Rotor assembly, motor, compressor and refrigeration equipment

Abstract

The invention provides a rotor assembly, a motor, a compressor and refrigeration equipment. The rotor assembly comprises a rotor iron core; the plurality of permanent magnet groups comprise a first permanent magnet group and a second permanent magnet group which are arranged in the rotor core at intervals along the circumferential direction of the rotor core, the rotor core between the first permanent magnet group and the second permanent magnet group forms a consequent pole, and the first permanent magnet group comprises a first permanent magnet and two second permanent magnets; the two second permanent magnets are radially arranged at intervals, and at least one part of the first permanent magnet is located on the radial inner sides of the two second permanent magnets; the magnetizing direction of the second permanent magnets is tangential, and the magnetizing direction of the first permanent magnets is radial. Wherein the magnetizing directions of the two second permanent magnets are opposite, and the magnetizing direction of the first permanent magnet faces the outer side of the rotor iron core; or, the magnetizing directions of the two second permanent magnets are opposite, and the magnetizing direction of the first permanent magnet faces the inner side of the rotor iron core.

Description

Technical Field

[0001] The present invention relates to the technical field of motor equipment, and more specifically, to a rotor assembly, a motor, a compressor, and a refrigeration device. Background Art

[0002] Currently, for conventional alternating-pole permanent magnet motors, there are problems of weak demagnetization resistance and large equivalent air gap, resulting in low air-gap magnetic flux, slightly low power density, and restricting their application in occasions with high demagnetization resistance requirements.

[0003] In related technologies, the rotors of permanent magnet motors use high-grade permanent magnets to improve power density, resulting in an increase in the production cost of permanent magnet motors and limited cost reduction. Summary of the Invention

[0004] Embodiments of the present invention aim to solve at least one of the technical problems existing in the prior art.

[0005] To this end, a first aspect of embodiments of the present invention provides a rotor assembly.

[0006] A second aspect of embodiments of the present invention provides a motor.

[0007] A third aspect of embodiments of the present invention provides a compressor.

[0008] A fourth aspect of embodiments of the present invention provides a refrigeration device.

[0009] In view of this, according to the first aspect of embodiments of the present invention, a rotor assembly is provided. The rotor assembly includes: a rotor core; a plurality of permanent magnet groups, including a first permanent magnet group and a second permanent magnet group that are arranged at intervals in the circumferential direction of the rotor core. The rotor core between the first permanent magnet group and the second permanent magnet group forms alternating poles. The first permanent magnet group includes a first permanent magnet and two second permanent magnets. The two second permanent magnets are arranged at intervals radially. At least a part of the first permanent magnet is located radially inside the two second permanent magnets; the magnetization direction of the second permanent magnet is tangential, and the magnetization direction of the first permanent magnet is radial; wherein, the magnetization directions of the two second permanent magnets face each other, and the magnetization direction of the first permanent magnet is towards the outside of the rotor core; or, the magnetization directions of the two second permanent magnets are opposite to each other, and the magnetization direction of the first permanent magnet is towards the inside of the rotor core.

[0010] The rotor assembly provided by embodiments of the present invention includes a rotor core and a plurality of permanent magnet groups. Specifically, the plurality of permanent magnet groups include a first permanent magnet group and a second permanent magnet group, and along the circumferential direction of the rotor core, the first permanent magnet group and the second permanent magnet group are arranged at intervals. That is to say, there is a silicon steel pole between the first permanent magnet group and the second permanent magnet group.

[0011] The rotor core between the first permanent magnet group and the second permanent magnet group forms alternating poles, that is, the motor having the rotor assembly is an alternating pole motor.

[0012] The first permanent magnet group includes a first permanent magnet and two second permanent magnets, and the two second permanent magnets are radially spaced apart, that is, the two second permanent magnets are spaced apart along the circumferential direction of the rotor core, and each second permanent magnet extends along the radial direction of the rotor core.

[0013] At least a portion of the first permanent magnet is located radially inward of the two second permanent magnets.

[0014] The magnetization direction of the first permanent magnet is radial, and the magnetization direction of the second permanent magnet is tangential.

[0015] When the first permanent magnet group is magnetized, when the magnetization directions of the two second permanent magnets face each other, the magnetization direction of the first permanent magnet is toward the outside of the rotor core, that is, the magnetization direction of the first permanent magnet is radially outward. When the magnetization directions of the two second permanent magnets face each other, the magnetization direction of the first permanent magnet is toward the inside of the rotor core, that is, the magnetization direction of the first permanent magnet is radially inward.

[0016] That is to say, the magnetization direction of the first permanent magnet is consistent with the magnetization direction of each second permanent magnet, that is, magnetization is simultaneously inward or outward. Thus, the magnetic circuit of the first permanent magnet is connected in parallel with the magnetic circuit of each second permanent magnet, so that the first permanent magnet group has a certain magnetic concentration effect. Even if the magnetic properties of the first permanent magnet are poor, it can achieve the same magnetic energy output effect when combined with the two second permanent magnets.

[0017] Therefore, the first permanent magnet can be a low-grade permanent magnet, so as to reduce the amount of high-grade permanent magnets while achieving the same magnetic energy output effect, thereby ensuring performance while reducing the production cost of the motor with the rotor assembly and improving the motor utilization rate.

[0018] In addition, the rotor assembly provided by the above technical solution of the present invention also has the following additional technical features:

[0019] In some technical solutions, optionally, the magnetism of the first permanent magnet is smaller than the magnetism of at least one second permanent magnet.

[0020] In this technical solution, since the first permanent magnet is arranged radially inside the two second permanent magnets, the amount of the two second permanent magnets is reduced accordingly, and the magnetic properties of the first permanent magnet are poorer than those of at least one second permanent magnet, that is, the first permanent magnet is a low-grade permanent magnet, and at least one second permanent magnet is a high-grade permanent magnet. Thus, while achieving the same magnetic energy output effect, the amount of high-grade permanent magnets can be reduced, the production cost of the motor with the rotor assembly can be reduced while ensuring the performance, the motor utilization rate can be improved, and the multi-pole structure can be matched.

[0021] Moreover, since the magnetism of the first permanent magnet is poorer than that of at least one second permanent magnet, it is relatively less affected by the demagnetization magnetic field, thereby improving the anti-demagnetization ability, reducing the magnetic leakage of the rotor assembly, and improving the torque performance of the motor with the rotor assembly.

[0022] Optionally, the second permanent magnet group uses high-grade rare earth permanent magnets to ensure the performance of the motor having the rotor assembly.

[0023] Optionally, along the circumferential direction of the rotor core, the first permanent magnet group and the second permanent magnet group are alternately arranged. It can be understood that the first permanent magnet group and the second permanent magnet group are of different types, that is, the motor having the rotor assembly is a composite permanent magnet hybrid alternating pole motor. Specifically, the first permanent magnet group includes a SPOKE-shaped permanent magnet group, and the second permanent magnet group includes a V-shaped permanent magnet group.

[0024] In some technical solutions, optionally, the rotor core is provided with a plurality of magnet slots, and a plurality of permanent magnet groups are respectively arranged in the plurality of magnet slots; the rotor assembly also includes at least one air slot, and at least one air slot is provided in the rotor core and connected to the at least one magnet slot.

[0025] In this technical solution, it is defined that the rotor core is provided with a plurality of magnet slots, and a plurality of permanent magnet groups are arranged in the plurality of magnet slots in a one-to-one correspondence, that is, the plurality of permanent magnet groups are all embedded in the rotor core. Thus, compared with the surface-mounted alternating-pole permanent magnet motor in the related technology, the anti-demagnetization capability of the rotor assembly can be effectively improved, the magnetic leakage of the rotor assembly can be reduced, and the torque performance of the motor having the rotor assembly can be improved.

[0026] The rotor assembly further comprises at least one air slot, specifically, at least one air slot is arranged on the rotor core, and at least one air slot is connected to at least one magnet slot. It can be understood that each air slot is arranged through the axial direction of the rotor core.

[0027] By providing at least one air slot, it is helpful to increase the magnetic circuit path, increase the magnetic field saturation, reduce leakage flux, and thus improve the torque performance of the motor with the rotor assembly, thereby improving the torque performance of the motor with the rotor assembly.

[0028] Specifically, the number of the air slots is at least two, and at least two air slots are connected to one magnet slot, or at least two air slots are connected to different magnet slots respectively.

[0029] Optionally, at least one air slot is arranged near the magnetic bridge located radially outside the permanent magnet group to increase the length of the magnetic bridge radially outside the permanent magnet group and improve the magnetic field saturation, which is beneficial to reduce the leakage flux of the rotor assembly and improve the torque performance of the motor.

[0030] Alternatively, at least one air slot is disposed close to the magnetic bridge located radially inside the permanent magnet group to reduce magnetic leakage radially inside the permanent magnet group and further improve the torque performance of the motor.

[0031] Optionally, at least one air slot is located radially inside the first permanent magnet, so as to reduce inner magnetic leakage and improve the reliability of the first permanent magnet.

[0032] Optionally, at least two air slots are respectively located on both sides of the second permanent magnet group along the circumferential direction.

[0033] In some technical solutions, optionally, at least one air slot is located radially inside the first permanent magnet group; and / or at least one air slot is located at an end of the second permanent magnet group along the circumferential direction of the rotor core.

[0034] In this technical solution, it is defined that at least one air slot is located radially inside the first permanent magnet group, and / or at least one air slot is located at an end of the second permanent magnet group along the circumferential direction of the rotor core.

[0035] Specifically, at least one air slot is arranged radially inside the first permanent magnet group, so as to increase the magnetic circuit path, increase the magnetic field saturation, and effectively reduce the leakage magnetic flux radially inside the first permanent magnet group, thereby improving the torque performance of the motor having the rotor assembly.

[0036] Optionally, there are at least two air slots located radially inside the first permanent magnet group to further reduce the magnetic leakage effect radially inside the first permanent magnet group, improve the anti-demagnetization capability, and thereby improve the torque performance of the motor having the rotor assembly.

[0037] At least one air slot is located at one end of the second permanent magnet group along the circumferential direction of the rotor core.

[0038] Alternatively, the at least one air slot is located at the other end of the second permanent magnet group along the circumferential direction of the rotor core.

[0039] Alternatively, air slots are provided at both ends of the second permanent magnet group along the circumference of the rotor core. The arrangement may be based on actual needs.

[0040] By setting an air slot at at least one end of the second permanent magnet group along the circumference of the rotor core, it is beneficial to increase the length of the radially outer magnetic bridge of the second permanent magnet group, improve the magnetic field saturation, reduce the leakage magnetic flux of the rotor assembly, and improve the torque performance of the motor.

[0041] In some technical solutions, optionally, the multiple magnet slots include a first magnet slot, at least one air slot is located radially inside the first magnet slot and connected to the first magnet slot, and the first permanent magnet group is arranged in the first magnet slot.

[0042] In this technical solution, it is defined that a plurality of magnet slots include a first magnet slot. Specifically, a first permanent magnet group is arranged in the first magnet slot. It can be understood that the first magnet slot is arranged through the axial direction of the rotor core. In other words, the first permanent magnet group is embedded in the rotor core, so that compared with the surface-mounted alternating pole permanent magnet motor in the related art, the anti-demagnetization ability of the rotor assembly can be effectively improved, the magnetic leakage of the rotor assembly can be reduced, and the torque performance of the motor having the rotor assembly can be improved.

[0043] At least one air slot is located radially inside the first magnet slot and is connected to the first magnet slot, thereby increasing the magnetic circuit path and the magnetic field saturation, thereby effectively reducing the leakage magnetic flux radially inside the first permanent magnet group, thereby improving the torque performance of the motor having the rotor assembly.

[0044] In some technical schemes, optionally, the multiple magnet slots also include a second magnet slot, and along the circumferential direction of the rotor core, at least one air slot is located at the end of the second magnet slot and is connected to the second magnet slot, and the second permanent magnet group is arranged in the second magnet slot.

[0045] In this technical solution, it is defined that a plurality of magnet slots include a second magnet slot. Specifically, the second permanent magnet group is arranged in the second magnet slot. It can be understood that the second magnet slot is arranged through the axial direction of the rotor core. In other words, the second permanent magnet group is embedded in the rotor core, so that compared with the surface-mounted alternating pole permanent magnet motor in the related art, the anti-demagnetization ability of the rotor assembly can be effectively improved, the magnetic leakage of the rotor assembly can be reduced, and the torque performance of the motor having the rotor assembly can be improved.

[0046] At least one air slot is located at the end of the second magnet slot and is connected to the second magnet slot, which is beneficial to increase the length of the radially outer magnetic bridge of the second permanent magnet group, improve the magnetic field saturation, reduce the leakage magnetic flux of the rotor assembly, and improve the torque performance of the motor.

[0047] In some technical schemes, optionally, the second permanent magnet group includes a third permanent magnet and a fourth permanent magnet, and a side of the third permanent magnet facing away from the center of the rotor core forms a preset angle δ with a side of the fourth permanent magnet facing away from the center of the rotor core, and the preset angle δ is an obtuse angle; wherein the magnetization direction of the third permanent magnet is the thickness direction of the third permanent magnet, and the magnetization direction of the fourth permanent magnet is the thickness direction of the fourth permanent magnet.

[0048] In this technical solution, it is defined that the second permanent magnet group includes a third permanent magnet and a fourth permanent magnet. Specifically, a side surface of the third permanent magnet facing away from the center of the rotor core is a first surface, and a side surface of the fourth permanent magnet facing away from the center of the rotor core is a second surface, wherein an obtuse angle is formed between the first surface and the second surface, that is, the second permanent magnet group is a V-shaped permanent magnet group, and the opening of the V-shape faces outward.

[0049] The magnetization direction of the third permanent magnet is the thickness direction of the third permanent magnet, that is, the third permanent magnet is magnetized along the thickness direction of the third permanent magnet.

[0050] The magnetization direction of the fourth permanent magnet is the thickness direction of the fourth permanent magnet, that is, the fourth permanent magnet is magnetized along the thickness direction of the fourth permanent magnet.

[0051] Optionally, the third permanent magnet and the fourth permanent magnet are both made of high-grade rare earth permanent magnets, that is, the third permanent magnet and the fourth permanent magnet have stronger magnetism.

[0052] In some technical solutions, optionally, the preset angle δ satisfies 100°≤δ≤145°.

[0053] In this technical solution, the value range of the preset angle δ is limited, that is, the obtuse angle between the first surface and the second surface is between 100° and 145°. That is, the angle between the magnetic tiles of the second permanent magnet group is limited to between 100° and 145°.

[0054] In some technical schemes, optionally, there is an angle α between a line connecting an end of the third permanent magnet facing away from the fourth permanent magnet and the center of the rotor core, and a line connecting an end of the fourth permanent magnet facing away from the third permanent magnet and the center of the rotor core, and the angle α satisfies 0.7π / p≤α≤1.2π / p; wherein P is the number of pole pairs of the rotor assembly.

[0055] In the technical solution, specifically, the end of the third permanent magnet facing away from the fourth permanent magnet is the first end, the end of the fourth permanent magnet facing away from the third permanent magnet is the second end, the line connecting the first end and the center of the rotor core is the first line, and the line connecting the second end and the center of the rotor core is the second line. The first line and the second line form an angle α, and the angle α is between 0.7π / p and 1.2π / p, where P is the number of pole pairs.

[0056] In some technical solutions, optionally, the thickness of at least one second permanent magnet is less than or equal to the thickness of the third permanent magnet; and / or the thickness of at least one second permanent magnet is less than or equal to the thickness of the fourth permanent magnet.

[0057] In this technical solution, it is defined that the thickness of at least one second permanent magnet is less than or equal to the thickness of the third permanent magnet.

[0058] Alternatively, the thickness of at least one second permanent magnet is less than or equal to the thickness of the fourth permanent magnet.

[0059] Alternatively, the thickness of at least one second permanent magnet is less than or equal to the thickness of the third permanent magnet, and the thickness of at least one second permanent magnet is less than or equal to the thickness of the fourth permanent magnet.

[0060] That is to say, by reducing the thickness of at least one second permanent magnet, that is, further reducing the amount of high magnetic material used in at least one second permanent magnet, the production cost of the motor having the rotor assembly can be reduced while ensuring performance, thereby improving the motor utilization rate and matching a multi-pole structure.

[0061] It can be understood that, since the first permanent magnet is located radially inside the two second permanent magnets, that is, the radial lengths of the two second permanent magnets are correspondingly reduced due to the provision of the first permanent magnet. By further reducing the thickness of at least one second permanent magnet, the amount of high magnetic material can be reduced as much as possible, thereby reducing the production cost of the motor.

[0062] Optionally, the thickness of each second permanent magnet is less than or equal to the thickness of the third permanent magnet, and / or the thickness of each second permanent magnet is less than or equal to the thickness of the fourth permanent magnet.

[0063] In some technical schemes, optionally, an angle β is formed between a center line of the second permanent magnet of the two second permanent magnets closer to the second permanent magnet group through the center of the rotor core and a line connecting an end of the fourth permanent magnet facing away from the third permanent magnet and the center of the rotor core, and the angle β satisfies 0.7π / p≤β≤1.2π / p; wherein P is the number of pole pairs of the rotor assembly.

[0064] In this technical solution, the center line of the second permanent magnet of the two second permanent magnets close to the second permanent magnet group through the center of the rotor core forms an angle β with the line connecting the end of the fourth permanent magnet away from the third permanent magnet and the center of the rotor core, that is, the second line forms an angle β with the center line of the second permanent magnet close to the second permanent magnet group through the center of the rotor core. And β is between 0.7π / p and 1.2π / p, where P is the number of pole pairs. That is, the range of the silicon steel pole angle is limited.

[0065] In some technical schemes, optionally, the center lines of the two second permanent magnets passing through the center of the rotor core are respectively the first center line and the second center line, and there is an angle γ between the first center line and the second center line, and the angle γ satisfies 0.7π / p≤γ≤1.2π / p; wherein P is the number of pole pairs of the rotor assembly.

[0066] In this technical solution, among the two second permanent magnets, the center line of one of the second permanent magnets passing through the center of the rotor core is the first center line, and the center line of the other second permanent magnet passing through the center of the rotor core is the second center line, wherein the angle between the first center line and the second center line is γ, and γ is between 0.7π / p and 1.2π / p, wherein P is the number of pole pairs.

[0067] In some technical solutions, optionally, the first permanent magnet includes ferrite; and / or at least one second permanent magnet includes a rare earth permanent magnet.

[0068] In this technical solution, the magnetic properties of the first permanent magnet and at least one second permanent magnet are defined. Specifically, the first permanent magnet includes ferrite, and it is understood that the ferrite is a low-grade permanent magnet, that is, the magnetic properties of the ferrite are poorer than those of the at least one second permanent magnet.

[0069] At least one second permanent magnet includes a rare earth permanent magnet. It can be understood that the rare earth permanent magnet is a high-grade permanent magnet, that is, the magnetism of the rare earth permanent magnet is stronger than that of the first permanent magnet.

[0070] Since the first permanent magnet is arranged radially inside the two second permanent magnets, the amount of the two second permanent magnets is reduced accordingly, and the magnetic properties of the first permanent magnet are poorer than those of at least one second permanent magnet, that is, the first permanent magnet is a low-grade permanent magnet, and at least one second permanent magnet is a high-grade permanent magnet. Thus, while achieving the same magnetic energy output effect, the amount of high-grade permanent magnets can be reduced, the production cost of the motor with the rotor assembly can be reduced while ensuring the performance, the motor utilization rate can be improved, and the multi-pole structure can be matched.

[0071] Moreover, since the magnetism of the first permanent magnet is poorer than that of at least one second permanent magnet, it is relatively less affected by the demagnetization magnetic field, thereby improving the anti-demagnetization ability, reducing the magnetic leakage of the rotor assembly, and improving the torque performance of the motor with the rotor assembly.

[0072] Optionally, each second permanent magnet is a rare earth permanent magnet to ensure the performance of the motor having the rotor assembly.

[0073] In some technical solutions, optionally, the rotor assembly further includes a magnetic bridge, which is arranged radially outside of at least one permanent magnet group, and / or the magnetic bridge is arranged radially inside of at least one permanent magnet group.

[0074] In this technical solution, it is defined that the rotor assembly further includes a magnetic bridge. Specifically, a magnetic bridge is arranged radially outside at least one permanent magnet group.

[0075] Alternatively, a magnetic bridge is arranged radially inside at least one permanent magnet group.

[0076] Alternatively, magnetic bridges are provided on both the radial inner side and the radial outer side of at least one permanent magnet group.

[0077] Alternatively, there are multiple permanent magnet groups, and among the multiple permanent magnet groups, at least one permanent magnet group is provided with a magnetic bridge on the radial inner side, and at least one of the remaining permanent magnet groups is provided with a magnetic bridge on the radial outer side. They are not listed here one by one. They can be specifically set according to actual needs.

[0078] By arranging a magnetic bridge on the radial inner side or radial outer side of at least one permanent magnet group, at least one permanent magnet group can be limited in the radial direction of the rotor core, thereby improving the installation stability of at least one permanent magnet group, thereby improving the operating stability and reliability of the motor having the rotor assembly.

[0079] Moreover, by providing a magnetic bridge, at least one permanent magnet group can be embedded in the rotor core, thereby effectively improving the anti-demagnetization capability of the rotor assembly, reducing magnetic leakage of the rotor assembly, and improving the torque performance of the motor having the rotor assembly.

[0080] Optionally, a magnetic bridge is provided on the radial inner side and / or radial outer side of each permanent magnet group, that is, each magnet group is embedded in the rotor core, thereby further improving the anti-demagnetization capability of the rotor assembly, reducing magnetic leakage of the rotor assembly, and improving the torque performance of the motor having the rotor assembly.

[0081] In some technical solutions, optionally, an outer wall of at least one magnetic bridge facing away from the center of the rotor core is provided with a chamfered surface.

[0082] In this technical solution, it is defined that at least one magnetic bridge is provided with a chamfered surface. Specifically, the outer wall of at least one magnetic bridge facing away from the center of the rotor core is provided with a chamfered surface. That is to say, the outer wall of at least one magnetic bridge located radially outside the permanent magnet group has a chamfered segment, that is, the outer wall of the radial outside of the tangentially magnetized permanent magnet is modified, which is beneficial to improve the air gap magnetic field, reduce torque fluctuations, and thereby enhance the torque performance of the motor having the rotor assembly.

[0083] Optionally, the outer wall of each magnetic bridge located radially outside the permanent magnet group has a chamfered segment to further improve the air gap magnetic field, reduce torque fluctuations, and thereby enhance the torque performance of the motor having the rotor assembly.

[0084] In some technical solutions, optionally, the rotor assembly further includes a magnetic barrier structure, which is disposed between an outer wall of the rotor core and at least one permanent magnet group.

[0085] In this technical solution, it is defined that the rotor assembly also includes a magnetic barrier structure, specifically, the magnetic barrier structure is arranged between the outer wall of the rotor core and at least one permanent magnet group. This is conducive to reducing stator saturation, improving the efficiency of the motor with the rotor assembly, improving the stress of the rotor assembly, and improving the reliability of the rotor assembly, thereby improving the reliability of the motor with the rotor assembly.

[0086] Optionally, a magnetic barrier structure is provided between the second permanent magnet group and the outer wall of the rotor core.

[0087] Optionally, the magnetic barrier structure comprises grooves or slits.

[0088] According to a second aspect of the present invention, there is provided an electric motor, comprising a rotor assembly as provided by any of the above technical solutions, and thus having all the beneficial technical effects of the rotor assembly, which will not be described in detail herein.

[0089] According to a third aspect of the present invention, a compressor is provided, comprising a rotor assembly or a motor as provided by any of the above technical solutions, thereby having all the beneficial technical effects of the rotor assembly or the motor, which will not be repeated here.

[0090] According to a fourth aspect of the present invention, there is provided a refrigeration device, comprising a compressor as provided by any of the above technical solutions, thereby having all the beneficial technical effects of the compressor, which will not be described in detail here.

[0091] Additional aspects and advantages according to the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0093] Figure 1 One of the structural schematic diagrams of the rotor in the related art is shown;

[0094] Figure 2 Shows Figure 1 The magnetic field line distribution diagram of the rotor in the related art shown;

[0095] Figure 3 The second schematic diagram of the structure of the rotor in the related art is shown;

[0096] Figure 4 Shows Figure 3The magnetic field line distribution diagram of the rotor in the related art shown;

[0097] Figure 5 One of the structural schematic diagrams of a rotor assembly according to an embodiment of the present invention is shown;

[0098] Figure 6 Shows Figure 5 A magnetic field line distribution diagram of the rotor assembly of the embodiment shown;

[0099] Figure 7 A second structural schematic diagram of a rotor assembly according to an embodiment of the present invention is shown;

[0100] Figure 8 A third structural schematic diagram of a rotor assembly according to an embodiment of the present invention is shown;

[0101] Fig. 9 Shows Figure 7 A magnetic field line distribution diagram of the rotor assembly of the embodiment shown;

[0102] Fig.10 A comparison chart of permanent magnet cost and demagnetization rate according to an embodiment of the present invention is shown.

[0103] in, Figures 1 to 4 The corresponding relationship between the reference numerals and the component names is as follows:

[0104] 10' rotor, 20' permanent magnet, 30' first permanent magnet, 40' second permanent magnet;

[0105] Figures 5 to 9 The corresponding relationship between the reference numerals and the component names is as follows:

[0106] 100 rotor assembly, 110 rotor core, 112 magnet slot, 113 first magnet slot, 114 second magnet slot, 116 first end, 117 second end, 120 permanent magnet group, 130 first permanent magnet group, 131 first permanent magnet, 132 second permanent magnet, 140 second permanent magnet group, 141 third permanent magnet, 142 fourth permanent magnet, 150 air slot, 160 magnetic bridge, 161 cambered surface, 170 magnetic barrier structure. DETAILED DESCRIPTION

[0107] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0108] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0109] Refer to the following Figures 5 to 10 The rotor assembly 100, the motor, the compressor and the refrigeration device provided according to some embodiments of the present invention are described.

[0110] In one embodiment according to the present application, Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, a rotor assembly 100 is proposed, and the rotor assembly 100 includes: a rotor core 110; a plurality of permanent magnet groups 120, including a first permanent magnet group 130 and a second permanent magnet group 140 arranged in the rotor core 110 along the circumferential direction of the rotor core 110 at intervals, the rotor core 110 between the first permanent magnet group 130 and the second permanent magnet group 140 constitutes an alternating pole, the first permanent magnet group 130 includes a first permanent magnet 131 and two second permanent magnets 132, and the two second permanent magnets 132 are The first permanent magnets 131 are arranged radially at intervals, and at least a portion of the first permanent magnet 131 is located radially inside the two second permanent magnets 132; the magnetization direction of the second permanent magnets 132 is tangential, and the magnetization direction of the first permanent magnet 131 is radial; wherein, the magnetization directions of the two second permanent magnets 132 are opposite, and the magnetization direction of the first permanent magnet 131 is toward the outside of the rotor core 110; or, the magnetization directions of the two second permanent magnets 132 are opposite, and the magnetization direction of the first permanent magnet 131 is toward the inside of the rotor core 110.

[0111] The rotor assembly 100 provided in an embodiment of the present invention includes a rotor core 110 and a plurality of permanent magnet groups 120. Specifically, the plurality of permanent magnet groups 120 include a first permanent magnet group 130 and a second permanent magnet group 140, and along the circumferential direction of the rotor core 110, the first permanent magnet group 130 and the second permanent magnet group 140 are arranged at intervals, that is, there is a silicon steel pole between the first permanent magnet group 130 and the second permanent magnet group 140.

[0112] The rotor core 110 between the first permanent magnet group 130 and the second permanent magnet group 140 forms alternating poles. That is, the motor having the rotor assembly 100 is an alternating pole motor.

[0113] The first permanent magnet group 130 includes a first permanent magnet 131 and two second permanent magnets 132 . The two second permanent magnets 132 are radially spaced apart, that is, the two second permanent magnets 132 are spaced apart along the circumferential direction of the rotor core 110 , and each second permanent magnet 132 extends along the radial direction of the rotor core 110 .

[0114] At least a portion of the first permanent magnet 131 is located radially inward of the two second permanent magnets 132 .

[0115] The magnetization direction of the first permanent magnet 131 is radial, and the magnetization direction of the second permanent magnet 132 is tangential.

[0116] When the first permanent magnet group 130 is magnetized, when the magnetization directions of the two second permanent magnets 132 face each other, the magnetization direction of the first permanent magnet 131 is toward the outside of the rotor core 110, that is, the magnetization direction of the first permanent magnet 131 is radially outward. When the magnetization directions of the two second permanent magnets 132 face each other, the magnetization direction of the first permanent magnet 131 is toward the inside of the rotor core 110, that is, the magnetization direction of the first permanent magnet 131 is radially inward.

[0117] That is to say, the magnetization direction of the first permanent magnet 131 is consistent with the magnetization direction of each second permanent magnet 132, that is, they are magnetized inwardly or outwardly at the same time. Thus, the magnetic circuit of the first permanent magnet 131 is connected in parallel with the magnetic circuit of each second permanent magnet 132, so that the first permanent magnet group 130 has a certain magnetic concentration effect. Even if the magnetic properties of the first permanent magnet 131 are poor, it can achieve the same magnetic energy output effect when combined with the two second permanent magnets 132.

[0118] Therefore, the first permanent magnet 131 can be made of a low-grade permanent magnet, so as to reduce the amount of high-grade permanent magnets while achieving the same magnetic energy output effect, thereby reducing the production cost of the motor with the rotor assembly 100 while ensuring performance and improving the motor utilization rate.

[0119] In some embodiments, optionally, the magnetism of the first permanent magnet 131 is smaller than the magnetism of the at least one second permanent magnet 132 .

[0120] In this embodiment, since the first permanent magnet 131 is arranged radially inside the two second permanent magnets 132, the amount of the two second permanent magnets 132 is reduced accordingly, and the magnetic properties of the first permanent magnet 131 are poorer than the magnetic properties of at least one second permanent magnet 132, that is, the first permanent magnet 131 is a low-grade permanent magnet, and at least one second permanent magnet 132 is a high-grade permanent magnet. Thus, while achieving the same magnetic energy output effect, the amount of high-grade permanent magnets can be reduced, the production cost of the motor having the rotor assembly 100 can be reduced while ensuring the performance, the motor utilization rate can be improved, and the multi-pole structure can be matched.

[0121] Moreover, since the magnetism of the first permanent magnet 131 is poorer than that of the at least one second permanent magnet 132, it is relatively less affected by the demagnetization magnetic field, thereby improving the anti-demagnetization ability, reducing the magnetic leakage of the rotor assembly 100, and improving the torque performance of the motor having the rotor assembly 100.

[0122] Figure 5 In the figure, the direction of the small arrows in the first permanent magnet 131 and the second permanent magnet 132 is one of the magnetization directions of the first permanent magnet 131 and the second permanent magnet 132 .

[0123] Optionally, the second permanent magnet group 140 uses permanent magnets with a high grade of rare earth to ensure the performance of the motor having the rotor assembly 100 .

[0124] Optionally, along the circumferential direction of the rotor core 110, the first permanent magnet group 130 and the second permanent magnet group 140 are alternately arranged. It can be understood that the first permanent magnet group 130 and the second permanent magnet group 140 are of different types, that is, the motor with the rotor assembly 100 is a composite permanent magnet hybrid alternating pole motor. Specifically, the first permanent magnet group 130 includes a SPOKE-shaped permanent magnet group, and the second permanent magnet group 140 includes a V-shaped permanent magnet group.

[0125] like Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, in some embodiments, optionally, the rotor core 110 is provided with a plurality of magnet slots 112, and a plurality of permanent magnet groups 120 are respectively arranged in the plurality of magnet slots 112; the rotor assembly 100 also includes at least one air slot 150, and at least one air slot 150 is provided in the rotor core 110 and is connected to at least one magnet slot 112.

[0126] In this embodiment, it is defined that the rotor core 110 is provided with a plurality of magnet slots 112, and a plurality of permanent magnet groups 120 are arranged in the plurality of magnet slots 112 in a one-to-one correspondence, that is, the plurality of permanent magnet groups 120 are all embedded in the rotor core 110, thereby effectively improving the anti-demagnetization ability of the rotor assembly 100, reducing the magnetic leakage of the rotor assembly 100, and improving the torque performance of the motor having the rotor assembly 100, compared with the surface-mounted alternating-pole permanent magnet motor in the related technology.

[0127] The rotor assembly 100 further includes at least one air slot 150. Specifically, at least one air slot 150 is disposed on the rotor core 110, and at least one air slot 150 is connected to at least one magnet slot 112. It can be understood that each air slot 150 is disposed through the rotor core 110 in the axial direction.

[0128] By providing at least one air slot 150 , it is helpful to increase the magnetic circuit path, increase the magnetic field saturation, reduce leakage flux, and thus improve the torque performance of the motor having the rotor assembly 100 .

[0129] Specifically, the number of the air slots 150 is at least two, and at least two air slots 150 are connected to one magnet slot 112, or at least two air slots 150 are respectively connected to different magnet slots 112. The specific configuration can be based on actual needs.

[0130] Optionally, at least one air slot 150 is arranged near the magnetic bridge 160 located radially outside the permanent magnet group 120 to increase the length of the magnetic bridge 160 radially outside the permanent magnet group 120 and improve the magnetic field saturation, which is beneficial to reducing the leakage magnetic flux of the rotor assembly 100 and improving the torque performance of the motor.

[0131] Alternatively, at least one air slot 150 is disposed close to the magnetic bridge 160 located radially inside the permanent magnet group 120 to reduce magnetic leakage radially inside the permanent magnet group 120 and further improve the torque performance of the motor.

[0132] Optionally, at least one air slot 150 is located radially inside the first permanent magnet 131 , so as to reduce the inner magnetic leakage and improve the reliability of the first permanent magnet 131 .

[0133] Optionally, at least two air slots 150 are respectively located on both sides of the second permanent magnet group 140 along the circumferential direction.

[0134] like Figure 7 As shown, one of the air slots 150 is along the circumferential direction of the rotor core 110 and the end away from the second permanent magnet group 140 is point R, and the other air slot 150 is along the circumferential direction of the rotor core 110 and the end away from the second permanent magnet group 140 is point S, wherein the line connecting point S and the center point O of the rotor core 110 is the third line, and the angle β' between the third line and the second line satisfies 0.05π / p≤β'≤0.20π / p, wherein P is the number of pole pairs of the rotor assembly 100.

[0135] like Figure 5 , Figure 7 and Figure 8 As shown, in some embodiments, optionally, at least one air slot 150 is located radially inside the first permanent magnet group 130 ; and / or at least one air slot 150 is located at the end of the second permanent magnet group 140 along the circumferential direction of the rotor core 110 .

[0136] In this embodiment, at least one air groove 150 is defined to be located radially inside the first permanent magnet group 130, and / or at least one air groove 150 is located at an end of the second permanent magnet group 140 along the circumferential direction of the rotor core 110.

[0137] Specifically, at least one air groove 150 is arranged radially inside the first permanent magnet group 130, so as to be able to increase the magnetic circuit path, increase the magnetic field saturation degree, and further effectively reduce the magnetic leakage radially inside the first permanent magnet group 130, thereby improving the torque performance of the motor having the rotor assembly 100.

[0138] Optionally, the number of air grooves 150 located radially inside the first permanent magnet group 130 is at least two, so as to further reduce the magnetic leakage effect radially inside the first permanent magnet group 130, improve the demagnetization resistance ability, and further improve the torque performance of the motor having the rotor assembly 100.

[0139] Specifically, at least one air groove 150 is located at one end of the second permanent magnet group 140 along the circumferential direction of the rotor core 110.

[0140] Alternatively, at least one air groove 150 is located at the other end of the second permanent magnet group 140 along the circumferential direction of the rotor core 110.

[0141] Alternatively, air grooves 150 are arranged at both ends of the second permanent magnet group 140 along the circumferential direction of the rotor core 110. Specifically, it can be set according to actual needs.

[0142] By arranging at least one air groove 150 at an end of the second permanent magnet group 140 along the circumferential direction of the rotor core 110, it is beneficial to increase the length of the magnetic bridge 160 radially outside the second permanent magnet group 140, improve the magnetic field saturation degree, and is beneficial to reducing the magnetic leakage of the rotor assembly 100 and improving the torque performance of the motor.

[0143] As Figure 5 、 Figure 7 and Figure 8 shown, in some embodiments, optionally, a plurality of magnet grooves 112 include a first magnet groove 113, at least one air groove 150 is located radially inside the first magnet groove 113 and communicates with the first magnet groove 113, and the first permanent magnet group 130 is arranged in the first magnet groove 113.

[0144] In this embodiment, a plurality of magnet slots 112 are defined including a first magnet slot 113. Specifically, a first permanent magnet group 130 is disposed in the first magnet slot 113. It can be understood that the first magnet slot 113 is disposed through the axial direction of the rotor core 110. In other words, the first permanent magnet group 130 is embedded in the rotor core 110, thereby effectively improving the anti-demagnetization capability of the rotor assembly 100, reducing magnetic leakage of the rotor assembly 100, and improving the torque performance of the motor having the rotor assembly 100, compared with the surface-mounted alternating-pole permanent magnet motor in the related art.

[0145] At least one air slot 150 is located radially inside the first magnet slot 113 and is connected to the first magnet slot 113, thereby increasing the magnetic circuit path and the magnetic field saturation, thereby effectively reducing the leakage magnetic flux radially inside the first permanent magnet group 130, thereby improving the torque performance of the motor having the rotor assembly 100.

[0146] like Figure 5 , Figure 7 and Figure 8 As shown, in some embodiments, optionally, the plurality of magnet slots 112 also include a second magnet slot 114, and along the circumferential direction of the rotor core 110, at least one air slot 150 is located at the end of the second magnet slot 114 and is connected to the second magnet slot 114, and the second permanent magnet group 140 is disposed in the second magnet slot 114.

[0147] In this embodiment, a plurality of magnet slots 112 are defined including a second magnet slot 114 . Specifically, the second permanent magnet group 140 is disposed in the second magnet slot 114 . It can be understood that the second magnet slot 114 is disposed through the axial direction of the rotor core 110 .

[0148] That is to say, the second permanent magnet group 140 is embedded in the rotor core 110, so that compared with the surface-mounted alternating-pole permanent magnet motor in the related technology, it can effectively improve the anti-demagnetization ability of the rotor assembly 100, reduce the magnetic leakage of the rotor assembly 100, and improve the torque performance of the motor having the rotor assembly 100.

[0149] At least one air slot 150 is located at the end of the second magnet slot 114 and is connected to the second magnet slot 114, which is beneficial to increase the length of the radially outer magnetic bridge 160 of the second permanent magnet group 140, improve the magnetic field saturation, and help reduce the leakage magnetic field of the rotor assembly 100 and improve the torque performance of the motor.

[0150] like Figure 5 , Figure 7 and Figure 8As shown, in some embodiments, optionally, the second permanent magnet group 140 includes a third permanent magnet 141 and a fourth permanent magnet 142, and a side of the third permanent magnet 141 facing away from the center of the rotor core 110 forms a preset angle δ with a side of the fourth permanent magnet 142 facing away from the center of the rotor core 110, and the preset angle δ is an obtuse angle; wherein the magnetization direction of the third permanent magnet 141 is the thickness direction of the third permanent magnet 141, and the magnetization direction of the fourth permanent magnet 142 is the thickness direction of the fourth permanent magnet 142.

[0151] In this embodiment, it is defined that the second permanent magnet group 140 includes a third permanent magnet 141 and a fourth permanent magnet 142. Specifically, a side surface of the third permanent magnet 141 facing away from the center of the rotor core 110 is a first surface, and a side surface of the fourth permanent magnet 142 facing away from the center of the rotor core 110 is a second surface, wherein an obtuse angle is formed between the first surface and the second surface, that is, the second permanent magnet group 140 is a V-shaped permanent magnet group 120, and the V-shaped opening faces outward.

[0152] The magnetization direction of the third permanent magnet 141 is the thickness direction of the third permanent magnet 141 , that is, the third permanent magnet 141 is magnetized along the thickness direction of the third permanent magnet 141 .

[0153] The magnetization direction of the fourth permanent magnet 142 is the thickness direction of the fourth permanent magnet 142 , that is, the fourth permanent magnet 142 is magnetized along the thickness direction of the fourth permanent magnet 142 .

[0154] Figure 5 In FIG. 1 , the directions of the small arrows in the third permanent magnet 141 and the fourth permanent magnet 142 are the magnetization directions of the third permanent magnet 141 and the fourth permanent magnet 142 .

[0155] Optionally, the third permanent magnet 141 and the fourth permanent magnet 142 are both made of high-grade rare earth permanent magnets, that is, the third permanent magnet 141 and the fourth permanent magnet 142 have stronger magnetism.

[0156] like Figure 8 As shown, in some embodiments, optionally, the preset angle δ satisfies 100°≤δ≤145°.

[0157] In this embodiment, the value range of the preset angle δ is limited, that is, the obtuse angle between the first surface and the second surface is between 100° and 145°. That is, the angle between the magnetic tiles of the second permanent magnet group 140 is limited to between 100° and 145°.

[0158] like Figure 7 and Figure 8As shown, in some embodiments, optionally, there is an angle α between a line connecting an end of the third permanent magnet 141 facing away from the fourth permanent magnet 142 and the center of the rotor core 110, and a line connecting an end of the fourth permanent magnet 142 facing away from the third permanent magnet 141 and the center of the rotor core 110, and the angle α satisfies 0.7π / p≤α≤1.2π / p; wherein P is the number of pole pairs of the rotor assembly 100.

[0159] In this embodiment, specifically, one end of the third permanent magnet 141 facing away from the fourth permanent magnet 142 is the first end 116, one end of the fourth permanent magnet 142 facing away from the third permanent magnet 141 is the second end 117, a line connecting the first end 116 and the center of the rotor core 110 is the first line, and a line connecting the second end 117 and the center of the rotor core 110 is the second line. The first line and the second line form an angle α, and the angle α is between 0.7π / p and 1.2π / p, where P is the number of pole pairs.

[0160] like Figure 7 As shown, the first end 116 is Figure 7 The position of point P in the middle, the second end 117, that is, the position of point Q, the line connecting the first end 116 and the center of the rotor core 110 is the first line, that is, the line connecting point P and the center point O of the rotor core 110 is the first line, and the line connecting the second end 117 and the center of the rotor core 110 is the second line, that is, the line connecting point Q and the center point O of the rotor core 110 is the second line.

[0161] The first line and the second line form an angle α, and the angle α is between 0.7π / p and 1.2π / p, where P is the number of pole pairs. Figure 7 As shown, P=4. That is, the range of the angle between the position P, Q where the gap first exists inside the silicon steel pole and the center O of the rotor core 110 is limited.

[0162] like Figure 5 As shown, in some embodiments, optionally, the thickness of at least one second permanent magnet 132 is less than or equal to the thickness of the third permanent magnet 141 ; and / or the thickness of at least one second permanent magnet 132 is less than or equal to the thickness of the fourth permanent magnet 142 .

[0163] In this embodiment, it is defined that the thickness of the at least one second permanent magnet 132 is less than or equal to the thickness of the third permanent magnet 141 .

[0164] Alternatively, the thickness of the at least one second permanent magnet 132 is less than or equal to the thickness of the fourth permanent magnet 142 .

[0165] Alternatively, the thickness of at least one second permanent magnet 132 is less than or equal to the thickness of the third permanent magnet 141, and the thickness of at least one second permanent magnet 132 is less than or equal to the thickness of the fourth permanent magnet 142. The thickness can be set according to actual needs.

[0166] That is to say, by reducing the thickness of at least one second permanent magnet 132, that is, further reducing the amount of high magnetic material used in at least one second permanent magnet 132, the production cost of the motor having the rotor assembly 100 can be reduced while ensuring performance, thereby improving the utilization rate of the motor and matching a multi-pole structure.

[0167] It can be understood that, since the first permanent magnet 131 is located radially inside the two second permanent magnets 132, that is, the radial lengths of the two second permanent magnets 132 are correspondingly reduced due to the provision of the first permanent magnet 131. By further reducing the thickness of at least one second permanent magnet 132, the amount of high magnetic material used can be reduced as much as possible, thereby reducing the production cost of the motor.

[0168] like Figure 5 As shown, the thickness of the second permanent magnet 132 is d1, and the thickness of the third permanent magnet 141 or the fourth permanent magnet 142 is d2, wherein d1≤d2.

[0169] Optionally, the thickness of each second permanent magnet 132 is less than or equal to the thickness of the third permanent magnet 141 , and / or the thickness of each second permanent magnet 132 is less than or equal to the thickness of the fourth permanent magnet 142 .

[0170] like Figure 5 , Figure 7 and Figure 8 As shown, in some embodiments, optionally, an angle β is formed between a center line of the second permanent magnet 132 of the two second permanent magnets 132 that is close to the second permanent magnet group 140 and passes through the center of the rotor core 110, and a line connecting the end of the fourth permanent magnet 142 that faces away from the third permanent magnet 141 and the center of the rotor core 110, and the angle β satisfies 0.7π / p≤β≤1.2π / p; wherein P is the number of pole pairs of the rotor assembly 100.

[0171] In this embodiment, the center line of the second permanent magnet 132 of the two second permanent magnets 132 that is close to the second permanent magnet group 140 and passes through the center of the rotor core 110 forms an angle β with the line connecting the end of the fourth permanent magnet 142 that is away from the third permanent magnet 141 and the center of the rotor core 110, that is, the second line forms an angle β with the center line of the second permanent magnet 132 that is close to the second permanent magnet group 140 and passes through the center of the rotor core 110. And β is between 0.7π / p and 1.2π / p, where P is the number of pole pairs. That is, the range of the silicon steel pole angle is limited.

[0172] It can be understood that the line connecting the position of the Q point and the center of the rotor core 110 is the second line.

[0173] like Figure 5, Figure 7 and Figure 8 As shown in Figure 7 and Figure 8 , in some embodiments, optionally, the center lines of the two second permanent magnets 132 passing through the center of the rotor core 110 are the first center line and the second center line respectively, and the angle γ between the first center line and the second center line satisfies 0.7π / p ≤ γ ≤ 1.2π / p; wherein, P is the number of pole pairs of the rotor assembly 100.

[0174] In this embodiment, among the two second permanent magnets 132, the center line of one second permanent magnet 132 passing through the center of the rotor core 110 is the first center line, and the center line of the other second permanent magnet 132 passing through the center of the rotor core 110 is the second center line. Among them, the included angle between the first center line and the second center line is γ, and γ is between 0.7π / p and 1.2π / p, where P is the number of pole pairs.

[0175] In some embodiments, optionally, the first permanent magnet 131 includes ferrite; and / or at least one second permanent magnet 132 includes rare earth permanent magnet.

[0176] In this embodiment, the magnetisms of the first permanent magnet 131 and at least one second permanent magnet 132 are defined. Specifically, the first permanent magnet 131 includes ferrite. It can be understood that ferrite is a low-grade permanent magnet, that is, the magnetism of ferrite is poorer than that of at least one second permanent magnet 132.

[0177] At least one second permanent magnet 132 includes rare earth permanent magnet. It can be understood that rare earth permanent magnet is a high-grade permanent magnet, that is, the magnetism of rare earth permanent magnet is stronger than that of the first permanent magnet 131.

[0178] Since the first permanent magnet 131 is arranged on the radial inner side of the two second permanent magnets 132, that is, the usage amount of the two second permanent magnets 132 is correspondingly reduced, and the magnetism of the first permanent magnet 131 is poorer than that of at least one second permanent magnet 132, that is, the first permanent magnet 131 is a low-grade permanent magnet and at least one second permanent magnet 132 is a high-grade permanent magnet. Thus, while achieving the same magnetic energy output effect, the usage amount of high-grade permanent magnets can be reduced, the production cost of the motor with the rotor assembly 100 can be reduced while ensuring the performance, the motor utilization rate can be improved, and a multi-pole structure can be matched.

[0179] Moreover, since the magnetism of the first permanent magnet 131 is poorer than that of at least one second permanent magnet 132, the influence of the demagnetizing magnetic field on it is relatively small, and thus the demagnetization resistance ability can be improved, the magnetic leakage of the rotor assembly 100 can be reduced, and the torque performance of the motor with the rotor assembly 100 can be improved.

[0180] Optionally, each second permanent magnet 132 is a rare earth permanent magnet to ensure the performance of the motor having the rotor assembly 100 .

[0181] like Figure 5 , Figure 7 and Figure 8 As shown, in some embodiments, optionally, the rotor assembly 100 further includes a magnetic bridge 160 , which is disposed radially outside of at least one permanent magnet group 120 , and / or the magnetic bridge 160 is disposed radially inside of at least one permanent magnet group 120 .

[0182] In this embodiment, it is defined that the rotor assembly 100 further includes a magnetic bridge 160 . Specifically, a magnetic bridge 160 is disposed radially outside of at least one permanent magnet group 120 .

[0183] Alternatively, a magnetic bridge 160 is disposed radially inside at least one permanent magnet group 120 .

[0184] Alternatively, magnetic bridges 160 are disposed on both the radial inner side and the radial outer side of at least one permanent magnet group 120 .

[0185] Alternatively, there are multiple permanent magnet groups 120, and among the multiple permanent magnet groups 120, at least one permanent magnet group 120 is provided with a magnetic bridge 160 on the radial inner side, and at least one of the remaining permanent magnet groups 120 is provided with a magnetic bridge 160 on the radial outer side. They are not listed here one by one. They can be set according to actual needs.

[0186] By arranging a magnetic bridge 160 on the radial inner side or radial outer side of at least one permanent magnet group 120, it is possible to limit the radial direction of at least one permanent magnet group 120 along the rotor core 110, thereby improving the installation stability of at least one permanent magnet group 120, and thereby improving the operating stability and reliability of the motor having the rotor assembly 100.

[0187] Moreover, by providing the magnetic bridge 160 , at least one permanent magnet group 120 can be embedded in the rotor core 110 , thereby effectively improving the anti-demagnetization capability of the rotor assembly 100 , reducing magnetic leakage of the rotor assembly 100 , and improving the torque performance of the motor having the rotor assembly 100 .

[0188] Optionally, a magnetic bridge 160 is provided on the radial inner side and / or radial outer side of each permanent magnet group 120, that is, each magnet group is embedded in the rotor core 110, thereby further improving the anti-demagnetization capability of the rotor assembly 100, reducing the magnetic leakage of the rotor assembly 100, and improving the torque performance of the motor having the rotor assembly 100.

[0189] like Figure 7 and Figure 8As shown, in some embodiments, optionally, an outer wall of at least one magnetic bridge 160 facing away from the center of the rotor core 110 is provided with a chamfered surface 161 .

[0190] In this embodiment, it is defined that at least one magnetic bridge 160 is provided with a chamfered surface 161. Specifically, the outer wall of at least one magnetic bridge 160 facing away from the center of the rotor core 110 is provided with a chamfered surface 161, that is, the outer wall of at least one magnetic bridge 160 located radially outside the permanent magnet group 120 has a chamfered segment, that is, the outer wall of the radial outside of the tangentially magnetized permanent magnet is modified, which is beneficial to improve the air gap magnetic field, reduce torque fluctuations, and further enhance the torque performance of the motor having the rotor assembly 100.

[0191] Optionally, the outer wall of each magnetic bridge 160 located radially outside the permanent magnet group 120 has a chamfered segment to further improve the air gap magnetic field, reduce torque fluctuations, and thereby enhance the torque performance of the motor having the rotor assembly 100 .

[0192] like Figure 7 and Figure 8 As shown, in some embodiments, optionally, the rotor assembly 100 further includes a magnetic barrier structure 170 , and the magnetic barrier structure 170 is disposed between the outer wall of the rotor core 110 and the at least one permanent magnet group 120 .

[0193] In this embodiment, it is defined that the rotor assembly 100 further includes a magnetic barrier structure 170. Specifically, the magnetic barrier structure 170 is disposed between the outer wall of the rotor core 110 and at least one permanent magnet group 120. This is beneficial to reducing stator saturation, improving the efficiency of the motor having the rotor assembly 100, improving the stress of the rotor assembly 100, and improving the reliability of the rotor assembly 100, thereby improving the reliability of the motor having the rotor assembly 100.

[0194] Optionally, a magnetic barrier structure 170 is disposed between the second permanent magnet group 140 and the outer wall of the rotor core 110 .

[0195] Optionally, the magnetic barrier structure 170 includes grooves or slits.

[0196] In a specific embodiment, Figure 1 As shown, it is a schematic diagram of the original first comparative example (related technology) p=4 rotor structure, and the conventional alternating poles only include the rotor 10', the permanent magnet 20' and the silicon steel pole. In this comparative example, the number of magnetic field pole pairs p=4, the number of permanent magnets 20' is 4, the number of silicon steel poles is 4, and the permanent magnets 20' and silicon steel poles are alternating. Among them, the angle of the silicon steel pole (β) is 35°, the permanent magnet pole (α) is 55°, and the angle occupied by the permanent magnet 20' is 55 degrees. The magnetization direction of all permanent magnets 20' is radially outward. As Figure 2, the magnetic field line distribution diagram of the first comparative example, through the joint action of 4 permanent magnet poles and 4 silicon steel poles, a total of 4 pairs of magnetic field poles are formed. The permanent magnets 20' are all made of high-grade rare earth permanent magnets.

[0197] like Figure 3 As shown, it is a schematic diagram of the rotor structure of p=4 of the second comparative example (related technology). The rotor 10' contains both a V-shaped permanent magnet group (the first permanent magnet 30') and a SPOKE-shaped permanent magnet group (the second permanent magnet 40'). The permanent magnet group (the first permanent magnet 30') is magnetized along the vertical direction of the V shape, and the permanent magnet group (the second permanent magnet 40') is magnetized along the circumferential direction. One of the methods is marked in the figure. The first permanent magnet 30' and the second permanent magnet 40' both adopt an embedded structure, and most of the permanent magnets are far away from the rotor surface. Between each permanent magnet, silicon steel poles are alternately contained in the circumferential direction. The first permanent magnet 30', the second permanent magnet 40' and the silicon steel pole occupy α=45°, β=45°, γ=45, α+2β+γ=180°=2×π / p×k, k=2 respectively. The first permanent magnet 30' is embedded in the rotor 10' by means of an external magnetic bridge, and the second permanent magnet 40' is embedded in the surface of the rotor 10' by means of an external magnetic bridge. The first permanent magnets 30' are not adjacent, and the angles α and β between the silicon steel pole and the second permanent magnet 40' both satisfy [0.7×π / p, 1.2×π / p]. The thickness of the second permanent magnet 40' is less than or equal to the thickness of the first permanent magnet 30', and α is the angle between the position where the gap first exists on the inner side of the silicon steel pole and the origin (the center of the rotor core). The V-shaped angle δ of the two permanent magnet pieces of the first permanent magnet 30' is 120°, which satisfies 100°~145°. Figure 4 The magnetic flux diagram of the second comparative example p=4 is shown in FIG. 1 , where the rotor can effectively generate a 4-pole magnetic field. The first permanent magnet 30 ′ and the second permanent magnet 40 ′ are both made of high-grade rare earth permanent magnets.

[0198] like Figure 5 As shown, it is a schematic diagram of the rotor structure of p=4 of the first embodiment of the present application. The rotor assembly 100 contains a V-shaped permanent magnet group (second permanent magnet group 140), a SPOKE-shaped permanent magnet group (second permanent magnet 132), and a straight-line permanent magnet group (first permanent magnet 131). The second permanent magnet group 140 is magnetized along the vertical direction of the V-shape, the second permanent magnet 132 is magnetized along the circumferential direction, and the first permanent magnet 131 is magnetized along the vertical direction of the straight line. The second permanent magnet 132 and the first permanent magnet 131 are magnetized toward the inside or outside of the rotor, and one of the methods is marked in the figure. The first permanent magnet 131, the second permanent magnet 132, and the second permanent magnet group 140 all adopt an embedded structure, and most of the permanent magnets are far away from the rotor surface. Between each permanent magnet group, silicon steel poles are alternately contained along the circumferential direction.

[0199] The second permanent magnet group 140 is the first pole, the two second permanent magnets 132 and the first permanent magnet 131 constitute the second pole, and the silicon steel pole constitutes the third pole, respectively occupying α = 45°, β = 45°, γ = 45, α + 2β + γ = 180° = 2 × π / p × k, k = 2. The two second permanent magnets 132 and the second permanent magnet group 140 are made of rare earth permanent magnet materials, and the first permanent magnet 131 is made of ferrite. The former permanent magnet has stronger magnetism than the latter, but the latter permanent magnet cost is much lower than the former.

[0200] The magnetic circuits of the two second permanent magnets 132 and the first permanent magnet 131 are connected in parallel, and have a certain magnetic concentration effect, so that even if the first permanent magnet 131 is of low grade and poor magnetic properties, it can achieve the same magnetic energy output effect when combined with the two second permanent magnets 132. The first permanent magnet group 130 is embedded in the rotor core 110 through an external magnetic bridge, and the second permanent magnet group 140 is embedded in the surface of the rotor core 110 through an external magnetic bridge. The second permanent magnet group 140 is not adjacent, and the angles α and β between the silicon steel pole and the first permanent magnet group 130 both satisfy [0.7×π / p, 1.2×π / p]. The thickness of the second permanent magnet 132 is less than or equal to the thickness of the second permanent magnet group 140, and α is the angle between the position PQ where the gap first exists on the inner side of the silicon steel pole and the origin. The V-shaped angle δ of the two permanent magnet pieces of the second permanent magnet group 140 is 120°, which satisfies 100°~145°. Figure 6 This is a schematic diagram of the flux linkage of the first embodiment when p=4. The rotor can effectively generate 4 pairs of pole magnetic fields.

[0201] Compared with the motor of the first comparative example, the motor has improved anti-demagnetization capability and improved reliability of embedded structure permanent magnets. Compared with the motor of the second comparative example, the amount of rare earth permanent magnets is reduced and replaced by ferrite, and the motor cost is further reduced.

[0202] like Figure 7 In the p=4 rotor structure of the second embodiment, the rotor assembly 100 simultaneously contains a V-shaped permanent magnet group (the second permanent magnet group 140), a SPOKE-shaped permanent magnet group (the second permanent magnet 132), and a straight-line permanent magnet group (the first permanent magnet 131). The permanent magnet group (the second permanent magnet group 140) is magnetized along the vertical direction of the V-shape, the second permanent magnet 132 is magnetized along the circumferential direction, and the first permanent magnet 131 is magnetized along the vertical direction of the straight line. The first permanent magnet 131 and the second permanent magnet 132 are magnetized toward the inside or the outside of the rotor, and one of the methods is marked in the figure.

[0203] The second permanent magnet 132 , the first permanent magnet 131 , and the second permanent magnet group 140 all adopt an embedded structure, and most of the permanent magnets are far away from the rotor surface.

[0204] Between each permanent magnet group, silicon steel poles are alternately contained along the circumferential direction.

[0205] The second permanent magnet group 140 is the first pole, the two second permanent magnets 132 and the first permanent magnet 131 constitute the second pole, and the silicon steel pole constitutes the third pole, respectively occupying α = 45°, β = 45°, γ = 45, α + 2β + γ = 180° = 2 × π / p × k, k = 2. The two second permanent magnets 132 and the second permanent magnet group 140 are made of rare earth permanent magnet materials, and the first permanent magnet 131 is made of ferrite. The former permanent magnet has stronger magnetism than the latter, but the latter permanent magnet cost is much lower than the former.

[0206] The magnetic circuits of the two second permanent magnets 132 and the first permanent magnet 131 are connected in parallel, and have a certain magnetic concentration effect, so that even if the first permanent magnet 131 is of low grade and poor magnetic properties, it can achieve the same magnetic energy output effect when combined with the two second permanent magnets 132. The first permanent magnet group 130 is embedded in the rotor core 110 through an external magnetic bridge, and the second permanent magnet group 140 is embedded in the surface of the rotor core 110 through an external magnetic bridge. The second permanent magnet group 140 is not adjacent, and the angles α and β between the silicon steel pole and the first permanent magnet group 130 both satisfy [0.7×π / p, 1.2×π / p]. The thickness of the second permanent magnet 132 is less than or equal to the thickness of the second permanent magnet group 140, and α is the angle between the position PQ where the gap first exists on the inner side of the silicon steel pole and the origin. The V-shaped angle δ of the two permanent magnet pieces of the second permanent magnet group 140 is 120°, which satisfies 100°~145°. Figure 6 The schematic diagram of the flux linkage of the first embodiment with p=4 is shown, and the rotor can effectively generate 4 pairs of pole magnetic fields. The second embodiment is based on the first embodiment, with the addition of hollowing of the outer magnetic bridge, rotor arc cutting and magnetic barriers.

[0207] like Figure 7 As shown, in the p=4 rotor structure of the second embodiment, air gaps (air slots 150) that penetrate the rotor are provided on both sides of the second permanent magnet group 140, that is, on both sides of PQ, and their extensions are points R and S respectively, and the angle between them and PQ is 10°, satisfying β'=0.05×π / p~0.20×π / p. The air gap is conducive to increasing the magnetic bridge outside the permanent magnet, reducing leakage and improving torque performance. A magnetic barrier structure 170 is provided on the outside of the second permanent magnet group 140, which is conducive to reducing saturation, improving motor efficiency, improving rotor stress, and improving rotor reliability. An air gap (air slot 150) is provided on the inside of the SPOKE pole (first permanent magnet group 130), and the air gap can also increase the length of the magnetic bridge inside the SPOKE pole permanent magnet, reduce leakage and improve torque performance.

[0208] like Figure 8As shown, the schematic diagram of the arc cutting and magnetic bridge of the second embodiment with p=4, the first permanent magnet group 130 and the second permanent magnet group 140 form a magnetic field of 4 pairs of poles together with the silicon steel pole. As in the first comparative example, an external magnetic bridge is set, and an arc cutting structure (arc cutting surface 161) is adopted. The arc cutting structure is beneficial to improving the air gap magnetic field and reducing torque fluctuation. The internal magnetic bridge of the SPOKE pole and the one-line pole uses an open magnetic bridge to reduce the inner leakage magnetic flux and ensure the reliability of the one-line pole. Fig. 9 The magnetic flux diagram of the second embodiment with p=4 is shown in FIG. 1 , and the rotor can effectively generate a 4-pole magnetic field. Compared with the motor of the first embodiment, the magnetic barrier, arc cutting and long magnetic bridge structure are beneficial to reducing magnetic leakage and improving torque performance.

[0209] like Fig.10 As shown, it is a comparison chart of the permanent magnet cost and demagnetization rate when p=4 according to the present invention. Compared with the first comparative example, the demagnetization rate of the motor in the first embodiment and the second embodiment is significantly improved, from 14.5% to less than 2%. The main reason is that the permanent magnets are all embedded in the rotor, and the low-grade ferrite of the inner first permanent magnet 131 is far away from the rotor, and it is less affected by the demagnetization magnetic field. If the permanent magnet cost in the first comparative example is defined as 1p.u., then in the second comparative example, the permanent magnet cost reduction limit is 10%. In order to further reduce the cost of permanent magnets, the cost of permanent magnets in the first and second embodiments proposed in this patent can be further reduced by 15% and 20%, and the cost of the motor is further reduced.

[0210] According to a second aspect of the present invention, there is provided a motor, comprising a rotor assembly 100 as provided in any of the above embodiments, and thus having all the beneficial technical effects of the rotor assembly 100, which will not be described in detail herein.

[0211] According to a third aspect of the present invention, a compressor is provided, comprising a rotor assembly 100 or a motor as provided in any of the above embodiments, thereby having all the beneficial technical effects of the rotor assembly 100 or the motor, which will not be repeated here.

[0212] According to a fourth aspect of the present invention, there is provided a refrigeration device, comprising a compressor as provided in any of the above embodiments, and thus having all the beneficial technical effects of the compressor, which will not be described in detail herein.

[0213] In the description of this specification, the terms "connection", "installation", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0214] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0215] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rotor assembly, It is characterized in that include: Rotor core; A plurality of permanent magnet groups, including a first permanent magnet group and a second permanent magnet group spaced apart in the rotor core along the circumferential direction of the rotor core, the rotor core between the first permanent magnet group and the second permanent magnet group constitutes alternating poles, the first permanent magnet group includes a first permanent magnet and two second permanent magnets, the two second permanent magnets are radially spaced apart, and at least a portion of the first permanent magnet is located radially inward of the two second permanent magnets; The magnetization direction of the second permanent magnet is tangential, and the magnetization direction of the first permanent magnet is radial; The magnetizing directions of the two second permanent magnets are opposite to each other, and the magnetizing direction of the first permanent magnet is toward the outside of the rotor core; or, the magnetizing directions of the two second permanent magnets are opposite to each other, and the magnetizing direction of the first permanent magnet is toward the inside of the rotor core.

2. The rotor assembly according to claim 1, It is characterized in that The magnetic properties of the first permanent magnet are lower than the magnetic properties of at least one of the second permanent magnets.

3. The rotor assembly according to claim 1, It is characterized in that The rotor core is provided with a plurality of magnet slots, and the plurality of permanent magnet groups are respectively arranged in the plurality of magnet slots; The rotor assembly further comprises: At least one air slot is provided in the rotor core and is connected to at least one of the magnet slots.

4. The rotor assembly according to claim 3, It is characterized in that At least one of the air slots is located radially inward of the first permanent magnet group; and / or at least one of the air slots is located at an end of the second permanent magnet group along the circumferential direction of the rotor core.

5. The rotor assembly according to claim 3, It is characterized in that The plurality of magnet slots include a first magnet slot, at least one of the air slots is located radially inward of the first magnet slot and is connected to the first magnet slot, and the first permanent magnet group is arranged in the first magnet slot.

6. The rotor assembly according to claim 3, It is characterized in that The plurality of magnet slots also include a second magnet slot. Along the circumferential direction of the rotor core, at least one air slot is located at the end of the second magnet slot and is connected to the second magnet slot. The second permanent magnet group is arranged in the second magnet slot.

7. A rotor assembly according to any one of claims 1 to 6, It is characterized in that The second permanent magnet group includes a third permanent magnet and a fourth permanent magnet, and a side of the third permanent magnet facing away from the center of the rotor core forms a preset angle δ with a side of the fourth permanent magnet facing away from the center of the rotor core, and the preset angle δ is an obtuse angle; The magnetization direction of the third permanent magnet is the thickness direction of the third permanent magnet, and the magnetization direction of the fourth permanent magnet is the thickness direction of the fourth permanent magnet.

8. The rotor assembly according to claim 7, It is characterized in that The preset angle δ satisfies 100°≤δ≤145°.

9. The rotor assembly according to claim 7, It is characterized in that An angle α is formed between a line connecting one end of the third permanent magnet facing away from the fourth permanent magnet and the center of the rotor core, and a line connecting one end of the fourth permanent magnet facing away from the third permanent magnet and the center of the rotor core, and the angle α satisfies 0.7π / p≤α≤1.2π / p; Wherein, P is the number of pole pairs of the rotor assembly.

10. The rotor assembly according to claim 7, It is characterized in that The thickness of at least one of the second permanent magnets is less than or equal to the thickness of the third permanent magnet; and / or The thickness of at least one of the second permanent magnets is less than or equal to the thickness of the fourth permanent magnet.

11. The rotor assembly according to claim 7, It is characterized in that An angle β is formed between a center line of the second permanent magnet of the two second permanent magnets that is close to the second permanent magnet group and passes through the center of the rotor core, and a line connecting an end of the fourth permanent magnet that faces away from the third permanent magnet and the center of the rotor core, and the angle β satisfies 0.7π / p≤β≤1.2π / p; Wherein, P is the number of pole pairs of the rotor assembly.

12. A rotor assembly according to any one of claims 1 to 6, It is characterized in that The center lines of the two second permanent magnets passing through the center of the rotor core are respectively a first center line and a second center line, and an angle γ is formed between the first center line and the second center line, and the angle γ satisfies 0.7π / p≤γ≤1.2π / p; Wherein, P is the number of pole pairs of the rotor assembly.

13. A rotor assembly according to any one of claims 1 to 6, It is characterized in that The first permanent magnet comprises ferrite; and / or At least one of said second permanent magnets comprises a rare earth permanent magnet.

14. A rotor assembly according to any one of claims 1 to 6, It is characterized in that Also includes: The magnetic bridge is arranged on the radial outside of at least one of the permanent magnet groups, and / or the magnetic bridge is arranged on the radial inside of at least one of the permanent magnet groups.

15. The rotor assembly according to claim 14, It is characterized in that An outer wall of at least one of the magnetic bridges facing away from the center of the rotor core is provided with a chamfered surface.

16. A rotor assembly according to any one of claims 1 to 6, It is characterized in that Also includes: The magnetic barrier structure is arranged between the outer wall of the rotor core and at least one of the permanent magnet groups.

17. A motor, It is characterized in that Comprising a rotor assembly as claimed in any one of claims 1 to 16.

18. A compressor, It is characterized in that include: A rotor assembly as claimed in any one of claims 1 to 16; or The electric machine as claimed in claim 17.

19. A refrigeration device, It is characterized in that Comprising the compressor of claim 18.

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