A high-strength, leak-proof magnetic rotor structure for drive motors in new energy vehicles

Abstract

This utility model discloses a high-strength anti-magnetic leakage rotor structure for a new energy vehicle drive motor, including a rotor core and permanent magnets embedded in double V-shaped permanent magnet slots evenly distributed around its circumference. The permanent magnets are joined in segments using a bonding process, with gap fit between them and the permanent magnet slots, and fixed with adhesive. A semi-arc-shaped magnetic isolation bridge is provided at the opening end of each permanent magnet slot, with the first magnetic isolation bridge between slots a and b, and the second magnetic isolation bridge between slots c and d. This utility model improves the rotor's mechanical strength through optimized magnetic isolation bridge structure, enabling it to withstand a peak speed of 16,000 rpm and avoiding the risk of rotor scorching at high speeds. Precise control of the magnetic isolation bridge thickness increases magnetic resistance, reduces magnetic leakage, and improves the utilization rate of the permanent magnets. The segmented magnet design balances anti-demagnetization performance and cost, while reducing eddy current losses and rotor temperature rise. This structure achieves synergistic optimization of high-speed reliability, anti-magnetic leakage effect, and economy, making it suitable for the needs of high-speed, lightweight new energy vehicle drive motors.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, specifically to a high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor. Background Technology

[0002] With the rapid development of the global new energy vehicle industry, the market has placed increasingly stringent demands on the performance of drive motors. High speed, lightweight design, and high efficiency have become the core directions for motor technology iteration. On the one hand, consumers' demands for vehicle range and power response speed continue to increase, forcing drive motors to achieve higher power output within limited installation space. By increasing the motor speed, power density can be significantly improved and energy loss reduced while keeping the overall weight and volume of the motor basically unchanged, thus directly contributing to the improvement of the range of new energy vehicles. On the other hand, the automotive manufacturing industry's pursuit of platformization and integration has led to the gradual replacement of traditional direct-drive motor solutions with integrated electric drive axle systems. This integrated design effectively shortens the transmission path and reduces system weight by integrating core components such as the motor, reducer, and axle, but it also poses higher challenges to the structural compactness and operational stability of the motor.

[0003] However, in the process of increasing motor speed, the rotor, as the core moving component, faces severe technical bottlenecks. As motor speed increases, the rotor experiences enormous radial and tangential stresses under centrifugal force. The junction between the permanent magnet and the rotor core, and the connection structure between the magnetic poles, become critical areas of stress concentration. In traditional rotor structures, the permanent magnet slots and magnetic isolation bridges designed to fix the permanent magnets often struggle to balance the dual requirements of "mechanical strength" and "leakage prevention": increasing the thickness of the magnetic isolation bridge to ensure structural strength reduces the magnetic resistance between the magnetic poles, causing a large amount of magnetic flux to pass through the bridge and form a leakage magnetic circuit, reducing the magnetic energy utilization rate of the permanent magnets and thus affecting motor efficiency; thinning the magnetic isolation bridge to reduce leakage magnetic flux results in insufficient resistance to centrifugal force, making it prone to deformation or even breakage at high speeds, leading to loosening and detachment of the permanent magnets. In severe cases, this can cause rotor and stator rubbing, directly leading to motor failure, affecting not only normal vehicle operation but also potential safety hazards.

[0004] Furthermore, there is room for optimization in the fixing method of permanent magnets and the selection of magnets in existing rotor structures. Traditional permanent magnets mostly use integral magnets, which are simple in structure, but have large eddy current losses at high speeds, which can easily lead to increased rotor temperature and exacerbate the risk of magnet demagnetization. At the same time, it is difficult to balance high-temperature stability and cost control with a single grade of magnet. If high-performance magnets are used exclusively, the manufacturing cost will increase significantly, while low-cost magnets cannot meet the anti-demagnetization requirements at high speeds.

[0005] Against this backdrop, designing a rotor structure that can both improve the mechanical strength of the rotor through structural optimization to withstand high-speed centrifugal force and reduce magnetic leakage and losses through precise control of the magnetic bridge parameters and magnet configuration has become the key to breaking through the current performance bottleneck of drive motors and is of great significance to promoting the reliability and economy of new energy vehicle drive systems. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a high-strength, leak-proof magnetic rotor structure for new energy vehicles. By optimizing the magnetic bridge structure, the mechanical strength is increased by more than 10%, reducing the centrifugal force on the rotor during motor operation and enabling the motor to reach a peak speed of 16,000 rpm. This ensures the safe and reliable operation of the motor and the entire vehicle during operation, preventing rotor rubbing due to excessive centrifugal force, which could lead to motor failure and affect safety and reliability.

[0007] The technical solution adopted in this utility model is: a high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor, comprising:

[0008] Rotor core;

[0009] The double V-shaped permanent magnet slot group is evenly distributed on the rotor core in the circumferential direction, including a first V-shaped slot group composed of permanent magnet slot a and permanent magnet slot b, and a second V-shaped slot group composed of permanent magnet slot c and permanent magnet slot d.

[0010] The angle between permanent magnet slot a and permanent magnet slot b is 106°-107°, and the angle between permanent magnet slot c and permanent magnet slot d in the second V-shaped slot group is 117°-118°.

[0011] Permanent magnets A and B are embedded in the first V-shaped groove group;

[0012] Permanent magnets C and D are embedded in the second V-shaped groove group;

[0013] A first magnetic isolation bridge is provided at the opening end of the first V-shaped groove group and a second magnetic isolation bridge is provided at the opening end of the second V-shaped groove group.

[0014] The first and second magnetic isolation bridges are both semi-circular symmetrical structures composed of multiple gradually changing arcs, with the first magnetic isolation bridge having a thickness of 2.6 mm and the second magnetic isolation bridge having a thickness of 0.8 mm.

[0015] Furthermore, the permanent magnets A, B, C, and D are bonded together in sections using a segmented bonding process, with UH grade magnets at both ends and SH grade magnets in the middle.

[0016] Furthermore, the permanent magnets A, B, C, and D are fitted with corresponding permanent magnet slots a, b, c, and d with a clearance and are fixed with glue.

[0017] Furthermore, the gradient circular arc structures of the first and second magnetic isolation bridges are symmetrically distributed along the radial direction of the rotor.

[0018] The beneficial effects of this utility model are:

[0019] 1. High-strength resistance to centrifugal force: By optimizing the structural design of the first and second magnetic isolation bridges and adopting a symmetrical structure composed of multiple gradually changing circular arcs, the rotor can withstand peak speeds of up to 16,000 rpm. This design effectively disperses the centrifugal force generated during high-speed rotation, avoids structural damage caused by stress concentration, and significantly improves the reliability of the rotor at high speeds.

[0020] 2. Stable Fixation of Permanent Magnets: The permanent magnets are fixed to the permanent magnet slots with a clearance fit and glue. Combined with the circumferentially even distribution of the double V-shaped permanent magnet slots, this ensures that the permanent magnets will not shift or loosen during high-speed rotation. This dual fixing method improves the overall stability of the rotor and extends the service life of the motor.

[0021] 3. Reduced magnetic leakage loss: The semi-circular design and specific thickness parameters of the magnetic isolation bridges (2.6mm for the first bridge and 0.8mm for the second) effectively increase magnetic resistance and reduce magnetic leakage. Tests show that compared to traditional structures, this invention reduces magnetic leakage coefficient by approximately 15%, significantly improving the magnetic energy utilization rate of the permanent magnet.

[0022] 4. Optimized magnetic field distribution: The angle between permanent magnet slots a and b is 106°-107°, and the angle between permanent magnet slots c and d is 117°-118°. This specific angle design optimizes the air gap magnetic field distribution, making the back electromotive force waveform closer to a sine wave, reducing harmonic content, and thus reducing motor torque fluctuations and noise.

[0023] 5. Segmented Magnet Design: The permanent magnets are manufactured using a segmented bonding process, with UH grade magnets at both ends and SH grade magnets in the middle. This design effectively reduces magnet costs by approximately 20% while ensuring rotor high-temperature stability and demagnetization resistance, achieving a balance between performance and economy.

[0024] 6. Reduced eddy current losses: The segmented magnet design also reduces eddy current losses, lowering the rotor temperature rise during high-speed operation. Tests show that, under the same operating conditions, the rotor temperature of this invention is approximately 10°C lower than that of the traditional structure, further improving the motor's efficiency and reliability.

[0025] 7. Clearance Fit and Adhesive Fixation: The clearance fit design between the permanent magnet and the permanent magnet slot facilitates assembly, while adhesive fixing ensures reliable connection. This design simplifies the manufacturing process, improves production efficiency, and reduces assembly costs.

[0026] 8. Symmetrical structure design: The symmetrical structure design of the permanent magnet slot and the magnetic bridge facilitates mold manufacturing and processing, reduces errors in the production process, and improves product consistency and yield. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0028] Figure 2 This is a schematic diagram of the structure of the first magnetic isolation bridge in this utility model;

[0029] Figure 3 This is a schematic diagram of the structure of the second magnetic isolation bridge in this utility model;

[0030] In the diagram: 1-rotor core, 2-permanent magnet slot a, 3-permanent magnet slot b, 4-permanent magnet slot c, 5-permanent magnet slot d, 6-permanent magnet A, 7-permanent magnet B, 8-permanent magnet C, 9-permanent magnet D, 10-first magnetic isolation bridge, 11-second magnetic isolation bridge. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0032] like Figures 1 to 3 As shown, this utility model is a high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor, including a rotor core 1, permanent magnet slots a2, b3, c4, d5, permanent magnets A6, B7, C8, and D9, a first magnetic isolation bridge 10, and a second magnetic isolation bridge 11. The rotor core 1 is uniformly provided with double V-shaped permanent magnet slots circumferentially. Permanent magnet A6 is embedded in permanent magnet slot a2, permanent magnet B7 in permanent magnet slot b3, permanent magnet C8 in permanent magnet slot c4, and permanent magnet D9 in permanent magnet slot d5. A magnetic isolation bridge is provided at the open end of each permanent magnet slot, and the magnetic isolation bridge is semi-arc-shaped.

[0033] In practice, the permanent magnets and their corresponding slots are fitted with a clearance fit and fixed together with adhesive. This design facilitates assembly and ensures the stability of the permanent magnets during high-speed rotation. The clearance fit tolerance is controlled between 0.05-0.1mm, and the adhesive used is a high-temperature resistant, high-strength epoxy resin that can withstand the high temperatures and centrifugal forces during motor operation, effectively preventing the permanent magnets from loosening or falling off, thus improving the reliability and service life of the rotor.

[0034] Permanent magnets A6, B7, C8, and D9, and permanent magnet slots a2, b3, c4, and d5 are evenly distributed circumferentially on rotor core 1. This symmetrical structural design not only facilitates mold manufacturing and processing, reduces errors in the production process, and improves product consistency and yield, but also optimizes the air gap magnetic field distribution, making the back electromotive force waveform closer to a sine wave, reducing harmonic content, and thus reducing motor torque fluctuations and noise.

[0035] Permanent magnet slots a2 and b3 are symmetrical, with an included angle of 106°-107°; permanent magnet slots c4 and d5 are also symmetrical, with an included angle of 117°-118°. This specific angle design, precisely calculated and optimized, effectively improves the motor's torque density and efficiency. By adjusting the included angle between the permanent magnet slots, the magnetic field distribution generated by the permanent magnets can be altered, allowing for better coupling between the magnetic field and the magnetic field generated by the stator windings, thereby improving the motor's output torque and efficiency.

[0036] Permanent magnets A6, B7, C8, and D9 all employ a segmented bonding process. The two ends of each permanent magnet are made of UH grade magnets, while the middle section uses SH grade magnets. UH grade magnets possess high coercivity and high-temperature resistance, effectively resisting high-temperature demagnetization and making them suitable for the high-temperature ends of the motor during high-speed operation. While SH grade magnets have slightly lower performance than UH grade magnets, their lower cost allows for significant cost reduction in the middle section while maintaining motor performance. Actual testing shows that compared to using only UH grade magnets, this segmented magnet design reduces magnet costs by approximately 20% while maintaining essentially the same motor performance.

[0037] A first magnetic isolation bridge 10 is provided between permanent magnet slots a2 and b3. The first magnetic isolation bridge 10 has a symmetrical structure composed of multiple gradually changing arc segments and a thickness of 2.6 mm. A second magnetic isolation bridge 11 is provided between permanent magnet slots c4 and d5. The second magnetic isolation bridge 11 also has a symmetrical structure composed of multiple gradually changing arc segments and a thickness of 0.8 mm. This special magnetic isolation bridge design has multiple advantages. First, the symmetrical structure composed of multiple gradually changing arc segments can effectively disperse the centrifugal force generated during high-speed rotation, avoiding structural damage caused by stress concentration, and significantly improving the mechanical strength of the rotor, enabling it to withstand peak speeds up to 16,000 rpm. Second, by precisely controlling the thickness of the magnetic isolation bridge, the magnetic resistance between magnetic poles can be increased while ensuring structural strength, reducing magnetic leakage. Tests show that compared with traditional structures, the magnetic leakage coefficient of this invention is reduced by approximately 15%, significantly improving the magnetic energy utilization rate of the permanent magnets, thereby improving the efficiency of the motor.

[0038] During motor operation, the rotor structure of this invention effectively reduces eddy current losses. The segmented magnet design reduces eddy current paths and losses, thereby lowering the rotor temperature rise during high-speed operation. Tests show that under the same operating conditions, the rotor temperature of this invention is approximately 10°C lower than that of the traditional structure, further improving the motor's efficiency and reliability. Simultaneously, the lower temperature also reduces the risk of demagnetization of the permanent magnets, extending the motor's service life.

[0039] In summary, this utility model achieves significant beneficial effects in terms of mechanical performance, magnetic properties, and cost control through optimized rotor structure. This rotor structure is suitable for various new energy vehicle drive motors, especially high-speed motors with high power density and reliability requirements, and has broad application prospects. The preferred embodiments of this utility model have been described in detail above with reference to the accompanying drawings. However, this utility model is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, and these simple modifications all fall within the protection scope of this utility model.

[0040] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this utility model will not describe the various possible combinations separately. Furthermore, various different embodiments of this utility model can also be arbitrarily combined, as long as they do not violate the spirit of this utility model, and they should also be regarded as the content disclosed by this utility model.

Claims

1. A high-strength, anti-magnetic-leakage rotor structure for a new energy vehicle drive motor, characterized in that, include: Rotor core (1); The double V-shaped permanent magnet slot group is evenly distributed on the rotor core (1) in the circumferential direction, including the first V-shaped slot group composed of permanent magnet slot a (2) and permanent magnet slot b (3) and the second V-shaped slot group composed of permanent magnet slot c (4) and permanent magnet slot d (5); The angle between permanent magnet groove a (2) and permanent magnet groove b (3) is 106°-107°, and the angle between permanent magnet groove c and permanent magnet groove d in the second V-shaped groove group is 117°-118°. Permanent magnet A (6) and permanent magnet B (7) are embedded in the first V-shaped groove group; Permanent magnets C (8) and D (9) are embedded in the second V-shaped groove group. A first magnetic isolation bridge (10) is provided at the opening end of the first V-shaped groove group and a second magnetic isolation bridge (11) is provided at the opening end of the second V-shaped groove group. The first magnetic isolation bridge (10) and the second magnetic isolation bridge (11) are both composed of a semi-arc symmetrical structure formed by multiple gradually changing arcs, and the thickness of the first magnetic isolation bridge (10) is 2.6 mm, and the thickness of the second magnetic isolation bridge (11) is 0.8 mm.

2. The high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor according to claim 1, characterized in that: The permanent magnets A, B, C, and D (6, 7, 8, and 9) are bonded together in sections, with UH grade magnets at both ends and SH grade magnets in the middle.

3. The high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor according to claim 1, characterized in that: The permanent magnets A, B, C, D (6, 7, 8, 9) are fitted with the corresponding permanent magnet slots a, b, c, d (2, 3, 4, 5) with a clearance and are fixed with glue.

4. The high-strength anti-leakage magnetic rotor structure for a new energy vehicle drive motor according to claim 1, characterized in that: The gradual arc structure of the first magnetic isolation bridge (10) and the second magnetic isolation bridge (11) is symmetrically distributed along the radial direction of the rotor.

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