Motor rotor with magnetic barrier, motor and compressor

Abstract

The application discloses a motor rotor with magnetic barriers, a motor and a compressor, wherein the motor rotor with magnetic barriers comprises a rotor core, a plurality of curved slots and a plurality of magnetic barrier groups; the plurality of curved slots are arranged at the rotor core and are arranged at intervals along the circumferential direction of the rotor core, and the two ends of the curved slots extend towards the edges of the rotor core; the plurality of magnetic barrier groups are arranged on the side of the plurality of curved slots away from the center of the rotor core, and each magnetic barrier group comprises a plurality of magnetic barrier holes arranged at intervals along the extension direction of the slot wall of the curved slot; the included angle between the two ends of one layer of magnetic barrier holes and the line between the center of the rotor core is a, and a satisfies a >= (1 / 8)*(2pi / p), wherein p is the pole number of the motor in which the motor rotor with magnetic barriers is arranged. The motor rotor with magnetic barriers can improve the motor efficiency by improving the magnetic resistance torque, thereby reducing the amount of rare earth permanent magnets.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a motor rotor with magnetic barriers, a motor, and a compressor. Background Technology

[0002] A permanent magnet synchronous motor (IPM) is a type of motor that has a layer of permanent magnets placed inside the rotor and mainly utilizes permanent magnet torque, with reluctance torque as an auxiliary.

[0003] The formula for combining reluctance torque and permanent magnet torque is as follows:

[0004] T=mp*(Lq-Ld)*id*iq+mp*ψPM*iq. in,

[0005] T represents the output torque of the motor. Increasing the value of T can improve the motor performance. The first term in the equation after T is the reluctance torque, and the second term is the permanent magnet torque. ΨPM is the maximum value of the stator-rotor coupling magnetic flux generated by the permanent magnet of the motor. m is the number of phases of the stator conductor. Ld and Lq are the d-axis and q-axis inductances, respectively. The d-axis refers to the axis that coincides with the axis of the main magnetic pole, and the q-axis refers to the axis that is perpendicular to the axis of the main magnetic pole. The perpendicularity refers to the electrical angle. id and iq are the components of the armature current in the d-axis and q-axis directions, respectively.

[0006] Current technologies primarily improve motor performance by enhancing the performance of permanent magnets, specifically by increasing the output torque of the permanent magnets, thereby improving motor efficiency. A common approach is to incorporate rare-earth permanent magnets. However, the widespread application of this type of motor is limited because rare-earth elements are non-renewable resources and expensive. Furthermore, simply improving permanent magnet performance alone cannot meet the urgent need for further increases in motor efficiency. Additionally, most current motors employ two or more layers of permanent magnets, leading to high costs, weak demagnetization resistance, and impacting production cycle time and rotor performance. Summary of the Invention

[0007] The main objective of this invention is to propose a motor rotor with magnetic barriers, which aims to improve motor efficiency by increasing reluctance torque, thereby reducing the amount of rare earth permanent magnets used.

[0008] To achieve the above objectives, the present invention proposes a motor rotor with magnetic barriers, wherein the motor rotor with magnetic barriers comprises:

[0009] Rotor core;

[0010] Multiple curved slots are disposed on the rotor core and arranged at circumferential intervals along the rotor core, with both ends of the curved slots extending toward the edge of the rotor core; and

[0011] Multiple magnetic barrier groups are disposed on the side of the multiple curved slots away from the center of the rotor core. Each magnetic barrier group includes at least one layer of magnetic barrier holes spaced apart along the d-axis direction of the rotor of the motor with magnetic barriers. The number of magnetic barrier holes in one layer is set to be multiple. The multiple magnetic barrier holes are spaced apart along the extension direction of the slot wall of the curved slot. The angle formed by the lines connecting the two ends of the magnetic barrier holes in one layer to the center of the rotor core is α, which satisfies α≥(1 / 8)*(2π / p), where p is the number of poles of the motor where the rotor of the motor with magnetic barriers is located.

[0012] In one embodiment, the groove has a first sidewall and a second sidewall disposed opposite to each other, both the first sidewall and the second sidewall protruding toward the center of the rotor core.

[0013] In one embodiment, a straight-axis magnetic channel is formed between any two adjacent magnetic barrier holes in one layer of magnetic barrier holes.

[0014] In one embodiment, the motor rotor with magnetic barriers further includes a plurality of permanent magnets, which are mounted on a plurality of grooves.

[0015] In one embodiment, the permanent magnet has a thickness T in the d-axis direction of the motor rotor with magnetic barriers. The magnetic barrier hole has a first side and a second side disposed opposite to each other. The second side is located on the side of the first side away from the center of the rotor core. The distance from the first side to the second side is the thickness H of the magnetic barrier hole, satisfying T > H.

[0016] In one embodiment, in a cross section perpendicular to the axial direction of the motor rotor with magnetic barriers, the thickness of the middle portion of the permanent magnet is greater than the thickness of the two ends of the permanent magnet.

[0017] In one embodiment, there is a gap between the two ends of the permanent magnet and the two ends of the groove into which it is embedded, the gap being used to fill a non-magnetic medium.

[0018] In one embodiment, the groove is U-shaped.

[0019] In one embodiment, the groove is arranged in a V-shape.

[0020] In one embodiment, the groove is arranged in an arc shape.

[0021] The present invention also proposes an electric motor, the electric motor comprising a motor rotor with magnetic barriers and a stator sleeved on the outside of the motor rotor with magnetic barriers, the stator comprising a stator core and windings wound on stator teeth. The motor rotor with magnetic barriers comprises a rotor core, a plurality of curved slots and a plurality of magnetic barrier groups; the plurality of curved slots are disposed on the rotor core and are arranged at intervals along the circumference of the rotor core, the two ends of the curved slots extending toward the edge of the rotor core; the plurality of magnetic barrier groups are disposed on the side of the plurality of curved slots away from the center of the rotor core, the magnetic barrier group comprising at least one layer of magnetic barrier holes arranged at intervals along the d-axis direction of the motor rotor with magnetic barriers, the number of magnetic barrier holes in one layer being multiple, the plurality of magnetic barrier holes being arranged at intervals along the extension direction of the slot wall of the curved slot; the angle formed by the lines connecting the two ends of the magnetic barrier holes in one layer to the center of the rotor core is α, satisfying α≥(1 / 8)*(2π / p), where p is the number of poles of the motor in which the motor rotor with magnetic barriers is located.

[0022] Optionally, the thickness of the motor rotor with magnetic barriers along its axial direction is not less than the thickness of the stator along its axial direction.

[0023] The present invention also proposes a compressor, the compressor including a motor, the motor including a motor rotor having magnetic barriers, and a stator sleeved on the outside of the motor rotor having magnetic barriers, the stator including a stator core and windings wound on stator teeth. The motor rotor with magnetic barriers includes a rotor core, multiple curved slots, and multiple magnetic barrier groups. The multiple curved slots are disposed on the rotor core and are arranged at intervals along the circumference of the rotor core, with both ends of the curved slots extending toward the edge of the rotor core. The multiple magnetic barrier groups are disposed on the side of the multiple curved slots away from the center of the rotor core. Each magnetic barrier group includes at least one layer of magnetic barrier holes arranged at intervals along the d-axis direction of the motor rotor with magnetic barriers. The number of magnetic barrier holes in one layer is set to be multiple, and the multiple magnetic barrier holes are arranged at intervals along the extension direction of the slot wall of the curved slot. The angle formed by the lines connecting the two ends of the magnetic barrier holes in one layer to the center of the rotor core is α, which satisfies α ≥ (1 / 8) * (2π / p), where p is the number of poles of the motor in which the motor rotor with magnetic barriers is located.

[0024] The present invention discloses a motor rotor with magnetic barriers, comprising a rotor core, multiple curved slots, and multiple magnetic barrier groups. The multiple curved slots are disposed on the rotor core and arranged at intervals along the circumference of the rotor core, with both ends of the curved slots extending toward the edge of the rotor core. The multiple magnetic barrier groups are disposed on the side of the multiple curved slots away from the center of the rotor core. Each magnetic barrier group includes at least one layer of magnetic barrier holes arranged at intervals along the d-axis direction of the motor rotor with magnetic barriers. The number of magnetic barrier holes in one layer is multiple, and the multiple magnetic barrier holes are arranged at intervals along the extension direction of the slot wall. The angle formed by the lines connecting the two ends of each magnetic barrier hole in one layer to the center of the rotor core is α, satisfying α ≥ (1 / 8) * (2π / p), where p is the number of poles of the motor in which the motor rotor with magnetic barriers is located. When the included angle α satisfies a≥(1 / 8)*(2π / p), the q-axis inductance of the motor rotor can be significantly increased, which increases the difference in inductance between the d-axis and q-axis, further improving the reluctance torque and resulting in a larger electromagnetic torque per unit current, thereby increasing the motor's efficiency. The curved slot in this invention is mainly used to place permanent magnets, and the curved slot is designed as a single-layer structure, which increases the thickness of the permanent magnets placed in the slot, thereby improving the permanent magnets' resistance to demagnetization and ensuring the reliability of the motor. At the same time, the amount of permanent magnets used in a single-layer curved slot is reduced compared to a double-layer structure, thus reducing the production cost of the motor rotor. Furthermore, the production efficiency of a single-layer curved slot motor rotor is also higher than that of a double-layer curved slot motor rotor. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a structural embodiment of the motor rotor with magnetic barriers of the present invention;

[0027] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0028] Figure 3 This is a schematic diagram of another embodiment of the motor rotor with magnetic barriers of the present invention;

[0029] Figure 4 This is a schematic diagram showing the relationship between the output torque of the motor of the present invention and the range of the included angle α.

[0030] Explanation of icon numbers:

[0031] label name label name 10 Motor rotor with magnetic barrier 310 Magnetic barrier hole 100 Rotor core 311 First side 200 Curved groove 312 Second side 210 First side wall 400 Direct-axis magnetic channel 220 Second side wall 500 permanent magnet 300 Magnetic barrier group 600 Cross-axis magnetic channel

[0032] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0035] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0036] This invention proposes an embodiment of a motor rotor with magnetic barriers, namely, a permanent magnet assisted synchronous reluctance motor rotor, mainly used in air conditioning compressors, electric vehicles, and fan systems. Synchronous reluctance motors have multiple layers of rotor magnetic barriers and operate by relying on reluctance torque generated by rotor magnetic circuit asymmetry. This type of motor has advantages such as low cost, simple manufacturing, and low rotor losses, but it suffers from disadvantages such as low power factor and torque density, and large torque ripple. To improve the torque and power factor of this type of motor, a certain amount of low-performance permanent magnets (ferrite or bonded neodymium iron boron) can be inserted into the rotor magnetic barriers to assist excitation, thereby reducing the excitation component of the motor current and generating permanent magnet torque. This is the permanent magnet assisted synchronous reluctance motor.

[0037] When designing permanent magnets in magnetic barriers, the influence of permanent magnet flux on the degree of magnetic circuit saturation needs to be considered. High permanent magnet flux easily leads to magnetic circuit saturation, reducing the rotor's saliency ratio; while low flux has a smaller impact on improving torque and power factor. Although low-performance permanent magnets have lower coercivity, their demagnetization curves exhibit better linearity.

[0038] The formula for combining reluctance torque and permanent magnet torque is as follows:

[0039] T=mp*(Lq-Ld)*id*iq+mp*ψPM*iq. in,

[0040] T represents the motor's output torque. Increasing the value of T improves motor performance. The first term in the equation after T is the reluctance torque, and the second term is the permanent magnet torque. ΨPM is the maximum value of the stator-rotor coupling flux generated by the permanent magnets. m is the number of phases of the stator conductors. Ld and Lq are the d-axis and q-axis inductances, respectively. The d-axis is the axis coinciding with the main magnetic pole axis, and the q-axis is the axis perpendicular to the main magnetic pole axis, where perpendicularity refers to the electrical angle. id and iq are the components of the armature current in the d-axis and q-axis directions, respectively. According to the formula, increasing the difference between Ld and Lq inductances and ψpm both increase the output torque. That is, while keeping either the reluctance torque or the permanent magnet torque constant, increasing the other can increase the motor's total output torque, thereby improving the motor's efficiency.

[0041] Current technologies primarily improve motor performance by enhancing the performance of permanent magnets, specifically by increasing the output torque of the permanent magnets, thereby improving motor efficiency. A common approach is to incorporate rare-earth permanent magnets. However, the widespread application of this type of motor is limited because rare-earth elements are non-renewable resources and expensive. Furthermore, simply improving permanent magnet performance alone cannot meet the urgent need for further increases in motor efficiency. Additionally, most current motors employ two or more layers of permanent magnets, leading to high costs, weak demagnetization resistance, and impacting production cycle time and rotor performance.

[0042] Please see Figures 1 to 3In one embodiment of the present invention, the motor rotor 10 with magnetic barriers includes a rotor core 100, a plurality of curved slots 200, and a plurality of magnetic barrier groups 300; the plurality of curved slots 200 are disposed on the rotor core 100 and arranged at intervals along the circumference of the rotor core 100, with both ends of the curved slots extending toward the edge of the rotor core 100; the plurality of magnetic barrier groups 300 are disposed on the side of the plurality of curved slots 200 away from the center of the rotor core 100, and the magnetic barrier groups 300 encompass... The system includes at least one layer of magnetic barrier holes 310 spaced along the d-axis of the motor rotor 10 with magnetic barriers. The number of magnetic barrier holes 310 in one layer is set to be multiple. The multiple magnetic barrier holes 310 are spaced along the extension direction of the groove wall of the curved groove 200. The included angle between the two ends of the magnetic barrier holes 310 and the center of the rotor core 100 is α, which satisfies α≥(1 / 8)*(2π / p), where p is the number of poles of the motor where the motor rotor 10 with magnetic barriers is located.

[0043] Specifically, the motor rotor includes a rotor core 100 and a permanent magnet 500. The rotor core 100 is formed by stacking silicon steel plates and has a certain stacking height. The rotor core 100 is driven by the magnetic force of the permanent magnet 500, allowing the motor rotor to rotate relative to the motor stator, thus achieving normal motor operation. The rotor core 100 is formed by stacking high-permeability materials or silicon steel laminations, resulting in high magnetic flux, high structural strength, and ease of processing.

[0044] Multiple curved slots 200 are formed on the rotor core 100. The curved slots 200 are curved in shape, and may have one or more curved sections; there is no specific limitation. When a curved slot 200 has multiple curved sections, its shape is roughly wavy. The multiple curved slots 200 are arranged at intervals along the circumference of the rotor core 100, specifically evenly distributed around the center of the rotor core 100. The two ends of each curved slot 200 extend towards the edge of the rotor core 100, forming an area between them and the edge of the rotor core 100 for mounting multiple magnetic barrier groups 300. The multiple magnetic barrier groups 300 are located on the side of each curved slot 200 away from the center of the rotor core 100. It should be noted that the curved slots 200 are mainly used to mount permanent magnets 500, and since permanent magnets 500 have magnetic poles, the number of curved slots 200 is set to an even number, such as... Figure 1As shown, six curved slots 200 are arranged circumferentially around the rotor core 100. Each curved slot 200 contains at least one permanent magnet 500. The permanent magnets 500 in any two adjacent curved slots 200 have opposite polarities. The permanent magnets 500 are distributed alternately with N and S poles along the circumference of the rotor core 100. In this embodiment, the curved slots 200 are configured as a single-layer structure. Compared to the double-layer structure of motor rotors in the prior art, placing permanent magnets 500 in the single-layer curved slots 200 allows for increased thickness of the permanent magnets 500 within a limited volume, thereby improving the demagnetization resistance of the permanent magnets 500 and enhancing the reliability of the motor. Simultaneously, the production efficiency of the single-layer curved slot structure motor rotor is also higher. Furthermore, the number of permanent magnets 500 required in the single-layer curved slots 200 is relatively reduced, resulting in a lower overall usage of permanent magnets 500. Therefore, the production cost of the rotor can be further reduced, thereby lowering the production cost of the motor.

[0045] The magnetic barrier group 300 includes at least one layer of magnetic barrier holes 310 spaced apart along the extension direction of the groove wall of the curved groove 200. The number of magnetic barrier holes 310 in one layer is multiple. The magnetic barrier holes 310 can be filled with air or other non-magnetic materials. The groove wall of the curved groove 200 can be a first sidewall 210 near the edge of the rotor core 100, or a second sidewall 220 near the center of the rotor core 100. The extension directions of the first sidewall 210 and the second sidewall 220 can be the same or different. In this embodiment, the extension directions of the first sidewall 210 and the second sidewall 220 are approximately the same. Therefore, the multiple magnetic barrier holes 310 are spaced apart along the extension direction of the first sidewall 210 or the extension direction of the second sidewall 220 of the curved groove 200. A direct-axis magnetic channel 400 is formed between two adjacent magnetic barrier holes 310. The magnetic reluctance of the direct-axis magnetic channel 400 in the d-axis direction is small, resulting in high magnetic flux and large inductance Ld. Meanwhile, the magnetic reluctance in the q-axis direction, which is located at the center line of the magnetic barrier hole 310, is very high, resulting in small inductance Lq. This increases the inductance difference between the d-axis and q-axis directions, thereby improving the torque output capability of the motor. On the other hand, the magnetic barrier hole 310 is located between the first sidewall 210 of the curved groove 200 and the edge of the rotor core 100. This reduces the impact on the permanent magnet force, regulates the magnetic field line path, weakens magnetic field harmonics in the air gap, and alleviates magnetic saturation. During the rotation of the motor rotor, a magnetic barrier is formed to improve the power density and torque density of the motor, enhance the motor's overload capacity, and effectively improve the motor's torque pulsation. This significantly improves motor performance and enhances product competitiveness while reducing the amount of permanent magnet 500 used in the motor, thus reducing production costs.

[0046] Please see Figure 1 and Figure 4 The angle between the two ends of the magnetic barrier hole 310 and the center of the rotor core 100 is α. When the angle α satisfies α≥(1 / 8)*(2π / p) (p is the number of poles of the motor where the motor rotor 10 with magnetic barrier is located), the q-axis inductance of the motor rotor can be significantly improved, which can increase the difference between the inductances of the motor d-axis and q-axis, which is more conducive to improving the reluctance torque of the motor, so that a larger electromagnetic torque is generated per unit current, thereby improving the efficiency of the motor.

[0047] The present invention provides a motor rotor 10 with magnetic barriers, comprising a rotor core 100, a plurality of curved slots 200, and a plurality of magnetic barrier groups 300. The plurality of curved slots 200 are disposed on the rotor core 100 and arranged at intervals along the circumference of the rotor core 100, with both ends of each curved slot extending toward the edge of the rotor core 100. The plurality of magnetic barrier groups 300 are disposed on the side of the plurality of curved slots away from the center of the rotor core 100, and the magnetic barrier groups 300 include those along... The rotor 10 of the motor with magnetic barriers has at least one layer of magnetic barrier holes 310 spaced apart along the d-axis direction. Multiple magnetic barrier holes 310 are arranged in one layer, spaced apart along the circumference of the rotor core 100. The angle α formed by the lines connecting the two ends of each magnetic barrier hole 310 to the center of the rotor core 100 satisfies α ≥ (1 / 8)*(2π / p), where p is the number of poles of the motor containing the magnetic barrier rotor 10. When the angle α satisfies α ≥ (1 / 8)*(2π / p), the q-axis inductance of the motor rotor can be significantly increased, leading to a larger difference in inductance between the d-axis and q-axis. This is more conducive to increasing the reluctance torque of the motor, resulting in a larger electromagnetic torque per unit current, thereby improving the efficiency of the motor. The curved groove 200 in this invention is mainly used to house the permanent magnet 500. The curved groove 200 is designed as a single-layer structure, which increases the thickness of the permanent magnet 500 placed within it, thereby improving the demagnetization resistance of the permanent magnet 500 and ensuring the reliability of the motor. Simultaneously, the amount of permanent magnet 500 used in the single-layer curved groove 200 is reduced compared to the double-layer structure, thus lowering the production cost of the motor rotor. Furthermore, the single-layer curved groove 200 structure motor rotor also has higher production efficiency compared to the double-layer curved groove 200 structure.

[0048] Please see Figure 1Based on the above embodiments, the curved groove 200 has a first sidewall 210 and a second sidewall 220 arranged opposite to each other, and both the first sidewall 210 and the second sidewall 220 protrude toward the center of the rotor core 100. Specifically, the curved groove 200 has a first sidewall 210 and a second sidewall 220 arranged opposite to each other. The first sidewall 210 is arranged close to the center of the rotor core 100, and the second sidewall 220 is arranged away from the center of the rotor core 100. Since the magnetic barrier group 300 includes at least one layer of magnetic barrier holes 310 arranged circumferentially along the rotor core 100, and the number of magnetic barrier holes 310 is set to multiple, the arrangement of multiple magnetic barrier holes 310 requires a certain space. The second sidewall 220 is arranged towards the edge of the rotor core 100. In this way, an area is formed between the second sidewall 220 and the edge of the rotor core 100. The multiple magnetic barrier groups 300 are arranged on the side of the multiple curved grooves 200 away from the center of the rotor core 100, that is, in the area formed between the second sidewall 220 and the edge of the rotor core 100.

[0049] Please see Figures 1 to 3 Furthermore, a direct-axis magnetic channel 400 is formed between any two adjacent magnetic barrier holes 310 in the first layer. Specifically, the direct-axis magnetic channel 400 has low magnetic reluctance and high magnetic flux in the d-axis direction, and large inductance Ld; while the q-axis direction, located at the center line of the magnetic barrier hole 310, has very high magnetic reluctance and small inductance Lq. This increases the inductance difference between the d-axis and q-axis directions, i.e., increases the value of (Lq-Ld) in the formula T=mp*(Lq-Ld)*id*iq+mp*ψPM*iq, thereby improving the torque output capability of the motor. The surface of the magnetic channel can be coated with a magnetic material to achieve better magnetic conduction.

[0050] Please see Figures 1 to 3In one embodiment, the motor rotor 10 with magnetic barriers further includes a plurality of permanent magnets 500, which are installed in a plurality of curved slots 200. Specifically, to ensure the performance of the motor rotor 10 with magnetic barriers, the number of permanent magnets 500 is set to be no less than the number of curved slots 200, and at least one permanent magnet 500 should be placed in each curved slot 200. The shape of the permanent magnet 500 is adapted to the shape of the curved slot 200, and at least two oppositely arranged sides of the permanent magnet 500 abut against the inner wall surface of the curved slot 200 to ensure the stability of the permanent magnet 500 after it is installed in the curved slot 200. Regarding the selection of permanent magnet 500 material, to maximize the permanent magnet torque of the motor, it is generally desirable to select a high-performance permanent magnet 500, and to fill the slot 200 as completely as possible with permanent magnet 500. However, in terms of utilizing reluctance torque, a higher remanent flux density of permanent magnet 500 is not always better. As the remanent flux density of permanent magnet 500 increases, the motor rotor will saturate, leading to a decrease in inductance. Among these, rotor magnetic circuit saturation has a greater impact on q-axis inductance. In addition, research has found that an appropriate amount of remanent flux density of permanent magnet 500 can cause a certain degree of saturation in the gap between the two ends of permanent magnet 500 and the two ends of slot 200, which is very beneficial for reducing d-axis inductance. Since the main output torque of the motor is reluctance torque, especially when the motor enters the high-speed field weakening region, the proportion of reluctance torque in the total electromagnetic torque further increases. Therefore, selecting appropriate permanent magnet 500 material properties to influence the difference between d-axis and q-axis inductance is crucial.

[0051] Please see Figure 1In one embodiment, the thickness of the permanent magnet 500 along the axial direction of the motor rotor 10d with magnetic barriers is T. The magnetic barrier hole 310 has a first side 311 and a second side 312 disposed opposite to each other. The second side 312 is located on the side of the first side 311 away from the center of the rotor core 100. The distance from the first side 311 to the second side 312 is the thickness H of the magnetic barrier hole 310, satisfying T > H. Specifically, the greater the thickness of the permanent magnet 500 along the axial direction of the motor rotor 10d with magnetic barriers, the greater the permanent magnet torque of the motor, thereby increasing the output torque and efficiency of the motor. Meanwhile, to ensure that the magnetic circuit in the quadrature-axis magnetic channel 600 is not blocked, the thickness of the magnetic barrier hole 310 should not be too large. Therefore, the thickness of the permanent magnet 500 is set to be greater than the thickness of one layer of magnetic barrier hole 310. The thickness of the magnetic barrier hole 310 refers to the distance from the first side 311 to the second side 312 of the magnetic barrier hole 310. If the first side 311 and the second side 312 are arranged parallel to each other, the thickness of the magnetic barrier hole 310 refers to the shortest distance from the first side 311 to the second side 312. If the first side 311 and the second side 312 are not arranged parallel to each other, the thickness of the magnetic barrier hole 310 refers to the distance from the first side 311 to the second side 312 near the middle part of the magnetic barrier hole 310. If the magnetic barrier hole 310 has an irregular design, the thickness of the magnetic barrier hole 310 can be the average value between the maximum distance and the minimum distance from the first side 311 to the second side 312.

[0052] Please see Figure 1 In one embodiment, in a cross-section perpendicular to the axial direction of the motor rotor 10 with magnetic barriers, the thickness of the middle portion of the permanent magnet 500 is greater than the thickness of its two ends. Specifically, the permanent magnet 500 can be configured as having a thicker middle and thinner ends, making the thickness of the middle portion of the permanent magnet 500 greater than the thickness of its two ends. Taking an arc-shaped permanent magnet 500 as an example, arc-shaped permanent magnets 500 are prone to local demagnetization in the middle inner surface area. Designing the arc-shaped permanent magnet 500 as having a thicker middle and thinner ends can alleviate the local demagnetization phenomenon. In addition, this design of the permanent magnet 500 with unequal thickness can also prevent the permanent magnet 500 from sliding within the curved groove 200, improving the stability of the permanent magnet 500 during installation within the curved groove 200. Furthermore, a cross-axis magnetic channel 600 is formed between the layer of magnetic barrier holes 310 near the curved groove 200 and the curved groove 200. If the permanent magnet 500 adopts a structure that is thick in the middle and thin at both ends, the width of the cross-axis magnetic channel 600 will be increased, thereby increasing the q-axis inductance, that is, increasing the value of Lq, which increases the inductance difference between Ld and Lq, increases the reluctance torque, and thus improves the torque output capability of the motor.

[0053] Please see Figures 1 to 3 In one embodiment, a gap exists between the two ends of the permanent magnet 500 and the two ends of the groove 200 into which it is embedded. This effectively avoids the concentration of the d-axis armature magnetomotive force at the ends of the permanent magnet 500, thus significantly improving the demagnetizing current of the motor. The gap can be filled with air, or further, with a non-magnetic medium. Specifically, filling the gap with air or a non-magnetic medium prevents the ends of the permanent magnet 500 from easily demagnetizing and becoming unsaturated with magnetization, while also improving the motor's resistance to demagnetization.

[0054] Please see Figure 3 In one embodiment, the curved groove 200 is U-shaped. Specifically, when the curved groove 200 is U-shaped, it can be divided into three parts: a left part, a bottom part, and a right part. These three parts can be interconnected or isolated from each other, as long as their approximate U-shape is maintained. The permanent magnet 500 is rectangular in shape. Because the forming of an arc-shaped permanent magnet 500 is significantly affected by the material and requires more finishing processes in the later stages of forming, while the forming and processing of a rectangular permanent magnet 500 are relatively simple, using a rectangular permanent magnet 500 can improve production efficiency and has strong versatility. The permanent magnet 500 can be placed in any one of the three parts (left, bottom, and right), any two of the three parts, or all of the three parts; there are no specific limitations.

[0055] In another embodiment, the curved groove 200 is V-shaped (not shown). Specifically, when the curved groove 200 is V-shaped, it can be divided into a left half and a right half, and the permanent magnet 500 is rectangular. The permanent magnet 500 can be installed in the left half of the curved groove 200, in the right half, or in both halves.

[0056] Please see Figure 1 In another embodiment, the curved groove 200 is arc-shaped. Specifically, when the curved groove 200 is arc-shaped, the permanent magnet 500 can also be arc-shaped, and the shape of the permanent magnet 500 is adapted to the shape of the curved groove 200, and the permanent magnet 500 is adapted to be installed in the curved groove 200.

[0057] This invention also proposes an electric motor, comprising a motor rotor 10 with magnetic barriers and a stator sleeved on the outside of the motor rotor 10 with magnetic barriers. The stator includes a stator core and windings wound on stator teeth. The specific structure of the motor rotor 10 with magnetic barriers is as described in the above embodiments. Since this motor adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here. This motor can be applied in air conditioning compressors, electric vehicles, and fan systems, etc., and can increase the utilization of motor reluctance torque, thereby improving motor efficiency.

[0058] In one embodiment, the thickness of the motor rotor 10 with magnetic barriers along its axial direction is not less than the thickness of the stator along its axial direction (not shown). The permanent magnet 500 is installed in the curved slots 200 of the rotor core 100. Making the motor rotor 10 with magnetic barriers thicker allows for a larger volume of permanent magnet 500 placed in the rotor core 100, thereby increasing the permanent magnet torque of the motor and improving its output capacity.

[0059] The present invention also proposes a compressor, which includes the aforementioned motor. The specific structure of the motor is as described in the above embodiments. Since this compressor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0060] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An electric machine rotor with magnetic barriers, characterized in that, The motor rotor with magnetic barriers comprises: a rotor core; a plurality of curved slots arranged on the rotor core and spaced along the circumferential direction of the rotor core, both ends of the curved slots extending towards the edges of the rotor core, and the plurality of curved slots being arranged in a single layer; and a plurality of magnetic barrier groups, each of the curved slots corresponding to one of the magnetic barrier groups arranged on the side of the curved slot away from the center of the rotor core, each of the magnetic barrier groups comprising at least one layer of magnetic barrier holes arranged along the d-axis direction of the motor rotor with magnetic barriers, the number of the magnetic barrier holes in one layer being a plurality, and the plurality of magnetic barrier holes being arranged along the extension direction of the slot wall of the curved slot; the included angle between the two ends of the magnetic barrier holes in one layer and the line between the center of the rotor core is a, and a satisfies a≥(1 / 8)*(2π / p), wherein p is the pole number of the motor in which the motor rotor with magnetic barriers is arranged; the motor rotor with magnetic barriers further comprises a plurality of permanent magnets, and the plurality of permanent magnets are arranged in the plurality of curved slots; the thickness of the permanent magnet along the d-axis direction of the motor rotor with magnetic barriers is T, the magnetic barrier hole has oppositely arranged first and second side edges, the length of the first side edge is greater than the length of the second side edge, and the magnetic barrier hole is arranged in a fan shape; the second side edge is located on the side of the first side edge away from the center of the rotor core, the distance between the first side edge and the second side edge is the thickness H of the magnetic barrier hole, and T>H is satisfied; a gap is arranged between the two ends of the permanent magnet and the two ends of the curved slot in which the permanent magnet is arranged, and the gap is used to fill non-magnetic medium.

2. The electric machine rotor with magnetic barriers of claim 1, wherein, the curved slot has oppositely arranged first and second side walls, and both the first and second side walls are convex towards the center of the rotor core.

3. The electric motor rotor with magnetic barriers of claim 2, wherein, a straight-axis magnetic flux channel is formed between any two adjacent magnetic barrier holes in one layer of the magnetic barrier holes.

4. The electric motor rotor with magnetic barriers of claim 1, wherein, in the cross section perpendicular to the axial direction of the motor rotor with magnetic barriers, the thickness of the middle part of the permanent magnet is greater than the thickness of the two ends of the permanent magnet.

5. The electric motor rotor with magnetic barriers of claim 1, wherein, the curved slot is arranged in a U shape.

6. The electric motor rotor with magnetic barriers of claim 1, wherein, the curved slot is arranged in a V shape.

7. The electric motor rotor with magnetic barriers of claim 1, wherein, the curved slot is arranged in an arc shape.

8. An electric machine characterized by the motor rotor with magnetic barriers comprises the motor rotor with magnetic barriers according to any one of claims 1 to 7, and a stator sleeved outside the motor rotor with magnetic barriers, the stator comprising a stator core and a winding wound on the stator teeth.

9. The electric machine of claim 8, wherein, the thickness of the motor rotor with magnetic barriers along the axial direction is not less than the thickness of the stator along the axial direction.

10. A compressor characterized by, the compressor comprises the motor according to claim 8.

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