Rotor assembly, motor and household appliance

Abstract

The invention relates to the technical field of motors, and discloses a rotor assembly, a motor and a household electrical appliance, the rotor assembly comprises a rotating shaft, a plastic package body and an iron core, the plastic package body is connected to the rotating shaft, and the iron core is connected to the plastic package body; wherein the plastic package body is packaged between the rotating shaft and the iron core, the iron core surrounds the rotating shaft, at least one of the two end faces of the plastic package body is provided with a thickness reducing hole in the axial direction of the rotating shaft, and the thickness reducing hole is located between the rotating shaft and the iron core. The thickness reducing holes are formed in the end face of the plastic package body, the wall thickness of the position, between the rotating shaft and the iron core, of the plastic package body is reduced, the wall thickness of all positions of the plastic package body is uniform, shrinkage of all positions is uniform in the injection molding process, and the defects of internal shrinkage cavities, overlarge internal stress, uneven deformation and the like of the plastic package body are overcome; and the structural strength and the dimensional precision of the rotor assembly can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a rotor assembly, a motor and a household appliance. Background Art

[0002] In the related art, the rotor of a motor generally includes a rotating shaft, a plastic-sealed body and an iron core, and the rotating shaft and the iron core are connected into one body through the plastic-sealed body. Among them, some rotors adopt an iron core with a split structure. Since the radial distance between the iron core and the rotating shaft is relatively large, the thickness of the plastic-sealed body at this position is relatively large. Therefore, in the injection molding process, the plastic-sealed body is prone to excessive local shrinkage, resulting in defects such as internal shrinkage holes, excessive internal stress and uneven deformation in the plastic-sealed body. These defects will affect the structural strength and dimensional accuracy of the rotor, and further affect the performance of the motor and the service life of the rotor. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a rotor assembly, by providing a thickness-reducing hole in the plastic-sealed body, preventing the local thickness from being too large, and improving the structural strength and dimensional accuracy of the rotor.

[0004] The present invention also provides a motor having the above rotor assembly.

[0005] The present invention further provides a household appliance using the above motor.

[0006] According to the rotor assembly of the first aspect embodiment of the present invention, it includes a rotating shaft, a plastic-sealed body and an iron core. The plastic-sealed body is connected to the rotating shaft, and the iron core is connected to the plastic-sealed body. Among them, the plastic-sealed 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-sealed body is provided with a thickness-reducing hole, and the thickness-reducing hole is located between the rotating shaft and the iron core.

[0007] The rotor assembly according to the first aspect embodiment of the present invention has at least the following beneficial effects:

[0008] By providing a thickness-reducing hole in the plastic-sealed body, the wall thickness of the plastic-sealed body between the rotating shaft and the iron core is reduced, and the wall thickness of each part of the plastic-sealed body is made uniform. In the injection molding process, the shrinkage of each position is uniform, preventing defects such as internal shrinkage holes, excessive internal stress and uneven deformation in the plastic-sealed body, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0009] According to some embodiments of the first aspect of the present invention, a plurality of the thickness-reducing holes are provided on the end face of the plastic-sealed body, and the plurality of thickness-reducing holes are evenly distributed around the circumferential direction of the rotating shaft.

[0010] According to some embodiments of the first aspect of the present invention, a plurality of the thickness reduction holes are respectively provided on two end faces of the encapsulation body, and the thickness reduction holes at both ends of the encapsulation body correspond to each other in the circumferential direction of the encapsulation body, or the thickness reduction holes at both ends of the encapsulation body are offset in the circumferential direction of the encapsulation body.

[0011] According to some embodiments of the first aspect of the present invention, a first reinforcing rib is formed between the thickness reduction holes at both ends of the encapsulation body. Along the axial direction of the rotating shaft, the thickness of the first reinforcing rib is the first wall thickness, and along the radial direction of the rotating shaft, the minimum distance between the thickness reduction 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.

[0012] According to some embodiments of the first aspect of the present invention, a second reinforcing rib is formed between two adjacent thickness reduction holes. Along the circumferential direction of the rotating shaft, the thickness of the second reinforcing rib is the third wall thickness, and along the radial direction of the rotating shaft, the minimum distance between the thickness reduction 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.

[0013] According to some embodiments of the first aspect of the present invention, the thickness reduction hole at one end of the encapsulation body is annular, and the thickness reduction holes at the other end of the encapsulation body are multiple and are evenly distributed around the circumferential direction of the rotating shaft.

[0014] According to some embodiments of the first aspect of the present invention, a plurality of the thickness reduction holes are provided on one end face of the encapsulation body, and the plurality of thickness reduction 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 reduction hole and the other end face of the encapsulation body.

[0015] According to some embodiments of the first aspect of the present invention, a plurality of the thickness reduction holes are provided at one end of the encapsulation body, and the plurality of thickness reduction holes are evenly distributed around the circumferential direction of the rotating shaft, and the thickness reduction holes penetrate through the encapsulation body.

[0016] According to some embodiments of the first aspect of the present invention, along the axial direction of the rotating shaft, the cross-sectional area of the thickness reduction hole gradually decreases from the end face of the encapsulation body to the inside of the encapsulation body.

[0017] According to some embodiments of the first aspect of the present invention, along the radial direction of the rotating shaft, the midline of the thickness reduction hole is an arc line, and the arc line is concentrically arranged with the rotating shaft.

[0018] The motor according to the embodiment of the second aspect of the present invention includes the rotor assembly described in the embodiment of the first aspect. The rotor assembly includes a rotating shaft, a plastic encapsulation body, and an iron core. The plastic encapsulation body is connected to the rotating shaft, and the iron core is 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, and 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. By providing a thickness-reducing hole on the end face of the plastic encapsulation body, the wall thickness of the plastic encapsulation body at the position between the rotating shaft and the iron core is reduced, and the wall thickness of each part of the plastic encapsulation body is made uniform. During injection molding, the shrinkage of each position is uniform, preventing defects such as internal shrinkage holes, excessive internal stress, and uneven deformation of the plastic encapsulation body, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0019] The household appliance according to the embodiment of the third aspect of the present invention includes the motor described in the embodiment of the second aspect.

[0020] Some additional aspects and advantages of the present invention will be given in the following description, some will become obvious from the following description, or will be understood through the practice of the present invention. Description of the Drawings

[0021] The additional aspects and advantages of the present invention will become obvious and easy to understand in the description of the embodiments in conjunction with the following drawings, wherein:

[0022] Figure 1 It is a schematic structural view of the rotor assembly according to the embodiment of the first aspect of the present invention;

[0023] Figure 2 It is a cross-sectional view of the rotor assembly according to the embodiment of the first aspect of the present invention;

[0024] Figure 3 is Figure 2 The partial enlarged view at A of;

[0025] Figure 4 It is an exploded schematic view of the rotor assembly according to the embodiment of the first aspect of the present invention;

[0026] Figure 5 It is a schematic structural view of the plastic encapsulation body in some embodiments of the first aspect of the present invention;

[0027] Figure 6 It is a cross-sectional view of the plastic encapsulation body in some embodiments of the first aspect of the present invention;

[0028] Figure 7 It is a cross-sectional view of the plastic encapsulation body in some other embodiments of the first aspect of the present invention.

[0029] The attached reference numerals are as follows:

[0030] Rotating shaft 100;

[0031] Plastic encapsulation body 200, thickness-reducing hole 201, first reinforcing rib 210, second reinforcing rib 220, third reinforcing rib 230;

[0032] Iron core 300, permanent magnet 310. Specific embodiments

[0033] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0034] In the description of the present invention, it should be understood that with regard to the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0035] In the description of the present invention, if the first and second are described only for the purpose of distinguishing technical features, it should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0036] In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0037] Motors are often used in household appliances. It can be used for a blower to drive air flow, or for various pumps, or directly use the motor to drive a rotating structure. Currently, the rotor of a motor usually includes a rotating shaft, a plastic encapsulation body, and an iron core. The rotating shaft and the iron core are connected as a whole through the plastic encapsulation body. Since the radial distance between the iron core and the rotating shaft is relatively large, the thickness of the plastic encapsulation body at this position is larger than that at other positions. Therefore, in the injection molding process, the plastic encapsulation body is prone to excessive local shrinkage, resulting in defects such as internal shrinkage holes, excessive internal stress, and uneven deformation in the plastic encapsulation body. These defects will affect the structural strength and dimensional accuracy of the rotor, and further affect the performance of the motor and the service life of the rotor.

[0038] For this reason, an embodiment of the first aspect of the present invention proposes a rotor assembly. By providing a thickness-reducing hole in the plastic encapsulation body, the wall thickness of each position of the plastic encapsulation body is made similar, preventing excessive local shrinkage.

[0039] Refer toFigures 1 to 5 , an embodiment of the first aspect of the present invention provides a rotor assembly, including a rotating shaft 100, a plastic-sealed body 200, and an iron core 300. The plastic-sealed body 200 is connected to the rotating shaft 100, the iron core 300 is connected to the plastic-sealed body 200, the iron core 300 surrounds the rotating shaft 100, and the two are concentrically arranged; the plastic-sealed body 200 is usually an injection molded part, which fixes the rotating shaft 100 and the iron core 300 in the cavity of the mold, and then injection molding is carried out. After the plastic-sealed body 200 is cooled and solidified, the rotating shaft 100, the plastic-sealed body 200, and the iron core 300 are fixed together as a whole, with firm connection, good product consistency, reduced assembly steps, and is beneficial to reducing production costs. A plurality of permanent magnets 310 are arranged inside the iron core 300. Usually, 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 circumferential direction of the rotating shaft 100.

[0040] It can be understood that, due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic-sealed body 200 at this position is greater than that at other positions, and local shrinkage and deformation are likely to occur during injection molding. Therefore, along the axial direction of the rotating shaft 100, a thickness-reducing hole 201 is provided in the end face of the plastic-sealed body 200, and the thickness-reducing hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness-reducing hole 201 in the end face of the plastic-sealed body 200, the wall thickness of the plastic-sealed body 200 at the position between the rotating shaft 100 and the iron core 300 is reduced, so that the wall thickness of each part of the plastic-sealed body 200 is uniform. During injection molding, the shrinkage of each position of the plastic-sealed body 200 is more uniform, preventing defects such as internal shrinkage holes, excessive internal stress, and uneven deformation of the plastic-sealed body 200, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly, and is beneficial to improving the performance and service life of the motor.

[0041] It can be understood that the thickness-reducing hole 201 can be provided only on one end face of the plastic-sealed body 200, or the thickness-reducing hole 201 can be provided on both end faces of the plastic-sealed body 200. The thickness-reducing hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape, and distribution method of the thickness-reducing hole 201.

[0042] It can be understood that the number of thickness-reducing holes 201 provided at the end faces of the plastic-sealed body 200 is multiple, such as three, four, etc., and the multiple thickness-reducing holes 201 are evenly distributed circumferentially around the rotating shaft 100. This is mainly because the rotor assembly is a rotating component in the motor. The multiple thickness-reducing holes 201 being evenly distributed circumferentially is beneficial to the dynamic balance of the rotor assembly and reduces the impact on the rotational operation of the rotor assembly. Among them, the number of thickness-reducing holes 201 can be odd. The total number of odd-numbered thickness-reducing holes 201 being evenly distributed on the outer circumference of the rotating shaft 100 is beneficial to preventing the plastic-sealed body 200 from having a relatively large weight on one side. During the rotation of the rotor assembly, the total number of odd-numbered thickness-reducing holes 201 helps to improve the dynamic balance of the rotor assembly. Of course, the number of thickness-reducing holes 201 can also be even.

[0043] Referring Figures 1 to 3 , in some embodiments of the first aspect of the present invention, thickness-reducing holes 201 are provided on both end faces of the plastic-sealed body 200, and the number of thickness-reducing holes 201 provided on each end face of the plastic-sealed body 200 is multiple, and the number of thickness-reducing holes 201 at both ends of the plastic-sealed body 200 is the same. As Figure 1 shown, the multiple thickness-reducing holes 201 are evenly distributed circumferentially around the rotating shaft 100, which is beneficial to the dynamic balance of the rotor assembly. The number of thickness-reducing holes 201 can be odd, such as five. The five thickness-reducing holes 201 are evenly distributed on the outer circumference of the rotating shaft 100, which is beneficial to preventing the plastic-sealed body 200 from having a relatively large weight on one side. During the operation of the motor, the five thickness-reducing holes 201 help to improve the dynamic balance of the rotor assembly and improve the performance of the motor. Moreover, the number of thickness-reducing holes 201 at both ends of the plastic-sealed body 200 is five. When the rotor assembly rotates, the circumferentially evenly distributed thickness-reducing holes 201 are beneficial to the rotational stability of the rotor assembly, making the performance of the motor more stable.

[0044] Referring Figure 2 and Figure 3 , in some embodiments of the first aspect of the present invention, in the circumferential direction of the rotating shaft 100, the multiple thickness-reducing holes 201 at both ends of the plastic-sealed body 200 correspond one by one, that is, the number is equal and the circumferential positions are the same, making the rotational balance of the plastic-sealed body 200 better and beneficial to adjusting the dynamic balance of the rotor assembly.

[0045] It can be understood that in the circumferential direction of the rotating shaft 100, the multiple thickness-reducing holes 201 at both ends of the plastic-sealed body 200 can also be staggered, that is, the thickness-reducing holes 201 at both ends of the plastic-sealed body 200 are equal in number but different in circumferential position. For example, the five thickness-reducing holes 201 can be staggered by 30 degrees. The multiple thickness-reducing holes 201 at both ends of the plastic-sealed body 200 are arranged in a staggered manner. When the rotor assembly rotates, it is beneficial to reduce the excessive weight on one side, beneficial to improving the dynamic balance of the rotor assembly, and the operation is more stable and reliable.

[0046] It can be understood that the encapsulation body 200 is provided with a thickness-reducing hole 201 only at one of its end faces. In order to achieve the purpose of uniform wall thickness everywhere, the thickness-reducing hole 201 needs to extend to near the other end face of the encapsulation body 200. Therefore, the depth of the thickness-reducing hole 201 is close to the axial length of the encapsulation body 200. In order to improve the structural strength of the encapsulation body 200, multiple thickness-reducing holes 201 can be provided, and a rib plate is formed between two adjacent thickness-reducing holes 201 to improve the structural strength and stiffness of the encapsulation body 200 and enhance the performance of the rotor assembly. Alternatively, the thickness-reducing hole 201 is set as an annular hole and surrounds the rotating shaft 100. Reinforcing ribs can be provided on the inner wall of the annular hole, either on the single inner wall of the annular hole or on the double inner walls of the annular hole, and the reinforcing ribs are used to improve the structural strength and stiffness of the encapsulation body 200 and enhance the performance of the rotor assembly.

[0047] It can be understood that thickness-reducing holes 201 are provided at both ends of the encapsulation body 200, and the thickness-reducing holes 201 at both ends of the encapsulation body 200 are not connected. A first reinforcing rib 210 is formed between the thickness-reducing holes 201 at both ends of the encapsulation body 200. Along the axial direction of the rotating shaft 100, the thickness of the first reinforcing rib 210 is the first wall thickness L1, and along the radial direction of the rotating shaft 100, the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100 is the 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 encapsulation body 200, since the thickness of the first reinforcing rib 210 is equal to the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100, the shrinkage of the peripheral wall of the thickness-reducing hole 201 during cooling and solidification can be made consistent, avoiding excessive local shrinkage, which is beneficial to enhancing the structural strength and dimensional accuracy of the rotor assembly. In addition, the second wall thickness L2 and the first wall thickness L1 can also be close. For example, the dimensional 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 encapsulation body 200, the shrinkage of the peripheral wall of the thickness-reducing hole 201 during cooling and solidification is relatively close, avoiding excessive local shrinkage, which is beneficial to enhancing the structural strength and dimensional accuracy of the rotor assembly.

[0048] Refer to Figure 5It can be understood that a plurality of thickness-reducing holes 201 are provided on the end face of the plastic-sealed body 200. A second reinforcing rib 220 is formed between two adjacent thickness-reducing holes 201. Along the circumferential direction of the rotating shaft 100, the thickness of the second reinforcing rib 220 is the third wall thickness L3. Along the radial direction of the rotating shaft 100, the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100 is 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-sealed body 200, since the thickness of the second reinforcing rib 220 is equal to the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100, the shrinkage of the peripheral wall of the thickness-reducing 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. In addition, the second wall thickness L2 and the third wall thickness L3 can also be close to each other. For example, the dimensional 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-sealed body 200, the shrinkage of the peripheral wall of the thickness-reducing hole 201 during cooling and shaping is relatively close, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0049] It can be understood that the shape of the thickness-reducing hole 201 can be various shapes without limitation, as long as it can achieve the purpose of reducing the wall thickness of the plastic-sealed body 200 between the rotating shaft 100 and the iron core 300. For example, the shapes of the thickness-reducing holes 201 at both ends of the plastic-sealed body 200 are different. At one end of the plastic-sealed body 200, it is the first hole, and at the other end of the plastic-sealed body 200, it is the second hole. The first hole is circular, and there are a plurality of second holes. The plurality of second holes are evenly distributed along the circumferential direction of the rotating shaft 100. A reinforcing rib is formed between two 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-sealed body 200, the shrinkage of the peripheral wall of the thickness-reducing hole 201 during cooling and shaping is consistent, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0050] It can be understood that considering that the first hole is annular and is not beneficial to the structural strength of the plastic-sealed 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 circumferential direction of the rotating shaft 100. Along the radial direction of the rotating shaft 100, the reinforcing ribs can be provided on one side wall of the first hole, or can be provided on both side walls of the first hole, using the reinforcing ribs to improve the structural strength and stiffness of the plastic-sealed body 200 and enhance the performance of the rotor assembly.

[0051] Refer to Figure 6, in some other embodiments of the first aspect of the present invention, the encapsulation body 200 is provided with a plurality of thickness-reducing holes 201 only on one end face. The plurality of thickness-reducing holes 201 are evenly distributed circumferentially around 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 thickness-reducing hole 201 and the other end face of the encapsulation 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 thickness-reducing hole 201 and the rotating shaft 100 is the second wall thickness L2. The second wall thickness L2 is equal to or close to the fourth wall thickness L4. For example, the dimensional 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 encapsulation body 200, the circumferential walls of the thickness-reducing holes 201 can have consistent shrinkage during cooling and shaping, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0052] Refer to Figure 7 , in some other embodiments of the first aspect of the present invention, the encapsulation body 200 is provided with a plurality of thickness-reducing holes 201 only on one end face. The plurality of thickness-reducing holes 201 are evenly distributed circumferentially around the rotating shaft 100. Along the axial direction of the rotating shaft 100, the thickness-reducing holes 201 penetrate through the encapsulation body 200, and a second reinforcing rib is naturally formed between two adjacent thickness-reducing holes 201. The thickness of the second reinforcing rib is equal to or close to the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100. During the injection molding process of the encapsulation body 200, the circumferential walls of the thickness-reducing holes 201 can have consistent shrinkage during cooling and shaping, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0053] Refer to Figure 6 , along the axial direction of the rotating shaft 100, the thickness-reducing hole 201 is set to have a variable cross-section. The cross-sectional area of the thickness-reducing hole 201 gradually decreases from the end face of the encapsulation body 200 towards the inside of the encapsulation body 200. On the one hand, it is beneficial for demolding during the injection molding of the encapsulation body 200, and on the other hand, it is beneficial for increasing the structural strength of the encapsulation body 200.

[0054] Refer to Figure 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 as 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 requirement of adjusting the wall thickness uniformity of the encapsulation body 200, but also match the rotation characteristics of the rotor assembly, preventing the influence on the dynamic balance of the rotor assembly.

[0055] In the second aspect of the embodiments of the present invention, a motor is proposed. The motor includes the rotor assembly of the first aspect of the embodiments. The rotor assembly includes a rotating shaft 100, a plastic-sealed body 200, and an iron core 300. The plastic-sealed body 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the plastic-sealed body 200. The iron core 300 surrounds the rotating shaft 100, and the two are concentrically arranged. The plastic-sealed body 200 is usually an injection-molded part. The rotating shaft 100 and the iron core 300 are fixed in the cavity of the mold, and then injection molding is carried out. After the plastic-sealed body 200 is cooled and solidified, the rotating shaft 100, the plastic-sealed body 200, and the iron core 300 are fixed together as a whole, with firm connection, good product consistency, reduced assembly steps, and is beneficial to reducing production costs.

[0056] It can be understood that, due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic-sealed body 200 at this position is greater than that at other positions, and local shrinkage and deformation are likely to occur during injection molding. Therefore, along the axial direction of the rotating shaft 100, a thickness-reducing hole 201 is provided in the end face of the plastic-sealed body 200. The thickness-reducing hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness-reducing hole 201 in the end face of the plastic-sealed body 200, the wall thickness of the plastic-sealed body 200 at the position between the rotating shaft 100 and the iron core 300 is reduced, so that the wall thickness of each part of the plastic-sealed body 200 is uniform. During injection molding, the shrinkage of each position of the plastic-sealed body 200 is more uniform, preventing defects such as internal shrinkage holes, excessive internal stress, and uneven deformation of the plastic-sealed body 200, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly and is beneficial to improving the performance and service life of the motor.

[0057] It can be understood that the thickness-reducing hole 201 can be provided only in one end face of the plastic-sealed body 200, or the thickness-reducing hole 201 can be provided in both end faces of the plastic-sealed body 200. The thickness-reducing hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape, and distribution method of the thickness-reducing holes 201.

[0058] It can be understood that the motor includes all the technical solutions of the rotor assembly and has all the technical effects of the rotor assembly, which will not be elaborated one by one.

[0059] In the third aspect of the embodiments of the present invention, a household appliance is proposed. The household appliance includes the motor described in the second aspect of the embodiments. The rotor assembly of the first aspect of the embodiments is applied in the motor. The rotor assembly includes a rotating shaft 100, a plastic-sealed body 200, and an iron core 300. The plastic-sealed body 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the plastic-sealed body 200. The iron core 300 surrounds the rotating shaft 100, and the two are concentrically arranged. The plastic-sealed body 200 is usually an injection-molded part. The rotating shaft 100 and the iron core 300 are fixed in the cavity of the mold, and then injection molding is carried out. After the plastic-sealed body 200 is cooled and solidified, the rotating shaft 100, the plastic-sealed body 200, and the iron core 300 are fixed together as a whole, with firm connection, good product consistency, reduced assembly steps, and is beneficial to reducing production costs.

[0060] It can be understood that, due to the large distance between the rotating shaft 100 and the iron core 300, the wall thickness of the plastic-sealed body 200 at this position is greater than that at other positions, and local excessive shrinkage and deformation are likely to occur during injection molding. Therefore, along the axial direction of the rotating shaft 100, a thickness-reducing hole 201 is provided in the end face of the plastic-sealed body 200, and the thickness-reducing hole 201 is located between the rotating shaft 100 and the iron core 300. By providing the thickness-reducing hole 201 in the end face of the plastic-sealed body 200, the wall thickness of the plastic-sealed body 200 at the position between the rotating shaft 100 and the iron core 300 is reduced, so that the wall thickness of each part of the plastic-sealed body 200 is uniform. During injection molding, the shrinkage of each position of the plastic-sealed body 200 is more uniform, preventing defects such as internal shrinkage holes, excessive internal stress, and uneven deformation of the plastic-sealed body 200, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly and is beneficial to improving the performance and service life of the motor.

[0061] It can be understood that the thickness-reducing hole 201 can be provided only on one end face of the plastic-sealed body 200, or the thickness-reducing hole 201 can be provided on both end faces of the plastic-sealed body 200. The thickness-reducing hole 201 can be specifically designed according to the specific structure of the motor, including the number, shape, and distribution mode of the thickness-reducing holes 201.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the purpose of the present invention.

Claims

1. Rotor assembly, characterized in that, Comprising: Rotating shaft; Plastic-sealed body, connected to the rotating shaft; Iron core, connected to the plastic-sealed body; Wherein, the plastic-sealed 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-sealed 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-sealed 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, wherein The two end faces of the plastic-sealed body are respectively provided with a plurality of the thickness-reducing holes, and the thickness-reducing holes at both ends of the plastic-sealed body are in one-to-one correspondence in the circumferential direction of the plastic-sealed body, or the thickness-reducing holes at both ends of the plastic-sealed body are staggered in the circumferential direction of the plastic-sealed 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-sealed 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, characterized in that, 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 claim 1, wherein, The thickness-reducing hole at one end of the plastic-sealed body is annular, and the thickness-reducing holes at the other end of the plastic-sealed body are multiple and are evenly distributed around the circumferential direction of the rotating shaft.

7. The rotor assembly according to claim 1, wherein, One end face of the plastic-sealed 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-sealed body.

8. The rotor assembly according to claim 1, wherein One end of the plastic-sealed 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-sealed body.

9. The rotor assembly according to claim 1, 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-sealed body to the inside of the plastic-sealed body.

10. The rotor assembly according to claim 1, characterized in that, 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. Electric motor, characterized in that, Comprising the rotor assembly according to any one of claims 1 to 10.

12. Household appliance, characterized in that, Comprising the motor according to claim 11.

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