Rotor core, rotor assembly, motor and electric appliance

Abstract

The invention provides a rotor iron core, a rotor assembly, a motor and an electric appliance, the rotor iron core comprises a plurality of iron core units arranged around the rotation axis of the rotor iron core, an accommodating space is defined between every two adjacent iron core units, the accommodating space is used for accommodating a permanent magnet, one of the iron core units is a first iron core unit, and the other iron core unit is a second iron core unit. In the circumferential direction of the rotating axis, the first iron core unit comprises a plurality of laminations which are arranged in a laminated mode in the direction parallel to the rotating axis, and one of the laminations is a first lamination; the side, away from the rotating axis, of the first lamination is provided with an end wall face, the end wall face is provided with a first groove body sunken in the direction close to the rotating axis, and the first groove body communicates with the containing space. The rotor iron core can reduce radial electromagnetic force harmonic waves when the motor runs, so that the performance of the motor is improved, and vibration and noise are reduced.

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 an electrical appliance. Background Art

[0002] Permanent magnet synchronous motors have high power density and torque density and are widely used in the field of household appliances. In order to meet the needs of users, the motors have corresponding performance requirements of high power density and low noise. One of the factors that affect the performance of the motor is the harmonics generated during the operation of the motor. The main source of harmonics is the cogging torque caused by the slot structure between the rotor and the stator, which will cause the torque pulsation of the permanent magnet motor. In particular, the torque pulsation of the permanent magnet synchronous motor will make the sinusoidality of the air gap magnetic field lower, resulting in a large radial electromagnetic force harmonic content when the motor is running, which will affect the performance of the motor and generate greater vibration and noise. Summary of the invention

[0003] The main purpose of the present invention is to provide a rotor core, a rotor assembly, a motor and an electrical appliance, which can reduce radial electromagnetic force harmonics when the motor is running, so as to improve the motor performance and reduce vibration and noise.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0005] A rotor core comprises a plurality of core units arranged around a rotation axis of the rotor core, a receiving space is defined between each two adjacent core units, the receiving space is used to receive a permanent magnet, one of the core units is a first core unit, 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, one of the laminations is a first lamination;

[0006] The first laminate has an end wall surface on one side away from the rotation axis, and the end wall surface has a first groove body that is recessed toward the direction close to the rotation axis, and the first groove body is connected to the accommodating space.

[0007] In some embodiments, the first lamination has a first side wall suitable for facing the permanent magnet, the first slot body has a first slot surface and a second slot surface arranged opposite to each other along the circumferential direction of the rotation axis, the first slot surface is connected to the first side wall and extends in a direction away from the first side wall, one end of the second slot surface is connected to the side of the first slot surface away from the first side wall, and the other end is located on the side of the first slot surface radially away from the rotation axis along the rotation axis.

[0008] In some embodiments, an included angle φ between the first groove surface and the second groove surface satisfies: 90°≤φ≤135°.

[0009] In some embodiments, the first stack has a first side wall suitable for facing the permanent magnet, and a first protrusion is provided at one end of the first side wall away from the rotation axis in the radial direction of the rotation axis. Along the radial direction of the rotation axis, the end of the first protrusion away from the rotation axis is used to define an end wall surface, and the first protrusion is suitable for abutting against the end of the permanent magnet away from the rotation axis.

[0010] In some embodiments, the first slot extends from a side of the first side wall close to the permanent magnet to a side of the first side wall away from the permanent magnet.

[0011] In some embodiments, one of the accommodation spaces is a first accommodation space, the first side wall is used to define the first accommodation space, the first accommodation space is symmetrical about the first plane, and the rotation axis is located in the first plane;

[0012] Along the circumferential direction of the rotation axis, the distance L between the first protrusion and the first plane is 1 and the distance L between the first side wall and the first plane 2 Satisfy: 0.4≤L 1 / L 2 ≤0.6.

[0013] In some embodiments, the end wall also has a second groove body that is recessed in a direction close to the rotation axis, and the second groove body is arranged opposite to the first groove body along the circumferential direction of the rotation axis, so that the first groove body is connected to the accommodating space on one side of the first stack, and the second groove body is connected to the accommodating space on the other side of the first stack.

[0014] In some embodiments, the first trough body and the second trough body are arranged symmetrically about the second plane, and the rotation axis is located in the second plane.

[0015] In some embodiments, along the radial direction of the rotation axis, the minimum distance between the first slot body and the rotation axis is smaller than the minimum distance between the second slot body and the rotation axis.

[0016] An embodiment of the second aspect of the present invention further provides a rotor assembly, comprising the rotor core of any one of the above embodiments and a plurality of permanent magnets.

[0017] An embodiment of the third aspect of the present invention further provides a motor, comprising a rotor assembly and a stator assembly according to any one of the above embodiments.

[0018] In some embodiments, the stator assembly includes a plurality of stator teeth arranged around the rotor assembly, one of the stator teeth being a first stator tooth, the first stator tooth having an inner wall adapted to face the end wall, and a distance between the end wall and the inner wall along the radial direction of the rotation axis being greater than or equal to 0.3 mm.

[0019] In some embodiments, the stator assembly includes a plurality of stator teeth arranged around the rotor assembly, one of the stator teeth is a first stator tooth, the first stator tooth has an inner wall suitable for facing the end wall, the end wall is defined by the first wall and the second wall, the first wall is located on the side of the second wall away from the permanent magnet along the circumferential direction of the rotation axis, and the first wall is located on the side of the second wall away from the rotation axis along the radial direction of the rotation axis, the second wall is used to define a first slot, and along the circumferential direction of the rotation axis, the length L of the first wall 3 Length L to the inner wall 4 Satisfy: 0.9≤L 3 / L 4 ≤1.1.

[0020] An embodiment of the fourth aspect of the present invention further provides an electrical appliance, comprising the motor of any of the above embodiments.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The rotor core of the present invention includes a plurality of core units arranged around the rotation axis of the rotor core, and a storage space is defined between each two adjacent core units, and the storage space is used to store permanent magnets, and one of the core units is a first core unit. Along the circumference of the rotation axis, the first core unit includes a plurality of laminations stacked and arranged in a direction parallel to the rotation axis, and one of the laminations is a first lamination. The first lamination has an end wall surface on the side away from the rotation axis, and the end wall surface has a first slot body that is recessed in the direction close to the rotation axis, and the first slot body is connected to the storage space. The arrangement of the first slot body is to form a relatively sunken structure relative to the unslotted end wall surface, and a larger gap is formed by sinking, so that the magnetic circuit can be guided to extend toward a position with a smaller gap, and the magnetic flux at this position is larger, which is conducive to improving the sinusoidality of the magnetic field and limiting the radial exciting force to a lower range. Therefore, the rotor core of the present invention can reduce the radial electromagnetic force harmonics when the motor is running, so as to improve the motor performance and reduce vibration and noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 A schematic side view of a rotor core provided in a first embodiment of the present invention;

[0025] Figure 2A schematic side view of a first laminate provided in a second embodiment of the present invention;

[0026] Figure 3 A side view schematic diagram of a first laminate provided in a first embodiment of the present invention;

[0027] Figure 4 for Figure 3 A local enlarged schematic diagram of the middle A;

[0028] Figure 5 A side view schematic diagram of a first laminate provided in a third embodiment of the present invention;

[0029] Figure 6 A side view schematic diagram of a first laminate and an adjacent laminate provided in a fourth embodiment of the present invention after being combined;

[0030] Figure 7 for Figure 6 A partial enlarged schematic diagram of point B in the middle;

[0031] Figure 8 A side view schematic diagram of a first laminate provided in a fourth embodiment of the present invention;

[0032] Fig. 9 A side view schematic diagram of a first laminate provided in a fifth embodiment of the present invention;

[0033] Fig.10 A schematic side view of a rotor assembly provided in an embodiment of the second aspect of the present invention;

[0034] Fig.11 A schematic side view of a rotor assembly and a stator assembly combined in an embodiment of the third aspect of the present invention;

[0035] Fig.12 for Fig.11 A partial enlarged schematic diagram of point C in the middle.

[0036] Description of Figure Numbers:

[0037] 10- rotor core;

[0038] 100-a first core unit;

[0039] 110 - first lamination;

[0040] 111-end wall; 1111-first slot body; 11111-first slot surface; 11112-second slot surface; 1112-second slot body; 112-first side wall; 113-first protrusion; 114-first wall surface; 115-second wall surface;

[0041] 200-accommodation space; 210-first accommodation space;

[0042] 300-Permanent magnet;

[0043] 400-rotor assembly;

[0044] 500-stator assembly; 510-first stator tooth; 511-inner wall;

[0045] P1 - first plane;

[0046] P2 - Second plane.

[0047] 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

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Permanent magnet synchronous motors have high power density and torque density and are widely used in the field of household appliances. In order to meet the needs of users, the motors have corresponding performance requirements of high power density and low noise. One of the factors that affect the performance of the motor is the harmonics generated during the operation of the motor. The main source of harmonics is the cogging torque caused by the slot structure between the rotor and the stator, which will cause the torque pulsation of the permanent magnet motor. In particular, the torque pulsation of the permanent magnet synchronous motor will make the sinusoidality of the air gap magnetic field lower, resulting in a large radial electromagnetic force harmonic content when the motor is running, which will affect the performance of the motor and generate greater vibration and noise.

[0052] Specifically, in the related art, the permanent magnet synchronous motor has a rotor assembly and a stator assembly, the rotor assembly is provided with permanent magnets, and the rotor assembly and the stator assembly respectively have relatively arranged rotor walls and stator walls, so that an air gap is formed between the two walls. In order to make the motor perform better, the magnetic flux of the permanent magnet should be transferred from the rotor wall to the stator wall along the rotation direction of the rotor, that is, the magnetic circuit direction is from the rotor wall to the stator wall, and based on the surrounding arrangement structure design of multiple stator / rotor units, the closer the magnetic flux around the stator wall is to the center part of its corresponding stator unit, the greater the sinusoidality of the magnetic field, that is, the magnetic flux or magnetic resistance at the air gap is close to a sinusoidal distribution, which is beneficial to reduce radial electromagnetic harmonics, so as to improve motor performance and reduce vibration and noise.

[0053] In view of this, see Figure 1-Figure 9 In an embodiment of the first aspect of the present invention, a rotor core 10 is provided.

[0054] The rotor core 10 can reduce radial electromagnetic force harmonics when the motor is running, so as to improve the motor performance and reduce vibration and noise.

[0055] The rotor core 10 includes a plurality of core units arranged around the rotation axis of the rotor core 10. It is understood that in some embodiments, the plurality of core units are arranged around the rotation axis to form a plurality of unit bodies of the rotor core 10. In particular, when viewed in a direction parallel to the rotation axis, the core units may be fan-shaped, and the core units may be arranged at equal intervals along the circumference of the rotation axis. For example, see Figure 1 In this embodiment, the rotor core 10 has eight core units.

[0056] An accommodation space 200 is defined between each two adjacent core units, and the accommodation space 200 is used to accommodate the permanent magnet 300. It can be understood that there is a space between the two adjacent core units that can accommodate the permanent magnet 300. Figure 1In this embodiment, the eight core units can jointly define eight accommodating spaces 200, so that the rotor assembly having the rotor core 10 needs to be correspondingly provided with eight permanent magnets 300, and the eight permanent magnets 300 are arranged one by one in the eight accommodating spaces 200. In another embodiment, there can also be a gap between the permanent magnet 300 and the core unit, and other materials can be filled between the two, so that the relative position between each permanent magnet 300 is fixed, or the relative position between the permanent magnet 300 and the core unit is fixed. In yet another embodiment, a plurality of permanent magnets 300 can also be correspondingly arranged in a single accommodating space 200. For example, see Figure 2 The maximum radial dimension of the permanent magnet 300 along the rotor assembly may correspond to the maximum radial dimension of the accommodating space 200. According to the above configuration, the accommodating space 200 may be defined by two circumferentially opposite wall surfaces between two adjacent core units.

[0057] See also Figure 1 , one of the core units is the first core unit 100. Along the circumferential direction of the rotation axis, the first core unit 100 includes a plurality of laminations stacked in a direction parallel to the rotation axis, and one of the laminations is a first lamination 110. It can be understood that at least one of the laminations is a first lamination 110, so in some embodiments, each lamination in the first core unit 100 may include a plurality of first laminations 110.

[0058] Regarding the arrangement of the first core unit 100, in some embodiments, the first core unit 100 can be connected to other core units; in other embodiments, along the circumference of the rotation axis, the first core unit 100 can be disconnected from other core units; in other embodiments, the first core unit 100 can be arranged with other core units at intervals on one side along the radial direction of the rotation axis, and can be connected to other core units on the other side along the radial direction of the rotation axis (for example, the side of the first core unit 100 close to the rotation axis can be connected to other core units, and the side away from the rotation axis can be arranged with other core units at intervals). For ease of description, see Figure 1 , the following is an embodiment in which the first core unit 100 is disconnected from the other core units along the circumferential direction of the rotation axis as an illustration, and different embodiments can be combined with each other between different technical solutions. 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 a rotor assembly and before injection molding. Therefore, in some embodiments, the state in which the first core unit 100 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 100 is separated from the other core units, and in the subsequent manufacturing steps, the injection molding process can be used to connect the core units of the rotor core 10 to each other.

[0059] See also Figure 2 , the first lamination 110 has an end wall surface 111 on one side away from the rotation axis. It can be understood that the end wall surface 111 is the end surface of the first lamination 110 away from the rotation axis in the radial direction of the rotation axis, and the stator assembly corresponding to the rotor core 10 can have an inner peripheral wall facing the rotor core 10, so the end wall surface 111 can be suitable for facing the inner peripheral wall of the stator assembly, so that the gap between the end wall surface 111 and the inner peripheral wall of the stator assembly is suitable for the magnetic circuit to pass through. Since multiple core units are arranged around the rotation axis of the rotor core 10, the side of each core unit away from the rotation axis can jointly define the outer peripheral wall of the rotor core 10, and an annular gap can be formed between the outer peripheral wall of the rotor core 10 and the inner peripheral wall of the stator assembly so that the magnetic circuit can extend circumferentially along the rotation axis; conversely, the side of each core unit close to the rotation axis can jointly enclose an inner ring space located on the side of the rotor core 10 close to the rotation axis, and the inner ring space can be used to fill injection molding material to connect the inner side parts of each rotor core 10, and a shaft can also be passed through the inner ring space so that the rotor core 10 can rotate around the rotation axis.

[0060] Based on the settings of the above embodiments, see Figure 2, the end wall surface 111 has a first slot body 1111 that is recessed toward the direction close to the rotation axis, and the first slot body 1111 is connected to the accommodating space 200. It can be understood that the first slot body 1111 sinks toward the direction close to the rotation axis, and is combined with the stator assembly to be sleeved on the rotor core 10, and the inner circumferential wall of the stator core faces the end surface of each rotor unit, so that along the radial direction of the rotation axis, the distance between the wall surface of the first slot body 1111 and the inner circumferential wall of the stator core is greater than the distance between the unslotted part of the end wall surface 111 and the inner circumferential wall of the stator core, that is, the setting of the first slot body 1111 causes the end wall surface 111 to sink in the radial direction, so that the distance between this part and the inner circumferential wall of the stator core is larger. Combined with the principle and requirements of the motor operation performance, the setting of the first slot body 1111 makes the gap between the slot and the inner circumferential wall of the stator core larger, and the gap between the end wall 111 of the unslotted part and the inner circumferential wall of the stator core smaller, so that the air magnetic resistance around the unslotted end wall 111 is smaller than the air magnetic resistance around the first slot body 1111, and the magnetic circuit generated by the permanent magnet 300 will be preferentially distributed at the position with smaller magnetic resistance, so that the above setting can make the magnetic circuit preferentially extend from the first slot body 1111 to the stator assembly around the unslotted end wall 111 to form a magnetic field loop. According to the demand for the magnetic field energy of the motor, the greater the sinusoidality of the magnetic field, that is, the closer the magnetic flux or magnetic resistance at the air gap is to the law of sinusoidal distribution, the more conducive it is to reduce the radial electromagnetic force harmonics, that is, to reduce the sinusoidal offset of the electromagnetic force. The setting of the first slot body 1111 is to form a larger gap by sinking, so that the magnetic circuit can be guided to extend to the position with smaller gap, and the magnetic flux at this position is larger, which is conducive to forming a magnetic field close to sinusoidal distribution.

[0061] According to the combination of the above embodiments, it can be seen that in some embodiments, the rotor core 10 includes a plurality of core units arranged around the rotation axis of the rotor core 10, and a receiving space 200 is defined between each two adjacent core units, and the receiving space 200 is used to receive the permanent magnet 300, and one of the core units is the first core unit 100. Along the circumferential direction of the rotation axis, the first core unit 100 includes a plurality of laminations stacked in a direction parallel to the rotation axis, and one of the laminations is the first lamination 110. The first lamination 110 has an end wall 111 on one side away from the rotation axis, and the end wall 111 has a first slot body 1111 that is recessed in a direction close to the rotation axis, and the first slot body 1111 is connected to the receiving space 200. The first slot body 1111 is set to form a relatively sunken structure relative to the unslotted end wall 111, and a larger gap is formed by sinking, so that the magnetic circuit can be guided to extend toward a position with a smaller gap, and the magnetic flux at this position is larger, which is conducive to improving the sinusoidality of the magnetic field and limiting the radial exciting force to a lower range. Therefore, the rotor core 10 of the present invention can reduce the radial electromagnetic force harmonics when the motor is running, so as to improve the motor performance and reduce vibration and noise.

[0062] Based on the setting of the first slot body 1111, in addition to reducing the effect of radial electromagnetic force harmonics, through the larger gap formed at the first slot body 1111 and the position of the first slot body 1111 close to the permanent magnet 300, it is also possible to avoid the magnetic field from forming a closed loop at the rotor core 10 to a certain extent, thereby reducing the inter-pole leakage magnetic field of the rotor core 10 and improving the motor performance.

[0063] Regarding the specific form of the first slot body 1111. In some embodiments, the first slot body 1111 may be defined by an arcuate surface, that is, the end wall surface 111 may include an arcuate surface that is concave toward the direction close to the rotation axis, and the arcuate surface extends continuously and defines the first slot body 1111. In other embodiments, the first slot body 1111 may be defined by multiple wall sections. For details, see Figure 2 or Figure 3 In some embodiments, the first laminate 110 may have a first side wall 112 that is adapted to face the side of the permanent magnet 300. The first side wall 112 may be understood as a lateral wall surface that is arranged opposite to the side wall of the permanent magnet 300. Figure 4 In some embodiments, the first groove body 1111 may have a first groove surface 11111 and a second groove surface 11112 which are arranged opposite to each other along the circumferential direction of the rotation axis. The first groove surface 11111 may be connected to the first side wall 112 and extend in a direction away from the first side wall 112. It can be understood that the first groove surface 11111 located on the end wall surface 111 is connected to the first side wall 112, that is, the first groove body 1111 can be connected to the accommodating space 200 defined by the first side edge from the first groove surface 11111. On the other hand, one end of the second groove surface 11112 is connected to the side of the first groove surface 11111 away from the first side wall 112, and the other end is located on the side of the first groove surface 11111 away from the rotation axis along the radial direction of the rotation axis. It can be understood that the second slot surface 11112 can be connected to one end of the first slot surface 11111 away from the first side wall 112 and extend in a direction away from the first slot surface 11111, so that the other end of the second slot surface 11112 connected to the first slot surface 11111 is radially away from the rotation axis relative to the first slot surface 11111. Based on the above arrangement, it is convenient for the magnetic flux of the permanent magnet 300 to be distributed along the extension direction of the first side wall 112 and the extension direction of the second side wall, and because the second slot surface 11112 extends in a direction away from the first slot surface 11111, the arrangement is conducive to the guide magnetic path extending from the first side edge to one end of the first slot surface 11111 away from the first side edge, and then extending from one end of the first slot surface 11111 away from the first side edge to the other end of the second slot surface 11112 connected to the first slot surface 11111 (the gap is smaller at this location), that is, the guide magnetic path extends approximately along the circumference of the rotation axis to the other end to improve the sinusoidality of the magnetic field.

[0064] Based on the first slot surface 11111 and the second slot surface 11112 of the above embodiment, based on different magnetic circuit guidance requirements, different angles can be provided between the first slot surface 11111 and the second slot surface 11112. Specifically, in some embodiments, the angle φ between the first slot surface 11111 and the second slot surface 11112 can satisfy: 90°≤φ≤135°. It can be understood that the above-mentioned minimum angle limit allows the magnetic circuit to extend roughly along the circumferential direction of the rotation axis to the other end, that is, when it is greater than 90°, the second slot surface 11112 extends in a direction away from the first slot surface 11111; in addition, the above-mentioned maximum angle limit allows the radial distance of the end wall surface 111 from the rotation axis to the inner circumferential wall of the stator assembly along the rotation axis to gradually increase within the extension range from one end of the first slot surface 11111 connecting the first side edge to the end of the second slot surface 11112 away from the first slot surface 11111, that is, the radial distance of the end wall surface 111 from the inner circumferential wall of the stator assembly along the rotation axis can be gradually reduced, and within the range of 135°, the gap change is relatively smooth to facilitate the guidance of the magnetic circuit, and the end of the second slot surface 11112 away from the first slot surface 11111 has a certain gap difference relative to the position of the first slot surface 11111, so that the magnetic circuit can be extended to the side with a smaller gap as much as possible through the setting of the gap difference.

[0065] Based on the configuration of the first side wall 112 in the above embodiment, see Figure 3-Figure 4 , along the radial direction of the rotation axis, the first side wall 112 may be provided with a first protrusion 113 at one end away from the rotation axis. In some embodiments, the first protrusion 113 may be adapted to abut against the end of the permanent magnet 300 away from the rotation axis, that is, the first protrusion 113 may be used to limit the movement of the permanent magnet 300 in a direction away from the rotation axis. Since the first protrusion 113 is provided at the end of the first side wall 112 away from the rotation axis, see Figure 3-Figure 4 , along the radial direction of the rotation axis, the end of the first protrusion 113 away from the rotation axis can be used to define the end wall 111. Therefore, in some embodiments, the first protrusion 113 can be arranged at the circumferential end of the first stack 110 along the rotation axis, and the wall surface of the end of the first protrusion 113 away from the rotation axis constitutes the end wall 111 of this end.

[0066] For the above-mentioned first protrusion 113, in some embodiments, the first protrusion 113 will be filled with an injection molding to improve the integrity of the rotor assembly. In order to enhance the connection stability between the first protrusion 113 and the injection molding, the outer edges of the first protrusion 113 can form a clamping effect on the permanent magnet 300. Specifically, in some embodiments, the first protrusion 113 may have a convex surface suitable for facing the permanent magnet 300, and the positive projection of the convex surface on a plane perpendicular to the axis of rotation is the first projection. The first projection may be a straight line. Based on this, the first projection may extend in a direction away from the first side wall 112. From one end of the first projection close to the first side wall 112 to one end away from the first side wall 112, the distance between the first projection and the axis of rotation along the radial direction of the axis of rotation may gradually increase. The raised surface may be located at the inner part of the first protrusion 113 for engaging with the permanent magnet 300, and the raised surface may be at a certain angle relative to the radial direction of the rotation axis, so that the tilt angle may be used to suppress the centrifugal force exerted on the injection molded body, so as to prevent the injection molded body from separating from the rotor core 10 during high-speed rotation. Furthermore, in order to achieve a better centrifugal limiting effect, the length of the first projection may be greater than 1 mm.

[0067] According to the arrangement of the first protrusion 113 in the above-mentioned embodiment, a groove surface of the first groove body 1111 can also be defined, that is, the end of the first protrusion 113 away from the rotation axis can be used to define the first groove surface 11111. The first protrusion 113 can have a first end and a second end arranged relatively to each other along the circumference of the rotation axis, and the first groove surface 11111 can have a third end and a fourth end arranged relatively to each other along the circumference of the rotation axis, wherein the first end is connected to the first side, and the second end is located on the side of the permanent magnet 300 corresponding to the first side close to the first side along the circumference of the rotation axis, and the first groove surface 11111 extends from the third end to the fourth end. Based on this, the first groove body 1111 and the first protrusion 113 can have different relative positional relationships. For details, see Figure 5 In the first relative position embodiment, the first slot body 1111 may be located between the first end and the second end, and the third end and the fourth end of the first slot body 1111 may be located between the first end and the second end, that is, the first slot body 1111 may be located on the side of the first wall surface 114 close to the permanent magnet 300 along the circumferential direction of the rotation axis. Figure 3In the second relative position embodiment, the first slot body 1111 may extend from the side of the first side wall 112 close to the permanent magnet 300 to the side of the first side wall 112 away from the permanent magnet 300. That is to say, the third end of the first slot body 1111 may be located between the first end and the second end (the third end may also coincide with the second end), and the opposite fourth end may be located on the side of the first end away from the permanent magnet 300. It can be understood that in the above two embodiments, the first slot body 1111 may extend from the end of the first protrusion 113 close to the permanent magnet 300 to the end of the first protrusion 113 away from the permanent magnet 300, or from the end of the first protrusion 113 close to the permanent magnet 300 to the side of the first side wall 112 away from the permanent magnet 300. Therefore, according to different magnetic field distribution requirements, the first slot body 1111 may be extended to different positions.

[0068] Based on the configuration of the first side wall 112 in the above embodiment, see Figure 6-Figure 7 In some embodiments, one of the accommodating spaces 200 may be a first accommodating space 210, and the first side wall 112 may be used to define the first accommodating space 210. That is to say, along the circumference of the rotation axis, the first side wall 112 may define the first accommodating space 210 together with the other side wall opposite thereto. The first accommodating space 210 may be symmetrical about the first plane P1, and the rotation axis may be located within the first plane P1. It can be understood that the first plane P1 is the middle plane of the two side walls defining the first accommodating space 210, so that the first plane P1 divides the first accommodating space 210 in half. Based on the above arrangement, in some embodiments, along the circumference of the rotation axis, the distance L between the first protrusion 113 and the first plane P1 is 1 and the distance L between the first side wall 112 and the first plane P1 2 Can satisfy: 0.4≤L 1 / L 2 ≤0.6. Exemplarily, in some embodiments, L 1 / L 2 For the above definition, since the structure of the first protrusion 113 can play a limiting role on the one hand, but on the other hand, its extended structure is prone to magnetic leakage, in order to make the first protrusion 113 have a certain limiting effect and reduce magnetic leakage, the extended length of the first protrusion 113 (that is, the value L of the first protrusion 113 from the first plane P1) can be 1) and the length of the accommodation space 200. It should be noted that, in some embodiments, the laminations on the other side opposite to the first side may also be provided with protrusions, and the above-mentioned embodiment only defines the distance from the first protrusion 113 to the first plane P1 in the middle. For the embodiment in which the laminations on both sides have protrusions, the limiting relationship between the distance between the two protrusions and the distance between the corresponding two side walls can be equivalently obtained, that is, when the laminations on both sides of the rotor core 10 along the circumferential direction are provided with protrusions, and the opposite walls on both sides define the first accommodation space 210, the distance between the two protrusions along the circumferential direction of the rotation axis can be 40%-60% of the width of the first accommodation space 210.

[0069] It should be noted that, in the present invention, the distance between two positions along the circumference of the rotation axis is defined as the arc length corresponding to one of the circumferences of the rotation axis, between the two positions.

[0070] See also Figure 8 In some embodiments, the end wall surface 111 may further include a second slot body 1112 that is recessed toward the direction close to the rotation axis. The second slot body 1112 is arranged opposite to the first slot body 1111 along the circumferential direction of the rotation axis, so that the first slot body 1111 is connected to the accommodation space 200 on one side of the first stack 110, and the second slot body 1112 is connected to the accommodation space 200 on the other side of the first stack 110. It can be understood that along the circumferential direction of the rotation axis, the other side opposite to the first slot body 1111 may include the second slot body 1112, so that the first slot body 1111 and the second slot body 1112 may be respectively located on both sides of the first stack 110 along the circumferential direction of the rotation axis, so as to guide the magnetic circuits on both sides of the first stack 110 to extend toward the middle position with a smaller gap, thereby making the motor have a better sinusoidality.

[0071] The second slot body 1112 described above can be combined with the arrangement of the first side edge in the above embodiment. Specifically, in some embodiments, the first stack 110 can also have a second side wall suitable for facing the other side of the permanent magnet 300. It can be understood that the first side wall 112 and the second side wall are two side walls of the first stack 110 arranged oppositely along the circumference of the rotation axis. Along the circumference of the rotation axis, the first side wall 112 can face the permanent magnet 300 on one side of the first stack 110, and the second side wall can face the permanent magnet 300 on the other side of the first stack 110, and the two can be used to define two adjacent accommodation spaces 200 respectively. Based on the second side wall described above, in some embodiments, the second slot body 1112 can be connected to the second side wall and extend in a direction away from the second side wall. It can be understood that the second slot body 1112 can extend from the second side edge toward the middle of the first stack 110 (or can be understood as extending toward the first slot body 1111), and at the same time, the second slot body 1112 can be connected to the accommodation space 200 correspondingly defined by the second side edge. In addition, the extension form of the second slot body 1112 can also refer to the extension form of the first slot body 1111 in the above-mentioned different embodiments, which will not be repeated here.

[0072] For the first tank body 1111 and the second tank body 1112, see Figure 8 In some embodiments, the first slot body 1111 and the second slot body 1112 can be symmetrically arranged about the second plane P2, and the rotation axis can be located in the second plane P2. It can be understood that the symmetrical arrangement of the two slot bodies can make the magnetic circuits on both sides of the first lamination 110 extend toward the middle position with a smaller gap in the same effect when the motor rotates forward and reverse, that is, when the rotor core 10 rotates in two circumferential directions in opposite directions, the symmetrically arranged first slot body 1111 and the second slot body 1112 can play the same role in guiding the magnetic circuit. Fig. 9In other embodiments, along the radial direction of the rotation axis, the minimum distance between the first slot body 1111 and the rotation axis may be smaller than the minimum distance between the second slot body 1112 and the rotation axis. It is understandable that, corresponding to the above-mentioned embodiment, the first slot body 1111 and the second slot body 1112 may be arranged asymmetrically, and the depth of the first slot body 1111 may be smaller than the depth of the second slot body 1112. According to the different depths of the two slot bodies, when the magnetic field strengths on both sides of the first stack 110 along the circumferential direction of the rotation axis are different, the first slot body 1111 and the second slot body 1112 located on both sides may have different magnetic permeability effects. For example, when the magnetic field strength around the first slot body 1111 is smaller than the magnetic field strength around the second slot body 1112, that is, the depth of the first slot body 1111 may be smaller than the depth of the second slot body 1112, so that the second slot body 1112 has a stronger guiding effect on the magnetic field. In addition, corresponding to the asymmetric arrangement of the two slots, in some embodiments, along the circumferential direction of the rotation axis, the extension length of the first slot 1111 may be smaller than the extension length of the second slot 1112. According to the different extension lengths of the two slots, the two slots can have different guiding effects on the magnetic field. For example, when the extension length of the second slot 1112 is greater than the extension length of the first slot 1111, the second slot 1112 can have a stronger guiding effect on the magnetic field.

[0073] See also Figure 1-Figure 10 The embodiment of the second aspect of the present invention further provides a rotor assembly 400, see Fig.10 The rotor assembly 400 includes the rotor core 10 of any of the above embodiments and a plurality of permanent magnets 300 .

[0074] See also Fig.10 , in some embodiments, the rotor assembly 400 may further include an injection molded body. In some embodiments, when each rotor core 10 is arranged disconnected from each other, the injection molded body is coated on the outside of the rotor core 10, and the injection molded body fills the gap between the rotor core 10 and the rotating shaft, and the injection molded body connects the rotating shaft and the rotor core 10 respectively. The rotating shaft may not be directly connected to each core unit, but is indirectly connected through the injection molded body. In the specific processing process, the relative position between the rotating shaft and the rotor core 10 can be located first, and then injection molding can be performed in the gap between the two to form an injection molded body, so that the injection molded body wraps the outer wall surface of the rotor core 10 and fills the gap between the rotating shaft and the rotor core 10, thereby achieving the purpose of fixing the rotating shaft and the rotor core 10. The injection molded body can also protect the rotor core 10 and increase the service life of the rotor core 10. To further improve the connection stability of the injection molded body, refer to Figure 1-Figure 10 In some embodiments, the rotor core 10 may be provided with an axial through hole, which may extend in the stacking direction of the plurality of laminations (ie, the thickness direction) so that the injection material can be poured into the axial through hole during the rotor injection molding.

[0075] See also Figure 1-Figure 11 The embodiment of the third aspect of the present invention further provides a motor, which includes a rotor assembly 400 and a stator assembly 500 of any of the above embodiments.

[0076] The motor according to the embodiment of the third aspect. Fig.11 In some embodiments, the stator assembly 500 may include a plurality of stator teeth arranged around the rotor assembly 400. Specifically, the stator core may include a stator yoke and a plurality of stator teeth, and the plurality of stator teeth may be uniformly distributed along the inner side of the stator yoke with the center of the motor as the center. In order to make the electrode have better performance, the ratio of the number of stator teeth to the number of laminations may be 3:2. One of the stator teeth is a first stator tooth 510. The first stator tooth 510 has an inner side wall 511 suitable for facing the end wall 111. It can be understood that the stator assembly 500 can be sleeved on the rotor assembly 400, and the inner side wall 511 of the first stator tooth 510 facing the end wall 111 can form a closed magnetic field loop from the end wall 111 to the inner side wall 511. Based on the above arrangement, in some embodiments, along the radial direction of the rotation axis, the value of the end wall 111 from the inner side wall 511 may be greater than or equal to 0.3 mm. It can be understood that the groove body portion of the end wall 111 (which may include multiple grooves such as the first groove body 1111, the second groove body 1112, etc.) and the wall surface of the end wall 111 facing the inner wall 511 and protruding toward the inner wall 511 relative to the groove body portion both satisfy that the gap with the inner wall 511 is greater than or equal to 0.3 mm, so that the gap at the groove body is greater than or equal to 0.3 mm, which makes the groove body have a better magnetic circuit guiding effect. The gap at the wall surface facing the inner wall 511 is greater than or equal to 0.3 mm, which can make the motor performance better and the sinusoidality of the magnetic field of this part higher.

[0077] The first stator tooth 510 is arranged based on the above embodiment. Fig.12In some embodiments, the end wall 111 may be defined by a first wall 114 and a second wall 115. The first wall 114 may be located on the side of the second wall 115 away from the permanent magnet 300 along the circumferential direction of the rotation axis. The first wall 114 may be located on the side of the second wall 115 away from the rotation axis in the radial direction of the rotation axis, and the second wall 115 is used to define the first slot 1111. According to the above definition, it can be understood that in some embodiments, the second wall 115 may be the wall of the first laminate 110 close to the permanent magnet 300, and one end of the first wall 114 may be connected to the end of the second wall 115 away from the permanent magnet 300 along the circumferential direction of the rotation axis, and extend in the direction close to the first stator tooth 510, and then the first wall 114 may protrude toward the inner wall 511 relative to the second wall 115. Based on the above arrangement, in some embodiments, along the circumferential direction of the rotation axis, the length L of the first wall 114 is 3 The length L of the inner wall 511 4 Can satisfy: 0.9≤L 3 / L 4 ≤1.1. Exemplarily, in some embodiments, L 3 / L 4 It can be one of 0.9, 0.95, 1, 1.05, and 1.1. It is understandable that the ratio of the length of the main arc (i.e., the first wall 114) of the rotor core located at the end wall 111 to the length of the inner arc of the stator tooth shoe (i.e., the inner wall 511) can be between 0.9 and 1.1. The above definition can make the magnetic field at the gap more concentrated and the sinusoidality of the magnetic field higher.

[0078] It should be noted that, in the present invention, the length L of the first wall 114 is defined as 3 The length L of the inner wall 511 4 The tangent line used (i.e. Fig.12 Middle arc length L 4 and L 3 The dotted lines on both sides are expressed as follows: (taking the first wall 114 as an example) The first wall 114 has two ends along the circumference of the rotation axis, wherein each end point is used to connect with the wall adjacent to the first wall 114, and the line connecting one of the end points and the rotation axis defines a tangent line on this side, and the same is true for the tangent line on the other side. Similarly, the length of the above two walls along the circumference of the rotation axis is expressed as the arc length formed by the orthographic projection of the wall along the direction parallel to the rotation axis.

[0079] An embodiment of the fourth aspect of the present invention further provides an electrical appliance, wherein the motor comprises the motor of any of the above embodiments.

[0080] Thanks to the improvements on the rotor core 10 in the above embodiments, the rotor assembly 400 of the second embodiment, the motor of the third embodiment, and the electrical appliance of the second 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.

[0081] 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, wherein an accommodation space is defined between each two adjacent core units, and the accommodation space is used to accommodate a permanent magnet, and one of the core units is a first core unit. Along the circumferential direction of the rotation axis, the first core unit comprises a plurality of laminations stacked and arranged in a direction parallel to the rotation axis, and one of the laminations is a first lamination; The first laminate has an end wall surface on a side away from the rotation axis, and the end wall surface has a first groove body that is recessed in a direction close to the rotation axis, and the first groove body is connected to the accommodating space.

2. The rotor core according to claim 1, characterized in that: The first stack has a first side wall suitable for facing the permanent magnet, the first slot body has a first slot surface and a second slot surface arranged opposite to each other along the circumferential direction of the rotation axis, the first slot surface is connected to the first side wall and extends in a direction away from the first side wall, one end of the second slot surface is connected to the side of the first slot surface away from the first side wall, and the other end is located on the side of the first slot surface away from the rotation axis along the radial direction of the rotation axis.

3. The rotor core according to claim 2, characterized in that: An included angle φ between the first groove surface and the second groove surface satisfies: 90°≤φ≤135°.

4. The rotor core according to claim 1, characterized in that: The first stack has a first side wall suitable for facing the permanent magnet. Along the radial direction of the rotation axis, the end of the first side wall away from the rotation axis is provided with a first protrusion. Along the radial direction of the rotation axis, the end of the first protrusion away from the rotation axis is used to define the end wall surface. The first protrusion is suitable for abutting against the end of the permanent magnet away from the rotation axis.

5. The rotor core according to claim 4, characterized in that: The first slot body extends from a side of the first side wall close to the permanent magnet to a side of the first side wall far from the permanent magnet.

6. The rotor core according to claim 4, characterized in that: One of the accommodating spaces is a first accommodating space, the first side wall is used to define the first accommodating space, the first accommodating space is symmetrical about a first plane, and the rotation axis is located in the first plane; Along the circumferential direction of the rotation axis, a value L1 of the first protrusion from the first plane and a value L2 of the first side wall from the first plane satisfy: 0.4≤L1 / L2≤0.

6.

7. The rotor core according to claim 1, characterized in that: The end wall surface also has a second groove body recessed in a direction close to the rotation axis, and the second groove body is arranged opposite to the first groove body along the circumferential direction of the rotation axis, so that the first groove body is connected to the accommodating space on one side of the first stack, and the second groove body is connected to the accommodating space on the other side of the first stack.

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

9. The rotor core according to claim 7, characterized in that: Along the radial direction of the rotation axis, the minimum distance between the first slot body and the rotation axis is smaller than the minimum distance between the second slot body and the rotation axis.

10. A rotor assembly, characterized in that: include: The rotor core according to any one of claims 1 to 9; as well as, Multiple permanent magnets.

11. A motor, characterized in that: include: The rotor assembly according to claim 10; as well as, Stator assembly.

12. The motor according to claim 11, characterized in that The stator assembly includes a plurality of stator teeth arranged around the rotor assembly, one of the stator teeth being a first stator tooth, the first stator tooth having an inner side wall adapted to face the end wall, and a distance between the end wall and the inner side wall along the radial direction of the rotation axis being greater than or equal to 0.3 mm.

13. The motor according to claim 11, characterized in that The stator assembly includes a plurality of stator teeth arranged around the rotor assembly, one of the stator teeth being a first stator tooth, the first stator tooth having an inner side wall suitable for facing the end wall, the end wall being defined by a first wall and a second wall, the first wall being located on a side of the second wall away from the permanent magnet along the circumferential direction of the rotation axis, and the first wall being located on a side of the second wall away from the rotation axis along the radial direction of the rotation axis, the second wall being used to define the first slot body, and along the circumferential direction of the rotation axis, a length L3 of the first wall and a length L4 of the inner side wall satisfy: 0.9≤L3 / L4≤1.

1.

14. An electrical appliance, characterized in that: include: A motor as claimed in any one of claims 11 to 13.

Images