Rotor and motor

Abstract

The invention provides a rotor and a motor, in a cross section perpendicular to a rotation axis of a rotor core, a plurality of linear magnetic steel grooves are distributed along the circumferential direction of the rotor core, and permanent magnets are installed in the magnetic steel grooves; a plurality of magnetic barrier holes are formed between the magnetic steel grooves and the outer peripheral wall of the rotor core, and the plurality of magnetic barrier holes are symmetrically arranged about the d axis; the magnetic barrier holes comprise a first magnetic barrier hole and a second magnetic barrier hole which are positioned on the same side of the d axis; the first magnetic barrier hole is provided with a first end facing the q axis and a second end facing the d axis, and the width of the first end of the first magnetic barrier hole is smaller than that of the second end of the first magnetic barrier hole; the second magnetic barrier hole is provided with a first end facing the magnetic steel groove and a second end facing the peripheral wall of the rotor core, and the width of the first end of the second magnetic barrier hole is smaller than that of the second end; by using the characteristic of large magnetic resistance of the magnetic barrier holes, the magnetic flux path is controlled, the magnetic flux is shaped, the cogging torque and the harmonic wave of the counter electromotive force are effectively improved, and the noise vibration is reduced.

Description

Technical Field

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

[0002] Most existing rotors adopt a single-line magnet structure, such as the utility model patent with publication number CN213043483U, which discloses a single-line rotor core structure. Figure 1 As shown, by arranging a single permanent magnet on both sides along the d-axis, it has the advantages of low cost, fast production cycle and simple structure. However, the magnetic circuit design does not consider leakage flux optimization, resulting in low motor efficiency. In addition, the magnetic coupling between the stator slots and the rotor permanent magnet is strong, resulting in large slot torque, obvious torque pulsation and high back EMF harmonic content. It cannot meet the current market's core demand for low noise and high efficiency of variable frequency compressors.

[0003] For example, utility model patent CN205141856U discloses a rotor assembly and a motor having the same. Figure 2 As shown, a rotor structure with magnetic barrier holes is adopted. By blocking the leakage magnetic path through magnetic barrier holes in the rotor core, the cogging torque and back EMF harmonics can be reduced to a certain extent. However, there are key drawbacks: ① The position, size, number, and shape of the magnetic barrier holes lack systematic design. Simply opening round or square holes results in limited magnetic flux shaping effect; ② The contradiction between magnetic circuit optimization and power density is not balanced. After opening magnetic barrier holes, the effective magnetic conduction area of ​​the rotor decreases, leading to a decrease in reluctance torque and damage to the motor's power density and efficiency; ③ Using only magnetic barrier holes with openings in a single direction makes it impossible to accurately optimize for the leakage magnetic characteristics of different regions. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention provides a rotor and motor that utilize the high magnetic reluctance of the magnetic barrier hole to control the magnetic flux path, shape the magnetic flux, effectively improve the harmonics of cogging torque and back EMF, reduce noise and vibration, and reduce phase current and copper loss under the same torque.

[0005] The technical effects to be achieved by this invention are realized through the following technical aspects: This invention provides a rotor, including a rotor core; In a cross section perpendicular to the rotation axis of the rotor core, a plurality of I-shaped magnetic slots are distributed along the circumference of the rotor core, and permanent magnets are installed in the magnetic slots. A plurality of magnetic barrier holes are provided between the magnetic steel slot and the outer peripheral wall of the rotor core, and the plurality of magnetic barrier holes are symmetrically arranged about the d-axis. The magnetic barrier hole includes a first magnetic barrier hole and a second magnetic barrier hole located on the same side of the d-axis. The first magnetic barrier aperture has a first end facing the q-axis and a second end facing the d-axis, and the width of the first end of the first magnetic barrier aperture is smaller than the width of the second end; The second magnetic barrier hole has a first end facing the magnet slot and a second end facing the outer peripheral wall of the rotor core, wherein the width of the first end of the second magnetic barrier hole is smaller than the width of the second end.

[0006] In some implementations, a first nick is formed on the outer peripheral wall of the rotor core at the position corresponding to the first magnetic barrier hole; The first magnetic barrier hole has a first sidewall and a second sidewall parallel to the first slashed arc, and a third sidewall parallel to the magnetic groove; The first sidewall connects the third sidewall and the second end of the first magnetic barrier hole, the third sidewall connects the first end of the first magnetic barrier hole, and the second sidewall connects the first end and the second end of the first magnetic barrier hole. The second sidewall is located on the side of the first magnetic barrier hole near the first shaving arc.

[0007] In some implementations, the shortest distance between the first sidewall and the first slashed arc is d1, the shortest distance between the second sidewall and the first slashed arc is d2, and the shortest distance between the second end of the second magnetic barrier hole and the extension line of the first slashed arc is d3. The d1 and d2 satisfy the following relationship: 1.8 < d2 < 3.1d1 ≤ 1.85; The d3 satisfies the following relationship: 2.02 < d3 ≤ 2.05.

[0008] In some implementations, the length of the first shaving arc is L, the length of the first sidewall is L1, and the length of the second sidewall is L2. The L and L1 satisfy the following relationship: 0.0876L≤L1<0.0878L; The L and L2 satisfy the following relationship: 0.211L≤L2<0.212L.

[0009] In some implementations, the shortest distance between the third sidewall and the magnetic groove is defined as H1, and the shortest distance between the first end of the second magnetic barrier hole and the magnetic groove is defined as H2. H1 satisfies the following relationship: 0.5 < H1 ≤ 0.55; The H2 satisfies the following relationship: 0.75 < H2 ≤ 0.8.

[0010] In some implementations, let the area of ​​the permanent magnet be S, the area of ​​the first magnetic barrier hole be S1, and the area of ​​the second magnetic barrier hole be S2. The S1 and S2 satisfy the following relationship: 1.09≤S1 / S2≤1.095; The S, S1, and S2 satisfy the following relationship: 0.14 < (S1 + S2) × 2 / S ≤ 0.15.

[0011] In some implementations, the arc length of the second end of the second magnetic barrier hole relative to the outer peripheral wall of the rotor core is set to L3. The L3 satisfies the following relationship: 0.054≤L3<0.055.

[0012] In some implementations, the first end of the second magnetic barrier hole has a fourth sidewall parallel to the magnetic groove, and a fifth sidewall and a sixth sidewall are connected between the fourth sidewall and the second end of the second magnetic barrier hole. Let the angle between the fourth sidewall and the fifth sidewall be θ1, and let the angle between the fourth sidewall and the sixth sidewall be θ2; The θ1 satisfies the following relationship: 86°<θ1≤88°; The θ2 satisfies the following relationship: 100°<θ2≤102°.

[0013] In some implementations, the second end of the first magnetic barrier hole is arc-shaped; Let the angle between the tangent edge of the arc and the d-axis be θ3; The θ3 satisfies the following relationship: 18.65°<θ3≤18.75°.

[0014] The present invention also provides an electric motor comprising the rotor described in any of the preceding claims.

[0015] In summary, the present invention has at least the following advantages: 1. The present invention provides a rotor in which multiple first magnetic barrier holes and second magnetic barrier holes are arranged symmetrically about the d-axis between the magnetic steel slots and the outer peripheral wall of the rotor core. By utilizing the high magnetic reluctance of the magnetic barrier holes, the magnetic flux path is controlled. Through finite element simulation, corresponding constraints are made on the size, proportion and relative position of the first and second magnetic barrier holes to balance magnetic circuit optimization and power density. Through magnetic flux shaping, the harmonics of cogging torque and back EMF are effectively improved, noise vibration is reduced, and phase current and copper loss are reduced under the same torque.

[0016] 2. The motor provided by the present invention, after applying the above-mentioned rotor, can effectively improve the harmonics of cogging torque and back EMF, reduce noise and vibration, and reduce phase current and copper loss under the same torque. Attached Figure Description

[0017] Figure 1 andFigure 2 This is a schematic diagram of a rotor in the background art; Figure 3 A schematic diagram of the rotor provided in Embodiment 1 of the present invention; Figure 4 This is a diagram illustrating the rotor provided in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the first magnetic barrier hole and the second magnetic barrier hole provided in Embodiment 2 of the present invention; Figure 6 This is a comparison diagram of the solutions provided in Embodiment 2 of the present invention; Figure 7 This is a comparison diagram of the no-load back EMF waveform provided in Embodiment 2 of the present invention; Figure 8 This is a comparison diagram of the empty tooth groove to rectangle transformation provided in Embodiment 2 of the present invention; Marked in the image: 100. Rotor core; 110. Magnet slot; 120. First magnetic barrier hole; 121. First side wall; 122. Second side wall; 123. Third side wall; 130. Second magnetic barrier hole; 131. Fourth side wall; 132. Fifth side wall; 133. Sixth side wall; 140. First shaving arc. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more comprehensive description will be given below in conjunction with the accompanying drawings and specific embodiments. The drawings illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0019] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0022] Example 1: Please see Figure 3 A rotor includes a rotor core 100, which serves as the basic support and core component for magnetic circuit conduction of the rotor. It is typically made of silicon steel sheets through precision stamping, stacking, pressing, and curing. Its structural design takes into account key performance requirements such as magnetic permeability, mechanical strength, and eddy current loss control.

[0023] In a cross-section perpendicular to the rotation axis of the rotor core 100, multiple straight magnetic slots 110 are distributed circumferentially along the rotor core 100. This straight-line structure design has the advantages of simple processing technology and short magnetic transmission path. A permanent magnet is installed in each magnetic slot 110. The magnetic pole direction of the permanent magnet is uniformly arranged according to the excitation requirements of the motor. The outer contour of the permanent magnet is completely fitted with the inner contour of the magnetic slot 110. A reliable connection with the rotor core 100 is achieved by interference fit or adhesive fixation, ensuring that the permanent magnet will not loosen or shift during the high-speed rotation of the rotor.

[0024] Multiple magnetic barrier holes are provided between the magnetic steel groove 110 and the outer peripheral wall of the rotor core 100, and the multiple magnetic barrier holes are symmetrically arranged about the d-axis.

[0025] To further optimize the electromagnetic performance of the rotor, multiple magnetic barrier holes are set in a specific area between the magnet slot 110 and the outer peripheral wall of the rotor core 100. These magnetic barrier holes, as key magnetic circuit optimization structures of the rotor core 100, can effectively block stray magnetic fields from forming eddy current loops inside the rotor, reducing energy loss during motor operation. It is worth noting that the multiple magnetic barrier holes are symmetrically arranged about the d-axis of the rotor, which is the central axis of the main magnetic field generated by the permanent magnet. This symmetrical layout ensures that the magnetic circuit parameters on both sides of the d-axis are perfectly matched, so that the rotor maintains a stable magnetic field distribution during rotation, thereby improving the smoothness of motor operation and control accuracy.

[0026] The magnetic barrier holes include a first magnetic barrier hole 120 and a second magnetic barrier hole 130 located on the same side of the d-axis; the first magnetic barrier hole 120 has a first end facing the q-axis and a second end facing the d-axis, and the width of the first end of the first magnetic barrier hole 120 is smaller than the width of the second end; the second magnetic barrier hole 130 has a first end facing the magnet slot 110 and a second end facing the outer peripheral wall of the rotor core 100, and the width of the first end of the second magnetic barrier hole 130 is smaller than the width of the second end.

[0027] Both the first magnetic barrier hole 120 and the second magnetic barrier hole 130 are located in the leakage magnetic concentration area of ​​the rotor core 100, that is, at both ends of the permanent magnet and the outer peripheral edge of the rotor core 100. Specifically, the first magnetic barrier hole 120 is located on the side of the magnetic pole region closer to the q-axis, while the second magnetic barrier hole 130 is located on the side of the magnetic pole region closer to the d-axis. The second end of the first magnetic barrier hole 120 faces the d-axis, while the second end of the second magnetic barrier hole 130 faces the outer peripheral wall of the rotor core 100. Since the width of the second end of the first magnetic barrier hole 120 is greater than the width of its first end, and the width of the second end of the second magnetic barrier hole 130 is greater than the width of its first end, the first magnetic barrier hole 120 can block the axial leakage magnetic flux at the end of the permanent magnet, while the second magnetic barrier hole 130 can block the radial leakage magnetic flux at the edge of the rotor core 100.

[0028] Furthermore, the first magnetic barrier hole can regulate the magnetic field lines near the q-axis and d-axis, avoiding chaotic magnetic field distribution. It can suppress harmonic components in the air gap magnetic field, making the air gap magnetic flux density waveform closer to a sine wave, thereby reducing the harmonic distortion rate of the armature back electromotive force, reducing torque pulsation and noise during motor operation, and improving operational stability.

[0029] Permanent magnets in the magnet slots are prone to magnetic leakage during operation, which reduces the efficiency of magnetic field utilization. The second magnetic barrier holes are distributed along the magnet slots and the outer peripheral wall of the rotor core, forming a magnetic barrier structure. This blocks the ineffective leakage of magnetic lines of force from the permanent magnets to the outer periphery of the rotor core, forcing more magnetic lines of force to be transmitted to the stator through the air gap, thereby improving the utilization rate of permanent magnet torque and reducing the amount of permanent magnets required for the same output power.

[0030] In this embodiment, both the first magnetic barrier hole 120 and the second magnetic barrier hole 130 are located in the leakage magnetic concentration area of ​​the rotor core 100. Through their combined action, they achieve full-area magnetic flux shaping. The first magnetic barrier hole 120 blocks the axial leakage magnetic flux at the end of the permanent magnet, and the second magnetic barrier hole 130 blocks the radial leakage magnetic flux at the edge of the rotor core 100. This effectively improves the harmonics of cogging torque and back EMF, and reduces noise and vibration. Under the same torque, it reduces phase current and copper losses.

[0031] Example 2: This embodiment makes further structural optimizations based on Embodiment 1. Please refer to... Figure 3 Based on the above Figures 4-8 .

[0032] In this embodiment, a first shaving arc 140 is formed on the outer peripheral wall of the rotor core 100 at the position corresponding to the first magnetic barrier hole 120; the first magnetic barrier hole 120 has a first sidewall 121 and a second sidewall 122 parallel to the first shaving arc 140, and a third sidewall 123 parallel to the magnet slot 110; the first sidewall 121 connects the third sidewall 123 and the second end of the first magnetic barrier hole 120, the third sidewall 123 connects the first end of the first magnetic barrier hole 120, and the second sidewall 122 connects the first end and the second end of the first magnetic barrier hole 120; the second sidewall 122 is located on the side of the first magnetic barrier hole 120 close to the first shaving arc 140.

[0033] Specifically, forming a first shaving 140 on the outer peripheral wall of the rotor core 100 can improve the electromagnetic performance of the motor and enhance its operational stability and efficiency. For example... Figure 3 As shown, R is the maximum outer diameter of the rotor core 100. The first shaving arc 140 is formed by cutting along the maximum outer diameter R. The first shaving arc 140 corresponds to the position of the first magnetic barrier hole 120. As can be seen from Embodiment 1, the first magnetic barrier hole 120 is located on the side of the magnetic pole region close to the q axis and is symmetrically distributed relative to the d axis. Therefore, it is equivalent to that the first magnetic barrier hole 120 is opened on both sides of the q axis between two adjacent magnetic pole regions, and the first shaving arc 140 is formed on the outer peripheral wall of the rotor core 100 at the position of the first magnetic barrier hole 120 on both sides of the q axis.

[0034] By forming the first shaving arc 140 in the aforementioned specific area, the local air gap length can be adjusted as needed. For example, if the air gap is increased at the first shaving arc 140, the magnetic reluctance will be increased accordingly, which can suppress the harmonic components in the air gap magnetic flux density and make the magnetic flux density distribution closer to a sine wave, thereby effectively reducing torque pulsation and improving the smoothness of motor operation.

[0035] Designing the first sidewall 121 and the second sidewall 122 of the first magnetic barrier hole 120 to be parallel to the first slash 140 allows the first magnetic barrier hole 120 to be arranged along the circumferential magnetic field transition direction of the rotor, effectively blocking the circumferential eddy current path on the rotor surface and reducing rotor eddy current losses during high-speed rotation. Designing the third sidewall 123 of the first magnetic barrier hole 120 to be parallel to the magnetic steel groove 110 allows the first magnetic barrier hole 120 to be arranged along the extension direction of the permanent magnet's magnetic field, precisely blocking the lateral leakage magnetic flux diffusing from the end of the permanent magnet to adjacent magnetic poles, forcing more main magnetic flux to enter the stator radially through the air gap, and improving magnetic energy utilization.

[0036] In some embodiments, the shortest distance between the first sidewall 121 and the first slashed arc 140 is d1, the shortest distance between the second sidewall 122 and the first slashed arc 140 is d2, and the shortest distance between the second end of the second magnetic barrier hole 130 and the extension line of the first slashed arc 140 is d3.

[0037] The shortest distance d1 between the first sidewall 121 and the first slash 140 and the shortest distance d2 between the second sidewall 122 and the first slash 140 satisfy the following relationship: 1.8 < d2 < 3.1d1 ≤ 1.85; the shortest distance d3 between the second end of the second magnetic barrier hole 130 and the extension line of the first slash 140 satisfies the following relationship: 2.02 < d3 ≤ 2.05.

[0038] The relationship between the shortest distance d1 between the first sidewall 121 and the first shaving arc 140 and the shortest distance d2 between the second sidewall 122 and the first shaving arc 140 is essentially a dual and precise control of the air gap length in the pole shoe region and the magnetic resistance distribution inside the rotor, which together form a complementary magnetic circuit optimization effect.

[0039] Specifically, the first magnetic barrier hole 120 and the second magnetic barrier hole 130 block leakage magnetic flux and eddy current paths inside the rotor. The corresponding first shaving arc 140 increases the magnetic reluctance in the pole shoe region by increasing the local air gap. Limiting the distance between the first magnetic barrier hole 120, the second magnetic barrier hole 130, and the first shaving arc 140 allows the internal magnetic reluctance blocking of the first magnetic barrier hole 120 and the second magnetic barrier hole 130 to form a synergistic region with the external air gap magnetic reluctance increase of the first shaving arc 140. This region corresponds precisely to the magnetic field transition zone between permanent magnet poles. By precisely controlling the distance, the distribution of air gap magnetic flux density can be made closer to a sine wave, effectively suppressing harmonic components and thus reducing torque pulsation and operating noise. If the distance is too large, the air gap regulation effect of the first shaving arc 140 cannot synergize with the internal magnetic reluctance optimization of the magnetic barrier hole, and the magnetic flux density harmonic suppression effect in the pole shoe region will be significantly weakened. If the distance is too small, it will lead to excessively high local magnetic reluctance, obstructing the main magnetic flux conduction and reducing the motor output torque.

[0040] In some embodiments, the length of the first shaving arc 140 is L, the length of the first sidewall 121 is L1, and the length of the second sidewall 122 is L2.

[0041] The length L of the first slashed arc 140 and the length L1 of the first sidewall 121 satisfy the following relationship: 0.0876L≤L1<0.0878L; the length L of the first slashed arc 140 and the length L2 of the second sidewall 122 satisfy the following relationship: 0.211L≤L2<0.212L.

[0042] Specifically, the first sidewall 121 and the second sidewall 122, through the air medium inside the rotor, block the transverse magnetic leakage and circumferential eddy current paths inside the rotor core 100, and their lengths determine the circumferential coverage range. The length L of the first shaving arc 140 determines the circumferential coverage range of the external air gap magnetic reluctance enhancement, that is, the length of the magnetic field transition region optimized by the shaving arc in the pole shoe region. Therefore, by limiting the relationship between the length L of the first shaving arc 140 and the length L1 of the first sidewall 121 to the range of 0.0876L≤L1<0.0878L, and by limiting the relationship between the length L of the first shaving arc 140 and the length L2 of the second sidewall 122 to the range of 0.211L≤L1<0.212, the magnetic reluctance blocking range of the first magnetic barrier hole 120 inside the rotor can completely overlap or highly cover the magnetic reluctance enhancement range of the first shaving arc 140 outside the air gap, forming a globally coordinated magnetic reluctance optimization region. This region corresponds precisely to the magnetic field transition zone between the permanent magnet poles, which can suppress magnetic flux density harmonics from the inside out and avoid optimization blind spots caused by the mismatch in length between the two. For example, if the first shaving arc 140 is too long and the first sidewall 121 or the second sidewall 122 is too short, some shaving arc areas will lack the cooperation of internal magnetic barriers, and the harmonic suppression effect will be greatly reduced. Conversely, the leakage magnetic field blocked by the first magnetic barrier hole 120 cannot be further optimized by external shaving arc, and the magnetic energy utilization rate will decrease.

[0043] Furthermore, the lengths of the first sidewall 121 and the second sidewall 122 determine the circumferential range of the internal stress concentration zone, while the length of the first slashed arc 140 determines the circumferential range of the outer peripheral stress concentration zone. Limiting the length relationship between these two dimensions allows the stress distribution ranges of the two weak areas to match, preventing situations where the first slashed arc 140 is too long and the magnetic barrier hole is too short, resulting in stress at the edge of the first slashed arc 140 being unable to be dispersed through the internal structure, or where the magnetic barrier hole is too long and the first slashed arc 140 is too short, causing stress at the end of the first magnetic barrier hole 120 to concentrate in the unoptimized outer peripheral region.

[0044] Furthermore, let H1 be the shortest distance between the third sidewall 123 and the magnetic groove 110, and let H2 be the shortest distance between the first end of the second magnetic barrier hole 130 and the magnetic groove 110.

[0045] The shortest distance H1 between the third sidewall 123 and the magnetic groove 110 satisfies the following relationship: 0.5 < H1 ≤ 0.55; the shortest distance H2 between the first end of the second magnetic barrier hole 130 and the magnetic groove 110 satisfies the following relationship: 0.75 < H2 ≤ 0.8.

[0046] In some embodiments, the area of ​​the permanent magnet is S, the area of ​​the first magnetic barrier hole 120 is S1, and the area of ​​the second magnetic barrier hole 130 is S2. The area S1 of the first magnetic barrier hole 120 and the area S2 of the second magnetic barrier hole 130 satisfy the following relationship: 1.09≤S1 / S2≤1.095; the area S of the permanent magnet, the area S1 of the first magnetic barrier hole 120 and the area S2 of the second magnetic barrier hole 130 satisfy the following relationship: 0.14<(S1+S2)×2 / S≤0.15.

[0047] The area S of the permanent magnet determines its effective magnetomotive force output capability; that is, the larger the area, the greater the total main magnetic flux provided. The areas S1 of the first magnetic barrier hole 120 and S2 of the second magnetic barrier hole 130 determine its total reluctance control capability; that is, the larger the area, the stronger the blocking effect on leakage flux inside the rotor. Limiting the relationship between the area S of the permanent magnet, the area S1 of the first magnetic barrier hole 120, and the area S2 of the second magnetic barrier hole 130 allows for a precise match between the magnetomotive force supply and reluctance control, avoiding imbalances where supply exceeds control or control exceeds supply.

[0048] Specifically, if the area S of the permanent magnet is much larger than the areas S1 and S2 of the first magnetic barrier hole 120 and the second magnetic barrier hole 130, the magnetomotive force provided by the permanent magnet is too large. However, the total magnetic reluctance control capability of the first magnetic barrier hole 120 and the second magnetic barrier hole 130 is insufficient, which cannot effectively block a large amount of transverse leakage magnetic flux, resulting in a decrease in the proportion of main magnetic flux, a significant reduction in motor efficiency and power density, and a substantial increase in eddy current losses caused by leakage magnetic flux.

[0049] If the areas S1 and S2 of the first magnetic barrier hole 120 and the second magnetic barrier hole 130 are much larger than the area S of the permanent magnet, the magnetic reluctance control capability is excessive. Although it can completely block the leakage magnetic flux, it will excessively restrict the conduction path of the main magnetic flux, and may even lead to the saturation of the iron core in the magnetic bridge or pole shoe area. The main magnetic flux cannot effectively enter the stator through the air gap, and the motor output torque is seriously insufficient.

[0050] Here, by reasonably limiting the relationship between the area S of the permanent magnet, the area S1 of the first magnetic barrier hole 120, and the area S2 of the second magnetic barrier hole 130, the dual objectives of controlling the leakage magnetic flux ratio within the design threshold and maximizing the main magnetic flux conduction efficiency can be achieved, ensuring that the magnetic energy utilization rate is at the optimal level.

[0051] In some embodiments, the arc length of the second end of the second magnetic barrier hole 130 relative to the outer peripheral wall of the rotor core 100 is L3; the arc length L3 of the second end of the second magnetic barrier hole 130 relative to the outer peripheral wall of the rotor core 100 satisfies the following relationship: 0.054≤L3<0.055.

[0052] It is known that the first end of the second magnetic barrier hole 130 faces the direction of the magnet slot 110, and the second end faces the outer peripheral wall of the rotor core 100. That is, the second magnetic barrier hole 130 is radially distributed. Its radial outer length, that is, the arc length L3 of the second end of the second magnetic barrier hole 130 relative to the outer peripheral wall of the rotor core 100, directly determines the coverage range of the second magnetic barrier hole 130 in the pole shoe region.

[0053] The pole shoe region is the critical path for the transmission of the main magnetic flux of the permanent magnet to the air gap, and it is also the main transition region for lateral leakage magnetic flux. The arc length L3 of the second end of the second magnetic barrier hole 130 relative to the outer peripheral wall of the rotor core 100 can be used to achieve gradient control of the magnetic reluctance in the pole shoe region.

[0054] If the length is longer, the second magnetic barrier hole 130 is closer to the outer peripheral wall of the rotor core 100. In this case, the second magnetic barrier hole 130 has a larger magnetic reluctance blocking range in the pole shoe region, which can more effectively block the transverse leakage magnetic flux spreading from the end of the permanent magnet to the adjacent magnetic pole, and force the main magnetic flux to enter the air gap radially and vertically, thereby improving the magnetic energy utilization rate. At the same time, the larger coverage range can optimize the magnetic flux density distribution in the pole shoe region, suppress harmonic components, and reduce torque pulsation.

[0055] If the length is relatively short and the second magnetic barrier hole 130 is far from the outer peripheral wall of the rotor core 100, the leakage magnetic blocking effect of the second magnetic barrier hole 130 is concentrated inside the rotor. The magnetic resistance in the pole shoe region is relatively low, and the main magnetic flux conduction is smoother. However, the suppression effect of transverse leakage magnetic flux will be weakened. It is suitable for scenarios with higher requirements for main magnetic flux output and stronger tolerance for torque ripple.

[0056] In this embodiment, the arc length L3 of the second end of the second magnetic barrier hole 130 relative to the outer peripheral wall of the rotor core 100 is limited to a suitable range, which can realize the radial orientation optimization of the magnetic circuit and precisely control the magnetic resistance distribution in the pole shoe region.

[0057] In some embodiments, the first end of the second magnetic barrier hole 130 has a fourth sidewall 131 parallel to the magnetic groove 110, and a fifth sidewall 132 and a sixth sidewall 133 are connected between the fourth sidewall 131 and the second end of the second magnetic barrier hole 130; let the included angle between the fourth sidewall 131 and the fifth sidewall 132 be θ1, and let the included angle between the fourth sidewall 131 and the sixth sidewall 133 be θ2. The included angle θ1 between the fourth sidewall 131 and the fifth sidewall 132 satisfies the following relationship: 86°<θ1≤88°; the included angle θ2 between the fourth sidewall 131 and the sixth sidewall 133 satisfies the following relationship: 100°<θ2≤102°.

[0058] Specifically, the first end of the second magnetic barrier hole 130, which is close to the magnetic groove 110, is a key transition node for the main magnetic flux of the permanent magnet and the lateral leakage magnetic flux to enter the region of the second magnetic barrier hole 130. The limitation of the angle on both sides of this end is essentially a shaping of the magnetic flux inflow path.

[0059] The stress concentration factor at right-angle corners is much higher than that at smooth transition structures. If the second magnetic barrier hole 130 inlet cavity is at a right angle, under the long-term action of centrifugal force and electromagnetic force, microcracks are very likely to be generated at the corner, which will then expand into macro-cracks, eventually leading to the permanent magnet falling off and the rotor failing.

[0060] By rationally limiting the included angle θ1 between the fourth sidewall 131 and the fifth sidewall 132 to 86°<θ1≤88°, and the included angle θ2 between the fourth sidewall 131 and the sixth sidewall 133 to 100°<θ2≤102°, the centrifugal force of the permanent magnet can be transmitted more smoothly to the solid area of ​​the rotor core 100 through the sidewall of the magnet slot 110, avoiding deformation of the sidewall of the magnet slot 110 due to stress concentration, and thus preventing displacement or loosening of the permanent magnet during rotation.

[0061] In some embodiments, the second end of the first magnetic barrier hole 120 is arc-shaped; let the angle between the tangent side of the arc and the d-axis be θ3; the angle θ3 between the tangent side of the arc and the d-axis satisfies the following relationship: 18.65°<θ3≤18.75°.

[0062] Specifically, the d-axis is the core direction of the main magnetic flux of the permanent magnet, and the magnetic flux density harmonics mainly originate from the non-uniform magnetic reluctance distribution in the main magnetic flux path. The limitation of the angle θ3 between the arc-shaped tangent and the d-axis makes the transition between the first magnetic barrier hole 120 and the main magnetic flux path of the d-axis smoother.

[0063] If the angle design is unreasonable, such as being too large or too small, it will cause a sudden change in magnetic reluctance, which will form a local magnetic concentration in the d-axis magnetic circuit, triggering additional harmonic components and exacerbating torque pulsation.

[0064] Here, by limiting the optimal angle, the regulation of the d-axis magnetic reluctance by the first magnetic barrier hole 120 can be made to change in a gradient, avoiding sudden changes in magnetic reluctance, effectively suppressing d-axis magnetic flux density harmonics, and reducing torque pulsation and operating noise.

[0065] See Figures 6-8 , Figure 6 A comparison chart of the proposed solutions has been set up, including the background technologies. Figure 1 The rotor with a non-magnetic barrier hole structure shown in the background art Figure 2 The rotor shown includes a conventional magnetic barrier hole structure, a rotor with only one set of first magnetic barrier holes 120, a rotor with only one set of second magnetic barrier holes 130, and the rotor provided in this embodiment; Figure 7 for Figure 6 The following is a comparison of the no-load back EMF waveforms of the five schemes shown;Figure 8 for Figure 6 The diagram shows a comparison of the five schemes for converting tooth grooves to rectangles under no-load conditions.

[0066] Depend on Figure 7 and Figure 8 It can be seen that the rotor provided in this embodiment has the highest effective value of back EMF and the lowest value of cogging torque.

[0067] Example 3: This embodiment provides a motor based on embodiment 1 or 2, including the rotor in embodiment 1 or 2.

[0068] The motor provided in this embodiment, after applying the above-mentioned rotor, can effectively improve the harmonics of cogging torque and back EMF, reduce noise and vibration, and reduce phase current and copper loss under the same torque.

[0069] The above description is merely an example and illustration of the structure of this invention, and while the description is specific and detailed, it should not be construed as limiting the scope of this invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this invention, and these obvious substitutions all fall within the protection scope of this invention.

Claims

1. A rotor, characterized in that, Including rotor core (100); In a cross section perpendicular to the rotation axis of the rotor core (100), a plurality of I-shaped magnetic steel slots (110) are distributed along the circumference of the rotor core (100), and permanent magnets are installed in the magnetic steel slots (110). A plurality of magnetic barrier holes are provided between the magnetic steel groove (110) and the outer peripheral wall of the rotor core (100), and the plurality of magnetic barrier holes are symmetrically arranged about the d-axis; The magnetic barrier holes include a first magnetic barrier hole (120) and a second magnetic barrier hole (130) located on the same side of the d-axis. The first magnetic barrier hole (120) has a first end facing the q-axis and a second end facing the d-axis, and the width of the first end of the first magnetic barrier hole (120) is smaller than the width of the second end; The second magnetic barrier hole (130) has a first end facing the magnet slot (110) and a second end facing the outer peripheral wall of the rotor core (100), and the width of the first end of the second magnetic barrier hole (130) is smaller than the width of the second end.

2. The rotor according to claim 1, characterized in that, A first nicked arc (140) is formed on the outer peripheral wall of the rotor core (100) at the position corresponding to the first magnetic barrier hole (120). The first magnetic barrier hole (120) has a first sidewall (121) and a second sidewall (122) parallel to the first slashed arc (140), and a third sidewall (123) parallel to the magnetic groove (110). The first sidewall (121) connects the third sidewall (123) and the second end of the first magnetic barrier hole (120), the third sidewall (123) connects the first end of the first magnetic barrier hole (120), and the second sidewall (122) connects the first end and the second end of the first magnetic barrier hole (120). The second sidewall (122) is located on the side of the first magnetic barrier hole (120) near the first shaving arc (140).

3. The rotor according to claim 2, characterized in that, wherein... The shortest distance between the first sidewall (121) and the first shaving arc (140) is d1, the shortest distance between the second sidewall (122) and the first shaving arc (140) is d2, and the shortest distance between the second end of the second magnetic barrier hole (130) and the extension line of the first shaving arc (140) is d3. The d1 and d2 satisfy the following relationship: 1.8 < d2 < 3.1d1 ≤ 1.85; The d3 satisfies the following relationship: 2.02 < d3 ≤ 2.

05.

4. The rotor according to claim 2, characterized in that, wherein... The length of the first shaving arc (140) is L, the length of the first sidewall (121) is L1, and the length of the second sidewall (122) is L2; The L and L1 satisfy the following relationship: 0.0876L≤L1<0.0878L; The L and L2 satisfy the following relationship: 0.211L≤L2<0.212L.

5. The rotor according to claim 2, characterized in that, wherein... The shortest distance between the third sidewall (123) and the magnetic groove (110) is H1, and the shortest distance between the first end of the second magnetic barrier hole (130) and the magnetic groove (110) is H2. H1 satisfies the following relationship: 0.5 < H1 ≤ 0.55; The H2 satisfies the following relationship: 0.75 < H2 ≤ 0.

8.

6. The rotor according to claim 1, characterized in that, wherein... The area of ​​the permanent magnet is S, the area of ​​the first magnetic barrier hole (120) is S1, and the area of ​​the second magnetic barrier hole (130) is S2. The S1 and S2 satisfy the following relationship: 1.09≤S1 / S2≤1.095; The S, S1, and S2 satisfy the following relationship: 0.14 < (S1 + S2) × 2 / S ≤ 0.

15.

7. The rotor according to claim 1, characterized in that, Let L3 be the arc length of the second end of the second magnetic barrier hole (130) relative to the outer peripheral wall of the rotor core (100); The L3 satisfies the following relationship: 0.054≤L3<0.

055.

8. The rotor according to claim 1, characterized in that, The first end of the second magnetic barrier hole (130) has a fourth sidewall (131) parallel to the magnetic groove (110), and a fifth sidewall (132) and a sixth sidewall (133) are connected between the fourth sidewall (131) and the second end of the second magnetic barrier hole (130). Let the angle between the fourth sidewall (131) and the fifth sidewall (132) be θ1, and let the angle between the fourth sidewall (131) and the sixth sidewall (133) be θ2; The θ1 satisfies the following relationship: 86°<θ1≤88°; The θ2 satisfies the following relationship: 100°<θ2≤102°.

9. The rotor according to claim 1, characterized in that, The second end of the first magnetic barrier hole (120) is arc-shaped; Let the angle between the tangent edge of the arc and the d-axis be θ3; The θ3 satisfies the following relationship: 18.65°<θ3≤18.75°.

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

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