Rotor core, rotor assembly, motor and air conditioner

Abstract

The utility model discloses a rotor core, a rotor assembly, a motor and an air conditioner, the rotor core rotates around a rotation axis, the rotor core comprises a plurality of iron core units arranged at intervals along the circumferential direction of the rotor core, an installation groove for installing a permanent magnet is formed between two adjacent iron core units, each iron core unit comprises an outer magnetic bridge and an inner magnetic bridge, the outer magnetic bridge and the inner magnetic bridge are located on the same side of the iron core unit in the circumferential direction, the outer magnetic bridge and the inner magnetic bridge are used for limiting the two ends, in the radial direction of the rotor iron core, of the permanent magnet respectively, the iron core unit comprises a plurality of punching sheet units arranged in a stacked mode in the direction of the rotating axis, and the side walls of part of the punching sheet units protrude towards the mounting grooves to form the outer magnetic bridge; and / or the side walls of part of the punching sheet units protrude towards the mounting grooves to form inner magnetic bridges. The rotor core of the utility model can reduce magnetic leakage, improve the utilization rate of the permanent magnets, and improve the efficiency of the motor.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical equipment, in particular to a rotor core, a rotor assembly, a motor and an air conditioner. Background Art

[0002] The efficiency of the motor is one of the factors affecting the overall energy efficiency of the air conditioner. In the related technology, the rotor slot of the motor is small, the magnetic pole leakage is large, and the utilization rate of the permanent magnet is low, which leads to a decrease in the motor efficiency and affects the overall energy efficiency of the air conditioner. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a rotor core which can reduce magnetic leakage and improve the utilization rate of permanent magnets to improve the efficiency of the motor.

[0004] The utility model also provides a rotor assembly, a motor and an air conditioner having the rotor core.

[0005] According to the rotor core of the embodiment of the first aspect of the utility model, it rotates around the rotation axis, and the rotor core includes a plurality of core units arranged at intervals along the circumference of the rotor core, and an installation groove for installing a permanent magnet is formed between two adjacent core units. The core unit includes an outer magnetic bridge and an inner magnetic bridge, and the outer magnetic bridge and the inner magnetic bridge are located on the same side of the core unit along the circumference, and the outer magnetic bridge and the inner magnetic bridge are respectively used to limit the permanent magnet at both ends of the radial direction of the rotor core, and the core unit includes a plurality of punching sheet units stacked along the direction of the rotation axis, and the side walls of some of the punching sheet units protrude toward the installation groove to form the outer magnetic bridge, and / or the side walls of some of the punching sheet units protrude toward the installation groove to form the inner magnetic bridge.

[0006] The rotor core according to the embodiment of the first aspect of the utility model has at least the following beneficial effects: by forming the external magnetic bridge only on part of the punching sheet units, or the internal magnetic bridge only on part of the punching sheet units, or the external magnetic bridge and the internal magnetic bridge are respectively formed on part of the punching sheet units, the distance between the outer ends and / or the inner ends of some positions of two adjacent core units is increased, thereby increasing the magnetic resistance between the outer ends and / or the inner ends of two adjacent core units, that is, reducing the magnetic permeability, thereby reducing the leakage magnetic flux of the permanent magnet, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet, which is beneficial to improving the no-load back electromotive force and efficiency of the motor.

[0007] According to some embodiments of the utility model, the plurality of punching sheet units include a second punching sheet unit, the second punching sheet unit having two first side walls opposing each other along the circumferential direction, the first side walls extending along the radial direction to a first outer wall surface of the second punching sheet unit opposing the rotation axis and a first inner wall surface of the second punching sheet unit close to the rotation axis.

[0008] According to some embodiments of the utility model, the plurality of punching sheet units also include a first punching sheet unit, the first punching sheet unit includes a first magnetic bridge and a second magnetic bridge, the first magnetic bridge and the second magnetic bridge are located on one side of the first punching sheet unit along the circumferential direction, the first magnetic bridge and the second magnetic bridge are respectively located at both ends of the first punching sheet unit along the radial direction, the first magnetic bridge is a part of the outer magnetic bridge, and the second magnetic bridge is a part of the inner magnetic bridge.

[0009] According to some embodiments of the utility model, the core unit includes two first punching sheet groups and one second punching sheet group stacked along the direction of the rotation axis, the two first punching sheet groups are respectively located at both ends of the second punching sheet group, the first punching sheet group includes a plurality of first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of second punching sheet units stacked along the direction of the rotation axis.

[0010] According to some embodiments of the utility model, the core unit includes a first punching sheet group and two second punching sheet groups stacked along the direction of the rotation axis, the first punching sheet group is located between the two second punching sheet groups, the first punching sheet group includes a plurality of the first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of the second punching sheet units stacked along the direction of the rotation axis.

[0011] According to some embodiments of the utility model, the core unit includes a plurality of first punching sheet groups and a plurality of second punching sheet groups stacked along the direction of the rotation axis, and the plurality of first punching sheet groups and the plurality of second punching sheet groups are arranged alternately, the first punching sheet group includes a plurality of first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of second punching sheet units stacked along the direction of the rotation axis.

[0012] According to some embodiments of the utility model, the plurality of punching sheet units include a third punching sheet unit, the third punching sheet unit includes a third magnetic bridge, the third magnetic bridge is located on one side of the third punching sheet unit along the circumferential direction and at one end of the third punching sheet unit close to the rotation axis, the third magnetic bridge is a part of the inner magnetic bridge, and the third punching sheet unit has two second side walls opposite to each other along the circumferential direction, the second side walls extend along the radial direction to the second outer wall surface of the third punching sheet unit opposite to the rotation axis.

[0013] According to some embodiments of the utility model, the plurality of punching sheet units include a fourth punching sheet unit, the fourth punching sheet unit includes a fourth magnetic bridge, the fourth magnetic bridge is located on one side of the fourth punching sheet unit along the circumferential direction and at an end of the fourth punching sheet unit away from the rotation axis, the fourth magnetic bridge is a part of the external magnetic bridge, and the fourth punching sheet unit has two third side walls that are opposite to each other along the circumferential direction, and the third side walls extend along the radial direction to the second inner wall surface of the fourth punching sheet unit close to the rotation axis.

[0014] According to some embodiments of the utility model, a slot is further defined between two adjacent core units, the slot is located at one end of the mounting slot away from the rotation axis and connected to the mounting slot, and along the circumferential direction, the minimum width of the slot is W, satisfying: 1mm≤W≤7.4mm.

[0015] According to some embodiments of the present invention, along the radial direction, the maximum width of the outer magnetic bridge is L, and the maximum outer diameter of the rotor core is D, satisfying: 0.02D≤L≤0.025D.

[0016] According to some embodiments of the present invention, along the direction of the rotation axis, the total height of the external magnetic bridge is h, and the height of the rotor core is H, satisfying: H / 9≤h≤H / 3.

[0017] According to the second embodiment of the utility model, the rotor assembly comprises an injection molded body and the rotor core of the first embodiment of the utility model, wherein the rotor core is wound around the outer circumference of the injection molded body, and the inner magnetic bridge is embedded in the injection molded body.

[0018] According to the rotor assembly of the embodiment of the second aspect of the utility model, there are at least the following beneficial effects: since the rotor assembly adopts the above-mentioned rotor core, by forming the external magnetic bridge only in part of the punching sheet units, or the internal magnetic bridge only in part of the punching sheet units, or the external magnetic bridge and the internal magnetic bridge are respectively formed in part of the punching sheet units, the distance between the outer ends and / or the inner ends of some positions of two adjacent core units is increased, thereby increasing the magnetic resistance between the outer ends and / or the inner ends of two adjacent core units, that is, reducing the magnetic permeability, thereby reducing the leakage magnetic flux of the permanent magnet, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet, which is beneficial to improving the no-load back electromotive force and efficiency of the motor.

[0019] The motor according to the third embodiment of the utility model comprises the rotor assembly and the stator assembly of the second embodiment of the utility model, wherein the stator assembly is wound around the outer circumference of the rotor assembly.

[0020] The motor according to the embodiment of the third aspect of the utility model has at least the following beneficial effects: since the motor adopts the above-mentioned rotor assembly, by forming the external magnetic bridge only on part of the punching sheet units, or the internal magnetic bridge only on part of the punching sheet units, or the external magnetic bridge and the internal magnetic bridge are respectively formed on part of the punching sheet units, the distance between the outer ends and / or the inner ends of some positions of two adjacent core units is increased, thereby increasing the magnetic resistance between the outer ends and / or the inner ends of two adjacent core units, that is, reducing the magnetic permeability, thereby reducing the leakage magnetic flux of the permanent magnet, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet, which is beneficial to improving the no-load back electromotive force and efficiency of the motor.

[0021] An air conditioner according to an embodiment of the fourth aspect of the utility model comprises the motor according to the embodiment of the third aspect of the utility model.

[0022] The air conditioner according to the embodiment of the fourth aspect of the utility model has at least the following beneficial effects: since the air conditioner adopts the above-mentioned motor, by forming the external magnetic bridge only on part of the punching sheet units, or the internal magnetic bridge only on part of the punching sheet units, or the external magnetic bridge and the internal magnetic bridge are respectively formed on part of the punching sheet units, the distance between the outer ends and / or the inner ends of some positions of two adjacent core units is increased, thereby increasing the magnetic resistance between the outer ends and / or the inner ends of two adjacent core units, that is, reducing the magnetic permeability, thereby reducing the leakage magnetic flux of the permanent magnet, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet, which is beneficial to improving the no-load back electromotive force and efficiency of the motor and improving the energy efficiency of the air conditioner.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0025] Figure 1 It is an axial schematic diagram of the motor in the embodiment of the utility model;

[0026] Figure 2 It is an axial schematic diagram of the first rotor punching sheet in the embodiment of the utility model;

[0027] Figure 3 It is an axial schematic diagram of the second rotor punching sheet in the embodiment of the utility model;

[0028] Figure 4 It is an axial schematic diagram of the third rotor punching sheet in the embodiment of the utility model;

[0029] Figure 5 It is an axial schematic diagram of the fourth rotor punching sheet in the embodiment of the utility model;

[0030] Figure 6 is a schematic diagram of the structure of the rotor assembly in some embodiments of the utility model;

[0031] Figure 7 is a front view of a rotor core in some embodiments of the utility model;

[0032] Figure 8 It is a front view of the rotor core in other embodiments of the utility model;

[0033] Fig. 9 It is a front view of the rotor core in other embodiments of the utility model;

[0034] Fig.10 It is a columnar schematic diagram comparing the no-load back electromotive force of the motor in some embodiments of the utility model with the prior art.

[0035] Reference numerals:

[0036] First rotor punching sheet 100; first punching sheet unit 110; first mounting groove 120; first magnetic bridge 130; second magnetic bridge 140; first notch 150;

[0037] The second rotor punching sheet 200; the second punching sheet unit 210; the second mounting groove 220; the first side wall 230; the first outer wall surface 240; the first inner wall surface 250; the second notch 260;

[0038] The third rotor punching sheet 300; the third punching sheet unit 310; the third mounting groove 320; the third magnetic bridge 330; the second side wall 340; the second outer wall surface 350; the third notch 360;

[0039] Fourth rotor punching sheet 400; fourth punching sheet unit 410; fourth mounting groove 420; fourth magnetic bridge 430; third side wall 440; second inner wall surface 450; fourth notch 460;

[0040] Rotor assembly 1000; rotor core 1100; first punching sheet group 1110; second punching sheet group 1120; core unit 1130; permanent magnet 1200; injection molding body 1300;

[0041] Stator assembly 2000;

[0042] Main magnetic circuit X; leakage magnetic circuit Y. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0046] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, assembling, and matching should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0047] The efficiency of the motor is one of the factors affecting the overall energy efficiency of the air conditioner. Taking a permanent magnet motor as an example, the rotor core of a permanent magnet motor is usually composed of a plurality of sector-shaped parts arranged at intervals along the direction around the axis of rotation, and the permanent magnet is installed in the mounting groove between two adjacent sector-shaped parts. In the related art, the distance between the outer ends or the inner ends of two adjacent sector-shaped parts is small, that is, the notch of the mounting groove is small, or the outer ends or the inner ends of two adjacent sector-shaped parts are connected, resulting in a large magnetic permeability between the outer ends or the inner ends of the two adjacent sector-shaped parts, and part of the magnetic flux lines (i.e., leakage magnetic path Y) of the magnetic field generated by the permanent magnet is directly closed between the outer ends or the inner ends of the two adjacent sector-shaped parts without passing through the stator assembly, thereby causing leakage magnetic flux, and the leakage magnetic flux accounts for a large proportion of the total magnetic flux. The utilization rate of the permanent magnet is low, resulting in a decrease in motor efficiency, which affects the overall energy efficiency of the air conditioner.

[0048] For this purpose, refer to Figures 1 to 10 As shown, the first embodiment of the utility model provides a rotor core 1100, which is applied to the rotor assembly 1000 of the motor of the air conditioner. The motor here can be used to drive the wind wheel of the outdoor unit of the air conditioner to rotate, or to drive the wind wheel of the indoor unit of the air conditioner to rotate, and the motor is a permanent magnet motor.

[0049] Reference Figure 1 and Figure 6 As shown, it can be understood that the rotor assembly 1000 of the motor includes a rotor core 1100, an injection molded body 1300 and a plurality of permanent magnets 1200. Specifically, the rotor core 1100 has a central axis, and the rotor core 1100 rotates around the central axis, and the central axis of the rotor core 1100 is the rotation axis. The rotor core 1100 is composed of a plurality of rotor punchings stacked along the direction of the rotation axis, and the rotor core 1100 includes a plurality of core units 1130 spaced apart along the circumferential direction, the circumferential direction is the direction around the rotation axis, and the direction along the rotation axis is defined as the axial direction of the rotor core 1100.

[0050] Reference Figure 2As shown, it can be understood that the plurality of rotor punching sheets include a first rotor punching sheet 100 and a second rotor punching sheet 200. Specifically, the first rotor punching sheet 100 includes a plurality of first punching sheet units 110 arranged at intervals along the circumference of the rotor core 1100. A first mounting groove 120 is defined between two adjacent first punching sheet units 110, and the number of the first mounting grooves 120 is equal to the number of the first punching sheet units 110. On the projection plane perpendicular to the axis of rotation, the projection of the first punching sheet unit 110 is roughly fan-shaped, and the projection of the first mounting groove 120 is roughly rectangular. It is easy to understand that the inner ends and outer ends of the two adjacent first punching sheet units 110 are disconnected, that is, each first punching sheet unit 110 is independent, which is conducive to the production of sample arrangement on the silicon steel plate, reducing waste, improving material utilization, and reducing costs. The inner end is the end close to the axis of rotation, and the outer end is the end away from the axis of rotation. It is easy to understand that the inner ends and outer ends of the two adjacent core units 1130 are also disconnected.

[0051] Reference Figure 2 As shown, it can be understood that the first punching unit 110 also includes a first magnetic bridge 130 and a second magnetic bridge 140, which are located on one side of the first punching unit 110 along the circumference of the rotor core 1100 and extend along the circumference of the rotor core 1100, and the first magnetic bridge 130 protrudes toward the first mounting groove 120, and the first magnetic bridge 130 is located at the end of the first mounting groove 120 away from the rotation axis, that is, the first magnetic bridge 130 is located at the outer end of the first mounting groove 120, and the first magnetic bridge 130 is a part of the outer magnetic bridge. The second magnetic bridge 140 is located at the end of the first mounting groove 120 close to the rotation axis, and the second magnetic bridge 140 protrudes toward the first mounting groove 120, that is, the second magnetic bridge 140 is located at the inner end of the first mounting groove 120, and the second magnetic bridge 140 is a part of the inner magnetic bridge.

[0052] Reference Figure 3 As shown, it can be understood that the second rotor sheet 200 includes a plurality of second sheet units 210 arranged at intervals along the circumference of the rotor core 1100, and a second mounting groove 220 is defined between two adjacent second sheet units 210, and the number of the second mounting grooves 220 is equal to the number of the second sheet units 210. And the number of the second sheet units 210 is equal to the number of the first sheet units 110. Similarly, on the projection plane perpendicular to the axis of rotation, the projection of the second sheet unit 210 is roughly fan-shaped, and the projection of the second mounting groove 220 is roughly rectangular. The inner ends and outer ends of two adjacent second sheet units 210 are disconnected, that is, each second sheet unit 210 is independent, and refers to the first sheet unit 110, which will not be repeated here.

[0053] Reference Figure 1As shown, it can be understood that the number of permanent magnets 1200 is equal to the number of first mounting slots 120. In this embodiment, the number of first punching units 110, the number of first mounting slots 120, the number of second punching units 210, the number of second mounting slots 220, and the number of permanent magnets 1200 are all ten. Of course, the above numbers are not specifically limited here.

[0054] Reference Figure 3 As shown, it can be understood that the second mounting groove 220 has two first side walls 230 arranged oppositely along the circumferential direction of the rotor core 1100. The wall surface of the second punching unit 210 close to the rotation axis is defined as the first inner wall surface 250, and the wall surface of the second punching unit 210 away from the rotation axis is defined as the first outer wall surface 240. The outer ends of the two first side walls 230 extend to the first outer wall surface 240 along the radial direction of the rotor core 1100, and the inner ends of the two first side walls 230 extend to the first inner wall surface 250 along the radial direction of the rotor core 1100, that is, the structure corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis in the second punching unit 210 is cancelled, and the outer end of the second mounting groove 220 is fully open. Therefore, the distance between the outer ends and the distance between the inner ends of two adjacent second punching units 210 can be increased.

[0055] Reference Figure 1 and Figure 6As shown, it can be understood that a plurality of first rotor sheets 100 and a plurality of second rotor sheets 200 are stacked and arranged in the direction of the rotation axis to form a rotor core 1100, the first sheet unit 110 and the second sheet unit 210 are arranged correspondingly in the axial direction of the rotor core 1100, and the first installation groove 120 and the second installation groove 220 are arranged correspondingly in the axial direction of the rotor core 1100 and are connected to form an installation groove for installing the permanent magnet 1200. It is easy to understand that the plurality of first sheet units 110 and the plurality of second sheet units 210 correspondingly arranged in the axial direction of the rotor core 1100 are connected by a buckle connection portion and form a core unit 1130 of the rotor core 1100, that is, the plurality of sheet units constituting the core unit 1130 include the first sheet unit 110 and the second sheet unit 210. The plurality of first magnetic bridges 130 correspondingly arranged in the axial direction of the rotor core 1100 constitute an outer magnetic bridge, and the plurality of second magnetic bridges 140 correspondingly arranged in the axial direction of the rotor core 1100 constitute an inner magnetic bridge. The permanent magnet 1200 is installed in the plurality of first mounting grooves 120 and the plurality of second mounting grooves 220 correspondingly arranged and connected in the axial direction of the rotor core 1100, wherein the first magnetic bridge 130 abuts against the outer end of the permanent magnet 1200, and the second magnetic bridge 140 abuts against the inner end of the permanent magnet 1200. Therefore, the permanent magnet 1200 can be limited in the radial direction of the rotor core 1100 by the first magnetic bridge 130 and the second magnetic bridge 140, and during the operation of the motor, that is, during the rotation of the rotor assembly 1000, the first magnetic bridge 130 can provide an inward supporting force to the permanent magnet 1200 to offset the centrifugal force acting on the permanent magnet 1200, so as to avoid the permanent magnet 1200 from loosening during the operation of the motor and affecting the performance of the motor. At the same time, the force of the first magnetic bridge 130 on the permanent magnet 1200 and the force of the second magnetic bridge 140 on the permanent magnet 1200 act on the same axial position of the permanent magnet 1200 along the axial direction of the rotor core 1100. The use of the permanent magnet 1200 makes the force more balanced and the installation stability better.

[0056] Reference Figure 1 and Figure 6 As shown, it can be understood that the rotor core 1100 is wound around the outer periphery of the injection molding body 1300, that is, a plurality of core units 1130 are arranged around the outer periphery of the injection molding body 1300, and the second magnetic bridge 140 is embedded in the injection molding body 1300, and the injection molding body 1300 is filled to the inner end of the permanent magnet 1200, that is, the space between the inner ends of two adjacent core units 1130 is filled with the injection molding body 1300. Thereby, the plurality of core units 1130 are relatively positioned in the circumferential direction of the rotor core 1100, and the rotor core 1100 is connected as a whole, thereby improving the structural stability of the rotor core 1100. Generally speaking, the injection molding body 1300 is also wrapped around the outer periphery of the rotating shaft, so that the rotating shaft is connected to the rotor assembly 1000 and can rotate synchronously.

[0057] Reference Figure 2 and Figure 3 As shown, it can be understood that the notch formed between the outer ends of two adjacent first punching sheet units 110 is defined as the first notch 150, and the notch formed between the outer ends of two adjacent second punching sheet units 210 is defined as the second notch 260. Obviously, along the circumference of the rotor core 1100, the slot width of the second notch 260 is greater than the slot width of the first notch 150. It is easy to understand that the first notch 150 and the second notch 260 are air. The plurality of first notches 150 and the plurality of second notches 260 correspondingly arranged in the axial direction of the rotor core 1100 constitute the notch formed between two adjacent core units 1130.

[0058] It is easy to understand that the magnetic resistance of air and the injection-molded body 1300 is greater than the magnetic resistance of the iron core, that is, the magnetic permeability of air and the injection-molded body 1300 is less than the magnetic permeability of the iron core.

[0059] Since the second punching sheet unit 210 cancels the structure corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis, the slot width of the second slot 260 increases, and the distance between the inner ends of two adjacent second punching sheet units 210 increases. In other words, in the entire rotor core 1100, the equivalent distance between the outer ends of two adjacent core units 1130 increases, and the equivalent distance between the outer ends is the average value of the slot widths of the multiple first slots 150 and the multiple second slots 260 correspondingly arranged along the axial direction of the rotor core 1100. Similarly, the equivalent distance between the inner ends of two adjacent core units 1130 increases. Therefore, the magnetic resistance between the outer ends and the inner ends of two adjacent core units 1130 can be increased, that is, the magnetic permeability between the outer ends and the inner ends of two adjacent core units 1130 can be reduced, thereby reducing the magnetic flux between the outer ends and the inner ends of two adjacent core units 1130, that is, reducing the leakage magnetic flux of the permanent magnet 1200, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet 1200, which is conducive to improving the no-load back electromotive force and efficiency of the motor. At the same time, since the second punching unit 210 cancels the structure corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis, the material of the rotor core 1100 can be reduced, thereby reducing the material cost of the rotor core 1100 and the motor. Without increasing the cost of the motor, the performance of the motor can be optimized, and it has higher practicality and economy. In addition, the rotor core 1100 is composed of only two specifications of rotor punchings, which can reduce the number of molds, reduce processing difficulty, and reduce processing costs.

[0060] Reference Fig.10As shown, after canceling the structure in the second punching unit 210 corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis, the no-load back EMF of the motor is 107.4 V, while the no-load back EMF of the motor in the prior art is 102.3 V. Obviously, the no-load back EMF of the motor in this embodiment is increased by 5.1 V, which effectively improves the performance of the motor.

[0061] Reference Figure 2 As shown, it can be understood that the first punching unit 110 includes two first magnetic bridges 130, and the two first magnetic bridges 130 are respectively located on both sides of the first punching unit 110 along the circumference of the rotor core 1100. Generally speaking, the first punching unit 110 has a center line arranged in the radial direction, and the two first magnetic bridges 130 are symmetrically arranged about the center line of the first punching unit 110. Therefore, in the rotor assembly 1000, the two first magnetic bridges 130 located at the outer ends of the first mounting groove 120 and arranged oppositely in the circumference of the rotor core 1100 respectively contact the outer ends of the permanent magnet 1200, so that the permanent magnet 1200 is subjected to balanced force, and the installation stability of the permanent magnet 1200 is further improved.

[0062] Reference Figure 2 As shown, it can be understood that, similarly, the first punching sheet unit 110 includes two second magnetic bridges 140, the two second magnetic bridges 140 are respectively located on both sides of the first punching sheet unit 110 along the circumferential direction of the rotor core 1100, and the two second magnetic bridges 140 are symmetrically arranged about the center line of the first punching sheet unit 110. Therefore, the two second magnetic bridges 140 located at the inner end of the first mounting groove 120 and arranged oppositely in the circumferential direction of the rotor core 1100 respectively contact the inner end of the permanent magnet 1200, so that the force of the permanent magnet 1200 is balanced, and the installation stability of the permanent magnet 1200 is further improved.

[0063] Reference Figure 2As shown, it can be understood that a first notch 150 is defined between two adjacent first punching sheet units 110, and the first notch 150 is located at one end of the first mounting groove 120 away from the rotation axis and connected to the first mounting groove 120, that is, the first notch 150 is located at the outer end of the first mounting groove 120. In this embodiment, the first notch 150 is the space between the two first magnetic bridges 130 located at the outer end of the first mounting groove 120 and arranged oppositely in the circumferential direction of the rotor core 1100. The minimum width of the notch formed between two adjacent core units 1130 along the circumferential direction of the rotor core 1100 is defined as W. It is easy to understand that the minimum width of the notch formed between two adjacent core units 1130 is the minimum width of the first notch 150 along the circumferential direction of the rotor core 1100, and the minimum width of the first notch 150 is the minimum distance between the two wall surfaces arranged oppositely in the two first magnetic bridges 130 located at the outer end of the first mounting groove 120 and arranged oppositely in the circumferential direction of the rotor core 1100. The minimum width W of the slot formed between two adjacent core units 1130 satisfies: 1mm≤W≤7.4mm. If W<1mm, the minimum width of the first slot 150 is too small, the magnetic permeability between the outer ends of two adjacent first punching sheet units 110 is large, the magnetic leakage increases, and the performance of the motor is poor; if W>7mm, the minimum width of the first slot 150 is too large, and under the premise that the maximum outer diameter of the rotor core 1100 remains unchanged, the maximum width of the first punching sheet unit 110 along the circumference of the rotor core 1100 is reduced, resulting in the narrowing of the channel of the main magnetic circuit X, the magnetic resistance of the channel of the main magnetic circuit X becomes larger, and the performance of the motor is also deteriorated. Therefore, making 1mm≤W≤7.4mm can reduce magnetic leakage and improve the performance of the motor.

[0064] It is easy to understand that in the embodiment where the first punching sheet unit 110 includes only one first magnetic bridge 130 , the first notch 150 , ie, the space between the first magnetic bridge 130 and the adjacent first punching sheet unit 110 , will not be described in detail herein.

[0065] Reference Figure 1 and Figure 2As shown, it can be understood that the maximum width of the outer magnetic bridge along the radial direction of the rotor core 1100 is defined as L. It is easy to understand that the maximum width of the outer magnetic bridge is the maximum width of the first magnetic bridge 130 along the radial direction of the rotor core 1100, and L is the maximum distance between the two radially opposite walls of the first magnetic bridge 130 along the rotor core 1100. The maximum outer diameter of the rotor core 1100 is defined as D, which is also the maximum outer diameter of the first rotor punching 100, and D is twice the maximum distance between the outer peripheral wall of the rotor core 1100 and the rotation axis. The maximum width L of the outer magnetic bridge and the maximum outer diameter D of the rotor core 1100 satisfy: 0.02D≤L≤0.025D. If L is less than 0.02D, the maximum width of the external magnetic bridge is too small, and the structural strength of the external magnetic bridge is low. During the rotation of the rotor assembly 1000, the insufficient support force of the external magnetic bridge on the permanent magnet 1200 will cause the permanent magnet 1200 to loosen or fall off, affecting the normal operation of the motor; if L is greater than 0.025D, the maximum width of the external magnetic bridge is too large, the magnetic resistance at the external magnetic bridge is small, and the leakage magnetic flux increases, affecting the performance of the motor. Therefore, making 0.02D≤L≤0.025D ​​can ensure the installation stability of the permanent magnet 1200, reduce the leakage magnetic flux, and optimize the performance of the motor.

[0066] Reference Figure 7 As shown, it can be understood that in the embodiment where the rotor core 1100 includes a plurality of first rotor sheets 100 and a plurality of second rotor sheets 200, the plurality of sheet units are divided into two first sheet groups 1110 and one second sheet group 1120, the two first sheet groups 1110 and one second sheet group 1120 are stacked in the direction of the rotation axis, and the two first sheet groups 1110 are respectively located at the two ends of the second sheet group 1120 in the direction of the rotation axis, and the lamination process is simple, which is conducive to reducing production costs. Among them, the first sheet group 1110 includes a plurality of first sheet units 110 stacked in the direction of the rotation axis, and the second sheet group 1120 includes a plurality of second sheet units 210 stacked in the direction of the rotation axis. Therefore, the first magnetic bridges 130 of the two first punching sheet groups 1110 respectively limit the two ends of the outer side of the permanent magnet 1200 along the direction of the rotation axis and improve the supporting force, and the second magnetic bridges 140 of the two first punching sheet groups 1110 respectively limit the two ends of the inner side of the permanent magnet 1200 along the direction of the rotation axis, so that the inner and outer sides of the two ends of the permanent magnet 1200 along the direction of the rotation axis are supported, so that the force of the permanent magnet 1200 is balanced, and the installation stability of the permanent magnet 1200 is further improved to prevent the permanent magnet 1200 from loosening or falling off. In this embodiment, each first punching sheet group 1110 includes two first punching sheet units 110, and the second punching sheet group 1120 includes thirty-two second punching sheet units 210.

[0067] Reference Figure 8As shown, it can be understood that in other embodiments, a plurality of punching sheet units are divided into a first punching sheet group 1110 and two second punching sheet groups 1120, a first punching sheet group 1110 and two second punching sheet groups 1120 are stacked in the direction of the rotation axis, and a first punching sheet group 1110 is located between two second punching sheet groups 1120, and the lamination process is simple. Among them, the first punching sheet group 1110 includes a plurality of first punching sheet units 110 stacked in the direction of the rotation axis, and the second punching sheet group 1120 includes a plurality of second punching sheet units 210 stacked in the direction of the rotation axis. Similarly, the first magnetic bridge 130 limits the outer end of the permanent magnet 1200 at the middle position of the axial direction of the rotor core 1100 and provides a supporting force, and the second magnetic bridge 140 limits the inner end of the permanent magnet 1200 at the middle position of the axial direction of the rotor core 1100, which is conducive to improving the installation stability of the permanent magnet 1200 and preventing the permanent magnet 1200 from loosening or falling off.

[0068] Reference Fig. 9 As shown, it can be understood that in other embodiments, the plurality of punching sheet units are divided into a plurality of first punching sheet groups 1110 and a plurality of second punching sheet groups 1120, and the plurality of first punching sheet groups 1110 and the plurality of second punching sheet groups 1120 are stacked and arranged along the direction of the rotation axis, and the plurality of first punching sheet groups 1110 and the plurality of second punching sheet groups 1120 are alternately arranged. The first punching sheet group 1110 includes a plurality of first punching sheet units 110 stacked and arranged along the direction of the rotation axis, and the second punching sheet group 1120 includes a plurality of second punching sheet units 210 stacked and arranged along the direction of the rotation axis. Therefore, the first magnetic bridges 130 of the multiple first punching sheet groups 1110 respectively limit the multiple positions of the outer side of the permanent magnet 1200 along the direction of the rotation axis and improve the supporting force, and the second magnetic bridges 140 of the multiple first punching sheet groups 1110 respectively limit the multiple positions of the inner side of the permanent magnet 1200 along the direction of the rotation axis, so that the multiple positions of the permanent magnet 1200 along the direction of the rotation axis are supported, thereby further improving the installation stability of the permanent magnet 1200 and preventing the permanent magnet 1200 from loosening or falling off.

[0069] Reference Figure 4As shown, it can be understood that in other embodiments, the multiple rotor punchings of the rotor core 1100 include a first rotor punching 100, a second rotor punching 200 and a third rotor punching 300, wherein the structures of the first rotor punching 100 and the second rotor punching 200 can refer to the above description and will not be repeated here. Specifically, the third rotor punching 300 includes a plurality of third punching units 310 arranged at intervals along the circumference of the rotor core 1100, and a third mounting groove 320 is defined between two adjacent third punching units 310, and the number of the third mounting grooves 320 is equal to the number of the third punching units 310. And the number of the third punching units 310 is equal to the number of the first punching units 110. Similarly, on the projection plane perpendicular to the rotation axis, the projection of the third punching unit 310 is roughly fan-shaped, and the projection of the third mounting groove 320 is roughly rectangular. The inner ends and the outer ends of two adjacent third punching sheet units 310 are disconnected, that is, each third punching sheet unit 310 is independent, and is referred to as the first punching sheet unit 110, which will not be described again here.

[0070] Reference Figure 4 As shown, it can be understood that the third punching unit 310 includes a third magnetic bridge 330, which is located on one side of the third punching unit 310 along the circumference of the rotor core 1100 and extends along the circumference of the rotor core 1100, and the third magnetic bridge 330 is located at one end of the third mounting groove 320 close to the rotation axis, that is, the third magnetic bridge 330 is located at the inner end of the third mounting groove 320, and the third magnetic bridge 330 protrudes toward the third mounting groove 320, and the third magnetic bridge 330 is a part of the inner magnetic bridge. It can be understood that the number of the third magnetic bridges 330 of the third punching unit 310 can be one or two. When the third punching unit 310 includes two third magnetic bridges 330, reference can be made to the embodiment in which the first punching includes two second magnetic bridges 140, which will not be repeated here.

[0071] Reference Figure 4As shown, it can be understood that the third installation groove 320 has two second side walls 340 arranged oppositely along the circumference of the rotor core 1100, and the wall surface of the third punching unit 310 on the side away from the rotation axis is defined as the second outer wall surface 350. The outer ends of the two second side walls 340 extend to the second outer wall surface 350 along the radial direction of the rotor core 1100, that is, the structure corresponding to the outer magnetic bridge in the direction of the rotation axis in the third punching unit 310 is cancelled, and the outer end of the third installation groove 320 is fully open. Therefore, the distance between the outer ends of two adjacent third punching units 310 can be increased. The notch formed between the outer ends of two adjacent third punching units 310 is defined as the third notch 360. Obviously, along the circumference of the rotor core 1100, the slot width of the third notch 360 is greater than the slot width of the first notch 150. It is easy to understand that the third notch 360 is air. The third notch 360 is a part of the notch formed between two adjacent core units 1130.

[0072] It can be understood that the number of the first rotor sheet 100, the second rotor sheet 200 and the third rotor sheet 300 are all multiple and are stacked in the direction of the rotation axis to form the rotor core 1100, the first sheet unit 110, the second sheet unit 210 and the third sheet unit 310 are arranged in the axial direction of the rotor core 1100, and the first installation groove 120, the second installation groove 220 and the third installation groove 320 are arranged in the axial direction of the rotor core 1100 and connected to form an installation groove for installing the permanent magnet 1200. It is easy to understand that the multiple first sheet units 110, the multiple second sheet units 210 and the multiple third sheet units 310 correspondingly arranged in the axial direction of the rotor core 1100 are connected by the buckle connection and form the core unit 1130 of the rotor core 1100. That is, the multiple sheet units constituting the core unit 1130 include the first sheet unit 110, the second sheet unit 210 and the third sheet unit 310. The plurality of first magnetic bridges 130 correspondingly arranged in the axial direction of the rotor core 1100 constitute an outer magnetic bridge, and the plurality of second magnetic bridges 140 and the plurality of third magnetic bridges 330 correspondingly arranged in the axial direction of the rotor core 1100 constitute an inner magnetic bridge. The permanent magnet 1200 is installed in the plurality of first mounting grooves 120, the plurality of second mounting grooves 220 and the plurality of third mounting grooves 320 correspondingly arranged and connected in the axial direction of the rotor core 1100, wherein the first magnetic bridge 130 abuts against the outer end of the permanent magnet 1200, and the second magnetic bridge 140 and the third magnetic bridge 330 abut against the inner end of the permanent magnet 1200. Therefore, the permanent magnet 1200 can be limited in the radial direction of the rotor core 1100 by the first magnetic bridge 130, the second magnetic bridge 140 and the third magnetic bridge 330, and during the operation of the motor, that is, during the rotation of the rotor assembly 1000, the first magnetic bridge 130 can provide an inward support force to the permanent magnet 1200 to offset the centrifugal force acting on the permanent magnet 1200, so as to avoid the permanent magnet 1200 from loosening during the operation of the motor and affecting the performance of the motor. At the same time, the inner end limit of the permanent magnet 1200 by the third magnetic bridge 330 is added to further improve the installation stability of the permanent magnet 1200.

[0073] Similarly, since the second punching unit 210 cancels the structure corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis, and the third punching unit 310 cancels the structure corresponding to the outer magnetic bridge in the direction of the rotation axis, in the entire rotor core 1100, the equivalent distance between the outer ends of two adjacent core units 1130 increases, and the equivalent distance between the outer ends here is the average value of the slot widths of the plurality of first slots 150, the plurality of second slots 260, and the plurality of third slots 360 correspondingly arranged along the axial direction of the rotor core 1100. Similarly, the equivalent distance between the inner ends of two adjacent core units 1130 increases, thereby reducing the leakage magnetic flux of the permanent magnet 1200, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet 1200, which is conducive to improving the no-load back electromotive force and efficiency of the motor. At the same time, the material of the rotor core 1100 can be reduced, thereby reducing the material cost of the rotor core 1100 and the motor. Without increasing the cost of the motor, the performance of the motor can be optimized, which has higher practicality and economy.

[0074] Reference Figure 5 As shown, it can be understood that in other embodiments, the multiple rotor punchings of the rotor core 1100 include a first rotor punching 100, a second rotor punching 200 and a fourth rotor punching 400, wherein the structures of the first rotor punching 100 and the second rotor punching 200 can refer to the above description and will not be repeated here. Specifically, the fourth rotor punching 400 includes a plurality of fourth punching units 410 arranged at intervals along the circumference of the rotor core 1100, and a fourth mounting groove 420 is defined between two adjacent fourth punching units 410, and the number of the fourth mounting grooves 420 is equal to the number of the fourth punching units 410. And the number of the fourth punching units 410 is equal to the number of the first punching units 110. Similarly, on the projection plane perpendicular to the rotation axis, the projection of the fourth punching unit 410 is roughly fan-shaped, and the projection of the fourth mounting groove 420 is roughly rectangular. The inner ends and the outer ends of two adjacent fourth punching sheet units 410 are disconnected, that is, each fourth punching sheet unit 410 is independent, and is referred to as the first punching sheet unit 110, which will not be described again here.

[0075] Reference Figure 5As shown, it can be understood that the fourth punching unit 410 includes a fourth magnetic bridge 430, which is located on one side of the fourth punching unit 410 along the circumference of the rotor core 1100 and extends along the circumference of the rotor core 1100, and the fourth magnetic bridge 430 is located at the end of the fourth mounting slot 420 away from the rotation axis, that is, the fourth magnetic bridge 430 is located at the outer end of the fourth mounting slot 420, and the fourth magnetic bridge 430 protrudes toward the fourth mounting slot 420, and the fourth magnetic bridge 430 is a part of the outer magnetic bridge. It can be understood that the number of the fourth magnetic bridges 430 of the fourth punching unit 410 can be one or two. When the fourth punching unit 410 includes two fourth magnetic bridges 430, the embodiment in which the first punching includes two second magnetic bridges 140 can be referred to, and no further description is given here. The notch formed between the outer ends of two adjacent fourth punching units 410 is defined as the fourth notch 460. It is easy to understand that the fourth notch 460 is air. The fourth slot 460 is a portion of a slot formed between two adjacent core units 1130 .

[0076] Reference Figure 5 As shown, it can be understood that the fourth installation groove 420 has two third side walls 440 arranged oppositely along the circumferential direction of the rotor core 1100, and the wall surface of the fourth punching unit 410 close to the rotation axis is defined as the second inner wall surface 450. The inner ends of the two second side walls 340 extend to the second inner wall surface 450 along the radial direction of the rotor core 1100, that is, the structure corresponding to the inner magnetic bridge in the direction of the rotation axis in the fourth punching unit 410 is cancelled. Therefore, the distance between the inner ends of two adjacent fourth punching units 410 can be increased.

[0077] It is understandable that the lamination method of the first rotor punching sheet 100, the second rotor punching sheet 200 and the fourth rotor punching sheet 400 can refer to the lamination method of the first rotor punching sheet 100, the second rotor punching sheet 200 and the third rotor punching sheet 300, which will not be described in detail here. Among them, the first magnetic bridge 130 and the fourth magnetic bridge 430 are against the outer end of the permanent magnet 1200, and the second magnetic bridge 140 is against the inner end of the permanent magnet 1200. Therefore, the permanent magnet 1200 can be limited in the radial direction of the rotor core 1100 by the first magnetic bridge 130, the second magnetic bridge 140 and the fourth magnetic bridge 430, and during the operation of the motor, that is, the rotation of the rotor assembly 1000, the first magnetic bridge 130 and the fourth magnetic bridge 430 can provide an inward supporting force to the permanent magnet 1200 to offset the centrifugal force acting on the permanent magnet 1200, thereby preventing the permanent magnet 1200 from loosening during the operation of the motor and affecting the performance of the motor. At the same time, the outer end limitation and support of the permanent magnet 1200 by the fourth magnetic bridge 430 is increased to further improve the installation stability of the permanent magnet 1200.

[0078] Similarly, since the second punching unit 210 cancels the structure corresponding to the inner magnetic bridge and the outer magnetic bridge in the direction of the rotation axis, and the fourth punching unit 410 cancels the structure corresponding to the inner magnetic bridge in the direction of the rotation axis, in the entire rotor core 1100, the equivalent distance between the outer ends of two adjacent core units 1130 increases, and the equivalent distance between the outer ends here is the average value of the slot widths of the plurality of first slots 150, the plurality of second slots 260, and the plurality of fourth slots 460 correspondingly arranged along the axial direction of the rotor core 1100. Similarly, the equivalent distance between the inner ends of two adjacent core units 1130 increases, thereby reducing the leakage magnetic flux of the permanent magnet 1200, reducing the proportion of the leakage magnetic flux in the total magnetic flux, and improving the utilization rate of the permanent magnet 1200, which is conducive to improving the no-load back electromotive force and efficiency of the motor. At the same time, the material of the rotor core 1100 can be reduced, thereby reducing the material cost of the rotor core 1100 and the motor. Without increasing the cost of the motor, the performance of the motor can be optimized, which has higher practicality and economy.

[0079] It can be understood that in other embodiments, the multiple rotor punchings of the rotor core 1100 include the first rotor punching 100 and the third rotor punching 300, or include the first rotor punching 100 and the fourth rotor punching 400, or include the first rotor punching 100, the third rotor punching 300 and the fourth rotor punching 400. Please refer to the above description and will not be repeated here. It can reduce leakage magnetic field and improve the efficiency of the motor.

[0080] Reference Figure 7 As shown, it can be understood that, generally speaking, along the direction of the rotation axis, the thickness of the first rotor punching sheet 100, the second rotor punching sheet 200, the third rotor punching sheet 300 and the fourth rotor punching sheet 400 are equal and are equal thickness punching sheets, which reduces the specifications of the silicon steel sheets used and helps to reduce costs.

[0081] Reference Figure 7 As shown, it can be understood that, along the direction of the rotation axis, the total height of the external magnetic bridge is defined as h, the thickness of the first rotor punching sheet 100 and the fourth rotor punching sheet 400 are both defined as T, and the height of the rotor core 1100 is defined as H, which is the distance between the walls of the rotor core 1100 at both ends along the axial direction. The number of first rotor punching sheets 100 in the rotor core 1100 is defined as M, and the number of fourth rotor punching sheets 400 is defined as N, wherein, since the first rotor punching sheet 100 and the fourth rotor punching sheet 400 both include the external magnetic bridge, and the rotor core 1100 includes at least one of the first rotor punching sheet 100 and the fourth rotor punching sheet 400, therefore, h = T*(M+N), satisfying: H / 9≤h≤H / 3.

[0082] It is understandable that, in an embodiment in which the rotor core 1100 does not include the first rotor punching sheet 100 , M=0; in an embodiment in which the rotor core 1100 does not include the fourth rotor punching sheet 400 , N=0.

[0083] Reference Figure 7 As shown, it can be understood that, under the premise that the height H of the rotor core 1100 along the axial direction remains unchanged, if h<H / 9, the total height of the outer magnetic bridge of the rotor core 1100 is too small, the structural strength of the outer magnetic bridge is low, and during the rotation of the rotor assembly 1000, the insufficient support force of the outer magnetic bridge on the permanent magnet 1200 will cause the permanent magnet 1200 to loosen or fall off, affecting the normal operation of the motor; if h>H / 3, the total height of the outer magnetic bridge of the rotor core 1100 is too large, the magnetic resistance at the outer magnetic bridge is small, the leakage magnetic flux increases, and the performance of the motor is affected. Therefore, making H / 9≤T*(M+N)≤H / 3 can ensure the installation stability of the permanent magnet 1200, reduce the leakage magnetic flux, and optimize the performance of the motor.

[0084] The rotor assembly 1000 of the second embodiment of the utility model includes an injection-molded body 1300 and the rotor core 1100 of the first embodiment of the utility model. Please refer to the above description and it will not be repeated here.

[0085] Since the rotor assembly 1000 adopts all the technical solutions of the rotor core 1100 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0086] The motor of the third embodiment of the present invention comprises the rotor assembly 1000 and the stator assembly 2000 of the second embodiment of the present invention, wherein the stator assembly 2000 is wound around the outer circumference of the rotor assembly 1000.

[0087] Since the motor adopts all the technical solutions of the rotor assembly 1000 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0088] The air conditioner of the fourth embodiment of the utility model includes the motor of the third embodiment of the utility model, which is described above with reference to the above description and will not be described again here.

[0089] Since the air conditioner adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0090] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. The rotor core rotates around the axis of rotation. Features: The rotor core includes a plurality of core units arranged at intervals along the circumference of the rotor core, and an installation groove for installing a permanent magnet is formed between two adjacent core units. The core unit includes an outer magnetic bridge and an inner magnetic bridge, and the outer magnetic bridge and the inner magnetic bridge are located on the same side of the core unit along the circumference, and the outer magnetic bridge and the inner magnetic bridge are respectively used to limit the two ends of the permanent magnet along the radial direction of the rotor core. The core unit includes a plurality of punching unit units stacked along the direction of the rotation axis, and the side walls of some of the punching units protrude toward the installation groove to form the outer magnetic bridge, and / or the side walls of some of the punching units protrude toward the installation groove to form the inner magnetic bridge.

2. The rotor core according to claim 1, Features: The plurality of punching sheet units include a second punching sheet unit having two first side walls opposed to each other along the circumferential direction, the first side walls extending along the radial direction to a first outer wall surface of the second punching sheet unit opposed to the rotation axis and a first inner wall surface of the second punching sheet unit close to the rotation axis.

3. The rotor core according to claim 2, Features: The multiple punching sheet units also include a first punching sheet unit, which includes a first magnetic bridge and a second magnetic bridge. The first magnetic bridge and the second magnetic bridge are located on one side of the first punching sheet unit along the circumferential direction, and the first magnetic bridge and the second magnetic bridge are respectively located at both ends of the first punching sheet unit along the radial direction. The first magnetic bridge is a part of the outer magnetic bridge, and the second magnetic bridge is a part of the inner magnetic bridge.

4. The rotor core according to claim 3, Features: The core unit includes two first punching sheet groups and one second punching sheet group stacked along the direction of the rotation axis, the two first punching sheet groups are respectively located at the two ends of the second punching sheet group, the first punching sheet group includes a plurality of first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of second punching sheet units stacked along the direction of the rotation axis.

5. The rotor core according to claim 3, Features: The core unit includes a first punching sheet group and two second punching sheet groups stacked along the direction of the rotation axis, the first punching sheet group is located between the two second punching sheet groups, the first punching sheet group includes a plurality of the first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of the second punching sheet units stacked along the direction of the rotation axis.

6. The rotor core according to claim 3, Features: The core unit includes a plurality of first punching sheet groups and a plurality of second punching sheet groups stacked along the direction of the rotation axis, and the plurality of first punching sheet groups and the plurality of second punching sheet groups are alternately arranged. The first punching sheet group includes a plurality of first punching sheet units stacked along the direction of the rotation axis, and the second punching sheet group includes a plurality of second punching sheet units stacked along the direction of the rotation axis.

7. The rotor core according to claim 1, Features: The plurality of punching sheet units include a third punching sheet unit, the third punching sheet unit includes a third magnetic bridge, the third magnetic bridge is located on one side of the third punching sheet unit along the circumferential direction and at one end of the third punching sheet unit close to the rotation axis, the third magnetic bridge is a part of the inner magnetic bridge, the third punching sheet unit has two second side walls that are opposite to each other along the circumferential direction, the second side walls extend along the radial direction to the second outer wall surface of the third punching sheet unit that is opposite to the rotation axis.

8. The rotor core according to claim 1, Features: The plurality of punching sheet units include a fourth punching sheet unit, the fourth punching sheet unit includes a fourth magnetic bridge, the fourth magnetic bridge is located on one side of the fourth punching sheet unit along the circumferential direction and at an end of the fourth punching sheet unit away from the rotation axis, the fourth magnetic bridge is a part of the outer magnetic bridge, the fourth punching sheet unit has two third side walls that are opposite to each other along the circumferential direction, and the third side walls extend along the radial direction to the second inner wall surface of the fourth punching sheet unit close to the rotation axis.

9. The rotor core according to claim 1, Features: A notch is further defined between two adjacent core units. The notch is located at one end of the mounting groove away from the rotation axis and connected to the mounting groove. Along the circumferential direction, the minimum width of the notch is W, satisfying: 1mm≤W≤7.4mm.

10. The rotor core according to claim 1, Features: Along the radial direction, the maximum width of the outer magnetic bridge is L, and the maximum outer diameter of the rotor core is D, satisfying: 0.02D≤L≤0.025D.

11. The rotor core according to claim 1, Features: Along the direction of the rotation axis, the total height of the outer magnetic bridge is h, and the height of the rotor core is H, satisfying: H / 9≤h≤H / 3.

12. Rotor assembly, It is characterized in that include: Injection molding; The rotor core according to any one of claims 1 to 11, wherein the rotor core is wound around the outer periphery of the injection molded body, and the inner magnetic bridge is embedded in the injection molded body.

13. Motor, It is characterized in that include: The rotor assembly as claimed in claim 12; The stator assembly is wound around the outer circumference of the rotor assembly.

14. Air conditioner, It is characterized in that Comprising the motor as claimed in claim 13.

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