CN222301508U - Rotor components, motors and household appliances - Google Patents

Abstract

The utility model discloses a rotor assembly, a motor and a household appliance. The rotor assembly includes a rotor core and a plurality of permanent magnets. The rotor core includes 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 and arranged along the direction of the rotation axis. An installation groove is defined between two adjacent core units. A groove is provided on the side of the core unit away from the rotation axis. The plurality of permanent magnets are correspondingly installed in the plurality of installation grooves. The utility model provides a groove, which can reduce the material consumption of the rotor core and save material costs. When the groove is not provided, the magnetic field on the side of the core unit away from the rotation axis is weak, so the material can be reduced while maintaining the motor performance. When the punching sheet monomer is arranged, the position of the portion corresponding to the groove on the punching sheet monomer can be fully utilized, so that the arrangement is more compact, waste is reduced, and it is beneficial to improve the utilization rate of the silicon steel plate, thereby reducing the production cost of the rotor assembly.

Description

Rotor assembly, motor and household appliance

Technical Field

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

Background

The brushless direct current motor is widely applied to various household appliances due to the simple structure and reliable operation, the market competition of the household appliances is vigorous, and the pursuit of low cost is particularly important. The motor is one of the core components of the household appliance, and the production cost of the household appliance is closely related to the production cost of the motor. In the related art, the whole production cost, especially the material cost, of the existing external rotor motor is higher, the utilization rate of the silicon steel plate in the production process is lower, and the production cost of the motor is still higher on the premise of not affecting the performance of the motor.

Disclosure of utility model

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides the rotor assembly which has low production cost and high silicon steel plate utilization rate and can ensure the performance of the motor.

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

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

The rotor assembly rotates around the rotation axis and comprises a rotor core, a plurality of iron core units and a plurality of permanent magnets, wherein the iron core units are arranged at intervals along the circumferential direction of the rotor core, each iron core unit is composed of a plurality of punching sheet monomers which are arranged in a stacked mode along the direction of the rotation axis, a mounting groove is defined between two adjacent iron core units, a groove is formed in one side, away from the rotation axis, of each iron core unit, and the permanent magnets are correspondingly arranged in the mounting grooves.

The rotor assembly at least has the advantages that the groove is formed in one side, deviating from the rotation axis, of the iron core unit, the material consumption of the silicon steel plate can be reduced, the material cost is reduced, the magnetic field on one side, deviating from the rotation axis, of the iron core unit is weaker when the groove is not formed, the influence on the whole magnetic field strength of the iron core unit is smaller after the groove is formed, the material is reduced, the performance of a motor can be guaranteed, and meanwhile, after the groove is formed, the position of the part, corresponding to the groove, of the punching unit can be fully utilized when the punching unit is used for discharging a sample, so that the discharging is tighter, waste is reduced, the utilization rate of the silicon steel plate is improved, the processing cost is reduced, and the whole production cost of the rotor assembly can be reduced.

According to an embodiment of the first aspect of the present utility model, the grooves penetrate both ends of the rotor core in the direction of the rotation axis.

According to an embodiment of the first aspect of the present utility model, the core unit has a center line arranged in a radial direction of the rotor core, and the side wall of the groove includes first and second wall surfaces arranged opposite in the circumferential direction, the first and second wall surfaces being symmetrically arranged with respect to the center line.

According to an embodiment of the first aspect of the present utility model, the first wall surface and the second wall surface both extend to the center line, and an included angle between the first wall surface and the second wall surface is not smaller than 90 °.

According to an embodiment of the first aspect of the present utility model, an included angle between the first wall surface and the second wall surface is an acute angle, and one end of the first wall surface, which is close to the rotation axis, is in transitional connection with one end of the second wall surface, which is close to the rotation axis, through an arc surface.

According to the embodiment of the first aspect of the utility model, the maximum depth of the groove is H, and the maximum width of the iron core unit is W along the radial direction of the rotor iron core, so that H/W is more than or equal to 1/3 and less than or equal to 2/3.

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

According to an embodiment of the first aspect of the present utility model, two first limiting portions and two second limiting portions are respectively provided, the two first limiting portions are respectively located at two sides of the core unit along the circumferential direction, and the two second limiting portions are respectively located at two sides of the core unit along the circumferential direction.

According to an embodiment of the first aspect of the present utility model, the core unit is provided with positioning holes penetrating through both ends of the core unit in the direction of the rotation axis.

According to an embodiment of the first aspect of the present utility model, the core unit is provided with injection holes penetrating through both ends of the core unit in the direction of the rotation axis.

According to an embodiment of the first aspect of the present utility model, the rotor assembly further includes an overmold, and a portion of the overmold fills the injection hole.

An electric machine according to an embodiment of the second aspect of the utility model comprises a rotor assembly according to an embodiment of the first aspect of the utility model, the electric machine further comprising a stator assembly, the rotor assembly being arranged around the periphery of the stator assembly.

Compared with the prior art, the motor provided by the embodiment of the utility model has the advantages that the rotor assembly in the motor is provided with the iron core unit, the groove is arranged on one side of the iron core unit, which is away from the rotation axis, so that the material consumption of the silicon steel plate can be reduced, the material cost can be reduced, the influence on the whole magnetic field strength of the iron core unit is smaller after the groove is arranged due to weaker magnetic field on one side of the iron core unit, which is away from the rotation axis, when the groove is not arranged, the material is reduced, the motor performance can be ensured, and meanwhile, after the groove is arranged, the position of the part, corresponding to the groove, of the punching sheet monomer can be fully utilized when the punching sheet monomer is used for arranging the pattern, so that the pattern is more compact, the waste is reduced, the utilization rate of the silicon steel plate is improved, and the motor manufacturing cost is reduced while the motor performance is maintained.

An embodiment of the third aspect of the present utility model comprises an electric motor according to the embodiment of the second aspect of the present utility model.

Compared with the prior art, the household appliance has the advantages that the motor is arranged in the household appliance, the iron core unit is arranged on the rotor component in the motor, and the groove is arranged on one side, away from the rotation axis, of the iron core unit, so that the consumption of silicon steel sheets can be reduced, and the material cost is saved; meanwhile, after the grooves are arranged, the positions of parts corresponding to the grooves on the punching sheet monomers can be fully utilized when the punching sheet monomers are arranged for discharging, so that the discharging is more compact, the waste is reduced, the utilization rate of a silicon steel plate is improved, and the manufacturing cost of the household appliance is reduced while the performance is kept.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is an axial schematic view of a rotor assembly with one of the permanent magnets removed in an embodiment of a first aspect of the present utility model;

Fig. 2 is an enlarged view at a in fig. 1;

FIG. 3 is an axial schematic view of an electric machine in an embodiment of a second aspect of the utility model;

FIG. 4 is an axial schematic view of a core unit in some embodiments of the first aspect of the utility model;

FIG. 5 is an axial schematic view of a core unit in further embodiments of the first aspect of the utility model;

FIG. 6 is a schematic illustration of the layout of the sheet monomer in the web in some embodiments of the first aspect of the utility model;

Fig. 7 is a partial view of a layout of a sheet of monomer in a web in further embodiments of the first aspect of the utility model.

Reference numerals:

Rotor core 100, permanent magnet 101;

a material plate 110, a sheet unit 111, a concave portion 112, a branching portion 113;

The iron core unit 120, the mounting groove 121, the groove 122, the center line 123, the first wall surface 124, the second wall surface 125, the positioning hole 126, the injection molding hole 127, the first limiting part 128, the second limiting part 129, the third wall surface 130 and the fourth wall surface 131;

Stator assembly 140, stator teeth 141, windings 142, and winding slots 143.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, a number means one or more, a number means two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, mounting, connection, assembly, cooperation, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical solution.

Brushless DC motors are widely used in the fields of fans, pumps, robots, unmanned aerial vehicles, electric vehicles, precision instruments, household appliances, and the like because of their advantages of high efficiency, long life, low noise, high precision control, and the like. The market competition of the household appliances is strong at present, and the pursuit of low cost is particularly important. The motor is one of the core components of the household appliance, and the production cost of the household appliance is closely related to the production cost of the motor. In the related art, the whole production cost of the existing external rotor motor is higher, particularly the material cost, and the utilization rate of the material in the production process is lower, so that the production cost of the motor is still higher on the premise of not influencing the performance of the motor, namely the cost of the motor is still difficult to reduce on the premise of not compressing the size of the rotor. The rotor core in the existing external rotor motor is formed by laminating a plurality of punching sheets, the punching sheets are obtained after punching processing of silicon steel material plates, and it can be understood that the plurality of punching sheets are arranged on the material plates, however, the arrangement mode of the existing punching sheets is not ideal enough, the utilization rate of the material plates is not high enough, more material waste is caused in the production process, and the production cost is difficult to reduce.

To solve the above technical problems, referring to fig. 1, an embodiment of a first aspect of the present utility model provides a rotor assembly for use in a motor of a home appliance including a refrigerator, an air conditioner, a washing machine, and the like. As can be appreciated, referring to fig. 3, the motor includes a rotor assembly and a stator assembly 140, the stator assembly 140 including a plurality of stator teeth 141 with winding slots 143 between adjacent two of the stator teeth 141, windings 142 being provided at the winding slots 143.

It will be appreciated that the rotor core 100 has a central axis, i.e., the axis of rotation of the rotor core 100, which rotates about the axis of rotation of the outer Zhou Bingrao of the stator assembly 140. It should be noted that, for convenience of description and understanding, the direction around the rotation axis of the rotor assembly is referred to as a circumferential direction C in the present application.

Referring to fig. 1 and 3, the rotor assembly includes a rotor core 100 and a plurality of permanent magnets 101, the rotor core 100 including a plurality of core units 120 equally spaced apart in a circumferential direction C, a mounting groove 121 being defined between adjacent two core units 120, and the plurality of permanent magnets 101 being correspondingly mounted in the plurality of mounting grooves 121. It will be appreciated that the plurality of permanent magnets 101 and the plurality of core units 120 are staggered in the circumferential direction C, i.e., one permanent magnet 101 is provided between two adjacent core units 120.

Referring to fig. 2, the core unit 120 has a center line 123 arranged in a radial direction of the rotor core 100, and the core unit 120 includes a first stopper 128 and a second stopper 129 located at the same side in the circumferential direction C, the first stopper 128 and the second stopper 129 each being convexly disposed toward the mounting groove 121. Specifically, the first limiting portion 128 is located on one side, far away from the rotation axis, of the iron core unit 120, the second limiting portion 129 is located on one side, close to the rotation axis, of the iron core unit 120, and along the radial direction of the rotor core 100, the first limiting portion 128 abuts against one end, far away from the rotation axis, of the permanent magnet 101, the second limiting portion 129 abuts against one end, close to the rotation axis, of the permanent magnet 101, limiting of the permanent magnet 101 is achieved, 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.

Referring to fig. 2, it can be understood that the first limiting portions 128 and the second limiting portions 129 on the core unit 120 are respectively provided with two first limiting portions 128, which are respectively located at two sides of the core unit 120 along the circumferential direction C, and two second limiting portions 129, which are respectively located at two 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 firm, being beneficial to improving the structural stability of the rotor core 100, avoiding vibration generated during the operation of the motor, and being beneficial to ensuring the performance of the motor.

Referring to fig. 1, the recess 122 is provided at a side of the core unit 120 facing away from the rotation axis, so that the material consumption of the core unit 120 can be reduced, thereby realizing saving of material cost.

It will be appreciated that, during operation of the external rotor motor, the magnetic field direction starts from the permanent magnet 101 (refer to the magnetic induction line N in fig. 3), sequentially passes through the iron core unit 120 located at 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, and the magnetic field passes through the stator teeth 141 located at the other side of the winding 142 after passing through the winding 142, passes through the air gap again, and passes through the iron core unit 120 located at the other side of the permanent magnet 101, and then returns to the permanent magnet 101, from which it can be known that the magnetic field is conducted to the side of the rotor assembly close to the rotation axis, the magnetic induction line density of the iron core unit 120 at the side facing away from the rotation axis is lower, and the magnetic field is weaker, after the groove 122 is provided therein, the influence on the magnetic field strength of the whole iron core unit 120 is smaller, so that the material consumption of the rotor iron core 100 can be saved while the performance of the motor is maintained, and the material cost is facilitated to be reduced.

It is understood that the core unit 120 is composed of a plurality of lamination units 111 arranged in a lamination manner in the direction of the rotation axis, and the lamination units 111 are formed by punching silicon steel plates. Referring to fig. 6, a material plate 110 is a silicon steel plate, and a sheet metal unit 111 is disposed on the material plate 110.

Referring to fig. 6, it can be understood that the die unit 111 is provided with recesses 112, and a plurality of recesses 112 arranged in the rotation axis direction constitute grooves 122. It can be appreciated that the grooves 122 penetrate through both ends of the rotor core 100 in the direction of the rotation axis, so that the material consumption of the core unit 120 can be effectively reduced, the cost is significantly reduced, and each of the lamination units 111 constituting the core unit 120 is provided with the concave portion 112, so that only one lamination unit 111 is provided, the number of dies can be reduced, and the processing cost is reduced.

In another embodiment, the grooves 122 may not penetrate through two ends of the rotor core 100, the core unit 120 includes a plurality of lamination units 111 without the concave portions 112, and the lamination units 111 without the concave portions 112 may be arranged at any position of the core unit 120 in a concentrated manner or alternatively arranged with the lamination units 111 with the concave portions 112, so as to achieve the effect of reducing the material consumption.

Referring to fig. 6, it can be understood that the sheet unit 111 includes the branch portions 113 located at both sides of the recess 112, when the sheet 110 is discharged, any one of the branch portions 113 on the sheet unit 111 is inserted into the recess 112 of the adjacent sheet unit 111 along the width direction of the sheet 110, and two branch portions 113 located on different sheet units 111 can be received in one recess 112 along the length direction of the sheet 110, so that the recess 112 is provided on the sheet unit 111, the area of the sheet 110 occupied by two adjacent sheet units 111 along the width direction of the sheet 110 can be reduced, and more sheet units 111 can be arranged on the same area of the sheet 110, thereby improving the utilization rate of the sheet 110.

It can be appreciated that, at present, the material plate 110 is blanked through the die, the die can blank out a plurality of single punching sheets 111 on the material plate 110 with a certain area, when the concave parts 112 are arranged on the single punching sheets 111, more single punching sheets 111 can be arranged on the material plate 110 with the same area, so that the die can produce a plurality of single punching sheets 111 after blanking the material plate 110 once, which is beneficial to improving the processing efficiency and reducing the production cost.

Referring to fig. 2, the side wall of the groove 122 includes a first wall surface 124 and a second wall surface 125 that are arranged opposite to each other in the circumferential direction C, the first wall surface 124 and the second wall surface 125 are symmetrically arranged with respect to the center line 123, and the first wall surface 124 and the second wall surface 125 are planar. It can be understood that the permanent magnets 101 with the same specification are symmetrically disposed on two sides of the core unit 120, so that in the actual working process, the magnetic field passing through the core unit 120 is symmetrical with respect to the central line 123, and therefore, the symmetrical first wall surface 124 and the symmetrical second wall surface 125 are disposed on the groove 122, so that the hollowing conditions of the areas on two sides of the central line 123 on the core unit 120 are the same, the influence on the magnetic field on two sides of the central line 123 is the same, the magnetic field is uniformly distributed, and vibration caused by nonuniform magnetic field in the motor operation process is avoided.

Meanwhile, since the profile of the groove 122 is symmetrical, the symmetrical structure of the concave portion 112 for the lamination units 111 makes it unnecessary to distinguish the installation direction of each lamination unit 111 during the installation of the rotor core 100, thereby simplifying the installation steps, reducing the reject ratio caused by the installation error, and thus ensuring the production efficiency.

Referring to fig. 4, it can be understood that the inner ends of the first wall surface 124 and the second wall surface 125, which are close to the rotation axis, extend to the center line 123, that is, the intersection of the first wall surface 124 and the second wall surface 125 is located on the center line 123, and the included angle between the first wall surface 124 and the second wall surface 125 is not less than 90 °, that is, the two are perpendicular to each other or the included angle is an obtuse angle, which can avoid the adhesion between the material plate 110 and the die during the blanking process, thereby avoiding defective products and ensuring the efficiency of discharging and discharging waste materials.

It can be appreciated that if the included angle between the first wall surface 124 and the second wall surface 125 is smaller than 90 °, the sheet unit 111 is easy to adhere to the die during the blanking process, so that the layout is difficult or the defect of the cutting surface is generated, which results in high reject ratio and reduced production efficiency.

For this reason, referring to fig. 4, an included angle α between the first wall surface 124 and the second wall surface 125 is defined, and when the included angle α is an acute angle, one end of the first wall surface 124 near the rotation axis is in transitional connection with one end of the second wall surface 125 near the rotation axis through an arc surface. Defining the cambered surface S between the first wall surface 124 and the second wall surface 125, which are connected with each other, can avoid the adhesion between the die or the punching cutter and the punching sheet unit 111, thereby avoiding processing flaws and improving the yield and the processing efficiency.

Referring to fig. 7, since the end of the branching portion 113 on the sheet member 111 has a portion protruding in the circumferential direction C to form the first limiting portion 128, after the cambered surface S is provided between the first wall surface 124 and the second wall surface 125, the gap between the first limiting portion 128 on the branching portion 113 and the cambered surface S located on the recess 112 can be reduced during the discharging process, so that the amount of waste is reduced, and the utilization rate of the material plate 110 is improved.

Referring to FIG. 4, in 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.ltoreq.H/W.ltoreq.2/3.

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 surface 130 is disposed on a side of the first limiting portion 128 away from the rotation axis, and a fourth wall surface 131 is disposed on a side wall of the core unit 120 close to the rotation axis, and in actual measurement, the maximum width W of the core unit 120 is the maximum distance between the third wall surface 130 and the fourth wall surface 131 along the radial direction of the rotor core 100.

It should be noted that, the furthest end of the core unit 120 from the rotation axis is defined to have the largest circumscribed circle Q ₁, and the closest end of the core unit 120 from the rotation axis is defined to have the smallest inscribed circle Q ₂.

It is understood that when the third wall surface 130 is located on the circumscribed circle Q ₁, the radius of the largest circumscribed circle Q ₁ is the maximum distance between the third wall surface 130 and the rotation axis, the center of the largest circumscribed circle Q ₁ is located on the rotation axis, and when the fourth wall surface 131 is located on the inscribed circle Q ₂, the radius of the smallest inscribed circle Q ₂ is the minimum distance between the fourth wall surface 131 and the rotation axis, and the center of the smallest inscribed circle Q ₂ is located on the rotation axis, so that the maximum width W of the core unit 120 is the difference between the radius of the largest circumscribed circle Q ₁ and the radius of the smallest inscribed circle Q ₂ along the radial direction of the rotor core 100.

It will be appreciated that when H/W <1/3, the depth of the groove 122 in the radial direction of the rotor core 100 is small, the amount of material cut out for the core unit 120 is small, and the effect on the magnetic field is small, however, the amount of material saving is insufficient, the effect of saving the cost is not significant enough, and thus the significant reduction of the material cost while maintaining the motor performance cannot be satisfied. For the layout, when H/W <1/3, the area of each sheet unit 111 is increased, so that the number of sheet units 111 arranged on a material plate 110 with a certain area is reduced, thereby reducing the utilization rate of the material plate 110, reducing the number of sheet units 111 manufactured by each punching, and reducing the processing efficiency, which cannot meet the requirements.

When H/W >2/3, the depth of the groove 122 in the radial direction of the rotor core 100 is large, the amount of material removed from the core unit 120 is large, and the strength of the core unit 120 is easily reduced, so that the structural strength of the rotor core 100 is insufficient, vibration is easily generated during rotation, and the performance of the motor is reduced. When the depth of the groove 122 in the radial direction of the rotor core 100 is too large, the amount of material removed from the core unit 120 in the circumferential direction C is too large, which may cause the magnetic flux on the core unit 120 to be easily saturated, and thus the magnetic field to be weakened, which may reduce the performance of the motor, and may not meet the requirements. Therefore, the reduction of manufacturing cost while maintaining the motor performance can be achieved only when 1/3.ltoreq.H/W.ltoreq.2/3 is satisfied between the maximum depth H of the recess 122 and the maximum width W of the core unit 120.

When the included angle α is an obtuse angle, referring to fig. 4, the intersection of the first wall surface 124 and the second wall surface 125 is located on the center line 123 and defined as an intersection G, so the maximum depth H of the groove 122 is the shortest distance between the maximum circumscribed circle Q ₁ and the intersection G.

In other embodiments, when the included angle α is an acute angle, referring to fig. 5, the end of the first wall surface 124 near the rotation axis is in transitional connection with the end of the second wall surface 125 near the rotation axis through an arc surface S, which defines an intersection point F between the arc surface S and the center line 123, and the maximum depth H of the groove 122 is the shortest distance between the maximum circumscribing circle Q ₁ and the intersection point F.

Referring to fig. 2, the core unit 120 is provided with positioning holes 126, and the positioning holes 126 penetrate both ends of the core unit 120 in the direction of the rotation axis. It can be appreciated that the core unit 120 is formed by a plurality of lamination units 111 stacked along the rotation axis direction, and the positioning accuracy and the mounting efficiency can be improved by positioning the lamination units 111 through the positioning holes 126 during the lamination mounting process. On the other hand, during the process of mounting the core unit 120 and the permanent magnet 101, the rotor core 100 can be integrally positioned through the positioning holes 126, and simultaneously, during the process of assembling the motor, the rotor assembly can be integrally positioned through the positioning holes 126, thereby being beneficial to improving the accuracy and efficiency of the mounting.

The core unit 120 is provided with injection holes 127, the injection holes 127 penetrate through two ends of the core unit 120 along the direction of the rotation axis, it is understood that in the injection process, the core unit 120 and the prearranged permanent magnets 101 are placed into a mold, injection molding materials in a molten state are injected into a mold cavity through an injection molding machine, after injection molding is completed, high-temperature and high-pressure plastics are rapidly cooled and solidified, the core unit 120 and the permanent magnets 101 are wrapped to form a plastic wrapping body covered on the rotor core 100, the plastic wrapping body can be simultaneously covered on the radial outer wall of the rotor core 100 and two end wall surfaces along the direction of the rotation axis, and meanwhile, the plastic wrapping body is also filled in the injection holes 127, so that the firm connection between the core unit 120 and the permanent magnets 101 is ensured.

It can be appreciated that the positioning hole 126 and the injection molding hole 127 are both located on the central line 123, so that the positioning hole 126 and the injection molding hole 127 can remove the same area from both sides of the core unit 120 along the central line 123, and have the same influence on the magnetic field, and the influence on the magnetic field is minimal, thereby avoiding vibration generated in the motor running process due to uneven magnetic field distribution, and realizing the maintenance of the performance of the motor. Meanwhile, the positioning hole 126 and the injection molding hole 127 are positioned on the central line 123, so that the structure of the punching sheet unit 111 is simplified, when the punching sheet unit 111 is laminated to form the iron core unit 120, the installation direction is not required to be distinguished, and the defect that the positioning hole 126 or the injection molding hole 127 cannot penetrate through two ends of the rotor iron core 100 due to installation errors is avoided, so that the reject ratio of products can be reduced, the installation operation can be simplified, and the installation efficiency can be improved.

An electric machine according to an embodiment of the second aspect of the present utility model includes a rotor assembly according to an embodiment of the first aspect of the present utility model, and further includes a stator assembly 140, the rotor assembly being wound around an outer periphery of the stator assembly 140. The motor has at least all the beneficial effects brought by the technical proposal of the embodiment because the motor adopts all the technical proposal of the rotor assembly of the embodiment.

The household appliance according to the third aspect of the present utility model comprises the motor according to the second aspect of the present utility model, and the household appliance at least has all the advantages brought by the technical solutions of the foregoing embodiments, because all the technical solutions of the foregoing embodiments are adopted in the household appliance.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.

Claims (13)

1. The rotor subassembly, around rotation axis rotation, its characterized in that includes:

The rotor iron core comprises a plurality of iron core units which are arranged at intervals along the circumferential direction of the rotor iron core, wherein each iron core unit consists of a plurality of punching sheet monomers which are arranged in a stacking manner along the direction of the rotating axis, an installation groove is defined between every two adjacent iron core units, and a groove is formed in one side, away from the rotating axis, of each iron core unit;

and the permanent magnets are correspondingly arranged in the mounting grooves.

2. The rotor assembly of claim 1 wherein said grooves extend through both ends of said rotor core in the direction of said axis of rotation.

3. The rotor assembly as recited in claim 1, wherein the core unit has a center line arranged in a radial direction of the rotor core, and the side wall of the groove includes first and second wall surfaces arranged opposite in the circumferential direction, the first and second wall surfaces being symmetrically arranged with respect to the center line.

4. The rotor assembly of claim 3 wherein said first wall and said second wall each extend to said centerline and wherein said first wall and said second wall are at an angle of no less than 90 °.

5. The rotor assembly of claim 3 wherein the first wall has an acute angle with respect to the second wall, and wherein the end of the first wall adjacent the axis of rotation is in transitional engagement with the end of the second wall adjacent the axis of rotation via an arcuate surface.

6. The rotor assembly of claim 1 wherein said grooves have a maximum depth H and said core units have a maximum width W in a radial direction of said rotor core, satisfying 1/3.ltoreq.H/W.ltoreq.2/3.

7. The rotor assembly of claim 1, wherein the core unit includes a first limit portion and a second limit portion located on the same side in the circumferential direction, the first limit portion and the second limit portion are each disposed protruding toward the mounting groove, and the first limit portion and the second limit portion respectively abut against two ends of the permanent magnet in the radial direction of the rotor core.

8. The rotor assembly of claim 7, wherein the first limiting portion and the second limiting portion are respectively provided with two first limiting portions, the two first limiting portions are respectively located at two sides of the iron core unit along the circumferential direction, and the two second limiting portions are respectively located at two sides of the iron core unit along the circumferential direction.

9. The rotor assembly of claim 1 wherein said core unit is provided with locating holes extending through both ends of said core unit in the direction of said axis of rotation.

10. The rotor assembly of claim 1 wherein said core unit is provided with injection holes extending through both ends of said core unit in the direction of said axis of rotation.

11. The rotor assembly of claim 10 wherein said rotor assembly further comprises an overmold, a portion of said overmold filling said injection molded hole.

12. An electric motor, comprising:

A stator assembly;

A rotor assembly as claimed in any one of claims 1 to 11, which is provided around the periphery of the stator assembly.

13. Household appliance, characterized in that it comprises an electric motor according to claim 12.