Rotor punching sheet, rotor iron core, rotor, motor, power assembly and vehicle

Abstract

The invention provides a rotor punching sheet, a rotor iron core, a rotor, a motor, a power assembly and a vehicle. The rotor punching sheet comprises a punching sheet body. The punching sheet body is provided with an air groove. The punching sheet body is provided with a first magnetic pole area A and a second magnetic pole area B which are different in magnetic field distribution, a central axis is arranged between the first magnetic pole area A and the second magnetic pole area B, only one side of the central axis is provided with an air slot, or the air slots on two sides of the central axis are asymmetrically distributed relative to the central axis. And the asymmetrically distributed air slots are arranged, so that the harmonic amplitude of the magnetic pole region on the relatively strong side can be weakened, the air gap magnetic fields on the two sides tend to be symmetrically distributed, the vibration noise problem caused by the magnetic field change is further reduced, the torque pulsation of the motor rotor is reduced, and the output performance of the motor is improved.

Description

Technical Field

[0001] The present application belongs to the field of motor technology, and specifically relates to a rotor punching sheet, a rotor core, a rotor, a motor, a power assembly and a vehicle. Background Art

[0002] As an important component of permanent magnet motor, the improvement of rotor punching's magnetic circuit and air gap magnetic field is of great significance to the power output performance of the motor.

[0003] In the related art, when the motor rotor is rotating, the air gap magnetic flux waveform tends to shift to one side, that is, the air gap magnetic field asymmetry phenomenon, which will cause torque pulsation and vibration noise risks of the motor rotor and affect the motor output performance. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a rotor punching, a rotor core, a rotor, a motor, a power assembly and a vehicle, which can solve the problem of vibration and noise caused by the asymmetric air gap magnetic field in the related art.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a rotor punching sheet, including a punching sheet body;

[0007] An air groove is provided on the punch body;

[0008] The punching sheet body has a first magnetic pole region and a second magnetic pole region with different magnetic field distributions, a central axis is provided between the first magnetic pole region and the second magnetic pole region, the air groove is provided on only one side of the central axis, or the air grooves on both sides of the central axis are asymmetrically distributed about the central axis.

[0009] Optionally, each of the first magnetic pole regions and the corresponding second magnetic pole region form a magnetic pole, the air slots are provided in each of the magnetic poles, and the air slots in at least one of the magnetic poles are asymmetrically distributed about the central axis.

[0010] Optionally, the punching sheet body is an amorphous alloy punching sheet.

[0011] Optionally, the arc length or area of ​​the air slot located in the second magnetic pole region is greater than the arc length or area of ​​the air slot located in the first magnetic pole region.

[0012] Optionally, the air groove is arranged at the outer edge of the punch body, or the air groove is arranged in the punch body and penetrates along the thickness direction of the punch body.

[0013] Optionally, part of the air grooves are arranged at the outer edge of the punch body, and part of the air grooves are arranged in the punch body and pass through along the thickness direction of the punch body.

[0014] Optionally, a magnetic steel groove is provided in the punch body, and the magnetic steel groove is used to install the magnet.

[0015] Optionally, the air groove is connected to the magnetic steel groove.

[0016] Optionally, the two magnetic steel slots located in the first magnetic pole region extend in different directions, and / or, a certain gap exists between the two magnetic steel slots located in the second magnetic pole region and extend in different directions.

[0017] Optionally, the air slot is located in the second magnetic pole region and close to the magnetic steel slot.

[0018] Optionally, the air slot is located between the magnetic steel slot of the first magnetic pole region and the magnetic steel slot of the second magnetic pole region.

[0019] Optionally, the first magnetic pole region and / or the second magnetic pole region is fan-shaped, and a radial dimension of the air groove along the fan shape is greater than a thickness of the punching sheet body.

[0020] Optionally, the distance between two magnetic steel slots located in the first magnetic pole region is W1, the distance between two magnetic steel slots located in the second magnetic pole region is W2, and W1>W2.

[0021] Optionally, a size of a single air groove along the circumferential direction of the outer edge of the punch body, or a circumference of a single air groove is L, and L≥0.2 mm.

[0022] Optionally, the magnetic steel slot includes a mounting portion and an air gap portion that are interconnected;

[0023] The mounting portion is used to mount the magnet.

[0024] Optionally, the air gap portion is arc-shaped.

[0025] Optionally, the punching sheet body is an amorphous alloy punching sheet.

[0026] Optionally, the thickness of a single punching sheet body is t, 0.01mm≤t≤0.03mm.

[0027] An embodiment of the present application further provides a rotor core, comprising any of the rotor punchings described above, wherein a plurality of the rotor punchings are stacked.

[0028] The embodiment of the present application also provides a rotor, comprising a magnet and the above-mentioned rotor core;

[0029] The magnet is connected to the punching sheet body.

[0030] Optionally, the volume of the magnet located in the first magnetic polar region is greater than the volume of the magnet located in the second magnetic polar region.

[0031] An embodiment of the present application also provides a motor, comprising the above-mentioned rotor.

[0032] An embodiment of the present application also provides a powertrain, comprising the above-mentioned motor.

[0033] An embodiment of the present application also provides a vehicle, comprising the above-mentioned motor or powertrain.

[0034] The rotor punching provided in the embodiment of the present application has an air slot on the punching body, and the air slot can be set on the outer edge of the punching body, or, it can be set inside the punching body to form a hole-shaped structure. The punching body has a central axis and a first magnetic pole region and a second magnetic pole region. The magnetic field distribution of the first magnetic pole region and the second magnetic pole region is different, and the central axis is located between the first magnetic pole region and the second magnetic pole region. The air slot can be set only on one side of the central axis, or the air slots on both sides of the central axis are asymmetrically distributed about the central axis. That is, the shape and / or size of the air slots on both sides of the central axis are different. When the motor is powered on, the rotor rotates, and a certain air gap magnetic field is generated between the stator. Due to the influence of the rotation of the rotor, the magnetic density waveform tends to shift to one side of the rotor central axis, causing the asymmetry of the air gap magnetic field between the first magnetic pole region and the second magnetic pole region. The air slots with asymmetrical distribution can weaken the harmonic amplitude on the stronger side, so that the air gap magnetic fields on both sides tend to be symmetrically distributed, further reducing the vibration and noise problems caused by magnetic field changes, reducing the torque pulsation of the motor rotor, and improving the output performance of the motor.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0037] Figure 1 This is a schematic diagram of the first air slot structure in the embodiment of the present application;

[0038] Figure 2 is a schematic diagram of the second air slot structure in the embodiment of the present application;

[0039] Figure 3 is a schematic diagram of the third air slot structure in the embodiment of the present application;

[0040] Figure 4 This is a schematic diagram of the magnet arrangement in the embodiment of the present application;

[0041] Figure 5 It is the numerical simulation result of torque pulsation of the rotor with air slots provided in the embodiment of the present application;

[0042] Figure 6 It is a comparison between the symmetrical magnetic pole rotor punching sheet and the asymmetrical magnetic pole rotor punching sheet structure provided in the embodiment of the present application;

[0043] Figure 7 It is a comparison between the symmetrical rotor air gap magnetic field and the asymmetrical rotor air gap magnetic field;

[0044] Figure 8 It is a simulation comparison of symmetrical rotor flux density and asymmetrical rotor flux density;

[0045] Fig. 9 This is the magnetic flux density distribution cloud diagram under high load of amorphous rotor;

[0046] Fig.10 It is the BH curve of amorphous rotor;

[0047] Fig.11 It is a schematic diagram of the magnetic circuit analytical model of the amorphous rotor;

[0048] Fig.12 It is a comparison of the BH curves of amorphous materials and silicon steel materials;

[0049] Fig.13 It is a schematic diagram of the rotor core structure provided in an embodiment of the present application.

[0050] Description of reference numerals:

[0051] 1- punch body, 11- air slot, 11a- outer edge air slot, 11b- inner air slot, 12- magnetic steel slot, 121- mounting portion, 122- air gap portion, 2- magnet, d- center axis, A- first magnetic pole region, B- second magnetic pole region, a- magnetic pole. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0054] The rotor punchings, rotor cores, rotors, motors, powertrains and vehicles provided in the embodiments of the present application are described in detail below with reference to specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0055] Reference Figures 1 to 3 An embodiment of the present application provides a rotor punching sheet, including a punching sheet body 1; an air slot 11 is provided on the punching sheet body 1; the punching sheet body has a first magnetic pole region A and a second magnetic pole region B with different magnetic field distributions, a central axis d is provided between the first magnetic pole region A and the second magnetic pole region B, the air slot 11 is provided on only one side of the central axis d, or the air slots 11 on both sides of the central axis d are asymmetrically distributed about the central axis d.

[0056] Specifically, if Figures 1 to 3As shown in the figure, the rotor punching provided in the embodiment of the present application includes a punching body 1, and the punching body 1 can be made of silicon steel, pure copper or amorphous alloy. An air slot 11, also known as a harmonic slot, is provided on the punching body 1. The air slot 11 can be provided on the outer edge of the punching body 1, or, it can be provided inside the punching body 1 in a hole-shaped manner. The shape of the air slot 11 can be set to be strip-shaped, triangular, sawtooth-shaped or arc-shaped. The punching body 1 has a plurality of first magnetic pole regions A and a plurality of second magnetic pole regions B, and the center axis d axis is between the first magnetic pole region A and the second magnetic pole region B. Each first magnetic pole region A and a second magnetic pole region B form a fan-shaped area, and the center axis passing through the center of the fan-shaped area and located between the first magnetic pole region A and the second magnetic pole region B is the d axis. The front side of the rotor rotation, that is, the side where the rotor has not rotated, is defined as the first magnetic pole region A, and the rear side of the rotation, that is, the side where the rotor has rotated, is defined as the second magnetic pole region B. Due to the influence of the motor current and the rotation of the rotor, the magnetic field strength of the first magnetic pole region A is usually greater than that of the second magnetic pole region B. The distribution pattern of the air slots 11 about the d-axis is as follows: the air slots 11 are only provided on one side of the d-axis, in other words, the air slots 11 are only provided in the first magnetic pole region A or the second magnetic pole region B; or, the air slots 11 are provided on both sides of the d-axis, but the air slots 11 in the first magnetic pole region A and the air slots 11 in the second magnetic pole region B are asymmetrically distributed about the d-axis. Specifically, at least one of the shape, number and size of the air slots 11 on both sides of the d-axis is different. For example, in the direction of the outer edge of the punch body 1, the size of the air slots 11 on one side of the d-axis is larger than the size of the air slots 11 on the other side of the d-axis, or, the number of air slots 11 on one side of the d-axis is larger than the number of air slots 11 on the other side of the d-axis, or, the setting position of the air slots 11 is closer to one side of the d-axis rather than being symmetrically arranged about the d-axis. Figure 1 As shown, the air slot 11 is different from the magnetic steel slot 12 , the air slot 11 is independently provided from the magnetic steel slot 12 , or the air slot 11 is not directly connected to the part of the magnetic steel slot 12 where the magnet 2 is installed.

[0057] When the motor is powered on, the rotor rotates and generates a certain air gap magnetic field between the stator and the rotor. Due to the influence of the rotor's rotation, the magnetic flux density waveform tends to shift to one side of the rotor's central axis, causing the air gap magnetic field to be asymmetric. This asymmetry of the air gap magnetic field is similar to Figure 7 The right part in the figure is particularly obvious in the motor rotor of the asymmetric magnetic pole type. The air slots 11 arranged on the rotor punching sheet in an asymmetric distribution about the d-axis will strengthen the harmonic amplitude on one side to a certain extent, for example, Figure 7 As shown in the figure, the harmonic amplitude of the air gap magnetic field on the left side of the d-axis is stronger than that on the right side of the d-axis. Therefore, the air slot 11 can be set only on the left side of the d-axis, or the number of air slots 11 on the left side of the d-axis is larger than that on the right side of the d-axis, so that the air gap magnetic fields on both sides tend to be symmetrically distributed. This reduces the vibration and noise caused by the change of the magnetic field and reduces the torque pulsation of the motor rotor. Figure 5This is the numerical simulation result of the torque pulsation of the rotor with air slots in the embodiment of the present application. The closer to the data point on the lower left of the figure, the higher the asymmetric distribution of the air slots, and the smaller the torque pulsation value of the rotor; the closer to the data point on the upper right of the figure, the lower the asymmetric distribution of the air slots, and the higher the torque pulsation value of the rotor. Therefore, it is verified that setting air slots that are asymmetrically distributed about the d-axis can reduce the torque pulsation of the motor rotor.

[0058] The rotor punching provided in the embodiment of the present application is provided with air grooves on the punching body. The air grooves are asymmetrically distributed about the central axis of the punching body, so that the air gap magnetic field on both sides of the central axis tends to be symmetrically distributed, further reducing the vibration and noise problems caused by the change of the magnetic field, reducing the torque pulsation of the motor rotor, and improving the output performance of the motor.

[0059] Optionally, refer to Figure 1 and Fig.13 Each of the first magnetic pole regions A and the corresponding second magnetic pole region B form a magnetic pole a, each of the magnetic poles a is provided with the air slot 11, and the air slots 11 in at least one of the magnetic poles a are asymmetrically distributed about the central axis d.

[0060] Specifically, if Figure 1 and Fig.13 As shown, there are multiple magnetic poles a on the rotor punching sheet, and the magnetic poles a are fan-shaped areas, including a first magnetic pole area A and a second magnetic pole area B. The magnetic poles a are magnetic field areas formed by the magnets 2 on the punching sheet, that is, the magnets 2 are arranged in each fan-shaped area to form magnetic poles. An air slot 11 is arranged in each magnetic pole a, and in each magnetic pole a. Among them, the air slots 11 in at least one magnetic pole a are asymmetrically distributed about the central axis d. The more air slots 11 arranged in the magnetic poles a are asymmetrically distributed about the d axis, the easier it is to further reduce the vibration and noise problems caused by changes in the magnetic field.

[0061] Optionally, refer to Figures 1 to 3 , the arc length or area of ​​the air slot 11 located in the second magnetic pole region B is greater than the arc length or area of ​​the air slot 11 located in the first magnetic pole region A.

[0062] Specifically, if Figure 1As shown in the figure, if the motor rotor rotates in the direction indicated by the arrow in the figure, that is, in the clockwise direction, the front side of the rotor in the direction of rotation is the right side of the central axis d, that is, the first magnetic pole region A, and the rear side of the rotor in the direction of rotation is the left side of the central axis d, that is, the second magnetic pole region B. In practice, it is found that the rotor air gap magnetic flux waveform is approximately sinusoidally distributed along the circumference of the air gap, but the amplitude of the magnetic flux waveform on the front side in the direction of rotation is slightly higher than the amplitude of the magnetic flux waveform on the rear side in the direction of rotation. In order to change the air gap magnetic field distribution and weaken the amplitude of the magnetic flux waveform on the front side in the direction of rotation, the arc length or area of ​​the air slot 11 in the second magnetic pole region B is set to be greater than the arc length or area of ​​the air slot 11 in the first magnetic pole region A. This includes the following two situations: when the air slot 11 is arranged on the outer edge of the punching sheet body 1 in the shape of an open slot, the arc length of the air slot 11 in the second magnetic pole region B is greater than the arc length of the air slot 11 in the first magnetic pole region A; when the air slot 11 is arranged inside the punching sheet body 1 in the shape of a hole, the aperture of the air slot 11 in the second magnetic pole region B is greater than the aperture of the air slot 11 in the first magnetic pole region A, that is, the area of ​​the air slot 11 in the second magnetic pole region B is greater than the area of ​​the air slot 11 in the first magnetic pole region A.

[0063] Optionally, refer to Figures 1 to 3 The air groove 11 is arranged at the outer edge of the punch body 1 , or the air groove 11 is arranged inside the punch body 1 and penetrates along the thickness direction of the punch body 1 .

[0064] Optionally, part of the air grooves 11 are arranged at the outer edge of the punch body 1 , and part of the air grooves 11 are arranged inside the punch body 1 and pass through the punch body 1 along the thickness direction.

[0065] Specifically, the air slots 11 are classified into three types. Figure 1 As shown, the air groove 11 is arranged at the outer edge of the punch body 1 in the shape of an open groove, namely, the outer edge air groove 11a. Figure 2 As shown, the air groove 11 is arranged inside the punch body 1 and penetrates through the thickness direction to form a through hole, which is filled with air, namely the internal air groove 11b. Figure 3 As shown, the above two structures are combined, that is, a part of the air slots 11 are arranged on the outer edge of the punch body 1, and the other part of the air slots 11 are arranged inside the punch body 1, and the effect of reducing the vibration and reducing the rotation pulsation of the rotor is more significant. These three forms can effectively change the air gap magnetic field distribution, further reduce the vibration and noise problems caused by the change of the magnetic field, reduce the torque pulsation of the motor rotor, and improve the output performance of the motor.

[0066] Optionally, refer to Figure 4 A magnetic steel groove 12 is provided in the punching sheet body 1, and the magnetic steel groove 12 is used to install the magnet 2.

[0067] Specifically, if Figure 4As shown in the figure, a magnetic steel slot 12 is provided in the punching body 1, that is, an embedded structure is adopted, and the magnet 2 is embedded in the magnetic steel slot 12, which can effectively protect the magnet 2, reduce the risk of demagnetization, and the motor power density is higher.

[0068] Optionally, refer to Figure 3 , the air groove 11 is connected to the magnetic steel groove 12.

[0069] Specifically, if Figure 3 As shown in the figure, when the air groove 11 is arranged on the outer edge or inside of the punch body 1, the air groove 11 can be connected with the magnetic steel groove 12. Since the air groove 11 is asymmetrically distributed about the d-axis, the magnetic steel grooves 12 on both sides of the d-axis are also asymmetrically distributed about the d-axis, further reducing the vibration noise problem caused by the change of the magnetic field.

[0070] Optionally, refer to Figures 1 to 3 The two magnetic steel slots 12 located in the first magnetic pole region A extend in different directions, and / or the two magnetic steel slots 12 located in the second magnetic pole region B extend in different directions.

[0071] Specifically, if Figures 1 to 3 As shown, there is a certain angle between the two layers of magnetic steel slots 12 in at least one magnetic pole region, that is, the two layers of magnetic steel slots 12 are arranged non-parallel, and the two magnetic steel slots 12 in the first magnetic pole region A and / or the second magnetic pole region B extend in different directions to form a "V" shape distribution. Compared with the parallel arrangement, the magnetic density of the magnetic pole region can be improved. In this embodiment, there is a certain angle between the two magnetic steel slots 12 in the first magnetic pole region A and the second magnetic pole region B.

[0072] Optionally, refer to Figures 1 to 3 The air slot 11 is located in the second magnetic pole region B and is close to the magnetic steel slot 12 .

[0073] The air slot 11 is located between the magnetic steel slot 12 of the first magnetic pole region A and the magnetic steel slot 12 of the second magnetic pole region B.

[0074] Specifically, if Figures 1 to 3As shown in the diagram, there are two types of relative positions of the air slot 11 and the magnetic steel slots 12 on both sides of the central axis d. The first type is that the air slot 11 is located in the second magnetic pole region B, and is close to the magnetic steel slot 12 in the second magnetic pole region B. At least one air slot 11 is provided at each magnetic steel slot 12 close to the second magnetic pole region B. In this embodiment, two outer edge air slots 11a and one inner air slot 11b are provided at the magnetic steel slot 12 close to the bottom in the second magnetic pole region B, and one outer edge air slot 11a and two inner air slots 11b are provided at the magnetic steel slot 12 close to the top in the second magnetic pole region B; the second type is that the air slot 11 is provided between the magnetic steel slot 12 in the first magnetic pole region A and the magnetic steel slot 12 in the second magnetic pole region B, but because the air slots 11 are non-aligned with respect to the central axis d, the distribution of the air slots 11 in the first magnetic pole region A and the second magnetic pole region B is different. Both distribution methods can reduce the vibration and noise problems caused by magnetic field changes and reduce the torque pulsation of the motor rotor.

[0075] Optionally, the first magnetic pole region A and / or the second magnetic pole region B is fan-shaped, and a radial dimension of the air slot 11 along the fan shape is greater than a thickness of the punching sheet body 1 .

[0076] Specifically, the first magnetic pole region A and / or the second magnetic pole region B are fan-shaped. In this embodiment, the first magnetic pole region A and the second magnetic pole region B are both fan-shaped. The radial dimension of the air groove 11 along the fan shape is larger than the thickness of the punching sheet body 1, which is convenient for stamping to form the air groove 11 and easy to assemble.

[0077] Optionally, refer to Figure 4 The distance between the two magnetic steel slots 12 located in the first magnetic pole region A is W1, and the distance between the two magnetic steel slots 12 located in the second magnetic pole region B is W2, W1>W2.

[0078] Specifically, if Figure 4 As shown in the figure, both the first magnetic pole region A and the second magnetic pole region B have two layers of magnetic steel slots 12, the distance between the two layers of magnetic steel slots 12 in the first magnetic pole region A is W1, and the distance between the two layers of magnetic steel slots 12 in the second magnetic pole region B is W2, and the distance between the two layers of magnetic steel slots 12 can represent the width of the magnetic flux path. By setting W1>W2, the local magnetic flux saturation phenomenon is further alleviated, and the output performance degradation caused by the local magnetic flux saturation under the heavy load state of the motor is improved.

[0079] Optionally, refer to Figures 1 to 3 The size of a single air groove 11 along the circumferential direction of the outer edge of the punch body 1, or the circumference of a single air groove 11 is L, and L≥0.2mm.

[0080] Specifically, if Figures 1 to 3As shown, when the air slot 11 is opened at the outer edge of the punch body 1, its dimension extending circumferentially along the outer edge of the punch body 1 is L, and when the air slot 11 is opened inside the punch body 1, its circumference is L, L ≥ 0.2mm. Only when L ≥ 0.2mm, the performance of the air slot 11 in reducing the vibration noise of the magnetic field and reducing the torque pulsation of the motor rotor can be guaranteed.

[0081] Optionally, refer to Figure 4 The magnetic steel slot 12 includes a mounting portion 121 and an air gap portion 122 that are interconnected; the mounting portion 121 is used to mount the magnet 2.

[0082] Specifically, if Figure 4 As shown in FIG. 1 , the mounting portion 121 is in a bar shape and is used to load and fix the magnet 2. The air gap portion 122 is located at at least one end of the mounting portion 121 and is connected to the mounting portion 121. The air gap portion 122 is filled with air to remove the stress generated during the loading of the magnet 2 and reduce magnetic leakage.

[0083] Optionally, refer to Figure 4 , the air gap portion 122 is arc-shaped.

[0084] Specifically, if Figure 4 As shown in the figure, the air gap portion 122 is arc-shaped with a circular arc transition angle, which further reduces the stress and improves the stability of the rotor structure.

[0085] Optionally, the punching sheet body 1 is an amorphous alloy punching sheet.

[0086] Specifically, amorphous alloy materials have advantages such as low loss and good mechanical strength, but they also have the problem of low saturation magnetic flux density. Amorphous alloy materials include but are not limited to iron-based amorphous alloys, iron-nickel-based amorphous alloys and cobalt-based amorphous alloys. Fig.12 It can be seen that the magnetic permeability of amorphous alloy materials is close to that of air at around 1.5-1.6T compared to silicon steel, that is, its saturation magnetic flux density is very low. Above 0.8T, the magnetic permeability of amorphous materials begins to deteriorate significantly. At the same time, due to the decrease in its saturation magnetic flux density, amorphous alloy motors require a larger current at medium and high loads to compensate for the torque loss caused by the decrease in inductance. However, whether it is an amorphous alloy or silicon steel motor, the problem of local magnetic flux saturation can be solved by setting the volume of the magnet 2 on the front side of the rotor rotation direction to be larger than the volume of the magnet 2 on the rear side of the rotor rotation direction, thereby improving the reluctance torque and reducing the amount and cost of permanent magnets.

[0087] Optionally, refer to Fig.13 The thickness of the single punch body 1 is t, 0.01mm≤t≤0.03mm.

[0088] Specifically, in order to ensure the rotor structural strength and magnetic flux, the thickness of the punching sheet body 1 is controlled between 0.01 mm and 0.03 mm. In this embodiment, the thickness of a single punching sheet body 1 is set to 0.025 mm.

[0089] The present application also provides a rotor core, wherein a plurality of rotor punching sheets are stacked to form the rotor core, thereby increasing the output magnetic resistance torque of the motor and improving the output performance of the motor. When a single rotor core is provided with five punching sheet bodies 1, the total thickness of the single rotor core is between 0.05 mm and 0.15 mm.

[0090] The embodiment of the present application also provides a rotor, comprising a magnet 2 and the rotor core in the above embodiment, wherein the magnet 2 is connected to the punching sheet body 1. The vibration and noise problems caused by the change of the magnetic field can be reduced, and the torque pulsation of the motor rotor can be reduced.

[0091] Optionally, refer to Figure 4 The volume of the magnet 2 located in the first magnetic pole region A is greater than the volume of the magnet 2 located in the second magnetic pole region B.

[0092] Specifically, if Figure 4 As shown in the figure, the magnet 2 is connected to the punch body 1. The magnet 2 is a permanent magnet and can be attached to the outer periphery of the punch body 1, or embedded in the punch body 1. The latter is adopted in this embodiment. The volume of the magnet 2 located in the first magnetic pole region A on the front side of the rotor rotation direction is greater than the volume of the magnet 2 located in the second magnetic pole region B on the rear side of the rotor rotation direction. Figure 6 , the left picture shows a rotor structure in which magnets are symmetrically distributed in comparison with the related art.

[0093] During the operation of the motor, the torque is composed of permanent magnet torque and reluctance torque. When the motor is running at a high load, the magnetic permeability will decrease due to the increase in motor saturation, resulting in a decrease in output torque. Fig. 9 Taking the amorphous rotor as an example, the magnetic flux density distribution cloud diagram under high load is shown. In the figure, area I is the stator yoke, area II is the stator tooth, and area III is the narrow area of ​​the rotor interlayer magnetic steel. Fig.10 From the BH curve of the amorphous rotor, we can see that in the above three areas, area I, i.e. the stator yoke, belongs to the linear area on the left, and its local magnetic flux density is generally less than 1.4 T, while area II and area III, i.e. the narrow area between the stator teeth and the rotor layer, belong to the nonlinear area on the right, and its local magnetic flux density is generally greater than 1.4 T. Establish a magnetic circuit analytical model such as Fig.11As shown, the q-axis is shown by a dotted line, and the d-axis is shown by a solid line. In the rotor part, the focus of the d-axis magnetic field and the q-axis magnetic field is at the position of the black dot in the figure above, that is, the armature and the permanent magnetic field are superimposed, and the rotor's highest magnetic density point is located at the black dot in the magnetic circuit. In the related art, the magnets of the motor rotor are symmetrically distributed, that is, the first magnetic pole region A in the figure, that is, the magnetic steel on the front side of the rotation direction, is the same as the second magnetic pole region B, that is, the magnetic steel on the rear side of the rotation direction, and is symmetrically distributed about the d-axis. By moving the magnetic steel to the front pole region, that is, setting the volume of the magnet 2 on the front side of the rotor rotation direction to be larger than the volume of the magnet 2 on the rear side of the rotor rotation direction, the above-mentioned problem that the superposition point of the armature and the permanent magnetic field is located at the narrowest part of the rotor magnetic steel layer can be solved.

[0094] Therefore, by reducing some permanent magnets in the rear pole region, the permanent magnets on both sides of the d-axis are distributed asymmetrically, and the magnetic flux of the magnetic steel in the front pole region is large, and the magnetic flux in the rear pole region is small, that is, the saturation degree around the superposition point of the armature and the permanent magnetic field in the rear pole region can be reduced, thereby improving the magnetic circuit saturation of the q-axis, so that the magnetic flux of the q-axis is increased by 5%, and the highest saturation point is moved forward to Fig.11 At the middle gray point. Figure 7 As shown in the figure, by reducing the volume of the rear pole magnet, the air gap magnetic field, which was originally symmetrically distributed, also becomes asymmetrically distributed. Figure 8 The schematic diagram of the comparison between the magnetic flux density of a symmetrical rotor and the magnetic flux density of an asymmetrical rotor is shown. It can be seen from the figure that the local saturation area of ​​the rotor decreases, so when the motor is under high load operation, the reluctance torque will increase. By alleviating the saturation degree, the problem of the decrease in reluctance torque caused by local saturation is solved, and the utilization rate of the permanent magnet, that is, the torque and the quality of the permanent magnet, is improved, reducing the amount of rare earth used in the motor.

[0095] Therefore, in the asymmetrically distributed magnet structure, since the asymmetrical distribution of the air gap magnetic field is more significant, the role of setting asymmetrically distributed air slots is more obvious, which is used to weaken the asymmetrical distribution of the air gap magnetic field and reduce the vibration and noise problems caused by the magnetic field changes.

[0096] An embodiment of the present application also provides a motor, including the rotor in the above embodiment, to improve the motor efficiency and output performance.

[0097] The embodiment of the present application also provides a powertrain, including the motor of the above embodiment, which can improve the output performance of the powertrain.

[0098] An embodiment of the present application also provides a vehicle, comprising the motor or powertrain in the above embodiment, to improve the vehicle's power performance.

[0099] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0100] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A rotor punching, characterized in that: It comprises a punching sheet body (1); The punch body (1) is provided with an air groove (11); The punching sheet body has a first magnetic pole region (A) and a second magnetic pole region (B) with different magnetic field distributions, a central axis (d) is provided between the first magnetic pole region (A) and the second magnetic pole region (B), the air groove (11) is provided on only one side of the central axis (d), or the air grooves (11) on both sides of the central axis (d) are asymmetrically distributed about the central axis (d).

2. The rotor punching according to claim 1, characterized in that: Each of the first magnetic pole regions (A) and the corresponding second magnetic pole region (B) form a magnetic pole (a), each of the magnetic poles (a) is provided with an air slot (11), and the air slot (11) in at least one of the magnetic poles (a) is asymmetrically distributed about the central axis (d).

3. The rotor punching according to claim 1, characterized in that: The punching sheet body (1) is an amorphous alloy punching sheet.

4. The rotor punching according to claim 3, characterized in that: The arc length or area of ​​the air slot (11) located in the second magnetic pole region (B) is greater than the arc length or area of ​​the air slot (11) located in the first magnetic pole region (A).

5. The rotor punching according to claim 3, characterized in that: The air groove (11) is arranged at the outer edge of the punch body (1), or the air groove (11) is arranged inside the punch body (1) and penetrates along the thickness direction of the punch body (1).

6. The rotor punching according to claim 3, characterized in that: Part of the air groove (11) is arranged on the outer edge of the punch body (1), and part of the air groove (11) is arranged inside the punch body (1) and penetrates along the thickness direction of the punch body (1).

7. The rotor punching according to claim 3, characterized in that: A magnetic steel groove (12) is provided in the punching sheet body (1), and the magnetic steel groove (12) is used to install the magnet (2).

8. The rotor punching according to claim 7, characterized in that: The air groove (11) is in communication with the magnetic steel groove (12).

9. The rotor punching according to claim 7, characterized in that: The two magnetic steel slots (12) located in the first magnetic pole region (A) extend in different directions, and / or the two magnetic steel slots (12) located in the second magnetic pole region (B) extend in different directions.

10. The rotor punching according to claim 7, characterized in that: The air slot (11) is located in the second magnetic pole region (B) and is close to the magnetic steel slot (12).

11. The rotor punching according to claim 7, characterized in that: The air slot (11) is located between the magnetic steel slot (12) of the first magnetic pole region (A) and the magnetic steel slot (12) of the second magnetic pole region (B).

12. The rotor punching according to claim 3, characterized in that: The first magnetic pole region (A) and / or the second magnetic pole region (B) are in a sector shape, and the radial dimension of the air slot (11) along the sector shape is greater than the thickness of the punching sheet body (1).

13. The rotor punching according to claim 7, characterized in that: The distance between the two magnetic steel slots (12) located in the first magnetic pole region (A) is W1, and the distance between the two magnetic steel slots (12) located in the second magnetic pole region (B) is W2, W1>W2.

14. The rotor punching according to claim 4, characterized in that: The size of a single air groove (11) along the circumferential direction of the outer edge of the punch body (1), or the circumference of a single air groove (11) is L, and L is ≥ 0.2 mm.

15. The rotor punching according to claim 7, characterized in that: The magnetic steel slot (12) comprises a mounting portion (121) and an air gap portion (122) which are connected to each other; The mounting portion (121) is used to mount the magnet (2).

16. The rotor punching according to claim 15, characterized in that: The air gap portion (122) is arc-shaped.

17. The rotor punching according to any one of claims 1 to 16, characterized in that: The thickness of a single punching sheet body (1) is t, 0.01mm≤t≤0.03mm.

18. A rotor core, characterized in that: The invention comprises a plurality of rotor punching sheets according to any one of claims 1 to 17, wherein the plurality of rotor punching sheets are stacked.

19. A rotor, characterized in that: comprising a magnet (2) and the rotor core as claimed in claim 18; The magnet (2) is connected to the punching sheet body (1).

20. The rotor according to claim 19, characterized in that The volume of the magnet (2) located in the first magnetic pole region (A) is greater than the volume of the magnet (2) located in the second magnetic pole region (B).

21. A motor, characterized in that: Comprising the rotor as claimed in claim 20.

22. A powertrain, characterized in that: Including the motor as claimed in claim 21.

23. A vehicle, characterized in that: Includes the motor according to claim 21 or the powertrain according to claim 22.

Images