Rotor laminations, rotor assemblies and permanent magnet motors

Abstract

This utility model discloses a rotor lamination, a rotor assembly, and a permanent magnet motor, comprising: a lamination body with a central shaft hole; permanent magnet slots for mounting permanent magnets, the slots being evenly distributed circumferentially and extending radially along the lamination body; magnetic isolation slots evenly distributed circumferentially and located between the inner ends of two adjacent permanent magnet slots; and weight reduction holes evenly distributed circumferentially and adjacent to the outer side of the magnetic isolation slots. A rotor assembly includes the aforementioned rotor laminations, with multiple rotor laminations stacked and bonded together. A rotor shaft is interference-fitted into the shaft hole of the rotor assembly, and permanent magnets are glued and fixed into the permanent magnet slots of the rotor assembly. A permanent magnet motor includes the aforementioned rotor assembly. This utility model's rotor lamination, rotor assembly, and permanent magnet motor can improve magnetic flux utilization, reduce magnetic leakage, reduce eddy current losses, improve torque output stability, and increase motor efficiency.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor lamination, rotor assembly and permanent magnet motor. Background Technology

[0002] Traditional brushless DC motors suffer from severe magnetic leakage between permanent magnet slots, reducing magnetic energy utilization. Although magnetic isolation slots are incorporated to address this leakage, improper dimensional matching between the permanent magnet slots and the magnetic isolation slots can easily lead to localized magnetic saturation or insufficient mechanical strength.

[0003] as follows Figure 5 As shown, the permanent magnet slots in the motor rotor core are relatively short, and the position and size of the magnetic isolation slots are inappropriate, being too far from the permanent magnet slots, leading to localized magnetic saturation in the rotor core. Furthermore, traditional rotor core structures often have rivets or overlapping rivet points between each permanent magnet slot, increasing eddy current losses in the core, reducing motor efficiency, and interfering with the main magnetic flux path, causing unnecessary magnetic flux leakage or loss. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to solve the technical problems of large eddy current loss, magnetic flux leakage and low motor efficiency in the prior art, this utility model provides a rotor lamination, rotor assembly and permanent magnet motor, which can improve magnetic flux utilization, reduce magnetic leakage, reduce eddy current loss, improve torque output stability and improve motor efficiency.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a rotor lamination, comprising:

[0006] A lamination body, wherein the lamination body has a central shaft hole;

[0007] Permanent magnet slots for mounting permanent magnets are evenly distributed in the circumferential direction of the lamination body and extend radially along the lamination body.

[0008] The magnetic isolation grooves are evenly distributed in the circumferential direction of the lamination body and are located between the inner ends of two adjacent permanent magnet grooves.

[0009] The magnet slot is rectangular, and the axis of symmetry of the long side of the permanent magnet slot passes through the center of the lamination body. The distance between the inner side of the permanent magnet slot and the center of the lamination body is L1. The inner arc radius of the magnetic isolation slot is R1, and L1 / R1 = 0.95 - 1.05 is satisfied.

[0010] The rotor lamination of this utility model optimizes the layout of permanent magnet slots, magnetic isolation slots and weight reduction holes. The weight reduction holes can play a role in heat dissipation without affecting the magnetic circuit, thereby improving magnetic flux utilization, reducing magnetic leakage, and improving the stability of torque output.

[0011] Furthermore, in order to optimize the magnetic circuit direction, the inner arc radius of the magnetic isolation groove is R1, and the outer arc radius of the magnetic isolation groove is R2, and R2-R1=0.5-1.5mm is satisfied.

[0012] Furthermore, in order to further optimize the magnetic circuit and reduce magnetic leakage loss, the inner arc radius R1 of the magnetic isolation groove and the radius R of the lamination body satisfy: R1 / R = 0.4 - 0.6.

[0013] Furthermore, in order to block lateral leakage of magnetic flux, the wall thickness between the opposite sides of the magnetic isolation groove and the permanent magnet groove is s, and the thickness of the lamination body is t, and s / t = 0.5 - 1 is satisfied.

[0014] Furthermore, in order to reduce the weight of the rotor lamination, the rotor lamination also includes weight reduction holes, which are evenly distributed in the circumferential direction of the lamination body and are adjacent to the outer side of the magnetic isolation groove.

[0015] Furthermore, the diameter D1 of the weight-reducing hole and the radius R of the lamination body satisfy: D1 / R = 0.05 - 0.10. This avoids a decrease in rotor structural strength or magnetic circuit leakage due to an excessively large diameter of the weight-reducing hole.

[0016] Furthermore, the distance L2 between the center of the weight-reducing hole and the center of the lamination body satisfies the following condition with respect to the radius R of the lamination body: L2 / R = 0.5 - 0.6. This allows the weight-reducing hole to be located away from the high-stress areas of the permanent magnet slots and the outer edge of the rotor, thus not affecting the magnetic circuit.

[0017] Another technical solution adopted by this utility model to solve its technical problem is: a rotor assembly, including multiple rotor laminations as described above, the multiple rotor laminations are stacked and bonded together as a whole, a rotor shaft is interference-fitted into the shaft hole of the rotor assembly, and a permanent magnet is bonded and fixed in the permanent magnet slot of the rotor assembly by adhesive.

[0018] Furthermore, in order to prevent the rotor shaft from rotating relative to the rotor assembly, a plurality of anti-rotation ribs are evenly spaced on the outer circumference of the rotor shaft, and the anti-rotation ribs are arranged along the axial direction of the rotor shaft.

[0019] Another technical solution adopted by this utility model to solve its technical problem is: a permanent magnet motor, including the above-mentioned rotor assembly.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] 1. The rotor lamination, rotor assembly and permanent magnet motor of this utility model reduce rotational inertia by designing weight-reducing holes, and can be used in conjunction with magnetic isolation grooves to assist heat dissipation and improve operating stability in high-temperature environments. This reduces manufacturing costs without sacrificing magnetic performance, while improving the material utilization rate of rotor laminations.

[0022] 2. The rotor lamination, rotor assembly and permanent magnet motor of this utility model optimize the layout and parameters of permanent magnet slots and magnetic isolation slots, improve magnetic flux utilization, reduce magnetic leakage, ensure that the magnetic field of permanent magnets acts uniformly on the air gap area, avoid magnetic circuit saturation or local weak magnetic problems, thereby improving the linearity of torque output, and ensuring the magnetic isolation effect while taking into account structural strength.

[0023] 3. The rotor laminations, rotor assembly, and permanent magnet motor of this utility model adopt an adhesive (glue) lamination process, which can effectively maintain the electrical insulation between rotor laminations, block the eddy current path between layers, thereby reducing the eddy current loss of the iron core caused by rivets or rivets, avoiding the introduction of such magnetic or non-magnetic foreign objects in the key areas of the magnetic circuit, maintaining the continuity and integrity of the magnetic circuit, ensuring that the magnetic flux generated by the permanent magnet can more effectively act on the air gap through the iron core, and improving the magnetic energy utilization rate. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is a schematic diagram of the rotor lamination of this utility model;

[0026] Figure 2 This is a three-dimensional structural diagram of the rotor assembly;

[0027] Figure 3 This is a schematic diagram showing the assembly of the rotor assembly with the rotor shaft and permanent magnets.

[0028] Figure 4 This is a schematic diagram of the simulation results of the motor's magnetic field;

[0029] Figure 5 This is a schematic diagram of the structure of an existing rotor lamination.

[0030] In the figure: 1. Lamination body, 11. Shaft hole, 12. Permanent magnet slot, 13. Magnetic isolation slot, 14. Weight reduction hole, 2. Rotor shaft, 21. Anti-rotation rib, 3. Permanent magnet. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0032] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and 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 of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] like Figure 1 As shown, a rotor lamination includes: a lamination body 1. The lamination body 1 has a shaft hole 11 at its center. Permanent magnet slots 12 are evenly distributed circumferentially on the lamination body 1 and extend radially along the lamination body 1. Magnetic isolation slots 13 are evenly distributed circumferentially on the lamination body 1 and are located between the inner ends of two adjacent permanent magnet slots 12. Weight reduction holes 14 are evenly distributed circumferentially on the lamination body 1 and are adjacent to the outer side of the magnetic isolation slots 13.

[0035] Preferably, the permanent magnet slot 12 is rectangular, and the axis of symmetry of the long side of the permanent magnet slot 12 passes through the center of the lamination body 1, ensuring that the magnetic field direction is consistent with the rotor radial direction and maximizing the effectiveness of the magnetic flux path. The rectangular filling shape of the permanent magnet 3 can increase the magnet volume ratio (fill rate), enhance the air gap magnetic flux density, and thus increase the motor power density.

[0036] Specifically, the distance between the inner side of the permanent magnet slot 12 and the center of the lamination body 1 is L1, and the inner radius of the magnetic isolation slot 13 is R1, satisfying L1 / R1 = 0.95 - 1.05. This ensures that the magnetic field of the permanent magnet 3 acts uniformly in the air gap region, avoiding magnetic circuit saturation or local magnetic weakness, thereby improving the linearity of torque output.

[0037] The following table analyzes the impact of the ratio of the same magnetic slot size L1 / R1 on magnetic circuit performance:

[0038]

[0039] As shown in the table above, when the ratio of the magnetic isolation groove size L1 / R1 is in the range of 0.95 to 1.05, the magnetic circuit saturation is the lowest and the leakage flux suppression effect is the best. Preferably, when L1 / R1 = 1.00, the magnetic circuit symmetry, air gap magnetic flux density uniformity, and torque output stability are all optimal.

[0040] Preferably, the included angle between adjacent permanent magnet slots 12 satisfies 360 / P, where P is the number of poles of the permanent magnet 3, and P is an even number. This ensures the symmetry of the magnetic field distribution and reduces torque pulsation. The even-numbered pole design also avoids vibration noise caused by magnetic field asymmetry, making it suitable for high-precision control scenarios (such as servo motors).

[0041] Specifically, the magnetic isolation groove 13 is located between adjacent permanent magnet grooves 12, and the wall thickness between the opposite sides of the magnetic isolation groove 13 and the permanent magnet groove 12 is s, while the thickness of the lamination body 1 is t, satisfying s / t = 0.5 - 1. By limiting the wall thickness ratio between the magnetic isolation groove 13 and the permanent magnet groove 12, lateral magnetic flux leakage can be blocked, and insufficient mechanical strength due to excessively thin walls can be avoided. Furthermore, the magnetic isolation effect of the magnetic isolation groove 13 is guaranteed, while avoiding the risk of lamination deformation or breakage due to excessively thin walls, thus balancing process feasibility and reliability.

[0042] The following table shows the data for the magnetic isolation slot wall thickness ratio s / t design, obtained by verifying the magnetic isolation effect and high-speed rotor rotation test using Ansys Maxwell. It demonstrates the influence of different ratios on the magnetic isolation effect and mechanical strength (resistance to deformation / fracture). The data in the table is based on cold-rolled non-oriented silicon steel (grade 50W470) with a thickness of 0.50 mm.

[0043]

[0044]

[0045] As can be seen from the table above, good performance can be obtained at s / t = 0.5-1, and peak performance is achieved at s / t = 0.7-0.8 (leakage magnetic field suppression of 12%-15%, zero structural risk), achieving a perfect balance between magnetic isolation and mechanical strength.

[0046] Specifically, the inner radius of the magnetic shielding groove 13 is R1, and the outer radius of the magnetic shielding groove 13 is R2, satisfying R2-R1=0.5-1.5mm. Furthermore, the inner radius R1 of the magnetic shielding groove 13 and the radius R of the lamination body 1 satisfy: R1 / R=0.4-0.6, further optimizing the magnetic circuit and reducing magnetic leakage loss.

[0047] Specifically, the diameter D1 of the weight-reducing hole 14 and the radius R of the lamination body 1 satisfy: D1 / R = 0.05 - 0.10. This minimizes damage to the stacked structure of the rotor laminations, while the high strength characteristics of the cold-rolled non-oriented electrical steel strip further ensure the overall rigidity of the rotor. The weight-reducing hole 14, the permanent magnet slot 12, and the magnetic isolation slot 13 can be stamped simultaneously, resulting in less wear on the stamping die, extending die life, and reducing mass production costs.

[0048] Specifically, the distance L2 between the center of the weight reduction hole 14 and the center of the lamination body 1 satisfies the following condition with respect to the radius R of the lamination body 1: L2 / R = 0.5 - 0.6. The weight reduction hole 14 is located far from the permanent magnet slot 12 and the magnetic isolation slot 13 to ensure that it has no significant impact on the main magnetic circuit and avoids additional magnetic leakage. Combined with the magnetic isolation design of the magnetic isolation slot 13, the overall magnetic field distribution is more concentrated, reducing air gap magnetic flux density fluctuations. By removing redundant material through the weight reduction hole 14, manufacturing costs can be reduced without sacrificing magnetic performance, while improving the material utilization rate of the rotor laminations.

[0049] The weight-reduction hole 14 ensures weight reduction while avoiding a decrease in the structural strength of the rotor lamination or magnetic circuit leakage due to excessive hole diameter. Simultaneously, it ensures that the weight-reduction hole 14 is located in the central region of the rotor lamination, away from the high-stress areas of the permanent magnet slot 12 and the outer edge of the lamination body 1. This arrangement balances the stress distribution under centrifugal force, preventing fatigue cracks caused by stress concentration.

[0050] The weight-reducing holes 14 and the magnetic isolation grooves 13 serve to assist in heat dissipation. They act as internal heat dissipation channels for the rotor, promoting the flow of cooling media (such as air or oil mist) and accelerating heat transfer from the permanent magnet 3 region to the outside, thus improving operational stability under high-temperature conditions. The evenly distributed weight-reducing holes 14 can reduce the risk of thermal deformation of the rotor caused by temperature gradients and avoid demagnetization of the permanent magnet 3 due to local overheating.

[0051] like Figure 2 and Figure 3As shown, a rotor assembly includes multiple rotor laminations as described above. These laminations are stacked and bonded together. A rotor shaft 2 is interference-fitted into the shaft hole 11 of the rotor assembly, and a permanent magnet 3 is glued and fixed into the permanent magnet slot 12 of the rotor assembly. The adhesive (glue) lamination process effectively maintains electrical insulation between the laminations, blocking interlayer eddy current paths and significantly reducing core eddy current losses caused by rivets or rivets, as mentioned in the background art. This improvement directly enhances the motor's operating efficiency. The glue lamination process also avoids introducing magnetically conductive or non-magnetically conductive foreign objects into critical areas of the magnetic circuit, maintaining the continuity and integrity of the magnetic circuit. This ensures that the magnetic flux generated by the permanent magnet 3 can more effectively act on the air gap through the core, improving magnetic energy utilization. The glue lamination process is simpler and more efficient than mechanical riveting and provides good interlayer adhesion, ensuring the structural integrity and stability of the rotor assembly under high-speed rotation.

[0052] Specifically, multiple anti-rotation ribs 21 are evenly spaced on the outer circumference of the rotor shaft 2, and the anti-rotation ribs 21 are arranged along the axial direction of the rotor shaft 2.

[0053] A permanent magnet motor includes the rotor assembly described above. Figure 4 The simulation results for the motor magnetic field are as follows: the outer diameter R of the motor rotor is 23.5 mm, the number of permanent magnet poles is 10, the material thickness of the steel strip is t = 0.5 mm, the wall thickness between the magnetic isolation groove 13 and the permanent magnet groove 12 is s = 0.3 mm, the inner arc radius of the magnetic isolation groove 13 is R1 = 11.7 mm, the outer arc radius of the magnetic isolation groove 13 is R2 = 12.7 mm, the distance from the inner side of the permanent magnet groove 12 to the center of the lamination body 1 is L1 = 11.5 mm, the diameter of the weight reduction hole 14 is D1 = 1.8 mm, the distance from the center of the weight reduction hole 14 to the center of the lamination body 1 is L2 = 14.5 mm; s / t = 0.6, R2 - R1 = 1 mm, L1 / R1 = 1, R1 / R = 0.5, D1 / R1 = 0.06, L2 / R = 0.55. As can be seen from the magnetic field cloud diagram, there is a region with a low magnetic field density between the permanent magnet slots 12, which has no significant impact on the main magnetic circuit. Therefore, weight reduction holes 14 can be placed in this region.

[0054] In summary, the rotor laminations, rotor assembly, and permanent magnet motor of this invention can improve magnetic flux utilization, reduce magnetic leakage, reduce eddy current losses, improve torque output stability, and increase motor efficiency.

[0055] The above description is based on the preferred embodiments of this utility model. Through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined by the scope of the claims.

Claims

1. A rotor lamination, characterized by include: A lamination body (1) has a central shaft hole (11); Permanent magnet slots (12) for mounting permanent magnets (3) are evenly distributed in the circumferential direction of the lamination body (1) and extend radially along the lamination body (1). The magnetic isolation groove (13) is evenly distributed in the circumferential direction of the lamination body (1) and is located between the inner ends of two adjacent permanent magnet grooves (12); The magnet groove (12) is rectangular, and the axis of symmetry of the long side of the permanent magnet groove (12) passes through the center of the lamination body (1). The distance between the inner side of the permanent magnet groove (12) and the center of the lamination body (1) is L1. The inner radius of the magnetic isolation groove (13) is R1, and L1 / R1 = 0.95 - 1.05 is satisfied.

2. The rotor lamination of claim 1, wherein, The inner radius of the magnetic shielding groove (13) is R1, and the outer radius of the magnetic shielding groove (13) is R2, and R2-R1=0.5-1.5mm.

3. The rotor lamination of claim 2, wherein, The inner arc radius R1 of the magnetic isolation groove (13) and the radius R of the lamination body (1) satisfy: R1 / R = 0.4 - 0.

6.

4. The rotor lamination of claim 1, wherein, The wall thickness between the opposite sides of the magnetic isolation groove (13) and the permanent magnet groove (12) is s, and the thickness of the lamination body (1) is t, and s / t = 0.5 - 1 is satisfied.

5. The rotor lamination of claim 1, wherein, The rotor lamination also includes weight reduction holes (14), which are evenly distributed in the circumferential direction of the lamination body (1) and are adjacent to the outer side of the magnetic isolation groove (13).

6. The rotor lamination of claim 5, wherein, The diameter D1 of the weight reduction hole (14) and the radius R of the lamination body (1) satisfy: D1 / R = 0.05 - 0.

10.

7. The rotor lamination of claim 5 or 6, characterized in that The distance L2 between the center of the weight reduction hole (14) and the center of the stamping body (1) satisfies the following condition with respect to the radius R of the stamping body (1): L2 / R = 0.5 - 0.

6.

8. A rotor assembly characterized by, The rotor assembly includes multiple rotor laminations as described in any one of claims 1-7, the multiple rotor laminations are stacked and bonded together as a whole, a rotor shaft (2) is interference-fitted into the shaft hole (11) of the rotor assembly, and a permanent magnet (3) is fixedly bonded to the permanent magnet slot (12) of the rotor assembly by adhesive.

9. The rotor assembly of claim 8, wherein, Multiple anti-rotation ribs (21) are evenly spaced on the outer circumference of the rotor shaft (2), and the anti-rotation ribs (21) are arranged along the axial direction of the rotor shaft (2).

10. A permanent magnet electric machine characterized by, Includes the rotor assembly as described in claim 8 or 9.

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