Rotor assembly, motor, and household appliance

Abstract

The present application discloses a rotor assembly, a motor, and a household appliance, wherein the rotor assembly comprises a rotating shaft (100), a plastic package body (200), and iron core (300). The plastic package body (200) is connected to the rotating shaft (100), and the iron core (300) is connected to the plastic package body (200); the plastic package body (200) is packaged between the rotating shaft (100) and the iron core (300), the iron core (300) is arranged around the rotating shaft (100), thickness reduction holes (201) are formed on at least one of the two end faces of the plastic package body (200) in the axial direction of the rotating shaft (100), and the thickness reduction holes (201) are located between the rotating shaft (100) and the iron core (300).

Description

Rotor components, motors and household appliances

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202410042112.7 filed on January 10, 2024, entitled “Rotor assembly, motor and household appliance”, and application number 202420068878.8 filed on January 10, 2024, entitled “Rotor assembly, motor and household appliance”. The entire contents of the above patent applications are incorporated into this application by reference. Technical Field

[0003] The present application relates to the field of motor technology, and in particular to a rotor assembly, a motor and a household appliance. Background Art

[0004] In related art, a motor's rotor typically consists of a rotating shaft, a plastic encapsulation, and an iron core, with the shaft and iron core connected as a single unit via the plastic encapsulation. Some rotors utilize a split-core structure. Due to the large radial distance between the iron core and the rotating shaft, the plastic encapsulation at this location is thicker. Consequently, the plastic encapsulation is prone to localized excessive shrinkage during injection molding, leading to defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. These defects can affect the rotor's structural strength and dimensional accuracy, ultimately impacting the motor's performance and rotor's service life. Summary of the Invention

[0005] The present application aims to at least partially solve one of the technical problems existing in the prior art. To this end, the present application proposes a rotor assembly and a motor having the rotor assembly.

[0006] The present application also proposes a household appliance using the above motor.

[0007] According to the rotor assembly of the first aspect embodiment of the present application, the rotor assembly includes a rotating shaft, a plastic-encapsulated body and an iron core, the plastic-encapsulated body is connected to the rotating shaft, and the iron core is connected to the plastic-encapsulated body; wherein the plastic-encapsulated body is plastic-encapsulated between the rotating shaft and the iron core, the iron core surrounds the rotating shaft, and along the axial direction of the rotating shaft, at least one of the two end faces of the plastic-encapsulated body is provided with a thickness reduction hole, and the thickness reduction hole is located between the rotating shaft and the iron core.

[0008] According to some embodiments of the present application, a plurality of the thickness-reducing holes are provided on the end surface of the plastic package body, and the plurality of the thickness-reducing holes are evenly distributed around the circumference of the rotating shaft.

[0009] According to some embodiments of the present application, the two end faces of the plastic package body are respectively provided with a plurality of the thickness reduction holes, and the thickness reduction holes at both ends of the plastic package body correspond to each other in the circumferential direction of the plastic package body, or the thickness reduction holes at both ends of the plastic package body are staggered in the circumferential direction of the plastic package body.

[0010] According to some embodiments of the present application, a first reinforcing rib is formed between the thickness-reducing holes at both ends of the plastic package body. Along the axial direction of the rotating shaft, the thickness of the first reinforcing rib is the first wall thickness. Along the radial direction of the rotating shaft, the minimum distance between the thickness-reducing hole and the rotating shaft is the second wall thickness. The difference between the second wall thickness and the first wall thickness is less than or equal to 0.5 mm.

[0011] According to some embodiments of the present application, a second reinforcing rib is formed between two adjacent reduced thickness holes, and along the circumference of the rotating shaft, the thickness of the second reinforcing rib is the third wall thickness. Along the radial direction of the rotating shaft, the minimum distance between the reduced thickness hole and the rotating shaft is the second wall thickness, and the difference between the second wall thickness and the third wall thickness is less than or equal to 0.5 mm.

[0012] According to some embodiments of the present application, the thickness reduction hole located at one end of the plastic packaging body is annular, and there are multiple thickness reduction holes located at the other end of the plastic packaging body, and they are evenly distributed around the circumference of the rotating shaft.

[0013] According to some embodiments of the present application, a plurality of the thickness-reducing holes are provided on one end face of the plastic-sealed body, and the plurality of the thickness-reducing holes are evenly distributed around the circumference of the rotating shaft. Along the axial direction of the rotating shaft, a third reinforcing rib is formed between the bottom wall of the thickness-reducing hole and the other end face of the plastic-sealed body.

[0014] According to some embodiments of the present application, a plurality of the thickness-reducing holes are provided at one end of the plastic package body, the plurality of the thickness-reducing holes are evenly distributed around the circumference of the rotating shaft, and the thickness-reducing holes penetrate the plastic package body.

[0015] According to some embodiments of the present application, along the axial direction of the rotating shaft, the cross-sectional area of ​​the thickness-reducing hole gradually decreases from the end surface of the plastic-encapsulated body toward the interior of the plastic-encapsulated body.

[0016] According to some embodiments of the present application, along the radial direction of the rotating shaft, the midline of the thickness-reducing hole is an arc line, and the arc line is concentrically arranged with the rotating shaft.

[0017] According to an embodiment of the second aspect of the present invention, the motor includes the rotor assembly described in the embodiment of the first aspect, the rotor assembly including a rotating shaft, a plastic-encapsulated body and an iron core, the plastic-encapsulated body is connected to the rotating shaft, and the iron core is connected to the plastic-encapsulated body; wherein the plastic-encapsulated body is wrapped between the rotating shaft and the iron core, the iron core surrounds the rotating shaft, and along the axial direction of the rotating shaft, at least one of the two end faces of the plastic-encapsulated body is provided with a thickness reduction hole, and the thickness reduction hole is located between the rotating shaft and the iron core.

[0018] The household appliance according to the third embodiment of the present application includes the motor described in the second embodiment.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Additional aspects and advantages of the present application will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0021] FIG1 is a schematic structural diagram of a rotor assembly according to an embodiment of the present application;

[0022] FIG2 is a cross-sectional view of a rotor assembly according to an embodiment of the present application;

[0023] FIG3 is a partial enlarged view of point A in FIG2 ;

[0024] FIG4 is an exploded schematic diagram of a rotor assembly according to an embodiment of the present application;

[0025] FIG5 is a schematic structural diagram of a plastic package body in some embodiments of the present application;

[0026] FIG6 is a cross-sectional view of a plastic package body in some embodiments of the present application;

[0027] FIG7 is a cross-sectional view of a plastic package body in some other embodiments of the present application.

[0028] The accompanying figures are as follows:

[0029] Rotating shaft 100;

[0030] Plastic package body 200, thickness reduction hole 201, first reinforcing rib 210, second reinforcing rib 220, third reinforcing rib 230;

[0031] Iron core 300 and permanent magnet 310 . Modes for Carrying Out the Invention

[0032] The following describes in detail embodiments of the present application. 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 application and are not to be construed as limiting the present application.

[0033] In the description of this application, it should be understood that descriptions involving orientations, 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. They are only for the convenience of describing this application 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. Therefore, they cannot be understood as limitations on this application.

[0034] In the description of this application, if there is a description of first or second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0035] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting 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 this application based on the specific content of the technical solution.

[0036] Electric motors are commonly used in household appliances, whether for fans to drive air flow, various pumps, or simply to drive rotating structures. Currently, a motor's rotor typically consists of a shaft, a plastic encapsulation, and an iron core, with the shaft and iron core connected as one piece via the plastic encapsulation. Due to the large radial distance between the iron core and the shaft, the thickness of the plastic encapsulation at that location is greater than at other locations. Consequently, the plastic encapsulation is prone to localized shrinkage during injection molding, leading to defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. These defects can affect the rotor's structural strength and dimensional accuracy, ultimately impacting the motor's performance and rotor life.

[0037] To this end, an embodiment of the first aspect of the present application proposes a rotor assembly, which provides thickness-reducing holes in the plastic package body so that the wall thickness at each position of the plastic package body is similar, thereby preventing excessive local shrinkage.

[0038] 1 to 5 , an embodiment of the first aspect of the present application provides a rotor assembly, comprising a rotating shaft 100, a plastic encapsulation body 200, and an iron core 300. The plastic encapsulation body 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the plastic encapsulation body 200. The iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically. The plastic encapsulation body 200 is typically an injection molded part. The rotating shaft 100 and the iron core 300 are fixed in a mold cavity and then injection molded. After the plastic encapsulation body 200 cools and sets, the rotating shaft 100, the plastic encapsulation body 200, and the iron core 300 are fixed together as a whole, the connection is stable, and the product consistency is good, the assembly steps are reduced, and production costs are reduced. The iron core 300 is internally provided with a plurality of permanent magnets 310. Typically, the iron core 300 is provided with permanent magnet slots, and the permanent magnets 310 are installed in the permanent magnet slots. The plurality of permanent magnets 310 are evenly distributed along the circumference of the rotating shaft 100.

[0039] It is understandable that due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic package 200 at this location is greater than at other locations, which makes it easy for localized shrinkage and deformation to occur during injection molding. Therefore, a thickness reduction hole 201 is provided in the end surface of the plastic package 200 along the axial direction of the rotating shaft 100, and the thickness reduction hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness reduction hole 201 on the end surface of the plastic package 200, the wall thickness of the plastic package 200 at the location between the rotating shaft 100 and the iron core 300 is reduced, making the wall thickness of the plastic package 200 uniform throughout the plastic package 200. During injection molding, the plastic package 200 shrinks more evenly at various locations, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation of the plastic package 200. This helps to improve the structural strength and dimensional accuracy of the rotor assembly, and improves the performance and service life of the motor.

[0040] It can be understood that the thickness reduction hole 201 can be set only on one end face of the plastic package body 200, or the thickness reduction hole 201 can be set on both end faces of the plastic package body 200. The thickness reduction hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0041] It is understood that the number of reduced-thickness holes 201 provided on the end surface of the plastic-encapsulated body 200 is multiple, such as three or four, and the multiple reduced-thickness holes 201 are evenly distributed circumferentially around the rotating shaft 100. This is primarily because the rotor assembly is a rotating component in the motor, and the multiple reduced-thickness holes 201 are evenly distributed circumferentially to facilitate dynamic balancing of the rotor assembly and reduce the impact on the rotating operation of the rotor assembly. The number of reduced-thickness holes 201 can be an odd number, and the total number of reduced-thickness holes 201, which is an odd number, is evenly distributed around the outer circumference of the rotating shaft 100, which helps prevent the plastic-encapsulated body 200 from being overweight on one side. During the rotation of the rotor assembly, the total number of reduced-thickness holes 201 helps improve the dynamic balance of the rotor assembly. Of course, the number of reduced-thickness holes 201 can also be an even number.

[0042] Referring to Figures 1 to 3, in some embodiments of the present application, a reduced-thickness hole 201 is provided on both end surfaces of the plastic encapsulation body 200. Furthermore, there are multiple reduced-thickness holes 201 provided on each end surface of the plastic encapsulation body 200, and the number of reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 is the same. As shown in Figure 1, the multiple reduced-thickness holes 201 are evenly distributed around the circumference of the rotating shaft 100, which is beneficial for the dynamic balance of the rotor assembly. The number of reduced-thickness holes 201 can be an odd number, such as five. The five reduced-thickness holes 201 are evenly distributed around the circumference of the rotating shaft 100, which helps prevent the plastic encapsulation body 200 from being overweight on one side. During motor operation, the five reduced-thickness holes 201 help improve the dynamic balance of the rotor assembly and enhance motor performance. Furthermore, the number of reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 is five. The evenly distributed reduced-thickness holes 201 around the circumference of the rotating shaft 100 contribute to the rotational stability of the rotor assembly during rotation, resulting in more stable motor performance.

[0043] 2 and 3 , in some embodiments of the present application, in the circumferential direction of the rotating shaft 100 , the multiple thickness-reducing holes 201 at both ends of the plastic-encapsulated body 200 correspond one to one, that is, the number is equal and the circumferential position is the same, so that the rotational balance of the plastic-encapsulated body 200 is better, which is conducive to adjusting the dynamic balance of the rotor assembly.

[0044] It is understood that the multiple reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 can also be staggered circumferentially around the rotating shaft 100. That is, the number of reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 is equal, but the circumferential positions are different. For example, the five reduced-thickness holes 201 can be staggered by 30 degrees. The staggered arrangement of the multiple reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 helps reduce excessive weight on one side when the rotor assembly rotates, improves the dynamic balance of the rotor assembly, and ensures more stable and reliable operation.

[0045] It is understandable that the plastic package body 200 is provided with a reduced thickness hole 201 only on one end face. In order to achieve the purpose of uniform wall thickness at all locations, the reduced thickness hole 201 needs to extend to the other end face close to the plastic package body 200. Therefore, the depth of the reduced thickness hole 201 is close to the axial length of the plastic package body 200. In order to improve the structural strength of the plastic package body 200, multiple reduced thickness holes 201 can be provided, and ribs are formed between two adjacent reduced thickness holes 201 to improve the structural strength and rigidity of the plastic package body 200 and enhance the performance of the rotor assembly. Alternatively, the reduced thickness hole 201 is provided as an annular hole and surrounds the rotating shaft 100. Reinforcing ribs are provided on the inner wall of the annular hole. The reinforcing ribs can be provided on one side of the inner wall of the annular hole, or on both sides of the inner wall of the annular hole. The reinforcing ribs are used to improve the structural strength and rigidity of the plastic package body 200 and enhance the performance of the rotor assembly.

[0046] It is understood that both ends of the plastic encapsulation body 200 are provided with a reduced-thickness hole 201, and the reduced-thickness holes 201 at both ends of the plastic encapsulation body 200 are not connected. A first reinforcing rib 210 is formed between the reduced-thickness holes 201 at both ends of the plastic encapsulation body 200. Along the axial direction of the rotating shaft 100, the thickness of the first reinforcing rib 210 is a first wall thickness L1. Along the radial direction of the rotating shaft 100, the minimum distance between the reduced-thickness hole 201 and the rotating shaft 100 is a second wall thickness L2, and the second wall thickness L2 is equal to the first wall thickness L1. During the injection molding process of the plastic encapsulation body 200, because the thickness of the first reinforcing rib 210 is equal to the minimum distance between the reduced-thickness hole 201 and the rotating shaft 100, the circumferential wall of the reduced-thickness hole 201 can shrink uniformly during cooling and finalizing, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly. In addition, the second wall thickness L2 can also be similar to the first wall thickness L1. For example, the size difference between the second wall thickness L2 and the first wall thickness L1 is less than or equal to 0.5 mm. During the injection molding process of the plastic package body 200, the shrinkage of the surrounding wall of the thickening hole 201 during cooling and shaping is relatively similar, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0047] Referring to FIG. 5 , it can be understood that the end surface of the plastic package body 200 is provided with a plurality of reduced-thickness holes 201, with a second reinforcing rib 220 formed between two adjacent reduced-thickness holes 201. Along the circumference of the rotating shaft 100, the thickness of the second reinforcing rib 220 is equal to the third wall thickness L3. Along the radial direction of the rotating shaft 100, the minimum distance between the reduced-thickness hole 201 and the rotating shaft 100 is equal to the second wall thickness L2, and the second wall thickness L2 is equal to the third wall thickness L3. During the injection molding process of the plastic package body 200, because the thickness of the second reinforcing rib 220 is equal to the minimum distance between the reduced-thickness hole 201 and the rotating shaft 100, the circumferential wall of the reduced-thickness hole 201 can shrink uniformly during cooling and finalizing, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly. In addition, the second wall thickness L2 and the third wall thickness L3 can also be similar, for example, the size difference between the second wall thickness L2 and the third wall thickness L3 is less than or equal to 0.5 mm. During the injection molding process of the plastic package body 200, the shrinkage of the surrounding wall of the thickening hole 201 during cooling and shaping is relatively similar, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0048] It is understood that the shape of the thickness reduction hole 201 can be various, without limitation, as long as the purpose of reducing the wall thickness of the plastic package 200 between the rotating shaft 100 and the iron core 300 is achieved. For example, the thickness reduction hole 201 at each end of the plastic package 200 has different shapes, with a first hole at one end of the plastic package 200 and a second hole at the other end of the plastic package 200. The first hole is annular, and there are multiple second holes, and the multiple second holes are evenly distributed around the circumference of the rotating shaft 100. A reinforcing rib is formed between adjacent second holes, and the thickness of the reinforcing rib is equal to or relatively close to the minimum distance between the second hole and the rotating shaft 100. During the injection molding process of the plastic package 200, the peripheral wall of the thickness reduction hole 201 shrinks uniformly during cooling and finalizing, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0049] It is understandable that, considering that the first hole is annular, which is not conducive to the structural strength of the plastic package body 200, a plurality of reinforcing ribs can be provided on the side wall of the first hole. The plurality of reinforcing ribs are evenly distributed along the circumference of the rotating shaft 100. Along the radial direction of the rotating shaft 100, reinforcing ribs can be provided on one side wall of the first hole, or on both side walls of the first hole. The reinforcing ribs are utilized to improve the structural strength and rigidity of the plastic package body 200 and enhance the performance of the rotor assembly.

[0050] 6 , in some other embodiments of the present application, the plastic package body 200 is provided with a plurality of reduced thickness holes 201 only on one end face, and the plurality of reduced thickness holes 201 are evenly distributed around the circumference of the rotating shaft 100. Along the axial direction of the rotating shaft 100, a third reinforcing rib 230 is formed between the bottom wall of the reduced thickness hole 201 and the other end face of the plastic package body 200. Along the axial direction of the rotating shaft 100, the thickness of the third reinforcing rib 230 is the fourth wall thickness L4. Along the radial direction of the rotating shaft 100, the minimum distance between the reduced thickness hole 201 and the rotating shaft 100 is the second wall thickness L2. The second wall thickness L2 is equal to or similar to the fourth wall thickness L4. For example, the size difference between the second wall thickness L2 and the fourth wall thickness L4 is less than or equal to 0.5 mm. During the injection molding process of the plastic package body 200, the shrinkage of the peripheral wall of the reduced thickness hole 201 during cooling and shaping can be made uniform, thereby avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0051] Referring to Figure 7, in some other embodiments of the present application, the plastic packaging body 200 is provided with multiple thickness reduction holes 201 only on one end face, and the multiple thickness reduction holes 201 are evenly distributed around the circumference of the rotating shaft 100. Along the axial direction of the rotating shaft 100, the thickness reduction holes 201 penetrate the plastic packaging body 200, and two adjacent thickness reduction holes 201 are naturally formed with second reinforcing ribs. The thickness of the second reinforcing ribs is equal to or close to the minimum distance between the thickness reduction holes 201 and the rotating shaft 100. During the injection molding process of the plastic packaging body 200, the shrinkage of the peripheral wall of the thickness reduction hole 201 during cooling and shaping can be made consistent, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0052] 6 , the thickness-reducing hole 201 is set to a variable cross-section along the axial direction of the rotating shaft 100 , and the cross-sectional area of ​​the thickness-reducing hole 201 gradually decreases from the end surface of the plastic package body 200 to the interior of the plastic package body 200 . On the one hand, this is beneficial to the demolding of the plastic package body 200 during injection molding, and on the other hand, it is beneficial to increase the structural strength of the plastic package body 200 .

[0053] 5 , it can be understood that, since the rotating shaft 100 is cylindrical and the iron core 300 is concentrically arranged around the rotating shaft 100 , the gap between the rotating shaft 100 and the iron core 300 is annular. Therefore, along the radial direction of the rotating shaft 100 , the midline of the thickness-reducing hole 201 is designed to be an arc line, and the arc line is concentrically arranged with the rotating shaft 100 , so that the shape of the thickness-reducing hole 201 matches the gap between the rotating shaft 100 and the iron core 300 , which can not only meet the requirements of adjusting the wall thickness of the plastic package body 200 to be uniform, but also match the rotation characteristics of the rotor assembly to prevent affecting the dynamic balance of the rotor assembly.

[0054] The second embodiment of the present application proposes a motor, which includes a rotor assembly of the first embodiment. The rotor assembly includes a rotating shaft 100, a plastic package body 200 and an iron core 300. The plastic package body 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the plastic package body 200. The iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically; the plastic package body 200 is usually an injection molded part, and the rotating shaft 100 and the iron core 300 are fixed in the mold cavity and then injection molding is performed. After the plastic package body 200 is cooled and shaped, the rotating shaft 100, the plastic package body 200 and the iron core 300 are fixed as one, the connection is firm, and the product consistency is good, the assembly steps are reduced, and it is beneficial to reduce production costs.

[0055] It is understandable that due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic package 200 at this location is greater than at other locations, which makes it easy for localized shrinkage and deformation to occur during injection molding. Therefore, a thickness reduction hole 201 is provided in the end surface of the plastic package 200 along the axial direction of the rotating shaft 100, and the thickness reduction hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness reduction hole 201 on the end surface of the plastic package 200, the wall thickness of the plastic package 200 at the location between the rotating shaft 100 and the iron core 300 is reduced, making the wall thickness of the plastic package 200 uniform throughout the plastic package 200. During injection molding, the plastic package 200 shrinks more evenly at various locations, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation of the plastic package 200. This helps to improve the structural strength and dimensional accuracy of the rotor assembly, and improves the performance and service life of the motor.

[0056] It can be understood that the thickness reduction hole 201 can be set only on one end face of the plastic package body 200, or the thickness reduction hole 201 can be set on both end faces of the plastic package body 200. The thickness reduction hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0057] It is understandable that the motor includes all technical solutions of the rotor assembly and has all technical effects of the rotor assembly, which will not be described one by one.

[0058] The third embodiment of the present application proposes a household appliance, which includes the motor described in the second embodiment, and the rotor assembly of the first embodiment is applied in the motor, the rotor assembly including a rotating shaft 100, a plastic package body 200 and an iron core 300, the plastic package body 200 is connected to the rotating shaft 100, the iron core 300 is connected to the plastic package body 200, the iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically; the plastic package body 200 is usually an injection molded part, the rotating shaft 100 and the iron core 300 are fixed in the mold cavity, and then injection molding is performed, after the plastic package body 200 is cooled and shaped, the rotating shaft 100, the plastic package body 200 and the iron core 300 are fixed as one, the connection is firm, and the product consistency is good, the assembly steps are reduced, and it is beneficial to reduce production costs.

[0059] It is understandable that due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic package 200 at this location is greater than at other locations, which makes it easy for localized shrinkage and deformation to occur during injection molding. Therefore, a thickness reduction hole 201 is provided in the end surface of the plastic package 200 along the axial direction of the rotating shaft 100, and the thickness reduction hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness reduction hole 201 on the end surface of the plastic package 200, the wall thickness of the plastic package 200 at the location between the rotating shaft 100 and the iron core 300 is reduced, making the wall thickness of the plastic package 200 uniform throughout the plastic package 200. During injection molding, the plastic package 200 shrinks more evenly at various locations, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation of the plastic package 200. This helps to improve the structural strength and dimensional accuracy of the rotor assembly, and improves the performance and service life of the motor.

[0060] It can be understood that the thickness reduction hole 201 can be set only on one end face of the plastic package body 200, or the thickness reduction hole 201 can be set on both end faces of the plastic package body 200. The thickness reduction hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0061] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. Rotor assembly, comprising: Rotating shaft; Plastic encapsulation body, connected to the rotating shaft; And Iron core, connected to the plastic encapsulation body; Wherein, the plastic encapsulation body is wrapped between the rotating shaft and the iron core, the iron core surrounds the rotating shaft, along the axial direction of the rotating shaft, at least one of the two end faces of the plastic encapsulation body is provided with a thickness-reducing hole, and the thickness-reducing hole is located between the rotating shaft and the iron core.

2. The rotor assembly according to claim 1, wherein, The end face of the plastic encapsulation body is provided with a plurality of the thickness-reducing holes, and the plurality of thickness-reducing holes are evenly distributed around the circumferential direction of the rotating shaft.

3. The rotor assembly according to claim 1 or 2, wherein, The two end faces of the plastic encapsulation body are respectively provided with a plurality of the thickness-reducing holes, and the thickness-reducing holes at both ends of the plastic encapsulation body correspond to each other in the circumferential direction of the plastic encapsulation body, or the thickness-reducing holes at both ends of the plastic encapsulation body are offset in the circumferential direction of the plastic encapsulation body.

4. The rotor assembly according to claim 3, wherein, A first reinforcing rib is formed between the thickness-reducing holes at both ends of the plastic encapsulation body. Along the axial direction of the rotating shaft, the thickness of the first reinforcing rib is the first wall thickness. Along the radial direction of the rotating shaft, the minimum distance between the thickness-reducing hole and the rotating shaft is the second wall thickness, and the difference between the second wall thickness and the first wall thickness is less than or equal to 0.5 mm.

5. The rotor assembly according to claim 3 or 4, wherein, A second reinforcing rib is formed between two adjacent thickness-reducing holes. Along the circumferential direction of the rotating shaft, the thickness of the second reinforcing rib is the third wall thickness. Along the radial direction of the rotating shaft, the minimum distance between the thickness-reducing hole and the rotating shaft is the second wall thickness, and the difference between the second wall thickness and the third wall thickness is less than or equal to 0.5 mm.

6. The rotor assembly according to any one of claims 1 to 5, wherein, The thickness-reducing hole at one end of the plastic encapsulation body is circular, and the thickness-reducing holes at the other end of the plastic encapsulation body are multiple and are evenly distributed around the circumferential direction of the rotating shaft.

7. The rotor assembly according to any one of claims 1 to 6, wherein, One end face of the plastic encapsulation body is provided with a plurality of the thickness-reducing holes, and the plurality of thickness-reducing holes are evenly distributed around the circumferential direction of the rotating shaft. Along the axial direction of the rotating shaft, a third reinforcing rib is formed between the bottom wall of the thickness-reducing hole and the other end face of the plastic encapsulation body.

8. The rotor assembly according to any one of claims 1 to 7, wherein, One end of the plastic encapsulation body is provided with a plurality of the thickness-reducing holes, and the plurality of thickness-reducing holes are evenly distributed around the circumferential direction of the rotating shaft, and the thickness-reducing holes penetrate through the plastic encapsulation body.

9. The rotor assembly according to any one of claims to 8, wherein, Along the axial direction of the rotating shaft, the cross-sectional area of the thickness-reducing hole gradually decreases from the end face of the plastic encapsulation body to the inside of the plastic encapsulation body.

10. The rotor assembly according to any one of claims 1 to 9, wherein, Along the radial direction of the rotating shaft, the midline of the thickness-reducing hole is an arc line, and the arc line is concentrically arranged with the rotating shaft.

11. Motor, comprising the rotor assembly according to any one of claims 1 to 10.

12. Household appliance, comprising the motor according to claim 11.

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