Rotor, motor and air conditioner

Abstract

The embodiment of the utility model provides a rotor, a motor and an air conditioner. The rotor comprises a rotating shaft, a rotor core, a plurality of magnetic steels and an annular magnetic resistance structure. The rotor iron core comprises a plurality of iron core units, the iron core units are arranged at intervals in the circumferential direction of the rotating shaft, and a containing space is defined between every two adjacent iron core units. And the plurality of magnetic steels are respectively arranged in the corresponding accommodating spaces. The radial inner end faces of the iron core units and the outer circumferential face of the rotating shaft are arranged at intervals, the radial inner end faces of the magnetic steel and the outer circumferential face of the rotating shaft are arranged at intervals, and the radial inner end faces of the iron core units do not exceed the radial inner end faces of the magnetic steel in the direction close to the rotating shaft in the radial direction. The annular magnetic resistance structure is filled in the interval area between the iron core unit and the rotating shaft and the interval area between the magnetic steel and the rotating shaft. According to the rotor provided by the embodiment of the invention, the magnetic induction line of the magnetic steel cannot be transmitted to the radial inner side of the magnetic steel through the radial inner end face of the iron core unit, so that the magnetic leakage of the radial inner end of the magnetic steel is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a rotor, an electric machine and an air conditioner. BACKGROUND

[0002] Compared with traditional electric machines, permanent magnet synchronous electric machines have the advantages of simple structure, high efficiency and good performance, and are widely used in various fields.

[0003] The magnetic field generated by the stator winding of the permanent magnet synchronous electric machine interacts with the magnetic field generated by the rotor to provide driving torque for the rotor. However, during the operation of the permanent magnet synchronous electric machine, part of the magnetic flux does not pass through the working magnetic circuit, resulting in magnetic flux leakage and affecting the performance of the electric machine. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the embodiments of the present application aim to provide a rotor, an electric machine and an air conditioner, which can help to reduce magnetic flux leakage.

[0005] In a first aspect, the embodiments of the present application provide a rotor, comprising:

[0006] a rotating shaft;

[0007] a rotor core comprising a plurality of core units, the plurality of core units being arranged at intervals along the circumference of the rotating shaft, and a containing space being defined between each adjacent two core units;

[0008] a plurality of magnetic steels, each being arranged in a corresponding containing space;

[0009] a radial inner end surface of the core unit is arranged at an interval from the outer circumferential surface of the rotating shaft, and a radial inner end surface of the magnetic steel is arranged at an interval from the outer circumferential surface of the rotating shaft, and the radial inner end surface of the core unit is closer to the rotating shaft than the radial inner end surface of the magnetic steel;

[0010] a ring-shaped magnetic resistance structure filling the interval between the core unit and the rotating shaft, and filling the interval between the magnetic steel and the rotating shaft.

[0011] In some embodiments, the distance between the outer circumferential surface of the rotating shaft and the radial inner end surface of the core unit is 1.5mm-3mm; and / or, the ratio of the distance between the outer circumferential surface of the rotating shaft and the radial inner end surface of the core unit to the radius of the rotor is 0.03-0.06.

[0012] In some embodiments, the distance between the outer circumferential surface of the rotating shaft and the radial inner end surface of the magnetic steel is 1mm-1.5mm; and / or, the ratio of the distance between the outer circumferential surface of the rotating shaft and the radial inner end surface of the magnetic steel to the radius of the rotor is 0.02-0.05.

[0013] In some embodiments, the rotor has a radius, and the difference between the radius of the rotor and the dimension of the magnetic steel along the radial direction of the rotor is 1mm-3.5mm.

[0014] In some embodiments, the magnetic steel comprises a reduced portion and a uniform-width portion, the uniform-width portion is connected to the radially outer end of the reduced portion, along the radial direction of the rotor and towards the direction of the rotation axis, the uniform-width portion has the same circumferential dimension, and the reduced portion has a reduced circumferential dimension.

[0015] In some embodiments, the ratio of the diameter of the circumscribed circle of the reduced portion to the diameter of the rotor is 0.25-0.75.

[0016] In some embodiments, in the orthogonal projection in the plane perpendicular to the rotation axis, the projection of the uniform-width portion is a rectangle;

[0017] the projection of the reduced portion is a trapezoid; or, the projection of the reduced portion is substantially a triangle, and the radially inner end of the reduced portion is formed with a first rounded corner.

[0018] In some embodiments, the ratio of the circumferential dimension of the uniform-width portion to the diameter of the rotor is 0.06-0.15.

[0019] In some embodiments, the magnetic steel comprises a contracted portion, the contracted portion is connected to the radially outer end of the uniform-width portion, along the radial direction of the rotor and away from the direction of the rotation axis, and the contracted portion has a reduced circumferential dimension.

[0020] In some embodiments, the ratio of the diameter of the inscribed circle of the contracted portion to the diameter of the rotor is 0.68-0.87.

[0021] In some embodiments, the reduced portion comprises a first wall surface and a second wall surface oppositely arranged along the circumferential direction, along the radial direction towards the direction close to the rotation axis, the first wall surface and the second wall surface extend towards each other, and the included angle between the first wall surface and the second wall surface is 15 degrees-36 degrees.

[0022] In some embodiments, the radially outer end surface of the core unit comprises a first arc segment, a second arc segment and a third arc segment sequentially connected along the circumferential direction of the rotor, the first arc segment and the second arc segment have different curvatures, and the second arc segment and the third arc segment have different curvatures.

[0023] In some embodiments, the center of the second arc segment is located on the rotation axis of the rotation axis;

[0024] The first arc-shaped segment and the third arc-shaped segment are symmetrically arranged about a symmetric plane of the second arc-shaped segment, the symmetric plane passing through a midpoint of an arc length of the second arc-shaped segment and the rotation axis; and / or, a ratio of a central angle corresponding to the second arc-shaped segment to an included angle between two adjacent magnetic steels is 0.2-0.7.

[0025] In some embodiments, a ratio of a distance between a center of a circle corresponding to the first arc-shaped segment and the rotation axis to a radius of the rotor is 0.38-0.8.

[0026] In a second aspect, an embodiment of the present application provides an electric machine, comprising a stator assembly and the rotor according to any of the embodiments of the present application, wherein the stator assembly is arranged around an outer periphery of the rotor.

[0027] In a third aspect, an embodiment of the present application provides an air conditioner, comprising the electric machine according to any of the embodiments of the present application.

[0028] The rotor provided by the embodiments of the present application has the advantages that the two adjacent core units are arranged at intervals in the circumferential direction, and there is no core unit at the radially inner end of the magnetic steel, which helps to reduce the magnetic flux leakage and also helps to increase the magnetic resistance at the radially inner end of the core unit. Moreover, the radially inner end surface of the core unit is arranged at an interval from the outer peripheral surface of the rotation shaft, so that the magnetic flux lines are not easy to pass through the rotation shaft, that is, the magnetic flux lines are not easy to leak from the rotation shaft. The radially inner end surface of the magnetic steel is arranged at an interval from the outer peripheral surface of the rotation shaft, which facilitates the assembly between the magnetic steel and the rotation shaft. Moreover, the radially inner end surface of the core unit is arranged at a distance of not more than the radially inner end surface of the magnetic steel in the direction of approaching the rotation shaft in the radial direction, so that the magnetic flux lines of the magnetic steel cannot pass through the radially inner end surface of the core unit to the radially inner side of the magnetic steel, thereby helping to reduce the magnetic flux leakage at the radially inner end of the magnetic steel.

[0029] Moreover, the rotor provided by the embodiments of the present application fills the interval region between the core unit and the rotation shaft and the interval region between the magnetic steel and the rotation shaft with the annular magnetic resistance structure, which can on the one hand improve the connection strength between the core unit and the rotation shaft and between the magnetic steel and the rotation shaft by using the annular magnetic resistance structure, and on the other hand, the annular magnetic resistance structure can further increase the magnetic resistance at the radially inner end of the core unit, thereby helping to further reduce the magnetic flux leakage. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A schematic view of the electric machine provided by the embodiments of the present application in a vertical projection view perpendicular to the rotation shaft;

[0031] Figure 2 A schematic view of the rotor in the structure shown in FIG. 1; Figure 1 A schematic view of the rotor in the structure shown in FIG. 2;

[0032] Figure 3 A schematic view of the rotor in the structure shown in FIG. 3; Figure 1 A schematic view of the rotor in the structure shown in FIG. 4;

[0033] Figure 4 Fig. 1 is a schematic structural diagram of a rotor core according to an embodiment of the present application; Figure 3 Fig. 2 is a schematic sectional view of the structure shown in Fig. 1 along the A-A direction;

[0034] Figure 5 Fig. 3 is a schematic structural diagram of a part C in Fig. 2; Figure 4

[0035] Figure 6 Fig. 4 is a schematic sectional view of the structure shown in Fig. 1 along the B-B direction; Figure 3

[0036] Figure 7 Fig. 5 is a schematic structural diagram of a part D in Fig. 4; Figure 6

[0037] Figure 8 Fig. 6 is a schematic structural diagram of another angle of the rotor in the structure shown in Fig. 1; Figure 1

[0038] Figure 9 Fig. 7 is a schematic sectional view of the structure shown in Fig. 1 along the E-E direction; Figure 8

[0039] Figure 10 Fig. 8 is a schematic sectional view of the structure shown in Fig. 1 along the F-F direction; Figure 8

[0040] Figure 11 Fig. 9 is a schematic structural diagram of a rotor core unit provided by an embodiment of the present application;

[0041] Figure 12 Fig. 10 is a schematic structural diagram of a part of a rotor core provided by an embodiment of the present application;

[0042] Figure 13 Fig. 11 is a schematic combination diagram of a rotor core and a magnetic steel before injection molding provided by a first embodiment of the present application;

[0043] Figure 14 Fig. 12 is a schematic combination diagram of a rotor core and a magnetic steel before injection molding provided by a second embodiment of the present application;

[0044] Figure 15 Fig. 13 is a schematic combination diagram of a rotor core and a magnetic steel before injection molding provided by a third embodiment of the present application;

[0045] Figure 16 Fig. 14 is a schematic combination diagram of a rotor core and a magnetic steel before injection molding provided by a fourth embodiment of the present application;

[0046] Figure 17 Fig. 15 is a schematic structural diagram of a rotor core unit in the structure shown in Fig. 1 and Fig. 4; Figure 15 Figure 16 Fig. 16 is a schematic structural diagram of a rotor core unit in the structure shown in Fig. 7 and Fig. 8.

[0047] Legend of Reference Signs ​​​​​​​

[0048] 10, rotor; 11, rotor core; 111, core unit; 1111, radially inner end of core unit; 1112, radially outer end of core unit; 1113, tooth portion; 1114, injection molding hole; 1115, positioning hole; 1116, protrusion; 112, accommodating space; 12, magnetic steel; 121, reduced portion; 122, equal-width portion; 122a, first round corner; 1221, first wall surface; 1222, second wall surface; 123, constricted portion; 1231, third wall surface; 1232, fourth wall surface; 123a, second round corner; 124, radially inner end of magnetic steel; 125, radially outer end of magnetic steel; 13, rotating shaft; 14, injection molding piece; 141, annular magnetoresistance structure; S1, first arc segment; S2, second arc segment; S3, third arc segment; 20, stator assembly. DETAILED DESCRIPTION

[0049] The embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0050] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the embodiments of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0051] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0052] In the embodiments of the present application, unless specifically defined and limited otherwise, a first feature is "on", "under", "above", or "over" a second feature can mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, the first feature "over", "above", or "on" the second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height. The first feature "under", "below", or "on" the second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the first feature is lower than the second feature in horizontal height.

[0053] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0054] The present application provides a rotor 10, please refer to Figure 2 The rotor 10 includes a rotating shaft 13, a rotor core 11 and a plurality of magnetic steels 12.

[0055] The rotating shaft 13 serves as the rotation center of the rotor 10 and is responsible for transmitting torque.

[0056] The rotor core 11 includes a plurality of core units 111, and the plurality of core units 111 are arranged in a circumferential direction of the rotating shaft 13 with intervals, and a containing space 112 is defined between each two adjacent core units 111.

[0057] It should be noted that the interval arrangement means that there is an interval between the two adjacent core units 111 in the circumferential direction, and the two adjacent core units 111 are not in contact.

[0058] The plurality of magnetic steels 12 are respectively arranged in the corresponding containing spaces 112. That is, one containing space 112 is used to place one magnetic steel 12, and the containing space 112 and the magnetic steel 12 have a one-to-one mapping relationship. The two adjacent magnetic steels 12 are separated by the core unit 111, which helps to optimize the magnetic circuit and reduce the eddy current loss.

[0059] In this embodiment, the magnetic steel 12 is located in the accommodating space defined by the two adjacent core units 111. The magnetic steel 12 generates the main magnetic flux. The main magnetic flux path is as follows: inside the magnetic steel 12, the magnetic lines of force are directed from the S pole to the N pole of the magnetic steel 12; outside the magnetic steel 12, the magnetic lines of force are directed from the N pole of the magnetic steel 12, and then pass through the core unit 111 adjacent to the N pole of the magnetic steel 12, the air gap between the rotor 10 and the stator assembly 20, the stator assembly 20, the air gap between the stator assembly 20 and the rotor 10, the core unit 111 adjacent to the S pole of the magnetic steel 12, and then return to the S pole of the magnetic steel 12.

[0060] However, in some related technologies, the radially inner ends of the core units are connected to each other along the circumferential direction of the rotating shaft, and the magnetic lines of force directed from the N pole of the magnetic steel do not completely pass through the main magnetic flux path. Outside the magnetic steel, a part of the magnetic lines of force of the radially inner end of the magnetic steel pass through the N pole of the magnetic steel, the radially inner end of the core unit adjacent to the N pole of the magnetic steel, the core unit or the rotating shaft located at the radially inner end of the magnetic steel, the radially inner end of the core unit adjacent to the S pole of the magnetic steel, and then return to the S pole of the magnetic steel. This part of the magnetic lines of force does not pass through the air gap, i.e., leakage magnetic flux is generated. At this time, the core unit located at the radially inner end of the magnetic steel and the rotating shaft both cause leakage magnetic flux.

[0061] In this application, the two adjacent core units 111 are not in contact along the circumferential direction, i.e., there is no core unit 111 at the radially inner end 124 of the magnetic steel 12, and thus the magnetic lines of force do not leak from the core unit 111 located at the radially inner end 124 of the magnetic steel 12, which helps to reduce leakage magnetic flux.

[0062] Moreover, the two adjacent core units 111 are spaced apart along the circumferential direction, which helps to increase the magnetic resistance at the radially inner end 1111 of the core unit 111 and to reduce leakage magnetic flux.

[0063] For example, referring to Figs. 1 to 4, Figure 13 , Figure 14 , Figure 15 and Figure 16 , the radially inner end surface 1111a of the core unit 111 is spaced apart from the outer circumferential surface 13a of the rotating shaft 13.

[0064] In this embodiment, the two adjacent core units 111 are spaced apart along the circumferential direction, so that the magnetic lines of force are not easy to pass through the rotating shaft 13, i.e., the magnetic lines of force are not easy to leak from the rotating shaft 13, which helps to reduce leakage magnetic flux.

[0065] For example, referring to Figs. 1 to 4, Figure 13 , Figure 14 , Figure 15 and Figure 16The radially inner end surface 124a of the magnetic steel 12 is arranged spaced apart from the outer circumferential surface 13a of the rotating shaft 13. In this way, the assembly between the magnetic steel 12 and the rotating shaft 13 is facilitated. For example, the annular magnetic blocking structure 141 described below can be filled between the radially inner end surface 124a of the magnetic steel 12 and the outer circumferential surface 13a of the rotating shaft 13.

[0066] It should be noted that the end surface in the radially inner end surface refers to a surface, and the radially inner end surface refers to a surface facing the rotating shaft in the radially inner end direction. For example, the radially inner end surface 1111a of the core unit 111 refers to a surface facing the rotating shaft 13 in the radially inner end 1111 of the core unit 111.

[0067] Exemplarily, the radially inner end surface 1111a of the core unit 111 is not more than the radially inner end surface 124a of the magnetic steel 12 in the direction of approaching the rotating shaft 13 in the radial direction. In this way, the magnetic induction lines of the magnetic steel 12 cannot be transmitted to the radially inner side of the magnetic steel 12 through the radially inner end surface 1111a of the core unit 111, thereby helping to reduce the magnetic leakage of the radially inner end 124 of the magnetic steel 12.

[0068] In some embodiments, the rotor 10 includes an annular magnetic blocking structure 141, which fills the spacing region between the core unit 111 and the rotating shaft 13, and fills the spacing region between the magnetic steel 12 and the rotating shaft 13.

[0069] In this embodiment, on the one hand, the annular magnetic blocking structure 141 can be used to improve the connection strength between the core unit 111 and the rotating shaft 13, and between the magnetic steel 12 and the rotating shaft 13, and on the other hand, the annular magnetic blocking structure 141 can further increase the magnetic resistance at the radially inner end 1111a of the core unit 111, thereby helping to further reduce the magnetic leakage.

[0070] It can be understood that the connection mode between the rotor core 11, the magnetic steel 12 and the rotating shaft 13 is not limited.

[0071] For example, in some embodiments, the rotor core 11, the magnetic steel 12 and the rotating shaft 13 are connected by an injection molding process.

[0072] In this embodiment, please refer to Figure 2 The rotor 10 includes an injection molding part 14, and the rotor core 11, the magnetic steel 12 and the rotating shaft 13 are connected by the injection molding part 14.

[0073] For example, the rotor core 11, the magnetic steel 12 and the rotating shaft 13 can be placed in a mold, and then the injection material of the injection part 14 is injected into the mold, the injection material of the injection part 14 is wrapped outside the rotor core 11, and also fills the interval area between the magnetic steel 12 and the core unit 111, the interval area between the magnetic steel 12 and the rotating shaft 13, and the interval area between the core unit 111 and the rotating shaft 13. After cooling and forming, the magnetic steel 12 and the core unit 111, the magnetic steel 12 and the rotating shaft 13, and the core unit 111 and the rotating shaft 13 are connected through the injection part 14, and the injection part 14 serves as an appearance part of the rotor 10.

[0074] In this embodiment, the annular magnetic resistance structure 141 is part of the injection part 14.

[0075] It should be noted that the annular magnetic resistance structure 141 refers to an annular structure formed by filling the injection material of the injection part 14 in the interval area between the core unit 111 and the rotating shaft 13 and in the interval area between the magnetic steel 12 and the rotating shaft 13 and then cooling and forming.

[0076] For example, the material of the injection part 14 includes at least one of plastic, epoxy resin, polyurethane and silicone rubber.

[0077] In some embodiments, the core unit 111 is formed with at least one injection hole 1114 for filling the injection material of the injection part 14. In this way, the bonding force between the injection part 14 and the core unit 111 can be increased.

[0078] For example, the injection hole 1114 extends in the axial direction of the rotating shaft.

[0079] For example, the shape of the injection hole 1114 is not limited. For example, the injection hole 1114 can be a circular hole, a square hole or a semicircular hole.

[0080] In some embodiments, referring to Figure 10 and Figure 11 the core unit 111 is formed with a positioning hole 1115, and when the injection material of the injection part 14 is poured, the positioning hole 1115 is used for inserting a positioning part to position the core unit 111. After the injection material of the injection part 14 is cooled and formed, the positioning part is removed from the positioning hole 1115. For example, the positioning part can be a positioning pin of an injection molding machine.

[0081] In some embodiments, the distance d1 between the outer circumferential surface 13a of the rotating shaft 13 and the radially inner end surface 1111a of the core unit 111 is 1.5 mm to 3 mm. That is, 1.5 mm≤d1≤3 mm, for example, d1 can be 1.5 mm, 1.8 mm, 2 mm, 2.1 mm, 2.5 mm, 3 mm, etc. By controlling d1 within a reasonable range, on the one hand, the distance between the core unit 111 and the rotating shaft 13 is not too close, thereby helping to reduce the magnetic leakage, and at the same time, the thickness of the annular magnetic resistance structure 141 in the radial direction is not too small, thereby helping to improve the structural strength of the annular magnetic resistance structure 141; on the other hand, the distance between the core unit 111 and the rotating shaft 13 is not too far, so that, in the case of the same radius of the rotor 10, the radial size of the core unit 111 and the radial size of the magnetic steel 12 can be increased.

[0082] In some embodiments, the ratio of the distance d1 between the outer circumferential surface 13a of the rotating shaft 13 and the radially inner end surface 1111a of the core unit 111 to the radius of the rotor 10 is 0.03 to 0.06.

[0083] It should be noted that, in the embodiments of the present application, the radius of the rotor 10 refers to the radius of the circumscribed circle G2 of the rotor core 11, that is, D2 / 2. The diameter of the rotor 10 described below refers to the diameter of the circumscribed circle G2 of the rotor core 11.

[0084] That is, 0.03≤d1 / (D2 / 2)≤0.06, for example, d1 / (D2 / 2) can be 0.03, 0.04, 0.05, 0.06, etc. In this way, in the case of the same radius of the rotor, by controlling the ratio of d1 to D2 / 2 within a reasonable range, the distance between the core unit 111 and the rotating shaft 13 is moderate, which will not be too close, thereby helping to reduce the magnetic leakage, and at the same time, the thickness of the annular magnetic resistance structure 141 in the radial direction will not be too small, thereby helping to improve the structural strength of the annular magnetic resistance structure 141; on the other hand, the distance between the core unit 111 and the rotating shaft 13 is not too far, so that, in the case of the same radius of the rotor 10, the radial size of the core unit 111 and the radial size of the magnetic steel 12 can be increased.

[0085] It should be noted that the circumscribed circle G2 of the rotor core 11 refers to the circle with the center of the rotating shaft 13 as the center and the diameter that is the largest tangent to the radially outer end surface 1112a of the projection of the plurality of core units 111 in the vertical projection plane of the rotating shaft 13.

[0086] It should be noted that the end face in the radial outer end face refers to the surface, the radial outer end face refers to the surface of the radial outer end away from the rotating shaft, for example, the radial outer end face 1112b of the core unit 111 refers to the surface of the radial outer end 1112 of the core unit away from the rotating shaft 13.

[0087] In some embodiments, the distance d2 between the outer circumferential surface 13a of the rotating shaft 13 and the radial inner end face 124a of the magnetic steel 12 is 1mm-1.5mm. That is, 1mm≤d2≤1.5mm, for example, d2 can be 1mm, 1.1mm, 1.2mm, 1.5mm, etc. By controlling d2 within a reasonable range, it is beneficial to make the annular magnetic resistance structure 141 have a certain thickness in the radial direction, which helps to improve the structural strength of the annular magnetic resistance structure 141, and also helps to increase the radial size of the magnetic steel 12 under the condition that the radius of the rotor core 11 is the same.

[0088] In some embodiments, the ratio of the distance d2 between the outer circumferential surface 13a of the rotating shaft 13 and the radial inner end face 124a of the magnetic steel 12 to the radius of the rotor 10 is 0.02-0.05. That is, 0.02≤d2 / (D2 / 2)≤0.05, d2 / (D2 / 2) can be 0.02, 0.03, 0.04, 0.05. In this way, under the condition that the radius of the rotor is the same, by controlling the ratio of d2 / (D2 / 2) within a reasonable range, it is beneficial to make the distance between the magnetic steel 12 and the rotating shaft 13 moderate, neither too close to make the annular magnetic resistance structure 141 have a certain thickness in the radial direction, which helps to improve the structural strength of the annular magnetic resistance structure 141, nor too far away, which helps to increase the radial size of the magnetic steel 12 under the condition that the radius of the rotor core 11 is the same.

[0089] In some embodiments, as shown in Figure 13 and Figure 14 The difference between the radius of the rotor 10, that is, the radius D2 / 2 of the circumscribed circle G2 of the rotor core 11, and the size H of the magnetic steel 12 in the radial direction of the rotor 10 is 1mm-3.5mm. That is, 1mm≤D2 / 2-H≤3.5mm. For example, D2 / 2-H can be 1mm, 1.5mm, 2mm, 3mm, 3.5mm, etc. By controlling the difference between the radius D2 / 2 of the circumscribed circle of the rotor core 11 and the size H of the magnetic steel 12 in the radial direction of the rotor 10 within a reasonable range, the size of the magnetic steel 12 in the radial direction of the rotor 10 can be as long as possible, while still not affecting the assembly between the magnetic steel 12 and the rotor core 11.

[0090] In some embodiments, the magnetic steel 12 includes a reduced portion 121 and a constant-width portion 122, and in the direction of the radial direction of the rotor 10 and towards the rotating shaft 13, the constant-width portion 122 has the same circumferential size, and the reduced portion 121 has a reduced circumferential size.

[0091] In this embodiment, by arranging the reduced portion 122 at the radially inner end 12b of the equal-width portion 121, the size of the magnetic steel 12 along the radius of the rotor 10 can be increased as much as possible in the case of the same size of the radius of the rotor 10, so that the overall size of the magnetic steel 12 along the radius of the rotor 10 can be longer, which helps to increase the number of magnetic induction lines of the magnetic steel 12, so that the number of magnetic induction lines passing through the core unit 111 is increased, and thus the number of magnetic induction lines passing through the air gap between the stator assembly 20 and the rotor 10 is increased, which helps to improve the air gap flux density, and ultimately helps to improve the driving torque and the motor power; it also helps to miniaturize the overall motor design.

[0092] In some embodiments, the ratio of the diameter D1 of the circumscribed circle G1 of the reduced portion 121 to the diameter D2 of the circumscribed circle G2 of the rotor core 11 of the rotor 10 is 0.25-0.75. That is, 0.25≤D1 / D2≤0.75. For example, D1 / D2 can be 0.25, 0.35, 0.4, 0.5, 0.65, 0.75, etc.

[0093] It should be noted that the circumscribed circle G1 of the reduced portion 121 refers to, in the vertical projection of the plane perpendicular to the rotation axis 13, the circle with the center of the rotation axis 13 as the center and the largest diameter tangent to the radially outer end surface of the projection of the plurality of reduced portions 121.

[0094] In the case of the same radius of the rotor 10, if the diameter D1 of the circumscribed circle of the reduced portion 122 is too large, the radial size of the equal-width portion 121 will necessarily be reduced, and at this time the overall volume of the magnetic steel 12 will be reduced, which will in turn reduce the effective magnetic flux of the magnetic steel 12 through the core, resulting in a reduction in the driving torque; if the diameter D1 of the circumscribed circle of the reduced portion 122 is too small, the equal-width portion 121 will be too close to the rotation axis, especially in the case of a large number of magnetic steels 12, the circumferential spacing 1111a between the radially inner ends of the two adjacent equal-width portions 121 will also be too small, and at this time the circumferential size of the core unit 111 between the radially inner ends of the two adjacent equal-width portions 121 will also be too small, which will in turn reduce the effective magnetic flux of the magnetic steel 12 through the core, resulting in a reduction in the driving torque.

[0095] In this embodiment, by arranging the diameter D1 of the circumscribed circle of the reduced portion 122 within a reasonable range, on the one hand, it helps to avoid the diameter D1 of the circumscribed circle of the reduced portion 122 being too small to reduce the overall volume of the magnetic steel 12, and on the other hand, it helps to avoid the diameter D1 of the circumscribed circle of the reduced portion 122 being too large to make the circumferential size of the core unit 111 between the radially inner ends of the two adjacent equal-width portions 121 too small.

[0096] Exemplarily, in the vertical projection of the plane perpendicular to the rotation axis 13, the projection of the equal-width portion 122 is a rectangle.

[0097] In some embodiments, as shown in Figure 13 In the orthogonal projection in the plane perpendicular to the rotation axis 13, the projection of the tapering portion 121 is a trapezoid.

[0098] Exemplarily, the projection of the tapering portion 121 can be an isosceles trapezoid.

[0099] In some other embodiments, as shown in Figure 14 In the orthogonal projection in the plane perpendicular to the rotation axis 13, the projection of the tapering portion 121 is substantially a triangle, and the radially inner end of the tapering portion 121 is formed with a first rounded corner 122a. The first rounded corner 122a can avoid the radially inner end of the tapering portion 121, i.e. the radially inner end 124 of the magnetic steel 12, forming a sharp corner as much as possible.

[0100] In some embodiments, as shown in Figure 13 and Figure 14 The ratio of the circumferential dimension L of the uniform width portion 122 to the diameter D2 of the circumscribed circle G2 of the rotor core 11, i.e. the diameter of the rotor 10, is 0.06-0.15. That is, 0.06≤L / D2≤0.15. For example, L / D2 can be 0.06, 0.07, 0.09, 0.1, 0.12, 0.14, 0.15, etc. By controlling L / D2 within a reasonable range, it is helpful to make the circumferential dimension of the uniform width portion 122 reasonable, and it is helpful to make the overall volume of the magnetic steel 12 appropriate, and it is helpful to reduce the probability of magnetic saturation occurring.

[0101] In some embodiments, as shown in Figure 13 and Figure 14 The tapering portion 121 comprises a first wall surface 1221 and a second wall surface 1222 oppositely arranged along the circumference, and the first wall surface 1221 and the second wall surface 1222 extend towards each other along the radial direction towards the rotation axis 13.

[0102] It should be noted that the first wall surface 1221 can be a plane or a curved surface. The second wall surface 1222 can be a plane or a curved surface.

[0103] Exemplarily, the included angle α1 between the first wall surface 1221 and the second wall surface 1222 is 15-36 degrees. That is, 15 degrees≤α1≤36 degrees. For example, α1 can be 15 degrees, 20 degrees, 25 degrees, 28 degrees, 30 degrees, 36 degrees, etc.

[0104] It should be noted that the included angle between the first wall surface 1221 and the second wall surface 1222 refers to the acute angle formed by the first wall surface 1221 and the second wall surface 1222 extending towards each other along the radial direction.

[0105] By controlling the included angle a1 between the first wall surface 1221 and the second wall surface 1222 within a reasonable range, the size reduction of the reduced portion 121 in the circumferential direction is controlled, so that the size of the reduced portion 121 in the circumferential direction is within a suitable range. For example, refer to Figure 13 and Figure 14 The magnetic steel 12 includes an equal-width portion 122 connected to the radially outer end of the reduced portion 121, and the equal-width portion 122 has the same circumferential dimension in the radial direction of the rotor 10.

[0106] For example, the equal-width portion 122 and the reduced portion 121 are integrally formed.

[0107] In some embodiments, as shown in Figure 11 The radially outer end 1112 of the core unit 111 has protrusions 1116 formed on opposite sides in the circumferential direction, and the magnetic steel 12 is located radially inward of the protrusions 1116. The protrusions 1116 are used to limit the radially outer end 125 of the magnetic steel 12 in the radial direction of the rotor 10, so that the magnetic steel 12 is more stably located in the accommodation space 112.

[0108] For example, as shown in Figure 12 The dimension b of the protrusion 1116 in the radial direction of the rotor 10 is 0.5mm-1.5mm. That is, 0.5mm≤b≤1.5mm. For example, b can be 0.5mm, 0.6mm, 0.8mm, 0.9mm, 1.2mm, 1.5mm, etc. By controlling the protrusion 1116 within a reasonable range, on the one hand, the protrusion 1116 can limit the magnetic steel 12, and on the other hand, it is also helpful to avoid the protrusion 1111 being too large in the radial direction to affect the size of the magnetic steel 12 in the radial direction.

[0109] For example, the protrusions 1116 of adjacent two core units 111 have a distance in the circumferential direction. In this way, while limiting the magnetic steel 12, the adjacent two core units 111 are also not in contact, which helps to reduce magnetic leakage.

[0110] For example, as shown in Figure 12 The distance c1 between the protrusions 1116 of adjacent two core units 111 in the circumferential direction is 1.5mm-3.5mm. That is, 1.5mm≤c1≤3.5mm. For example, c1 can be 1.5mm, 1.8mm, 2mm, 2.5mm, 3.5mm, etc. By controlling the distance c1 between the protrusions 1116 of adjacent two core units 111 within a reasonable range, on the one hand, the protrusion 1116 has a certain size in the circumferential direction to limit the radially outer end 125 of the magnetic steel 12, and on the other hand, it is also helpful to avoid the two protrusions 1116 contacting to generate magnetic leakage.

[0111] In some embodiments, as shown inFigure 15 and Figure 16 The magnetic steel 12 comprises a contraction portion 123 connected to the radially inner end of the equal-width portion 122, and the contraction portion 123 is reduced in the circumferential dimension in the direction away from the rotation axis 13 along the radial direction of the rotor 10.

[0112] In this embodiment, by arranging the contraction portion 123 at the radially outer end of the equal-width portion 122, the contraction portion 123 can play a role in adjusting the overall volume of the magnetic steel 12 in the case that the radial dimension of the magnetic steel 12 is sufficient, which helps to avoid the situation that the overall volume of the magnetic steel 12 is too large to cause magnetic saturation.

[0113] Exemplarily, the ratio of the diameter of the inscribed circle D3 of the contraction portion 123 to the diameter D2 of the circumscribed circle G2 of the rotor core 11 of the rotor 10 is 0.68-0.87. That is, D3 / D2 is 0.68-0.87, for example, D3 / D2 can be 0.68, 0.69, 0.7, 0.75, 0.78, 0.8, 0.86, 0.87, etc. By controlling D3 / D2 within a reasonable range, in the case that the radial dimension of the rotor 10 is limited, it helps to control D3 within a reasonable range, thereby helping to control the radial dimension of the contraction portion 123.

[0114] It should be noted that the inscribed circle D3 of the contraction portion 123 refers to, in the orthogonal projection perpendicular to the rotation axis 13, the smallest circle with the center of the rotation axis 13 as the center and tangent to the radially inner end face of the projection of the plurality of contraction portions 123.

[0115] In some embodiments, referring to Figure 15 and Figure 16 The contraction portion 123 comprises a third wall surface 1231 and a fourth wall surface 1232 oppositely arranged along the circumferential direction, and the third wall surface 1231 and the fourth wall surface 1232 extend towards each other along the radial direction towards the rotation axis 13.

[0116] In this embodiment, the extension direction of the third wall surface 1231 intersects the radial direction of the rotor 10, and the extension direction of the fourth wall surface 1232 intersects the radial direction of the rotor 10. At this time, the extension direction of the wall surface of the core unit 111 abutting against the third wall surface 1231 also intersects the radial direction of the rotor 10, and the extension direction of the wall surface of the core unit 111 abutting against the fourth wall surface 1232 also intersects the radial direction of the rotor 10, thereby enabling the two adjacent core units 111 to limit the radial direction of the radially outer end 125 of the magnetic steel 12. In this embodiment, referring to Figure 17 It is not necessary to arrange the limiting structure at the radially outer end 1112 of the core unit 111.

[0117] Exemplarily, referring to Figure 17The distance c2 between the radially outer end faces 1112a of two adjacent core units 111 in the circumferential direction is 0.04-0.08 times the diameter D2 of the rotor core 11, i.e. 0.04≤c2 / D2≤0.08, for example, c2 / D2 can be 0.04, 0.05, 0.06, 0.07, 0.08. In this way, a suitable distance is provided between the radially outer ends 1112 of two adjacent core units 111, which helps to reduce magnetic leakage and enables the injection molding material of the injection molding part 14 to fill the space between the radially outer end faces 1112a of two adjacent core units 111.

[0118] It should be noted that the third wall surface 1231 can be a flat surface or a curved surface. The fourth wall surface 1232 can be a flat surface or a curved surface.

[0119] For example, as shown in Figure 15 and Figure 16 , the angle a2 between the third wall surface 1231 and the fourth wall surface 1232 is 15-36 degrees, i.e. 15≤a2≤36. For example, a2 can be 15, 20, 25, 28, 30, 36 degrees, etc.

[0120] It should be noted that the angle between the third wall surface 1231 and the fourth wall surface 1232 refers to the acute angle formed by the third wall surface 1231 and the fourth wall surface 1232 extending towards each other in the radial direction.

[0121] By controlling the angle a2 between the third wall surface 1231 and the fourth wall surface 1232 within a reasonable range, the degree of reduction in the circumferential dimension of the shrinkage part 123 can be controlled, so that the circumferential dimension of the shrinkage part 123 is within a suitable range.

[0122] For example, the shrinkage part 123 and the constant-width part 122 are integrally formed.

[0123] For example, as shown in Figure 15 , the projection of the shrinkage part 123 is a trapezoid in the vertical projection on the plane perpendicular to the rotation axis 13.

[0124] For example, the projection of the shrinkage part 123 can be an isosceles trapezoid.

[0125] In some other embodiments, as shown in Figure 16 , the projection of the shrinkage part 123 is substantially a triangle in the vertical projection on the plane perpendicular to the rotation axis 13, and the radially inner end of the shrinkage part 123 is formed with a second rounded corner 123a. The second rounded corner 123a can avoid the radially outer end of the shrinkage part 123, i.e. the radially outer end 125 of the magnet steel 12, from forming an acute angle.

[0126] It should be noted that in some embodiments, the magnetic steel 12 can simultaneously include the reduced portion 121, the equal-width portion 122 and the contracted portion 123, and the reduced portion 121, the equal-width portion 122 and the contracted portion 123 are sequentially connected along the radial direction of the rotor 10.

[0127] In this embodiment, the ratio of the diameter D1 of the circumscribed circle G1 of the reduced portion 121 to the diameter D2 of the circumscribed circle G2 of the rotor 10, i.e. the diameter of the rotor core 11, can be 0.32-0.54. That is, 0.32≤D1 / D2≤0.54, for example, D1 / D2 can be 0.32, 0.35, 0.4, 0.5, etc.

[0128] In some embodiments, the magnetic steel 12 can only include the equal-width portion 122 and the reduced portion 121, and the reduced portion 121 and the equal-width portion 122 are sequentially connected along the radial direction of the rotor. In this embodiment, the magnetic steel 12 can not include the contracted portion 123.

[0129] In some embodiments, the radially inner end 1111 of the core unit 111 has at least one tooth portion 1113, as shown in Figure 4 and Figure 5 The tooth portion 1113 protrudes from the radially inner end surface 1111b of the core unit 111 along the radial direction of the rotor 10, and the tooth portion 1113 exceeds the radially inner end surface 124a of the magnetic steel 12 in the direction of approaching the rotor shaft 13 along the radial direction. In this way, the tooth portion 1113 can be in contact with the injection molding material of the injection molding part 14, thereby helping to increase the contact area between the core unit 111 and the injection molding material of the injection molding part 14, and helping to increase the bonding force between the core unit 111 and the injection molding part 14. Moreover, the volume of the tooth portion 1113 is relatively small, which can increase the bonding force between the core unit 111 and the injection molding part 14 while reducing the magnetic flux leakage as much as possible.

[0130] For example, the at least one tooth portion 1113 protrudes at the edge of the circumferential direction of the radially inner end surface 1111a of the core unit 111. In this way, the magnetic flux leakage can also be reduced as much as possible.

[0131] In some embodiments, the number of tooth portions 1113 is one, and one tooth portion 1113 protrudes at the edge of one end of the axial direction of the radially inner end surface 111b of the core unit 111.

[0132] In some embodiments, as shown in Figure 11As shown, the number of the tooth portions 1113 is two, and the two tooth portions 1113 are protruded at the edges of the radially inner end surface 1111a of the core unit 111 at the two ends in the axial direction. That is, the two tooth portions 1113 are used to increase the binding force between the two ends of the core unit 111 in the axial direction and the injection molding part 14, so that the connection between the core unit 111 and the injection molding part 14 is more stable, and at the same time, the magnetic field generated by the magnetic steel 12 can only leak to the radially inner side of the magnetic steel 12 through the two tooth portions 1113, that is, the connection strength between the core unit 111 and the injection molding part 14 is ensured as much as possible, and the magnetic leakage is reduced as much as possible.

[0133] For example, the shape of the tooth portion 1113 can be dovetail tooth.

[0134] In some embodiments, as shown in Figure 12 and Figure 17 As shown, the radially outer end surface 1112a of the core unit 111 includes a first arc segment S1, a second arc segment S2 and a third arc segment S3 connected in sequence in the circumferential direction of the rotor 10, the curvatures of the first arc segment S1 and the second arc segment S2 are different, and the curvatures of the second arc segment S2 and the third arc segment S3 are different. By designing the radially outer end surface 1112a of the core unit 111 as arc segments, it is helpful to optimize the air gap magnetic field distribution between the stator assembly 20 and the rotor 10, so that the air gap magnetic field is closer to the ideal sinusoidal waveform, which helps to reduce the harmonic content of the motor and helps to reduce the torque ripple of the motor.

[0135] Moreover, the curvatures of the first arc segment S1 and the second arc segment S2 are different, and the curvatures of the second arc segment S2 and the third arc segment S3 are different, that is, the first arc segment S1, the second arc segment S2 and the third arc segment S3 do not belong to the same circular arc of a circumference, which helps to further optimize the air gap magnetic field distribution between the stator and the rotor 10, thereby further reducing the harmonic content of the motor.

[0136] For example, the center of the second arc segment S2 is located on the rotation axis of the rotating shaft 13. That is, the second arc segment S2 is arranged concentrically with the rotating shaft 13.

[0137] In some embodiments, the first arc segment S1 and the third arc segment S3 are symmetrically arranged about the symmetry plane of the second arc segment S2.

[0138] It should be noted that the symmetry plane of the second arc segment S2 passes through the midpoint of the arc length of the second arc segment S2 and the rotation axis.

[0139] For example, the ratio of the distance between the center O1 corresponding to the first arc segment S1 and the rotation axis to the radius of the rotor 10, that is, the radius of the circumscribed circle of the rotor core 11, is 0.38-0.8. Please refer to Figure 12The distance between the center O1 of the first arc segment S1 and the axis of rotation is the distance R1 between the center O1 and the center O2, which is 0.38 ≤ R1 / (D1 / 2) ≤ 0.8. For example, R1 / (D1 / 2) can be 0.38, 0.5, 0.6, 0.7, 0.8, etc. By limiting the distance R1, the position of the center O1 of the first arc segment S1 is defined. Furthermore, since the first arc segment S1 and the third arc segment S3 are symmetrical about the second arc segment S2, the position of the center O3 of the third arc segment S3 is also defined.

[0140] For example, such as Figure 12 As shown, the ratio of the central angle θ corresponding to the second arc segment S2 to the angle β between the two adjacent magnets 12 is 0.2 to 0.7. That is, 0.2 ≤ θ / β ≤ 0.7. For example, θ / β can be 0.2, 0.3, 0.4, 0.6, 0.7, etc.

[0141] It should be noted that the magnet 12 has a plane of symmetry. The plane of symmetry of the magnet 12 passes through the axis of rotation and is used to divide the magnet 12 into two identical parts. The included angle β between two adjacent magnets 12 refers to the included angle between the planes of symmetry of two adjacent magnets 12.

[0142] In this embodiment, given the limited size of the rotor core 11, by limiting the ratio of the central angle θ corresponding to the second arc segment S2 to the included angle β between two adjacent magnets 12, the ratio of the arc length of the second arc segment S2 to the circumferential distance between the two adjacent magnets 12 is kept within a reasonable range. This helps to further optimize the magnetic circuit structure and reduce harmonic content. For example, please refer to... Figure 13 and Figure 14 The magnet 12 is magnetized tangentially, meaning that one of the two opposing walls of the magnet 12 along the axial direction forms the N pole and the other forms the S pole. Moreover, when multiple magnets 12 are placed into the corresponding receiving space 112, the N poles of two adjacent magnets 12 are opposite each other circumferentially, and the S poles of two adjacent magnets 12 are opposite each other circumferentially.

[0143] Based on the rotor 10 provided in the embodiments of this application, please refer to Figure 1 This application also provides an electric motor, which includes a stator assembly 20 and a rotor 10 in any embodiment of this application, wherein the stator assembly 20 is disposed around the outer periphery of the rotor 10.

[0144] The stator assembly 20 is used to generate a rotating magnetic field to drive the rotor 10 to rotate circumferentially.

[0145] Based on the motor provided in the embodiments of this application, this application also provides an air conditioner, which includes the motor provided in any embodiment of this application. That is, the motor provided in the embodiments of this application can be applied to an air conditioner.

[0146] The motor can be applied to an outdoor unit of an air conditioner, and an indoor cabinet or indoor hanging machine, etc. The internal space of the air conditioner is limited, and thus the performance of the motor and the overall miniaturized design are particularly necessary.

[0147] The various embodiments / implementation provided in the present application can be combined with each other without producing contradictions, if necessary.

[0148] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A rotor characterized by, The application relates to a rotor, comprising: a rotating shaft; a rotor core comprising a plurality of core units, the core units being arranged in a circumferential direction of the rotating shaft, and a space being defined between every two adjacent core units; a plurality of magnetic steels, each of which is arranged in a corresponding space; a radially inner end surface of the core unit is arranged in a spaced manner with respect to an outer circumferential surface of the rotating shaft, and a radially inner end surface of the magnetic steel is arranged in a spaced manner with respect to the outer circumferential surface of the rotating shaft, and the radially inner end surface of the core unit is arranged in a direction of approaching the rotating shaft in a radial direction and does not exceed the radially inner end surface of the magnetic steel; a ring-shaped magnetic blocking structure is arranged in a space between the core unit and the rotating shaft, and in a space between the magnetic steel and the rotating shaft.

2. The rotor of claim 1, wherein A distance between the outer circumferential surface of the rotating shaft and the radially inner end surface of the core unit is 1.5mm-3mm; and / or, a ratio of the distance between the outer circumferential surface of the rotating shaft and the radially inner end surface of the core unit to a radius of the rotor is 0.03-0.

06.

3. The rotor of claim 1, wherein A distance between the outer circumferential surface of the rotating shaft and the radially inner end surface of the magnetic steel is 1mm-1.5mm; and / or, a ratio of the distance between the outer circumferential surface of the rotating shaft and the radially inner end surface of the magnetic steel to the radius of the rotor is 0.02-0.

05.

4. The rotor of claim 1, wherein A difference between the radius of the rotor and a dimension of the magnetic steel in a radial direction of the rotor is 1mm-3.5mm.

5. The rotor of claim 1, wherein The magnetic steel comprises a reduced portion and a uniform-width portion, the uniform-width portion is connected to a radially outer end of the reduced portion, and in a radial direction of the rotor and in a direction of approaching the rotating shaft, a circumferential dimension of the uniform-width portion is the same, and a circumferential dimension of the reduced portion is reduced.

6. The rotor of claim 5, wherein A ratio of a diameter of a circumscribed circle of the reduced portion to a diameter of the rotor is 0.25-0.

75.

7. The rotor of claim 5, wherein In a vertical projection perpendicular to the rotating shaft, a projection of the uniform-width portion is a rectangle; A projection of the reduced portion is a trapezoid; or, the projection of the reduced portion is substantially a triangle, and a radially inner end of the reduced portion is formed with a first round corner.

8. The rotor of claim 5, wherein A ratio of a circumferential dimension of the uniform-width portion to the diameter of the rotor is 0.06-0.

15.

9. The rotor of claim 5, wherein The magnetic steel comprises a contracted portion, the contracted portion is connected to a radially outer end of the uniform-width portion, and in a radial direction of the rotor and in a direction of moving away from the rotating shaft, a circumferential dimension of the contracted portion is reduced.

10. The rotor of claim 9, wherein A ratio of a diameter of an inscribed circle of the contracted portion to the diameter of the rotor is 0.68-0.

87.

11. The rotor of claim 5, wherein The reduced portion comprises a first wall surface and a second wall surface arranged in a spaced manner in a circumferential direction, and in a radial direction, the first wall surface and the second wall surface extend in a direction of approaching each other, and an included angle between the first wall surface and the second wall surface is 15 degrees-36 degrees.

12. The rotor of claim 1, wherein A radially outer end surface of the core unit comprises a first arc segment, a second arc segment and a third arc segment connected in sequence in a circumferential direction of the rotor, curvatures of the first arc segment and the second arc segment are different, and curvatures of the second arc segment and the third arc segment are different.

13. The rotor of claim 12, wherein A center of the second arc segment is located on a rotating axis of the rotating shaft; The first arc-shaped segment and the third arc-shaped segment are symmetrically arranged about a symmetry plane of the second arc-shaped segment, the symmetry plane passing through a midpoint of an arc length of the second arc-shaped segment and the rotation axis; and / or a ratio of a central angle of the second arc-shaped segment to an included angle between two adjacent magnetic steels is 0.2-0.

7.

14. The rotor of claim 13, wherein A ratio of a distance between a center of the first arc-shaped segment and the rotation axis to a radius of the rotor is 0.38-0.

8.

15. An electric machine characterized by The motor comprises a stator assembly and a rotor as claimed in any one of claims 1-14, the stator assembly being arranged around an outer periphery of the rotor.

16. An air conditioner characterized by comprising: The motor as claimed in claim 15.

Images