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 a rotor core and a plurality of permanent magnets, the rotor core comprises a plurality of iron core units arranged at intervals along the circumferential direction of the rotor core, and each iron core unit is composed of a plurality of punching sheet monomers stacked along the direction of a rotation axis. An installation groove is defined between every two adjacent iron core units, a groove is formed in the side, away from the rotating axis, of each iron core unit, and the multiple permanent magnets are correspondingly installed in the multiple installation grooves. According to the utility model, the grooves are arranged, the material consumption of the rotor iron core can be reduced, the material cost is saved, and the magnetic field of one side, deviating from the rotating axis, in the iron core unit without the grooves is weaker, so that the material is reduced and the motor performance can be maintained at the same time; when the punching sheet single bodies are subjected to stock layout, the positions of the parts, corresponding to the grooves, on the punching sheet single bodies can be fully utilized, so that the stock layout is tighter, waste materials are reduced, the utilization rate of silicon steel plates is improved, and the production cost of the rotor assembly is reduced.

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] Brushless DC motors are widely used in various household appliances due to their simple structure and reliable operation. At present, the market competition for household appliances is fierce, and the pursuit of low cost has become particularly important. As one of the core components of household appliances, the production cost of household appliances is closely related to the production cost of motors. In the relevant technology, the overall production cost of the current external rotor motor is relatively high, especially the material cost, and the utilization rate of silicon steel plates in the production process is low. Under the premise of not affecting the performance of the motor, the production cost of the motor is still high. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a rotor assembly with low production cost, high silicon steel plate utilization rate, and can ensure the performance of the motor.

[0004] The utility model also provides a motor with the rotor assembly.

[0005] The utility model also provides a household appliance with the motor.

[0006] According to the rotor assembly of the first aspect of the utility model, it rotates around the rotation axis and includes: a rotor core, including a plurality of core units arranged at intervals along the circumference of the rotor core, the core unit is composed of a plurality of punching sheet monomers stacked along the direction of the rotation axis, an installation groove is defined between two adjacent core units, and a groove is provided on the side of the core unit away from the rotation axis; a plurality of permanent magnets are correspondingly installed in the plurality of installation grooves.

[0007] According to the rotor assembly of the embodiment of the first aspect of the utility model, there are at least the following beneficial effects: by setting a groove on the side of the core unit away from the rotation axis, the material consumption of the silicon steel plate can be reduced, which is beneficial to reducing the material cost; because the magnetic field on the side of the core unit away from the rotation axis is weaker when the groove is not set, the setting of the groove has less impact on the overall magnetic field strength of the core unit, thereby reducing the material while ensuring the performance of the motor; at the same time, after the groove is set, when arranging the punching sheet monomers, the position of the part corresponding to the groove on the punching sheet monomer can be fully utilized, making the arrangement more compact and reducing waste, which is beneficial to improving the utilization rate of the silicon steel plate and reducing the processing cost, thereby reducing the overall production cost of the rotor assembly.

[0008] According to an embodiment of the first aspect of the utility model, the groove passes through both ends of the rotor core along the direction of the rotation axis.

[0009] According to an embodiment of the first aspect of the utility model, the core unit has a center line arranged along the radial direction of the rotor core, and the side wall of the groove includes a first wall surface and a second wall surface arranged opposite to each other along the circumferential direction, and the first wall surface and the second wall surface are arranged symmetrically relative to the center line.

[0010] According to an embodiment of the first aspect of the utility model, both the first wall surface and the second wall surface extend to the center line, and an angle between the first wall surface and the second wall surface is not less than 90°.

[0011] According to an embodiment of the first aspect of the utility model, the angle between the first wall surface and the second wall surface is an acute angle, and an end of the first wall surface close to the rotation axis and an end of the second wall surface close to the rotation axis are connected by an arc surface transition.

[0012] According to an embodiment of the first aspect of the utility model, along the radial direction of the rotor core, the maximum depth of the groove is H, and the maximum width of the core unit is W, satisfying: 1 / 3≤H / W≤2 / 3.

[0013] According to an embodiment of the first aspect of the utility model, the core unit includes a first limiting portion and a second limiting portion located on the same side along the circumferential direction, the first limiting portion and the second limiting portion are both protruding toward the mounting groove, and the first limiting portion and the second limiting portion respectively abut against the two ends of the permanent magnet along the radial direction of the rotor core.

[0014] According to an embodiment of the first aspect of the utility model, two of the first limiting parts and two of the second limiting parts are provided, the two first limiting parts are respectively located on both sides of the core unit along the circumferential direction, and the two second limiting parts are respectively located on both sides of the core unit along the circumferential direction.

[0015] According to an embodiment of the first aspect of the utility model, the core unit is provided with a positioning hole, and the positioning hole passes through both ends of the core unit along the direction of the rotation axis.

[0016] According to an embodiment of the first aspect of the utility model, the core unit is provided with an injection hole, and the injection hole passes through both ends of the core unit along the direction of the rotation axis.

[0017] According to an embodiment of the first aspect of the utility model, the rotor assembly further includes a plastic overmolding body, and a portion of the plastic overmolding body fills the injection molding hole.

[0018] The motor according to the second embodiment of the present invention comprises the rotor assembly of the first embodiment of the present invention, and the motor further comprises a stator assembly, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

[0019] The motor according to the embodiment of the second aspect of the utility model has at least the following beneficial effects: compared with the prior art, the rotor assembly in the motor is provided with an iron core unit, and a groove is provided on the side of the iron core unit away from the rotation axis, which can reduce the material consumption of the silicon steel plate and is beneficial to reducing the material cost; since the magnetic field on the side of the iron core unit away from the rotation axis is weaker when the groove is not provided, the provision of the groove has less impact on the overall magnetic field strength of the iron core unit, thereby ensuring the performance of the motor while reducing the material; at the same time, after the groove is provided, when arranging the punching sheet monomers, the position of the part corresponding to the groove on the punching sheet monomer can be fully utilized, making the arrangement more compact, reducing waste, and being beneficial to improving the utilization rate of the silicon steel plate, thereby achieving the goal of reducing the manufacturing cost of the motor while maintaining the performance of the motor.

[0020] A household appliance according to an embodiment of the third aspect of the utility model includes the motor according to the embodiment of the second aspect of the utility model.

[0021] The household appliance according to the embodiment of the third aspect of the utility model has at least the following beneficial effects: compared with the prior art, the household appliance is provided with a motor, the rotor assembly in the motor is provided with an iron core unit, and a groove is provided on the side of the iron core unit away from the rotation axis, which can reduce the amount of silicon steel sheets used and thus save material costs; at the same time, when the groove is not provided, the magnetic field on the side of the iron core unit away from the rotation axis is weaker, while after the groove is provided, the influence on the overall magnetic field strength of the iron core unit is smaller, thereby ensuring the performance of the motor while reducing materials; at the same time, after the groove is provided, when the punching sheet monomers are arranged, the position of the part corresponding to the groove on the punching sheet monomer can be fully utilized, making the arrangement more compact and reducing waste, which is beneficial to improving the utilization rate of the silicon steel sheet, thereby achieving the goal of reducing the manufacturing cost of the household appliance while maintaining performance.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 is an axial schematic diagram of a rotor assembly in an embodiment of the first aspect of the utility model with one of the permanent magnets removed;

[0025] Figure 2 yes Figure 1A in the enlarged view;

[0026] Figure 3 is an axial schematic diagram of a motor in an embodiment of the second aspect of the utility model;

[0027] Figure 4 is an axial schematic diagram of a core unit in some embodiments of the first aspect of the utility model;

[0028] Figure 5 is an axial schematic diagram of an iron core unit in some other embodiments of the first aspect of the utility model;

[0029] Figure 6 It is a schematic diagram of the arrangement of punching sheet units in a material plate in some embodiments of the first aspect of the utility model;

[0030] Figure 7 It is a partial view of the arrangement of punching sheet units in a material plate in other embodiments of the first aspect of the utility model.

[0031] Reference numerals:

[0032] Rotor core 100; Permanent magnet 101;

[0033] Material plate 110; punching sheet unit 111; recess 112; branch portion 113;

[0034] Core unit 120; mounting slot 121; groove 122; center line 123; first wall 124; second wall 125; positioning hole 126; injection hole 127; first limiting portion 128; second limiting portion 129; third wall 130; fourth wall 131;

[0035] Stator assembly 140 ; ​​stator teeth 141 ; winding 142 ; winding slots 143 . DETAILED DESCRIPTION

[0036] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0038] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model based on the specific content of the technical solution.

[0040] Brushless DC motors are widely used in fans, pumps, robots, drones, electric vehicles, precision instruments, household appliances and other fields due to their advantages such as high efficiency, long life, low noise and high-precision control. At present, the market competition for household appliances is fierce, and the pursuit of low cost has become particularly important. As one of the core components of household appliances, the production cost of household appliances is closely related to the production cost of motors. In the related art, the overall production cost of the current outer rotor motor is relatively high, especially the material cost, and the utilization rate of materials in the production process is low. Under the premise of not affecting the performance of the motor, the production cost of the motor is still high, that is, it is still difficult to reduce the cost of the motor without compressing the rotor size. At present, the rotor core in the outer rotor motor is stacked by multiple punching sheets, and the punching sheets are obtained by punching and processing of silicon steel sheets. It is understandable that multiple punching sheets are arranged on the sheet, but the current arrangement of the punching sheets is not ideal, and the utilization rate of the sheet is not high enough, resulting in more material waste in the production process and difficulty in reducing production costs.

[0041] To solve the above technical problems, refer to Figure 1 As shown, the embodiment of the first aspect of the utility model provides a rotor assembly for use in a motor of a household appliance, the household appliance including a refrigerator, an air conditioner, a washing machine, etc. It can be understood that, with reference to Figure 3 The motor includes a rotor assembly and a stator assembly 140 . The stator assembly 140 includes a plurality of stator teeth 141 . A winding slot 143 is provided between two adjacent stator teeth 141 . A winding 142 is provided at the winding slot 143 .

[0042] It can be understood that the rotor core 100 has a central axis, and the central axis of the rotor core 100 is the rotation axis of the rotor assembly, and the rotor assembly surrounds the outer circumference of the stator assembly 140 and rotates around the rotation axis. It should be noted that for ease of description and understanding, the direction surrounding the rotation axis of the rotor assembly is referred to as the circumferential direction C in this application.

[0043] Reference Figure 1 and Figure 3 The rotor assembly includes a rotor core 100 and a plurality of permanent magnets 101. The rotor core 100 includes a plurality of core units 120 arranged at equal intervals along the circumferential direction C. An installation slot 121 is defined between two adjacent core units 120. The plurality of permanent magnets 101 are correspondingly installed in the plurality of installation slots 121. It can be understood that, along the circumferential direction C, the plurality of permanent magnets 101 and the plurality of core units 120 are arranged alternately, that is, one permanent magnet 101 is provided between two adjacent core units 120.

[0044] Reference Figure 2 The core unit 120 has a center line 123 arranged along the radial direction of the rotor core 100. The core unit 120 includes a first limiting portion 128 and a second limiting portion 129 located on the same side along the circumferential direction C. The first limiting portion 128 and the second limiting portion 129 are both protruded toward the mounting groove 121. Specifically, the first limiting portion 128 is located on the side of the core unit 120 away from the rotation axis, and the second limiting portion 129 is located on the side of the core unit 120 close to the rotation axis. Along the radial direction of the rotor core 100, the first limiting portion 128 abuts against the end of the permanent magnet 101 away from the rotation axis, and the second limiting portion 129 abuts against the end of the permanent magnet 101 close to the rotation axis, so as to limit the permanent magnet 101, so that the permanent magnet 101 is firmly installed in the rotor core 100, and the permanent magnet 101 is prevented from being separated from the rotor core 100 when the rotor assembly rotates.

[0045] Reference Figure 2 It can be understood that there are two first limiting portions 128 and two second limiting portions 129 on the core unit 120, and the two first limiting portions 128 are respectively located on both sides of the core unit 120 along the circumferential direction C, and the two second limiting portions 129 are respectively located on both sides of the core unit 120 along the circumferential direction C, so that the contact between the core unit 120 and the permanent magnet 101 is increased along the radial direction of the rotor core 100, thereby making the connection more secure, which is beneficial to improving the structural stability of the rotor core 100, avoiding vibration during the operation of the motor, and ensuring the performance of the motor.

[0046] Reference Figure 1 A groove 122 is provided on the side of the core unit 120 away from the rotation axis, which can reduce the material usage of the core unit 120, thereby saving material costs.

[0047] It can be understood that during the operation of the outer rotor motor, the magnetic field direction starts from the permanent magnet 101 (refer to Figure 3The magnetic flux lines N) in the core unit 120 on one side of the permanent magnet 101, the air gap between the stator assembly 140 and the rotor assembly, the stator teeth 141 and the winding 142 in sequence. The magnetic field passes through the winding 142 and then passes through the stator teeth 141 on the other side of the winding 142, and passes through the air gap again, the core unit 120 on the other side of the permanent magnet 101, and then returns to the permanent magnet 101. It can be seen that the magnetic field is transmitted to the side of the rotor assembly close to the rotation axis, and the magnetic flux lines density on the side of the core unit 120 away from the rotation axis is lower and the magnetic field is weaker. After the groove 122 is set here, the overall magnetic field strength of the core unit 120 is less affected. Therefore, the material usage of the rotor core 100 can be saved while maintaining the motor performance, which is beneficial to reducing material costs.

[0048] It can be understood that the core unit 120 is composed of a plurality of punching sheet monomers 111 stacked and arranged along the direction of the rotation axis, and the punching sheet monomers 111 are formed by punching a silicon steel plate. Figure 6 The material plate 110 is a silicon steel plate, and the punching sheet units 111 are arranged on the material plate 110 .

[0049] Reference Figure 6 It can be understood that the punching sheet monomer 111 is provided with a recess 112, and a plurality of recesses 112 arranged along the rotation axis direction form a groove 122. It can be understood that the groove 122 runs through both ends of the rotor core 100 along the rotation axis direction, which can effectively reduce the material usage of the core unit 120 and significantly reduce the cost. In addition, each punching sheet monomer 111 constituting the core unit 120 is provided with a recess 112, so that there is only one type of punching sheet monomer 111, which can reduce the number of molds, thereby reducing the processing cost.

[0050] In another embodiment, the groove 122 may not pass through both ends of the rotor core 100. The core unit 120 includes a plurality of punching sheet units 111 without the recess 112. The plurality of punching sheet units 111 without the recess 112 may be stacked and concentrated at any position of the core unit 120, or may be staggered with the punching sheet units 111 with the recess 112, which can also achieve the effect of reducing material usage.

[0051] Reference Figure 6It can be understood that the punching sheet monomer 111 includes branch portions 113 located on both sides of the recess 112. When arranging the sample in the material plate 110, along the width direction of the material plate 110, any branch portion 113 on the punching sheet monomer 111 is inserted into the recess 112 of the adjacent punching sheet monomer 111, and along the length direction of the material plate 110, one recess 112 can accommodate two branch portions 113 located on different punching sheet monomers 111. Therefore, providing the recess 112 on the punching sheet monomer 111 can reduce the area of ​​the material plate 110 occupied by two adjacent punching sheet monomers 111 along the width direction of the material plate 110, so that more punching sheet monomers 111 can be arranged on the material plate 110 of the same area, thereby improving the utilization rate of the material plate 110.

[0052] It can be understood that, currently, the material sheet 110 is punched out by a mold, and the mold can punch out multiple punching sheet units 111 on a certain area of ​​the material sheet 110 once. When a recess 112 is provided on the punching sheet unit 111, more punching sheet units 111 can be arranged on the material sheet 110 of the same area, so that the mold can produce a larger number of punching sheet units 111 after punching out the material sheet 110 once, which is beneficial to improving processing efficiency and thus reducing production costs.

[0053] Reference Figure 2 The side wall of the groove 122 includes a first wall surface 124 and a second wall surface 125 which are arranged relatively along the circumferential direction C. The first wall surface 124 and the second wall surface 125 are arranged symmetrically with respect to the center line 123, and the first wall surface 124 and the second wall surface 125 are planes. It can be understood that permanent magnets 101 of the same specification are symmetrically arranged on both sides of the core unit 120. Therefore, in the actual working process, the magnetic field passing through the core unit 120 is symmetrical with respect to the center line 123. Therefore, symmetrical first wall surfaces 124 and second wall surfaces 125 are arranged on the groove 122, so that the hollowing conditions of the areas on both sides of the center line 123 on the core unit 120 are the same, and the influence on the magnetic field on both sides of the center line 123 is the same, so that the magnetic field is evenly distributed, avoiding vibration caused by uneven magnetic field during the operation of the motor.

[0054] At the same time, since the outer contour of the groove 122 is a symmetrical shape, for the punching sheet unit 111, the symmetrical structure of the recess 112 makes it unnecessary to distinguish the installation direction of each punching sheet unit 111 during the installation process of the rotor core 100, thereby simplifying the installation steps and reducing the defective rate caused by installation errors, thereby ensuring production efficiency.

[0055] Reference Figure 4It can be understood that the inner ends of the first wall 124 and the second wall 125 close to the axis of rotation both extend to the center line 123, that is, the intersection of the first wall 124 and the second wall 125 is located on the center line 123, and the angle between the first wall 124 and the second wall 125 is not less than 90°, that is, the two are perpendicular to each other or the angle is an obtuse angle, which can avoid adhesion between the sheet 110 and the mold during the punching process, thereby avoiding defective products and ensuring the efficiency of material unloading and waste discharge.

[0056] It is understandable that if the angle between the first wall 124 and the second wall 125 is less than 90°, the punching unit 111 is likely to adhere to the mold during the punching process, which may lead to difficulties in pattern arrangement or produce surface defects and other adverse effects, resulting in a high defect rate and reduced production efficiency.

[0057] For this purpose, refer to Figure 4 , the angle between the first wall 124 and the second wall 125 is defined as α. When the angle α is an acute angle, the end of the first wall 124 close to the rotation axis and the end of the second wall 125 close to the rotation axis are connected by an arc transition. The arc S connecting the first wall 124 and the second wall 125 is defined to prevent the mold or the punching knife from sticking to the punching sheet 111, thereby avoiding processing defects and improving the yield rate and processing efficiency.

[0058] Reference Figure 7 Since the end of the branch portion 113 on the punching sheet monomer 111 has a portion protruding along the circumferential direction C that constitutes the first limiting portion 128, after the arc surface S is set between the first wall surface 124 and the second wall surface 125, the gap between the first limiting portion 128 on the branch portion 113 and the arc surface S located on the recessed portion 112 can be reduced during the pattern arrangement process, thereby reducing the amount of waste material and helping to improve the utilization rate of the material plate 110.

[0059] Reference Figure 4 , along the radial direction of the rotor core 100 , the maximum depth of the groove 122 is H, and the maximum width of the core unit 120 is W, satisfying: 1 / 3≤H / W≤2 / 3.

[0060] It can be understood that the two first limiting portions 128 are symmetrical about the center line 123, and along the radial direction of the rotor core 100, a third wall 130 is provided on the side of the first limiting portion 128 away from the rotation axis. At the same time, a fourth wall 131 is provided on the side wall of the core unit 120 close to the rotation axis. In actual measurement, the maximum width W of the core unit 120 is the maximum distance between the third wall 130 and the fourth wall 131 along the radial direction of the rotor core 100.

[0061] It should be noted that the end of the core unit 120 farthest from the rotation axis is defined as having a maximum circumscribed circle Q1, and the end of the core unit 120 closest to the rotation axis is defined as having a minimum inscribed circle Q2.

[0062] It can be understood that when the third wall 130 is located on the circumscribed circle Q1, the radius of the maximum circumscribed circle Q1 is the maximum distance between the third wall 130 and the axis of rotation, and the center of the maximum circumscribed circle Q1 is located on the axis of rotation; when the fourth wall 131 is located on the inscribed circle Q2, the radius of the minimum inscribed circle Q2 is the minimum distance between the fourth wall 131 and the axis of rotation, and the center of the minimum inscribed circle Q2 is located on the axis of rotation. Therefore, along the radial direction of the rotor core 100, the maximum width W of the core unit 120 is the radius difference between the maximum circumscribed circle Q1 and the minimum inscribed circle Q2.

[0063] It is understandable that when H / W is less than 1 / 3, the depth of the groove 122 along the radial direction of the rotor core 100 is small, the amount of material removed from the core unit 120 is small, and the impact on the magnetic field is also small, but it will lead to insufficient material savings and insufficient cost savings, so it is not possible to significantly reduce material costs while maintaining motor performance. For layout, when H / W is less than 1 / 3, the area of ​​each punching sheet 111 will increase, resulting in a decrease in the number of punching sheets 111 arranged on a certain area of ​​the sheet 110, thereby reducing the utilization rate of the sheet 110 and reducing the number of punching sheets 111 produced by each punching, resulting in low processing efficiency and failure to meet requirements.

[0064] When H / W>2 / 3, the depth of the groove 122 along the radial direction of the rotor core 100 is large, and the amount of material removed from the core unit 120 is large, which easily leads to a reduction in the strength of the core unit 120, thereby making the structural strength of the rotor core 100 insufficient, and easily generating vibrations during rotation, thereby reducing the performance of the motor. In addition, when the depth of the groove 122 along the radial direction of the rotor core 100 is too large, the amount of material removed from the core unit 120 along the circumferential direction C is also too large, which will cause the magnetic flux on the core unit 120 to be easily saturated, thereby causing the magnetic field to weaken, which will reduce the performance of the motor and fail to meet the requirements. Therefore, only when the maximum depth H of the groove 122 and the maximum width W of the core unit 120 satisfy 1 / 3≤H / W≤2 / 3, can the manufacturing cost be reduced while maintaining the performance of the motor.

[0065] It should be noted that when the angle α is an obtuse angle, refer to Figure 4 The intersection of the first wall 124 and the second wall 125 is located on the center line 123 and is defined as the intersection G. Therefore, the maximum depth H of the groove 122 is the shortest distance between the maximum circumscribed circle Q1 and the intersection G.

[0066] In other embodiments, when the angle α is an acute angle, refer to Figure 5 One end of the first wall 124 close to the rotation axis is transitionally connected with the other end of the second wall 125 close to the rotation axis through an arc surface S, and the arc surface S and the center line 123 are defined to have an intersection F, and the maximum depth H of the groove 122 is the shortest distance between the maximum circumscribed circle Q1 and the intersection F.

[0067] Reference Figure 2 The core unit 120 is provided with a positioning hole 126, and the positioning hole 126 passes through both ends of the core unit 120 along the direction of the rotation axis. It can be understood that the core unit 120 is composed of a plurality of punching sheet monomers 111 stacked along the direction of the rotation axis. During the installation of the stacked sheets, the plurality of punching sheet monomers 111 can be positioned through the positioning holes 126, which can improve the positioning accuracy and installation efficiency. On the other hand, during the installation of the core unit 120 and the permanent magnet 101, the rotor core 100 can be positioned as a whole through the positioning holes 126; at the same time, during the assembly of the motor, the rotor assembly can be positioned as a whole through the positioning holes 126, which is conducive to improving the accuracy and efficiency of the installation.

[0068] The core unit 120 is provided with an injection hole 127, and the injection hole 127 passes through both ends of the core unit 120 along the direction of the rotation axis. It can be understood that during the injection molding process, the core unit 120 and the pre-arranged permanent magnets 101 are placed in the mold, and the molten injection material is injected into the mold cavity by the injection molding machine. After the injection molding is completed, it is cooled, and the high-temperature and high-pressure plastic will quickly cool and solidify, wrapping the core unit 120 and the permanent magnet 101, forming a plastic body covering the rotor core 100. The plastic body can simultaneously cover the outer wall of the rotor core 100 along its radial direction and the wall surfaces at both ends along the direction of the rotation axis. At the same time, the plastic body is also filled in the injection hole 127, thereby ensuring a stable connection between the core unit 120 and the permanent magnet 101.

[0069] It is understandable that the positioning hole 126 and the injection hole 127 are both located on the center line 123, which can make the positioning hole 126 and the injection hole 127 remove the same area on both sides of the core unit 120 along the center line 123, have the same impact on the magnetic field, and have the smallest impact on the magnetic field, thereby avoiding vibration during the operation of the motor due to uneven distribution of the magnetic field, and maintaining the performance of the motor. At the same time, the positioning hole 126 and the injection hole 127 are located on the center line 123, which is conducive to simplifying the structure of the punching sheet monomer 111. When the punching sheet monomer 111 is stacked to form the core unit 120, there is no need to distinguish the installation direction, avoiding installation errors that cause the positioning hole 126 or the injection hole 127 to fail to penetrate the two ends of the rotor core 100, thereby reducing the defective rate of the product, simplifying the installation operation, and improving the installation efficiency.

[0070] The motor of the second embodiment of the utility model comprises the rotor assembly of the first embodiment of the utility model, and the motor further comprises a stator assembly 140, and the rotor assembly is wound around the outer circumference of the stator assembly 140. 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 by the technical solutions of the above embodiment.

[0071] The household appliance of the third embodiment of the utility model comprises the motor of the second embodiment of the utility model. Since the household appliance adopts all the technical solutions of the motor of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments.

[0072] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A rotor assembly, rotating about an axis of rotation, characterized in that: include: The rotor core comprises a plurality of core units arranged at intervals along the circumference of the rotor core, wherein the core units are composed of a plurality of punching sheet monomers stacked and arranged along the direction of the rotation axis, a mounting groove is defined between two adjacent core units, and a groove is provided on a side of the core unit away from the rotation axis; A plurality of permanent magnets are correspondingly installed in the plurality of installation slots.

2. The rotor assembly according to claim 1, characterized in that: The groove passes through both ends of the rotor core along the direction of the rotation axis.

3. The rotor assembly according to claim 1, characterized in that: The core unit has a center line arranged along the radial direction of the rotor core, and the side wall of the groove includes a first wall surface and a second wall surface arranged opposite to each other along the circumferential direction, wherein the first wall surface and the second wall surface are arranged symmetrically with respect to the center line.

4. The rotor assembly according to claim 3, characterized in that: The first wall surface and the second wall surface both extend to the center line, and an angle between the first wall surface and the second wall surface is not less than 90°.

5. The rotor assembly according to claim 3, characterized in that: The included angle between the first wall surface and the second wall surface is an acute angle, and one end of the first wall surface close to the rotation axis and one end of the second wall surface close to the rotation axis are connected through an arc surface transition.

6. The rotor assembly according to claim 1, characterized in that: Along the radial direction of the rotor core, the maximum depth of the groove is H, and the maximum width of the core unit is W, satisfying: 1 / 3≤H / W≤2 / 3.

7. The rotor assembly according to claim 1, characterized in that: The core unit includes a first limiting portion and a second limiting portion located on the same side along the circumferential direction, the first limiting portion and the second limiting portion are both protruding toward the mounting groove, and the first limiting portion and the second limiting portion respectively abut against both ends of the permanent magnet along the radial direction of the rotor core.

8. The rotor assembly according to claim 7, characterized in that: Two of the first limiting parts and two of the second limiting parts are provided, the two first limiting parts are respectively located on both sides of the core unit along the circumferential direction, and the two second limiting parts are respectively located on both sides of the core unit along the circumferential direction.

9. The rotor assembly according to claim 1, characterized in that: The core unit is provided with a positioning hole, and the positioning hole passes through both ends of the core unit along the direction of the rotation axis.

10. The rotor assembly according to claim 1, characterized in that: The core unit is provided with an injection hole, and the injection hole passes through both ends of the core unit along the direction of the rotation axis.

11. The rotor assembly according to claim 10, characterized in that: The rotor assembly further includes a plastic package, and a portion of the plastic package fills the injection hole.

12. A motor, characterized in that include: stator assembly; The rotor assembly according to any one of claims 1 to 11, wherein the rotor assembly is wound around the outer circumference of the stator assembly.

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

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