Motors and Axial Fans

Abstract

To provide a motor that suppresses wind leakage in the radial direction of a motor.SOLUTION: The motor includes a rotor, a stator, and a housing that covers the rotor and stator from the radial direction outward. The housing includes a first housing 4 located on one side in an axial direction and a second housing located on the other side in the axial direction. The first and second housings each have opposing surfaces 30 facing each other in the axial direction. At least portions of areas of the facing surfaces on each of the first and second housings are in contact with each other. The facing surfaces of at least one of the first and second housings have partially a protruding portion 31 protruding in the axial direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a motor and an axial fan. [Background technology]

[0002] A conventional motor has a base and a cover. The base houses a stator. The stator rotates a fan wheel. The base and the cover are joined to each other in the axial direction. The base and the cover are joined to each other in the axial direction, thereby covering the fan wheel from the radial outside (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China Utility Model No. 205047539 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described conventional configuration, there is a possibility that wind may leak from the joint between the base and the cover, that is, in the radial direction of the motor.

[0005] An object of the present invention is to suppress air leakage in the radial direction of a motor. [Means for solving the problem]

[0006] An exemplary motor of the present invention includes a rotor rotatable about a central axis extending vertically, a stator for rotating the rotor, and a housing for covering the rotor and the stator from the radial outside. The housing has a first housing located on one side in the axial direction and a second housing located on the other side in the axial direction. The first housing and the second housing each have opposing surfaces that face each other in the axial direction. At least a portion of the opposing surfaces of the first housing and the second housing contact each other. At least one of the opposing surfaces of the first housing and the second housing has a protruding portion that protrudes in the axial direction.

[0007] An exemplary axial flow fan of the present invention includes the above-mentioned motor and a rotor blade attached to the rotor. Effect of the Invention

[0008] According to the exemplary motor and axial fan of the present invention, it is possible to suppress air leakage in the radial direction of the motor. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an axial flow fan according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the axial flow fan and the motor according to the embodiment. [Diagram 3] FIG. 3 is a perspective view of a housing according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a lead wire holding structure according to the embodiment. [Diagram 5] FIG. 5 is a perspective view of the first housing according to the embodiment as viewed from above in the axial direction. [Figure 6] FIG. 6 is a perspective view of the second housing according to the embodiment as viewed from below in the axial direction. [Figure 7] FIG. 7 is a plan view of the cylindrical portion according to the embodiment as viewed from the axial direction. [Figure 8]FIG. 8 is a schematic diagram showing a joint portion between a first housing and a second housing according to the embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a joint portion between a first housing and a second housing according to a modified example. [Figure 10] FIG. 10 is an enlarged view of a part of the protruding portion according to the embodiment. [Figure 11] FIG. 11 is an enlarged view of a part of a protruding portion according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

[0011] In this specification, the direction in which the central axis CA of the motor 100 extends is referred to as the "axial direction," and the axial direction is defined as the up-down direction. However, this definition of the up-down direction does not limit the orientation and positional relationship of the motor 100 when in use.

[0012] In this specification, one axial direction is referred to as "downward" and the other axial direction is referred to as "upward." In addition, for each component, the lower end is referred to as the "lower end" and the upper end is referred to as the "upper end." In addition, for each component, the end face of the lower end that faces downward is referred to as the "lower end surface," and the end face of the upper end that faces upward is referred to as the "upper end surface."

[0013] In this specification, the direction perpendicular to the central axis CA is referred to as the "radial direction." In addition, in the radial direction, the direction approaching the central axis CA is referred to as the "radial inner direction," and the direction moving away from the central axis CA is referred to as the "radial outer direction." In addition, in each component, the side surface facing radially inward is referred to as the "radial inner side surface," and the side surface facing radially outward is referred to as the "radial outer side surface."

[0014] In this specification, the circumferential direction about the central axis CA is referred to as the "circumferential direction."

[0015] <1. Axial flow fan> Fig. 1 is a perspective view of an axial fan 200 according to an embodiment of the present invention. Fig. 2 is an exploded perspective view of the axial fan 200 and a motor 100 according to an embodiment of the present invention.

[0016] An axial flow fan 200 according to the embodiment generates an airflow. The axial flow fan 200 includes a motor 100 and a rotor blade 210. The motor 100 is an outer rotor type. The rotor blade 210 is attached to the motor 100. Specifically, the rotor blade 210 is attached to a rotor 1, which will be described later. The motor 100 rotates the rotor blade 210. The rotation of the rotor blade 210 generates an airflow.

[0017] <2. Motor> The motor 100 according to the embodiment includes a rotor 1, a stator 2, and a housing 3. The motor 100 also includes a shaft 10.

[0018] The shaft 10 is disposed along a central axis CA extending vertically. The shaft 10 is rotatable around the central axis CA. The shaft 10 is supported by a shaft holder 410. The shaft holder 410 extends in an axial direction along the central axis CA in a cylindrical shape. A bearing (not shown) that rotatably supports the shaft 10 is attached to a radially inner surface of the shaft holder 410.

[0019] The rotor 1 is rotatable about a central axis CA that extends vertically. The rotor 1 has a yoke 11 that is a cylindrical yoke with a lid. A yoke lid portion 111 that is a lid portion of the yoke 11 is disk-shaped and centered on the central axis CA. The yoke lid portion 111 has an opening at the radial center. The upper end of the shaft 10 is fixed to the radial inner surface of the opening of the yoke lid portion 111. A yoke cylindrical portion 112 that is a cylindrical portion of the yoke 11 extends downward from the radial outer edge of the yoke lid portion 111. A magnet (not shown) is fixed to the radial inner surface of the yoke cylindrical portion 112.

[0020] The stator 2 rotates the rotor 1. The stator 2 is annular about a central axis CA and is disposed radially inward of the rotor 1. The radial outer surface of the stator 2 faces the radial inner surface of the rotor 1. Specifically, the radial outer surface of the stator 2 faces a magnet fixed to a radial inner surface of the yoke 11. The radial inner surface of the stator 2 is fixed to a radial outer surface of the shaft holder 410.

[0021] The stator 2 includes a stator core 21, an insulator 22, a coil (not shown), and a substrate 23. The stator core 21 is an annular magnetic body centered on a central axis CA, and is a laminated body in which a plurality of plate-shaped electromagnetic steel sheets are stacked in the axial direction. A radially outer surface of the stator core 21 faces a magnet in the radial direction. A radially inner surface of the stator core 21 is fixed to a radially outer surface of a shaft holder 410.

[0022] The insulator 22 covers at least a portion of the stator core 21. The insulator 22 is an insulating member made of resin or the like. The coil is formed by winding a conductive wire around the stator core 21 via the insulator 22. The substrate 23 is electrically connected to the coil. Various electronic components are mounted on the substrate 23.

[0023] The motor 100 includes lead wires 24. The lead wires 24 are electrically connected to the stator 2. More specifically, a plurality of the lead wires 24 are connected to a substrate 23. The lead wires 24 are drawn out to the outside of the motor 100.

[0024] The housing 3 covers the rotor 1 and the stator 2 from the radial outside. The housing 3 also covers the rotor blades 210 attached to the rotor 1 from the radial outside.

[0025] <3. Housing> Fig. 3 is a perspective view of the housing 3 according to the embodiment. Fig. 4 is a schematic diagram showing a holding structure for the lead wire 24 according to the embodiment. For convenience, the lead wire 24 is shown in cross section in Fig. 4.

[0026] The housing 3 has a first housing 4 and a second housing 5. The first housing 4 is located on one side in the axial direction. The second housing 5 is located on the other side in the axial direction. That is, the first housing 4 is located on the lower side. The second housing 5 is located on the upper side.

[0027] Further, the first housing 4 and the second housing 5 each have a tubular portion 300 extending in the axial direction. The tubular portions 300 of the first housing 4 and the second housing 5 are joined to each other in the axial direction. Hereinafter, the tubular portion 300 of the first housing 4 may be given the reference symbol 400 and referred to as the first tubular portion 400, and the tubular portion 300 of the second housing 5 may be given the reference symbol 500 and referred to as the second tubular portion 500.

[0028] The cylindrical portion 300 covers the rotor 1 and the stator 2 from the radially outward side. The rotor blades 210 are attached to the rotor 1. Therefore, the rotor blades 210 are covered from the radially outward side by the cylindrical portion 300. The cylindrical portion 300 guides, in the axial direction, an airflow generated radially inward of the cylindrical portion 300 by the rotation of the rotor blades 210.

[0029] Further, the cylindrical portion 300 has a wiring portion 301 on which the lead wire 24 is arranged. Specifically, the first housing 4 has a recessed portion 401 on the first cylindrical portion 400. The second housing 5 has a protruding portion 501 on the second cylindrical portion 500.

[0030] The recess 401 is recessed downward from the upper end surface of the first cylindrical portion 400 and penetrates from the radially inner side to the radially outer side of the first cylindrical portion 400. The protrusion 501 protrudes downward from the lower end surface of the second cylindrical portion 500. The protrusion 501 is disposed in the recess 401.

[0031] The wiring portion 301 is composed of a recess 401 and a protrusion 501. Specifically, the wiring portion 301 is composed of a gap between the bottom of the recess 401 and the tip of the protrusion 501 in the axial direction. The lead wire 24 is disposed in the gap between the bottom of the recess 401 and the tip of the protrusion 501 in the axial direction. In other words, a through hole for wiring is formed by the gap between the bottom of the recess 401 and the tip of the protrusion 501 in the axial direction. The lead wire 24 is drawn from the radially inner side of the housing 3 to the radially outer side through the through hole.

[0032] By disposing the lead wire 24 in the gap between the bottom of the recess 401 and the tip of the protrusion 501 in the axial direction, even if the lead wire 24 tries to move in the axial direction, the tip of the protrusion 501 comes into contact with the lead wire 24. Therefore, the axial movement of the lead wire 24 can be restricted. As a result, the lead wire 24 can be prevented from being displaced in the axial direction. That is, the lead wire 24 can be reliably fixed.

[0033] <4. 1st housing and 2nd housing> <4-1. Joining work> The first housing 4 and the second housing 5 are joined to each other by, for example, a snap-fit ​​method. Note that the first housing 4 and the second housing 5 may also be joined to each other by using fastening members such as screws.

[0034] For example, in joining the first housing 4 and the second housing 5, first, the stator 2 connected to the lead wires 24 is placed in the first housing 4, and then the second housing 5 is joined to the first housing 4. Alternatively, the stator 2 is placed in the first housing 4, and then the lead wires 24 are connected to the stator 2, and then the second housing 5 is joined to the first housing 4. By forming the housing 3 with the first housing 4 and the second housing 5, the through hole for wiring can be divided into upper and lower parts, eliminating the need to pass the lead wires 24 through the through hole. This makes it easier to join the first housing 4 and the second housing 5.

[0035] <4-2. Opposite surfaces> Fig. 5 is a perspective view of the first housing 4 according to the embodiment when viewed from above in the axial direction. Fig. 6 is a perspective view of the second housing 5 according to the embodiment when viewed from below in the axial direction.

[0036] The first housing 4 and the second housing 5 each have an opposing surface 30 that faces each other in the axial direction. Specifically, the cylindrical portion 300 has the opposing surface 30 at an end surface in the axial direction. At least a portion of the opposing surfaces 30 of the first housing 4 and the second housing 5 contact each other.

[0037] Specifically, the first housing 4 has an opposing surface 30 on an upper end surface of the first cylindrical portion 400. The second housing 5 has an opposing surface 30 on a lower end surface of the second cylindrical portion 500. The opposing surface 30 of the first cylindrical portion 400 and the opposing surface 30 of the second cylindrical portion 500 are in contact with each other at least partially. In the following description, the opposing surface 30 of the first housing 4 may be given the reference numeral 40 and referred to as the first opposing surface 40, and the opposing surface 30 of the second housing 5 may be given the reference numeral 50 and referred to as the second opposing surface 50.

[0038] The first opposing surface 40 and the second opposing surface 50 may be in contact over their entire surfaces. Also, contact areas and non-contact areas may be mixed between the first opposing surface 40 and the second opposing surface 50. That is, in the joining operation of the first housing 4 and the second housing 5, it is not necessary for the first opposing surface 40 and the second opposing surface 50 to be in contact over their entire surfaces.

[0039] For example, the protrusions 31, which will be described later, of the first opposing surface 40 and the second opposing surface 50 may be in contact with each other, while the concave surfaces 32, which will be described later, of the first opposing surface 40 and the second opposing surface 50 may be spaced apart from each other. Alternatively, the protrusions 31, which will be described later, of the first opposing surface 40 and the second opposing surface 50 may be in contact with each other, and the concave surfaces 32, which will be described later, of the first opposing surface 40 and the second opposing surface 50 may be in at least partial contact with each other.

[0040] <4-3.Protrusion> FIG. 7 is a plan view of the tube portion 300 according to the embodiment as viewed from the axial direction. FIG. 7 is a plan view of the first housing 4 as viewed from above in the axial direction. FIG. 8 is a schematic diagram showing a joint portion between the first housing 4 and the second housing 5 according to the embodiment. FIG. 9 is a schematic diagram showing a joint portion between the first housing 4 and the second housing 5 according to a modified example. In FIG. 8 and FIG. 9, the left-right direction of the drawings is the radial direction. Also, the direction from right to left of the drawings is the radial inward direction, and the direction from left to right of the drawings is the radial outward direction. In FIG. 8 and FIG. 9, the direction of the airflow in the radial inner direction of the tube portion 300 is indicated by a dashed arrow.

[0041] At least one of the opposing surfaces 30 of the first housing 4 and the second housing 5 has a protruding portion 31 protruding in the axial direction in a part thereof. In this configuration, the protruding portion 31 of one opposing surface 30 can be brought into contact with the other opposing surface 30 in a concentrated manner. As a result, by increasing the flatness precision of the protruding portion 31, even if the flatness precision of the portion of the opposing surface 30 other than the protruding portion 31 is low, the adhesion of the joint portion between the first housing 4 and the second housing 5 is improved. In other words, it is not necessary to increase the flatness precision over the entire surface of the opposing surface 30 in order to improve the adhesion of the joint portion between the first housing 4 and the second housing 5. As a result, the adhesion of the joint portion between the first housing 4 and the second housing 5 can be easily improved.

[0042] Furthermore, since the adhesion of the joint portion between the first housing 4 and the second housing 5 can be improved, it is possible to suppress air leakage in the radial direction from the joint portion between the first housing 4 and the second housing 5. In other words, it is possible to suppress air leakage in the radial direction of the motor 100.

[0043] The protrusion 31 is a portion of the opposing surface 30 that protrudes in a planar manner in the axial direction, and is a part of the opposing surface 30. That is, when viewed from the axial direction, the area of ​​the protrusion 31 is smaller than the area of ​​the entire opposing surface 30. Since the area of ​​the protrusion 31 is small in this manner, the protrusion 31 can be easily formed with high flatness accuracy.

[0044] In this embodiment, the opposing surfaces 30 of the first housing 4 and the second housing 5 each have a protrusion 31. Also, the protrusions 31 of the first housing 4 and the second housing 5 each come into contact with each other. That is, the first opposing surface 40 of the first housing 4 has a protrusion 31. The second opposing surface 50 of the second housing 5 has a protrusion 31. Also, the protrusions 31 of the first opposing surface 40 and the second opposing surface 50 each come into contact with each other. This increases the accuracy of the flatness of both the protrusion 31 of the first opposing surface 40 and the protrusion 31 of the second opposing surface 50, thereby further improving the adhesion of the joint between the first housing 4 and the second housing 5.

[0045] Moreover, the protruding portion 31 extends in the circumferential direction along the radial inner edge of the tubular portion 300 when viewed from the axial direction. Specifically, the opposing surface 30 has the protruding portion 31 and a concave surface 32 that is concave in the axial direction relative to the protruding portion 31. When viewed from the axial direction, the concave surface 32 is not disposed radially inward of the protruding portion 31. In other words, when viewed from the axial direction, the radial inner edge of the protruding portion 31 becomes the radial inner edge of the tubular portion 300.

[0046] In a configuration in which the protruding portion 31 extends in the circumferential direction along the radial inner edge of the tubular portion 300, it is possible to suppress the occurrence of a step on the radial inner side surface of the tubular portion 300 (see FIG. 8). Specifically, in a configuration in which the concave surface 32 is disposed radially inward from the protruding portion 31 as in a modified example (see FIG. 9) described later, the joint portion between the first housing 4 and the second housing 5 on the radial inner side surface of the tubular portion 300 is recessed radially outward. That is, the radial inner side surface of the tubular portion 300 is not flat. For this reason, the airflow may enter the recess at the joint portion between the first housing 4 and the second housing 5, and the air may not flow smoothly. On the other hand, in the configuration of the embodiment shown in FIG. 8, the joint portion between the first housing 4 and the second housing 5 is flat, so that it is possible to suppress the axial airflow from becoming unstable on the radial inner side of the tubular portion 300.

[0047] In this embodiment, the first opposing surface 40 of the first housing 4 and the second opposing surface 50 of the second housing 5 each have a protrusion 31. In this configuration, as shown in Fig. 8, radially inner portions of the opposing surfaces 30 are joined to each other. This makes it possible to further improve the adhesion between the first housing 4 and the second housing 5 while suppressing the airflow from becoming unstable radially inside the tubular portion 300.

[0048] The amount by which the protruding portion 31 protrudes from the concave surface 32 is extremely small. Therefore, if the protruding portion 31 is crushed when the first housing 4 and the second housing 5 are joined together, at least a portion of the concave surfaces 32 of the first housing 4 and the second housing 5 may come into contact with each other.

[0049] As a modified example, as shown in Fig. 9, the concave surface 32 may be disposed radially inward from the protruding portion 31. In the configuration of the embodiment shown in Fig. 8, foreign matter from the radial outside may enter the gap between the first housing 4 and the second housing 5 in the axial direction. On the other hand, the configuration of the modified example shown in Fig. 9 can effectively prevent foreign matter from entering from the radial outside. However, in the configuration of the modified example shown in Fig. 9, a step is generated on the radially inner surface of the tubular portion 300, unlike the configuration of the embodiment shown in Fig. 8.

[0050] <4-4-1. Annular part of protrusion> The protruding portion 31 has an annular portion 310 that is continuous in the circumferential direction, sandwiching the wiring portion 301, when viewed in the axial direction. For example, the annular portion 310 has a continuous circular ring shape that sandwiches the wiring portion 301 when viewed in the axial direction. That is, the protruding portion 31 of the first housing 4 has an annular portion 310 that is continuous in the circumferential direction, sandwiching the recessed portion 401, when viewed in the axial direction (see FIG. 7). Moreover, the protruding portion 31 of the second housing 5 has an annular portion 310 that is continuous in the circumferential direction, sandwiching the convex portion 501, when viewed in the axial direction.

[0051] This makes it possible to improve the adhesion between the first housing 4 and the second housing 5 in a configuration in which the lead wire 24 is pulled out radially outward from the radial inside of the tubular portion 300 via the wiring portion 301 in all parts other than the wiring portion 301.

[0052] <4-4-2. Fillet of protruding part> Fig. 10 is an enlarged view of a part of the protrusion 31 according to the embodiment. Fig. 10 shows an enlarged view of the part surrounded by the dashed line in Fig. 7.

[0053] The annular portion 310 has an outer edge portion 311 that contacts the radial outer edge of the tubular portion 300 when viewed from the axial direction. In other words, the annular portion 310 has a portion that becomes the radial outer edge of the tubular portion 300 when viewed from the axial direction. In further other words, a part of the radial outer edge of the annular portion 310 becomes the radial outer edge of the tubular portion 300 when viewed from the axial direction.

[0054] Moreover, the protruding portion 31 has a fillet portion 320 that extends from both circumferential sides of the outer edge portion 311 to the radial outer edge of the tubular portion 300 as viewed from the axial direction. The fillet portion 320 is disposed at a corner of a substantially triangular shape defined by the radial outer edge of the tubular portion 300 and the radial outer edge of the annular portion 310 as viewed from the axial direction. That is, the fillet portion 320 has a substantially triangular shape with one side being an arc as viewed from the axial direction. Also, the arc-shaped side of the fillet portion 320 runs along the radial outer edge of the annular portion 310 as viewed from the axial direction.

[0055] Here, the first housing 4 and the second housing 5 are resin molded products manufactured using a mold. That is, in the manufacturing process of the first housing 4 and the second housing 5, a mold having projections and recesses corresponding to the projections and recesses of the opposing surface 30 is used.

[0056] If the protrusion 31 does not have the fillet 320, a mold having a substantially triangular corner, i.e., a minute acute angle, is required, and the manufacturing cost of the mold increases. On the other hand, if the protrusion 31 has the fillet 320, there is no need to provide a minute acute angle in the mold, and therefore the manufacturing cost of the mold becomes easier. As a result, the manufacturing cost of the mold can be reduced.

[0057] <4-4-3. Modifications of protrusions> FIG. 11 is an enlarged view of a part of the protruding portion 31 according to the modified example.

[0058] In the modified example, the concave surface 32 of the opposing surface 30 that is axially recessed relative to the protruding portion 31 extends over the entire area radially outward of the protruding portion 31 when viewed in the axial direction. In other words, in the modified example, as shown in Fig. 11, unlike the embodiment shown in Fig. 10, the protruding portion 31 does not have an outer edge portion 311 that contacts the radial outer edge of the tubular portion 300 when viewed in the axial direction.

[0059] Specifically, in the modified example, the concave surface 32 is annular in a continuous manner in the circumferential direction, sandwiching the wiring portion 301, as viewed from the axial direction. In other words, the concave surface 32 surrounds the entire protruding portion 31 from the radially outer side as viewed from the axial direction. In further other words, the concave surface 32 is present over the entire radially outer side of the protruding portion 31 as viewed from the axial direction.

[0060] In the configuration of the modified example (see FIG. 11), unlike the configuration of the embodiment (see FIG. 10), even if fillet portion 320 is not separately provided, an increase in the manufacturing cost of the mold can be suppressed.

[0061] <5.Other> The embodiments of the present invention have been described above. Note that the scope of the present invention is not limited to the above-mentioned embodiments. The present invention can be implemented by adding various modifications within the scope of the gist of the invention. In addition, the above-mentioned embodiments can be combined in any suitable manner. [Industrial Applicability]

[0062] The present invention can be used, for example, as a motor for an axial flow fan. [Explanation of symbols]

[0063] 1 rotor 2 Stator 3. Housing 4. First Housing 5 Second Housing 24 Lead Wire 30 Opposite Surface 31 Protrusion 32 Concave 100 Motor 200 Axial Fan 210 Moving blade 300 Cylinder 301 Wiring section 310 Circular section 311 Outer edge 320 Fillet CA center axis

Claims

1. A rotor that can rotate around a central axis that extends vertically; A stator that rotates the rotor; a housing that covers the rotor and the stator from the radially outward side, The housing includes: A first housing located on one side in the axial direction; a second housing located on the other side in the axial direction, the first housing and the second housing each have an opposing surface that faces each other in an axial direction, At least a portion of the opposing surfaces of the first housing and the second housing contact each other, the opposing surface of at least one of the first housing and the second housing has a protruding portion protruding in an axial direction, The protruding portion is a portion of the opposing surface that protrudes in a planar shape in the axial direction, and is a part of the opposing surface, the opposing surfaces of the first housing and the second housing each have the protrusion, the protrusions of the first housing and the second housing contact each other; The opposing surface has a concave surface that is recessed in the axial direction relative to the protruding portion, the protruding portions of the first housing and the second housing are in contact with each other, while the concave surfaces of the first housing and the second housing are spaced apart from each other in an axial direction; The concave surface is not disposed radially inward of the protruding portion when viewed in the axial direction, The first housing and the second housing each have a cylindrical portion extending in an axial direction, The cylindrical portion is covering the rotor and the stator from the radially outward side; The opposing surface is provided at an end surface in the axial direction, The protrusion extends circumferentially along a radial inner edge of the cylindrical portion when viewed in the axial direction.

2. a lead wire electrically connected to the stator; the cylindrical portion has a wiring portion on which the lead wire is disposed, The motor according to claim 1 , wherein the protrusion has a continuous annular portion in a circumferential direction with the wiring portion therebetween when viewed in the axial direction.

3. The annular portion has an outer edge portion that is in contact with a radial outer edge of the cylindrical portion when viewed in the axial direction, the protruding portion has fillet portions extending from both circumferential sides of the outer edge portion to the radial outer edge of the cylindrical portion as viewed in the axial direction, The motor according to claim 2 , wherein the fillet portion is disposed at a corner of a triangle defined by a radial outer edge of the cylindrical portion and a radial outer edge of the annular portion when viewed from the axial direction.

4. A motor according to any one of claims 1 to 3, and a rotor blade attached to the rotor.

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