Rotor core, rotor assembly, motor and household appliance

Abstract

The utility model discloses a rotor iron core, a rotor assembly, a motor and a household electrical appliance, and relates to the technical field of motors, the rotor iron core rotates around a rotation axis, the rotor iron core comprises one or more magnet yoke segments, each magnet yoke segment comprises a plurality of magnet yoke units and a plurality of bending parts, the plurality of magnet yoke units are sequentially arranged along the direction around the rotation axis, and the bending parts are arranged on the magnet yoke units. Each magnet yoke section comprises a plurality of bent parts, each bent part is connected between two adjacent magnet yoke units, the width of each bent part is smaller than that of each magnet yoke unit in the radial direction of the rotor iron core, and the magnet yoke section further comprises two butt joint parts which are located at the two ends of the magnet yoke section in the direction around the rotating axis respectively; wherein the one or more magnet yoke sections are connected into a ring shape through the butt joint parts. The rotor iron core is easy to produce and low in production cost.

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 core of the motor is generally made of cold-rolled steel plates, such as processed into a ring shape through a winding process, but this method is complex and difficult to process, and it is difficult to control the roundness of the rotor core, and the processing cost is high. Another example is the lamination process, where multiple ring-shaped punchings are processed on the cold-rolled steel plate, and then the multiple ring-shaped punchings are stacked into a ring-shaped rotor core. However, this method will produce a lot of waste, resulting in material waste and high material costs. 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 which is easy to produce and has low production cost.

[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 rotates around the rotation axis and includes one or more yoke segments, wherein the yoke segment includes multiple yoke units and multiple bending portions, wherein the multiple yoke units are arranged in sequence along the direction around the rotation axis, and each bending portion is connected between two adjacent yoke units, and along the radial direction of the rotor core, the width of the bending portion is smaller than the width of the yoke unit, and the yoke segment also includes two docking portions, which are respectively located at the two ends of the yoke segment along the direction around the rotation axis; wherein one or more yoke segments are connected into a ring shape through the docking portions.

[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 yoke segment is formed by connecting a plurality of yoke units through a bending portion, and the width of the bending portion is smaller than the width of the yoke unit in the radial direction, the bending portion is easy to bend. When processing the yoke segment, a plurality of yoke units can be processed into a yoke segment arranged linearly first, so as to arrange the samples tightly on the silicon steel plate, thereby reducing waste, improving the utilization rate of materials, and helping to reduce material costs; then the yoke segment is bent at the position of the bending portion, so that the yoke segment is annular or arc-shaped, and finally one or more yoke segments are connected to form an annular rotor core through a docking portion, which has good integrity, can reduce the number of parts, has a simple production process, is conducive to reducing production difficulty, and is easy to ensure the roundness of the rotor core, thereby reducing process costs. Therefore, the overall production cost of the rotor core is reduced.

[0007] According to some embodiments of the present invention, along the radial direction of the rotor core, the bent portion is connected to a side of the yoke unit away from the rotation axis.

[0008] According to some embodiments of the present invention, a stress release groove is provided between two adjacent yoke units of the yoke segment, and the stress release groove is located on a side of the bending portion close to the rotation axis.

[0009] According to some embodiments of the present invention, adjacent butting portions are fixed by welding.

[0010] According to some embodiments of the present invention, one of the two docking parts of the yoke segment is configured as a slot, and the other docking part is configured as a buckle that cooperates with the slot.

[0011] According to some embodiments of the present invention, the slot width increases gradually from the slot opening to the slot bottom.

[0012] According to some embodiments of the present invention, the slot width increases first and then decreases from the slot opening to the slot bottom.

[0013] According to the rotor assembly of the second aspect embodiment of the utility model, it includes the rotor core of the first aspect embodiment of the utility model and a plurality of permanent magnets, wherein the plurality of permanent magnets are arranged at intervals along the circumference of the rotor core, and the permanent magnets are arranged on one side of the rotor core close to the rotation axis.

[0014] According to the rotor assembly of the second embodiment of the utility model, at least the following beneficial effects are achieved: since the rotor assembly adopts the above-mentioned rotor core, since the yoke segment is formed by connecting a plurality of yoke units through a bending portion, and the width of the bending portion is smaller than the width of the yoke unit in the radial direction, the bending portion is easy to bend, and when processing the yoke segment, a plurality of yoke units can be processed into a yoke segment arranged linearly first, so as to arrange the samples closely on the silicon steel plate, thereby reducing waste, improving the utilization rate of materials, and helping to reduce material costs; then the yoke segment is bent at the position of the bending portion, so that the yoke segment is annular or arc-shaped, and finally one or more yoke segments are connected to form an annular rotor core through a docking portion, which has good integrity, can reduce the number of parts, has a simple production process, is conducive to reducing production difficulty, and is easy to ensure the roundness of the rotor core, thereby reducing process costs. Therefore, the overall production cost of the rotor core and the rotor assembly is reduced.

[0015] According to some embodiments of the present invention, the number of the yoke units is N, and the number of the permanent magnets is M, satisfying: M is an integer multiple of N.

[0016] According to some embodiments of the present invention, the permanent magnet has a center line arranged along the radial direction of the rotor core, and the center line passes through the bending portion or the joint between two adjacent joint portions.

[0017] The motor according to the third aspect of the present invention comprises a stator assembly and a rotor assembly according to the second aspect of the present invention, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

[0018] The motor according to the third embodiment of the utility model has at least the following beneficial effects: since the motor adopts the above-mentioned rotor assembly, since the yoke segment is formed by connecting multiple yoke units through a bending portion, and the width of the bending portion is smaller than the width of the yoke unit in the radial direction, the bending portion is easy to bend. When processing the yoke segment, a yoke segment with multiple yoke units arranged linearly can be first processed so as to arrange the samples tightly on the silicon steel plate, thereby reducing waste, improving the utilization rate of materials, and helping to reduce material costs; then the yoke segment is bent at the position of the bending portion so that the yoke segment is annular or arc-shaped, and finally one or more yoke segments are connected to form an annular rotor core through a docking portion, which has good integrity, can reduce the number of parts, has a simple production process, is conducive to reducing production difficulty, and is easy to ensure the roundness of the rotor core, thereby reducing process costs. Therefore, the overall production cost of the rotor core and the motor is reduced.

[0019] The household appliance according to the fourth embodiment of the utility model includes the motor according to the third embodiment of the utility model.

[0020] According to the household appliance of the fourth aspect of the utility model, there are at least the following beneficial effects: since the household appliance adopts the above-mentioned motor, since the yoke segment is formed by connecting a plurality of yoke units through a bending portion, and the width of the bending portion is smaller than the width of the yoke unit in the radial direction, the bending portion is easy to bend, and when processing the yoke segment, a plurality of yoke units can be processed into a yoke segment arranged linearly first, so as to arrange the samples closely on the silicon steel plate, thereby reducing waste, improving the utilization rate of materials, and helping to reduce material costs; then the yoke segment is bent at the position of the bending portion, so that the yoke segment is annular or arc-shaped, and finally one or more yoke segments are connected to form an annular rotor core through a docking portion, which has good integrity, can reduce the number of parts, has a simple production process, is conducive to reducing production difficulty, and is easy to ensure the roundness of the rotor core, thereby reducing process costs. Therefore, the overall production cost of the rotor core and household appliances is reduced.

[0021] 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

[0022] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 It is a schematic diagram of the motor axial direction in some embodiments of the utility model;

[0024] Figure 2 yes Figure 1 A in the enlarged view;

[0025] Figure 3 It is a schematic structural diagram of a straight-strip yoke segment in some embodiments of the utility model;

[0026] Figure 4 yes Figure 3 A partial schematic diagram of the middle yoke section;

[0027] Figure 5 It is a schematic diagram of two yoke sections butted against each other in other embodiments of the utility model;

[0028] Figure 6 It is a schematic diagram of two yoke sections butted against each other in some other embodiments of the utility model;

[0029] Figure 7 It is an axial schematic diagram of the rotor core in other embodiments of the utility model;

[0030] Figure 8 It is an axial schematic diagram of the rotor core in other embodiments of the utility model;

[0031] Fig. 9 This is a schematic diagram of silicon steel plate arrangement in an embodiment of the utility model;

[0032] Fig.10 It is a schematic diagram of the distribution of some magnetic flux lines in the rotor assembly in the embodiment of the utility model.

[0033] Reference numerals:

[0034] Rotor assembly 1000; stator assembly 2000;

[0035] Rotor core 100;

[0036] Magnetic yoke section 200; Magnetic yoke unit 210; Bending portion 220; Butt joint portion 230; Slot 231; First wall surface 2311; Second wall surface 2312; Buckle 232; Stress release slot 240;

[0037] Permanent magnet 300;

[0038] Silicon steel plate 400; punching segment 410;

[0039] Center line Z. DETAILED DESCRIPTION

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 annular and wound around the outer periphery of the stator. Generally speaking, the rotor core is made of cold-rolled steel sheets. In related technologies, for example, the cold-rolled steel sheets (such as silicon steel sheets) are processed into annular shapes through a winding process. However, this processing method is complex and difficult to process. It is also difficult to control the roundness of the rotor core, which affects the assembly and performance of the motor, and the processing cost is relatively high. For another example, the rotor core is processed through a lamination process. First, an annular punching sheet is punched out on the cold-rolled steel sheet, and then multiple punching sheets are stacked in sequence along the direction of the rotor's rotation axis to form an annular rotor core. However, since the punching sheet is annular, on the one hand, it is not conducive to sample arrangement, and on the other hand, more waste will be generated, the material utilization rate is low, resulting in material waste and high material cost.

[0045] For this purpose, refer to Figures 1 to 10As shown, the first embodiment of the utility model provides a rotor core 100, which is a component of a rotor assembly 1000 and is specifically applied to a motor of a household appliance, where the household appliance may be an air conditioner, a washing machine, a refrigerator, etc. The motor is an outer rotor motor.

[0046] Reference Figure 1 As shown, it can be understood that the motor includes a rotor assembly 1000 and a stator assembly 2000 , the rotor assembly 1000 is arranged around the outer circumference of the stator assembly 2000 and can rotate relative to the stator assembly 2000 , and the central axis of the rotor assembly 1000 is the rotation axis of the rotor assembly 1000 .

[0047] Reference Figure 1 As shown, it can be understood that the rotor assembly 1000 includes a rotor core 100 and a plurality of permanent magnets 300. Specifically, the rotation axis of the rotor assembly 1000 is the rotation axis of the rotor core 100. The rotor core 100 is annular and is formed by connecting one or more yoke segments 200.

[0048] It can be understood that the rotor core 100 is composed of a plurality of rotor punchings stacked along the direction of the rotation axis, and thus the yoke section 200 is also composed of a plurality of punching segments 410 stacked along the direction of the rotation axis, and one or more coplanar punching segments 410 form a rotor punching. Therefore, when producing the rotor core 100, it is necessary to first punch out a plurality of punching segments 410 on the silicon steel plate 400.

[0049] Reference Figures 2 to 4 As shown, it can be understood that the yoke section 200 includes a plurality of yoke units 210 and a plurality of bent portions 220. Specifically, on the projection plane perpendicular to the rotation axis, the projection of each yoke unit 210 is a fan ring, that is, a part of a ring, and the central angle corresponding to the inner contour line and the outer contour line of the fan ring is about 30°, so that the projection of each yoke unit 210 is roughly an elongated structure. Here, the inner side is the side close to the rotation axis, and the outer side is the side away from the rotation axis.

[0050] Reference Figure 1 and Figure 3As shown, it can be understood that in each yoke segment 200, the number of the bending portions 220 is one less than the number of the yoke units 210, and the multiple yoke units 210 are connected in sequence through the multiple bending portions 220, that is, the two ends of each bending portion 220 are respectively connected to the two adjacent yoke units 210, so that the yoke segment 200 has a chain structure. Along the radial direction of the rotor core 100, the width of the bending portion 220 is smaller than the width of the yoke unit 210. The width of the bending portion 220 is the distance between the two wall surfaces of the bending portion 220 that are opposite to each other along the radial direction of the rotor core 100, that is, W1; the width of the yoke unit 210 is the distance between the two wall surfaces of the yoke unit 210 that are opposite to each other along the radial direction of the rotor core 100, that is, W2. Therefore, the flexibility of the bending portion 220 is better than that of the yoke unit 210, and the bending portion 220 can be bent in a direction perpendicular to the rotation axis, so that the two adjacent yoke units 210 can be bent. For example, the yoke segment 200 in which the plurality of yoke units 210 are arranged linearly is bent into an arc or a circle.

[0051] Reference Fig. 9 As shown, it can be understood that when producing the yoke segment 200, a straight-bar-shaped punching segment 410 can be first punched out on the silicon steel sheet 400, and a plurality of punching segments 410 are sequentially stacked along the direction of the rotation axis to form a yoke segment 200 in which a plurality of yoke units 210 are linearly arranged, and then the yoke segment 200 is bent into an arc or ring shape, that is, a plurality of yoke units 210 are distributed in a ring shape or an arc shape, and a plurality of yoke units 210 are sequentially connected along the direction around the rotation axis so as to be further processed into the rotor core 100. Since the punching segments 410 are all straight-bar-shaped, a plurality of punching segments 410 can be closely arranged on the silicon steel sheet, and the arrangement is close, which is conducive to reducing the sheet material between two adjacent punching segments 410, thereby reducing waste, improving the material utilization rate of the silicon steel sheet 400, and further reducing the material cost. In addition, a plurality of yoke units 210 are connected into a whole through the bending portion 220, which has good integrity, can reduce the number of parts, and is simpler in process.

[0052] Reference Figure 2 and Figure 3 As shown, it can be understood that the yoke segment 200 also includes docking portions 230 respectively located at both ends along the length direction. The length direction of the yoke segment 200 is the arrangement direction of the multiple yoke units 210, or the circumference of the rotor core 100, and the circumference of the rotor core 100 is the direction around the rotation axis. In other words, the yoke segment 200 includes two docking portions 230, and the two docking portions 230 are respectively located on the back sides of the yoke units 210 at both ends. The two docking portions 230 can both be end faces or a combination of a dovetail portion and a dovetail groove, etc. For example, the docking portions 230 are both end faces, connected by welding, and the structure of the docking portion 230 is simple, which is convenient for punching, and the connection process of the two docking portions 230 is simple, which is conducive to reducing the process cost.

[0053] Reference Figure 1 As shown, it can be understood that in this embodiment, the rotor core 100 includes a yoke segment 200. Specifically, the yoke segment 200 includes ten yoke units 210. The yoke segment 200 is bent into a ring shape and the docking parts 230 at both ends are connected to each other, that is, a ring-shaped rotor core 100 is formed. Therefore, when producing the rotor core 100, a plurality of straight strip-shaped punching segments 410 are first punched out from the silicon steel plate 400, and the plurality of punching segments 410 are stacked along the thickness direction (i.e., the direction of the rotation axis) to form the yoke segment 200. At this time, the plurality of yoke units 210 of the yoke segment 200 are arranged linearly. Then, the entire yoke segment 200 is bent into a ring shape, and the docking parts 230 at both ends are welded, that is, a ring-shaped rotor core 100 is obtained. The production process is simple, which is conducive to reducing the production difficulty, thereby reducing the process cost. At the same time, the rotor core 100 including only one yoke segment 200 has better integrity, good structural strength, fewer parts, simpler process, and can well ensure the roundness of the rotor core 100, so as to facilitate the assembly of the rotor assembly 1000 and the stator assembly 2000. In addition, a plurality of straight strip-shaped punching segments 410 can be closely arranged on the silicon steel plate 400, and the close arrangement is conducive to reducing waste, improving the material utilization rate of the silicon steel plate 400, and thus reducing the material cost. Therefore, the overall production cost of the rotor core 100 is reduced.

[0054] Reference Figure 7 As shown, in other embodiments, it can be understood that the rotor core 100 includes a plurality of yoke segments 200, specifically, the rotor core 100 includes two yoke segments 200, and the two yoke segments 200 have the same structure, that is, the number of yoke units 210 of the two yoke segments 200 is equal, and each yoke segment 200 includes five yoke units 210. Similarly, after a plurality of punch segments 410 are stacked into a yoke segment 200, the two yoke segments 200 are bent into semicircles, the two semicircular yoke segments 200 are connected end to end, and the corresponding docking portions 230 are welded, thereby forming a ring-shaped rotor core 100. Similarly, it is possible to reduce process costs and material costs, and improve the material utilization rate of the silicon steel plate 400.

[0055] Reference Figure 8As shown, in other embodiments, it can be understood that the rotor core 100 can also include three yoke segments 200, wherein two yoke segments 200 include three yoke units 210, and another yoke segment 200 includes four yoke units 210. Similarly, after a plurality of punch segments 410 are stacked into a yoke segment 200, the three yoke segments 200 are bent into arcs, the three arc-shaped yoke segments 200 are connected end to end in sequence, and the corresponding docking portions 230 are welded, thereby forming a ring-shaped rotor core 100. Similarly, it is possible to reduce process costs and material costs, and improve the material utilization rate of the silicon steel plate 400.

[0056] Of course, it is understandable that the composition of the rotor core 100 is not limited to including the above-mentioned number of yoke segments 200, and the number of yoke units 210 included in each yoke segment 200 is also not limited to the above description.

[0057] Reference Figure 1 and Figure 2 As shown, it can be understood that, along the radial direction of the rotor core 100, the width of the bending portion 220 is smaller than the width of the yoke unit 210, so that the flexibility of the bending portion 220 can be increased, so that the bending portion 220 can be bent, so that the straight yoke segment 200 can be easily bent into an arc or ring shape, which is convenient for production. At the same time, the end of the bending portion 220 along the circumference of the rotor core 100 is connected to the end of the yoke unit 210 along the circumference of the rotor core 100, which is far away from the rotation axis, and the side of the opposite ends of the two adjacent yoke units 210 close to the rotation axis is disconnected, so as to facilitate the bending operation of the yoke segment 200, and the wall surface of the bending portion 220 along the radial direction of the rotor core 100 away from the rotation axis forms a part of the outer peripheral wall of the rotor core 100, so that the outer peripheral wall of the rotor core 100 is a continuous wall surface and is conducive to ensuring roundness.

[0058] Reference Figures 2 to 4As shown, it can be understood that a stress release groove 240 is provided between two adjacent yoke units 210 in each yoke segment 200, and the stress release groove 240 is located on the side of the bending portion 220 close to the rotation axis. Specifically, on the projection plane perpendicular to the rotation axis, the projection of the stress release groove 240 is a circular hole. Of course, the projection of the stress release groove 240 can also be a square hole, a waist-shaped hole, an elliptical hole, etc. The stress release groove 240 penetrates the rotor core 100 along the direction of the rotation axis. In the adjacent two yoke units 210 of each yoke segment 200, the two yoke units 210 are respectively provided with groove bodies projected as semicircular holes on the projection plane perpendicular to the rotation axis on opposite sides, and the openings of the two grooves are arranged oppositely. After the yoke segment 200 is bent into a ring or an arc, the two groove bodies arranged oppositely in the adjacent two yoke units 210 of each yoke segment 200 are combined to form a stress release groove 240. Therefore, when the yoke section 200 is bent, the presence of the stress release groove 240 can release the stress, thereby avoiding the disadvantage of the bending portion 220 being broken during the bending process and improving reliability.

[0059] Reference Figure 5 As shown, in other embodiments, it can be understood that in the embodiment where the rotor core 100 includes at least two yoke segments 200, two adjacent yoke segments 200 are connected by the cooperation of the dovetail and the dovetail groove. That is to say, of the two docking portions 230 of each yoke segment 200, one of the docking portions 230 is set as a dovetail structure, and the other docking portion 230 is set as a dovetail groove structure that cooperates with the dovetail structure. Specifically, of the two docking portions 230 of each yoke segment 200, one of the docking portions 230 is set as a slot 231, and the other docking portion 230 is set as a buckle 232 that cooperates with the slot 231, and the buckle 232 can be accommodated in the slot 231 and realize the snap fit, so as to realize the mutual connection of the two yoke segments 200. The locking groove 231 is recessed at one end of the yoke unit 210 along the circumference of the rotor core 100 , and the buckle 232 is protruded at the other end of the yoke unit 210 along the circumference of the rotor core 100 .

[0060] Reference Figure 5As shown, it can be understood that the slot 231 is defined to have a first wall 2311 and a second wall 2312 that are arranged opposite to each other along the radial direction of the rotor core 100, and the distance between the first wall 2311 and the second wall 2312 is the slot width of the slot 231. Along the circumferential direction of the rotor core 100, from the notch of the slot 231 to the bottom of the slot, the slot width of the slot 231 increases. Specifically, on the projection plane perpendicular to the axis of rotation, the projection of the slot 231 is a trapezoid, and is an isosceles trapezoid. Correspondingly, the projection of the buckle 232 is also an isosceles trapezoid. Of course, it is easy to understand that the projections of the slot 231 and the buckle 232 can also be other shapes, and the projection shapes of the slot 231 and the buckle 232 need to be kept consistent, and the buckle 232 can be accommodated in the slot 231 and achieve a snap fit.

[0061] Taking the rotor core 100 including two yoke segments 200 as an example, after the two yoke segments 200 are bent into arcs respectively, the slot 231 of the first yoke segment 200 and the buckle 232 of the second yoke segment 200 are arranged relative to each other in the circumferential direction of the rotor core 100, and the buckle 232 of the first yoke segment 200 and the slot 231 of the second yoke segment 200 are arranged relative to each other in the circumferential direction of the rotor core 100, and the buckle 232 of the first yoke segment 200 is inserted into the slot 231 of the second yoke segment 200 along the direction of the rotation axis. At the same time, the buckle 232 of the second yoke segment 200 is inserted into the slot 231 of the first yoke segment 200 until the buckle 232 is completely accommodated in the slot 231, so that the two yoke segments 200 can be connected into an annular rotor core 100, the connection is stable and reliable, and the assembly operation is simple, which is conducive to reducing the process cost.

[0062] Similarly, when the rotor core 100 includes three or more yoke segments 200 , the three or more yoke segments 200 can be connected into a ring-shaped rotor core 100 in the above manner, which will not be described in detail herein.

[0063] Reference Figure 6 As shown, in other embodiments, it can be understood that along the circumference of the rotor core 100, from the slot opening of the slot 231 to the slot bottom, the slot width of the slot 231 first increases and then decreases. For example, on a projection plane perpendicular to the axis of rotation, the contour line of the projection of the slot 231 is a major arc (i.e., an arc corresponding to a circular angle greater than 180°), and correspondingly, the projection of the buckle 232 matches the projection of the slot 231. Therefore, similarly. The buckle 232 can be inserted into the slot 231 on another yoke segment 200 along the direction of the axis of rotation and realize a snap fit to achieve the connection between the two yoke segments 200. It will not be repeated here.

[0064] Of course, it is understandable that in an embodiment where the rotor core 100 includes only one yoke segment 200, when the height of the yoke segment 200 along the direction of the rotation axis is relatively small, after the yoke segment 200 is bent into a ring shape, since the yoke segment 200 has a certain flexibility in the direction of the rotation axis, the buckle 232 at one end of the yoke segment 200 can also be inserted into the slot 231 at the other end along the direction of the rotation axis, thereby connecting the two ends of the yoke segment 200 together to form a ring-shaped rotor core 100.

[0065] Reference Figure 1 As shown, it can be understood that in the rotor assembly 1000 of this embodiment, a plurality of permanent magnets 300 are arranged at equal intervals along the circumference of the rotor core 100, and the permanent magnets 300 are located on the side of the rotor core 100 close to the rotation axis. That is to say, a plurality of permanent magnets 300 are arranged at equal intervals along the circumference of the rotor core 100 on the inner circumferential wall of the rotor core 100. For example, the permanent magnets 300 are fixed to the inner circumferential wall of the rotor core 100 by adhesive bonding. In this way, on the one hand, it is convenient to install the permanent magnets 300, and on the other hand, there is no core structure between two adjacent permanent magnets 300, that is, there is air or a filled injection molded body between two adjacent permanent magnets 300. It is easy to understand that the magnetic resistance of the air or the injection molded body is much greater than the magnetic resistance of the core structure. Therefore, the leakage magnetic field between two adjacent permanent magnets 300 can be significantly reduced, that is, the inter-pole leakage magnetic field is reduced, thereby improving the utilization rate of the permanent magnets 300.

[0066] Reference Figure 1 As shown, it is easy to understand that in the entire rotor core 100, there are stress release grooves 240 and fine gaps at the disconnection position between a portion of two adjacent yoke units 210, and between another portion of two adjacent yoke units 210, there are docking parts 230 and 230 connected, and there are also certain fine gaps between the docking parts 230 and 230. The magnetic resistance at the stress release grooves 240 and the fine gaps is much greater than the magnetic resistance of the rotor core 100.

[0067] Reference Fig.10 As shown, it can be understood that the permanent magnet 300 is an axisymmetric structure, and the center line Z of the permanent magnet 300 is the symmetry axis, and the center line Z of the permanent magnet 300 is arranged along the radial direction of the rotor core 100. It is easy to understand that in the rotor assembly 1000, the magnetic field formed by the permanent magnet 300 is transmitted to the rotor core 100, and the direction of most of the magnetic flux lines at the rotor core 100 is from the center line Z of the permanent magnet 300 to the two sides of the center line Z along the circumferential direction of the rotor core 100, Fig.10 The dotted lines in the figure are magnetic flux lines.

[0068] Reference Figure 2 and Fig.10As shown, for this reason, in order to avoid the need for magnetic flux lines to pass through the stress release groove 240 and the slit as much as possible, the center line Z of some permanent magnets 300 is arranged in the bending part 220, specifically, the center line Z of the permanent magnet 300 passes through the stress release groove 240 and the slit at the disconnected position along the radial direction of the rotor core 100, and the center line Z of another part of the permanent magnet 300 passes through the docking part of the docking part 230 along the radial direction of the rotor core 100, and also passes through the slit at the docking part. Therefore, it is possible to avoid a large number of magnetic flux lines passing through the stress release groove 240 and the slit to weaken the magnetic field, thereby reducing the weakening effect of the stress release groove 240 and the slit on the magnetic field, which is conducive to improving the utilization rate of the permanent magnet 300, and then improving the performance of the motor. Therefore, in order to ensure that the spacing between multiple permanent magnets 300 is equal and to avoid the need for magnetic flux lines to pass through the stress release groove 240 and the slit as much as possible, the number of yoke units 210 is defined as N, and the number of permanent magnets 300 is defined as M, and M is satisfied to be an integer multiple of N. That is to say, the number of permanent magnets 300 is an integer multiple of the number of yoke units 210. In this embodiment, the number of yoke units 210 is ten, and the number of permanent magnets 300 is also ten, that is, N=10, M=10, and in this case, M is one times N. At this time, the center line Z of each permanent magnet 300 passes through the joint of the bending portion 220 and the joint portion 230 in a one-to-one correspondence.

[0069] Of course, in other embodiments, M=10 and N=5 may be satisfied. In this case, M is twice N. Among any three permanent magnets 300 continuously arranged along the circumference of the rotor core 100, the center lines of the permanent magnets 300 located at both ends of the circumference of the rotor core 100 respectively pass through the joints of the bending portion 220 or the joint portion 230 in a one-to-one correspondence, and the center line of the permanent magnet 300 located in the middle passes through the yoke unit 210. Therefore, it is also possible to avoid a large number of magnetic flux lines passing through the stress release grooves 240 and the slits to weaken the magnetic field, thereby improving the utilization rate of the permanent magnets 300 and further improving the performance of the motor.

[0070] Of course, the number N of the yoke units 210 and the number M of the permanent magnets 300 may also be other combinations, as long as M is an integer multiple of N, which will not be elaborated here.

[0071] The rotor assembly 1000 of the second embodiment of the utility model includes the rotor core 100 of the first embodiment of the utility model, which will not be described in detail here.

[0072] Since the rotor assembly 1000 adopts all the technical solutions of the rotor core 100 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0073] The motor of the third embodiment of the utility model includes the rotor assembly 1000 of the second embodiment of the utility model, which will not be described in detail here.

[0074] 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.

[0075] The household appliance of the fourth embodiment of the utility model includes the motor of the third embodiment of the utility model, which will not be described in detail here.

[0076] 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.

[0077] 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, rotating about an axis of rotation, characterized in that: include: One or more yoke segments, the yoke segment comprising a plurality of yoke units and a plurality of bent portions, the plurality of yoke units being arranged in sequence along the direction around the rotation axis, each of the bent portions being connected between two adjacent yoke units, and the width of the bent portion being smaller than the width of the yoke unit along the radial direction of the rotor core, the yoke segment further comprising two butt joints, the two butt joints being respectively located at two ends of the yoke segment along the direction around the rotation axis; Wherein, one or more of the yoke segments are connected into a ring shape through the butt joint.

2. The rotor core according to claim 1, characterized in that: Along the radial direction, the bent portion is connected to a side of the yoke unit away from the rotation axis.

3. The rotor core according to claim 1 or 2, characterized in that: A stress release groove is provided between two adjacent yoke units of the yoke segment, and the stress release groove is located on a side of the bending portion close to the rotation axis.

4. The rotor core according to claim 1, characterized in that: The adjacent butting parts are fixed by welding.

5. The rotor core according to claim 1, characterized in that: Among the two docking parts of the yoke segment, one of the docking parts is configured as a slot, and the other docking part is configured as a buckle that cooperates with the slot.

6. The rotor core according to claim 5, characterized in that: The slot width of the card slot increases gradually from the slot opening to the slot bottom.

7. The rotor core according to claim 5, characterized in that: The slot width increases first and then decreases from the slot opening to the slot bottom.

8. A rotor assembly, characterized in that: include: The rotor core according to any one of claims 1 to 7; A plurality of permanent magnets are arranged at intervals along the circumferential direction of the rotor core, and the permanent magnets are arranged on a side of the rotor core close to the rotation axis.

9. The rotor assembly according to claim 8, characterized in that: The number of the yoke units is N, the number of the permanent magnets is M, and M is an integer multiple of N.

10. The rotor assembly according to claim 9, characterized in that: The permanent magnet has a center line arranged along the radial direction of the rotor core, and the center line passes through the bending portion or the joint of two adjacent joint portions.

11. A motor, characterized in that include: stator assembly; The rotor assembly according to any one of claims 8 to 10, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

12. A household appliance, characterized in that Comprising the motor as claimed in claim 11.

Images