Rotor punchings, rotor cores, motors and electrical equipment

Abstract

The present invention discloses a rotor punching sheet, a rotor core, a motor and an electric device. The rotor punching sheet comprises: a rotor body, which is a ring-shaped member with an axial hole at the center. The rotor body has multiple groups of magnetic pole units along its own circumference, and each group of magnetic pole units comprises: a first magnetic steel slot group, which includes two first magnetic steel slots; a second magnetic steel slot group, which is arranged at intervals from the first magnetic steel slot group along the radial direction of the rotor body, and the second magnetic steel slot group is close to the axial hole relative to the first magnetic steel slot group, and the second magnetic steel slot group includes two second magnetic steel slots, and the second magnetic steel slot and the first magnetic steel slot are respectively used to install permanent magnets. According to the rotor punching sheet of the embodiment of the present invention, the uniformity of magnetic field distribution can be improved and magnetic flux leakage can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and more specifically, to a rotor punching sheet, a rotor core motor and an electrical device. Background Art

[0002] At present, in the existing technology, permanent magnet synchronous motors are mainly divided into surface rotor structure, built-in rotor structure and claw pole rotor magnetic circuit structure according to the different positions of the permanent magnets in the rotor. The permanent magnets in the built-in rotor are protected by the pole shoes, and the magnetic resistance torque generated by the asymmetry of its rotor magnetic circuit structure also helps to improve the overload capacity and power density of the motor. In addition, it is easy to diffuse "weak magnetic field" and other characteristics, making it the first choice for high-speed motors. With the trend of high-speed permanent magnet motors and the continuous reduction of energy consumption, the requirements for motor rotor strength, heat dissipation, leakage magnetic field, vibration and noise are also getting higher and higher. Summary of the invention

[0003] An object of the present invention is to provide a rotor punching sheet that can at least solve one of the technical problems of the prior art, such as uneven magnetic field distribution, magnetic flux leakage, vibration and noise.

[0004] Another object of the present invention is to provide a rotor core comprising the above-mentioned rotor punching sheet.

[0005] Another object of the present invention is to provide a motor, comprising the above-mentioned rotor core.

[0006] Another object of the present invention is to provide an electrical device comprising the above-mentioned motor.

[0007] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0008] According to the rotor punching of the embodiment of the first aspect of the present invention, it includes: a rotor body, the rotor body is an annular member with an axial hole at the center, the rotor body has multiple groups of magnetic pole units along its own circumference, and each group of the magnetic pole units includes: a first magnetic steel slot group, the first magnetic steel slot group includes two first magnetic steel slots, the two first magnetic steel slots are located on both sides of the radial center line d axis of the magnetic pole unit, one end of each of the first magnetic steel slots is close to the axial hole and the d axis, one end of the two first magnetic steel slots are spaced apart and have a first magnetic isolation bridge therebetween, and the other end of each of the first magnetic steel slots is away from the axial hole and the d axis; a second magnetic steel slot group, the second magnetic steel slot group and the first magnetic steel slot group are spaced apart along the radial direction of the rotor body, and the first magnetic steel slot group The second magnetic steel slot group is close to the shaft hole relative to the first magnetic steel slot group, and the second magnetic steel slot group includes two second magnetic steel slots, and the second magnetic steel slots and the first magnetic steel slots are respectively used to install permanent magnets, and the two second magnetic steel slots are located on both sides of the d-axis, one end of each of the second magnetic steel slots is close to the shaft hole and the d-axis, and the other end of each of the second magnetic steel slots is far away from the shaft hole and the d-axis, and the other ends of the two second magnetic steel slots are spaced apart and distributed, and a magnetic isolation hole group and a magnetic isolation bridge group are provided therebetween, the magnetic isolation hole group includes a plurality of magnetic isolation holes, and the magnetic isolation bridge group includes a second magnetic isolation bridge and a third magnetic isolation bridge, the second magnetic isolation bridge is located between the other end of the second magnetic steel slot and the magnetic isolation hole, and the third magnetic isolation bridge 6 is located between two adjacent magnetic isolation holes.

[0009] Optionally, the two first magnetic steel grooves are symmetrically arranged about the d axis; the inner side wall of the first magnetic steel groove includes a first long side and a second long side that are oppositely arranged and distributed in parallel and a first short side and a second short side that are oppositely arranged, the second long side is close to the axial hole relative to the first long side, and the first short side is far away from the axial hole relative to the second short side.

[0010] Optionally, an angle between the first long side and the d-axis is θ1, 62°≤θ1≤67°.

[0011] Optionally, in the radial direction of the rotor body 1 , the widths of the first magnetic isolation bridges at various positions are equal and are a1, wherein 1.6 mm≤a1≤2.2 mm.

[0012] Optionally, the first short side is provided with a first magnetic isolation groove, and the inner side wall of the first magnetic isolation groove includes a first side wall, a second side wall, a third side wall and a fourth side wall connected in sequence, the first side wall is connected to the first long side and coincides with the outer extension line of the first long side, the fourth side wall is parallel to the first long side and the second long side, the fourth side wall intersects with the first short side, the third side wall intersects with the fourth side wall and the angle therebetween is β1, the first side wall intersects with the second side wall and the angle therebetween is β2, 124°≤β1≤136°, 141°≤β2≤153°; the closest distance between the inner side wall of the first magnetic isolation groove and the yoke of the rotor punching is L1, the distance between the position where the fourth side wall intersects with the first short side and the second long side is L2, and the distance between the first long side and the second long side is L6; wherein 1.74mm≤L1≤2.26mm; L2=0.37*L6.

[0013] Optionally, the second short side is provided with a second magnetic isolation groove, and the inner side wall of the second magnetic isolation groove includes a fifth side wall, a sixth side wall and a seventh side wall connected in sequence, the fifth side wall is connected to the first long side and coincides with the outer extension line of the first long side, and the length of the fifth side wall is L5; the seventh side wall intersects and is perpendicular to the first short side, the length of the seventh side wall is L4, the seventh side wall is parallel to the second long side and the distance from the second long side is L3; wherein L5=0.11*L6; L3=L2; L4=3.91*L5.

[0014] Optionally, the two second magnetic steel grooves are symmetrically arranged about the d axis, and the inner side walls of the second magnetic steel grooves include a third long side and a fourth long side that are relatively arranged and distributed in parallel, and a third short side and a fourth short side that are relatively arranged, and the fourth long side is close to the axial hole relative to the third long side, and the third short side is far away from the axial hole relative to the fourth short side.

[0015] Optionally, the third short side is provided with a third magnetic isolation groove, the inner side wall of the third magnetic isolation groove includes a first side edge, a second side edge, and a third side edge, the first side edge is connected to the third long side and coincides with the outer extension line of the third long side, the third side edge is parallel to the third long side and the fourth long side, the angle between the first side edge and the second side edge is β3, 122°≤β3≤134°; the spacing between the third long side and the fourth long side is d5, the spacing between the third side edge and the fourth long side is d2, and the closest distance between the third magnetic isolation groove and the yoke of the rotor punching is d1; d2=0.29*d5; d5=1.13*L6; d1=L1.

[0016] Optionally, a fourth magnetic isolation groove is set on the fourth short side, the inner side wall of the fourth magnetic isolation groove includes a fourth side, a fifth side and a sixth side, the shape of the fourth magnetic isolation groove is a rectangle, the fourth side is connected to the third long side and coincides with the outer extension line of the third long side, the length of the fourth side is d4; the distance between the sixth side and the fourth long side is d3; wherein, d4=0.164*d5; d3=d2.

[0017] Optionally, the number of the magnetic isolation holes is three and they are divided into two side magnetic isolation holes and one middle magnetic isolation hole. The center of the middle magnetic isolation hole is located on the d-axis, and the two side magnetic isolation holes are symmetrically distributed relative to the d-axis. The shape of the middle magnetic isolation hole is different from that of the side magnetic isolation holes located on both sides.

[0018] Optionally, the side magnetic isolation hole is in a trapezoidal shape, comprising an upper base, a lower base, a first waist, and a second waist, wherein the second waist is parallel to the fifth side, and the distance between the two is b1; the distance between the upper base and the lower base is b2; the line between the center point of the fifth side and the position one-third of b2 away from the axial hole is perpendicular to the d-axis, the length of the upper base is c3, and the length of the lower base is c1; c1=1.77*(d5-d3); c3=0.11*c1; b1=1.25*a1; b2=1.08*d5.

[0019] Optionally, a chamfer is set at the connection position between one end of the upper base and the second waist, and the radius of the chamfer is R1, and a chamfer is set at the connection position between the other end of the upper base and the first waist, and the radius of the chamfer is R2; a chamfer is set at the connection position between the lower base and the second waist, and the radius of the chamfer is R3, and the radius of the chamfer corresponding to the lower base and the first waist is equal to R2; wherein 1.8mm≤R1≤2.1mm; R2=0.5*R1; R3=0.6*R1.

[0020] Optionally, the shape of the middle magnetic hole is a rectangle, and the middle magnetic hole has two long sides and two short sides that are spaced apart, and the distance between the two long sides is the same as the distance between the upper base and the lower base; the length of the long side is c2, the four chamfered corner radii of the middle magnetic hole are all R4, the short side is parallel to the first waist and the distance between the two is b3; wherein, c2=1.05*c1; R4=0.47*R1; b3=1.6*b1.

[0021] Optionally, a width of the third magnetic isolation bridge is different from a width of the second magnetic isolation bridge.

[0022] Optionally, the angle between the third long side and the d-axis is θ2, wherein 39°≤θ2≤44°.

[0023] Optionally, a dovetail groove is provided at the inner edge of the rotor body near the shaft hole, the center of the dovetail groove is on the center line of the q-axis, the center line of the q-axis is the radial center line of the rotor body, and two adjacent magnetic pole units are symmetrically distributed relative to the center line of the q-axis, and the dovetail groove includes: a first edge; a second edge, one end of the second edge is connected to the first edge, the second edge is perpendicular to the first edge and has a length of f2; a third edge, one end of the third edge is connected to the other end of the second edge, the spacing between the other ends of the two third edges is f1, the length of the first edge is f3, the line between the other ends of the two third edges is parallel to the first edge, the distance between the two parallel lines is f4, and the distance from the midpoint of the fourth long side to the q-axis is f5; wherein f1=0.73*f5; f2=0.163*f1; f3=1.83*f1; f4=5.4*f2.

[0024] Optionally, a marking groove is provided on the inner edge of the rotor body near the axial hole, and the marking groove is a semicircular arc with a radius of R5. The angle formed by the sixth side and the fourth short side is γ, and the center of the marking groove is at the intersection of the bisector of the angle γ and the inner diameter of the rotor body; wherein 1.5*f2≤R5≤2.3*f2.

[0025] According to the rotor core of the embodiment of the second aspect of the present invention, the rotor core includes a plurality of rotor punchings stacked together, and the rotor punchings are any of the rotor punchings described above.

[0026] The motor according to the third aspect of the present invention comprises any one of the above-mentioned rotor cores.

[0027] An electrical device according to an embodiment of the fourth aspect of the present invention comprises any of the above-mentioned motors.

[0028] According to the rotor punching of the embodiment of the present invention, by adopting the double V-shaped topology structure technical solution, the uniformity of the magnetic field distribution can be improved, and the magnetic field can be more evenly distributed on the rotor surface, which is beneficial to improving the magnetic field stability and working efficiency of the motor; it can reduce magnetic flux leakage and improve the closure of the magnetic circuit, which is beneficial to improving the torque density of the motor and increasing the weak magnetic expansion range; it can reduce pulsation noise, and use the magnetic resistance principle to guide the magnetic lines of force, which can effectively change the direction of the magnetic circuit and the magnetic field distribution, reduce the magnetic field fluctuation of the motor, achieve the sinusoidal effect of the air gap magnetic field, reduce the harmonic content of the air gap magnetic density, and effectively reduce the torque pulsation.

[0029] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0031] Figure 1 is a schematic structural diagram of a rotor core according to an embodiment of the present invention; Figure 2 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 3 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 4 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 5 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 6 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 7 is a partial enlarged view of a rotor core according to an embodiment of the present invention; Figure 8 It is a partial enlarged view of the rotor core according to an embodiment of the present invention.

[0032] Reference Numbers Rotator body 1; shaft hole 1-1; First magnetic steel slot 2; first long side 2-1; second long side 2-2; first short side 2-3; second short side 2-4; The first magnetic isolation bridge 3; The second magnetic steel slot 4; the third long side 4-1; the fourth long side 4-2; the third short side 4-3; the fourth short side 4-4; The second magnetic isolation bridge 5; The third magnetic isolation bridge 6; First magnetic isolation groove 7; first side wall 7-1; second side wall 7-2; third side wall 7-3; fourth side wall 7-4; Yoke 8; The second magnetic isolation groove 9; the fifth side wall 9-1; the sixth side wall 9-2; the seventh side wall 9-3; A third magnetic isolation groove 10; a first side edge 10-1; a second side edge 10-2; a third side edge 10-3; Fourth magnetic isolation groove 11; fourth side 11-1; fifth side 11-2; sixth side 11-3; Side magnetic hole 12; upper bottom 12-1; lower bottom 12-2; first waist 12-3; second waist 12-4; The middle magnetic hole 13; the long side 13-1; the short side 13-2; Dovetail groove 14; first side 14-1; second side 14-2; third side 14-3; Marking slot 15. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0034] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0035] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0036] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0037] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] The rotor punching according to the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0039] like Figures 1 to 8 As shown, the rotor punching sheet according to an embodiment of the present invention includes a rotor sheet body 1.

[0040] Specifically, the rotor body 1 is an annular member with an axial hole 1-1 at the center, and the rotor body 1 has multiple groups of magnetic pole units along its own circumference. Each group of magnetic pole units includes a first magnetic steel slot group and a second magnetic steel slot group, the first magnetic steel slot group includes two first magnetic steel slots 2, the two first magnetic steel slots 2 are located on both sides of the radial centerline d axis of the magnetic pole unit, one end of each first magnetic steel slot 2 is close to the axial hole 1-1 and the d axis, one end of the two first magnetic steel slots 2 is spaced apart and has a first magnetic isolation bridge 3 between them, the other end of each first magnetic steel slot 2 is away from the axial hole 1-1 and the d axis, the second magnetic steel slot group and the first magnetic steel slot group are spaced apart along the radial direction of the rotor body 1, the second magnetic steel slot group is close to the axial hole 1-1 relative to the first magnetic steel slot group, and the second magnetic steel slot group includes two first magnetic steel slots 2. Two magnetic steel slots 4, the second magnetic steel slot 4 and the first magnetic steel slot 2 are respectively used to install permanent magnets, the two second magnetic steel slots 4 are located on both sides of the d-axis, one end of each second magnetic steel slot 4 is close to the axial hole 1-1 and the d-axis, and the other end of each second magnetic steel slot 4 is far away from the axial hole 1-1 and the d-axis, the other ends of the two second magnetic steel slots 4 are spaced apart and distributed, and a magnetic isolation hole group and a magnetic isolation bridge group are provided therebetween, the magnetic isolation hole group includes a plurality of magnetic isolation holes, the magnetic isolation bridge group includes a second magnetic isolation bridge 5 and a third magnetic isolation bridge 6, the second magnetic isolation bridge 5 is located between the other end of the second magnetic steel slot 4 and the magnetic isolation hole, and the third magnetic isolation bridge 6 is located between two adjacent magnetic isolation holes.

[0041] In other words, the rotor punching according to the embodiment of the present invention mainly includes a rotor body 1, and an axial hole 1-1 is arranged at the center of the rotor body 1. The rotor body 1 has multiple groups of magnetic pole units along its own circumference, that is, the circumference of the rotor body 1 includes several magnetic pole units. Each magnetic pole unit is provided with a plurality of magnetic steel slots, and the plurality of magnetic steel slots are regularly spaced along the radial direction of the rotor body 1. Specifically, each group of magnetic pole units includes two layers of magnetic steel slot groups, specifically a first magnetic steel slot group and a second magnetic steel slot group. The second magnetic steel slot group and the first magnetic steel slot group are spaced apart and distributed in the radial direction of the rotor body 1, and the second magnetic steel slot group is closer to the axial hole 1-1 than the first magnetic steel slot group.

[0042] Moreover, each layer of magnetic steel slot group includes two magnetic steel slots, and permanent magnets can be installed in the magnetic steel slots. Specifically, the first magnetic steel slot group includes two first magnetic steel slots 2, and the second magnetic steel slot group includes two second magnetic steel slots 4. Permanent magnets can be installed in the first magnetic steel slots 2 and the second magnetic steel slots 4, for example, permanent magnets of the same size are arranged in the two first magnetic steel slots 2, and permanent magnets of the same size are arranged in the two second magnetic steel slots 4.

[0043] Furthermore, the first magnetic steel slot group includes two first magnetic steel slots 2, one first magnetic steel slot 2 is located on one side of the radial center line d-axis of the magnetic pole unit, and the other first magnetic steel slot 2 is located on the other side of the radial center line d-axis of the magnetic pole unit. One end of each first magnetic steel slot 2 is close to the axial hole 1-1 and the d-axis, and one ends of the two first magnetic steel slots 2 are spaced apart. It can be seen that the shape of the first magnetic steel slot group is V-shaped.

[0044] Similarly, the second magnetic steel slot group includes two second magnetic steel slots 4, one second magnetic steel slot 4 is located on one side of the d-axis, and the other second magnetic steel slot 4 is located on the other side of the d-axis. One end of each second magnetic steel slot 4 is close to the shaft hole 1-1 and the d-axis, and the other end of each second magnetic steel slot 4 is away from the shaft hole 1-1 and the d-axis. The other ends of the two second magnetic steel slots 4 are spaced apart and distributed. It can be seen that the shape of the second magnetic steel slot group is V-shaped. Since the second magnetic steel slot group and the first magnetic steel slot group are spaced apart and distributed in the radial direction of the rotor body 1, the second magnetic steel slot group and the first magnetic steel slot group form a double V-shaped magnetic steel slot.

[0045] In addition, one ends of the two first magnetic steel slots 2 are spaced apart and have a first magnetic isolation bridge 3 therebetween, that is, a first magnetic isolation bridge 3 is formed between the two first magnetic steel slots 2 of the first magnetic steel slot group away from the axial hole 1 - 1 .

[0046] The other ends of the two second magnetic steel slots 4 are spaced apart and arranged with a magnetic isolation hole group and a magnetic isolation bridge group between them. The magnetic isolation hole group includes a plurality of magnetic isolation holes. The magnetic isolation bridge group includes a second magnetic isolation bridge 5 and a third magnetic isolation bridge 6. The second magnetic isolation bridge 5 is located between the other end of the second magnetic steel slot 4 and the magnetic isolation hole, and the third magnetic isolation bridge 6 is located between two adjacent magnetic isolation holes. In other words, a plurality of magnetic isolation holes, a second magnetic isolation bridge 5 and a third magnetic isolation bridge 6 are arranged between the two second magnetic steel slots 4 of the second magnetic steel slot group close to the shaft hole 1-1.

[0047] In this embodiment, by adopting the double V-type topology structure technical solution, the uniformity of magnetic field distribution can be improved, and the magnetic field can be more evenly distributed on the rotor surface, which is beneficial to improving the magnetic field stability and working efficiency of the motor; it can reduce magnetic flux leakage and improve the closure of the magnetic circuit, which is beneficial to improving the torque density of the motor and increasing the weak magnetic expansion range; it can reduce pulsation noise, and use the magnetic resistance principle to guide the magnetic lines of force, which can effectively change the direction of the magnetic circuit and the magnetic field distribution, reduce the magnetic field fluctuation of the motor, achieve the sinusoidal effect of the air gap magnetic field, reduce the harmonic content of the air gap magnetic density, and effectively reduce the torque pulsation.

[0048] According to one embodiment of the present invention, the two first magnetic steel slots 2 are symmetrically arranged about the d axis, that is, the first magnetic steel slot group far away from the shaft hole 1-1 is a V-shaped magnetic steel slot symmetrically distributed relative to the d axis. Among them, the inner side wall of the first magnetic steel slot 2 includes a first long side 2-1 and a second long side 2-2 that are relatively arranged and parallel, and a first short side 2-3 and a second short side 2-4 that are relatively arranged, that is, the inner side wall of the first magnetic steel slot 2 includes a first long side 2-1, a second long side 2-2, a first short side 2-3 and a second short side 2-4, the first long side 2-1 and the second long side 2-2 are parallel to each other and are arranged at intervals, and are arranged relatively, the first short side 2-3 and the second short side 2-4 are arranged at intervals, and are arranged relatively, and the first long side 2-1, the first short side 2-3, the second long side 2-2 and the second short side 2-4 can be connected in sequence to form a quasi-rectangle. The second long side 2-2 is close to the shaft hole 1-1 relative to the first long side 2-1, and the first short side 2-3 is far away from the shaft hole 1-1 relative to the second short side 2-4. In this embodiment, the shape of the first magnetic steel slot 2 is limited to a rectangular shape, which is convenient for installing the permanent magnet. In addition, the two first magnetic steel slots 2 form a V-shaped structure, which can make the magnetic field distribution on the motor stator more uniform, smooth the magnetic field change, reduce magnetic force fluctuations, and effectively reduce the vibration generated during the operation of the motor.

[0049] In some specific embodiments of the present invention, Figure 4 As shown, the angle between the first long side 2-1 and the d-axis is θ1, 62°≤θ1≤67°, for example, θ1 is 62°, 63°, 62°, 65°, 66° or 67°, etc., which can improve the magnetic flux distribution, reduce magnetic saturation and eddy current loss, thereby reducing iron loss and helping to improve the efficiency and power factor of the motor.

[0050] According to one embodiment of the present invention, Figure 4 As shown, in the radial direction of the rotor body 1, the width of each position of the first magnetic isolation bridge 3 is equal and is a1, that is, the first magnetic isolation bridge 3 formed between the two first magnetic steel slots 2 of the first magnetic steel slot group away from the shaft hole 1-1 is a magnetic isolation bridge with equal width along the radial direction of the rotor body 1, wherein 1.6mm≤a1≤2.2mm, for example, a1 is 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm or 2.2mm, etc. The limitation of a1 is conducive to optimizing the rotor stress according to the rotor stress distribution, ensuring the output capacity of the motor while effectively reducing the rotor stress.

[0051] In some specific embodiments of the present invention, the first short side 2-3 is provided with a first magnetic isolation groove 7, that is, one end of the first magnetic steel groove 2 is provided with a first magnetic isolation groove 7. The inner side wall of the first magnetic isolation groove 7 includes a first side wall 7-1, a second side wall 7-2, a third side wall 7-3 and a fourth side wall 7-4 connected in sequence, the first side wall 7-1 is connected to the first long side 2-1 and coincides with the outer extension line of the first long side 2-1, the fourth side wall 7-4 is parallel to the first long side 2-1 and the second long side 2-2, and the fourth side wall 7-4 intersects with the first short side 2-3, as shown in FIG. Figure 5 As shown, the third side wall 7-3 and the fourth side wall 7-4 intersect and the angle between them is β1, 124°≤β1≤136°, for example, β1 is 124°, 125°, 128°, 130°, 133°, 135° or 136°, etc.; the first side wall 7-1 and the second side wall 7-2 intersect and the angle between them is β2, 141°≤β2≤153°, for example, β2 is 141°, 143°, 145°, 148°, 150°, 151° or 153°, etc. In this embodiment, by limiting 124°≤β1≤136°, 141°≤β2≤153°, the direction of the magnetic circuit can be guided and the magnetic leakage at the end of the magnetic steel slot can be reduced.

[0052] like Figure 5 As shown, the closest distance between the inner wall of the first magnetic isolation groove 7 and the yoke 8 of the rotor punching is L1, that is, the closest distance between the first magnetic isolation groove 7 and the outer circle of the rotor punching and the yoke 8 is L1. The distance between the intersection of the fourth side wall 7-4 and the first short side 2-3 and the second long side 2-2 is L2, and the distance between the first long side 2-1 and the second long side 2-2 is L6, that is, the width of the first magnetic isolation groove 7 is L6; wherein 1.74mm≤L1≤2.26mm, for example, L1 is 1.74mm, 1.78mm, 1.82mm, 1.93mm, 2.10mm, 2.25mm or 2.26mm, etc.; L2=0.37*L6. Wherein limiting L1 is conducive to optimizing the rotor stress according to the rotor stress distribution, ensuring the output capacity of the motor while effectively reducing the rotor stress.

[0053] In this embodiment, by limiting the size of the first magnetic isolation groove 7, the intensity and direction of the magnetic field near the q-axis can be adjusted, thereby realizing the control of the magnetic field distribution of the motor, reducing the torque pulsation of the motor, and improving the running stability and reliability of the motor; the eddy current loop can be interrupted, the flow path of the eddy current and the eddy current loss can be reduced, and the motor core can be divided into a number of magnetic circuit units, limiting the diffusion and leakage of the magnetic field, reducing the magnetic leakage near the q-axis, and improving the efficiency of the motor. The q-axis centerline is the radial centerline of the rotor body 1, and two adjacent magnetic pole units are symmetrically distributed relative to the q-axis centerline.

[0054] According to one embodiment of the present invention, the second short side 2-4 is provided with a second magnetic isolation groove 9, that is, the other end of the first magnetic steel groove 2 is provided with a second magnetic isolation groove 9. The inner side wall of the second magnetic isolation groove 9 includes a fifth side wall 9-1, a sixth side wall 9-2 and a seventh side wall 9-3 connected in sequence, and the fifth side wall 9-1 is connected to the first long side 2-1 and coincides with the outer extension line of the first long side 2-1, such as Figure 5 As shown, the length of the fifth side wall 9-1 is L5; the seventh side wall 9-3 intersects and is perpendicular to the second short side 2-4, that is, perpendicular to the width direction of the first magnetic steel slot 2; the length of the seventh side wall 9-3 is L4; the seventh side wall 9-3 is parallel to the second long side 2-2 and the distance from the second long side 2-2 is L3; wherein L5=0.11*L6; L3=L2; L4=3.91*L5.

[0055] In this embodiment, by using the second magnetic isolation groove 9 that meets the above conditions, the strength and direction of the magnetic field near the d-axis can be adjusted, thereby realizing the control of the magnetic field distribution of the motor, reducing the torque pulsation of the motor, and improving the operating stability and reliability of the motor; the eddy current loop can be interrupted, the flow path of the eddy current and the eddy current loss can be reduced, the motor core can be divided into several magnetic circuit units, the diffusion of the magnetic field and the leakage of magnetic flux can be limited, the magnetic leakage loss can be reduced near the d-axis, and the efficiency of the motor can be improved.

[0056] According to one embodiment of the present invention, the two second magnetic steel slots 4 are symmetrically arranged about the d-axis, that is, the second magnetic steel slot group close to the shaft hole 1 - 1 is a V-shaped magnetic steel slot symmetrically distributed relative to the d-axis.

[0057] Among them, the inner side wall of the second magnetic steel slot 4 includes a third long side 4-1 and a fourth long side 4-2 that are relatively arranged and distributed in parallel, and a third short side 4-3 and a fourth short side 4-4 that are relatively arranged, that is, the inner side wall of the second magnetic steel slot 4 includes a third long side 4-1, a fourth short side 4-4, a fourth long side 4-2 and a third short side 4-3 that are connected in sequence, wherein the third long side 4-1 and the fourth long side 4-2 are spaced apart and distributed and are parallel to each other, and the third short side 4-3 and the fourth short side 4-4 are spaced apart and distributed and are relatively arranged. The fourth long side 4-2 is close to the shaft hole 1-1 relative to the third long side 4-1, and the third short side 4-3 is far away from the shaft hole 1-1 relative to the fourth short side 4-4. In this embodiment, by limiting and determining the size of the second magnetic steel slot 4 and optimizing the shape of the second magnetic steel slot 4, it is helpful to improve the torque density and power density of the motor and reduce the generation of high-order harmonics of the motor.

[0058] In some specific embodiments of the present invention, the third short side 4-3 is provided with a third magnetic isolation groove 10, and the inner side wall of the third magnetic isolation groove 10 includes a first side 10-1, a second side 10-2, and a third side 10-3. The first side 10-1 is connected to the third long side 4-1 and coincides with the outer extension line of the third long side 4-1. The third side 10-3 is parallel to the third long side 4-1 and the fourth long side 4-2. Figure 6 As shown, the angle between the first side 10 - 1 and the second side 10 - 2 is β3, 122°≤β3≤134°, for example, β3 is 122°, 125°, 128°, 130°, 133° or 134°, etc.

[0059] In this embodiment, by adopting a third magnetic isolation groove 10 that meets the above conditions, the strength and direction of the magnetic field near the q-axis can be adjusted, thereby realizing the control of the magnetic field distribution of the motor, reducing the torque pulsation of the motor, and improving the operating stability and reliability of the motor; the eddy current loop can be interrupted, the flow path and eddy current loss of the eddy current can be reduced, and the motor core can be divided into several magnetic circuit units, limiting the diffusion of the magnetic field and magnetic leakage phenomenon, reducing magnetic leakage loss near the q-axis, and improving the efficiency of the motor.

[0060] Among them, Figure 6 As shown, the spacing between the third long side 4-1 and the fourth long side 4-2 is d5, that is, the width of the third magnetic isolation groove 10 is d5, the spacing between the third side 10-3 and the fourth long side 4-2 is d2, and the closest distance between the third magnetic isolation groove 10 and the yoke 8 of the rotor punching is d1, that is, the closest distance between the third magnetic isolation groove 10 and the outer circle of the rotor punching on the yoke 8 is d1; d2=0.29*d5; d5=1.13*L6; d1=L1, that is, 1.74mm≤L1=d1≤2.26mm.

[0061] In this embodiment, by limiting L1 and d1, it is beneficial to optimize the rotor stress according to the rotor stress distribution, thereby ensuring the output capacity of the motor while effectively reducing the rotor stress.

[0062] According to one embodiment of the present invention, a fourth magnetic isolation groove 11 is provided on the fourth short side 4-4, and the inner side wall of the fourth magnetic isolation groove 11 includes a fourth side 11-1, a fifth side 11-2 and a sixth side 11-3. The shape of the fourth magnetic isolation groove 11 is rectangular, and the fourth side 11-1 is connected to the third long side 4-1 and coincides with the outer extension line of the third long side 4-1. Figure 6 As shown, the length of the fourth side 11 - 1 is d4; the distance between the sixth side 11 - 3 and the fourth long side 4 - 2 is d3; wherein, d4=0.164*d5; d3=d2.

[0063] In this embodiment, by adopting the fourth magnetic isolation groove 11 that meets the above conditions, the intensity and direction of the magnetic field near the d-axis can be adjusted, thereby realizing the control of the magnetic field distribution of the motor, reducing the torque pulsation of the motor, and improving the operating stability and reliability of the motor; the eddy current loop can be interrupted, the flow path and eddy current loss of the eddy current can be reduced, the motor core can be divided into several magnetic circuit units, the diffusion of the magnetic field and the leakage of magnetic flux can be limited, the magnetic leakage loss can be reduced near the d-axis, and the efficiency of the motor can be improved.

[0064] In some specific embodiments of the present invention, the number of magnetic isolation holes is three, that is, three magnetic isolation holes are provided in the area between the two second magnetic steel slots 4 of the second magnetic steel slot group close to the shaft hole 1-1. The three magnetic isolation holes are divided into two side magnetic isolation holes 12 and one middle magnetic isolation hole 13, the center of the middle magnetic isolation hole 13 is located on the d-axis, the two side magnetic isolation holes 12 are symmetrically distributed relative to the d-axis, and the shape of the middle magnetic isolation hole 13 is different from the shape of the side magnetic isolation holes 12 located on both sides, that is, the rotor body 1 is provided with three magnetic isolation holes of different shapes along the center of the d-axis, for example, two trapezoidal side magnetic isolation holes 12 are mirror-symmetrical about the center line of the d-axis, and the center of the middle magnetic isolation hole 13 falls on the center line of the d-axis. In this embodiment, by adopting the above three magnetic isolation holes, it is possible to control and optimize the distribution of the magnetic field, reduce magnetic field leakage, reduce magnetic loss, reduce electromagnetic interference, and improve motor efficiency and stability on the basis of ensuring the overall mechanical strength of the motor.

[0065] In some specific embodiments of the present invention, the side isolation magnetic hole 12 is shaped like a trapezoid, and the side isolation magnetic hole 12 includes an upper base 12-1, a lower base 12-2, a second waist 12-4, and a first waist 12-3, that is, the trapezoidal side isolation magnetic hole 12 includes an upper base 12-1, a second waist 12-4, a lower base 12-2, and a first waist 12-3 connected in sequence. The first waist 12-3 is parallel to the fifth side 11-2, and the distance between the two is b1. The distance between the upper base 12-1 and the lower base 12-2 is b2; the line between the center point of the fifth side 11-2 and the one-third position of b2 away from the axial hole 1-1 is perpendicular to the d-axis, that is, the line between the one-half position of the fifth side 11-2 and the upper third point of b2 is perpendicular to the center line of the d-axis. As shown Figure 7 As shown, the length of the upper base 12-1 is c3, and the length of the lower base 12-2 is c1; c1=1.77*d5-d3; c3=0.11*c1; b1=1.25*a1; b2=1.08*d5.

[0066] In this embodiment, by limiting the range of b1, the structural strength of the rotor can be enhanced; by limiting the size of the trapezoidal magnetic isolation hole (side magnetic isolation hole 12), the direction of the magnetic circuit can be changed and the torque pulsation of the motor can be reduced.

[0067] According to one embodiment of the present invention, Figure 7As shown, a chamfer is set at the connection position between one end of the upper bottom 12-1 and the first waist 12-3, and the radius of the chamfer is R1, and a chamfer is set at the connection position between the other end of the upper bottom 12-1 and the second waist 12-4, and the radius of the chamfer is R2; a chamfer is set at the connection position between the lower bottom 12-2 and the first waist 12-3, and the radius of the chamfer corresponding to the lower bottom 12-2 and the second waist 12-4 is equal to R2; wherein 1.8mm≤R1≤2.1mm, for example, R1 is 1.8mm, 1.9mm, 2.0mm or 2.1mm, etc.; R2=0.5*R1; R3=0.6*R1. In this embodiment, by further optimizing the shape of the side magnetic hole 12, the magnetic field inhomogeneity between the stator and the rotor can be reduced, and the electromagnetic force fluctuation, such as torque pulsation, can be reduced, which helps to reduce vibration, reduce noise, and improve the overall stability and performance of the motor.

[0068] According to one embodiment of the present invention, Figure 7 As shown, the shape of the middle magnetic isolation hole 13 is rectangular, with two long sides 13-1 and two short sides 13-2 spaced apart. The distance between the two long sides 13-1 is the same as the distance between the upper base 12-1 and the lower base 12-2, both of which are b2. It can be seen that in this embodiment, in the radial direction of the magnetic pole unit, the widths of the three magnetic isolation holes are the same; the length of the long side 13-1 is c2, the four chamfered corners of the middle magnetic isolation hole 13 are all R4, the short side 13-2 is parallel to the second waist 12-4 and the distance between the two is b3; among them, c2=1.05*c1; R4=0.47*R1; b3=1.6*b1.

[0069] In this embodiment, by limiting the range of b3, the structural strength of the rotor can be enhanced; by limiting the size of the rectangular magnetic isolation hole (middle magnetic isolation hole 13), the direction of the magnetic circuit can be further changed and the torque pulsation of the motor can be reduced.

[0070] In some specific embodiments of the present invention, the width of the third magnetic isolation bridge 6 is different from the width of the second magnetic isolation bridge 5. That is to say, the second magnetic isolation bridge 5 and the third magnetic isolation bridge 6 of unequal width are arranged between the two second magnetic steel slots 4 of the second magnetic steel slot group close to the shaft hole 1-1. In this embodiment, by adopting the second magnetic isolation bridge 5 and the third magnetic isolation bridge 6 of unequal width, it is possible to ensure the strength of the rotor structure, and to optimize the magnetic circuit flow path, reduce the magnetic leakage between the magnetic isolation bridges, and improve the torque density of the motor.

[0071] According to one embodiment of the present invention, Figure 4 As shown, the angle between the third long side 4 - 1 and the d-axis is θ2, where 39°≤θ2≤44°, for example, θ2 is 39°, 40°, 41°, 42°, 43° or 44°.

[0072] It should be noted that the combination of the two angles θ1 and θ2, as well as the widths L6 and d5 of the two double V-shaped magnetic steel slots, can increase the ratio of the motor's cross-axis inductance to the direct-axis inductance and improve the salient pole ratio. After the salient pole ratio is improved, the motor's utilization rate of the reluctance torque is also improved. When the motor outputs the same magnitude of permanent magnet torque, the electromagnetic torque of the motor can be improved. At the same time, the content of the fundamental wave and harmonics in the air gap magnetic field is related to the two angles θ1 and θ2. By limiting the values ​​of the two angles, the waveform of the air gap synthetic magnetic field can be optimized, the harmonic content in the air gap magnetic field can be effectively reduced, and the sinusoidality of the air gap magnetic field waveform can be improved, thereby reducing the tooth torque and torque pulsation of the permanent magnet synchronous motor and reducing the vibration noise of the motor.

[0073] According to one embodiment of the present invention, a dovetail groove 14 is provided at the inner edge of the rotor body 1 close to the shaft hole 1-1, that is, a dovetail groove 14 is provided on the rotor punching close to the shaft hole 1-1. The center of the dovetail groove 14 is on the q-axis center line, which is the radial center line of the rotor body 1. Two adjacent magnetic pole units are symmetrically distributed relative to the q-axis center line. The dovetail groove 14 includes: a first side 14-1, a second side 14-2, and a third side 14-3.

[0074] Specifically, one end of the second side 14-2 is connected to the first side 14-1, the second side 14-2 is perpendicular to the first side 14-1 and has a length of f2, and one end of the third side 14-3 is connected to the other end of the second side 14-2. Figure 8 As shown, the spacing between the other ends of the two third sides 14-3 is f1, that is, the opening length of the dovetail groove 14 close to the axial hole 1-1 is f1, the length of the first side 14-1 is f3, and the line between the other ends of the two third sides 14-3 is parallel to the first side 14-1, that is, the first side 14-1 of the upper part of the dovetail groove 14 is parallel to the straight line connecting the two end points of the opening of the lower part of the dovetail groove 14, the distance between the two parallel lines is f4, and the distance from the midpoint of the fourth long side 4-2 to the q-axis is f5; wherein f1=0.73*f5; f2=0.163*f1; f3=1.83*f1; f4=5.4*f2.

[0075] In this embodiment, by adopting a dovetail slot 14 that meets the above conditions, the weight of the rotor can be reduced, the moment of inertia of the rotor can be reduced; the surface area can be increased, the heat dissipation and conduction can be improved, and the normal operating temperature of the motor can be maintained; at the same time, the magnetic circuit direction of the motor can be optimized, the degree of closure of the magnetic flux on the rotor can be increased, and the torque pulsation of the motor can be reduced.

[0076] In some specific embodiments of the present invention, the inner edge of the rotor body 1 near the shaft hole 1-1 is provided with a marking groove 15, that is, the rotor punching near the shaft hole 1-1 is provided with a marking groove 15 that affects the magnetic circuit. Figure 8As shown, the marking groove 15 is a semicircular arc with a radius of R5, the angle formed by the sixth side 11-3 and the fourth short side 4-4 is γ, and the center of the marking groove 15 is at the intersection of the bisector of the angle γ and the inner diameter of the rotor body 1. In other words, the fourth magnetic isolation groove 11 and the second magnetic steel groove 4 can form an angle γ, and the angle γ is specifically formed by the sixth side 11-3 and the fourth short side 4-4. The intersection of the bisector of the angle γ and the inner diameter of the rotor body 1 is the center of the marking groove 15. Among them, 1.5*f2≤R5≤2.3*f2. In this embodiment, by providing the above-mentioned marking groove 15, the magnetic circuit direction of the motor can be further optimized and the torque pulsation of the motor can be reduced.

[0077] In addition, after simulation, it is found that in the rotor punching, the magnetic isolation groove, the magnetic isolation hole group, the dovetail groove 14 and the marking groove 15 can be superimposed to reduce the torque pulsation of the motor, as shown in the following Table 1: Table 1 The present invention further provides a rotor core, which includes a plurality of rotor punchings stacked in layers, and the rotor punchings are the rotor punchings described in any of the above embodiments. Since the rotor punchings have the advantages of improving the uniformity of magnetic field distribution and reducing magnetic flux leakage, and the rotor core of the embodiment of the present invention includes the rotor punchings of any of the above embodiments, the rotor core of the embodiment of the present invention also has the same advantages, which will not be described in detail here.

[0078] The present invention also provides a motor, comprising the rotor core of any one of the above embodiments, which has the advantages of improving efficiency and reducing noise.

[0079] The present invention also provides an electrical device, including a motor according to any one of the above embodiments, which has the advantages of improving efficiency and reducing noise.

[0080] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A rotor punching, characterized in that: include: A rotor body (1), the rotor body (1) being an annular member with an axial hole (1-1) arranged at the center, the rotor body (1) having a plurality of groups of magnetic pole units along its circumference, each group of the magnetic pole units comprising: A first magnetic steel slot group, the first magnetic steel slot group comprising two first magnetic steel slots (2), the two first magnetic steel slots (2) being located on both sides of a radial centerline d-axis of the magnetic pole unit, one end of each first magnetic steel slot (2) being close to the shaft hole (1-1) and the d-axis, one end of the two first magnetic steel slots (2) being spaced apart and having a first magnetic isolation bridge (3) therebetween, and the other end of each first magnetic steel slot (2) being away from the shaft hole (1-1) and the d-axis; a second magnetic steel slot group, wherein the second magnetic steel slot group and the first magnetic steel slot group are arranged at intervals along the radial direction of the rotor body (1), the second magnetic steel slot group is close to the shaft hole (1-1) relative to the first magnetic steel slot group, the second magnetic steel slot group comprises two second magnetic steel slots (4), the second magnetic steel slots (4) and the first magnetic steel slots (2) are respectively used to install permanent magnets, the two second magnetic steel slots (4) are located on both sides of the d-axis, one end of each second magnetic steel slot (4) is close to the shaft hole (1-1) to and the d-axis, the other end of each of the second magnetic steel slots (4) is away from the axial hole (1-1) and the d-axis, the other ends of the two second magnetic steel slots (4) are spaced apart and a magnetic isolation hole group and a magnetic isolation bridge group are provided between them, the magnetic isolation hole group includes a plurality of magnetic isolation holes, the magnetic isolation bridge group includes a second magnetic isolation bridge (5) and a third magnetic isolation bridge (6), the second magnetic isolation bridge (5) is located between the other end of the second magnetic steel slot (4) and the magnetic isolation hole, and the third magnetic isolation bridge (6) is located between two adjacent magnetic isolation holes.

2. The rotor punching according to claim 1, characterized in that: The two first magnetic steel slots (2) are symmetrically arranged about the d axis; The inner side wall of the first magnetic steel slot (2) comprises a first long side (2-1) and a second long side (2-2) which are arranged opposite to each other and distributed in parallel, and a first short side (2-3) and a second short side (2-4) which are arranged opposite to each other, wherein the second long side (2-2) is closer to the shaft hole (1-1) relative to the first long side (2-1), and the first short side (2-3) is farther away from the shaft hole (1-1) relative to the second short side (2-4).

3. The rotor punching according to claim 2, characterized in that: The included angle between the first long side (2-1) and the d-axis is θ1, and 62°≤θ1≤67°.

4. The rotor punching according to claim 3, characterized in that: In the radial direction of the rotor body (1), the width of each position of the first magnetic isolation bridge (3) is equal and is a1, wherein 1.6 mm≤a1≤2.2 mm.

5. The rotor punching according to claim 4, characterized in that: The first short side (2-3) is provided with a first magnetic isolation groove (7); the inner side wall of the first magnetic isolation groove (7) comprises a first side wall (7-1), a second side wall (7-2), a third side wall (7-3) and a fourth side wall (7-4) connected in sequence; the first side wall (7-1) is connected to the first long side (2-1) and coincides with an outer extension line of the first long side (2-1); the fourth side wall (7-4) is parallel to the first long side (2-1) and the second long side (2-2); the fourth side wall (7-4) intersects with the first short side (2-3); the third side wall (7-3) and the fourth side wall (7-4) intersect with an angle β1 therebetween; the first side wall (7-1) and the second side wall (7-2) intersect with an angle β2 therebetween; 124°≤β1≤136°, 141°≤β2≤153°; The shortest distance between the inner wall of the first magnetic isolation groove (7) and the yoke (8) of the rotor punching sheet is L1, the distance between the intersection of the fourth side wall (7-4) and the first short side (2-3) and the second long side (2-2) is L2, and the distance between the first long side (2-1) and the second long side (2-2) is L6; wherein 1.74mm≤L1≤2.26mm; L2=0.37*L6.

6. The rotor punching according to claim 5, characterized in that: The second short side (2-4) is provided with a second magnetic isolation groove (9), the inner side wall of the second magnetic isolation groove (9) comprises a fifth side wall (9-1), a sixth side wall (9-2) and a seventh side wall (9-3) which are connected in sequence, the fifth side wall (9-1) is connected to the first long side (2-1) and coincides with the outer extension line of the first long side (2-1), the length of the fifth side wall (9-1) is L5; the seventh side wall (9-3) intersects and is perpendicular to the first short side (2-3), the length of the seventh side wall (9-3) is L4, the seventh side wall (9-3) is parallel to the second long side (2-2) and the distance from the second long side (2-2) is L3; wherein L5=0.11*L6; L3=L2; L4=3.91*L5.

7. The rotor punching according to claim 5, characterized in that: The two second magnetic steel slots (4) are symmetrically arranged about the d axis, and the inner side wall of the second magnetic steel slot (4) comprises a third long side (4-1) and a fourth long side (4-2) which are arranged opposite to each other and distributed in parallel, and a third short side (4-3) and a fourth short side (4-4) which are arranged opposite to each other, the fourth long side (4-2) is closer to the shaft hole (1-1) relative to the third long side (4-1), and the third short side (4-3) is farther away from the shaft hole (1-1) relative to the fourth short side (4-4).

8. The rotor punching according to claim 7, characterized in that: The third short side (4-3) is provided with a third magnetic isolation groove (10), the inner side wall of the third magnetic isolation groove (10) comprises a first side edge (10-1), a second side edge (10-2), and a third side edge (10-3), the first side edge (10-1) is connected to the third long side (4-1) and coincides with an outer extension line of the third long side (4-1), the third side edge (10-3) is parallel to the third long side (4-1) and the fourth long side (4-2), and the angle between the first side edge (10-1) and the second side edge (10-2) is β3, 122°≤β3≤134°; The distance between the third long side (4-1) and the fourth long side (4-2) is d5, the distance between the third side (10-3) and the fourth long side (4-2) is d2, and the shortest distance between the third magnetic isolation groove (10) and the yoke (8) of the rotor punching is d1; d2=0.29*d5; d5=1.13*L6; d1=L1.

9. The rotor punching according to claim 8, characterized in that: The fourth short side (4-4) is provided with a fourth magnetic isolation groove (11), the inner side wall of the fourth magnetic isolation groove (11) comprises a fourth side (11-1), a fifth side (11-2) and a sixth side (11-3), the shape of the fourth magnetic isolation groove (11) is rectangular, the fourth side (11-1) is connected to the third long side (4-1) and coincides with the outer extension line of the third long side (4-1), the length of the fourth side (11-1) is d4; the distance between the sixth side (11-3) and the fourth long side (4-2) is d3; wherein d4=0.164*d5; d3=d2.

10. The rotor punching according to claim 9, characterized in that: The number of the magnetic isolation holes is three and they are divided into two side magnetic isolation holes (12) and one middle magnetic isolation hole (13); the center of the middle magnetic isolation hole (13) is located on the d-axis; the two side magnetic isolation holes (12) are symmetrically distributed relative to the d-axis; and the shape of the middle magnetic isolation hole (13) is different from the shape of the side magnetic isolation holes (12) located on both sides.

11. The rotor punching according to claim 10, characterized in that: The side magnetic isolation hole (12) is in the shape of a trapezoid, comprising an upper base (12-1), a lower base (12-2), a first waist (12-3), and a second waist (12-4), wherein the second waist (12-4) is parallel to the fifth side (11-2), and the distance between the two is b1; the distance between the upper base (12-1) and the lower base (12-2) is b2; a line between a center point of the fifth side (11-2) and a position one-third of the distance from b2 to the axial hole (1-1) is perpendicular to the d-axis, the length of the upper base (12-1) is c3, and the length of the lower base (12-2) is c1; c1=1.77*(d5-d3); c3=0.11*c1; b1=1.25*a1; b2=1.08*d5.

12. The rotor punching according to claim 11, characterized in that: A chamfer is provided at a position where one end of the upper base (12-1) is connected to the second waist (12-4), and the radius of the chamfer is R1; a chamfer is provided at a position where the other end of the upper base (12-1) is connected to the first waist (12-3), and the radius of the chamfer is R2; a chamfer is provided at a position where the lower base (12-2) is connected to the second waist (12-4), and the radius of the chamfer is R3; the radius of the chamfer corresponding to the lower base (12-2) and the first waist (12-3) is equal to R2; wherein 1.8 mm ≤ R1 ≤ 2.1 mm; R2 = 0.5*R1; R3 = 0.6*R1.

13. The rotor punching according to claim 12, characterized in that: The middle magnetic hole (13) is in the shape of a rectangle. The middle magnetic hole (13) has two long sides (13-1) and two short sides (13-2) that are spaced apart from each other. The distance between the two long sides (13-1) is the same as the distance between the upper base (12-1) and the lower base (12-2). The length of the long side (13-1) is c2. The four fillet radii of the middle magnetic hole (13) are all R4. The short side (13-2) is parallel to the first waist (12-3) and the distance between the two is b3. Wherein, c2=1.05*c1; R4=0.47*R1; b3=1.6*b1.

14. The rotor punching according to claim 1, characterized in that: The width of the third magnetic isolation bridge (6) is different from the width of the second magnetic isolation bridge (5).

15. The rotor punching according to claim 7, characterized in that: The included angle between the third long side (4-1) and the d-axis is θ2, wherein 39°≤θ2≤44°.

16. The rotor punching according to claim 9, characterized in that: The rotor body (1) is provided with a dovetail groove (14) near the inner edge of the shaft hole (1-1), the center of the dovetail groove (14) is on the q-axis center line, the q-axis center line is the radial center line of the rotor body (1), and two adjacent magnetic pole units are symmetrically distributed relative to the q-axis center line. The dovetail groove (14) comprises: Side 1 (14-1); a second side (14-2), one end of the second side (14-2) being connected to the first side (14-1), the second side (14-2) being perpendicular to the first side (14-1) and having a length of f2; A third side (14-3), one end of the third side (14-3) is connected to the other end of the second side (14-2), the spacing between the other ends of the two third sides (14-3) is f1, the length of the first side (14-1) is f3, the line between the other ends of the two third sides (14-3) is parallel to the first side (14-1), the distance between the two parallel lines is f4, and the distance from the midpoint of the fourth long side (4-2) to the q-axis is f5; wherein f1=0.73*f5; f2=0.163*f1; f3=1.83*f1; f4=5.4*f2.

17. The rotor punching according to claim 16, characterized in that: The rotor body (1) is provided with a marking groove (15) near the inner edge of the shaft hole (1-1); the marking groove (15) is a semicircular arc with a radius of R5; the angle formed by the sixth side (11-3) and the fourth short side (4-4) is γ; the center of the marking groove (15) is at the intersection of the bisector of the angle γ and the inner diameter of the rotor body (1); wherein 1.5*f2≤R5≤2.3*f2.

18. A rotor core, characterized in that: The rotor core comprises a plurality of rotor punchings stacked together, and the rotor punchings are rotor punchings according to any one of claims 1-17.

19. A motor, characterized in that: Comprising the rotor core as claimed in claim 18.

20. An electrical equipment, characterized in that: Includes the motor as claimed in claim 19.

Images