Rotor assembly, permanent magnet auxiliary synchronous reluctance motor and electric vehicle

Abstract

The utility model provides a rotor assembly, a permanent magnet auxiliary synchronous reluctance motor and an electric automobile, the rotor assembly comprises a rotor iron core; the rotor iron core is provided with a plurality of magnetic poles, the axial surface of the rotor iron core is taken as a projection surface, a first permanent magnet groove and a second permanent magnet groove are formed in the rotor iron core under the same magnetic pole, the first permanent magnet groove and the second permanent magnet groove are symmetrically arranged about a d axis, and the length directions of the first permanent magnet groove and the second permanent magnet groove extend towards the center of the rotor iron core; the first permanent magnet groove comprises a first groove body and a second groove body, the second permanent magnet groove comprises a third groove body and a fourth groove body, and a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet are respectively arranged in the first groove body, the second groove body, the third groove body and the fourth groove body in the radial direction of the rotor iron core. The rotor topological structure formed by the utility model can adapt to a motor with a higher rotating speed due to higher mechanical strength.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, and particularly relates to a rotor assembly, a permanent magnet assisted synchronous reluctance motor, and an electric vehicle. Background Technique

[0002] Currently, the driving motors used in electric vehicles are mainly permanent magnet synchronous motors. Permanent magnet synchronous motors have advantages such as high power density and high efficiency, and their development is closely related to the development of permanent magnet materials. The advent of neodymium iron boron permanent magnets with high magnetic energy product has promoted the rapid development of permanent magnet motors. However, at the same time, it has also brought problems of cost and permanent magnet material supply. High-performance permanent magnets contain rare earth elements, and the price of rare earth has fluctuated significantly in recent years. Moreover, due to geopolitical and other factors, the supply chain of rare earth is not stable. Therefore, permanent magnet motors will develop towards tungsten rare earth or less rare earth in the future, while ensuring that the motor has a high power density.

[0003] The torque of the permanent magnet assisted synchronous reluctance motor includes two types: permanent magnet torque and reluctance torque. Compared with the permanent magnet synchronous motor, the permanent magnet assisted synchronous reluctance motor improves the proportion of reluctance torque through the design of multiple magnetic barriers, can reduce the usage amount of permanent magnets, and reduce the requirements for the performance of permanent magnets. However, due to the complexity of the rotor structure, the cogging torque and torque ripple of the permanent magnet assisted synchronous reluctance motor are relatively large, and the motor vibration and noise are relatively large.

[0004] In the related art, for the permanent magnet assisted synchronous reluctance motor, due to the relatively large usage amount of permanent magnets and the relatively short distance between the permanent magnets and the rotor core, the mechanical strength of the rotor core is insufficient. When the motor runs at high speed, under the action of centrifugal force, the rotor laminations are easily deformed and damaged. Summary of the Utility Model

[0005] The utility model provides a rotor assembly, a permanent magnet assisted synchronous reluctance motor, and an electric vehicle, which can solve the technical problem that the distance between the permanent magnet and the rotor core in the related art is relatively short, resulting in insufficient mechanical strength of the rotor core.

[0006] The utility model provides a rotor assembly, which includes a rotor core;

[0007] The rotor core has a plurality of magnetic poles. Taking the axial plane of the rotor core as the projection plane, in the same magnetic pole, a first permanent magnet slot and a second permanent magnet slot are formed on the rotor core. The first permanent magnet slot and the second permanent magnet slot are symmetrically arranged about the d-axis, and the length directions of the first permanent magnet slot and the second permanent magnet slot extend towards the center of the rotor core;

[0008] The first permanent magnet slot includes a first slot body and a second slot body, and the second permanent magnet slot includes a third slot body and a fourth slot body. In the radial direction of the rotor core, the second slot body is located outside the first slot body, and the fourth slot body is located outside the third slot body. There is a first magnetic isolation bridge between the first slot body and the second slot body, and a second magnetic isolation bridge between the first slot body and the second slot body;

[0009] A first permanent magnet, a second permanent magnet, a third permanent magnet, and a fourth permanent magnet are respectively arranged in the first slot body, the second slot body, the third slot body, and the fourth slot body.

[0010] In some embodiments, one ends of the first slot body and the third slot body facing the center of the rotor core are close to each other, and one ends of the first slot body and the third slot body facing the outer circle of the rotor core are far from each other. The first slot body and the third slot body form an opening facing the outer circle of the rotor core.

[0011] In some embodiments, along the circumferential direction of the rotor core, a third permanent magnet slot is arranged between the first permanent magnet slot and the third permanent magnet slot, and a fifth permanent magnet is arranged in the third permanent magnet slot.

[0012] In some embodiments, in the circumferential direction of the rotor core, an inner permanent magnet slot is arranged between the first permanent magnet slot and the second permanent magnet slot. The inner permanent magnet slot includes a first inner slot body and a second inner slot body. The first inner slot body and the second inner slot body are symmetrically arranged about the d-axis. One ends of the first inner slot body and the second inner slot body facing the center of the rotor core are close to each other, and a third magnetic isolation bridge is formed between the first inner slot body and the second inner slot body. One ends of the first inner slot body and the second inner slot body facing the outer circle of the rotor core are far from each other; a sixth permanent magnet and a seventh permanent magnet are respectively arranged in the first inner slot body and the second inner slot body;

[0013] In the radial direction of the rotor core, the first inner slot body and the second inner slot body are located outside the third permanent magnet slot.

[0014] In some embodiments, the third permanent magnet slot has an inverted trapezoidal structure, the fifth permanent magnet has an inverted hexagonal structure. The first side of the fifth permanent magnet is attached to the long side of the third permanent magnet slot, the second side of the fifth permanent magnet is attached to the short side of the third permanent magnet slot, the third side and the fourth side of the fifth permanent magnet are respectively attached to the inclined sides of the third permanent magnet slot, and the fifth side and the sixth side of the fifth permanent magnet are respectively perpendicular to the first side of the fifth permanent magnet.

[0015] In some embodiments, the length of the first side of the fifth permanent magnet is q, the length of the second side of the fifth permanent magnet is p, the circumferential width of the first permanent magnet and the third permanent magnet is n, and the circumferential width of the sixth permanent magnet and the seventh permanent magnet is m; the included angle between the inner side in the length direction of the sixth permanent magnet and the inner side in the length direction of the seventh permanent magnet is a, the included angle between the inner side in the length direction of the second permanent magnet and the inner side in the length direction of the fourth permanent magnet is b, the included angle between the inner side in the length direction of the first permanent magnet and the inner side in the length direction of the third permanent magnet is c, the inner sides in the length direction of the first slot and the second slot are respectively parallel to the two hypotenuses of the third permanent magnet slot, and the perpendicular distance between the inner side in the length direction of the first slot and the inner side in the length direction of the second slot and the hypotenuse of the third permanent magnet slot is i;

[0016] The length p of the second side of the fifth permanent magnet satisfies:

[0017] The length q of the first side of the fifth permanent magnet satisfies: q = n;

[0018] The included angle c between the inner side in the length direction of the first permanent magnet and the inner side in the length direction of the third permanent magnet satisfies: c = a*(2.4 - 2.5);

[0019] Wherein, the width m is 7.3 mm - 7.6 mm, and the width n is 8.4 mm - 8.7 mm.

[0020] In some embodiments, a fifth slot is further formed on the rotor core. One end of the fifth slot is communicated with the first slot, and the other end of the fifth slot is communicated with the second slot. The fifth slot is trapezoidal. In the radial direction of the rotor core, the third permanent magnet slot is located outside the short side of the fifth slot;

[0021] The length of the short side of the fifth slot is j, the distances between the inner sides in the width direction of the first inner slot and the second inner slot and the long side of the third permanent magnet slot are both k, the radial widths of the first magnetic isolation bridge and the second magnetic isolation bridge are both h, the distance k satisfies: k = 1.4h, and the length j satisfies: j = h;

[0022] Wherein, the radial width h is 2.44 mm - 2.45 mm.

[0023] In some embodiments, under the same magnetic pole, a weight reduction slot is further formed on the rotor core. In the radial direction of the rotor core, the weight reduction slot is located inside the first permanent magnet slot and the second permanent magnet slot.

[0024] A permanent magnet assisted synchronous reluctance motor includes a rotor assembly, and the rotor assembly is the above-mentioned rotor assembly.

[0025] An electric vehicle includes a permanent magnet assisted synchronous reluctance motor, and the permanent magnet assisted synchronous reluctance motor is the above-mentioned permanent magnet assisted synchronous reluctance motor.

[0026] A rotor assembly, a permanent magnet assisted synchronous reluctance motor, and an electric vehicle provided by the present utility model have the following beneficial effects:

[0027] In this embodiment, the first permanent magnet slot and the second permanent magnet slot are of a segmented structure, that is, the first slot body and the second slot body do not communicate with each other, thus forming a first magnetic isolation bridge. The third slot body and the fourth slot body also do not communicate, thus forming a second magnetic isolation bridge. The permanent magnet is of a segmented structure, and the first permanent magnet, the second permanent magnet, the third permanent magnet, and the fourth permanent magnet are respectively installed in the first slot body, the second slot body, the third slot body, and the fourth slot body. Based on the segmented installation of the permanent magnets in the slot bodies, the first magnetic isolation bridge and the second magnetic isolation bridge are respectively formed, which can increase the utilization rate of the rotor core. By changing the settings of the permanent magnet slots and the magnetic isolation bridges on the rotor core, the installation of the permanent magnets on the rotor core is made more compact, and the electromagnetic performance of the motor is ensured, improving the mechanical strength of the rotor core. The rotor topology structure formed in this embodiment has a relatively high mechanical strength and can adapt to motors with higher speeds. Description of the Drawings

[0028] In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0029] Figure 1 It is a schematic diagram of the rotor assembly of the embodiment of the present utility model;

[0030] Figure 2 It is a schematic diagram of the first permanent magnet slot and the second permanent magnet slot of the embodiment of the present utility model;

[0031] Figure 3 It is a schematic diagram of the third permanent magnet slot of the embodiment of the present utility model;

[0032] Figure 4 It is a schematic diagram of the fifth permanent magnet of the embodiment of the present utility model;

[0033] Figure 5 It is a schematic diagram of the length p, the length q, the width m, and the width n of the present utility model;

[0034] Figure 6 is the motor torque diagram in the related art;

[0035] Figure 7 is the motor torque diagram in this embodiment;

[0036] Figure 8 is the mechanical stress diagram of the motor rotor in the related technology

[0037] Figure 9 is the mechanical stress diagram of the motor rotor in this embodiment;

[0038] Figure 10 is the rotor structure in the related technology.

[0039] Accompanying drawings: 1 - rotor core; 2 - first permanent magnet slot; 3 - second permanent magnet slot; 4 - first slot; 401 - inner side edge in the length direction of the first slot; 41 - first permanent magnet; 411 - inner side edge in the length direction of the first permanent magnet; 5 - second slot; 51 - second permanent magnet; 511 - inner side edge in the length direction of the second permanent magnet; 6 - third slot; 601 - inner side edge in the length direction of the third slot; 61 - third permanent magnet; 611 - inner side edge in the length direction of the third permanent magnet; 7 - fourth slot; 71 - fourth permanent magnet; 711 - inner side edge in the length direction of the fourth permanent magnet; 81 - first magnetic isolation bridge; 82 - second magnetic isolation bridge; 9 - third permanent magnet slot; 901 - long side of the third permanent magnet slot; 902 - short side of the third permanent magnet slot; 903 - inclined side of the third permanent magnet slot; 91 - fifth permanent magnet; 911 - first side of the fifth permanent magnet; 912 - second side of the fifth permanent magnet; 913 - third side of the fifth permanent magnet; 914 - fourth side of the fifth permanent magnet; 915 - fifth side of the fifth permanent magnet; 916 - sixth side of the fifth permanent magnet; 10 - fifth slot; 110 - short side of the fifth slot; 11 - first inner slot; 111 - sixth permanent magnet; 1111 - inner side edge in the length direction of the sixth permanent magnet; 12 - second inner slot; 121 - seventh permanent magnet; 1211 - inner side edge in the length direction of the seventh permanent magnet; 13 - third magnetic isolation bridge; 14 - weight reduction slot. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0041] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present utility model; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0042] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation other than the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0043] In addition, it should be noted that using words such as "first", "second", etc. to limit components is only for the convenience of differentiating the corresponding components. Without separate statement, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present utility model.

[0044] See in conjunction with Figure 1As shown in the figure, according to an embodiment of the present utility model, a rotor assembly is provided, which includes a rotor core 1; the rotor core 1 has a plurality of magnetic poles. Taking the axial plane of the rotor core 1 as the projection plane, under the same magnetic pole, a first permanent magnet slot 2 and a second permanent magnet slot 3 are formed on the rotor core 1. The first permanent magnet slot 2 and the second permanent magnet slot 3 are symmetrically arranged about the d-axis, and the length directions of the first permanent magnet slot 2 and the second permanent magnet slot 3 extend towards the center of the rotor core 1; the first permanent magnet slot 2 includes a first slot body 4 and a second slot body 5, the second permanent magnet slot 3 includes a third slot body 6 and a fourth slot body 7. In the radial direction of the rotor core 1, the second slot body 5 is located outside the first slot body 4, and the fourth slot body 7 is located outside the third slot body 6. There is a first magnetic isolation bridge 81 between the first slot body 4 and the second slot body 5, and a second magnetic isolation bridge 82 between the first slot body 4 and the second slot body 5; a first permanent magnet 41, a second permanent magnet 51, a third permanent magnet 61 and a fourth permanent magnet 71 are respectively arranged in the first slot body 4, the second slot body 5, the third slot body 6 and the fourth slot body 7.

[0045] Combined with Figure 10 , the first permanent magnet slot 2 and the second permanent magnet slot 3 in the prior art are through slots symmetrically arranged about the d-axis, and the permanent magnets are also installed as a whole in the first permanent magnet slot 2 and the second permanent magnet slot 3. Moreover, inner permanent magnets are arranged at the ends of the first permanent magnet slot 2 and the second permanent magnet slot 3 facing the center of the rotor core 1. This setting makes the permanent magnets as a whole close to the center of the rotor core 1. A first inner slot body 11 and a second inner slot body 12 symmetrically arranged about the d-axis are respectively arranged between the first permanent magnet slot 2 and the second permanent magnet slot 3. In the radial direction of the rotor core 1, the distance between the inner permanent magnet and the inner sides of the first inner slot body 11 and the second inner slot body 12 in the width direction is relatively large. This distribution method of the permanent magnets results in equivalent stresses in multiple magnetic isolation bridges, and the mechanical strength of the rotor core 1 is relatively low.

[0046] In this embodiment, the first permanent magnet slot 2 and the second permanent magnet slot 3 are of a segmented structure, that is, the first slot body 4 and the second slot body 5 do not communicate with each other, thus forming the first magnetic isolation bridge 81, and the third slot body 6 and the fourth slot body 7 do not communicate either, thus forming the second magnetic isolation bridge 82. The permanent magnets are of a segmented structure, and the first permanent magnet 41, the second permanent magnet 51, the third permanent magnet 61 and the fourth permanent magnet 71 are respectively installed in the first slot body 4, the second slot body 5, the third slot body 6 and the fourth slot body 7. Based on the segmented installation of the permanent magnets in the slot bodies, the first magnetic isolation bridge 81 and the second magnetic isolation bridge 82 are respectively formed, which can increase the utilization rate of the rotor core 1. Through the setting of the permanent magnet slots and magnetic isolation bridges of the rotor core 1, the installation of the permanent magnets on the rotor core 1 is made more compact, and the electromagnetic performance of the motor is ensured, and the mechanical strength of the rotor core 1 is improved. The rotor topology structure formed in this embodiment has a relatively high mechanical strength and can be applied to motors with higher speeds.

[0047] It should be noted that in this embodiment Figures 1 to 5 For the structure shown, with the axial plane of the rotor core 1 as the projection plane, only the structure of one magnetic pole is shown.

[0048] Combined with reference to Figure 1 and Figure 2 As shown, one end of the first slot 4 and the third slot 6 facing the center of the rotor core 1 are close to each other, and one end of the first slot 4 and the third slot 6 facing the outer circle of the rotor core 1 are far from each other. The first slot 4 and the third slot 6 form an opening facing the outer circle of the rotor core 1.

[0049] In this embodiment, since the first slot 4 and the second slot 5 are separated, and the third slot 6 and the fourth slot 7 are separated. In the radial direction of the rotor core 1, the circumferential width centers of the second slot 5 and the fourth slot 7 are on the central extension line of the rotor core 1. If the angle of the opening increases, the first slot 4 and the third slot 6 tilt relative to the central extension line of the rotor core 1, making the first slot 4 and the third slot 6 closer to the outer circle of the rotor core 1, that is, the first permanent magnet 41 and the third permanent magnet 61 are closer to the outer circle of the rotor core 1, and the distance between one end of the first permanent magnet 41 and the third permanent magnet 61 facing the center of the rotor core 1 and the center of the rotor core 1 increases. The permanent magnets in this embodiment are of a segmented structure. Without adjusting the positions of the second slot 5 and the fourth slot 7, only by adjusting the size of the opening, the first permanent magnet 41 and the third permanent magnet 61 can be made closer to the outer circle of the rotor core 1. The overall installation structure of the permanent magnets is compact, shortening the magnetic field line travel path, and improving the torque without changing the performance of the motor.

[0050] As a specific implementation manner, one end of the second slot 5 and the fourth slot 7 facing the center of the rotor core 1 are close to each other, and one end of the second slot 5 and the fourth slot 7 facing the outer circle of the rotor core 1 are far from each other. The geometric center line in the length direction of the second slot 5 is on the central extension line of the rotor core 1, and the geometric center line in the length direction of the fourth slot 7 is also on the central extension line of the rotor core 1, that is, the setting angles of the second slot 5 and the fourth slot 7 do not tilt relative to the central extension line of the rotor core 1, while the geometric center lines in the length directions of the first slot 4 and the third slot 6 are not on the central extension line of the rotor core 1 but are deflected.

[0051] As a specific implementation manner, the included angle between the inner side edge in the length direction of the second slot 5 and the inner side edge in the length direction of the fourth slot 7 is smaller than the included angle of the opening. Through this setting, the angles of the second permanent magnet 51 and the fourth permanent magnet 71 are kept unchanged, while the first permanent magnet 41 and the third permanent magnet 61 are tilted by a certain angle, making the first permanent magnet 41 and the third permanent magnet 61 closer to the outer circle of the rotor core 1 as a whole.

[0052] Referring to Figure 3 and Figure 4 As shown, along the circumferential direction of the rotor core 1, a third permanent magnet slot 9 is provided between the first slot 4 and the third slot 6, and a fifth permanent magnet 91 is provided in the third permanent magnet slot 9.

[0053] Referring to Figure 10 As shown, the inner permanent magnet in the related art is closer to the center of the rotor core 1, while the fifth permanent magnet 91 in this embodiment is located between the first permanent magnet 41 and the third permanent magnet 61, that is, the fifth permanent magnet 91 is located in the opening. This setting increases the distance between the fifth permanent magnet 91 and the center of the rotor core 1, and the fifth permanent magnet 91 is closer to the outer circle of the rotor core 1. In this embodiment, with the same effective volume and the same grade of permanent magnets, by changing the installation positions and installation methods of the first permanent magnet 41, the third permanent magnet 61, and the fifth permanent magnet 91, the stress of the rotor laminations is reduced, the strength of the rotor core 1 is increased, and the rotor can adapt to a motor with a higher speed. Considering from the aspect of motor performance, the structure of this embodiment can make the installation of the permanent magnets more compact, shorten the traveling path of the magnetic lines of force, make the permanent magnets closer to the outer circle of the rotor core 1, and contribute to improving the torque. In addition, through Figure 6 and Figure 7 The simulation data shows that the arrangement method of the permanent magnet slots and permanent magnets in this embodiment also weakens the cogging torque and torque ripple of the motor, reduces the motor vibration, reduces the noise generated during the operation of the motor, and ensures the safe, reliable and stable operation of the motor.

[0054] As another implementation manner, in order to ensure the use of permanent magnets with the same effective volume, this embodiment is to set the fifth permanent magnet 91. The rotor assembly of this embodiment can improve the utilization rate of the rotor core 1 without reducing the electromagnetic performance of the motor, make the arrangement of the permanent magnets more compact, and can improve the mechanical strength of the rotor core 1. In another embodiment, if the fifth permanent magnet 91 is not provided, the electromagnetic performance of the motor can be ensured by increasing the circumferential widths of the first permanent magnet 41 and the third permanent magnet 61. In this way, the circumferential widths of the first slot 4 and the third slot 6 also need to be increased. In order to reduce the generation of magnetic leakage, the length of the short side 110 of the fifth slot 10 needs to be increased. At this time, the included angle between the inner side 411 in the length direction of the first permanent magnet 411 and the inner side 611 in the length direction of the third permanent magnet 611 will decrease, which instead leads to a more cumbersome arrangement of the first permanent magnet 41 and the third permanent magnet 61, and is not conducive to the lightweight design of the rotor core 1. The preferred way is to set the fifth permanent magnet 91.

[0055] Referring to Figure 1 and Figure 2As shown, in the circumferential direction of the rotor core 1, an inner permanent magnet slot is provided between the first permanent magnet slot 2 and the second permanent magnet slot 3. The inner permanent magnet slot includes a first inner slot body 11 and a second inner slot body 12. The first inner slot body 11 and the second inner slot body 12 are symmetrically arranged about the d-axis. The ends of the first inner slot body 11 and the second inner slot body 12 facing the center of the rotor core 1 are close to each other, and a third magnetic isolation bridge 13 is formed between the first inner slot body 11 and the second inner slot body 12. The ends of the first inner slot body 11 and the second inner slot body 12 facing the outer circle of the rotor core 1 are far from each other. A sixth permanent magnet 111 and a seventh permanent magnet 121 are respectively arranged in the first inner slot body 11 and the second inner slot body 12. In the radial direction of the rotor core 1, the first inner slot body 11 and the second inner slot body 12 are located outside the third permanent magnet slot 9.

[0056] In this embodiment, the first permanent magnet slot 2 and the second permanent magnet slot 3 are symmetrically arranged about the d-axis and are integrally V-shaped. The first inner slot body 11 and the second inner slot body 12 are also symmetrically arranged about the d-axis and are also integrally V-shaped. That is, the first permanent magnet slot 2, the second permanent magnet slot 3, the first inner slot body 11 and the second inner slot body 12 form a double-V structure. This structure is more compact and makes full use of the rotor laminations.

[0057] Combined Figures 3 to 5 As shown, the third permanent magnet slot 9 has an inverted trapezoidal structure, and the fifth permanent magnet 91 has an inverted hexagonal structure. The first side 911 of the fifth permanent magnet 91 is attached to the long side 901 of the third permanent magnet slot 9. The second side 912 of the fifth permanent magnet 91 is attached to the short side 902 of the third permanent magnet slot 9. The third side 913 and the fourth side 914 of the fifth permanent magnet 91 are respectively attached to the inclined sides 903 of the third permanent magnet slot 9. The fifth side 915 and the sixth side 916 of the fifth permanent magnet 91 are respectively perpendicular to the first side 911 of the fifth permanent magnet 91.

[0058] In this embodiment, the geometric center line in the width direction of the fifth permanent magnet 91 extends on the center extension line of the rotor core 1. That is, the two ends in the width direction of the fifth permanent magnet 91 are symmetrically arranged about the d-axis. The six sides of the fifth permanent magnet 91 are sequentially connected. The third side 913 and the fourth side 914 of the fifth permanent magnet 91 are symmetrically arranged about the d-axis. The fifth side 915 and the sixth side 916 of the fifth permanent magnet 91 are symmetrically arranged about the d-axis. Among them, the fifth side 915 and the sixth side 916 of the fifth permanent magnet 91 are respectively perpendicular to the first side 911 of the fifth permanent magnet 91. After the fifth permanent magnet 91 is installed in the third permanent magnet slot 9, the four sides of the fifth permanent magnet 91 are attached to the four sides of the third permanent magnet slot 9. In this embodiment, the third permanent magnet slot 9 is set to an inverted trapezoidal structure, which can insert the most permanent magnets in the least area, enhance the motor performance, play a role in concentrating the magnetic field, and this setting is an anti-fooling design to prevent the permanent magnet from being installed backwards during installation.

[0059] As a specific embodiment, the inner side edge in the length direction of the first groove body 4 is parallel to one of the inclined edges 903 of the third permanent magnet groove 9, and the inner side edge in the length direction of the third groove body 6 is parallel to the other inclined edge 903 of the third permanent magnet groove 9. This setting makes the arrangement structure of the permanent magnets more compact.

[0060] Combined with Figures 3 to 5 As shown, the length of the first side 911 of the fifth permanent magnet 91 is q, the length of the second side 912 of the fifth permanent magnet 91 is p, the circumferential width of the first permanent magnet 41, the second permanent magnet 51, the third permanent magnet 61 and the fourth permanent magnet 71 is n, and the circumferential width of the sixth permanent magnet 111 and the seventh permanent magnet 121 is m; the included angle between the inner side edge 1111 in the length direction of the sixth permanent magnet 111 and the inner side edge 1211 in the length direction of the seventh permanent magnet 121 is a, the included angle between the inner side edge 511 in the length direction of the second permanent magnet 51 and the inner side edge 711 in the length direction of the fourth permanent magnet 71 is b, the included angle between the inner side edge 411 in the length direction of the first permanent magnet 411 and the inner side edge 611 in the length direction of the third permanent magnet 61 is c, the inner side edge 401 in the length direction of the first groove body 4 and the inner side edge 601 in the length direction of the third groove body 6 are respectively arranged parallel to the two inclined edges 903 of the third permanent magnet groove 9, and the perpendicular distances between the inner side edge 401 in the length direction of the first groove body 4 and the inner side edge 601 in the length direction of the third groove body 6 and the inclined edge 903 of the third permanent magnet groove 9 are both i;

[0061] The length p of the second side of the fifth permanent magnet 91 satisfies:

[0062] In this embodiment, with reference to Figure 1 As shown, this embodiment is mainly to ensure that under the premise of the same overall volume of the permanent magnets, the arrangement of the permanent magnets is changed to reduce the maximum equivalent stress on the motor while meeting the electromagnetic performance of the motor, so that the rotor structure of this motor can adapt to higher speeds, lower torque ripple, and reduce harmonic content. For the installation dimensions of the fifth permanent magnet 91, first determine the dimensions of the fifth permanent magnet 91 according to the total volume of the permanent magnets and the electromagnetic performance of the motor. Compared with the prior art, the circumferential width m and the circumferential width n in this embodiment are the original permanent magnet dimensions and are not adjusted; when setting the perpendicular distance i, the mechanical strength here needs to be considered, and its value is determined through multiple simulations. The length of i is set to 3 mm to ensure the mechanical strength of the rotor; considering i and the angle c evenly to ensure the performance of the motor, that is, the torque size meets the requirements. For the convenience of permanent magnet processing, the first side 911 of the fifth permanent magnet 91 is set to have the same length as the circumferential width n of the first permanent magnet 41 and the third permanent magnet 61. Also, due to stress simulation, the size of the air magnetic barrier here is determined.

[0063] The length q of the first side of the fifth permanent magnet 91 satisfies: q = n; the included angle c between the first permanent magnet 41 and the third permanent magnet 61 satisfies: c = a*(2.4 - 2.5); where, the width m is 7.3 mm - 7.6 mm, preferably 7.5 mm; the width n is 8.4 mm - 8.7 mm, preferably 8.5 mm; the included angle a is 30°; the preferred value is 2.4, and the included angle c is 73.2°.

[0064] In this embodiment, by limiting the length p of the second side 912 and the length q of the first side 911 of the fifth permanent magnet 91, the size of the magnetic steel can be selected to reduce the torque ripple and the harmonic content on the premise of ensuring the output torque. The included angle c can reduce the torque ripple of the motor, reduce the harmonic content of the motor, and reduce the motor vibration on the premise of ensuring the mechanical strength of the motor rotor core 1.

[0065] In this embodiment, the rotor structure of this embodiment is a 12-pole motor rotor, and the angle occupied by each pole is 30 degrees. Since the electromagnetic performance of the magnetic tile of the permanent magnet assisted reluctance motor is not good enough, in order to ensure the required electromagnetic performance, it is necessary to place the magnetic tiles to the maximum extent. There is enough space for the upper-layer magnetic tiles, so the angle is the same as the angle occupied by the magnetic pole, and two layers of magnetic tiles are placed. However, the installation position becomes smaller towards the center of the circle, so the magnetic tiles are divided into blocks. Considering the electromagnetic performance and mechanical strength, the included angle c and the included angle a are constrained to achieve the required electromagnetic performance and mechanical strength.

[0066] Combined with Figure 1 As shown, a fifth groove 10 is also formed on the rotor core 1. One end of the fifth groove 10 communicates with the first groove 4, and the other end of the fifth groove communicates with the second groove 5. The fifth groove 10 is trapezoidal. In the radial direction of the rotor core 1, the third permanent magnet groove 9 is located outside the short side 110 of the fifth groove 10;

[0067] The length of the short side 110 of the fifth groove 10 is j, the vertical distances from the inner sides in the width direction of the first inner groove 11 and the second inner groove 12 to the long side 901 of the third permanent magnet groove 9 are both k, and the radial widths of the first magnetic isolation bridge 81 and the second magnetic isolation bridge 82 are both h. The distance k satisfies: k = 1.4h, and the length j satisfies: j = h; where, the radial width h is 2.44 mm - 2.45 mm.

[0068] Combined with reference to stress Figure 9, the position with the maximum stress is at the third magnetic isolation bridge 13. Here, the rotor core 1 is mainly affected by the weight of the fifth permanent magnet 91 and the magnitude of the distance k. When the size and weight of the fifth permanent magnet 91 have been selected, the value of the distance k can be determined to ensure the mechanical strength of the rotor lamination. The distance k is related to the radial width h. Ensure the installation positions of the first permanent magnet 41, the third permanent magnet 61, and the fifth permanent magnet 91 to ensure the electromagnetic performance of the motor while guaranteeing the mechanical strength of the rotor core 1. When the first permanent magnet 41, the third permanent magnet 61, and the fifth permanent magnet 91 are reduced proportionally, to ensure the output of the motor, the radial width h will be reduced accordingly, and at the same time, the distance k will also be reduced according to the proportion to ensure the mechanical strength of the rotor core 1.

[0069] In this embodiment, the radial width h is limited within this range mainly to ensure the mechanical performance of the motor. If the radial width h is too large, the distances between the first permanent magnet 41 and the third permanent magnet 61 and the outer circle of the rotor core 1 are lengthened, the magnetic force path is lengthened, and the motor output is insufficient, resulting in a reduction in motor torque. The distance k is related to the radial width h. When the value of the radial width h decreases, the first permanent magnet 41 and the third permanent magnet 61 will move towards the outer circle of the rotor core 1 as a whole, which can increase a part of the motor torque, but the corresponding mechanical strength will decrease, making the motor unable to meet higher speeds. The radial width h is 2.44 mm - 2.45 mm, which can not only ensure the mechanical strength of the rotor core 1 but also not affect the performance of the motor.

[0070] As a specific implementation manner, the inner side edge in the width direction of the second slot 5 and the outer side edge in the width direction of the first slot 4 form the first magnetic isolation bridge 81, the inner side edge in the width direction of the fourth slot 7 and the outer side edge in the width direction of the third slot 6 form the second magnetic isolation bridge 82, a third magnetic isolation bridge 13 is formed between the end of the first inner slot 11 in the length direction close to the rotor core 1 and the end in the rotor core 1 in the length direction of the second inner slot 12, a fourth magnetic isolation bridge is formed between the outer side edge in the width direction of the second slot 5 and the outer circle of the rotor core 1, a fifth magnetic isolation bridge is formed between the outer side edge in the width direction of the first inner slot 11 and the outer circle of the rotor core 1, a sixth magnetic isolation bridge is formed between the outer side edge in the width direction of the second inner slot 12 and the outer circle of the rotor core 1, a seventh magnetic isolation bridge is formed between the outer side edge in the width direction of the fourth slot 7 and the outer circle of the rotor core 1. The radial widths of the fourth magnetic isolation bridge, the fifth magnetic isolation bridge, the sixth magnetic isolation bridge, and the seventh magnetic isolation bridge are 1.5 mm - 1.6 mm. Limiting the widths of the respective magnetic isolation bridges within this range can reduce magnetic leakage, reduce the cogging torque and torque ripple of the motor, reduce the vibration and noise of the motor, and ensure the output of the motor torque on the premise of ensuring the mechanical strength of the rotor core 1.

[0071] As a specific implementation manner, the outer side of the first groove body 4 in the length direction is connected to the outer side of the first groove body 4 in the width direction through an arc, the outer side of the second groove body 5 in the length direction is connected to the outer side of the first groove body 4 in the width direction through an arc, and the long side 901 of the third permanent magnet groove 9 is connected to the two hypotenuse sides 903 through an arc. The arc connection can improve the distribution of magnetic lines of force, make the change of magnetic lines of force smoother and more uniform, and ensure the performance of the motor.

[0072] As a specific implementation manner, the second permanent magnet 51, the fourth permanent magnet 71, the sixth permanent magnet 111, and the seventh permanent magnet 121 are rectangular permanent magnets, which are convenient for processing dimensions. Moreover, the first inner groove body 11 and the second inner groove body 12 are respectively provided with clamping grooves, which are convenient for the installation of the sixth permanent magnet 111 and the seventh permanent magnet 121. Shoulder portions are respectively provided on the outer side of the second groove body 5 in the length direction and the outer side of the fourth groove body 7 in the length direction to fix the permanent magnets, prevent the permanent magnets from slipping, and increase the mechanical strength of the rotor core 1.

[0073] As a specific implementation manner, the first permanent magnet 41 and the third permanent magnet 61 include a rectangular section and a wedge section. The rectangular section and the wedge section form a pentagon-shaped permanent magnet. The rectangular section faces the center of the rotor core 1, and the wedge section faces the outer circle of the rotor core 1. Considering from the aspect of mechanical strength, since the rotor core 1 rotates, the permanent magnet is subjected to a centrifugal force and is thrown towards the outer circle of the rotor core 1. This setting makes the outer side of the first permanent magnet 41 in the width direction and the outer side of the third permanent magnet 61 in the width direction respectively closely fit with the first groove body 4 and the third groove body 6, reducing stress concentration. There is no need to process shoulder portions anymore. Considering from the process perspective, it is a foolproof design and is not easy to be installed wrongly. Shoulder portions are respectively provided on the outer side of the first groove body 4 in the length direction and the outer side of the third groove body 6 in the length direction to fix the first permanent magnet 41 and the third permanent magnet 61, facilitating the confirmation of the installation direction of the permanent magnets and simplifying the process flow.

[0074] Combined Figure 1 As shown, under the same magnetic pole, a weight-reducing groove 14 is also provided on the rotor core 1. In the radial direction of the rotor core 1, the weight-reducing groove 14 is located inside the first permanent magnet groove 2 and the second permanent magnet groove 3.

[0075] In this embodiment, due to the setting manner of the first permanent magnet 41 and the third permanent magnet 61 compared with the related art, the distances between the first permanent magnet 41 and the third permanent magnet 61 and the center of the rotor core 1 are increased, which can provide a setting space for the weight-reducing groove 14.

[0076] Specifically, the diameter d of the weight reduction groove 14 is 16 mm, and the distance s between the long side of the fifth groove body 10 and the center of the rotor core 1 is 16 mm. This setting can effectively utilize the rotor core 1 on the premise of ensuring the mechanical strength of the rotor core 1, drill holes in places where the magnetic lines of force do not pass through, reduce the use of silicon steel sheets, reduce the overall weight of the motor, save manufacturing costs, and increase the power density of the motor.

[0077] As a specific implementation manner, the inner side edge in the width direction of the second groove body 5 is arranged parallel to the outer side edge in the width direction of the first groove body 4, the inner side edge in the width direction of the fourth groove body 7 is arranged parallel to the outer side edge in the width direction of the third groove body 6, the inner side edge 401 in the length direction of the first groove body 4 is arranged parallel to the inclined side 903 of the third permanent magnet groove 9, and the inner side edge 601 in the length direction of the third groove body 6 is arranged parallel to the inclined side 903 of the third permanent magnet groove 9. The parallel arrangement adopted in this embodiment can increase the installation compactness of the permanent magnet grooves on the premise of ensuring the output torque of the motor and the mechanical strength of the rotor core 1, and provide space for the setting of the weight reduction groove 143.

[0078] Refer to Figure 8 , in the related art, the permanent magnet is integrally installed in the first permanent magnet groove 2 and the second permanent magnet groove 3, and an inner permanent magnet is further arranged at one end of the first permanent magnet groove 2 and the second permanent magnet groove 3 facing the center of the rotor core 1. The equivalent stress is concentrated at the position of the magnetic isolation bridge at 3, and the maximum equivalent stress occurs at the magnetic isolation bridge near the center of the rotor core 1. Refer to Figure 9 , in this embodiment, the integral permanent magnet is divided into blocks, and the first permanent magnet 41 and the third permanent magnet 61 move towards the outer circle of the rotor core 1, which equivalently achieves the effect of widening the magnetic isolation bridge near the center of the rotor core 1, reduces stress concentration, improves the mechanical strength of the rotor lamination, and avoids deformation of the rotor lamination.

[0079] A permanent magnet assisted synchronous reluctance motor includes a rotor assembly, and the rotor assembly is the above-mentioned rotor assembly.

[0080] An electric vehicle includes a permanent magnet assisted synchronous reluctance motor, and the permanent magnet assisted synchronous reluctance motor is the above-mentioned permanent magnet assisted synchronous reluctance motor.

[0081] In this embodiment, due to the high demand for NVH of new energy vehicles, when the rotor assembly of this embodiment is adopted, the NVH performance of the motor is fully considered. Through the permanent magnet groove design and magnetic isolation bridge design of the motor rotor core 1, the cogging torque and torque ripple of the motor are reduced, thereby reducing the motor vibration and the noise generated during the operation of the motor, ensuring the safe, reliable and stable operation of the motor, and solving the problem of large noise of the permanent magnet assisted synchronous reluctance motor.

[0082] Those skilled in the art can easily understand that, on the premise of no conflict, the above advantageous ways can be freely combined and superimposed.

[0083] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model. The above is only the preferred implementation manner of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and modifications can be made without departing from the technical principle of the present utility model, and these improvements and modifications should also be regarded as within the protection scope of the present utility model.

Claims

1. A rotor assembly, characterized in that, Comprising: A rotor core (1); The rotor core (1) has a plurality of magnetic poles. Taking the axial plane of the rotor core (1) as the projection plane, in the same magnetic pole, a first permanent magnet slot (2) and a second permanent magnet slot (3) are formed on the rotor core (1). The first permanent magnet slot (2) and the second permanent magnet slot (3) are symmetrically arranged with respect to d-axis. The length directions of the first permanent magnet slot (2) and the second permanent magnet slot (3) extend towards the center of the rotor core (1); The first permanent magnet slot (2) includes a first slot body (4) and a second slot body (5), and the second permanent magnet slot (3) includes a third slot body (6) and a fourth slot body (7). In the radial direction of the rotor core (1), the second slot body (5) is located outside the first slot body (4), and the fourth slot body (7) is located outside the third slot body (6). A first magnetic isolation bridge (81) is provided between the first slot body (4) and the second slot body (5), and a second magnetic isolation bridge (82) is provided between the first slot body (4) and the second slot body (5); A first permanent magnet (41), a second permanent magnet (51), a third permanent magnet (61) and a fourth permanent magnet (71) are respectively arranged in the first slot body (4), the second slot body (5), the third slot body (6) and the fourth slot body (7).

2. The rotor assembly according to claim 1, wherein One ends of the first slot body (4) and the third slot body (6) facing the center of the rotor core (1) are close to each other, and one ends of the first slot body (4) and the third slot body (6) facing the outer circle of the rotor core (1) are far from each other. The first slot body (4) and the third slot body (6) form an opening facing the outer circle of the rotor core (1).

3. The rotor assembly according to claim 1, wherein Along the circumferential direction of the rotor core (1), a third permanent magnet slot (9) is provided between the first slot body (4) and the third slot body (6), and a fifth permanent magnet (91) is arranged in the third permanent magnet slot (9).

4. The rotor assembly according to claim 3, wherein In the circumferential direction of the rotor core (1), an inner permanent magnet slot is provided between the first permanent magnet slot (2) and the second permanent magnet slot (3). The inner permanent magnet slot includes a first inner slot body (11) and a second inner slot body (12). The first inner slot body (11) and the second inner slot body (12) are symmetrically arranged with respect to d-axis. One ends of the first inner slot body (11) and the second inner slot body (12) facing the center of the rotor core (1) are close to each other, and a third magnetic isolation bridge (13) is formed between the first inner slot body (11) and the second inner slot body (12). One ends of the first inner slot body (11) and the second inner slot body (12) facing the outer circle of the rotor core (1) are far from each other. A sixth permanent magnet (111) and a seventh permanent magnet (121) are respectively arranged in the first inner slot body (11) and the second inner slot body (12); In the radial direction of the rotor core (1), the first inner slot body (11) and the second inner slot body (12) are located outside the third permanent magnet slot (9).

5. The rotor assembly according to claim 4, wherein, The third permanent magnet slot (9) has an inverted trapezoidal structure, the fifth permanent magnet (91) has an inverted hexagonal structure, the first side (911) of the fifth permanent magnet (91) is attached to the long side (901) of the third permanent magnet slot (9), the second side (912) of the fifth permanent magnet (91) is attached to the short side (902) of the third permanent magnet slot (9), the third side (913) and the fourth side (914) of the fifth permanent magnet (91) are respectively attached to the inclined sides (903) of the third permanent magnet slot (9), and the fifth side (915) and the sixth side (916) of the fifth permanent magnet (91) are respectively perpendicular to the first side (911) of the fifth permanent magnet (91).

6. The rotor assembly according to claim 5, characterized in that, The length of the first side (911) of the fifth permanent magnet (91) is q, the length of the second side (912) of the fifth permanent magnet (91) is p, the circumferential widths of the first permanent magnet (41) and the third permanent magnet (61) are n, and the circumferential widths of the sixth permanent magnet (111) and the seventh permanent magnet (121) are m; the included angle between the inner side (1111) in the length direction of the sixth permanent magnet (111) and the inner side (1211) in the length direction of the seventh permanent magnet (121) is a, the included angle between the inner side (511) in the length direction of the second permanent magnet (51) and the inner side (711) in the length direction of the fourth permanent magnet (71) is b, the included angle between the inner side (411) in the length direction of the first permanent magnet (41) and the inner side (611) in the length direction of the third permanent magnet (61) is c, the inner side (401) in the length direction of the first slot body (4) and the inner side (601) in the length direction of the third slot body (6) are respectively arranged parallel to the two inclined sides (903) of the third permanent magnet slot (9), and the perpendicular distances between the inner side (401) in the length direction of the first slot body (4) and the inner side (601) in the length direction of the third slot body (6) and the inclined side (903) of the third permanent magnet slot (9) are both i; The length p of the second side of the fifth permanent magnet (91) satisfies: The length q of the first side of the fifth permanent magnet (91) satisfies: q = n; The included angle c between the inner side (411) in the length direction of the first permanent magnet (41) and the inner side (611) in the length direction of the third permanent magnet (61) satisfies: c = a * (2.4 - 2.5); Among them, the width m is 7.3 mm - 7.6 mm, and the width n is 8.4 mm - 8.7 mm.

7. The rotor assembly according to claim 5, characterized in that, A fifth slot body (10) is further formed on the rotor core (1). One end of the fifth slot body (10) communicates with the first slot body (4), the other end of the fifth slot body (10) communicates with the second slot body (5), the fifth slot body (10) is trapezoidal, and in the radial direction of the rotor core (1), the third permanent magnet slot (9) is located outside the short side (110) of the fifth slot body (10); The length of the short side (110) of the fifth groove body (10) is j, the distances between the inner sides in the width direction of the first inner groove body (11) and the second inner groove body (12) and the long side (901) of the third permanent magnet groove (9) are both k, the radial widths of the first magnetic isolation bridge (81) and the second magnetic isolation bridge (82) are both h, the distance k satisfies: k = 1.4h, and the length j satisfies: j = h; Wherein, the radial width h is 2.44 mm - 2.45 mm.

8. The rotor assembly according to any one of claims 1 to 7, characterized in that, Under the same magnetic pole, a weight reduction groove (14) is further formed on the rotor core (1), and in the radial direction of the rotor core (1), the weight reduction groove (14) is located inside the first permanent magnet groove (2) and the second permanent magnet groove (3).

9. A permanent magnet assisted synchronous reluctance motor, comprising a rotor assembly, characterized in that, The rotor assembly is the rotor assembly according to any one of claims 1 to 8.

10. An electric vehicle, comprising a permanent magnet assisted synchronous reluctance motor, characterized in that, The permanent magnet assisted synchronous reluctance motor is the permanent magnet assisted synchronous reluctance motor according to claim 9.

Images