Unmanned vehicle

Abstract

An unmanned vehicle (1) comprises: a motor (6); a circuit board (8); a housing (2) that has an opening (23) toward the outside; and a base (7) that closes the opening (23) of the housing (2). The motor (6) and a cylinder (72) surrounding the motor (6) are provided on a first surface (71a) of the base (7) facing the outside of the housing (2). The circuit board (8) and a portion (73) holding the circuit board (8) are provided on a second surface (71b) of the base (7) facing the inside of the housing (2). The base (7) is provided with a through hole (77) passing through the base (7), and the cylinder (72) and the through hole (77) form a fluid flow path that leads to the outside of the housing (2).

Description

Drone 【0001】 The present invention relates to a drone. 【0002】 For example, Patent Document 1 discloses an aircraft. In this aircraft, a blower fan takes in external air from an air inlet of a frame portion to generate an air flow, thereby controlling a temperature rise of an electric component unit disposed within the frame portion. 【0003】 Japanese Patent Application Laid-Open No. 2020-131781 【0004】 For example, when the aircraft flies in rainy weather, it is assumed that rainwater enters the frame portion from the air inlet. When rainwater enters the frame portion, it may adversely affect the motor within the frame portion or increase the weight of the aircraft. As a result, there is a risk that stable flight may be hindered. 【0005】 Therefore, one of the problems of the present invention is to provide a drone capable of improving drainage. 【0006】 The drone according to one aspect of the present invention includes a motor, a circuit board, a housing having an opening facing the outside, and a base closing the opening of the housing. On a first surface of the base facing the outside of the housing, the motor and a cylinder surrounding the motor are provided. On a second surface of the base facing the inside of the housing, the circuit board and a portion for holding the circuit board are provided. The base is provided with a through hole penetrating the base, and the cylinder and the hole form a fluid flow path leading to the outside of the housing. 【0007】 It is a perspective view schematically showing a part of the structure of a drone 1 according to an embodiment of the present invention. It is a cross-sectional view taken along line 2-2 of FIG. 1. It is a perspective view schematically showing the structure of a motor unit 4 according to a specific example. It is a perspective view schematically showing the structure of a motor unit 4 according to a specific example. It is an exploded perspective view schematically showing the structure of a motor unit 4 according to a specific example. It is an exploded perspective view schematically showing the structure of a motor unit 4 according to a specific example. It is a cross-sectional view taken along line 7-7 of FIG. 2. 【0008】Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Figure 1 is a schematic perspective view showing a part of the structure of an unmanned aircraft 1 according to an embodiment of the present invention. The unmanned aircraft 1 is, for example, a vertical take-off and landing (VTOL) drone. This VTOL drone, as an example, includes a first rotor used during vertical take-off and landing, and a second rotor and fixed wings used during horizontal flight. That is, the first rotor generates lift, while the second rotor generates thrust. 【0009】 In the following description of the embodiments relating to the unmanned aircraft 1, terms such as "up," "down," "front," and "rear" are used for convenience. However, the terms "up" and "down" do not necessarily correspond to up and down in the direction of gravity, and are defined for convenience when considering the unmanned aircraft 1 alone. Similarly, the terms "front" and "rear" do not necessarily correspond to front and rear in the flight direction of the unmanned aircraft 1, and are defined for convenience when considering the unmanned aircraft 1 alone. 【0010】 The unmanned aircraft 1 comprises a housing 2 and a rotor blade device 3 incorporated into the housing 2. The housing 2 extends, for example, in the front-rear direction of the unmanned aircraft 1. The rotor blade device 3 constitutes the first rotor blade described above. In this example, the housing 2 has a first portion 21 located on the lower side and a second portion 22 located on the upper side. The second portion 22 covers the first portion 21 from above, thereby creating a hollow internal space within the housing 2. The first portion 21 and the second portion 22 of the housing 2 are formed, for example, by integral molding from a resin material. 【0011】 The housing 2 has an opening 23 formed in the first portion 21. The opening 23 opens outwards from the housing 2. In this example, the opening 23 opens upwards. The opening 23 connects the internal space of the housing 2 to the external space outside the housing 2. The opening 23 is defined, for example, as a circle. 【0012】A specific example of a rotor blade device 3 includes a motor unit 4 and a propeller 5. The motor unit 4 is located within an opening 23. In this example, a portion of the motor unit 4 is housed within the internal space of the housing 2, while the other portion of the motor unit 4 is located in the external space of the housing 2 (the space outside the housing 2). The propeller 5 is attached to the upper end of the motor unit 4 located in the external space of the housing 2. The motor unit 4 supports the propeller 5 so as to be rotatable about an axis x. In this example, the axis x extends in the vertical direction of the unmanned aircraft 1. 【0013】 The propeller 5, acting as a rotor, is attached to the rotor of the motor unit 4 via a fixing member (not shown), such as a screw. In this example, the propeller 5 consists of two blades 51, 51 extending in opposite directions perpendicular to the axis x. The two blades 51, 51 have the same shape. Other propellers with different numbers of blades may also be used. Lift is generated for the unmanned aircraft 1 by the rotation of the propeller 5 around the axis x. 【0014】 The unmanned aircraft 1 further comprises an airframe (not shown) that houses various components such as a control device for controlling the drive of the unmanned aircraft 1, a battery, various sensors, and a camera. In one example, a pair of fixed wings extend horizontally from this airframe in opposite directions. For example, a housing 2 extending in the front-to-back direction is fixed to the underside of each fixed wing. Rotary-wing devices 3 are positioned at the front and rear ends of the housing 2. A second rotor is also positioned at the rear end of the airframe around an axis defined horizontally. The battery and other components inside the airframe and the rotary-wing devices 3 are connected to each other by wiring, etc. However, this configuration is just one example, and the unmanned aircraft 1 may have a different configuration. 【0015】Figure 2 is a cross-sectional view along line 2-2 in Figure 1. Figures 3 and 4 are perspective views schematically showing the structure of a motor unit 4 according to one specific example. Figures 5 and 6 are exploded perspective views schematically showing the structure of a motor unit 4 according to one specific example. Figures 3 and 5 are perspective views and exploded perspective views of the motor unit 4 viewed from above, respectively, and Figures 4 and 6 are perspective views and exploded perspective views of the motor unit 4 viewed from below, respectively. Referring to Figures 2 to 6 together, the motor unit 4 includes a motor 6, a base 7, and a circuit board 8. 【0016】 The base 7 has a flat plate portion (hereinafter referred to as the "flat plate portion") 71. The flat plate portion 71 extends, for example, along a plane perpendicular to the axis x. The flat plate portion 71 forms a first surface, i.e., an upper surface 71a, facing outward from the housing 2, and a second surface, i.e., a lower surface 71b, facing inward from the housing 2. In this example, the upper surface 71a and the lower surface 71b are defined to be parallel to each other. The base 7 has a cylinder 72 provided on the upper surface 71a of the flat plate portion 71, and a projection 73 (see Figures 2 and 6) provided on the lower surface 71b of the flat plate portion 71. 【0017】 The flat plate portion 71 has, for example, a rectangular contour in a plan view along the axis of rotation axis along the axis x. In this example, the shorter side of the flat plate portion 71 has dimensions that approximately match the diameter (dimension) of the outer surface of the cylinder 72. The flat plate portion 71 has an outer circumference portion 74 defined on the outer circumference side of the cylinder 72 and an inner circumference portion 75 defined on the inner circumference side of the cylinder 72 in the radial direction perpendicular to the axis x. That is, the cylinder 72 defines the boundary between the outer circumference portion 74 and the inner circumference portion 75. For example, four holes 71c are formed at the four corners of the outer circumference portion 74, penetrating the flat plate portion 71 from the upper surface 71a to the lower surface 71b. 【0018】On the other hand, multiple (four in this example) bosses 25 are formed on the inner surface of the second portion 22 of the housing 2. Each boss 25 is formed on the inner surface of a portion of the second portion 22 (an intermediate portion between the inner circumference 22a and the outer circumference 22b) 22c. In this example, the inner circumference 22a extends in an annular shape around the opening 23 to form the opening 23. The outer circumference 22b is an annular region on the outer side of the inner circumference 22a. The intermediate portion 22c is an annular region between the inner circumference 22a and the outer circumference 22b in the radial direction. In this example, the intermediate portion 22c is defined along a virtual circle centered on axis x, passing through the central axes of the four bosses 25. 【0019】 The four bosses 25 are positioned at locations corresponding to the four holes 71c in the flat plate portion 71. The outer circumference 74 of the flat plate portion 71, i.e., the base 7, is attached to the intermediate portion 22c of the second portion 22, i.e., the housing 2, by screwing a fixing member 26, such as a screw, through the holes 71c of the flat plate portion 71 into the bosses 25 of the housing 2 (see Figure 2). In other words, the holes 71c are mounting holes for attaching the base 7 to the housing 2. The cylinder 72 is formed in a cylindrical shape with axis x as the center. When the base 7 is attached to the intermediate portion 22c of the second portion 22, the inner circumference 22a of the second portion 22 extends further inward than the inner circumference surface of the cylinder 72 and covers at least partially the inner circumference surface of the cylinder 72. The space between the cylinder 72 and the inner circumference 22a is sealed. 【0020】 Four holes 71d are formed in the inner circumference 75 of the flat plate portion 71, penetrating the flat plate portion 71 from the upper surface 71a to the lower surface 71b (see Figure 5). The holes 71d are mounting holes for attaching the motor 6 to the base 7. Specifically, the motor 6 is fixed to the base 7 by screwing fixing members (not shown), such as screws, into the motor 6 through the holes 71d in the flat plate portion 71. In the radial direction perpendicular to the axis x, the diameter (dimension) of the outer surface of the motor 6 is smaller than the diameter (dimension) of the inner surface of the cylinder 72. In this way, the cylinder 72 of the base 7 surrounds the motor 6. That is, the outer surface of the motor 6 faces the inner surface of the cylinder 72 at a predetermined distance (see Figures 2 and 3). 【0021】A projection 76 is provided on the lower surface 71b of the flat plate portion 71, projecting downward from the inner circumference 75. The projection 76 is formed, for example, in a cylindrical shape. A through hole 77 is provided within this projection 76. The through hole 77 connects the internal space and the external space of the housing 2. In this example, in the inner circumference 75 of the flat plate portion 71, the through hole 77 is located at the rearmost side in the front-rear direction of the unmanned vehicle 1. As shown particularly in Figures 2 and 5, the through hole 77 is located adjacent to the rear inner circumference surface in the front-rear direction of the cylinder 72 of the unmanned vehicle 1. Thus, in a projected view along the axis x in the direction of rotation, the through hole 77 is located outside the contour of the circuit board 8 (see Figures 2 and 4). 【0022】 On the other hand, as shown in Figure 2, a drain port 27 is formed in the first portion 21 of the housing 2. The drain port 27 opens outward on the lower surface of the housing 2. In this example, in the front-rear direction of the unmanned vehicle 1, the drain port 27 is located behind the through hole 77. The drain port 27 connects the internal space and the external space of the housing 2. The protrusion 76 and the drain port 27 are connected by, for example, a tubular member (hereinafter referred to as "pipe") 28. The pipe 28 is, for example, a tube made of a flexible resin material. Thus, the cylinder 72 of the base 7, the through hole 77, the pipe 28, and the drain port 27 form a fluid flow path that connects to the external space of the housing 2 (see Figure 2). 【0023】 As shown in Figures 5 and 6, the upper surface 71a of the flat plate portion 71 is provided with a projection 78 that protrudes upward from the inner circumference 75. The projection 78 is formed, for example, in the shape of an elongated cylinder. A hole 79 is provided within this projection 78. The hole 79 penetrates from the upper surface 71a to the lower surface 71b of the flat plate portion 71. The hole 79 is located within the projection area of ​​the motor 6 in the direction of the rotation axis along the axis x. This hole 79 is for passing one or more wires (not shown) that extend from, for example, the body or circuit board 8 of the unmanned aircraft 1 to the coil of the motor 6. 【0024】The protruding portion 78 protrudes upward from the upper surface 71a of the flat plate portion 71 to a predetermined height. Therefore, even if liquid such as rainwater accumulates on the upper surface 71a of the flat plate portion 71, it is possible to prevent the rainwater from entering the hole 79 beyond the protruding portion 78. The wiring inside the hole 79 may be covered with a sealing member made of, for example, silicone. That is, by sealing the hole 79 with such a sealing member, it is possible to prevent rainwater from entering the housing 2 through the hole 79. 【0025】 As shown in Figure 6, the projection 73 formed on the lower surface 71b of the flat plate portion 71 has a plurality of (four in this example) bosses 73a and a block 73b surrounded by the four bosses 73a. In this example, both the projection 73, i.e., the bosses 73a and the block 73b, are positioned inside the contour of the inner circumference portion 75 in a projected view along the axis x in the rotation axis direction. The base 7 is integrally formed from a metal material with high thermal conductivity, such as aluminum. 【0026】 On the other hand, the main body 81 of the circuit board 8 (hereinafter referred to as the "board body") has a plurality of holes 82 (four in this example) formed in it. The holes 82 penetrate from the upper surface 81a to the lower surface 81b of the board body 81. The four bosses 73a are provided at positions corresponding to the positions of the four holes 82 in the board body 81. The board body 81, i.e., the circuit board 8, is attached to the flat plate portion 71 of the base 7 by screwing fixing members (not shown), such as screws, through the holes 82 in the board body 81 into the bosses 73a of the flat plate portion 71. The protruding portion 73 of the flat plate portion 71 corresponds to the part that holds the circuit board 8. 【0027】One or more electronic components 83 are mounted on the upper surface 81a of the substrate body 81. The electronic components 83 can control the rotational speed of the motor 6, i.e., the propeller 5, by controlling the voltage applied to the motor 6. The circuit board 8 on which the electronic components 83 are mounted constitutes a so-called ESC (Electronic Speed ​​Controller). The upper surface of the electronic components 83 is in contact with the lower surface of the block 73b of the protruding portion 73 via, for example, a thermally conductive material (hereinafter referred to as "thermal conductive material") 84. The block 73b has, for example, a flat rectangular parallelepiped shape. The thermal conductive material 84 is, for example, a sheet of a metal material with high thermal conductivity. 【0028】 Figure 7 is a perspective cross-sectional view along the line 7-7 in Figure 2. Referring together to Figures 2 and 5 to 7, a motor 6 according to one specific example has a frame 61, a stator 62, a bearing 63, and a rotor 64. The frame 61 is located inside the cylinder 72. The frame 61 has a disc-shaped portion (hereinafter referred to as the "disc portion") 61a that is located on the lower side of the motor 6. The disc portion 61a has four screw holes 61b that correspond to the holes 71d of the flat plate portion 71. The frame 61, i.e., the motor 6, is connected to the base 7 by screwing fixing members (not shown), such as screws, through the holes 71d of the flat plate portion 71 into the screw holes 61b of the disc portion 61a. 【0029】 The frame 61 has a portion (hereinafter referred to as the "annular portion") 61c that protrudes in an annular shape downward from the lower surface of the disc portion 61a. The disc portion 61a has one or more (three in this example) openings 61d that penetrate the disc portion 61a on the inner circumference side of the annular portion 61c (see Figure 6). Each opening 61d is formed, for example, in a sector shape in a plan view along the rotation axis direction along the axis x. The disc portion 61a further has openings 61e for passing wiring (not shown). In this example, three openings 61d and one opening 61e are arranged in the circumferential direction around the axis x. 【0030】When the motor 6, or frame 61, is fixed to the flat plate portion 71 of the base 7, the disc portion 61a and the flat plate portion 71 face each other with a predetermined gap in the direction of rotation along the axis x. Thus, the three openings 61d of the disc portion 61a face the upper surface 71a of the flat plate portion 71 of the base 7. Fluid passes through the three openings 61d between the internal space S of the motor 6 and the external space of the motor 6. On the other hand, the opening 61e of the disc portion 61a faces the hole 79 of the flat plate portion 71 of the base 7. In this way, wiring from the body of the unmanned aircraft 1 and the circuit board 8 can extend into the motor 6 through the hole 79 and the opening 61e. 【0031】 On the upper surface of the disc portion 61a, a first wall 61f is formed that rises upright in an annular shape from the upper surface on the inner circumference side, and a second wall 61g rises upright in an annular shape from the upper surface on the outer circumference side of the first wall 61f. In this example, the first wall 61f and the second wall 61g are continuous without interruption in the circumferential direction. The outer rings of two bearings 63, 63 are held on the inner circumference surface of the first wall 61f. The outer rings of the bearings 63 are fitted onto the inner circumference surface of the first wall 61f and fixed by, for example, an adhesive. The bearings 63 are, for example, ball bearings. The first wall 61f constitutes the part that supports the bearings 63 according to the present invention. The frame 61 is formed from a metal material having high thermal conductivity, such as aluminum. 【0032】 The outer circumferential surface of the first wall 61f is spaced apart from the inner circumferential surface of the second wall 61g. In this way, an annular space is formed between the outer circumferential surface of the first wall 61f and the inner circumferential surface of the second wall 61g. This space forms part of the internal space S of the motor 6. The opening 61d of the frame 61 is in communication with this annular space. The stator 62 is fixed to the outer circumferential surface of the second wall 61g. That is, the second wall 61g constitutes the part that supports the stator 62 according to the present invention. The stator 62 has a stator core 62a, a plurality of coils 62b, and a plurality of insulators 62c. 【0033】The stator core 62a is formed from, for example, a laminate of magnetic material and functions as a yoke for the stator 62. The stator core 62a has an annular portion (hereinafter referred to as the "annular portion") 62d fixed to the outer circumferential surface of the second wall 61g, and a plurality of teeth 62e extending radially outward from the annular portion 62d. A coil 62b is wound around each tooth 62e. An insulator 62c made of insulating material is placed between the teeth 62e and the coil 62b. In this way, electrical insulation is established between the stator core 62a and the coil 62b. A magnetic pole portion 62f is formed at the outer circumferential end of each tooth 62e of the stator core 62a. 【0034】 A thermally conductive member (hereinafter referred to as "thermal conductive member") 61h may be sandwiched between the lower end of the coil 62b and the upper surface of the disc portion 61a of the frame 61 (see Figure 2). The thermal conductive member 61h is, for example, clay-like or grease-like, and is a thermal conductive material that is fluid yet can maintain its shape. Thermal conductive materials include, for example, resin materials such as EPDM or silicone. The thermal conductive member 61h can make gapless contact with the coil 62b and the frame 61. In this example, the thermal conductive member 61h is arranged in a continuous, annular manner between the coil 62b and the frame 61. In this way, the thermal conductive member 61h can transfer heat from the coil 62b to the frame 61. 【0035】 On the other hand, a rotor 64 is supported on the inner rings of the bearings 63, 63 so as to be rotatable around the axis x. The rotor 64 has a shaft 64a, an upper cover (hereinafter referred to as the "upper cover") 64b, a yoke 64c, a magnet 64d, and a lower cover (hereinafter referred to as the "lower cover") 64e. The shaft 64a is supported by two bearings 63, 63. The shaft 64a is formed, for example, in a cylindrical shape. The upper cover 64b is fixed to the shaft 64a. The upper cover 64b is formed in a disc shape along a plane perpendicular to the axis x. In this example, no opening is formed on the surface between the inner and outer circumferences of the upper cover 64b, and a continuous surface is formed in the radial and circumferential directions. A propeller 5 is connected to the shaft 64a and the upper cover 64b. 【0036】 A generally cylindrical yoke 64c is attached to the outer peripheral end of the upper cover 64b. A cylindrical magnet 64d is attached to the inner circumferential surface of the yoke 64c. The yoke 64c is made of, for example, a magnetic material. The magnet 64d is, for example, a permanent magnet. The magnet 64d may be a single cylindrical permanent magnet. The inner circumferential surface of the magnet 64d faces the magnetic pole portion 62f of the stator core 62a with a predetermined magnetic gap in the radial direction. When current is supplied to the coil 62b, a magnetic interaction is generated between the coil 62b and the magnet 64d. This magnetic interaction allows the rotor 64 to rotate about the axis x. The motor 6 is a so-called outer rotor type motor. 【0037】 The lower cover 64e is formed in an annular shape around the axis x. The lower cover 64e is attached to the lower end of the yoke 64c. The lower cover 64e extends downward from the yoke 64c and then bends inward. In this way, the lower cover 64e faces radially to the outer end of the disc portion 61a of the frame 61, and faces the lower surface of the outer end of the disc portion 61a in the direction of the rotation axis. Furthermore, the inner end of the lower cover 64e faces the outer surface of the annular portion 61c on the lower surface of the disc portion 61a of the frame 61. In this way, an annular gap is formed between the lower cover 64e and the frame 61. This gap forms a so-called labyrinth structure. The internal space S and the external space of the motor 6 are fluidly connected through this gap. 【0038】 As shown in Figure 2, in the direction of rotation axis, the inner circumference 22a of the housing 2 is on the base 7 side relative to the rotor 64. Specifically, most of the rotor 64 is positioned above (outside) the inner circumference 22a of the housing 2. In this example, the inner surface of the opening 23 formed in the inner circumference 22a of the housing 2 faces the outer surfaces of the motor 6's yoke 64c and lower cover 64e in the radial direction with a predetermined gap between them. Also, the inner surface of the cylinder 72 of the base 7 faces the outer surfaces of the motor 6's yoke 64c and lower cover 64e in the radial direction with a predetermined gap between them. 【0039】 As shown in Figures 6 and 7, a mesh-like member 65 may be placed on the upper surface of the disc portion 61a of the base 7 between the first wall 61f and the second wall 61g. This member 65 extends circumferentially around the axis x. The member 65 closes the opening 61d of the disc portion 61a. The member 65 is formed from, for example, a sheet having a plurality of fine holes. The member 65 is formed from, for example, a resin material. With this member 65, it is possible to suppress the inflow of dust and the like into the internal space S of the motor 6 from the opening 61d of the disc portion 61a. 【0040】 In the unmanned aircraft 1 described above, when current is supplied to the coil 62b, the rotor 64, or propeller 5, rotates around the axis x. The unmanned aircraft 1 can ascend or descend by controlling the lift generated by the rotation of this propeller 5. For example, in rainy weather, rainwater falling from above the unmanned aircraft 1 falls onto the rotor 64 of the motor 6 and the flat plate portion 71 of the base 7. This rainwater is caught by the flat plate portion 71. After that, the rainwater enters the pipe 28 through the through hole 77 and is discharged into the outside space from the drain port 27 of the housing 2. In this way, the intrusion of rainwater into the housing 2 can be suppressed. As a result, the drainage performance of the unmanned aircraft 1 can be improved. 【0041】 In particular, the through-hole 77 is located at the rear of the cylinder 72. Therefore, for example, during horizontal flight, it is assumed that rainwater will collect at the rear of the cylinder 72 due to the airflow flowing from the front to the rear of the unmanned aircraft 1. As a result, rainwater falling into the cylinder 72 can be efficiently discharged from the through-hole 77 through the pipe 28 to the outside space through the drain port 27. The flat plate portion 71 may have an inclined position that intersects the axis x at a predetermined angle depending on the flight attitude of the unmanned aircraft 1. For example, the flat plate portion 71 may have an orientation that makes it easy for rainwater, etc., to flow towards the through-hole 77 when the unmanned aircraft 1 is in flight. 【0042】Also, when the drone 1 is flying, heat is generated in the coil 62b to which current is supplied and the electronic components 83 on the circuit board 8. For example, the heat of the coil 62b is transmitted to the flat plate portion 71 of the base 7 via the heat conduction member 61h and the frame 61. On the other hand, the heat of the electronic components 83 on the circuit board 8 is transmitted to the flat plate portion 71 of the base 7 via the heat conduction member 84 and the block 73b. For example, during rainy weather, rainwater is received by the flat plate portion 71, so the heat of the flat plate portion 71 is conducted from the upper surface of the flat plate portion 71 to the rainwater. Thus, the rainwater itself is discharged to the external space through the through hole 77, the pipe 28, and the drain port 27. Also, heat is released from the flat plate portion 71 into the atmosphere. As a result, the coil 62b and the electronic components 83 can be cooled. 【0043】 For example, it is expected that the wind blows strongly against the drone 1 during rainy weather compared to sunny weather, so it is assumed that the power consumption increases in maintaining the attitude of the drone 1. That is, it is expected that the amount of heat generated in the coil 62b and the electronic components 83 also increases. According to the above configuration, even in such a case, the coil 62b and the electronic components 83 can be efficiently cooled, so a further increase in the output of the drone 1 can be achieved. Note that even during sunny weather, since the flat plate portion 71 of the base 7 is in contact with the external space, heat can be released from the flat plate portion 71 to the external space by the airflow flowing along the flat plate portion 71. 【0044】 As described above, the present invention has been described through the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention. 【0045】 The embodiments described above are for facilitating the understanding of the present invention and are not for limiting and interpreting the present invention. Also, the above embodiments do not limit the objects to which the present invention is applied, and the present invention can include any object as its application object. Each component included in the above embodiments and its arrangement, material, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. 【0046】 For example, the present invention includes differences that arise in the implementation of manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined to the extent that they do not conflict with the technical requirements. In addition, each component can be selectively combined as appropriate to achieve at least some of the above-mentioned problems and effects. 【0047】 1 Unmanned aircraft, 2 Housing, 21 First part, 22 Second part, 22a Inner circumference, 2b Outer circumference, 22c Intermediate part, 23 Opening, 25 Boss, 26 Fixing member, 27 Drain port, 28 Tubular member (tube), 3 Rotary wing device, 4 Motor unit, 5 Propeller, 51 Blade, 6 Motor, 61 Frame, 61a Disc-shaped part (Disc part), 61b Screw hole, 61c Annular protruding part (Annular part), 61d Opening, 61e Opening, 61f First wall (Part supporting bearing 63), 61g Second wall (Part supporting stator 62), 61h Thermally conductive member (Thermal conductive member), 62 Stator, 62a Stator core, 62b Coil, 62c Insulator, 62d Annular part (Annular part), 62e Teeth, 62f Magnetic pole part, 63 64. Bearing, 64. Rotor, 64a. Shaft, 64b. Upper cover, 64c. Yoke, 64d. Magnet, 64e. Lower cover, 65. Mesh-like member, 7. Base, 71. Flat plate portion, 71a. First surface (top), 71b. Second surface (bottom), 71c. Hole, 71d. Hole, 72. Cylinder, 73. Protrusion, 73a. Boss, 73b. Block, 74. Outer circumference, 75. Inner circumference, 76. Protrusion, 77. Through hole, 78. Protrusion, 79. Hole, 8. Circuit board, 81. Main body (board body), 81a. Top surface, 81b. Bottom surface, 82. Hole, 83. Electronic component, 84. Thermally conductive member, x-axis.

Claims

1. An unmanned aircraft comprising a motor, a circuit board, a housing having an opening that faces outward, and a base that closes the opening of the housing, wherein the first surface of the base facing outward from the housing is provided with the motor and a cylinder surrounding the motor, and the second surface of the base facing inward from the housing is provided with the circuit board and a portion for holding the circuit board, and the base is provided with a through hole that penetrates the base, and the cylinder and the through hole form a fluid passage that connects to the outside of the housing.

2. The unmanned aircraft according to claim 1, wherein the base comprises an outer periphery and a cylinder located inside the outer periphery, and the outer periphery of the base is attached to a portion on the outer periphery side of the inner periphery that forms the opening of the housing.

3. The unmanned aircraft according to claim 1 or 2, wherein the motor comprises a stator and a frame supporting the stator, and the frame located inside the cylinder is connected to the base.

4. The unmanned aircraft according to any one of claims 1 to 3, wherein the motor comprises a bearing, the frame comprises a portion for supporting the stator and a portion for supporting the bearing, and a space is formed radially between the portion for supporting the stator and the portion for supporting the bearing.

5. The unmanned aircraft according to any one of claims 1 to 4, wherein the motor comprises a rotor, and in the direction of rotation, the inner circumference of the housing is on the base side relative to the rotor.

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