Rotor punching sheet and magnetic steel rotor structure

Abstract

The utility model relates to the technical field of motors, and discloses a rotor punching sheet and a magnetic steel rotor structure, and the rotor punching sheet comprises a rotor punching sheet body which is divided into a plurality of magnetic pole areas which are arranged in the circumferential direction, and each magnetic pole area is provided with at least three magnetic steel groove layers at intervals along the radial direction of the rotor punching sheet body; at least one magnetic isolation hole group is formed between every two adjacent magnetic steel groove layers, and each magnetic isolation hole group comprises two magnetic isolation holes which are symmetrically arranged about the d axis. The magnetic isolation holes are symmetrically arranged on the rotor side, so that the direction of a magnetic circuit of the motor can be changed, the air gap flux density waveform can be optimized, the waveform distortion rate can be reduced, and the sound pressure level of the motor can be reduced. Each two adjacent magnetic steel groove layers are provided with a magnetic isolation hole group to form multiple layers of magnetic leakage barriers, magnetic leakage paths between all adjacent magnetic steel grooves are blocked layer by layer, the proportion of magnetic leakage flux is reduced, the harmonic content is further reduced, the distortion rate of an air gap magnetic field is reduced, and the sound pressure level of high-frequency electromagnetic noise is reduced.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a rotor lamination and magnet rotor structure. Background Technology

[0002] An embedded permanent magnet synchronous motor is a common type of motor. Its key feature is that permanent magnets are directly embedded in the rotor, thus eliminating the need for a traditional electrical excitation system. The motor rotates through the interaction between the magnetic field generated by the permanent magnets and the magnetic field generated by the armature windings in the stator.

[0003] Motor NVH (Noise, Vibration, and Harshness) refers to the comprehensive performance issues related to noise, vibration, and harshness generated during motor operation. It is a core indicator for measuring motor comfort and reliability. In the drive motors of new energy vehicles, NVH performance directly affects the quietness of the cabin and the driving experience, which is especially crucial for high-end electric vehicles. Compared with ordinary permanent magnet synchronous motors, built-in multi-layer permanent magnet synchronous motors have more rotor layers, a higher saliency ratio, and a larger proportion of reluctance torque in electromagnetic torque. However, with the increase in the saliency ratio, the vibration and noise problems of the motor become more prominent. Utility Model Content

[0004] In view of this, the present invention provides a rotor lamination and magnet rotor structure to solve the problem of vibration and noise in existing built-in multi-layer magnet permanent magnet synchronous motors.

[0005] In a first aspect, this utility model provides a rotor lamination, comprising:

[0006] The rotor lamination body is divided into multiple circumferentially arranged magnetic pole regions. Each magnetic pole region is provided with at least three layers of magnetic steel slots at intervals along the radial direction of the rotor lamination body. At least one group of magnetic isolation holes is provided between each two adjacent layers of magnetic steel slots. The group of magnetic isolation holes includes two magnetic isolation holes that are respectively arranged symmetrically about the d-axis.

[0007] The beneficial effects of the aforementioned rotor laminations are as follows: After symmetrically opening magnetic isolation holes on the rotor side, these holes hinder the propagation of the magnetic field, altering the original magnetic circuit and guiding the magnetic lines of force along a new path. This changes the direction of the motor's magnetic circuit, making the magnetic field distribution in the air gap more rational, optimizing the air gap magnetic flux density waveform, and bringing it closer to an ideal sine wave, thus reducing the distortion rate of the air gap magnetic flux density waveform. When the distortion rate of the air gap magnetic flux density waveform decreases, the vibration and noise caused by harmonics will also decrease accordingly, thereby reducing the sound pressure level emitted by the motor during operation and making the motor run more quietly.

[0008] The magnetic isolation holes between adjacent magnet slot layers form a high magnetic reluctance barrier, blocking the leakage magnetic path from the magnet slot opening to the rotor core. The magnetic isolation hole group is arranged symmetrically about the d-axis to avoid magnetic circuit asymmetry caused by opening on one side and to prevent the introduction of new even-order harmonics.

[0009] This invention improves the sinusoidal nature of the air gap magnetic flux density and reduces the harmonic content. On the one hand, it reduces torque pulsation when the vehicle is running at low speed, and on the other hand, it can reduce core loss and eddy currents in the magnet when running at high speed, thereby increasing the vehicle's driving range and reducing the risk of magnet demagnetization.

[0010] Each pair of adjacent magnetic steel slot layers is equipped with a magnetic isolation hole group to form a multi-layer magnetic leakage barrier, which blocks the magnetic leakage path between all adjacent magnetic steel slots layer by layer, reduces the proportion of magnetic leakage flux, further reduces the harmonic content, reduces the air gap magnetic field distortion rate, and reduces the high-frequency electromagnetic noise sound pressure level.

[0011] In one alternative embodiment, the magnetic isolation hole is located near the outer peripheral edge of the magnetic pole region.

[0012] In one alternative implementation, the magnetic shielding hole is configured as an elongated strip or a circle.

[0013] In one alternative embodiment, each layer of the magnetic steel groove includes at least one magnetic steel groove, the ends of which are chamfered.

[0014] The beneficial effects of the above technical solution are: it can increase the magnetic flux path and reduce the magnetic circuit saturation, thereby reducing the sound pressure level of the motor.

[0015] In one alternative implementation, the chamfer is a combination of a rounded segment and a sloping segment, with the rounded segment and the sloping segment transitioning smoothly.

[0016] Secondly, this utility model also provides a magnetic rotor structure, comprising:

[0017] The rotor core is formed by stacking multiple rotor laminations.

[0018] Multiple magnets are provided, each of which is embedded in a magnet groove.

[0019] In one optional embodiment, when each layer of the magnetic slots includes at least two magnetic slots, reinforcing ribs are provided between two adjacent magnetic slots and between the magnetic slots and the outer periphery of the magnetic pole region, thereby improving the stress on the rotor laminations.

[0020] In one alternative embodiment, a magnetic isolation bridge region is formed between two adjacent magnetic steel slots, and the reinforcing ribs are disposed in the magnetic isolation bridge region.

[0021] In one optional embodiment, the rotor lamination has three layers of magnet slots, arranged sequentially from the inside to the outside along the radial direction of the rotor core: a first magnet slot layer, a second magnet slot layer, and a third magnet slot layer. The first magnet slot layer includes at least two first magnet slots, which are configured as V-shaped or U-shaped. The second magnet slot layer includes at least two second magnet slots, which are configured as V-shaped or U-shaped. The third magnet slot layer includes at least two third magnet slots, which are configured as V-shaped or straight.

[0022] The magnet has three layers, which are arranged from the inside out as a first magnet layer, a second magnet layer and a third magnet layer. The arrangement of the first magnet layer is the same as that of the first magnet groove layer, the arrangement of the second magnet layer is the same as that of the second magnet groove layer, and the arrangement of the third magnet layer is the same as that of the third magnet groove layer.

[0023] In one alternative implementation, the pole arc coefficients of the first, second, and third magnet layers are different, causing the air gap magnetic flux density waveform to approach a multi-step stepped wave.

[0024] In one optional embodiment, the first, second, and third magnet layers are all configured in a V-shape. The first magnet layer includes four first magnets, the second magnet layer includes two second magnets, and the third magnet layer includes two third magnets. The two outer first magnets have an included angle of 20°, the two inner first magnets have an included angle of 10°, the two second magnets have an included angle of 30°, and the third magnets have an included angle of 60°.

[0025] The first and second magnet layers are both V-shaped, and the third magnet layer is straight. The first magnet layer includes four first magnets, the second magnet layer includes two second magnets, and the third magnet layer includes one third magnet. The two outermost first magnets have an angle of 20°, the two outermost second magnets have an angle of 30°, and the outermost third magnet has an angle of 180°.

[0026] The first magnet layer is V-shaped, the second magnet layer is U-shaped, and the third magnet layer is straight. The first magnet layer includes four first magnets, and the second magnet layer includes four second magnets; or

[0027] The first magnet layer is V-shaped, the second magnet layer is U-shaped, and the third magnet layer is straight. The first magnet layer includes four first magnets, the second magnet layer includes three second magnets, and the third magnet layer includes one third magnet; or

[0028] The first and second magnet layers are both U-shaped, and the third magnet layer is straight. The first magnet layer includes three first magnets, the second magnet layer includes three second magnets, and the third magnet layer includes one third magnet. The two outermost first magnets have a 90° angle, the two outermost second magnets have a 20° angle, and the third magnet has a 180° angle.

[0029] The first and second magnet layers are both U-shaped, and the third magnet layer is straight. The first magnet layer includes four first magnets, the second magnet layer includes four second magnets, and the third magnet layer includes one third magnet. The two outermost first magnets have a 60° angle, the two outermost second magnets have a 60° angle, and the third magnet has a 180° angle.

[0030] The first and second magnet layers are both U-shaped, and the third magnet layer is V-shaped. The first magnet layer includes three or four first magnets, the second magnet layer includes three or four second magnets, and the third magnet layer includes two third magnets.

[0031] In summary, the technical solution of this utility model has the following advantages:

[0032] This invention effectively improves the electromagnetic noise problem of the motor by beveling the ends of the magnet slots and symmetrically opening magnetic isolation holes on the rotor side.

[0033] This invention features a three-layer magnet slot layer in the rotor laminations, improving the sinusoidal nature of the air gap magnetic flux density and reducing harmonic content. This reduces torque pulsation at low vehicle speeds and decreases core losses and magnet eddy currents at high speeds, thereby increasing the vehicle's driving range and mitigating the risk of magnet demagnetization. Furthermore, this invention increases the reluctance torque ratio, improves the motor's saliency ratio, reduces motor losses in the high-speed operating range, and enhances motor efficiency and vehicle driving range. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This utility model provides a schematic diagram of the structure of a magnetic pole region in a rotor lamination.

[0036] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0037] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of this utility model;

[0039] Figure 5 This is a schematic diagram of the structure of Embodiment 4 of this utility model;

[0040] Figure 6 This is a schematic diagram of the structure of Embodiment 5 of the present invention;

[0041] Figure 7 This is a structural schematic diagram of Embodiment 6 of the present invention.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Magnetic pole region; 2. Magnetic steel groove layer; 21. First magnetic steel groove layer; 22. Second magnetic steel groove layer; 23. Third magnetic steel groove layer; 3. Magnetic isolation hole; 4. Chamfer; 5. d-axis; 6. Reinforcing rib. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0045] Motor NVH (Noise, Vibration, and Harshness) refers to the comprehensive performance issues related to noise, vibration, and harshness generated during motor operation. It is a core indicator for measuring motor comfort and reliability. In the drive motors of new energy vehicles, NVH performance directly affects the quietness of the cabin and the driving experience, which is especially crucial for high-end electric vehicles. Compared with ordinary permanent magnet synchronous motors, built-in multi-layer permanent magnet synchronous motors have more rotor layers, a higher saliency ratio, and a larger proportion of reluctance torque in electromagnetic torque. However, with the increase in the saliency ratio, the vibration and noise problems of the motor become more prominent.

[0046] Existing three-layer magnet structures suffer from magnetic leakage and uneven magnetic circuits within the rotor due to the lack of magnetic isolation holes. This leads to deterioration of the air gap magnetic flux density waveform, increased electromagnetic force fluctuations, and ultimately significant vibration and noise problems. To address this, this invention provides a rotor lamination that cuts off the magnetic leakage path at its source and optimizes the magnetic flux density waveform by symmetrically arranging magnetic isolation holes. Furthermore, this invention incorporates magnetic isolation hole groups between every two adjacent magnet slot layers, forming a multi-layered magnetic leakage barrier. This further reduces harmonic content, lowers the air gap magnetic field distortion rate, and reduces the high-frequency electromagnetic noise sound pressure level.

[0047] The following explains the technical terms used in this utility model.

[0048] Magnetic bridge: In the rotor structure of a built-in permanent magnet synchronous motor, the narrow iron core area between the magnets prevents the magnetic flux generated by the permanent magnet from being directly short-circuited inside the rotor, forcing the magnetic flux to enter the stator through the air gap, thereby forming effective electromagnetic coupling.

[0049] Air gap magnetic flux density: The average magnetic field strength in the air gap region between the rotor and stator of a motor. It is a core parameter for measuring the magnetic field energy density of a motor and directly affects the motor's torque output, efficiency, and electromagnetic compatibility. Ideally, the air gap magnetic flux density waveform is a sine wave, resulting in low motor torque ripple and low losses. In reality, due to the influence of the magnetic circuit structure, the waveform deviates from a sine wave, forming a stepped wave or a non-sine wave containing higher harmonics.

[0050] Air gap magnetic flux density waveform distortion rate: This indicates the degree of deviation of the actual magnetic flux density distribution waveform in the air gap from the ideal sine wave.

[0051] Harmonic content: The proportion of higher harmonic components to the fundamental component in the air gap magnetic flux density waveform. At low speeds, harmonics can cause cogging torque pulsation, leading to increased motor vibration and noise. At high speeds, harmonics generate additional eddy current losses in the stator core and simultaneously induce eddy current losses in the magnets, resulting in temperature rise.

[0052] Pole arc coefficient: This refers to the ratio of the pole arc length to the pole pitch of a motor, denoted by the symbol αp. The pole arc length is the projected length of the magnetic pole on the circumference of the air gap, while the pole pitch is the distance between the axes of two adjacent magnetic poles along the circumference of the air gap.

[0053] Salient pole ratio: This is a key parameter of built-in permanent magnet synchronous motors. It is defined as the ratio of quadrature axis inductance (Lq) to direct axis inductance (Ld). The higher the salient pole ratio, the greater the difference in magnetic reluctance between the d-axis and q-axis, and the more significant the magnetic reluctance torque generated by the motor.

[0054] Reluctance torque ratio: This refers to the proportion of reluctance torque in the total output torque of a built-in permanent magnet synchronous motor. The total output torque is the sum of reluctance torque and permanent magnet torque. Reluctance torque is generated by the rotor salient pole effect (the difference in reluctance between the d-axis and q-axis). Permanent magnet torque is generated by the interaction between the permanent magnet magnetic field and the stator current.

[0055] d-axis (intersecting axis): aligned with the magnetization direction of the permanent magnet. The magnetic circuit is mainly supplied by the permanent magnet, and the magnetic resistance is minimized under ideal conditions.

[0056] q-axis (direct axis): perpendicular to d-axis, the magnetic circuit needs to pass through the rotor core and air gap, and the magnetic resistance is relatively large.

[0057] Combination Figures 1 to 4 As shown, the embodiments of this utility model will be described in detail below with reference to the rotor laminations of the first aspect of this utility model and the magnet rotor structure of the second aspect of this utility model.

[0058] According to an embodiment of the present invention, in a first aspect, a rotor lamination is provided, combined with... Figures 1 to 7 As shown, the rotor includes a rotor lamination body, which is divided into multiple circumferentially arranged magnetic pole regions 1. Each magnetic pole region 1 has multiple layers of magnetic steel slots 2 spaced apart along the radial direction of the rotor lamination body. Each layer of magnetic steel slots 2 includes at least one magnetic steel slot. At least one set of magnetic isolation holes is provided between each pair of adjacent magnetic steel slot layers 2. The set of magnetic isolation holes includes two magnetic isolation holes 3 respectively arranged symmetrically about the d-axis 5.

[0059] The aforementioned rotor laminations, with symmetrically opened magnetic isolation holes on the rotor side, impede the propagation of the magnetic field, altering the original magnetic circuit and guiding the magnetic lines of force along a new path. This changes the direction of the motor's magnetic circuit, resulting in a more rational distribution of the magnetic field in the air gap, optimizing the air gap magnetic flux density waveform, and making it closer to an ideal sine wave, thus reducing the distortion rate of the air gap magnetic flux density waveform. As the distortion rate of the air gap magnetic flux density waveform decreases, vibrations and noise caused by harmonics also decrease accordingly, thereby lowering the sound pressure level emitted by the motor during operation and making the motor run more quietly.

[0060] The magnetic isolation holes between adjacent magnet slot layers form a high magnetic reluctance barrier, blocking the leakage magnetic path from the magnet slot opening to the rotor core. The magnetic isolation hole group is symmetrically arranged about the d-axis to avoid magnetic circuit asymmetry caused by single-sided openings and prevent the introduction of new even-order harmonics. Reducing leakage magnetic field enhances the sinusoidal nature of the air gap magnetic field, decreases the amplitude of higher-order spatial harmonics, and correspondingly reduces the amplitude of radial electromagnetic force waves, weakening the electromagnetic force waves and lowering the harmonic content. The reduced air gap magnetic field distortion rate lowers the sound pressure level of high-frequency electromagnetic noise, thereby resolving motor NVH issues.

[0061] This embodiment improves the sinusoidal nature of the air gap magnetic flux density and reduces the harmonic content. On the one hand, it reduces torque pulsation when the vehicle is running at low speed, and on the other hand, it can reduce core loss and eddy currents in the magnets when running at high speed, thereby increasing the vehicle's driving range and reducing the risk of magnet demagnetization.

[0062] When the magnet slot layer 2 has three or more layers, if only one layer of magnet slot layer is provided with a magnetic isolation hole group, the leakage magnetic flux of only one layer of magnet slot is blocked. The leakage magnetic flux paths between other adjacent layers are not controlled, resulting in a still high overall leakage magnetic flux and a high residual air gap magnetic flux density waveform distortion rate, which cannot fully optimize the magnetic field waveform. The unblocked leakage magnetic flux causes residual spatial harmonics, resulting in a still large amplitude of high-frequency electromagnetic force waves and a high high-frequency noise sound pressure level of the motor. To solve this problem, in this embodiment, a magnetic isolation hole group is provided for every two adjacent magnet slot layers to form a multi-layer leakage magnetic barrier, blocking the leakage magnetic flux paths between all adjacent magnet slots layer by layer, thus reducing the proportion of leakage magnetic flux. Furthermore, it further reduces the harmonic content, reduces the air gap magnetic field distortion rate, and lowers the high-frequency electromagnetic noise sound pressure level.

[0063] In some embodiments, the magnetic isolation hole 3 is located near the outer peripheral edge of the magnetic pole region 1. The outer peripheral magnetic isolation hole blocks the leakage magnetic path at the edge of the magnetic pole, forcing more magnetic flux to enter the stator through the air gap and improving the effective magnetic flux utilization rate.

[0064] In some embodiments, the magnetic isolation hole 3 is set to be elongated or circular, and can be selected according to the specific actual situation to adapt to different magnetic field distribution requirements and manufacturing process requirements, so that the magnetic steel rotor structure can adapt to different application scenarios and performance requirements, and optimize overall performance and efficiency.

[0065] In some embodiments, the number of magnetic isolation holes 3 may be one or more. When multiple magnetic isolation holes 3 are provided, these magnetic isolation holes 3 may be evenly distributed or arranged in a specific manner between the magnetic steel groove layers.

[0066] In some embodiments, the ends of the magnet slot are provided with a chamfer 4, which can increase the magnetic flux path, reduce the magnetic circuit saturation, and thus reduce the sound pressure level of the motor. The chamfer 4 can reduce higher-order spatial harmonics and decrease the total harmonic distortion rate of the air gap magnetic flux density.

[0067] The ends of the magnet slot are rounded, and the chamfered corner 4 is a combination of rounded and inclined segments. The smooth transition between the rounded and inclined segments increases the magnetic flux path and optimizes the magnetic field distribution, making the magnetic circuit smoother and reducing magnetic resistance and energy loss. The combination of the rounded magnet slot ends and the chamfered corner 4 reduces local concentration and distortion of the magnetic field, thereby further reducing motor noise and vibration.

[0068] Furthermore, the chamfer 4 also includes a notch at the end of the magnetic steel groove, where the magnetic bridge fills the notch, thereby increasing the magnetic flux path.

[0069] According to an embodiment of this utility model, in a second aspect, a magnetic steel rotor structure is provided, specifically a novel low-noise multilayer magnetic steel rotor structure for new energy vehicle motors, comprising a rotor core and magnets. The rotor core is formed by stacking multiple rotor laminations. Multiple magnets are provided, each magnet being embedded in a magnet slot layer. The magnets are permanent magnets, and the magnets and magnet slot layers 2 can be fixed by interference fit and epoxy resin adhesive to prevent them from detaching during high-speed centrifugal force.

[0070] In some embodiments, the more layers of magnets in the rotor laminations, the greater the stress on the rotor laminations. To improve the stress on the rotor laminations, when each magnet slot layer 2 includes at least two magnet slots, reinforcing ribs 6 are provided between adjacent magnet slots and between the magnet slots and the outer periphery of the magnetic pole region 1, thus improving the stress on the rotor laminations. A magnetic bridge region is formed between adjacent magnet slots, and the reinforcing ribs 6 are provided in the magnetic bridge region.

[0071] Currently, the rotor magnetic pole structure of electric motors is typically a single-layer magnet structure (I-shaped, V-shaped) and a double-layer magnet structure (double I-shaped, double V-shaped, ▽-shaped, U+V-shaped, U+I-shaped). These rotor magnetic pole structures mainly have the following problems: First, in built-in permanent magnet synchronous motors, due to the saturation of the magnetic bridge, the harmonic content in the air gap magnetic flux density is higher than in surface-mounted permanent magnet synchronous motors. These harmonics increase motor torque pulsation at low speeds, leading to increased motor vibration and noise. At high speeds, these harmonics generate additional harmonic core losses and eddy current losses in the stator, increasing motor losses and reducing efficiency, thus affecting the driving range of electric vehicles. Simultaneously, the increased eddy current losses lead to higher magnet temperatures, affecting the performance of the permanent magnets and increasing the risk of localized demagnetization. Secondly, the reluctance torque has a small proportion and a low saliency ratio. Especially in the high-speed deep field weakening region, the reluctance torque utilization rate is low, which makes the loss greater and the efficiency lower when the motor is running in the deep field weakening region.

[0072] To address the aforementioned issues, the rotor laminations in this embodiment have three magnet slot layers 2, arranged radially from the inside out as a first magnet slot layer 21, a second magnet slot layer 22, and a third magnet slot layer 23. The magnets are arranged in three layers, arranged from the inside out as a first magnet layer, a second magnet layer, and a third magnet layer, with each layer having a different pole arc coefficient. The three-layer air gap magnetic flux density waveform approximates a stepped wave with three wavefronts, and its fundamental air gap magnetic flux density amplitude and harmonic content are determined by the pole arc coefficients αp1, αp2, and αp3. Referring to the principle of multi-level stepped waves, the more steps there are, the lower the harmonic content and the higher the sinusoidal intensity of the waveform, thus reducing the harmonic content.

[0073] It should be noted that the pole arc coefficient is the ratio of the effective coverage arc of the magnetic pole on the air gap circumference to the pole pitch (the distance between the axes of adjacent magnetic poles). The pole arc length of each layer of magnets is different, forming a stepped layout.

[0074] In this embodiment, the magnet slot layer 2 of the rotor lamination is provided with three layers, which improves the sinusoidal nature of the air gap magnetic flux density and reduces the harmonic content. On the one hand, it reduces the torque pulsation when the vehicle is running at low speed. On the other hand, it can reduce the core loss and magnet eddy current when running at high speed, improve the vehicle's driving range, and at the same time reduce the risk of magnet demagnetization.

[0075] This embodiment increases the reluctance torque ratio (the difference between q-axis inductance and d-axis inductance is larger), improves the motor saliency ratio, reduces motor losses in the high-speed operating range, and improves motor efficiency and vehicle range.

[0076] More specifically, the first magnet slot layer 21 includes at least two first magnet slots, and the first magnet slot layer 21 is configured in a V-shape or a U-shape. The second magnet slot layer 22 includes at least two second magnet slots, and the second magnet slot layer 22 is configured in a V-shape or a U-shape. The third magnet slot layer 23 includes at least two third magnet slots, and the third magnet slot layer 23 is configured in a V-shape or a straight line shape.

[0077] The magnets are arranged in three layers, from the inside out: a first magnet layer, a second magnet layer, and a third magnet layer. The arrangement of the first magnet layer is the same as that of the first magnet groove layer 21; the arrangement of the second magnet layer is the same as that of the second magnet groove layer 22; and the arrangement of the third magnet layer is the same as that of the third magnet groove layer 23. The first magnet layer includes at least two first magnets, and the first magnet layer is configured in a V-shape or a U-shape. The second magnet layer includes at least two second magnets, and the second magnet layer is configured in a V-shape or a U-shape. The third magnet layer includes at least two third magnets, and the third magnet layer is configured in a V-shape or a straight line.

[0078] Example 1

[0079] This embodiment discloses a magnetic rotor structure, combined with... Figure 2 As shown, based on the specific structural form of the three-layer magnet rotor, all three layers of magnets are designed with a V-shaped structure. To improve the stress of the rotor laminations, a magnetic bridge of appropriate size is designed in the middle of the slots of the first magnet layer. Specifically, to ensure better process performance, the two magnets in the second layer are of the same size, the two magnets in the third layer are of the same size, and the four magnets in the first layer are of the same size. To better ensure the output performance of the motor's reluctance torque, the included angle α1 of the outermost first magnet layer is 20°, the included angle α2 of the innermost first magnet layer is 10°, the included angle α2 of the second magnet layer is 30°, and the included angle α3 of the third magnet layer is 60°.

[0080] Example 2

[0081] This embodiment discloses a magnetic rotor structure, combined with... Figure 3 As shown, based on Example 1, while maintaining the pole arc coefficient of the third magnet layer groove, the third magnet layer groove can be adjusted to a straight line shape. The third magnet layer changes from two magnets of the same size to one magnet, eliminating the magnetic isolation bridge between the two magnets, reducing magnet leakage, increasing permanent magnet torque, and resulting in better torque output performance of the motor. The included angle α1 of the first magnet layer is 20°, the included angle α2 of the second magnet layer is 30°, and the included angle α3 of the third magnet layer is 180°.

[0082] Example 3

[0083] This embodiment discloses a magnetic rotor structure, combined with... Figure 4 As shown, based on Example 2, while keeping the pole arc coefficient of the second magnet layer groove unchanged, the second magnet layer groove can be adjusted from a V-shape to a U-shape of four magnets. The four magnets are the same size. Adjusting the magnets to a U-shape can reduce the magnetic resistance of the q-axis magnetic circuit and better utilize the magnetic resistance torque of the motor.

[0084] Example 4

[0085] This embodiment discloses a magnetic rotor structure, combined with... Figure 5 As shown, based on Example 2, while keeping the polar arc coefficient of the second magnet layer groove unchanged, the second magnet layer groove can be adjusted from a V-shape to a U-shape. In the U-shape, the three magnets are the same size. The V-shaped magnet groove has one reinforcing rib in the middle, and the U-shaped magnet groove has two reinforcing ribs in the middle, thereby increasing the number of reinforcing ribs. This can improve the centrifugal stress of the lamination and increase the peak speed of the motor.

[0086] Example 5

[0087] This embodiment discloses a magnetic rotor structure, combined with... Figure 6 As shown, based on Example 4, while keeping the pole arc coefficient of the first magnet layer groove unchanged, the first magnet layer groove can be adjusted from a V-shape to a U-shape. In the U-shape, the three magnets are of the same size, and the number of first magnet layers is reduced from four to three, improving the manufacturing process of the motor. Specifically, the included angle α1 of the first magnet layer is 90°, the included angle α2 of the second magnet layer is 20°, and the angle α3 of the third magnet layer is 180°.

[0088] Example 6

[0089] This embodiment discloses a magnetic rotor structure, combined with... Figure 7As shown, based on Example 3, while keeping the pole arc coefficient of the three-layer magnet slot constant, the first magnet layer slot can be adjusted from a V-shape to a U-shape with four magnets. By adjusting the included angle between the magnets, the magnetic reluctance of the q-axis magnetic circuit can be reduced, thus better utilizing the reluctance torque of the motor. Specifically, the four magnets in the first layer are of the same size; the included angle α1 of the outermost first magnet layer is 20°, and the included angle α2 of the innermost first magnet layer is 60°. The four magnets in the second layer are also of the same size; the included angle α21 of the outermost second magnet layer is 30°, the included angle α22 of the innermost second magnet layer is 170°, and the included angle α3 of the third magnet layer is 180°.

[0090] Example 7

[0091] This embodiment discloses a magnet rotor structure. The first and second magnet slots can be V-shaped, U-shaped with three magnets, or U-shaped with four magnets. The third magnet slot can be V-shaped or straight. The rotor topology can be any combination of the above.

[0092] When the first and second magnet layers in this embodiment are both U-shaped and the third magnet layer is V-shaped, the number of reinforcing ribs arranged in the magnetic pole region 1 is greater than the number of reinforcing ribs arranged in other embodiments, thereby making the strength of the formed rotor lamination higher.

[0093] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A rotor lamination, characterized by The rotor lamination body is divided into a plurality of circumferentially arranged magnetic pole regions (1), each of the magnetic pole regions (1) is provided with at least three layers of magnetic steel slot layers (2) in a radial direction of the rotor lamination body; at least one group of magnetic isolation holes is arranged between each two adjacent layers of the magnetic steel slot layers (2), and the group of magnetic isolation holes comprises two magnetic isolation holes (3) symmetrically arranged about a d-axis (5). The magnetic isolation hole (3) is arranged at a position close to an outer peripheral edge of the magnetic pole region (1).

2. The rotor lamination of claim 1, wherein, The magnetic isolation hole (3) is arranged in a long strip shape or a circular shape.

3. The rotor lamination of claim 1, wherein, Each of the magnetic steel slot layers (2) comprises at least one magnetic steel slot, and an end portion of the magnetic steel slot is provided with a chamfer (4).

4. The rotor lamination of any of claims 1-3, wherein, The chamfer (4) is in a form of a combination of a circular arc segment and an inclined segment, and the circular arc segment and the inclined segment are smoothly connected.

5. The rotor lamination of claim 4, wherein, The rotor lamination body is divided into a plurality of circumferentially arranged magnetic pole regions (1), each of the magnetic pole regions (1) is provided with at least three layers of magnetic steel slot layers (2) in a radial direction of the rotor lamination body; at least one group of magnetic isolation holes is arranged between each two adjacent layers of the magnetic steel slot layers (2), and the group of magnetic isolation holes comprises two magnetic isolation holes (3) symmetrically arranged about a d-axis (5).

6. A magnetic steel rotor structure, characterized by, The magnetic isolation hole (3) is arranged at a position close to an outer peripheral edge of the magnetic pole region (1). The magnetic isolation hole (3) is arranged in a long strip shape or a circular shape. Each of the magnetic steel slot layers (2) comprises at least one magnetic steel slot, and an end portion of the magnetic steel slot is provided with a chamfer (4).

7. The magnetic steel rotor structure of claim 6 wherein, The chamfer (4) is in a form of a combination of a circular arc segment and an inclined segment, and the circular arc segment and the inclined segment are smoothly connected.

8. The magnetic steel rotor structure of claim 6 or 7, wherein, The rotor lamination body is divided into a plurality of circumferentially arranged magnetic pole regions (1), each of the magnetic pole regions (1) is provided with at least three layers of magnetic steel slot layers (2) in a radial direction of the rotor lamination body; at least one group of magnetic isolation holes is arranged between each two adjacent layers of the magnetic steel slot layers (2), and the group of magnetic isolation holes comprises two magnetic isolation holes (3) symmetrically arranged about a d-axis (5). The magnetic isolation hole (3) is arranged at a position close to an outer peripheral edge of the magnetic pole region (1).

9. The magnetic steel rotor structure of claim 8, wherein The magnetic isolation hole (3) is arranged in a long strip shape or a circular shape.

10. The magnetic steel rotor structure of claim 8, wherein Each of the magnetic steel slot layers (2) comprises at least one magnetic steel slot, and an end portion of the magnetic steel slot is provided with a chamfer (4). The chamfer (4) is in a form of a combination of a circular arc segment and an inclined segment, and the circular arc segment and the inclined segment are smoothly connected. The rotor lamination body is divided into a plurality of circumferentially arranged magnetic pole regions (1), each of the magnetic pole regions (1) is provided with at least three layers of magnetic steel slot layers (2) in a radial direction of the rotor lamination body; at least one group of magnetic isolation holes is arranged between each two adjacent layers of the magnetic steel slot layers (2), and the group of magnetic isolation holes comprises two magnetic isolation holes (3) symmetrically arranged about a d-axis (5). The magnetic isolation hole (3) is arranged at a position close to an outer peripheral edge of the magnetic pole region (1). The magnetic isolation hole (3) is arranged in a long strip shape or a circular shape. Each of the magnetic steel slot layers (2) comprises at least one magnetic steel slot, and an end portion of the magnetic steel slot is provided with a chamfer (4). The chamfer (4) is in a form of a combination of a circular arc segment and an inclined segment, and the circular arc segment and the inclined segment are smoothly connected. The rotor lamination body is divided into a plurality of circumferentially arranged magnetic pole regions (1), each of the magnetic pole regions (1) is provided with at least three layers of magnetic steel slot layers (2) in a radial direction of the rotor lamination body; at least one group of magnetic isolation holes is arranged between each two adjacent layers of the magnetic steel slot layers (2), and the group of magnetic isolation holes comprises two magnetic isolation holes (3) symmetrically arranged about a d-axis (5). The magnetic isolation hole (3) is arranged at a position close to an outer peripheral edge of the magnetic pole region (1). The magnetic isolation hole (3) is arranged in a long strip shape or a circular shape. Each of the magnetic steel slot layers (2) comprises at least one magnetic steel slot, and an end portion of the magnetic steel slot is provided with a chamfer (4). The chamfer (4) is in a form of a combination of a circular arc segment and an inclined segment, and the circular arc segment and the inclined segment are smoothly connected. The first magnetic steel layer and the second magnetic steel layer are both arranged as V-shaped, the third magnetic steel layer is arranged as a single letter type, the first magnetic steel layer includes four first magnetic steels, the second magnetic steel layer includes two second magnetic steels, and the third magnetic steel layer includes one third magnetic steel. The first magnetic steel layer is arranged as V-shaped, the second magnetic steel layer is arranged as U-shaped, and the third magnetic steel layer is arranged as a single letter type. The first magnetic steel layer is arranged as V-shaped, the second magnetic steel layer is arranged as U-shaped, and the third magnetic steel layer is arranged as a single letter type. The first magnetic steel layer and the second magnetic steel layer are both arranged as U-shaped, the third magnetic steel layer is arranged as a single letter type, the first magnetic steel layer includes three first magnetic steels, the second magnetic steel layer includes three second magnetic steels, and the third magnetic steel layer includes one third magnetic steel. The first magnetic steel layer and the second magnetic steel layer are both arranged as U-shaped, the third magnetic steel layer is arranged as a single letter type, the first magnetic steel layer includes four first magnetic steels, the second magnetic steel layer includes four second magnetic steels, and the third magnetic steel layer includes one third magnetic steel. The first magnetic steel layer and the second magnetic steel layer are both arranged as U-shaped, the third magnetic steel layer is arranged as a single letter type, the first magnetic steel layer includes three first magnetic steels, the second magnetic steel layer includes three second magnetic steels, and the third magnetic steel layer includes one third magnetic steel. The first magnetic steel layer and the second magnetic steel layer are both arranged as U-shaped, the third magnetic steel layer is arranged as a single letter type, the first magnetic steel layer includes four first magnetic steels, the second magnetic steel layer includes four second magnetic steels, and the third magnetic steel layer includes one third magnetic steel.

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