Motor rotor and permanent magnet synchronous reluctance motor

Abstract

The application discloses a motor rotor and a permanent magnet synchronous reluctance motor, and the motor rotor comprises a rotor body, a magnetic steel slot group is arranged on the rotor body, the magnetic steel slot group comprises first grooves and second grooves, the first grooves and the second grooves are arranged at intervals on the rotor body, the first grooves are closer to the outer edge of the rotor body than the second grooves, a first magnetic steel is arranged in the first grooves, and a second magnetic steel is arranged in the second grooves, the residual magnetism of the second magnetic steel is smaller than that of the first magnetic steel, and the coercive force of the second magnetic steel is greater than that of the first magnetic steel. Since the residual magnetism of the first magnetic steel is high and the first magnetic steel is closer to the air gap, the air gap magnetic density can be increased, the running current can be reduced, and thus the low-frequency performance of the permanent magnet synchronous reluctance motor can be improved. In addition, since the coercive force of the first magnetic steel is low, the first magnetic steel is easier to magnetize, the field-weakening current can be reduced, and thus the high-frequency performance of the permanent magnet synchronous reluctance motor can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor equipment, in particular to a motor rotor and a permanent magnet synchronous reluctance motor. BACKGROUND

[0002] Permanent magnet motors generate a main magnetic field by embedding magnetic steel in the motor rotor. Due to its small size, high efficiency, high power density, simple structure and high reliability, it is widely used in various industries. With the concept of carbon neutralization, electric vehicles and wind power have developed rapidly, and the demand for high-performance rare earth neodymium iron boron magnetic steel has increased day by day, driving up the price of magnetic steel materials.

[0003] Permanent magnet synchronous reluctance motors use a multi-layer magnetic steel slot rotor structure to increase the magnetic reluctance torque ratio, and use low-cost, low-performance ferrite magnetic steel instead of rare earth neodymium iron boron magnetic steel, which greatly reduces the cost while ensuring motor performance, and is widely used in air conditioner compressors. However, permanent magnet synchronous reluctance motors require flux weakening control under high frequency conditions, which increases the operating current and increases the internal copper loss, reducing energy efficiency. In addition, the permanent magnet synchronous reluctance motor uses ferrite magnetic steel with low residual magnetism, resulting in low air gap flux density and poor low frequency performance. In particular, the new air conditioner national standard for energy efficiency has higher requirements for the overall efficiency of the motor, and the permanent magnet synchronous reluctance motor needs to be further improved to meet the new air conditioner national standard for energy efficiency. SUMMARY

[0004] Therefore, it is necessary to provide a motor rotor and a permanent magnet synchronous reluctance motor that can effectively improve the air gap flux density of the permanent magnet synchronous reluctance motor, has a magnetic adjustment function, can effectively reduce the flux weakening current under high frequency conditions, and can comprehensively improve the performance of the permanent magnet synchronous reluctance motor.

[0005] A motor rotor comprises a rotor body, a magnetic steel slot group provided on the rotor body, the magnetic steel slot group comprising a first groove and a second groove, the first groove and the second groove being spaced apart on the rotor body, the first groove being closer to the outer edge of the rotor body than the second groove, a first magnetic steel installed in the first groove, and a second magnetic steel installed in the second groove, the residual magnetism of the second magnetic steel being smaller than that of the first magnetic steel, and the coercive force of the second magnetic steel being greater than that of the first magnetic steel.

[0006] In the motor rotor, the magnetic steel slot group comprises the first groove and the second groove arranged at intervals, and the first groove is closer to the outer edge of the rotor body than the second groove, i.e. the first groove is closer to the air gap than the second groove. When the first magnetic steel is installed in the first groove and the second magnetic steel is installed in the second groove, the remanence of the first magnetic steel is higher, and the first magnetic steel is closer to the air gap. Therefore, the air gap magnetic flux density is increased, the operating current is reduced, and the low-frequency performance of the permanent magnet synchronous reluctance motor is improved. In addition, the coercive force of the first magnetic steel is lower, and the magnetic field is easier to adjust, so that the field weakening current is reduced, and the high-frequency performance of the permanent magnet synchronous reluctance motor is improved.

[0007] The technical solutions are further described below:

[0008] In one of the embodiments, the cross-sectional area of the first magnetic steel perpendicular to the axial direction of the rotor body is S1, and the cross-sectional area of the second magnetic steel perpendicular to the axial direction of the rotor body is S2, wherein 0.8

[0009] In one of the embodiments, the first groove and the second groove are circular arc grooves and are axially symmetrical along the radial direction of the rotor body. The bending directions of the first groove and the second groove are both towards the outer edge of the rotor body. The first groove and the second groove are unequal-width grooves. The widest part of the first groove is referred to as a first protruding part, and the first protruding part is closest to the center of the rotor body in the first groove. The widest part of the second groove is referred to as a second protruding part, and the second protruding part is closest to the center of the rotor body in the second groove.

[0010] In one of the embodiments, an arc-shaped magnetic flux guide channel is formed between the first groove and the second groove. The widest part of the magnetic flux guide channel is referred to as a third protruding part, and the third protruding part is closest to the center of the rotor body in the magnetic flux guide channel. The width of the first protruding part is K1, the width of the second protruding part is K2, and the width of the third protruding part is K3, wherein 0.29

[0011] In one of the embodiments, the first groove is a "one" type structure, and the second groove is a circular arc structure. Along the extension direction of the second groove, the width of the second groove decreases from the middle part to the opposite ends.

[0012] In one of the embodiments, the first groove is a "U" type structure or a "V" type structure, and the second groove is a "U" type structure or a "V" type structure.

[0013] In one of the embodiments, a first air slot is formed between the end of the first magnetic steel and the end of the first slot along the extension direction of the first slot, and a first air magnetic barrier is arranged in the first air slot; a second air slot is formed between the end of the second magnetic steel and the end of the second slot along the extension direction of the second slot, and a second air magnetic barrier is arranged in the second air slot.

[0014] In one of the embodiments, a first magnetic bridge is formed between the first air slot and the outer edge of the rotor body, a second magnetic bridge is formed between the second air slot and the outer edge of the rotor body, and the width W1 of the first magnetic bridge is equal to the width W2 of the second magnetic bridge.

[0015] In one of the embodiments, the width W1 of the first magnetic bridge satisfies 0.5≤W1 / δ≤1.2, wherein δ is the width of the air gap between the stator and the rotor body.

[0016] In one of the embodiments, the first magnetic steel is an alnico magnetic steel, and the second magnetic steel is a ferrite magnetic steel.

[0017] The application also provides a permanent magnet synchronous reluctance motor, which comprises the motor rotor as described above. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and explain them, which do not limit the present application in any manner.

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the accompanying drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0020] In addition, the drawings are not drawn in the ratio of 1:1, and the relative sizes of the various elements are only exemplarily drawn in the drawings, but not necessarily drawn in the true ratio. In the drawings:

[0021] Figure 1 FIG. 1 is a structural schematic diagram of a magnetic steel slot group on a rotor body in an embodiment of the present application;

[0022] Figure 2 FIG. 2 is a structural schematic diagram of a motor rotor in an embodiment of the present application;

[0023] Figure 3 FIG. 3 is a structural schematic diagram of a first bent protrusion, a second bent protrusion and a third bent protrusion in a motor rotor in an embodiment of the present application;

[0024] Figure 4 Fig. 1 is a structural schematic diagram of a motor rotor according to an embodiment of the present application; Figure 3 Fig. 2 is a structural enlarged schematic diagram of the structure at circle A in Fig. 1;

[0025] Figure 5 Fig. 3 is a structural schematic diagram of a motor rotor according to another embodiment of the present application;

[0026] Figure 6 Fig. 4 is a structural schematic diagram of a motor rotor according to still another embodiment of the present application.

[0027] The labels of the elements in the figures are as follows:

[0028] 10, motor rotor; 110, rotor body; 111, magnetic steel slot group; 1111, first groove; 1112, second groove; 1113, first air slot; 1114, second air slot; 112, magnetic flux guide channel; 113, first magnetic isolation bridge; 114, second magnetic isolation bridge; 120, first magnetic steel; 130, second magnetic steel. DETAILED DESCRIPTION

[0029] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of ways beyond the specific embodiments described and claimed herein, and it is therefore intended that the present application not be limited to the embodiments presented herein. Instead, the scope of the present application covers all modifications and alternatives coming within the scope of the present application.

[0030] Figure 1 Fig. 5 is a structural schematic diagram of the magnetic steel slot group 111 on the rotor body 110 according to an embodiment of the present application. Figure 2 Fig. 1 is a structural schematic diagram of a motor rotor according to an embodiment of the present application; Figure 1 and Figure 2 According to an embodiment of the present application, a motor rotor 10 is provided, which includes a rotor body 110, a first magnetic steel 120 and a second magnetic steel 130. The rotor body 110 is provided with a magnetic steel slot group 111. The magnetic steel slot group 111 includes a first groove 1111 and a second groove 1112, and the first groove 1111 and the second groove 1112 are arranged at intervals on the rotor body 110, with the first groove 1111 being closer to the outer edge of the rotor body 110 than the second groove 1112. The first magnetic steel 120 is installed in the first groove 1111. The second magnetic steel 130 is installed in the second groove 1112, and the residual magnetism of the second magnetic steel 130 is smaller than that of the first magnetic steel 120, and the coercive force of the second magnetic steel 130 is greater than that of the first magnetic steel 120.

[0031] In the motor rotor 10, the magnetic steel slot group 111 comprises the first groove 1111 and the second groove 1112 which are arranged at intervals, and the first groove 1111 is closer to the outer edge of the rotor body 110 than the second groove 1112, i.e. the first groove 1111 is closer to the air gap than the second groove 1112. Therefore, when the first magnetic steel 120 is arranged in the first groove 1111 and the second magnetic steel 130 is arranged in the second groove 1112, the remanence of the first magnetic steel 120 is higher, and it is closer to the air gap. In this way, the air gap magnetic density can be increased, and the operating current can be reduced, so that the low frequency performance of the permanent magnet synchronous reluctance motor can be improved. In addition, the coercive force of the first magnetic steel 120 is lower, so it is easier to magnetize, and the field weakening current can be reduced, so that the high frequency performance of the permanent magnet synchronous reluctance motor can be improved.

[0032] Specifically, in the embodiment, the first groove 1111 and the second groove 1112 are arranged at intervals along the radial direction of the rotor body 110.

[0033] Specifically, in the embodiment, the first magnetic steel 120 is an alnico magnetic steel, and the second magnetic steel 130 is a ferrite magnetic steel.

[0034] It should be noted that, in the embodiment, the alnico magnetic steel is a magnetic steel with both high remanence and low coercive force. The ferrite magnetic steel is a magnetic steel with both low remanence and high coercive force. When the alnico magnetic steel is placed in the first groove 1111, because its coercive force is low, it can be easily magnetized. In addition, because it is closer to the outer edge of the rotor body 110, it is easier to magnetize, and the field weakening current can be effectively reduced, so that the high frequency performance of the permanent magnet synchronous reluctance motor can be improved.

[0035] On the basis of the above embodiment, in an embodiment, referring to Figure 1 , the rotor body 110 is provided with a plurality of magnetic steel slot groups 111, and the plurality of magnetic steel slot groups 111 are arranged at intervals along the circumferential direction of the rotor body 110. Therefore, when the magnetic steel is placed in the magnetic steel slot group 111, the N pole and the S pole can be alternately arranged on the rotor body 110, so that the motor rotor 10 can be normally used.

[0036] Specifically, in the embodiment, as shown in Figure 1 , the plurality of magnetic steel slot groups 111 are arranged at equal intervals along the circumferential direction of the rotor body 110. In this way, the magnetic poles can be uniformly distributed on the circumference of the rotor body 110, so that the magnetic poles of the permanent magnet synchronous reluctance motor are symmetrically distributed, the torque pulse of the permanent magnet synchronous reluctance motor under load can be effectively reduced, and the vibration and noise of the permanent magnet synchronous reluctance motor can be reduced.

[0037] It should be noted that the number of the magnetic steel slot groups 111 on the rotor body 110 is double. For example, 4, 6 or 8, etc. Specifically, in the embodiment, the magnetic steel slot group 111 is provided with 6.

[0038] On the basis of the above embodiment, in an embodiment, the cross-sectional area of the first magnetic steel 120 perpendicular to the axial direction of the rotor body 110 is S1. The cross-sectional area of the second magnetic steel 130 perpendicular to the axial direction of the rotor body 110 is S2. Wherein, 0.8 < S1 / S2 < 0.95. By limiting the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130, the demagnetization resistance of the magnetic steel can be improved. If the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130 is too small, the magnetic steel is easy to demagnetize, which is not conducive to the safe operation of the motor rotor 10 and the permanent magnet synchronous reluctance motor. Therefore, the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130 is set to be greater than 0.8. At the same time, if the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130 is too large, although it can ensure the safety of the operation of the motor rotor 10, but it is not easy to realize the magnetic adjustment of the magnetic steel. Therefore, the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130 is less than 0.95. It can be seen that when the ratio of the cross-sectional area of the first magnetic steel 120 to the cross-sectional area of the second magnetic steel 130 is between 0.8 and 0.95, i.e. 0.8 < S1 / S2 < 0.95, the magnetic steel can be more easily adjusted, the magnetic adjustment current and the field weakening current can be effectively reduced in high frequency working condition, and the high frequency performance of the permanent magnet synchronous reluctance motor can be improved.

[0039] Please refer to Figures 1 to 3 On the basis of the above embodiment, in an embodiment, the first groove 1111 and the second groove 1112 are both circular arc grooves and are respectively axisymmetric structures along the radial direction of the rotor body 110. The bending directions of the first groove 1111 and the second groove 1112 are both towards the outer edge of the rotor body 110. And the first groove 1111 and the second groove 1112 are both unequal width grooves. Wherein, the widest part in the first groove 1111 is called the first bulge, and the first bulge is the shortest distance from the center of the rotor body 110 in the first groove 1111. The widest part in the second groove 1112 is called the second bulge, and the second bulge is the shortest distance from the center of the rotor body 110 in the second groove 1112. In this way, the magnetic flux direction of the magnetic steel in the rotor body 110 can be changed, thereby improving the air gap magnetic field distribution of the permanent magnet synchronous reluctance motor, reducing the harmonic ratio, and optimizing the torque ripple of the permanent magnet synchronous reluctance motor.

[0040] It should be noted that the "width of the first groove 1111" refers to the vertical distance between the two circular arc-shaped edges in the first groove 1111 along the radial direction of the rotor body 110. The "width of the second groove 1112" refers to the vertical distance between the two circular arc-shaped edges in the second groove 1112 along the radial direction of the rotor body 110.

[0041] Specifically, as shown in Figure 1 the first groove 1111 gradually decreases from the middle of the first groove 1111 to the end of the first groove 1111 along the extension direction of the first groove 1111. And the width of the second groove 1112 gradually decreases from the middle of the second groove 1112 to the end of the second groove 1112 along the extension direction of the second groove 1112. Wherein, the middle of the first groove 1111 is the first protruding part, and the middle of the second groove 1112 is the second protruding part.

[0042] Further, please refer to Figures 1 to 3 On the basis of the above embodiment, in an embodiment, an arc-shaped magnetic flux guide channel 112 is formed between the first groove 1111 and the second groove 1112. The widest part in the magnetic flux guide channel 112 is called the third protruding part, and the third protruding part is the shortest from the center of the rotor body 110 in the magnetic flux guide channel 112. The width of the first protruding part is K1, the width of the second protruding part is K2, and the width of the third protruding part is K3, wherein 0.29 < K3 / (K1+K2) < 0.5. If the ratio between the width K1 of the first protruding part, the width K2 of the second protruding part and the width K3 of the third protruding part is too small, the magnetic circuit saturation will be increased, and the performance of the permanent magnet synchronous reluctance motor will be reduced. Therefore, the ratio between the width K1 of the first protruding part, the width K2 of the second protruding part and the width K3 of the third protruding part is greater than 0.29. At the same time, if the ratio between the width K1 of the first protruding part, the width K2 of the second protruding part and the width K3 of the third protruding part is too large, the rotor body 110 leakage will be increased, and the performance of the permanent magnet synchronous reluctance motor will be reduced. Therefore, the ratio between the width K1 of the first protruding part, the width K2 of the second protruding part and the width K3 of the third protruding part is less than 0.5. It can be seen that when the ratio between the width K1 of the first protruding part, the width K2 of the second protruding part and the width K3 of the third protruding part is between 0.29 and 0.5, i.e. 0.29 < K3 / (K1+K2) < 0.5, the influence of the permanent magnet flux on the saturation degree of the magnetic circuit can be reduced, the rotor saliency ratio can be increased, and the efficiency of the permanent magnet synchronous reluctance motor can be improved.

[0043] Alternatively, in other embodiments, as Figure 5As shown, the first groove 1111 is in a "one" type structure. The second groove 1112 is in a circular arc structure. And along the extension direction of the second groove 1112, the width of the second groove 1112 from the middle to the opposite ends decreases. In this way, the first magnetic steel 120 with high residual magnetism can be placed closer to the outer edge of the rotor body 110 in a limited space on the rotor body 110, thereby further increasing the air gap flux and further improving the efficiency of the permanent magnet synchronous reluctance motor.

[0044] Specifically, when the first groove is in a "one" type structure, the width of the first groove is equal at each part along the extension direction of the first groove. In addition, the bending direction of the second groove 1112 is towards the outer edge of the rotor body 110.

[0045] Alternatively, in other embodiments, as shown in FIG. 1C, Figure 6 As shown, the first groove 1111 is in a "U" type structure or in a "V" type structure, and the second groove 1112 is in a "U" type structure or in a "V" type structure. Compared with the "one" type structure, the "V" type structure groove and the "U" type structure groove can make the magnetic steel placed inside have a better magnetic aggregation effect, and can improve the utilization rate of the magnetic steel. In addition, the "U" type structure or the "V" type structure groove has a smaller processing difficulty compared with the circular arc structure, which can improve the processing technology of the rotor body 110. At the same time, the magnetic steel installed in the "U" type structure groove or the "V" type structure groove is in a strip structure, and the strip structure magnetic steel is more convenient to process compared with the arc structure magnetic steel, which improves the processing technology of the magnetic steel.

[0046] Specifically, when the first groove is in a "U" type structure or in a "V" type structure, the width of the first groove is equal at each part along the extension direction of the first groove. Similarly, when the second groove is in a "U" type structure or in a "V" type structure, the width of the second groove is equal at each part along the extension direction of the second groove. In addition, the bending direction of the first groove 1111 and the second groove 1112 is towards the outer edge of the rotor body 110.

[0047] Alternatively, in other embodiments, the shapes of the first groove 1111 and the second groove 1112 are not specifically limited, for example, both shapes are the same, which can be one of "one" type, "V" type, circular arc ("C" type), "W" type and "U" type. Or the shapes are not the same, for example, the first groove 1111 is in a "one" type structure, and the second groove 1112 is in a circular arc structure; or the first groove 1111 is in a "V" type structure, and the second groove 1112 is in a "U" type structure, and so on.

[0048] Because the part between the adjacent magnetic poles is easy to produce air gap field distortion under the armature reaction, in order to reduce the influence of the armature reaction on the torque ripple, please refer toFigures 2 to 6 On the basis of the above-mentioned embodiments, in an embodiment, a first air slot 1113 is formed between the end of the first magnetic steel 120 and the end of the first slot 1111 along the extension direction of the first slot 1111, and a first air magnetic barrier is arranged in the first air slot 1113. A second air slot 1114 is formed between the end of the second magnetic steel 130 and the end of the second slot 1112 along the extension direction of the second slot 1112, and a second air magnetic barrier is arranged in the second air slot 1114. The first air magnetic barrier and the second air magnetic barrier can reduce the magnetic leakage of the permanent magnet synchronous reluctance motor, improve the air gap flux density, and further improve the torque.

[0049] In order to enhance the mechanical strength of the motor rotor 10 while limiting the magnetic leakage, please refer to Figure 2 , Figure 3 and Figure 4 On the basis of the above-mentioned embodiments, in an embodiment, a first air slot 1113 is formed between the end of the first magnetic steel 120 and the end of the first slot 1111 along the extension direction of the first slot 1111, and a first air magnetic barrier is arranged in the first air slot 1113. A second air slot 1114 is formed between the end of the second magnetic steel 130 and the end of the second slot 1112 along the extension direction of the second slot 1112, and a second air magnetic barrier is arranged in the second air slot 1114. The first air magnetic barrier and the second air magnetic barrier can reduce the magnetic leakage of the permanent magnet synchronous reluctance motor, improve the air gap flux density, and further improve the torque.

[0050] Further, on the basis of the above-mentioned embodiments, in an embodiment, please continue to refer to Figure 2 , Figure 3 and Figure 4 The width W1 of the first magnetic barrier 113 is equal to the width W2 of the second magnetic barrier 114. In this way, the processing difficulty of the first magnetic barrier 113 and the second magnetic barrier 114 can be reduced, and the mechanical strength of the motor rotor is more uniform.

[0051] On the basis of the above-mentioned embodiments, in an embodiment, the width W1 of the first magnetic barrier 113 satisfies 0.5≤W1 / δ≤1.2, wherein δ is the width of the air gap between the stator and the rotor body 110. By limiting the ratio of the width W1 of the first magnetic barrier 113 to the width δ of the air gap, the guiding effect of the magnetic lines can be better, the magnetic pole leakage can be effectively reduced, and the efficiency of the permanent magnet synchronous reluctance motor can be improved.

[0052] The application also provides a permanent magnet synchronous reluctance motor comprising the motor rotor 10 as above. Tests show that the efficiency of the permanent magnet synchronous reluctance motor can be improved by more than 1% under low-frequency 20Hz working conditions and high-frequency 100Hz working conditions. It can be seen that the permanent magnet synchronous reluctance motor using the motor rotor 10 has high performance.

[0053] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features.

[0054] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixing", and the like are to be construed in a broad sense, for example, they can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection via an intermediate medium; can be internal communication between two elements, or interaction between two elements, unless specifically defined otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] In the present application, unless specifically defined otherwise, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0056] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be an intermediate element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical", "horizontal", "up", "down", "left", "right", and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0057] The technical features of the above embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present application.

[0058] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A motor rotor, characterized in that, include: The rotor body is provided with a magnetic steel groove group, which includes a first groove and a second groove. The first groove and the second groove are arranged at intervals on the rotor body, and the first groove is closer to the outer edge of the rotor body than the second groove. The first magnet is installed in the first trench; and The second magnet is installed in the second groove, and the remanence of the second magnet is less than that of the first magnet, and the coercivity of the second magnet is greater than that of the first magnet. The widest part in the first groove is called the first curved protrusion, and the first curved protrusion is the shortest distance from the center of the rotor body in the first groove. The widest part in the second groove is called the second curved protrusion, and the second curved protrusion is the shortest distance from the center of the rotor body in the second groove. An arc-shaped magnetic channel is formed between the first groove and the second groove. The widest part of the magnetic channel is called the third bend, and the third bend is the shortest distance from the center of the rotor body in the magnetic channel. The width of the first bend is K1, the width of the second bend is K2, and the width of the third bend is K3, where 0.29 < K3 / (K1+K2) < 0.

5.

2. The motor rotor according to claim 1, characterized in that, The area of ​​the cross-section of the first magnet in the axial direction perpendicular to the rotor body is S1, and the area of ​​the cross-section of the second magnet in the axial direction perpendicular to the rotor body is S2, wherein 0.8 < S1 / S2 < 0.

95.

3. The motor rotor according to claim 1, characterized in that, Both the first groove and the second groove are arc-shaped grooves and are axially symmetrical along the radial direction of the rotor body. The bending direction of both the first groove and the second groove is towards the outer edge of the rotor body, and both the first groove and the second groove are grooves of unequal width.

4. The motor rotor according to claim 1, characterized in that, The first groove is a straight line structure, the second groove is an arc-shaped structure, and along the extension direction of the second groove, the width of the second groove decreases from the middle to the opposite ends.

5. The motor rotor according to claim 1, characterized in that, The first groove is a "U" shaped structure or a "V" shaped structure, and the second groove is a "U" shaped structure or a "V" shaped structure.

6. The motor rotor according to any one of claims 1-5, characterized in that, Along the extension direction of the first groove, a first air groove is formed between the end of the first magnet and the end of the first groove, and a first air magnetic barrier is provided in the first air groove; along the extension direction of the second groove, a second air groove is formed between the end of the second magnet and the end of the second groove, and a second air magnetic barrier is provided in the second air groove.

7. The motor rotor according to claim 6, characterized in that, On the rotor body, a first magnetic isolation bridge is formed between the first air slot and the outer edge of the rotor body, and a second magnetic isolation bridge is formed between the second air slot and the outer edge of the rotor body, and the width W1 of the first magnetic isolation bridge is equal to the width W2 of the second magnetic isolation bridge.

8. The motor rotor according to claim 7, characterized in that, The width W1 of the first magnetic isolation bridge satisfies 0.5≤W1 / δ≤1.2, where δ is the width of the air gap between the stator and the rotor body.

9. The motor rotor according to any one of claims 1-5, characterized in that, The first magnet is an AlNiCo magnet, and the second magnet is a ferrite magnet.

10. A permanent magnet synchronous reluctance motor, characterized in that, Includes the motor rotor as described in any one of claims 1-9.

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