A rotor lamination, a rotor core, a rotor, and an electric machine
By designing a staggered and symmetrical structure of inner and outer permanent magnet slots on the rotor laminations, the problem of large harmonics in the rotor laminations was solved, thereby improving motor performance and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GREE ELECTRIC APPLIANCE INC OF ZHUHAI
- Filing Date
- 2025-05-15
- Publication Date
- 2026-05-29
Smart Images
Figure CN224305555U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of motor technology, specifically to a rotor lamination, a rotor core, a rotor, and a motor. Background Technology
[0002] Permanent magnet motors, using permanent magnet materials for excitation, do not require external energy to establish a magnetic field within the motor's air gap. This results in a high power factor and high efficiency under heavy loads. Furthermore, permanent magnet motors have high power density and are relatively small in size and weight. With increasingly stringent national energy consumption standards, the application of permanent magnet motors is becoming increasingly widespread.
[0003] When a permanent magnet synchronous motor (PMSM) is running, the energized stator coils exert a demagnetizing effect on the permanent magnets on the rotor. During normal operation, the operating current is relatively small, and the magnetic field strength generated by the armature windings is insufficient to demagnetize the permanent magnets. However, when the motor encounters abnormal conditions, such as stalled rotor or short circuit, a sudden surge in current can easily lead to irreversible demagnetization of the permanent magnets, affecting motor performance and reliability. To ensure normal motor operation, the demagnetization characteristics of the permanent magnets need to be thoroughly analyzed and verified during motor development to ensure demagnetization margin and improve motor reliability. Furthermore, the motor's structure and inverter are the main factors causing low-order current harmonics in PMSMs. Motor-related factors include cogging effect, magnetic circuit saturation effect, and rotor pole structure, which can lead to output voltage distortion. These factors can cause excessive cogging torque and harmonics, thus affecting motor performance, application precision, and accuracy.
[0004] Because existing rotor laminations have technical problems such as large harmonics, this utility model studies and designs a rotor lamination, a rotor core, a rotor, and a motor. Utility Model Content
[0005] Therefore, the technical problem to be solved by this utility model is to overcome the defect of large harmonics in the rotor laminations of the prior art, thereby providing a rotor lamination, rotor core, rotor and motor.
[0006] To solve the above problems, this utility model provides a rotor lamination, which includes:
[0007] The lamination body and the permanent magnet slot are provided on the lamination body. The permanent magnet slot includes an inner permanent magnet slot and an outer permanent magnet slot. Along the radial direction of the rotor lamination, the outer permanent magnet slot is located outside the inner permanent magnet slot. The lamination body has a d-axis. The outer permanent magnet slot includes an outer first permanent magnet slot and an outer second permanent magnet slot. The outer first permanent magnet slot is located on one side of the d-axis, and the outer second permanent magnet slot is located on the other side of the d-axis. The outer first permanent magnet slot and the outer second permanent magnet slot are symmetrical with respect to the d-axis.
[0008] The lamination body also has an inner permanent magnet groove centerline L, which is parallel to the d-axis and spaced at a predetermined distance greater than 0. The inner permanent magnet groove includes an inner first permanent magnet groove located on one side of L and an inner second permanent magnet groove located on the other side of L. The inner first permanent magnet groove and the inner second permanent magnet groove have the same shape and area. The minimum distance between the inner first permanent magnet groove and L and the minimum distance between the inner second permanent magnet groove and L are equal. However, the inner first permanent magnet groove and the inner second permanent magnet groove are asymmetrical with respect to L.
[0009] In some implementations...
[0010] In contrast, the inner first permanent magnet slot is disposed relatively close to the outer circumferential surface of the rotor lamination, and the inner second permanent magnet slot is disposed relatively far away from the outer circumferential surface of the rotor lamination. The minimum distance between the inner first permanent magnet slot and the outer circumferential surface is greater than the minimum distance between the inner second permanent magnet slot and the outer circumferential surface.
[0011] In some implementations...
[0012] The distance between the center line L of the inner permanent magnet groove and the d axis is d1, and dl = 1.2~1.6mm.
[0013] In some implementations...
[0014] When the motor rotates clockwise, the inner permanent magnet slot is biased towards the clockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the clockwise direction;
[0015] When the motor rotates counterclockwise, the inner permanent magnet slot is biased towards the counterclockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the counterclockwise direction.
[0016] In some implementations...
[0017] The inner first permanent magnet slot is located on one side of L in the counterclockwise direction, and the inner second permanent magnet slot is located on one side of L in the clockwise direction.
[0018] When the motor rotates clockwise, the minimum distance between the inner first permanent magnet slot and the d-axis is less than the minimum distance between the inner second permanent magnet slot and the d-axis.
[0019] When the motor rotates counterclockwise, the minimum distance between the inner first permanent magnet slot and the d-axis is greater than the minimum distance between the inner second permanent magnet slot and the d-axis.
[0020] In some implementations...
[0021] Along the radial direction of the rotor lamination, the outermost edge of the inner first permanent magnet slot is the first arc edge, and the outermost edge of the inner second permanent magnet slot is the second arc edge. The center of the first arc edge coincides with the center point O of the shaft hole of the rotor lamination, and the center of the second arc edge coincides with the center point O of the shaft hole of the rotor lamination. The radius of the first arc edge is R1, the radius of the second arc edge is R2, and the radius of the rotor lamination is R. There are constraints: R2 = R1 - (-0.1~0.15) mm, R1 = R - (0.8~1.2) mm.
[0022] In some implementations...
[0023] Along the radial direction of the rotor lamination, the inner end of the inner first permanent magnet slot and the inner end of the inner second permanent magnet slot are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an inner magnetic isolation bridge a. The width of the inner magnetic isolation bridge a along the circumferential direction of the rotor lamination is da. Along the radial direction of the rotor lamination, the inner end of the outer first permanent magnet slot and the inner end of the outer second permanent magnet slot are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an outer magnetic isolation bridge b. The width of the outer magnetic isolation bridge b along the circumferential direction of the rotor lamination is db. There are constraints: db = 0.8~1.8mm, da = (1.5~2)db, d1 = da-db.
[0024] This utility model also provides a rotor core, which includes the aforementioned rotor laminations, with multiple layers of rotor laminations stacked to form the rotor core.
[0025] This utility model also provides a rotor, which includes the aforementioned rotor core and a permanent magnet disposed in the permanent magnet slot.
[0026] This utility model also provides an electric motor, which includes the aforementioned rotor.
[0027] The rotor lamination, rotor core, rotor, and motor provided by this utility model have the following beneficial effects:
[0028] 1. This utility model divides the permanent magnet slots on the rotor lamination into inner and outer permanent magnet slots. The outer permanent magnet slots include an outer first and an outer second permanent magnet slot symmetrically arranged with respect to the d-axis. The inner permanent magnet slots include an inner first and an inner second permanent magnet slot. The inner first and inner second permanent magnet slots are the same size and shape, and they are asymmetrically arranged with respect to the center line L, which is a line offset parallel to the d-axis. This makes the outer permanent magnet slot B2 symmetrical about the magnetic pole center line d-axis, just like traditional rotor laminations, while the inner permanent magnet slot B1 is asymmetrical about the d-axis and forms a misaligned symmetry about the center line L. Unlike traditional rotor laminations, the asymmetrical rotor structure of this utility model can reduce magnetic leakage between magnetic poles, increase air gap magnetic flux density, enhance the fundamental wave content, obtain an air gap waveform with better sinusoidal characteristics, improve harmonic distortion rate, reduce and improve harmonics, and has a significant effect on suppressing cogging torque.
[0029] 2. This utility model further improves upon the following: when the rotor laminations are rotated clockwise, the inner permanent magnet slots are biased towards the clockwise side of the d-axis, i.e., L is located at a position where the d-axis is shifted clockwise by d1; when the motor rotates counterclockwise, the inner permanent magnet slots are biased towards the counterclockwise side of the d-axis, i.e., L is located at a position where the d-axis is shifted counterclockwise by d1. This ensures that the motor output torque remains essentially unchanged after the inner permanent magnets are shifted, and the magnetic field distribution is optimized, while the cogging torque and harmonic content are reduced.
[0030] 3. This utility model also sets the distance dl between the L and d axes to satisfy dl = 1.2~1.6mm. This constraint relationship can effectively reduce the leakage magnetic field between poles without affecting the main magnetic circuit, reduce the risk of demagnetization at the sharp corners of the permanent magnet, increase the high magnetic density area on the permanent magnet, improve the anti-demagnetization performance of the permanent magnet, expand the high magnetic density area on the permanent magnet, increase the magnetic density of the easily demagnetized area at the sharp corners of the permanent magnet, and significantly reduce the risk of demagnetization of the permanent magnet.
[0031] 4. This utility model further incorporates an outermost edge of the inner permanent magnet slot along the radial direction of the rotor lamination, composed of a first arc edge B111 and a second arc edge B121. The centers of the first arc edge B111 and the second arc edge B121 coincide with the center point O of the rotor shaft hole. The radius of the first arc edge B111 is R1, the radius of the second arc edge B121 is R2, and the radius of the rotor lamination is R. A constraint relationship exists: R2 = R1 - (-0.1~0.15) mm, R1 = R - (0.8~1.2) mm. This constraint relationship causes the first arc edge B111 and the second arc edge B121 to form magnetic isolation bridges with the outer edge of the rotor, ensuring a small difference in the width of the magnetic isolation bridges on both sides. This results in a staggered symmetrical structure of the inner permanent magnet slot about the straight line L. This staggered symmetrical structure, after optimized design, effectively alleviates high-order harmonic phenomena, significantly increases the fundamental amplitude, and makes the waveform closer to a sine wave, effectively reducing cogging torque. At the same time, it prevents the magnetic bridges on both sides from being too large, which would lead to severe magnetic leakage and reduce the electromagnetic performance of the motor. Conversely, it prevents the magnetic bridges from being too small, which would cause stress concentration in the rotor and reduce the rotor strength. Satisfying this constraint relationship ensures that the rotor strength meets the requirements while maintaining the optimal output torque performance of the motor. Attached Figure Description
[0032] Figure 1 This is a top view of the rotor lamination of this utility model;
[0033] Figure 2 yes Figure 1 Enlarged view of a portion of the structure within the first pole of the rotor lamination. Figure 1 ;
[0034] Figure 3 yes Figure 1 Enlarged view of a portion of the structure within the first pole of the rotor lamination. Figure 2 ;
[0035] Figure 4 This is a diagram showing the effect of optimizing the magnetic flux density of the rotor lamination permanent magnet compared with existing technologies.
[0036] Figures 5a-5b This is a diagram showing the effect of back EMF harmonic optimization compared with existing technologies;
[0037] Figure 6 This is a schematic diagram of the magnetic bridge portion of the rotor lamination of this utility model.
[0038] The reference numerals in the attached figures are as follows:
[0039] A. Lamination body; B. Permanent magnet slot; C. Permanent magnet; D. Weight reduction slot; E. Rotor shaft hole;
[0040] B1, Inner permanent magnet slot; B2, Outer permanent magnet slot; B11, First inner permanent magnet slot; B12, Second inner permanent magnet slot; B21, First outer permanent magnet slot; B22, Second outer permanent magnet slot; d-axis, center line of magnetic poles; L, center line of inner permanent magnet slot; dl, distance between d-axis and L;
[0041] B111, First arc edge; B121, Second arc edge; R, Rotor lamination radius; R1, Radius of the first arc edge; R2, Radius of the second arc edge;
[0042] a. Inner layer magnetic bridge; b. Outer layer magnetic bridge; da. Width of the inner layer magnetic bridge; db. Width of the outer layer magnetic bridge. Detailed Implementation
[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, 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 utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.
[0044] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0045] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0046] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.
[0047] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0048] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.
[0049] like Figure 1-6 As shown, this utility model provides a rotor lamination, which includes:
[0050] The rotor lamination body A and the permanent magnet slot B are disposed on the rotor lamination body A. The permanent magnet slot B includes an inner permanent magnet slot B1 and an outer permanent magnet slot B2. Along the radial direction of the rotor lamination, the outer permanent magnet slot B2 is located outside the inner permanent magnet slot B1. The rotor lamination body A has a d-axis. The outer permanent magnet slot B2 includes an outer first permanent magnet slot B21 and an outer second permanent magnet slot B22. The outer first permanent magnet slot B21 is located on one side of the d-axis (preferably on one side of the d-axis along the circumferential direction of the rotor lamination), and the outer second permanent magnet slot B22 is located on the other side of the d-axis (preferably on the other side of the d-axis along the circumferential direction of the rotor lamination). The outer first permanent magnet slot B21 and the outer second permanent magnet slot B22 are symmetrical with respect to the d-axis.
[0051] The lamination body A also has an inner permanent magnet groove centerline L, which is parallel to the d-axis and spaced at a predetermined distance greater than 0. The inner permanent magnet groove B1 includes an inner first permanent magnet groove B11 located on one side of L and an inner second permanent magnet groove B12 located on the other side of L (preferably located on both sides of L along the circumferential direction of the rotor lamination). The inner first permanent magnet groove B11 and the inner second permanent magnet groove B12 have the same shape and area. The minimum distance between the inner first permanent magnet groove B11 and L and the minimum distance between the inner second permanent magnet groove B12 and L are equal. However, the inner first permanent magnet groove B11 and the inner second permanent magnet groove B12 are asymmetrical with respect to L.
[0052] This invention divides the permanent magnet slots on the rotor lamination into inner and outer permanent magnet slots. The outer permanent magnet slots include an outer first and an outer second permanent magnet slot symmetrically arranged with respect to the d-axis. The inner permanent magnet slots include an inner first and an inner second permanent magnet slot. The inner first and inner second permanent magnet slots are the same size and shape, and they are asymmetrically arranged with respect to the center line L, which is a line offset parallel to the d-axis. This makes the outer permanent magnet slot B2 symmetrical about the magnetic pole center line d-axis, like traditional rotor laminations, while the inner permanent magnet slot B1 is asymmetrical about the d-axis and forms a misaligned symmetry about the center line L. Unlike traditional rotor laminations, the asymmetrical rotor structure of this invention can reduce magnetic leakage between magnetic poles, increase air gap magnetic flux density, enhance the fundamental wave content, obtain an air gap waveform with better sinusoidal characteristics, improve harmonic distortion rate, reduce and improve harmonics, and has a significant effect on suppressing cogging torque.
[0053] This invention addresses the problems of poor demagnetizing performance, high cogging torque, and high harmonic content in existing lamination structures for motors. It proposes a single-pole asymmetric rotor lamination about the d-axis. Multi-objective optimization is performed, using demagnetizing performance and harmonic content as optimization targets. The resulting asymmetric rotor lamination structure improves motor reliability, effectively enhances the sinusoidal nature of the air gap magnetic field, reduces harmonics, weakens cogging torque, and improves demagnetizing performance while maintaining the motor's output torque, thus achieving high performance and high efficiency. Figures 5a-5b As shown.
[0054] In some implementations...
[0055] In contrast, the inner first permanent magnet slot B11 is disposed relatively close to the outer circumferential surface of the rotor lamination, and the inner second permanent magnet slot B12 is disposed relatively far away from the outer circumferential surface of the rotor lamination. The minimum distance between the inner first permanent magnet slot B11 and the outer circumferential surface is greater than the minimum distance between the inner second permanent magnet slot B12 and the outer circumferential surface.
[0056] This is the preferred positional relationship of the two permanent magnet slots in the inner layer of this utility model. The first permanent magnet slot in the inner layer is relatively close to the outer circle of the rotor, and the second permanent magnet slot in the inner layer is relatively close to the rotor shaft hole. The distances of the first permanent magnet slot and the second permanent magnet slot in the inner layer from L are equal, thus forming a staggered and symmetrical structure of the two permanent magnet slots in the inner layer. Therefore, it can reduce the leakage magnetic flux between magnetic poles, increase the air gap magnetic flux density, enhance the fundamental wave content, obtain an air gap waveform with better sinusoidal characteristics, improve the harmonic distortion rate, and at the same time have a significant effect on suppressing cogging torque.
[0057] In some implementations...
[0058] The distance between L and the d axis is d1, and dl = 1.2 to 1.6 mm.
[0059] This invention also sets the distance dl between the L and d axes to satisfy dl = 1.2~1.6mm. This constraint relationship can effectively reduce the leakage magnetic field between poles without affecting the main magnetic circuit, reduce the risk of demagnetization at the sharp corners of the permanent magnet, increase the high magnetic density area on the permanent magnet, improve the anti-demagnetization performance of the permanent magnet, expand the high magnetic density area on the permanent magnet, increase the magnetic density of the easily demagnetized area at the sharp corners of the permanent magnet, and significantly reduce the risk of demagnetization of the permanent magnet.
[0060] In some implementations...
[0061] When the motor rotates clockwise, the inner permanent magnet slot B1 is biased towards the clockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the clockwise direction;
[0062] When the motor rotates counterclockwise, the inner permanent magnet slot B1 is biased towards the counterclockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the counterclockwise direction.
[0063] This invention further improves upon the following: when the rotor laminations are rotated clockwise, the inner permanent magnet slots are biased towards the clockwise side of the d-axis, i.e., L is located at a position where the d-axis is shifted clockwise by d1; when the motor rotates counterclockwise, the inner permanent magnet slots are biased towards the counterclockwise side of the d-axis, i.e., L is located at a position where the d-axis is shifted counterclockwise by d1. This ensures that the motor output torque remains essentially unchanged after the inner permanent magnets are shifted, and the magnetic field distribution is optimized, while cogging torque and harmonic content are reduced.
[0064] In some implementations...
[0065] The inner first permanent magnet groove B11 is located on the counterclockwise side of L, and the inner second permanent magnet groove B12 is located on the clockwise side of L.
[0066] When the motor rotates clockwise, the minimum distance between the inner first permanent magnet slot B11 and the d-axis is less than the minimum distance between the inner second permanent magnet slot B12 and the d-axis.
[0067] When the motor rotates counterclockwise, the minimum distance between the inner first permanent magnet slot B11 and the d-axis is greater than the minimum distance between the inner second permanent magnet slot B12 and the d-axis.
[0068] This describes the relative positional relationship between the inner first permanent magnet slot and the inner second permanent magnet slot of this utility model and L. This allows L to be located at a position shifted d1 clockwise along the d-axis when the motor rotates clockwise, and at a position shifted d1 counterclockwise along the d-axis when the motor rotates counterclockwise. In this embodiment, the motor rotates counterclockwise, so the inner permanent magnet slot B1 is biased towards the counterclockwise side of the d-axis, that is, L is on the left side of the d-axis. This ensures that the motor output torque remains basically unchanged after the inner permanent magnet is shifted, and the magnetic field distribution is optimized, reducing cogging torque and harmonic content.
[0069] In some implementations...
[0070] Along the radial direction of the rotor lamination, the outermost edge of the inner first permanent magnet slot B11 is the first arc edge B111, and the outermost edge of the inner second permanent magnet slot B12 is the second arc edge B121. The center of the first arc edge B111 coincides with the center point O of the shaft hole of the rotor lamination, and the center of the second arc edge B121 coincides with the center point O of the shaft hole of the rotor lamination. The radius of the first arc edge B111 is R1, the radius of the second arc edge B121 is R2, and the radius of the rotor lamination is R. There are constraints: R2 = R1 - (-0.1~0.15) mm, R1 = R - (0.8~1.2) mm.
[0071] This invention further incorporates a design where the outermost edge of the inner permanent magnet slot is composed of a first arc edge B111 and a second arc edge B121. The centers of the first and second arc edges B111 and B121 coincide with the center point O of the rotor shaft hole. The radius of the first arc edge B111 is R1, the radius of the second arc edge B121 is R2, and the radius of the rotor lamination is R. A constraint relationship exists: R2 = R1 - (-0.1~0.15) mm, R1 = R - (0.8~1.2) mm. This constraint relationship causes the first and second arc edges B111 and B121 to form magnetic isolation bridges with the outer edge of the rotor, ensuring a small difference in the width of the magnetic isolation bridges on both sides. This results in a staggered symmetrical structure of the inner permanent magnet slot about the straight line L. This staggered symmetrical structure, after optimized design, effectively alleviates high-order harmonic phenomena, significantly increases the fundamental amplitude, and makes the waveform closer to a sine wave, effectively reducing cogging torque. At the same time, it prevents the magnetic bridges on both sides from being too large, which would lead to severe magnetic leakage and reduce the electromagnetic performance of the motor. Conversely, it prevents the magnetic bridges from being too small, which would cause stress concentration in the rotor and reduce the rotor strength. Satisfying this constraint relationship ensures that the rotor strength meets the requirements while maintaining the optimal output torque performance of the motor.
[0072] In some implementations...
[0073] Along the radial direction of the rotor lamination, the inner end of the inner first permanent magnet slot B11 and the inner end of the inner second permanent magnet slot B12 are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an inner magnetic isolation bridge a. The width of the inner magnetic isolation bridge a in the circumferential direction of the rotor lamination is da. Along the radial direction of the rotor lamination, the inner end of the outer first permanent magnet slot B21 and the inner end of the outer second permanent magnet slot B22 are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an outer magnetic isolation bridge b. The width of the outer magnetic isolation bridge a in the circumferential direction of the rotor lamination is db. There are constraints: db = 0.8~1.8mm, da = (1.5~2)db, d1 = da-db.
[0074] The inner magnetic isolation bridge a of this invention is formed from the near-axial end of the inner permanent magnet slot B1, and the circumferential width of the inner magnetic isolation bridge a is da. The outer magnetic isolation bridge b is formed from the near-axial end of the outer permanent magnet slot B2, and the circumferential width of the outer magnetic isolation bridge b is db. There are constraint relationships: db = 0.8~1.8mm, da = (1.5~2)db, d1 = da-db. This constraint relationship can effectively reduce inter-pole leakage magnetic flux without affecting the main magnetic circuit, reduce the risk of demagnetization at the sharp corners of the permanent magnet, increase the high magnetic density area on the permanent magnet, and improve the demagnetization resistance of the permanent magnet. Figure 4 As shown, Figure 4 The figure shows the magnetic flux density distribution cloud map on the permanent magnet. As can be seen from the figure, the rotor structure of this utility model expands the high magnetic flux density area on the permanent magnet and increases the magnetic flux density in the easily demagnetized area at the sharp corner of the permanent magnet, which greatly reduces the risk of demagnetization of the permanent magnet.
[0075] This utility model also provides a rotor core, which includes the aforementioned rotor laminations, with multiple layers of rotor laminations stacked to form the rotor core.
[0076] This utility model also provides a rotor, which includes the aforementioned rotor core and a permanent magnet disposed in the permanent magnet slot B.
[0077] Figure 1 The rotor lamination of this utility model includes a rotor lamination and a permanent magnet C. The rotor lamination includes a lamination body A, a permanent magnet slot B, a weight reduction slot D, and a shaft hole E, etc. The permanent magnet C is inserted into the permanent magnet slot B. The permanent magnet slot and the weight reduction slot are evenly and spaced apart in the circumferential direction of the rotor lamination.
[0078] This invention proposes an asymmetric rotor lamination for the d-axis. Multi-objective optimization is performed with demagnetization performance and harmonic content as optimization targets. The final result is the asymmetric rotor lamination structure proposed in this invention. The optimized motor scheme significantly improves demagnetization performance and reduces harmonic content and cogging torque while ensuring that the average torque remains basically unchanged.
[0079] It can solve the following technical problems:
[0080] 1. By optimizing the position and size of the permanent magnet slots in the inner rotor laminations, the magnetic field distribution is improved, the motor's anti-demagnetization performance is enhanced, and the motor's harmonic content is reduced.
[0081] 2. By optimizing the fit between the inner and outer permanent magnet slots, the electromagnetic performance is guaranteed while the magnetic field distribution is optimized, reducing harmonic content and cogging torque.
[0082] This utility model also provides an electric motor, which includes the aforementioned rotor.
[0083] This invention addresses the problems of poor demagnetizing performance, high cogging torque, and high harmonic content in existing lamination structures for motors. It proposes a single-pole asymmetric rotor lamination about the d-axis. Multi-objective optimization is performed, using demagnetizing performance and harmonic content as optimization targets. The resulting asymmetric rotor lamination structure improves motor reliability, effectively enhances the sinusoidal nature of the air gap magnetic field, reduces harmonics, weakens cogging torque, and improves demagnetizing performance while maintaining the motor's output torque, thus achieving high performance and high efficiency. The optimized motor design improves demagnetizing performance by 35% and reduces back EMF harmonic content by 33% while maintaining a relatively constant average torque.
[0084] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model. The above description is only a preferred embodiment of this utility model. 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 this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.
Claims
1. A rotor lamination, characterized in that: include: The lamination body (A) and the permanent magnet slot (B) are disposed on the lamination body (A). The permanent magnet slot (B) includes an inner permanent magnet slot (B1) and an outer permanent magnet slot (B2). Along the radial direction of the rotor lamination, the outer permanent magnet slot (B2) is located outside the inner permanent magnet slot (B1). The lamination body (A) has a d-axis. The outer permanent magnet slot (B2) includes an outer first permanent magnet slot (B21) and an outer second permanent magnet slot (B22). The outer first permanent magnet slot (B21) is located on one side of the d-axis, and the outer second permanent magnet slot (B22) is located on the other side of the d-axis. The outer first permanent magnet slot (B21) and the outer second permanent magnet slot (B22) are symmetrical with respect to the d-axis. The lamination body (A) also has an inner permanent magnet groove centerline L, which is parallel to the d-axis and spaced at a predetermined distance greater than 0. The inner permanent magnet groove (B1) includes an inner first permanent magnet groove (B11) located on one side of the L and an inner second permanent magnet groove (B12) located on the other side of the L. The inner first permanent magnet groove (B11) and the inner second permanent magnet groove (B12) have the same shape and area. The minimum distance between the inner first permanent magnet groove (B11) and the L and the minimum distance between the inner second permanent magnet groove (B12) and the L are equal. However, the inner first permanent magnet groove (B11) and the inner second permanent magnet groove (B12) are asymmetrical with respect to the L.
2. The rotor lamination according to claim 1, characterized in that: In contrast, the inner first permanent magnet slot (B11) is disposed relatively close to the outer circumferential surface of the rotor lamination, and the inner second permanent magnet slot (B12) is disposed relatively far away from the outer circumferential surface of the rotor lamination. The minimum distance between the inner first permanent magnet slot (B11) and the outer circumferential surface is greater than the minimum distance between the inner second permanent magnet slot (B12) and the outer circumferential surface.
3. The rotor lamination according to claim 1, characterized in that: The distance between the center line L of the inner permanent magnet groove and the d axis is d1, and dl = 1.2~1.6mm.
4. The rotor lamination according to claim 1, characterized in that: When the motor rotates clockwise, the inner permanent magnet slot (B1) is biased towards the clockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the clockwise direction; When the motor rotates counterclockwise, the inner permanent magnet slot (B1) is biased towards the counterclockwise side of the d-axis, that is, L is located at the position where the d-axis is translated d1 in the counterclockwise direction.
5. The rotor lamination according to claim 4, characterized in that: The inner first permanent magnet slot (B11) is located on the counterclockwise side of L, and the inner second permanent magnet slot (B12) is located on the clockwise side of L. When the motor rotates clockwise, the minimum distance between the inner first permanent magnet slot (B11) and the d-axis is less than the minimum distance between the inner second permanent magnet slot (B12) and the d-axis. When the motor rotates counterclockwise, the minimum distance between the inner first permanent magnet slot (B11) and the d-axis is greater than the minimum distance between the inner second permanent magnet slot (B12) and the d-axis.
6. The rotor lamination according to claim 1, characterized in that: Along the radial direction of the rotor lamination, the outermost edge of the inner first permanent magnet slot (B11) is the first arc edge (B111), and the outermost edge of the inner second permanent magnet slot (B12) is the second arc edge (B121). The center of the first arc edge (B111) coincides with the center point O of the shaft hole of the rotor lamination, and the center of the second arc edge (B121) coincides with the center point O of the shaft hole of the rotor lamination. The radius of the first arc edge (B111) is R1, the radius of the second arc edge (B121) is R2, and the radius of the rotor lamination is R. There are constraints: R2 = R1 - (-0.1~0.15) mm, R1 = R - (0.8~1.2) mm.
7. The rotor lamination according to claim 1, characterized in that: Along the radial direction of the rotor lamination, the inner end of the inner first permanent magnet slot (B11) and the inner end of the inner second permanent magnet slot (B12) are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an inner magnetic isolation bridge a. The width of the inner magnetic isolation bridge a in the circumferential direction of the rotor lamination is da. Along the radial direction of the rotor lamination, the inner end of the outer first permanent magnet slot (B21) and the inner end of the outer second permanent magnet slot (B22) are opposite to each other in the circumferential direction of the rotor lamination, and the interval between them forms an outer magnetic isolation bridge b. The width of the outer magnetic isolation bridge b in the circumferential direction of the rotor lamination is db. There are constraints: db = 0.8~1.8mm, da = (1.5~2)db, d1 = da-db.
8. A rotor core, characterized in that: The rotor laminations include any one of claims 1-7, wherein multiple layers of rotor laminations are stacked to form a rotor core.
9. A rotor, characterized in that: The rotor core as described in claim 8 further includes a permanent magnet disposed in the permanent magnet slot (B).
10. An electric motor, characterized in that: Includes the rotor as described in claim 9.