Drone

Abstract

To improve a cooling structure of a motor for a drone.SOLUTION: A stator case includes a first flow path extending in a circumferential direction and through which a refrigerant flows. A heat exchanger includes a shaft portion coaxial with a shaft and a plurality of leg portions extending radially from the shaft portion. Each of the plurality of leg portions includes a second flow path through which the refrigerant flows. Each of the plurality of leg portions is a heat exchange unit that performs heat exchange between wind generated by rotation of a rotor blade and the refrigerant flowing through the second flow path. The shaft portion includes a pump that generates a flow for circulating the refrigerant between the first flow path and the second flow path.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to drones. [Background technology]

[0002] Conventionally, flying objects with rotors, commonly called drones, are known. A motor is used to rotate the rotors of these drones. A motor is an example of a rotating machine. In such motors, cooling the heat generated in the stator and other components is an important issue.

[0003] Patent Document 1 discloses a propeller device for driving a ship. This propeller device has a structure in which the motor rotor and propeller are integrated, with a stator located on the outer periphery. Since this type of propeller device is intended for use on ships, it is expected that the stator will be cooled by seawater. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-245889 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the cooling effect of seawater cannot be obtained for motors that rotate propellers used in aerial vehicles such as drones. Furthermore, motors for drones are particularly required to be small and lightweight, and a cooling structure that can accommodate this is required.

[0006] For this reason, there has traditionally been room for improvement in the cooling structure of drone motors.

[0007] The present invention aims to improve the cooling structure of a motor for a drone. [Means for solving the problem]

[0008] A drone according to one aspect of the present invention includes a stator, a rotor facing the stator across a gap, a stator case that houses the stator, a heat exchanger arranged on one axial side of the stator case, a shaft that is a rotating shaft that rotates with rotation of the rotor, and rotor blades that rotate with rotation of the rotor, wherein the stator case has a first flow path that extends circumferentially and through which a refrigerant flows, the heat exchanger has a shaft portion that is coaxial with the shaft and a plurality of legs that extend radially from the shaft portion, each of the plurality of legs having a second flow path through which the refrigerant flows, each of the plurality of legs being a heat exchanger that exchanges heat between wind generated by rotation of the rotor blades and the refrigerant flowing through the second flow path, and the shaft portion has a pump that generates a flow that circulates the refrigerant between the first flow path and the second flow path. It is characterized by:

[0009] In the drone of one aspect described above, the heat exchanger is arranged on the intake side of the rotor.

[0010] In the drone of one aspect described above, the pump unit is driven by rotation of the rotor.

[0011] In one aspect of the drone described above, the rotating wing is integral with the rotor.

[0012] The drone of one aspect described above is characterized in that it has a wind guidance section that guides the wind generated by the rotation of the rotor to the heat exchange section.

[0013] In one aspect of the drone described above, the air guidance section is a cylindrical member that covers at least the radially outer side of the heat exchange section.

[0014] In one aspect of the drone described above, the second flow path comprises a third flow path through which the refrigerant flows from the pump to the first flow path, and a fourth flow path through which the refrigerant flows from the first flow path to the pump, and each of the multiple legs has a through hole that penetrates axially between the third flow path and the fourth flow path.

[0015] In one aspect of the drone described above, each of the plurality of legs has a lattice in the through hole.

[0016] In the drone of one aspect described above, each of the plurality of legs has a fin.

[0017] In one aspect of the drone described above, the drone is characterized by having a bridge that connects adjacent legs among the plurality of legs, and a support portion that supports the bridge on the stator case. [Effects of the Invention]

[0018] According to one aspect of the present invention, it is possible to improve the cooling structure of a motor for a drone. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view of a drone 100 according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 1 is a perspective view of a main part 105 of the drone 100 with the air guide member 101 removed. [Figure 3] FIG. 10 is a perspective view showing the main part 105 in a direction in which the -Z side is visible. [Figure 4] FIG. 2 is an exploded perspective view showing the main part 105. [Figure 5] FIG. 1 is a plan view of the drone 100 as seen from the +Z side. [Figure 6] FIG. 1 is a cross-sectional plan view of the drone 100 taken along the position of the refrigerant flow paths extending radially within the legs 112, 113, and 114. [Figure 7]2 is an enlarged cross-sectional plan view showing the vicinity of a pump portion 300. FIG. [Figure 8] 1 is a side cross-sectional view of the drone 100 taken at the position of a refrigerant flow path extending axially within the leg 112. FIG. [Figure 9] 1 is a side cross-sectional view showing the drone 100 cut at the position of a refrigerant flow path extending axially within the leg 113. FIG. [Figure 10] 1 is a side cross-sectional view of the drone 100 taken at the position of a coolant flow path extending axially within the leg 114. FIG. [Figure 11] FIG. 1 is a plan cross-sectional view showing the drone 100 cut at the position of a refrigerant flow path extending circumferentially in a plane perpendicular to the axial direction within the stator case 120. [Figure 12] FIG. 10 is a plan view of a drone 100 according to a second embodiment of the present invention, viewed from the +Z side. [Figure 13] FIG. 10 is a plan view of the drone 100 according to the third embodiment of the present invention, viewed from the +Z side. [Figure 14] FIG. 10 is a plan view of a drone 100 according to a fourth embodiment of the present invention, viewed from the +Z side. [Figure 15] FIG. 11 is a perspective view of a main part 105 of a drone 100 according to a fifth embodiment of the present invention, from which a wind guide member 101 has been removed. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a rotating machine and a drone using the rotating machine according to an embodiment of the present invention will be described with reference to the drawings. Note that in the drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0021] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z axis direction is parallel to the axial direction of the central axis J shown in FIG. 1. The Y axis direction is parallel to the radial direction of the central axis J, in which the leg portion 112 in FIG. 1 extends. The X axis direction is perpendicular to both the Z axis direction and the Y axis direction. In each of the X axis direction, the side indicated by the arrow in the drawing is the positive side, and the opposite side is the negative side.

[0022] In the following description, the positive side (+Z side) in the Z-axis direction will be referred to as "one side," and the negative side (-Z side) in the Z-axis direction will be referred to as "the other side." Note that "one side" and "the other side" are names used merely for the purpose of explanation and do not limit the actual positional relationship or direction. Unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) will be referred to simply as "axial direction," the radial direction centered on the central axis J will be referred to simply as "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be referred to simply as "circumferential direction." In the radial direction, the side closer to the central axis J will be referred to as "radially inner," and the side away from the central axis J will be referred to as "radially outer." In the circumferential direction, the clockwise side when viewed from the +Z side to the -Z side will be referred to as "one circumferential side," and the counterclockwise side will be referred to as "the other circumferential side."

[0023] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted by less than 45° with respect to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction (Z-axis direction), but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted by an angle of less than 45° with respect to each other. Furthermore, "extending in a direction perpendicular to the axial direction" includes not only extending in a direction perpendicular to the axial direction (Z-axis direction) but also extending in a direction tilted by less than 45° with respect to the direction perpendicular to the axial direction (Z-axis direction).

[0024] First Embodiment 1 is a perspective view of a drone according to a first embodiment of the present invention. The drone 100 has a motor 200 and a rotor 151. The motor 200 is an example of a rotary machine. The drone 100 flies by receiving lift generated by the rotation of the rotor 151.

[0025] The motor 200 has a stator 180 (see FIG. 4) housed in the stator case 120, a rotor 150 facing the stator 180 across a gap, and a shaft 152. The shaft 152 is a rotation axis of the motor 200 that extends in the axial direction along the central axis J. In this embodiment, the rotor 151 is integral with the rotor 150 and the shaft 152, and when the rotor 150 rotates around the shaft 152, the rotor 151 also rotates.

[0026] The drone 100 also has a heat exchanger 110 and an air guide member 101 arranged on one axial side of the stator case 120. The heat exchanger 110 has an axial portion 111 coaxial with the shaft 152, and legs 112, 113, and 114 extending radially from the axial portion 111. The air guide member 101 is an example of an air guide portion that guides the wind generated by the rotation of the rotor 151 to the legs 112, 113, and 114 that function as heat exchanging portions of the heat exchanger 110. In this embodiment, a configuration having three legs, namely the legs 112, 113, and 114, has been shown, but the present invention is not limited to this and may have a configuration having multiple legs.

[0027] 2 is a perspective view of the main part 105 with the air guide member 101 removed from the drone 100 of FIG. 1. Each of the legs 112, 113, and 114 of the heat exchanger 110 extends radially from the shaft 111, then extends to the other axial side, and stands on a surface on one axial side of the stator case 120. Each of the legs 112, 113, and 114 is fixed to the surface on one axial side of the stator case 120 by adhesive, welding, or the like. As will be described in detail later, the legs 112, 113, and 114 function as heat exchangers that exchange heat with the refrigerant.

[0028] FIG. 3 is a perspective view of the main part 105, with the -Z side visible. A stator cover 190 is disposed on the other axial side of the stator case 120. FIG. 4 is an exploded perspective view of the main part 105. The shaft 152 is fixed to the shaft part 111 via a bearing 140. The impeller 130 is fixed to one axial end of the shaft 152. The shaft part 111 of the heat exchanger 110 has a bottomed cylindrical shape with a bottom on one axial side, and the impeller 130 is housed inside the cylinder of the shaft part 111.

[0029] The rotor 150 has a magnet 160 and a magnet cover 170 that prevents the magnet 160 from falling off. The stator 180 has a stator core 181 and a winding 182 wound around the stator core 181. The rotor 150 is disposed radially inside the stator 180 and faces the stator 180 in the radial direction across a gap. In this embodiment, the motor 200 is a radial gap motor, but the present invention is also applicable to an axial gap motor.

[0030] FIG. 5 is a plan view of the drone 100 as seen from the +Z side. FIG. 6 is a cross-sectional view of the drone 100 taken at the position of a refrigerant flow path extending radially within the leg 112. The heat exchanger 110 has a pump unit 300. The shaft 111 of the heat exchanger 110 functions as a pump casing for the pump unit 300. The cylindrical interior of the shaft 111 of the heat exchanger 110 functions as a refrigerant flow path 115 within the pump casing of the pump unit 300. The refrigerant flow path 115 is a flow path through which a refrigerant that cools the motor 200 flows. The refrigerant is, for example, oil. The refrigerant may be liquid or gas. The refrigerant flow path 115 is the space between the inner wall of the cylinder of the shaft 111 and the impeller 130. The refrigerant flow path 115 is connected to refrigerant flow paths 116a and 117a that extend radially within the leg 112. Coolant flow path 115 is connected to coolant flow paths 1116a and 1117a extending radially within leg portion 113. Coolant flow path 115 is connected to coolant flow paths 2116a and 2117a extending radially within leg portion 114.

[0031] FIG. 7 is an enlarged plan cross-sectional view showing the vicinity of the pump unit 300. The impeller 130 is a cascade impeller. The impeller 130 has multiple teeth 131 extending radially outward. The heat exchanger 110 has partitions 118 that protrude into the refrigerant flow passage 115 at circumferential positions of the legs 112. The radially inner end of the partitions 118 is located radially outward from the radially outer ends of the teeth 131. The partitions 118 are located on the other circumferential side of the refrigerant flow passage 116a and on one circumferential side of the refrigerant flow passage 117a within the circumferential width of the legs 112. The heat exchanger 110 has partitions 1118 that protrude into the refrigerant flow passage 115 at circumferential positions of the legs 113. The radially inner end of the partitions 1118 is located radially outward from the radially outer ends of the teeth 131. The partition 1118 is located on the other circumferential side of the refrigerant flow path 1116a and on one circumferential side of the refrigerant flow path 1117a within the circumferential width of the leg 113. The heat exchanger 110 has a partition 2118 that protrudes into the refrigerant flow path 115 at a circumferential position of the leg 114. The radially inner end of the partition 2118 is located radially outward of the radially outer end of the tooth 131. The partition 2118 is located on the other circumferential side of the refrigerant flow path 2116a and on one circumferential side of the refrigerant flow path 2117a within the circumferential width of the leg 114.

[0032] 8 is a side cross-sectional view of the drone 100 taken at the position of the refrigerant flow paths extending axially within the leg 112. The leg 112 has refrigerant flow paths 116b and 117b extending axially. The radially outer end of the refrigerant flow path 116a is connected to one axial end of the refrigerant flow path 116b. The radially outer end of the refrigerant flow path 117a is connected to one axial end of the refrigerant flow path 117b.

[0033] The stator case 120 has axially extending refrigerant flow paths 121 and 122. The other axial end of the refrigerant flow path 116b is connected to one axial end of the refrigerant flow path 121. The other axial end of the refrigerant flow path 117b is connected to one axial end of the refrigerant flow path 122.

[0034] 9 is a side cross-sectional view of the drone 100 taken at the position of the refrigerant flow paths extending axially within the leg 113. The leg 113 has refrigerant flow paths 1116b and 1117b extending axially. The radially outer end of the refrigerant flow path 1116a is connected to one axial end of the refrigerant flow path 1116b. The radially outer end of the refrigerant flow path 1117a is connected to one axial end of the refrigerant flow path 1117b.

[0035] The stator case 120 has axially extending refrigerant flow paths 1121 and 1122. The other axial end of the refrigerant flow path 1116b is connected to one axial end of the refrigerant flow path 1121. The other axial end of the refrigerant flow path 1117b is connected to one axial end of the refrigerant flow path 1122.

[0036] 10 is a side cross-sectional view of the drone 100 taken at the position of the refrigerant flow paths extending axially within the leg 114. The leg 114 has refrigerant flow paths 2116b and 2117b extending axially. The radially outer end of the refrigerant flow path 2116a is connected to one axial end of the refrigerant flow path 2116b. The radially outer end of the refrigerant flow path 2117a is connected to one axial end of the refrigerant flow path 2117b.

[0037] Stator case 120 has axially extending refrigerant flow paths 2121 and 2122. The other axial end of refrigerant flow path 2116b is connected to one axial end of refrigerant flow path 2121. The other axial end of refrigerant flow path 2117b is connected to one axial end of refrigerant flow path 2122.

[0038] 11 is a plan cross-sectional view of the drone 100 taken along the position of a refrigerant flow path extending circumferentially on a plane perpendicular to the axial direction within the stator case 120. The stator case 120 has refrigerant flow paths 123, 1123, and 2123 extending circumferentially on a plane perpendicular to the axial direction.

[0039] The other axial end of refrigerant flow path 121 is connected to the other circumferential end of refrigerant flow path 123. The other axial end of refrigerant flow path 122 is connected to one circumferential end of refrigerant flow path 2123. Stator case 120 has separation portion 124 between the other circumferential end of refrigerant flow path 123 and the one circumferential end of refrigerant flow path 2123.

[0040] The other axial end of refrigerant flow path 1121 is connected to the other circumferential end of refrigerant flow path 1123. The other axial end of refrigerant flow path 1122 is connected to one circumferential end of refrigerant flow path 123. Stator case 120 has separation portion 1124 between the other circumferential end of refrigerant flow path 1123 and the one circumferential end of refrigerant flow path 123.

[0041] The other axial end of refrigerant flow path 2121 is connected to the other circumferential end of refrigerant flow path 2123. The other axial end of refrigerant flow path 2122 is connected to one circumferential end of refrigerant flow path 1123. Stator case 120 has separation portion 2124 between the other circumferential end of refrigerant flow path 2123 and the one circumferential end of refrigerant flow path 1123.

[0042] Here, the flow of the refrigerant in the drone 100 will be described. The drone 100 has a closed flow path that circulates the refrigerant through refrigerant flow paths 115, 117a, 117b, 122, 2123, 2121, 2116b, 2116a, and 115. The drone 100 also has a closed flow path that circulates the refrigerant through refrigerant flow paths 115, 2117a, 2117b, 2122, 1123, 1121, 1116b, 1116a, and 115, in order. The drone 100 also has a closed flow path that circulates the refrigerant through refrigerant flow paths 115, 1117a, 1117b, 1122, 123, 121, 116b, 116a, and 115, in order. The refrigerant is sealed in these closed circulation paths.

[0043] When the drone 100 is driven, the rotor 150 rotates in one circumferential direction around the central axis J as the rotation axis. This rotation of the rotor 150 causes the rotor 151 to generate lift, causing the drone 100 to lift off. The rotation of the rotor 151 generates wind from one axial side to the other axial side of the drone 100. For this reason, one axial side of the drone 100 is sometimes called the intake side, and the other axial side is sometimes called the exhaust side.

[0044] Rotation of rotor 150 in one circumferential direction rotates shaft 152 in one circumferential direction via rotor blades 151. Rotation of shaft 152 in one circumferential direction rotates impeller 130 fixed to one axial end of shaft 152 in one circumferential direction.

[0045] When impeller 130 rotates in one circumferential direction, pump unit 300 operates to suck the refrigerant in refrigerant flow path 2116a into refrigerant flow path 115 and discharge the refrigerant in refrigerant flow path 115 into refrigerant flow path 117a. The refrigerant sent to refrigerant flow path 117a by pump unit 300 flows through refrigerant flow path 2123 in stator case 120, thereby cooling stator 180 housed in stator case 120. That is, as the refrigerant flows through refrigerant flow path 2123 in stator case 120, it exchanges heat with stator case 120, which has become heated by the heat of stator 180. Thereafter, the refrigerant flows through refrigerant flow path 2116a and returns to refrigerant flow path 115, where it circulates.

[0046] Similarly, when impeller 130 rotates in one circumferential direction, pump unit 300 operates to suck the refrigerant in refrigerant flow path 1116a into refrigerant flow path 115 and discharge the refrigerant in refrigerant flow path 115 into refrigerant flow path 2117a. The refrigerant sent out by pump unit 300 to refrigerant flow path 2117a flows through refrigerant flow path 1123 in stator case 120, thereby cooling stator 180 housed in stator case 120. That is, as the refrigerant flows through refrigerant flow path 1123 in stator case 120, it exchanges heat with stator case 120, which has become heated by the heat of stator 180. Thereafter, the refrigerant flows through refrigerant flow path 1116a and returns to refrigerant flow path 115, where it circulates.

[0047] Similarly, when impeller 130 rotates in one circumferential direction, pump unit 300 operates to suck the refrigerant in refrigerant flow path 116a into refrigerant flow path 115 and discharge the refrigerant in refrigerant flow path 115 into refrigerant flow path 1117a. The refrigerant sent out to refrigerant flow path 1117a by pump unit 300 flows through refrigerant flow path 123 in stator case 120, thereby cooling stator 180 housed in stator case 120. That is, as the refrigerant flows through refrigerant flow path 123 in stator case 120, it exchanges heat with stator case 120, which has become heated by the heat of stator 180. Thereafter, the refrigerant flows through refrigerant flow path 116a and returns to refrigerant flow path 115, where it circulates.

[0048] The legs 112, 113, and 114 of the heat exchanger 110 are cooled by the wind generated by the rotation of the rotor 151. Because the legs 112, 113, and 114 are located on the intake side of the wind generated by the rotor 151, they are cooled more than if they were located on the exhaust side. The refrigerant is cooled as it flows through the refrigerant flow paths 116a and 117a, 1116a and 1117a, and 2116a and 2117a in the legs 112, 113, and 114, which function as heat exchangers. That is, the refrigerant exchanges heat with the legs 112, 113, and 114, which are cooled by the wind generated by the rotation of the rotor 151, by flowing through the refrigerant flow paths 116a and 117a, 1116a and 1117a, and 2116a and 2117a in the legs 112, 113, and 114.

[0049] In this embodiment, the air guide member 101 is provided to guide the wind generated by the rotation of the rotor 151 toward the legs 112, 113 and 114.

[0050] The air guide member 101 is an example of a cylindrical member that covers at least the radial outside of the leg portions 112, 113, and 114 that serve as heat exchangers. As shown in FIG. 1 , the air guide member 101 is a cylindrical member with an outer diameter that is approximately equal to the outer diameter of the stator case 120. The axial length of the air guide member 101 is longer than the length from one axial surface of the stator case 120 to one axial surface of the leg portion 112. If the air guide member 101 is not provided, air taken into the rotor 151 from the outside may reach the rotor 151 by passing through the other axial side of the leg portion 112 having the refrigerant flow paths 116a and 117a, the leg portion 113 having the refrigerant flow paths 1116a and 1117a, and the leg portion 114 having the refrigerant flow paths 2116a and 2117a. In this case, the amount of air flowing toward the leg portion 112 is small, and the leg portion 112 cannot be cooled efficiently. When the air guide member 101 is provided, the air intake to the rotor 151 can be guided toward the legs 112, 113 and 114 without passing through the other axial side of the legs 112, 113 and 114, thereby enabling more efficient cooling of the legs 112.

[0051] According to this embodiment, the flow of the refrigerant can be generated by the impeller 130 that rotates together with the rotor 150, and there is no need to provide an external power source for the pump section 300, which makes it possible to make the drone 100 smaller and lighter.

[0052] Furthermore, according to this embodiment, by providing a heat exchanger that cools the drone 100 using the wind generated by the rotor 151 that drives the drone 100, a more efficient cooling structure for the drone motor can be provided.

[0053] Second Embodiment 12 is a plan view of a drone 100 according to a second embodiment of the present invention, viewed from the +Z side. In the second embodiment, only differences from the first embodiment will be described, and the same reference numerals will be used to denote the same parts as in the first embodiment, and description thereof will be omitted.

[0054] The leg portion 112 according to the second embodiment has refrigerant flow paths 116a and 117a, similar to the first embodiment. Similarly, the leg portion 113 according to the second embodiment has refrigerant flow paths 1116a and 1117a, similar to the first embodiment. Furthermore, the leg portion 114 according to the second embodiment has refrigerant flow paths 2116a and 2117a, similar to the first embodiment.

[0055] The second embodiment differs from the first embodiment in that leg 112 according to the second embodiment has a through-hole 501 that penetrates axially and extends radially between refrigerant flow paths 116a and 117a. Similarly, leg 113 according to the second embodiment has a through-hole 502 that penetrates axially and extends radially between refrigerant flow paths 1116a and 1117a. Furthermore, leg 114 according to the second embodiment has a through-hole 503 that penetrates axially and extends radially between refrigerant flow paths 2116a and 2117a.

[0056] According to this embodiment, the legs 112, 113, and 114 have through holes 501, 502, and 503, and the wind generated by the rotation of the rotor 151 passes through the through holes 501, 502, and 503, thereby allowing the legs 112, 113, and 114 to be cooled more efficiently.

[0057] Third Embodiment 13 is a plan view of the drone 100 according to the third embodiment of the present invention as seen from the +Z side. In the third embodiment, only the differences from the second embodiment will be described, and the same reference numerals will be used to denote the same parts as in the second embodiment, and the description thereof will be omitted.

[0058] The third embodiment differs from the second embodiment in that the leg 112 according to the third embodiment has fins 504 arranged radially on both circumferential sides. Similarly, the leg 113 according to the third embodiment has fins 505 arranged radially on both circumferential sides. Furthermore, the leg 114 according to the third embodiment has fins 506 arranged radially on both circumferential sides.

[0059] According to this embodiment, legs 112, 113, and 114 have fins 504, 505, and 506, which improves the heat dissipation properties of legs 112, 113, and 114, allowing legs 112, 113, and 114 to be cooled more efficiently.

[0060] <Fourth embodiment> 14 is a plan view of a drone 100 according to a fourth embodiment of the present invention, viewed from the +Z side. In the fourth embodiment, only differences from the third embodiment will be described, and the same reference numerals will be used to denote the same parts as in the third embodiment, and description thereof will be omitted.

[0061] The fourth embodiment differs from the third embodiment in that leg portion 112 according to the fourth embodiment has a lattice 507 in through hole 501. Similarly, leg portion 113 according to the fourth embodiment has a lattice 508 in through hole 502. Furthermore, leg portion 114 according to the fourth embodiment has a lattice 509 in through hole 503.

[0062] According to this embodiment, the legs 112, 113, and 114 have the lattice 507, the lattice 508, and the lattice 509, so that the strength of the legs 112, 113, and 114 can be increased.

[0063] Fifth Embodiment 15 is a perspective view of a main part 105 of a drone 100 according to a fifth embodiment of the present invention, from which the air guide member 101 has been removed. In the fifth embodiment, only the differences from the third embodiment will be described, and the same reference numerals will be used to denote the same parts as in the third embodiment, and the description thereof will be omitted.

[0064] The fifth embodiment differs from the third embodiment in that the drone 100 according to the fifth embodiment has a bridge 601 that bridges between the leg 112 and the leg 113, and a support section 604 that supports the bridge 601 on the stator case 120. Similarly, the drone 100 according to the fifth embodiment has a bridge 602 that bridges between the leg 113 and the leg 114, and a support section 605 that supports the bridge 602 on the stator case 120. The drone 100 according to the fifth embodiment also has a bridge 603 that bridges between the leg 114 and the leg 112, and a support section 606 that supports the bridge 603 on the stator case 120. That is, the drone 100 according to the fifth embodiment has a bridge that bridges between adjacent legs among the multiple legs, and a support section that supports the bridge.

[0065] According to this embodiment, the drone 100 has the bridge 601 and the support portion 604, the bridge 602 and the support portion 605, and the bridge 603 and the support portion 606, thereby increasing the strength of the legs 112, 113, and 114.

[0066] The present invention is not limited to the above-described embodiments, and various improvements and design changes may be made without departing from the spirit of the present invention. In addition, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The present invention also includes partial combinations of the configurations of the above-described embodiments. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0067] 100...drone, 110...heat exchanger, 120...stator case, 150...rotor, 151...rotating blade, 152...shaft, 180...stator, 200...motor

Claims

1. a stator; a rotor facing the stator across a gap; a stator case that houses the stator; a heat exchanger disposed on one axial side of the stator case; a shaft that is a rotation axis that rotates due to rotation of the rotor; a rotor blade that rotates due to rotation of the rotor; and the stator case has a first flow path extending in a circumferential direction and through which a refrigerant flows, The heat exchanger has a shaft portion coaxial with the shaft and a plurality of legs extending radially from the shaft portion, Each of the plurality of legs has a second flow path through which the coolant flows, each of the plurality of legs is a heat exchanger that exchanges heat between wind generated by rotation of the rotor blades and the refrigerant flowing through the second flow path; The shaft portion has a pump that generates a flow that circulates the coolant between the first flow path and the second flow path. A drone characterized by

2. The heat exchanger is disposed on the intake side of the rotor. The drone according to claim 1 .

3. The pump unit is driven by rotation of the rotor. The drone according to claim 1 .

4. The rotor blades are integral with the rotor. The drone according to claim 1 .

5. an air guide section that guides air generated by the rotation of the rotor blades to the heat exchange section; The drone according to claim 1 .

6. The airflow guidance section is a cylindrical member that covers at least the radially outer side of the heat exchange section. The drone according to claim 5 .

7. the second flow path includes a third flow path through which the refrigerant flows from the pump to the first flow path, and a fourth flow path through which the refrigerant flows from the first flow path to the pump, Each of the plurality of leg portions has a through hole that penetrates in the axial direction between the third flow path and the fourth flow path. The drone according to claim 1 .

8. Each of the plurality of legs has a lattice in the through hole. The drone according to claim 7 .

9. Each of the plurality of legs has a fin. The drone according to claim 1 .

10. a bridge connecting adjacent legs among the plurality of legs, and a support column supporting the bridge on the stator case, The drone according to claim 1 .

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