Rotor assembly, motor and household appliance

Abstract

The utility model discloses a rotor assembly, a motor and a household electrical appliance, the rotor assembly comprises an inner iron core, an outer iron core, a plurality of magnetic shoes and a plastic-coated body, the outer iron core is provided with at least one first through hole, and at least one end of the outer iron core protrudes out of the end portion of the inner iron core; the plurality of magnetic shoes are mounted on the outer peripheral wall of the outer iron core; the plastic-coated body comprises a first wall body, a second wall body and a third wall body, the first wall body covers the end face of the outer iron core and is provided with a second through hole, the inner peripheral wall of the second through hole is arranged along the periphery of the first through hole, and the second wall body covers the end face of the inner iron core; the third wall body covers the inner peripheral wall of the structure, protruding out of the inner iron core, in the outer iron core and is connected with the first wall body and the second wall body, at least one groove is formed in the connecting position of the first wall body and the third wall body, and the groove is located in the side, close to the inner iron core in the radial direction of the rotor assembly, of the first through hole. The rotor assembly of the utility model can reduce the weld lines of the plastic-coated body, enhance the structural strength of the plastic-coated body, and reduce the occurrence of cracking phenomena.

Description

Technical Field

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

[0002] The rotor's magnetic segments are typically secured to the core using overmolding. This overmolding wraps around the rotor's inner and outer cores, creating a constraint between them. However, this overmolding structure creates weld lines around the outer core openings. These weld lines weaken the overmolding's structural strength and create high stresses at these locations, leading to cracking and compromising the rotor assembly's structural stability. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a rotor assembly that can reduce the weld line of the plastic-coated body, enhance the structural strength of the plastic-coated body, reduce the occurrence of cracking, and improve the structural stability of the rotor assembly.

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

[0005] According to the rotor assembly of the first embodiment of the present invention, the rotor assembly includes an inner iron core; an outer iron core arranged along the outer periphery of the inner iron core, the outer iron core being provided with at least one first through hole arranged along the axial direction of the rotor assembly, at least one end of the outer iron core along the axial direction protruding from the end of the inner iron core along the axial direction; a plurality of magnetic tiles mounted on the outer peripheral wall of the outer iron core and arranged at intervals along the circumference of the outer iron core; a plastic package wrapped around the inner iron core, the outer iron core and the plurality of magnetic tiles, the plastic package including a first wall body and a second wall body located at the same end. body and a third wall body, the first wall body covers the end surface of the outer iron core and is provided with a second through hole, the inner circumferential wall of the second through hole is arranged along the outer circumference of the first through hole, the second wall body covers the end surface of the inner iron core, the third wall body covers the inner circumferential wall of the structure of the outer iron core protruding from the inner iron core and connects the first wall body and the second wall body respectively, and at least one groove is provided at the connection between the first wall body and the third wall body, and the groove is located on the side of the first through hole close to the inner iron core along the radial direction of the rotor assembly.

[0006] According to the rotor assembly of the embodiment of the first aspect of the present invention, there are at least the following beneficial effects: by wrapping the inner iron core, the outer iron core and the multiple magnetic tiles with a plastic body, the inner iron core, the outer iron core and the multiple magnetic tiles are constrained to each other and form a whole, wherein, by providing a second through hole with an inner peripheral wall arranged along the outer periphery of the first through hole in the first wall of the plastic body, and providing at least one groove located on the side of the first through hole close to the inner iron core along the radial direction of the rotor assembly at the connection between the first wall and the third wall, that is, the groove is also located on the side of the second through hole close to the inner iron core along the radial direction of the rotor assembly, thereby eliminating the weld line at the position of the groove, thereby reducing the number of weld lines of the plastic body, effectively coping with the impact of stress, reducing the occurrence of cracking, achieving enhanced structural strength of the plastic body, and improving the structural stability of the rotor assembly.

[0007] According to some embodiments of the present invention, two ends of the groove respectively pass through the inner peripheral wall of the second through hole and the wall surface of the third wall body close to the inner iron core.

[0008] According to some embodiments of the present invention, the groove includes a bottom wall perpendicular to the axial direction, and the bottom wall is flush with the end face of the outer iron core or located between the plane where the end face of the outer iron core is located and the plane where the end face of the inner iron core is located.

[0009] According to some embodiments of the present invention, the plastic-encapsulated body further includes at least one first connecting rib, which is connected between the second wall body and the third wall body and is located on one side of the second through hole along the radial direction.

[0010] According to some embodiments of the present invention, one end of the first connecting rib facing away from the second wall extends to the end surface of the first wall, and the overmolded body is provided with the groove located on at least one side of each first connecting rib along the circumferential direction.

[0011] According to some embodiments of the present invention, along the circumferential direction, the groove extends from the first connecting rib to both sides of the first connecting rib, and the end of the first connecting rib away from the second wall body extends to the bottom wall of the groove, and the bottom wall is perpendicular to the axial direction.

[0012] According to some embodiments of the present invention, the plastic-encapsulated body further includes at least one second connecting rib, which is connected between the second wall body and the third wall body and is located on one side of the first connecting rib along the circumferential direction.

[0013] According to some embodiments of the present invention, the diameter of the maximum circumscribed circle of the groove at two opposite ends along the circumferential direction is less than or equal to the diameter of the maximum circumscribed circle of the second through hole at two opposite ends along the circumferential direction.

[0014] According to some embodiments of the present invention, the plastic body also includes a fourth wall and a plurality of protrusions, the fourth wall is located at the same end as the first wall and covers the end face of the magnetic tile, the fourth wall is provided with a plurality of third through holes, and the plurality of third through holes correspondingly expose partial end faces of the plurality of magnetic tiles, and the plurality of protrusions protrude from the end face of the fourth wall and are respectively arranged around the periphery of the plurality of third through holes.

[0015] According to some embodiments of the present invention, the protrusion is annular, and on a projection plane perpendicular to the axial direction, the projection of the inner circumferential wall of the protrusion coincides with the projection of the inner circumferential wall of the third through hole.

[0016] The motor according to the second embodiment of the present invention includes the rotor assembly according to the first embodiment of the present invention.

[0017] According to the embodiment of the second aspect of the present invention, the motor has at least the following beneficial effects: since the motor adopts the above-mentioned rotor assembly, the inner iron core, the outer iron core and the multiple magnetic tiles are wrapped by the plastic body, so that the inner iron core, the outer iron core and the multiple magnetic tiles are constrained to each other and form a whole, wherein, a second through hole with an inner peripheral wall arranged along the outer periphery of the first through hole is provided in the first wall of the plastic body, and at least one groove is provided at the connection between the first wall and the third wall, which is located on the side of the first through hole close to the inner iron core along the radial direction of the rotor assembly, that is, the groove is also located on the side of the second through hole close to the inner iron core along the radial direction of the rotor assembly, thereby removing the weld line at the position of the groove, thereby reducing the number of weld lines of the plastic body, effectively coping with the impact of stress, reducing the occurrence of cracking, and enhancing the structural strength of the plastic body and improving the structural stability of the rotor assembly.

[0018] A household appliance according to an embodiment of the third aspect of the present invention includes the motor according to the embodiment of the second aspect of the present invention.

[0019] According to the household appliance of the embodiment of the third aspect of the present invention, there are at least the following beneficial effects: since the household appliance adopts the above-mentioned motor, the inner iron core, the outer iron core and the multiple magnetic tiles are wrapped by the plastic body, so that the inner iron core, the outer iron core and the multiple magnetic tiles are constrained to each other and form a whole, wherein, a second through hole is arranged along the outer periphery of the first through hole on the inner peripheral wall of the first wall of the plastic body, and at least one groove is provided at the connection between the first wall and the third wall, which is located on the side of the first through hole close to the inner iron core along the radial direction of the rotor assembly, that is, the groove is also located on the side of the second through hole close to the inner iron core along the radial direction of the rotor assembly, thereby removing the weld line at the position of the groove, thereby reducing the number of weld lines of the plastic body, effectively coping with the impact of stress, reducing the occurrence of cracking, and enhancing the structural strength of the plastic body and improving the structural stability of the rotor assembly.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a schematic structural diagram of a rotor assembly in one embodiment of the present invention;

[0023] Figure 2 This is an axial schematic diagram of the rotor assembly in the embodiment of the present invention after removing the plastic covering;

[0024] Figure 3 yes Figure 1 Schematic diagram of the structure of the encapsulated body shown;

[0025] Figure 4 This is a schematic structural diagram of a rotor assembly in another embodiment of the present invention;

[0026] Figure 5 yes Figure 4 Schematic diagram of the structure of the encapsulated body shown;

[0027] Figure 6 It is a structural schematic diagram of a rotor assembly in another embodiment of the present invention.

[0028] Reference numerals:

[0029] Inner iron core 100; shaft hole 110;

[0030] Outer core 200; first through hole 210; concave portion 220; convex portion 230;

[0031] Magnetic tile 300;

[0032] The plastic package 400 , the first wall 410 , the second through hole 411 , the second wall 420 , the fourth through hole 421 , the third wall 430 , the fourth wall 440 , the protrusion 441 , the third through hole 442 , the groove 450 , the bottom wall 451 , the first connecting rib 460 , and the second connecting rib 470 . DETAILED DESCRIPTION

[0033] The following describes embodiments of the present invention in detail. 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0034] In the description of the present invention, 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 the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0035] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0036] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0037] Reference Figures 1 to 6 As shown, the first embodiment of the present invention provides a rotor assembly for use in a motor of a household appliance, wherein the household appliance may include but is not limited to a refrigerator, an air conditioner, a water dispenser, and a washing machine. The rotor assembly of the motor will be described in detail below.

[0038] Reference Figure 2 As shown, it can be understood that the rotor assembly provided by the present invention is a surface-mounted rotor structure. Specifically, the rotor assembly includes an inner iron core 100, an outer iron core 200, a plurality of magnetic tiles 300 and a plastic package 400.

[0039] Generally speaking, the inner core 100 and the outer core 200 are respectively composed of a plurality of punching sheets stacked along the axial direction of the rotor assembly. The axial direction of the rotor assembly is defined as the direction of the rotation axis of the rotor assembly, the circumferential direction of the rotor assembly is defined as the direction around the rotation axis, and the radial direction of the rotor assembly is defined as the direction perpendicular to the rotation axis and pointing from the outer peripheral wall of the rotor assembly to the rotation axis and its opposite direction. The axial direction of the inner core 100 and the axial direction of the outer core 200 are the axial direction of the rotor assembly, the circumferential direction of the inner core 100 and the circumferential direction of the outer core 200 are the circumferential direction of the rotor assembly, and the radial direction of the inner core 100 and the radial direction of the outer core 200 are the radial direction of the rotor assembly. In addition, along the radial direction, the side close to the rotation axis is defined as the inner side, and the side away from the rotation axis is defined as the outer side.

[0040] Reference Figure 2As shown, it can be understood that the inner core 100 and the outer core 200 are annular, wherein the outer contour of the cross section (perpendicular to the axial direction) of the inner core 100 is generally rectangular. An axial hole 110 is provided at the radially intermediate position of the inner core 100. The axial hole 110 extends axially through both end surfaces of the inner core 100, with the end surfaces being perpendicular to the axial direction of the inner core 100. The axial hole 110 is used to mount the rotating shaft of the rotor assembly. It is easy to understand that the centerline of the axial hole 110 coincides with the rotation axis of the rotor assembly.

[0041] Reference Figure 2 As shown, it can be understood that the outer contour of the cross section of the outer core 200 is generally circular, and the inner circumferential wall of the outer core 200 is provided with a plurality of recesses 220 and a plurality of protrusions 230, which are alternately arranged along the circumference of the outer core 200. The outer core 200 is arranged along the outer circumference of the inner core 100 and surrounds the inner core 100. The inner circumferential wall of the outer core 200 and the outer circumferential wall of the inner core 100 are spaced apart in the radial direction of the rotor assembly, that is, there is a gap between the inner circumferential wall of the outer core 200 and the outer circumferential wall of the inner core 100.

[0042] Along the axial direction of the rotor assembly, the outer core 200 is taller than the inner core 100, and the inner core 100 is positioned between the axial ends of the outer core 200. Therefore, the axial ends of the outer core 200 protrude beyond the axial ends of the inner core 100. This reduces the material usage of the inner core 100, thereby lowering costs, while still ensuring the structural strength of the rotor assembly.

[0043] Of course, one axial end of the outer core 200 may be flush with one axial end of the inner core 100 , and the other axial end of the outer core 200 may protrude from the other axial end of the inner core 100 .

[0044] Reference Figure 2 As shown, it is understood that multiple magnetic tiles 300 are respectively mounted on the outer peripheral wall of the outer core 200 and are arranged at equal intervals along the circumference of the outer core 200. The cross-sectional outer contour of the magnetic tiles 300 is generally arc-shaped, and the surface of the magnetic tiles 300 facing the wall of the inner core 100 is affixed to the outer peripheral wall of the outer core 200. The magnetic tiles 300 can be bonded to the outer peripheral wall of the outer core 200 using glue to achieve preliminary fixation and positioning. Alternatively, if the magnetic tiles 300 and the outer core 200 are not bonded, the magnetic tiles 300 can be positioned on the outer peripheral wall of the outer core 200 using a mold.

[0045] Reference Figure 1As shown, it can be understood that the overmolded body 400 is made of engineering plastics through an injection molding process. Specifically, the inner core 100, the outer core 200 and the multiple magnetic tiles 300 are positioned through the mold so that the relative positions of the inner core 100, the outer core 200 and the multiple magnetic tiles 300 remain unchanged, and the molten engineering plastic is injected into the mold. The engineering plastic fills the space between the outer core 200 and the inner core 100, and the engineering plastic is molded on the two end faces of the outer core 200, the two end faces of the inner core 100, the two end faces of the magnetic tiles 300, the partial wall surface of the magnetic tiles 300 facing away from the inner core 100, and the inner circumferential wall of the partial structure of the outer core 200 protruding axially from the inner core 100. After the engineering plastic is cooled, a plastic body 400 is formed that wraps around the inner core 100, the outer core 200 and the multiple magnetic tiles 300. The plastic body 400 can make the inner core 100, the outer core 200 and the multiple magnetic tiles 300 relatively fixed and form a whole, which is beneficial to improving the structural stability of the rotor assembly. The end surface is a wall surface corresponding to one end of the main body along the axial direction of the rotor assembly. Generally speaking, the end surface is perpendicular to the axial direction of the rotor assembly.

[0046] It is understood that, because the outer cross-section of the inner core 100 is generally rectangular, after the overmolded body 400 fills the space between the inner core 100 and the outer core 200, a circumferential constraint can be formed between the overmolded body 400 and the inner core 100. Similarly, because the inner circumferential wall of the outer core 200 is provided with a plurality of recesses 220 and a plurality of protrusions 230 arranged alternately along the axial direction, after the overmolded body 400 fills the space between the inner core 100 and the outer core 200, the portion of the overmolded body 400 located in the recesses 220 and the protrusions 230 of the outer core 200 form a circumferential constraint between the rotor assembly, thereby constraining the overmolded body 400 and the outer core 200. Therefore, the inner core 100, the outer core 200, and the overmolded body 400 form a circumferential constraint and relative fixation between the rotor assembly, which helps to ensure the structural strength and stability of the rotor assembly.

[0047] Reference Figure 1 As shown, it can be understood that the overmolding body 400 is overmolded onto both end surfaces of the outer core 200, both end surfaces of the inner core 100, both end surfaces of the magnetic tile 300, and the inner circumferential wall of the portion of the outer core 200 that protrudes axially from the inner core 100. The following describes in detail the structure of one end of the rotor assembly where the axial end of the outer core 200 protrudes from the axial end of the inner core 100. For embodiments where both ends of the outer core 200 protrude axially from both ends of the inner core 100, the description is for either end of the rotor assembly. For the overmolding body 400, the detailed structure of one end of the rotor assembly is described in detail, and the specific structure of the other end can refer to the specific structure of the aforementioned one end.

[0048] Reference Figure 1 and Figure 3 As shown, it can be understood that the overmolded body 400 includes a first wall 410, a second wall 420, and a third wall 430. The first wall 410, the second wall 420, and the third wall 430 are located at the same end of the overmolded body 400 along the axial direction of the rotor assembly. The first wall 410 is generally annular and covers and adheres to the end surface of the outer core 200. The second wall 420 is generally annular and covers and adheres to the end surface of the inner core 100. The third wall 430 extends along the axial direction of the rotor assembly and is arranged along the circumference of the rotor assembly. The third wall 430 covers and adheres to the inner circumferential wall of the portion of the outer core 200 that protrudes axially from the inner core 100. The third wall 430 is integrally connected to the first wall 410 and the second wall 420 at both ends of the axial direction of the rotor assembly.

[0049] It is understood that the specific structure of the other end of the overmolded body 400 along the axial direction of the rotor assembly can be referred to the above description and will not be repeated here. Therefore, a constraint is formed between the first wall 410 and the outer iron core 200 in the axial direction of the rotor assembly, and a constraint is formed between the second wall 420 and the inner iron core 100 in the axial direction of the rotor assembly. Moreover, because the third wall 430 is connected between the first wall 410 and the second wall 420, the outer iron core 200 and the inner iron core 100 can be constrained in the axial direction. In this way, the axial constraint formed between the overmolded body 400, the outer iron core 200 and the inner iron core 100 in the rotor assembly is conducive to ensuring the structural strength and stability of the rotor assembly.

[0050] Reference Figure 1 and Figure 3 As shown, it can be understood that, in order to facilitate positioning of the outer core 200 during the injection molding process, the outer core 200 is provided with at least one first through hole 210 arranged along the axial direction of the rotor assembly.

[0051] Specifically, the outer core 200 is provided with a plurality of first through holes 210, which correspond one-to-one to the protrusions 230, and each first through hole 210 is located on the radially outer side of the corresponding protrusion 230 along the rotor assembly. Therefore, the influence of the first through holes 210 on the structural strength of the outer core 200 can be reduced.

[0052] Before injection molding the overmolded body 400, the outer core 200 can be positioned by inserting a plurality of positioning rods and other positioning components corresponding to the plurality of first through holes 210 to ensure the accurate position of the outer core 200. To avoid the positioning components used to position the outer core 200, the overmolded body 400 is provided with a plurality of second through holes 411. The second through holes 411 correspond one-to-one with the first through holes 210, and the inner peripheral walls of the second through holes 411 are arranged along the outer periphery of the first through holes 210 so that the positioning components can be easily removed after the injection molding is completed. After the positioning components are removed, the first through holes 210 can be used as heat dissipation holes to accelerate the heat dissipation of the rotor assembly and ensure operational reliability.

[0053] In this embodiment, the outer core 200 has four protrusions 230 and four recesses 220, four first through holes 210, and correspondingly, four second through holes 411. Of course, the number of protrusions 230, recesses 220, first through holes 210, and second through holes 411 may also be five, six, or more.

[0054] Similarly, to facilitate installation of the rotating shaft, the overmolded body 400 is further provided with a fourth through-hole 421. The fourth through-hole 421 is disposed in the second wall 420, and the inner circumference of the fourth through-hole 421 surrounds the shaft hole 110. Therefore, when installing the rotating shaft, the rotating shaft is sequentially passed through the fourth through-hole 421 and the shaft hole 110. The rotating shaft and the inner circumference of the shaft hole 110 form an interference fit, thereby securing the rotating shaft to the inner core 100.

[0055] It is understandable that due to the complex structure of the overmolded body 400, during the injection molding process, multiple streams of engineering plastic fluid are typically injected into the mold. At the intersection of the two streams of engineering plastic, the two parts of engineering plastic do not completely fit together after cooling, resulting in a small gap, i.e., a weld line. As the engineering plastic cools and shrinks, under the action of shrinkage stress, the overmolded body 400 is prone to cracking at the weld line, and the cracks can further penetrate into the interior of the overmolded body 400, causing cracks in areas where no weld line exists, severely weakening the structural strength of the overmolded body 400 and affecting the structural stability of the rotor assembly. Generally speaking, since the first wall 410 is provided with a second through hole 411, the weld line primarily appears around the second through hole 411. Furthermore, the weld line primarily appears on the radially inner side of the rotor assembly at the second through hole 411 on the overmolded body 400. The weld line is generally arranged along the radial direction of the rotor assembly, and the shrinkage stress at this location is relatively large.

[0056] For this purpose, refer to Figure 1 and Figure 3As shown, it can be understood that at least one groove 450 is provided at the connection between the first wall body 410 and the third wall body 430, and the groove 450 is located on the side of the first through hole 210 close to the inner iron core 100 along the radial direction of the rotor assembly, that is, the groove 450 is located on the side of the first through hole 210 along the radial direction of the rotor assembly. It can also be understood that the groove 450 is located on the side of the second through hole 411 along the radial direction of the rotor assembly.

[0057] Specifically, the groove 450 is recessed along the axial direction of the rotor assembly. Both ends of the groove 450 along the radial direction of the rotor assembly may be closed, or at least one end may be open. For example, both ends of the groove 450 along the radial direction of the rotor assembly may be closed. Alternatively, the groove 450 may be open on the radially outer side of the rotor assembly, or on the radially inner side of the rotor assembly, or both ends of the groove 450 along the radial direction of the rotor assembly may be open.

[0058] It is easy to understand that by providing the groove 450 at the connection between the first wall 410 and the third wall 430, it can be understood that after the overmolded body 400 is formed, a portion of the structure at the connection between the first wall 410 and the third wall 430 is dug out or cut away to obtain the groove 450. At the same time, the groove 450 is located at the primary location of the weld line on the overmolded body 400. Therefore, the structure on the overmolded body 400 containing the weld line can be removed, that is, the weld line is partially removed, thereby preventing cracking under the action of shrinkage stress and further cracking of structures on the overmolded body 400 that do not have weld lines. This reduces the number of weld lines on the overmolded body 400, effectively copes with the impact of shrinkage stress, and thus enhances the structural strength of the overmolded body 400, especially the structural strength under temperature shock loads, thereby effectively improving the structural stability of the rotor assembly.

[0059] Reference Figure 1 and Figure 3 As shown, it can be understood that in this embodiment, the groove 450 is open at both ends along the radial direction of the rotor assembly. In other words, the groove 450 extends through the inner circumferential wall of the second through hole 411 and the wall surface of the third wall 430 near the inner core 100. This eliminates the entire weld line in the radial direction of the rotor assembly, minimizing the risk of cracking, effectively addressing the impact of shrinkage stress, and enhancing the structural strength of the overmolded body 400 and the structural stability of the rotor assembly.

[0060] Reference Figure 1 and Figure 3As shown, it can be understood that the groove 450 has a bottom wall 451, which is the wall surface of the groove 450 perpendicular to the axial direction of the rotor assembly. The bottom wall 451 of the groove 450 is flush with the end surface of the outer iron core 200, or the bottom wall 451 of the groove 450 is located between the plane where the end surface of the outer iron core 200 is located and the plane where the end surface of the inner iron core 100 is located. In other words, the depth of the groove 450 is greater than the thickness of the first wall 410 along the axial direction of the rotor assembly. Therefore, the depth of the groove 450 can be increased, and the entire weld line in the axial direction of the rotor assembly can be removed as much as possible, thereby minimizing the risk of cracking, effectively responding to the impact of shrinkage stress, and enhancing the structural strength of the overmolded body 400 and improving the structural stability of the rotor assembly.

[0061] Reference Figure 1 and Figure 3 As shown, it is understandable that because the groove 450 is located radially inward of the second through-hole 411 in the rotor assembly, the groove 450 somewhat affects the connection strength of the third wall 430, and thus the overall structural strength of the overmolded body 400. To further enhance the structural strength of the overmolded body 400, the overmolded body 400 also includes first connecting ribs 460. The first connecting ribs 460 correspond one-to-one with the second through-holes 411. In other words, the number of first connecting ribs 460 is equal to the number of second through-holes 411, and there are four of each.

[0062] Specifically, the first connecting rib 460 is connected between the second wall 420 and the third wall 430, and the first connecting rib 460 is located on the radial side of the second through hole 411 of the rotor assembly. In other words, the first connecting rib 460 is located on the radially inner side of the second through hole 411 of the rotor assembly, and each first connecting rib 460 is located on the radially inner side of each second through hole 411 of the rotor assembly. It can also be understood that the first connecting rib 460 corresponds to the protrusion 230. Generally speaking, in the circumferential direction of the rotor assembly, the position of the first connecting rib 460 corresponds to the middle position of the second through hole 411. Therefore, the first connecting rib 460 can enhance the connection strength between the third wall 430 and the second wall 420, thereby further enhancing the structural strength of the overmolded body 400.

[0063] Reference Figure 1 and Figure 3As shown, it can be understood that to further enhance the structural strength of the overmolded body 400, the overmolded body 400 also includes second connecting ribs 470. Specifically, the number of second connecting ribs 470 is equal to the number of first connecting ribs 460, and there are also four second connecting ribs 470. Similarly, the second connecting rib 470 is connected between the second wall 420 and the third wall 430, and the end of the second connecting rib 470 facing away from the third wall 430 extends to the end surface of the first wall 410. The four second connecting ribs 470 and the four first connecting ribs 460 are arranged alternately along the circumference of the rotor assembly, that is, the second connecting ribs 470 are arranged corresponding to the recesses 220. Therefore, the second connecting ribs 470 can further enhance the connection strength between the third wall 430 and the second wall 420, thereby further enhancing the structural strength of the overmolded body 400.

[0064] Reference Figure 1 and Figure 3 As shown, it can be understood that the end of the first connecting rib 460 facing away from the second wall 420 extends to the end surface of the first wall 410. In other words, the end surface of the first connecting rib 460 facing away from the second wall 420 is flush with the end surface of the first wall 410. The overmolded body 400 is provided with a groove 450 located on at least one side of each first connecting rib 460 along the circumference of the rotor assembly. For example, each first connecting rib 460 corresponds to one groove 450, and the groove 450 is located on one side of the corresponding first connecting rib 460 along the circumference of the rotor assembly; alternatively, each first connecting rib 460 corresponds to two grooves 450, and the two grooves 450 are respectively located on both sides of the corresponding second connecting rib 470 along the circumference of the rotor assembly.

[0065] Generally speaking, due to the presence of the first connecting ribs 460, weld lines primarily exist on both sides of the first connecting ribs 460 along the circumference of the rotor assembly. Therefore, in this embodiment, each first connecting rib 460 corresponds to two grooves 450. This minimizes the number of weld lines, reduces the risk of cracking, effectively addresses the impact of shrinkage stress, enhances the structural strength of the overmolded body 400, and improves the structural stability of the rotor assembly.

[0066] Of course, in the solution where each first connecting rib 460 corresponds to one groove 450 , the number of weld lines can also be reduced.

[0067] Reference Figure 4 and Figure 5As shown, it will be appreciated that in other embodiments, the groove 450 extends from the middle of the first connecting rib 460 along the circumference of the rotor assembly to both sides of the first connecting rib 460 along the circumference of the rotor assembly, and further extends from the end of the first connecting rib 460 facing away from the second wall 420 to the bottom wall 451 of the groove 450. Along the circumference of the rotor assembly, the groove 450 covers the location of the first connecting rib 460. As will be readily appreciated, the width of the groove 450 is greater than the thickness of the first connecting rib 460. In other words, in addition to the removal or excision of the junction between the first wall 410 and the third wall 430, a portion of the structure at the end of the first connecting rib 460 facing away from the second wall 420 is also removed or excised to form the groove 450. Therefore, the groove 450 covers a wide area along the circumference of the rotor assembly, facilitating the maximum removal of weld lines on both sides of the first connecting rib 460, minimizing the risk of cracking, effectively addressing the impact of shrinkage stress, and thereby enhancing the structural strength of the overmolded body 400 and improving the structural stability of the rotor assembly.

[0068] Reference Figure 3 and Figure 5 As shown, it will be understood that in any of the above embodiments, along the circumference of the rotor assembly, the diameter of the largest circumscribed circle at opposite ends of the groove 450 is less than or equal to the diameter of the largest circumscribed circle at opposite ends of the second through-hole 411. In other words, along the circumference of the rotor assembly, the range of the second through-hole 411 is greater than or equal to the range of the groove 450. Because the groove 450 is connected to the second through-hole 411, while providing the groove 450 can reduce the weld line, the disadvantage of the groove 450 being too large along the circumference of the rotor assembly, which would lead to a decrease in the connection strength between the first wall 410 and the third wall 430, is avoided, thereby effectively ensuring the structural strength of the overmolded body 400.

[0069] Reference Figure 6 As shown, it is understood that the overmolded body 400 further includes a fourth wall 440 and a plurality of protrusions 441. The fourth wall 440 and the plurality of protrusions 441 are described in detail below using one end of the rotor assembly along the axial direction as an example, and the structure of the other end can refer to the structure of the one end described above.

[0070] Specifically, the fourth wall 440, along with the first wall 410, the second wall 420, and the third wall 430, are located at the same end of the overmolded body 400 along the axial direction of the rotor assembly. The fourth wall 440 has a generally annular cross-section, and the inner periphery of the fourth wall 440 transitions to the outer periphery of the first wall 410. Furthermore, the fourth wall 440 covers and adheres to the end faces of the plurality of magnetic tiles 300. Therefore, the fourth wall 440 and the plurality of magnetic tiles 300 form a constraint in the axial direction of the rotor assembly, thereby securing the magnetic tiles 300 and ensuring the structural stability of the rotor assembly.

[0071] During the injection molding process, in order to facilitate the positioning of the magnetic tiles 300, a plurality of positioning structures such as ejectors are generally used to respectively contact the two ends of the plurality of magnetic tiles 300 along the axial direction of the rotor assembly. For this purpose, after the injection molding is completed and the engineering plastic is cooled, the overmolded body 400 is formed with a plurality of third through holes 442 for the plurality of positioning structures such as ejectors to pass through.

[0072] Reference Figure 6 As shown, specifically, third through holes 442 are provided in the fourth wall 440, and the positions of the plurality of third through holes 442 correspond to the positions of the plurality of magnetic tiles 300. If each magnetic tile 300 is positioned at one end by only one positioning structure, such as a pin, then the third through holes 442 at one axial end of the overmolded body 400 along the rotor assembly correspond one-to-one with each magnetic tile 300. If each magnetic tile 300 is positioned at one end by two positioning structures, such as pins, then one end of the magnetic tile 300 corresponds to two third through holes 442, and so on. It is easy to understand that after removing the positioning structure, such as the pin, the third through holes 442 can expose a portion of the end surface of the magnetic tile 300.

[0073] It is understandable that since the fourth wall 440 is provided with a third through hole 442, a weld line will be formed on the outer periphery of the third through hole 442, and the shrinkage stress at this position is large, which is prone to cracking, seriously weakening the structural strength of the plastic body 400 and affecting the structural stability of the rotor assembly.

[0074] For this purpose, refer to Figure 6 As shown, it can be understood that the protrusion 441 is provided protrudingly on the end surface of the fourth wall 440. The protrusion 441 is annular and arranged around the outer periphery of the third through hole 442. The outer contour of the protrusion 441 can be circular, rectangular, or other polygonal, and multiple protrusions 441 are arranged in a one-to-one correspondence with multiple third through holes 442. Therefore, by providing the protrusion 441, the thickness of the peripheral structure of the third through hole 442 in the axial direction of the rotor assembly can be significantly increased, thereby significantly reducing the shrinkage stress of the peripheral structure of the third through hole 442, reducing the risk of cracking, and improving the structural strength of the plastic body 400, especially the structural strength when coping with temperature shock loads, thereby improving the structural stability of the rotor assembly.

[0075] Reference Figure 6 As shown, it can be understood that, on a projection plane perpendicular to the axial direction of the rotor assembly, the projection of the inner circumferential wall of protrusion 441 coincides with the projection of the inner circumferential wall of third through hole 442. In other words, there is no step structure between the inner circumferential wall of protrusion 441 and the inner circumferential wall of third through hole 442, which helps simplify the mold structure and reduce production costs. In addition, the thickness of the periphery of third through hole 442 in the axial direction of the rotor assembly is ensured to be relatively large, significantly reducing the shrinkage stress of the peripheral structure of third through hole 442, reducing the risk of cracking, and thus improving the structural strength of overmolded body 400.

[0076] The motor according to the second embodiment of the present invention includes the rotor assembly according to the first embodiment of the present invention.

[0077] Since the motor adopts all the technical solutions of the rotor assembly of the above embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above embodiment.

[0078] The household appliance of the third embodiment of the present invention includes the motor of the second embodiment of the present invention. The household appliance may include but is not limited to a refrigerator, an air conditioner, a water dispenser, and a washing machine, which will not be described in detail here.

[0079] Since the household appliance adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above embodiment.

[0080] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention 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 invention.

Claims

1. A rotor assembly, characterized in that: include: inner iron core; an outer iron core arranged along the outer circumference of the inner iron core, the outer iron core being provided with at least one first through hole arranged along the axial direction of the rotor assembly, and at least one end of the outer iron core along the axial direction protruding from an end of the inner iron core along the axial direction; A plurality of magnetic tiles are mounted on the outer peripheral wall of the outer iron core and are spaced apart along the circumference of the outer iron core; A plastic-encapsulated body wrapped around the inner iron core, the outer iron core and the plurality of magnetic tiles, the plastic-encapsulated body comprising a first wall, a second wall and a third wall located at the same end, the first wall covering the end surface of the outer iron core and provided with a second through hole, the inner circumferential wall of the second through hole being arranged along the outer circumference of the first through hole, the second wall covering the end surface of the inner iron core, the third wall covering the inner circumferential wall of the structure of the outer iron core protruding from the inner iron core and respectively connecting the first wall and the second wall, at least one groove being provided at the connection between the first wall and the third wall, and the groove being located on the side of the first through hole close to the inner iron core along the radial direction of the rotor assembly.

2. The rotor assembly according to claim 1, wherein: Two ends of the groove respectively pass through the inner peripheral wall of the second through hole and the wall surface of the third wall body close to the inner iron core.

3. The rotor assembly according to claim 1, wherein: The groove includes a bottom wall perpendicular to the axial direction, and the bottom wall is flush with the end surface of the outer iron core or located between the plane where the end surface of the outer iron core is located and the plane where the end surface of the inner iron core is located.

4. The rotor assembly according to any one of claims 1 to 3, characterized in that: The plastic-encapsulated body further includes at least one first connecting rib, which is connected between the second wall body and the third wall body and is located on one side of the second through hole along the radial direction.

5. The rotor assembly according to claim 4, characterized in that: One end of the first connecting rib facing away from the second wall extends to the end surface of the first wall, and the overmolded body is provided with the groove located on at least one side of each first connecting rib along the circumferential direction.

6. The rotor assembly according to claim 4, wherein: Along the circumferential direction, the groove extends from the first connecting rib to both sides of the first connecting rib, and one end of the first connecting rib away from the second wall body extends to the bottom wall of the groove, and the bottom wall is perpendicular to the axial direction.

7. The rotor assembly according to claim 4, wherein: The plastic-encapsulated body further includes at least one second connecting rib, which is connected between the second wall body and the third wall body and is located on one side of the first connecting rib along the circumferential direction.

8. The rotor assembly according to claim 1, wherein: The diameter of the maximum circumscribed circle at two opposite ends of the groove along the circumferential direction is smaller than or equal to the diameter of the maximum circumscribed circle at two opposite ends of the second through hole along the circumferential direction.

9. The rotor assembly according to claim 1, wherein: The plastic-encapsulating body also includes a fourth wall and a plurality of protrusions. The fourth wall is located at the same end as the first wall and covers the end surface of the magnetic tile. The fourth wall is provided with a plurality of third through holes. The plurality of third through holes correspondingly expose part of the end surfaces of the plurality of magnetic tiles. The plurality of protrusions protrude from the end surface of the fourth wall and are respectively arranged around the periphery of the plurality of third through holes.

10. The rotor assembly according to claim 9, wherein: The protrusion is annular, and on a projection plane perpendicular to the axial direction, a projection of an inner circumferential wall of the protrusion coincides with a projection of an inner circumferential wall of the third through hole.

11. The motor is characterized in that A rotor assembly comprising any one of claims 1 to 10.

12. A household appliance, characterized in that Including the motor according to claim 11.

Images