Rotor lamination, rotor and electric machine

Abstract

The application relates to the technical field of motors, in particular to a rotor lamination, a rotor and a motor, wherein the outer contour of the rotor lamination is a non-circular closed continuous curve, the closed continuous curve is inscribed in a circular A, and the closed continuous curve has more than two intersection points with the circular A, wherein the closed continuous curve forms a curve segment between each two adjacent intersection points, and a gap is formed between each curve segment and the circular A; the tangent line of each point on the curve segment is located on the side of the curve segment which is away from the center of the rotor lamination. According to the scheme, the rotor lamination can have higher strength while having unequal air gap characteristics, so that the rotor lamination can withstand higher rotating speed, and the rotor lamination can be better applied to high-speed motors.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a rotor lamination, a rotor, and a motor. Background Technology

[0002] Compared to traditional motors, permanent magnet synchronous motors (IPMs) offer advantages such as simple structure, high output efficiency, good speed regulation, and no environmental pollution, making them a major research direction for high-speed motors. However, in the design of IPMs, the permanent magnets are inserted into the rotor core, resulting in high torque. However, IPMs also suffer from high torque ripple and significant vibration during operation, which negatively impacts motor performance.

[0003] Existing related technologies disclose a built-in rotor lamination, such as Figure 1 As shown, the built-in rotor lamination has a notch 10' on its circular outer contour. Although the notch 10' on its outer contour can optimize the air gap waveform, it will weaken the strength of the rotor lamination and cannot meet the requirements of high-speed rotor operation. Therefore, the rotor lamination cannot be used in high-speed motors and needs to be improved. Summary of the Invention

[0004] In view of this, the present invention provides a rotor lamination, a rotor, and a motor, and the main technical problem to be solved is: how to improve the strength of the rotor lamination.

[0005] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a rotor lamination, wherein the outer contour of the rotor lamination is a non-circular closed continuous curve, the closed continuous curve is inscribed in a circle A and has two or more intersection points with the circle A, wherein the closed continuous curve forms a curve segment between each two adjacent intersection points, and each curve segment forms a gap with the circle A;

[0007] The tangents at each point on the curve segment are all located on the side of the curve segment away from the center of the rotor lamination.

[0008] In some embodiments, a rectangular coordinate system is established in a section perpendicular to the central axis of the rotor lamination, and the coordinates of each point on the closed continuous curve conform to the Reilly equation in the rectangular coordinate system.

[0009] In some embodiments, the Reilly equation for the closed continuous curve is:

[0010] x=d / 2*cos(afa)-e*cos(3*afa)*cos(afa)-3*e*sin(3*afa)*sin(afa);

[0011] y=d / 2*sin(afa)-e*cos(3*afa)*sin(afa)+3*e*sin(3*afa)*cos(afa);

[0012] Where afa = 360*t, t is the time period constant, (x, y) are the coordinates of each point on the closed continuous curve in the rectangular coordinate system, d is the diameter parameter of circle A, and e is the curvature parameter of the equation.

[0013] In some embodiments, the rotor laminations are provided with magnetic slot groups in the regions corresponding to each pole of the rotor, and each magnetic slot group includes a first magnetic slot, a second magnetic slot, and a third magnetic slot arranged sequentially and at intervals along the circumference of the rotor laminations.

[0014] In some embodiments, the side of the first magnet groove opposite to the second magnet groove has a first air groove section; and / or, the side of the third magnet groove opposite to the second magnet groove has a second air groove section.

[0015] In some embodiments, both the first and third magnet grooves have magnet mounting sections on the side closest to the second magnet groove; the side of the second magnet groove closest to the first magnet groove is used to abut against one side of the internal magnet, and the side of the second magnet groove closest to the third magnet groove is used to abut against the other side of the internal magnet.

[0016] In some embodiments, the second magnet slot has a symmetry plane L passing through the center of the rotor lamination, and the first magnet slot and the third magnet slot are symmetrically arranged relative to the symmetry plane L.

[0017] Secondly, embodiments of the present invention also provide a rotor, which may include any of the rotor laminations described above.

[0018] In some embodiments, when the side of the first magnet groove opposite to the second magnet groove has a first air groove section, and the side of the third magnet groove opposite to the second magnet groove has a second air groove section, the first air groove section and / or the second air groove section are filled with insulating material.

[0019] Thirdly, embodiments of the present invention also provide an electric motor, which may include any of the rotors described above.

[0020] By employing the above technical solutions, the rotor laminations, rotor, and motor of the present invention have at least the following beneficial effects:

[0021] 1. Because the closed continuous curve is inscribed within the circle A, the outer trajectory of the rotor lamination during rotation is circular, which satisfies the rotor dynamics requirements. Furthermore, since a gap is formed between the curve segment and the circle A, the rotor lamination can possess unequal air gap characteristics during operation, thus optimizing the sinusoidal air gap waveform and reducing high-order harmonic content. Compared to existing technologies that create unequal air gap characteristics by notching the outer edge of a circular rotor lamination or by making it a polygonal rotor lamination, the outer contour of the rotor lamination of this invention is a closed continuous curve. Since no notch is needed, the structural strength is better, and this closed continuous curve reduces stress concentration on the outer contour, resulting in higher strength. Additionally, since each curve segment of the rotor lamination bulges outward in a radial direction, compared to a concave design, the outward bulging design uses more material, resulting in higher rotor lamination strength. Overall, through the above technical solutions, the rotor lamination can possess both unequal air gap characteristics and higher strength, thereby withstanding higher speeds, making the rotor lamination of this invention better suited for use in high-speed motors.

[0022] 2. The curve formed by the outer contour of the rotor lamination of the present invention conforms to the Reichelic curve equation formula. By adjusting the curvature parameter e of the equation, the rotor lamination can be adapted to motors of different power, improving the versatility of the rotor. Moreover, the Reichelic shape of the rotor lamination gives it the characteristic of unequal air gap, which can optimize the sinusoidal nature of the air gap waveform, reduce the content of high-order harmonics, reduce torque pulsation and unbalanced magnetic pull, and improve motor performance.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a rotor lamination in the prior art;

[0026] Figure 2 This is a schematic diagram of a rotor lamination in a rectangular coordinate system xoy on a section perpendicular to its central axis, according to an embodiment of the present invention.

[0027] Figure 3This is a schematic diagram of one pole region of a rotor lamination;

[0028] Figure 4 It is a 3D view of the rotor laminations;

[0029] Figure 5 This is a schematic diagram of the structure of the first magnet;

[0030] Figure 6 This is a schematic diagram of the second magnet;

[0031] Figure 7 This is a graph showing the relationship between the unbalanced magnetic pull and the rotational speed of a conventional circular rotor.

[0032] Figure 8 This is a graph showing the relationship between the unbalanced magnetic pull and the rotational speed of the Reilly rotor of the present invention at a speed of 20000 RPM;

[0033] Figure 9 This is a diagram of harmonic values ​​for a standard circular lamination.

[0034] Figure 10 This is a harmonic value diagram of the Reilly-shaped rotor lamination of the present invention.

[0035] Reference numerals: 1. Closed continuous curve; 2. Magnet slot group; 3. Second magnet; 4. First magnet; 5. Lamination assembly positioning hole; 11. Curved segment; A1. Circular arc segment; 21. First magnet slot; 22. Second magnet slot; 23. Third magnet slot; 211. First air slot segment; 231. Second air slot segment; 100. Rotor lamination; 101. Mandrel hole. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0038] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] like Figure 2 As shown, one embodiment of the present invention provides a rotor lamination 100, the outer contour of which is a non-circular closed continuous curve 1, inscribed in a circle A. Alternatively, circle A is the circumcircle of the closed continuous curve 1. The closed continuous curve 1 intersects circle A at two or more points. Between each pair of adjacent intersection points, a curve segment 11 is formed on the closed continuous curve 1. A gap B is formed between each curve segment 11 and circle A. The tangent at each point on the curve segment 11 is located on the side of the curve segment 11 away from the center of the rotor lamination 100; in other words, the curve segment 11 protrudes radially outward from the rotor lamination 100.

[0040] To more easily explain the above technical solutions: (e.g.) Figure 1 As shown, take the two adjacent intersection points as intersection point M1 and intersection point M2, the closed continuous curve 1 forms curve segment 11 between intersection point M1 and intersection point M2, the circle A forms arc segment A1 between intersection point M1 and intersection point M2, and the aforementioned gap B is formed between curve segment 11 and arc segment A1. The width L of gap B along the radial direction of the rotor lamination gradually increases from intersection point M1 to intersection point M2, and then gradually decreases.

[0041] In the above example, since the closed continuous curve 1 is inscribed in circle A, the outer trajectory of the rotor lamination 100 during rotation is circular, which satisfies the rotor dynamics performance. Furthermore, since a gap B is formed between the curve segment 11 and circle A, the rotor lamination 100 can have unequal air gap characteristics during operation, thus optimizing the sinusoidal shape of the air gap waveform and reducing the content of higher harmonics. Compared to the prior art that creates unequal air gap characteristics by notching the outer edge of the circular rotor lamination 100 or by making it a polygonal rotor lamination 100, the outer contour of the rotor lamination 100 of the present invention is a closed continuous curve. Since no notch is needed, the structural strength is better, and this closed continuous curve reduces stress concentration on the outer contour, resulting in higher strength. In addition, since each curve segment 11 of the rotor lamination 100 protrudes radially outward, compared to the concave design, the outwardly convex design uses more material, resulting in higher strength for the rotor lamination 100. In general, the above technical solutions enable the rotor lamination 100 to have both unequal air gap characteristics and higher strength, thereby allowing it to withstand higher speeds and making the rotor lamination 100 of the present invention more suitable for use in high-speed motors.

[0042] For ease of processing, such as Figure 1 As shown, a rectangular coordinate system xoy is established within a section perpendicular to the central axis of the rotor lamination 100. The coordinates of each point on the aforementioned closed continuous curve 1 conform to the Reilly equation within this rectangular coordinate system xoy. In a specific application example, the Reilly equation for the aforementioned closed continuous curve 1 is:

[0043] x=d / 2*cos(afa)-e*cos(3*afa)*cos(afa)-3*e*sin(3*afa)*sin(afa);

[0044] y=d / 2*sin(afa)-e*cos(3*afa)*sin(afa)+3*e*sin(3*afa)*cos(afa);

[0045] Where afa = 360*t, t is the time period constant, (x, y) are the coordinates of each point on the closed continuous curve 1 in the rectangular coordinate system, d is the diameter parameter of circle A, and e is the curvature parameter of the equation.

[0046] In the above example, by adjusting the diameter parameter d of the circumscribed circle A of the rotor lamination 100 and the equation curvature parameter e, and combining this with electromagnetic scheme optimization, the equation curvature parameter e corresponding to rotor laminations 100 with different outer diameters can be determined, achieving optimal motor performance. Furthermore, the rotor lamination 100 of this invention adopts a Reichstag curve equation; by adjusting the equation curvature parameter e, it can be adapted to motors of different power, improving rotor versatility.

[0047] The rotor lamination 100 of this invention has a Reichol-shaped profile, resulting in strong integrity and no stress concentration at its edges, thus achieving higher strength and enabling higher speeds. Furthermore, the Reichol-shaped profile of the rotor lamination 100 allows for unequal air gaps by adjusting the curvature parameter e, optimizing the sinusoidal nature of the air gap waveform and improving motor performance.

[0048] The rotor lamination 100 of the present invention can withstand higher speeds, reduce the content of higher harmonics, and reduce cogging torque and torque pulsation. At the same time, the Reykjavik shape of the rotor lamination 100 gives it unequal air gap characteristics, which can optimize the sinusoidal nature of the air gap waveform, reduce unbalanced magnetic pull, and reduce vibration and noise during motor operation. Compared with the prior art, it can effectively reduce costs and assembly difficulty, and is conducive to optimizing motor design to better meet motor performance requirements.

[0049] For high-speed rotors, studies have shown that when the rotor speed is below 15000 RPM, the curvature parameter e of the aforementioned Reilly equation should be selected as 1 to 1.5. However, when the rotor speed is above 15000 RPM, the curvature parameter e of the Reilly equation should be less than 1.

[0050] Figure 7 This diagram illustrates the relationship between the unbalanced magnetic pull and the rotational speed of a conventional circular rotor lamination. Figure 8 A graph showing the relationship between the unbalanced magnetic pull and the curvature parameter e of the Reilly equation for a rotor employing the Reilly-shaped rotor lamination 100 of the present invention at a speed of 20000 RPM is illustrated. Figure 8 As shown, the unbalanced magnetic pull of the Reilly rotor of this invention has a quadratic linear relationship with the curvature parameter e of the Reilly equation. It can be seen that when the curvature e is chosen to be around 1.2, the unbalanced magnetic pull of the rotor reaches its minimum. Figure 7 and Figure 8 As shown, at the same rotational speed of 20,000 RPM, compared with the conventional circular rotor, the unbalanced magnetic pull of the Reylow-shaped rotor of the present invention is significantly reduced, with a maximum reduction of 15%.

[0051] in, Figure 9 A harmonic distortion diagram of a conventional circular rotor lamination is shown. Figure 10 A harmonic value diagram of a Reilly-shaped rotor lamination 100 of the present invention is shown. Figure 9 and Figure 10 In both figures, the horizontal axis represents higher-order harmonics. 3 represents the 3rd harmonic, 5 represents the 5th harmonic, 7 represents the 7th harmonic, 11 represents the 11th harmonic, 13 represents the 13th harmonic, and 19 represents the 19th harmonic. For example... Figure 9 and 10As shown, comparing the harmonic value diagrams of conventional circular rotor laminations and Reylock-shaped rotor laminations 100, the total harmonic content of conventional circular rotor laminations is 1.51%, while the total harmonic content of the Reylock-shaped rotor laminations 100 of the present invention is 0.94%. Thus, the Reylock-shaped rotor laminations 100 of the present invention show a 0.57% reduction in back EMF harmonic content, and a significant reduction in high-order harmonic content.

[0052] like Figure 3 As shown, each region on the rotor lamination 100 corresponding to each rotor pole is provided with a magnet slot group 2. The rotor has staggered N and S poles along its circumference. The region on the rotor lamination 100 corresponding to each rotor pole (N or S pole) can be called a pole region, and each pole region is provided with a magnet slot group 2. The magnets in each magnet slot group 2 have the same polarity. Each magnet slot group 2 includes a first magnet slot 21, a second magnet slot 22, and a third magnet slot 23 arranged sequentially and at intervals along the circumference of the rotor lamination 100. A magnetic isolation bridge is formed between adjacent magnet slots to prevent magnetic leakage within each magnet slot.

[0053] In the example above, each magnet slot is used for magnet insertion and installation, giving the rotor a built-in magnet structure. Furthermore, by increasing the number of magnet slots in each pole region, the magnetism of the rotor in each pole region can be increased, thereby increasing the motor's output power and meeting the different output power requirements of the motor.

[0054] Among them, such as Figure 1 As shown, the rotor presented in this invention has 6 poles, but is not limited to 6 poles.

[0055] like Figure 3 As shown, the side of the first magnet slot 21 facing away from the second magnet slot 22 may have a first air slot section 211, which can improve the leakage magnetic performance of the rotor lamination 100 between adjacent pole regions.

[0056] like Figure 3 As shown, the third magnet slot 23 has a second air slot section 231 on the side opposite to the second magnet slot 22. The second air slot section 231 can improve the leakage magnetic performance of the rotor lamination 100 between adjacent pole regions.

[0057] like Figure 3 and Figure 4As shown, both the first magnet groove 21 and the third magnet groove 23 have magnet mounting sections on the side closest to the second magnet groove 22. The side of the second magnet groove 22 closest to the first magnet groove 21 is used to abut against one side of the internal magnet, and the side of the second magnet groove 22 closest to the third magnet groove 23 is used to abut against the other side of the internal magnet. In other words, there is no air groove section on the side of the second magnet groove 22 closest to the first magnet groove 21, and there is also no air groove section on the side of the second magnet groove 22 closest to the third magnet groove 23.

[0058] In the above example, after magnets are inserted into the first magnet slot 21, the second magnet slot 22 and the third magnet slot 23, the three magnets are arranged in sequence, which has the advantages of optimizing magnetic flux density and back EMF waveform.

[0059] like Figure 3 As shown, the aforementioned second magnet slot 22 has a symmetry plane L, which passes through the center of the rotor lamination 100. The first magnet slot 21 and the third magnet slot 23 are also symmetrically arranged relative to the symmetry plane L, which has the advantage of further optimizing the magnetic flux density and back EMF waveform.

[0060] like Figure 4 As shown, the rotor lamination 100 has a mandrel hole 101 at its center for mandrel mounting. The rotor lamination 100 also has lamination assembly positioning holes 5 extending through both ends. The number of lamination assembly positioning holes 5 can be two or more, and they are evenly spaced around the circumference of the rotor lamination 100.

[0061] An embodiment of the present invention also provides a rotor that may include any of the rotor laminations 100 described above. In this example, because the rotor uses the rotor laminations 100 described above, the rotor laminations 100 can have higher strength while possessing unequal air gap characteristics, thereby being able to withstand higher speeds, making the rotor laminations 100 of the present invention better applicable to high-speed motors.

[0062] When the first magnetic groove 21 has a first air groove section 211 on the side opposite to the second magnetic groove 22, and the third magnetic groove 23 has a second air groove section 231 on the side opposite to the second magnetic groove 22, magnets are inserted into the first magnetic groove 21, the second magnetic groove 22, and the third magnetic groove 23. The first air groove section 211 and / or the second air groove section 231 are filled with insulating materials, which serve the purpose of magnetic isolation and fixing the magnets.

[0063] In a specific application example, such as Figure 4 As shown, a second magnet 3 is inserted into both the first magnet slot 21 and the third magnet slot 23. Figure 6 A schematic diagram of a second magnet 3 is shown. A first magnet 4 is inserted into the second magnet slot 22. Figure 5A schematic diagram of the structure of a first magnet 4 is shown. Two second magnets 3 and one first magnet 4 constitute the first stage of the rotor, and the polarity of each magnet in the same pole is the same. The first magnet 4 and the second magnet 3 can be the same magnet or different magnets, depending on the specific circumstances.

[0064] The rotor of the present invention can be manufactured according to the following method:

[0065] First, stack the rotor laminations 100 to the designed stacking height; then, apply magnetic adhesive to the first magnet 4 and the second magnet 3, and insert each first magnet 4 and each second magnet 3 into the corresponding magnetic slot. Note that the polarity of each magnet in each pole of the rotor is the same, and the polarity of adjacent poles is opposite. The pole adjacent to the N pole is the S pole; then, fill the insulating material that constitutes the insulating component into the first air slot section 211 and the second air slot section 231 to achieve the purpose of magnetic isolation and fixing the magnets; then, use the upper and lower rotor baffles to fix the stacked rotor laminations 100 and magnets; finally, put the assembled motor rotor onto the mandrel through the mandrel hole 101.

[0066] One embodiment of the present invention also proposes an electric motor, which may include any of the rotors described above. In this example, because the motor uses the aforementioned rotor, the rotor laminations 100 can have higher strength while possessing unequal air gap characteristics, thereby being able to withstand higher speeds, making the rotor laminations 100 of the present invention better applicable to high-speed motors.

[0067] For ease of understanding, the overall structure of the present invention will be described below, and its working principle will be explained.

[0068] This invention relates to the design of a novel rotor lamination 100, which can be applied to electric motors. The rotor lamination 100 and rotor mentioned in this invention are suitable for most permanent magnet synchronous motors. The curve formed by the outer contour of this novel rotor lamination 100 conforms to the Reichelic curve equation formula. By adjusting the curvature parameter e of the equation, the rotor lamination 100 can be adapted to motors of different power, improving rotor versatility. Furthermore, the Reichelic shape of the rotor lamination 100 gives it unequal air gap characteristics, which optimizes the sinusoidal nature of the air gap waveform, reduces high-order harmonic content, decreases torque pulsation and unbalanced magnetic pull, and improves motor performance.

[0069] Compared with the rotor laminations in the prior art, the rotor lamination 100 of the present invention adopts a Reylow-shaped outline, which not only gives the rotor lamination 100 the characteristics of unequal air gap, optimizes the sinusoidal nature of the air gap waveform, reduces unbalanced magnetic pull, and reduces vibration and noise during motor operation, but also has high structural strength and strong integrity. There is no stress concentration at the edge of the rotor lamination 100, which can withstand higher speeds, making the rotor better suited for use in high-speed motors.

[0070] The rotor lamination 100 of the present invention has a strong integral shape due to its Reilly-shaped outline. Compared with the rotor laminations with notches on the outer edge in the prior art, the present invention can effectively reduce costs, reduce assembly difficulty, and help optimize motor design to better meet motor performance requirements.

[0071] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A rotor lamination, characterized in that, The outer contour of the rotor lamination (100) is a non-circular closed continuous curve (1). The closed continuous curve (1) is inscribed in a circle A and has two or more intersection points with the circle A. The closed continuous curve (1) forms a curve segment (11) between each two adjacent intersection points, and each curve segment (11) forms a gap (B) with the circle A. Among them, the tangents at each point on the curve segment (11) are all located on the side of the curve segment (11) away from the center of the rotor lamination (100); A rectangular coordinate system is established in the cross section perpendicular to the central axis of the rotor lamination (100), and the coordinates of each point on the closed continuous curve (1) conform to the Reilly equation formula in the rectangular coordinate system. The Reilly equation for the closed continuous curve (1) is as follows: x=d / 2*cos(afa)-e*cos(3*afa)*cos(afa)-3*e*sin(3*afa)*sin(afa); y=d / 2*sin(afa)-e*cos(3*afa)*sin(afa)+3*e*sin(3*afa)*cos(afa); Where afa=360*t, t is the time period constant, (x, y) are the coordinates of each point on the closed continuous curve (1) in the rectangular coordinate system, d is the diameter parameter of circle A, and e is the curvature parameter of the equation.

2. The rotor lamination as described in claim 1, characterized in that, The rotor lamination (100) is provided with a magnetic slot group (2) in the area corresponding to each pole of the rotor. Each magnetic slot group (2) includes a first magnetic slot (21), a second magnetic slot (22) and a third magnetic slot (23) arranged sequentially and at intervals along the circumference of the rotor lamination (100).

3. The rotor lamination as described in claim 2, characterized in that, The first magnet groove (21) has a first air groove section (211) on the side opposite to the second magnet groove (22); and / or, the third magnet groove (23) has a second air groove section (231) on the side opposite to the second magnet groove (22).

4. The rotor lamination as described in claim 2, characterized in that, Both the first magnet groove (21) and the third magnet groove (23) have magnet mounting sections on the side closest to the second magnet groove (22); the side of the second magnet groove (22) closest to the first magnet groove (21) is used to abut against one side of the internal magnet, and the side of the second magnet groove (22) closest to the third magnet groove (23) is used to abut against the other side of the internal magnet.

5. The rotor lamination as described in claim 2, characterized in that, The second magnet slot (22) has a symmetry plane L, which passes through the center of the rotor lamination (100), and the first magnet slot (21) and the third magnet slot (23) are symmetrically arranged relative to the symmetry plane L.

6. A rotor, characterized in that, Includes the rotor lamination (100) according to any one of claims 1 to 5.

7. The rotor as claimed in claim 6, characterized in that, When the rotor lamination (100) is the rotor lamination of claim 5, the first air slot (211) and / or the second air slot (231) are filled with insulating material.

8. An electric motor, characterized in that, Includes the rotor as described in claim 6 or 7.

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