Rotor core, rotor assembly, motor and household appliance

Abstract

The utility model discloses a rotor core, a rotor assembly, a motor and a household electrical appliance, the rotor core comprises one or a plurality of yoke portion sections connected into a ring, each yoke portion section comprises a plurality of yoke portion single bodies and a plurality of bending portions, in each yoke portion section, the plurality of yoke portion single bodies are sequentially arranged along the circumferential direction of the rotor core, and the bending portions are arranged along the circumferential direction of the rotor core. Every two adjacent yoke part single bodies are connected through a bending part, and each yoke part section comprises a plurality of yoke part punching sheets which are stacked in the axial direction of the rotor iron core. The rotor iron core is further provided with a plurality of installation grooves used for installing the permanent magnets, the installation grooves are arranged at intervals in the circumferential direction, and the installation grooves are formed in the wall face, facing the rotating axis of the rotor iron core, of the yoke section. The rotor iron core is low in production cost and convenient to assemble.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and in particular to a rotor core, a rotor assembly, a motor and a household appliance. Background Art

[0002] The rotor yoke of an outer rotor motor is generally annular and made of cold-rolled steel sheets (such as silicon steel sheets). When punching the annular rotor yoke sheet, a lot of waste is generated, resulting in material waste, low utilization of the cold-rolled steel sheets, and high production costs. At the same time, it is difficult to position the permanent magnets in existing outer rotor motors, making assembly inconvenient. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a rotor core with low production cost and easy assembly.

[0004] The utility model also provides a rotor assembly, a motor and a household appliance having the rotor core.

[0005] According to the rotor core of the first aspect of the present invention, the embodiment comprises one or more yoke sections connected in a ring shape, wherein the yoke sections comprise a plurality of yoke monomers and a plurality of bending portions, wherein in each of the yoke sections, a plurality of the yoke monomers are sequentially arranged along the circumference of the rotor core, and two adjacent yoke monomers are connected via a bending portion, and each of the yoke sections comprises a plurality of yoke punchings stacked along the axial direction of the rotor core; the rotor core is further provided with a plurality of mounting grooves for mounting permanent magnets, wherein the plurality of mounting grooves are spaced apart along the circumferential direction, and the mounting grooves are formed on the wall surface of the yoke section facing the rotation axis of the rotor core.

[0006] The rotor core according to the embodiment of the first aspect of the utility model has at least the following beneficial effects: since the bending portion is easy to bend, when processing the yoke section, a plurality of straight strip-shaped yoke punching sheets can be first punched out on the silicon steel plate, and the plurality of straight strip-shaped yoke punching sheets can be stacked into a yoke section. At this time, the plurality of yoke monomers of the yoke section are arranged linearly, and then the yoke section is bent into a ring or arc shape through the bending portion, and then it can be assembled into a ring-shaped rotor core. Therefore, when punching out the yoke punching sheets, a plurality of straight strip-shaped yoke punching sheets can be closely arranged on the silicon steel plate, that is, the arrangement is close, which is conducive to reducing waste, improving the utilization rate of the silicon steel plate, and thus reducing material costs. At the same time, since the rotor core is provided with installation grooves, on the one hand, it is convenient to position the permanent magnets during assembly, which facilitates assembly, improves production efficiency and reduces production costs. On the other hand, the provision of installation grooves can directly reduce material usage, and when arranging multiple yoke punching sheets, the positions on the silicon steel plate corresponding to the installation grooves can be fully utilized, so that multiple straight yoke punching sheets can be arranged more closely on the silicon steel plate, further improving the utilization rate of the silicon steel plate, thereby reducing the overall production cost of the rotor core.

[0007] According to some embodiments of the present invention, each yoke unit is provided with a mounting groove.

[0008] According to some embodiments of the present invention, a portion of the structure of each mounting groove is located in one of the two adjacent yoke monomers, and another portion of the structure is located in the other yoke monomer.

[0009] According to some embodiments of the utility model, the yoke section is also provided with a plurality of through holes, and the plurality of through holes are arranged one-to-one corresponding to the plurality of bending portions, a portion of the structure of the through hole is located in one of the two adjacent yoke monomers, and another portion of the structure is located in the other yoke monomer.

[0010] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum size of the through hole is H 1 The minimum thickness of the yoke unit is H 2 , satisfying: 0.2≤H 1 / H 2 ≤0.8.

[0011] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum size of the through hole is H 1 The maximum thickness of the yoke unit is H 3 , satisfying: 0.05≤H 1 / H 3 ≤0.2.

[0012] According to some embodiments of the present invention, along the circumferential direction, the maximum size of the through hole is W. 1, the maximum width of the mounting groove is W 2 , satisfying: 0.01≤W 1 / W 2 ≤0.1.

[0013] According to some embodiments of the present invention, the rotor core further includes a limiting portion located between two adjacent mounting grooves, and along the circumferential direction, the maximum size of the through hole is W. 1 , the minimum width of the limit portion is W 3 , satisfying: 0.05≤W 1 / W 3 ≤0.2.

[0014] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum size of the through hole is H 1 The minimum distance between the inner wall of the through hole and the wall of the limiting portion facing the rotation axis is H 4 , satisfying: 0.05≤H 1 / H 4 ≤0.2

[0015] According to the rotor core of the embodiment of the second aspect of the utility model, it includes a plurality of yoke monomers, which are arranged in sequence along the circumference of the rotor core and assembled into a ring. Among two adjacent yoke monomers, one of the yoke monomers is provided with a positioning groove, and the other yoke monomer is provided with a positioning protrusion, which is accommodated in the positioning groove. The yoke monomers include a plurality of punching sheet monomers stacked along the axial direction of the rotor core; the rotor core is also provided with a plurality of installation grooves for installing permanent magnets, and each of the installation grooves is formed correspondingly on the wall surface of each yoke monomer facing the rotation axis of the rotor core.

[0016] According to the rotor core of the second embodiment of the utility model, at least the following beneficial effects are achieved: since the rotor core is composed of a plurality of yoke monomers, when processing the rotor core, a plurality of punching sheet monomers can be punched out on the silicon steel plate first, and the plurality of punching sheet monomers are stacked into a yoke monomer, and then the plurality of yoke monomers are assembled into a ring-shaped rotor core through the positioning protrusion and the positioning groove. Therefore, since the curvature of a single punching sheet monomer is small, when punching the punching sheet monomer, the plurality of punching sheet monomers can be closely arranged on the silicon steel plate, that is, the arrangement is close, which is conducive to reducing waste and improving the utilization rate of the silicon steel plate, thereby reducing the material cost. At the same time, since the rotor core is provided with an installation groove, on the one hand, it is convenient to position the permanent magnet during assembly, convenient to assemble, improve production efficiency and reduce production cost, on the other hand, the installation groove can directly reduce the amount of material used, and when arranging the plurality of punching sheet monomers, the position corresponding to the installation groove on the silicon steel plate can be fully utilized, so that the plurality of punching sheet monomers can be arranged more closely on the silicon steel plate, further improving the utilization rate of the silicon steel plate, thereby reducing the overall production cost of the rotor core.

[0017] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum width of the positioning protrusion is H 5 The minimum distance between the wall surface of the positioning protrusion and the wall surface of the yoke monomer away from the rotation axis is H 6 , satisfying: 0.1≤H 5 / H 6 ≤2.

[0018] According to some embodiments of the present invention, the rotor core further includes a limiting portion located between two adjacent mounting grooves, and along the radial direction of the rotor core, the maximum width of the positioning protrusion is H 5 The minimum distance between the wall surface of the positioning protrusion and the wall surface of the limiting portion facing the rotation axis is H 7 , satisfying: 0.1≤H 5 / H 7 ≤2.

[0019] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum width of the positioning protrusion is H 5 The minimum thickness of the yoke unit is H 2 , satisfying: 0.5≤H 5 / H 2 ≤2.

[0020] According to some embodiments of the present invention, along the radial direction of the rotor core, the maximum width of the positioning protrusion is H 5 The maximum thickness of the yoke unit is H 3 , satisfying: 0.1≤H 5 / H 3≤0.8.

[0021] According to the rotor assembly of the third embodiment of the utility model, it includes the rotor core of the first or second embodiment of the utility model, and a plurality of permanent magnets, wherein the plurality of permanent magnets are correspondingly installed in the plurality of installation slots.

[0022] According to the rotor assembly of the third embodiment of the utility model, there are at least the following beneficial effects: the rotor assembly can make the arrangement tight due to the use of the above-mentioned rotor core, which is conducive to reducing waste and improving the utilization rate of silicon steel plates, thereby reducing material costs. At the same time, since the rotor core is provided with a mounting groove, on the one hand, it is convenient to position the permanent magnet during assembly, which is convenient for assembly, improves production efficiency and reduces production costs. On the other hand, the installation groove can directly reduce the amount of material used, and the position corresponding to the installation groove on the silicon steel plate can be fully utilized during the arrangement, so that the arrangement is tighter, further improving the utilization rate of the silicon steel plate, and then reducing the overall production cost of the rotor assembly.

[0023] According to some embodiments of the present invention, a portion of the structure of the permanent magnet is accommodated in the installation groove, and another portion of the structure protrudes from the installation groove, and two opposite wall surfaces of two adjacent permanent magnets conflict with each other.

[0024] According to some embodiments of the present invention, along the radial direction of the rotor core, the minimum thickness of the yoke unit is H 2 The maximum thickness of the yoke unit is H 3 , satisfying: 0.1≤H 2 / H 3 ≤0.5.

[0025] According to some embodiments of the present invention, the rotor core further includes a limiting portion located between two adjacent mounting grooves, and along the circumferential direction, the maximum width of the mounting groove is W. 2 , the minimum width of the limit portion is W 3 , satisfying: 0.1≤W 3 / W 2 ≤0.5.

[0026] The motor according to the fourth embodiment of the utility model comprises a stator assembly and a rotor assembly according to the third embodiment of the utility model, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

[0027] The motor according to the fourth aspect of the utility model has at least the following beneficial effects: the motor can make the arrangement tight due to the use of the above-mentioned rotor assembly, which is conducive to reducing waste and improving the utilization rate of silicon steel plates, thereby reducing material costs. At the same time, since the rotor core is provided with a mounting groove, on the one hand, it is convenient to position the permanent magnet during assembly, which is convenient for assembly, improves production efficiency and reduces production costs. On the other hand, the installation groove can directly reduce the amount of material used, and the position corresponding to the installation groove on the silicon steel plate can be fully utilized during the arrangement, so that the arrangement is tighter, further improving the utilization rate of the silicon steel plate, and then reducing the overall production cost of the motor.

[0028] The household appliance according to the fifth embodiment of the utility model includes the motor according to the fourth embodiment of the utility model.

[0029] The household appliance according to the fifth embodiment of the utility model has at least the following beneficial effects: the household appliance can make the arrangement tight due to the use of the above-mentioned motor, which is conducive to reducing waste and improving the utilization rate of silicon steel plates, thereby reducing material costs. At the same time, since the rotor core is provided with a mounting groove, on the one hand, it is convenient to position the permanent magnet during assembly, which is convenient for assembly, improves production efficiency and reduces production costs. On the other hand, the installation groove can directly reduce the amount of material used, and the position corresponding to the installation groove on the silicon steel plate can be fully utilized during arrangement, so that the arrangement is tighter, further improving the utilization rate of the silicon steel plate, and thus reducing the overall production cost of the household appliance.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0032] Figure 1 is an axial schematic diagram of a rotor assembly in some embodiments of the utility model;

[0033] Figure 2 yes Figure 1 A in the enlarged view;

[0034] Figure 3 is an axial schematic diagram of a yoke section in some embodiments of the present utility model;

[0035] Figure 4 yes Figure 3 The enlarged view of point B in the figure;

[0036] Figure 5 yes Figure 3 The enlarged view of point C in the figure;

[0037] Figure 6 is an axial schematic diagram of a yoke section in other embodiments of the utility model;

[0038] Figure 7 It is a partial axial schematic diagram of the cooperation between the permanent magnet and the yoke monomer in other embodiments of the utility model;

[0039] Figure 8 is an axial schematic diagram of a rotor core in some embodiments of the utility model;

[0040] Fig. 9 yes Figure 8 The enlarged view of D in the figure;

[0041] Fig.10 It is a schematic diagram of the structure of the yoke monomer in some embodiments of the utility model;

[0042] Fig.11 It is a schematic diagram of the arrangement of yoke sections in some embodiments of the utility model;

[0043] Fig.12 It is a schematic diagram of the arrangement of yoke sections in other embodiments of the utility model;

[0044] Fig.13 It is a schematic diagram of the arrangement of yoke monomers in some embodiments of the utility model;

[0045] Fig.14 It is a simulation diagram of magnetic field distribution of a motor in the prior art;

[0046] Fig.15 It is a simulation diagram of the magnetic field distribution of the motor in some embodiments of the utility model;

[0047] Fig.16 It is a simulation diagram of the magnetic flux distribution of the motor in some embodiments of the utility model;

[0048] Fig.17 It is a curve diagram of the air gap flux density of the motor in the prior art changing with the rotation angle of the motor;

[0049] Fig.18 It is a curve diagram showing the change of the air gap flux density of the motor with the rotation angle of the motor in some embodiments of the utility model.

[0050] Reference numerals:

[0051] Rotor assembly 1000;

[0052] Permanent magnet 100;

[0053] Yoke section 200; yoke unit 210; bending portion 220; through hole 230; positioning protrusion 240; positioning groove 250; mounting groove 260; limiting portion 270;

[0054] Silicon steel plate 300 ; yoke punching sheet 310 ; punching sheet unit 311 ; concave position 312 ; convex structure 313 . DETAILED DESCRIPTION

[0055] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0056] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0057] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0058] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model based on the specific content of the technical solution.

[0059] As an important component of household appliances such as air conditioners, washing machines, and refrigerators, the performance and production cost of motors affect the performance and production cost of such household appliances to a certain extent. Motors generally include outer rotor motors and inner rotor motors. For outer rotor motors, their rotor cores are usually ring-shaped and wound around the outer periphery of the stator. Generally speaking, the rotor core is made of cold-rolled steel plates (such as silicon steel plates). In the related art, when the annular rotor yoke punching sheets are punched, a lot of waste is generated, resulting in material waste, low utilization of cold-rolled steel plates, and high production costs. At the same time, the permanent magnets of existing outer rotor motors are only attached to the inner circumferential wall of the rotor yoke, which makes it difficult to position the permanent magnets and inconvenient to assemble.

[0060] For this purpose, refer to Figures 1 to 18As shown, the first embodiment of the utility model provides a rotor core, which is a component of the rotor assembly 1000 and is specifically used in the motor of a household appliance. The household appliance here can be an air conditioner, a washing machine, a refrigerator, etc.

[0061] It can be understood that the motor is an external rotor motor, and the motor includes a stator assembly and a rotor assembly 1000, wherein the rotor assembly 1000 is arranged around the outer circumference of the stator assembly and can rotate relative to the stator assembly, and the central axis of the rotor assembly 1000 is the rotation axis. The structural composition of the stator assembly may include an iron core and a winding, which will not be repeated here.

[0062] It is understood that in the following description, the axial direction is the direction of the rotation axis of the rotor assembly 1000, the circumferential direction is the direction around the rotation axis of the rotor assembly 1000, and the radial direction is the direction perpendicular to the rotation axis of the rotor assembly 1000 and pointing from the rotation axis to the outer peripheral wall of the rotor assembly 1000 and the opposite direction. Among them, the outer side is the side away from the rotation axis of the rotor assembly 1000, and the inner side is the side close to the rotation axis of the rotor assembly 1000.

[0063] The structure of the rotor core is described in detail below by taking the rotor assembly 1000 as an example.

[0064] Reference Figure 1 and Figure 2 As shown, it can be understood that the rotor assembly 1000 includes a rotor core and a plurality of permanent magnets 100, the rotor core is in a circular ring shape, and the central axis of the rotor assembly 1000 is the central axis of the rotor core. A plurality of permanent magnets 100 are mounted on the inner peripheral wall of the rotor core and are arranged at equal intervals along the circumferential direction, that is, the permanent magnets 100 are located between the rotor core and the stator assembly, and in the radial direction, there is a certain gap, i.e., an air gap, between the permanent magnets 100 and the stator assembly. Each permanent magnet 100 corresponds to a magnetic pole of the rotor assembly 1000. In this embodiment, the number of permanent magnets 100 is 14, and of course, the number of permanent magnets 100 can also be 12, 16, etc.

[0065] Reference Figure 3 and Figure 4As shown, it can be understood that the rotor core includes a yoke section 200 connected in a circular ring shape. Specifically, the yoke section 200 includes a plurality of yoke monomers 210 and a plurality of bending portions 220, wherein the number of the yoke monomers 210 is the same as the number of the permanent magnets 100. Of course, in other embodiments, the number of the yoke monomers 210 may be less than or greater than the number of the permanent magnets 100. On the projection plane perpendicular to the axis of rotation, the projection of the yoke section 200 is in a circular ring shape, and the projection of the yoke monomer 210 is roughly a fan ring, that is, a part of a ring shape, and the central angle corresponding to the outer wheel contour line of the fan ring is about 26°, and the arc is small, so that the projection of each yoke monomer 210 is roughly an elongated structure.

[0066] Reference Figure 3 and Figure 4 As shown, it can be understood that a plurality of yoke monomers 210 are arranged at intervals along the circumferential direction, the number of the bending portions 220 is one less than the number of the yoke monomers 210, and the two ends of each bending portion 220 are respectively connected to the ends of two adjacent yoke monomers 210, that is, two adjacent yoke monomers 210 are connected through a bending portion 220. It is easy to understand that there is no bending portion 220 between a group of adjacent yoke monomers 210, the two opposite walls between the group of adjacent yoke monomers 210 are planes and can conflict with each other, and the group of adjacent yoke monomers 210 are fixed by welding, so that the yoke section 200 forms a complete ring and has a stable structure. In this embodiment, since the rotor core only includes one yoke section 200, the integrity is better, the structural strength is higher, the number of parts is small, the process is simpler, and the roundness of the rotor core can be well guaranteed, so that the rotor assembly 1000 and the stator assembly can be assembled.

[0067] Reference Figure 4 and Figure 5 As shown, it can be understood that in the yoke section 200, the bending portion 220 is connected to the side of the circumferential end of the yoke monomer 210 that is away from the rotation axis, while the side of the opposite ends of two adjacent yoke monomers 210 that is close to the rotation axis is disconnected. This facilitates the bending operation of the yoke section 200, and enables the wall surface of the bending portion 220 that is radially away from the rotation axis to form a part of the outer peripheral wall of the rotor core, so that the outer peripheral wall of the rotor core is a continuous wall surface and is conducive to ensuring roundness, so as to be firmly connected to the housing of the motor.

[0068] It can be understood that the bending portion 220 is easier to bend than the yoke monomer 210, that is, the flexibility of the bending portion 220 is better than that of the yoke monomer 210, and the bending portion 220 can be bent along the circumferential direction. Therefore, when producing a circular rotor core, a straight yoke section 200 can be processed first. At this time, the yoke section 200 is in a chain structure, and the multiple yoke monomers 210 in the yoke section 200 are arranged in a linear arrangement, that is, the multiple yoke monomers 210 are arranged in sequence along the length direction of the yoke section 200. Then, by bending the bending portion 220, the straight yoke section 200 can be bent into a ring shape, and the two ends of the yoke section 200 are welded and fixed to obtain a circular rotor core.

[0069] Reference Figures 2 to 4 As shown, it can be understood that the rotor core is also provided with a plurality of mounting grooves 260, and the number of the mounting grooves 260 is equal to the number of the permanent magnets 100. The mounting groove 260 is formed on the inner peripheral wall of the rotor core, specifically, the mounting groove 260 is formed on the inner peripheral wall of the yoke section 200 (i.e., the wall facing the axis of rotation), the mounting groove 260 is an arc-shaped groove and is recessed outward, the opening of the mounting groove 260 faces the stator assembly, and on the projection plane perpendicular to the axis of rotation, the projection of the groove wall of the mounting groove 260 is an arc line, and the center of the circle where the arc line is located deviates from the axis of rotation and is located between the arc line and the axis of rotation. A plurality of permanent magnets 100 are arranged at equal intervals along the circumferential direction, each permanent magnet 100 is correspondingly installed in each mounting groove 260, and the wall surface of the permanent magnet 100 away from the axis of rotation is attached to the groove wall of the mounting groove 260, and generally speaking, the permanent magnet 100 is bonded and fixed to the groove wall of the mounting groove 260. The wall surfaces of the plurality of permanent magnets 100 facing the rotation axis form the inner circumferential wall of the rotor assembly 1000. Therefore, when assembling the rotor assembly 1000, the permanent magnets 100 can be positioned using the mounting grooves 260, which facilitates the positioning of the permanent magnets 100 in the circumferential direction, facilitates assembly, improves assembly efficiency, and reduces process costs.

[0070] Reference Figures 1 to 4 As shown, it can be understood that in this embodiment, the number of yoke monomers 210 and mounting grooves 260 is equal, and each mounting groove 260 is correspondingly formed in each yoke monomer 210, that is, a mounting groove 260 is set on the wall surface of each yoke monomer 210 facing the axis of rotation. Therefore, when the straight strip yoke section 200 is bent during the production process, the mounting groove 260 can always remain intact, with good integrity, low deformation probability, and small dimensional error, which is conducive to accurately positioning the permanent magnet 100 and improving the fit between the permanent magnet 100 and the groove wall of the mounting groove 260, thereby improving the installation accuracy, installation stability and installation efficiency of the permanent magnet 100.

[0071] Reference Figure 4As shown, it can be understood that the yoke monomer 210, the mounting groove 260 and the permanent magnet 100 are all axisymmetric structures, and the center lines of the yoke monomer 210, the mounting groove 260 and the permanent magnet 100 are all arranged radially. In this embodiment, the center line of the mounting groove 260 coincides with the center line of the yoke monomer 210, that is, the mounting groove 260 is located in the middle position of the yoke monomer 210 along the circumferential direction. At this time, at the position of the mounting groove 260, the thickness of the yoke monomer 210 along the radial direction increases from the center line to both sides of the circumferential direction, and presents a structure that is narrow in the middle and wide on both sides. It is easy to understand that at this time, the bending portion 220 is connected to the position of the yoke monomer 210 where the thickness along the radial direction is wider.

[0072] Reference Figure 2 and Figure 4 As shown, it is easy to understand that, due to the installation groove 260, the yoke monomer 210 is formed with a limiting structure located on both sides of the installation groove 260 in the circumferential direction. In the rotor core, two adjacent limiting structures in two adjacent yoke monomers 210 are combined to form a limiting portion 270, that is, the limiting portion 270 is protruded toward the stator assembly relative to the installation groove 260. Therefore, the limiting portion 270 and the installation groove 260 cooperate to achieve the circumferential limitation of the permanent magnet 100.

[0073] Reference Figure 2 As shown, it can be understood that the center line of the permanent magnet 100 coincides with the center line of the yoke monomer 210 and the center line of the mounting groove 260. It is easy to understand that in the motor, the magnetic flux lines of the magnetic field of the permanent magnet 100 are arranged symmetrically about its center line, and the density of the magnetic flux lines increases from its center line to both sides of the circumference, that is, the magnetic flux at the position of the center line of the permanent magnet 100 on the yoke monomer 210 is small. Therefore, the design of a smaller radial thickness at the middle position of the yoke monomer 210 has less impact on the magnetic field, and the magnetic flux at the middle position of the yoke monomer 210 is not easy to saturate, that is, the arc-shaped mounting groove 260 has less impact on the performance of the motor. Figure 2 The dashed lines are magnetic flux lines.

[0074] Reference Fig.11 As shown, it can be understood that the rotor core is composed of a plurality of rotor punchings arranged in an axial stacked manner, and correspondingly, the yoke section 200 includes a plurality of yoke punchings 310 arranged in an axial stacked manner, and each yoke punching 310 includes a plurality of punching monomers 311, and the punching monomers 311 correspond to the yoke monomers 210, that is, a plurality of punching monomers 311 arranged in a corresponding manner in the axial direction constitute the yoke monomer 210. Therefore, when producing the rotor core, a plurality of yoke punchings 310 can be punched out on the silicon steel plate 300 first. It is easy to understand that a recessed position 312 corresponding to the mounting groove 260 is provided in the punching monomer 311, and a protruding structure 313 corresponding to the limiting portion 270 is formed.

[0075] Reference Figure 3 and Fig.11 , Fig.12 As shown, when producing the straight strip yoke section 200, a plurality of straight strip yoke punching sheets 310 can be punched out on the silicon steel plate 300. For the straight strip yoke punching sheets 310, when arranging on the silicon steel plate 300, a plurality of punching sheet monomers 311 of each yoke punching sheet 310 are arranged in sequence along the length direction of the yoke punching sheet 310, so that a plurality of yoke punching sheets 310 can be closely arranged along the length direction perpendicular to the yoke punching sheet 310, so as to achieve an optimized arrangement layout, which is conducive to reducing waste, thereby improving the utilization rate of the silicon steel plate 300 and reducing material costs. At the same time, since the punching sheet monomer 311 is provided with a concave position 312, on the one hand, the concave position 312 can directly reduce the material consumption to reduce the material cost, and on the other hand, for two adjacent yoke punching sheets 310, one of the yoke punching sheets 310 can be arranged in reverse in a direction perpendicular to the length direction of the yoke punching sheet 310, that is, the concave positions 312 of the two yoke punching sheets 310 are arranged relatively, and the yoke punching sheets 310 arranged in reverse are offset by a certain distance in the length direction of the yoke punching sheet 310, so that the convex structure 313 of one yoke punching sheet 310 is accommodated in the concave position 312 of the other yoke punching sheet 310, so that the position corresponding to the concave position 312 on the silicon steel plate 300 can be fully utilized, so that the two adjacent yoke punching sheets 310 are arranged more closely. In this way, the two yoke punching sheets 310 are arranged in sequence in a direction perpendicular to the length direction of the yoke punching sheet 310 as a group, which can further reduce waste, improve the utilization rate of the silicon steel plate 300, and reduce material costs. Therefore, the overall production cost of the rotor core can be greatly reduced.

[0076] It is understandable that in other embodiments, the rotor core includes multiple yoke segments 200, for example, the rotor core includes two yoke segments 200, and the number of yoke monomers 210 of the two yoke segments 200 is equal or unequal, or the rotor core includes three yoke segments 200, and the number of yoke monomers 210 of the three yoke segments 200 may also be equal or unequal, or the rotor core includes more yoke segments 200, which will not be described in detail here. Similarly, when producing the rotor core, a straight yoke segment 200 may be produced first, and then each yoke segment 200 may be bent into an arc, and multiple arc-shaped yoke segments 200 may be assembled into a ring shape, and the ends of two adjacent yoke segments 200 may be welded and fixed to obtain a ring-shaped rotor core. Similarly, when producing the straight yoke section 200, the layout can be optimized to reduce waste, thereby improving the utilization rate of the silicon steel plate 300, reducing material costs, and greatly reducing the overall production cost of the rotor core, which will not be repeated here.

[0077] Reference Figure 4 and Figure 5As shown, it can be understood that the yoke section 200 is also provided with a plurality of through holes 230, the number of the through holes 230 is equal to the number of the bending parts 220, and each through hole 230 is respectively located on the side of each bending part 220 facing the rotation axis. Specifically, the through hole 230 axially penetrates the two end faces of the yoke section 200, and the projection of the through hole 230 on the projection plane perpendicular to the rotation axis can be circular, square, elliptical, etc. A part of the structure of the through hole 230 is formed in one yoke monomer 210, and the other part is formed in another adjacent yoke monomer 210. Therefore, by providing the through hole 230, when the yoke section 200 is bent, the bending stress can be released, avoiding the disadvantage of the bending part 220 being broken during the bending process, and avoiding the disadvantage of the structures of the two adjacent yoke monomers 210 being squeezed against each other and causing deformation, thereby improving the manufacturability.

[0078] Reference Figure 6 As shown, it can be understood that in other embodiments, the number of mounting grooves 260 is equal to the number of yoke monomers 210, and each mounting groove 260 is formed between two adjacent yoke monomers 210. That is to say, a part of the structure of the mounting groove 260 is located in one yoke monomer 210, and the other part of the structure is located in another adjacent yoke monomer 210. Therefore, half grooves are respectively provided at both ends of the yoke monomer 210 along the circumferential direction, and the two half grooves are symmetrically arranged about the center line of the yoke monomer 210. After the yoke section 200 is bent, the two adjacent half grooves are combined to form the mounting groove 260. The specific structural form of the mounting groove 260 can refer to the above description and will not be repeated here. At the position of the half groove, the thickness of the yoke monomer 210 along the radial direction decreases from the center line to the circumferential sides, and presents a structure that is wide in the middle and narrow on both sides. It is easy to understand that at this time, the bending portion 220 is connected to the position of the yoke monomer 210 where the width is narrower along the radial direction. Correspondingly, a limiting portion 270 located between the two half slots is formed in the middle of the yoke unit 210 . The limiting portion 270 is protruded toward the stator assembly relative to the mounting slot 260 , and can also limit the permanent magnet 100 in the circumferential direction.

[0079] Reference Figure 7As shown, it can be understood that, since the magnetic flux lines of the magnetic field of the permanent magnet 100 are arranged symmetrically about its center line, and the density of the magnetic flux lines increases from its center line to both sides of the circumference, the magnetic flux at the position of the center line of the permanent magnet 100 on the yoke monomer 210 is small, and the magnetic flux lines will not pass through the center line of the permanent magnet 100. The magnetic resistance in the fine gap between the through hole 230 and the disconnection of the two adjacent yoke monomers 210 is greater than that of the yoke monomer 210. For this reason, in the rotor assembly 1000, the two adjacent yoke monomers 210 are arranged symmetrically, and the symmetric center lines of the two adjacent yoke monomers 210 are arranged radially, and the symmetric center lines of the two adjacent yoke monomers 210 coincide with the center lines of the mounting slot 260 and the center line of the permanent magnet 100. Therefore, the magnetic flux of the permanent magnet 100 can be prevented from passing through the through hole 230 and the fine gap between two adjacent yoke monomers 210 to weaken the magnetic field, thereby effectively improving the utilization rate of the permanent magnet 100 and reducing the impact on the motor performance. Figure 7 The dashed lines are magnetic flux lines.

[0080] Reference Figures 8 to 10 As shown, it can be understood that the second embodiment of the utility model also provides another structure of the rotor core. Specifically, the rotor core includes a plurality of yoke monomers 210, and the plurality of yoke monomers 210 are arranged in sequence along the circumferential direction. Among two adjacent yoke monomers 210, one yoke monomer 210 is provided with a positioning groove 250 at the end along the circumferential direction, and the other yoke monomer 210 is provided with a positioning convex portion 240 at the end along the circumferential direction, and the outer contour of the positioning convex portion 240 matches the outer contour of the positioning groove 250. It can also be understood that each yoke monomer 210 is provided with a positioning convex portion 240 at one end along the circumferential direction, and a positioning groove 250 at the other end. On the projection plane perpendicular to the axis of rotation, the outer contour of the positioning convex portion 240 can be semicircular, trapezoidal or square, etc. Adjacent positioning convex portions 240 and positioning grooves 250 are docked, so that a plurality of yoke monomers 210 are assembled into a ring, that is, the rotor core. It is easy to understand that after the rotor assembly 1000 is installed in the housing of the motor, the rotor core and the housing have an interference fit, and under the pressure of the housing on the rotor core directed toward the axis of rotation, the rotor core can be firmly assembled together, and the structure has good stability.

[0081] Reference Figures 8 to 10 As shown, it can be understood that, similarly, each yoke unit 210 is respectively provided with a mounting groove 260 to position and mount the permanent magnet 100, which will not be described in detail here.

[0082] It can be understood that, similarly, each yoke monomer 210 is composed of a plurality of punching sheet monomers 311 stacked along the axial direction, that is, the yoke monomer 210 includes a plurality of punching sheet monomers 311 stacked along the axial direction, and the curvature of each punching sheet monomer 311 is relatively small.

[0083] Table 1

[0084] parameter After Improvement Prior art Speed ​​(rpm) 1800 1800 Torque(Nm) 1.066 1.066 Copper loss(W) 27.54 26.44 Iron loss(W) 4.4 3.8 <![CDATA[Volume (mm 3 )]]> 154480 213896 efficiency(%) 80 80.5 Back EMF(V) 210 160 Cost (Yuan) 6 8 <![CDATA[Power density (W / mm 3 )]]> 1.4 1 <![CDATA[Torque density (Nm / mm 3 )]]> 1.4 1

[0085] Reference Figure 8 and Fig.13 As shown, therefore, when producing the rotor core, a plurality of punching sheet monomers 311 can be first punched out on the silicon steel plate 300, and the plurality of punching sheet monomers 311 can be stacked into a yoke monomer 210, and then the plurality of yoke monomers 210 can be assembled into an annular rotor core through the positioning protrusion 240 and the positioning groove 250. Since the curvature of a single punching sheet monomer 311 is small, when arranging on the silicon steel plate 300, multiple punching sheet monomers 311 can be arranged in a rectangular array, and some punching sheet monomers 311 can be arranged in reverse, so that the protruding structure 313 corresponding to the limiting portion 270 on the punching sheet monomer 311 is accommodated in the concave position 312 corresponding to the mounting groove 260 on another punching sheet monomer 311, so that the position corresponding to the concave position 312 on the silicon steel plate 300 can be fully utilized, so that multiple punching sheet monomers 311 are closely arranged on the silicon steel plate 300, and the layout is optimized, which is conducive to reducing waste and improving the utilization rate of the silicon steel plate 300, thereby reducing material costs and further reducing the overall production cost of the rotor core. At the same time, since the rotor core is assembled by multiple yoke monomers 210 through the positioning convex portion 240 and the positioning groove 250, no bending operation is required, which effectively avoids the risk of rotor core breakage caused by the bending operation, thereby making the structural stability of the rotor core better.

[0086] As shown in Table 1, it can be understood that, for the motor using the improved rotor core, relative to the prior art solution, at the same speed, the output torque, loss and efficiency do not change much, while the production cost drops from 8 yuan to 6 yuan, a 25% drop in production cost, which is a significant reduction in production cost.

[0087] Reference Figure 4 and Figure 5 As shown, it can be understood that, for the rotor core provided with the through hole 230, along the radial direction of the rotor core, the maximum size (ie, the inner diameter) of the through hole 230 is defined as H 1 , the minimum thickness of the yoke unit 210 is H 2 , the maximum thickness of the yoke unit 210 is H 3 The minimum distance between the inner wall of the through hole 230 and the wall of the limiting portion 270 facing the rotation axis is H 4 Among them, H 1 That is, the distance between the two points on the inner wall of the through hole 230 with the largest distance in the radial direction of the rotor core, H 2 That is, the minimum distance between the outer wall surface of the yoke unit 210 and the groove wall of the installation groove 260, H 3That is, the maximum distance between the outer wall surface of the yoke unit 210 and the wall surface of the stopper 270 facing the rotation axis. 1 , W 1 That is, it is the distance between two locations on the inner wall of the through hole 230 that are the largest in the circumferential direction of the rotor core.

[0088] Reference Figure 4 As shown, it can be understood that along the circumference of the rotor core, the maximum width of the mounting slot 260 is W 2 , the minimum width of the limiting portion 270 is W 3 .W 2 That is, the maximum distance between the two ends of the groove wall of the installation groove 260 along the circumferential direction, W 3 That is, it is the minimum distance between the two ends of the wall surface of the limiting portion 270 facing the rotation axis in the circumferential direction.

[0089] Reference Figure 4 and Figure 5 As shown, it can be understood that the maximum radial dimension H of the through hole 230 is 1 and the minimum thickness H of the yoke unit 210 2 Satisfy 0.2≤H 1 / H 2 ≤0.8. For the through hole 230 located in the structure with the smallest thickness in the yoke monomer 210, if H 1 / H 2 If H is too small, the maximum radial dimension of the through hole 230 is too small, which is not conducive to bending and eliminating bending stress. 1 / H 2 If the through hole 230 is too large, the radial thickness of the bent portion 220 will become smaller, the structural strength will be poor, and the overall structural strength of the rotor core will be affected. The influence of the through hole 230 being located in the structure with the largest thickness in the yoke monomer 210 is similar to that of the through hole 230 being located in the structure with the smallest thickness in the yoke monomer 210. In addition, setting the size of the through hole 230 according to the minimum thickness of the yoke monomer 210 can also avoid the disadvantage of the maximum radial size of the through hole 230 being too large and weakening the magnetic field, thereby ensuring the performance of the motor. Therefore, 0.2≤H 1 / H 2 ≤0.8, for example H 1 / H 2 The value of is 0.2, 0.4, 0.6 or 0.8, etc., which can ensure the structural strength of the rotor core and the performance of the motor, while ensuring the operability of the bending and facilitating production.

[0090] Reference Figure 4 and Figure 5 As shown, it can be understood that the maximum radial dimension H of the through hole 230 is 1 and the maximum thickness H of the yoke unit 210 3Satisfy 0.05≤H 1 / H 3 ≤0.2. For the through hole 230 located in the structure with the largest thickness in the yoke monomer 210, if H 1 / H 3 If H is too small, the maximum radial dimension of the through hole 230 is too small, which is not conducive to bending and eliminating bending stress. 1 / H 3 If the thickness of the through hole 230 is too large, the radial thickness of the bent portion 220 will become smaller, the structural strength will be poor, and the overall structural strength of the rotor core will be affected. In addition, the magnetic resistance at the through hole 230 will be large, which will seriously weaken the magnetic field and affect the performance of the motor. For the structure where the through hole 230 is located in the yoke unit 210 with the smallest thickness, the size of the through hole 230 is set according to the maximum thickness of the yoke unit 210, so that the size of the through hole 230 can be smaller, avoiding affecting the overall structural strength of the bent portion 220 and the rotor core. Therefore, 0.05≤H 1 / H 3 ≤0.2, for example H 1 / H 3 The value of is 0.05, 0.08, 0.15 or 0.2, etc., which can ensure the structural strength of the rotor core and the performance of the motor, while ensuring the operability of the bending and facilitating production.

[0091] Reference Figure 4 and Figure 5 As shown, it can be understood that the maximum dimension W of the through hole 230 along the circumferential direction is 1 and the maximum width W of the mounting groove 260 2 Satisfy 0.01≤W 1 / W 2 ≤0.1. It is easy to understand that the through hole 230 and the mounting groove 260 are both hollow structures in the yoke unit 210, and when the maximum inner diameter of the rotor assembly 1000 is the same, the size of the mounting groove 260 reflects the size of the permanent magnet 100 to a certain extent, that is, reflects the size of the magnetic field. 1 / W 2 If W is too small, the through hole 230 is too small to bend, and the mounting groove 260 is too large to affect the overall structural strength of the yoke monomer 210, and the magnetic flux of the yoke monomer 210 is easily saturated; 1 / W 2 If the through hole 230 is too large, the magnetic field will be affected and the structural strength of the bending portion 220 will be reduced. If the mounting groove 260 is too small, the magnetic field will be reduced and the motor performance will be reduced. Therefore, 0.01≤W 1 / W 2 ≤0.1, e.g. W 1 / W 2The value of is 0.02, 0.05, 0.08 or 0.1, etc., so as to take into account the overall structural strength, bending operability and magnetic field size of the yoke monomer 210, so that the overall structural strength of the rotor core is high and the performance of the motor is improved.

[0092] Reference Figure 4 and Figure 5 As shown, it can be understood that the maximum dimension W of the through hole 230 along the circumferential direction is 1 and the minimum width W of the limiting portion 270 3 Satisfy 0.05≤W 1 / W 3 ≤0.2. That is, the size of the through hole 230 is set by the minimum width of the limit portion 270. Similarly, the size of the through hole 230 is within a reasonable range to ensure the operability of the bending, the structural strength of the rotor core and the performance of the motor. In addition, for the position of the through hole 230 at the limit portion 270, the size of the through hole 230 will affect the structural strength of the limit portion 270 and affect the installation of the permanent magnet 100, so that the size of the through hole 230 is within a reasonable range, which can ensure that the structural strength of the limit portion 270 can provide sufficient support and limiting effect on the permanent magnet 100.

[0093] Reference Figure 5 As shown, it can be understood that the maximum radial dimension H of the through hole 230 is 1 and the minimum distance H between the through hole 230 and the wall of the limiting portion 270 facing the rotation axis. 4 Satisfy 0.05≤H 1 / H 4 ≤0.2. That is, the relationship between the size of the through hole 230 and the position on the limiting portion 270 is defined. 0.05≤H 1 / H 4 ≤0.2, to prevent the through hole 230 from being too close to the wall surface of the limiting portion 270 toward the rotation axis, which would cause the radial thickness of the bending portion 220 to be too large, thereby affecting the operability of the bending. At the same time, to prevent the through hole 230 from being too far from the wall surface of the limiting portion 270 toward the rotation axis, which would cause the structural strength of the bending portion 220 to decrease.

[0094] Reference Fig. 9 As shown, it can be understood that, for the yoke unit 210 provided with the positioning protrusion 240, along the radial direction of the rotor core, the maximum width of the positioning protrusion 240 is defined as H 5 The minimum distance between the wall surface of the positioning protrusion 240 and the wall surface of the yoke unit 210 away from the rotation axis is H 6 The minimum distance between the wall surface of the positioning protrusion 240 and the wall surface of the limiting portion 270 facing the rotation axis is H 7 , the minimum thickness of the yoke unit 210 is H 2 , the maximum thickness of the yoke unit 210 is H3 .

[0095] Reference Fig. 9 As shown, it can be understood that the maximum width H of the positioning protrusion 240 5 The minimum distance H between the wall surface of the positioning protrusion 240 and the wall surface of the yoke unit 210 away from the rotation axis 6 Satisfy 0.1≤H 5 / H 6 ≤2. It is easy to understand that the minimum distance H between the wall surface of the positioning protrusion 240 and the wall surface of the yoke unit 210 away from the rotation axis is 6 To a certain extent, it reflects the radial thickness of the structure located outside the corresponding positioning groove 250 in another yoke unit 210. 5 / H 6 If H is too small, the maximum width of the positioning protrusion 240 is too small, the strength of the butt joint structure between two adjacent yoke monomers 210 is low, the connection is unstable, and the overall connection strength of the rotor core is affected; if H 5 / H 6 If the thickness of the structure of the other yoke unit 210 located outside the corresponding positioning groove 250 is too small, the structural strength is low, and the overall connection strength of the rotor core is also affected. 5 / H 6 ≤2, for example H 5 / H 6 The value is 0.5, 1, 1.5 or 2 to ensure that the rotor core as a whole has sufficient connection strength and structural stability.

[0096] Reference Fig. 9 As shown, it can be understood that the maximum width H of the positioning protrusion 240 5 and the minimum distance H between the wall surface of the positioning protrusion 240 and the wall surface of the limiting portion 270 facing the rotation axis. 7 Satisfy 0.1≤H 5 / H 7 ≤2. It is easy to understand that the minimum distance H between the wall surface of the positioning protrusion 240 and the wall surface of the limiting portion 270 facing the rotation axis is 7 To a certain extent, it reflects the radial thickness of the structure located inside the corresponding positioning groove 250 in another yoke unit 210. 5 / H 7 If H is too small, the maximum width of the positioning protrusion 240 is too small, the strength of the butt joint structure between two adjacent yoke monomers 210 is low, the connection is unstable, and the overall connection strength of the rotor core is affected; if H 5 / H 7If the thickness of the structure located inside the corresponding positioning groove 250 in the other yoke unit 210 is too small, the structural strength is low, and the overall connection strength of the rotor core is also affected. 5 / H 7 ≤2, for example H 5 / H 7 The value is 0.5, 1, 1.5 or 2 to ensure that the rotor core as a whole has sufficient connection strength and structural stability.

[0097] Reference Fig. 9 As shown, it can be understood that the maximum width H of the positioning protrusion 240 5 and the minimum thickness H of the yoke unit 210 2 Satisfy 0.5≤H 5 / H 2 ≤2. If H 5 / H 2 If H is too small, the maximum width of the positioning protrusion 240 is too small, the strength of the butt joint structure between two adjacent yoke monomers 210 is low, the connection is unstable, and the overall connection strength of the rotor core is affected; if H 5 / H 2 If H is too large, the minimum thickness of the yoke unit 210 will be too small, and the structural strength of the rotor core will decrease. 5 / H 2 ≤2, for example H 5 / H 2 The value of is 0.5, 1, 1.5 or 2, etc., which can improve the overall connection strength and overall structural strength of the rotor core to ensure structural stability.

[0098] Reference Fig. 9 As shown, it can be understood that the maximum width H of the positioning protrusion 240 5 and the maximum thickness H of the yoke unit 210 3 Satisfy 0.1≤H 5 / H 3 ≤0.8. If H 5 / H 3 If H is too small, the maximum width of the positioning protrusion 240 is too small, the strength of the butt joint structure between two adjacent yoke monomers 210 is low, the connection is unstable, and the overall connection strength of the rotor core is affected; if H 5 / H 3 If H is too large, the maximum thickness of the yoke unit 210 is too small, the magnetic flux of the yoke unit 210 is easily saturated, the utilization rate of the permanent magnet 100 is reduced, and the performance of the motor is affected. 5 / H 3 ≤0.8, for example H 5 / H 3The value of 0.2, 0.4, 0.6 or 0.8, etc., can improve the overall connection strength of the rotor core and ensure the performance of the motor.

[0099] Reference Figure 1 and Figure 2 As shown, it can be understood that the third aspect of the utility model embodiment also provides a rotor assembly 1000, which will not be repeated here. In the rotor assembly 1000, a part of the structure of the permanent magnet 100 is accommodated in the mounting groove 260, and another part of the structure protrudes from the mounting groove 260. Specifically, the permanent magnet 100 has a bread-like structure, the wall surface of the permanent magnet 100 facing the rotation axis is an arc surface and the center of the circle where the arc surface is located coincides with the rotation axis, and the middle position of the wall surface of the permanent magnet 100 away from the rotation axis is protruded outward, that is, the permanent magnet 100 has a structure that is thick in the middle and narrow at both ends along the circumferential direction, which is conducive to increasing the amount of permanent magnet 100, enhancing the magnetic field, and thus improving the performance of the motor. At the same time, the magnetic flux of the magnetic field generated by the permanent magnet 100 is concentrated on the protruding position on the permanent magnet 100, thereby optimizing the magnetic flux distribution, making the magnetic flux distribution closer to a sinusoidal waveform, reducing the harmonic component of the magnetic flux, and reducing iron loss, thereby increasing the amplitude of the air gap magnetic flux, increasing the frequency, and increasing the back electromotive force, thereby improving the power density and torque density of the motor. At the same time, the air gap magnetic flux distribution is also closer to a sinusoidal waveform, thereby reducing the reluctance torque and cogging torque, thereby improving the output torque and efficiency of the motor and improving the running stability of the motor.

[0100] Reference Fig.14 As shown, it is easy to understand that in the prior art, the magnetic field at the position corresponding to the middle of the rotor core and the permanent magnet 100 is the weakest, and the magnetic field at the position corresponding to the position between the rotor core and two adjacent permanent magnets 100 is the strongest. The uneven distribution of the magnetic field will cause magnetic flux saturation at a local position of the rotor core and affect the performance of the motor.

[0101] Reference Fig.15 and Fig.16 As shown, it can be understood that, thanks to the installation groove 260 provided on the rotor core and the bread-shaped structure of the permanent magnet 100, the distribution of magnetic flux lines in the motor is more reasonable, and the magnetic field distribution on the rotor core is more uniform, avoiding the disadvantage of weakening the magnetic field due to excessive saturation of the magnetic field at a local position of the rotor core, thereby effectively ensuring the performance of the motor.

[0102] Reference Fig.17 and Fig.18As shown, it can be understood that in the prior art, the maximum value of the air gap flux density is about 0.47T, which is a small amplitude, while in the motor structure of the present application, the maximum value of the air gap flux density is about 0.64T, which is a large amplitude. The amplitude of the air gap flux density is greatly improved, so that the back electromotive force can be increased, thereby effectively improving the power density and torque density of the motor. Referring to Table 1, the back electromotive force of the motor of the present application is 210V, which is 50V higher than the back electromotive force of the motor of the prior art, and the back electromotive force is significantly increased; at the same time, the power density of the motor of the present application is 1.4W / mm 3 , torque density is 1.4Nm / mm 3 The power density is increased by 0.4W / mm compared with the existing technology 3 The torque density is increased by 0.4Nm / mm compared with the existing technology 3 , the power density and torque density are significantly improved.

[0103] Reference Figure 1 As shown, it can be understood that the two relative wall surfaces of two adjacent permanent magnets 100 conflict with each other, that is, the maximum width of the permanent magnet 100 along the circumferential direction is greater than the maximum width of the mounting groove 260 along the circumferential direction, so that the inner circumferential wall of the rotor assembly 1000 is continuous, and the disadvantage of the deterioration of the tooth slot torque caused by the existence of a gap between two adjacent permanent magnets 100 can be avoided, which is beneficial to improving the running smoothness of the motor.

[0104] Reference Figure 4 As shown, it can be understood that the minimum thickness H of the yoke unit 210 2 and the maximum thickness H of the yoke unit 210 3 , satisfying 0.1≤H 2 / H 3 ≤0.5. The minimum thickness and maximum thickness of the yoke unit 210 are related to the structural strength and magnetic flux saturation of the yoke unit 210. 2 / H 3 If H is too small, the minimum thickness of the yoke monomer 210 is too small, the structural strength is reduced, and the maximum thickness of the yoke monomer 210 is too large, which will compress the space of the stator assembly and affect the performance of the motor; if H 2 / H 3 If H is too large, the maximum thickness of the yoke unit 210 will be too small, and the yoke unit 210 will be prone to magnetic flux saturation, which will affect the performance of the motor. 2 / H 3 ≤0.5, for example H 2 / H 3 The value of 0.1, 0.2, 0.3, 0.4 or 0.5 can ensure the structural strength of the rotor core and improve the performance of the motor.

[0105] Reference Figure 4 As shown, it can be understood that the maximum width W of the mounting groove 260 2 and the minimum width W of the limiting portion 270 3 Satisfy 0.1≤W 3 / W 2 ≤0.5. It is easy to understand that the maximum width of the mounting groove 260 is inversely proportional to the minimum width of the limiting portion 270. 3 / W 2 If W is too small, the minimum width of the limiting portion 270 is too small, the structural strength is reduced, which is not conducive to limiting the permanent magnet 100, and the maximum width of the mounting groove 260 is too large, the amount of the permanent magnet 100 is increased, and the cost is increased; if W 3 / W 2 If the minimum width of the stopper 270 is too large, the maximum width of the mounting slot 260 will be too small, and the amount of the permanent magnet 100 will be reduced, which will affect the performance of the motor. 3 / W 2 ≤0.5, which can ensure the performance of the motor and the structural strength of the rotor core while reducing costs.

[0106] The motor of the fourth embodiment of the utility model comprises a stator assembly and a rotor assembly 1000 of any of the above embodiments. The rotor assembly 1000 is wound around the outer circumference of the stator assembly and will not be described in detail here.

[0107] Since the motor adopts all the technical solutions of the rotor assembly 1000 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0108] The household appliance of the fifth aspect of the present invention includes a motor in any of the above embodiments, which will not be described in detail here.

[0109] Since the household appliance adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0110] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A rotor core, characterized in that: include: One or more yoke sections connected in a ring shape, the yoke sections comprising a plurality of yoke monomers and a plurality of bending portions, in each of the yoke sections, a plurality of the yoke monomers are sequentially arranged along the circumference of the rotor core, two adjacent yoke monomers are connected via one bending portion, and each of the yoke sections comprises a plurality of yoke punchings stacked and arranged along the axial direction of the rotor core; The rotor core is also provided with a plurality of mounting grooves for mounting permanent magnets, the plurality of mounting grooves are arranged at intervals along the circumferential direction, and the mounting grooves are formed on the wall surface of the yoke section facing the rotation axis of the rotor core.

2. The rotor core according to claim 1, characterized in that: Each of the yoke units is provided with one mounting groove.

3. The rotor core according to claim 1, characterized in that: A portion of the structure of each mounting groove is located in one of the two adjacent yoke monomers, and another portion of the structure is located in the other yoke monomer.

4. The rotor core according to any one of claims 1 to 3, characterized in that: The yoke section is also provided with a plurality of through holes, and the plurality of through holes are arranged one-to-one corresponding to the plurality of bending portions, a part of the structure of the through hole is located in one of the two adjacent yoke monomers, and another part of the structure is located in the other yoke monomer.

5. The rotor core according to claim 4, characterized in that: Along the radial direction of the rotor core, the maximum size of the through hole is H1, and the minimum thickness of the yoke unit is H2, satisfying: 0.2≤H1 / H2≤0.

8.

6. The rotor core according to claim 4, characterized in that: Along the radial direction of the rotor core, the maximum size of the through hole is H1, and the maximum thickness of the yoke unit is H3, satisfying: 0.05≤H1 / H3≤0.

2.

7. The rotor core according to claim 4, characterized in that: Along the circumferential direction, the maximum dimension of the through hole is W1, and the maximum width of the mounting groove is W2, satisfying: 0.01≤W1 / W2≤0.

1.

8. The rotor core according to claim 4, characterized in that: The rotor core further includes a limiting portion located between two adjacent mounting grooves. Along the circumferential direction, the maximum dimension of the through hole is W1, and the minimum width of the limiting portion is W3, satisfying: 0.05≤W1 / W3≤0.

2.

9. The rotor core according to claim 8, characterized in that: Along the radial direction of the rotor core, the maximum size of the through hole is H1, and the minimum distance between the inner wall of the through hole and the wall surface of the limiting portion facing the rotation axis is H4, satisfying: 0.05≤H1 / H4≤0.

2.

10. A rotor core, characterized in that: include: A plurality of yoke monomers, wherein the plurality of yoke monomers are sequentially arranged along the circumference of the rotor core and assembled into a ring shape, wherein one of the adjacent two yoke monomers is provided with a positioning groove, and the other yoke monomer is provided with a positioning convex portion, and the positioning convex portion is accommodated in the positioning groove, and the yoke monomer comprises a plurality of punching sheet monomers stacked along the axial direction of the rotor core; The rotor core is further provided with a plurality of mounting grooves for mounting permanent magnets, and each of the mounting grooves is correspondingly formed on a wall surface of each yoke unit facing the rotation axis of the rotor core.

11. The rotor core according to claim 10, characterized in that: Along the radial direction of the rotor core, the maximum width of the positioning protrusion is H5, and the minimum distance between the wall surface of the positioning protrusion and the wall surface of the yoke unit away from the rotation axis is H6, satisfying: 0.1≤H5 / H6≤2.

12. The rotor core according to claim 10, characterized in that: The rotor core also includes a limiting portion located between two adjacent mounting grooves. Along the radial direction of the rotor core, the maximum width of the positioning protrusion is H5, and the minimum distance between the wall surface of the positioning protrusion and the wall surface of the limiting portion toward the rotation axis is H7, satisfying: 0.1≤H5 / H7≤2.

13. The rotor core according to claim 10, characterized in that: Along the radial direction of the rotor core, the maximum width of the positioning protrusion is H5, and the minimum thickness of the yoke unit is H2, satisfying: 0.5≤H5 / H2≤2.

14. The rotor core according to claim 10, characterized in that: Along the radial direction of the rotor core, the maximum width of the positioning protrusion is H5, and the maximum thickness of the yoke unit is H3, satisfying: 0.1≤H5 / H3≤0.

8.

15. A rotor assembly, characterized in that: include: The rotor core according to any one of claims 1 to 14; A plurality of permanent magnets are correspondingly installed in the plurality of installation slots.

16. The rotor assembly according to claim 15, characterized in that: A part of the structure of the permanent magnet is accommodated in the installation groove, and another part of the structure protrudes from the installation groove, and two opposite wall surfaces of two adjacent permanent magnets are in conflict with each other.

17. The rotor assembly according to claim 15, characterized in that: Along the radial direction of the rotor core, the minimum thickness of the yoke unit is H2, and the maximum thickness of the yoke unit is H3, satisfying: 0.1≤H2 / H3≤0.

5.

18. The rotor assembly according to claim 15, characterized in that: The rotor core further includes a limiting portion located between two adjacent mounting grooves. Along the circumferential direction, the maximum width of the mounting groove is W2, and the minimum width of the limiting portion is W3, satisfying: 0.1≤W3 / W2≤0.

5.

19. A motor, characterized in that The invention comprises a stator assembly and a rotor assembly according to any one of claims 15 to 18, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

20. A household appliance, characterized in that Comprising the motor as claimed in claim 19.

Images