Rotor lamination, rotor core and electric machine

Abstract

The application provides a rotor lamination, a rotor core and a motor. The rotor lamination comprises a lamination body, a first magnetic steel, a second magnetic steel and a third magnetic steel. The first magnetic steel is installed in a first magnetic steel slot, and the magnetization direction of the first magnetic steel is tangential magnetization. A second magnetic steel slot is arranged between adjacent first magnetic steel slots, and the magnetization direction of the second magnetic steel is radial magnetization. A third magnetic steel slot is arranged on the radial outer side of the second end of the first magnetic steel slot, and the third magnetic steel is installed in the third magnetic steel slot. The magnetization direction of the third magnetic steel is towards the radial outer side of the lamination body, and a first acute angle is formed between the magnetization direction of the third magnetic steel and the magnetization direction of the second magnetic steel, so that the magnetic lines of force converge towards the radial outer side of the lamination body. The magnetization direction of the third magnetic steel can effectively guide the magnetic lines of force to the air gap, avoid the magnetic lines of force forming a useless closed loop inside the rotor or leaking too early, and thus improve the utilization rate of the magnetic steel.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a rotor lamination, a rotor core, and a motor. Background Technology

[0002] Permanent magnet servo motors are widely used in industrial robots, machine tools, medical devices, automobiles, and other fields due to their high power density and high torque output. However, high precision must be guaranteed simultaneously under the high power density conditions of servo motors, requiring small output torque fluctuations and smooth motor operation. Hybrid rotor cores are a motor design that combines radial and tangential magnets. This design effectively improves the air gap magnetic flux density, increases output torque, and enhances load capacity, achieving a high power density and high torque output motor. While hybrid rotors increase rotor magnetic flux density through magnets with multiple magnetization directions, this design results in significant magnetic leakage within the rotor, leading to low magnet utilization. Therefore, there is room for optimization in the internal magnetic circuit design of hybrid rotors. Summary of the Invention

[0003] This invention provides a rotor lamination, a rotor core, and a motor, which can solve the technical problem that the magnets in a hybrid rotor core have large magnetic leakage inside the rotor, resulting in low magnet utilization.

[0004] This invention provides a rotor lamination, which includes a lamination body, a first magnet, a second magnet, and a third magnet;

[0005] The lamination body has a plurality of first magnet slots in the circumferential direction. In the radial direction of the lamination body, the first end of the first magnet slot extends radially inward to the lamination body, and the second end of the first magnet slot extends radially outward to the lamination body. The first magnet is installed in the first magnet slot, and the magnetization direction of the first magnet is tangential magnetization.

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

[0007] A third magnet groove is provided radially outward at the second end of the first magnet groove. The third magnet is installed in the third magnet groove. The magnetization direction of the third magnet is directed radially outward towards the lamination body. The magnetization direction of the third magnet and the magnetization direction of the second magnet form a first acute angle, so that the magnetic lines of force converge radially outward towards the lamination body.

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

[0009] In some embodiments, the rotor lamination has a shaft hole, the second magnet slot is located radially outside the shaft hole, and a magnetic isolation hole is provided between the shaft hole and the second magnet slot, so that a first magnetic isolation bridge is formed between the radially outside of the magnetic isolation hole and the second magnet slot, so that the magnetic lines of force of the first magnet converge radially outside the lamination body.

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

[0011] In some embodiments, a magnetic pole is formed between the radial extension lines of adjacent first magnetic grooves, and the outer circular contour corresponding to the magnetic pole is provided with a tangent structure so that the radial outer side of the magnetic pole protrudes outward.

[0012] In some embodiments, the slit structure includes a first slit and a second slit, the magnetic pole has a central axis, the first slit and the second slit are symmetrically arranged about the central axis, one end of the first slit and the second slit are connected to each other, the other end of the first slit and the second slit extend to the radial extension line of the corresponding first magnetic groove, and the connection between the first slit and the second slit is convex inward.

[0013] In some embodiments, both the first and second tangents include a gradient segment, a change segment, and a smooth segment connected in sequence. The end of the gradient segment away from the change segment intersects the central axis, and the end of the smooth segment away from the change segment is connected to the smooth segment of the adjacent magnetic pole.

[0014] In some embodiments, the center of the rotor lamination is O0, the transition section and the change section are eccentrically arranged relative to the center O0, the center of the transition section is O1, the center of the change section is O2, and the straight-line distance between the center O1 and the center O0 is less than the straight-line distance between the center O2 and the center O0.

[0015] A rotor core includes a plurality of rotor laminations stacked together, wherein the rotor laminations are those described above.

[0016] An electric motor includes a rotor core, wherein the rotor core is the rotor core described above.

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

[0018] In this invention, the first magnet is tangentially magnetized, and the magnetic lines of force it generates are widely distributed in the circumferential direction. This effectively utilizes the circumferential space of the rotor to increase the magnetic flux density in the air gap. The second magnet is radially magnetized away from the center, and its magnetic lines of force extend outward in the radial direction. This works in conjunction with the magnetic lines of force of the first magnet, making the magnetic flux distribution inside the rotor more reasonable, thereby improving the power density of the motor. The magnetization direction of the third magnet towards the radial outside forms a first acute angle with the magnetization direction of the second magnet, causing the magnetic lines of force to converge radially outward, further concentrating the magnetic flux near the air gap, enhancing the magnetic density in the air gap, and improving the output power of the motor. The combination of tangential magnetization of the first magnet and radial magnetization of the second magnet creates a composite magnetic field distribution inside the magnetic poles. The interaction between the tangential and radial magnetic fields of the first and second magnets causes the magnetic lines of force to converge inwards on the inner side of the poles, which is beneficial for improving the motor's torque output capability. The first acute angle formed between the magnetization direction of the third magnet and the magnetization direction of the second magnet guides the magnetic lines of force to converge radially outwards, resulting in a more uniform magnetic flux density distribution in the air gap and increasing the magnetic flux in the air gap, thereby improving the motor's torque coefficient and increasing the output torque. In terms of optimizing the magnetic circuit and improving magnet utilization, the three different magnetization directions allow the magnetic lines of force generated by the magnets to better cooperate and guide each other inside the rotor. The synergistic effect of the first and second magnets ensures a reasonable distribution of magnetic lines of force inside the poles, reducing magnetic leakage on the inner side of the poles. The magnetization direction arrangement of the third magnet can effectively guide the magnetic lines of force to the air gap, avoiding the formation of useless closed loops or premature leakage of magnetic lines of force inside the rotor, thereby improving the utilization rate of the magnet, making fuller use of the magnetic properties of the magnet, and optimizing the magnetic circuit structure of the motor. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the rotor laminations according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the first to third magnets according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the first to third magnet slots according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram showing the magnetization directions from the first magnet to the third magnet;

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

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

[0026] Figure 7 This is a diagram showing the magnetic field lines distribution of the magnetic poles in an embodiment of the present invention.

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

[0028] Figure 9 Diagram showing the relationship between air gap magnetic flux density and tangential structure in this embodiment;

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

[0030] Attached Figures: 1-First magnet; 2-Second magnet; 3-Third magnet; 4-Punch body; 5-First magnet groove; 6-Second magnet groove; 7-Third magnet groove; 8-Shaft hole; 9-Magnetic isolation hole; 10-First magnetic isolation bridge; 11-Cut edge structure; 12-Magnetic pole; 13-First cut edge; 14-Second cut edge; 151-Gradual transition section; 152-Change section; 153-Smooth section; 16-Second magnetic isolation bridge; 17-Third magnetic isolation bridge. Detailed Implementation

[0031] 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 some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used here to describe the spatial positional relationship of a device or feature as shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation of the device as described in the figure. For example, if a device in the figure is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures.

[0034] See also Figures 1 to 4 As shown, according to an embodiment of the present invention, a rotor lamination is provided, comprising a lamination body 4, a first magnet 1, a second magnet 2, and a third magnet 3; the lamination body 4 has a plurality of first magnet slots 5 formed in the circumferential direction; in the radial direction of the lamination body 4, the first end of the first magnet slot 5 extends radially inward toward the lamination body 4, and the second end of the first magnet slot 5 extends radially outward toward the lamination body 4; the first magnet 1 is installed in the first magnet slot 5, and the magnetization direction of the first magnet 1 is tangential magnetization P1; between adjacent first magnet slots 5 A second magnet groove 6 is provided, and the second magnet groove 6 is close to the first end of the first magnet groove 5. The second magnet 2 is installed in the second magnet groove 6, and the magnetization direction of the second magnet 2 is radial magnetization P2. A third magnet groove 7 is provided radially outside the second end of the first magnet groove 5, and the third magnet 3 is installed in the third magnet groove 7. The magnetization direction of the third magnet 3 is towards the radial outside of the stamping body 4, and the magnetization direction of the third magnet 3 and the magnetization direction of the second magnet 2 form a first acute angle β, so that the magnetic lines of force converge towards the radial outside of the stamping body 4.

[0035] It is worth noting that in this embodiment, the magnetization direction of the first magnet 1 is tangential magnetization P1, that is, its magnetization direction is the circumferential tangential direction. Although the magnetization direction of the first magnet 1 is tangential magnetization P1, the tangential directions of adjacent first magnets 1 are opposite, that is, the magnetization directions of adjacent first magnets 1 are opposite in the tangential direction, both pointing towards the magnetization direction of the second magnet 2. The magnetization direction of the second magnet 2 is radial magnetization P2, that is, its magnetization direction is either towards the center of the lamination body 4 or away from the center of the lamination body 4. In this embodiment, the magnetization direction of the second magnet 2 is away from the center of the lamination body 4. The magnetization direction of the third magnet 3 is radially outward from the lamination body 4. That is, the magnetization direction of the third magnet 3 is neither tangential nor radial. Circumferentially, the magnetization direction of the third magnet 3 is also deflected relative to the magnetization direction of the first magnet 1; that is, the magnetization direction of the third magnet 3 is biased towards the outer circle of the rotor lamination, not towards the center of the rotor lamination. Furthermore, the first magnet 1, the second magnet 2, and the third magnet 3 are magnetized in specific directions before being installed in their respective magnet slots. After magnetization, they are installed into the magnet slots, and the magnet mounting slots are also designed according to the installation requirements of the magnets.

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

[0037] In this embodiment, the first magnet 1 is tangentially magnetized P1, and the magnetic lines of force it generates are widely distributed in the circumferential direction. This can effectively utilize the circumferential space of the rotor to increase the magnetic flux density in the air gap. The second magnet 2 is radially magnetized P2 away from the center, and its magnetic lines of force extend outward in the radial direction. This works in conjunction with the magnetic lines of force of the first magnet 1 to make the magnetic flux distribution inside the rotor more reasonable, thereby improving the power density of the motor. The magnetization direction of the third magnet 3 towards the radial outside forms a first acute angle β with the magnetization direction of the second magnet 2, causing the magnetic lines of force to converge radially outward, further concentrating the magnetic flux near the air gap, enhancing the magnetic density in the air gap, and improving the output power of the motor. The combination of tangential magnetization P1 of the first magnet 1 and radial magnetization P2 of the second magnet 2 creates a composite magnetic field distribution inside the magnetic pole 12. The interaction between the tangential magnetic field of the first magnet 1 and the radial magnetic field of the second magnet 2 causes the magnetic lines of force to converge inwards inside the magnetic pole 12, which is beneficial to improving the torque output capability of the motor. The first acute angle β formed between the magnetization direction of the third magnet 3 and the magnetization direction of the second magnet 2 guides the magnetic lines of force to converge radially outwards, making the magnetic flux density distribution in the air gap more uniform and increasing the magnetic flux in the air gap, thereby improving the torque coefficient of the motor and increasing the output torque. In terms of optimizing the magnetic circuit and improving the utilization rate of the magnets, the three different magnetization directions allow the magnetic lines of force generated by the magnets to better cooperate and guide each other inside the rotor. The synergistic effect of the first magnet 1 and the second magnet 2 makes the magnetic lines of force reasonably distributed inside the magnetic pole 12, reducing the leakage flux of the magnets inside the magnetic pole 12. The magnetization direction arrangement of the third magnet 3 can effectively guide the magnetic lines of force to the air gap, avoiding the formation of useless closed loops or premature leakage of magnetic lines of force inside the rotor, thereby improving the utilization rate of the magnet, making fuller use of the magnetic properties of the magnet, and optimizing the magnetic circuit structure of the motor.

[0038] See also Figures 1 to 4 As shown, the third magnet groove 7 is located on the radial extension line of the second end of the first magnet groove 5. The magnetization direction of the first magnet 1 and the magnetization direction of the second magnet 2 form a second acute angle α, and the angle of the second acute angle α is greater than the angle of the first acute angle β, so that the magnetic lines of force converge inward in the inner region of the magnetic pole 12.

[0039] Specifically, since the first magnet 1 is tangentially magnetized P1, there is an angle between the first magnet 1 and the second magnet 2. The magnetization direction of the first magnet 1 is tangentially magnetized P1, and the magnetization direction of the second magnet 2 is radially magnetized P2 away from the center. A third magnet groove 7 is set on the radial extension line of the second end of the first magnet groove 5, and a second acute angle α is formed between the magnetization direction of the first magnet 1 and the magnetization direction of the second magnet 2. The angle of this second acute angle α is greater than the first acute angle β between the first magnet 1 and the third magnet 3. Due to the existence of this second acute angle α, when the first magnet 1 and the second magnet 2 are installed on the lamination body 4, the tangential magnetic lines of force generated by the first magnet 1 and the radial magnetic lines of force generated by the second magnet 2 intersect in the inner region of the magnetic pole 12. Since the angle of the second acute angle α is large, the magnetic lines of force generate an inward converging effect in the inner region of the magnetic pole 12. The inner region of magnetic pole 12 is equivalent to a convergence point of magnetic field lines. Magnetic field lines converge into this region from multiple directions of the first magnet 1 and the second magnet 2. This convergence effect can effectively reduce the magnetic leakage of the magnets in the inner region of magnetic pole 12, because the magnetic field lines are guided to the region where magnetic energy needs to be exerted, instead of leaking out disorderly in the inner region of magnetic pole 12.

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

[0041] As a specific implementation method, the first acute angle is β and the second acute angle is α. There is no specific value limit for the angle β, but preferably 1 / 2α < β < α is sufficient to meet the requirements.

[0042] See also Figures 1 to 6As shown, the rotor lamination has a shaft hole 8, and the second magnet slot 6 is located radially outside the shaft hole 8. A magnetic isolation hole 9 is provided between the shaft hole 8 and the second magnet slot 6, so that the radially outer side of the magnetic isolation hole 9 and the second magnet slot 6 form a first magnetic isolation bridge 10, causing the magnetic lines of force of the first magnet 1 to converge radially outward of the lamination body 4. In other embodiments, by setting the magnetic isolation hole 9 and reasonably limiting the magnetization direction of the magnet, flexible design can be made for different motor performance requirements. For example, the size and shape of the magnetic isolation hole 9 and the magnetization angle of the magnet can be adjusted according to the power level and torque requirements of the motor. This design flexibility allows the motor to better adapt to various application scenarios and meet different industrial needs.

[0043] Specifically, the shaft hole 8 is the central part of the rotor lamination, mainly used to install the motor shaft. Since the shaft hole 8 itself does not have a magnetized magnet, the magnetic field strength around it is relatively weak. It is mainly the magnetic field of the surrounding magnet that affects the edge of this area. The magnetic isolation hole 9 is located on the radial outer side of the shaft hole 8. Its main function is to isolate the magnetic circuit and prevent the magnetic lines of force from forming a local closed loop or generating too much leakage magnetic field in the area around the shaft hole 8 and between the second magnet slot 6. It guides the magnetic lines of force to flow more radially outward to the lamination body 4. The second magnet 2 is installed in the second magnet slot 6. Its magnetization direction is radial magnetization P2 away from the center. The first magnetic isolation bridge 10 formed between the radial outer side of the magnetic isolation hole 9 and the second magnet slot 6 plays a guiding role in the magnetic field. Due to the presence of the first magnetic isolation bridge 10, the magnetic lines of force of the first magnet 1 are guided by the shape and position of the magnetic isolation bridge when passing through the magnetic isolation bridge, and converge towards the radial outer side of the lamination body 4. The magnetic field near the shaft hole 8 is relatively weak, while under the action of the magnetic isolation hole 9 and the first magnetic isolation bridge 10, the magnetic lines of force converge more radially outward. In particular, under the synergistic effect of the first magnet 1 and the second magnet 2, the magnetic field gradually strengthens in the radial direction and diffuses outward. At the air gap, the magnetic lines of force can be more concentrated and distributed, forming a stronger magnetic field.

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

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

[0046] As one specific implementation method, see [link to relevant documentation] Figure 7 and Figure 8 As shown, since the second magnet 2 is located between the two first magnets 1, when the magnetic isolation hole 9 is set on the radial inner side of the second magnet 2, the second magnet groove 6 and its side ( Figure 5 A second magnetic isolation bridge 16 is formed between the first magnetic steel groove 5 (on the left side of the orientation) and the second magnetic steel groove 6 and its other side ( Figure 5A third magnetic isolation bridge 17 is formed between the first magnet slot 5 (located on the right side of the center). A second magnetic isolation bridge 16 is located between the second magnet slot 6 and the first magnet slot 5 on its left. The second magnetic isolation bridge 16 is relatively narrow and acts as a guide for the magnetic field. When the radial magnetic lines of force of the second magnet 2 near the shaft hole 8 pass through the second magnetic isolation bridge 16, they are guided by the shape and position of the bridge and converge towards the region of the first magnet slot 5 on the left. Simultaneously, the tangential magnetic lines of force of the first magnet 1 on the left interact with the magnetic lines of force of the second magnet 2, forming a concentrated area of ​​the magnetic field in this region. A third magnetic isolation bridge 17 is located between the second magnet slot 6 and the first magnet slot 5 on its right. Similar to the second magnetic isolation bridge 16, the third magnetic isolation bridge 17 also acts as a guide for the magnetic field. The magnetic lines of force of the second magnet 2 converge towards the region of the first magnet slot 5 on the right through the third magnetic isolation bridge 17 and interact with the tangential magnetic lines of force of the first magnet 1 on the right, forming another concentrated area of ​​the magnetic field. Guided by the second magnetic isolation bridge 16 and the third magnetic isolation bridge 17, the magnetic lines of force of the second magnet 2 mainly extend towards the regions of the first magnet slots 5 on both sides. Simultaneously, due to the presence of the magnetic isolation hole 9, the magnetic lines of force of the second magnet 2 are somewhat restricted radially inward, resulting in less leakage towards the shaft hole 8. That is, the magnetic lines of force of the second magnet 2 near the shaft hole 8 are guided by the second magnetic isolation bridge 16 and the third magnetic isolation bridge 17, while the magnetic lines of force of the second magnet 2 near the outer side converge towards the magnetic pole 12. The magnetic lines of force of the second magnet 2 can more effectively converge towards the air gap radially outward. Guided by the second magnetic isolation bridge 16 and the third magnetic isolation bridge 17, the magnetic lines of force of the first magnet 1 on the left and right sides interact with the magnetic lines of force of the second magnet 2, forming a concentrated and strengthened magnetic field in the region near the second magnet slot 6. At the same time, the tangential magnetic lines of force of the first magnet 1 are widely distributed in the circumferential direction, and the magnetic field gradually weakens in the region away from the second magnet slot 6, forming a relatively uniform magnetic field distribution. Overall, this arrangement makes the magnetic field distribution inside the rotor laminations more reasonable. The magnetic field near the shaft hole 8 is relatively weak, reducing magnetic leakage in this area. Under the guidance of the second magnetic isolation bridge 16 and the third magnetic isolation bridge 17, the magnetic lines of force of the second magnet 2 effectively extend to the area of ​​the first magnet slot 5 on both sides and interact with the magnetic lines of force of the first magnet 1 to form a concentrated area of ​​magnetic field. The magnetic lines of force in these concentrated areas further converge towards the air gap, enhancing the magnetic field at the air gap.

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

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

[0049] In one specific implementation, although one end of the magnetic isolation hole 9 extends towards the first magnetic groove 5 on one side of the second magnetic groove 6, and the other end of the magnetic isolation hole 9 extends towards the first magnetic groove 5 on the other side of the second magnetic groove 6, the total circumferential length of the magnetic isolation hole 9 extending to the first magnetic groove 5 accounts for 1 / 3 of the total width of the first magnetic groove 5. That is, no magnetic isolation hole 9 is provided on the radial inner side corresponding to 2 / 3 of the circumferential length of the first magnetic groove 5. In the radial direction, the width of the magnetic isolation hole 9 needs to be determined according to the rotor processing conditions. The radial width of the first magnetic isolation bridge 10 is close to the minimum size that satisfies the structural strength. The distance between the radial inner side of the magnetic isolation hole 9 and the inner side of the rotor lamination is greater than the radial width of the first magnetic isolation bridge 10. The magnetic flux density in the regions of the first magnetic isolation bridge 10, the second magnetic isolation bridge 16, and the third magnetic isolation bridge 17 is maximized, so that the rotor lamination tends to saturate, reducing internal magnetic leakage and ensuring that more magnetic lines of force converge to the outside.

[0050] In one specific implementation, the first magnet 1 and the second magnet 2 are conventional magnets, while the third magnet 3 is a conventional or stronger magnet. A material with greater coercivity than the first magnet 1 can be selected, resulting in stronger magnetism and achieving a magnetizing effect. Furthermore, the cross-sectional dimensions of the three magnets are slightly smaller than the corresponding magnet slot cross-sectional dimensions, facilitating installation and adhesive fixation. The length of the magnets is the same as the stack height of the rotor core, ensuring minimal longitudinal magnetic leakage.

[0051] See also Figures 1 to 6 As shown, a magnetic pole 12 is formed between the radial lines of adjacent first magnetic grooves 5. Here, the radial line refers to a straight line extending outward from the center of the lamination body 1. The outer circular contour corresponding to the magnetic pole 12 is provided with a tangent structure 11 so that the radial outer side of the magnetic pole 12 protrudes outward.

[0052] Specifically, existing hybrid rotor cores neglect the influence of trimming on factors such as the length of the rotor pole arc and the size of the air gap, which leads to a decrease in the motor's back EMF and a reduction in output torque. In this embodiment, to ensure that the air gap size changes more smoothly when the designed rotor core is fitted with the stator, the outer circular contour corresponding to the magnetic pole 12 is provided with a trimming structure 11, which makes the radial outer side of the magnetic pole 12 bulge outward. This changes the shape and size of the air gap. The outwardly bulging shape of the magnetic pole 12 increases the magnetic field coverage of the magnetic pole 12 on the radial outer side. Most of the magnetic lines of force interact with the stator through the magnetic pole 12 region. At the same time, the size of the pole shoe at the top of the magnet is effectively reduced, increasing the air gap size at the top of the magnet. This design can effectively increase the air gap magnetic flux density and reduce output torque pulsation.

[0053] It is worth noting that in this embodiment, the slit structure 11 is formed by cutting off the outer circular contour of the lamination body 4 based on the outer circular contour of the lamination body 4, so that the radial outer side of the magnetic pole 12 is convex outward, rather than a regular and smooth arc structure. Preferably, the top of the magnetic pole 12 is convex outward. Since multiple first magnets 1 are provided, multiple magnetic poles 12 are formed, and the lamination body 4 between each adjacent first magnet groove 5 can form such a magnetic pole 12 region.

[0054] See also Figures 1 to 6 As shown, the slit structure 11 includes a first slit 13 and a second slit 14. The magnetic pole 12 has a central axis. The first slit 13 and the second slit 14 are symmetrically arranged about the central axis. One end of the first slit 13 and the second slit 14 are connected to each other. The other ends of the first slit 13 and the second slit 14 extend to the radial extension lines of the corresponding first magnetic grooves 5. The connection between the first slit 13 and the second slit 14 is convex inward.

[0055] In this embodiment, the connection between the first tangent 13 and the second tangent 14 protrudes inward, forming a convex structure on the radially outer side of the magnetic pole 12. This convex structure concentrates the magnetic flux, making the magnetic flux density at the air gap more concentrated and enhanced at the magnetic pole 12, thus increasing the amplitude of the air gap magnetic flux density. The tangent structure 11 changes the shape of the air gap, and this modulation effect helps optimize the air gap magnetic flux density distribution, thereby improving the back EMF and output torque of the motor. Because the tangent structure 11 makes the radially outer side of the magnetic pole 12 protrude outward, the air gap becomes relatively smaller at the magnetic pole 12, thereby enhancing the air gap magnetic flux density at that location. The enhanced air gap magnetic flux density can improve the back EMF of the motor.

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

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

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

[0059] See also Figure 6As shown, the center of the rotor lamination is O0. The gradual transition section 151 and the changing section 152 are eccentrically set relative to the center O0. The center of the gradual transition section 151 is O1, and the center of the changing section 152 is O2. The straight-line distance between the center O1 and the center O0 is less than the straight-line distance between the center O2 and the center O0. The arc length of the gradual transition section 151 is L1, the arc length of the changing section 152 is L2, and the arc length of the smooth section 153 is L3.

[0060] Specifically, the transition segment 151 and the change segment 152 are eccentrically set relative to the center O0. The straight-line distance between the center O1 and the center O0 is also the offset distance. The change segment 152 is an arc in the circle of the center O1. The starting point of the change segment 152 is connected to the transition segment 151. The change segment 152 is an arc at one end of the circle of the center O2. The starting point of the smooth segment 153 is connected to the change segment 152. The smooth segment 153 is formed by chamfering the change segment 152. The curvature of the arc of the change segment 152 is greater than the curvature of the smooth segment 153. If the smooth segment 153 is not set, and the arc of the change segment 152 continues to extend radially towards the first magnet groove 5, the curvature of the outer circle contour corresponding to the first magnet groove 5 will also be large, resulting in large output torque pulsation. Setting the smooth segment 153 makes the air gap change smoothly at this point, avoiding large fluctuations that affect the motor torque output.

[0061] In this embodiment, the gradual narrowing section 151 narrows the inner side of the magnetic pole 12, reducing magnetic flux congestion, lowering the peak magnetic flux density, and preventing magnetic saturation. The changing section 152 connects the gradual narrowing section 151 and the smoothing section 153, and its shape change further optimizes the magnetic flux distribution, making the magnetic flux more evenly distributed throughout the entire magnetic pole 12 region. The smoothing section 153 connects to the smoothing section 153 of the adjacent magnetic pole 12, making the air gap magnetic flux density distribution between the magnetic poles 12 more uniform, reducing magnetic flux leakage, and enhancing magnetic circuit coherence. The optimized magnetic flux distribution makes the magnetic flux density in the air gap more uniform and concentrated, improving the motor's back EMF and power generation performance. At the same time, the uniform air gap magnetic flux density distribution allows the current in the stator winding to interact with a stronger magnetic field, enhancing the motor's torque output capability. The symmetrical tangential structure 11 and the optimized design of each section make the magnetic field distribution more stable, reducing torque fluctuations and electromagnetic vibrations, and improving the smoothness and reliability of motor operation.

[0062] As a specific implementation, this embodiment takes the radial extension line of the geometric center of the first magnet groove 5 as a reference, selects the minimum size point of the pre-set punch body 4 at the top of the first magnet 1, connects one end of the smooth segment 153 to this minimum size point, and connects the other end to the variable segment 152. The smooth segment 153 is formed by chamfering the variable segment 152. Specifically, the center O3 of the smooth segment 153 is located outside the punch body 4, and the center O3 is located on the radial extension line of the geometric center of the first magnet groove 5. The smooth segment 153 is a small arc segment in the circle of the center O3. The angle between the extended arc of the variation segment 152 and the normal at the minimum dimension point is small (equivalent to the rotor outer circle being concave inwards further according to the arc length of the variation segment 152, and the slope of this concave part is larger), and the air gap length is larger. This causes the torque output to decrease when the rotor rotates to a certain angle, resulting in a larger peak-to-peak torque output and larger torque pulsation during operation, which affects the torque output. Setting the smooth segment 153 can make the air gap change more gently at this point, avoiding large fluctuations that affect the motor torque output.

[0063] A rotor core includes a plurality of rotor laminations stacked together, wherein the rotor laminations are those described above.

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

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

[0066] After adopting the above scheme, in conjunction with [see also...] Figure 9 The relationship between air gap magnetic flux density and arc length is illustrated in the diagram. Simulations were performed simultaneously on the rotor designed in this embodiment and the rotor of the traditional scheme. While maintaining a constant amount of magnets, the relationship between air gap magnetic flux density and arc length was compared between the different designs. In this comparison, the rotor outer diameter and stator dimensions remained unchanged. Within the air gap arc segment around the rotor, the average air gap magnetic flux density between the rotor and stator in this embodiment is 0.9399T, with a maximum value of 1.4154T. In the traditional scheme, the average air gap magnetic flux density between the rotor and stator is 0.9105T, with a maximum value of 1.3908T. This embodiment improves the rotor magnetic field strength and effectively increases the air gap magnetic flux density. Furthermore, referring to [reference needed]... Figure 10 The output torque varies with time. Similarly, while keeping the amount of magnets constant, the output torque of different design schemes is compared with the running time. Within one electrical cycle, the average output torque of the motor in this embodiment is 1.2811 N∙m, with a torque ripple of 2.65%, while the average output torque of the motor in the traditional scheme is 1.2609 N∙m, with a torque ripple of 3.21%. This embodiment can effectively improve the motor torque output and reduce torque ripple while increasing the output, thus increasing the motor's operational stability.

[0067] In one specific implementation, the rotor core is made of a magnetically conductive metal material, such as low-carbon steel with high magnetic permeability and high magnetic saturation coefficient. The shaft hole 8 is an opening on the inner side of the rotor lamination, and its fit with the shaft is usually an interference fit. The size is determined by the specific design of the motor shaft. The outer circle of the rotor core contacts the air gap and then fits with the motor stator. The outer circle is trimmed with three arc segments as designed in this patent.

[0068] An electric motor includes a rotor core, wherein the rotor core is as described above.

[0069] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

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

Claims

1. A rotor lamination, characterized in that, include: The lamination body (4), the first magnet (1), the second magnet (2) and the third magnet (3); The lamination body (4) has a plurality of first magnet slots (5) in the circumferential direction. In the radial direction of the lamination body (4), the first end of the first magnet slot (5) extends radially inward to the lamination body (4), and the second end of the first magnet slot (5) extends radially outward to the lamination body (4). The first magnet (1) is installed in the first magnet slot (5), and the magnetization direction of the first magnet (1) is tangential magnetization. A second magnet groove (6) is provided between adjacent first magnet grooves (5), and the second magnet groove (6) is close to the first end of the first magnet groove (5). The second magnet (2) is installed in the second magnet groove (6), and the magnetization direction of the second magnet (2) is radial magnetization. A third magnet groove (7) is provided on the radially outer side of the second end of the first magnet groove (5). The third magnet (3) is installed in the third magnet groove (7). The magnetization direction of the third magnet (3) is directed toward the radially outer side of the stamping body (4). The magnetization direction of the third magnet (3) and the magnetization direction of the second magnet (2) form a first acute angle, so that the magnetic lines of force converge toward the radially outer side of the stamping body (4). The third magnet groove (7) is located on the radial extension line of the second end of the first magnet groove (5). The magnetization direction of the first magnet (1) and the magnetization direction of the second magnet (2) form a second acute angle, and the angle of the second acute angle is greater than the angle of the first acute angle, so that the magnetic lines of force converge in the inner region of the magnetic pole (12).

2. The rotor lamination according to claim 1, characterized in that, The rotor lamination has a shaft hole (8), and the second magnet groove (6) is located on the radial outer side of the shaft hole (8). A magnetic isolation hole (9) is provided between the shaft hole (8) and the second magnet groove (6), so that a first magnetic isolation bridge (10) is formed between the radial outer side of the magnetic isolation hole (9) and the second magnet groove (6), so that the magnetic lines of the first magnet (1) converge on the radial outer side of the lamination body (4).

3. The rotor lamination according to claim 2, characterized in that, In the circumferential direction of the rotor lamination, one end of the magnetic isolation hole (9) extends toward the first magnetic groove (5) on one side of the second magnetic groove (6), and the other end of the magnetic isolation hole (9) extends toward the first magnetic groove (5) on the other side of the second magnetic groove (6). The circumferential length of the magnetic isolation hole (9) is greater than the circumferential length of the second magnetic groove (6).

4. The rotor lamination according to claim 1, characterized in that, A magnetic pole (12) is formed between the radial lines of adjacent first magnetic grooves (5). The outer circular contour of the magnetic pole (12) is provided with a tangent structure (11) so that the radial outer side of the magnetic pole (12) protrudes outward.

5. The rotor lamination according to claim 4, characterized in that, The slit structure (11) includes a first slit (13) and a second slit (14). The magnetic pole (12) has a central axis. The first slit (13) and the second slit (14) are symmetrically arranged about the central axis. One end of the first slit (13) and the second slit (14) are connected to each other. The other end of the first slit (13) and the second slit (14) extend to the radial line of the corresponding first magnetic groove (5). The connection between the first slit (13) and the second slit (14) is convex inward.

6. The rotor lamination according to claim 5, characterized in that, The first cut edge (13) and the second cut edge (14) both include a gradient segment (151), a change segment (152) and a smooth segment (153) connected in sequence. The end of the gradient segment (151) away from the change segment (152) intersects the central axis, and the end of the smooth segment (153) away from the change segment (152) is connected to the smooth segment (153) of the adjacent magnetic pole (12).

7. The rotor lamination according to claim 6, characterized in that, The center of the rotor lamination is O0. The gradual transition section (151) and the changing section (152) are eccentrically arranged relative to the center O0. The center of the gradual transition section (151) is O1, and the center of the changing section (152) is O2. The straight-line distance between the center O1 and the center O0 is less than the straight-line distance between the center O2 and the center O0.

8. A rotor core comprising a plurality of stacked rotor laminations, characterized in that, The rotor lamination is the rotor lamination as described in any one of claims 1 to 7.

9. An electric motor, comprising a rotor core, characterized in that, The rotor core is the rotor core as described in claim 8.

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