Rotor punching sheet, rotor core, rotor, motor, powertrain and vehicle

Abstract

The present application discloses a rotor punching sheet, a rotor core, a rotor, a motor, a powertrain and a vehicle. The rotor punching sheet is suitable for assembling to form a permanent magnet motor, and includes a punching sheet body. There are a first magnetic pole region and a second magnetic pole region with different magnetic field distributions on the punching sheet body. There is a central axis between the first magnetic pole region and the second magnetic pole region. Magnet steel grooves are respectively arranged in the first magnetic pole region and the second magnetic pole region. At least some of the magnet steel grooves in the first magnetic pole region and the magnet steel grooves in the second magnetic pole region are provided with a first magnetic resistance groove. A first magnetic isolation bridge is formed between the magnet steel groove and the corresponding first magnetic resistance groove. The first magnetic isolation bridge meets certain requirements in the direction perpendicular to the central axis. It can accurately control the size of the first magnetic isolation bridge according to the thickness of the punching sheet, the maximum magnetic flux density of the permanent magnet motor, and the magnetic flux density of the rotor core, so that it can control the conduction of magnetic flux in different motors, and also play a key supporting role to prevent the punching sheet from cracking or being damaged under mechanical stress.

Description

Technical Field

[0001] This application belongs to the technical field of motors, and particularly relates to a rotor punching sheet, a rotor core, a rotor, a motor, a power assembly and a vehicle. Background Art

[0002] Currently, most new energy-driven permanent magnet synchronous motors adopt an inner-inserted magnet structure, and the two magnetic poles of the rotor are connected by a magnetic isolation bridge.

[0003] When the rotational speed of the drive motor continues to increase, in order to ensure the reliable mechanical strength of the rotor during high-speed operation, the width of the magnetic isolation bridge needs to be as wide as possible. However, if the magnetic isolation bridge is too wide, it will cause a large amount of magnetic leakage in the motor, which will in turn trigger a series of problems, such as generating additional eddy current losses, increasing the motor temperature, affecting thermal stability and service life, reducing motor efficiency, causing more reactive power in the current, lowering the power factor, resulting in a decrease in motor magnetic flux and peak torque, reducing the starting torque and affecting the starting performance, and also generating uneven magnetic pulling force, causing additional vibration and noise during motor operation. Summary of the Invention

[0004] This application aims to provide a rotor punching sheet, which can solve the problem of increased magnetic leakage caused by the increase in the width of the magnetic isolation bridge in the related art.

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

[0006] In a first aspect, an embodiment of this application provides a rotor punching sheet suitable for assembling to form a permanent magnet motor, including a punching sheet body. The punching sheet body has a first magnetic pole region and a second magnetic pole region with different magnetic field distributions, and there is a central axis between the first magnetic pole region and the second magnetic pole region; magnetic steel grooves are respectively arranged in the first magnetic pole region and the second magnetic pole region, and at least part of the magnetic steel grooves in the first magnetic pole region and the magnetic steel grooves in the second magnetic pole region are provided with first magnetic resistance grooves, and a first magnetic isolation bridge is formed between the magnetic steel groove and the corresponding first magnetic resistance groove; along the direction perpendicular to the central axis, the minimum distance of the first magnetic isolation bridge is L1, and the L1 satisfies , where is the thickness of the punching sheet body, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0007] Optionally, at least two first magnetic resistance grooves are provided between at least part of the magnetic steel grooves in the first magnetic pole region and the magnetic steel grooves in the second magnetic pole region opposite along the central axis, and a second magnetic isolation bridge is formed between adjacent two first magnetic resistance grooves; along the direction perpendicular to the central axis, the minimum distance of the second magnetic isolation bridge is L2, and the L2 satisfies , where is the thickness of the punching sheet body, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0008] Optionally, at least one second magnetic flux blocking groove is provided between some adjacent first magnetic flux blocking grooves.

[0009] Optionally, a third magnetic isolation bridge is formed between the first magnetic flux blocking groove and the second magnetic flux blocking groove; along the direction perpendicular to the central axis, the minimum distance of the third magnetic isolation bridge is L3, and the L3 satisfies , where is the thickness of the punching sheet body, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0010] Optionally, at least two second magnetic flux blocking grooves are provided between the magnetic steel grooves in at least part of the first magnetic pole region and the magnetic steel grooves in the second magnetic pole region opposite along the central axis; a fourth magnetic isolation bridge is formed between two adjacent second magnetic flux blocking grooves; along the direction perpendicular to the central axis, the minimum distance of the fourth magnetic isolation bridge is L4, and the L4 satisfies , where is the thickness of the punching sheet body, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0011] Optionally, the width of the second magnetic flux blocking groove is L5; 1≤(L5) / L≤6, where, in the case of including the first magnetic isolation bridge and the third magnetic isolation bridge, L is the minimum value of the L1 and the L3; in the case of including the first magnetic isolation bridge, the third magnetic isolation bridge and the fourth magnetic isolation bridge, the L is the minimum value of the L1, the L3 and the L4; in the case of including the first magnetic isolation bridge, the second magnetic isolation bridge and the third magnetic isolation bridge, the L is the minimum value of the L1, the L2 and the L3; in the case of including the first magnetic isolation bridge, the second magnetic isolation bridge, the third magnetic isolation bridge and the fourth magnetic isolation bridge, the L is the minimum value of the L1, the L2, the L3 and the L4.

[0012] Optionally, the center line of any one of the first magnetic flux blocking grooves has an included angle θ1 with the central axis, and the center line of any one of the magnetic steel grooves has an included angle θ2 with the central axis; θ1 and θ2 satisfy: 10°≤|θ2 - θ1|≤70°.

[0013] Optionally, the shape of the first magnetic blocking groove includes one or more of a rounded rectangle and an arc shape.

[0014] Optionally, the shape of the first magnetic blocking groove includes a Y shape, and the first magnetic blocking grooves are arranged in sequence along the central axis.

[0015] Optionally, along the central axis, from the outer edge of the punching sheet body towards the inside of the punching sheet body, the width of the first magnetic blocking groove in the direction perpendicular to the central axis gradually increases.

[0016] Optionally, one of the first magnetic blocking grooves away from the outer edge of the punching sheet body is composed of a rectangular part and two outwardly extending arms, and the two outwardly extending arms are rounded rectangles and are symmetric along the central axis.

[0017] Optionally, the shape of the first magnetic blocking groove is composed of a strip-shaped part and two trumpet-shaped openings; the two trumpet-shaped openings are respectively arranged at both ends of the strip-shaped part; the opening of each trumpet-shaped opening faces the corresponding side of the magnetic steel groove.

[0018] Optionally, the punching sheet body is further provided with a second magnetic blocking groove, and the center line of the second magnetic blocking groove in the direction parallel to the central axis coincides with the central axis.

[0019] Optionally, the length of the first magnetic blocking groove in the direction parallel to the central axis is greater than or equal to the length of the end of the magnetic steel groove close to the first magnetic blocking groove in the direction parallel to the central axis; and / or, the length of the second magnetic blocking groove in the direction parallel to the central axis is greater than or equal to the length of the end of the magnetic steel groove close to the second magnetic blocking groove in the direction parallel to the central axis.

[0020] In a second aspect, an embodiment of the present application provides a rotor core, including the rotor punching sheet as described in any one of the above, and a plurality of the rotor punching sheets are stacked.

[0021] In a third aspect, an embodiment of the present application provides a rotor, including the above-mentioned rotor core.

[0022] In a fourth aspect, an embodiment of the present application provides a motor, including the above-mentioned rotor.

[0023] In a fifth aspect, an embodiment of the present application provides a powertrain, including the above-mentioned motor.

[0024] In a sixth aspect, an embodiment of the present application provides a vehicle, including the above-mentioned motor or the above-mentioned powertrain.

[0025] In the embodiment of the present application, for the first magnetic isolation bridge formed between the magnetic steel groove and the corresponding first magnetic blocking groove, the distance L1 satisfies , and the thickness of the punching sheet body The maximum magnetic flux density of the permanent magnet motor and the magnetic flux density of the rotor core in the permanent magnet motor are closely related. The size of the first magnetic isolation bridge can be accurately adjusted according to different factors such as the thickness of the punching sheet and the magnetic flux, so that it can control the conduction of magnetic flux under different motor operating conditions. When the motor is operating at high load and the magnetic flux demand increases, the first magnetic isolation bridge allows sufficient magnetic flux to pass through to meet the motor's torque demand; while under low load or special working conditions, it can limit the magnetic flux to prevent magnetic saturation and ensure the stable operation of the motor. The first magnetic isolation bridge not only regulates the magnetic flux in the magnetic circuit but also plays a key supporting role in the mechanical structure. During the high-speed rotation of the motor, the rotor punching sheet has to bear huge mechanical stresses such as centrifugal force. The first magnetic isolation bridge with a reasonable width can ensure the integrity and stability of the punching sheet structure, preventing the punching sheet from cracking or being damaged under mechanical stress due to the opening of the magnetic steel slot and the magnetic blocking slot.

[0026] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Brief Description of the Drawings

[0027] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0028] Figure 1 is a schematic diagram of a rotor punching sheet provided by an embodiment of the present application;

[0029] Figure 2 is Figure 1 a partial structural schematic diagram of the rotor punching sheet in

[0030] Figure 3 is a schematic diagram of the magnet arrangement of the rotor punching sheet provided by an embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the magnetic isolation bridge arrangement of the rotor punching sheet provided by an embodiment of the present application;

[0032] Figure 5 is a schematic diagram of the magnetic isolation bridge arrangement of the rotor punching sheet provided by an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of the first magnetic blocking slot arrangement of the rotor punching sheet provided by an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of the first magnetic blocking slot arrangement of the rotor punching sheet provided by an embodiment of the present application;

[0035] Figure 8It is the second schematic diagram of the magnetic resistance slot setting of the rotor punching sheet provided by the embodiment of the present application;

[0036] Figure 9 It is the third schematic diagram of the magnetic resistance slot setting of the rotor punching sheet provided by the embodiment of the present application;

[0037] Figure 10 It is the fourth schematic diagram of the magnetic resistance slot setting of the rotor punching sheet provided by the embodiment of the present application;

[0038] Figure 11 It is the fifth schematic diagram of the magnetic resistance slot setting of the rotor punching sheet provided by the embodiment of the present application.

[0039] Reference numerals:

[0040] Punching sheet body - 1, first magnetic pole region - 1a, second magnetic pole region - 1b, magnet slot - 11, first magnetic pole region magnet slot - 11a, second magnetic pole region magnet slot - 11b, mounting portion - 111, air gap portion - 112, first magnetic resistance slot - 12, first magnetic isolation bridge - 13, second magnetic isolation bridge - 14, second magnetic resistance slot - 15, third magnetic isolation bridge - 16, fourth magnetic isolation bridge - 17, third magnetic resistance slot - 18, magnet - 2. Detailed implementation manners

[0041] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present application and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0042] The terms "first" and "second" in the description and claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0044] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0045] The drive system and vehicle provided by the embodiments of the present application will be described in detail below with reference to the drawings through specific embodiments and their application scenarios.

[0046] See Figures 1 to 11 , the rotor punching sheet provided in some embodiments of the present application is suitable for assembling to form a permanent magnet motor, including a punching sheet body 1. There are a first magnetic pole region 1a and a second magnetic pole region 1b with different magnetic field distributions on the punching sheet body 1. There is a central axis d between the first magnetic pole region 1a and the second magnetic pole region 1b. Magnet steel grooves 11 are respectively arranged in the first magnetic pole region 1a and the second magnetic pole region 1b. A first magnetic resistance groove 12 is arranged between at least part of the magnet steel grooves 11 in the first magnetic pole region 1a and the magnet steel grooves 11 in the second magnetic pole region 1b. A first magnetic isolation bridge 13 is formed between the magnet steel groove 11 and the corresponding first magnetic resistance groove 12. Along the direction perpendicular to the central axis d, the minimum distance of the first magnetic isolation bridge 13 is L1, and L1 satisfies , where is the thickness of the punching sheet body 1, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0047] In the embodiments of the present application, the first magnetic pole region 1a and the second magnetic pole region 1b are specific regions on the rotor for installing magnets. The magnet steel groove 11 is a structure on the motor rotor punching sheet for installing magnets. The magnetic resistance groove is a groove with a specific shape and size on the motor rotor punching sheet. The magnetic isolation bridge refers to the connection structure between two magnetic poles of the permanent magnet motor rotor.

[0048] The rotor punching sheet provided by the embodiment of the present application has a punching sheet body 1 divided into a first magnetic pole region 1a and a second magnetic pole region 1b with different magnetic field distributions, and separated by the central axis d. During the operation of the permanent magnet motor, the magnetic fields in different regions cooperate orderly according to the operation requirements of the motor. For example, at the moment of motor startup, the magnetic field in a specific magnetic pole region takes the lead to make the rotor start rotating quickly; when entering the stable operation stage, the magnetic fields in each magnetic pole region cooperate to maintain the uniform rotation of the rotor.

[0049] The magnet slots 11 respectively arranged in the first magnetic pole region 1a and the second magnetic pole region 1b provide precise spaces for the placement of the magnets 2. The magnetic flux generated by the magnets 2 can participate in the electromagnetic conversion process of the motor in a more orderly and efficient manner under the constraint and guidance of the magnet slots 11, reducing the disorderly diffusion and loss of the magnetic flux, greatly improving the utilization efficiency of the magnetic flux, and thus enhancing the overall performance of the motor.

[0050] During the operation of the motor, without the magnetic flux blocking slots, some magnetic flux may deviate from the main magnetic path due to the slight inhomogeneity of the magnetic circuit, forming useless circulating currents inside the motor, which not only consume energy but also may interfere with the normal operation of the main magnetic field. The existence of the first magnetic flux blocking slot 12 greatly reduces the generation of such stray magnetic flux. The first magnetic flux blocking slot 12 arranged between the magnet slots 11 in at least part of the first magnetic pole region 1a and the magnet slots 11 in the second magnetic pole region 1b enables more magnetic flux to be concentrated in the main magnetic path, significantly improving the magnetic energy utilization rate of the motor and reducing unnecessary energy loss.

[0051] The minimum distance L1 of the first magnetic isolation bridge 13 formed between the magnet slot 11 and the corresponding first magnetic flux blocking slot 12 satisfies and is closely related to the thickness of the punching sheet body 1, the maximum magnetic flux density of the permanent magnet motor, and the magnetic flux density of the rotor core in the permanent magnet motor. The size of the first magnetic isolation bridge 13 can be precisely adjusted to control the conduction of the magnetic flux under different motor operating conditions. When the motor is operating at high load and the magnetic flux demand increases, the first magnetic isolation bridge 13 allows enough magnetic flux to pass through to meet the torque demand of the motor; while under low load or special working conditions, it can limit the magnetic flux to prevent magnetic saturation from occurring and ensure the stable operation of the motor.

[0052] The first magnetic isolation bridge 13 can not only regulate the magnetic flux in the magnetic circuit but also play a key supporting role in the mechanical structure. During the high-speed rotation of the motor, the rotor punching sheet has to bear huge mechanical stresses such as centrifugal force. The first magnetic isolation bridge 13 with a reasonable width can ensure the integrity and stability of the punching sheet structure, preventing the punching sheet from cracking or being damaged under the action of mechanical stresses due to the opening of the magnet slots 11 and the magnetic flux blocking slots. While ensuring the magnetic performance, it extends the service life of the motor and improves the reliability of the motor operation.

[0053] Optionally, referring to Figure 4 , Figure 5 and Figure 8 , at least two first magnetic flux blocking grooves 12 are provided between the magnetic steel grooves 11 in at least a part of the first magnetic pole region 1a and the magnetic steel grooves 11 in the second magnetic pole region 1b opposite along the central axis d, and a second magnetic isolation bridge 14 is formed between two adjacent first magnetic flux blocking grooves 12; along the direction perpendicular to the central axis d, the minimum distance of the second magnetic isolation bridge 14 is L2, and L2 satisfies , where is the thickness of the punching sheet body 1, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0054] In the embodiment of the present application, the rotor includes multiple layers of magnetic steel grooves. Two magnetic steel grooves 11 opposite along the central axis d are magnetic steel grooves of the same layer. For example, Figure 5 the magnetic steel groove 11a of the first magnetic pole region and the magnetic steel groove 11b of the second magnetic pole region opposite along the central axis d shown in

[0055] are a set of magnetic steel grooves oppositely arranged along the central axis d, and at least two first magnetic flux blocking grooves 12 are provided between them.

[0056] The arrangement of multiple first magnetic flux blocking grooves 12 can more effectively block the leakage of magnetic flux between different magnetic pole regions compared with a single magnetic flux blocking groove. The magnetic flux between adjacent magnetic steel grooves 11 is divided and blocked by multiple magnetic flux blocking grooves, making it more difficult for the magnetic flux to form a stray path, thereby further improving the concentration and utilization rate of the magnetic field, reducing magnetic loss, and helping to improve the efficiency and performance of the motor. The presence of the second magnetic isolation bridge 14 and the design of its minimum distance L2 can more finely adjust the magnetic flux between different magnetic pole regions. By making L2 satisfy the relationship with the thickness of the punching sheet body 1 , the conduction of magnetic flux can be precisely controlled according to the specific operating conditions and performance requirements of the motor, making the magnetic field distribution more reasonable and optimized. For example, under different load conditions of the motor, the magnetic field strength of different magnetic pole regions can be better balanced to ensure stable torque output of the motor.

[0057] The setting of multiple first magnetic flux blocking grooves 12 and the second magnetic isolation bridge 14 increases the structural complexity of the punching sheet to a certain extent, but also makes the structure of the punching sheet more stable. The second magnetic isolation bridge 14 plays an auxiliary role in bearing mechanical stress, and works together with the first magnetic isolation bridge 13 to improve the structural strength and stability of the rotor punching sheet during the high-speed rotation of the motor, reduce the risk of punching sheet damage caused by factors such as centrifugal force, and extend the service life of the motor.

[0058] Optionally, referring to Figures 2 to 8 , at least one second magnetic flux blocking groove 15 is provided between some adjacent first magnetic flux blocking grooves 12.

[0059] In the embodiment of the present application, the addition of the second magnetic flux blocking groove 15 further increases the obstruction to magnetic flux leakage. By arranging the second magnetic flux blocking groove 15 between adjacent first magnetic flux blocking grooves 12, it becomes more difficult for magnetic flux to penetrate these areas, thereby more effectively preventing the generation of stray magnetic flux, improving the purity and utilization rate of the motor magnetic field, and contributing to the improvement of the motor efficiency and performance.

[0060] The second magnetic flux blocking groove 15 helps to optimize the uniformity of the magnetic circuit inside the motor. Due to the uneven distribution of the magnetic field inside the motor, by arranging the second magnetic flux blocking groove 15 between adjacent first magnetic flux blocking grooves 12, the local magnetic field can be finely adjusted, making the magnetic flux distribution in the magnetic circuit more uniform, reducing problems such as local overheating and torque fluctuation caused by magnetic field non-uniformity, and improving the overall performance and operation quality of the motor.

[0061] Optionally, referring to Figure 4 , Figure 8 , Figure 11 , a third magnetic flux isolating bridge 16 is formed between the first magnetic flux blocking groove 12 and the second magnetic flux blocking groove 15; along the direction perpendicular to the central axis d, the minimum distance of the third magnetic flux isolating bridge 16 is L3, and L3 satisfies , where is the thickness of the punching sheet body 1, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0062] In the embodiment of the present application, the existence of the third magnetic flux isolating bridge 16 and the precise design of L3 can more accurately control the path of magnetic flux. By making L2 satisfy the relationship with the thickness of the punching sheet body 1 , the maximum magnetic flux density of the permanent magnet motor and the magnetic flux density of the rotor core in the permanent magnet motor as defined by , it can ensure that under different motor operating conditions, the magnetic flux is conducted along the designed path, reducing the disorder and leakage of magnetic flux, improving the controllability of the magnetic field, and thus enhancing the performance and efficiency of the motor.

[0063] The third magnetic flux isolating bridge 16 further enhances the magnetic flux isolation ability. It forms an additional magnetic flux isolation area between the first magnetic flux blocking groove 12 and the second magnetic flux blocking groove 15, and together with the first magnetic flux isolating bridge 13 and the second magnetic flux isolating bridge 14, forms a more perfect magnetic flux isolation system, effectively preventing the magnetic flux between different magnetic pole regions from interfering with each other, making the magnetic field distribution clearer and more stable, and contributing to the improvement of the power factor and torque output of the motor.

[0064] The third magnetic isolation bridge 16 increases the structural strength of the punching sheet to a certain extent. During the operation of the motor, especially at high speeds of rotation, the punching sheet needs to withstand large centrifugal and electromagnetic forces. The presence of the third magnetic isolation bridge 16 can disperse these forces, improve the overall structural stability of the punching sheet, reduce the possibility of deformation or damage of the punching sheet, thereby extending the service life of the motor and improving the reliability of motor operation.

[0065] Optionally, referring to Figure 4 , at least two second magnetic flux blocking grooves 15 are provided between the magnetic steel grooves 11 in at least part of the first magnetic pole region 1a and the magnetic steel grooves 11 in the second magnetic pole region 1b opposite along the central axis d, and a fourth magnetic isolation bridge 17 is formed between two adjacent second magnetic flux blocking grooves 15; a fourth magnetic isolation bridge 17 is formed between two adjacent second magnetic flux blocking grooves 15; along the direction perpendicular to the central axis d, the minimum distance of the fourth magnetic isolation bridge 17 is L4, and L4 satisfies , where is the thickness of the punching sheet body 1, is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

[0066] In the embodiments of the present application, the added second magnetic flux blocking grooves 15 and the fourth magnetic isolation bridge 17 further refine the control of the magnetic field. The multiple second magnetic flux blocking grooves 15 can more precisely block and guide the magnetic flux, making the magnetic field distribution more uniform and regular, and reducing the leakage and distortion of the magnetic flux. Through the precise design of L4, the magnetic flux between different magnetic pole regions is adjusted more precisely, the magnetic field pattern is optimized, and the performance and efficiency of the motor are improved.

[0067] The fourth magnetic isolation bridge 17 between two adjacent second magnetic flux blocking grooves 15 works together with other magnetic isolation bridges (such as the first magnetic isolation bridge 13, the second magnetic isolation bridge 14, and the third magnetic isolation bridge 16) to form a more complex and effective magnetic flux blocking structure. This structure can more effectively prevent the "short circuit" of the magnetic flux between different magnetic pole regions, further improve the magnetic isolation effect of the motor, reduce the magnetic loss, and contribute to improving the operation efficiency and stability of the motor under different working conditions.

[0068] The presence of the fourth magnetic isolation bridge 17 increases the complexity and integrity of the punching sheet structure, which helps to improve the structural stability of the punching sheet during the operation of the motor. When the motor rotates at high speed, it can withstand a certain centrifugal force and electromagnetic force, and together with other magnetic isolation bridges and magnetic flux blocking grooves, it jointly ensures the structural integrity of the punching sheet, further reducing the risk of deformation or damage of the punching sheet, thereby extending the service life of the motor and improving the reliability of the motor.

[0069] Optionally, referring to Figure 4 、 Figure 7 and Figure 9, the width of the second magnetic blocking groove 15 is L5; 1 ≤ (L5) / L ≤ 6, where, in the case of including the first magnetic isolation bridge 13 and the third magnetic isolation bridge 16, L is the minimum value of L1 and L3; in the case of including the first magnetic isolation bridge 13, the third magnetic isolation bridge 16 and the fourth magnetic isolation bridge 17, L is the minimum value of L1, L3 and L4; in the case of including the first magnetic isolation bridge 13, the second magnetic isolation bridge 14 and the third magnetic isolation bridge 16, L is the minimum value of L1, L2 and L3; in the case of including the first magnetic isolation bridge 13, the second magnetic isolation bridge 14, the third magnetic isolation bridge 16 and the fourth magnetic isolation bridge 17, L is the minimum value of L1, L2, L3 and L4.

[0070] In the embodiment of the present application, when (L5) / L is in the range of 1 to 6, the magnetic blocking ability of the second magnetic blocking groove 15 and the magnetic conduction ability of the magnetic isolation bridge can reach a better balance. If (L5) / L is too small, the width of the second magnetic blocking groove 15 is too narrow relative to the magnetic isolation bridge, and the magnetic blocking effect is not obvious. A large amount of magnetic flux may leak, affecting the magnetic field distribution and efficiency of the motor; if (L5) is too large, the second magnetic blocking groove 15 is too wide, which may overly block the magnetic path, resulting in insufficient magnetic flux and a decrease in the torque output and performance of the motor. By reasonably controlling this ratio, it can ensure that the magnetic circuit of the motor not only has good magnetic isolation performance but also can ensure sufficient magnetic flux conduction, optimizing the overall magnetic circuit performance of the motor.

[0071] The reasonable combination of the width of the second magnetic blocking groove 15 and the minimum distance of the magnetic isolation bridge can make the magnetic flux more evenly distributed between different magnetic pole regions, reducing the distortion and non-uniformity of the local magnetic field. It can improve the torque stability of the motor, reduce torque ripple, and reduce the vibration and noise during motor operation.

[0072] The size design of the magnetic isolation bridge and the magnetic blocking groove not only affects the magnetic circuit performance but is also closely related to the structural strength of the punching sheet. If the width of the second magnetic blocking groove 15 is too large ((L5) / L > 6), it will weaken the overall structural strength of the punching sheet. When the motor rotates at high speed, the punching sheet may be deformed or even damaged due to the inability to withstand the centrifugal force and electromagnetic force; if the width of the second magnetic blocking groove 15 is too small ((L5) / L < 1), although the structural strength may be guaranteed, the magnetic circuit performance will be affected. Controlling L5 / L within the range of 1 to 6 can maintain the structural integrity of the punching sheet while ensuring the magnetic circuit performance, enabling the punching sheet to withstand various mechanical loads during the operation of the motor and extending the service life of the motor.

[0073] It can be understood that L1 is the distance of any first magnetic isolation bridge 13 on the punching sheet body; L2 is the distance of any second magnetic isolation bridge 14 on the punching sheet body; L3 is the distance of any third magnetic isolation bridge 16 on the punching sheet body; L4 is the distance of any fourth magnetic isolation bridge 17 on the punching sheet body.

[0074] Meanwhile, restricting the ratio of the width of the second magnetic blocking groove 15 to the minimum distance of the magnetic isolation bridge within a certain range is beneficial to simplifying the manufacturing process of the motor punching sheet. In actual production, a reasonable dimensional ratio can make the processing of the punching sheet more convenient, reduce the processing difficulty and errors, and improve the production efficiency and product quality. For example, in the blanking process, a suitable dimensional ratio can make the design and manufacturing of the die simpler, reduce the die cost and the scrap rate during the blanking process. By optimizing the ratio of the width of the second magnetic blocking groove 15 to the minimum distance of the magnetic isolation bridge, materials can be reasonably utilized and the material cost can be reduced on the premise of ensuring the motor performance. It can avoid wasting materials due to the excessive width of the second magnetic blocking groove 15, and at the same time prevent the need to use higher-performance (usually more expensive) materials to make up for the unqualified motor performance caused by the too small width. In this way, while meeting the motor performance requirements, the cost can be effectively controlled and the market competitiveness of the product can be improved.

[0075] Optionally, referring to Figures 5 to 6 , the center line of any first magnetic blocking groove 12 and the central axis d have an included angle θ1, and the center line of any magnet groove 11 and the central axis d have an included angle θ2; θ1 and θ2 satisfy: 10° ≤ |θ2 - θ1| ≤ 70°.

[0076] In the embodiment of the present application, when the first magnetic blocking groove 12 is a rounded rectangle, the center line is the axis of symmetry along the length direction of the rounded rectangle; when the first magnetic blocking groove 12 is an arc, the center line is the tangent line at the central position of the inner end of the arc groove close to the punching sheet body 1.

[0077] By limiting the included angle difference, the relative positions of the first magnetic blocking groove 12 and the magnet groove 11 are made more reasonable, which can effectively guide and restrict the magnetic flux direction, reduce magnetic flux leakage and distortion, make the magnetic field distribution more uniform, and thus improve the performance and efficiency of the motor. In a permanent magnet motor, the air-gap magnetic field can be made closer to a sine distribution, reduce the harmonic content, and improve the power factor and torque output of the motor.

[0078] A suitable included angle difference helps to optimize the torque characteristics of the motor. It can make the magnetic field generated by the magnet 2 interact better with the magnetic field generated by the stator winding, improve the torque coefficient, increase the output torque of the motor, and at the same time reduce the torque ripple, making the motor operate more smoothly. Applying this kind of motor in an electric vehicle can improve the acceleration performance and driving stability of the vehicle.

[0079] Optionally, referring to Figures 2 to 8 , the shape of the first magnetic blocking groove 12 includes one or more of a rounded rectangle and an arc.

[0080] In the embodiment of the present application, the first magnetic resistance grooves 12 in the shape of rounded rectangles and arcs can make the magnetic flux smoothly transition at the edges of the grooves, avoiding the magnetic flux concentration phenomenon that may be caused by right-angled shapes. The first magnetic resistance grooves 12 in the shape of rounded rectangles and arcs can avoid the stress concentration problem caused by sharp corners. During the operation of the motor, it is affected by various forces such as electromagnetic force and thermal stress. The grooves in the shape of right angles are prone to stress concentration at the corners, resulting in cracks or even fractures in the punching sheet. By using rounded or arc shapes, the stress can be evenly distributed around the grooves, improving the structural strength and reliability of the punching sheet.

[0081] In addition, the rounded rectangles and arcs are relatively regular, and in the manufacturing process of the punching sheet, whether it is stamping, etching or other processing techniques, they are easier to implement, which can reduce the processing difficulty and cost.

[0082] Optionally, referring to Figure 9 , the shape of the first magnetic resistance groove 12 includes a Y shape, and the first magnetic resistance grooves 12 are arranged in sequence along the central axis d.

[0083] In the embodiment of the present application, the first magnetic resistance grooves 12 in the Y shape increase the contact area and path length between the magnetic resistance grooves and the magnetic flux, can more effectively block the leakage of the magnetic flux, guide the magnetic flux to be distributed according to the designed path, reduce the magnetic leakage phenomenon, thereby improving the magnetic utilization rate and efficiency of the motor.

[0084] The Y-shaped first magnetic resistance grooves 12 arranged in sequence along the central axis d can symmetrically adjust and optimize the magnetic field. It helps to make the air-gap magnetic field of the motor more uniform and improve the electromagnetic performance of the motor. By enhancing the magnetic resistance effect and optimizing the magnetic field distribution, the motor can achieve a higher power output under the same volume and weight, thereby improving the power density of the motor.

[0085] In addition, the first magnetic resistance grooves 12 in the Y shape also increase the heat dissipation area of the punching sheet to a certain extent. The motor generates heat during operation, and good heat dissipation performance helps to reduce the temperature of the motor, improve the efficiency and service life of the motor. The arrangement in sequence along the central axis d is also beneficial to the uniform distribution of heat in the punching sheet, avoiding the occurrence of local overheating.

[0086] Optionally, referring to Figure 9 , along the central axis d, from the outer edge of the punching sheet body 1 to the inside of the punching sheet body 1, the width of the first magnetic resistance groove 12 in the direction perpendicular to the central axis d gradually becomes larger.

[0087] In the embodiments of the present application, since the magnetic field strength near the outer edge of the punching sheet in the motor is relatively weak, while the magnetic field strength near the interior is relatively strong. Therefore, designing the first magnetic flux blocking groove 12 with a gradually increasing width from the outer edge to the interior can more reasonably adjust the magnetic flux blocking effect according to the change of the magnetic field strength. At the outer edge where the magnetic field is weak, a relatively small width of the magnetic flux blocking groove can meet a certain magnetic flux blocking requirement, while at the interior where the magnetic field is strong, by increasing the width of the magnetic flux blocking groove, the magnetic flux can be effectively blocked, making the magnetic field distribution more uniform. This gradually changing width design can better fit the distribution curve of the magnetic flux inside the motor, reduce the leakage of the magnetic flux from the outer edge of the punching sheet body 1 to the interior, improve the controllability of the magnetic circuit, and enable more magnetic flux to interact with the stator winding through the air gap according to the designed path, thereby enhancing the electromagnetic performance of the motor.

[0088] The first magnetic flux blocking groove 12 with a gradually changing width helps to relieve the stress concentration problem during the manufacturing and operation of the punching sheet. During the stamping process of the punching sheet, the deformation degrees of the outer edge and the interior are different. The gradually changing groove width design can make the stress distribution inside the punching sheet more uniform, reducing the cracking or deformation of the punching sheet caused by stress concentration. During the operation of the motor, it can also better withstand the action of electromagnetic force and mechanical force, improving the mechanical strength and stability of the punching sheet.

[0089] Optionally, referring to Figure 9 , one first magnetic flux blocking groove 12 far from the outer edge of the punching sheet body 1 is composed of a rectangular part and two outwardly extending arms, and the two outwardly extending arms are rounded rectangles and are symmetric along the central axis d.

[0090] In the embodiments of the present application, when the first magnetic flux blocking groove 12 is composed of a rectangular part and two outwardly extending arms, the center line of the first magnetic flux blocking groove 12 is the center line of one of the outwardly extending arms.

[0091] The rectangular part of the first magnetic flux blocking groove 12 can block and guide the magnetic flux in the main direction, while the two outwardly extending rounded rectangular arms can more finely control the direction of the magnetic flux. Since they are symmetric along the central axis d, the magnetic field can be made more symmetric and uniform in this area, reducing the distortion and local concentration of the magnetic flux, which helps to improve the sinusoidality of the air gap magnetic field of the motor, thereby improving the electromagnetic performance of the motor. The rounded rectangular arms can effectively expand the magnetic flux blocking range, more flexibly control the magnetic flux at the edge, prevent the abnormal leakage or diffusion of the magnetic flux at the edge, and improve the utilization rate and controllability of the magnetic field.

[0092] Optionally, referring to Figure 10 , the shape of the first magnetic flux blocking groove 12 is composed of a strip part and two trumpet-shaped openings; the two trumpet-shaped openings are respectively arranged at both ends of the strip part; the opening of each trumpet-shaped opening faces the corresponding side magnetic steel groove 11.

[0093] In the embodiment of the present application, when the first magnetic flux blocking groove 12 is composed of a strip-shaped part and two horn-shaped openings, the center line of the first magnetic flux blocking groove 12 is the center line of one of the arms on one side of one of the horn-shaped openings.

[0094] The rectangular part of the first magnetic flux blocking groove 12 can effectively block and guide the magnetic flux in the main area, while the four rounded rectangular arms extending outward from the four corners of the rectangle can finely regulate the magnetic flux in multiple directions. This structure is symmetric along the central axis d, which can make the magnetic field more evenly and symmetrically distributed in the punching sheet, greatly reducing the distortion and local concentration of the magnetic flux, making the air-gap magnetic field of the motor closer to the ideal sinusoidal distribution, and thus effectively improving the electromagnetic performance of the motor. The four rounded rectangular arms can expand the magnetic flux blocking range, form a denser magnetic flux blocking network in a specific area of the punching sheet, create a stronger obstruction to the leakage of the magnetic flux, effectively constrain the magnetic flux to propagate within the designed path, improve the utilization rate of the magnetic field, enable the magnetic flux generated by the magnet 2 to interact with the stator winding more efficiently, and enhance the power factor and efficiency of the motor.

[0095] Although the structure of the first magnetic flux blocking groove 12 with this shape seems complex, it is relatively regular as a whole. In the manufacturing of the punching sheet, whether it is stamping, etching or other forming processes, it has certain regularity and is convenient for processing operations. The die design and manufacturing are relatively easy, which can reduce the processing difficulty and cost.

[0096] Optionally, referring to Figure 10 , along the central axis d, from the outer edge of the punching sheet body 1 towards the inside of the punching sheet body 1, the width of the first magnetic flux blocking groove 12 in the direction perpendicular to the central axis d gradually increases, and the length of the first magnetic flux blocking groove 12 in the direction parallel to the central axis d also gradually increases. Among them, for the layer of magnetic steel grooves 11 close to the outer edge of the punching sheet body 1, the magnetic steel grooves 11 in the first magnetic pole region 1a and the magnetic steel grooves 11 in the second magnetic pole region 1b are connected as one magnetic steel groove; for the second layer of magnetic steel grooves 11 close to the outer edge of the punching sheet body 1, no first magnetic flux blocking groove 12 is provided between the magnetic steel grooves 11 in the first magnetic pole region 1a and the magnetic steel grooves 11 in the second magnetic pole region 1b.

[0097] In the embodiments of the present application, since the magnetic field strength near the outer edge of the punching sheet in the motor is relatively weak, while the magnetic field strength near the inside is strong. Therefore, no first magnetic flux blocking groove 12 is provided at the edge, and the number of first magnetic flux blocking grooves 12 gradually increases from the outer edge to the inside, and the width in the direction perpendicular to the central axis d gradually becomes larger, which can enable the punching sheet body 1 to more reasonably adjust the magnetic flux blocking effect according to the change of the magnetic field strength. At the outer edge where the magnetic field is weak, a relatively small width of the magnetic flux blocking groove can meet a certain magnetic flux blocking requirement, while at the inside where the magnetic field is strong, by increasing the width of the magnetic flux blocking groove, the magnetic flux can be effectively blocked, making the magnetic field distribution more uniform. This gradually changing width design can better fit the distribution curve of the magnetic flux inside the motor, reduce the leakage of the magnetic flux from the outer edge to the inside of the punching sheet body 1, improve the controllability of the magnetic circuit, and allow more magnetic flux to interact with the stator winding through the air gap along the designed path, thereby enhancing the electromagnetic performance of the motor.

[0098] The first magnetic flux blocking groove 12 with both the width and length gradually changing helps to relieve the stress concentration problem during the manufacturing and operation of the punching sheet. During the stamping process of the punching sheet, the deformation degrees of the outer edge and the inside are different. The gradually changing groove width and groove length design can make the stress distribution inside the punching sheet more uniform, reducing the cracking or deformation of the punching sheet caused by stress concentration. When the motor is running, it can also better withstand the action of electromagnetic force and mechanical force, improving the mechanical strength and stability of the punching sheet.

[0099] Optionally, referring to Figure 10 , the punching sheet body 1 is further provided with a second magnetic flux blocking groove 15, and the center line of the second magnetic flux blocking groove 15 in the direction parallel to the central axis d coincides with the central axis d.

[0100] In the embodiments of the present application, since the center line of the second magnetic flux blocking groove 15 coincides with the central axis d, it can accurately constrain and guide the magnetic flux in the axial direction of the punching sheet, prevent the excessive leakage or diffusion of the magnetic flux along the central axis d direction, make the magnetic flux more concentrated in the required area, improve the utilization efficiency of the magnetic field, optimize the magnetic field distribution inside the motor, and further enhance the performance of the motor. At the same time, it helps to further enhance the magnetic field symmetry of the punching sheet with respect to the central axis d, making the magnetic field more uniformly distributed in the axial direction during the operation of the motor, reducing the electromagnetic force imbalance caused by magnetic field asymmetry, and improving the stability and reliability of the motor operation.

[0101] Optionally, referring to Figures 2 to 11 , the length of the first magnetic flux blocking groove 12 in the direction parallel to the central axis d is greater than or equal to the length of the end of the magnet groove 11 close to the first magnetic flux blocking groove 12 in the direction parallel to the central axis d; and / or, the length of the second magnetic flux blocking groove 15 in the direction parallel to the central axis d is greater than or equal to the length of the end of the magnet groove 11 close to the second magnetic flux blocking groove 15 in the direction parallel to the central axis d.

[0102] In the embodiments of the present application, when the length of the first magnetic flux blocking groove 12 along the direction parallel to the central axis d is greater than or equal to the corresponding length of the magnet groove 11 near the first magnetic flux blocking groove 12, the first magnetic flux blocking groove 12 can more fully block the magnetic flux emitted from the magnet groove 11, so that it is distributed according to the designed magnetic path direction, reducing the leakage of magnetic flux and stray magnetic fields.

[0103] The same is true for the second magnetic flux blocking groove 15. When the length along the direction parallel to the central axis d is greater than or equal to the corresponding length of the magnet groove 11 near the second magnetic flux blocking groove 15, it can effectively block the magnetic flux at one end of the magnet groove 11 near it, avoiding the diffusion of magnetic flux in unnecessary areas, thereby optimizing the magnetic path distribution of the entire motor and improving the utilization efficiency of magnetic energy.

[0104] The embodiments of the present application also provide a rotor core. A plurality of the above-mentioned rotor punching sheets are stacked to form a rotor core, reducing magnetic field distortion and magnetic leakage phenomena, improving the magnetic utilization rate of the motor, and enhancing the electromagnetic torque output ability of the motor.

[0105] The embodiments of the present application also provide a rotor, including a magnet 2 and the rotor core in the above embodiments. The magnet 2 is connected to the punching sheet body 1, which can reduce magnetic leakage and improve magnetic utilization rate.

[0106] The embodiments of the present application also provide a motor, including the rotor in the above embodiments, which can improve the efficiency of the motor.

[0107] The embodiments of the present application also provide a powertrain, including the motor in the above embodiments, which can improve the output performance of the powertrain.

[0108] The embodiments of the present application also provide a vehicle, including the motor or powertrain in the above embodiments, which can improve the power performance of the vehicle.

[0109] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means 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 application. 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.

[0110] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A rotor punching sheet, suitable for being assembled to form a permanent magnet motor, characterized in that, It includes a punching sheet body (1), on which there are a first magnetic pole region (1a) and a second magnetic pole region (1b) with different magnetic field distributions, and there is a central axis (d) between the first magnetic pole region (1a) and the second magnetic pole region (1b); Magnet slots (11) are respectively arranged in the first magnetic pole region (1a) and the second magnetic pole region (1b), and a first magnetic resistance slot (12) is arranged between at least part of the magnet slots (11) in the first magnetic pole region (1a) and the magnet slots (11) in the second magnetic pole region (1b), and a first magnetic isolation bridge (13) is formed between the magnet slot (11) and the corresponding first magnetic resistance slot (12); In the direction perpendicular to the central axis (d), the minimum distance of the first magnetic isolation bridge (13) is L1, and L1 satisfies , where is the thickness of the punching sheet body (1), is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

2. The rotor punching sheet according to claim 1, wherein At least two of the first magnetic resistance slots (12) are arranged between at least part of the magnet slots (11) in the first magnetic pole region (1a) and the magnet slots (11) in the second magnetic pole region (1b) opposite along the central axis (d), and a second magnetic isolation bridge (14) is formed between two adjacent first magnetic resistance slots (12); In a direction perpendicular to the central axis (d), the minimum distance of the second magnetic isolation bridge (14) is L2, and L2 satisfies , where is the thickness of the punching sheet body (1), is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

3. The rotor punching sheet according to claim 2, characterized in that, At least one second magnetic resistance slot (15) is arranged between some adjacent first magnetic resistance slots (12).

4. The rotor punching sheet according to claim 3, wherein, A third magnetic isolation bridge (16) is formed between the first magnetic resistance slot (12) and the second magnetic resistance slot (15); In a direction perpendicular to the central axis (d), the minimum distance of the third magnetic isolation bridge (16) is L3, and L3 satisfies , where is the thickness of the punching sheet body (1), is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

5. The rotor punching sheet according to claim 4, characterized in that, At least two of the second magnetic resistance slots (15) are arranged between at least part of the magnet slots (11) in the first magnetic pole region (1a) and the magnet slots (11) in the second magnetic pole region (1b) opposite along the central axis (d), and a fourth magnetic isolation bridge (17) is formed between two adjacent second magnetic resistance slots (15); A fourth magnetic isolation bridge (17) is formed between two adjacent second magnetic resistance slots (15); In a direction perpendicular to the central axis (d), the minimum distance of the fourth magnetic isolation bridge (17) is L4, and L4 satisfies , where is the thickness of the punching sheet body (1), is the maximum magnetic flux density of the permanent magnet motor, is the magnetic flux density of the rotor core in the permanent magnet motor.

6. The rotor punching sheet according to claim 5, characterized in that, The width of the second magnetic resistance slot (15) is L5; 1≤(L5) / L≤6, where, when including the first magnetic isolation bridge (13) and the third magnetic isolation bridge (16), L is the minimum value of L1 and L3; When including the first magnetic isolation bridge (13), the third magnetic isolation bridge (16) and the fourth magnetic isolation bridge (17), L is the minimum value of L1, L3 and L4; When including the first magnetic isolation bridge (13), the second magnetic isolation bridge (14) and the third magnetic isolation bridge (16), L is the minimum value of L1, L2 and L3; When including the first magnetic isolation bridge (13), the second magnetic isolation bridge (14), the third magnetic isolation bridge (16) and the fourth magnetic isolation bridge (17), L is the minimum value of L1, L2, L3 and L4.

7. The rotor punching sheet according to claim 1, wherein, The center line of any one of the first magnetic resistance slots (12) has an included angle θ1 with the central axis (d), and the center line of any one of the magnet slots (11) has an included angle θ2 with the central axis (d); θ1 and θ2 satisfy: 10°≤|θ2 - θ1|≤70°.

8. The rotor punching sheet according to claim 1, wherein, The shape of the first magnetic resistance slot (12) includes one or more of a rounded rectangle and an arc shape.

9. The rotor punching sheet according to claim 1, wherein The shape of the first magnetic resistance slot (12) includes a Y shape, and the first magnetic resistance slots (12) are arranged in sequence along the central axis (d).

10. The rotor punching sheet according to claim 9, wherein Along the central axis (d), from the outer edge of the punching sheet body (1) towards the inside of the punching sheet body (1), the width of the first magnetic resistance groove (12) in the direction perpendicular to the central axis (d) gradually increases.

11. The rotor punching sheet according to claim 10, characterized in that, One of the first magnetic resistance grooves (12) far from the outer edge of the punching sheet body (1) consists of a rectangular part and two outwardly extending arms. The two outwardly extending arms are rounded rectangles and are symmetrical along the central axis (d).

12. The rotor punching sheet according to claim 1, characterized in that, The shape of the first magnetic resistance groove (12) consists of a strip part and two trumpet-shaped opening parts; The two trumpet-shaped opening parts are respectively arranged at both ends of the strip part; The opening of each trumpet-shaped opening part faces the corresponding magnetic steel groove (11).

13. The rotor punching sheet according to claim 11 or 12, characterized in that, The punching sheet body (1) is further provided with a third magnetic resistance groove (18). The center line of the third magnetic resistance groove (18) in the direction parallel to the central axis (d) coincides with the central axis (d).

14. The rotor punching sheet according to claim 3, characterized in that, The length of the first magnetic resistance groove (12) in the direction parallel to the central axis (d) is greater than or equal to the length of the end of the magnetic steel groove (11) close to the first magnetic resistance groove (12) in the direction parallel to the central axis (d); and / or, The length of the second magnetic resistance groove (15) in the direction parallel to the central axis (d) is greater than or equal to the length of the end of the magnetic steel groove (11) close to the second magnetic resistance groove (15) in the direction parallel to the central axis (d).

15. A rotor core, characterized in that, Comprising a plurality of rotor punching sheets according to any one of claims 1 to 14, and the plurality of rotor punching sheets are stacked.

16. A rotor, characterized in that, Comprising the rotor core according to claim 15.

17. A motor, characterized in that, Comprising the rotor according to claim 16.

18. A powertrain, characterized in that, Comprising the motor according to claim 17.

19. A vehicle, characterized in that, Comprising the motor according to claim 17 or the power assembly according to claim 18.

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