Rotor, motor and vehicle

Abstract

The invention provides a rotor, a motor and a vehicle, the rotor comprises a rotor iron core, permanent magnets, a first magnetic bridge connecting part and a wrapping layer, the rotor iron core comprises a plurality of rotor punching sheets arranged in a laminated manner, the rotor punching sheets are provided with a plurality of magnet grooves, the permanent magnets are arranged in the magnet grooves, the first magnetic bridge connecting part is connected with the rotor punching sheets, and the wrapping layer is connected with the rotor punching sheets. The first magnetic bridge connecting parts are located in the magnet grooves, and the wrapping layer wraps the outer peripheral surface of the rotor core and is used for providing pressing force for the rotor core. Heat generated by the motor stator is not easy to transfer to the rotor core and the permanent magnets, magnetic performance reduction of the permanent magnets is avoided, and performance and stability of the rotor are guaranteed. Compared with a conventional motor and a built-in permanent magnet motor applying the rotor core, the motor provided by the invention can reach a higher rotating speed and realize higher power density under the condition that the same rotor outer diameter and the same permanent magnet built-in form and size are adopted, so that an electric vehicle has better power performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and more specifically, relates to a rotor, a motor, and a vehicle. Background Art

[0002] In a conventional permanent magnet synchronous motor at high speeds, the stress at the rotor magnetic bridge part is extremely likely to exceed the material yield strength, thereby restricting the further increase of the motor speed or power. In related technologies, there is a method of reducing the rotor outer diameter to lower the stress at the rotor magnetic bridge part below the material yield strength, but this will reduce the motor torque. There is also a method of setting a relatively thick magnetic bridge to strengthen the strength of the magnetic bridge part, but this will increase the risk of motor magnetic leakage and reduce the performance of the motor torque and efficiency. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems existing in the prior art or related technologies.

[0004] In view of this, in a first aspect, the present invention provides a rotor, including: a rotor core including a plurality of stacked rotor punching sheets, with a plurality of magnet slots provided on the rotor punching sheets; permanent magnets disposed in the magnet slots; a first magnetic bridge connecting portion connected to the rotor punching sheet, the first magnetic bridge connecting portion being located in the magnet slot; and a wrapping layer wrapping around the outer peripheral surface of the rotor core, the wrapping layer being used to provide a pressing force to the rotor core.

[0005] A plurality of rotor punching sheets can be stacked axially to form a rotor core. Magnet slots are provided on each rotor punching sheet, and the number of magnet slots is multiple, and the multiple magnet slots are distributed circumferentially on the rotor punching sheet. A part of the rotor punching sheet located radially inside the magnet slot and a part of the rotor punching sheet located radially outside the magnet slot are connected by the first magnetic bridge connecting portion. The rotor punching sheet and the magnet slot are connected into an integral structure by the magnetic bridge connecting portion, which keeps the rotor punching sheet as a whole, facilitating integrated manufacturing and processing, and the process is simpler. For a non-integral structure, the first problem it brings is that the production tools for the punching sheet structure become more complex. During the process of its processing and forming, a variety of complex processes, tooling, and fasteners are required to fix the separated components of the rotor, greatly increasing the production cost, and the difficulty of assembling and laminating the rotor core punching sheet structures of several parts increases, seriously affecting the production line. In addition, the punching sheet structure in this related technology can only adopt the traditional straight pole design and cannot adopt the skewed pole design, restricting the improvement space of the motor NVH (noise, vibration, and acoustic roughness, etc.) performance.

[0006] The wrapping layer is arranged in a circular ring shape and wraps around the radial outer peripheral side of the rotor core. After adding the wrapping layer, the wrapping layer generates a pre-pressure on the rotor core. By utilizing the properties of the wrapping layer's tensile resistance and deformation resistance, when the rotor core rotates at high speed, this pre-pressure is balanced with the centrifugal force to prevent the deformation of the rotor core and the radial flinging of the permanent magnets, and resist the action of the centrifugal force. The wrapping layer can enhance the mechanical strength of the rotor itself. By utilizing the properties of tensile resistance and deformation resistance, it can effectively improve the tensile resistance and fatigue resistance of the rotor, achieve high-speed operation of the rotor, and improve the power output capacity of the motor. On the other hand, the wrapping layer also makes the rotor core and the permanent magnets located in a relatively enclosed cavity and isolated from the cavity of the stator. When the motor is operating, the heat generated by the motor stator is not easily transferred to the rotor core and the permanent magnets, avoiding the decline of the magnetic properties of the permanent magnets, thus ensuring the performance and stability of the rotor. Comparing the conventional motor and the built-in permanent magnet motor applying the above rotor core, under the same rotor outer diameter, the same form and size of the built-in permanent magnets, the motor of the present application can reach a higher speed, achieve a higher power density, and make the electric vehicle have better dynamic performance.

[0007] At high speeds of the motor, since the wrapping layer plays a role in wrapping the rotor, the stress of the magnetic bridge connection part is not easily exceeded the material yield strength, and thus the motor speed or power can be further increased. Moreover, due to the existence of the wrapping layer, the magnetic bridge connection part is not easily broken, so the usage amount of the magnetic bridge connection part can be reduced, the risk of magnetic leakage of the motor can be lowered, and the performance such as the torque and efficiency of the motor can be ensured.

[0008] In addition, the rotor according to the above technical solution provided by the present invention may further have the following additional technical features:

[0009] In some technical solutions, optionally, the magnet slot includes a first magnet slot and a second magnet slot. The radial outer ends of the first magnet slot and the second magnet slot are far away from each other. The rotor punching has an axis. In the radial cross-section of the rotor punching, it is set that the connecting line L1 and the connecting line L2 pass through the axis. The connecting line L1 has an intersection point A1 with the first magnet slot, and the connecting line L2 has an intersection point A2 with the second magnet slot. In the first magnet slot, the intersection point A1 is located between the permanent magnet and the outer peripheral surface of the rotor punching. In the second magnet slot, the intersection point A2 is located between the permanent magnet and the outer peripheral surface of the rotor punching. The connecting line L1 and the connecting line L2 have an included angle α1, and α1 satisfies 0.32×360 / p≤α1≤0.4×360 / p, where p is the number of pole pairs of the rotor.

[0010] The part of the first magnet slot and the second magnet slot that adapts to the permanent magnet forms a first pole arc angle α1 with the outer peripheral circle of the rotor punching sheet, that is, the angle α1 between the connecting line L1 and the connecting line L2. The first pole arc angle α1 satisfies 0.32×360 / p ≤ α1 ≤ 0.4×360 / p. In a permanent magnet synchronous motor, the air-gap synthetic magnetic field in the motor includes a fundamental magnetic field and a harmonic magnetic field. The content and proportion of the fundamental magnetic field and the harmonic magnetic field in the air-gap synthetic magnetic field directly determine the torque output ability of the motor and the performance of reducing noise. And the larger the fundamental magnetic field, the smaller the harmonic magnetic field, the higher the torque output, and the better the noise reduction performance of the motor. On the contrary, the smaller the output torque, the worse the noise reduction performance. The magnitudes of the fundamental magnetic field and the harmonic magnetic field in the air-gap magnetic field are directly related to the pole arc angle α1 in the rotor, and the value range of the included angle α1 is associated with the number of pole pairs of the rotor. The number of pole pairs is the number of groups of permanent magnets. Since the number of pole pairs of different motors may be different, the angle of the pole arc angle will also change. Simply limiting the angle range of the pole arc angle is likely to deviate from the change of the rotor structure. That is, the value range of the pole arc angle is related to the number of pole pairs, which can further improve the accuracy of determining the value range of the pole arc angle. Limiting the pole arc angle within the above range can optimize the waveform of the air-gap synthetic magnetic field, effectively reduce the content of the harmonic magnetic field in the air-gap magnetic field, make the air-gap magnetic field waveform approach a sine waveform, thereby reducing the cogging torque and torque ripple of the permanent magnet synchronous motor, reducing the vibration and noise of the motor. Moreover, when the content of the harmonic magnetic field decreases, the iron loss generated by the high-frequency harmonic magnetic field can be reduced, and the iron loss of the motor in the high-speed range can be reduced, improving the output torque and efficiency of the motor, which is beneficial to improving the performance of the motor.

[0011] In some technical solutions, optionally, in the radial cross-section of the rotor punching sheet, the first magnet slot and the second magnet slot are symmetric with respect to the magnetic pole center line L4 of the rotor punching sheet.

[0012] The first magnet slot and the second magnet slot are symmetrically distributed with respect to the magnetic pole center line L4, and the distance between the first magnet slot and the second magnet slot increases in the direction away from the axis, which can effectively reduce the harmonic content in the air-gap magnetic field and improve the motor performance.

[0013] In some technical solutions, optionally, the first magnet slot and the second magnet slot have an included angle α2, and α1 and α2 satisfy 0.75×α1×p ≤ α2 ≤ 1.33×α1×p.

[0014] The larger the size of the rotor, the smaller the number of rotor pole pairs, and the relatively larger the range of angles that the included angle between the first magnet slot and the second magnet can be set. The smaller the size of the rotor and the more the number of poles, the relatively smaller the range of angles that the included angle between the first magnet slot and the second magnet can be set accordingly. Therefore, the included angle between the first magnet slot and the second magnet slot can reflect the optimal included angle design of the magnetic steel under different rotor sizes. Therefore, the included angle α2 is affected by the included angle α1 and the number of pole pairs p. Simply limiting the angle range of the pole arc angle is likely to deviate from the optimal design of the rotor. To further improve the accuracy of determining the value range of the included angle between the first magnet slot and the second magnet, limiting the included angle between the first magnet slot and the second magnet within the above range can effectively improve the output torque of the motor, optimize the waveform of the air-gap synthetic magnetic field, reduce the content of harmonic magnetic fields in the air-gap magnetic field, reduce the iron loss generated by the high-frequency harmonic magnetic fields, reduce the iron loss of the motor in the high-speed range, improve the output torque and efficiency of the motor, and is beneficial to improving the performance of the motor.

[0015] In some technical solutions, optionally, the permanent magnet includes a first permanent magnet and a second permanent magnet. The first permanent magnet is located in the first magnet slot, and the second permanent magnet is located in the second magnet slot; the diameter of the rotor punching is D, and the length of the first permanent magnet is L. D and L satisfy 1.9 < (D×sin(1 / 2α1)) / (L×sin(1 / 2α2)) < 2.6.

[0016] The length value of the first magnet slot has a greater impact on the magnetic resistance of the direct-axis magnetic circuit of the motor, that is, it has a greater impact on the inductance of the direct-axis magnetic circuit. The included angle between the first magnet slot and the second magnet slot and the value of the pole arc angle have a greater impact on the magnetic resistance of the quadrature-axis magnetic circuit of the motor, that is, they have a greater impact on the inductance of the quadrature-axis magnetic circuit. The saliency ratio of the motor is the ratio of the quadrature-axis inductance to the direct-axis inductance. The electromagnetic torque of the motor is the reluctance torque plus the permanent magnet torque. There is a positive numerical relationship between the amount of permanent magnet used and the permanent magnet torque. By making the above numerical matching with the length value of the first magnet slot, the included angle α2 between the first magnet slot and the second magnet slot, and the value of the pole arc angle α1, the ratio of the quadrature-axis inductance to the direct-axis inductance of the motor can be increased, and the saliency ratio can be improved. After the saliency ratio is improved, the utilization rate of the reluctance torque of the motor is also improved. When the motor outputs the same magnitude of electromagnetic torque, the permanent magnet torque can be smaller. Thus, the amount of permanent magnet used can be reduced, thereby reducing the cost.

[0017] In some technical solutions, optionally, the rotor punching is further provided with a third magnet slot and a fourth magnet slot. The radially outer ends of the first magnet slot and the second magnet slot are away from each other. The third magnet slot and the fourth magnet slot are located on the radial outside of the first magnet slot and the second magnet slot. The third magnet slot and the fourth magnet slot are symmetric with respect to the magnetic pole center line L4; the rotor further includes a third permanent magnet and a fourth permanent magnet. The third permanent magnet is located in the third magnet slot, and the fourth permanent magnet is located in the fourth magnet slot.

[0018] The rotor punching sheet is further provided with a third magnet slot and a fourth magnet slot that are symmetrically distributed about the magnetic pole center line L4. The distance between the third magnet slot and the fourth magnet slot increases in the direction away from the shaft hole of the rotor core, which can effectively reduce the harmonic content in the air-gap magnetic field and improve the motor performance. The third permanent magnet and the fourth permanent magnet are embedded in their corresponding magnet slots. The third magnet slot and the fourth magnet slot are located radially outside the first magnet slot and the second magnet slot. Considering the different requirements of motors in different application scenarios for motor torque, power, and NVH performance, the third magnet slot and the fourth magnet slot located outside the first magnet slot and the second magnet slot and the third permanent magnet and the fourth permanent magnet embedded inside the third magnet slot and the fourth magnet slot are added to form a double-layer magnetic pole structure with the first magnet slot and the second magnet slot. Through the combined action of the first permanent magnet, the second permanent magnet, the third permanent magnet, and the fourth permanent magnet, a series magnetic concentration structure with 4 permanent magnets per pole is formed for the motor, which can significantly increase the motor output torque and power. At the same time, by jointly adjusting the magnetic field distribution under each pole of the rotor with the four permanent magnets, it is more conducive to the sinusoidal design of the air-gap magnetic field, thereby improving the motor vibration and noise.

[0019] In some technical solutions, optionally, the rotor further includes: a second magnetic bridge connection part connected to the rotor punching sheet, and the second magnetic bridge connection part is located in the third magnet slot and / or the fourth magnet slot.

[0020] The third magnet slot and the fourth magnet slot form at least one second magnetic bridge connection part on the rotor punching sheet for keeping the rotor punching sheet as a whole. Specifically, the rotor punching sheet and the magnet slot are connected into an integral structure through the second magnetic bridge connection part, which makes the rotor core punching sheet remain as a whole, facilitating integrated manufacturing and processing, and the process is simpler. For a non-integral structure, the first problem it brings is that the production tools for the punching sheet structure become more complex. During the process of its machining and forming, a variety of complex processes, tooling, and fasteners are required to fix the separated components of the rotor, greatly increasing the production cost. Secondly, the difficulty of assembling and laminating several parts of the rotor punching sheet increases, seriously affecting the production line.

[0021] In some technical solutions, optionally, in the radial cross-section of the rotor punching sheet, it is set that the connecting line L5 and the connecting line L6 pass through the axis. The connecting line L5 has an intersection point A3 with the third magnet slot, and the connecting line L6 has an intersection point A4 with the fourth magnet slot. In the third magnet slot, the intersection point A3 is located between the third permanent magnet and the outer peripheral surface of the rotor punching sheet. In the fourth magnet slot, the intersection point A4 is located between the fourth permanent magnet and the outer peripheral surface of the rotor punching sheet. The connecting line L5 and the connecting line L6 have an included angle α3, and α3 satisfies 0.45×α2 ≤ α3 ≤ 0.67×α2.

[0022] The part of the third magnet slot and the fourth magnet slot that fits the permanent magnet forms a second pole arc angle α3 with the outer circumferential circle of the rotor punching sheet, that is, the angle α3 between the connecting line L5 and the connecting line L6. α3 and α2 satisfy 0.45×α2 ≤ α3 ≤ 0.67×α2. When the second pole arc angle α3 is correlated with the angle α2, the inner and outer layers of magnet slots are correlated in structure and size, and the inner and outer layers of magnet slots can further improve the performance of the motor through mutual cooperation.

[0023] In some technical solutions, optionally, the third magnet slot and the fourth magnet slot have an angle α4, and α3 and α4 satisfy 1.22×α3×p ≤ α4 ≤ 1.65×α3×p.

[0024] A V-shaped angle α4 is formed between the third magnet slot and the fourth magnet slot, satisfying 1.22×α3×p ≤ α4 ≤ 1.65×α3×p. Specifically, the air-gap synthetic magnetic field in the motor is generated by the combined action of the permanent magnets in the inner-layer magnetic poles and the outer-layer magnetic poles, which includes a fundamental wave and harmonics. The content and proportion of the fundamental wave and harmonics in the air-gap magnetic field directly determine the torque output ability and NVH performance of the motor. The larger the fundamental wave and the smaller the harmonics, the higher the torque output and the better the NVH performance of the motor. Conversely, the smaller the output torque and the worse the NVH performance. The content, proportion, size of the fundamental wave and harmonics in the air-gap magnetic field are directly related to the size of the pole arc angle. By simultaneously making the above numerical matching of the sizes of the third magnet slot and the fourth magnet slot, it is possible to jointly optimize the waveform of the air-gap synthetic magnetic field with the size matching of the third magnet slot and the fourth magnet slot, effectively reduce the harmonic content in the air-gap magnetic field, improve the sinusoidality of the air-gap magnetic field waveform, thereby reducing the cogging torque and torque ripple of the permanent magnet synchronous motor and reducing the vibration and noise of the motor.

[0025] In some technical solutions, optionally, an auxiliary slot is provided on the outer peripheral surface of the rotor punching sheet, and the auxiliary slot extends along the axial direction of the rotor punching sheet.

[0026] On the outer peripheral wall of the rotor punching sheet, multiple groups of recessed auxiliary grooves are arranged at intervals. The auxiliary grooves extend along the axial direction of the rotor core, and the auxiliary grooves penetrate the axial end faces of the rotor core. Specifically, the torque pulsation and spatial electromagnetic force of the motor are the main sources of the tangential and radial vibration noises of the motor. Since the vehicle-mounted permanent magnet synchronous motor has a wide operating speed range and complex operating conditions, the main torque pulsation orders and radial electromagnetic force densities within its entire speed range need to be optimized and considered. However, due to the large differences in current and current angle under various operating conditions. In the related art, adopting a certain optimization measure can only reduce the motor NVH performance under its specific operating conditions, but cause the deterioration of the NVH performance under other operating conditions, and often at the cost of sacrificing the torque, power, and efficiency performance of the motor. In the present invention, by reasonably setting the recessed auxiliary grooves, the above situation can be effectively avoided, the peak power of the motor can be increased, the armature reaction of the motor can be reduced, and the influence on the peak torque performance of the motor is also small. In addition, the iron loss and demagnetization performance of the motor are directly related to the armature reaction of the motor. The smaller the armature reaction, the lower the iron loss of the motor, the better the demagnetization resistance ability, and the more beneficial to the output performance of the motor.

[0027] In some technical solutions, optionally, the wrapping layer includes: a wound wrapping layer or a tubular wrapping layer.

[0028] The wrapping layer is formed by winding carbon fiber filaments around the outer peripheral edge of the rotor punching sheet, or the wrapping layer is a sleeve. By sleeving a sleeve on the rotor punching sheet, the mechanical strength of the rotor structure is improved, so that the rotor can operate reliably at high speeds.

[0029] In some technical solutions, optionally, the wrapping layer includes a carbon fiber wrapping layer.

[0030] In some technical solutions, optionally, the rotor includes a segmented skewed pole rotor or a continuous skewed pole rotor.

[0031] The rotor core is assembled in a segmented skewed pole or continuous skewed pole manner. The optimization combination effect of the magnetic pole structure parameters in the motor has a limited effect on improving the air gap magnetic field waveform. Especially the tooth harmonics, which are the main sources of the motor vibration noise. Therefore, it is also necessary to further weaken the harmonic content in combination with the segmented skewed pole of the rotor. The segmented skewed pole can, while ensuring the electromagnetic torque of the motor, minimize the end leakage magnetic flux of the permanent magnet, improve the utilization rate of the permanent magnet, weaken the cogging torque, reduce the motor torque pulsation, and at the same time improve the air gap magnetic field distribution, reduce the distortion rate of the air gap magnetic field, and improve the NVH performance of the motor.

[0032] In a second aspect, the present invention proposes a motor, including: a stator; and a rotor as in the first aspect, the rotor being disposed inside the stator.

[0033] In some technical solutions, optionally, there is an air gap between the rotor and the stator. The length of the air gap is N1, and the thickness of the wrapping layer is N2, satisfying N2 ≤ 0.75N1.

[0034] The thickness of the wrapping layer is less than or equal to 75% of the air gap of the permanent magnet synchronous motor. The air gap is formed between the inner diameter of the stator and the outer diameter of the rotor of the permanent magnet synchronous motor. If the thickness of the wrapping layer is too thin, it is not sufficient to provide strength support for the rotor. If the wrapping layer is too thick, it is not conducive to the output of the motor torque performance. Moreover, if its thickness exceeds 75% of the air gap, there may also be a risk of rotor rubbing against the stator. Therefore, a reasonable thickness needs to be set to ensure that the wrapping layer can both support the strength of the rotor at high speeds and ensure the normal operation of the motor.

[0035] In some technical solutions, optionally, the thickness of the wrapping layer is N2, satisfying 0.2 mm ≤ N2 ≤ 2 mm.

[0036] Within this range, the wrapping layer can both support the strength of the rotor at high speeds and ensure the normal operation of the motor.

[0037] In a third aspect, the present invention proposes a vehicle, including: the motor as in the second aspect.

[0038] The additional aspects and advantages of the present invention will become obvious in the following description section, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0040] Figure 1 One of the schematic structural diagrams of the rotor in the embodiment of the present invention is shown;

[0041] Figure 2 The schematic structural diagram of the wrapping layer in the embodiment of the present invention is shown;

[0042] Figure 3 Another schematic structural diagram of the rotor in the embodiment of the present invention is shown;

[0043] Figure 4 One of the schematic partial structural diagrams of the rotor punching sheet in the embodiment of the present invention is shown;

[0044] Figure 5 Another schematic partial structural diagram of the rotor punching sheet in the embodiment of the present invention is shown;

[0045] Figure 6 Another schematic partial structural diagram of the rotor punching sheet in the embodiment of the present invention is shown;

[0046] Figure 7Shows the fourth partial structural schematic diagram of the rotor punching sheet in the embodiment of the present invention;

[0047] Figure 8 Shows the fifth partial structural schematic diagram of the rotor punching sheet in the embodiment of the present invention;

[0048] Figure 9 Shows the sixth partial structural schematic diagram of the rotor punching sheet in the embodiment of the present invention;

[0049] Figure 10 Shows the seventh partial structural schematic diagram of the rotor punching sheet in the embodiment of the present invention;

[0050] Figure 11 Shows the eighth partial structural schematic diagram of the rotor punching sheet in the embodiment of the present invention;

[0051] Figure 12 Shows the structural schematic diagram of the rotor core in the embodiment of the present invention;

[0052] Figure 13 Shows the partial structural schematic diagram of the motor in the embodiment of the present invention;

[0053] Figure 14 Shows the curve graph of the skew wave distortion rate of the air gap magnetic field varying with α1 / p / 360 in the embodiment of the present invention;

[0054] Figure 15 Shows the curve graph of the output torque of the motor varying with α2 / α1 / p in the embodiment of the present invention;

[0055] Figure 16 Shows the curve graph of the output torque and torque ripple of the motor varying with (D×sin(1 / 2α1)) / (L×sin(1 / 2α2)) in the embodiment of the present invention;

[0056] Figure 17 Shows the curve graph of the radial electromagnetic force of the motor varying with α3 / α2 in the embodiment of the present invention;

[0057] Figure 18 Shows the curve graph of the output torque of the motor varying with α4 / α3 / p in the embodiment of the present invention;

[0058] Figure 19 Shows the curve graph of the peak torque of the motor varying with the rotational speed in the embodiment of the present invention;

[0059] Figure 20 Shows the bar graph of the peak rotational speed of the motor of the rotor scheme in the related art and the rotor scheme in the present invention.

[0060] Reference numerals:

[0061] 100 Rotor, 110 Rotor Core, 111 Rotor Punching Sheet, 112 Magnet Slot, 113 First Magnet Slot, 114 Second Magnet Slot, 115 Third Magnet Slot, 116 Fourth Magnet Slot, 117 Auxiliary Slot, 120 Permanent Magnet, 121 First Permanent Magnet, 122 Second Permanent Magnet, 130 First Magnetic Bridge Connection Portion, 140 Wrapping Layer, 151 Third Permanent Magnet, 152 Fourth Permanent Magnet, 160 Second Magnetic Bridge Connection Portion, 171 First Magnetic Isolation Slot, 172 Second Magnetic Isolation Slot, 173 Third Magnetic Isolation Slot, 174 Fourth Magnetic Isolation Slot, 200 Stator, 210 Air Gap. Detailed Embodiment

[0062] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0063] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0064] The following refers to Figures 1 to 20 Describe a rotor, a motor and a vehicle provided according to some embodiments of the present invention.

[0065] Combined with Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, in an embodiment of the present invention, a rotor 100 is proposed, including: a rotor core 110, a permanent magnet 120, a first magnetic bridge connection portion 130 and a wrapping layer 140. The rotor core 110 includes a plurality of stacked rotor punching sheets 111. A plurality of magnet slots 112 are provided on the rotor punching sheet 111. The permanent magnet 120 is disposed in the magnet slot 112. The first magnetic bridge connection portion 130 is connected to the rotor punching sheet 111. The first magnetic bridge connection portion 130 is located in the magnet slot 112. The wrapping layer 140 wraps around the outer peripheral surface of the rotor core 110. The wrapping layer 140 is used to provide a pressing force to the rotor core 110.

[0066] A plurality of rotor punching sheets 111 are stacked axially ( Figure 12 The arrow direction at label b in Figure 3The arrow at position a points to the circumferential distribution of the rotor punching sheet 111. A part of the rotor punching sheet 111 located radially inside the magnet slot 112 and a part of the rotor punching sheet 111 located radially outside the magnet slot 112 are connected by the first magnetic bridge connecting part 130. The rotor punching sheet 111 and the magnet slot 112 are connected into an integral structure through the magnetic bridge connecting part, which keeps the rotor punching sheet 111 as a whole, facilitating integrated manufacturing and processing, and the process is simpler. For a non-integral structure, the first problem it brings is that the production tools for the punching sheet structure become more complex. During the process of its machining and forming, a variety of complex processes, tooling, and fasteners are required to fix the separated components of the rotor 100, greatly increasing the production cost, and the difficulty of assembling and laminating the punching sheet structures of several parts of the rotor core 110 increases, seriously affecting the production line. In addition, the punching sheet structure in this related technology can only adopt the traditional straight pole design and cannot adopt the skewed pole design, restricting the improvement space of the motor NVH (noise, vibration, and acoustic roughness, etc.) performance.

[0067] The wrapping layer 140 is arranged in an annular shape and wraps around the radial ( Figure 3 The arrow at position c points to the radial outer peripheral edge side of the rotor punching sheet 111. After adding the wrapping layer 140, the wrapping layer 140 generates a pre-pressure on the rotor core 110. Utilizing the properties of the tensile resistance and deformation resistance of the wrapping layer 140, when the rotor core 110 rotates at a high speed, this pre-pressure is balanced with the centrifugal force to prevent the deformation of the rotor core 110 and the radial flinging of the permanent magnet 120, resisting the action of the centrifugal force. The wrapping layer 140 can strengthen the mechanical strength of the rotor 100 itself. Utilizing the properties of the tensile resistance and deformation resistance, it can effectively improve the tensile resistance and fatigue resistance of the rotor 100, realize the high-speed operation of the rotor 100, and improve the power output capacity of the motor. On the other hand, the wrapping layer 140 also makes the rotor core 110 and the permanent magnet 120 located in a relatively closed cavity and isolated from the cavity of the stator 200. When the motor is working, the heat generated by the motor stator 200 is not easily transferred to the rotor core 110 and the permanent magnet 120, avoiding the decline of the magnetic performance of the permanent magnet 120, thereby ensuring the performance and stability of the rotor 100. Comparing a conventional motor with an interior permanent magnet motor applying the above rotor core 110, under the same outer diameter of the rotor 100, the same built-in form and size of the permanent magnet 120, the motor of the present application can reach a higher speed, achieve a higher power density, and make the electric vehicle have better dynamic performance.

[0068] When the motor is at high speed, since the wrapping layer 140 wraps the rotor 100, the stress of the magnetic bridge connection part is not likely to exceed the material yield strength, so that the motor speed or power can be further increased. Moreover, due to the existence of the wrapping layer 140, the magnetic bridge connection part is not likely to break, thereby reducing the usage amount of the magnetic bridge connection part, reducing the risk of magnetic leakage of the motor, and ensuring the performance such as motor torque and efficiency.

[0069] Figure 19 and Figure 20 shows a comparison of the peak torque and the highest operable speed of the motor between the motor in the related art and the built-in permanent magnet motor using the above-mentioned rotor core 110. Under the condition of the same outer diameter of the rotor 100, the same built-in form and size of the permanent magnet 120, the comparison curves are as follows. Figure 20 It can be seen that after the wrapping layer 140 is added to the rotor 100, the highest operable speed of the motor is significantly increased. Figure 20 The arrow in [the figure] is used to show that the increase in the highest operable speed is greater than 30%. Under the condition of the same motor volume, the present application realizes higher torque density and power density, and can make the electric vehicle have better dynamic performance.

[0070] Combined with Figure 3 and Figure 4 As shown, in some embodiments, optionally, the magnet slot 112 includes a first magnet slot 113 and a second magnet slot 114. The radially outer ends of the first magnet slot 113 and the second magnet slot 114 are away from each other. The rotor punching 111 has an axis. In the radial cross-section of the rotor punching 111, it is set that the connection line L1 and the connection line L2 pass through the axis. The connection line L1 has an intersection point A1 with the first magnet slot 113, and the connection line L2 has an intersection point A2 with the second magnet slot 114. In the first magnet slot 113, the intersection point A1 is located between the permanent magnet 120 and the outer peripheral surface of the rotor punching 111. In the second magnet slot 114, the intersection point A2 is located between the permanent magnet 120 and the outer peripheral surface of the rotor punching 111. The connection line L1 and the connection line L2 have an included angle α1, and α1 satisfies 0.32×360 / p≤α1≤0.4×360 / p, where p is the number of pole pairs of the rotor.

[0071] The portion of the first magnet slot 113 and the second magnet slot 114 that fits the permanent magnet 120 forms a first pole arc angle α1 (i.e., the angle α1 between L1 and L2 above) with the outer circumferential circle of the rotor punching 111. The first pole arc angle α1 satisfies 0.32×360 / p ≤ α1 ≤ 0.4×360 / p. In a permanent magnet synchronous motor, the synthetic magnetic field in the air gap 210 of the motor includes a fundamental magnetic field and a harmonic magnetic field, and the content and proportion of the fundamental magnetic field and the harmonic magnetic field in the synthetic magnetic field in the air gap 210 directly determine the torque output ability of the motor and the noise reduction performance. Moreover, the larger the fundamental magnetic field, the smaller the harmonic magnetic field, the higher the torque output, and the better the noise reduction performance of the motor. On the contrary, the smaller the output torque, the worse the noise reduction performance. The magnitudes of the fundamental magnetic field and the harmonic magnetic field in the air gap 210 magnetic field are directly related to the pole arc angle in the rotor 100, i.e., α1, and the value range of the included angle α1 is associated with the number of pole pairs of the rotor 100. The number of pole pairs is the number of groups of the permanent magnet 120. Since the number of pole pairs of different motors may be different, the angle of the pole arc angle will also change. Simply limiting the angle range of the pole arc angle is likely to deviate from the change in the structure of the rotor 100, that is, the value range of the pole arc angle is related to the number of pole pairs, which can further improve the accuracy of determining the value range of the pole arc angle. Limiting the pole arc angle within the above range can optimize the waveform of the synthetic magnetic field in the air gap 210, effectively reduce the content of the harmonic magnetic field in the air gap 210 magnetic field, make the waveform of the air gap 210 magnetic field approach a sine waveform, thereby reducing the cogging torque and torque ripple of the permanent magnet synchronous motor, reducing the vibration noise of the motor, and moreover, when the content of the harmonic magnetic field is reduced, the iron loss generated due to the high-frequency harmonic magnetic field can be reduced, and the iron loss of the motor in the high-speed range can be reduced, improving the output torque and efficiency of the motor, which is beneficial to improving the performance of the motor.

[0072] One end of the first magnet slot 113 penetrates through the outer peripheral surface of the rotor punching 111 to form a first magnetic isolation slot 171 on the rotor punching 111, and one end of the second magnet slot 114 penetrates through the outer peripheral surface of the rotor punching 111 to form a second magnetic isolation slot 172 on the rotor punching 111.

[0073] Figure 14 The waveform diagram of the harmonic distortion rate of the air gap 210 magnetic field of the motor with 48 slots and 8 poles as an example changing with α1 / p / 360 is shown. From Figure 14 It can be seen that taking p = 8 as an example, the structure satisfying the above formula can effectively reduce the harmonic distortion rate of the air gap 210 magnetic field.

[0074] In a possible application, such as Figure 4As shown, the first magnetic bridge connecting portion 130 is disposed between the first magnet slot 113 and the second magnet slot 114. A part of the first magnet slot 113 extends to the radially outer peripheral wall of the rotor punching 111, and a part of the second magnet slot 114 also extends to the radially outer peripheral wall of the rotor punching 111, so that the radially outer peripheral wall of the rotor punching 111 is an open structure. As Figure 6 shown, there is no first magnetic bridge connecting portion 130 between the first magnet slot 113 and the second magnet slot 114. The first magnetic bridge connecting portion 130 is disposed at the position where the first magnet slot 113 penetrates the radially outer peripheral wall of the rotor punching 111, and the first magnetic bridge connecting portion 130 is disposed at the position where the second magnet slot 114 penetrates the radially outer peripheral wall of the rotor punching 111. As Figure 7 shown, the first magnetic bridge connecting portion 130 is disposed between the first magnet slot 113 and the second magnet slot 114. The first magnetic bridge connecting portion 130 is disposed at the position where the first magnet slot 113 penetrates the radially outer peripheral wall of the rotor punching 111, or the first magnetic bridge connecting portion 130 is disposed at the position where the second magnet slot 114 penetrates the radially outer peripheral wall of the rotor punching 111. The specific magnetic bridge combination form can be designed according to actual requirements.

[0075] The above magnetic bridge combination design can also adjust the direction of magnetic flux lines to reduce magnetic leakage. This not only makes the magnetic leakage of the permanent magnet small, which is beneficial to improving the torque density and power density of the motor, but also can reduce the risk that the magnetic bridge is prone to failure and fracture at high rotational speeds of the rotor 100. In addition, the above first magnetic bridge connecting portion 130 can also be set as a very thin magnetic isolation bridge structure, which is only used to keep the iron core matrix as a complete individual when processing the rotor 100 body, so as to facilitate the picking, placing and assembling operations of the rotor 100 body workpiece after stamping. This magnetic bridge is not a structure that fixes the rotor core 110 and bears stress when the rotor 100 rotates. Its width only needs to be greater than or equal to twice the thickness of the rotor punching 111. Considering that the rotor punching 111 is formed by stamping, the stamping stress of its die is extremely likely to cause deformation and damage to the thinner magnetic bridge part. Therefore, a certain minimum width is reserved for the magnetic bridge part to resist the problem of compressive deformation damage. When the rotor 100 rotates, the magnetic bridge may break, but since the rotor 100 is wrapped with the wrapping layer 140, the overall strength of the rotor 100 will not be affected. In a conventional interior permanent magnet motor, as the outer diameter of the rotor 100 increases or the rotational speed increases, the magnetic bridge needs to be thickened. However, in this embodiment, the width of the magnetic bridge has nothing to do with the outer diameter of the rotor 100 and the maximum rotational speed of the rotor 100. Only the die accuracy and the minimum machinable size of the silicon steel sheet need to be considered. For example, when using 0.25 mm silicon steel sheet to make the rotor punching 111, from a design perspective, the width of the magnetic bridge only needs to be set to ≥0.5 mm.

[0076] As Figure 5As shown, in some embodiments, optionally, in the radial cross-section of the rotor punching 111, the first magnet slot 113 and the second magnet slot 114 are symmetric with respect to the magnetic pole center line L4 of the rotor punching 111.

[0077] The first magnet slot 113 and the second magnet slot 114 are symmetrically distributed with respect to the magnetic pole center line L4. The magnetic pole center line L4 coincides with one of the radial lines of the rotor punching 111. The distance between the first magnet slot 113 and the second magnet slot 114 increases in the direction away from the axis. This can effectively reduce the harmonic content in the magnetic field of the air gap 210 and improve the performance of the motor.

[0078] Combined Figure 8 and Figure 9 As shown, in some embodiments, optionally, the first magnet slot 113 and the second magnet slot 114 have an included angle α2, and α1 and α2 satisfy 0.75×α1×p ≤ α2 ≤ 1.33×α1×p.

[0079] The larger the size of the rotor 100, the smaller the number of pole pairs of the rotor 100, and the relatively larger the angle range that the included angle between the first magnet slot 113 and the second magnet can be set. The smaller the size of the rotor 100 and the more the number of poles, the relatively smaller the angle range that the included angle between the first magnet slot 113 and the second magnet can be set accordingly. Therefore, the included angle between the first magnet slot 113 and the second magnet slot 114 can reflect the optimal included angle design of the permanent magnet under different rotor 100 sizes. Therefore, the included angle α2 is affected by the included angle α1 and the number of pole pairs p. Simply limiting the angle range of the pole arc angle is likely to deviate from the optimal design of the rotor 100. To further improve the accuracy of determining the value range of the included angle between the first magnet slot 113 and the second magnet, limiting the included angle between the first magnet slot 113 and the second magnet within the above range can effectively increase the output torque of the motor, optimize the waveform of the synthetic magnetic field in the air gap 210, reduce the content of the harmonic magnetic field in the air gap 210 magnetic field, reduce the iron loss generated by the high-frequency harmonic magnetic field, reduce the iron loss of the motor in the high-speed range, improve the output torque and efficiency of the motor, and is beneficial to improving the performance of the motor.

[0080] Figure 15 Shows the waveform diagram of the motor output torque varying with α1 and α2 in a 48-slot 8-pole motor as an example. From Figure 15 it can be seen that for the rotor 100 structure satisfying the above conditions, the magnetic chain of the rotor 100 increases, the saturation degrees of the direct axis and the quadrature axis are low, the permanent magnet torque and reluctance torque of the motor increase, and the total output torque increases.

[0081] Combined Figure 3 and Figure 7As shown, in some embodiments, optionally, the permanent magnet 120 includes a first permanent magnet 121 and a second permanent magnet 122. The first permanent magnet 121 is located in the first magnet slot 113, and the second permanent magnet 122 is located in the second magnet slot 114. The diameter of the rotor punching 111 is D, and the length of the first permanent magnet 121 is L. D and L satisfy 1.9 < (D×sin(1 / 2α1)) / (L×sin(1 / 2α2)) < 2.6.

[0082] The length value of the first magnet slot 113 has a greater influence on the magnetic resistance of the direct-axis magnetic circuit of the motor, that is, it has a greater influence on the inductance of the direct-axis magnetic circuit. The included angle between the first magnet slot 113 and the second magnet slot 114 and the value of the pole arc angle have a greater influence on the magnetic resistance of the quadrature-axis magnetic circuit of the motor, that is, they have a greater influence on the inductance of the quadrature-axis magnetic circuit. The saliency ratio of the motor is the ratio of the quadrature-axis inductance to the direct-axis inductance. The electromagnetic torque of the motor is the reluctance torque plus the permanent magnet torque. There is a positive correlation numerical relationship between the amount of the permanent magnet 120 and the permanent magnet torque. By making the above numerical matching with the length value of the first magnet slot 113, as well as the included angle α2 between the first magnet slot 113 and the second magnet slot 114 and the pole arc angle α1, the ratio of the quadrature-axis inductance to the direct-axis inductance of the motor can be increased, and the saliency ratio can be improved. After the saliency ratio is improved, the utilization rate of the reluctance torque of the motor is also improved. When the motor outputs the same magnitude of electromagnetic torque, the permanent magnet torque can be smaller. Thus, the amount of the permanent magnet 120 can be reduced, thereby reducing the cost.

[0083] In a possible application, the lengths of the first permanent magnet 121 and the second permanent magnet 122 are equal. Therefore, the second permanent magnet 122 also satisfies the above conditions.

[0084] Figure 16 The waveform diagrams of the output torque and torque ripple of the motor with 48 slots and 8 poles as an example changing with (D×sin(1 / 2α1)) / (L×sin(1 / 2α2)) are given. Among them, B1 represents the motor output torque, and B2 represents the motor torque ripple. From Figure 16 As can be seen from the figure, for the rotor 100 structure that satisfies the above conditions, the motor has low harmonic content, high output torque, and small torque ripple. Taking the pole-slot combination of 48 slots and 8 poles as an example, the torque ripple of the motor under this structure is low, and the performance of reducing noise is good. During the optimization process, when the value of (D×sin(1 / 2α1)) / (C1×sin(1 / 2α2)) is relatively large, the torque ripple of the motor in the medium and low speed range is relatively small, and the performance of removing noise is relatively good.

[0085] Combined with Figure 3 and Figure 8As shown, in some embodiments, optionally, the rotor punching sheet 111 is further provided with a third magnet slot 115 and a fourth magnet slot 116. The radially outer ends of the first magnet slot 113 and the second magnet slot 114 are away from each other. The third magnet slot 115 and the fourth magnet slot 116 are located radially outside the first magnet slot 113 and the second magnet slot 114, and the third magnet slot 115 and the fourth magnet slot 116 are symmetric with respect to the magnetic pole center line L4. The rotor 100 further includes a third permanent magnet 151 and a fourth permanent magnet 152. The third permanent magnet 151 is located in the third magnet slot 115, and the fourth permanent magnet 152 is located in the fourth magnet slot 116.

[0086] The rotor punching sheet 111 is further provided with a third magnet slot 115 and a fourth magnet slot 116 that are symmetrically distributed with respect to the magnetic pole center line L4. The distance between the third magnet slot 115 and the fourth magnet slot 116 increases in the direction away from the shaft hole of the rotor core 110, which can effectively reduce the harmonic content in the air gap 210 magnetic field and improve the motor performance. The third permanent magnet 151 and the fourth permanent magnet 152 are embedded in their corresponding magnet slots 112. The third magnet slot 115 and the fourth magnet slot 116 are located radially outside the first magnet slot 113 and the second magnet slot 114. Considering that motors in different application scenarios have different requirements for motor torque, power, and NVH performance, the third magnet slot 115 and the fourth magnet slot 116 located outside the first magnet slot 113 and the second magnet slot 114 and the third permanent magnet 151 and the fourth permanent magnet 152 embedded inside the third magnet slot 115 and the fourth magnet slot 116 are added to form a double-layer magnetic pole structure with the first magnet slot 113 and the second magnet slot 114. Through the combined action of the first permanent magnet 121, the second permanent magnet 122, the third permanent magnet 151, and the fourth permanent magnet 152, a series magnetic concentration structure with 4 permanent magnets 120 in each pole of the motor is formed, which can significantly increase the motor output torque and power. At the same time, by jointly adjusting the magnetic field distribution under each pole of the rotor 100 by the four permanent magnets 120, it is more conducive to the sinusoidal design of the air gap 210 magnetic field, thereby improving the motor vibration and noise.

[0087] As Figure 8 shown, in some embodiments, optionally, the rotor 100 further includes: a second magnetic bridge connecting portion 160. The second magnetic bridge connecting portion 160 is connected to the rotor punching sheet 111, and the second magnetic bridge connecting portion 160 is located in the third magnet slot 115 and / or the fourth magnet slot 116.

[0088] The third magnet slot 115 and the fourth magnet slot 116 form at least one second magnetic bridge connection part 160 on the rotor punching 111 for keeping the rotor punching 111 as a whole. Specifically, the rotor punching 111 and the magnet slot 112 are connected into an integral structure through the second magnetic bridge connection part 160, which makes the rotor core 110 punching keep as a whole, facilitating integrated manufacturing and processing with a simpler process. For a non-integral structure, the first problem is that the production tools for the punching structure become more complex. During the process of its machining and forming, a variety of complex processes, tooling and fasteners are required to fix the separated components of the rotor 100, greatly increasing the production cost. Secondly, the difficulty of assembling and laminating several parts of the rotor punching 111 increases, seriously affecting the production line.

[0089] Similar to the first magnet slot 113 and the second magnet slot 114, there are also various combinations of magnetic bridges for the third magnet slot 115 and the fourth magnet slot 116. Assuming that the number of magnetic bridge forms formed by the first magnet slot 113, the second magnet slot 114 and the rotor punching 111 is a, then the number of magnetic bridge forms formed by the third magnet slot 115, the fourth magnet slot 116 and the rotor punching 111 is also a. Then the types of magnetic bridge forms formed by the two groups of magnet slots 112 and the rotor punching 111 are a×a. Exemplarily, as Figure 8 shown, a first magnetic bridge connection part 130 is provided between the first magnet slot 113 and the second magnet slot 114, and a second magnetic bridge connection part 160 is also provided between the third magnet slot 115 and the fourth magnet slot 116. An open structure exists between the first magnet slot 113, the second magnet slot 114, the third magnet slot 115, the fourth magnet slot 116 and the radial outer peripheral wall of the rotor punching 111. Or, as Figure 9 shown, the inner sides of the first magnet slot 113 and the second magnet slot 114 are a connected non-magnetic bridge structure, and the inner sides of the third magnet slot 115 and the fourth magnet slot 116 are also a connected non-magnetic bridge structure. Magnetic bridges (the first magnetic bridge connection part 130 and the second magnetic bridge connection part 160 respectively) are formed between the radial outsides of all the magnet slots 112 and the radial outer peripheral wall of the rotor punching 111. Or, as Figure 10 shown, the inner sides of the first magnet slot 113 and the second magnet slot 114 are a connected non-magnetic bridge structure, and the inner sides of the third magnet slot 115 and the fourth magnet slot 116 are also a connected non-magnetic bridge structure. Magnetic bridges are formed between the radial outsides of the second magnet slot 114 and the fourth magnet slot 116 and the radial outer peripheral wall of the rotor punching 111. The specific magnetic bridge combination form can be designed according to actual requirements and is not limited here.

[0090] In some embodiments, optionally, in the radial cross-section of the rotor punching sheet 111, it is set that the connecting line L5 and the connecting line L6 pass through the axis. The connecting line L5 has an intersection point A3 with the third magnet slot 115, and the connecting line L6 has an intersection point A4 with the fourth magnet slot 116. In the third magnet slot 115, the intersection point A3 is located between the third permanent magnet 151 and the outer peripheral surface of the rotor punching sheet 111. In the fourth magnet slot 116, the intersection point A4 is located between the fourth permanent magnet 152 and the outer peripheral surface of the rotor punching sheet 111. The connecting line L5 and the connecting line L6 have an included angle α3, and α3 satisfies 0.45×α2 ≤ α3 ≤ 0.67×α2.

[0091] The parts of the third magnet slot 115 and the fourth magnet slot 116 that are adapted to the permanent magnet 120 form a second pole arc angle α3 (i.e., the included angle α3 between L5 and L6) with the outer peripheral circle of the rotor punching sheet 111. When α3 and α2 are correlated with each other, the inner and outer two-layer magnet slots 112 are structurally and dimensionally correlated with each other, and the inner and outer two-layer magnet slots 112 can further improve the performance of the motor through mutual cooperation.

[0092] One end of the third magnet slot 115 penetrates the outer peripheral surface of the rotor punching sheet 111 to form a third magnetic isolation slot 173 on the rotor punching sheet 111. One end of the fourth magnet slot 116 penetrates the outer peripheral surface of the rotor punching sheet 111 to form a fourth magnetic isolation slot 174 on the rotor punching sheet 111.

[0093] In some embodiments, optionally, the third magnet slot 115 and the fourth magnet slot 116 have an included angle α4, and α3 and α4 satisfy 1.22×α3×p ≤ α4 ≤ 1.65×α3×p.

[0094] A V-shaped included angle α4 is formed between the third magnet slot 115 and the fourth magnet slot 116, satisfying 1.22×α3×p ≤ α4 ≤ 1.65×α3×p. Specifically, the synthetic magnetic field in the air gap 210 of the motor is generated by the combined action of the permanent magnets 120 in the inner-layer magnetic poles and the outer-layer magnetic poles, which includes a fundamental wave and harmonics. The content and proportion of the fundamental wave and harmonics in the air gap 210 magnetic field directly determine the torque output ability and NVH performance of the motor. The larger the fundamental wave and the smaller the harmonics, the higher the torque output and the better the NVH performance of the motor. Conversely, the smaller the output torque and the worse the NVH performance. The content proportion and size of the fundamental wave and harmonics in the air gap 210 magnetic field are directly related to the size of the pole arc angle. By simultaneously making the above numerical matching for the sizes of the third magnet slot 115 and the fourth magnet slot 116, it is possible to jointly optimize the waveform of the synthetic magnetic field in the air gap 210 with the size matching of the third magnet slot 115 and the fourth magnet slot 116, effectively reduce the harmonic content in the air gap 210 magnetic field, improve the sinusoidality of the air gap 210 magnetic field waveform, thereby reducing the cogging torque and torque ripple of the permanent magnet synchronous motor and reducing the vibration and noise of the motor.

[0095] Figure 17 The waveform diagrams showing the radial electromagnetic forces of a motor with 48 slots and 8 poles as an example at the 0th order in space and the 24th and 48th orders in time varying with α3 / α2 are presented. Among them, B3 represents the numerical value of the 24th-order electromagnetic force, and B4 represents the numerical value of the 48th-order electromagnetic force. From Figure 17 it can be seen that for the rotor 100 structure satisfying the above conditions, the numerical values of the 24th-order and 48th-order electromagnetic forces of the motor are low, which is beneficial to reducing the NVH of the motor and improving the riding experience of users on electric vehicles.

[0096] Figure 18 it can be seen that for the rotor 100 structure satisfying the above conditions, the permanent magnet torque and reluctance torque of the motor increase, and the total output torque increases.

[0097] As Figure 11 shown, in some embodiments, optionally, the outer peripheral surface of the rotor punching sheet 111 is provided with auxiliary slots 117, and the auxiliary slots 117 extend along the axial direction of the rotor punching sheet 111.

[0098] Multiple groups of recessed auxiliary slots are spaced on the outer peripheral wall of the rotor punching sheet 111. The auxiliary slots 117 extend along the axial direction of the rotor core 110 and penetrate the axial end faces of the rotor core 110. Specifically, the torque ripple and spatial electromagnetic force of the motor are the main sources of the tangential and radial vibration noises of the motor. For a vehicle-mounted permanent magnet synchronous motor, due to its wide operating speed range and complex operating conditions, the main torque ripple orders and radial electromagnetic force densities within its full speed range need to be optimized and considered. However, due to the large differences in current and current angle under various operating conditions, in the related art, adopting a certain optimization measure can only reduce the NVH performance of the motor under its specific operating conditions, resulting in the deterioration of the NVH performance under other operating conditions, and often at the cost of sacrificing the torque, power, and efficiency performance of the motor. In the present invention, by reasonably setting the recessed auxiliary slots 117, the above situation can be effectively avoided, the peak power of the motor can be increased, the armature reaction of the motor can be reduced, and the influence on the peak torque performance of the motor is also small. In addition, the iron loss and demagnetization performance of the motor are directly related to the armature reaction of the motor. The smaller the armature reaction, the lower the iron loss of the motor, the better the demagnetization resistance ability, and the more beneficial to the output performance of the motor.

[0099] In some embodiments, optionally, the wrapping layer 140 includes: a wrapped wrapping layer or a tubular wrapping layer.

[0100] The wrapping layer 140 is formed by winding carbon fiber filaments around the outer peripheral edge of the rotor punching sheet 111, or the wrapping layer 140 is a sleeve, and by sleeving a sleeve on the rotor punching sheet 111, the mechanical strength of the rotor 100 structure is improved, so that the rotor 100 can operate reliably at high speeds.

[0101] In a possible application, the wrapping layer 140 includes a carbon fiber wrapping layer.

[0102] As Figure 12 shown, in some embodiments, optionally, the rotor 100 includes a segmented skewed pole rotor 100 or a continuous skewed pole rotor 100.

[0103] The rotor core 110 is assembled in a segmented skewed pole or continuous skewed pole manner. The optimization combination effect of the magnetic pole structure parameters in the motor has a limited effect on improving the magnetic field waveform of the air gap 210. Especially the tooth harmonics among them are the main sources of the motor vibration and noise. Therefore, it is necessary to further weaken the harmonic content in combination with the segmented skewed pole of the rotor 100. The segmented skewed pole can, while ensuring the electromagnetic torque of the motor, minimize the end leakage flux of the permanent magnet, improve the utilization rate of the permanent magnet, weaken the cogging torque, reduce the torque ripple of the motor, and at the same time improve the magnetic field distribution of the air gap 210, reduce the distortion rate of the magnetic field of the air gap 210, and improve the NVH performance of the motor.

[0104] Exemplarily, taking a 48-slot 8-pole scheme as an example, the rotor 100 is axially laminated and assembled by six segments of rotor cores 110. The offset between adjacent two segments of rotor cores 110 is a predetermined angle of 2.5° or 0°. This skewed pole method and skewed pole angle can achieve the skewed pole effect of the rotor 100, reduce the torque fluctuation of the motor, and improve the noise, vibration and harshness performance of the motor during operation.

[0105] As Figure 13 shown, in an embodiment of the present invention, a motor is proposed, including: a stator 200 and the rotor 100 in any of the above embodiments. The rotor 100 is disposed inside the stator 200 and can achieve the same technical effects, which will not be elaborated here.

[0106] As Figure 13 shown, in some embodiments, optionally, there is an air gap 210 between the rotor 100 and the stator 200. The length of the air gap 210 is N1, and the thickness of the wrapping layer 140 is N2, satisfying N2 ≤ 0.75N1.

[0107] The thickness of the wrapping layer 140 is less than or equal to 75% of the air gap 210 of the permanent magnet synchronous motor. The inner diameter of the stator 200 and the outer diameter of the rotor 100 of the permanent magnet synchronous motor form the air gap 210. If the thickness of the wrapping layer 140 is too thin, it is not sufficient to provide strength support for the rotor 100. If the wrapping layer 140 is too thick, it is not conducive to the output of the motor torque performance. And if its thickness exceeds 75% of the air gap 210, there may also be a risk of the rotor 100 rubbing against the stator. Therefore, a reasonable thickness needs to be set to ensure that the wrapping layer 140 can both support the strength of the rotor 100 at high speed and ensure the normal operation of the motor.

[0108] For the solution of forming the wrapping layer 140 by winding carbon fiber filaments, the minimum number of winding turns is one turn. When the carbon fiber filaments are wound only once on the outer edge of the rotor core 110, the diameter of the carbon fiber filaments is 0.2 to 1.5 mm. When the carbon fiber filaments are wound multiple times on the outer edge of the rotor core 110, carbon fiber filaments with a smaller diameter can be used.

[0109] In some embodiments, optionally, the thickness N2 of the wrapping layer 140 satisfies 0.2 mm ≤ N2 ≤ 2 mm.

[0110] Within this range, the wrapping layer 140 can not only support the strength of the rotor 100 at high speeds but also ensure the normal operation of the motor.

[0111] In an embodiment of the present invention, a vehicle is proposed, including: the motor as in the second aspect, and the same technical effects can be achieved, which will not be elaborated here.

[0112] Among them, the vehicle can be a traditional fuel vehicle or a new energy vehicle. Among them, new energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid vehicles, fuel cell electric vehicles, hydrogen engine vehicles, etc.

[0113] In the present invention, the term "a plurality of" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "connected to", "fixed" and other terms should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0114] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0115] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rotor, characterized in that, Comprising: A rotor core including a plurality of stacked rotor punching sheets, with a plurality of magnet slots provided on the rotor punching sheets; Permanent magnets disposed in the magnet slots; A first magnetic bridge connection part connected to the rotor punching sheet, and the first magnetic bridge connection part is located in the magnet slot; A wrapping layer wrapped around the outer peripheral surface of the rotor core, and the wrapping layer is used to provide a pressing force to the rotor core.

2. The rotor according to claim 1, characterized in that, The magnet slot includes a first magnet slot and a second magnet slot. The radially outer ends of the first magnet slot and the second magnet slot are away from each other. The rotor punching sheet has an axis. In the radial cross-section of the rotor punching sheet, a set of connection lines L1 and L2 pass through the axis. The connection line L1 has an intersection point A1 with the first magnet slot, and the connection line L2 has an intersection point A2 with the second magnet slot. In the first magnet slot, the intersection point A1 is located between the permanent magnet and the outer peripheral surface of the rotor punching sheet. In the second magnet slot, the intersection point A2 is located between the permanent magnet and the outer peripheral surface of the rotor punching sheet. The connection line L1 and the connection line L2 have an included angle α1, and α1 satisfies 0.32×360 / p ≤ α1 ≤ 0.4×360 / p, where p is the number of pole pairs of the rotor.

3. The rotor according to claim 2, characterized in that, In the radial cross-section of the rotor punching sheet, the first magnet slot and the second magnet slot are symmetric with respect to the magnetic pole center line L4 of the rotor punching sheet.

4. The rotor according to claim 3, characterized in that, The first magnet slot and the second magnet slot have an included angle α2, and α1 and α2 satisfy 0.75×α1×p ≤ α2 ≤ 1.33×α1×p.

5. The rotor according to claim 4, characterized in that, The permanent magnet includes a first permanent magnet and a second permanent magnet. The first permanent magnet is located in the first magnet slot, and the second permanent magnet is located in the second magnet slot; The diameter of the rotor punching sheet is D, and the length of the first permanent magnet is L. D and L satisfy 1.9 < (D×sin(1 / 2α1)) / (L×sin(1 / 2α2)) < 2.

6.

6. The rotor according to claim 4, characterized in that The rotor punching sheet is further provided with a third magnet slot and a fourth magnet slot. The radially outer ends of the first magnet slot and the second magnet slot are away from each other. The third magnet slot and the fourth magnet slot are located radially outside the first magnet slot and the second magnet slot, and the third magnet slot and the fourth magnet slot are symmetric with respect to the magnetic pole center line L4; The rotor further includes a third permanent magnet and a fourth permanent magnet. The third permanent magnet is located in the third magnet slot, and the fourth permanent magnet is located in the fourth magnet slot.

7. The rotor according to claim 6, wherein The rotor further includes: A second magnetic bridge connection part connected to the rotor punching sheet, and the second magnetic bridge connection part is located in the third magnet slot and / or the fourth magnet slot.

8. The rotor according to claim 6, characterized in that, In the radial cross-section of the rotor punching sheet, it is set that the connecting line L5 and the connecting line L6 pass through the axis. The connecting line L5 has an intersection point A3 with the third magnet slot, and the connecting line L6 has an intersection point A4 with the fourth magnet slot. In the third magnet slot, the intersection point A3 is located between the third permanent magnet and the outer peripheral surface of the rotor punching sheet. In the fourth magnet slot, the intersection point A4 is located between the fourth permanent magnet and the outer peripheral surface of the rotor punching sheet. The connecting line L5 and the connecting line L6 have an included angle α3, and α3 satisfies 0.45×α2 ≤ α3 ≤ 0.67×α2.

9. The rotor according to claim 8, characterized in that, The third magnet slot and the fourth magnet slot have an included angle α4, and α3 and α4 satisfy 1.22×α3×p ≤ α4 ≤ 1.65×α3×p.

10. The rotor according to any one of claims 1 to 9, characterized in that, The outer peripheral surface of the rotor punching sheet is provided with an auxiliary slot, and the auxiliary slot extends along the axial direction of the rotor punching sheet.

11. The rotor according to any one of claims 1 to 9, characterized in that, The wrapping layer includes: a winding wrapping layer or a tubular wrapping layer.

12. The rotor according to any one of claims 1 to 9, characterized in that, The wrapping layer includes a carbon fiber wrapping layer.

13. The rotor according to any one of claims 1 to 9, characterized in that, The rotor includes a segmented skewed pole rotor or a continuous skewed pole rotor.

14. A motor, characterized in that, Including: A stator; The rotor according to any one of claims 1 to 13, and the rotor is arranged inside the stator.

15. The motor according to claim 14, characterized in that, There is an air gap between the rotor and the stator, the length of the air gap is N1, and the thickness of the wrapping layer is N2, satisfying N2 ≤ 0.75N1.

16. The motor according to claim 15, characterized in that, The thickness of the wrapping layer is N2, satisfying 0.2 mm ≤ N2 ≤ 2 mm.

17. A vehicle, characterized in that, Including: The motor according to any one of claims 14 to 16.

Images