A rotor lamination structure, motor

Abstract

The utility model provides a rotor punching piece structure, motor, wherein rotor punching piece structure includes: main body is provided with first group magnetic steel groove on the main body, a group first group magnetic steel groove includes two magnetic steel grooves, two magnetic steel grooves are about d axle symmetrical arrangement, and magnetic steel groove has first end and second end, and first end is provided with first air groove, and second end is provided with second air groove, first air groove, second air groove are linked together with magnetic steel groove, and first air groove has first side, second side and third side, and one end of first side, one end of third side are connected with the first end of magnetic steel groove, and the other end of first side, the other end of third side are connected through second side, and the length of first side is dB21, and the length of third side is dB23, and it satisfies, dB21 / dB23=2.2~2.4. According to the utility model, can improve the anti demagnetization performance of rotor.

Description

Technical Field

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

[0002] Energy and environmental issues have driven the vigorous development of the new energy vehicle industry. As the core drive mechanism of new energy vehicles, the motor directly affects the stability and reliability of vehicle operation. Benefiting from its advantages in efficiency, power density, and power factor, permanent magnet motors are widely used in the new energy vehicle field. Compared to surface-mounted permanent magnet synchronous motors, built-in permanent magnet synchronous motors have stronger field weakening and speed-spreading capabilities, better matching the wide speed range requirements of automotive motors, and therefore enjoy wider application.

[0003] Because the operating temperature of motors in new energy vehicles is typically high, permanent magnets, as a crucial component of the motor, are often at risk of demagnetization. Furthermore, 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. Therefore, the demagnetization problem of permanent magnets must be a key consideration during the motor design phase. The motor's structure is a major factor contributing to low-order current harmonics in permanent magnet synchronous motors. Factors such as cogging effect, magnetic circuit saturation effect, and rotor pole structure can cause output voltage distortion. These factors can result in excessive motor harmonics, thereby affecting motor performance, application precision, and accuracy.

[0004] Therefore, this invention designs a rotor lamination structure and a motor that can improve the rotor's anti-demagnetization performance while ensuring that the average torque remains basically unchanged. Utility Model Content

[0005] Therefore, this utility model provides a rotor lamination structure and a motor that can improve the rotor's anti-demagnetization performance.

[0006] To solve the above problems, this utility model provides a rotor lamination structure, including: a main body, on which a first set of magnet slots are provided, multiple sets of the first set of magnet slots are arranged at intervals along the circumference of the main body, each set of the first set of magnet slots includes two magnet slots, the two magnet slots are arranged symmetrically about the d-axis, each magnet slot has a first end and a second end, the first end is arranged close to the outer peripheral wall of the main body relative to the second end, the first end is provided with a first air slot, and the second end is provided with a second air slot;

[0007] The first air trough and the second air trough are connected to the magnet trough. The first air trough has a first side, a second side and a third side. One end of the first side and one end of the third side are connected to the first end of the magnet trough. The other end of the first side and the other end of the third side are connected through the second side. The length of the first side is dB21 and the length of the third side is dB23, which satisfies dB21 / dB23 = 2.2~2.4.

[0008] In some embodiments, the second side has an angle α with the d-axis, which satisfies α = 17° to 20°.

[0009] In some embodiments, the third side and the first side have an included angle b, which satisfies b = 0° to 2°.

[0010] In some embodiments, the two magnetic slots of the first set of magnetic slots are arranged in a V-shape, with the first side, the second side, and the third side forming a straight line. The first side and the second side extend along the d-axis toward the q-axis. The connection between the second side and the first side, and the connection between the second side and the third side, are connected by a first arc. The connection between the magnetic slot and the first side, and the connection between the magnetic slot and the third side, are connected by a second arc. The opening of the second arc faces toward the center of the main body.

[0011] In some embodiments, the main body is further provided with multiple sets of second sets of magnetic steel grooves, which correspond one-to-one with the first set of magnetic steel grooves. Along the radial outward direction of the main body, the second sets of magnetic steel grooves and the first sets of magnetic steel grooves are arranged sequentially, and the second sets of magnetic steel grooves and the first sets of magnetic steel grooves are arranged at intervals.

[0012] In some embodiments, an auxiliary groove is provided between the second group of magnet grooves and the first group of magnet grooves. Along the direction from the d-axis to the q-axis, the first air groove and the auxiliary groove are arranged sequentially, and the first air groove and the auxiliary groove are arranged at intervals.

[0013] In some embodiments, the auxiliary groove has a fourth side and a fifth side, the fourth side and the fifth side are straight, and the fourth side and the fifth side extend radially along the main body. The fourth side, the fifth side and the second side are arranged in parallel. One end of the fourth side and one end of the fifth side, and the other end of the fourth side and the other end of the fifth side are connected by an arc. The opening of the arc at one end of the fourth side is arranged facing the opening of the arc at the other end of the fourth side.

[0014] In some implementations, the distance between the fourth side and the second side is dD1, and the distance between the fifth side and the second side is dD2, which satisfies dD1 / dD2 = 0.4 to 0.6.

[0015] In some embodiments, the width of the second air groove and the width of the first air groove are smaller than the width of the magnet groove along the radial direction of the body.

[0016] This utility model also provides an electric motor, which includes the aforementioned rotor lamination structure.

[0017] The rotor lamination structure and motor provided by this utility model have the following beneficial effects:

[0018] With the length of the first side being dB21 and the length of the third side being dB23, the condition dB21 / dB23 = 2.2 to 2.4 is satisfied. Since the first air slot near the outer edge of the rotor has the greatest resistance to the demagnetizing magnetic field lines, it can effectively block the demagnetizing magnetic field lines from passing through the permanent magnet, thus improving the motor's anti-demagnetizing performance. At the same time, the constraint of the length of the first side of the first air slot being dB21 can ensure that the output torque of the motor is guaranteed while optimizing the anti-demagnetizing performance. It prevents the motor from having serious magnetic leakage due to the first side being too long, resulting in a significant drop in output torque, while the length being too short will have too little resistance to the demagnetizing magnetic field. Attached Figure Description

[0019] To more clearly illustrate the embodiments of this utility model 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. 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 lamination structure of this utility model;

[0021] Figure 2 This is a schematic diagram of a set of magnet slots in the rotor lamination structure of this utility model. Figure 1 ;

[0022] Figure 3 This is a schematic diagram of a set of magnet slots in the rotor lamination structure of this utility model. Figure 2 ;

[0023] Figure 4 This is a schematic diagram of a set of magnet slots in the rotor lamination structure of this utility model. Figure 3 ;

[0024] Figure 5This is a comparison diagram of the rotor lamination structure of this utility model and the demagnetization area of ​​the prior art;

[0025] Figure 6 This is a comparison diagram of the rotor lamination structure of this utility model and the back electromotive force harmonics of the prior art.

[0026] The attached figures are labeled as follows:

[0027] 1. Main body; 2. Magnet slot; 3. Permanent magnet; 4. Auxiliary slot; 5. Second set of magnet slots; 6. First set of magnet slots; 7. First air slot; 8. First side; 9. Second side; 10. Third side; 11. Fourth side; 12. Fifth side; 13. Shaft hole. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] See also Figure 1-6 As shown, according to an embodiment of the present invention, a rotor lamination structure is provided, comprising: a main body 1, wherein a first set of magnet slots 6 are provided on the main body 1, and multiple sets of the first set of magnet slots 6 are arranged at intervals along the circumference of the main body 1, each set of the first set of magnet slots 6 includes two magnet slots 2, the two magnet slots 2 are arranged symmetrically about the d-axis, each magnet slot 2 has a first end and a second end, the first end is arranged close to the outer peripheral wall of the main body 1 relative to the second end, the first end is provided with a first air slot 7, and the second end is provided with a second air slot;

[0033] The first air slot 7 and the second air slot are connected to the magnet slot 2. The first air slot 7 has a first side 8, a second side 9 and a third side 10. One end of the first side 8 and one end of the third side 10 are connected to the first end of the magnet slot 2. The other end of the first side 8 and the other end of the third side 10 are connected through the second side 9. The length of the first side 8 is dB21 and the length of the third side 10 is dB23, which satisfies dB21 / dB23 = 2.2~2.4. In this technical solution, the length of the first side 8 is dB21 and the length of the third side 10 is dB23, which satisfies dB21 / dB23 = 2.2~2.4. Since the first air slot 7 near the outer edge of the rotor of the magnet slot 2 has the greatest resistance to the demagnetizing magnetic lines, it can effectively block the demagnetizing magnetic lines from passing through the permanent magnet, thereby improving the motor's anti-demagnetizing performance. At the same time, the constraint of the length of the first side 8 of the first air slot 7 (dB21) can ensure that the output torque of the motor is guaranteed while optimizing the anti-demagnetizing performance. It prevents the motor from having serious magnetic leakage due to the excessive length of the first side 8, which would cause a significant drop in output torque. Conversely, if the length is too short, the resistance to the demagnetizing magnetic field will be too small.

[0034] See also Figure 5 As shown, the black area is the area prone to demagnetization. Compared with the prior art, the rotor lamination structure of this utility model significantly reduces the area of ​​the magnet prone to demagnetization and improves the anti-demagnetization performance.

[0035] In the rotor lamination structure of this utility model, since the permeability of air is greater than that of permanent magnets, the demagnetized magnetic lines preferentially pass through the first air groove 7. The first air groove 7 of the rotor lamination structure of this utility model extends in the q-axis direction, increasing the area of ​​the air groove, which can effectively block the magnetic lines of force from passing through the permanent magnets.

[0036] The rotor lamination structure of this utility model has dB21 = 2.2 ~ 2.9 mm and dB22 = 1.1 ~ 1.2 mm for rotor laminations with an outer diameter of D205 ~ D240.

[0037] In some embodiments, the second side 9 has an angle α with the d-axis, satisfying α = 17°–20°. The third side 10 has an angle b with the first side 8, satisfying b = 0°–2°. In this technical solution, the first air slot 7 near the rotor outer edge formed by the first side 8, the second side 9, and the third side 10 extends in the q-axis direction. Extending in the q-axis direction ensures the electromagnetic performance of the motor, while extending in the opposite direction would lead to a significant increase in torque pulsation. Through the constraint relationship of α = 17°–20° and b = 0°–2°, the first air slot 7 near the rotor outer edge improves the demagnetizing performance of the motor while optimizing the magnetic field distribution, obtaining a waveform with better sinusoidal characteristics, and reducing the harmonic content of the back EMF waveform. Furthermore, the first air slot 7 can disperse concentrated magnetic field lines, making the magnetic field distribution more uniform, thereby improving the sinusoidal characteristics of the back EMF waveform.

[0038] See also Figure 6 As shown in the figure, the horizontal axis represents time, and the vertical axis represents back electromotive force (EMF). Compared with the prior art, the rotor lamination structure of this invention produces a significantly smoother and flatter curve for the back EMF harmonics, indicating a lower harmonic content. In other words, the rotor lamination structure of this invention can effectively reduce the harmonic content of the back EMF waveform.

[0039] In some embodiments, the two magnetic grooves 2 of the first set of magnetic grooves 6 are arranged in a V-shape, the first side 8, the second side 9 and the third side 10 are straight, the first side 8 and the second side 9 extend along the d-axis toward the q-axis, the connection between the second side 9 and the first side 8 and the connection between the second side 9 and the third side 10 are connected by a first arc, the connection between the magnetic groove 2 and the first side 8 and the connection between the magnetic groove 2 and the third side 10 are connected by a second arc, and the opening of the second arc faces toward the center of the main body 1. In this technical solution, the first side 8, the second side 9, and the third side 10 are in a straight line. The first side 8 and the second side 9 extend along the d-axis toward the q-axis. The connection between the second side 9 and the first side 8, and the connection between the second side 9 and the third side 10, are connected by a first arc. The connection between the magnetic groove 2 and the first side 8, and the connection between the magnetic groove 2 and the third side 10, are connected by a second arc. The opening of the second arc faces the center of the main body 1. In other words, the first side 8, the second side 9, and the third side 10 are connected by rounded corners, which can avoid stress concentration and facilitate processing.

[0040] In some embodiments, the main body 1 is further provided with multiple sets of second sets of magnetic steel grooves 5, which correspond one-to-one with the first set of magnetic steel grooves 6. Along the radial outward direction of the main body 1, the second sets of magnetic steel grooves 5 and the first sets of magnetic steel grooves 6 are arranged sequentially, with intervals between them. In this technical solution, each set of second sets of magnetic steel grooves 5 also includes two magnetic steel grooves 2. The two magnetic steel grooves 2 of the second set of magnetic steel grooves 5 are arranged in a V-shape and are symmetrical about the d-axis. Each end of the magnetic steel groove 2 of the second set of magnetic steel grooves 5 has a third air groove, which is connected to the magnetic steel groove 2 of the second set of magnetic steel grooves 5. Furthermore, the width of the third air groove is smaller than the width of the magnetic steel groove 2 of the second set of magnetic steel grooves 5. Through the third air groove, the permanent magnet 3 in the magnetic steel groove 2 of the second set of magnetic steel grooves 5 can be effectively limited. Both the magnetic slot 2 of the second group of magnetic slots 5 and the magnetic slot 2 of the first group of magnetic slots 6 are equipped with permanent magnets 3. That is to say, the rotor lamination structure of this utility model is a double-layer permanent magnet slot structure.

[0041] To address the issues of poor demagnetization resistance and high harmonic content in existing lamination-structured motors, this invention employs a multi-objective optimization approach, focusing on demagnetization resistance and harmonic content. While maintaining the motor's output torque, it improves motor reliability, effectively enhances the sinusoidal nature of the air gap magnetic field, reduces harmonics, and improves the motor's demagnetization resistance, thereby achieving high performance and high efficiency. The optimized motor design, while maintaining a substantially unchanged average torque, reduces the irreversible demagnetization region by 61%, improves demagnetization resistance by 52%, and reduces back EMF harmonic content by 30%.

[0042] In some embodiments, an auxiliary groove 4 is provided between the second set of magnet grooves 5 and the first set of magnet grooves 6. Along the direction from the d-axis to the q-axis, the first air groove 7 and the auxiliary groove 4 are arranged sequentially, with the first air groove 7 and the auxiliary groove 4 spaced apart. In this technical solution, the auxiliary groove 4, preferably elliptical in shape, is positioned near the first air groove 7, which can better improve the distribution of magnetic field lines at this location and effectively reduce the irreversible demagnetization area on the permanent magnet.

[0043] In some embodiments, the auxiliary groove 4 has a fourth side 11 and a fifth side 12, which are straight lines and extend radially along the main body 1. The fourth side 11, fifth side 12, and second side 9 are arranged in parallel. One end of the fourth side 11 and one end of the fifth side 12, and the other end of the fourth side 11 and the other end of the fifth side 12 are connected by an arc. The opening of the arc at one end of the fourth side 11 faces the opening of the arc at the other end of the fourth side 11. In this technical solution, the opening of the arc at one end of the fourth side 11 and the opening of the arc at the other end of the fourth side 11 face each other. The arc connection effectively avoids stress concentration.

[0044] In some embodiments, the distance between the fourth side 11 and the second side 9 is dD1, and the distance between the fifth side 12 and the second side 9 is dD2, satisfying dD1 / dD2 = 0.4~0.6. In this technical solution, the distance between the fourth side 11 and the second side 9 is dD1, and the distance between the fifth side 12 and the second side 9 is dD2, satisfying dD1 / dD2 = 0.4~0.6. This constraint relationship optimizes the effect of the auxiliary slot 4 in hindering the demagnetizing magnetic field and optimizing the distribution of magnetic lines of force, effectively reducing the demagnetizing risk of the permanent magnets in the first set of magnetic slots 6 and the second set of magnetic slots 5 near the auxiliary slot 4, while also reducing harmonic content and making the back electromotive force waveform more sinusoidal.

[0045] The rotor lamination structure of this utility model has a dD1 = 1.2 to 1.5 mm for rotor laminations with an outer diameter of D205 to D240.

[0046] See also Figure 5 , Figure 6 As shown, compared with the traditional rotor lamination structure, the motor using the rotor lamination structure of this utility model reduces the irreversible demagnetization area by 61%, improves the anti-demagnetization performance by 52%, and reduces the back EMF harmonic content by 30% while ensuring that the output torque remains basically unchanged.

[0047] In some embodiments, along the radial direction of the main body, the width of the second air groove and the width of the first air groove 7 are smaller than the width of the magnet groove 2. In this technical solution, by making the widths of the second air groove and the first air groove 7 smaller than the width of the magnet groove 2, the permanent magnet 3 in the magnet groove 2 of the first set of magnet grooves 6 can be limited, improving the stability of the rotor. Furthermore, the main body 1 is also provided with a shaft hole 13 for assembling a rotating shaft.

[0048] This invention relates to a rotor lamination structure, which undergoes multi-objective optimization targeting demagnetization performance and harmonic content. The resulting rotor lamination structure significantly improves demagnetization resistance and reduces harmonic content while maintaining a relatively constant average torque. Optimizing the shape and size of the permanent magnet slots in the inner rotor laminations increases the magnetic reluctance near the demagnetization point, thereby enhancing the motor's demagnetization resistance. Furthermore, adding auxiliary slot structures improves the rotor's magnetic flux distribution, reducing harmonic content while simultaneously improving the motor's demagnetization resistance.

[0049] This utility model also provides an electric motor, including the rotor lamination structure described above.

[0050] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0051] 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 structure, characterized in that: include: The main body (1) is provided with a first set of magnetic steel grooves (6). Multiple sets of the first set of magnetic steel grooves (6) are arranged at intervals along the circumference of the main body (1). Each set of the first set of magnetic steel grooves (6) includes two magnetic steel grooves (2). The two magnetic steel grooves (2) are arranged symmetrically about the d-axis. The magnetic steel groove (2) has a first end and a second end. The first end is arranged close to the outer peripheral wall of the main body (1) relative to the second end. The first end is provided with a first air groove (7), and the second end is provided with a second air groove. The first air slot (7) and the second air slot are connected to the magnet slot (2). The first air slot (7) has a first side (8), a second side (9) and a third side (10). One end of the first side (8) and one end of the third side (10) are connected to the first end of the magnet slot (2). The other end of the first side (8) and the other end of the third side (10) are connected through the second side (9). The length of the first side (8) is dB21 and the length of the third side (10) is dB23, which satisfies dB21 / dB23 = 2.2 to 2.

4.

2. The rotor lamination structure according to claim 1, characterized in that: The second side (9) has an angle a with the d-axis, which satisfies a = 17° to 20°.

3. The rotor lamination structure according to claim 1, characterized in that: The third side (10) and the first side (8) have an included angle b, which satisfies b = 0° to 2°.

4. The rotor lamination structure according to claim 1, characterized in that: The two magnetic grooves (2) of the first set of magnetic grooves (6) are arranged in a V-shape. The first side (8), the second side (9) and the third side (10) are straight. The first side (8) and the second side (9) extend along the d-axis toward the q-axis. The connection between the second side (9) and the first side (8) and the connection between the second side (9) and the third side (10) are connected by a first arc. The connection between the magnetic groove (2) and the first side (8) and the connection between the magnetic groove (2) and the third side (10) are connected by a second arc. The opening of the second arc faces the center of the main body (1).

5. The rotor lamination structure according to claim 1, characterized in that: The main body (1) is also provided with multiple sets of second sets of magnetic steel grooves (5), which correspond one-to-one with the first set of magnetic steel grooves (6). Along the radial outward direction of the main body (1), the second set of magnetic steel grooves (5) and the first set of magnetic steel grooves (6) are arranged in sequence, and the second set of magnetic steel grooves (5) and the first set of magnetic steel grooves (6) are arranged at intervals.

6. The rotor lamination structure according to claim 5, characterized in that: An auxiliary groove (4) is provided between the second group of magnet grooves (5) and the first group of magnet grooves (6). Along the direction from the d-axis to the q-axis, the first air groove (7) and the auxiliary groove (4) are arranged in sequence, and the first air groove (7) and the auxiliary groove (4) are arranged at intervals.

7. The rotor lamination structure according to claim 6, characterized in that: The auxiliary groove (4) has a fourth side (11) and a fifth side (12). The fourth side (11) and the fifth side (12) are straight lines. The fourth side (11) and the fifth side (12) extend radially along the main body (1). The fourth side (11), the fifth side (12), and the second side (9) are arranged in parallel. One end of the fourth side (11) and one end of the fifth side (12), and the other end of the fourth side (11) and the other end of the fifth side (12) are connected by an arc. The opening of the arc at one end of the fourth side (11) is arranged facing the opening of the arc at the other end of the fourth side (11).

8. The rotor lamination structure according to claim 6, characterized in that: The distance between the fourth side (11) and the second side (9) is dD1, and the distance between the fifth side (12) and the second side (9) is dD2, which satisfies that dD1 / dD2 = 0.4 to 0.

6.

9. The rotor lamination structure according to claim 1, characterized in that: Along the radial direction of the main body, the width of the second air groove and the width of the first air groove (7) are smaller than the width of the magnet groove (2).

10. An electric motor, characterized in that: The rotor lamination structure includes any one of claims 1-9.

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