Rotor lamination, rotor assembly, motor and vehicle

Abstract

The present application relates to a rotor lamination, a rotor assembly, a motor, and a vehicle. The rotor lamination comprises a plurality of magnetic pole units circumferentially arranged on the rotor lamination. Each magnetic pole unit comprises a first magnetic steel slot group and a second magnetic steel slot group; the second magnetic steel slot group is located on the inner side of the first magnetic steel slot group in the radial direction of the rotor lamination; the first magnetic steel slot group comprises a first main slot suitable for allowing insertion of a first magnetic steel; the second magnetic steel slot group comprises a second main slot suitable for allowing insertion of a second magnetic steel; and the width of the first main slot is greater than that of the second main slot.

Description

A rotor lamination, rotor assembly, motor and vehicle

[0001] This application claims priority to Chinese patent applications filed on January 2, 2025, with application number 202510005756.3 entitled "A rotor lamination, rotor assembly, motor and vehicle" and application number 202520005522.4 entitled "A rotor lamination, rotor assembly, motor and vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of rotor lamination technology, and in particular relates to a rotor lamination, rotor assembly, motor and vehicle. Background Technology

[0003] The average torque of an electric motor represents its maximum output capacity and affects the vehicle's acceleration from 0 to 100 km / h. Torque ripple represents the motor's NVH performance, characterizing the vehicle's quietness. Both the average torque and torque ripple of an electric motor are closely related to the structural design of the rotor laminations.

[0004] However, the existing rotor lamination structure design is unreasonable, which makes the rotor lamination process complex and costly, and at the same time, it cannot effectively balance the average torque and torque ripple of the motor, thus affecting the motor performance.

[0005] Application content

[0006] The technical problem to be solved by this application is: addressing the issue that the existing rotor lamination structure design is unreasonable, resulting in complex and costly rotor lamination processes, and failing to effectively balance the average torque and torque ripple of the motor, thus affecting motor performance. The application provides a rotor lamination, rotor assembly, motor, and vehicle.

[0007] To solve the above-mentioned technical problems, on the one hand, embodiments of this application provide a rotor lamination, including a plurality of magnetic pole units arranged circumferentially along the rotor lamination, each magnetic pole unit including a first magnetic slot group and a second magnetic slot group, the second magnetic slot group being located inside the first magnetic slot group in the radial direction of the rotor lamination;

[0008] The first magnet slot group includes a first main slot suitable for inserting a first magnet, and the second magnet slot group includes a second main slot suitable for inserting a second magnet. The width of the first main slot is greater than the width of the second main slot.

[0009] According to an embodiment of this application, in the rotor lamination, the second magnet slot group is located radially inside the first magnet slot group. The first magnet slot group includes a first main slot for inserting a first magnet, and the second magnet slot group includes a second main slot for inserting a second magnet. The width of the first main slot is greater than the width of the second main slot. By setting the width of the first main slot to be greater than the width of the second main slot, it is beneficial to ensure the average torque while reducing torque ripple. Furthermore, it eliminates the need to create harmonic slots on the outer edge of the rotor lamination. This arrangement simplifies the rotor lamination process, reduces costs, and simultaneously ensures the average torque of the motor, suppresses torque ripple, and improves motor performance.

[0010] Optionally, the length of the first main body groove is less than the length of the second main body groove.

[0011] Optionally, the ratio of the width of the first main body groove to the width of the second main body groove is a, where a is greater than 1 and less than or equal to 5.

[0012] Optionally, the ratio of the width of the first main body groove to the width of the second main body groove is a, where a is greater than 1 and less than or equal to 3.

[0013] Optionally, the outer edge of the rotor lamination is a smooth arc surface.

[0014] Optionally, the first magnet slot group includes a first magnet slot and a second magnet slot arranged at intervals, and the second magnet slot group includes a third magnet slot and a fourth magnet slot arranged at intervals; each of the first and second magnet slots includes a first main slot, and each of the third and fourth magnet slots includes a second main slot; the first magnet slot and the second magnet slot form an angle with their openings facing the outer edge of the rotor lamination, and the angle between the first magnet slot and the second magnet slot is in the range of 150°-160°; the third magnet slot and the fourth magnet slot form an angle with their openings facing the outer edge of the rotor lamination, and the angle between the third magnet slot and the fourth magnet slot is in the range of 110°-120°.

[0015] Optionally, along the circumferential direction of the rotor lamination, the distance between the outer end of the first magnet slot and the outer end of the second magnet slot is less than the distance between the outer end of the third magnet slot and the outer end of the fourth magnet slot; the distance between the inner end of the first magnet slot and the inner end of the second magnet slot is less than the distance between the inner end of the third magnet slot and the inner end of the fourth magnet slot.

[0016] Optionally, the rotor lamination has a d-axis and a q-axis extending radially along the rotor lamination, a single magnetic pole unit is symmetrical about the d-axis, and two adjacent magnetic pole units are symmetrical about the q-axis.

[0017] Optionally, a first magnetic isolation bridge is formed between the first magnet slot group and the outer edge of the rotor lamination, and a second magnetic isolation bridge is formed between the second magnet slot group and the outer edge of the rotor lamination; the size of the first magnetic isolation bridge is smaller than the size of the second magnetic isolation bridge along the radial direction of the rotor lamination; a first weight reduction hole is provided on the second magnetic isolation bridge.

[0018] Optionally, the minimum distance between the outer edge of the rotor lamination and the first magnet is 1-2 mm, and the minimum distance between the outer edge of the rotor lamination and the second magnet is 1-2 mm.

[0019] Optionally, the rotor lamination is further provided with a second weight reduction hole and a third weight reduction hole. Along the radial direction of the rotor lamination, the second weight reduction hole is located between the inner end of the first magnet slot group and the outer edge of the rotor lamination, and the third weight reduction hole is located between the inner end of the first magnet slot group and the inner end of the second magnet slot group. The d-axis passes through the second weight reduction hole and the third weight reduction hole, and the second weight reduction hole and the third weight reduction hole are symmetrical about the d-axis.

[0020] The second weight-reducing hole is circular, and the third weight-reducing hole is teardrop-shaped or elliptical, extending along the d-axis.

[0021] Optionally, the rotor lamination is further provided with a fourth weight reduction hole. Along the radial direction of the rotor lamination, the fourth weight reduction hole is located between the second magnet slot group and the inner hole of the rotor lamination. Along the circumferential direction of the rotor lamination, the fourth weight reduction hole is located between two adjacent magnetic pole units. The q-axis passes through the fourth weight reduction hole, and the fourth weight reduction hole is symmetrical about the q-axis.

[0022] On the other hand, embodiments of this application provide a rotor assembly, including a rotor core, a plurality of first magnets and a plurality of second magnets. The rotor core is obtained by stacking a plurality of the above-mentioned rotor laminations. The first magnets are inserted into the first main body slots, and the second magnets are inserted into the second main body slots. The width of the first magnets is greater than the width of the second magnets.

[0023] Optionally, the length of the first magnet is less than the length of the second magnet.

[0024] Optionally, the ratio of the width of the first magnet to the width of the second magnet is b, where b is greater than 1 and less than or equal to 5.

[0025] Optionally, the ratio of the width of the first magnet to the width of the second magnet is b, where b is greater than 1 and less than or equal to 3.

[0026] In another aspect, embodiments of this application provide an electric motor, including a housing, a stator assembly, and the aforementioned rotor assembly, wherein the rotor assembly and the stator assembly are disposed in the housing, and the rotor assembly is rotatable relative to the stator assembly.

[0027] In another aspect, embodiments of this application provide a vehicle including the aforementioned motor. Attached Figure Description

[0028] Figure 1 is a schematic diagram of a rotor lamination provided in an embodiment of this application;

[0029] Figure 2 is a partial schematic diagram of a rotor lamination provided in an embodiment of this application;

[0030] Figure 3 is an efficiency map of a motor using rotor laminations according to an embodiment of this application;

[0031] Figure 4 is a diagram showing the maximum external characteristics of a motor using rotor laminations according to an embodiment of this application.

[0032] The reference numerals in the accompanying drawings are as follows: 100, rotor lamination; 101, inner hole; 10, magnetic pole unit; V1, first magnet; V2, second magnet; 1, first magnet slot group; 11, first main slot; 12, first magnet slot; 121, first structural slot; 122, second structural slot; 13, second magnet slot; 2, second magnet slot group; 21, second main slot; 22, third magnet slot; 221, third structural slot; 222, fourth structural slot; 23, fourth magnet slot; 3, first magnetic isolation bridge; 4, second magnetic isolation bridge; 5, first weight reduction hole; 6, second weight reduction hole; 7, third weight reduction hole; 8, fourth weight reduction hole. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] As shown in Figures 1 and 2, one embodiment of this application provides a rotor lamination 100, including a plurality of magnetic pole units 10 arranged circumferentially along the rotor lamination 100. Each magnetic pole unit 10 includes a first magnetic slot group 1 and a second magnetic slot group 2. The second magnetic slot group 2 is located radially inside the first magnetic slot group 1. The first magnetic slot group 1 includes a first main slot 11 suitable for inserting a first magnet V1, and the second magnetic slot group 2 includes a second main slot 21 suitable for inserting a second magnet V2. The width of the first main slot 11 is greater than the width of the second main slot 21. The first main slot 11 and the second main slot 21 have a long side and a short side. Here, the long side dimension of the first main slot 11 is defined as the length of the first main slot 11, and the short side dimension of the first main slot 11 is defined as the width of the first main slot 11. Similarly, the long side dimension of the second main slot 21 is defined as the length of the second main slot 21, and the short side dimension of the second main slot 21 is defined as the width of the second main slot 21.

[0035] Therefore, the first main body groove 11 and the second main body groove 21 can be rectangular or rectangular in shape. For example, a rectangular shape can be formed by chamfering (beveled or rounded corners) at the four corners. The aforementioned shapes are merely examples and do not constitute a limitation on this embodiment. The first main body groove 11 and the second main body groove 21 in this embodiment can also be other shapes with long sides and short sides.

[0036] In this article, the outer edge of the rotor lamination 100 is the outer edge of the rotor lamination 100, the inner side is the side of the rotor lamination 100 that points to its center, and the outer side is the side of the rotor lamination 100 that points to its outer edge.

[0037] It should be noted that, since the first main slot 11 is used to insert the first magnet V1 and the second main slot 12 is used to insert the second magnet V2, in order to stably install the first magnet V1 and the second magnet V2 in the first main slot 11 and the second main slot 12, the size of the first main slot 11 should be slightly larger than the size of the first magnet V1, and both should increase or decrease proportionally. Similarly, the size of the second main slot 12 should be slightly larger than the size of the second magnet V2, and both should increase or decrease proportionally. Furthermore, since changes in the magnet size will have different effects on motor performance (such as average torque and torque ripple), the size setting of the main slots on the rotor lamination 100 used for inserting magnets is also particularly critical.

[0038] According to the rotor lamination 100 of this application embodiment, the second magnet slot group 2 is located radially inside the first magnet slot group 1 of the rotor lamination 100. The first magnet slot group 1 includes a first main slot 11 for inserting a first magnet V1, and the second magnet slot group 2 includes a second main slot 21 for inserting a second magnet V2. The width of the first main slot 11 is greater than the width of the second main slot 21. In the prior art, the width of the first main slot 11 is usually smaller than the width of the second main slot 21. In order to achieve a balance between average torque and torque ripple, the reduction of torque ripple requires opening harmonic slots on the outer edge of the rotor lamination 100, which leads to complex manufacturing process and high cost of the rotor lamination. The inventors of this application have found through experimental simulation that reducing the width of the second main slot 21 and increasing the width of the first main slot 11 so that the width of the second main slot 21 is smaller than the width of the first main slot 11 is beneficial to ensure average torque while reducing torque ripple, and at the same time, it is not necessary to open harmonic slots on the outer edge of the rotor lamination 100. Therefore, this application sets the width of the first main slot 11 to be greater than the width of the second main slot 21. The outer edge of the rotor lamination 100 does not need to be opened with harmonic slots to ensure the average torque while reducing torque pulsation. This setting can simplify the process of rotor lamination 100, reduce costs, ensure the average torque of the motor, suppress the torque pulsation of the motor, and improve the performance of the motor.

[0039] In one embodiment, referring to Figure 1, the ratio of the width of the first main slot 11 to the width of the second main slot 21 is 'a', where 'a' is greater than 1 and less than or equal to 5. Using the average torque and torque ripple of the motor as performance indicators, simulation experiments were conducted by designing different combinations of the dimensions of the first magnet V1 and the second magnet V2. It was found that when the ratio of the width of the first magnet V1 to the width of the second magnet V2 is greater than 1 and less than or equal to 5, the motor has a higher average torque and smaller torque ripple, resulting in good motor performance. Furthermore, it was concluded that the ratio 'a' of the width of the first main slot 11 to the width of the second main slot 21 should be set to be greater than 1 and less than or equal to 5.

[0040] In one embodiment, referring to Figure 1, the ratio of the width of the first main slot 11 to the width of the second main slot 21 is 'a', where 'a' is greater than 1 and less than or equal to 3. Based on the above embodiment, the influence of the ratio of the width of the first main slot 11 to the width of the second main slot 21 on the demagnetizing performance of the motor is further considered. Since the demagnetizing performance of the motor is directly related to the widths of the first magnet V1 and the second magnet V2, and the widths of the first magnet V1 and the second magnet V2 are determined by the widths of the first main slot 11 and the second main slot 21, "whether demagnetization occurs" is further introduced as the main evaluation index in the simulation experiment to determine the preferred range of the ratio 'a'. Through simulation experiments, it can be concluded that when the value of 'a' exceeds 3, the motor begins to demagnetize, and the motor performance deteriorates. Therefore, it is preferable that 'a' is greater than 1 and less than or equal to 3.

[0041] In one embodiment, the outer edge of the rotor lamination 100 is a smooth arc surface, meaning that the outer edge of the rotor lamination 100 is not slotted. In existing high-speed motors, harmonic slots are typically created on the outer edge of the rotor lamination to reduce torque ripple and address NVH (noise, vibration, and harshness) issues. However, in this application, since the width of the first main slot 11 is set to be greater than the width of the second main slot 21, it is sufficient to suppress torque ripple. Therefore, the outer edge of the rotor lamination 100 can be designed as a smooth arc surface without harmonic slots, ensuring a balance between the motor's electromagnetic characteristics and NVH. This is also more conducive to the manufacturing of the rotor lamination 100 and results in lower costs.

[0042] In one embodiment, referring to FIG1, the first magnet slot group 1 includes a first magnet slot 12 and a second magnet slot 13 spaced apart, and the second magnet slot group 2 includes a third magnet slot 22 and a fourth magnet slot 23 spaced apart. Each of the first and second magnet slots 12 and 13 includes a first main slot 11, and each of the third and fourth magnet slots 22 and 23 includes a second main slot 21. The first and second magnet slots 12 and 13 form an angle with their openings facing the outer edge of the rotor lamination 100, and the angle between the first and second magnet slots 12 and 13 ranges from 150° to 160°. The third and fourth magnet slots 22 and 23 form an angle with their openings facing the outer edge of the rotor lamination 100, and the angle between the third and fourth magnet slots 22 ranges from 110° to 120°. The first and second magnet slots 12 and 13 are located within the opening formed by the angle between the third and fourth magnet slots 22 and 23.

[0043] As an example, the included angle between the first magnet groove 12 and the second magnet groove 13 can be 150°, 152°, 154°, 156°, 158° or 160°, and the included angle between the third magnet groove 22 and the fourth magnet groove 23 can be 110°, 112°, 114°, 116°, 118° or 120°.

[0044] It should be noted that the included angle between the first magnet slot 12 and the second magnet slot 13 is the angle formed by the long sides of the two first main slots 11, and the included angle between the third magnet slot 22 and the fourth magnet slot 23 is the angle formed by the long sides of the two second main slots 21. The included angles between the first magnet slot 12 and the second magnet slot 13, and between the third magnet slot 22 and the fourth magnet slot 23, can be adjusted according to the dimensions of the rotor lamination 100.

[0045] In one embodiment, referring to Figures 1 and 2, along the circumferential direction of the rotor lamination 100, the distance between the outer end of the first magnet slot 12 and the outer end of the second magnet slot 13 is less than the distance between the outer end of the third magnet slot 22 and the outer end of the fourth magnet slot 23; the distance between the inner end of the first magnet slot 12 and the inner end of the second magnet slot 13 is less than the distance between the inner end of the third magnet slot 22 and the inner end of the fourth magnet slot 23. Here, the inner end refers to the end of the magnet slot near the radially inner side of the rotor lamination 100, and the outer end refers to the end of the magnet slot near the radially outer side of the rotor lamination 100.

[0046] Since the first magnet slot 12 and the second magnet slot 13 are located within the opening formed by the angle between the third magnet slot 22 and the fourth magnet slot 23, the space occupied by the first magnet slot group 1, composed of the first magnet slot 12 and the second magnet slot 13, is relatively small. The mass in this area is also small, resulting in a small centrifugal force and minimal impact on the strength of the rotor lamination 100. Therefore, the inner end distance between the first magnet slot 12 and the second magnet slot 13 can be set smaller, and the saved space can be used to fill more first magnets V1 in the first magnet slot group 2 to improve magnetization. Conversely, the second magnet slot group 2 occupies a larger space, has a larger mass in this area, and generates a larger centrifugal force, significantly impacting the strength of the rotor lamination 100. Therefore, the inner end distance between the third magnet slot 22 and the fourth magnet slot 23 should be set larger to release stress and improve the strength of the rotor lamination 100. Therefore, in this embodiment, the distance between the inner end of the first magnet slot 12 and the inner end of the second magnet slot 13 is set to be less than the distance between the inner end of the third magnet slot 22 and the inner end of the fourth magnet slot 23, which can improve the magnetization while ensuring the strength of the rotor lamination 100.

[0047] In one embodiment, referring to FIG1, the length of the first main slot 11 is less than the length of the second main slot 21. Since the angled openings of the first magnet slot 12 and the second magnet slot 13, and the angled openings of the third magnet slot 22 and the fourth magnet slot 23, all face the outer edge of the rotor lamination 100, and the first magnet slot 12 and the second magnet slot 13 are located within the angled openings of the third magnet slot 22 and the fourth magnet slot 23, setting the length of the first main slot 11 to be less than the length of the second main slot 21 is more conducive to arranging more magnets in a limited space.

[0048] In one embodiment, referring to Figures 1 and 2, the rotor lamination 100 has a d-axis and a q-axis extending radially along the rotor lamination 100, a single magnetic pole unit 10 is symmetrical about the d-axis, and two adjacent magnetic pole units 10 are symmetrical about the q-axis.

[0049] In one embodiment, referring to FIG1, from the radially inner side to the radially outer side of the rotor lamination 100, the first magnet slot 12 and the second magnet slot 13 gradually move away from the d-axis, and the third magnet slot 22 and the fourth magnet slot 23 gradually move away from the d-axis. The first magnet slot 12 and the second magnet slot 13 are symmetrical about the d-axis, and the third magnet slot 22 and the fourth magnet slot 23 are symmetrical about the d-axis.

[0050] In one embodiment, referring to Figures 1 and 2, a first magnetic isolation bridge 3 is formed between the first magnetic slot group 1 and the outer edge of the rotor lamination 100, and a second magnetic isolation bridge 4 is formed between the second magnetic slot group 2 and the outer edge of the rotor lamination 100. Along the radial direction of the rotor lamination 100, the size of the first magnetic isolation bridge 3 is smaller than the size of the second magnetic isolation bridge 4.

[0051] In one embodiment, a first weight-reducing hole 5 is provided on the second magnetic isolation bridge 4. The first weight-reducing hole 5 serves two purposes: firstly, it reduces weight and releases stress on the second magnetic isolation bridge 4; secondly, it reduces magnetic leakage. Thus, taking a motor with an outer diameter of 210mm as an example, the maximum speed of the motor can reach over 20,000rpm.

[0052] In one embodiment, the minimum distance between the outer edge of the rotor lamination 100 and the first magnet V1 is 1-2 mm, and the minimum distance between the outer edge of the rotor lamination 100 and the second magnet V2 is 1-2 mm. Furthermore, the range of distances between the outer edge of the rotor lamination 100 and the first magnet V1, and the range of distances between the outer edge of the rotor lamination 100 and the second magnet V2, can be determined based on the magnitude of the centrifugal force generated at a motor speed of 20,000 rpm and the dimensions of the rotor assembly.

[0053] As an example, the minimum distance between the outer edge of the rotor lamination 100 and the first magnet V1 can be 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm or 2mm, and the minimum distance between the outer edge of the rotor lamination 100 and the second magnet V2 can be 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm or 2mm.

[0054] In one embodiment, referring to Figures 1 and 2, the rotor lamination 100 is further provided with a second weight reduction hole 6 and a third weight reduction hole 7. Along the radial direction of the rotor lamination 100, the second weight reduction hole 6 is located between the inner end of the first magnet slot group 1 (the end near the center of the rotor lamination 100) and the outer edge of the rotor lamination 100, and the third weight reduction hole 7 is located between the inner end of the first magnet slot group 1 and the inner end of the second magnet slot group 2. The d-axis passes through the second weight reduction hole 6 and the third weight reduction hole 7, and the second weight reduction hole 6 and the third weight reduction hole 7 are symmetrical about the d-axis.

[0055] In one embodiment, referring to Figures 1 and 2, the second weight-reducing hole 6 is circular, and the third weight-reducing hole 7 is teardrop-shaped or elliptical, extending along the d-axis. The shape and position of the second and third weight-reducing holes 6 and 7 are determined according to the shape and position of the low-stress distribution in the region. The second weight-reducing hole 6 is located in the low-stress region between the first magnet slot group 1 and the outer edge of the rotor lamination 100, and the third weight-reducing hole 7 is located in the low-stress region between the first magnet slot group 1 and the second magnet slot group 2. By setting weight-reducing holes in the low-stress region that correspond to the shape and position of the low-stress distribution, the weight of the rotor lamination 100 can be reduced without affecting its structural strength. Furthermore, the internal stress of the rotor lamination 100 can be dispersed and released, avoiding stress concentration, thereby improving the fatigue life and reliability of the rotor lamination 100.

[0056] In one embodiment, referring to FIG1, a fourth weight reduction hole 8 is also provided on the rotor lamination 100. Along the radial direction of the rotor lamination 100, the fourth weight reduction hole 8 is located between the second magnet slot group 2 and the inner hole 101 of the rotor lamination 100. Along the circumferential direction of the rotor lamination 100, the fourth weight reduction hole 8 is located between two adjacent magnetic pole units 10. The q-axis passes through the fourth weight reduction hole 8, and the fourth weight reduction hole 8 is symmetrical about the q-axis.

[0057] Referring to Figure 1, the first magnetic steel groove 12 and the second magnetic steel groove 13 are provided with a first structural groove 121 and a second structural groove 122 at both ends, and the first main body groove 11 is connected between the first structural groove 121 and the second structural groove 122.

[0058] Referring to Figure 1, the third magnetic steel groove 22 and the fourth magnetic steel groove 23 are provided with a third structural groove 221 and a fourth structural groove 222 at both ends, and the second main body groove 21 is connected between the third structural groove 221 and the fourth structural groove 222.

[0059] On the other hand, embodiments of this application provide a rotor assembly, including a rotor core, a plurality of first magnets V1 and a plurality of second magnets V2. The rotor core is obtained by stacking a plurality of the aforementioned rotor laminations 100. Specifically, the rotor laminations 100 are stacked at a certain angle to form the rotor core. The first magnets V1 are inserted into the first main body slot 11, and the second magnets V2 are inserted into the second main body slot 21. The width of the first magnets V1 is greater than the width of the second magnets V2. In this document, "a plurality of" refers to two or more.

[0060] In one embodiment, referring to Figure 2, the length of the first magnet V1 is less than the length of the second magnet V2.

[0061] In one embodiment, referring to Figure 2, the ratio of the width of the first magnet V1 to the width of the second magnet V2 is b, where b is greater than 1 and less than or equal to 5. Using the average torque and torque ripple of the motor as performance indicators, by designing different combinations of the dimensions of the first magnet V1 and the second magnet V2 and conducting simulation experiments, it can be concluded that when the ratio of the width of the first magnet V1 to the width of the second magnet V2 is greater than 1 and less than or equal to 5, the motor has a higher average torque and smaller torque ripple, resulting in good motor performance.

[0062] In one embodiment, referring to Figure 2, the ratio of the width of the first magnet V1 to the width of the second magnet V2 is b, where b is greater than 1 and less than or equal to 3. Based on the above embodiment, further considering the influence of the ratio of the width of the first magnet V1 to the width of the second magnet V2 on the demagnetizing performance of the motor, the simulation experiment further introduces "whether demagnetization occurs" as the main evaluation index to determine the optimal range of the ratio b. The simulation experiment shows that when the value of b exceeds 3, the motor begins to demagnetize, and the motor performance deteriorates. Therefore, b is preferably greater than 1 and less than or equal to 3.

[0063] The width direction of the first magnet V1 corresponds to the width direction of the first main body groove 11, and the length direction of the first magnet V1 corresponds to the length direction of the first main body groove 11. The width direction of the second magnet V2 corresponds to the width direction of the second main body groove 21, and the length direction of the second magnet V2 corresponds to the length direction of the second main body groove 21.

[0064] Referring to Figure 2, the width of the first magnet V1 is C, and the length of the first magnet V1 is D; the width of the second magnet V2 is A, and the length of the second magnet V2 is B.

[0065] The first magnet V1 is fixed to the rotor lamination 100 using magnetic adhesive or injection molding compound, and the second magnet V2 is fixed to the rotor lamination 100 using magnetic adhesive or injection molding compound.

[0066] In another aspect, embodiments of this application provide an electric motor, including the rotor assembly described in the above embodiments.

[0067] The motor also includes a housing and a stator assembly, with the rotor assembly and stator assembly housed within the housing, and the rotor assembly capable of rotating relative to the stator assembly.

[0068] In another aspect, this application provides a vehicle that includes the motor described in the above embodiments.

[0069] The vehicle is a new energy vehicle, such as a hybrid vehicle or a pure electric vehicle.

[0070] Figure 3 is an efficiency map of the motor using the rotor lamination 100 according to an embodiment of this application. The darker the color, the larger the value, indicating a higher motor efficiency. As shown in Figure 1, the area with an efficiency greater than 80% accounts for 97.43%, and the area with an efficiency greater than 90% accounts for 87.56%. The distribution area of ​​motor efficiency above 96% is relatively large, which is higher than that of existing technologies using conventional rotor laminations. In Figure 3, the horizontal axis represents the motor speed, and the vertical axis represents the motor torque.

[0071] [Corrected according to Rule 91, 05.12.2025] Figure 4 is the maximum external characteristic diagram of the motor using the rotor lamination 100 of this application embodiment, representing the maximum operating capacity of the motor. Especially after the inflection point, after entering the field weakening stage, the power can still be maintained, indicating that the motor performance characteristics are stable. The power remains stable as the motor speed increases, which is good for the continuous performance of the entire vehicle and beneficial to the acceleration performance at maximum speed. In Figure 4, the horizontal axis is the motor speed, the left vertical axis is the motor torque, and the right vertical axis is the motor power. MAX_T represents the maximum torque curve, and MAX_P represents the maximum power curve. The maximum external characteristic data are shown in the table below:

[0072] The design method of the motor in this application is as follows:

[0073] First, the average torque Tavg and torque ripple Tpkavg of the motor are used as optimization targets, and the level values ​​of optimization parameters A, B, C, and D are determined.

[0074] Furthermore, an experimental orthogonal array was established, and relevant experimental results were obtained through finite element simulation.

[0075] Furthermore, the data obtained from finite element simulation are processed to analyze the influence of each optimization parameter on the target average torque Tavg and torque ripple Tpkavg, and the optimal parameter combination scheme is determined.

[0076] The optimization parameters and level values ​​for A, B, C, and D are shown in Table 1.

[0077] Table 1 Optimization parameters and level values

[0078] Furthermore, the average torque Tavg and torque pulsation Tpkavg under rated operating conditions were selected as optimization objectives, an orthogonal array was established, and the corresponding optimization objective values ​​were obtained through finite element simulation. The results are shown in Table 2.

[0079] Table 2 Experimental matrix and finite element simulation results

[0080] Furthermore, to study the impact of each optimization parameter on the target, it is first necessary to perform an average value analysis on the orthogonal experimental results. For example, the average value of the width A of the second magnet V2 at level 1 is calculated as shown in formula (1); the average value of the torque pulsation Tpkavg of the width A of the second magnet V2 at level 1 is calculated as shown in formula (2). Similarly, the average values ​​of the performance indicators of other variables at each level value can be calculated, and the results are shown in Table 3. Tavg(A1)=1 / 3[Tavg(1)+Tavg(2)+Tavg(3)] (1)

[0081] In the above formula (1): Tavg(n) is the value of the average torque in the nth experiment; Tavg(A1) is the average value of the average torque of variable A at level 1. Tpkavg(A1)=1 / 3[Tpkavg(1)+Tpkavg(2)+Tpkavg(3)] (2)

[0082] In the above formula (2): Tpkavg(n) is the value of torque ripple in the nth experiment; Tpkavg(A1) is the average value of torque ripple of variable A at level 1.

[0083] Table 3 shows the average values ​​of each performance index at each parameter level.

[0084] Furthermore, by analyzing the variance SS, the proportion of influence of each optimization parameter on the optimization objective value can be obtained. The formula for calculating the variance SS is:

[0085] In the above formula: m(X) i ) represents the average value of a certain performance index of variable X at level i in Table 3; m represents the sum of the average values ​​of a certain performance index of variable X at all levels. The variance SS calculation results are shown in Table 4.

[0086] Table 4. Variance and weights of performance indicators at three levels for each optimization parameter.

[0087] Furthermore, as shown in Tables 3 and 4, the main factors affecting the average torque of the motor are variables B and C. The larger the values ​​of variables B and C, the greater the average torque of the motor. Therefore, the average torque of the motor can be increased by increasing the width of the first magnet V1 and the length of the second magnet V2. The main factors affecting torque ripple are variables A and C. The smaller the value of variable A and the larger the value of variable C, the smaller the torque ripple. Therefore, the torque ripple of the motor can be suppressed by increasing the width of the first magnet V1 and decreasing the width of the second magnet V2. With the goal of maximizing average torque and minimizing torque ripple, the optimal combination of the corresponding level values ​​of the optimization parameters is determined to reduce torque ripple while ensuring average torque.

[0088] Furthermore, the study investigated the influence of the relative widths (C) of the first magnet V1 and the second magnet V2 on the average torque and torque ripple, depending on whether harmonic slots were opened on the outer edge of the rotor. Simulation analysis was conducted with average torque and torque ripple as optimization objectives, and the results are shown in Table 5.

[0089] Table 5

[0090] As shown in Table 5, when A > C and A = C, opening harmonic slots on the outer edge of the rotor helps reduce torque ripple. However, when A < C, even without opening harmonic slots on the outer edge of the rotor, a higher average torque and lower torque ripple can still be achieved. Therefore, compared to the first magnet V1 having a smaller width than the second magnet V2, setting the width of the first magnet V1 to be greater than the width of the second magnet V2 can simplify the manufacturing process of the rotor lamination 100 and reduce costs while improving the average torque and reducing torque ripple.

[0091] Furthermore, the outer diameter range of the rotor assembly is first customized to be within a reasonable range, such as 140-150mm, which can be adjusted according to the size of the rotor assembly.

[0092] Furthermore, the positions of the first magnet V1 and the second magnet V2 are set, allowing for flexible adjustments to meet different requirements while satisfying performance requirements. The position of the first magnet V1 is selected within a suitable distance from the outer edge of the rotor lamination 100, for example, 1-2 mm; the position of the second magnet V2 is selected within a suitable distance from the outer edge of the rotor lamination 100, for example, 1-2 mm. The above distances can be adjusted according to the dimensions of the rotor assembly.

[0093] Furthermore, the included angles between the first magnet slot 12 and the second magnet slot 13, and between the third magnet slot 22 and the fourth magnet slot 23 are set respectively. To ensure performance, the setting of the included angles between the first magnet slot 12 and the second magnet slot 13, and between the third magnet slot 22 and the fourth magnet slot 23 is also crucial. The included angle between the first magnet slot 12 and the second magnet slot 13 is selected between 150° and 160°, and the included angle between the third magnet slot 22 and the fourth magnet slot 23 is selected between 110° and 120°. The above included angles can be adjusted according to the size of the rotor lamination 100.

[0094] Furthermore, the influence of the ratio range of the width (C) of the first magnet V1 and the width (A) of the second magnet V2 on the average torque, torque ripple, and demagnetization performance was studied. The average torque, torque ripple, and whether demagnetization occurred were used as optimization objectives for simulation analysis, and the results are shown in Table 6.

[0095] Table 6

[0096] Furthermore, the width dimensions of the first main slot 11 and the second main slot 21 are constrained (i.e., the width dimensions of the first magnet V1 and the second magnet V2 are constrained). By selecting the average torque and checking for demagnetization, the width ratio of the first main slot 11 and the second main slot 21 is determined (i.e., the width ratio b of the first magnet V1 and the second magnet V2 is determined). As can be seen from Table 6, considering both the average torque and torque ripple, the advantageous range of the average torque is 215.98 Nm to 266.2 Nm, and the advantageous range of the torque ripple is 3.3634% to 4.2805%, which corresponds to a range of b greater than 1 and less than or equal to 5. However, since the demagnetization performance of the motor is directly related to the width of the first magnet V1 and the second magnet V2, simulation experiments show that when the value of b exceeds 3, the motor begins to demagnetize, and the motor performance deteriorates. Therefore, when "demagnetization" is introduced as an additional consideration, the optimal ranges for average torque and torque ripple are 215.98 Nm to 253.92 Nm and 3.3634% to 3.5433%, respectively. This yields an optimal range for b of greater than 1 and less than or equal to 3. Furthermore, by appropriately selecting the dimensions of the first magnet V1 and the second magnet V2, torque ripple can be reduced while increasing the average torque.

[0097] Furthermore, after determining the basic topology of the rotor lamination 100, mechanical properties are checked, and while meeting the performance requirements, a margin is left to optimize the structural strength.

[0098] Furthermore, to ensure that the large-diameter rotor lamination 100 meets the requirements of high speed and high strength, first weight reduction holes 5, second weight reduction holes 6, third weight reduction holes 7 and fourth weight reduction holes 8 are drilled on the rotor lamination 100 to reduce the mass of the rotor lamination 100 and release stress, so as to increase the speed of the motor and make the stress of the entire design meet the material's own characteristics.

[0099] Furthermore, the stator design is optimized to meet the requirements of the motor in multiple dimensions such as NVH, efficiency, demagnetization, mechanical characteristics, and strength, and the design is then finalized.

[0100] As can be seen from the above experimental analysis process, this application sets the width of the first main slot 11 to be greater than the width of the second main slot 21, so that the outer edge of the rotor lamination 100 does not need to open harmonic slots to ensure the average torque while reducing torque pulsation. This setting can simplify the process of rotor lamination 100, reduce costs, ensure the average torque of the motor, suppress the torque pulsation of the motor, and improve the performance of the motor.

[0101] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rotor lamination, characterized in that, It includes a plurality of magnetic pole units arranged circumferentially along the rotor lamination, each magnetic pole unit including a first magnetic slot group and a second magnetic slot group, the second magnetic slot group being located inside the first magnetic slot group in the radial direction of the rotor lamination; The first magnet slot group includes a first main slot suitable for inserting a first magnet, and the second magnet slot group includes a second main slot suitable for inserting a second magnet. The width of the first main slot is greater than the width of the second main slot.

2. The rotor lamination as described in claim 1, characterized in that, The length of the first main body groove is less than the length of the second main body groove.

3. The rotor lamination as described in claim 1, characterized in that, The ratio of the width of the first main body groove to the width of the second main body groove is a, where a is greater than 1 and less than or equal to 5.

4. The rotor lamination as described in claim 1, characterized in that, The ratio of the width of the first main body groove to the width of the second main body groove is a, where a is greater than 1 and less than or equal to 3.

5. The rotor lamination as described in claim 1, characterized in that, The outer edge of the rotor lamination is a smooth arc surface.

6. The rotor lamination as described in claim 1, characterized in that, The first magnet slot group includes a first magnet slot and a second magnet slot arranged at intervals, and the second magnet slot group includes a third magnet slot and a fourth magnet slot arranged at intervals; each of the first and second magnet slots includes a first main slot, and each of the third and fourth magnet slots includes a second main slot; the first magnet slot and the second magnet slot form an angle with their openings facing the outer edge of the rotor lamination, and the angle between the first magnet slot and the second magnet slot is in the range of 150°-160°; the third magnet slot and the fourth magnet slot form an angle with their openings facing the outer edge of the rotor lamination, and the angle between the third magnet slot and the fourth magnet slot is in the range of 110°-120°.

7. The rotor lamination as described in claim 6, characterized in that, Along the circumferential direction of the rotor lamination, the distance between the outer end of the first magnet slot and the outer end of the second magnet slot is less than the distance between the outer end of the third magnet slot and the outer end of the fourth magnet slot; the distance between the inner end of the first magnet slot and the inner end of the second magnet slot is less than the distance between the inner end of the third magnet slot and the inner end of the fourth magnet slot.

8. The rotor lamination as described in claim 1, characterized in that, A first magnetic isolation bridge is formed between the first magnetic slot group and the outer edge of the rotor lamination, and a second magnetic isolation bridge is formed between the second magnetic slot group and the outer edge of the rotor lamination; the size of the first magnetic isolation bridge is smaller than the size of the second magnetic isolation bridge along the radial direction of the rotor lamination; a first weight reduction hole is provided on the second magnetic isolation bridge.

9. The rotor lamination as described in claim 1, characterized in that, The rotor lamination has a d-axis and a q-axis extending radially along the rotor lamination, and a single magnetic pole unit is symmetrical about the d-axis, and two adjacent magnetic pole units are symmetrical about the q-axis; The rotor lamination is also provided with a second weight reduction hole and a third weight reduction hole. Along the radial direction of the rotor lamination, the second weight reduction hole is located between the inner end of the first magnet slot group and the outer edge of the rotor lamination, and the third weight reduction hole is located between the inner end of the first magnet slot group and the inner end of the second magnet slot group. The d-axis passes through the second weight reduction hole and the third weight reduction hole, and the second weight reduction hole and the third weight reduction hole are symmetrical about the d-axis. The second weight-reducing hole is circular, and the third weight-reducing hole is teardrop-shaped or elliptical, extending along the d-axis.

10. The rotor lamination as described in claim 1, characterized in that, The rotor lamination has a d-axis and a q-axis extending radially along the rotor lamination, and a single magnetic pole unit is symmetrical about the d-axis, and two adjacent magnetic pole units are symmetrical about the q-axis; The rotor lamination is also provided with a fourth weight reduction hole. Along the radial direction of the rotor lamination, the fourth weight reduction hole is located between the second magnet slot group and the inner hole of the rotor lamination. Along the circumferential direction of the rotor lamination, the fourth weight reduction hole is located between two adjacent magnetic pole units. The q-axis passes through the fourth weight reduction hole, and the fourth weight reduction hole is symmetrical about the q-axis.

11. A rotor assembly, characterized in that, It includes a rotor core, a plurality of first magnets and a plurality of second magnets. The rotor core is obtained by stacking a plurality of rotor laminations as described in any one of claims 1-10. The first magnets are inserted into the first main body slots, and the second magnets are inserted into the second main body slots. The width of the first magnets is greater than the width of the second magnets.

12. The rotor assembly as claimed in claim 11, characterized in that, The length of the first magnet is less than the length of the second magnet.

13. The rotor assembly as claimed in claim 11, characterized in that, The ratio of the width of the first magnet to the width of the second magnet is b, where b is greater than 1 and less than or equal to 5.

14. The rotor assembly as claimed in claim 11, characterized in that, The ratio of the width of the first magnet to the width of the second magnet is b, where b is greater than 1 and less than or equal to 3.

15. An electric motor, characterized in that, It includes a housing, a stator assembly, and a rotor assembly as described in any one of claims 11-14, wherein the rotor assembly and the stator assembly are disposed in the housing, and the rotor assembly is rotatable relative to the stator assembly.

16. A vehicle, characterized in that, Includes the motor as described in claim 15.

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