Rotor punching sheet, rotor, motor and vehicle
By designing a rotor punch with arc-shaped and "V" permanent magnet slots, the problem of insufficient motor power density in the prior art is solved, and the effect of significantly improving the torque density and magnetic field strength of the motor is achieved.
Patent Information
- Application Number
- CN202421428878.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-20
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-06-20
AI Technical Summary
In the prior art, the rotor punching plate cannot effectively improve the power density of the motor, resulting in insufficient performance of the motor.
A rotor punch is designed, which includes a first permanent magnet groove of a long arcuate groove, a second and third permanent magnet groove of a "V" shape, and a corresponding combination of air grooves to increase the surface area of the magnet groove and improve the magnetic field distribution.
The torque density and magnetic field strength of the motor are significantly improved, the performance of the motor is enhanced, and the problem of insufficient power density of the motor in the prior art is solved.
Smart Images
Figure CN222868622U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electric motors, and in particular to a rotor punching sheet, a rotor, an electric motor and a vehicle. Background Art
[0002] With the development of life, people pay more and more attention to environmental protection and energy saving in their daily life. In terms of travel, more and more people will choose travel methods without emission pollution, such as bicycles, electric vehicles and electric cars. Among them, considering the comfort, more people will choose electric cars to travel.
[0003] Electric vehicles mainly use electricity as their energy source, which is converted into mechanical energy through electric motors, thereby providing power for various components and enabling electric vehicles to operate. In electric motors, the stator and rotor are the key to their operation.
[0004] The rotor may be formed by stacking a plurality of rotor punchings. The slots provided on the rotor punchings in the prior art have limited gain effect on the magnetic flux during operation and cannot improve the power density of the motor. Utility Model Content
[0005] The utility model aims to provide a rotor punching sheet, a rotor, an electric motor and a vehicle, aiming to solve the problem in the prior art that the rotor punching sheet cannot improve the power density of the electric motor.
[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0007] In the first aspect, the utility model provides a rotor punching sheet, comprising a punching sheet body, on which an axial hole and a plurality of permanent magnet slot groups arranged around the axial hole are provided. The permanent magnet slot group comprises a first permanent magnet slot, a second permanent magnet slot and a third permanent magnet slot. The first permanent magnet slot is an arc-shaped long slot extending along the circumference of the axial hole, and the first permanent magnet slot is arched in a direction away from the axial hole. The second permanent magnet slot and the third permanent magnet slot are both long slots. The two ends of the second permanent magnet slot in the length direction are respectively the first end and the second end, and the two ends of the third permanent magnet slot in the length direction are respectively the third end and the fourth end. The first end, the first permanent magnet slot and the third end are arranged in sequence along the circumference of the axial hole. From the first end to the second end, the second permanent magnet slot extends toward the axial hole and is inclined toward the third permanent magnet slot. From the third end to the fourth end, the third permanent magnet slot extends toward the axial hole and is inclined toward the second permanent magnet slot. The second end and the fourth end are arranged at intervals along the circumference of the axial hole.
[0008] In the rotor punching provided in the embodiment of the present application, the first permanent magnet slot is arched in the direction away from the shaft hole, which can increase the surface area inside the first permanent magnet slot, increase the air gap magnetic density, increase the magnetic field strength, and thus increase the torque density of the motor. The "V"-shaped second permanent magnet slot and the third permanent magnet slot can increase the salient pole rate of the motor and increase the magnetic field concentration effect of the motor, thereby significantly increasing the magnetic field strength of the rotor and the torque density of the motor.
[0009] In some embodiments, the first permanent magnet slot is an arc-shaped long slot.
[0010] In some embodiments, the two ends of the first permanent magnet slot in the length direction are the fifth end and the sixth end respectively. The punching sheet body is further provided with a first air slot, which is located on the side of the fifth end facing away from the sixth end and is connected to the first permanent magnet slot. The first air slot extends from one end facing the first permanent magnet slot to one end facing away from the first permanent magnet slot, toward the outer edge of the punching sheet body.
[0011] In some embodiments, the end of the first air slot facing the first permanent magnet slot is a connecting end, the slot width of the connecting end is smaller than the slot width of the fifth end, and a stop surface is formed between the inner wall surface of the first air slot and the inner wall surface of the first permanent magnet slot.
[0012] In some embodiments, the first permanent magnet slot includes a first inner wall surface and a second inner wall surface opposite to each other. The first air slot includes a third inner wall surface and a fourth inner wall surface opposite to each other. The first inner wall surface is connected to the third inner wall surface, and the stop surface is arranged between the second inner wall surface and the fourth inner wall surface.
[0013] In some embodiments, the stop surface is connected to the fourth inner wall surface, and a concave surface is connected between the stop surface and the second inner wall surface, and the concave surface is recessed in a direction away from the first inner wall surface.
[0014] In some embodiments, the end of the first air slot facing the first permanent magnet slot is a connecting end, and the inner wall surface of the connecting end is an arc surface, which is arched toward the outer edge of the punching sheet body.
[0015] In some embodiments, the outer edge of the punch body includes an arc edge. The arc edge is located on the side of the first permanent magnet slot facing away from the axial hole. The first air slot extends from one end facing the first permanent magnet slot to the end facing away from the first permanent magnet slot toward the arc edge, and the center line of the arc surface is colinear with the center line of the arc edge.
[0016] In some embodiments, the shortest distance between the first permanent magnet slot and the outer edge of the punch body is greater than or equal to 1.5 mm.
[0017] In some embodiments, the shortest distance between the first air groove and the outer edge of the punch body is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0018] In some embodiments, an included angle between the second permanent magnet slot and the third permanent magnet slot is greater than or equal to 80° and less than or equal to 110°.
[0019] In some embodiments, the punch body is further provided with a second air groove, which is located on the side of the first end facing away from the second end and is connected to the second permanent magnet groove. The second air groove extends from one end facing the second permanent magnet groove to one end facing away from the second permanent magnet groove, toward the outer edge of the punch body.
[0020] In some embodiments, the shortest distance between the second air groove and the outer edge of the punch body is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0021] In some embodiments, the punch body is further provided with a third air groove, which is located on a side of the second end facing away from the first end and is connected to the second permanent magnet groove.
[0022] In some embodiments, the punch body is further provided with a fourth air groove, which is located on a side of the fourth end opposite to the third end and is connected to the third permanent magnet groove. Along the circumference of the shaft hole, the shortest distance between the third air groove and the fourth air groove is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0023] In some embodiments, a portion of an outer edge of the punch body between the first air slot and the second air slot includes a concave edge.
[0024] In some embodiments, the concave edge includes an arc segment and a straight edge segment tangent to the arc segment.
[0025] In some embodiments, the radius of the arc segment is greater than or equal to 3 mm and less than or equal to 5 mm.
[0026] In some embodiments, the recessed depth of the recessed edge is greater than or equal to 0.6 mm and less than or equal to 1.5 mm.
[0027] In some embodiments, the length of the recessed edge in the circumferential direction of the axial hole is greater than or equal to 1.5 mm and less than or equal to 2.5 mm.
[0028] In a second aspect, the utility model provides a rotor, comprising any one of the above-mentioned rotor punchings, a first permanent magnet, a second permanent magnet and a third permanent magnet. The number of rotor punchings is multiple, and the multiple rotor punchings are stacked in sequence. The first permanent magnet is installed in the first permanent magnet slot, and the shape of the first permanent magnet matches the shape of the first permanent magnet slot. The second permanent magnet is installed in the second permanent magnet slot, and the shape of the second permanent magnet matches the shape of the second permanent magnet slot. The third permanent magnet is installed in the third permanent magnet slot, and the shape of the third permanent magnet matches the shape of the third permanent magnet slot.
[0029] In a third aspect, the utility model provides an electric motor, comprising a rotor and a stator. The stator is located outside the rotor.
[0030] In a fourth aspect, the utility model provides a vehicle, comprising wheels and an electric motor, wherein the electric motor is rotatably connected to the wheels. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0032] Figure 1 A schematic diagram of the structure of a rotor punching provided by the utility model;
[0033] Figure 2 It is a schematic diagram of the structure of a rotor punching sheet in the prior art;
[0034] Figure 3 This is one of the structural schematic diagrams of part of the rotor punching provided by the utility model;
[0035] Figure 4 A torque diagram when the first permanent magnet slot in a rotor punching provided by the utility model is a circular arc slot;
[0036] Figure 5 A torque diagram when the first permanent magnet slot in a rotor punching provided by the utility model is a straight slot;
[0037] Figure 6 The second structural schematic diagram of a part of the rotor punching provided by the utility model;
[0038] Figure 7 The third structural schematic diagram of a part of the rotor punching provided by the utility model;
[0039] Figure 8 The tooth slot torque diagram of the concave edge of some rotor punchings provided by the utility model adopts a circular arc segment plus a straight edge segment structure;
[0040] Fig. 9 The utility model provides a tooth groove torque diagram in which the concave edges of some rotor punching sheets adopt an arc-shaped structure.
[0041] Reference numerals:
[0042] 100-rotor punching sheet; 10-punching sheet body; 101-shaft hole; 11-permanent magnet slot group; 111-first permanent magnet slot; 1111-fifth end; 1112-sixth end; 1113-stop surface; 1115-first inner wall surface; 1116-second inner wall surface; 1117-concave surface; 112-second permanent magnet slot; 1121-first end; 1122-second end; 113-third permanent magnet slot; 1131-third end; 1132 -the fourth end; 12-the first air groove; 121-the connecting end; 122-the third inner wall surface; 123-the fourth inner wall surface; 13-the magnetic isolation bridge; 131-the first magnetic isolation bridge; 132-the second magnetic isolation bridge; 133-the third magnetic isolation bridge; 14-the second air groove; 15-the third air groove; 16-the recessed edge; 17-the weight reduction groove; 18-the fourth air groove; 200-the permanent magnet; 21-the first permanent magnet; 22-the second permanent magnet; 23-the third permanent magnet. DETAILED DESCRIPTION
[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0044] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside" and the like indicate directions or positional relationships based on the directions or relative positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. Unless otherwise specified, the above-mentioned directional description can be flexibly set in the process of actual application under the condition that the relative positional relationship shown in the accompanying drawings is satisfied.
[0045] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "plurality" means two or more.
[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0047] In the embodiments of the present invention, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, article or device including the element.
[0048] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.
[0049] As people's quality of life improves, more and more people begin to pay attention to energy conservation and environmental protection. For daily travel, they will choose a more environmentally friendly way of using electricity than gasoline cars, including but not limited to electric cars and electric bicycles. Because using electricity as a driving tool will not produce exhaust gas due to incomplete combustion of gasoline. And electricity can be converted from a variety of disposable energy sources and is easier to produce. Therefore, choosing to use electricity as a means of travel as the main energy source can reduce the dependence on fossil fuels in daily life and promote sustainable development.
[0050] Based on this, the present application provides a vehicle, which may include an electric motor and a transmission assembly. The transmission assembly is connected to the electric motor.
[0051] Compared with fuel engines, electric motors have higher energy conversion efficiency, which allows more energy to be used to drive the vehicle. Electric motors do not directly emit exhaust gas during operation, which helps reduce urban air pollution and greenhouse gas emissions. In addition, electric motors can output maximum torque at the moment of starting the vehicle. Compared with fuel engine vehicles that need to increase the speed to a specific range to reach peak torque, vehicles using electric motors have faster acceleration performance.
[0052] Specifically, in new energy vehicles, the electric motor is usually set in the power system, connected to the transmission component, outputs torque to the transmission component, and enables the transmission component to transmit power to various components in the new energy vehicle to make each component operate.
[0053] In some embodiments, the present application further provides an electric motor, which may include a rotor and a stator. The stator is located outside the rotor.
[0054] According to the working principle, electric motors can be divided into synchronous motors and asynchronous motors, among which synchronous motors can be divided into permanent magnet synchronous motors and electrically excited synchronous motors. Permanent magnet synchronous motors are widely used in pure electric or hybrid new energy vehicles, household appliances, industrial equipment, robots and other equipment due to their advantages such as high torque density, high efficiency, good stability and high reliability.
[0055] The permanent magnet synchronous motor mainly consists of a stator and a rotor. The stator is the fixed part of the motor, usually arranged around the rotor. The stator can be composed of an iron core and windings. There are multiple sets of slots on the inner surface of the iron core for embedding the three-phase windings. When three-phase alternating current passes through these windings, a rotating magnetic field is generated in the stator.
[0056] The rotor is the rotating part of the motor, which contains the shaft and permanent magnets. The shaft is used to output power to other parts. The unique feature of permanent magnet synchronous motors is that permanent magnets are used to replace the excitation winding in traditional synchronous motors.
[0057] When the three-phase AC power supply is turned on, AC flows through the stator winding, generating a rotating magnetic field that changes with time. The permanent magnets in the rotor generate a constant magnetic field, which interacts with the rotating magnetic field generated by the stator. Based on the principle that the magnetic lines of force minimize the path length, the permanent magnets in the rotor will try to maintain the minimum magnetic resistance path with the rotating magnetic field of the stator, so that the permanent magnets rotate synchronously with the stator magnetic field.
[0058] The rotation of the permanent magnet drives the entire rotor to rotate, and the rotation of the rotor drives the internal shaft to rotate, and the shaft drives the transmission assembly to connect and provide power for the transmission assembly. This interaction generates driving torque and realizes the conversion of electrical energy into mechanical energy.
[0059] Among them, permanent magnets, also known as permanent magnets or hard magnets, are materials with spontaneous magnetization properties that can maintain a strong magnetization state and magnetism for a long time even after the external magnetic field is removed.
[0060] Exemplarily, the material of the permanent magnet may be an alloy permanent magnet material or a ferrite permanent magnet material. Specifically, the permanent magnet may be neodymium iron boron. These materials can provide a strong magnetic field, ensuring that the motor has a high efficiency and power density. The material used to make the permanent magnet is not specifically limited, as long as it can keep the permanent magnet in a strong magnetized state for a long time.
[0061] In some embodiments, the present application also provides a rotor, such as Figure 1 As shown, Figure 1 The utility model provides a schematic diagram of the structure of a rotor punching 100, which may include a rotor punching 100, a first permanent magnet 21 ( Figure 3 )、The second permanent magnet 22 ( Figure 3 ) and the third permanent magnet 23 ( Figure 3 The number of rotor punchings is multiple, and the multiple rotor punchings are stacked in sequence. The first permanent magnet 21, the second permanent magnet 22 and the third permanent magnet 23 are located in the rotor punchings.
[0062] In order to reduce eddy current loss, the rotor is usually made of laminated silicon steel sheets. After the rotor punching is installed, there will be a small gap between two adjacent rotor punchings. These gaps can be used as heat channels to discharge heat and improve the heat dissipation effect of the entire rotor. At the same time, the manufacturing process of a single rotor punching is relatively simple, and this method is easy to automate production, which improves the production efficiency of rotor punchings and rotors.
[0063] In order to install the permanent magnet in the rotor, a permanent magnet slot can be set on the rotor punching sheet, and the permanent magnet is set in the permanent magnet slot. The position of the permanent magnet slot determines the placement position of the permanent magnet. At the same time, when the motor is running, in order to make the permanent magnet generate a stable magnetic field and ensure the stable operation of the motor, the position of the permanent magnet in the permanent magnet slot should be stable. Therefore, the shape of the permanent magnet should be consistent with the shape of the permanent magnet slot.
[0064] In related technologies, such as Figure 2 As shown, Figure 2 The structure diagram of the rotor punching sheet in the prior art is shown in FIG. The shape and location of the permanent magnet 200 slots for accommodating the permanent magnets 200 are relatively random, so that the rotor cannot have a higher torque density and work efficiency. Among them, most of the permanent magnet 200 slots are straight slots or are arched towards the direction close to the shaft hole.
[0065] In some embodiments, Figure 1 As shown, the present application also provides a rotor punching sheet 100, which may include a punching sheet body 10, on which is provided an axial hole 101 and a plurality of permanent magnet slot groups 11 arranged around the axial hole 101. The permanent magnet slot group 11 includes a first permanent magnet slot 111, a second permanent magnet slot 112 and a third permanent magnet slot 113.
[0066] The first permanent magnet slot 111 is an arc-shaped long slot extending along the circumference of the shaft hole 101, and the first permanent magnet slot 111 is arched in the direction away from the shaft hole 101. The second permanent magnet slot 112 and the third permanent magnet slot 113 are both long slots. The two ends of the second permanent magnet slot 112 in the length direction are respectively a first end 1121 and a second end 1122, and the two ends of the third permanent magnet slot 113 in the length direction are respectively a third end 1131 and a fourth end 1132.
[0067] The first end 1121, the first permanent magnet slot 111 and the third end 1131 are arranged in sequence along the circumference of the shaft hole 101. From the first end 1121 to the second end 1122, the second permanent magnet slot 112 extends toward the shaft hole 101 and is inclined toward the third permanent magnet slot 113. From the third end 1131 to the fourth end 1132, the third permanent magnet slot 113 extends toward the shaft hole 101 and is inclined toward the second permanent magnet slot 112. The second end 1122 and the fourth end 1132 are spaced apart along the circumference of the shaft hole 101.
[0068] In the rotor punching 100 provided in the embodiment of the present application, since the second permanent magnet slots 112 are inclined toward the third permanent magnet slots 113 and the third permanent magnet slots 113 are inclined toward the second permanent magnet slots 112 , the second permanent magnet slots 112 and the third permanent magnet slots 113 can form a non-connected “V” shape.
[0069] The first permanent magnet slot 111 is arched in a direction away from the shaft hole 101, which can increase the surface area inside the first permanent magnet slot, increase the air gap magnetic density, increase the magnetic field strength, and thus increase the torque density of the motor. The "V"-shaped second permanent magnet slot 112 and the third permanent magnet slot 113 can increase the salient pole rate of the motor and increase the magnetic field concentration effect of the motor, thereby significantly increasing the magnetic field strength of the rotor and the torque density of the motor.
[0070] Among them, since the magnetic permeability of the rotor core is greater than the magnetic permeability of the permanent magnet and the air. Among them, the magnetic permeability is inversely proportional to the magnetic resistance, and the inductance is proportional to the magnetic resistance. As a result, in the permanent magnet group forming a triangular structure between the first permanent magnet, the second permanent magnet and the third permanent magnet, the magnetic resistance of the d axis is greater than the magnetic resistance of the q axis. Therefore, this setting method can significantly improve the magnetic field strength of the rotor and improve the torque density of the motor.
[0071] At the same time, the combination of multiple magnetic steel slots can also save the amount of magnetic steel. Generally, the higher the salient pole ratio, the greater the reluctance torque of the motor. The reluctance torque can improve the output torque capacity of the motor. That is, when the amount of permanent magnets remains unchanged, increasing the salient pole ratio and the torque of the motor is equivalent to reducing the amount of permanent magnets and saving the amount of magnetic steel while ensuring that the torque remains unchanged.
[0072] For example, Figure 1As shown, a plurality of permanent magnet slot groups 11 can be evenly spaced along the circumference of the shaft hole 101. In this way, the magnetic field of each part of the rotor punching 100 can be evenly distributed, and the force output by the motor will be more uniform and stable.
[0073] The first permanent magnet 21 is installed in the first permanent magnet slot 111, and the shape of the first permanent magnet 21 matches the shape of the first permanent magnet slot 111. The second permanent magnet 22 is installed in the second permanent magnet slot 112, and the shape of the second permanent magnet 22 matches the shape of the second permanent magnet slot 112. The third permanent magnet 23 is installed in the third permanent magnet slot 113, and the shape of the third permanent magnet 23 matches the shape of the third permanent magnet slot 113.
[0074] In some embodiments, Figure 3 As shown, Figure 3 This is one of the structural schematic diagrams of a portion of the rotor punching sheet 100 provided by the utility model. The first permanent magnet slot 111 can be a long arc-shaped slot.
[0075] At this time, the wall of the first permanent magnet slot 111 is relatively smooth, so that a relatively regular permanent magnet 200 can be placed inside it. The magnetic field generated by the relatively regular permanent magnet 200 is also more stable, which is conducive to the stable output of the motor.
[0076] At the same time, compared with the straight groove, the arc-shaped permanent magnet 200 groove can increase the surface area of the permanent magnet 200 arranged inside it toward the air gap edge, thereby increasing the air gap magnetic density, improving the utilization of the permanent magnet 200, and thus improving the torque density of the motor.
[0077] When the first permanent magnet slot 111 is a straight slot, a slot arched toward the shaft hole 101, and a slot arched toward the shaft hole 101, and when the rotor punching sheets 100 where the three slots are located have the same width and the same thickness, the average torque can be shown in Table 1 below.
[0078] Table 1
[0079]
[0080] like Figure 4 and Figure 5 shown. Figure 4 This is a torque diagram when the first permanent magnet slot in the rotor punching sheet 100 provided by the utility model is a circular arc slot. Figure 5 This is a torque diagram when the first permanent magnet slot in the rotor punching sheet 100 provided by the utility model is a straight slot.
[0081] It can be concluded that when the first permanent magnet slot 111 is a slot that arches toward the direction close to the shaft hole 101, the average torque of the rotor punching 100 in which it is located is small. When the first permanent magnet slot 111 is a straight slot, the average torque of the rotor punching 100 in which it is located ranks second. When the first permanent magnet slot 111 is a slot that arches toward the direction away from the shaft hole 101, the average torque of the rotor punching 100 in which it is located is high.
[0082] Among them, although the area of the permanent magnet 200 installed in the groove that arches toward the direction close to the shaft hole 101 increases, the average torque is still small.
[0083] At the same time, it can be seen from the above chart that when the first permanent magnet slot 111 is a slot that is arched in the direction away from the shaft hole 101, when other characteristics remain unchanged, the plane area of the permanent magnet increases by 0.3%, but the torque increases by 0.7%. The rotor punching 100 in which it is located can greatly improve the utilization rate of the permanent magnet 200, thereby greatly improving the torque density.
[0084] For example, Figure 1 As shown, the line from the midpoint of the arc of the first permanent magnet slot 111 to its center coincides with the line from the midpoint of the arc to the center of the shaft hole 101. In this way, the first permanent magnet slot 111 can be symmetrical relative to the line from the midpoint of the arc to the center of the shaft hole 101, so that the permanent magnet 200 placed therein is symmetrical, so that the magnetic field generated by the permanent magnet 200 in the rotor as a whole is relatively stable, so that the motor can output smoothly.
[0085] In other embodiments, the shape of the first permanent magnet slot 111 can be relatively smooth at both ends and have an arc-shaped protrusion in the middle. In this way, the area of the permanent magnet 200 can be increased to increase the torque density of the motor.
[0086] In some embodiments, Figure 3 As shown, the two ends of the first permanent magnet slot 111 in the length direction are respectively the fifth end 1111 and the sixth end 1112. The punch body 10 is also provided with a first air slot 12, which is located on the side of the fifth end 1111 facing away from the sixth end 1112 and is connected to the first permanent magnet slot 111. The first air slot 12 extends from one end facing the first permanent magnet slot 111 to one end facing away from the first permanent magnet slot 111, toward the outer edge of the punch body 10.
[0087] A magnetic isolation bridge 13 may be formed between the first air slot 12 at the fifth end 1111 facing away from the sixth end 1112 and the outer edge of the punch body 10, and the magnetic isolation bridge 13 may include a first magnetic isolation bridge 131. The first magnetic isolation bridge 131 is located from the side of the first air slot 12 facing away from the first permanent magnet slot 111 to the side of the outer edge of the punch body 10. When the size of the first magnetic isolation bridge 131 is small, the magnetic leakage of the rotor can be reduced and the torque density of the rotor can be improved.
[0088] Therefore, by providing the first air slot 12 on one side close to the outer edge of the punching sheet body 10 , the size of the first magnetic isolation bridge 131 can be made smaller, thereby reducing the magnetic leakage of the rotor and improving the torque density of the rotor.
[0089] At the same time, a first air slot 12 is also present on the side of the sixth end 1112 facing away from the fifth end 1111. Along a line connecting the midpoint of the first permanent magnet slot 111 to the center of the shaft hole 101, two first air slots 12 are symmetrically arranged.
[0090] In some embodiments, Figure 3 As shown, the end of the first air slot 12 facing the first permanent magnet slot 111 is a connecting end 121 , the slot width of the connecting end 121 is smaller than the slot width of the fifth end 1111 , and a stop surface 1113 is formed between the inner wall surface of the first air slot 12 and the inner wall surface of the first permanent magnet slot 111 .
[0091] Only when the slot width of the connecting end 121 of the first air slot 12 is smaller than the slot width of the fifth end 1111 of the first permanent magnet slot 111, can a stop slot width difference be formed between the two slots, thereby forming a stop surface 1113. The stop surface 1113 can limit the permanent magnet 200 in the first permanent magnet slot 111, prevent the first permanent magnet 200 from moving in the direction along the length of the first permanent magnet slot 111, and ensure the positional stability of the permanent magnet 200. The permanent magnet 200 with a stable position can generate a stable magnetic field, making the output of the motor more stable.
[0092] The number of the stop surfaces 1113 may be two, and the two stop surfaces 1113 are symmetrically arranged along a line from the midpoint of the arc of the first permanent magnet slot 111 to the center of the shaft hole 101 .
[0093] In other embodiments, the rotor sheet 100 may further include a stopper. The stopper may be located between the communication end 121 and the fifth end 1111, with one end connected to the first permanent magnet slot 111. The stopper may also limit the position of the permanent magnet 200.
[0094] In some embodiments, Figure 6 As shown, Figure 6The second structural schematic diagram of a portion of the rotor punching sheet 100 provided by the utility model, the first permanent magnet slot 111 includes a first inner wall surface 1115 and a second inner wall surface 1116 opposite to each other. The first air slot 12 includes a third inner wall surface 122 and a fourth inner wall surface 123 opposite to each other. The first inner wall surface 1115 is connected to the third inner wall surface 122, and the stop surface 1113 is arranged between the second inner wall surface 1116 and the fourth inner wall surface 123.
[0095] The first inner wall surface 1115 and the third inner wall surface 122 may be located on the side of the second inner wall surface 1116 and the fourth inner wall surface 123 away from the shaft hole 101. At this time, the stop surface 1113 is located on the side of the first permanent magnet 200 close to the shaft hole 101.
[0096] In other embodiments, the first inner wall surface 1115 and the third inner wall surface 122 may be located on the side of the second inner wall surface 1116 and the fourth inner wall surface 123 close to the shaft hole 101. In this case, the stop surface 1113 is located on the side of the first permanent magnet 200 away from the shaft hole 101.
[0097] In some embodiments, Figure 6 As shown, the stop surface 1113 is connected to the fourth inner wall surface 123 , and a concave surface 1117 is connected between the stop surface 1113 and the second inner wall surface 1116 , and the concave surface 1117 is recessed in a direction away from the first inner wall surface 1115 .
[0098] Because the various grooves on the punching sheet body 10 are punched at a high speed and force during forming, and the size of the stop surface 1113 is small, in order to ensure the existence of the stop surface 1113, a concave surface 1117 can be punched out on one side of the stop surface 1113 during stamping, so that the stop surface 1113 can have a stable structure, so that it can stably limit the position of the permanent magnet 200.
[0099] In some embodiments, Figure 6 As shown, one end of the first air slot 12 facing the first permanent magnet slot 111 is a connecting end 121 , and the inner wall surface of the connecting end 121 is an arc surface, which is arched toward the outer edge of the punch body 10 .
[0100] In this way, the side of the first magnetic isolation bridge 131 close to the shaft hole 101 is arc-shaped.
[0101] Exemplarily, the shape of the first air groove 12 near the outer edge of the punch body 10 may be an arc shape.
[0102] In other embodiments, the shape of the first air slot 12 near the outer edge of the punch body 10 may also be a straight line. Specifically, the shape of the first air slot 12 near the outer edge of the punch body 10 is not specifically limited and may also be other shapes.
[0103] In some embodiments, Figure 6 As shown, the outer edge of the punch body 10 includes an arc edge. The arc edge is located at the first permanent magnet slot 111 facing away from the shaft hole 101 ( Figure 1 The first air slot 12 extends from one end facing the first permanent magnet slot 111 to the end facing away from the first permanent magnet slot 111 toward the edge of the arc, and the center line of the arc surface is collinear with the center line of the arc edge.
[0104] Therefore, both ends of the first magnetic isolation bridge 131 are arc-shaped, and the center lines of the arcs at both ends are collinear, so the shapes of both sides of the first magnetic isolation bridge 131 can be unified, which can ensure the uniformity of the size of each part of the magnetic isolation bridge 131, thereby maintaining the stability of the rotor operation.
[0105] In some embodiments, the shortest distance between the first permanent magnet slot 111 and the outer edge of the punch body 10 is greater than or equal to 1.5 mm.
[0106] In order to ensure the overall strength of the rotor sheet 100, the shortest distance between the first permanent magnet slot 111 and the outer edge of the sheet body 10 should not be too small. When the shortest distance between the first permanent magnet slot 111 and the outer edge of the sheet body 10 is small, the permanent magnet 200 in the first permanent magnet slot 111 is likely to damage the sheet body during rotation, causing the sheet body to warp, deform, and other problems, affecting the performance of the motor.
[0107] For example, the specific range of the shortest distance between the first permanent magnet slot 111 and the outer edge of the punch body 10 may be 1.5 mm, 1.7 mm, 2.0 mm, 2.5 mm, etc.
[0108] In some embodiments, the shortest distance between the first air groove 12 and the outer edge of the punch body 10 is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0109] The shortest distance between the first air slot 12 and the outer edge of the punching sheet body 10 is the size of the first magnetic isolation bridge 131. In order to reduce the magnetic leakage of the rotor assembly and improve its torque density, the size of the first magnetic isolation bridge 131 is usually set as small as possible. At the same time, in order to ensure the mechanical strength and manufacturability of the rotor punching sheet 100, the size of each bridge is usually set larger. Therefore, the size range of the first magnetic isolation bridge 131 can be set between 0.5mm and 2mm.
[0110] Exemplarily, the size range of the first magnetic isolation bridge 131 may be 0.5 mm, 0.8 mm, 1.0 mm, 1.6 mm, 2 mm, etc.
[0111] In some embodiments, the angle between the second permanent magnet slot 112 and the third permanent magnet slot 113 is greater than or equal to 80° and less than or equal to 110°.
[0112] Exemplarily, the angle between the second permanent magnet slot 112 and the third permanent magnet slot 113 may be 80°, 82°, 90°, 95°, 106°, 110°, etc.
[0113] In some embodiments, Figure 3 and Figure 6 As shown, the punch body 10 is further provided with a second air groove 14, which is located on the side of the first end 1121 facing away from the second end 1122 and is connected to the second permanent magnet groove 112. The second air groove 14 extends from one end facing the second permanent magnet groove 112 to one end facing away from the second permanent magnet groove 112, toward the outer edge of the punch body 10.
[0114] A second magnetic isolation bridge 132 can be formed between the second air slot 14 at the first end 1121 facing away from the second end 1122 and the outer edge of the punch body 10. When the size of the second magnetic isolation bridge 132 is small, the magnetic leakage of the rotor can be reduced and the torque density of the rotor can be improved.
[0115] At the same time, there is also a second air slot 14 on the side of the third end 1131 facing away from the fourth end 1132. Figure 1 ) The two second air grooves 14 are symmetrically arranged.
[0116] In some embodiments, the shortest distance between the second air groove 14 and the outer edge of the punch body 10 is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0117] In order to reduce the magnetic leakage of the rotor assembly and improve its torque density, the size of the second magnetic isolation bridge 132 is usually set as small as possible. At the same time, in order to ensure the mechanical strength and manufacturability of the rotor punching 100, the size of each bridge is usually set larger. Therefore, the size range of the second magnetic isolation bridge 132 can be set between 0.5mm and 2mm.
[0118] Exemplarily, the size range of the second magnetic isolation bridge 132 may be 0.5 mm, 0.8 mm, 1.0 mm, 1.6 mm, 2 mm, etc.
[0119] A stop surface 1113 and a concave surface 1117 are also provided between the second air slot 14 and the second permanent magnet slot 112. A stop surface 1113 and a concave surface 1117 are also provided between the third air slot 15 and the second permanent magnet slot 112.
[0120] In some embodiments, Figure 3 and Figure 6 As shown, the punch body 10 is further provided with a third air groove 15 , which is located at a side of the second end 1122 facing away from the first end 1121 and is connected to the second permanent magnet groove 112 .
[0121] The third air groove 15 connected to the second permanent magnet groove 112 can reduce the shortest distance between the space connected to the second permanent magnet groove 112 and the space where the third permanent magnet groove 113 is located.
[0122] In some embodiments, Figure 3 and Figure 6 As shown, the punch body 10 is further provided with a fourth air groove 18, which is located on the side of the fourth end 1132 facing away from the third end 1131 and is connected to the third permanent magnet groove 113. Along the circumference of the shaft hole, the shortest distance between the third air groove 15 and the fourth air groove 18 is greater than or equal to 0.5 mm and less than or equal to 2 mm.
[0123] In one permanent magnet slot group 11 , the fourth air slot 18 and the third air slot 15 are combined to form a third magnetic isolation bridge 133 , and the shortest distance between the fourth air slot 18 and the third air slot 15 is the size of the third magnetic isolation bridge 133 .
[0124] In order to reduce the magnetic leakage of the rotor assembly and improve its torque density, the size of the third magnetic isolation bridge 133 is usually set as small as possible. At the same time, in order to ensure the mechanical strength and manufacturability of the rotor punching 100, the size of each bridge is usually set larger. Therefore, the size range of the third magnetic isolation bridge 133 can be set between 0.5mm and 2mm.
[0125] Exemplarily, the size range of the third magnetic isolation bridge 133 may be 0.5 mm, 0.8 mm, 1.0 mm, 1.6 mm, 2 mm, etc.
[0126] A stop surface 1113 and a concave surface 1117 are also provided between the second air slot 14 and the third permanent magnet slot 113. A stop surface 1113 and a concave surface 1117 are also provided between the third air slot 15 and the third permanent magnet slot 113.
[0127] In some embodiments, Figure 7 As shown, Figure 7 This is the third structural schematic diagram of a portion of the rotor punching sheet 100 provided by the present invention. The outer edge of the portion of the punching sheet body 10 between the first air slot 12 and the second air slot 14 includes a recessed edge 16 .
[0128] Because the sizes of the first magnetic isolation bridge 131 and the second magnetic isolation bridge 132 must be small, the distance between the first air groove 12 and the second air groove 14 and the outer edge of the punch body 10 is short. Therefore, in order to ensure the strength of the punch body 10, the position of the depression should avoid the positions of the first air groove 12 and the second air groove 14 and be located between the first air groove 12 and the second air groove 14.
[0129] The recessed edge 16 can increase the magnetic resistance at its location, thereby improving the magnetic flux density waveform of the air gap, improving the harmonic components in the air gap magnetic field, improving the torque pulsation of the motor, reducing the radial force caused by harmonics, improving the vibration noise of the motor, and comprehensively improving the user's comfort.
[0130] In other embodiments, the outer edge of the punch body 10 may not include the recessed edge 16 .
[0131] In some embodiments, Figure 7 As shown, the concave edge 16 may include an arc segment 161 and a straight edge segment 162 tangent to the arc segment 161 .
[0132] The concave edge 16 formed by the combination of the circular arc and the straight edge segment 162 tangent thereto has lower harmonic content and cogging torque in the air gap magnetic field than the circular arc-shaped concave edge 16 , and the operating efficiency of the motor is higher.
[0133] It can be understood that the new cogging torque formed by the concave edge 16 can compensate the original cogging torque to a certain extent, thereby reducing the amplitude of the total cogging torque.
[0134] Exemplarily, the concave edge 16 may include an arc segment 161 and a straight edge segment 162 .
[0135] In other embodiments, the concave edge 16 may further include an arc segment 161 and two straight edge segments 162. The two straight edge segments 162 are respectively located at two ends of the arc segment 161 and connected to the arc segment 161.
[0136] Specifically, compared with the arc-shaped concave edge 16 in the related art, the cogging torque is shown in Table 2 below.
[0137] Table 2
[0138]
[0139] like Figure 8 , Fig. 9 As shown, Figure 8 The tooth slot torque diagram of the concave edge of the partial rotor punching 100 provided by the utility model adopts the structure of arc segment 161 plus straight edge segment 162, Fig. 9The tooth groove torque diagram of the concave edge of the partial rotor punching 100 provided by the utility model adopts an arc-shaped structure.
[0140] Because the greater the torque of the concave edge 16 is, the more unstable the motor runs. Therefore, it can be seen from the above chart that when the concave edge is composed of a circular arc segment 161 and a straight edge segment 162, its cogging torque is smaller and the motor runs more smoothly.
[0141] In some embodiments, the radius of the arc segment 161 is greater than or equal to 3 mm and less than or equal to 5 mm.
[0142] The radius of the arc segment 161 in the concave edge 16 should not be too large or too small. When the radius of the arc segment 161 is too large, the shortest distance between the first permanent magnet slot 111 and the second permanent magnet slot 112 and the concave edge 16 will be too small, thereby affecting the strength of the rotor punching 100, making the rotor punching 100 prone to warping and breaking during operation.
[0143] When the radius of the arc segment 161 is too small, the effect of the concave edge 16 on the torque pulsation of the motor is also small, so that the output torque of the motor cannot achieve the expected effect and the operating efficiency of the motor cannot be improved well.
[0144] For example, the radius of the arc segment 161 in the concave edge 16 may be 3 mm, 3.6 mm, 4 mm, 5 mm, etc.
[0145] In some embodiments, the recessed depth of the recessed edge 16 is greater than or equal to 0.6 mm and less than or equal to 1.5 mm.
[0146] The concave depth of the concave edge 16 is not too large or too small. When the concave depth of the concave edge 16 is too large, the shortest distance between the first permanent magnet slot 111 and the second permanent magnet slot 112 and the concave edge 16 is small, thereby affecting the strength of the rotor punching 100, making the rotor punching 100 prone to warping and breaking during operation.
[0147] When the recessed depth of the recessed edge 16 is too small, the recessed edge 16 has a smaller effect on the torque pulsation of the motor, so that the output torque of the motor cannot achieve the expected effect and the operating efficiency of the motor cannot be improved well.
[0148] For example, the recessed depth of the recessed edge 16 may be 0.6 mm, 1 mm, 1.2 mm, 1.5 mm, etc.
[0149] In some embodiments, the length of the recessed edge 16 along the circumference of the shaft hole 101 is greater than or equal to 1.5 mm and less than or equal to 2.5 mm.
[0150] The length of the concave edge 16 along the circumference of the shaft hole 101 is not too large or too small. When the length of the concave edge 16 along the circumference of the shaft hole 101 is too large, the shortest distance between the first air slot 12 and the second air slot 14 and the concave edge 16 will be small, thereby affecting the strength of the rotor punching 100, making the rotor punching 100 prone to warping and breaking during operation.
[0151] When the length of the concave edge 16 along the circumference of the shaft hole 101 is too small, the effect of the concave edge 16 on improving the torque pulsation of the motor is also small, so that the output torque of the motor cannot achieve the expected effect and the operating efficiency of the motor cannot be improved well.
[0152] For example, the length of the recessed edge 16 along the circumference of the shaft hole 101 may be 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, etc.
[0153] In some embodiments, Figure 1 As shown, the punch body 10 may also be provided with a plurality of weight-reducing grooves 17. The plurality of weight-reducing grooves 17 are located between the permanent magnet slot group 11 and the shaft hole 101 and are arranged circumferentially around the shaft hole 101.
[0154] The weight reduction groove 17 is mainly arranged at a position where the permanent magnet 200 does not need to be installed, so as not to affect the normal magnetic field generated by the permanent magnet 200 and the operation of the rotor. The weight reduction groove 17 can reduce the material at the position where there is no actual effect on the rotor punching 100, and can reduce the mass of the rotor punching 100 as much as possible, thereby reducing the mass of the rotor itself.
[0155] For example, Figure 1 As shown, the shape of the weight-reducing groove 17 can be a "convex" shape.
[0156] There is no specific requirement for the shape of the weight-reducing groove 17 , as long as it does not affect the normal installation and operation of the permanent magnet 200 .
[0157] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.
[0158] The above are only specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A rotor punching sheet (100), characterized in that: include: A punching sheet body (10) is provided with an axial hole (101) and a plurality of permanent magnet slot groups (11) arranged around the axial hole (101); wherein: The permanent magnet slot group (11) comprises: A first permanent magnet slot (111), the first permanent magnet slot (111) being an arc-shaped long slot extending along the circumference of the shaft hole (101), and the first permanent magnet slot (111) arches in a direction away from the shaft hole (101); A second permanent magnet slot (112) and a third permanent magnet slot (113), wherein the second permanent magnet slot (112) and the third permanent magnet slot (113) are both long slots; the two ends of the second permanent magnet slot (112) in the length direction are respectively a first end (1121) and a second end (1122); the two ends of the third permanent magnet slot (113) in the length direction are respectively a third end (1131) and a fourth end (1132); the first end (1121), the first permanent magnet slot (111) and the third end (1131) are arranged along the axis hole (10 1); from the first end (1121) to the second end (1122), the second permanent magnet slot (112) extends toward the axial hole (101) and is inclined toward the third permanent magnet slot (113); from the third end (1131) to the fourth end (1132), the third permanent magnet slot (113) extends toward the axial hole (101) and is inclined toward the second permanent magnet slot (112); the second end (1122) and the fourth end (1132) are spaced apart along the circumferential direction of the axial hole (101).
2. The rotor punching sheet (100) according to claim 1, characterized in that: The first permanent magnet slot (111) is an arc-shaped long slot.
3. The rotor punching sheet (100) according to claim 1, characterized in that: Two ends of the first permanent magnet slot (111) in the length direction are respectively a fifth end (1111) and a sixth end (1112); The punching sheet body (10) is further provided with a first air groove (12), the first air groove (12) being located on a side of the fifth end (1111) facing away from the sixth end (1112) and being connected to the first permanent magnet groove (111); The first air groove (12) extends from an end facing the first permanent magnet groove (111) to an end facing away from the first permanent magnet groove (111) toward the outer edge of the punching sheet body (10).
4. The rotor punching sheet (100) according to claim 3, characterized in that: One end of the first air slot (12) facing the first permanent magnet slot (111) is a connecting end (121); The slot width of the connecting end (121) is smaller than the slot width of the fifth end (1111), and a stop surface (1113) is formed between the inner wall surface of the first air slot (12) and the inner wall surface of the first permanent magnet slot (111).
5. The rotor punching sheet (100) according to claim 4, characterized in that: The first permanent magnet slot (111) comprises a first inner wall surface (1115) and a second inner wall surface (1116) which are opposite to each other; the first air slot (12) comprises a third inner wall surface (122) and a fourth inner wall surface (123) which are opposite to each other; the first inner wall surface (1115) is connected to the third inner wall surface (122), and the stop surface (1113) is arranged between the second inner wall surface (1116) and the fourth inner wall surface (123).
6. The rotor punching sheet (100) according to claim 5, characterized in that: The stop surface (1113) is connected to the fourth inner wall surface (123), and a concave surface (1117) is connected between the stop surface (1113) and the second inner wall surface (1116), and the concave surface (1117) is concave in a direction away from the first inner wall surface (1115).
7. The rotor punching sheet (100) according to any one of claims 3 to 6, characterized in that: One end of the first air slot (12) facing the first permanent magnet slot (111) is a connecting end (121), and an inner wall surface of the connecting end (121) is an arc-shaped surface, and the arc-shaped surface is arched toward the outer edge of the punching sheet body (10).
8. The rotor punching sheet (100) according to claim 7, characterized in that: The outer edge of the punch body (10) comprises an arc edge; the arc edge is located on a side of the first permanent magnet slot (111) facing away from the shaft hole (101); The first air slot (12) extends from an end facing the first permanent magnet slot (111) to an end facing away from the first permanent magnet slot (111) toward the arc edge, and the center line of the arc surface is colinear with the center line of the arc edge.
9. The rotor punching sheet (100) according to any one of claims 1 to 6, characterized in that: The shortest distance between the first permanent magnet slot (111) and the outer edge of the punching sheet body (10) is greater than or equal to 1.5 mm.
10. The rotor punching sheet (100) according to any one of claims 3 to 6, characterized in that: The shortest distance between the first air groove (12) and the outer edge of the punch body (10) is greater than or equal to 0.5 mm and less than or equal to 2 mm.
11. The rotor punching sheet (100) according to any one of claims 1 to 6, characterized in that: The included angle between the second permanent magnet slot (112) and the third permanent magnet slot (113) is greater than or equal to 80° and less than or equal to 110°.
12. The rotor punching sheet (100) according to any one of claims 3 to 6, characterized in that: The punching sheet body (10) is further provided with a second air groove (14), the second air groove (14) being located on a side of the first end (1121) facing away from the second end (1122) and being connected to the second permanent magnet groove (112); The second air groove (14) extends from an end facing the second permanent magnet groove (112) to an end facing away from the second permanent magnet groove (112) toward the outer edge of the punching sheet body (10).
13. The rotor punching (100) according to claim 12, characterized in that: The shortest distance between the second air groove (14) and the outer edge of the punch body (10) is greater than or equal to 0.5 mm and less than or equal to 2 mm.
14. The rotor punching sheet (100) according to claim 3, characterized in that: The punching sheet body (10) is further provided with a third air groove (15), wherein the third air groove (15) is located on a side of the second end (1122) facing away from the first end (1121) and is connected to the second permanent magnet groove (112).
15. The rotor punching (100) according to claim 14, characterized in that: The punch body (10) is further provided with a fourth air groove (18), the fourth air groove (18) being located on a side of the fourth end (1132) facing away from the third end (1131) and being connected to the third permanent magnet groove (113); Along the circumferential direction of the axial hole (101), the shortest distance between the third air groove (15) and the fourth air groove (18) is greater than or equal to 0.5 mm and less than or equal to 2 mm.
16. The rotor punching (100) according to claim 12, characterized in that: The outer edge of the portion of the punch body (10) between the first air groove (12) and the second air groove (14) includes a concave edge (16).
17. The rotor punching (100) according to claim 16, characterized in that: The concave edge (16) comprises an arc segment and a straight edge segment tangent to the arc segment.
18. The rotor punching (100) according to claim 17, characterized in that: The radius of the arc segment is greater than or equal to 3 mm and less than or equal to 5 mm.
19. The rotor sheet (100) according to claim 16, characterized in that: The recessed depth of the recessed edge (16) is greater than or equal to 0.6 mm and less than or equal to 1.5 mm.
20. The rotor sheet (100) according to claim 16, characterized in that: The length of the recessed edge (16) along the circumference of the axial hole (101) is greater than or equal to 1.5 mm and less than or equal to 2.5 mm.
21. A rotor, characterized in that: include: The rotor punching (100) according to any one of claims 1 to 20, wherein the number of the rotor punching (100) is plural, and the plurality of the rotor punchings (100) are stacked in sequence; and A first permanent magnet (21), wherein the first permanent magnet (21) is installed in the first permanent magnet slot (111), and the shape of the first permanent magnet (21) matches the shape of the first permanent magnet slot (111); A second permanent magnet (22), wherein the second permanent magnet (22) is installed in the second permanent magnet slot (112), and the shape of the second permanent magnet (22) matches the shape of the second permanent magnet slot (112); A third permanent magnet (23), the third permanent magnet (23) is installed in the third permanent magnet slot (113), and the shape of the third permanent magnet (23) matches the shape of the third permanent magnet slot (113).
22. An electric motor, characterized in that: include: The rotor of claim 21; and The stator is located at the periphery of the rotor.
23. A vehicle, characterized in that: include: wheel; The electric motor of claim 22 is drivingly connected to the wheel.