Motors and Axial Fans

Abstract

To provide a motor capable of suppressing deformation of a housing of the motor.SOLUTION: A motor comprises: a rotor capable of rotating around a central axis extending vertically; a stator rotating the rotor; and a housing covering the rotor and the stator from the outward in a radial direction. The housing comprises: a first housing 4 located at one side in an axial direction; and a second housing 5 located at the other side in the axial direction. The housing has a through-hole 31 penetrating in the axial direction. The through-hole has: a first through-hole 430 arranged on the first housing; and a second through-hole 530 arranged on the second housing. At least one of the first and second through-holes has a small-diameter part 311 and a large-diameter part 312 having a hole diameter larger than that of the small-diameter part.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] A conventional motor includes a housing. The housing is made up of a first housing and a second housing. The first housing and the second housing are stacked on top of each other in the axial direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-105974 Summary of the Invention [Problem to be solved by the invention]

[0004] The first and second housings each have a through hole that connects them axially. The housings are fixed to other components by fastening members inserted into the through holes. In this configuration, when the housings are fixed with the fastening members, the fastening members may come into contact with the inner circumferential surface of the through hole, potentially causing deformation of the housing.

[0005] An object of the present invention is to suppress deformation of a motor housing. [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 that rotates the rotor, and a housing that radially covers the rotor and the stator. The housing includes 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 housing has through holes that pass through in the axial direction. The through holes include a first through hole disposed in the first housing and a second through hole disposed in the second housing. At least one of the first through hole and the second through hole has a small diameter portion and a large diameter portion whose hole diameter is larger than the small diameter portion.

[0007] An exemplary axial flow fan of the present invention includes the motor described above and rotor blades attached to the rotor. [Effects of the Invention]

[0008] According to the exemplary motor and axial flow fan of the present invention, deformation of the motor housing can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an axial flow fan according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the axial flow fan according to the embodiment. [Figure 3] FIG. 3 is a plan view of the housing according to the embodiment as viewed from the axial direction. [Figure 4] FIG. 4 is a perspective view of the first housing according to the embodiment. [Figure 5] FIG. 5 is a perspective view of the second housing according to the embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a lead wire holding structure by a housing according to the embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a fixing structure of the housing according to the embodiment using fastening members. [Figure 8] FIG. 8 is a cross-sectional view schematically showing the cross-sectional structure of a through-hole according to the embodiment. [Figure 9]FIG. 9 is a cross-sectional view schematically showing a cross-sectional structure of a through-hole according to a modified example. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a corner of the housing according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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 or positional relationship of the motor 100 when in use.

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

[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 "radially inner direction," and the direction moving away from the central axis CA is referred to as the "radially outer direction." In addition, for each component, the side surface facing radially inward is referred to as the "radially inner surface," and the side surface facing radially outward is referred to as the "radially outer surface."

[0014] <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 according to an embodiment of the present invention.

[0015] The axial flow fan 200 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.

[0016] <2. Motor> The motor 100 includes a rotor 1, a stator 2, and a housing 3. The motor 100 also includes a shaft 10.

[0017] The shaft 10 is arranged along a central axis CA that extends vertically. The shaft 10 is supported by a shaft holder 110. The shaft holder 110 extends axially in a cylindrical shape along the central axis CA. A bearing (not shown) that rotatably supports the shaft 10 is attached to the radially inner surface of the shaft holder 110.

[0018] 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, which is the 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 shaft 10 is fixed to the radially inner surface of the opening of the yoke lid portion 111. A yoke cylindrical portion 112, which is the 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 radially inner surface of the yoke cylindrical portion 112.

[0019] The stator 2 rotates the rotor 1. The stator 2 is annular and centered on a central axis CA that extends vertically, and is disposed radially inward of the rotor 1. The radially outer surface of the stator 2 faces the radially inner surface of the rotor 1. Specifically, the radially outer surface of the stator 2 faces a magnet fixed to the radially inner surface of the yoke 11. The radially inner surface of the stator 2 is fixed to the radially outer surface of the shaft holder 110.

[0020] The stator 2 includes a stator core 21, an insulator 22, a coil 23, and a circuit board 24. 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. The radially outer surface of the stator core 21 faces the magnet in the radial direction. The radially inner surface of the stator core 21 is fixed to the radially outer surface of the shaft holder 110.

[0021] 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 23 is formed by winding a conductive wire around the stator core 21 with the insulator 22 interposed therebetween. The circuit board 24 is electrically connected to the coil 23. Various electronic components are mounted on the circuit board 24.

[0022] The housing 3 covers the rotor 1 and the stator 2 from the radially outer side. The housing 3 also covers the rotor blades 210 attached to the rotor 1 from the radially outer side.

[0023] The motor 100 includes lead wires 20 (see FIG. 6). The lead wires 20 are electrically connected to the stator 2. Specifically, a plurality of lead wires 20 are connected to a circuit board 24. The lead wires 20 are drawn from the inside of the motor 100 to the outside. That is, the lead wires 20 are drawn from the radially inner side of the housing 3 to the radially outer side.

[0024] <3. Housing> FIG. 3 is a plan view of the housing 3 according to the embodiment, as viewed from the axial direction. In FIG. 3, components arranged radially inward of the tubular portion 300 are not shown. Also, in FIG. 3, a diagonal line connecting the vertices of the housing 3 in a plan view is indicated by a two-dot chain line. Hereinafter, this diagonal line will be simply referred to as the diagonal line of the housing 3. The diagonal line of the housing 3 is a line connecting the vertices of a pair of corner portions 30 arranged opposite each other across the central axis CA. FIG. 4 is a perspective view of a first housing 4 according to the embodiment. FIG. 5 is a perspective view of a second housing 5 according to the embodiment. FIG. 6 is a schematic diagram illustrating a holding structure for the lead wire 20 by the housing 3 according to the embodiment. In FIG. 6, the lead wire 20 is shown in cross section. FIG. 7 is a schematic diagram illustrating a fixing structure for the housing 3 according to the embodiment using a fastening member 600. In the following description, the member to which the housing 3 is fixed will be designated by the reference numeral 700 and will be referred to as the fixing member 700.

[0025] <3-1. Housing configuration> The outer shape of the housing 3 is a square with four corners 30 when viewed in the axial direction. Each corner 30 may be rounded. For example, each corner 30 has a rounded chamfered shape. However, each corner 30 may also have a right-angled shape. Each corner 30 may also have a C-chamfered shape.

[0026] Here, the housing 3 includes 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 upper side. The second housing 5 is located on the lower side. The first housing 4 and the second housing 5 are joined to each other in the axial direction.

[0027] The housing 3 has a cylindrical portion 300 centered on the central axis CA. That is, the first housing 4 and the second housing 5 each have a cylindrical portion 300 centered on the central axis CA. The cylindrical portions 300 of the first housing 4 and the second housing 5 are joined to each other in the axial direction. In the following description, when it is necessary to distinguish between the cylindrical portions 300 of the first housing 4 and the second housing 5, the cylindrical portion 300 of the first housing 4 will be given the reference numeral 400 and will be referred to as the first cylindrical portion 400, and the cylindrical portion 300 of the second housing 5 will be given the reference numeral 500 and will be referred to as the second cylindrical portion 500.

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

[0029] The second housing 5 holds the shaft holder 110. In other words, the second housing 5 holds the stator 2. Specifically, the second housing 5 has a base portion 510 that holds the stator 2. For example, the base portion 510 is the same member as the second housing 5 and is formed integrally with the second housing 5.

[0030] The base portion 510 is disk-shaped and centered on the central axis CA. The shaft holder 110 is fixed to the radial center of the base portion 510. The base portion 510 also has a plurality of connecting portions 510a extending radially outward from its radially outer surface. The connecting portions 510a are connected to the radially inner surface of the second cylindrical portion 500. In other words, the connecting portions 510a connect the base portion 510 and the second cylindrical portion 500.

[0031] The cylindrical portion 300 also has a wiring portion 301 on which the lead wire 20 is arranged. Specifically, the first housing 4 has a wiring convex portion 401 on the first cylindrical portion 400, and the second housing 5 has a wiring concave portion 501 on the second cylindrical portion 500.

[0032] The wiring protrusion 401 extends downward from the lower end surface of the first cylindrical portion 400. On the other hand, the wiring recess 501 is recessed downward from the upper end surface of the second cylindrical portion 500 and penetrates the second cylindrical portion 500 in the radial direction. The wiring protrusion 401 is disposed in the wiring recess 501.

[0033] The wiring portion 301 is composed of a wiring protrusion 401 and a wiring recess 501 (see FIG. 6). Specifically, the wiring portion 301 is composed of a gap between the tip of the wiring protrusion 401 and the bottom of the wiring recess 501 in the axial direction. The lead wire 20 is disposed in the gap between the tip of the wiring protrusion 401 and the bottom of the wiring recess 501 in the axial direction. In other words, a through hole for wiring is formed by the gap between the tip of the wiring protrusion 401 and the bottom of the wiring recess 501 in the axial direction. The lead wire 20 is drawn out from the radially inner side of the housing 3 to the radially outer side through the through hole.

[0034] Here, the housing 3 has through holes 31 that penetrate in the axial direction. For example, one through hole 31 is provided at each of the four corners 30. The through holes 31 are arranged on diagonal lines of the housing 3. A fastening member 600 (see FIG. 7) is arranged in the through hole 31.

[0035] Fastening member 600 has a threaded portion 610. For example, fastening member 600 is a tapping screw. The tapping screw as fastening member 600 is screwed into small diameter portion 311 (see FIG. 8) of through hole 31. In other words, small diameter portion 311 of through hole 31 is a hole into which fastening member 600 having threaded portion 610 is screwed.

[0036] For example, fixing member 700 has air outlet 700A. Fixing member 700 also has four mounting holes 710 arranged in the same pattern as the arrangement pattern of four through holes 31. Mounting holes 710 are holes that penetrate fixing member 700 in the axial direction, and have a hole diameter (inner diameter) larger than the outer diameter (nominal diameter) of the male thread of a tapping screw serving as fastening member 600.

[0037] The fixing member 700 contacts the upper end surface of the housing 3. That is, the fixing member 700 contacts the upper end surface of the first housing 4. Then, the fastening member 600 is inserted into the attachment hole 710 from above the fixing member 700 and screwed into the through hole 31. By screwing the fastening member 600 into the through hole 31, the through hole 31 is threaded, and the fastening member 600 is fixed to the through hole 31. In this way, the housing 3 is fixed to the fixing member 700.

[0038] Although not shown, the fixing member 700 may be brought into contact with the lower end surface of the housing 3. That is, the fixing member 700 may be brought into contact with the lower end surface of the second housing 5. Then, the fastening member 600 may be screwed into the through hole 31 from below the housing 3.

[0039] <3-2. Through holes in the first and second housings> <3-2-1. Implementation form> Fig. 8 is a cross-sectional view schematically showing the cross-sectional structure of the through-hole 31 according to the embodiment. Fig. 8 is a cross-sectional view of the housing 3 cut along a plane parallel to the axial direction.

[0040] The through hole 31 has a first through hole 430 and a second through hole 530. The first through hole 430 is disposed in the first housing 4. The second through hole 530 is disposed in the second housing 5. In other words, the through hole 31 is a hole that connects the first through hole 430 and the second through hole 530 in the axial direction. In further other words, the first through hole 430 and the second through hole 530 overlap each other when viewed in the axial direction.

[0041] Here, at least one of the first through hole 430 and the second through hole 530 has a small diameter portion 311 and a large diameter portion 312 having a larger diameter than the small diameter portion 311. With this configuration, when the fastening member 600 is screwed into the through hole 31, contact of the fastening member 600 with the inner circumferential surface of the large diameter portion 312 can be suppressed. In other words, the fastening member 600 is fixed to the through hole 31 by threading the inner circumferential surface of the small diameter portion 311. This can relieve stress generated around the large diameter portion 312 of the housing 3. As a result, deformation of the housing 3 can be suppressed.

[0042] The hole diameter of large diameter portion 312 is larger than the outer diameter of threaded portion 610 of fastening member 600. For example, the hole diameter of large diameter portion 312 is 5% to 20% larger than the outer diameter of threaded portion 610 of fastening member 600. This makes it possible to prevent fastening member 600 from contacting the inner circumferential surface of large diameter portion 312.

[0043] Furthermore, the axial length of small diameter portion 311 is shorter than the axial length of large diameter portion 312. For example, the axial length of small diameter portion 311 is shorter than the axial length of threaded portion 610 of fastening member 600. This reduces the area of through hole 31 that is threaded by fastening member 600, i.e., the area of through hole 31 that comes into contact with fastening member 600. This ensures that stress generated by screwing fastening member 600 into through hole 31 can be alleviated.

[0044] In the embodiment, the small diameter portion 311 and the large diameter portion 312 are provided in the first through hole 430. The small diameter portion 311 of the first through hole 430 is disposed on one side in the axial direction, and the large diameter portion 312 of the first through hole 430 is disposed on the other side in the axial direction. In other words, the small diameter portion 311 of the first through hole 430 is disposed on the upper end surface side of the first housing 4. In further other words, the first housing 4 has an opening formed by the small diameter portion 311 of the first through hole 430 on its upper end surface.

[0045] In first through hole 430, the portion extending downward from the upper end surface of first housing 4 down to first distance L1 is small diameter portion 311, and the entire portion below small diameter portion 311 is large diameter portion 312. In addition, small diameter portion 311 of first through hole 430 has a shorter axial length than large diameter portion 312 of first through hole 430.

[0046] For example, when the fixing member 700 is disposed above the housing 3, the fastening member 600 is screwed downward from the upper end surface side of the first housing 4. That is, the fastening member 600 is screwed downward from the upper portion of the first through hole 430. In this case, by providing the small diameter portion 311 and the large diameter portion 312 in the first through hole 430, it is possible to alleviate stress generated around the first through hole 430 in the first housing 4. This makes it possible to suppress deformation of the first housing 4.

[0047] Furthermore, in the first through-hole 430, the small diameter portion 311 has a greater thickness than the large diameter portion 312. That is, by arranging the small diameter portion 311 on the upper end surface side of the first housing 4, the strength of the upper end surface side of the first housing 4 can be ensured. This makes it possible to prevent the first housing 4 from deforming even if the fixing member 700 comes into contact with the upper end surface of the first housing 4 with a large pressure.

[0048] In the embodiment, the small diameter portion 311 and the large diameter portion 312 are further provided in the second through hole 530. The small diameter portion 311 of the second through hole 530 is disposed on the other axial side, and the large diameter portion 312 of the second through hole 530 is disposed on one axial side. In other words, the small diameter portion 311 of the second through hole 530 is disposed on the lower end surface side of the second housing 5. In yet another way, the second housing 5 has an opening formed by the small diameter portion 311 of the second through hole 530 on its lower end surface.

[0049] In second through hole 530, the portion extending upward from the lower end surface of second housing 5 up to second distance L2 is small diameter portion 311, and the entire portion above small diameter portion 311 is large diameter portion 312. Furthermore, small diameter portion 311 of second through hole 530 has a shorter axial length than large diameter portion 312 of second through hole 530. Note that first distance L1 and second distance L2 may be the same.

[0050] For example, when the fixing member 700 is disposed below the housing 3, the fastening member 600 is screwed upward from the lower end surface side of the second housing 5. That is, the fastening member 600 is screwed upward from the lower portion of the second through hole 530. In this case, by providing the small diameter portion 311 and the large diameter portion 312 in the second through hole 530, it is possible to alleviate stress generated around the second through hole 530 in the second housing 5. This makes it possible to suppress deformation of the second housing 5.

[0051] Furthermore, in the second through-hole 530, the small diameter portion 311 has a greater wall thickness than the large diameter portion 312. That is, by arranging the small diameter portion 311 on the lower end surface side of the second housing 5, the strength of the lower end surface side of the second housing 5 can be ensured. This makes it possible to prevent the second housing 5 from deforming even if the fixing member 700 comes into contact with the lower end surface of the second housing 5 with a large pressure.

[0052] In the embodiment, both first through hole 430 and second through hole 530 each have small diameter portion 311 and large diameter portion 312. As a result, whether fixing member 700 is arranged above housing 3 or below housing 3, deformation of housing 3 can be suppressed without changing the design of housing 3, for example.

[0053] <3-2-2. Variations> Fig. 9 is a cross-sectional view schematically showing the cross-sectional structure of a through-hole 31 according to a modified example. Fig. 9 is a cross-sectional view of the housing 3 cut along a plane parallel to the axial direction.

[0054] In a modified example, only one of the first through hole 430 and the second through hole 530 has the small diameter portion 311 and the large diameter portion 312. For example, the first through hole 430 has the small diameter portion 311 and the large diameter portion 312. On the other hand, the second through hole 530 has only the small diameter portion 311.

[0055] In the modified example, the axial length of the first through hole 430 is longer than in the above embodiment. For example, in the modified example, the axial length of each small diameter portion 311 of the first through hole 430 and the second through hole 530 is the same as in the above embodiment, and the axial length of the large diameter portion 312 of the first through hole 430 is longer than in the above embodiment. The large diameter portion 312 of the first through hole 430 is connected to the small diameter portion 311 of the second through hole 530.

[0056] In this modification, when the through hole 31 is viewed as a whole, similarly to the above embodiment, small diameter portions 311 are arranged on the upper end surface side of the first housing 4 and the lower end surface side of the second housing 5, and large diameter portion 312 is arranged axially between these two small diameter portions 311. Therefore, whether the fixing member 700 is arranged above the housing 3 or below the housing 3, it is possible to alleviate stress generated in the housing 3 when the housing 3 is fixed to the fixing member 700 using the fastening member 600. This makes it possible to suppress deformation of the housing 3.

[0057] <3-3. Outer edge of through hole> Fig. 10 is an enlarged cross-sectional view of a corner portion 30 of the housing 3 according to the embodiment. Fig. 10 is a cross-sectional view of the first housing 4 fixed to the second housing 5 cut along a plane parallel to the radial direction.

[0058] One of the first housing 4 and the second housing 5 has a protrusion 331 that protrudes radially inward from its radially inner surface. The other of the first housing 4 and the second housing 5 has a recess 332 that is recessed in the axial direction and in which the protrusion 331 is disposed. The protrusion 331 is provided on the outer edge of the through hole 31. That is, the protrusion 331 is provided on the radially inner side of the outer edge of one of the first through hole 430 and the second through hole 530. The recess 332 is provided on the radially inner side of the outer edge of the other of the first through hole 430 and the second through hole 530.

[0059] This configuration can increase the strength of the outer edge portion of one of the first through hole 430 and the second through hole 530, on which the protrusion 331 is provided. Furthermore, by providing the recess 332 on the outer edge portion of the other of the first through hole 430 and the second through hole 530, even if the protrusion 331 is provided on one of the outer edges, the protrusion 331 can be positioned in the recess 332.

[0060] The protrusion 331 is provided on the first housing 4. That is, the protrusion 331 is provided on the radially inward side of the outer edge of the first through hole 430. This increases the strength of the outer edge of the first through hole 430. For example, when the fastening member 600 is screwed into the first through hole 430, deformation of the outer edge of the first through hole 430 can be suppressed. That is, deformation of the first housing 4 can be suppressed.

[0061] Here, the second housing 5 has a relatively high strength because it has the base portion 510. On the other hand, the first housing 4 does not have a portion corresponding to the base portion 510. For this reason, it is preferable to provide a protrusion 331 on the outer edge of the first through hole 430 to increase the strength.

[0062] In a configuration in which the protrusion 331 is provided on the first housing 4, the recess 332 is provided on the second housing 5. That is, the recess 332 is provided on the radially inner side of the second through-hole 530. In this case, the recess 332 is recessed downward.

[0063] <4.Other> The embodiments of the present invention have been described above. However, the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented by adding various modifications within the scope of the gist of the invention. Furthermore, the above-described embodiments can be combined in any appropriate manner. [Industrial Applicability]

[0064] The present invention can be used, for example, as a motor for an axial flow fan. [Explanation of symbols]

[0065] 1 rotor 2 stator 3. Housing 4. First Housing 5 Second Housing 31 Through hole 100 motor 200 axial fan 210 Moving blade 311 Small diameter section 312 Large diameter section 331 Convex 332 recess 430 First through hole 530 Second through hole 600 Fastening members 610 Threaded part 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 outside in the radial direction, 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 housing has a through hole that penetrates in the axial direction, The through hole is a first through hole disposed in the first housing; a second through hole disposed in the second housing, At least one of the first through hole and the second through hole is A small diameter portion; a large diameter portion having a hole diameter larger than that of the small diameter portion, one of the first housing and the second housing has a protrusion protruding radially inward from a radially inner surface thereof, the other of the first housing and the second housing has a recess that is recessed in the axial direction and in which the protrusion is disposed, The protrusion is provided on the outer edge of the through hole.

2. the small diameter portion and the large diameter portion are provided in the first through hole, the small diameter portion of the first through hole is disposed on one side in the axial direction, The motor according to claim 1 , wherein the large diameter portion of the first through hole is disposed on the other side in the axial direction.

3. the small diameter portion and the large diameter portion are provided in the second through hole, the small diameter portion of the second through hole is disposed on the other side in the axial direction, The motor according to claim 1 , wherein the large diameter portion of the second through hole is disposed on one side in the axial direction.

4. the small diameter portion of the through hole is a hole into which a fastening member having a threaded portion is screwed, 4. The motor according to claim 1, wherein the hole diameter of the large diameter portion is larger than the outer diameter of the threaded portion.

5. 5. The motor according to claim 1, wherein the axial length of the small diameter portion is shorter than the axial length of the large diameter portion.

6. A rotor that can rotate around a central axis extending vertically; a stator that rotates the rotor; a housing that covers the rotor and the stator from the outside in the radial direction, 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 housing has a through hole that penetrates in the axial direction, The through hole is a first through hole disposed in the first housing; a second through hole disposed in the second housing, At least one of the first through hole and the second through hole is A small diameter portion; a large diameter portion having a hole diameter larger than that of the small diameter portion, The through hole is a hole that connects the first through hole and the second through hole in the axial direction.

7. A motor according to any one of claims 1 to 6; and a rotor blade attached to the rotor.

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