the magnet, reduce production costs, and simplify the process.

[0128] In one embodiment, such as Figure 8 and Figure 9 As shown, the fourth end face 232 is used to form two right angles with the two side faces 233 and 234 of the second magnet 230 distributed along the circumferential C of the built-in rotor 200.

[0129] In this embodiment, the fourth end face 232 is used to form two right angles with the two side faces 233 and 234 of the second magnet 230 distributed along the circumferential direction C of the built-in rotor 200. This allows the incoming magnet material to form the fourth end face 232 of the second magnet 230 and the two side faces 233 and 234 distributed along the circumferential direction C of the built-in rotor 200 without cutting. This results in high utilization of the incoming magnet material, which helps to reduce production costs and simplifies the production process.

[0130] In one embodiment, such as Figure 9 As shown, the third end face 231 is parallel to the fourth end face 232.

[0131] In this embodiment, the third end face 231 is parallel to the fourth end face 232, and the fourth end face 232 is planar, making the third end face 231 also planar. This eliminates the need for cutting the third end face 231 of the incoming magnet to form the second magnet 230, thus eliminating the need for cutting during the formation of the second magnet 230. This results in high overall utilization of the magnet during the manufacturing of the built-in rotor 200, which helps reduce production costs. Furthermore, it eliminates the need for additional processing of the second magnet 230, simplifying the manufacturing process of the built-in rotor 200.

[0132] In one embodiment, such as Figure 9 As shown, the line connecting the first end face 211 and the third end face 231 at the same end along the circumferential direction C of the built-in rotor 200 is parallel to the radial direction R of the built-in rotor 200.

[0133] In this embodiment, the lines connecting the first end face 211 and the third end face 231 along the same end of the circumferential direction C of the built-in rotor 200 are respectively denoted as L1 and L2. L1 and L2 are parallel to the radial direction R of the built-in rotor 200, so that after the first magnet 210 and the second magnet 230 are inserted into the rotor core 220, the magnet filling rate in the rotor core 220 is relatively high, which is beneficial to reduce the torque fluctuation of the built-in rotor 200 and improve the reliability of the built-in rotor 200.

[0134] It should be noted that a slight offset within a small angle range of 0-5° can also be considered as the line connecting the first end face 211 and the third end face 231 along the same end of the circumferential direction C of the built-in rotor 200 being parallel to the radial direction R of the built-in rotor 200.

[0135] In one embodiment, such as Figure 5 and Figure 9 As shown, along the arrangement direction A of the first end face 211 and the second end face 212, the sum of the lengths of the first magnet 210 and the second magnet 230 is less than or equal to half the difference between the outer diameter of the outer circumferential surface 221 and the inner diameter of the inner circumferential surface 224 of the rotor core 220.

[0136] In one embodiment, such as Figures 5 to 9 As shown, the built-in rotor 200 also includes a plurality of first rectangular magnets 240, with two first rectangular magnets 240 arranged on both sides of the first magnet 210 along the circumferential direction C of the built-in rotor 200. Along the arrangement direction A of the first end face 211 and the second end face 212, the length of the first rectangular magnet 240 is greater than the distance between the two ends 2121 and 2122 of the second end face 212 along the circumferential direction C of the built-in rotor 200 and the first end face 211. One end 241 of the first rectangular magnet 240 facing the axis O1 of the built-in rotor 200 protrudes from the first end face 211.

[0137] In the embodiments of this application, such as Figure 4 and Figure 9 As shown, two first rectangular magnets 240 are arranged on both sides of the first magnet 210 along the circumferential direction C of the built-in rotor 200, so that the two first rectangular magnets 240 can increase the magnet filling rate in the rotor core 220 of the built-in rotor 200, which is beneficial to reduce the torque fluctuation of the built-in rotor 200 and improve the reliability of the built-in rotor 200.

[0138] In the embodiments of this application, such as Figure 9As shown, along the arrangement direction A of the first end face 211 and the second end face 212, the length of the first rectangular magnet 240 is denoted as D3. The distances between the two ends 2121 and 2122 of the second end face 212 and the first end face 211 along the circumferential direction C of the built-in rotor 200 are D1 and D2, respectively. Because the first end face 211 is a plane, the magnets on both sides of the magnetic steel slot in the rotor core 220 used to accommodate the first magnet 210 will be missing. By setting D3 > D1 and D3 > D2, the first rectangular magnet 240 can compensate for and increase the magnetic steel filling rate in the rotor core 220, thereby optimizing the magnetic field distribution, increasing the air gap magnetic field strength, reducing torque fluctuation, and improving the overall efficiency of the built-in disc motor 21.

[0139] In this embodiment, one end 241 of the first rectangular magnet 240 facing the axis O1 of the built-in rotor 200 protrudes from the first end face 211, which makes it easier for the first rectangular magnet 240 to fill the two sides 213, 214 of the first magnet 210 with shorter lengths in the rotor core 220 along the radial R of the built-in rotor 200. This results in a high magnet filling rate in the rotor core 220, which can optimize the magnetic field distribution, increase the magnetic flux density, reduce torque fluctuations, improve the reliability of the built-in rotor 200, and improve the overall efficiency of the built-in disc motor 21.

[0140] In one embodiment, such as Figure 9 As shown, along direction B, which is perpendicular to the arrangement direction of the first end face 211 and the second end face 212, the width of the first rectangular magnet 240 is greater than or equal to 2 mm and less than or equal to 5 mm. This ensures that the first rectangular magnet 240 can both compensate for and increase the magnet filling rate in the rotor core 220 without making the volume too large, and that the magnet slot has sufficient space to accommodate the first magnet 210.

[0141] In one embodiment, such as Figures 5 to 9 As shown, the built-in rotor 200 also includes a plurality of second rectangular magnets 250, with two second rectangular magnets 250 arranged on both sides of the second magnet 230 along the circumferential direction C of the built-in rotor 200. The length of the second rectangular magnet 250 along the radial direction R of the built-in rotor 200 is less than the distance between the third end face 231 and the fourth end face 232.

[0142] In this embodiment, two second rectangular magnets 250 are arranged on both sides of the second magnet 230 along the circumferential direction C of the built-in rotor 200. Because the fourth end face 232 of the second magnet 230 is flat, the magnets on both sides of the magnet slot in the rotor core 220 used to accommodate the second magnet 230 are missing. This allows the two second rectangular magnets 250 to compensate for and increase the magnet filling rate in the rotor core 220 of the built-in rotor 200, optimize the magnetic field distribution, increase the magnetic flux density, reduce torque fluctuation, improve the reliability of the built-in rotor 200, and improve the overall efficiency of the built-in disc motor 21.

[0143] In the embodiments of this application, such as Figure 9 As shown, the length of the second rectangular magnet 250 along the radial direction R of the built-in rotor 200 is denoted as D4, and the distance between the third end face 231 and the fourth end face 232 is denoted as D5. D4 < D5, which allows the magnetic field distribution to be optimized by filling the second rectangular magnet 250 on both sides of the second magnet 230, thereby increasing the magnetic flux density and reducing torque fluctuations. At the same time, it reduces the use of magnetic steel material to form the second rectangular magnet 250, saving materials and helping to reduce production costs.

[0144] In one embodiment, such as Figure 9 As shown, along direction B, which is perpendicular to the arrangement direction of the first end face 211 and the second end face 212, the width of the second rectangular magnet 250 is greater than or equal to 2 mm and less than or equal to 5 mm. This ensures that the second rectangular magnet 250 can both compensate for the magnet filling rate in the rotor core 220 and avoid making the volume too large, so that the magnet slot has enough space to accommodate the second magnet 230.

[0145] In one embodiment, such as Figure 9 As shown, one end 251 of the second rectangular magnet 250 facing the axis O1 of the built-in rotor 200 is flush with the third end face 231, and the other end 252 of the second rectangular magnet 250 away from the axis O1 of the built-in rotor 200 is spaced apart from the first end face 211.

[0146] In this embodiment, the end 251 of the second rectangular magnet 250 facing the axis O1 of the built-in rotor 200 is flush with the third end face 231, so that the second rectangular magnet 250 can reduce the leakage magnetic field at both ends 2311 and 2312 of the third end face 231 of the second magnet 230, so that more of the magnetic field is directed to the air gap between the built-in rotor 200 and the stator 300, thereby increasing the main magnetic flux density and output torque.

[0147] In this embodiment, one end 251 of the second rectangular magnet 250 facing the axis O1 of the built-in rotor 200 is flush with the third end face 231. The length of the second rectangular magnet 250 along the radial direction R of the built-in rotor 200 is less than the distance between the third end face 231 and the fourth end face 232. The fourth end face 232 of the second magnet 230 is adjacent to the first end face 211 of the first magnet 210, so that the other end 252 of the second rectangular magnet 250 away from the axis O1 of the built-in rotor 200 is spaced apart from the first end face 211.

[0148] In one embodiment, such as Figure 5 and Figure 9 As shown, one end 251 of the second rectangular magnet 250 facing the axis O1 of the built-in rotor 200 protrudes from the third end face 231, and the end 251 of the second rectangular magnet 250 facing the axis O1 of the built-in rotor 200 is flush with the inner circumferential surface 224 of the rotor core 220. This allows the second rectangular magnet 250 to reduce the leakage magnetic field at both ends 2311 and 2312 of the third end face 231 of the second magnet 230, so that more of the magnetic field is directed to the air gap between the built-in rotor 200 and the stator 300, thereby increasing the main magnetic flux density and output torque.

[0149] In one embodiment, such as Figure 8 As shown, the second rectangular magnet 250 has the same shape as the first rectangular magnet 240.

[0150] In this embodiment, the first rectangular magnet 240 and the second rectangular magnet 250 can use the same specification of magnet material, which standardizes the magnets and reduces the types of magnets used in the built-in rotor 200, thus helping to reduce production costs.

[0151] Figure 11 This is another schematic diagram of the built-in rotor 200 provided in the embodiments of this application.

[0152] In one embodiment, such as Figures 7 to 9 , Figure 11 As shown, the built-in rotor 200 also includes a third magnet 260, which is stacked at intervals on the first magnet 210 along the axial direction O of the built-in rotor 200. The length of the third magnet 260 along the circumferential direction C of the built-in rotor 200 is less than the length of the first magnet 210. The third magnet 260 has a fifth end face 261 and a sixth end face 262 arranged opposite each other along the radial direction R of the built-in rotor 200. The fifth end face 261 is closer to the axis O1 of the built-in rotor 200 than the sixth end face 262. The fifth end face 261 is parallel to the first end face 211.

[0153] In this embodiment, the length of the third magnet 260 along the circumferential direction C of the built-in rotor 200 is denoted as D6, and the length of the first magnet 210 is denoted as D7. The third magnet 260 is stacked on the first magnet 210 at intervals O along the axial direction O of the built-in rotor 200, where D6 < D7. This allows the third magnet 260 to be used to gather the magnetic lines of force in the built-in rotor 200, thereby enhancing the strength of the magnets in the built-in rotor 200, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0154] In this embodiment, the fifth end face 261 and the sixth end face 262 of the third magnet 260 are arranged opposite each other along the radial direction R of the built-in rotor 200. The fifth end face 261 is closer to the axis O1 of the built-in rotor 200 than the sixth end face 262. The first end face 211 is planar, and the fifth end face 261 is parallel to the first end face 211, making the fifth end face 261 of the third magnet 260 also planar. This eliminates the need to cut the incoming magnet material to form the fifth end face 261, which is beneficial to improving the utilization rate of the magnet and reducing production costs. It also allows the fifth end face 261 of the third magnet 260 to be flush with the first end face 211 of the first magnet 210 along the axial direction O of the built-in rotor 200, so that the third magnet 260 can better gather the magnetic lines of force generated by the first magnet 210.

[0155] In one embodiment, such as Figure 11 As shown, along direction B, which is perpendicular to the arrangement direction of the first end face 211 and the second end face 212, the length difference between the first magnet 210 and the third magnet 260 is greater than or equal to 4 mm. This allows the third magnet 260 to be used to gather the magnetic lines of force in the built-in rotor 200, thereby enhancing the strength of the magnets in the built-in rotor 200, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0156] In one embodiment, such as Figures 5 to 9 , Figure 11 As shown, the built-in rotor 200 also includes a fourth magnet 270, which is stacked on top of the second magnet 230 at intervals along the axial direction O of the built-in rotor 200. Along the circumferential direction C of the built-in rotor 200, the length of the fourth magnet 270 is less than the length of the second magnet 230. The fourth magnet 270 has a seventh end face 271 and an eighth end face 272 arranged opposite to each other along the radial direction R of the built-in rotor 200. The seventh end face 271 is closer to the axis O1 of the built-in rotor 200 than the eighth end face 272. The eighth end face 272 is parallel to the fifth end face 261.

[0157] In this embodiment, the fourth magnet 270 is stacked on top of the second magnet 230 at intervals along the axial direction O of the built-in rotor 200. Along the circumferential direction C of the built-in rotor 200, the length of the fourth magnet 270 is less than the length of the second magnet 230, so that the fourth magnet 270 can be used to gather the magnetic lines of force in the built-in rotor 200, thereby enhancing the strength of the magnets in the built-in rotor 200, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0158] In this embodiment, the fourth magnet 270 has a seventh end face 271 and an eighth end face 272 arranged opposite to each other along the radial direction R of the built-in rotor 200. The seventh end face 271 is closer to the axis O1 of the built-in rotor 200 than the eighth end face 272. The eighth end face 272 is parallel to the fifth end face 261, and the fifth end face 261 is parallel to the first end face 211, so that the eighth end face 272 is a plane. Therefore, it is not necessary to cut the incoming magnet to form the eighth end face 272, which is beneficial to improve the utilization rate of the magnet and reduce the production cost.

[0159] In one embodiment, such as Figure 11 As shown, along direction B, which is perpendicular to the arrangement direction of the first end face 211 and the second end face 212, the length difference between the second magnet 230 and the fourth magnet 270 is greater than or equal to 4 mm. This allows the fourth magnet 270 to be used to gather the magnetic lines of force in the built-in rotor 200, thereby enhancing the strength of the magnets in the built-in rotor 200, increasing the air gap magnetic flux density, enhancing torque output, improving the magnetic field waveform, and reducing torque pulsation.

[0160] In one embodiment, such as Figure 8 As shown, the first magnet 210, the second magnet 230, the first rectangular magnet 240, and the second rectangular magnet 250 are high-coercivity magnets, while the third magnet 260 and the fourth magnet 270 are low-coercivity magnets. This helps to reduce magnetic leakage, enhance magnetic field strength, reduce eddy current losses, and improve the reliability of the built-in rotor 200.

[0161] In one embodiment, such as Figure 8 As shown, the first magnet 210, the second magnet 230, the third magnet 260 and the fourth magnet 270 are made of four different types of magnets, while the first rectangular magnet 240 and the second rectangular magnet 250 are made of the same type of magnet. This means that the built-in rotor 200 in this embodiment only needs to use five types of magnets, which helps to reduce production costs.

[0162] In one embodiment, such as Figure 8As shown, the combination of the first magnet 210, the second magnet 230, the third magnet 260, the fourth magnet 270, the first rectangular magnet 240, and the second rectangular magnet 250, compared to using a combination of magnets with two curved end faces arranged radially R along the built-in rotor 200, can increase the utilization rate of the magnets by more than 15%. It can also improve the strength of the magnets and prevent the risk of cracking in the magnetic bridge.

[0163] In one embodiment, such as Figure 6 As shown, the first magnet 210, the second magnet 230, the third magnet 260, the fourth magnet 270, the first rectangular magnet 240, and the second rectangular magnet 250 are integrated into a single structure. This simplifies the assembly of the built-in rotor 200 and also enhances its structural strength and stability.

[0164] In one embodiment, such as Figure 8 As shown, the first magnet 210, the second magnet 230, the first rectangular magnet 240, the second rectangular magnet 250, the third magnet 260 and the fourth magnet 270 can be segmented into at least two sub-magnets along the radial R or the circumferential C of the built-in rotor 200. The segmentation of the magnets helps to reduce the eddy current loss on the surface of the magnets and helps to reduce the torque fluctuation of the built-in rotor 200.

[0165] In one embodiment, such as Figure 7 and Figure 8 As shown, the first magnet 210, the second magnet 230, the third magnet 260, the fourth magnet 270, the first rectangular magnet 240, and the second rectangular magnet 250 are of a split structure, which can be divided into two sub-magnets along the arrangement direction A of the first end face 211 and the second end face 212. The two sub-magnets of the second magnet 230, the fourth magnet 270, the first rectangular magnet 240, and the second rectangular magnet 250 are of the same shape and size. One sub-magnet of the first magnet 210, closer to the axis O1 of the built-in rotor 200, is rectangular. The other sub-magnet, away from the axis O1 of the built-in rotor 200, has two end faces arranged opposite each other along the radial direction R of the built-in rotor 200. One end face is flat, and the other is curved. The curved surface is used to form the second end face 212 of the first magnet 210. The third magnet 260 has a rectangular sub-magnet near the axis O1 of the built-in rotor 200. The other sub-magnet, away from the axis O1 of the built-in rotor 200, has two end faces arranged opposite each other along the radial direction R of the built-in rotor 200. One end face is flat, and the other is curved. The curved surface forms the sixth end face 262 of the third magnet 260. Segmenting the magnets helps reduce eddy current losses on the magnet surface and reduces torque ripple in the built-in rotor 200.

[0166] In one embodiment, such as Figure 9As shown, the first magnet 210, the second magnet 230, the third magnet 260, and the fourth magnet 270 are divided into two sub-magnets along the circumference of the built-in rotor 200. The two sub-magnets are identical in shape and size. The length of one sub-magnet of the first magnet 210 along the arrangement direction A of the first end face 211 and the second end face 212 gradually decreases from the end closer to the other sub-magnet to the end farther away from the other sub-magnet. This segmentation of the magnets helps reduce eddy current losses on the magnet surface and reduces torque fluctuations in the built-in rotor 200.

[0167] Figure 12 This is another schematic diagram of the rotor core 220 provided in the embodiments of this application. Figure 13 This is another schematic diagram of the built-in rotor 200 provided in the embodiments of this application.

[0168] In one embodiment, such as Figure 4 , Figure 12 and Figure 13 As shown, the rotor core 220 includes a plurality of first magnet slots 222 and a plurality of second magnet slots 223. The plurality of first magnet slots 222 and the plurality of second magnet slots 223 are arranged at intervals along the circumferential direction C of the built-in rotor 200. Each first magnet slot 222 and a second magnet slot 223 are arranged adjacent to and communicate with each other along the radial direction R of the built-in rotor 200. The first magnet slots 222 penetrate the outer circumferential surface 221 of the rotor core 220, and the second magnet slots 223 penetrate the inner circumferential surface 224 of the rotor core 220. The first magnet slots 222 are used to accommodate the first magnet 210 and the first rectangular magnet 240, and the second magnet slots 223 are used to accommodate the second magnet 230 and the second rectangular magnet 250.

[0169] In one embodiment, such as Figure 4 As shown, along the circumferential direction C of the built-in rotor 200, the minimum distance between two adjacent second magnet slots 223 is greater than or equal to 2 mm. This helps ensure that the rotor core 220 has sufficient structural strength and improves the reliability of the built-in rotor 200.

[0170] In one embodiment, such as Figure 9 and Figure 12 As shown, the line connecting the first magnet slot 222 and the second magnet slot 223 at the same end along the circumferential direction C of the built-in rotor 200 is translated outward by a distance 'a' along the circumferential direction C. The angle between this line and the arrangement direction A of the first end face 211 and the second end face 212 is β, where β = 360° / 4P, and P is the number of pole pairs of the built-in disc motor 21. Figure 5For example, the built-in disc motor 21 has 5 pole pairs. A first magnet 210, a second magnet 230, a third magnet 260, a fourth magnet 270, two first rectangular magnets 240, and two second rectangular magnets 250 form a magnet unit. Two magnet units form one pole pair. Where a ≥ 1 mm.

[0171] Figure 14 This is another schematic diagram of the rotor core 220 provided in the embodiments of this application. Figure 15 This is another schematic diagram of the built-in rotor 200 provided in the embodiments of this application.

[0172] In one embodiment, such as Figure 4 , Figure 14 and Figure 15 As shown, the rotor core 220 also includes multiple third magnet slots 225 and multiple fourth magnet slots 226. The multiple third magnet slots 225 and multiple fourth magnet slots 226 are arranged at intervals along the circumferential direction C of the built-in rotor 200. Each third magnet slot 225 and one fourth magnet slot 226 are adjacent to and communicate with each other along the radial direction R of the built-in rotor 200. The third magnet slot 225 penetrates the outer circumferential surface 221 of the rotor core 220, and the fourth magnet slot 226 penetrates the inner circumferential surface 224 of the rotor core 220. The third magnet slot 225 is used to accommodate a third magnet 260, and the fourth magnet slot 226 is used to accommodate a fourth magnet 270. Along the axial direction O of the built-in rotor 200, the third magnet slot 225 is spaced apart from the first magnet slot 222, and the fourth magnet slot 226 is spaced apart from the second magnet slot 223. Along the circumferential direction C of the built-in rotor 200, the third magnet slot 225 is spaced apart from the first rectangular magnet 240, and the fourth magnet slot 226 is spaced apart from the second rectangular magnet 250.

[0173] in, Figure 14 The first rectangular magnet 240 and the second rectangular magnet 250 in the diagram are only schematic representations and do not represent specific structures.

[0174] Figure 16 This is another schematic diagram of the rotor core 220 provided in the embodiments of this application.

[0175] In one embodiment, such as Figure 12 , Figure 13 and Figure 16As shown, the rotor core 220 also includes a plurality of first reinforcing ribs 227. The first reinforcing ribs 227 extend along the radial direction R of the built-in rotor 200 within the first magnet slot 222 and the second magnet slot 223. The first reinforcing ribs 227 are used to improve the structural strength of the rotor core 220, reduce the deformation of the rotor core 220 after winding, and improve the reliability of the built-in rotor 200. The first reinforcing ribs 227 can also be used to separate the first magnet 210 and the second magnet 230 along the circumferential direction C of the built-in rotor 200, so that the first magnet 210 and the second magnet 230 are segmented. The segmentation of the magnets helps to reduce the eddy current loss on the surface of the magnets and reduce torque fluctuation.

[0176] In one embodiment, such as Figure 16 As shown, the number of first reinforcing ribs 227 in the first magnet slot 222 and the second magnet slot 223 is one. This allows the first magnet 210 and the second magnet 230 to be arranged in segments, which helps to reduce eddy current losses on the magnet surface and reduces torque fluctuations in the built-in rotor 200.

[0177] Figure 17 This is another schematic diagram of the rotor core 220 provided in the embodiments of this application.

[0178] In another embodiment, such as Figure 17 As shown, the number of first reinforcing ribs 227 in the first magnet slot 222 and the second magnet slot 223 is two or more. This allows the first magnet 210 and the second magnet 230 to be arranged in multiple segments, which helps to reduce eddy current losses on the magnet surface and reduce torque fluctuations in the built-in rotor. It also helps to improve the structural strength of the rotor core 220.

[0179] In one embodiment, such as Figure 12 and Figure 16 As shown, along the circumferential direction C of the built-in rotor 200, the width of the first reinforcing rib 227 is less than or equal to 3mm. This ensures that the first reinforcing rib 227 enhances the structural strength of the rotor core 220 without excessively occupying the space of the magnet slots inside the rotor core 220, and also helps to concentrate the magnetic lines of force of the first magnet 210 and the second magnet 230.

[0180] In one embodiment, such as Figures 14 to 16 As shown, the rotor core 220 also includes a plurality of second reinforcing ribs 228. The second reinforcing ribs 228 extend along the radial direction R of the built-in rotor 200 within the third magnet slot 225 and the fourth magnet slot 226. The second reinforcing ribs 228 are used to improve the structural strength of the rotor core 220. The second reinforcing ribs 228 can also be used to separate the third magnet 260 and the fourth magnet 270 along the circumferential direction C of the built-in rotor 200, so that the third magnet 260 and the fourth magnet 270 are segmented. The segmentation of the magnets helps to reduce the eddy current loss on the surface of the magnets and reduce torque fluctuation.

[0181] In one embodiment, the width of the second reinforcing rib 228 along the circumferential direction C of the built-in rotor 200 is greater than or equal to 0. This ensures that the second reinforcing rib 228 enhances the structural strength of the rotor core 220 without excessively occupying the space of the magnet slots within the rotor core 220.

[0182] In one embodiment, the number of second reinforcing ribs 228 within the third magnet slot 225 is one or more. This allows the third magnet 260 and the fourth magnet 270 to be arranged in segments, which helps reduce eddy current losses on the magnet surface and reduces torque fluctuations in the built-in rotor. It also helps improve the structural strength of the rotor core 220.

[0183] In one embodiment, such as Figure 4 As shown, the first magnet slot 222 includes a first reinforcing rib 227, while the third magnet slot 225 does not have a second reinforcing rib 228. This simplifies the machining process of the rotor core 220.

[0184] In one embodiment, such as Figure 16 As shown, the rotor core 220 includes multiple partial arcs 229. These partial arcs 229 are located on the outer side of the end face of the rotor core 220 along the axial direction O of the built-in rotor 200 and along the circumferential direction C of the built-in rotor 200. A portion of the partial arcs 229 are arranged between the first magnet slot 222 and the third magnet slot 225, while another portion is arranged between the second magnet slot 223 and the fourth magnet slot 226. The partial arcs 229 can reduce torque fluctuations and magnetic leakage in the built-in rotor 200, optimize the NVH performance of the built-in rotor 200, and improve output torque.

[0185] In one embodiment, such as Figure 16 As shown, the partial arc trimming 229 is semi-cylindrical, with a circular cross-section diameter greater than or equal to 3mm. This partial arc trimming 229 can reduce torque fluctuations and leakage flux in the built-in rotor 200, optimize the NVH performance of the built-in rotor 200, and improve output torque.

[0186] In one embodiment, such as Figure 16 As shown, the rotor core 220 includes multiple magnetic leakage holes 2210. These holes 2210 penetrate the rotor core 220 along the radial direction R of the built-in rotor 200. A portion of the magnetic leakage holes 2210 are arranged along the axial direction O of the built-in rotor 200 between the first reinforcing rib 227 and the second reinforcing rib 228, while another portion are arranged along the circumferential direction C of the built-in rotor 200 between two adjacent first magnet slots 222. The magnetic leakage holes 2210 can reduce torque fluctuations and magnetic leakage in the built-in rotor 200, optimize the NVH performance of the built-in rotor 200, and improve output torque.

[0187] In one embodiment, the diameter of the magnetic flux leakage hole 2210 is greater than or equal to 0. This allows the magnetic flux leakage hole 2210 to reduce torque ripple and magnetic flux leakage in the built-in rotor, optimize the NVH performance of the built-in rotor, and improve output torque.

[0188] In one embodiment, such as Figure 4 As shown, the rotor core 220 includes multiple core fixing holes 2211. The multiple core fixing holes 2211 are arranged at intervals with the first magnet slot 222 and the second magnet slot 223 along the circumferential direction C of the built-in rotor 200. The core fixing holes 2211 penetrate the rotor core 220 along the axial direction O of the built-in rotor 200, so that the rotor core 220 can be fixed to the sheath of the built-in rotor 200, thereby realizing the installation and fixing of the rotor core 220.

[0189] The built-in disc motor, powertrain, and electric vehicle provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and embodiments of this application. The description of the embodiments above is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in specific embodiments and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A built-in disc motor, characterized in that, Includes an embedded rotor, wherein a plurality of first magnets of the embedded rotor are arranged at circumferential intervals along the embedded rotor and inserted radially into the rotor core of the embedded rotor, wherein: The first magnet is inserted into the rotor core from the outer peripheral surface of the rotor core along the radial direction of the built-in rotor. The first end face of the first magnet is a plane, and the second end face of the first magnet opposite to the first end face along the radial direction of the built-in rotor is an arc surface.

2. The built-in disc motor according to claim 1, characterized in that, The first end face is configured to form two right angles with the two sides of the first magnet distributed circumferentially along the built-in rotor.

3. The built-in disc motor according to claim 1 or 2, characterized in that, Along the arrangement direction of the first end face and the second end face, the distance between the second end face and the first end face gradually decreases from the midpoint of the second end face along the circumferential direction of the built-in rotor to both sides.

4. The built-in disc motor according to any one of claims 1-3, characterized in that, Along the arrangement direction of the first end face and the second end face, the distance between the two ends of the second end face along the circumferential direction of the built-in rotor and the first end face is equal.

5. The built-in disc motor according to any one of claims 1-4, characterized in that, The built-in rotor further includes a plurality of second magnets, each second magnet being arranged radially inside a first magnet. Each second magnet includes a third end face and a fourth end face arranged radially opposite to each other on the built-in rotor, the fourth end face being closer to the first end face than the third end face. The fourth end face is parallel to the first end face.

6. The built-in disc motor according to claim 5, characterized in that, The fourth end face is used to form two right angles with the two sides of the second magnet distributed circumferentially along the built-in rotor.

7. The built-in disc motor according to claim 5, characterized in that, The third end face is parallel to the fourth end face.

8. The built-in disc motor according to claim 7, characterized in that, The line connecting the first end face and the third end face at the same end along the circumference of the built-in rotor is parallel to the radial direction of the built-in rotor.

9. The built-in disc motor according to any one of claims 5-8, characterized in that, The built-in rotor also includes a plurality of first rectangular magnets, with two first rectangular magnets arranged on either side of the first magnet along the circumference of the built-in rotor, wherein: Along the arrangement direction of the first end face and the second end face, the length of the first rectangular magnet is greater than the distance between the two ends of the second end face along the circumference of the built-in rotor and the first end face, and one end of the first rectangular magnet facing the axis of the built-in rotor protrudes from the first end face.

10. The built-in disc motor according to claim 9, characterized in that, The built-in rotor also includes a plurality of second rectangular magnets, with two second rectangular magnets arranged on either side of the second magnet along the circumference of the built-in rotor, wherein: The length of the second rectangular magnet along the radial direction of the built-in rotor is less than the distance between the third end face and the fourth end face.

11. The built-in disc motor according to claim 10, characterized in that, One end of the second rectangular magnet facing the axis of the built-in rotor is flush with the third end face, and the other end of the second rectangular magnet away from the axis of the built-in rotor is spaced apart from the first end face.

12. The built-in disc motor according to claim 10, characterized in that, The second rectangular magnet has the same shape as the first rectangular magnet.

13. The built-in disc motor according to any one of claims 1-12, characterized in that, The built-in rotor further includes a third magnet, which is stacked at intervals with the first magnet along the axial direction of the built-in rotor. The length of the third magnet along the circumferential direction of the built-in rotor is less than the length of the first magnet. The third magnet has a fifth end face and a sixth end face arranged opposite each other along the radial direction of the built-in rotor. The fifth end face is closer to the axis of the built-in rotor than the sixth end face. The fifth end face is parallel to the first end face.

14. A powertrain, characterized in that, The powertrain includes a reducer and a built-in disc motor as described in claim 13, wherein the motor shaft of the built-in disc motor is driven to the input shaft of the reducer.

15. An electric vehicle, characterized in that, The electric vehicle includes a frame and a powertrain as described in claim 14, the powertrain being configured to receive electrical energy supplied by a power battery to drive the wheels.

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