Rotor structure and electric machine

Abstract

The utility model discloses a rotor structure and motor. The rotor structure includes rotor core and magnetic steel unit. Rotor core is set up with a plurality of magnetic steel groove, and magnetic steel unit includes the outer layer magnetic steel, middle layer magnetic steel and inner layer magnetic steel who arranges in turn along the radial direction of rotor end face. Among them, define the straight line between the right angle point of each magnetic steel close to rotor surface and the center of rotor core respectively as first connecting line, second connecting line and third connecting line. The included angle of first connecting line, second connecting line and third connecting line with the axis of main magnetic pole is first included angle, second included angle and third included angle respectively. The electrical angle range of first included angle is 36.7 °-37.7 °, the electrical angle range of second included angle is 47.8 °-57.8 °, and the electrical angle range of third included angle is 73.9 °-74.9 °. The rotor structure can make the magnetic flux of different layers realize staggered distribution in space, thereby effectively inhibiting the cogging torque and electromagnetic force fluctuation, reducing noise and vibration.

Description

Technical Field

[0001] This utility model relates to the field of motor drive structure technology, and in particular to a rotor structure and motor. Background Technology

[0002] With the development of industrial automation, electric vehicles, and high-efficiency motor systems, permanent magnet synchronous motors (PMSMs) are widely used in new energy vehicles, industrial servo systems, and other fields due to their high power density, high efficiency, and good speed regulation performance. As one of the core components of a motor, the rotor's structural design has a crucial impact on the overall performance of the motor. In particular, in permanent magnet motors, the arrangement of the magnets directly affects the motor's magnetic field distribution, air gap magnetic flux density, torque output, and energy efficiency.

[0003] In the rotor structure of related technologies, magnets are usually arranged in a single layer, at equal intervals or at equal angles in the magnet slots of the rotor core. Although the structure is simple and easy to process, it is prone to problems such as large leakage flux, high loss and large torque pulsation under high-speed operation, heavy load or high-performance application scenarios, which affect the efficiency and stability of the motor. Utility Model Content

[0004] The purpose of this invention is to provide a rotor structure and motor. This rotor structure has three layers of magnets, which, compared to a two-layer magnet structure, allows for better flux design, lower torque ripple, and higher power density by providing more degrees of freedom. This makes it suitable for motor applications with higher requirements for high performance, low noise, and high stability. Furthermore, by limiting the electrical angle range of the included angle between the three layers of magnets, the magnetic flux density waveform can be made closer to a sine wave, thereby improving the motor's electromagnetic performance and NVH (Noise, Vibration, and Harshness) performance.

[0005] This utility model discloses a rotor structure, which includes:

[0006] The rotor core has multiple magnet slots.

[0007] The magnet unit includes an outer layer magnet, a middle layer magnet, and an inner layer magnet arranged sequentially along the radial direction of the rotor end face. The outer layer magnet, the middle layer magnet, and the inner layer magnet are respectively arranged in a plurality of magnet slots.

[0008] Specifically, the line connecting the right-angle point of the outer layer magnet near the rotor surface and the center of the rotor core is defined as the first line, and the angle between the first line and the axis of the main magnetic pole is defined as the first angle, with an electrical angle range of 36.7°-37.7°; the line connecting the right-angle point of the middle layer magnet near the rotor surface and the center of the rotor core is defined as the second line, and the angle between the second line and the axis of the main magnetic pole is defined as the second angle, with an electrical angle range of 47.8°-57.8°; the line connecting the right-angle point of the inner layer magnet near the rotor surface and the center of the rotor core is defined as the third line, and the angle between the third line and the axis of the main magnetic pole is defined as the third angle, with an electrical angle range of 73.9°-74.9°.

[0009] Furthermore, the electrical angle of the first included angle is 37°-37.4°.

[0010] Furthermore, the electrical angle of the second included angle is 52.6°-53°.

[0011] Furthermore, the electrical angle of the third included angle is 74.2°-74.6°.

[0012] Furthermore, the outer magnet, the middle magnet, and the inner magnet each include two individual magnet units, and the two magnet units are arranged symmetrically along the axis of the main magnetic pole.

[0013] Furthermore, the number of the outer layer magnet, the middle layer magnet, and the inner layer magnet are all multiple sets, and the multiple sets of the outer layer magnet, the multiple sets of the middle layer magnet, and the multiple sets of the inner layer magnet are arranged evenly at intervals along the circumference of the rotor surface in the magnet slot.

[0014] Furthermore, the rotor end face is defined as the projection reference plane, the orthogonal projection of the outer magnet on the projection reference plane is the first projection, the orthogonal projection of the middle magnet on the projection reference plane is the second projection, and the orthogonal projection of the inner magnet on the projection reference plane is the third projection. The lengths of the first projection, the second projection, and the third projection are not exactly the same.

[0015] Furthermore, the first projection, the second projection, and / or the third projection are in a "V" shape.

[0016] Furthermore, the first projection, the second projection, and / or the third projection are arc-shaped.

[0017] This utility model embodiment further discloses a motor, which includes:

[0018] Stator; and

[0019] The rotor structure described above.

[0020] The rotor structure and motor provided by this utility model have at least the following beneficial effects, including but not limited to:

[0021] 1) The rotor structure has three layers of magnets, which can achieve better magnetic flux design, lower torque ripple and higher power density by providing more degrees of freedom compared to the double-layer magnet structure. It is suitable for motor application scenarios with higher requirements for high performance, low noise and high stability.

[0022] 2) By limiting the electrical angle range of the included angle of the three layers of magnets, this rotor structure can make the magnetic flux density waveform closer to a sine wave, thereby improving the electromagnetic performance and NVH performance of the motor. Attached Figure Description

[0023] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0024] Figure 1 A schematic diagram of the rotor structure provided in an embodiment of this utility model;

[0025] Figure 2 This is a partially enlarged schematic diagram of the rotor structure provided in an embodiment of the present invention.

[0026] Icon: 100 - Rotor structure;

[0027] 10-Rotor core; 101-Rotor end face; 102-Rotor surface;

[0028] 111 - Outer layer magnet; 112 - Middle layer magnet; 113 - Inner layer magnet;

[0029] 121 - First line; 122 - Second line; 123 - Third line; 124 - First included angle; 125 - Second included angle; 126 - Third included angle. Detailed Implementation

[0030] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] Please refer to Figure 1 and Figure 2 This application provides a rotor structure 100, which includes a rotor core 10 and magnet units. The rotor core 10 has multiple magnet slots; the magnet units include an outer layer magnet 111, a middle layer magnet 112, and an inner layer magnet 113 arranged sequentially along the radial direction of the rotor end face 101. The outer layer magnet 111, middle layer magnet 112, and inner layer magnet 113 are respectively arranged in the multiple magnet slots; wherein, the line connecting the right-angle point of the outer layer magnet 111 near the rotor surface 102 and the center of the rotor core 10 is defined as the first connecting line 121, and the angle between the first connecting line 121 and the axis of the main magnetic pole (i.e., the d-axis in the figure) is defined as the first included angle 124, the electrical angle range of the first included angle 124 being 36.7°- 37.7°; The line connecting the right-angle point of the middle layer magnet 112 near the rotor surface 102 and the center of the rotor core 10 is defined as the second line 122, and the angle between the second line 122 and the axis of the main magnetic pole is defined as the second angle 125, with the electrical angle range of the second angle 125 being 47.8°-57.8°; The line connecting the right-angle point of the inner layer magnet 113 near the rotor surface 102 and the center of the rotor core 10 is defined as the third line 123, and the angle between the third line 123 and the axis of the main magnetic pole is defined as the third angle 126, with the electrical angle range of the third angle 126 being 73.9°-74.9°.

[0033] It should be noted that rotor end face 101 refers to the plane containing the end of rotor core 10 (e.g., Figure 1 The rotor surface 102 refers to the plane in the circumferential direction of the rotor core 10 (e.g., the plane in the plane). Figure 1 (The side of the rotor core 10 as marked in the image).

[0034] It should also be noted that the electrical angle = mechanical angle × number of motor pole pairs, which more accurately reflects the spatial distribution of the magnetic field. This facilitates precise control of the spatial position of each layer of magnets in a multi-layered magnet structure, ensuring the rationality of the magnetic flux path design and the effectiveness of magnetic field control. For example, when the number of motor pole pairs is 4, the mechanical angle corresponding to the electrical angle of 37.2° is approximately 9.3° (i.e., 37.2 ÷ 4).

[0035] It is worth noting that by arranging outer layer magnets 111, middle layer magnets 112, and inner layer magnets 113 radially distributed in the rotor core 10, a more complex and optimized magnetic flux path can be constructed inside the rotor, effectively improving the uniformity of the air gap magnetic flux density distribution, thereby enhancing motor efficiency and torque output performance. Simultaneously, the arrangement angle and position of each layer of magnets are limited by specific electrical angles, allowing for high design flexibility while maintaining a compact structure. This facilitates parameter optimization design in conjunction with motor performance indicators (such as starting torque, overload capacity, and efficiency curves). Furthermore, the multi-layer magnet design can increase the effective magnetic flux per unit volume through reasonable magnet volume distribution, while also considering heat dissipation and magnetic circuit efficiency, contributing to increased motor power density and meeting the miniaturization and lightweight requirements of high-performance motors. Most importantly, the different layers of magnets are arranged within a spatial angle range with specific electrical angles. In particular, the outer, middle and inner layers of magnets 113 are arranged in the regions with electrical angles of 36.7°-37.7°, 47.8°-57.8° and 73.9°-74.9°, respectively. This makes the magnetic flux waveform closer to a sine wave and enables the magnetic flux of different layers to be distributed in a staggered manner in space. This effectively suppresses the fluctuation of cogging torque and electromagnetic force, and reduces noise and vibration.

[0036] In some embodiments, the electrical angle of the first included angle 124 is 37°-37.4°. It is understood that, compared to the electrical angle range of 36.7°-37.7°, this electrical angle range can further prevent the relative position of the outer magnet from being too close to or too far from the d-axis, thereby improving the overall electromagnetic performance and NVH performance.

[0037] In some embodiments, the electrical angle of the second included angle 125 is 52.6°-53°. It is understood that, compared to the electrical angle range of 47.8°-57.8°, this electrical angle range can further prevent the relative position of the middle layer magnets from being too close to or too far from the d-axis, thereby improving the overall electromagnetic performance and NVH performance.

[0038] In some embodiments, the electrical angle of the third included angle 126 is 74.2°-74.6°. It is understood that, compared to the electrical angle range of 73.9°-74.9°, this electrical angle range can further prevent the relative position of the inner magnets from being too close to or too far from the d-axis, thereby improving the overall electromagnetic performance and NVH performance.

[0039] It is worth noting that, in the preferred embodiment, the electrical angles of the first included angle 124 can be set to 37.2°, the second included angle 125 to 52.8°, and the third included angle 126 to 74.4°, in conjunction with the aforementioned electrical angle settings. Simulation experiments have verified that this electrical angle setting method can further ensure the precise spatial arrangement of the outer magnet 111, the middle magnet 112, and the inner magnet 113, making the magnetic flux density waveform closer to a sine wave. By optimizing the position and proportion of the magnets, the weight and cost of the magnets are not increased without weakening the electromagnetic performance.

[0040] like Figure 2 As shown, the outer magnet 111, the middle magnet 112 and the inner magnet 113 each include two magnet units, and the two magnet units are arranged symmetrically along the axis of the main magnetic pole.

[0041] It is worth noting that the outer magnet 111, the middle magnet 112, and the inner magnet 113 are all composed of two individual magnets, and are arranged symmetrically along the main magnetic pole axis. This makes the overall arrangement of the magnets on the rotor more symmetrical, thereby forming a more balanced magnetic field distribution, which helps to reduce magnetic imbalance and vibration during motor operation. Simultaneously, the symmetrical arrangement of the magnets effectively counteracts torque fluctuations caused by asymmetrical magnetic fields, thus reducing torque pulsation and cogging torque during motor operation, improving operational stability and noise control.

[0042] Please refer to this again. Figure 1 The number of outer layer magnets 111, middle layer magnets 112 and inner layer magnets 113 are all multiple sets, and the multiple sets of outer layer magnets 111, multiple sets of middle layer magnets 112 and multiple sets of inner layer magnets 113 are evenly spaced in the magnet slots along the circumference of the rotor surface 102.

[0043] It is worth noting that in one embodiment of this example, the number of outer magnets 111, middle magnets 112 and inner magnets 113 are all 8 sets, with an interval angle of 45°, to ensure that the magnet units can be evenly distributed on the rotor end face 101.

[0044] Optionally, the rotor end face 101 is defined as the projection reference plane, the orthogonal projection of the outer magnet 111 on the projection reference plane is the first projection, the orthogonal projection of the middle magnet 112 on the projection reference plane is the second projection, and the orthogonal projection of the inner magnet 113 on the projection reference plane is the third projection. The lengths of the first projection, the second projection, and the third projection are not exactly the same.

[0045] Specifically, the differentiated design of the radial projection length of different layers of magnets helps to solve the resonance interference problem in the spatial distribution of magnets, thereby effectively suppressing harmonic magnetic field components, reducing cogging torque and torque pulsation, and improving the smoothness of motor operation.

[0046] Please refer to this again. Figure 1 and Figure 2 The first projection, the second projection, and / or the third projection form a "V" shape.

[0047] Understandably, this structural design helps guide magnetic flux to distribute more naturally along a "V"-shaped path, reducing magnetic flux leakage and excessively high local magnetic flux density, thus improving overall magnetic field utilization efficiency. Simultaneously, the "V"-shaped structure increases the relative angle between the magnet and the magnetic circuit to some extent, resulting in a more rational magnetic flux density distribution. This reduces localized overheating and high magnetic load areas, improves the magnet's resistance to demagnetization under high temperature and high load conditions, and extends its service life. Depending on the specific implementation environment, the first, second, and / or third projections can also be arc-shaped.

[0048] This embodiment of the invention further discloses an electric motor, which includes a stator and the rotor structure 100 described above. This electric motor possesses all the beneficial effects of the rotor structure 100.

[0049] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0050] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0051] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention shown herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0052] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0053] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0054] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0055] The above description of the embodiments shown in this utility model (including the content in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments of the utility model, and such modifications will be within the spirit and scope of the utility model.

[0056] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A rotor structure, characterized in that, include: The rotor core has multiple magnet slots. The magnet unit includes an outer layer magnet, a middle layer magnet, and an inner layer magnet arranged sequentially along the radial direction of the rotor end face. The outer layer magnet, the middle layer magnet, and the inner layer magnet are respectively arranged in a plurality of magnet slots. Specifically, the line connecting the right-angle point of the outer layer magnet near the rotor surface and the center of the rotor core is defined as the first line, and the angle between the first line and the axis of the main magnetic pole is defined as the first angle, with an electrical angle range of 36.7°-37.7°; the line connecting the right-angle point of the middle layer magnet near the rotor surface and the center of the rotor core is defined as the second line, and the angle between the second line and the axis of the main magnetic pole is defined as the second angle, with an electrical angle range of 47.8°-57.8°; the line connecting the right-angle point of the inner layer magnet near the rotor surface and the center of the rotor core is defined as the third line, and the angle between the third line and the axis of the main magnetic pole is defined as the third angle, with an electrical angle range of 73.9°-74.9°.

2. The rotor structure according to claim 1, characterized in that, The electrical angle of the first included angle is 37°-37.4°.

3. The rotor structure according to claim 1, characterized in that, The electrical angle of the second included angle is 52.6°-53°.

4. The rotor structure according to claim 1, characterized in that, The electrical angle of the third included angle is 74.2°-74.6°.

5. The rotor structure according to claim 1, characterized in that, The outer magnet, the middle magnet, and the inner magnet each include two magnet units, and the two magnet units are arranged symmetrically along the axis of the main magnetic pole.

6. The rotor structure according to claim 5, characterized in that, The number of outer layer magnets, middle layer magnets and inner layer magnets are all multiple sets, and the multiple sets of outer layer magnets, multiple sets of middle layer magnets and multiple sets of inner layer magnets are evenly spaced in the magnet slots along the circumference of the rotor end face.

7. The rotor structure according to claim 1, characterized in that, The rotor end face is defined as the projection reference plane. The orthogonal projection of the outer magnet onto the projection reference plane is the first projection. The orthogonal projection of the middle magnet onto the projection reference plane is the second projection. The orthogonal projection of the inner magnet onto the projection reference plane is the third projection. The lengths of the first projection, the second projection, and the third projection are not exactly the same.

8. The rotor structure according to claim 7, characterized in that, The first projection, the second projection, and / or the third projection form a "V" shape.

9. The rotor structure according to claim 7, characterized in that, The first projection, the second projection, and / or the third projection are arc-shaped.

10. An electric motor, characterized in that, include: stator; as well as The rotor structure as described in any one of claims 1-9.

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