Rotor structure and electric machine

Abstract

The application provides a rotor structure and a motor. The rotor structure comprises a rotor core (1), the rotor core (1) is provided with filling grooves (2), rectangular magnetic steel grooves (3) and arc-shaped magnetic steel grooves (4), the rotor core (1) comprises a rotor outer circle, the filling grooves (2) comprise q-axis filling grooves (21), the arc-shaped magnetic steel grooves (4) are respectively provided with the rectangular magnetic steel grooves (3) at two ends, the rectangular magnetic steel grooves (3) are provided with the q-axis filling grooves (21) on one side close to the rotor outer circle, the q-axis filling grooves (21), the rectangular magnetic steel grooves (3) and the arc-shaped magnetic steel grooves (4) on the same layer form a magnetic barrier layer, the number of the magnetic barrier layers is at least two layers, the rectangular magnetic steel grooves (3) are provided with rectangular permanent magnets (5), and the arc-shaped magnetic steel grooves (4) are provided with arc-shaped permanent magnets (6). According to the rotor structure, the utilization rate of the permanent magnet is improved, the core loss is reduced, the harmonics are reduced, vibration and noise are reduced, and the motor efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to a rotor structure and a motor. Background Technology

[0002] The self-starting permanent magnet assisted synchronous reluctance motor (SPMSRM) is an important branch of modern motor technology. It cleverly combines the high efficiency of a permanent magnet motor (PMSM) with the structural simplicity and starting capability of a synchronous reluctance motor (SynRM), demonstrating significant advantages in modern industrial and consumer electronics fields that demand high efficiency, high performance, and low maintenance costs. Especially in applications requiring frequent starts and stops and wide-range speed regulation, such as air conditioning systems, electric vehicle drives, and home appliances, the SPMSRM combines the high-efficiency magnetic flux source provided by permanent magnets, the self-starting capability of a synchronous reluctance motor, and the copper-loss-free characteristics of an asynchronous motor, making it an ideal choice.

[0003] The self-starting permanent magnet assisted synchronous reluctance motor adopts a combination of permanent magnets and reluctance effect in its structure. The permanent magnets provide the basic torque, while the reluctance effect utilizes the high permeability material of the rotor (such as a squirrel cage structure) to generate additional asynchronous torque during startup. This design not only retains the advantages of high efficiency and no rotor copper loss of permanent magnet motors, but also overcomes their disadvantage of difficult starting, enabling the motor to maintain high operating efficiency over a wide operating range.

[0004] However, despite the numerous advantages of self-starting permanent magnet assisted synchronous reluctance motors, their air gap magnetic field often fails to achieve an ideal sinusoidal waveform. This is due to limitations in the rotor structure and the arrangement of the permanent magnets. Significant spatial harmonics exist in the air gap magnetic field, leading to a series of negative effects, including the generation of harmonic electromotive force, the flow of harmonic current, increased torque pulsation, aggravated motor vibration and noise, and increased core losses. These issues directly impact the motor's performance, reliability, and service life, especially in precision applications such as aerospace and precision manufacturing, where vibration and noise control requirements are extremely stringent.

[0005] Therefore, for self-starting permanent magnet assisted synchronous reluctance motors, optimizing the air gap magnetic field and reducing the amplitude of spatial harmonics to make its magnetic flux density distribution closer to a sine wave has become one of the key technical points for improving motor performance. By improving rotor design and adopting a more reasonable permanent magnet arrangement and magnetic circuit structure, harmonic content can be effectively reduced, electromagnetic torque fluctuations can be reduced, and motor vibration and noise can be reduced, thereby achieving higher levels of motor performance and user experience.

[0006] However, current designs for self-starting permanent magnet assisted synchronous reluctance motors often struggle to achieve a balance between reducing harmonics, vibration and noise reduction, and improving efficiency. On the one hand, reducing magnetic flux density harmonics and torque ripple requires meticulous magnetic circuit design and optimized permanent magnet layout; on the other hand, achieving self-starting capability and reducing rotor losses also present design challenges. Therefore, developing a rotor structure that can effectively balance these requirements while improving the overall performance of the motor has become a pressing problem in the field of motor design. Summary of the Invention

[0007] The main objective of this invention is to provide a rotor structure and motor that can improve the utilization rate of permanent magnets, reduce core losses, reduce harmonics, reduce vibration and noise, and improve motor efficiency.

[0008] To achieve the above objectives, according to one aspect of the present invention, a rotor structure is provided, including a rotor core, on which a filling groove, a rectangular magnet groove, and an arc-shaped magnet groove are provided. The rotor core includes a rotor outer circle, the filling groove includes a q-axis filling groove, rectangular magnet grooves are respectively provided at both ends of the arc-shaped magnet groove, and a q-axis filling groove is provided on the side of the rectangular magnet groove near the rotor outer circle. The q-axis filling groove, the rectangular magnet groove, and the arc-shaped magnet groove located in the same layer form a magnetic barrier layer, and the number of magnetic barrier layers is at least two layers. A rectangular permanent magnet is provided in the rectangular magnet groove, and an arc-shaped permanent magnet is provided in the arc-shaped magnet groove.

[0009] Furthermore, at one pole, two rectangular magnetic slots located in the same layer are symmetrical about the d-axis, and the two rectangular magnetic slots form an included angle β, where 0° < β ≤ 90°.

[0010] Furthermore, in a pole, in the rectangular magnetic steel groove and the arc-shaped magnetic steel groove located in the same layer, the angle between the center line of the rectangular magnetic steel groove extending along the magnetization direction and the center line of the arc-shaped magnetic steel groove extending along the magnetization direction is δ, 45°≤δ≤90°.

[0011] Furthermore, 50°≤δ≤90°.

[0012] Furthermore, in two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets is k1, the width of the magnetic channel between adjacent rectangular permanent magnets is k2, and the width of the magnetic channel between adjacent q-axis filling grooves is k3, where k3 > k2 > k1.

[0013] Furthermore, the thickness of the rectangular permanent magnet is w2, and the thickness of the arc-shaped permanent magnet is w1, where w1 = w2.

[0014] Furthermore, in two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets is k1, the width of the magnetic channel between adjacent rectangular permanent magnets is k2, the thickness of the arc-shaped permanent magnet is w1, and the thickness of the rectangular permanent magnet is w2, where k1 > w1 and k2 > w2.

[0015] Furthermore, k1≥2×w1, k2≥1.8×w2.

[0016] Furthermore, the filling groove also includes a d-axis filling groove, which is located radially outside the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the q-axis filling groove is D1, and the minimum distribution circle diameter of the d-axis filling groove is D2, where D2 ≥ D1.

[0017] Furthermore, the filling groove also includes a d-axis filling groove, which is located radially outside the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the d-axis filling groove is D2, and the diameter of the rotor outer circle is D, where 0.8×D≤D2≤0.9×D.

[0018] Furthermore, the filling groove also includes a d-axis filling groove, which is located radially outside the magnetic barrier layer along the d-axis direction. Under one pole, there are multiple d-axis filling grooves, the distance between two adjacent d-axis filling grooves is w6, the thickness of the arc-shaped permanent magnet is w1, and w6≥w1.

[0019] Furthermore, a first connecting rib is provided between the rectangular magnetic steel groove and the arc-shaped magnetic steel groove, and a second connecting rib is provided between the rectangular magnetic steel groove and the q-axis filling groove. The width of the first connecting rib is w4, and the width of the second connecting rib is w5, where w5 ≤ w4.

[0020] Furthermore, within a section perpendicular to the central axis of the rotor core, the length of the rectangular permanent magnet located radially outward along the d-axis is l1, and the length of the rectangular permanent magnet located radially inward along the d-axis is l2, where l1 < l2 < 1.43 × l1; and / or, the outer arc length of the arc-shaped permanent magnet located radially outward along the d-axis is l3, and the outer arc length of the arc-shaped permanent magnet located radially inward along the d-axis is l4, where l3 < l4 < 1.14 × l3.

[0021] Furthermore, there is a third connecting rib between the filling groove and the outer circle of the rotor. The width of the third connecting rib is w7, 0≤w7≤2σ, where σ is the air gap width between the stator structure and the rotor structure.

[0022] Furthermore, the filling groove also includes independent filling grooves, which are located between the magnetic barrier layer and the q-axis. The spacing between adjacent independent filling grooves on both sides of the q-axis decreases along the q-axis direction, and the included angle α between the centerlines of adjacent independent filling grooves satisfies 3°≤α≤16°.

[0023] Furthermore, an arc-shaped groove is provided on the outer circle of the rotor, and the arc-shaped groove is located on the q-axis.

[0024] According to another aspect of the present invention, an electric motor is provided, comprising the rotor structure described above.

[0025] By applying the technical solution of this invention, the rotor structure forms a multi-layered magnetic barrier layer through the careful arrangement of filling slots, rectangular magnet slots, and arc-shaped magnet slots on the rotor core. Utilizing the synergistic effect of rectangular and arc-shaped permanent magnets in the d-axis and q-axis directions, the air gap magnetic field can be significantly optimized, reducing the content of magnetic flux density harmonics. This effectively reduces electromagnetic torque pulsation during motor operation, decreasing vibration and noise. Simultaneously, the presence of the filling slots also promotes the motor's self-starting capability, improving overall motor operating efficiency and stability. The rectangular magnet slots on the rotor core support rectangular permanent magnets, while the arc-shaped magnet slots support arc-shaped permanent magnets. The structural design of the arc-shaped permanent magnets guides the magnetic flux to be more concentrated, while the rectangular permanent magnets guide the magnetic flux to be concentrated along the d-axis, reducing core losses. The combination of arc-shaped and rectangular permanent magnets reduces magnetic flux leakage in the d-axis direction, improving the efficiency of the permanent magnets. The reasonable combination of arc-shaped and rectangular permanent magnets reduces the amplitude of magnetic flux density harmonics, thereby reducing radial electromagnetic force, lowering motor vibration and noise, and improving motor efficiency. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 A schematic diagram showing the dimensions of a rotor structure according to an embodiment of the present invention is shown;

[0028] Figure 2 A schematic diagram showing the dimensions of a rotor structure according to an embodiment of the present invention is shown;

[0029] Figure 3 A comparison diagram of the output torque of the motor of this invention and a motor of related technologies is shown;

[0030] Figure 4 A comparison diagram of the radial electromagnetic force of a motor according to an embodiment of the present invention and a motor of related technologies is shown;

[0031] Figure 5 A comparison diagram of the cogging torque of the motor of the present invention and the motor of the related art is shown.

[0032] The above figures include the following reference numerals:

[0033] 1. Rotor core; 11. Arc-shaped slot; 12. Screw hole; 2. Filling slot; 21. q-axis filling slot; 22. d-axis filling slot; 23. Independent filling slot; 3. Rectangular magnet slot; 4. Arc-shaped magnet slot; 5. Rectangular permanent magnet; 6. Arc-shaped permanent magnet; 7. First connecting rib; 8. Second connecting rib; 9. Third connecting rib. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] See also Figures 1 to 5 As shown, according to an embodiment of the present invention, the rotor structure includes a rotor core 1, on which a filling groove 2, a rectangular magnet groove 3, and an arc-shaped magnet groove 4 are provided. The rotor core 1 includes a rotor outer circle, the filling groove 2 includes a q-axis filling groove 21, and rectangular magnet grooves 3 are respectively provided at both ends of the arc-shaped magnet groove 4. The q-axis filling groove 21 is provided on the side of the rectangular magnet groove 3 near the rotor outer circle. The q-axis filling groove 21, the rectangular magnet groove 3, and the arc-shaped magnet groove 4 located in the same layer form a magnetic barrier layer. The number of magnetic barrier layers is at least two layers. A rectangular permanent magnet 5 is provided in the rectangular magnet groove 3, and an arc-shaped permanent magnet 6 is provided in the arc-shaped magnet groove 4.

[0036] This rotor structure forms a multi-layered magnetic barrier layer by carefully arranging filling slots 2, rectangular magnet slots 3, and arc-shaped magnet slots 4 on the rotor core 1. By utilizing the synergistic effect of rectangular permanent magnets 5 and arc-shaped permanent magnets 6 in the d-axis and q-axis directions, the air gap magnetic field can be significantly optimized, and the content of magnetic flux density harmonics can be reduced. This effectively reduces the pulsation of electromagnetic torque, vibration, and noise during motor operation. At the same time, the presence of filling slots 2 can also promote the self-starting capability of the motor, thus improving the overall operating efficiency and stability of the motor.

[0037] Specifically, the rectangular magnetic slots 3 on the rotor core 1 support rectangular permanent magnets 5, and the arc-shaped magnetic slots 4 support arc-shaped permanent magnets 6. The structural design of the arc-shaped permanent magnets 6 allows for more concentrated magnetic flux, while the rectangular permanent magnets 5 guide the magnetic flux towards the d-axis, reducing core losses. The combination of the arc-shaped and rectangular permanent magnets 6 reduces magnetic flux leakage along the d-axis, improving the efficiency of the permanent magnets. This optimal combination of arc-shaped and rectangular permanent magnets 6 reduces the amplitude of magnetic flux density harmonics, thereby reducing radial electromagnetic force, lowering motor vibration and noise, and improving motor efficiency.

[0038] The q-axis filling slot 21 provides the asynchronous torque required for self-starting of the motor without affecting the normal function of the permanent magnet, thus further optimizing the motor's starting characteristics.

[0039] The design of multiple magnetic barrier layers enables the magnetic circuit to be more compact and the air gap magnetic flux density distribution to be closer to a sine wave, thereby reducing harmonic content and improving the electromagnetic compatibility and mechanical noise of the motor.

[0040] In one embodiment, at one pole, two rectangular magnetic slots 3 located on the same layer are symmetrical about the d-axis, and the two rectangular magnetic slots 3 form an included angle β, where 0° < β ≤ 90°.

[0041] By setting two rectangular magnetic slots 3 located in the same layer to be symmetrical about the d-axis and forming an included angle β between 0° and 90° between the two rectangular magnetic slots 3, it is possible to ensure that the permanent magnet generates a uniform and stable magnetic field in the d-axis direction, which is beneficial to enhance the permanent magnet synchronous torque of the motor. At the same time, the symmetrical layout of the rectangular magnetic slots 3 helps to balance the magnetic circuit and reduce torque pulsation, thereby achieving smoother torque output during motor operation, reducing vibration and noise, and improving overall operating efficiency and reliability.

[0042] Specifically, the symmetrically arranged rectangular magnet slots 3 enable the magnetic flux to be more concentrated in the d-axis direction, reducing magnetic flux leakage in the q-axis direction, thereby optimizing the magnetic circuit structure of the motor. Simultaneously, the included angle β, set between 0° and 90°, ensures a reasonable distribution of the rectangular magnet slots 3 while utilizing the spatial advantages of the permanent magnets to improve the air gap magnetic flux density distribution, reduce the harmonic components of the magnetic flux waveform, and thus effectively reduce harmonic electromotive force and current, minimizing vibration and noise caused by electromagnetic force imbalance, ultimately achieving a comprehensive improvement in motor performance.

[0043] In one embodiment, in a pole, in the rectangular magnetic steel groove 3 and the arc-shaped magnetic steel groove 4 located on the same layer, the angle between the center line of the rectangular magnetic steel groove 3 extending along the magnetization direction and the center line of the arc-shaped magnetic steel groove 4 extending along the magnetization direction is δ, 45°≤δ≤90°.

[0044] In each pole, the rectangular magnetic groove 3 and the arc-shaped magnetic groove 4 in the same layer form an angle δ of 45° to 90° along the center line of the magnetization direction, which effectively promotes the optimized distribution of the magnetic field, enhances the magnetic flux concentration in the d-axis direction, and reduces the magnetic flux leakage in the q-axis direction. This significantly improves the magnetic utilization rate of the permanent magnet during motor operation, reduces magnetic flux density harmonics, reduces radial fluctuations of electromagnetic force, and effectively suppresses motor vibration and noise.

[0045] Specifically, the design of the specific included angle δ between the rectangular magnetic steel slot 3 and the arc-shaped magnetic steel slot 4 can maximize the use of the magnetic properties of the permanent magnet while ensuring that the motor has sufficient self-starting capability, reduce the nonlinear effects of the magnetic circuit, and make the air gap magnetic flux density distribution closer to the ideal sine waveform. This reduces energy loss caused by magnetic circuit imbalance and lowers the mechanical vibration and acoustic noise problems that may occur when the motor is running at high speed.

[0046] In one embodiment, 50°≤δ≤90°.

[0047] When the angle δ between the rectangular and curved magnetic slots along the centerline of the magnetization direction is precisely controlled within the range of 50° to 90°, this structural design can further optimize the magnetic flux path, ensure the maximization of the magnetic field strength in the d-axis direction, and reduce magnetic flux leakage in the q-axis direction. This effectively improves the magnetic utilization rate of the permanent magnet, reduces the magnetic flux harmonic content during motor operation, thereby achieving smaller torque pulsation, significantly reducing motor vibration and noise, enhancing the smooth operation of the motor, and improving overall efficiency.

[0048] In one embodiment, in two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets 6 is k1, the width of the magnetic channel between adjacent rectangular permanent magnets 5 is k2, and the width of the magnetic channel between adjacent q-axis filling grooves 21 is k3, where k3 > k2 > k1.

[0049] Between adjacent magnetic barrier layers, by ensuring that the width k1 of the magnetic conductive channel between the arc-shaped permanent magnets 6, the width k2 of the magnetic conductive channel between the rectangular permanent magnets 5, and the width k3 of the magnetic conductive channel between the q-axis filling grooves 21 satisfy the relationship k3>k2>k1, the distribution of magnetic flux in the rotor can be precisely controlled, reducing core loss and improving the electromagnetic energy conversion efficiency of the motor. At the same time, torque pulsation and vibration noise are reduced, achieving higher precision and stability during motor operation.

[0050] Specifically, the different settings of widths k3, k2, and k1 effectively control the flow of magnetic flux. This creates wider magnetic conduction channels between adjacent q-axis filling slots 21 and between adjacent rectangular permanent magnets 5, reducing magnetic flux blockage and leakage in these areas and improving the magnetic flux utilization rate of the permanent magnets. Simultaneously, a smaller k1 width limits excessive magnetic flux flow between the arc-shaped permanent magnets 6, preventing over-saturation of the rotor magnetic circuit and maintaining good electromagnetic force balance. This hierarchical magnetic channel width design ensures that the magnetic flux density waveform during motor operation is closer to an ideal sine wave, reducing harmonic interference and thus achieving more efficient electromagnetic torque generation while reducing mechanical vibration and electromagnetic noise.

[0051] In one embodiment, the thickness of the arc-shaped permanent magnet 6 is w1, and the thickness of the rectangular permanent magnet 5 is w2, where w1 = w2.

[0052] By designing the rectangular permanent magnet 5 and the arc-shaped permanent magnet 6 to have the same thickness, it is possible to ensure a more uniform magnetic field distribution and consistent magnetic flux density during motor operation. This guarantees the amount of permanent magnets used in each layer, avoids local protection, and improves the consistency of permanent magnet anti-demagnetization. As a result, it avoids the problem of magnetic circuit imbalance caused by different permanent magnet thicknesses, effectively enhances the electromagnetic torque of the motor, reduces the content of magnetic flux density harmonics, reduces motor vibration and noise, and improves the overall operating efficiency and mechanical stability of the motor.

[0053] The uniform design of permanent magnet thickness reduces nonlinear factors in the magnetic circuit, making the magnetic field strength in the d-axis and q-axis directions more coordinated. This reduces the tortuosity of magnetic lines of force in the rotor structure, optimizes the magnetic flux path, thereby reducing unnecessary core losses and improving motor efficiency. Simultaneously, permanent magnets of uniform thickness help the motor maintain good magnetic coupling under different operating conditions, reducing vibration and noise caused by uneven magnetic flux density.

[0054] In one embodiment, in two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets 6 is k1, the width of the magnetic channel between adjacent rectangular permanent magnets 5 is k2, the thickness of the arc-shaped permanent magnet 6 is w1, the thickness of the rectangular permanent magnet 5 is w2, k1 > w1, k2 > w2.

[0055] In adjacent magnetic barrier layers, by setting the width k1 of the magnetic conduction channel between the arc-shaped permanent magnets 6 to be greater than the thickness w1 of the arc-shaped permanent magnets 6, and the width k2 of the magnetic conduction channel between the rectangular permanent magnets 5 to be greater than the thickness w2 of the permanent magnets, this structural layout can precisely control the magnetic flux path, avoid magnetic circuit saturation, and ensure the effective distribution of permanent magnet magnetic flux in the d-axis and q-axis directions. This significantly improves electromagnetic torque, reduces magnetic flux density harmonics, and reduces vibration and noise during motor operation.

[0056] By limiting the relationship between the magnetic flux channel and the thickness of the permanent magnet, excessive concentration of magnetic flux between the permanent magnets can be prevented, local saturation of the magnetic circuit can be avoided, uniform flow of magnetic flux in the rotor core can be maintained, distortion of the magnetic flux waveform can be reduced, and the air gap magnetic field can be optimized. This reduces harmonic current and torque pulsation during motor operation and improves the electromagnetic torque and efficiency of the motor.

[0057] In one embodiment, k1≥2×w1, k2≥1.8×w2.

[0058] By limiting k1≥2×w1 and k2≥1.8×w2, sufficient space is provided for the flow of magnetic flux inside the rotor, avoiding magnetic circuit saturation caused by excessive concentration of magnetic flux, reducing the blockage of magnetic lines of force between magnetic barrier layers, ensuring unobstructed magnetic flux path, effectively reducing magnetic flux harmonics, significantly reducing vibration and noise caused by radial electromagnetic force, maintaining uniform distribution of magnetic flux in the d-axis and q-axis directions, improving the magnetic utilization rate of permanent magnets, reducing the distortion rate of magnetic flux waveform, optimizing the air gap magnetic field, reducing harmonic current and torque pulsation, enabling the motor to operate smoothly under various operating conditions, and reducing mechanical vibration and acoustic noise.

[0059] In one embodiment, the filling groove 2 further includes a d-axis filling groove 22, which is located radially outside the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the q-axis filling groove 21 is D1, and the minimum distribution circle diameter of the d-axis filling groove 22 is D2, where D2 ≥ D1.

[0060] In the rotor structure, by adding a d-axis filling groove 22 on the radially outer side of the magnetic barrier layer along the d-axis direction, and ensuring that its minimum distribution circle diameter D2 is greater than or equal to the minimum distribution circle diameter D1 of the q-axis filling groove 21, the magnetic field distribution on the outer periphery of the rotor can be effectively optimized, magnetic flux leakage can be reduced, and the cogging torque can be significantly reduced during motor operation. This improves the utilization rate of permanent magnets, achieves smaller magnetic flux density harmonic amplitude and radial electromagnetic force, thereby greatly reducing motor vibration and noise, and enhancing the efficiency and stability of motor operation.

[0061] The above design effectively widens the magnetic flux path at the outer edge of the rotor, reduces the leakage of magnetic flux in the d-axis direction to the outer periphery of the rotor, increases the directional flow of magnetic flux between the permanent magnet and the magnetic barrier layer, optimizes the magnetic circuit of the d-axis, which is conducive to improving the magnetic flux density and electromagnetic torque of the permanent magnet, reducing the harmonic components of the magnetic flux waveform, reducing the pulsation of the radial electromagnetic force, and achieving low vibration and low noise during motor operation.

[0062] In one embodiment, the filling groove 2 further includes a d-axis filling groove 22, which is located radially outside the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the d-axis filling groove 22 is D2, and the diameter of the outer circle of the rotor is D, where 0.8×D≤D2≤0.9×D.

[0063] In the rotor structure, by setting the d-axis filling groove 22 on the radially outer side of the magnetic barrier layer along the d-axis direction, and controlling its minimum distribution circle diameter D2 to be between 0.8 and 0.9 times the rotor outer circle diameter D, the magnetic field distribution during motor operation can be effectively adjusted, ensuring the optimization of the magnetic flux path, reducing magnetic flux leakage, while maintaining the mechanical strength of the rotor structure, reducing cogging torque, and reducing the amplitude of magnetic flux density harmonics. Thus, the electromagnetic force is evenly distributed throughout the entire operating range of the motor from startup to high-speed rotation, significantly reducing vibration and noise, and improving the electromagnetic efficiency and smoothness of the motor operation.

[0064] The placement of the d-axis filler slot 22 on the outer periphery of the rotor and the limitation of its diameter D2 allow the motor to fully utilize the asynchronous torque effect of the filler slot during startup, facilitating a smooth start. At high speeds, the filler slot reduces magnetic flux leakage along the d-axis, maintaining efficient flux flow between the permanent magnet and the magnetic barrier layer, preventing rotor magnetic circuit saturation, optimizing the air gap magnetic field waveform, reducing magnetic flux density harmonics, and minimizing radial electromagnetic force fluctuations. Simultaneously, limiting the diameter D2 to between 0.8×D and 0.9×D ensures that the filler slot on the rotor's outer edge is compatible with the overall dimensions of the motor, neither occupying excessive rotor space nor affecting the internal magnetic flux path, thus maintaining the motor's compactness and efficiency.

[0065] In one embodiment, the filling groove 2 further includes a d-axis filling groove 22, which is located radially outside the magnetic barrier layer along the d-axis direction. Under one pole, there are multiple d-axis filling grooves 22, the distance between two adjacent d-axis filling grooves 22 is w6, and the thickness of the arc-shaped permanent magnet 6 is w1, where w6 ≥ w1.

[0066] In the rotor structure, by setting multiple d-axis filling slots 22 on the radially outer side of the magnetic barrier layer along the d-axis direction, and ensuring that the distance w6 between two adjacent d-axis filling slots is at least equal to the thickness w1 of the arc-shaped permanent magnet 6, the magnetic flux distribution at the outer edge of the rotor can be optimized, reducing magnetic flux leakage. At the same time, by adjusting the number and layout of the filling slots, the cogging torque can be effectively reduced, magnetic flux density harmonics can be reduced, and radial electromagnetic force can be further reduced. Thus, during motor operation, especially from the start-up to acceleration phase, vibration and noise are significantly reduced, improving the motor's starting performance and smoothness. Meanwhile, it ensures that the motor can maintain high efficiency and low loss under high speed and high load conditions, enhancing the overall electromagnetic compatibility and operational stability.

[0067] Through the above design, the magnetic field in the d-axis direction can be adjusted by utilizing the layout of the filling slots, avoiding excessive leakage of magnetic flux at the outer edge of the rotor, maintaining effective flow of magnetic flux between the permanent magnet and the magnetic barrier layer, and optimizing the magnetic circuit of the d-axis. Simultaneously, the distribution of multiple d-axis filling slots can uniformly disperse the cogging effect, reduce cogging torque pulsation, lower the distortion rate of the magnetic flux density waveform, optimize the air gap magnetic field, facilitate the formation of asynchronous torque during motor startup, and ensure uniform distribution of electromagnetic force during operation, thereby reducing mechanical vibration and acoustic noise.

[0068] In one embodiment, a first connecting rib 7 is provided between the rectangular magnetic groove 3 and the arc-shaped magnetic groove 4, and a second connecting rib 8 is provided between the rectangular magnetic groove 3 and the q-axis filling groove 21. The width of the first connecting rib 7 is w4, and the width of the second connecting rib 8 is w5, where w5 ≤ w4.

[0069] In the rotor design, by setting a first connecting rib 7 with a width of w4 between the rectangular magnet slot 3 and the arc-shaped magnet slot 4, and setting a second connecting rib 8 with a width not greater than w4 between the rectangular magnet slot 3 and the q-axis filling slot 21, the mechanical stability of the rotor can be effectively enhanced. At the same time, the magnetic flux path can be optimized, magnetic circuit saturation can be reduced, and the magnetic flux can be more smoothly and concentratedly flowed in the d-axis and q-axis directions during motor operation, especially during the start-up and speed change stages. This reduces magnetic flux harmonics and vibration and noise caused by radial electromagnetic force.

[0070] The presence of the first connecting rib 7 and the second connecting rib 8 not only enhances the physical connection between the magnet slot and the filling slot and improves the rotor's ability to resist centrifugal force, but also the width relationship design of w5≤w4 allows the second connecting rib 8 to maintain sufficient mechanical strength while reducing the impact on the magnetic flux path, avoiding magnetic saturation caused by local narrowing of the magnetic circuit, maintaining the uniform distribution of magnetic flux inside the rotor, and optimizing the magnetic circuit design in the d-axis and q-axis directions.

[0071] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 1, the length of the rectangular permanent magnet 5 located radially outward along the d-axis direction is l1, and the length of the rectangular permanent magnet 5 located radially inward along the d-axis direction is l2, where l1 < l2 < 1.43 × l1.

[0072] In one embodiment, the outer arc length of the arc-shaped permanent magnet 6 located radially outward along the d-axis is l3, and the outer arc length of the arc-shaped permanent magnet 6 located radially inward along the d-axis is l4, where l3 < l4 < 1.14 × l3.

[0073] Within the radial cross-section of the rotor core, the length l1 of the rectangular permanent magnet 5 on the outer radial side along the d-axis is designed to be less than the length l2 of the rectangular permanent magnet 5 on the inner radial side, and l2 does not exceed 1.43 times l1. At the same time, the outer arc length l3 of the arc-shaped permanent magnet 6 on the outer radial side is ensured to be less than the outer arc length l4 of the arc-shaped permanent magnet 6 on the inner radial side, and l4 does not exceed 1.14 times l3. Through the above-mentioned structural layout of gradient magnet length and arc length, the magnetic flux distribution inside the motor can be significantly optimized, the magnetic circuit in the d-axis direction can be enhanced, and the leakage magnetic phenomenon can be reduced. At the same time, during the operation of the motor, especially under the conditions of speed change and load change, the electromagnetic response speed of the motor can be improved, the permanent magnet torque and reluctance torque can be increased, the cogging torque can be reduced, and the magnetic flux density harmonic amplitude can be reduced, thereby effectively reducing the radial electromagnetic force, significantly reducing the vibration and noise of the motor, and improving the electromagnetic efficiency and stability of the motor.

[0074] In one embodiment, a third connecting rib 9 is provided between the filling groove 2 and the outer circle of the rotor. The width of the third connecting rib 9 is w7, 0≤w7≤2σ, where σ is the air gap width between the stator structure and the rotor structure.

[0075] The presence of the third connecting rib 9 strengthens the connection between the filling groove and the outer edge of the rotor, improving the rotor's resistance to centrifugal force and thermal stress, and avoiding structural problems caused by high-speed rotation or temperature changes in the filling groove. Simultaneously, by setting w7 to 0≤w7≤2σ, the width of the third connecting rib 9 is ensured to be no more than twice the width of the air gap, reducing interference with the magnetic flux path, maintaining smooth magnetic flux flow within the rotor, avoiding local narrowing and magnetic saturation of the magnetic circuit, optimizing the magnetic circuit design in the d-axis and q-axis directions, and reducing magnetic flux density waveform distortion and radial electromagnetic force pulsation.

[0076] In one embodiment, the filling groove 2 further includes an independent filling groove 23, which is located between the magnetic barrier layer and the q-axis. The spacing between adjacent independent filling grooves 23 located on both sides of the q-axis decreases along the q-axis direction, and the included angle α between the centerlines of adjacent independent filling grooves 23 satisfies 3°≤α≤16°.

[0077] By setting independent filling slots 23 with decreasing spacing along the q-axis between the magnetic barrier layer and the q-axis, and controlling the included angle α between the centerlines of adjacent independent filling slots 23 to be between 3° and 16°, the magnetic field distribution inside the motor can be effectively modulated. Especially in different operating stages of the motor from start-up to acceleration, the decreasing spacing of the independent filling slots helps to balance the magnetic flux path and reduce cogging torque. At the same time, by limiting the range of the included angle α, the magnetic circuit in the q-axis direction is optimized, the amplitude of magnetic flux density harmonics is reduced, thereby reducing the radial electromagnetic force, significantly reducing vibration and noise during motor operation, and improving the electromagnetic efficiency and smoothness of motor operation.

[0078] The position and structural design of the independent filling slot 23 can improve the magnetic field distribution near the q-axis. By adjusting the magnetic flux flow path, it effectively disperses the cogging effect, reduces torque fluctuations caused by cogging, and improves the motor's starting capability and operational stability. The defined angle α ensures the modulation effect of the independent filling slot on the magnetic field, reducing magnetic flux density harmonics without excessively affecting the magnetic flux density of the magnet slot, thus maintaining harmony and balance of the magnetic field in the d-axis and q-axis directions.

[0079] In this embodiment, the independent filling groove 23 extends approximately along the q-axis direction.

[0080] In one embodiment, an arc-shaped groove 11 is provided on the outer circle of the rotor, and the arc-shaped groove 11 is located on the q-axis.

[0081] An arc-shaped slot 11 is provided on the outer circle of the rotor along the q-axis. The arc-shaped slot 11 can change the magnetic circuit impedance in the q-axis direction, effectively improving the magnetic flux distribution of the motor. Through the fine control of the magnetic field in the q-axis direction by the arc-shaped slot 11, stray magnetic flux in the magnetic circuit can be significantly reduced, the air gap magnetic flux waveform can be optimized, and the magnetic flux can be more concentrated in the d-axis, reducing leakage flux, reducing cogging torque, reducing magnetic flux harmonic content, and thus reducing radial electromagnetic force, achieving efficient vibration reduction and noise reduction of the motor. In addition, the introduction of the arc-shaped slot also helps to enhance the self-starting performance of the motor and reduce the stability of the electromagnetic torque.

[0082] In one embodiment, the rotor core 1 is provided with screw holes 12, and there are multiple screw holes 12, which are spaced apart along the circumference of the rotor core 1.

[0083] The rotor core 1 is composed of multiple rotor laminations stacked together. After the multiple rotor laminations are stacked, they are fixed together by connecting bolts provided in the screw holes 12.

[0084] In one embodiment, the magnetic barrier layer consists of two layers.

[0085] The magnetic barrier layer can also have three or more layers.

[0086] Figure 3 The figure shows the air gap magnetic flux density harmonic amplitude of a self-starting permanent magnet assisted synchronous reluctance motor. Compared with the prior art, the rotor structure of the motor in this embodiment of the invention can significantly reduce the 3rd and 7th major harmonics while keeping the fundamental amplitude basically unchanged. The air gap magnetic flux density distortion rate of this invention is reduced by 9% compared with the prior art, and the air gap magnetic flux density distribution can be optimized.

[0087] Figure 4The diagram shows the radial electromagnetic force of a self-starting permanent magnet assisted synchronous reluctance motor. In this embodiment, the main harmonics of the radial electromagnetic force are significantly reduced compared to existing technologies, resulting in excellent vibration and noise reduction. Specifically, the radial electromagnetic forces generated by the first-order tooth harmonics (32nd, 36th, and 40th orders) are reduced by 39%, 49%, and 78%, respectively. The comparison demonstrates that this invention effectively weakens the cogging effect, achieving vibration and noise reduction.

[0088] Figure 5 The diagram shows the cogging torque of a self-starting permanent magnet assisted synchronous reluctance motor. Compared with the prior art, the rotor structure of the motor in this embodiment of the invention can significantly reduce the cogging torque, thereby achieving the purpose of vibration reduction and noise reduction, reducing wear, and extending the service life of the motor and other mechanical components.

[0089] According to an embodiment of the present invention, the motor includes the rotor structure described above.

[0090] In this embodiment, the motor is a self-starting permanent magnet assisted synchronous reluctance motor.

[0091] 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 scope of exemplary embodiments according to the invention. 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.

[0092] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in sequences other than those illustrated or described herein.

[0093] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotor structure, characterized in that, The rotor core (1) includes a rotor core (1), which is provided with a filling groove (2), a rectangular magnet groove (3) and an arc-shaped magnet groove (4). The rotor core (1) includes an outer circle of the rotor. The filling groove (2) includes a q-axis filling groove (21). The two ends of the arc-shaped magnet groove (4) are respectively provided with the rectangular magnet groove (3). The rectangular magnet groove (3) is provided with the q-axis filling groove (21) on the side of the rectangular magnet groove (3) close to the outer circle of the rotor. The q-axis filling groove (21), the rectangular magnet groove (3) and the arc-shaped magnet groove (4) located in the same layer form a magnetic barrier layer. The number of magnetic barrier layers is at least two layers. A rectangular permanent magnet (5) is provided in the rectangular magnet groove (3) and an arc-shaped permanent magnet (6) is provided in the arc-shaped magnet groove (4). In two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets (6) is k1, the width of the magnetic channel between adjacent rectangular permanent magnets (5) is k2, and the width of the magnetic channel between adjacent q-axis filling grooves (21) is k3, where k3 > k2 > k1. In two adjacent magnetic barrier layers, the width of the magnetic channel between adjacent arc-shaped permanent magnets (6) is k1, the width of the magnetic channel between adjacent rectangular permanent magnets (5) is k2, the thickness of the arc-shaped permanent magnet (6) is w1, the thickness of the rectangular permanent magnet (5) is w2, k1>w1, k2>w2; k1≥2×w1, k2≥1.8×w2.

2. The rotor structure according to claim 1, characterized in that, At one pole, the two rectangular magnetic grooves (3) located in the same layer are symmetrical about the d axis, and the two rectangular magnetic grooves (3) form an included angle β, 0°<β≤90°.

3. The rotor structure according to claim 1, characterized in that, In a pole, in the rectangular magnetic steel groove (3) and the arc-shaped magnetic steel groove (4) located in the same layer, the angle between the center line of the rectangular magnetic steel groove (3) extending along the magnetization direction and the center line of the arc-shaped magnetic steel groove (4) extending along the magnetization direction is δ, 45°≤δ≤90°.

4. The rotor structure according to claim 3, characterized in that, 50°≤δ≤90°.

5. The rotor structure according to claim 1, characterized in that, The thickness of the rectangular permanent magnet (5) is w2, and the thickness of the arc-shaped permanent magnet (6) is w1, where w1 = w2.

6. The rotor structure according to claim 1, characterized in that, The filling groove (2) also includes a d-axis filling groove (22), which is located on the radial outer side of the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the q-axis filling groove (21) is D1, and the minimum distribution circle diameter of the d-axis filling groove (22) is D2, where D2 ≥ D1.

7. The rotor structure according to claim 1, characterized in that, The filling groove (2) also includes a d-axis filling groove (22), which is located on the radial outer side of the magnetic barrier layer along the d-axis direction. The minimum distribution circle diameter of the d-axis filling groove (22) is D2, and the diameter of the outer circle of the rotor is D, 0.8×D≤D2≤0.9×D.

8. The rotor structure according to claim 1, characterized in that, The filling groove (2) also includes a d-axis filling groove (22), which is located on the radial outer side of the magnetic barrier layer along the d-axis direction. Under one pole, there are multiple d-axis filling grooves (22), the distance between two adjacent d-axis filling grooves (22) is w6, the thickness of the arc-shaped permanent magnet (6) is w1, and w6≥w1.

9. The rotor structure according to claim 1, characterized in that, The rectangular magnetic steel groove (3) and the arc-shaped magnetic steel groove (4) have a first connecting rib (7), and the rectangular magnetic steel groove (3) and the q-axis filling groove (21) have a second connecting rib (8). The width of the first connecting rib (7) is w4, and the width of the second connecting rib (8) is w5, where w5≤w4.

10. The rotor structure according to claim 1, characterized in that, In a cross section perpendicular to the central axis of the rotor core (1), the length of the rectangular permanent magnet (5) located radially outward along the d-axis is l1, and the length of the rectangular permanent magnet (5) located radially inward along the d-axis is l2, l1 < l2 < 1.43 × l1; and / or, the outer arc length of the arc-shaped permanent magnet (6) located radially outward along the d-axis is l3, and the outer arc length of the arc-shaped permanent magnet (6) located radially inward along the d-axis is l4, l3 < l4 < 1.14 × l3.

11. The rotor structure according to claim 1, characterized in that, The filling groove (2) has a third connecting rib (9) between it and the outer circle of the rotor. The width of the third connecting rib (9) is w7, 0≤w7≤2σ, where σ is the air gap width between the stator structure and the rotor structure.

12. The rotor structure according to claim 1, characterized in that, The filling groove (2) also includes an independent filling groove (23), which is located between the magnetic barrier layer and the q axis. The spacing between adjacent independent filling grooves (23) on both sides of the q axis decreases along the q axis direction. The included angle α between the center lines of adjacent independent filling grooves (23) satisfies 3°≤α≤16°.

13. The rotor structure according to claim 1, characterized in that, An arc-shaped groove (11) is provided on the outer circle of the rotor, and the arc-shaped groove (11) is located on the q-axis.

14. An electric motor, characterized in that, The rotor structure includes any one of claims 1 to 13.

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