Rotor core, rotor assembly, motor and household appliance

Abstract

The invention provides a rotor iron core, a rotor assembly, a motor and a household electrical appliance, the rotor iron core comprises a plurality of iron core units arranged around the rotation axis of the rotor iron core, one of the iron core units is a first iron core unit, the first iron core unit is disconnected from other iron core units along the circumferential direction of the rotation axis, and the other iron core units are disconnected from the first iron core unit along the circumferential direction of the rotation axis. The first iron core unit comprises a plurality of laminations which are laminated in the direction parallel to the rotating axis, and one of the laminations is a first lamination; the first lamination is provided with a first side wall, the first side wall can face one side of the permanent magnet, the first side wall defines a first groove body, the first groove body is separated from the end, close to the rotating axis, of the first side wall, and the first groove body is used for injection molding. Through the arrangement of the side wall slots, the injection molding body can be connected to the rotor core and the permanent magnets at the same time, and the radial displacement of the rotor core is limited, so that the connection tightness of the rotor core can be enhanced.

Description

Technical Field

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

[0002] Permanent magnet synchronous motors have the characteristics of high efficiency, high power density and fast response, and are widely used in the field of household appliances. In order to meet the current needs of household appliances, motors are often designed in the direction of high power density. An existing rotor core manufactures the core units into a block structure, that is, the core units are not directly connected to each other, but the core units are connected into an integrated rotor core by filling injection molding material between the core units. The rotor core with the above design can reduce leakage magnetic field and improve the power density of the motor, but the core units of each block are only connected to the injection molding body, and the structural strength is weak. With the rotation of the rotor core, the connection between the core unit and the injection molding body is easy to loosen or detach, especially the radial force on the core unit will directly cause the core unit to detach from the injection molding body, which will affect the performance of the rotor core and even cause motor failure.

[0003] Therefore, how to ensure the connection strength of the rotor core while achieving high power density and taking into account production and manufacturing is a technical problem that needs to be urgently solved in this field. Summary of the invention

[0004] The main purpose of the present invention is to provide a rotor core, a rotor assembly, a motor and a household appliance, which can enhance the connection tightness of the rotor core.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] A rotor core comprises a plurality of core units arranged around a rotation axis of the rotor core, one of the core units being a first core unit, the first core unit being disconnected from the other core units along the circumferential direction of the rotation axis, the first core unit comprising a plurality of laminations stacked in a direction parallel to the rotation axis, one of the laminations being a first lamination;

[0007] The first laminate has a first side wall, which can face one side of the permanent magnet. The first side wall defines a first groove body, which is spaced apart from the end of the first side wall close to the rotation axis, and is used for injection molding.

[0008] In some embodiments, the distance between the end of the first laminate away from the rotation axis and the rotation axis is L1;

[0009] The radial dimension L2 of the first groove body along the rotation axis satisfies: L2<0.3L1,

[0010] and / or,

[0011] A circumferential dimension L3 of the first groove body along the rotation axis satisfies: L3<0.15L1.

[0012] In some embodiments, along the radial direction of the rotation axis, the distance between the end of the first stack away from the rotation axis and the end of the first stack close to the rotation axis is L4, and the minimum distance L5 between the first slot body and the end of the first stack close to the rotation axis satisfies: L5≥L4 / 2.

[0013] In some embodiments, the first side wall has a first end surface, the first end surface is used to define a first groove body, the first end surface is connected to an end of the first side wall close to the rotation axis, and the first end surface is perpendicular to the radial direction of the rotation axis.

[0014] In some embodiments, the first groove body is a rectangular groove; or, the first groove body is an arc groove; or, the first groove body is a triangular groove.

[0015] In some embodiments, the first side wall further defines a second groove body, the second groove body is located on a side of the first groove body close to the rotation axis, and the second groove body is used for injection molding.

[0016] In some embodiments, the first stack also has a second side wall, and the first side wall and the second side wall are arranged opposite to each other along the circumference of the rotation axis. Along the circumference of the rotation axis, the first side wall can face the permanent magnet on one side of the first stack, and the second side wall can face the permanent magnet on the other side of the first stack. The second side wall defines a third groove body, and the third groove body is separated from the end of the second side wall close to the rotation axis, and the third groove body is used for injection molding.

[0017] In some embodiments, the first slot body and the third slot body are arranged symmetrically about the first plane, and the rotation axis is located in the first plane.

[0018] In some embodiments, the first core unit further includes a second lamination, the second lamination having a third side wall, the third side wall can face one side of the permanent magnet, and the end of the third side wall close to the rotation axis has a first protrusion, and the first protrusion is used to abut against one end of the permanent magnet close to the rotation axis;

[0019] Along a direction parallel to the rotation axis, a first lamination is provided at both ends of the first core unit, and at least one second lamination is located between the two ends of the first core unit.

[0020] An embodiment of the second aspect of the present invention further provides a rotor assembly, comprising a rotor core of any of the above embodiments; an injection molded body; and a plurality of permanent magnets, wherein a receiving space is defined between each two adjacent core units, and at least one permanent magnet is disposed in each receiving space.

[0021] In some embodiments, the plurality of permanent magnets include a first magnet facing a first side wall, the wall surface of the first magnet facing the first side wall having a second protrusion, the second protrusion being at least partially located in the first slot body, and along the radial direction of the rotation axis, the side of the second protrusion close to the rotation axis and the side away from the rotation axis both face the first slot body.

[0022] The embodiment of the third aspect of the present invention further provides a rotor assembly, comprising a plurality of permanent magnets, an injection molded body and a rotor core, wherein the rotor core comprises a plurality of core units arranged around the rotation axis of the rotor core, an accommodation space is defined between each two adjacent core units, the accommodation space is used to accommodate the permanent magnet, one of the core units is a first core unit, the first core unit is disconnected from the other core units along the circumferential direction of the rotation axis, the first core unit comprises a plurality of laminations stacked in a direction parallel to the rotation axis, and one of the laminations is a first lamination;

[0023] The first stack has a first side wall, the first side wall faces the side of the permanent magnet, the first side wall and the permanent magnet together define a filling space, the filling space is used to fill the injection molded body, the filling space includes a first gap and a second gap, the first gap is located on the side of the second gap away from the rotation axis, and the first gap is larger than the second gap.

[0024] An embodiment of the third aspect of the present invention further provides an electric motor, comprising a rotor assembly according to any of the above embodiments.

[0025] An embodiment of the fourth aspect of the present invention further provides a household appliance, comprising the motor of any of the above embodiments.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] In the technical solution of the present invention, an accommodation space can be defined between two adjacent core units of the rotor core, and the first lamination in the core unit has a first side wall that can face the permanent magnet, and the first side wall defines a first slot body separated from the end of the first side wall close to the rotation axis, so that the injection molding filled between the first slot body and the permanent magnet can enhance the connection tightness of the rotor core. Specifically, the injection molding in the first slot body can simultaneously connect the first lamination and the permanent magnet, increase the injection molding connection area of ​​the first lamination on the side wall, and the injection molding can form a limiting clamping effect with the first slot body. When the first lamination is subjected to a force in the radial direction, the injection molding in the first slot body can abut against the first slot body, so that the injection molding can generate a limiting force in the radial direction on the first lamination to limit the displacement of the first lamination in the radial direction. At the same time, the injection molding can apply a force from the outer peripheral part of the first lamination to the inner peripheral part on the first lamination, and the force can effectively suppress the centrifugal force of the first lamination from the inner peripheral part to the outer peripheral part. Therefore, the rotor core of the present invention has a groove body for injection molding on the side wall facing the permanent magnet. The grooved side wall allows the injection molding body to be connected to the rotor core and the permanent magnet at the same time and limits the radial displacement of the rotor core, thereby enhancing the connection tightness of the rotor core. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1 A schematic side view of a rotor core provided in a first embodiment of the present invention;

[0030] Figure 2 A side view schematic diagram of a first laminate provided in a second embodiment of the present invention;

[0031] Figure 3 A schematic side view of a first laminate provided in a third embodiment of the present invention;

[0032] Figure 4 A side view schematic diagram of a first lamination provided in a fourth embodiment of the present invention; wherein the dot-dash line represents a portion of the radial direction and a portion of the circumferential direction of the rotation axis;

[0033] Figure 5 A side view schematic diagram of a first laminate provided in a fifth embodiment of the present invention;

[0034] Figure 6A side view schematic diagram of a first laminate provided in a sixth embodiment of the present invention;

[0035] Figure 7 A side view schematic diagram of a first laminate provided in a seventh embodiment of the present invention;

[0036] Figure 8 A side view schematic diagram of a first laminate provided in an eighth embodiment of the present invention;

[0037] Fig. 9 A side view schematic diagram of a second laminate provided in a ninth embodiment of the present invention;

[0038] Fig.10 A side view schematic diagram of a second laminate provided in a tenth embodiment of the present invention;

[0039] Fig.11 It is a three-dimensional schematic diagram of a first laminate and a second laminate provided in a tenth embodiment of the present invention after being combined;

[0040] Fig.12 A schematic side view of a rotor assembly provided in an embodiment of the second aspect of the present invention;

[0041] Fig.13 A schematic side view of a first laminate and a permanent magnet combined in another embodiment of the second aspect of the present invention;

[0042] Fig.14 A schematic side view of a rotor assembly provided in an embodiment of the third aspect of the present invention;

[0043] Fig.15 for Fig.14 A local enlarged schematic diagram of the middle A;

[0044] Fig.16 A schematic side view of a rotor assembly provided in another embodiment of the third aspect of the present invention; wherein the dotted line represents the boundary between the first gap and the second gap.

[0045] Description of Figure Numbers:

[0046] 10- rotor core;

[0047] 100a-a first core unit;

[0048] 110a-first stack;

[0049] 111a-first side wall; 1111a-first slot body; 1112a-second slot body; 1113a-first end face;

[0050] 112a- second side wall; 1121a- third tank body;

[0051] 120a-second laminate;

[0052] 121a-third side wall; 1211a-first protrusion;

[0053] 200-permanent magnet; 210-first magnet; 211-second protrusion;

[0054] 300a- rotor assembly;

[0055] 400-injection molding;

[0056] 300b- rotor assembly;

[0057] 310b- rotor core;

[0058] 311b-first core unit;

[0059] 3111b-first lamination;

[0060] 31111b-first side wall;

[0061] 600-filling space; 610-first gap; 620-second gap;

[0062] P - first plane.

[0063] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0066] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or", "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0067] An existing rotor core manufactures the core units into a block structure, that is, the core units are not directly connected to each other, but are connected into an integrated rotor core by filling injection molding material between the core units. The rotor core design of the above design can reduce magnetic leakage and improve the power density of the motor, but the core units of each block are only connected to the injection molding body, and the structural strength is weak. With the rotation of the rotor core, the connection between the core unit and the injection molding body is easy to loosen or detach, especially the radial force on the core unit will directly cause the core unit to detach from the injection molding body, which will affect the performance of the rotor core and even cause motor failure.

[0068] Specifically, part of the bonding force of the segmented core units of the above-mentioned conventional solution comes from the injection molding connection of the inner part of the core unit close to the rotation axis. Along the circumferential direction of the rotation axis, the inner area of ​​each rotor unit can enclose an inner annular area of ​​the rotor core, and the area can be filled with injection molding material to connect the inner parts of each core unit. In addition, part of the bonding force of the segmented core units comes from the injection molding connection of the outer part of the core unit away from the rotation axis. The outer peripheral wall surface of each core unit is connected to an injection molding body arranged around the outer periphery of the rotor core. The problem with the above-mentioned arrangement is that although the inner part of the rotor core The side annular area forms an integrated injection molded body, but the injection molded body is still only connected to the inner end of each core unit. The area available for connection in this part is small, and a good bonding effect cannot be guaranteed. In addition, the filling size of the outer part of the rotor core is limited by the design size of the rotor assembly, which will lead to insufficient connection strength of the injection molded body in the outer part. At the same time, part of the rotor core will also form a gap between the permanent magnet and the side wall in the circumferential direction of the rotation axis. In order to adapt to the close fit between the rotor core and the permanent magnet, this part of the gap often has less injection molded material that can flow into it, and the effect of improving the tightness of the connection is not obvious. Analyzing the above phenomenon, the current split rotor core already has an injection molded body as a connection during manufacturing. Therefore, relevant technical personnel often only pay attention to the installation stability of the permanent magnet, and take it for granted that the core unit has insufficient bonding force. Insufficient bonding force will cause the core unit to be separated from the injection molded body in the radial direction. In particular, the centrifugal force on the outer peripheral part of the core unit is relatively large, and the connection of this part is easier to separate. The above problem will be more obvious when the rotor core is larger and the rotation speed is faster, which will have a greater impact on the use of the rotor core.

[0069] In view of this, see Figure 1-Figure 13 The embodiment of the first aspect of the present invention provides a rotor core 10, which can improve the tightness of the injection molding connection of the rotor core 10.

[0070] The rotor core 10 includes a plurality of core units arranged around the rotation axis of the rotor core 10. An accommodation space is defined between two adjacent core units. The accommodation space is used to accommodate the permanent magnet 200. One of the core units is a first core unit 100a. The first core unit 100a is disconnected from the other core units along the circumferential direction of the rotation axis. It can be understood that in some embodiments, a plurality of core units are arranged around the rotation axis to form a plurality of unit bodies of the rotor core 10. According to the above arrangement, when viewed in a direction parallel to the rotation axis, the core units can be arranged in a fan-shaped manner. The core units can also be arranged at equal intervals along the circumferential direction of the rotation axis. For example, see Figure 1 In some embodiments, the rotor core 10 has ten core units.

[0071] Based on the surrounding arrangement of each core unit, an accommodation space is defined between two adjacent core units, and the accommodation space is used to accommodate the permanent magnet 200. It can be understood that there is a gap between two adjacent core units that can accommodate the permanent magnet 200. In some embodiments, a certain gap can be formed between the entire wall surface of the core unit and the permanent magnet 200 to facilitate the installation or fixation of the permanent magnet 200; or the permanent magnet 200 can form an interference fit with the adjacent core unit to achieve connection.

[0072] See also Figure 1 In this embodiment, ten core units can jointly define ten accommodation spaces, so that the rotor assembly 300a having the rotor core 10 needs to be provided with ten permanent magnets 200, and the ten permanent magnets 200 are arranged in the ten accommodation spaces one by one. In another embodiment, there can be a gap between the permanent magnet 200 and the core unit, so that the two relatively parallel walls can be used to place filling materials, so that the relative position of each permanent magnet 200 is fixed, or the relative position between the permanent magnet 200 and the core unit is fixed. In yet another embodiment, a plurality of permanent magnets 200 can be arranged in a single accommodation space. In some embodiments, see Figure 1 The maximum radial dimension of the permanent magnet 200 along the rotor assembly 300a may correspond to the maximum radial dimension of the accommodation space along the rotor assembly 300a. According to the above configuration, the accommodation space may be defined by two circumferentially opposite wall surfaces between two adjacent core units.

[0073] The core units in the rotor core 10 may be connected to each other to maintain the integrity of the rotor core 10, or may be disconnected from each other to avoid magnetic leakage at the connection. Figure 1 In this embodiment, each core unit is disconnected from each other. In other embodiments, a portion of the core units are connected to each other, and each core unit in another portion of the core units is disconnected from each other core unit.

[0074] See also Figure 1 , one of the core units is the first core unit 100a. Along the circumferential direction of the rotation axis, the first core unit 100a is disconnected from the other core units. It should be noted that the description and illustrations of the rotor core 10 in the present invention correspond to the state that the rotor core 10 is not assembled into the rotor assembly 300a and before injection molding. Therefore, in some embodiments, the state in which the first core unit 100a is disconnected from the other core units can be understood as that in a manufacturing process of the rotor core 10, the first core unit 100a is separated from the other core units, and in the subsequent manufacturing steps, the rotor core 10 can be connected as a whole by injection molding.

[0075] See also Figure 1-Figure 2 The first core unit 100a includes a plurality of laminations stacked in a direction parallel to the rotation axis, and one of the laminations is a first lamination 110a. It can be understood that at least one of the laminations is a first lamination 110a, so in some embodiments, each lamination in the first core unit 100a may include a plurality of first laminations 110a.

[0076] See also Figure 2 Based on the above configuration, the first laminate 110a has a first side wall 111a, and the first side wall 111a can face one side of the permanent magnet 200. It can be understood that the first side wall 111a is a lateral wall arranged opposite to the side wall of the permanent magnet 200. Combined with the description of the connection method of the permanent magnet 200, in different embodiments, the first side wall 111a as a whole can form a certain gap with the permanent magnet 200 to facilitate the installation or fixation of the permanent magnet 200; or the first side wall 111a can form an interference fit connection relationship with the permanent magnet 200. For the convenience of description, the following is an embodiment in which the first side wall 111a as a whole has a small gap with the permanent magnet 200 to facilitate the insertion and installation of the permanent magnet 200. In such embodiments, the above gap is used for the insertion and installation of the permanent magnet 200, and only a small amount of injection molding material can flow in within the tolerance range. In addition, different embodiments can be combined with each other between different technical solutions.

[0077] See also Figure 2 , the first side wall 111a defines a first groove body 1111a, and the first groove body 1111a is separated from the end of the first side wall 111a close to the rotation axis. It can be understood that the first groove body 1111a is located on the side of the end of the first side wall 111a close to the rotation axis away from the rotation axis. In some embodiments, the first side wall 111a has a recessed portion, so that the first groove body 1111a can be defined in the recessed portion of the first side wall 111a. In different embodiments, the surface defining the first groove body 1111a can be a wall surface extending as a whole, or a wall surface extending in multiple sections. For the above-mentioned arrangement of the first groove body 1111a, the first groove body 1111a is used for injection molding. It is understandable that the first side wall 111a can define a first slot body 1111a that is recessed in a direction away from the permanent magnet 200, so that the space between the first slot body 1111a and the wall surface of the permanent magnet 200 facing the first side wall 111a can be used to fill the injection molding material to form the injection molding body 400 filled in the first slot body 1111a. In different embodiments, the injection molding body 400 can fill the entire first slot body 1111a, or at least a portion of it can be located in the first slot body 1111a.

[0078] According to the combination of the above embodiments, it can be seen that in some embodiments, an accommodating space can be defined between two adjacent core units of the rotor core 10, and the first lamination 110a in the core unit has a first side wall 111a that can face the permanent magnet 200, and the first side wall 111a defines a first groove body 1111a separated from the end of the first side wall 111a close to the rotation axis, so that the filled injection molding body 400 between the first groove body 1111a and the permanent magnet 200 can enhance the connection tightness of the rotor core 10. Specifically, the injection molding body 400 in the first slot body 1111a can simultaneously connect the first stack 110a and the permanent magnet 200, increasing the injection molding connection area of ​​the first stack 110a on the side wall, and the injection molding body 400 can form a limiting clamping effect with the first slot body 1111a. When the first stack 110a is subjected to a force in the radial direction, the injection molding body 400 in the first slot body 1111a can abut against the first slot body 1111a, so that the injection molding body 400 can generate a limiting force in the radial direction on the first stack 110a to limit the displacement of the first stack 110a in the radial direction. At the same time, the injection molding body 400 can apply a force from the outer peripheral part of the first stack 110a to the inner peripheral part, which can effectively suppress the centrifugal force of the first stack 110a from the inner peripheral part to the outer peripheral part. Therefore, the rotor core 10 of the present invention has a groove body for injection molding on the side wall facing the permanent magnet 200. The grooved side wall enables the injection molding body 400 to be connected to the rotor core 10 and the permanent magnet 200 at the same time, and limits the radial displacement of the rotor core 10, thereby enhancing the connection tightness of the rotor core 10.

[0079] In some embodiments, the size of the first slot body 1111a can be limited so that the injection molding effect in the first slot body 1111a is improved without affecting the performance of the rotor core 10 and the corresponding motor, and the connection tightness of the rotor core 10 and the motor performance are improved. It can be understood that if the size of the first slot body 1111a is too large, it is easy to cause the size of the magnetic channel formed by the rotor core 10 to be too small, resulting in a high degree of saturation of the rotor core 10, which will further reduce the motor output torque and motor efficiency. In order to avoid the above-mentioned saturation phenomenon of the rotor core 10, the radial depth dimension and the circumferential depth dimension of the first slot body 1111a can be limited to a certain range, so as to meet the premise that the saturation degree of the rotor core 10 is not too high, so that the groove area at the first side wall 111a is larger and can be filled with more injection molding material to form a better connection tightness enhancement effect. For details, see. Figure 4In some embodiments, the end of the first lamination 110a away from the rotation axis may be L1 from the rotation axis. The end of the first side wall 111a away from the rotation axis may be understood as the end of the first side wall 111a located radially outward, so L1 may be understood as the maximum distance of the first lamination 110a from the rotation axis along the radial direction of the rotation axis. Based on the above L1 dimension, for example, in some embodiments, the radial dimension L2 of the first slot body 1111a along the rotation axis may satisfy: L2<0.3L1, wherein L2 may be understood as the depth of the first slot body 1111a in the radial direction of the rotation axis; in other embodiments, the circumferential dimension L3 of the first slot body 1111a along the rotation axis may satisfy: L3<0.15L1, wherein L3 may be understood as the depth of the first slot body 1111a in the circumferential direction of the rotation axis. It can be understood that, in some embodiments, the dimension of the first slot body 1111a satisfies the above range, which can enable the rotor core 10 to achieve enhanced bonding within a range of appropriate core saturation. It should be noted that the above-mentioned size limitations on L2 and L3 can be adjusted accordingly according to the different sizes of the rotor core 10 and different motor parameters and operating conditions.

[0080] From the above description of the rotating state of the rotor core 10, it can be seen that the rotor core 10 is easily disconnected from the injection molded body 400 after being subjected to a force in the radial direction, and when the rotor core 10 rotates, it is mainly subjected to the centrifugal force. In order to enable the rotor core 10 of the present invention to more effectively suppress the centrifugal force, the setting position of the first slot body 1111a can be further limited. For details, see Figure 4 In some embodiments, the distance between the end of the first laminate 110a away from the rotation axis of the second side wall 31112b and the end of the first laminate 110a close to the rotation axis of the second side wall 31112b is L4. Figure 4In some embodiments, the end of the first laminate 110a away from the rotation axis can be understood as the end of the first laminate 110a located on the outside in the radial direction. Similarly, the end of the first laminate 110a close to the rotation axis can be understood as the end of the first laminate 110a located on the inside in the radial direction. Therefore, L4 can be understood as the distance between the two ends of the first laminate 110a along the radial direction of the rotation axis. Based on the above definition, in some embodiments, the minimum dimension L5 of the first slot 1111a from the end of the first laminate 110a close to the rotation axis of the second side wall 31112b can satisfy: L5≥L4 / 2. Similarly, L5 can be understood as the minimum distance between the first groove body 1111a and the end of the first stack 110a close to the rotation axis of the second side wall 31112b in the radial direction along the rotation axis. Therefore, satisfying L5≥L4 / 2 can make the first groove body 1111a located between the midpoint of the two ends of the first stack 110a in the radial direction and the outer peripheral wall of the first stack 110a. It can be understood that the first slot body 1111a can be located on one side of the first side wall 111a close to the outer periphery of the first stack 110a. Since the centrifugal force applied to each position of the rotor core 10 is proportional to the distance between the position and the axis of rotation, the above arrangement makes the centrifugal force at the first slot body 1111a larger, and the limiting force of the injection molded body 400 on the first stack 110a toward the inside comes from the reaction force of the centrifugal force, so that the limiting force of the injection molded body 400 in the first slot body 1111a on the first stack 110a toward the inside is larger, and provides a better centrifugal force limiting effect.

[0081] See also Figure 4-Figure 6 In some embodiments, the first side wall 111a may have a first side wall 1113a, and the first side wall 1113a may be connected to the end of the first side wall 111a close to and away from the rotation axis. It can be understood that the first side wall 1113a is the surface of the first side wall 111a close to the rotation axis. In some embodiments, the first side wall 111a may be a multi-segment wall surface, and the multi-segment wall surface includes the first side wall 1113a. In some embodiments, the first side wall 1113a may be perpendicular to the radial direction of the rotation axis. It can be understood that the above-mentioned setting makes the injection molded body 400 connected at the first side wall 1113a also correspondingly a plane, so that the connection of the injection molded body 400 at this location is relatively stable, and the limiting force of the injection molded body 400 on the first laminate 110a toward the inside is perpendicular to the first side wall 1113a, and the limiting force can be parallel to the radial direction of the rotation axis, and the force in this direction makes the centrifugal force limiting effect better. For details, see Figure 4 or Figure 5 In some embodiments, along the radial direction of the rotation axis, the first side wall 1113a may be a straight side in the cross section of the rectangular groove of the first groove body 1111a; see Figure 6In some other embodiments, along the radial direction of the rotation axis, the first side wall 1113a may be a right-angled side in the triangular cross-section of the first slot body 1111a.

[0082] In accordance with different injection molding requirements, in different embodiments, the first groove body 1111a may have different shapes and structures. Figure 4-Figure 6 In some embodiments, the first groove body 1111a can be a polygonal groove of any shape. Specifically, in some embodiments, the first groove body 1111a can be a rectangular groove. The rectangular groove can make the connection of the injection molded body 400 filled in the first groove body 1111a more stable and not easy to fall off; in some embodiments, the two side end surfaces of the rectangular groove along the radial direction of the rotation axis can provide a radial force to the first laminate 110a, so as to provide a better limiting effect. For this type of embodiment, please refer to the above description of the embodiment in which the first side wall 1113a is perpendicular to the radial direction of the rotation axis. In addition, refer to Figure 6 In some embodiments, the first slot body 1111a may be a triangular slot. Figure 2-Figure 3 In other embodiments, the first groove body 1111a may also be an arc groove. Specifically, in different embodiments, along the radial direction of the rotation axis, the cross section of the first groove body 1111a may be an arc shape, and the arc shape may be a circular arc, an elliptical arc, or may be composed of multiple arcs corresponding to different centers of circles. The arc groove form can facilitate the injection molding material to be filled into the first groove body 1111a, and it is not easy to leave a filling gap, and it is convenient for the injection molding material to flow in the first groove body 1111a, thereby improving the connection tightness of the injection molding body 400 and the uniformity of filling.

[0083] Based on the configuration of the first slot body 1111a, in some embodiments, further slot bodies may be provided to achieve a better connection tightness enhancement effect. Figure 7In some embodiments, the first side wall 111a may further define a second groove body 1112a. The second groove body 1112a is located on a side of the first groove body 1111a close to the axis of rotation. The second groove body 1112a is used for injection molding. It can be understood that the above-mentioned second groove body 1112a is similar to the first groove body 1111a, the difference being that the first groove body 1111a is disposed on a side of the first side wall 111a away from the axis of rotation, while the second groove body 1112a is disposed on a side of the first side wall 111a close to the axis of rotation. Therefore, in some embodiments, the second groove body 1112a may have the same shape and structure as the first groove body 1111a. For different configurations of the second groove body 1112a, reference may be made to the above-mentioned related descriptions of different configurations of the first groove body 1111a, which will not be repeated here. Therefore, in some embodiments, the first side wall 111a may be provided with a first slot body 1111a on a side away from the rotation axis, and a second slot body 1112a may be provided on a side close to the rotation axis. The above configuration can make the slot body area of ​​the rotor core 10 used for filling and injection molding larger, thereby further enhancing the bonding force between the rotor core 10 and the permanent magnet 200. At the same time, since the first slot body 1111a and the second slot body 1112a can be respectively provided at the two ends of the first side wall 111a in the radial direction, the limiting force of the injection molded body 400 in the two slot bodies on the first stack 110a in the radial direction is more balanced, so that the connection between the first stack 110a and the injection molded body 400 is not easy to detach from either side, thereby achieving a better effect of enhancing the connection tightness.

[0084] In addition, see Figure 8In some embodiments, the first laminate 110a may further include a second side wall 112a, and the first side wall 111a may be arranged opposite to the second side wall 112a along the circumferential direction of the rotation axis. It can be understood that the first side wall 111a and the second side wall 112a are two side wall surfaces of the first laminate 110a arranged opposite to each other along the circumferential direction of the rotation axis. Along the circumferential direction of the rotation axis, the first side wall 111a may face the permanent magnet 200 on one side of the first laminate 110a, and the second side wall 112a may face the permanent magnet 200 on the other side of the first laminate 110a. It can be understood that, in the present embodiment, corresponding to the first side wall 111a and the second side wall 112a that are arranged relatively along the circumference of the rotation axis of the first laminate 110a, the first laminate 110a has two accommodating spaces along the circumference of the rotation axis, and the permanent magnet 200 can be placed in both accommodating spaces, and the above arrangement enables the first side wall 111a to face the permanent magnet 200 in the accommodating space close to the first side wall 111a, and the second side wall 112a can face the permanent magnet 200 in the accommodating space close to the second side wall 112a. Based on the above configuration, in some embodiments, the second side wall 112a can define a third slot 1121a. The third slot 1121a can be separated from the end of the second side wall 112a close to the rotation axis. In addition, the third slot 1121a can be used for injection molding. It can be understood that the configuration of the third slot body 1121a is similar to the first slot body 1111a described above, except that the third slot body 1121a is disposed on the second side wall 112a. Therefore, in some embodiments, the third slot body 1121a can be arranged relative to the first slot body 1111a along the circumferential direction of the rotation axis, and the third slot body 1121a can have the same shape and structure as the first slot body 1111a. For different configurations of the third slot body 1121a, please refer to the above descriptions of different configurations of the first slot body 1111a, which will not be repeated here.

[0085] For the embodiment in which the first stack 110a is provided with both the first slot body 1111a and the second slot body 1112a. Figure 8In some embodiments, the first slot body 1111a and the third slot body 1121a may be arranged symmetrically about the first plane P. It is understood that in some embodiments, the shape and structure of the first slot body 1111a and the third slot body 1121a may be the same, and the two are arranged symmetrically about the first plane P. The rotation axis may be located in the first plane P. It is understood that in some embodiments, the first plane P is the middle plane that evenly divides the first lamination 110a. When the first slot body 1111a and the third slot body 1121a are arranged symmetrically about the first plane P, it can be more convenient to design and process the first lamination 110a, reduce the design cost and processing cost of the first lamination 110a, and at the same time, the injection molding body 400 filled in the first slot body 1111a and the third slot body 1121a can provide a more symmetrical and uniform bonding force for the rotor core 10.

[0086] As can be seen from the above description of the core unit, the first core unit 100a includes a plurality of laminations stacked in a direction parallel to the rotation axis, including the first lamination 110a. In some embodiments, the first core unit 100a may include other laminations, which may be combined with the configuration of the first lamination 110a in the above embodiments to form a better effect of enhancing the tightness of the connection of the rotor core 10. For details, see Fig. 9 , in some embodiments, the first core unit 100a may further include a second lamination 120a. Similarly, the second lamination 120a may have a third side wall 121a. The third side wall 121a may face one side of the permanent magnet 200. It is understandable that, in some embodiments, the configuration of the second lamination 120a may be similar to that of the first lamination 110a described above. Based on this, the difference between the second lamination 120a and the first lamination 110a is that the end of the third side wall 121a close to the axis of rotation may have a first protrusion 1211a. The first protrusion 1211a may be used to abut against one end of the permanent magnet 200 close to the axis of rotation. It is understandable that, in some embodiments, the first protrusion 1211a may be used to limit the displacement of the permanent magnet 200 close to the axis of rotation. Among them, the extension structure of the first protrusion 1211a will make the magnetic energy distribution there uneven, thereby forming a certain amount of magnetic leakage between adjacent poles, thereby reducing the power density of the motor. Therefore, see Fig. 9 In some embodiments, the third side wall 121a may not have a slot structure, or it can be understood that the minimum distance from the permanent magnet 200 to each position of the third side wall 121a along the radial direction of the rotation axis is the same (excluding the manufacturing tolerance). Based on the above arrangement, the second lamination 120a can have the first protrusion 1211a while reducing the slot arrangement on the side wall surface, thereby avoiding further reduction in the power density of the motor. In addition, considering the need to enhance the tightness of the connection of the rotor core 10, see Fig.10 In some embodiments, the third side wall 121a may be provided with a groove body structure similar to the first groove body 1111a or the second groove body 1112a. For details, please refer to the above-mentioned related embodiments, which will not be repeated here.

[0087] For an embodiment in which the first core unit 100a includes both the first laminate 110a and the second laminate 120a. Fig.11 In some embodiments, along the direction parallel to the rotation axis, a first lamination 110a may be provided at both ends of the first core unit 100a, and at least one second lamination 120a may be located between the two ends of the first core unit 100a. It is understandable that the above arrangement enables the first laminations 110a and the second laminations 120a to be arranged in a staggered manner parallel to the direction along the rotation axis, and at least one first lamination 110a is provided at both ends of the first core unit 100a, so that the grooves on the first laminations 110a form injection channels located on both sides, and the injection material can flow from one end of the first lamination 110a to the other end along the injection channels.

[0088] Further, in some embodiments, the third side wall 121a of the second laminate 120a may include a fourth wall. In some embodiments, the fourth wall may be located on the side of the third side wall 121a close to the axis of rotation, and may be located on the side of the first slot body 1111a close to the axis of rotation. The fourth wall may define a fourth slot body that is recessed in a direction away from the permanent magnet 200, and the fourth slot body is used for injection molding. It is understood that the fourth slot body is similar to the second slot body 1112a. In some embodiments, the first laminate 110a is not provided with the second slot body 1112a (it can be understood that the first side wall 111a is not provided with a slot body on the side close to the axis of rotation), and the third side wall 121a of the second laminate 120a may be provided with a fourth slot body accordingly.

[0089] Based on the stacking arrangement of the first laminations 110a and the second laminations 120a, the combination of the laminations of the first core unit 100a can form a variable injection channel along the direction parallel to the rotation axis. For details, see Fig.11 In some embodiments, the first core unit 100a may include a plurality of first laminations 110a with different first slots 1111a disposed at different positions, so that two first laminations 110a can form injection channels staggered along the axial direction.

[0090] See also Fig.12The second aspect of the present invention further provides a rotor assembly 300a, which includes the rotor core 10, the injection molding body 400 and a plurality of permanent magnets 200 in any of the above embodiments. A receiving space is defined between each two adjacent core units, and at least one permanent magnet 200 is disposed in each receiving space. Fig.12 In some embodiments, the rotor assembly 300a may include a rotating shaft, wherein the rotating shaft may be disposed in the middle of the rotor core 10, and the axis of the rotating shaft may coincide with the rotation axis.

[0091] In some embodiments, the rotor assembly 300a may be provided with a protrusion corresponding to the slot of the rotor core 10, so as to further enhance the connection tightness of the rotor core 10. Fig.13 In some embodiments, the plurality of permanent magnets 200 may include a first magnet 210 facing the first side wall 111a. The wall surface of the first magnet 210 facing the first side wall 111a may have a second protrusion 211. The second protrusion 211 may be at least partially located in the first slot body 1111a. It is understood that the first magnet 210 is located in the accommodation space defined by the first side wall 111a, and the second protrusion 211 can extend into the first slot body 1111a. Along the radial direction of the rotation axis, the side of the second protrusion 211 close to the rotation axis and the side away from the rotation axis may both face the first slot body 1111a. It is understood that in some embodiments, the second protrusion 211 can abut against two surfaces of the first slot body 1111a that are arranged opposite to each other along the radial direction of the rotation axis. In some embodiments, the above arrangement enables the second protrusion 211 to abut against the first slot body 1111a when the rotor core 10 or the permanent magnet 200 moves in the radial direction of the rotation axis, generating an additional limiting effect, thereby further enhancing the connection tightness of the rotor core 10. In some embodiments, the second protrusion 211 may be partially located in the first slot body 1111a, and the gap between the two is filled with the injection molding 400. Through the dual connection limiting effect of the injection molding 400 and the second protrusion 211, the connection tightness of the rotor core 10 can be further improved.

[0092] See also Figure 14-16 The embodiment of the third aspect of the present invention further provides a rotor assembly 300b, specifically, see Fig.14 The rotor assembly 300b includes a plurality of permanent magnets 200, an injection molded body 400 and a rotor core 310b.

[0093] Specifically, the rotor core 310b includes a plurality of core units arranged around the rotation axis of the rotor core 310b. An accommodation space is defined between each two adjacent core units. The accommodation space is used to accommodate the permanent magnet 200. One of the core units is a first core unit 311b. The first core unit 311b is disconnected from the other core units along the circumferential direction of the rotation axis. The first core unit 311b includes a plurality of laminations stacked in a direction parallel to the rotation axis, and one of the laminations is a first lamination 3111b.

[0094] See also Figure 14-15 , based on the above configuration, the first lamination 3111b has a first side wall 31111b. The first side wall 31111b faces one side of the permanent magnet 200. It can be understood that the configuration of the above-mentioned first side wall 31111b is similar to the first side wall 111a in the first aspect embodiment. Based on this, the first side wall 31111b and the permanent magnet 200 jointly define a filling space 600. It can be understood that the fifth side wall opposite to the circumferential direction of the rotation axis and the wall surface of the permanent magnet 200 facing the fifth side wall can define a filling space 600 therebetween. The filling space 600 is filled with the injection molded body 400. Combined with the above embodiments, the filling space 600 can be similar to the function of the first slot body, and the injection molded body 400 in the filling space 600 can simultaneously connect the rotor core 310b and the permanent magnet 200. It should be noted that, in some embodiments, the filling space 600 can be used entirely to fill the injection molded body 400; in other embodiments, the filling space 600 can be used only partially to fill the injection molded body 400. In addition, in some embodiments, the groove of the first side wall 31111b or the groove of the permanent magnet 200 can be used to define the filling space 600. Further, the filling space 600 includes a first gap 610 and a second gap 620. The first gap 610 is located on the side of the second gap 620 away from the axis of rotation. It can be understood that the function of the first gap 610 is similar to that of the first slot body 1111a described above, and in some embodiments, the first gap 610 can be defined by the slot body wall located on the side away from the axis of rotation. Therefore, in some embodiments, the setting method of the first gap 610 can refer to the first slot body 1111a of the first embodiment described above; in other embodiments, the groove of the permanent magnet 200 can be used to define the first gap 610. In particular, the first gap 610 is larger than the second gap 620. It should be noted that, refer to Fig.16When the first side wall 31111b is a straight wall extending in the radial direction, the boundary position between the first gap 610 and the second gap 620 is the midpoint between the two ends of the first side wall 31111b in the radial direction. The above arrangement makes it possible for the volume of the injection molded body 400 in the first gap 610 to be larger than the volume of the injection molded body 400 in the second gap 620 after the injection molded body 400 is injected into the filling space 600 (the injection molded body 400 may not be filled in the second gap 620). When the first stack 3111b is subjected to a centrifugal force directed from the inner peripheral portion to the outer peripheral portion, the injection molded body 400 in the filling space 600 can generate a force in the opposite direction on the first stack 3111b, which is beneficial to suppress the centrifugal force and enhance the connection tightness of the rotor core 310b.

[0095] An embodiment of the fourth aspect of the present invention further provides a motor, which includes the rotor assembly 300a (or rotor assembly 300b) and the stator assembly in any of the above embodiments.

[0096] An embodiment of the fifth aspect of the present invention further provides a household appliance, which comprises the motor in any of the above embodiments.

[0097] Thanks to the improvement of the rotor core 10, the rotor assembly 300a of the second embodiment, the rotor assembly 300b of the third embodiment, the motor of the fourth embodiment, and the household appliance of the fifth embodiment of the present invention all have the same technical effects as the rotor core 10 in the above embodiments, which will not be described in detail here.

[0098] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A rotor core, characterized in that: The rotor core comprises a plurality of core units arranged around the rotation axis of the rotor core, one of the core units being a first core unit, the first core unit being disconnected from the other core units along the circumferential direction of the rotation axis, the first core unit comprising a plurality of laminations stacked in a direction parallel to the rotation axis, one of the laminations being a first lamination; The first laminate has a first side wall, the first side wall can face one side of the permanent magnet, the first side wall defines a first groove body, the first groove body is separated from the end of the first side wall close to the rotation axis, and the first groove body is used for injection molding.

2. The rotor core according to claim 1, characterized in that: The distance between the end of the first laminate away from the rotation axis and the rotation axis is L1; A radial dimension L2 of the first groove body along the rotation axis satisfies: L2<0.3L1, and / or a circumferential dimension L3 of the first groove body along the rotation axis satisfies: L3<0.15L1.

3. The rotor core according to claim 1, characterized in that: Along the radial direction of the rotation axis, the distance between the end of the first lamination away from the rotation axis and the end of the first lamination close to the rotation axis is L4, and the minimum distance L5 between the first slot body and the end of the first lamination close to the rotation axis satisfies: L5≥L4 / 2.

4. The rotor core according to claim 1, characterized in that: The first side wall has a first end surface, the first end surface is used to define the first slot body, the first end surface is connected to the end of the first side wall close to the rotation axis, and the first end surface is perpendicular to the radial direction of the rotation axis.

5. The rotor core according to claim 1, characterized in that: The first slot body is a rectangular slot; or, The first slot body is an arc-shaped slot; or, The first slot body is a triangular slot.

6. The rotor core according to claim 1, characterized in that: The first side wall further defines a second groove body, the second groove body is located on a side of the first groove body close to the rotation axis, and the second groove body is used for injection molding.

7. The rotor core according to claim 1, characterized in that: The first laminate also has a second side wall, and the first side wall and the second side wall are arranged opposite to each other along the circumference of the rotation axis. Along the circumference of the rotation axis, the first side wall can face the permanent magnet on one side of the first laminate, and the second side wall can face the permanent magnet on the other side of the first laminate. The second side wall defines a third groove body, and the third groove body is separated from the end of the second side wall close to the rotation axis, and the third groove body is used for injection molding.

8. The rotor core according to claim 7, characterized in that: The first slot body and the third slot body are arranged symmetrically with respect to a first plane, and the rotation axis is located in the first plane.

9. The rotor core according to claim 1, characterized in that: The first core unit further includes a second lamination, the second lamination having a third side wall, the third side wall being capable of facing a side of the permanent magnet, the end of the third side wall close to the rotation axis having a first protrusion, the first protrusion being used to abut against an end of the permanent magnet close to the rotation axis; Along a direction parallel to the rotation axis, one of the first laminations is disposed at both ends of the first core unit, and at least one of the second laminations is located between the two ends of the first core unit.

10. A rotor assembly, characterized in that: include: The rotor core according to any one of claims 1 to 9; Injection molding; as well as, A plurality of permanent magnets are provided, and a receiving space is defined between each two adjacent core units, and at least one permanent magnet is respectively arranged in each receiving space.

11. The rotor assembly according to claim 10, characterized in that The multiple permanent magnets include a first magnet facing the first side wall, the wall surface of the first magnet facing the first side wall has a second protrusion, the second protrusion is at least partially located in the first slot body, and along the radial direction of the rotation axis, the side of the second protrusion close to the rotation axis and the side away from the rotation axis both face the first slot body.

12. A rotor assembly, characterized in that: include: a plurality of permanent magnets; Injection molding; as well as, A rotor core, comprising a plurality of core units arranged around a rotation axis of the rotor core, wherein an accommodation space is defined between each two adjacent core units, the accommodation space being used to accommodate the permanent magnets, one of the core units being a first core unit, the first core unit being disconnected from the other core units along the circumferential direction of the rotation axis, the first core unit comprising a plurality of laminations stacked in a direction parallel to the rotation axis, one of the laminations being a first lamination; The first stack has a first side wall, the first side wall faces a side of the permanent magnet, the first side wall and the permanent magnet together define a filling space, the filling space is used to fill the injection molded body, the filling space includes a first gap and a second gap, the first gap is located on a side of the second gap away from the rotation axis, and the first gap is larger than the second gap.

13. A motor, characterized in that: include: The rotor assembly according to any one of claims 10 to 12; as well as, Stator assembly.

14. A household appliance, characterized in that: include: The motor as claimed in claim 13.

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