CN113381535B - Rotor assemblies, motors and electrical equipment - Google Patents

Abstract

The present invention provides a rotor assembly, a motor and an electrical device. The rotor assembly includes: a rotor core; a permanent magnet, one end face of the permanent magnet is connected to one end face of the rotor core; a rotor disk, connected to the other end face of the rotor core; and a plastic coating, covering at least a portion of the rotor core, at least a portion of the permanent magnet and at least a portion of the rotor disk, so that the rotor disk, the rotor core and the permanent magnet form an integrated structure. The present invention adopts an integrated plastic coating design for the rotor core, the permanent magnet and the rotor disk, which effectively enhances the structural strength of the rotor assembly, helps to overcome the centrifugal force when the rotor disk rotates, helps to prevent the permanent magnet from falling off, and reduces the axial deformation of the rotor caused by the operation of the rotor axial magnetic field, thereby avoiding the influence of the air gap uniformity and the air gap magnetic flux sinusoidality of the motor due to the axial deformation of the rotor assembly, helps to ensure the sinusoidality of the motor back electromotive force, and helps to reduce the cogging torque and torque pulsation of the motor.

Description

Rotor assembly, motor and electrical equipment

Technical Field

The invention relates to the technical field of motors, in particular to a rotor assembly, a motor comprising the rotor assembly and electrical equipment comprising the motor.

Background

In the application of the disc motor, the magnetic steel is easy to fall off due to the existence of axial magnetic attraction between the centrifugal force and the stator and the rotor of the motor, and the application of the disc motor is limited. At present, manufacturers generally adopt a mode of adhering permanent magnets to the surface of a rotor core. However, the disadvantage of this conventional structure is that the directly bonded magnet steel is not firm during the operation of the disc motor, and a phenomenon of massive or partial falling easily occurs, so that there is a great risk in the operation of the motor. The permanent magnet is pressed by the whole pressing plate, and the structure has the defects of large eddy current loss in the pressing plate and increased air gap of the motor due to the thickness of the pressing plate, thereby affecting the air gap density of the motor and the utilization rate of the permanent magnet.

Disclosure of Invention

In order to solve at least one of the above problems, an object of the present invention is to provide a rotor assembly.

It is a further object of the present invention to provide an electric machine comprising the above rotor assembly.

It is a further object of the present invention to provide an electrical apparatus comprising the above motor.

In order to achieve the above object, a technical solution of a first aspect of the present invention provides a rotor assembly, including a rotor core, a permanent magnet, a rotor disc, and a plastic-coated body, wherein one end surface of the permanent magnet is connected to one end surface of the rotor core, the rotor disc is made of a non-magnetic conductive material, the rotor disc is connected to the other end surface of the rotor core, and the plastic-coated body coats at least a part of the rotor core, at least a part of the permanent magnet, and at least a part of the rotor disc, so that the rotor core, the permanent magnet, and the rotor disc form an integral structure.

According to the rotor assembly provided by the technical scheme of the first aspect of the invention, the rotor core, the permanent magnets and the rotor disc are integrally formed by integrally coating, so that the rotor disc, the rotor core and the permanent magnets are fixedly connected. Compared with the existing bonding mode, the plastic coating mode effectively enhances the connection strength of the rotor iron core and the permanent magnet, the plastic coating body also plays a role in fixing and limiting the permanent magnet, and the connection area of the permanent magnet and other structures is increased, so that the risk that the permanent magnet is wholly or locally fallen off due to the fact that the surface bonding mode is unstable in the prior art is avoided, the permanent magnet is effectively prevented from falling off, and the running reliability of an axial flux permanent magnet motor (or a disc-type motor) is improved.

The setting of rotor disc is convenient for utilize the pivot of rotor disc and motor to realize fixed connection, and need not rotor core and pivot and link firmly, has both been favorable to reducing the connection degree of difficulty of rotor subassembly and pivot, still is favorable to guaranteeing the operational reliability of rotor subassembly. Meanwhile, compared with the existing pressing plate scheme, the non-magnetic rotor disc is beneficial to guaranteeing the overall strength of the rotor assembly and the contact flatness of the rotor disc and the rotor core on the basis of reducing eddy current loss.

The rotor core, the permanent magnets and the rotor disc are integrally molded, so that the rotor core, the permanent magnets and the rotor disc are integrally formed, the structural strength of the rotor assembly is effectively enhanced, the centrifugal force generated when the rotor disc rotates is overcome, the permanent magnets are prevented from falling off further, the axial deformation of the rotor caused by the operation of an axial magnetic field of the rotor is reduced, the air gap uniformity and the air gap magnetic density sine degree of the motor are prevented from being influenced due to the axial deformation of the rotor assembly, the sine degree of the counter potential of the motor is ensured, and the cogging torque and the torque pulsation of the motor are reduced.

In addition, the rotor assembly in the technical scheme provided by the invention can also have the following additional technical characteristics:

in any of the above technical solutions, the rotor core is formed by stacking silicon steel sheets along an axial direction of the rotor core.

Compared with a conventional integral rotor core, the rotor core of the scheme adopts a silicon steel sheet superposition design, which is beneficial to further reducing the eddy current loss in a rotor disc, thereby improving the operation efficiency of the motor.

In the above technical scheme, the rotor core is of a welded integrated structure.

The rotor core forms an integrated structure through welding, has high welding strength and mature process, thereby being beneficial to improving the structural strength of the rotor core and reducing the process difficulty. Of course, the rotor core may be integrally formed by gluing.

In the above technical scheme, the number of the permanent magnets is a plurality of, the plurality of permanent magnets are attached to the rotor core, and the plurality of permanent magnets are distributed in a circular array around the central axis of the rotor core.

The permanent magnet surface-mounted type motor has the advantages that the permanent magnet surface-mounted type motor is adopted, assembly between the permanent magnet and the rotor core is achieved, the process difficulty is simplified, production efficiency is improved, the connection strength between the permanent magnet and the rotor core is further improved, and the use reliability of the motor is further improved. The permanent magnets are distributed in a circular array around the central axis of the rotor core, so that the structure is regular, and the stable operation of the motor is facilitated.

In any of the above technical solutions, the end surface of the permanent magnet, which is far away from the rotor core, protrudes from the plastic coating body.

The end face of the permanent magnet, which is far away from the rotor core, protrudes out of the plastic coating body, so that the distance between the permanent magnet and the stator is reduced, the design of a small air gap of the motor is facilitated, the consumption of the permanent magnet is reduced, the utilization rate of the permanent magnet is improved, and the power density of the motor is increased. Specifically, the end face of the plastic coating body far away from the rotor core is marked as a plastic coating end face, two end faces of the permanent magnet are respectively marked as a first end face and a second end face, the first end face protrudes out of the plastic coating end face, and the second end face is connected with the end face of the rotor core. Of course, the permanent magnet may also be completely covered by the plastic coating.

In any of the above technical schemes, the outer side surface of the rotor core is provided with an outer groove, the plastic coating body is provided with an outer protrusion matched with the outer groove, the outer protrusion is embedded into the outer groove, and/or the rotor core is of an annular structure, the inner side surface of the rotor core is provided with an inner groove, the plastic coating body is provided with an inner protrusion matched with the inner groove, and the inner protrusion is embedded into the inner groove.

When the outer side surface of the rotor core is provided with the outer groove, liquid plastic can flow into the outer groove during plastic coating forming, and the liquid plastic is solidified to form an outer bulge, so that a part of the plastic coating body is embedded into the outer groove, the contact area of the rotor core and the plastic coating body is favorably increased, and the connection strength of the rotor core and the plastic coating body is further improved. Meanwhile, the outer groove can also be used as a welding position, so that the rotor core can be welded and molded conveniently.

Similarly, when the inner side surface of the rotor core is provided with the inner groove, liquid plastic flows into the inner groove during plastic coating forming, and is solidified to form an inner bulge, so that a part of the plastic coating body is embedded into the inner groove, the contact area of the rotor core and the plastic coating body is also favorably increased, and the connection strength of the rotor core and the plastic coating body is further improved.

In the above technical scheme, the rotor disk is of an annular structure, a through hole is formed in the inner side face of the rotor disk, the through hole corresponds to the inner groove of the rotor core, the plastic coating body is provided with a connecting column, and the connecting column is embedded into the through hole and the inner groove.

The inner side surface of the rotor disc is provided with the through hole, and the through hole corresponds to the inner groove of the rotor core, so that liquid plastic can flow into the through hole and the inner groove during plastic coating forming and is solidified to form a connecting column, the rotor disc and the rotor core are tightly and fixedly connected together, and the connecting strength of the rotor disc and the rotor core is improved.

Wherein the middle part of the rotor disc is provided with a shaft hole for accommodating the rotating shaft of the motor. Further, the inner side face of the rotor core is also provided with a positioning groove, the inner side face of the rotor disc is also provided with a positioning hole, and the positioning hole is correspondingly communicated with the positioning groove, so that the rotor core and the rotor disc can be accurately aligned during assembly.

In any technical scheme, the permanent magnet comprises two end faces and a side peripheral face, wherein the side peripheral face comprises a first side face, an outer side face, a second side face and an inner side face which are connected end to end in sequence, projections of the first side face, the outer side face, the second side face and the inner side face on the end faces are respectively a first side line, an outer side line, a second side line and an inner side line, projections of the side peripheral face on the end faces are of axisymmetric structures, a connecting line of the midpoint of the inner side line and the midpoint of the outer side line forms a symmetric axis of the axisymmetric structures, and the symmetric axis is configured to be suitable for being perpendicularly intersected with a central axis of a rotor assembly of the motor, the inner side line and the outer side line comprise two edge arc line segments and a middle section positioned between the two edge arc line segments, and the circle centers of the two edge arc segments of the inner side line and/or the circle centers of the two edge arc segments of the outer side line are positioned between the central axis and the outer side line.

The scheme adopts the optimized shape of the cambered surface for the inner side surface and the outer side surface of the permanent magnet, is favorable for increasing the distance between the end parts of two adjacent permanent magnets, thereby reducing magnetic leakage between corners of the two permanent magnets, improving the utilization rate of the permanent magnets on the basis of less permanent magnet consumption, and is favorable for sinusoidal air gap magnetic field and reducing counter potential harmonic wave, cogging torque and torque pulsation.

Specifically, the inner side surface and the outer side surface of the conventional sector permanent magnet are both concentrically arranged around the central axis of the rotor assembly. That is, the center of the projections of the inner side surface and the outer side surface of the existing sector-shaped permanent magnet on the end surface of the permanent magnet coincides with the projection of the central axis of the rotor assembly on the end surface of the permanent magnet. In this way, the outer side surfaces of two adjacent permanent magnets are positioned on the same cylindrical surface, and the inner side surfaces are also positioned on the same cylindrical surface. Thus, the end distances of the adjacent two permanent magnets are equal to the spacing between the first side and the second side of the adjacent two permanent magnets.

The shape of the permanent magnet is optimized, the two edge arc sections of the inner line are symmetrically arranged at two sides of the middle section of the inner line, and the two edge arc sections of the outer line are symmetrically arranged at two sides of the middle section of the outer line. When the centers of the two edge arc sections of the inner line are positioned between the central axis of the rotor assembly and the outer line, the radius of the inner corner part of the permanent magnet is reduced compared with the radius of the inner corner part of the conventional sector permanent magnet. Therefore, the edge parts of the inner side surfaces of the two adjacent permanent magnets are not on one cylindrical surface, and compared with the edge parts corresponding to the inner side surfaces in the prior art, the bending degree is deepened, so that the inner side corners shrink towards the middle part, the distance between the inner side end parts of the adjacent permanent magnets is favorably increased, the magnetic flux leakage of the inner side corners of the permanent magnets can be reduced, the utilization rate of magnetic steel is improved, the air gap is sinusoidal, and counter potential harmonic waves, cogging torque and torque pulsation are reduced.

Similarly, when the centers of the two edge arc sections of the outer line are positioned between the central axis and the outer line, the radius of the outer corner part of the permanent magnet is reduced compared with the existing sector permanent magnet. In this way, the edge parts of the outer side surfaces of two adjacent permanent magnets are not on one cylindrical surface, and compared with the edge parts corresponding to the outer side surfaces in the prior art, the bending degree is deepened, so that the inner side corners shrink towards the middle part, the distance between the outer side ends of the adjacent permanent magnets is favorably increased, the magnetic flux leakage of the outer side corners of the permanent magnets can be reduced, the air gap is sinusoidal, and counter potential harmonic waves, cogging torque and torque pulsation are reduced. Meanwhile, the permanent magnet is of a symmetrical structure, is regular in shape and is convenient to process.

It can be appreciated that in the application, the permanent magnet can be magnetic steel or made of other permanent magnetic materials. The motor is an axial flux permanent magnet motor, or a disc motor.

Wherein, the central axis of the air gap of the motor is collinear with the central axis of the rotor assembly, so the projection of the central axis of the rotor assembly on the end surface of the permanent magnet can be also recorded as the center of the air gap of the motor. Therefore, in the prior art, the center of the projection of the inner side surface and the outer side surface of the sector permanent magnet on the end surface of the permanent magnet is consistent with the center of the air gap. In the application, the circle center of the edge arc segment deviates from the circle center of the air gap and is inconsistent with the circle center of the air gap. The middle section of the inner line and the outer line can be a straight line section or an arc line section.

In the above technical solution, the middle section of the inner line is an arc section.

The middle section of the inner side line adopts an arc section, so that the inner side line is smoother, and the permanent magnet is convenient to process and shape.

In the above technical solution, the center of the middle section of the inner line is consistent with the centers of the two edge arc sections of the inner line.

In the above technical solution, the center of the inner line is located on the symmetry axis.

The inner line is actually a section of arc, and the circle center of the arc is positioned on the symmetry axis, so that the inner side surface is positioned on a cylindrical surface, the inner line can be integrally formed, the processing is convenient, and the processing efficiency of the permanent magnet is improved.

In the technical scheme, the inner side line is bent and protruded in a direction away from the outer side line, or the inner side line is bent and protruded in a direction close to the outer side line.

The inner side line is bent and protruded in the direction away from the outer side line, and then the inner side line is bent and protruded in the direction close to the central axis of the rotor assembly, so that the distance between the inner side ends of two adjacent permanent magnets is increased, missing detection between inner side corners between the adjacent permanent magnets is reduced, and the utilization rate of the magnetic steel is improved.

Or the inner side line can also be bent and protruded to the direction close to the outer side line according to the requirement, and the inner side line is specifically selected according to the practical application condition.

In any of the above technical solutions, two edge arc segments of the outer line are respectively marked as a first arc segment and a second arc segment, a middle segment of the outer line is a middle arc segment, the first arc segment and the second arc segment are symmetrical about the symmetry axis, the circle centers of the first arc segment and the second arc segment are consistent, and the circle center of the middle arc segment is located on the symmetry axis.

By the design, the permanent magnet is more regular in shape and more symmetrical in structure, so that the processing difficulty is further reduced, and the processing efficiency of the permanent magnet is further improved.

In the technical scheme, the circle centers of the first arc line segment, the second arc line segment and the inner side line segment are consistent, the circle center of the middle arc line segment is deviated from the circle center of the inner side line segment, or the circle centers of the first arc line segment, the middle arc line segment and the second arc line segment are consistent, the circle center of the outer side line segment is deviated from the circle center of the inner side line segment, or the circle center of the middle arc line segment is consistent with the circle center of the inner side line segment, the circle center of the middle arc line segment is deviated from the circle center of the first arc line segment and the circle center of the second arc line segment, or the circle centers of the first arc line segment, the second arc line segment, the circle center of the middle arc line segment and the circle center of the inner side line segment are consistent, or the circle centers of the first arc line segment, the second arc segment, the circle center of the middle arc segment and the circle center of the inner side line segment are mutually deviated.

For the case that the inner line is a whole arc, the center of the inner line (marked as O2), the centers of the first arc segment and the second arc segment of the outer line (marked as O3), and the center of the middle arc segment (marked as O1) have the following five positional relationships:

O2 and O3 are consistent, deviate from O1 and are inconsistent with O1, and the design is such that the cambered surface corresponding to the first arc line section (marked as a first side cambered surface), the cambered surface corresponding to the second arc line section (marked as a second side cambered surface) and the inner side surface (also can be called as an inner cambered surface) can be processed by the same working procedure, thereby being beneficial to improving the processing efficiency of the permanent magnet.

O1 and O3 are consistent, deviate from O2 and are inconsistent with O2, and the design is such that the whole outer side surface (also called as an extrados) can be processed by the same working procedure, thereby being beneficial to improving the processing efficiency of the permanent magnet.

O1 and O2 are consistent, deviate from O3 and are inconsistent with O3, and the design is such that the inner side surface (also called as an intrados surface) and the middle arc segment (also called as a middle surface) can be processed by the same process, thereby being beneficial to improving the processing efficiency of the permanent magnet.

O1, O2, O3 are unanimous, design such that medial surface (also can be called the intrados) and whole lateral surface (also can be called the extrados) accessible same process processing form, can adopt conventional pie permanent magnet to cut edge through both sides face and take shape fast, have reduced the processing degree of difficulty, are favorable to improving the machining efficiency of permanent magnet.

Or O1, O2 and O3 are inconsistent, and the specific shape of the permanent magnet can be reasonably designed according to the specific requirements of the motor.

In any of the above technical solutions, the first side line and the edge arc line are in smooth transition, and the second side line and the edge arc line are in smooth transition.

The design is convenient for the processing and forming of the permanent magnet, and is beneficial to improving the processing efficiency of the permanent magnet.

In any of the above technical solutions, the first side line and the second side line are straight line segments, and extension lines of the first side line and the second side line intersect to form an included angle α, where α=180°/P is satisfied between α and a pole pair number P of the rotor assembly.

The rotor assembly includes 2 times the number of permanent magnets P for the pole pair number P of the rotor. By the design, the permanent magnets are uniformly distributed along the circumferential direction of the rotor assembly.

In the above technical solution, an intersection point of extension lines of the first side line and the second side line is located on the symmetry axis and located between the central axis and the inner side line.

The design is favorable for further increasing the end distance between two adjacent permanent magnets, further improves corner magnetic leakage and further improves motor performance.

The technical scheme of the second aspect of the invention provides an electric machine, which comprises a stator assembly and the rotor assembly according to any one of the technical scheme of the first aspect, wherein the rotor assembly is matched with the stator assembly and is suitable for rotating relative to the stator assembly.

The motor provided by the second aspect of the present invention includes the rotor assembly according to any one of the first aspect, so that the motor has all the advantages of any one of the above technical aspects, and will not be described herein.

Specifically, the motor is an axial flux permanent magnet motor, or a disc motor.

The technical scheme of the third aspect of the invention provides electrical equipment, which comprises equipment main body and the motor according to the technical scheme of the second aspect, wherein the motor is connected with the equipment main body.

The electrical equipment provided by the technical scheme of the third aspect of the present invention includes the motor according to the technical scheme of the second aspect, so that the electrical equipment has all the beneficial effects of any one of the technical schemes, and is not described herein.

In the above technical solution, the electrical equipment may be, but is not limited to, a compressor, a fan, a pump, a refrigerator, an air conditioner and other household appliances, a vehicle, a multi-split air conditioner and other industrial equipment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic illustration of a rotor assembly according to some embodiments of the present disclosure;

FIG. 2 is a schematic structural view of a magnetic steel according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a magnetic steel according to an embodiment of the present invention;

FIG. 4 is a schematic structural view of a magnetic steel according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a magnetic steel according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a magnetic steel according to an embodiment of the present invention;

FIG. 7 is a schematic perspective view of a magnetic steel according to an embodiment of the present invention;

fig. 8 is a schematic structural view of a rotor core according to some embodiments of the present invention;

FIG. 9 is a schematic view of a rotor disk according to some embodiments of the present disclosure;

FIG. 10 is a schematic view of a plastic wrap according to some embodiments of the present invention;

FIG. 11 is a schematic block diagram of an electric machine according to some embodiments of the present invention;

fig. 12 is a schematic block diagram of an electrical device according to some embodiments of the present invention.

The correspondence between the reference numerals and the component names in fig. 1 to 12 is:

1 rotor assembly, 10 permanent magnets, 20 rotor cores, 30 rotor discs and 40 plastic-coated bodies;

11 first side, 110 second side, 111 first side line, 112 second side line, 120 inner side, 121 inner side line, 130 outer side, 131 first arc segment, 132 second arc segment, 133 middle arc segment, 141 first end face, 142 second end face;

21 an inner groove and 22 an outer groove;

31 through holes, 32 shaft holes;

41 outer bulges, 42 connecting columns and 43 plastic-coated end surfaces;

a 100 motor, 102 stator assembly;

200 an electrical device, 202 a device body.

Detailed Description

In order that the above-recited objects, features and advantages of the present application will be more clearly understood, a more particular description of the application will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.

A rotor assembly, a motor, and an electrical device according to some embodiments of the present invention are described below with reference to fig. 1 to 12.

As shown in fig. 1, an embodiment of the first aspect of the present invention provides a rotor assembly 1 including a rotor core 20, permanent magnets 10, a rotor disk 30, and a plastic encasement 40.

Specifically, one end face of the permanent magnet 10 is connected to one end face of the rotor core 20.

Rotor disk 30 is made of a non-magnetic conductive material, and rotor disk 30 is connected to the other end face of rotor core 20.

The overmold 40 encapsulates at least a portion of the rotor core 20, at least a portion of the permanent magnets 10, and at least a portion of the rotor disk 30, as shown in fig. 1, such that the rotor core 20, the permanent magnets 10, and the rotor disk 30 form a unitary structure.

The rotor assembly 1 provided by the embodiment of the first aspect of the present invention uses an integral molding mode to form an integral structure of the rotor core 20, the permanent magnets 10 and the rotor disc 30, so as to realize the fixed connection of the rotor disc 30, the rotor core 20 and the permanent magnets 10. Compared with the existing bonding mode, the plastic coating mode effectively enhances the connection strength of the rotor core 20 and the permanent magnet 10, the plastic coating body 40 also plays a role in fixing and limiting the permanent magnet 10, and increases the connection area of the permanent magnet 10 and other structures, so that the risk that the permanent magnet 10 is wholly or locally fallen off due to the fact that the surface bonding mode is unstable in the prior art is avoided, the permanent magnet 10 is effectively prevented from falling off, and the operation reliability of an axial flux permanent magnet motor (or called disc motor) is improved.

The arrangement of the rotor disc 30 is convenient for realizing fixed connection by utilizing the rotor disc 30 and the rotating shaft of the motor without fixedly connecting the rotor core 20 and the rotating shaft, thereby being beneficial to reducing the connection difficulty of the rotor assembly 1 and the rotating shaft and ensuring the operation reliability of the rotor assembly 1.

Meanwhile, compared with the existing pressing plate scheme, the non-magnetic rotor disc 30 is beneficial to ensuring the integral strength of the rotor assembly 1 and the contact flatness of the rotor disc 30 and the rotor core 20 on the basis of reducing eddy current loss.

The rotor core 20, the permanent magnet 10 and the rotor disc 30 are integrally molded, so that the rotor core 20, the permanent magnet 10 and the rotor disc 30 form an integrated structure, the structural strength of the rotor assembly 1 is effectively enhanced, the centrifugal force generated when the rotor disc 30 rotates is overcome, the permanent magnet 10 is prevented from falling off further, the axial deformation of the rotor caused by the operation of the axial magnetic field of the rotor is reduced, the air gap uniformity and the air gap magnetic density sine degree of the motor are prevented from being influenced due to the axial deformation of the rotor assembly 1, the sine degree of the counter potential of the motor is ensured, and the cogging torque and the torque pulsation of the motor are reduced.

Of course, for some motors, the rotor disc can be omitted, the permanent magnet is directly connected with the rotor core, and the rotor core can be connected with the rotating shaft in an injection molding mode.

Specifically, the number of permanent magnets 10 is plural, as shown in fig. 1. The plurality of permanent magnets 10 are surface-mounted on the rotor core 20, and the plurality of permanent magnets 10 are arranged in a circular array around the central axis of the rotor core 20.

The permanent magnet 10 is attached to the rotor core 20, so that the assembly between the permanent magnet 10 and the rotor core 20 is realized, the process difficulty is simplified, the production efficiency is improved, the connection strength between the permanent magnet 10 and the rotor core 20 is further improved, and the use reliability of the motor is further improved. The permanent magnets 10 are distributed in a circular array around the central axis of the rotor core 20, and the permanent magnet motor is regular in structure and beneficial to stable operation of the motor.

Further, the end surface of the permanent magnet 10 remote from the rotor core 20 protrudes from the plastic-coated body 40, as shown in fig. 1.

The end surface of the permanent magnet 10 far away from the rotor core 20 protrudes out of the plastic coating body 40, which is favorable for reducing the distance between the permanent magnet 10 and the stator, and is favorable for realizing the design of a small air gap of the motor, thereby reducing the dosage of the permanent magnet 10, improving the utilization rate of the permanent magnet 10 and increasing the power density of the motor.

Specifically, the end surface of the plastic coated body 40 away from the rotor core 20 is denoted as a plastic coated end surface 43, the two end surfaces of the permanent magnet 10 are denoted as a first end surface 141 and a second end surface 142, respectively, the first end surface 141 protrudes from the plastic coated end surface 43, and the second end surface 142 is connected to the end surface of the rotor core 20. The first end surface 141 protrudes from the plastic-coated end surface 43 by a distance H, as shown in fig. 1, and the size of H can be adjusted as required.

Of course, the permanent magnet 10 may be entirely covered by the plastic coating 40.

In some embodiments, further, the rotor core 20 is formed by lamination of silicon steel sheets in the axial direction of the rotor core 20, as shown in fig. 1.

Compared with the conventional integral rotor core 20, the rotor core 20 of the scheme adopts a silicon steel sheet superposition design, which is beneficial to further reducing the eddy current loss in the rotor disc 30, thereby improving the operation efficiency of the motor.

Of course, the rotor core 20 may be of an integral structure, and may be made of a solid magnetic conductive material in a block shape.

Wherein, the rotor core 20 is a welded integrated structure.

The rotor core 20 is welded to form an integrated structure, so that the welding strength is high, and the process is mature, thereby being beneficial to improving the structural strength of the rotor core 20 and reducing the process difficulty.

Of course, the rotor core 20 may be integrally formed by gluing.

In any of the above embodiments, further, the outer side 130 of the rotor core 20 is provided with the outer groove 22, as shown in fig. 8. The overmold 40 has an outer protrusion 41 that mates with the outer groove 22, as shown in FIG. 10. The outer protrusions 41 are embedded in the outer grooves 22.

Further, the rotor core 20 has a ring-like structure, as shown in fig. 8. The inner side 120 of the rotor core 20 is provided with an inner groove 21 as shown in fig. 8. The overmold 40 has an internal protrusion that mates with the internal recess 21, as shown in FIG. 10. The inner protrusions are embedded into the inner grooves 21.

When the outer side 130 of the rotor core 20 is provided with the outer groove 22, during plastic coating forming, liquid plastic flows into the outer groove 22 and is solidified to form the outer protrusion 41, so that a part of the plastic coating body 40 is embedded into the outer groove 22, which is beneficial to increasing the contact area between the rotor core 20 and the plastic coating body 40 and further improving the connection strength between the rotor core 20 and the plastic coating body 40. Meanwhile, the outer groove 22 can also be used as a welding position, so that the rotor core 20 can be welded and molded conveniently.

Wherein, the number of the outer grooves 22 is plural, and the plurality of the outer grooves 22 are distributed at intervals along the circumferential direction of the rotor core 20, and further evenly distributed.

Similarly, when the inner side 120 of the rotor core 20 is provided with the inner groove 21, liquid plastic flows into the inner groove 21 during plastic coating forming, and is solidified to form an inner protrusion, so that a part of the plastic coating body 40 is embedded into the inner groove 21, which is also beneficial to increasing the contact area between the rotor core 20 and the plastic coating body 40, and further improving the connection strength between the rotor core 20 and the plastic coating body 40.

Wherein, the quantity of interior recess 21 is a plurality of, and a plurality of interior recess 21 are along rotor core 20 circumference interval distribution, further evenly distributed.

Further, the rotor disk 30 has an annular structure as shown in fig. 9. The inner side 120 of the rotor disk 30 is provided with a through hole 31 as shown in fig. 9. The through hole 31 corresponds to the inner groove 21 of the rotor core 20, and the overmold 40 has a connecting post 42, as shown in fig. 10. The connection post 42 is inserted into the through hole 31 and the inner groove 21.

Through holes 31 are formed in the inner side surface 120 of the rotor disc 30, and the positions of the through holes 31 correspond to the positions of the inner grooves 21 of the rotor core 20, so that liquid plastic flows into the through holes 31 and the inner grooves 21 during plastic coating forming and is solidified to form connecting columns 42, so that the rotor disc 30 and the rotor core 20 are tightly and fixedly connected together, and the connection strength of the rotor disc 30 and the rotor core 20 is improved.

It will be appreciated that the portion of the connecting post 42 located in the inner recess 21 is the inner projection described above.

Wherein the middle part of the rotor disc 30 is provided with a shaft hole 32 for accommodating the rotating shaft of the motor. Further, the inner side 120 of the rotor core 20 is also provided with a positioning groove, as shown in fig. 8. The inner side 120 of the rotor disk 30 is also provided with locating holes, as shown in fig. 9. The positioning holes are correspondingly communicated with the positioning grooves, so that the rotor core 20 and the rotor disc 30 can be accurately aligned during assembly.

In a specific embodiment, the number of the positioning grooves is two, the two positioning grooves are symmetrically arranged, the size of each positioning groove is smaller than that of each inner groove 21, and each positioning groove is located at the middle position of two adjacent inner grooves 21. Accordingly, the number of the positioning holes is two, the size of the positioning holes is smaller than that of the through holes 31, and the positioning holes are positioned at the middle positions of the two adjacent through holes 31.

In any of the above embodiments, further, the permanent magnet 10 includes two end faces and side circumferential faces, as shown in fig. 7.

Specifically, the side circumferential surface includes a first side surface 11, an outer side surface 130, a second side surface 110, and an inner side surface 120, which are connected end to end in this order, as shown in fig. 7. The projections of the first side 11, the outer side 130, the second side 110 and the inner side 120 on the end surfaces are a first side line 111, an outer side line, a second side line 112 and an inner side line 121, respectively, as shown in fig. 2 to 6. The projection of the side circumferential surface on the end surface is an axisymmetric structure, and a line connecting the midpoint of the inner line 121 and the midpoint of the outer line forms a symmetry axis of the axisymmetric structure, and the symmetry axis is configured to be adapted to perpendicularly intersect with the central axis of the rotor assembly 1 of the motor. Both the inner line 121 and the outer line include two edge arc segments and a middle segment located between the two edge arc segments.

The centers of the two edge arc segments of the inner line 121 are located between the central axis and the outer line.

Or the centers of the two edge arc sections of the outer line are positioned between the central axis and the outer line.

Or the centers of the two edge arc segments of the inner line 121 and the centers of the two edge arc segments of the outer line are located between the central axis and the outer line.

The scheme adopts the optimized shape of the cambered surfaces for the inner side surface 120 and the outer side surface 130 of the permanent magnet 10, is favorable for increasing the distance between the end parts of two adjacent permanent magnets 10 on one hand, thereby reducing magnetic leakage between corners of the two permanent magnets, improving the utilization rate of the permanent magnet 10 on the basis of less consumption of the permanent magnets 10, and is favorable for reducing counter potential harmonic waves, cogging torque and torque pulsation on the other hand due to the optimized cambered surface design.

Specifically, in the conventional sector permanent magnet 10, the inner side 120 and the outer side 130 are both disposed concentrically around the central axis of the rotor assembly 1. That is, the center of the projections of the inner side 120 and the outer side 130 of the conventional sector-shaped permanent magnet 10 on the end face of the permanent magnet 10 coincides with the projection of the central axis of the rotor assembly 1 on the end face of the permanent magnet 10. Thus, the outer sides 130 of two adjacent permanent magnets 10 are located on the same cylindrical surface, and the inner sides 120 are also located on the same cylindrical surface. Therefore, the end distances of the adjacent two permanent magnets 10 are equal to the interval between the first side 11 and the second side 110 of the adjacent two permanent magnets 10.

The shape of the permanent magnet 10 is optimized, two edge arc sections of the inner line 121 are symmetrically arranged at two sides of the middle section of the inner line 121, and two edge arc sections of the outer line are symmetrically arranged at two sides of the middle section of the outer line. When the centers of the two edge arc segments of the inner line 121 are located between the central axis of the rotor assembly 1 and the outer line, the radius of the inner corner portion of the permanent magnet 10 is reduced compared to the conventional sector permanent magnet 10. In this way, the edge portions of the inner sides 120 of the adjacent two permanent magnets 10 are not on one cylindrical surface, and the edge portions corresponding to the inner sides 120 are bent to a greater extent than the prior art, so that the inner corners shrink toward the middle, which is beneficial to increasing the distance between the inner ends of the adjacent permanent magnets 10, thereby reducing the magnetic flux leakage of the inner corners of the permanent magnets 10, improving the utilization rate of the magnetic steel, sinusoidal the air gap, and reducing the counter potential harmonic wave, cogging torque and torque ripple.

Similarly, when the centers of the two edge arc segments of the outer line are located between the central axis and the outer line, the radius of the outer corner part of the permanent magnet 10 is reduced compared with the existing sector permanent magnet 10. In this way, the edge portions of the outer side surfaces 130 of the adjacent two permanent magnets 10 are not on one cylindrical surface, and the degree of bending is increased relative to the prior art, which corresponds to the edge portions of the outer side surfaces 130, so that the inner corners shrink toward the middle, which is advantageous in increasing the distance between the outer side ends of the adjacent permanent magnets 10, so that the leakage flux of the outer side corners of the permanent magnets 10 can be reduced, the air gap is sinusoidal, and the back-emf harmonics, cogging torque, and torque ripple are reduced. Meanwhile, the permanent magnet 10 has a symmetrical structure, is regular in shape and is convenient to process.

Wherein the central axis of the air gap of the motor is collinear with the central axis of the rotor assembly 1, so that the projection of the central axis of the rotor assembly 1 onto the end face of the permanent magnet 10 can also be noted as the air gap center of the motor. Therefore, in the prior art, the center of the projection of the inner side 120 and the outer side 130 of the sector permanent magnet 10 on the end face of the permanent magnet 10 coincides with the center of the air gap. In the application, the circle center of the edge arc segment deviates from the circle center of the air gap and is inconsistent with the circle center of the air gap. The middle sections of the inner line 121 and the outer line may be straight line sections or arc sections.

It is understood that in the present application, the permanent magnet 10 may be magnetic steel, or may be a permanent magnet 10 made of other permanent magnetic materials. The motor is an axial flux permanent magnet motor, or a disc motor.

Further, the middle section of the inner line 121 is an arc section.

The middle section of the inner side line 121 adopts an arc segment, so that the inner side line 121 is smoother, and the permanent magnet 10 is convenient to process and shape.

Further, the middle section of the inner line 121 coincides with the center of the two edge arc segments of the inner line 121, as shown in fig. 2 to 6.

The center of the inner line 121 is located on the symmetry axis, as shown in fig. 2 to 6.

In this way, the inner line 121 is actually a section of arc, and the center of the arc is located on the symmetry axis, so that the inner side 120 is located on a cylindrical surface, which can be integrally formed, is convenient for processing, and is beneficial to improving the processing efficiency of the permanent magnet 10.

Further, the inner line 121 is curved and protruded in a direction away from the outer line as shown in fig. 2 to 6.

The inner line 121 is bent and protruded in a direction away from the outer line, and then the inner line 121 is bent and protruded in a direction close to the central axis of the rotor assembly 1, which is advantageous to further increase the distance between the inner ends of the two adjacent permanent magnets 10, thereby further reducing missing detection between inner corners between the adjacent permanent magnets 10 and improving the utilization rate of the magnetic steel.

Of course, the inner line 121 may be curved and protruded in a direction approaching the outer line as required, which is similar to the shape of the conventional sector permanent magnet 10, and is specifically selected according to practical application conditions.

Further, two edge arc segments of the outer line are respectively denoted as a first arc segment 131 and a second arc segment 132, and a middle segment of the outer line is denoted as an arc segment and is denoted as a middle arc segment 133. The first arc segment 131 and the second arc segment 132 are symmetrical about an axis of symmetry, as shown in fig. 2 to 6, and the centers of the first arc segment 131 and the second arc segment 132 coincide, and the center of the middle arc segment 133 is located on the axis of symmetry.

By the design, the permanent magnet 10 is more regular in shape and more symmetrical in structure, so that the processing difficulty is further reduced, and the processing efficiency of the permanent magnet 10 is further improved.

For the case where the inner line 121 is a whole arc, the center of the air gap is denoted as O, the center of the inner line 121 (denoted as O2), the centers of the first arc segment 131 and the second arc segment 132 of the outer line (denoted as O3), and the center of the middle arc segment 133 (denoted as O1) have the following five positional relationships:

1) The center of the first arc segment 131, the center of the second arc segment 132, and the center of the inner line 121 are identical, and the center of the middle arc segment 133 is deviated from the center of the inner line 121, as shown in fig. 2.

In other words, O2 and O3 agree and deviate from O1, disagree with O1, as shown in FIG. 2. The design is such that the arc surface corresponding to the first arc segment 131 (denoted as the first side arc surface), the arc surface corresponding to the second arc segment 132 (denoted as the second side arc surface), and the inner side surface 120 (may also be referred to as the inner arc surface) can be processed by the same process, thereby being beneficial to improving the processing efficiency of the permanent magnet 10.

2) The center of the first arc segment 131, the center of the middle arc segment 133, and the center of the second arc segment 132 coincide, as shown in fig. 6, and the center of the outer line deviates from the center of the inner line 121.

In other words, O1 and O3 agree and deviate from O2, disagree with O2, as shown in FIG. 6. The design is such that the entire outer side 130 (which may also be referred to as an extrados) can be machined by the same process, thereby facilitating the improvement of the machining efficiency of the permanent magnet 10.

3) The center of the middle arc segment 133 coincides with the center of the inner line 121, and the center of the middle arc segment 133 is deviated from the centers of the first arc segment 131 and the second arc segment 132, as shown in fig. 5.

In other words, O1 and O2 agree and deviate from O3, disagree with O3, as shown in FIG. 5. By such design, the inner side surface 120 (also called an intrados surface) and the middle arc segment 133 (also called a middle surface) can be processed by the same process, which is beneficial to improving the processing efficiency of the permanent magnet 10.

4) The center of the first arc segment 131, the center of the middle arc segment 133, the center of the second arc segment 132, and the center of the inner line 121 are identical as shown in fig. 4.

In other words, O1, O2, O3 agree as shown in fig. 4. By adopting the design, the inner side surface 120 (also called as an inner cambered surface) and the whole outer side surface 130 (also called as an outer cambered surface) can be processed by the same process, and the conventional cake-shaped permanent magnet 10 can be rapidly formed by trimming the edges of the two side surfaces, so that the processing difficulty is reduced, and the processing efficiency of the permanent magnet 10 is improved.

5) The centers of the first and second arc segments 131 and 132, the center of the middle arc segment 133, and the center of the inner line 121 are offset from each other as shown in fig. 3.

In other words, all of O1, O2, and O3 are not uniform, and as shown in fig. 3, the specific shape of the permanent magnet 10 can be reasonably designed according to the specific needs of the motor.

In any of the above embodiments, the first side line 111 and the edge arc line are smoothly transited, and the second side line 112 and the edge arc line are smoothly transited.

By the design, the permanent magnet 10 is convenient to process and mold, and the processing efficiency of the permanent magnet 10 is improved.

In any of the above embodiments, the first side line 111 and the second side line 112 are straight line segments, and the extension lines of the first side line 111 and the second side line 112 intersect to form an included angle α. α and the pole pair number P of the rotor assembly 1 satisfy α=180°/P.

The rotor assembly 1 comprises a number of permanent magnets 10 that is 2 times P, with the pole pair number of the rotor being P. This design facilitates a uniform arrangement of the plurality of permanent magnets 10 in the circumferential direction of the rotor assembly 1.

Further, the intersection point of the extension lines of the first side line 111 and the second side line 112 is located on the symmetry axis and between the central axis and the inner side line 121, as shown in fig. 2 to 6.

The design is beneficial to further increasing the end distance between two adjacent permanent magnets 10, further improving corner magnetic leakage and further improving motor performance.

As shown in fig. 11, an embodiment of the second aspect of the present invention provides an electrical machine comprising a stator assembly 102 and a rotor assembly 1 according to any of the embodiments of the first aspect, the rotor assembly 1 being adapted to rotate relative to the stator assembly 102 in cooperation with the stator assembly 102.

The motor 100 according to the second embodiment of the present invention, which includes the rotor assembly 1 according to any one of the first embodiment, has all the advantages of any one of the above embodiments, and will not be described herein.

As shown in fig. 12, an electrical apparatus 200 provided according to an embodiment of the third aspect of the present invention includes an apparatus main body 202 and a motor 100 according to an embodiment of the second aspect, the motor 100 being connected to the apparatus main body 202.

Specifically, the electric machine 100 is an axial flux permanent magnet electric machine 100, or a disc electric machine 100.

The electrical apparatus 200 provided in the embodiment of the third aspect of the present invention includes the motor 100 in the embodiment of the second aspect, and thus has all the advantages of any of the above embodiments, which are not described herein.

In the above embodiment, the electric device 200 may be, but is not limited to, a compressor, a fan, a pump, a household appliance such as a refrigerator, an air conditioner, etc., an industrial device such as a vehicle, a multi-split air conditioner, etc.

Some specific embodiments are described below and in contrast to the prior art.

With the development of motor technology, permanent magnet brushless direct current motors are widely applied to various places in various fields, and disc permanent magnet brushless motors are gradually applied to places with high requirements on structural volume, such as fields of household appliances, vehicles, industry and the like, due to the advantages of compact structure, small volume and the like.

In the application of the disc motor, the magnetic steel is easy to fall off due to the existence of axial magnetic attraction between the centrifugal force and the stator and the rotor of the motor, and the application of the disc motor is limited. Permanent magnets are generally adopted to be bonded on the surface of a rotor core, but the traditional structure has the defects that in the operation process of a disc motor, directly bonded magnetic steel is not firmly bonded, and the phenomenon of whole or partial falling-off exists, so that the operation of the motor is at great risk. The permanent magnet is pressed by the whole pressing plate, and the structure has the defects of large eddy current loss in the pressing plate and increased air gap of the motor due to the thickness of the pressing plate, thereby affecting the air gap density of the motor and the utilization rate of the permanent magnet.

As a power source, the magnetic steel of the existing permanent magnet motor mostly adopts a sector shape or a circular shape. The processing difficulty of the fan-shaped magnetic steel is relatively large, the four corners have serious magnetic flux leakage, so that the local saturation of the motor rotor is serious, the counter potential harmonic wave, the cogging torque and the torque pulsation of the motor are large, and the utilization rate of the inner side face of the magnetic steel is not high. The processing of circular magnet steel is comparatively simple and easy, but the whole utilization ratio is not high, causes the motor back electromotive force less, has reduced the output ability of motor.

To this end, the invention proposes a number of rotor assemblies 1 for disc machines and disc machines comprising such rotor assemblies 1.

Specific example 1

A rotor assembly 1 comprises magnetic steel, a rotor core 20, a non-magnetic rotor disk 30 and a plastic coating body 40 which is formed by sequentially arranging the magnetic steel, the rotor core 20 and the rotor disk 30 into a whole. The magnetic steel comprises an upper surface, a lower surface, an inner cambered surface, an outer cambered surface and two side surfaces.

In the projection of the upper surface or the lower surface of the magnetic steel, the inner cambered surface is formed by a section of circular arc, the circle center of the circular arc forming the inner cambered surface is inconsistent with the circle center of the air gap, the outer cambered surface is formed by a left side surface, a right side surface and a middle surface, the left side surface and the right side surface are symmetrical about the middle surface, the circle centers of the left side surface and the right side surface are identical, and the circle center of the middle surface is positioned on the central symmetry line of the magnetic steel.

Specifically, for ease of understanding in conjunction with the drawings, two end faces of the magnetic steel are referred to as an upper surface and a lower surface, an inner side face 120 of the magnetic steel is referred to as an intrados, the radii of the inner side faces 120 are consistent, an outer side face 130 of the magnetic steel is referred to as an extrados, surfaces corresponding to a first arc segment 131, a middle arc segment 133 and a second arc segment 132 of the extrados are respectively referred to as a left side face, a middle face and a right side face, and a first side face 11 and a second side face 110 of the magnetic steel are simply referred to as two side faces.

The unique design of the magnetic steel of the disk motor is convenient for processing compared with the conventional sector magnetic shoe, reduces corner magnetic leakage, enables an air gap to be sinusoidal, and reduces counter potential harmonic waves, cogging torque and torque pulsation. The non-magnetic rotor disk 30 and the integral plastic-coated structure enhance the structural strength of the rotor, are beneficial to overcoming the centrifugal force when the rotor rotates, prevent the permanent magnet 10 from falling off, and reduce the axial deformation of the rotor. On the basis that no extra loss is caused, the non-magnetic rotor disc 30 is beneficial to ensuring the overall strength of the rotor and the planeness of the rotor core 20, and on the other hand, the rotor disc 30 is fixedly connected with a motor rotating shaft, so that the operation reliability of the rotor assembly 1 is ensured.

Further, the upper surface or the lower surface of the magnetic steel is surface-mounted on the rotor core 20, and the plurality of magnetic steels and the rotor core 20 are concentrically arranged, so that the design of the surface-mounted permanent magnet 10 simplifies the process difficulty.

Further, the plastic coating component is formed by sequentially arranging the magnetic steel, the rotor core 20 and the rotor disc 30 into a whole, and the upper surface or the lower surface of the magnetic steel, which is not adhered to the surface of the rotor core 20, protrudes out of the end surface of the plastic coating component.

The magnetic steel and the rotor core 20 are additionally fixedly connected together in a plastic-coated mode, so that the risk that the whole piece or part of the magnetic steel is fallen off due to infirm bonding of the magnetic steel bonded on the surface is avoided, and the running reliability of the motor is improved. In addition, the integral strength of the rotor structure is enhanced by the design form of integrally coating all the rotor components, the centrifugal force generated when the rotor disk 30 rotates is overcome, the axial deformation of the rotor caused by the operation of the axial magnetic field of the rotor is reduced, the air gap uniformity of the motor is influenced, the air gap density sine degree of the motor is influenced, the sine degree of counter electromotive force is ensured, and the cogging torque and torque pulsation of the motor are reduced. The end surface of the magnetic steel opposite to the air gap protrudes out of the end surface of the plastic coating body 40, so that the design of a small air gap of the motor is guaranteed, the consumption of the permanent magnet 10 is reduced, the utilization rate of the permanent magnet 10 is improved, and the power density of the motor is increased.

Further, rotor core 20 is formed by stacking silicon steel sheets in the axial direction, and there is an inner groove 21 at the inner radius of rotor core 20, and an outer groove 22 at the outer radius. Compared with a conventional integral iron core rotor, the rotor iron core 20 adopts a silicon steel sheet design, which is beneficial to reducing the eddy current loss in the rotor disc 30 and improving the operation efficiency of the motor.

Further, rotor core 20 is welded into an integral structure using outer grooves 22 of rotor core 20. And meanwhile, the outer groove 22 increases the contact surface of the plastic-coated structure, which is beneficial to enhancing the connection strength of the injection molding assembly and other parts of the rotor.

Further, through holes 31 are formed in the inner side 120 of the rotor disc 30, and the through holes 31 correspond to the positions of the grooves 21 in the rotor core 20, so that the rotor disc 30 and the rotor core 20 are conveniently and fixedly connected together during plastic coating.

Further, the circle center of the arc forming the intrados in the magnetic steel is positioned on the central symmetry line of the magnetic steel. So that the intrados can be integrally formed. When the circle center of the inner cambered surface and the circle center of the air gap are positioned on the same side of the inner cambered surface, the inner cambered surface is in a shape protruding away from the circle center of the air gap. Can be applied according to practical application conditions.

When the center of the intrados is positioned at the outer side of the magnetic steel, the distance between the end parts of the two adjacent magnetic steels is increased, so that the magnetic flux leakage between the corners of the two adjacent magnetic steels is reduced, and the utilization rate of the magnetic steel is improved.

Further, the centers of the left side surface and the right side surface of the magnetic steel are consistent with the center of the circular arc forming the intrados, as shown in fig. 2. Therefore, the left side surface, the right side surface and the inner cambered surface of the magnetic steel can be processed through the same working procedure, and the processing efficiency of the magnetic steel is improved.

Specific example 2

The difference from the specific example 1 is that the centers of the left side face, the right side face, and the intermediate face of the magnetic steel are identical as shown in fig. 6. The outer cambered surface of the magnetic steel formed at the moment can be integrally formed, so that the processing difficulty is reduced, the processing procedures are reduced, and the processing efficiency of the magnetic steel is improved.

Specific example 3

The difference from the specific example 1 is that the left side face, the right side face, and the intermediate face of the magnetic steel coincide with the center of the circular arc constituting the intrados face, as shown in fig. 4. At the moment, the magnetic steel can be rapidly formed by adopting the conventional round cake-shaped magnetic steel through the side trimming at the two sides, so that the processing difficulty is reduced, and the processing efficiency of the magnetic steel is improved.

Specific example 4

The difference from the specific example 1 is that the center of the middle surface of the magnetic steel coincides with the center of the intrados surface as shown in fig. 5. Therefore, the middle surface and the inner cambered surface of the magnetic steel can be processed through the same working procedure, and the processing efficiency of the magnetic steel is improved.

Specific example 5

The difference from the specific example 1 is that the centers of the left side face, the right side face and the middle face of the magnetic steel are identical, and the center of the center face is also inconsistent with the center of the intrados, as shown in fig. 3.

The inner side surface 120 and the outer side surface 130 of the magnetic steel adopt the optimized shape of the cambered surface, so that on one hand, the distance between the end parts of the two adjacent magnetic steels is increased, the magnetic leakage between the corners of the two adjacent magnetic steels is reduced, the utilization rate of the magnetic steel is improved on the basis of less consumption of the permanent magnet 10, and on the other hand, the optimized cambered surface design is favorable for the sinusoidal of an air gap magnetic field, and counter potential harmonic wave, cogging torque and torque pulsation are reduced.

In some embodiments, smooth transition is realized between the two side surfaces of the magnetic steel and the left side surface, the right side surface and the intrados surface, which is beneficial to the processing of the magnetic steel.

In some embodiments, the angle between the two sides of the magnetic steel is α, α=360/(2×p), where P is the pole pair number.

In the present invention, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, the term "plurality" then referring to two or more unless explicitly defined otherwise. The terms "mounted," "connected," "secured," and the like are to be construed broadly, as they are used in a fixed or removable connection, or as they are integral with one another, as they are directly or indirectly connected through intervening media. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or units referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention.

In the description of the present specification, the terms "one embodiment," "some embodiments," "particular embodiments," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (16)

1. A rotor assembly for an axial flux permanent magnet or disk motor comprising:

The rotor iron core is of an annular structure;

the axial end face of the permanent magnet is connected with the axial end face of the rotor core;

The rotor disc is made of a non-magnetic conductive material and is connected with the other axial end face of the rotor core;

a plastic-coated body that coats at least a portion of the rotor core, at least a portion of the permanent magnet, and at least a portion of the rotor disk so that the rotor core, the permanent magnet, and the rotor disk are of a unitary structure;

The permanent magnet includes:

Two end surfaces, and

The side peripheral surface comprises a first side surface, an outer side surface, a second side surface and an inner side surface which are sequentially connected end to end, the projections of the first side surface, the outer side surface, the second side surface and the inner side surface on the end surface are respectively a first side line, an outer side line, a second side line and an inner side line, the projections of the side peripheral surface on the end surface are of an axisymmetric structure, a connecting line of the midpoint of the inner side line and the midpoint of the outer side line forms a symmetrical axis of the axisymmetric structure, and the symmetrical axis is configured to be suitable for being perpendicularly intersected with the central axis of a rotor assembly of the motor;

The center of the two edge arc line segments of the inner line and/or the center of the two edge arc line segments of the outer line are/is positioned between the central axis and the outer line;

The first side line and the second side line are straight line segments, the extension lines of the first side line and the second side line intersect to form an included angle alpha, and alpha and the pole pair number P of the rotor assembly meet the conditions that alpha=180 degrees/P;

The intersection point of the extension lines of the first side line and the second side line is positioned on the symmetrical axis and between the central axis and the inner side line;

The projection of the central axis of the rotor assembly on the end face of the permanent magnet is recorded as the air gap circle center of the motor, and the circle center of the edge arc segment deviates from the air gap circle center and is inconsistent with the air gap circle center.

2. The rotor assembly of claim 1 wherein the rotor assembly comprises a plurality of rotor blades,

The rotor core is formed by laminating silicon steel sheets along the axial direction of the rotor core.

3. The rotor assembly of claim 2 wherein the rotor assembly comprises a plurality of rotor blades,

The rotor core is of a welded integrated structure.

4. A rotor assembly according to any one of claims 1 to 3,

The number of the permanent magnets is multiple, the permanent magnets are attached to the rotor core, and the permanent magnets are distributed in a circular array around the central axis of the rotor core.

5. A rotor assembly according to any one of claims 1 to 3,

The end face, far away from the rotor core, of the permanent magnet protrudes out of the plastic coating body.

6. A rotor assembly according to any one of claims 1 to 3,

The outer side surface of the rotor core is provided with an outer groove, the plastic coating body is provided with an outer bulge which is matched with the outer groove, the outer bulge is embedded into the outer groove, and/or

The inner side of the rotor core is provided with an inner groove, the plastic wrapping body is provided with an inner protrusion matched with the inner groove, and the inner protrusion is embedded into the inner groove.

7. The rotor assembly of claim 6 wherein the rotor assembly comprises a plurality of rotor blades,

The rotor disc is of an annular structure, a through hole is formed in the inner side face of the rotor disc, the through hole corresponds to the inner groove of the rotor core, the plastic wrapping body is provided with a connecting column, and the connecting column is embedded into the through hole and the inner groove.

8. A rotor assembly according to any one of claims 1 to 3,

The middle section of the inner line is an arc section.

9. The rotor assembly of claim 8 wherein the rotor assembly comprises a plurality of rotor blades,

The middle section of the inner line is consistent with the circle centers of the two edge arc sections of the inner line.

10. The rotor assembly of claim 9 wherein the rotor assembly comprises a plurality of rotor blades,

The center of the inner line is positioned on the symmetry axis.

11. The rotor assembly of claim 8 wherein the rotor assembly comprises a plurality of rotor blades,

The inner line is bent and protruded in a direction away from the outer line, or

The inner line is bent and protruded in a direction approaching to the outer line.

12. A rotor assembly according to any one of claims 1 to 3,

The two edge arc sections of the outer line are respectively marked as a first arc section and a second arc section, the middle section of the outer line is a middle arc section, the first arc section and the second arc section are symmetrical about the symmetry axis, the circle centers of the first arc section and the second arc section are consistent, and the circle center of the middle arc section is positioned on the symmetry axis.

13. The rotor assembly of claim 12 wherein the rotor assembly comprises a plurality of rotor blades,

The circle centers of the first arc line segment, the second arc line segment and the inner line segment are consistent, and the circle center of the middle arc line segment deviates from the circle center of the inner line segment, or

The center of the first arc line segment, the center of the middle arc line segment and the center of the second arc line segment are consistent, and the center of the outer line deviates from the center of the inner line, or

The center of the middle arc segment is consistent with the center of the inner line, and the center of the middle arc segment deviates from the centers of the first arc segment and the second arc segment, or

The circle center of the first arc segment, the circle center of the middle arc segment, the circle center of the second arc segment and the circle center of the inner line are consistent, or

The circle centers of the first arc line segment and the second arc line segment, the circle center of the middle arc line segment and the circle center of the inner side line are deviated from each other.

14. A rotor assembly according to any one of claims 1 to 3,

Smooth transition is carried out between the first side line and the edge arc segment;

And the second side line and the edge arc line are in smooth transition.

15. An electric machine, comprising:

Stator assembly, and

A rotor assembly as claimed in any one of claims 1 to 14, which is co-operable with the stator assembly and adapted to rotate relative thereto.

16. An electrical device, comprising:

an apparatus main body, and

The motor of claim 15, said motor being coupled to said device body.