Rotor assembly, motor and household appliance

Abstract

The utility model 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] This utility model relates to the field of motor technology, and in particular to a rotor assembly, a motor, and a household appliance. Background Technology

[0002] In related technologies, the rotor of an electric motor typically includes a shaft, a molded enclosure, and an iron core, with the shaft and iron core connected as a single unit by the molded enclosure. Some rotors employ a split-type iron core. Due to the large radial distance between the iron core and the shaft, the molded enclosure at that location is relatively thick. Consequently, during injection molding, the molded enclosure is prone to excessive local shrinkage, leading to defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. These defects affect the rotor's structural strength and dimensional accuracy, thus impacting the motor's performance and the rotor's lifespan. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a rotor assembly that, by setting thickness-reducing holes in the encapsulation, prevents excessive local thickness, thereby improving the structural strength and dimensional accuracy of the rotor.

[0004] This utility model also proposes a motor having the above-mentioned rotor assembly.

[0005] This utility model also proposes a household appliance that uses the above-mentioned motor.

[0006] According to a first aspect of the present invention, a 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. The plastic encapsulation body is plastic-coated 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 reduction hole, which is located between the rotating shaft and the iron core.

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

[0008] By setting thickness reduction holes on the molding compound, the wall thickness of the molding compound between the shaft and the iron core is reduced, and the wall thickness of the molding compound is made uniform throughout. During injection molding, the shrinkage at each position is uniform, which prevents defects such as internal shrinkage cavities, excessive internal stress and uneven deformation of the molding compound. This 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, the end face of the encapsulated body is provided with a plurality of the thickening holes, and the plurality of the thickening holes are evenly distributed around the rotating shaft in the circumferential direction.

[0010] According to some embodiments of the first aspect of the present invention, a plurality of thickness reduction holes are respectively provided on the two end faces of the molding compound, and the thickness reduction holes at both ends of the molding compound correspond one-to-one in the circumferential direction of the molding compound, or the thickness reduction holes at both ends of the molding compound are staggered in the circumferential direction of the molding compound.

[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 encapsulated body. Along the axial direction of the rotating shaft, the thickness of the first reinforcing rib is a first wall thickness. Along the radial direction of the rotating shaft, the minimum distance between the thickness reduction hole and the rotating shaft is a second wall thickness. 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 this utility model, a second reinforcing rib is formed between two adjacent thickening holes. The thickness of the second reinforcing rib is the third wall thickness along the circumferential direction of the rotating shaft. The minimum distance between the thickening hole and the rotating shaft along the radial direction is the second wall thickness. 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 located at one end of the molding compound is annular, and there are multiple thickness reduction holes located at the other end of the molding compound, which are evenly distributed around the axis of rotation.

[0014] According to some embodiments of the first aspect of the present invention, a plurality of thickening holes are provided on one end face of the molding body, the plurality of thickening holes are evenly distributed around the circumference of the rotating shaft, and a third reinforcing rib is formed between the bottom wall of the thickening hole and the other end face of the molding body along the axial direction of the rotating shaft.

[0015] According to some embodiments of the first aspect of the present invention, one end of the encapsulation body is provided with a plurality of the thickening holes, the plurality of the thickening holes being evenly distributed around the rotating shaft in the circumferential direction, and the thickening holes penetrating 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 molding compound to the interior of the molding compound.

[0017] According to some embodiments of the first aspect of this utility model, the center line of the thickness reduction hole along the radial direction of the rotating shaft is an arc-shaped line, and the arc-shaped line is concentrically arranged with the rotating shaft.

[0018] The motor according to a second aspect embodiment of the present invention includes the rotor assembly described in the first aspect embodiment. The rotor assembly includes a rotating shaft, a molding compound, and an iron core. The molding compound is connected to the rotating shaft, and the iron core is connected to the molding compound. The molding compound is molded between the rotating shaft and the iron core. The iron core surrounds the rotating shaft along its axial direction. At least one of the two end faces of the molding compound is provided with a thickness reduction hole located between the rotating shaft and the iron core. By providing a thickness reduction hole on the end face of the molding compound, the wall thickness of the molding compound between the rotating shaft and the iron core is reduced, and the wall thickness of the molding compound is made uniform throughout. During injection molding, the shrinkage at each location is uniform, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation in the molding compound. This is beneficial for improving the structural strength and dimensional accuracy of the rotor assembly.

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

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Additional aspects and advantages of this utility model will become apparent and readily understood in conjunction with the following description of the embodiments in conjunction with the accompanying drawings, wherein:

[0022] Figure 1 This is a schematic diagram of the rotor assembly according to the first aspect of the present invention;

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

[0024] Figure 3 for Figure 2 A magnified view of a portion at point A;

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

[0026] Figure 5 This is a schematic diagram of the structure of the encapsulant in some embodiments of the first aspect of this utility model;

[0027] Figure 6 This is a cross-sectional view of the encapsulation body in some embodiments of the first aspect of this utility model;

[0028] Figure 7 This is a cross-sectional view of the encapsulated body in some other embodiments of the first aspect of this utility model.

[0029] The attached icons are numbered as follows:

[0030] Shaft 100;

[0031] Plastic sealant 200, thickness reduction hole 201, first reinforcing rib 210, second reinforcing rib 220, third reinforcing rib 230;

[0032] Iron core 300, permanent magnet 310. Detailed Implementation

[0033] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein 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 this utility model, and should not be construed as limiting this utility model.

[0034] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In the description of this utility model, the use of "first" and "second" is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features or the order of the technical features.

[0036] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0037] Electric motors are frequently used in household appliances, whether in fans to drive airflow, in various pumps, or directly to drive rotating structures. Currently, a motor rotor typically consists of a shaft, a molded enclosure, and an iron core. The shaft and iron core are connected as one unit by the molded enclosure. Due to the large radial distance between the iron core and the shaft, the thickness of the molded enclosure at this location is greater than in other locations. Consequently, during injection molding, the molded enclosure is prone to excessive local shrinkage, leading to defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. These defects affect the rotor's structural strength and dimensional accuracy, thus impacting the motor's performance and the rotor's lifespan.

[0038] Therefore, an embodiment of the first aspect of this utility model proposes a rotor assembly, which, by setting a thickness reduction hole in the encapsulation body, makes the wall thickness of the encapsulation body similar at various positions, thus preventing excessive local shrinkage.

[0039] Reference Figures 1 to 5 The first aspect of this utility model provides a rotor assembly, including a rotating shaft 100, a molding compound 200, and an iron core 300. The molding compound 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the molding compound 200. The iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically. The molding compound 200 is typically an injection-molded part. The rotating shaft 100 and the iron core 300 are fixed in the cavity of a mold, and then injection molding is performed. After the molding compound 200 cools and solidifies, the rotating shaft 100, the molding compound 200, and the iron core 300 are fixed as a whole, with a stable connection and good product consistency. This reduces assembly steps and helps to reduce production costs. The iron core 300 has multiple permanent magnets 310 inside. Typically, the iron core 300 has permanent magnet slots, and the permanent magnets 310 are installed in the permanent magnet slots. The multiple permanent magnets 310 are evenly distributed along the circumference of the rotating shaft 100.

[0040] Understandably, due to the large distance between the shaft 100 and the core 300, the wall thickness of the molding compound 200 at this location is greater than at other locations. This can easily lead to excessive local shrinkage and deformation during injection molding. Therefore, a thickness reduction hole 201 is provided in the end face of the molding compound 200 along the axial direction of the shaft 100. The thickness reduction hole 201 is located between the shaft 100 and the core 300. By providing the thickness reduction hole 201 in the end face of the molding compound 200, the wall thickness of the molding compound 200 at the location between the shaft 100 and the core 300 is reduced, making the wall thickness of the molding compound 200 uniform throughout. During injection molding, the shrinkage of the molding compound 200 is more uniform, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. This is beneficial for improving the structural strength and dimensional accuracy of the rotor assembly, and ultimately for improving the performance and service life of the motor.

[0041] It is understandable that the thickness reduction hole 201 can be provided only on one end face of the molding compound 200, or the thickness reduction hole 201 can be provided on both end faces of the molding compound 200. The thickness reduction hole 201 can be designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0042] It is understandable that the number of thickness reduction holes 201 provided on the end face of the encapsulation body 200 is multiple, such as three or four, and these multiple thickness reduction 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, and the circumferentially even distribution of multiple thickness reduction holes 201 is beneficial to the dynamic balance of the rotor assembly and reduces the impact on the rotational operation of the rotor assembly. The number of thickness reduction holes 201 can be odd. An odd number of thickness reduction holes 201 evenly distributed on the outer circumference of the rotating shaft 100 helps prevent the encapsulation body 200 from having an excessive weight on one side. During the rotation of the rotor assembly, an odd number of thickness reduction holes 201 helps improve the dynamic balance of the rotor assembly. Of course, the number of thickness reduction holes 201 can also be even.

[0043] Reference Figures 1 to 3 In some embodiments of the first aspect of this utility model, thickness reduction holes 201 are provided on both end faces of the molding compound 200, and the number of thickness reduction holes 201 provided on each end face of the molding compound 200 is multiple, with the number of thickness reduction holes 201 being the same at both ends of the molding compound 200. For example... Figure 1 As shown, 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 evenly distributed on the outer circumference of the rotating shaft 100 helps to prevent the encapsulated body 200 from having an excessive weight on one side. When the motor is running, 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 encapsulated body 200 is five. When the rotor assembly rotates, the evenly distributed circumferential thickness-reducing holes 201 are beneficial to the rotational stability of the rotor assembly, making the motor performance more stable.

[0044] Reference Figure 2 and Figure 3 In some embodiments of the first aspect of this utility model, in the circumferential direction of the rotating shaft 100, the multiple thinning holes 201 at both ends of the encapsulation body 200 correspond one-to-one, that is, the number is equal and the circumferential position is the same, which makes the rotational balance of the encapsulation body 200 better and is beneficial to adjusting the dynamic balance of the rotor assembly.

[0045] Understandably, the multiple thickness reduction holes 201 at both ends of the molding compound 200 can also be staggered along the circumference of the rotating shaft 100. That is, the number of thickness reduction holes 201 at both ends of the molding compound 200 is equal, but their circumferential positions are different. For example, the five thickness reduction holes 201 can be staggered by 30 degrees. The staggered arrangement of the multiple thickness reduction holes 201 at both ends of the molding compound 200 helps to reduce excessive weight on one side when the rotor assembly rotates, which helps to improve the dynamic balance of the rotor assembly and makes the operation more stable and reliable.

[0046] Understandably, the molding compound 200 has a thickness reduction hole 201 on only one end face. To achieve uniform wall thickness, the thickness reduction hole 201 needs to extend to the other end face near the molding compound 200. Therefore, the depth of the thickness reduction hole 201 is close to the axial length of the molding compound 200. To improve the structural strength of the molding compound 200, multiple thickness reduction holes 201 can be provided, with stiffeners forming between adjacent holes 201 to improve the structural strength and rigidity of the molding compound 200 and enhance the performance of the rotor assembly. Alternatively, the thickness reduction hole 201 can be an annular hole surrounding the shaft 100, with reinforcing ribs provided on the inner wall of the annular hole. This could be done on one or both sides of the annular hole, using the reinforcing ribs to improve the structural strength and rigidity of the molding compound 200 and enhance the performance of the rotor assembly.

[0047] It is understood that both ends of the molding compound 200 are provided with thickness reduction holes 201, and the thickness reduction holes 201 at both ends of the molding compound 200 are not connected. A first reinforcing rib 210 is formed between the thickness reduction holes 201 at both ends of the molding compound 200. Along the axial direction of the rotating shaft 100, the thickness of the first reinforcing rib 210 is the first wall thickness L1. Along the radial direction of the rotating shaft 100, the minimum distance between the thickness reduction hole 201 and the rotating shaft 100 is the second wall thickness L2, which is equal to the first wall thickness L1. During the injection molding process of the molding compound 200, since the thickness of the first reinforcing rib 210 and the minimum distance between the thickness reduction hole 201 and the rotating shaft 100 are equal, the shrinkage of the peripheral wall of the thickness reduction 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. In addition, the second wall thickness L2 can 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 encapsulated body 200, the shrinkage of the peripheral wall of the reduced hole 201 during cooling and shaping is similar, which avoids excessive local shrinkage and helps to improve the structural strength and dimensional accuracy of the rotor assembly.

[0048] Reference Figure 5It is understood that the end face of the molding compound 200 is provided with multiple thickness-reducing holes 201, and a second reinforcing rib 220 is formed between two adjacent thickness-reducing 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 thickness-reducing 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 molding compound 200, because the thickness of the second reinforcing rib 220 and the minimum distance between the thickness-reducing hole 201 and the rotating shaft 100 are equal, 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. 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 encapsulated body 200, the shrinkage of the peripheral wall of the reduced hole 201 during cooling and shaping is similar, which avoids excessive local shrinkage and is conducive to improving the structural strength and dimensional accuracy of the rotor assembly.

[0049] It is understandable that the shape of the thickness reduction hole 201 can be various and not limited, as long as it can achieve the purpose of reducing the wall thickness of the molding compound 200 between the shaft 100 and the iron core 300. For example, the shapes of the thickness reduction holes 201 at both ends of the molding compound 200 can be different. One end of the molding compound 200 has a first hole, and the other end has a second hole. The first hole is annular, and there are multiple second holes, which are evenly distributed around the circumference of the shaft 100. A reinforcing rib is formed between adjacent second holes, and the thickness of the reinforcing rib is equal to or close to the minimum distance between the second hole and the shaft 100. During the injection molding process of the molding compound 200, the shrinkage of the peripheral wall of the thickness reduction hole 201 is consistent during cooling and shaping, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0050] Understandably, considering that the first hole is annular, which is detrimental to the structural strength of the encapsulated body 200, multiple reinforcing ribs can be provided on the side wall of the first hole. These reinforcing ribs are evenly distributed along the circumference of the rotating shaft 100 and 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 can be used to improve the structural strength and rigidity of the encapsulated body 200 and enhance the performance of the rotor assembly.

[0051] Reference Figure 6In some other embodiments of the first aspect of this utility model, the encapsulated body 200 has a plurality of thinning holes 201 on only one end face. The plurality of thinning 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 thinning hole 201 and the other end face of the encapsulated 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 thinning 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 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 encapsulated body 200, the peripheral wall of the thinning hole 201 can shrink uniformly during cooling and shaping, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0052] Reference Figure 7 In some other embodiments of the first aspect of this utility model, the encapsulated body 200 is provided with a plurality of thickening holes 201 on only one end face. The plurality of thickening holes 201 are evenly distributed around the circumference of the rotating shaft 100. Along the axial direction of the rotating shaft 100, the thickening holes 201 penetrate the encapsulated body 200. Two adjacent thickening holes 201 naturally form a second reinforcing rib. The thickness of the second reinforcing rib is equal to or close to the minimum distance between the thickening hole 201 and the rotating shaft 100. During the injection molding process of the encapsulated body 200, the peripheral wall of the thickening hole 201 can shrink uniformly during cooling and shaping, avoiding excessive local shrinkage, which is beneficial to improving the structural strength and dimensional accuracy of the rotor assembly.

[0053] Reference Figure 6 Along the axial direction of the rotating shaft 100, the thickening hole 201 is set as a variable cross section. The cross-sectional area of ​​the thickening hole 201 gradually decreases from the end face of the molding body 200 to the inside of the molding body 200. On the one hand, this is beneficial for demolding of the molding body 200 during injection molding, and on the other hand, it is beneficial for increasing the structural strength of the molding body 200.

[0054] Reference Figure 5 It is understandable that, since the rotating shaft 100 is cylindrical and the iron core 300 is arranged concentrically 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 center line of the thickness reduction hole 201 is designed as an arc line, and the arc line is arranged concentrically with the rotating shaft 100. This makes the shape of the thickness reduction hole 201 match the gap between the rotating shaft 100 and the iron core 300, which can not only satisfy the need to adjust the uniformity of the wall thickness of the encapsulated body 200, but also match the rotation characteristics of the rotor assembly and prevent the dynamic balance of the rotor assembly from being affected.

[0055] The second aspect of this utility model provides a motor, which includes the rotor assembly of the first aspect embodiment. The rotor assembly includes a rotating shaft 100, a molding compound 200, and an iron core 300. The molding compound 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the molding compound 200. The iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically. The molding compound 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 performed. After the molding compound 200 cools and solidifies, the rotating shaft 100, the molding compound 200, and the iron core 300 are fixed as one unit, with a stable connection and good product consistency. It reduces assembly steps and helps to reduce production costs.

[0056] Understandably, due to the large distance between the shaft 100 and the core 300, the wall thickness of the molding compound 200 at this location is greater than at other locations. This can easily lead to excessive local shrinkage and deformation during injection molding. Therefore, a thickness reduction hole 201 is provided in the end face of the molding compound 200 along the axial direction of the shaft 100. The thickness reduction hole 201 is located between the shaft 100 and the core 300. By providing the thickness reduction hole 201 in the end face of the molding compound 200, the wall thickness of the molding compound 200 at the location between the shaft 100 and the core 300 is reduced, making the wall thickness of the molding compound 200 uniform throughout. During injection molding, the shrinkage of the molding compound 200 is more uniform, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. This is beneficial for improving the structural strength and dimensional accuracy of the rotor assembly, and ultimately for improving the performance and service life of the motor.

[0057] It is understandable that the thickness reduction hole 201 can be provided only on one end face of the molding compound 200, or the thickness reduction hole 201 can be provided on both end faces of the molding compound 200. The thickness reduction hole 201 can be designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0058] It is understandable 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 here.

[0059] The third aspect of this utility model proposes a household appliance, which includes the motor described in the second aspect embodiment. The motor uses the rotor assembly of the first aspect embodiment. The rotor assembly includes a rotating shaft 100, a molding compound 200, and an iron core 300. The molding compound 200 is connected to the rotating shaft 100, and the iron core 300 is connected to the molding compound 200. The iron core 300 surrounds the rotating shaft 100, and the two are arranged concentrically. The molding compound 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 performed. After the molding compound 200 cools and solidifies, the rotating shaft 100, the molding compound 200, and the iron core 300 are fixed as one unit, with a stable connection and good product consistency. It reduces assembly steps and helps to reduce production costs.

[0060] Understandably, due to the large distance between the shaft 100 and the core 300, the wall thickness of the molding compound 200 at this location is greater than at other locations. This can easily lead to excessive local shrinkage and deformation during injection molding. Therefore, a thickness reduction hole 201 is provided in the end face of the molding compound 200 along the axial direction of the shaft 100. The thickness reduction hole 201 is located between the shaft 100 and the core 300. By providing the thickness reduction hole 201 in the end face of the molding compound 200, the wall thickness of the molding compound 200 at the location between the shaft 100 and the core 300 is reduced, making the wall thickness of the molding compound 200 uniform throughout. During injection molding, the shrinkage of the molding compound 200 is more uniform, preventing defects such as internal shrinkage cavities, excessive internal stress, and uneven deformation. This is beneficial for improving the structural strength and dimensional accuracy of the rotor assembly, and ultimately for improving the performance and service life of the motor.

[0061] It is understandable that the thickness reduction hole 201 can be provided only on one end face of the molding compound 200, or the thickness reduction hole 201 can be provided on both end faces of the molding compound 200. The thickness reduction hole 201 can be designed according to the specific structure of the motor, including the number, shape and distribution of the thickness reduction hole 201.

[0062] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A rotor assembly, characterized in that: include: Rotating shaft; A plastic sealing body connected to the rotating shaft; An iron core connected to the plastic package body; The plastic package 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 package body is provided with a thickness reduction hole, and the thickness reduction hole is located between the rotating shaft and the iron core.

2. The rotor assembly according to claim 1, characterized in that The end surface of the plastic package body is provided with a plurality of the thickness reduction holes, and the plurality of the thickness reduction holes are evenly distributed around the circumference of the rotating shaft.

3. The rotor assembly according to claim 1, characterized in that: 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.

4. The rotor assembly according to claim 3, characterized in that: 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.

5. The rotor assembly according to claim 3, characterized in that: A second reinforcing rib is formed between two adjacent reduced thickness 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 reduced thickness hole and the rotating shaft is the second wall thickness. 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, characterized in that The thickness reduction hole at one end of the plastic package body is in a circular shape, and there are a plurality of thickness reduction holes at the other end of the plastic package body, which are evenly distributed around the circumference of the rotating shaft.

7. The rotor assembly according to claim 1, characterized in that One end face of the plastic package body is provided with a plurality of the thickness reduction holes, which 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 reduction hole and the other end face of the plastic package body.

8. The rotor assembly according to claim 1, characterized in that One end of the plastic package body is provided with a plurality of the thickness reduction holes, the plurality of the thickness reduction holes are evenly distributed around the circumference of the rotating shaft, and the thickness reduction holes penetrate the plastic package body.

9. The rotor assembly according to claim 1, characterized in that: 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-sealed body to the interior 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. A motor, characterized in that Comprising a rotor assembly as claimed in any one of claims 1 to 10.

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

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