Rotor punching sheet, rotor core and motor

Abstract

The invention provides a rotor punching sheet, a rotor core and a motor. The rotor punching sheet comprises a punching sheet body, first magnetic steel, second magnetic steel and third magnetic steel. The first magnetic steel is mounted in the first magnetic steel groove, and the magnetizing direction of the first magnetic steel is tangential magnetizing; second magnetic steel grooves are arranged between the adjacent first magnetic steel grooves, and the magnetizing direction of the second magnetic steel is radial magnetizing. Third magnetic steel grooves are formed in the radial outer sides of the second ends of the first magnetic steel grooves, third magnetic steel is installed in the third magnetic steel grooves, the magnetizing direction of the third magnetic steel faces the radial outer side of the punching sheet body, and a first acute angle is formed between the magnetizing direction of the third magnetic steel and the magnetizing direction of the second magnetic steel, so that magnetic lines of force converge towards the radial outer side of the punching sheet body. According to the invention, the magnetizing direction of the third magnetic steel can effectively guide the magnetic lines to the air gap, thereby preventing the magnetic lines from forming a useless closed loop or premature leakage in the rotor, and improving the utilization rate of the magnetic steel.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and in particular relates to a rotor punching sheet, a rotor core and a motor. Background Art

[0002] Permanent magnet servo motors are widely used in industrial robots, machine tools, medical equipment, automobiles and other fields due to their high power density and high torque output. However, under the condition of high power density of servo motors, high precision must be guaranteed at the same time, and the output torque fluctuation of the servo motor must be small and the motor must run smoothly. The hybrid rotor core is a motor design that combines radial and tangential magnets. This design can effectively improve the air gap flux density of the motor, increase the output torque, increase the load capacity, and realize a high power density and high torque output motor. The hybrid rotor increases the rotor flux density through multiple magnets with different magnetizing directions, but this solution has a large amount of magnetic leakage inside the rotor, resulting in low magnet utilization. There is a certain amount of room for optimization design of the internal magnetic circuit of the hybrid rotor. Summary of the Invention

[0003] The present invention provides a rotor punching, a rotor core and a motor, which can solve the technical problem that the magnetic steel of the hybrid rotor core has large magnetic leakage inside the rotor, resulting in low utilization rate of the magnetic steel.

[0004] The present invention provides a rotor punching sheet, which includes a punching sheet body, a first magnetic steel, a second magnetic steel and a third magnetic steel;

[0005] The punching body is provided with a plurality of first magnetic steel grooves in the circumferential direction. In the radial direction of the punching body, the first ends of the first magnetic steel grooves extend radially inwardly of the punching body, and the second ends of the first magnetic steel grooves extend radially outwardly of the punching body. The first magnetic steel is installed in the first magnetic steel grooves, and the magnetization direction of the first magnetic steel is tangential magnetization.

[0006] A second magnetic steel slot is provided between adjacent first magnetic steel slots, and the second magnetic steel slot is close to the first end of the first magnetic steel slot. The second magnetic steel is installed in the second magnetic steel slot, and the magnetization direction of the second magnetic steel is radial magnetization.

[0007] A third magnetic steel slot is provided radially outside the second end of the first magnetic steel slot, and the third magnetic steel is installed in the third magnetic steel slot. The magnetization direction of the third magnetic steel is toward the radial outside of the punching sheet body, and a first acute angle is formed between the magnetization direction of the third magnetic steel and the magnetization direction of the second magnetic steel, so that the magnetic lines of force converge toward the radial outside of the punching sheet body.

[0008] In some embodiments, the third magnetic steel slot is located on the radial extension line of the second end of the first magnetic steel slot, and a second acute angle is formed between the magnetization direction of the first magnetic steel slot and the magnetization direction of the second magnetic steel, and the angle of the second acute angle is greater than the angle of the first acute angle, so that the magnetic lines of force converge inward in the inner area of ​​the magnetic pole.

[0009] In some embodiments, the rotor punching sheet is provided with an axial hole, the second magnetic steel slot is located radially outside the axial hole, and a magnetic isolation hole is provided between the axial hole and the second magnetic steel slot, so that a first magnetic isolation bridge is formed between the radial outside of the magnetic isolation hole and the second magnetic steel slot, so that the magnetic lines of force of the first magnetic steel converge toward the radial outside of the punching sheet body.

[0010] In some embodiments, in the circumferential direction of the rotor punching, one end of the magnetic isolation hole extends toward the first magnetic steel slot on one side of the second magnetic steel slot, and the other end of the magnetic isolation hole extends toward the first magnetic steel slot on the other side of the second magnetic steel slot, and the circumferential length of the magnetic isolation hole is greater than the circumferential length of the second magnetic steel slot.

[0011] In some embodiments, magnetic poles are formed between radial extension lines of adjacent first magnetic steel slots, and the outer circular contour corresponding to the magnetic poles is provided with a trimming structure so that the radial outer sides of the magnetic poles bulge outward.

[0012] In some embodiments, the cutting edge structure includes a first cutting edge and a second cutting edge, the magnetic pole has a central axis, the first cutting edge and the second cutting edge are symmetrically arranged about the central axis, one end of the first cutting edge and the second cutting edge are connected to each other, and the other ends of the first cutting edge and the second cutting edge respectively extend toward the radial extension line of the corresponding first magnetic steel slot, and the connection between the first cutting edge and the second cutting edge is arranged to protrude outward.

[0013] In some embodiments, the first cutting edge and the second cutting edge each include a gradient section, a changing section, and a smooth section connected in sequence, wherein one end of the gradient section away from the changing section intersects with the central axis, and one end of the smooth section away from the changing section is connected to the smooth section of the adjacent magnetic pole.

[0014] In some embodiments, the center of the rotor punching is O0, the gradient section and the changing section are eccentrically arranged relative to the center O0, the center of the gradient section is O1, the center of the changing section is O2, and the straight-line distance between the center O1 and the center O0 is smaller than the straight-line distance between the center O2 and the center O0.

[0015] A rotor core comprises a plurality of rotor punchings stacked together, wherein the rotor punchings are the above-mentioned rotor punchings.

[0016] A motor includes a rotor core, wherein the rotor core is the above-mentioned rotor core.

[0017] The rotor punching, rotor core and motor provided by the present invention have the following beneficial effects:

[0018] In the present invention, the first magnet is tangentially magnetized, and the magnetic lines of force generated by it are widely distributed in the circumferential direction, which can effectively utilize the circumferential space of the rotor to increase the magnetic flux density at the air gap. The second magnet is radially magnetized away from the center of the circle, and its magnetic lines of force expand outward in the radial direction, cooperating with the magnetic lines of force of the first magnet, so that the magnetic flux distribution inside the rotor is more reasonable, thereby improving the power density of the motor. The magnetization direction of the third magnet toward the radial outside forms a first acute angle with the magnetization direction of the second magnet, so that the magnetic lines of force converge toward the radial outside, further concentrating the magnetic flux near the air gap, enhancing the magnetic density at the air gap, and improving the output power of the motor. The combination of the tangential magnetization of the first magnet and the radial magnetization of the second magnet can form a composite magnetic field distribution inside the magnetic pole. The interaction between the tangential magnetic field of the first magnet and the radial magnetic field of the second magnet causes the magnetic lines of force to converge inward on the inside of the magnetic pole, which is beneficial to improving the torque output capacity of the motor. The first acute angle formed between the magnetization direction of the third magnet and the magnetization direction of the second magnet guides the magnetic lines of force to converge radially outward, making the magnetic flux distribution at the air gap more uniform and increasing the magnetic flux at the air gap, thereby improving the torque coefficient of the motor and increasing the output torque. In terms of optimizing the magnetic circuit and improving the utilization rate of the magnets, the three different magnetization directions enable the magnetic lines of force generated by the magnets to better cooperate and guide each other inside the rotor. The synergistic effect of the first and second magnets ensures that the magnetic lines of force are rationally distributed inside the magnetic pole, reducing the leakage of the magnets inside the magnetic pole. The magnetizing direction arrangement of the third magnet can effectively guide the magnetic lines of force to the air gap, preventing the magnetic lines of force from forming a useless closed loop inside the rotor or leaking prematurely, thereby improving the utilization rate of the magnet, making the magnetic properties of the magnet more fully exerted, and optimizing the magnetic circuit structure of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0020] Figure 1 Schematic diagram of a rotor punching according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the first to third magnetic steels according to an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the first to third magnetic steel slots according to an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the magnetization direction from the first magnetic steel to the third magnetic steel;

[0024] Figure 5 Schematic diagram of the first to third magnetic isolation bridges according to an embodiment of the present invention;

[0025] Figure 6 is a schematic diagram of a trimming structure according to an embodiment of the present invention;

[0026] Figure 7 Magnetic field line distribution diagram of the magnetic pole of an embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the first to third magnetic isolation bridges according to an embodiment of the present invention;

[0028] Figure 9 Relationship diagram between air gap magnetic flux density and trimming structure of the embodiment of the present invention;

[0029] Figure 10 This is a graph showing the relationship between the output torque and time in this embodiment.

[0030] Figures: 1-first magnet; 2-second magnet; 3-third magnet; 4-punch body; 5-first magnet slot; 6-second magnet slot; 7-third magnet slot; 8-axis hole; 9-magnetic isolation hole; 10-first magnetic isolation bridge; 11-cutting edge structure; 12-magnetic pole; 13-first cut edge; 14-second cut edge; 151-gradual section; 152-changing section; 153-smooth section; 16-second magnetic isolation bridge; 17-third magnetic isolation bridge. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0033] For ease of description, spatially relative terms such as "on," "above," "on the upper surface of," and "upper" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in a drawing is inverted, a device described as "above" or "on top of" the other devices or features would then be positioned "below" or "beneath" the other devices or features.

[0034] See also Figures 1 to 4 As shown, according to an embodiment of the present invention, a rotor punching is provided, which includes a punching body 4, a first magnetic steel 1, a second magnetic steel 2 and a third magnetic steel 3; the punching body 4 is provided with a plurality of first magnetic steel slots 5 in the circumferential direction, and in the radial direction of the punching body 4, the first ends of the first magnetic steel slots 5 extend radially inwardly of the punching body 4, and the second ends of the first magnetic steel slots 5 extend radially outwardly of the punching body 4, the first magnetic steel 1 is installed in the first magnetic steel slots 5, and the magnetization direction of the first magnetic steel 1 is tangential magnetization P1; between adjacent first magnetic steel slots 5 A second magnetic steel slot 6 is provided, and the second magnetic steel slot 6 is close to the first end of the first magnetic steel slot 5. The second magnetic steel 2 is installed in the second magnetic steel slot 6, and the magnetization direction of the second magnetic steel 2 is radial magnetization P2; a third magnetic steel slot 7 is provided radially outside the second end of the first magnetic steel slot 5, and the third magnetic steel 3 is installed in the third magnetic steel slot 7. The magnetization direction of the third magnetic steel 3 is toward the radial outside of the punching sheet body 4, and a first acute angle β is formed between the magnetization direction of the third magnetic steel 3 and the magnetization direction of the second magnetic steel 2, so that the magnetic lines of force converge toward the radial outside of the punching sheet body 4.

[0035] It is worth noting that the magnetization direction of the first magnetic steel 1 in this embodiment is tangential magnetization P1, that is, its magnetization direction is in the circumferential tangential direction. Although the magnetization direction of the first magnetic steel 1 is tangential magnetization P1, the tangential directions of adjacent first magnetic steels 1 are opposite, that is, the magnetization directions of adjacent first magnetic steels 1 are opposite in the tangential direction, and both point in the magnetization direction of the second magnetic steel 2. The magnetization direction of the second magnetic steel 2 is radial magnetization P2, that is, its magnetization direction is toward the center of the punching body 4 or away from the center of the punching body 4. In this embodiment, the magnetization direction of the second magnetic steel 2 is away from the center of the punching body 4. The magnetization direction of the third magnetic steel 3 is toward the radially outward side of the rotor lamination body 4. This means that the magnetization direction of the third magnetic steel 3 is neither tangential nor radial. In the circumferential direction, the magnetization direction of the third magnetic steel 3 is also deflected relative to the magnetization direction of the first magnetic steel 1. This means that the magnetization direction of the third magnetic steel 3 is biased toward the outer circumference of the rotor lamination, not toward the center of the rotor lamination. Furthermore, the first, second, and third magnetic steels 1, 2, and 3 are magnetized in a specific direction before being installed in their corresponding magnetic steel slots. After magnetization is complete, they are installed in the magnetic steel slots. Furthermore, the magnetic steel mounting slots are also configured based on the magnet installation requirements.

[0036] Specifically, the first magnetic steel 1 is installed in a circumferential distribution, and the first magnetic steel slot 5 extends from the radial inside to the radial outside, that is, the length direction of the first magnetic steel 1 extends in the radial direction of the punching body 4. The first magnetic steel 1 adopts a tangential magnetization P1 method, and its magnetization direction is the circumferential tangential direction. This magnetization method makes the magnetic lines of force mainly distributed along the circumferential direction. When the magnetic lines of force of the first magnetic steel 1 converge inward on the inner side of the magnetic pole 12, it is equivalent to forming a magnetic line convergence effect near the center of the rotor. The second magnetic steel 2 adopts radial magnetization P2, and its magnetization direction is away from the center of the punching body 4. A second magnetic steel slot 6 is arranged between adjacent first magnetic steel slots 5, and the second magnetic steel slot 6 is close to the first end of the first magnetic steel slot 5 (the end extending radially inwardly of the punching body 4). The magnetic lines of force of the second magnetic steel 2 will extend in the radial outward direction and cooperate with the magnetic lines of force of the first magnetic steel 1 on the inner side of the magnetic pole 12. The third magnetic steel 3 is installed in the third magnetic steel slot 7 outside the second end of the first magnetic steel slot 5 (the end extending radially outward from the lamination body 4). Its magnetization direction is toward the radial outward side of the lamination body 4 and forms a first acute angle β with the magnetization direction of the second magnetic steel 2. That is, there is an intersection between the magnetization direction extension line of the third magnetic steel slot 7 and the outer circle of the lamination body 4. This magnetization direction setting causes the magnetic lines of force of the third magnetic steel 3 to have an outward distribution at a certain angle in the radial outward direction. When the magnetic lines of force of the third magnetic steel 3 converge toward the radial outward side of the lamination body 4, they form a guiding relationship with the magnetic lines of force of the second magnetic steel 2 in the radial direction. The second magnetic steel 2 provides a radially outward magnetic line foundation, and the third magnetic steel 3, through its specific magnetization direction, further guides and converges the magnetic lines of force radially outward. This convergence effect can effectively reduce the magnetic flux leakage of the magnetic steel inside the rotor, improve the utilization rate of the magnetic steel, and make the magnetic lines of force distribution inside the rotor more reasonable, thereby optimizing the magnetic circuit of the motor and enhancing the performance of the motor.

[0037] In this embodiment, the first magnetic steel 1 adopts tangential magnetization P1, and the magnetic lines of force generated by it are widely distributed in the circumferential direction, which can effectively utilize the circumferential space of the rotor to increase the magnetic flux density at the air gap. The second magnetic steel 2 adopts radial magnetization P2 away from the center of the circle, and its magnetic lines of force extend outward in the radial direction. They cooperate with the magnetic lines of force of the first magnetic steel 1 to make the magnetic flux distribution inside the rotor more reasonable, thereby improving the power density of the motor. The magnetization direction of the third magnetic steel 3 toward the radial outside forms a first acute angle β with the magnetization direction of the second magnetic steel 2, so that the magnetic lines of force converge radially outward, further concentrating the magnetic flux near the air gap, enhancing the magnetic flux density at the air gap, and improving the output power of the motor. The combination of the tangential magnetization P1 of the first magnetic steel 1 and the radial magnetization P2 of the second magnetic steel 2 forms a composite magnetic field distribution inside the magnetic pole 12. The interaction between the tangential magnetic field of the first magnetic steel 1 and the radial magnetic field of the second magnetic steel 2 causes the magnetic lines of force to converge inward inside the magnetic pole 12, which is beneficial for improving the torque output capacity of the motor. The first acute angle β formed between the magnetization direction of the third magnetic steel 3 and the magnetization direction of the second magnetic steel 2 guides the magnetic lines of force to converge radially outward, making the magnetic flux distribution at the air gap more uniform and increasing the magnetic flux at the air gap, thereby improving the torque coefficient of the motor and increasing the output torque. In terms of optimizing the magnetic circuit and improving the utilization rate of the magnetic steel, the three different magnetization directions enable the magnetic lines of force generated by the magnetic steel to better cooperate and guide each other inside the rotor. The synergistic effect of the first magnetic steel 1 and the second magnetic steel 2 ensures that the magnetic lines of force are rationally distributed inside the magnetic pole 12, reducing the leakage of the magnetic steel inside the magnetic pole 12. The magnetization direction arrangement of the third magnetic steel 3 can effectively guide the magnetic lines of force to the air gap, preventing the magnetic lines of force from forming an useless closed loop inside the rotor or leaking prematurely, thereby improving the utilization rate of the magnetic steel, making the magnetic properties of the magnetic steel more fully exerted, and optimizing the magnetic circuit structure of the motor.

[0038] See also Figures 1 to 4 As shown, the third magnetic steel slot 7 is located on the radial extension line of the second end of the first magnetic steel slot 5, and a second acute angle α is formed between the magnetizing direction of the first magnetic steel slot 5 and the magnetizing direction of the second magnetic steel 2, and the angle of the second acute angle α is greater than the angle of the first acute angle β, so that the magnetic lines of force converge inward in the inner area of ​​the magnetic pole 12.

[0039] Specifically, since the first magnetic steel 1 adopts tangential magnetization P1, there is an angle between the first magnetic steel 1 and the second magnetic steel 2. The magnetization direction of the first magnetic steel 1 is tangential magnetization P1, and the magnetization direction of the second magnetic steel 2 is radial magnetization P2 away from the center of the circle. A third magnetic steel slot 7 is arranged on the radial extension line of the second end of the first magnetic steel slot 5, and a second acute angle α is formed between the magnetization direction of the first magnetic steel 1 and the magnetization direction of the second magnetic steel 2. The angle of this second acute angle α is greater than the first acute angle β between the first magnetic steel 1 and the third magnetic steel 3. Due to the existence of this second acute angle α, when the first magnetic steel 1 and the second magnetic steel 2 are installed on the punching body 4, the tangential magnetic lines of force generated by the first magnetic steel 1 and the radial magnetic lines of force generated by the second magnetic steel 2 intersect in the inner area of ​​the magnetic pole 12. Since the angle of the second acute angle α is large, the magnetic lines of force produce an inward convergence effect in the inner area of ​​the magnetic pole 12. The inner area of ​​the magnetic pole 12 is equivalent to a convergence point of magnetic lines of force. The magnetic lines of force are concentrated to this area from multiple directions of the first magnetic steel 1 and the second magnetic steel 2. This convergence effect can effectively reduce the leakage of the magnetic steel in the inner area of ​​the magnetic pole 12, because the magnetic lines of force are guided to the area where magnetic energy needs to be exerted, rather than leaking disorderly in the inner area of ​​the magnetic pole 12.

[0040] In this embodiment, a second acute angle α (greater than the first acute angle β) is formed between the magnetizing direction of the first magnetic steel slot 5 and the magnetizing direction of the second magnetic steel 2. This arrangement causes the tangential magnetic lines of force generated by the first magnetic steel 1 and the radial magnetic lines of force generated by the second magnetic steel 2 to intersect at a specific angle in the inner region of the magnetic pole 12. Compared to a case without this angle design, this intersection angle can guide the magnetic lines of force to be more evenly distributed in the inner region of the magnetic pole 12. Since the magnetic lines of force converge inwardly on the inner side of the magnetic pole 12, the scattered distribution of the magnetic lines of force in this area is reduced, making the transition of the magnetic lines of force from the inner side of the magnetic pole 12 to the air gap smoother, thereby improving the uniformity of the magnetic flux density at the air gap. Moreover, by properly setting the second acute angle α, the magnetic lines of force converge inwardly on the inner side of the magnetic pole 12, reducing the leakage flux of the magnetic steel in the inner region of the magnetic pole 12. The magnetic energy generated by the magnetic steel can be more fully utilized, improving the utilization rate of the magnetic steel, helping to optimize the magnetic circuit structure of the entire motor and more efficiently exerting the magnetic properties of the motor.

[0041] As a specific implementation, the first acute angle is β, the second acute angle is α, and the angle β is not limited to a specific value. Preferably, 1 / 2α<β<α can meet the needs.

[0042] See also Figures 1 to 6As shown, the rotor punching is provided with an axial hole 8, and the second magnetic steel slot 6 is located radially outside the axial hole 8. A magnetic isolation hole 9 is provided between the axial hole 8 and the second magnetic steel slot 6, so that a first magnetic isolation bridge 10 is formed between the radial outside of the magnetic isolation hole 9 and the second magnetic steel slot 6, so that the magnetic lines of force of the first magnetic steel 1 converge toward the radial outside of the punching body 4. In other embodiments, by providing the magnetic isolation hole 9 and reasonably limiting the magnetizing direction of the magnetic steel, flexible design can be performed to meet different motor performance requirements. For example, the size and shape of the magnetic isolation hole 9 and the magnetizing angle of the magnetic steel and other parameters can be adjusted according to the power level and torque requirements of the motor. This design flexibility enables the motor to better adapt to various application scenarios and meet different industrial needs.

[0043] Specifically, the shaft hole 8 is the central part of the rotor punching sheet and is mainly used to install the rotating shaft of the motor. Since the shaft hole 8 itself does not have a magnetized magnet, the magnetic field strength around it is relatively weak, mainly because the magnetic field of the surrounding magnets affects the edge of the area. The magnetic isolation hole 9 is located radially outside the shaft hole 8. Its main function is to isolate the magnetic circuit, prevent the magnetic lines of force from forming a local closed loop or generating excessive leakage magnetic field in the area around the shaft hole 8 and between the second magnetic steel slot 6, and guide the magnetic lines of force to flow more radially outside the punching sheet body 4. The second magnetic steel slot 6 is installed with a second magnetic steel 2, and its magnetization direction is radial magnetization P2 away from the center of the circle. The first magnetic isolation bridge 10 formed between the radial outside of the magnetic isolation hole 9 and the second magnetic steel slot 6 plays a role in guiding the magnetic field. Due to the existence of the first magnetic isolation bridge 10, the magnetic lines of force of the first magnetic steel 1 are guided by the shape and position of the magnetic isolation bridge when passing through the magnetic isolation bridge, and converge toward the radial outside of the punching sheet body 4. The magnetic field near the axial hole 8 is relatively weak, while under the action of the magnetic isolation hole 9 and the first magnetic isolation bridge 10, the magnetic lines of force converge more toward the radial outside. In particular, under the synergistic action of the first magnetic steel 1 and the second magnetic steel 2, the magnetic field gradually increases in the radial direction and diffuses outward. At the air gap, the magnetic lines of force can be distributed more concentratedly to form a stronger magnetic field.

[0044] In this embodiment, the magnetic isolation holes 9 form a first magnetic isolation bridge 10 between the shaft hole 8 and the second magnetic steel slot 6. By isolating the magnetic circuit, the magnetic lines of force are guided radially outward from the punch body 4, reducing the disordered distribution of the magnetic lines of force near the shaft hole 8. This allows more magnetic lines of force to be concentrated in the air gap, thereby enhancing the magnetic flux density in the air gap and improving the output torque and power density of the motor. The presence of the magnetic isolation holes 9 effectively blocks part of the magnetic leakage path between the magnetic steel and the shaft hole 8, preventing the magnetic lines of force from forming a local closed loop around the shaft hole 8. This reduces magnetic leakage of the magnetic steel inside the rotor, allowing more of the magnetic energy generated by the magnetic steel to be used to establish the external magnetic field, thereby improving the utilization rate of the magnetic steel.

[0045] In this embodiment, not only are specific magnetizing directions of the first magnetic steel 1, the second magnetic steel 2 and the third magnetic steel 3 limited, but a magnetic isolation hole 9 is also provided. The provision of the magnetic isolation hole 9 forms a first magnetic isolation bridge 10 between the shaft hole 8 and the second magnetic steel slot 6, isolating the magnetic circuit near the shaft hole 8 and the second magnetic steel slot 6. At the same time, the magnetizing directions of the three magnetic steels are limited so that the magnetic lines of force are distributed along a specific path inside the rotor. The first magnetic steel 1 is tangentially magnetized P1, and its magnetic lines of force are mainly distributed along the circumferential direction; the second magnetic steel 2 is radially magnetized P2 away from the center of the circle, and the magnetic lines of force expand outward; the third magnetic steel 3 is magnetized toward the radial outside and forms an acute angle with the second magnetic steel 2, guiding the magnetic lines of force to converge radially outward. This synergistic effect enables the magnetic lines of force to be more efficiently guided from the inside of the rotor to the air gap, thereby enhancing the magnetic density at the air gap. The improvement of the air gap magnetic density is a key factor in increasing the output torque and power density of the motor. The magnetic isolation hole 9 effectively blocks part of the magnetic leakage path between the magnet and the shaft hole 8. Under the limitation of the magnetizing direction of the three magnets, the magnetic lines of force are guided to the area where magnetic energy needs to be exerted, rather than leaking disorderly inside the rotor. In this way, the magnetic energy generated by the magnet can be used more for establishing the external magnetic field, thereby improving the utilization rate of the magnet.

[0046] As a specific implementation method, refer to Figure 7 and Figure 8 As shown, since the second magnetic steel 2 is located between the two first magnetic steels 1, when the magnetic isolation hole 9 is arranged on the radial inner side of the second magnetic steel 2, the second magnetic steel slot 6 and one side thereof ( Figure 5 A second magnetic isolation bridge 16 is formed between the first magnetic steel slot 5 on the left side of the direction, and the second magnetic steel slot 6 and the other side ( Figure 5A third magnetic isolation bridge 17 is formed between the first magnetic steel slot 5 (on the right side in the middle of the orientation). The second magnetic isolation bridge 16 is located between the second magnetic steel slot 6 and the first magnetic steel slot 5 on its left. The width of the second magnetic isolation bridge 16 is relatively narrow, and it plays a role in guiding the magnetic field. When the radial magnetic lines of force of the second magnetic steel 2 near the axial hole 8 pass through the second magnetic isolation bridge 16, they are guided by the shape and position of the bridge and converge toward the area of ​​the first magnetic steel slot 5 on the left. At the same time, the tangential magnetic lines of force of the first magnetic steel 1 on the left interact with the magnetic lines of force of the second magnetic steel 2, forming a concentrated magnetic field area in this area. The third magnetic isolation bridge 17 is located between the second magnetic steel slot 6 and the first magnetic steel slot 5 on its right. Similar to the second magnetic isolation bridge 16, the third magnetic isolation bridge 17 also plays a role in guiding the magnetic field. The magnetic lines of force of the second magnetic steel 2 converge toward the area of ​​the first magnetic steel slot 5 on the right through the third magnetic isolation bridge 17, and interact with the tangential magnetic lines of force of the first magnetic steel 1 on the right, forming another concentrated magnetic field area. Guided by the second and third magnetic isolation bridges 16 and 17, the magnetic flux of the second magnetic steel 2 primarily extends toward the first magnetic steel slots 5 on either side. Simultaneously, due to the presence of the magnetic isolation holes 9, the magnetic flux of the second magnetic steel 2 is restricted radially inward, less leaking toward the axial hole 8. Specifically, the magnetic flux of the second magnetic steel 2 near the axial hole 8 is guided by the second and third magnetic isolation bridges 16 and 17, while the magnetic flux of the second magnetic steel 2 near the outer side converges toward the magnetic poles 12. This allows the magnetic flux of the second magnetic steel 2 to more effectively converge radially toward the air gap. Guided by the second and third magnetic isolation bridges 16 and 17, the magnetic flux of the left and right first magnetic steels 1 interact with the magnetic flux of the second magnetic steel 2, concentrating and strengthening the magnetic field near the second magnetic steel slots 6. Simultaneously, the tangential magnetic flux of the first magnetic steel 1 is widely distributed circumferentially, while the magnetic field gradually weakens in areas farther from the second magnetic steel slots 6, resulting in a more uniform magnetic field distribution. From an overall perspective, this arrangement makes the magnetic field distribution inside the rotor punching more reasonable. The magnetic field near the shaft hole 8 is relatively weak, reducing the leakage magnetic field in this area. Under the guidance of the second magnetic isolation bridge 16 and the third magnetic isolation bridge 17, the magnetic lines of force of the second magnetic steel 2 effectively extend to the first magnetic steel slot 5 areas on both sides, and interact with the magnetic lines of force of the first magnetic steel 1 to form a concentrated area of ​​the magnetic field. The magnetic lines of force in these concentrated areas further converge toward the air gap, enhancing the magnetic field at the air gap.

[0047] See also Figures 1 to 6 As shown, in the circumferential direction of the rotor punching, one end of the magnetic isolation hole 9 extends toward the first magnetic steel slot 5 on one side of the second magnetic steel slot 6, and the other end of the magnetic isolation hole 9 extends toward the first magnetic steel slot 5 on the other side of the second magnetic steel slot 6, and the circumferential length of the magnetic isolation hole 9 is greater than the circumferential length of the second magnetic steel slot 6.

[0048] In this embodiment, one end of the magnetic isolation hole 9 extends toward the first magnetic steel slot 5 on one side of the second magnetic steel slot 6, and the other end extends toward the first magnetic steel slot 5 on the other side of the second magnetic steel slot 6. This extension creates a transition region between the magnetic isolation hole 9 and the second magnetic steel slot 6. In this transition region, the magnetic field strength gradually increases, and the magnetic lines of force converge from the edge of the magnetic isolation hole 9 toward the second magnetic steel slot 6 and the adjacent first magnetic steel slot 5. Because the circumferential length of the magnetic isolation hole 9 is greater than the circumferential length of the second magnetic steel slot 6, this transition region has a certain width in the circumferential direction, providing a buffer zone for the convergence and distribution of magnetic lines of force. In addition, the first magnetic steel slot 5 is mounted with a first magnetic steel 1, which is magnetized in a tangential magnetization direction P1. In the region where the magnetic isolation hole 9 extends to the first magnetic steel slot 5, the magnetic lines of force are affected by the shape of the magnetic isolation hole 9 and are distributed along the edge of the magnetic isolation hole 9 and the shape of the first magnetic steel slot 5. The tangential magnetic lines of force of the first magnetic steel 1 are widely distributed in the circumferential direction. In the area close to the magnetic isolation hole 9 , the magnetic lines of force converge toward the opening of the magnetic isolation hole 9 , forming a relatively concentrated magnetic field area.

[0049] As a specific embodiment, although one end of the magnetic isolation hole 9 extends toward the first magnetic steel slot 5 on one side of the second magnetic steel slot 6, and the other end of the magnetic isolation hole 9 extends toward the first magnetic steel slot 5 on the other side of the second magnetic steel slot 6, the total circumferential length of the magnetic isolation hole 9 extending to the first magnetic steel slot 5 accounts for 1 / 3 of the total width of the first magnetic steel slot 5, that is, no magnetic isolation hole 9 is provided on the radial inner side corresponding to 2 / 3 of the circumferential length of the first magnetic steel slot 5. In the radial direction, the width of the magnetic isolation hole 9 needs to be determined according to the rotor processing conditions. The radial width of the first magnetic isolation bridge 10 is close to the minimum size that meets the structural strength. The distance between the radial inner side of the magnetic isolation hole 9 and the inner side of the rotor punching is greater than the radial width of the first magnetic isolation bridge 10. The magnetic flux density in the areas of the first magnetic isolation bridge 10, the second magnetic isolation bridge 16, and the third magnetic isolation bridge 17 is made as large as possible, so that the rotor punching tends to saturate, internal magnetic leakage is reduced, and more magnetic lines of force are ensured to converge to the outside.

[0050] As a specific embodiment, the first and second magnetic steels 1 and 2 are conventional magnetic steels, while the third magnetic steel 3 is conventional or stronger. A material with a greater coercive force than the first magnetic steel 1 can be selected, resulting in stronger magnetism and achieving a magnetic concentration effect. Furthermore, the cross-sectional dimensions of the three magnetic steels are slightly smaller than those of the corresponding magnetic steel slots, facilitating installation and gluing. The length of the magnetic steels is the same as the stack height of the rotor core, ensuring minimal longitudinal magnetic leakage.

[0051] See also Figures 1 to 6 As shown, magnetic poles 12 are formed between radial lines of adjacent first magnetic steel slots 5. Here, radial lines refer to straight lines extending outward from the center of the punch body 1. The outer circular contour corresponding to the magnetic poles 12 is provided with a trimming structure 11 so that the radial outer side of the magnetic poles 12 bulges outward.

[0052] Specifically, the existing hybrid rotor core ignores the impact of factors such as the pole arc length and air gap size of the rotor pole during trimming, which will cause the motor back electromotive force to decrease and the output torque to decrease. In this embodiment, in order to ensure that the air gap size changes relatively smoothly when the designed rotor core is matched with the stator, the outer circular contour corresponding to the magnetic pole 12 is provided with a trimming structure 11, so that the radial outer side of the magnetic pole 12 bulges outward, which changes the shape and size of the air gap. The outwardly protruding shape of the magnetic pole 12 increases the magnetic field coverage range of the magnetic pole 12 on the radial outer side, and most of the magnetic lines of force interact with the stator through the magnetic pole 12 area. At the same time, the size of the pole shoe at the top of the magnet is effectively reduced, and the air gap size at the top of the magnet is increased. This design can effectively increase the air gap magnetic density and reduce the output torque pulsation.

[0053] It is worth noting that the trimming structure 11 in this embodiment is formed based on the outer contour of the punch body 4. The outer contour of the punch body 4 is reduced to form the trimming structure 11, so that the radial outer side of the magnetic pole 12 is outwardly convex, rather than a regular and smoothly transitioned arc structure. Preferably, the top of the magnetic pole 12 is outwardly convex. Since multiple first magnetic steels 1 are provided, multiple magnetic poles 12 are formed. Such a magnetic pole 12 region can be formed in the punch body 4 between each adjacent first magnetic steel slot 5.

[0054] See also Figures 1 to 6 As shown, the cutting edge structure 11 includes a first cutting edge 13 and a second cutting edge 14, the magnetic pole 12 has a central axis, the first cutting edge 13 and the second cutting edge 14 are symmetrically arranged about the central axis, one end of the first cutting edge 13 and the second cutting edge 14 are connected to each other, and the other ends of the first cutting edge 13 and the second cutting edge 14 extend respectively to the radial extension line of the corresponding first magnetic steel slot 5, and the connection between the first cutting edge 13 and the second cutting edge 14 is arranged to bulge outward.

[0055] In this embodiment, the junction of the first trim 13 and the second trim 14 protrudes outward, forming a raised structure on the radially outer side of the magnetic pole 12. This raised structure can concentrate magnetic flux, making the magnetic flux in the air gap more concentrated and enhanced at the position of the magnetic pole 12, thereby increasing the amplitude of the air gap magnetic flux. The trim structure 11 changes the shape of the air gap. This modulation effect helps optimize the air gap magnetic flux distribution, thereby improving the back electromotive force and output torque of the motor. Because the trim structure 11 causes the radially outer side of the magnetic pole 12 to protrude outward, the air gap becomes relatively smaller at the position of the magnetic pole 12, thereby enhancing the air gap magnetic flux at that location. The enhanced air gap magnetic flux can increase the back electromotive force of the motor.

[0056] See also Figure 6As shown, the first cutting edge 13 and the second cutting edge 14 each include a gradient section 151, a changing section 152 and a smooth section 153 connected in sequence. The end of the gradient section 151 away from the changing section 152 intersects with the central axis, and the end of the smooth section 153 away from the changing section 152 is connected to the smooth section 153 of the adjacent magnetic pole 12.

[0057] In this embodiment, the end of the gradient section 151 away from the changing section 152 intersects with the central axis. This design causes the magnetic pole 12 to gradually narrow in the area close to the central axis, so that the air gap size of the outer circle gradually changes when it approaches the top of the magnet. The changing section 152 plays a major role in this design, ensuring that the rotor punchings in the magnetic pole 12 area bulge outward and the air gap size is small. Most of the magnetic lines of force interact with the stator through the magnetic pole 12 area, while effectively reducing the size of the pole shoe at the top of the magnet and increasing the air gap size at the top of the magnet. This design can effectively increase the air gap magnetic density and reduce the output torque pulsation. The optimized magnetic flux distribution makes the magnetic density at the air gap more uniform and concentrated, especially on the radial outside of the magnetic pole 12, which helps to improve the back electromotive force of the motor, improve the power generation performance of the motor, and ensure that the motor can generate sufficient electrical energy output during operation. The continuity and uniform magnetic flux distribution of the smooth section 153 reduce the harmonic content of the air gap magnetic density, thereby reducing the torque fluctuation of the motor, which makes the motor more stable during operation, reduces vibration and noise, and improves the operation quality and reliability of the motor.

[0058] In this embodiment, the symmetrical trimming structure 11 and the optimized design of each segment make the magnetic field distribution more stable. This stability helps the motor maintain consistent performance under different operating conditions and reduces torque fluctuations and electromagnetic vibrations caused by changes in the magnetic field. By adjusting the specific shapes and sizes of the gradient segment 151, the changing segment 152, and the smooth segment 153, the magnetic flux distribution and magnetic field strength can be flexibly changed to adapt to different motor performance requirements. This design flexibility enables the motor to better meet the needs of specific application scenarios, such as high torque, high back electromotive force, low torque fluctuation, etc. The segmented design of each segment provides more adjustment space for motor parameter optimization. It can optimize the performance parameters of the motor by precisely controlling the geometric shape of each segment, thereby improving the overall performance of the motor. The smooth trimming structure 11 reduces the discontinuity of the surface of the magnetic pole 12 and reduces the magnetic resistance, which allows the magnetic flux to pass through the magnetic pole 12 more smoothly, reducing the loss of magnetic energy and improving the efficiency of the motor.

[0059] See also Figure 6As shown, the center of the rotor punching is O0, the gradient section 151 and the changing section 152 are eccentrically arranged relative to the center O0, the center of the gradient section 151 is O1, the center of the changing section 152 is O2, the straight-line distance between the centers O1 and O0 is smaller than the straight-line distance between the centers O2 and O0, the arc length of the gradient section 151 is L1, the arc length of the changing section 152 is L2, and the arc length of the smooth section 153 is L3.

[0060] Specifically, the gradual change section 151 and the changing section 152 are eccentrically arranged relative to the circle center O0, and the straight-line distance between the circle center O1 and the circle center O0 is also the offset distance. The changing section 152 is an arc in the circle with the circle center O1. The starting point of the changing section 152 is connected to the gradual change section 151. The changing section 152 is an end arc in the circle with the circle center O2. The starting point of the smooth section 153 is connected to the changing section 152. The smooth section 153 is formed by chamfering the changing section 152. The curvature of the arc of the changing section 152 is greater than the curvature of the smooth section 153. If the smooth section 153 is not provided, and the arc of the changing section 152 continues to extend toward the radial extension line of the first magnetic steel slot 5, the curvature of the outer circle contour corresponding to the first magnetic steel slot 5 is also large, resulting in large output torque pulsation. The smooth section 153 is provided to make the air gap change smoothly at this location, avoiding large fluctuations and affecting the motor torque output.

[0061] In this embodiment, the gradient section 151 gradually narrows the inner side of the magnetic pole 12, reducing magnetic flux crowding, lowering the peak magnetic density, and preventing magnetic saturation; the changing section 152 connects the gradient section 151 and the smooth section 153, and its shape change further optimizes the magnetic flux distribution, making the magnetic flux more evenly distributed throughout the entire magnetic pole 12 area. The smooth section 153 is connected to the smooth section 153 of the adjacent magnetic pole 12, making the air gap magnetic density distribution between the magnetic poles 12 more uniform, reducing magnetic flux leakage, and enhancing the continuity of the magnetic circuit. The optimized magnetic flux distribution makes the magnetic density in the air gap more uniform and concentrated, improving the motor's back electromotive force and power generation performance. At the same time, the uniform air gap magnetic density distribution allows the current in the stator winding to interact with a stronger magnetic field, enhancing the torque output capacity of the motor. The symmetrical cutting edge structure 11 and the optimized design of each section make the magnetic field distribution more stable, reduce torque fluctuations and electromagnetic vibrations, and improve the smoothness and reliability of the motor operation.

[0062] As a specific implementation method, this embodiment takes the radial extension line of the geometric center of the first magnetic steel slot 5 as a reference, selects the minimum size point of the punching body 4 preset at the top of the first magnetic steel 1, and one end of the smooth segment 153 is connected to this minimum size point, and the other end is connected to the changing segment 152. The smooth segment 153 is formed by chamfering the changing segment 152. Specifically, the center O3 of the smooth segment 153 is located outside the punching body 4, and the center O3 is located on the radial extension line of the geometric center of the first magnetic steel slot 5. The smooth segment 153 is a small arc in the circle with the center O3. The angle between the extended line of the arc of the changing section 152 and the normal at the minimum size point is small (equivalent to the outer circle of the rotor being recessed further inward according to the extension of the arc length of the changing section 152, and the slope of the recessed portion being larger), and the air gap length is large, so that when the rotor rotates to a specific angle, the torque output decreases, thereby making the peak-to-peak value of the torque output during operation larger, and the torque pulsation larger, affecting the torque output. Setting the smoothing section 153 can make the air gap change smoothly at this location, avoiding large fluctuations and affecting the motor torque output.

[0063] A rotor core comprises a plurality of rotor punchings which are stacked and arranged, wherein the rotor punchings are the above-mentioned rotor punchings.

[0064] Specifically, each rotor punching is provided with a first magnetic steel 1 with tangential magnetization P1, a second magnetic steel 2 with radial magnetization P2 and a third magnetic steel 3 with the magnetization direction facing radially outward. A magnetic isolation hole 9 is provided between the shaft hole 8 and the second magnetic steel slot 6. A first magnetic isolation bridge 10 is formed between the radial outer side of the magnetic isolation hole 9 and the second magnetic steel slot 6, and a magnetic pole 12 is formed between the radial extension lines of adjacent first magnetic steel slots 5. The outer circular contour corresponding to the magnetic pole 12 is provided with a cutting structure 11 so that the radial outer side of the magnetic pole 12 bulges outward.

[0065] In this embodiment, the magnets with different magnetization directions have a synergistic effect. The first magnet 1 is magnetized tangentially (P1), the second magnet 2 is magnetized radially (P2) away from the center of the circle, and the third magnet 3 is magnetized radially outward and forms an acute angle with the second magnet 2. This combination of magnetization directions makes the magnetic lines of force more concentrated and evenly distributed in the air gap, thereby enhancing the magnetic flux density in the air gap and improving the output torque and power density of the motor. The provision of the magnetic isolation hole 9 blocks the leakage flux path between the shaft hole 8 and the second magnetic steel slot 6. The first magnetic isolation bridge 10 guides the magnetic lines of force to converge in the air gap, reducing the disordered distribution of the magnetic lines of force inside the rotor and improving the utilization rate of the magnets. The optimized air gap magnetic flux distribution increases the back electromotive force of the motor and enhances the torque output capacity. The uniform magnetic field distribution enables the current in the stator winding to interact with a stronger magnetic field, thereby generating greater torque at the same current. The trimming structure 11 makes the air gap magnetic flux distribution more uniform, reduces the harmonic content, and thus reduces the torque fluctuation of the motor, which makes the motor more stable during operation, reduces vibration and noise, and improves the operation quality and reliability of the motor.

[0066] After adopting the above solution, combined with Figure 9 The relationship between air gap flux density and arc length is shown in the figure. The rotor designed in this embodiment and the rotor of the traditional scheme are simulated at the same time. While ensuring that the amount of magnetic steel remains unchanged, the relationship between the air gap flux density and arc length of different design schemes is compared. In this comparison, the outer diameter of the rotor and the size of the stator remain unchanged. In the air gap arc segment around the rotor, the average value of the air gap flux density between the rotor and the stator of this embodiment is 0.9399T, and the maximum value is 1.4154T. The average value of the air gap flux density between the rotor and the stator of the traditional scheme is 0.9105T, and the maximum value is 1.3908T. This embodiment improves the rotor magnetic field strength and effectively improves the air gap flux density. Secondly, in combination with reference to Figure 10 Output torque varies over time. Similarly, while maintaining the same amount of magnet steel, the output torque of different design solutions varies over operating time. Within one electrical cycle, the average output torque of the motor in this embodiment is 1.2811 N·m, with a torque ripple of 2.65%. The average output torque of the motor in the conventional solution is 1.2609 N·m, with a torque ripple of 3.21%. This embodiment effectively improves motor torque output, while simultaneously reducing torque ripple and enhancing motor operational stability.

[0067] As a specific embodiment, the rotor core is made of a magnetically conductive metal material, such as low-carbon steel with high magnetic conductivity and a high magnetic saturation coefficient. The shaft hole 8 is an opening on the inside of the rotor punching. It typically utilizes an interference fit with the shaft, with its size determined by the specific design of the motor shaft. The outer diameter of the rotor core contacts the air gap and then mates with the motor stator. The outer diameter is trimmed using the three arc segments designed in this patent.

[0068] A motor includes a rotor core, which is the above-mentioned rotor core.

[0069] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0070] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A rotor punching, characterized in that: include: Punching sheet body (4), first magnetic steel (1), second magnetic steel (2) and third magnetic steel (3); The punching sheet body (4) is provided with a plurality of first magnetic steel slots (5) in the circumferential direction. In the radial direction of the punching sheet body (4), the first end of the first magnetic steel slot (5) extends radially inwardly of the punching sheet body (4), and the second end of the first magnetic steel slot (5) extends radially outwardly of the punching sheet body (4). The first magnetic steel (1) is installed in the first magnetic steel slot (5), and the magnetization direction of the first magnetic steel (1) is tangential magnetization. A second magnetic steel slot (6) is provided between adjacent first magnetic steel slots (5), and the second magnetic steel slot (6) is close to the first end of the first magnetic steel slot (5); the second magnetic steel (2) is installed in the second magnetic steel slot (6), and the magnetization direction of the second magnetic steel (2) is radial magnetization; A third magnetic steel slot (7) is provided radially outside the second end of the first magnetic steel slot (5), and the third magnetic steel (3) is installed in the third magnetic steel slot (7). The magnetization direction of the third magnetic steel (3) is toward the radial outside of the punching sheet body (4), and a first acute angle is formed between the magnetization direction of the third magnetic steel (3) and the magnetization direction of the second magnetic steel (2), so that the magnetic lines of force converge toward the radial outside of the punching sheet body (4).

2. The rotor punching according to claim 1, characterized in that: The third magnetic steel slot (7) is located on the radial extension line of the second end of the first magnetic steel slot (5), and a second acute angle is formed between the magnetization direction of the first magnetic steel slot (5) and the magnetization direction of the second magnetic steel (2), and the angle of the second acute angle is greater than the angle of the first acute angle, so that the magnetic lines of force converge in the inner area of ​​the magnetic pole (12).

3. The rotor punching according to claim 1, characterized in that: The rotor punching sheet is provided with an axial hole (8), the second magnetic steel slot (6) is located radially outside the axial hole (8), and a magnetic isolation hole (9) is provided between the axial hole (8) and the second magnetic steel slot (6), so that a first magnetic isolation bridge (10) is formed between the radial outside of the magnetic isolation hole (9) and the second magnetic steel slot (6), so that the magnetic lines of force of the first magnetic steel (1) converge toward the radial outside of the punching sheet body (4).

4. The rotor punching according to claim 3, characterized in that: In the circumferential direction of the rotor punching sheet, one end of the magnetic isolation hole (9) extends toward the first magnetic steel slot (5) on one side of the second magnetic steel slot (6), and the other end of the magnetic isolation hole (9) extends toward the first magnetic steel slot (5) on the other side of the second magnetic steel slot (6), and the circumferential length of the magnetic isolation hole (9) is greater than the circumferential length of the second magnetic steel slot (6).

5. The rotor punching according to claim 1, characterized in that: Magnetic poles (12) are formed between radial lines of adjacent first magnetic steel slots (5), and the outer circular contour corresponding to the magnetic poles (12) is provided with a trimming structure (11) so that the radial outer side of the magnetic poles (12) bulges outward.

6. The rotor punching according to claim 5, characterized in that: The trimming structure (11) includes a first trimming (13) and a second trimming (14); the magnetic pole (12) has a central axis; the first trimming (13) and the second trimming (14) are symmetrically arranged about the central axis; one end of the first trimming (13) and the second trimming (14) are connected to each other; the other ends of the first trimming (13) and the second trimming (14) respectively extend toward the radial line of the corresponding first magnetic steel slot (5); and the connection between the first trimming (13) and the second trimming (14) is protruding outward.

7. The rotor punching according to claim 6, characterized in that: The first cutting edge (13) and the second cutting edge (14) both comprise a gradient section (151), a changing section (152) and a smooth section (153) connected in sequence, wherein one end of the gradient section (151) away from the changing section (152) intersects with the central axis, and one end of the smooth section (153) away from the changing section (152) is connected to the smooth section (153) of the adjacent magnetic pole (12).

8. The rotor punching according to claim 7, characterized in that: The center of the rotor punching is O0, the gradient section (151) and the changing section (152) are eccentrically arranged relative to the center O0, the center of the gradient section (151) is O1, the center of the changing section (152) is O2, and the straight-line distance between the center O1 and the center O0 is smaller than the straight-line distance between the center O2 and the center O0.

9. A rotor core comprising a plurality of rotor laminations stacked together, characterized in that: The rotor punching is the rotor punching according to any one of claims 1 to 8.

10. A motor comprising a rotor core, characterized in that: The rotor core is the rotor core according to claim 9.

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