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, the second rotor iron core is provided with a plurality of magnetic steel grooves which are formed in the circumferential direction of the second rotor iron core at intervals, second permanent magnets are arranged in the magnetic steel grooves, and the two ends of the second rotor assembly are each provided with a first rotor assembly; the first permanent magnet is arranged between the first rotor iron core and the second rotor assembly; protruding strips are arranged on the plane, perpendicular to the axial direction of the rotor assembly, of the first rotor iron core, grooves are formed in the end faces, facing the first rotor iron core, of the first permanent magnets, and the first rotor iron core and the first permanent magnets are connected in a matched mode through the protruding strips and the grooves. According to the scheme, the first rotor iron core and the first permanent magnet are connected through the protruding strips and the grooves, and the problem that the rotor assembly difficulty is large in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, 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. There are two main technical means to improve motor efficiency and torque density: one is to build permanent magnets into the motor to obtain a larger air gap flux density and a larger magnetic flux, but due to the fixed rotor magnetic circuit structure, the energy efficiency improvement is limited; the other 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 high efficiency and high torque density of motors, improving the magnetic field effect of the rotor is an effective way.

[0003] A permanent magnet motor is proposed in the prior art, which improves the energy efficiency of the permanent magnet motor by combining multiple rotor components. However, its structure of multiple magnetic flux sources leads to an increase in the magnetic flux density of the rotor core, local oversaturation of the rotor core leads to large core loss, and repulsive force exists between the rotor components, resulting in problems such as difficulty in assembly and low motor reliability.

[0004] With regard to the above-mentioned problem of difficulty in assembling the motor rotor, no effective solution has been proposed so far. 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 difficulty in assembling the motor rotor in the prior art.

[0006] To achieve the above object, according to one aspect of the present invention, there is provided a rotor assembly, including: a first rotor assembly, the first rotor assembly includes a first rotor core and a first permanent magnet arranged axially, the first rotor core is provided with a first shaft hole for a rotating shaft to pass through; a second rotor assembly, the second rotor assembly includes a second rotor core, the second rotor core is provided with a plurality of magnet slots arranged at intervals circumferentially along the second rotor core, second permanent magnets are arranged in the magnet slots, the second rotor core is provided with a second shaft hole for the rotating shaft to pass through, the first rotor assembly is respectively arranged at both axial ends of the second rotor assembly, and the first permanent magnet is arranged between the first rotor core and the end of the second rotor assembly; on the plane of the first rotor core perpendicular to the axial direction of the rotor assembly, at least one rib is arranged, the rib protrudes along the axial direction of the first rotor core, and is projected on one axial end face of the rotor assembly along the axial direction of the rotor assembly, the rib radially extends from the inner side of the first rotor core to the outer side; a groove is arranged on the end face of the first permanent magnet facing the first rotor core, and the rib is arranged corresponding to the groove, and the first rotor core and the first permanent magnet are connected by the cooperation of the rib and the groove.

[0007] Further, both the rib and the groove are multiple.

[0008] Further, an annular boss is protrudingly arranged on the end face of the first rotor core facing the first permanent magnet, the annular boss is arranged close to the inner circle of the first rotor core, and the annular boss extends along the axial direction of the first rotor core into the inner hole of the first permanent magnet.

[0009] Further, the rib extends along the outer wall of the annular boss to the outer circle of the first rotor core.

[0010] Further, there are two ribs, and the two ribs are located on the same straight line.

[0011] Further, the extension length of the rib in the radial direction of the first rotor core is a, and the distance between the outer circle and the inner circle of the first rotor core is b, where a≥0.25*b.

[0012] Further, the protruding height of the rib in the axial direction of the first rotor core is c, the axial thickness of the first rotor core is d, and the axial thickness of the first permanent magnet is e, where c≥0.1*(min(d)+e).

[0013] Further, 0.5*(min(d)+e)≥c≥0.2*e.

[0014] Further, the number of ribs is f, and the number of pole pairs of the rotor assembly is p, where the value of 2p / f is an integer.

[0015] Further, the first permanent magnet has an overall disc structure, and the first permanent magnet is divided into multiple different polarity regions according to the magnetization direction.

[0016] Further, the position where the groove is provided corresponds to the center line position of the polarity region of the first permanent magnet along the axial direction of the rotor assembly, or the position where the groove is provided corresponds to the magnetic pole demarcation line position between two adjacent polarity regions of the first permanent magnet along the axial direction of the rotor assembly.

[0017] Further, at least one bayonet is provided on the outer circumference of the first rotor core.

[0018] Further, the number of bayonets is g, and the value of g / 2 is an integer.

[0019] Further, there are multiple bayonets, and the multiple bayonets are arranged at intervals along the circumferential direction of the first rotor core. When projected onto an axial end face of the rotor assembly along the axial direction of the rotor assembly, an angle h is formed between the connection lines of the geometric centers of any two bayonets and the central axis of the first rotor core, where the value of h / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

[0020] Further, a second rotor core lobe is formed between two adjacent magnet slots on the second rotor core. The polarity region of the first permanent magnet axially adjacent to one of the second rotor core lobes is the first polarity, and the polarity 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.

[0021] Further, at least one of the first rotor core and the second rotor core is made of a magnetic conductive material.

[0022] 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.

[0023] 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.

[0024] Applying the technical solution of the present invention, the first rotor assembly and the second rotor assembly are simultaneously provided in the rotor assembly. The first rotor assembly and the second rotor assembly jointly provide a magnetic field for the motor, which can increase the magnetic flux of the motor, improve the output of the motor, and improve the magnetic flux concentration effect of the rotor. The first rotor core and the first permanent magnet are connected through the convex strip and the groove, which can reduce the assembly difficulty and solve the problem of large rotor assembly difficulty in the prior art. Description of the Drawings

[0025] The accompanying drawings of the specification, which form a part of the present 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 of the present invention. In the drawings:

[0026] Figure 1 shows a schematic structural diagram of a first embodiment of a rotor assembly according to the present invention;

[0027] Figure 2 shows a schematic structural diagram of a second embodiment of a rotor assembly according to the present invention;

[0028] Figure 3 shows a schematic structural diagram of a first embodiment of a first rotor assembly according to the present invention;

[0029] Figure 4 shows a schematic structural diagram of a second embodiment of a first rotor assembly according to the present invention;

[0030] Figure 5 shows a schematic structural diagram of a third embodiment of a first rotor assembly according to the present invention;

[0031] Figure 6 shows a schematic structural diagram of a first embodiment of a first rotor core according to the present invention;

[0032] Figure 7 shows a schematic structural diagram of a second embodiment of a first rotor core according to the present invention;

[0033] Figure 8 shows a schematic structural diagram of a third embodiment of a first rotor core according to the present invention;

[0034] Figure 9 shows a schematic structural diagram of a first embodiment of a second rotor assembly according to the present invention;

[0035] Figure 10 shows a schematic structural diagram of a second embodiment of a second rotor assembly according to the present invention;

[0036] Figure 11 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;

[0037] Figure 12 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;

[0038] Figure 13 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;

[0039] Figure 14Shows a comparison graph of the rotor core losses between the rotor assembly according to the present invention and the rotor assembly of the prior art;

[0040] Figure 15 Shows a comparison graph of the motor efficiency between the rotor assembly according to the present invention and the rotor assembly of the prior art.

[0041] Wherein, 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;

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

[0044] 23. Rib; 25. Groove; 26. Annular boss; 27. Bayonet;

[0045] L. Central axis. Detailed implementation manners

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

[0047] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify 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 embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprise" 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 clearly listed steps or units, but may include other steps or units that are not clearly listed or are 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 with Figures 1 to 10 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 and a first permanent magnet 24 arranged axially, the first rotor core 21 is provided with a first shaft hole 22 for a rotating shaft to pass through; a second rotor assembly 10, the second rotor assembly 10 includes a second rotor core 11, the second rotor core 11 is provided with a plurality of magnet slots arranged at intervals in the circumferential direction of the second rotor core 11, a second permanent magnet 12 is arranged in the magnet slots, the second rotor core 11 is provided with a second shaft hole 13 for a rotating shaft to pass through, the first rotor assembly 20 is arranged at both axial ends of the second rotor assembly 10 respectively, and the first permanent magnet 24 is arranged between the first rotor core 21 and the end of the second rotor assembly 10; on the plane of the first rotor core 21 perpendicular to the axial direction of the rotor assembly, at least one rib 23 is arranged, the rib 23 protrudes along the axial direction of the first rotor core 21, and is projected on an axial end face of the rotor assembly along the axial direction of the rotor assembly, the rib 23 radially extends from the inner side to the outer side of the first rotor core 21; a groove 25 is arranged on the end face of the first permanent magnet 24 facing the first rotor core 21, the rib 23 and the groove 25 are arranged correspondingly, and the first rotor core 21 and the first permanent magnet 24 are connected by the cooperation of the rib 23 and the groove 25.

[0052] Applying the technical solution of this embodiment, the first rotor assembly 20 and the second rotor assembly 10 are both arranged in the rotor assembly, and 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, improve the output of the motor, and improve the magnetic focusing effect of the rotor. The first rotor core 21 and the first permanent magnet 24 are connected by the rib 23 and the groove 25, which can reduce the assembly difficulty and solve the problem of large assembly difficulty of the rotor 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 assembly, 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 linkage 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 field lines emitted from the axial direction of the first rotor assembly 20 and the magnetic field 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 permanent magnet 24 and the first rotor core 21.

[0055] Specifically, a rib 23 is protrudingly arranged on the end face of the first rotor core 21 facing the first permanent magnet 24, a groove 25 is formed on the end face of the first permanent magnet 24 facing the first rotor core 21, the rib 23 and the groove 25 are arranged correspondingly, and the first rotor core 21 and the first permanent magnet 24 are connected by the cooperation of the rib 23 and the groove 25. The ribs 23 and the grooves 25 are arranged in one-to-one correspondence, which can realize the cooperation between the two, reduce the magnetic circuit length between the first permanent magnet 24 and the first rotor core 21, and reduce magnetic loss.

[0056] In this embodiment, the rib 23 is arranged on the first rotor core 21, and the rib 23 protrudes from the first rotor core 21 in the axial direction, which can disperse the path of the magnetic field lines of the first rotor assembly 20 entering the second rotor core 11, reduce the local saturation of the second rotor core 11 caused by the magnetic flux of the first rotor assembly 20, reduce the core loss of the rotor, and improve the motor efficiency.

[0057] In an exemplary embodiment of the present application, the first permanent magnet 24 and the groove 25 are integrally formed, and the first rotor core 21 and the rib 23 are integrally formed.

[0058] Furthermore, both the rib 23 and the groove 25 are multiple. Arranging multiple ribs 23 and grooves 25 can further ensure the accurate assembly and positioning of the first rotor core 21 and the first permanent magnet 24, and reduce the assembly difficulty.

[0059] Preferably, the rib 23 extends from the inner circle to the outer circle of the first rotor core 21.

[0060] In this embodiment, both the first rotor assembly 20 and the second rotor assembly 10 include permanent magnets, and the magnetic fields of the first permanent magnet 24 and the second permanent magnet 12 repel each other. The rib 23 radially extends from the inner side to the outer side of the first rotor core 21, which can conduct away part of the magnetic lines of force of the first permanent magnet 24, disperse the path of the magnetic lines of force of the first rotor assembly 20 entering the second rotor core 11, solve the problem of local oversaturation of the rotor core, reduce the loss of the rotor core, enable the magnetic lines of force of the first permanent magnet 24 to directly pass through the air gap in the radial direction and enter the stator, reduce the repulsive force between the first rotor assembly 20 and the second rotor assembly 10, and reduce the assembly difficulty.

[0061] In an exemplary embodiment of the present application, a plurality of ribs 23 are all arranged to extend from the inner circle of the first rotor core 21 to the outer circle of the first rotor core 21 to form a radial arrangement.

[0062] Further, an annular boss 26 is protrudingly arranged on the end surface of the first rotor core 21 facing the first permanent magnet 24. The annular boss 26 is arranged close to the inner circle of the first rotor core 21 and extends along the axial direction of the first rotor core 21 into the inner hole of the first permanent magnet 24. In this embodiment, the arrangement of the annular boss 26 can play roles such as positioning, supporting, and fixing in the production and assembly processes of the first rotor assembly 20 and the second rotor assembly 10.

[0063] Further, the rib 23 is arranged to extend from the outer wall of the annular boss 26 to the outer circle of the first rotor core 21. This can reduce the repulsive force between the first rotor assembly 20 and the second rotor assembly 10 and reduce the assembly difficulty.

[0064] Preferably, there are two ribs 23, and the two ribs 23 are located on the same straight line. This can make the two ribs 23 symmetric about the central axis L of the first rotor core 21 and avoid vibration noise caused by the imbalance of the first rotor core 21.

[0065] Specifically, the extension length of the rib 23 in the radial direction of the first rotor core 21 is a, and the distance between the outer circle and the inner circle of the first rotor core 21 is b. Among them, a≥0.25*b, and preferably, a≥0.5*b. By limiting the minimum value of the radial extension length of the rib 23, problems such as the unclear guiding effect on the magnetic field of the first permanent magnet 24, excessive repulsive force between the first rotor assembly 20 and the second rotor assembly 10, and difficult assembly caused by too small a size of the rib 23 can be avoided.

[0066] In this embodiment, as Figure 6 shown, b refers to the distance between two points where the ray emitted from the central axis L of the first rotor core 21 intersects the inner and outer sides of the first rotor core 21.

[0067] Specifically, the protruding height of the rib 23 in the axial direction of the first rotor core 21 is c, the axial thickness of the first rotor core 21 is d, and the axial thickness of the first permanent magnet 24 is e, where c ≥ 0.1 * (min(d) + e). By restricting the minimum value of the protruding height of the rib 23, the rib 23 can have a sufficient effect of dispersing the magnetic force path of the first permanent magnet 24, reducing the core loss, and improving the motor efficiency.

[0068] Preferably, 0.5 * (min(d) + e) ≥ c ≥ 0.2 * e. Further restricting the protruding height of the rib 23 can effectively reduce the core loss and improve the motor efficiency.

[0069] Wherein, the number of ribs 23 is f, the number of pole pairs of the rotor assembly is p, and the value of 2p / f is an integer. The fact that 2p / f is an integer can make the ribs 23 arranged on the first rotor core 21 symmetric, weakening the vibration noise caused by the imbalance of the first rotor core 21.

[0070] Furthermore, the first permanent magnet 24 is of an integral disc structure, and the first permanent magnet 24 is divided into multiple different polarity regions according to the magnetization direction. The integral disc structure can reduce the production and assembly costs of the first permanent magnet 24, and after magnetization, different polarity regions are distributed, which is conducive to realizing the cooperation with the polarity of the second permanent magnet 12.

[0071] Optionally, the setting position of the groove 25 corresponds to the center line position of the polarity region of the first permanent magnet 24 in the axial direction of the rotor assembly, so as to weaken the loss of the magnetic performance of the first permanent magnet 24.

[0072] Optionally, the setting position of the groove 25 corresponds to the position of the magnetic pole demarcation line between two adjacent polarity regions of the first permanent magnet 24 in the axial direction of the rotor assembly. Such a setting can weaken the loss of the magnetic performance of the first permanent magnet 24.

[0073] Furthermore, at least one bayonet 27 is provided on the outer circle of the first rotor core 21. The provision of the bayonet 27 is conducive to the circumferential fixation and positioning of the first rotor assembly 20. At the same time, by providing the bayonet 27 on the outer circle of the first rotor core 21, the shape change of the shaft hole of the rotor assembly can be avoided, and the fastening assembly of the rotor assembly and the rotor shaft can be realized.

[0074] Specifically, the bayonet 27 can be a semi-circular groove structure, a rectangular groove structure, etc.

[0075] Preferably, the number of bayonets 27 is g, and the value of g / 2 is an integer. Setting an even number of bayonets 27 can reduce the influence of the imbalance of the first rotor assembly on the motor vibration noise. In practical applications, the number of bayonets 27 should be set appropriately to avoid the problem of increasing the corresponding production process cost due to too many bayonets. Preferably, g = 2.

[0076] Further, there are multiple bayonets 27, and the multiple bayonets 27 are arranged at intervals along the circumferential direction of the first rotor core 21. When projected onto an axial end face of the rotor assembly along the axial direction of the rotor assembly, an included angle h is formed between the connecting lines of the geometric centers of any two bayonets 27 and the central axis of the first rotor core 21. Among them, the value of h / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly. Such a setting can ensure the relative position between the bayonet 27 and the polar region of the first rotor assembly 20, and reduce the circumferential positioning difficulty of the first rotor assembly 20 relative to the second rotor assembly 10.

[0077] Preferably, the value of h / (360 / 2p) is an odd number to ensure the uniqueness of the relative position between the first rotor assembly 20 and the second rotor assembly 10.

[0078] Further, a second rotor core lobe 111 is formed between two adjacent magnet slots on the second rotor core 11. The polar region of the first permanent magnet 24 axially adjacent to one of the second rotor core lobes 111 is the first polarity, and the polar regions of the two second permanent magnets 12 circumferentially adjacent to the second rotor core lobe 111 are the first polarity. The first polarity is N pole or S pole. In this way, the magnetic flux linkage of the first permanent magnet 24 and the second permanent magnet 12 can be superimposed, and the no-load magnetic flux linkage can be improved.

[0079] Preferably, 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. In this magnetization method, the magnetic flux linkage of the first permanent magnet 24 and the second permanent magnet 12 can be superimposed, and the no-load magnetic flux linkage can be improved.

[0080] Further, at least one of the first rotor core 21 and the second rotor core 11 is made of a magnetic conductive material.

[0081] In the embodiment of the present application, both the first rotor core 21 and the second rotor core 11 are 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.

[0082] 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.

[0083] Figure 11 Shows a comparison diagram of the magnetic flux concentrating coefficient of the rotor assembly of the present invention and the rotor assembly of the prior art. Figure 12 Shows a comparison diagram of the no-load magnetic flux linkage of the rotor assembly of the present invention and the rotor assembly of the prior art. Figure 13The figure shows a comparison diagram of the air-gap magnetic density between the rotor assembly of the present invention and that of the prior art. Figure 14 The figure shows a comparison diagram of the rotor core loss between the rotor assembly of the present invention and that of the prior art. Figure 15 The figure shows a comparison diagram of the motor efficiency between the rotor assembly of the present invention and that of the prior art. Combining Figures 11 - 15 It can be seen that by applying the technical solution of this embodiment, the rotor core loss can be effectively reduced, the magnetic concentration effect of the rotor can be improved, the assembly difficulty can be reduced, and the motor efficiency can be improved.

[0084] 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.

[0085] For the sake of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" and the like can be used here to describe the spatial position 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 shown 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 "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0086] In addition to the above, it should also be noted that the "one embodiment", "another embodiment", "embodiment" and the like 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 such feature, structure or characteristic can also be realized in combination with other embodiments and fall within the scope of the present invention.

[0087] In the above embodiments, the descriptions of the respective 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.

[0088] 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, comprising: 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 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), and a plurality of magnet slots are arranged on the second rotor core (11) at intervals in the circumferential direction of the second rotor core (11), and a second permanent magnet (12) is arranged in the magnet slots. The second rotor core (11) is provided with a second shaft hole (13) for the shaft to pass through. The first rotor assembly (20) is arranged at both axial ends of the second rotor assembly (10), and the first permanent magnet (24) is arranged between the first rotor core (21) and the end of the second rotor assembly (10); On the plane of the first rotor core (21) perpendicular to the axial direction of the rotor assembly, at least one rib (23) is arranged, and the rib (23) protrudes along the axial direction of the first rotor core (21). Projected on an axial end face of the rotor assembly along the axial direction of the rotor assembly, the rib (23) radially extends from the inner side of the first rotor core (21) to the outer side; A groove (25) is provided on the end face of the first permanent magnet (24) facing the first rotor core (21), and the rib (23) is arranged corresponding to the groove (25), and the first rotor core (21) and the first permanent magnet (24) are connected by the cooperation of the rib (23) and the groove (25).

2. The rotor assembly according to claim 1, characterized in that, Both the rib (23) and the groove (25) are multiple.

3. The rotor assembly according to claim 1, characterized in that, An annular boss (26) is protrudingly arranged on the end face of the first rotor core (21) facing the first permanent magnet (24), and the annular boss (26) is arranged close to the inner circle of the first rotor core (21), and the annular boss (26) extends along the axial direction of the first rotor core (21) into the inner hole of the first permanent magnet (24).

4. The rotor assembly according to claim 3, characterized in that, The rib (23) extends along the outer wall of the annular boss (26) towards the outer circle of the first rotor core (21).

5. The rotor assembly according to claim 3, characterized in that, There are two ribs (23), and the two ribs (23) are located on the same straight line.

6. The rotor assembly according to claim 1, characterized in that, The extension length of the rib (23) in the radial direction of the first rotor core (21) is a, and the distance between the outer circle and the inner circle of the first rotor core (21) is b, wherein a≥0.25*b.

7. The rotor assembly according to claim 1, It is characterized in that the protruding height of the convex strip (23) along the axial direction of the first rotor core (21) is c, the axial thickness of the first rotor core (21) is d, and the axial thickness of the first permanent magnet (24) is e, where c≥0.1*(min(d)+e).

8. The rotor assembly according to claim 7 It is characterized in that 0.5*(min(d)+e)≥c≥0.2*e.

9. The rotor assembly according to claim 1 It is characterized in that the number of the convex strips (23) is f, and the number of pole pairs of the rotor assembly is p, where the value of 2p / f is an integer.

10. The rotor assembly according to claim 1 It is characterized in that the first permanent magnet (24) is of an integral disk structure, and the first permanent magnet (24) is divided into a plurality of different polarity regions according to the magnetization direction.

11. The rotor assembly according to claim 1 or 10 It is characterized in that the position where the groove (25) is arranged corresponds to the center line position of the polarity region of the first permanent magnet (24) along the axial direction of the rotor assembly, or the position where the groove (25) is arranged corresponds to the position of the magnetic pole demarcation line between two adjacent polarity regions of the first permanent magnet (24) along the axial direction of the rotor assembly.

12. The rotor assembly according to claim 1 It is characterized in that at least one bayonet (27) is provided on the outer circle of the first rotor core (21).

13. The rotor assembly according to claim 12 It is characterized in that the number of the bayonets (27) is g, and the value of g / 2 is an integer.

14. The rotor assembly according to claim 12 It is characterized in that there are a plurality of the bayonets (27), and the plurality of bayonets (27) are arranged at intervals along the circumferential direction of the first rotor core (21). When projected onto an axial end face of the rotor assembly along the axial direction of the rotor assembly, an included angle h is formed between the connecting lines of the geometric centers of any two bayonets (27) and the central axis of the first rotor core (21), where the value of h / (360 / 2p) is an integer, and p is the number of pole pairs of the rotor assembly.

15. The rotor assembly according to claim 1 It is characterized in that 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. The first polarity is N pole or S pole.

16. The rotor assembly according to claim 1 It is characterized in that at least one of the first rotor core (21) and the second rotor core (11) is made of a magnetic conductive material.

17. The rotor assembly according to claim 1 It is characterized in that 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.

18. A permanent magnet motor, comprising a stator assembly and a rotor assembly, characterized in that the rotor assembly is the rotor assembly according to any one of claims 1 to 17, and the stator assembly is sleeved outside the rotor assembly.

Images