Rotor assembly and permanent magnet motor with same

Abstract

The invention provides a rotor assembly and a permanent magnet motor with the same. The rotor assembly comprises a first rotor assembly and a second rotor assembly, wherein the first rotor assembly comprises a first rotor iron core and a first permanent magnet which are arranged in the axial direction; the second rotor assembly comprises a second rotor iron core, a plurality of magnetic steel grooves are formed in the second rotor iron core, second permanent magnets are arranged in the magnetic steel grooves, and the first rotor assemblies are arranged at the two axial ends of the second rotor assembly respectively; wherein the first rotor core and the first permanent magnet are provided with a matching structure, the matching structure comprises a bulge and a groove which are matched with each other, one of the bulge and the groove is arranged on the first rotor core, and the other one of the bulge and the groove is arranged on the first permanent magnet. According to the scheme, the first rotor iron core and the first permanent magnet are assembled and connected through the matching structure, so that the assembling difficulty is reduced, and the problem of relatively low accuracy of rotor assembling in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of motor design, and in particular to a rotor assembly and a permanent magnet motor having the same. Background Art

[0002] Permanent magnet motors have the advantages of small size and high efficiency, and are widely used in air conditioners, industrial equipment, new energy vehicles and other fields. With the improvement of motor energy efficiency standards, higher requirements are put forward for the energy efficiency level of motors. For permanent magnet motors, it is necessary to further improve the efficiency and high torque density of motors. One of the main technical means to improve motor efficiency and torque density is to embed permanent magnets to obtain larger air gap magnetic density and larger magnetic flux, but due to the fixed rotor magnetic circuit structure, the energy efficiency improvement is limited; another means is to use the rotor structure to increase the motor salient pole ratio and increase the motor reluctance torque to make up for the lack of permanent magnet torque. Its efficiency can be comparable to that of permanent magnet motors, but it usually requires a larger rotor volume, which will make the motor torque density inferior to that of permanent magnet motors. For current permanent magnet motors, if we want to further achieve motor efficiency and high torque density, improving the rotor magnetic concentration effect is an effective way.

[0003] The prior art provides a new permanent magnet motor, which improves the energy efficiency of the permanent magnet motor by combining multiple rotor components. However, the structure is complex, and there are problems such as great difficulty in assembly and low assembly accuracy.

[0004] Currently, no effective solution has been proposed for the above-mentioned problem of low rotor assembly accuracy. Summary of the invention

[0005] The main purpose of the present invention is to provide a rotor assembly and a permanent magnet motor having the same, so as to solve the problem of low rotor assembly accuracy in the prior art.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, a rotor assembly is provided, comprising: a first rotor assembly, the first rotor assembly comprising a first rotor core and a first permanent magnet arranged in an axial direction, the first rotor core being provided with a first axial hole for a rotating shaft to pass through; a second rotor assembly, the second rotor assembly comprising a second rotor core, the second rotor core being provided with a plurality of magnetic steel slots, the plurality of magnetic steel slots being arranged circumferentially at intervals along the second axial hole of the second rotor core, the second permanent magnets being arranged in the magnetic steel slots, the first rotor assembly being respectively arranged at both axial ends of the second rotor assembly, the first permanent magnet being located between the ends of the first rotor core and the second rotor assembly; wherein the first rotor core and the first permanent magnet are provided with a matching structure, wherein the matching structure comprises mutually matching protrusions and grooves, one of the protrusions and the grooves being arranged on the first rotor core, and the other of the protrusions and the grooves being arranged on the first permanent magnet.

[0007] Further, a plurality of protrusions are provided on the outer edge of the first rotor core, the protrusions protrude towards the first permanent magnet, a plurality of grooves are provided on the outer edge of the first permanent magnet, and the grooves and the protrusions in the same first rotor assembly are arranged correspondingly, and the first rotor core and the first permanent magnet are connected by the cooperation of the protrusions and the grooves.

[0008] Further, protrusions are provided on the first rotor core, and when projected along the axial direction of the second rotor assembly, the positions of the protrusions on the two first rotor cores at both ends of the second rotor assembly are arranged differently.

[0009] Further, the protrusions on the two first rotor cores at both ends of the second rotor assembly are symmetrically arranged with respect to the radial center line of the first rotor core.

[0010] Further, when projected along the axial direction of the second rotor assembly, an included angle a is formed between the line connecting the geometric center of any one protrusion on the first rotor core at one end of the second rotor assembly and the central axis of the first rotor core and the line connecting the geometric center of the protrusion on the first rotor core at the other end of the second rotor assembly and the central axis of the first rotor core, wherein the value of a / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

[0011] Further, grooves are provided on the first permanent magnet, the first permanent magnet is of an integral disc structure, the first permanent magnet is divided into a plurality of different polarity regions according to the magnetization direction, and the positions of the grooves provided on the first permanent magnets at both axial ends of the second rotor assembly are arranged identically with respect to the polarity regions of the first permanent magnet.

[0012] Further, when projected along the axial direction of the rotor assembly on an axial end face of the rotor assembly, in the same first rotor assembly, the position of the protrusion provided on the first rotor core is arranged correspondingly to the center line position of the polarity region of the first permanent magnet, or the position of the protrusion provided on the first rotor core is arranged correspondingly to the position of the magnetic pole dividing line between adjacent polarity regions of the first permanent magnet.

[0013] Further, at least one bayonet is further provided on the outer edge of the first rotor core.

[0014] Further, when projected along the axial direction of the rotor assembly on an axial end face of the rotor assembly, the bayonet is arranged correspondingly to the position of the magnetic pole dividing line between adjacent polarity regions of the first permanent magnet.

[0015] Further, the number of bayonets provided on the first rotor core is b, wherein the value of 2p / b is an integer, and p is the number of pole pairs of the rotor.

[0016] Further, there are multiple bayonets, and the multiple bayonets are arranged at intervals along the circumferential direction of the first rotor core. The positions of the multiple bayonets provided on the first rotor core have a symmetry axis on the first rotor core.

[0017] Further, when projected onto an axial end face of the rotor assembly along the axial direction of the rotor assembly, on the same first rotor core, the included angle c is formed between the connection line of the geometric center of any one protrusion and the central axis of the first rotor core and the connection line of the geometric center of any one bayonet and the central axis of the first rotor core. Wherein, the value of c / (180 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

[0018] Further, a second rotor core lobe is formed between two adjacent magnetic steel grooves on the second rotor core. The polar region of the first permanent magnet axially adjacent to one of the second rotor core lobes is the first polarity, and the polar regions of the two second permanent magnets circumferentially adjacent to this second rotor core lobe are the first polarity. The first polarity is N pole or S pole.

[0019] Further, at least one of the first rotor core and the second rotor core is made of a magnetic conductive material.

[0020] Further, the first rotor core is formed by stamping a magnetic conductive steel plate, and / or the second rotor core is formed by laminating silicon steel sheets.

[0021] According to another aspect of the present invention, a permanent magnet motor is provided, including a stator assembly and a rotor assembly. The rotor assembly is the above-mentioned rotor assembly, and the stator assembly is sleeved outside the rotor assembly.

[0022] Applying the technical solution of the present invention, the first rotor assembly and the second rotor assembly are simultaneously arranged in the rotor assembly, greatly improving the magnetic focusing effect of the rotor; the first rotor core and the first permanent magnet are assembled and connected through a matching structure, which is convenient for the magnetization positioning of the first rotor assembly, reduces the assembly difficulty, improves the assembly accuracy and the reliability of the motor, and solves the problem of low accuracy of rotor assembly in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 The structural schematic diagram of the first embodiment of the rotor assembly according to the present invention is shown;

[0025] Figure 2 The structural schematic diagram of the second embodiment of the rotor assembly according to the present invention is shown;

[0026] Figure 3 Shows a schematic structural diagram of a first embodiment of a first rotor assembly according to the present invention;

[0027] Figure 4 Shows a schematic structural diagram of a second embodiment of a first rotor assembly according to the present invention;

[0028] Figure 5 Shows a schematic structural diagram of a third embodiment of a first rotor assembly according to the present invention;

[0029] Figure 6 Shows a schematic structural diagram of a fourth embodiment of a first rotor assembly according to the present invention;

[0030] Figure 7 Shows a schematic structural diagram of a first embodiment of a first rotor core according to the present invention;

[0031] Figure 8 Shows a schematic structural diagram of a second embodiment of a first rotor core according to the present invention;

[0032] Figure 9 Shows a schematic structural diagram of a fifth embodiment of a first rotor assembly according to the present invention;

[0033] Figure 10 Shows a schematic structural diagram of a first embodiment of a second rotor assembly according to the present invention;

[0034] Figure 11 Shows a schematic structural diagram of a second embodiment of a second rotor assembly according to the present invention;

[0035] Figure 12 Shows a schematic structural diagram of a third embodiment of a first rotor core according to the present invention;

[0036] Figure 13 Shows a schematic structural diagram of a fourth embodiment of a first rotor core according to the present invention;

[0037] Figure 14 Shows a schematic structural diagram of an embodiment of a first permanent magnet according to the present invention;

[0038] Figure 15 Shows a comparison diagram of the magnetic flux concentration coefficients of the rotor assembly according to the present invention and the rotor assembly of the prior art;

[0039] Figure 16 Shows a comparison diagram of the no-load magnetic flux linkage of the rotor assembly according to the present invention and the rotor assembly of the prior art;

[0040] Figure 17 Shows a comparison diagram of the air-gap magnetic flux density of the rotor assembly according to the present invention and the rotor assembly of the prior art.

[0041] Among them, the above-mentioned drawings include the following reference numerals:

[0042] 20. First rotor assembly; 21. First rotor core; 24. First permanent magnet; 22. First shaft hole; 25. Protrusion; 26. Groove; 27. Bayonet;

[0043] 10. Second rotor assembly; 11. Second rotor core; 111. Second rotor core segment; 12. Second permanent magnet; 13. Second shaft hole;

[0044] L1. Central axis;

[0045] L2. Magnetic pole dividing line. Detailed implementation manners

[0046] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0047] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the implementation manners of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0049] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present application is thorough and complete, and the concept of these exemplary embodiments is fully conveyed to those of ordinary skill in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and thus their descriptions will be omitted.

[0050] Combined Figures 1 to 14 As shown, according to a specific embodiment of the present application, a rotor assembly is provided.

[0051] Specifically, the rotor assembly includes: a first rotor assembly 20, the first rotor assembly 20 includes a first rotor core 21 arranged axially and a first permanent magnet 24, the first rotor core 21 is provided with a first shaft hole 22 for the shaft to pass through; a second rotor assembly 10, the second rotor assembly 10 includes a second rotor core 11, a plurality of magnet slots are provided on the second rotor core 11, the plurality of magnet slots are circumferentially spaced along the second shaft hole 13 of the second rotor core 11, second permanent magnets 12 are arranged in the magnet slots, and the first rotor assembly 20 is respectively arranged at both axial ends of the second rotor assembly 10, and the first permanent magnet 24 is located between the end of the first rotor core 21 and the second rotor assembly 10; wherein, the first rotor core 21 and the first permanent magnet 24 are provided with a matching structure, and the matching structure includes a protruding portion 25 and a recessed portion 26 that cooperate with each other, one of the protruding portion 25 and the recessed portion 26 is arranged on the first rotor core 21, and the other of the protruding portion 25 and the recessed portion 26 is arranged on the first permanent magnet 24.

[0052] Applying the technical solution of this embodiment, both the first rotor assembly 20 and the second rotor assembly 10 are arranged in the rotor assembly, greatly improving the magnetic concentration effect of the rotor; the first rotor core 21 and the first permanent magnet 24 are assembled and connected through the matching structure, which is convenient for the magnetization positioning of the first rotor assembly 20, reduces the assembly difficulty, improves the assembly accuracy and the reliability of the motor, and solves the problem of low accuracy of rotor assembly in the prior art.

[0053] Those skilled in the art should understand that by simultaneously arranging the first rotor assembly 20 and the second rotor assembly 10 in the rotor, the first rotor assembly 20 and the second rotor assembly 10 jointly provide a magnetic field for the motor, which can increase the magnetic flux of the motor and improve the motor output; the design of the relative positions of the first rotor assembly 20 and the second rotor assembly 10, arranging the first rotor assembly 20 at the axial end of the second rotor assembly 10, and the magnetic force lines emitted from the axial direction of the first rotor assembly 20 and the magnetic force lines emitted from the radial direction of the second rotor assembly 10 gather magnetic flux on the rotor core and then enter the air gap, which can significantly improve the magnetic flux concentration effect of the rotor.

[0054] Preferably, the first rotor core 21 is fixedly connected to the first permanent magnet 24. The fixing method of the first rotor core 21 and the first permanent magnet 24 is not limited to adsorption, adhesion, mechanical structure fixing, etc., as long as there is no relative movement between the first rotor core 21 and the first permanent magnet 24.

[0055] Furthermore, a plurality of protrusions 25 are provided on the outer edge of the first rotor core 21, the protrusions 25 protrude towards the first permanent magnet 24, a plurality of grooves 26 are provided on the outer edge of the first permanent magnet 24, and the grooves 26 in the same first rotor assembly 20 are arranged corresponding to the protrusions 25, and the first rotor core 21 and the first permanent magnet 24 are connected by the cooperation of the protrusions 25 and the grooves 26.

[0056] Furthermore, protrusions 25 are provided on the first rotor core 21, and when projected along the axial direction of the second rotor assembly 10, the positions of the protrusions 25 on the two first rotor cores 21 at both ends of the second rotor assembly 10 are arranged differently.

[0057] As Figure 12 and Figure 13 shown, where Figure 12 is the first rotor core 21 at the first end of the second rotor assembly 10, Figure 13 is the first rotor core 21 at the second end of the second rotor assembly 10. Such an arrangement facilitates the magnetization positioning of the first rotor assembly 20, makes the polarities of the corresponding regions of the first rotor assemblies 20 at both ends of the second rotor assembly 10 the same. At the same time, the different positions of the protrusions 25 have a corrective effect on the dynamic balance of the rotor, and can weaken the motor vibration caused by the imbalance of the rotor assembly.

[0058] Preferably, the positions of the grooves 26 provided on the two first permanent magnets 24 at both ends of the second rotor assembly 10 are arranged the same. As Figure 14 shown, the two first permanent magnets 24 at both ends of the second rotor assembly 10 are provided with grooves 26 at the same position, and just rotate an appropriate angle when assembling with the corresponding first rotor core 21.

[0059] Specifically, as Figure 12 、Figure 13 , Figure 3 As shown in Figure 3 , the protrusions 25 on the two first rotor cores 21 at both ends of the second rotor assembly 10 are symmetrically arranged with respect to the radial center line of the first rotor core 21. For example, Figure 12 in Figure 12 , on the first rotor core 21 at the first end of the second rotor assembly 10, a protrusion 25 is provided on the left side of the magnetic pole demarcation line L2 (coinciding with one of the radial center lines of the first rotor core 21), and there is no protrusion 25 on the right side. Correspondingly, Figure 13 in Figure 13 , on the first rotor core 21 at the second end of the second rotor assembly 10, a protrusion 25 is provided on the right side of the magnetic pole demarcation line L2 (coinciding with one of the radial center lines of the first rotor core 21), and there is no protrusion 25 on the left side.

[0060] Furthermore, when projected along the axial direction of the second rotor assembly 10, an angle a is formed between the connection line of the geometric center of any one protrusion 25 on the first rotor core 21 at one end of the second rotor assembly 10 and the central axis L1 of the first rotor core 21, and the connection line of the geometric center of the protrusion 25 on the first rotor core 21 at the other end of the second rotor assembly 10 and the central axis L1 of the first rotor core 21. Among them, the value of a / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

[0061] In this embodiment, as Figure 3 shown in Figure 3 , for the convenience of illustration, the two first rotor cores 21 at both ends of the second rotor assembly 10 have different radii after being projected along the axial direction. In the physical structure, the radii of the two first rotor cores 21 are approximately equal. The value of a / (360 / 2p) is an integer, that is, the angle a is an integer multiple of the pole arc angle occupied by one pole of the rotor assembly. This can achieve the correct magnetization positioning of the second rotor assembly 10, so that the polarities corresponding to both axial ends of the rotor assembly are the same. Under the polarity matching of the same polarities, the magnetic flux of the motor is the largest.

[0062] Furthermore, a groove 26 is provided on the first permanent magnet 24. The first permanent magnet 24 is of an integral disc structure. The first permanent magnet 24 is divided into multiple different polarity regions according to the magnetization direction. Such a setting can reduce the production and assembly costs of the first permanent magnet 24. After magnetization, different polarity regions are distributed to achieve the polarity matching with the second permanent magnet 12. The positions of the grooves 26 provided on the first permanent magnets 24 at both axial ends of the second rotor assembly 10 are set identically with respect to the polarity regions of the first permanent magnet 24.

[0063] Optionally, as Figure 12 and Figure 13As shown, a projection is made on an axial end face of the rotor assembly along the axial direction of the rotor assembly. In the same first rotor assembly 20, the position of the protrusion 25 provided on the first rotor core 21 is set corresponding to the position of the center line of the polar region of the first permanent magnet 24. By setting the position of the protrusion in this way, the problem of weakening of the effective magnetic field of the first permanent magnet 24 caused by an included angle between the magnetization direction of the first permanent magnet 24 and the axial direction of the rotor assembly can be avoided.

[0064] Optionally, in the same first rotor assembly 20, the position of the protrusion 25 provided on the first rotor core 21 is set corresponding to the position of the magnetic pole demarcation line between adjacent polar regions of the first permanent magnet 24. By setting the position of the protrusion in this way, the problem of weakening of the effective magnetic field of the first permanent magnet 24 caused by an included angle between the magnetization direction of the first permanent magnet 24 and the axial direction of the rotor assembly can be avoided.

[0065] Preferably, the first permanent magnet 24 is magnetized with alternating NS poles along the axial direction, and the position of the protrusion 25 is set corresponding to the position of the center line of the polar region of the first permanent magnet 24.

[0066] Furthermore, at least one bayonet 27 is provided on the outer edge of the first rotor core 21. By providing the bayonet 27 on the outer edge of the first rotor core 21, the change of the shape of the shaft hole of the rotor assembly can be avoided, and the tight assembly of the rotor assembly and the rotor shaft can be realized. The provision of the bayonet 27 is conducive to realizing the position positioning of the first rotor assembly 20 relative to the second rotor assembly 10 and the circumferential fixation of the first rotor assembly 20.

[0067] Specifically, as Figure 12 and Figure 13 shown, a projection is made on an axial end face of the rotor assembly along the axial direction of the rotor assembly. The bayonet 27 is set corresponding to the position of the magnetic pole demarcation line L2 between adjacent polar regions of the first permanent magnet 24. This can further improve the positioning and fixing effect of the first rotor assembly 20.

[0068] Preferably, the number of bayonets 27 provided on the first rotor core 21 is b, where the value of 2p / b is an integer, and p is the number of pole pairs of the rotor. This can make the first rotor core 21 a symmetric structure and reduce the influence of the imbalance of the first rotor assembly 20 on the vibration and noise of the motor.

[0069] Optionally, there are multiple bayonets 27, and the multiple bayonets 27 are arranged at intervals along the circumference of the first rotor core 21. The positions of the multiple bayonets 27 provided on the first rotor core 21 have a symmetry axis on the first rotor core 21. The provision of multiple bayonets 27 can further improve the installation and positioning effect of the first rotor core 21.

[0070] In an exemplary embodiment of the present application, a plurality of bayonet joints 27 are symmetrically arranged about the central axis L1 of the first rotor core 21, making the first rotor core 21 a geometrically symmetric figure, and reducing the influence of the imbalance of the first rotor assembly 20 on the vibration and noise of the motor.

[0071] Preferably, when projected onto an axial end face of the rotor assembly along the axial direction of the rotor assembly, on the same first rotor core 21, an angle c is formed between the line connecting the geometric center of any one protrusion 25 and the central axis L1 of the first rotor core 21, and the line connecting the geometric center of any one bayonet joint 27 and the central axis L1 of the first rotor core 21, where the value of c / (180 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

[0072] As Figure 3 shown, by restricting the angle c, the correct magnetization direction of the first rotor assembly 20 can be ensured. At the same time, the correct polarity matching between the first rotor assembly 20 and the second rotor assembly 10 can be ensured, realizing the maximization of the motor magnetic flux linkage.

[0073] Specifically, a second rotor core lobe 111 is formed between two adjacent magnet slots on the second rotor core 11. The polarity region of the first permanent magnet 24 axially adjacent to one of the second rotor core lobes 111 is the first polarity, and the polarity regions of the two second permanent magnets 12 circumferentially adjacent to this second rotor core lobe 111 are the first polarity, and the first polarity is N pole or S pole. Through this magnetization method, the superposition of the magnetic flux linkages of the first permanent magnet and the second permanent magnet can be realized, improving the no-load magnetic flux linkage.

[0074] In an exemplary embodiment of the present application, the first permanent magnet 24 is magnetized with alternating NS poles along the axial direction, and the second permanent magnet 12 is magnetized with alternating NS poles along the tangential direction. Under a certain pole, the magnetization directions of the first permanent magnet 24 and the second permanent magnet 12 both point to the second rotor core 11, realizing the superposition of the magnetic flux linkages of the first permanent magnet 24 and the second permanent magnet 12, and improving the no-load magnetic flux linkage.

[0075] Wherein, at least one of the first rotor core 21 and the second rotor core 11 is made of a magnetic conductive material. The first rotor core 21 and the second rotor core 11 made of a magnetic conductive material are the carriers of the motor magnetic field and the paths for the magnetic force lines to flow through.

[0076] In an exemplary embodiment of the present application, both the first rotor core 21 and the second rotor core 11 are made of a magnetic conductive material.

[0077] Preferably, the first rotor core 21 is formed by stamping a magnetic conductive steel plate, and the second rotor core 11 is formed by laminating silicon steel sheets.

[0078] Figure 15The figure shows a comparison chart of the magnetic flux concentration coefficients of the rotor assembly of the present invention and the rotor assembly of the prior art. Figure 16 The figure shows a comparison chart of the no-load magnetic flux of the rotor assembly of the present invention and the rotor assembly of the prior art. Figure 17 The figure shows a comparison chart of the air-gap magnetic density of the rotor assembly of the present invention and the rotor assembly of the prior art. Combining Figures 15 to 17 It can be seen that the rotor assembly in the embodiment of the present application effectively improves the magnetic flux concentration effect of the rotor, increases the magnetic flux of the motor, and improves the motor efficiency.

[0079] According to another specific embodiment of the present application, a permanent magnet motor is provided, which includes a stator assembly and a rotor assembly. The rotor assembly is the rotor assembly in the above embodiment, and the stator assembly is sleeved outside the rotor assembly. Preferably, the permanent magnet motor is a permanent magnet synchronous motor.

[0080] For the sake of description, spatial relative terms, such as "above...", "over...", "on the upper surface of...", "above", etc., can be used here to describe the spatial positional relationship between one device or feature and other devices or features as shown in the figure. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0081] In addition to the above, it should also be noted that the "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in connection with that embodiment being included in at least one embodiment generally described in the present application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in connection with any one embodiment, it is intended that the implementation of such feature, structure or characteristic in combination with other embodiments also falls within the scope of the present invention.

[0082] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] The above are only the 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 within the protection scope of the present invention.

Claims

1. A rotor assembly, characterized in that, it includes: A first rotor assembly (20), the first rotor assembly (20) includes a first rotor core (21) and a first permanent magnet (24) arranged axially, and a first shaft hole (22) for a rotating shaft to pass through is provided in the first rotor core (21); A second rotor assembly (10), the second rotor assembly (10) includes a second rotor core (11), a plurality of magnet slots are provided in the second rotor core (11), and the plurality of magnet slots are circumferentially spaced along the second shaft hole (13) of the second rotor core (11), a second permanent magnet (12) is arranged in the magnet slot, the first rotor assembly (20) is respectively arranged at both axial ends of the second rotor assembly (10), and the first permanent magnet (24) is located between the end of the first rotor core (21) and the second rotor assembly (10); Wherein, the first rotor core (21) and the first permanent magnet (24) are provided with a matching structure, and the matching structure includes a convex (25) and a concave (26) that cooperate with each other, and one of the convex (25) and the concave (26) is arranged on the first rotor core (21), and the other of the convex (25) and the concave (26) is arranged on the first permanent magnet (24).

2. The rotor assembly according to claim 1, characterized in that, A plurality of the convexes (25) are arranged on the outer edge of the first rotor core (21), the convexes (25) protrude towards the first permanent magnet (24), a plurality of the concaves (26) are arranged on the outer edge of the first permanent magnet (24), and the concaves (26) in the same first rotor assembly (20) are arranged corresponding to the convexes (25), and the first rotor core (21) and the first permanent magnet (24) are connected in cooperation through the convexes (25) and the concaves (26).

3. The rotor assembly according to claim 1, characterized in that, The convex (25) is arranged on the first rotor core (21), and when projected along the axial direction of the second rotor assembly (10), the positions of the convexes (25) on the two first rotor cores (21) at both ends of the second rotor assembly (10) are arranged differently.

4. The rotor assembly according to claim 3, characterized in that, The convexes (25) on the two first rotor cores (21) at both ends of the second rotor assembly (10) are symmetrically arranged with respect to the radial center line of the first rotor core (21).

5. The rotor assembly according to claim 3, characterized in that, Project along the axial direction of the second rotor assembly (10). The connecting line between the geometric center of any one of the protrusions (25) on the first rotor core (21) at one end of the second rotor assembly (10) and the central axis of the first rotor core (21) forms an angle a with the connecting line between the geometric center of the protrusion (25) on the first rotor core (21) at the other end of the second rotor assembly (10) and the central axis of the first rotor core (21). Here, the value of a / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

6. The rotor assembly according to claim 1, characterized in that the groove (26) is provided on the first permanent magnet (24). The first permanent magnet (24) is of an integral disc structure. The first permanent magnet (24) is divided into multiple different polar regions according to the magnetization direction. Relative to the polar regions of the first permanent magnet (24), the grooves (26) are provided at the same positions on the first permanent magnets (24) at the axial two ends of the second rotor assembly (10).

7. The rotor assembly according to claim 2 or 6, characterized in that Project along the axial direction of the rotor assembly on an axial end face of the rotor assembly. In the same first rotor assembly (20), the positions of the protrusions (25) provided on the first rotor core (21) are set corresponding to the center lines of the polar regions of the first permanent magnet (24), or the positions of the protrusions (25) provided on the first rotor core (21) are set corresponding to the magnetic pole dividing lines between the adjacent polar regions of the first permanent magnet (24).

8. The rotor assembly according to claim 2, characterized in that at least one bayonet (27) is further provided on the outer edge of the first rotor core (21).

9. The rotor assembly according to claim 8, characterized in that Project along the axial direction of the rotor assembly on an axial end face of the rotor assembly. The bayonet (27) is set corresponding to the position of the magnetic pole dividing line between the adjacent polar regions of the first permanent magnet (24).

10. The rotor assembly according to claim 8, characterized in that the number of the bayonets (27) provided on the first rotor core (21) is b, where the value of 2p / b is an integer, and p is the number of pole pairs of the rotor.

11. The rotor assembly according to claim 8, characterized in that there are multiple bayonets (27). The multiple bayonets (27) are arranged at intervals along the circumferential direction of the first rotor core (21). The positions of the multiple bayonets (27) provided on the first rotor core (21) have a symmetry axis on the first rotor core (21).

12. The rotor assembly according to claim 8, characterized in that Project along the axial direction of the rotor assembly on an axial end face of the rotor assembly. On the same first rotor core (21), the included angle c is formed between the line connecting the geometric center of any one of the protrusions (25) and the central axis of the first rotor core (21) and the line connecting the geometric center of any one of the bayonets (27) and the central axis of the first rotor core (21), where the value of c / (180 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

13. The rotor assembly according to claim 1, wherein, a second rotor core lobe (111) is formed between two adjacent magnet slots on the second rotor core (11), the polarity region of the first permanent magnet (24) axially adjacent to one of the second rotor core lobes (111) is the first polarity, and the polarity regions of the two second permanent magnets (12) circumferentially adjacent to the second rotor core lobe (111) are the first polarity, and the first polarity is N pole or S pole.

14. The rotor assembly according to claim 1, wherein, at least one of the first rotor core (21) and the second rotor core (11) is made of a magnetic conductive material.

15. The rotor assembly according to claim 1, wherein, the first rotor core (21) is formed by stamping a magnetic conductive steel plate, and / or the second rotor core (11) is formed by laminating silicon steel sheets.

16. A permanent magnet motor, comprising a stator assembly and a rotor assembly, wherein, the rotor assembly is the rotor assembly according to any one of claims 1 to 15, and the stator assembly is sleeved outside the rotor assembly.

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