Rotary electric machine

Abstract

A motor (60) includes a stator (61), a rotor (71), and a bearing (80). The stator (61) and the rotor (71) are aligned in an axial direction (AD). The stator (61) includes a stator coil (62) and a stator support part (63), and the rotor (71) includes a rotor magnet (72) and a rotor support part (73). The stator support part (63) includes a stator inner circumferential wall (66) to which the stator coil (62) is fixed. The rotor support part (73) includes a rotor opposite wall (74) to which the rotor magnet (72) is fixed. The bearing (80) is fixed to both the stator support part (63) and the rotor support part (73) and thereby supports the rotor (71) such that the rotor (71) can rotate relative to the stator (61).

Description

Rotating electric machines CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-109001 filed in Japan on July 5, 2024, the contents of which are incorporated by reference in their entirety.

[0002] The disclosure in this specification relates to rotating electrical machines.

[0003] Patent Document 1 describes an axial gap motor. In this motor, a stator and a rotor are aligned axially along a shaft. The stator and rotor are housed in a housing. In this motor, bearings that support the rotor rotatably relative to the stator are fixed to the shaft and the housing, respectively. The stator coils and rotor magnets are provided at positions spaced apart from the shaft on the outer periphery.

[0004] JP 2023-48086 A

[0005] However, in the above-mentioned Patent Document 1, since the bearing is fixed to the shaft, the bearing must be positioned in accordance with the shaft, and therefore, since the bearing is positioned away from the magnet of the rotor on the inner periphery, there is a concern that the portion of the rotor between the magnet and the shaft may be deformed.

[0006] One object of the present disclosure is to provide a rotating electric machine capable of suppressing deformation of the rotor.

[0007] The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the reference symbols in parentheses in the claims and this section are merely examples showing the correspondence between specific means described in the embodiments below as one aspect, and do not limit the technical scope.

[0008] In order to achieve the above object, the disclosed aspect is a rotating electric machine driven by a supply of electric power, comprising: a stator having an energized stator coil and a stator support portion supporting the stator coil; a rotor having rotor magnets aligned with the stator coil in the axial direction of the rotation axis and a rotor support portion supporting the rotor magnet, the rotor rotating around the rotation axis and aligned with the stator in the axial direction; and bearings fixed to the stator support portion and the rotor support portion, respectively, and supporting the rotor rotatably relative to the stator, wherein a portion of the stator is provided on the inner peripheral side of the rotor.

[0009] According to the above aspect, the bearings are fixed to the stator support portion and the rotor support portion, respectively, and support the rotor rotatably relative to the stator. This configuration increases the degree of freedom regarding the positional relationship between the stator coil and the rotor magnet and the bearing. Therefore, by arranging the bearing in a position on the rotor support portion where the portion between the rotor magnet and the bearing is less likely to deform, it is possible to suppress deformation of the rotor.

[0010] Furthermore, a portion of the stator is located on the inner periphery of the rotor. In this configuration, the bearing is located closer to the stator in the radial direction of the rotation axis, making it possible to reduce the radial size of the bearing. This makes it possible to suppress deformation of the bearing as well as deformation of the rotor.

[0011] 1 is a diagram showing the configuration of an eVTOL according to a first embodiment; a schematic vertical cross-sectional view of an EPU; a plan view of a motor as seen from the first rotor side; a schematic vertical cross-sectional view of the periphery of a bearing in a motor; a schematic vertical cross-sectional view of an EPU according to a second embodiment; a schematic vertical cross-sectional view of an EPU according to a third embodiment; a schematic vertical cross-sectional view of a motor according to a modified example 3-1; a schematic vertical cross-sectional view of a motor according to a modified example 3-2; a schematic vertical cross-sectional view of an EPU according to a fourth embodiment; a schematic vertical cross-sectional view of a motor according to a modified example 4-1; a schematic vertical cross-sectional view of a motor according to a modified example 4-2; a plan view of a motor as seen from the first rotor side; a schematic vertical cross-sectional view of a motor according to a fifth embodiment; a schematic vertical cross-sectional view of a motor according to a modified example 5-1; a schematic vertical cross-sectional view of a motor according to a sixth embodiment; a schematic vertical cross-sectional view of a motor according to a modified example 6-1; a schematic vertical cross-sectional view of a motor according to a seventh embodiment; a schematic vertical cross-sectional view of a motor according to an eighth embodiment; a schematic vertical cross-sectional view of a motor according to a ninth embodiment; and a schematic vertical cross-sectional view of a motor according to a tenth embodiment. 11. A schematic vertical cross-sectional view of a motor according to an eleventh embodiment. 2. A schematic vertical cross-sectional view of a motor according to a modified example 11-1. 3. A schematic vertical cross-sectional view of a motor according to a twelfth embodiment.

[0012] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0013] First Embodiment The propulsion system 30 shown in FIG. 1 is mounted on an eVTOL 10. The eVTOL 10 is an electric vertical take-off and landing aircraft. An electric vertical take-off and landing aircraft is an electric vertical take-off and landing aircraft capable of vertical take-off and landing. eVTOL is an abbreviation for electric Vertical Take-Off and Landing aircraft. The eVTOL 10 is an electric air vehicle that flies in the atmosphere and is sometimes referred to as an electric air vehicle. The eVTOL 10 is also an electric aircraft and is sometimes referred to as an electric aircraft. The eVTOL 10 is a manned air vehicle that carries a crew member. The crew member of the eVTOL 10 includes a pilot who operates or drives the aircraft. The propulsion system 30 is a system that drives the eVTOL 10 to fly. The propulsion system 30 is sometimes referred to as a flight system.

[0014] The eVTOL 10 has an airframe 11 and a propeller 20. The airframe 11 has an airframe main body 12 and wings 13. The airframe main body 12 is the fuselage of the airframe 11 and has a shape that extends, for example, in the front-to-rear direction. The wings 13 extend from the airframe main body 12, and multiple wings 13 are provided on the airframe main body 12. The wings 13 are fixed wings. The multiple wings 13 include main wings, a tail, and the like.

[0015] The eVTOL 10 has a cabin. The cabin is provided inside the eVTOL 10. For example, the cabin is the internal space of the aircraft body 12 and is formed by the aircraft body 12. The cabin can be a crew cabin 14 or a cargo bay. The crew cabin 14 can be a passenger cabin or a pilot cabin. The crew cabin 14 is provided with seats for crew members to sit in. The crew cabin 14 does not have to be occupied by crew members and may house cargo.

[0016] A plurality of propellers 20 are provided on the airframe 11. The eVTOL 10 is a multicopter having at least three propellers 20. For example, at least four propellers 20 are provided on the airframe 11. The propellers 20 are provided on each of the airframe body 12 and the wings 13. The propellers 20 rotate around a propeller axis. The propeller axis is the axis of rotation of the propeller 20. The propeller axis is, for example, the center line of the propeller 20. The propellers 20 can generate thrust and lift for the eVTOL 10. The propellers 20 are sometimes referred to as rotors or rotating blades.

[0017] The propeller 20 has propeller blades 21 and a propeller boss 22. A plurality of the propeller blades 21 are arranged in the circumferential direction of the propeller axis. The propeller boss 22 connects the plurality of propeller blades 21. In the propeller 20, a propeller shaft extends from the propeller boss 22 along the propeller axis.

[0018] Flight modes of the eVTOL 10 include vertical takeoff, vertical landing, cruise, and hovering. Flight modes are sometimes referred to as flight behaviors. In vertical takeoff, the eVTOL 10 can take off without running. In vertical takeoff, the eVTOL 10 may ascend vertically or may ascend diagonally upward. In vertical landing, the eVTOL 10 can land without running. In vertical landing, the eVTOL 10 may descend vertically or may descend diagonally downward.

[0019] Cruising is sometimes referred to as level flight. In cruising, the eVTOL 10 may fly horizontally without moving vertically, or may fly horizontally while moving vertically. Hovering is sometimes referred to as stationary flight. In hovering, the eVTOL 10 may fly as if stationary at a predetermined position in the air, or the eVTOL 10 may deviate vertically or horizontally from the predetermined position.

[0020] The flight modes of the eVTOL 10 also include lift. In lift, the eVTOL 10 moves up and down. As a lift, the eVTOL 10 may ascend diagonally upward or descend diagonally downward. The eVTOL 10 takes off vertically by lifting upward. The eVTOL 10 lands vertically by lifting downward.

[0021] The eVTOL 10 is a tilt rotor aircraft. The eVTOL 10 has an adjustable tilt angle for the propeller 20. The eVTOL 10 can have one propeller 20 function as both a lift propeller and a cruise propeller. For example, when the eVTOL 10 lifts, the tilt angle is adjusted so that the propeller 20 functions as a lift rotor. When the eVTOL 10 cruises, the tilt angle is adjusted so that the propeller 20 functions as a cruise rotor. Note that the eVTOL 10 does not have to be a tilt rotor aircraft. For example, the eVTOL 10 may have separate propellers 20 for lift and cruise.

[0022] The eVTOL 10 has a battery 31, a distributor 32, a communication unit 34, a flight control device 40, and an EPU 50. The battery 31, distributor 32, communication unit 34, flight control device 40, and EPU 50 are included in a propulsion system 30. Note that the propulsion system 30 only needs to include at least the flight control device 40 and the EPU 50. The flight control device 40 is sometimes referred to as a flight controller.

[0023] The battery 31 is electrically connected to the EPU 50. The battery 31 is a power supply unit that supplies power to the EPU 50 and corresponds to a power supply unit. The battery 31 is a DC voltage source that applies a DC voltage to the EPU 50. The battery 31 has a rechargeable secondary battery. Examples of such secondary batteries include a lithium ion battery and a nickel-metal hydride battery. The battery 31 is capable of storing power and corresponds to a power storage device. Note that a fuel cell, a generator, or the like may be used as the power supply unit in addition to or instead of the battery 31.

[0024] The distributor 32 is electrically connected to the battery 31 and the plurality of EPUs 50. The distributor 32 distributes power from the battery 31 to the plurality of EPUs 50. The battery 31 is electrically connected to the plurality of EPUs 50 via the distributor 32. The battery 31 supplies power to the EPUs 50 via the distributor 32.

[0025] The communication unit 34 is a communication device capable of wireless communication with an external device. The external device is a device located away from the eVTOL 10. Examples of external devices include communication devices installed in external facilities on the ground and communication devices installed in other flying vehicles. Examples of external facilities include a control center and a management center. The communication unit 34 is capable of communication with the flight control device 40. The communication unit 34 is connected to the flight control device 40 so that it can communicate via wired communication. Note that the communication unit 34 may also be capable of wireless communication with the flight control device 40.

[0026] 1 and 2, the EPU 50 is a device that drives the propeller 20 to rotate, and corresponds to a drive device. EPU is an abbreviation for Electric Propulsion Unit. The EPU 50 is sometimes referred to as an electric drive device or an electric drive system. An EPU 50 is provided for each of the multiple propellers 20. The EPUs 50 are arranged on the propellers 20 along the propeller axis. All of the multiple EPUs 50 are fixed to the airframe 11. The EPUs 50 support the propellers 20 so that they can rotate. The EPUs 50 are connected to the propellers 20. The propellers 20 are fixed to the airframe 11 via the EPUs 50.

[0027] The eVTOL 10 has a propulsion device. The propulsion device is formed to include a propeller 20 and an EPU 50. The propulsion device is a device for propelling the eVTOL 10. The propulsion device causes the eVTOL 10 to fly by rotating the propeller 20. The eVTOL 10 is a moving body that moves using the propulsion device. The eVTOL 10 is provided with a plurality of propulsion devices. One propulsion device includes one propeller 20 and one EPU 50 for driving the propeller 20. Note that only the EPU 50 of the propeller 20 and the EPU 50 may be referred to as the propulsion device.

[0028] The EPU 50 has a motor 60 and an inverter device 90. The motor 60 and the inverter device 90 are formed as a short columnar shape overall, and extend in the axial direction AD. The motor 60 and the inverter device 90 are aligned in the axial direction AD. The motor 60 and the inverter device 90 are stacked in the axial direction AD. The motor 60 and the inverter device 90 are provided coaxially. The center line of the inverter device 90 coincides with the motor axis line Cm. The motor 60 is provided between the inverter device 90 and the propeller 20 in the axial direction AD.

[0029] The motor 60 is driven to propel the eVTOL 10. The motor 60 is driven by power from the battery 31. The motor 60 corresponds to the propulsion drive unit. The motor 60 is the flight drive source for the eVTOL 10 and functions as an electric motor. The motor 60 is a multi-phase AC motor. For example, the motor 60 is a brushless motor. The motor 60 corresponds to a rotating electric machine. The motor 60 is a motor generator. The motor 60 functions as a generator during regeneration.

[0030] The motor 60 has a stator 61 and a rotor 71. The stator 61 is a fixed part. The stator 61 forms an armature. The stator 61 is fixed to the machine body 11 with bolts or the like. The rotor 71 is a rotating part that rotates relative to the stator 61. The rotor 71 forms a field element.

[0031] The motor 60 is an axial gap motor. The stator 61 and the rotor 71 are aligned in the axial direction AD with an axial gap between them. The motor 60 is also a double-rotor motor. The motor 60 has two rotors 71, a first rotor 71A and a second rotor 71B. The first rotor 71A and the second rotor 71B are aligned in the axial direction AD with the stator 61 between them. For example, the first rotor 71A is provided on the propeller 20 side in the axial direction AD. The second rotor 71B is provided on the inverter device 90 side in the axial direction AD. The motor 60 is sometimes referred to as a double axial gap motor.

[0032] The axial direction AD is the direction in which the motor axis Cm extends. The motor axis Cm is the rotation axis of the rotor 71. The rotor 71 rotates around the motor axis Cm. The motor axis Cm is, for example, the center line of the rotor 71. The motor axis Cm is also the center line of the motor 60 and the stator 61. The motor axis Cm corresponds to the rotation axis. With respect to the motor axis Cm, the axial direction AD, the radial direction RD, and the circumferential direction CD are perpendicular to one another. The outside of the radial direction RD is sometimes referred to as the radial outside or outer circumferential side. The inside of the radial direction RD is sometimes referred to as the radial inside or inner circumferential side.

[0033] The motor 60 is a housingless motor and does not have a housing. In the motor 60, the stator 61 and the rotor 71 are not housed in a housing. The outer surface of the motor 60 is formed by including the outer surface of the stator 61 and the outer surface of the rotor 71. For example, at least a portion of the outer peripheral surface of the motor 60 is formed by the outer peripheral surface of the stator 61. At least a portion of the end face of the motor 60 is formed by the outer surface of the rotor 71. On the outer surface of the motor 60, a pair of end faces are aligned in the axial direction AD via the outer peripheral surface. The stator 61 and the rotor 71 are open to the air outside the motor 60. In the motor 60, gas such as outside air flows along the outer surface of the stator 61 and the outer surface of the rotor 71.

[0034] The motor 60 has a motor space 601. The motor space 601 is the internal space of the motor 60. The motor space 601 accommodates a stator coil 62 and a rotor magnet 72, which will be described later. The motor space 601 corresponds to an accommodation space. The motor 60 accommodates the stator coil 62 and the rotor magnet 72.

[0035] A motor through-hole 602 is formed in the motor 60. The motor through-hole 602 penetrates the center of the motor 60 in the axial direction AD. With the motor through-hole 602 provided, the motor 60 is formed in an annular shape as a whole. The motor through-hole 602 is formed by the inner circumferential surface of the motor 60. The motor through-hole 602 is formed by at least one of the stator 61 and the rotor 71. In this embodiment, the motor through-hole 602 is formed only by the stator 61 out of the stator 61 and the rotor 71. The motor through-hole 602 is open in the axial direction AD.

[0036] The stator 61 is formed in an annular shape as a whole. The stator 61 has a stator coil 62 and a stator support portion 63. The stator coil 62 and the stator support portion 63 extend annularly in the circumferential direction CD. The stator coil 62 is a multi-phase coil. The stator coil 62 is sometimes referred to as a winding. The stator coil 62 is energized in response to power supply from the battery 31. The motor 60 is driven by energization of the stator coil 62. The stator coil 62 is formed to include a plurality of coil portions. The plurality of coil portions are arranged in the circumferential direction CD.

[0037] The stator support portion 63 supports the stator coil 62. The stator support portion 63 is made of a metal material or the like and has thermal conductivity. The stator support portion 63 is capable of dissipating heat from the stator coil 62 and the like to the outside of the motor 60. The stator support portion 63 is fixed to the machine body 11 with bolts or the like. The stator support portion 63 has a stator inner peripheral wall 66, a stator interposition portion 65, and the stator inner peripheral wall 66. The stator support portion 63 and the stator inner peripheral wall 66 are sometimes referred to as a stator core.

[0038] The stator inner peripheral wall 66 forms the inner peripheral surface of the motor 60. That is, the stator inner peripheral wall 66 forms a motor through-hole 602. The motor through-hole 602 corresponds to an inner peripheral air hole. The stator inner peripheral wall 66 also forms the inner peripheral surface of the stator 61. The stator inner peripheral wall 66 extends in a direction perpendicular to the radial direction RD. The stator inner peripheral wall 66 is formed in a cylindrical shape as a whole and extends in the axial direction AD. The stator inner peripheral wall 66 is provided on the inner peripheral side of the stator coil 62. The stator inner peripheral wall 66 supports the stator coil 62.

[0039] The stator inner circumferential wall 66 has an inner circumferential wall outer surface 66a and an inner circumferential wall inner surface 66b. The inner circumferential wall outer surface 66a is the outer surface of the stator inner circumferential wall 66. The inner circumferential wall outer surface 66a forms the motor through-hole 602. The inner circumferential wall inner surface 66b is the inner surface of the stator inner circumferential wall 66. The inner circumferential wall inner surface 66b is exposed to the motor space 601. At least a portion of the inner circumferential wall outer surface 66a and at least a portion of the inner circumferential wall inner surface 66b are included in the outer surface 63a of the stator support portion 63. For example, the outer surface 63a includes the entire inner circumferential wall outer surface 66a and the portion of the inner circumferential wall inner surface 66b exposed to the motor space 601.

[0040] The stator outer peripheral wall 64 forms the outer peripheral surface of the stator 61. The stator outer peripheral wall 64 extends in a direction perpendicular to the radial direction RD. The stator outer peripheral wall 64 is formed in a cylindrical shape as a whole and extends in the axial direction AD. The stator outer peripheral wall 64 is provided on the outer periphery side of the stator coil 62. The stator outer peripheral wall 64 is aligned in the radial direction RD with the stator inner peripheral wall 66 via the stator coil 62.

[0041] The stator interposition portion 65 is provided between the stator coil 62 and the stator outer peripheral wall 64 and the stator inner peripheral wall 66. The stator interposition portion 65 is in close contact with each of the stator coil 62, the stator outer peripheral wall 64, and the stator inner peripheral wall 66. The stator interposition portion 65 is formed from a resin material or the like. The stator interposition portion 65 has thermal conductivity. Heat from the stator coil 62 is easily dissipated to the stator outer peripheral wall 64 and the stator inner peripheral wall 66 via the stator interposition portion 65. The stator interposition portion 65 fixes the stator coil 62 to the stator outer peripheral wall 64 and the stator inner peripheral wall 66. The stator coil 62 may be fixed to the stator outer peripheral wall 64 and the stator inner peripheral wall 66 with fasteners such as bolts.

[0042] The rotor 71 has a rotor magnet 72 and a rotor support portion 73. The rotor magnet 72 is formed to include a magnet such as a permanent magnet. A plurality of rotor magnets 72 are arranged in the circumferential direction CD. The rotor magnet 72 is provided in a position facing the stator coil 62 with an axial gap therebetween. The rotor magnet 72 and the stator coil 62 are arranged in the axial direction AD. The rotor magnet 72 is sometimes referred to as a rotor magnet.

[0043] The rotor support portion 73 supports the rotor magnet 72. The rotor support portion 73 is made of a metal material or the like and has thermal conductivity. The rotor support portion 73 is capable of dissipating heat from the rotor magnet 72 and the like to the outside of the motor 60. The rotor support portion 73 has a rotor-facing wall 74. The rotor support portion 73 and the rotor-facing wall 74 are sometimes referred to as a rotor core.

[0044] The rotor-facing wall 74 forms an end surface of the motor 60. The rotor-facing wall 74 extends in a direction perpendicular to the axial direction AD. The rotor-facing wall 74 is formed in a plate shape overall. The rotor-facing wall 74 supports the rotor magnet 72. The rotor-facing wall 74 has a facing-wall outer surface 74a and a facing-wall inner surface 74b. The facing-wall outer surface 74a is the outer surface of the rotor-facing wall 74. The facing-wall outer surface 74a is included in the outer surface of the motor 60. The facing-wall inner surface 74b is the inner surface of the rotor-facing wall 74. The facing-wall inner surface 74b is exposed to the motor space 601. At least a portion of the facing-wall outer surface 74a and at least a portion of the facing-wall inner surface 74b are included in the outer surface 73a of the rotor support portion 73. For example, the outer surface 73a includes substantially the entire facing-wall outer surface 74a and a portion of the facing-wall inner surface 74b exposed to the motor space 601.

[0045] The rotor 71 is formed with a motor through-hole 602, and is therefore formed in an annular shape as a whole. The inner peripheral surface of the rotor 71 forms the motor through-hole 602. The motor through-hole 602 penetrates the center of the rotor 71 in the axial direction AD. The motor through-hole 602 is provided at a position spaced apart from the rotor magnet 72 on the inner peripheral side. The motor through-hole 602 penetrates the rotor-facing wall 74 in the axial direction AD.

[0046] The motor 60 has a rotor outer peripheral wall 76. The rotor outer peripheral wall 76 connects the first rotor 71A and the second rotor 71B. For example, the rotor outer peripheral wall 76 connects the rotor facing wall 74 of the first rotor 71A and the rotor facing wall 74 of the second rotor 71B. The rotor outer peripheral wall 76 corresponds to a rotor connecting portion. The rotor outer peripheral wall 76 extends in a direction perpendicular to the radial direction RD. The rotor outer peripheral wall 76 extends annularly in the circumferential direction CD along the outer circumferential edge of the rotor facing wall 74. The rotor outer peripheral wall 76 extends in the axial direction AD so as to span between the first rotor 71A and the second rotor 71B. The rotor outer peripheral wall 76 is located at a position spaced from the stator 61 toward the outer periphery. The rotor outer peripheral wall 76 forms the outer circumferential surface of the motor 60.

[0047] The rotor outer peripheral wall 76 rotates together with the rotors 71A and 71B. The rotor outer peripheral wall 76 fixes the first rotor 71A and the second rotor 71B so that one of the first rotor 71A and the second rotor 71B does not rotate relative to the other. The rotor outer peripheral wall 76 is included in at least one of the first rotor 71A and the second rotor 71B. For example, the rotor outer peripheral wall 76 is included in the rotor support portion 73 of at least one of the first rotor 71A and the second rotor 71B. The rotor outer peripheral wall 76 is provided at a position spaced apart from the rotor magnet 72 on the outer periphery side.

[0048] The motor 60 has an external coupling part 75. The external coupling part 75 couples the rotor 71 to an external device for the motor 60. Examples of the external device include the propeller 20 and a gear device 100 (described later). For example, the external coupling part 75 couples the rotor 71 to the gear device 100, thereby indirectly coupling the rotor 71 to the propeller 20. By coupling the external coupling part 75 and the propeller 20, the motor 60 can rotate the propeller 20 together with the rotor 71. The propeller 20 and the gear device 100 are targets rotated by the rotor 71. The propeller 20 and the gear device 100 correspond to rotation targets. The external coupling part 75 corresponds to a target coupling part. Note that the external coupling part 75 may be connected directly to the propeller 20 without going through the gear device 100.

[0049] The external coupling portion 75 is provided on at least one of the first rotor 71A and the second rotor 71B. For example, the external coupling portion 75 is provided only on the first rotor 71A out of the first rotor 71A and the second rotor 71B. The external coupling portion 75 is provided on the rotor facing wall 74. For example, the external coupling portion 75 of the first rotor 71A extends in the axial direction AD from the rotor facing wall 74 toward the propeller 20. The external coupling portion 75 is formed in a cylindrical shape. The center line of the external coupling portion 75 coincides with the motor axis Cm. The external coupling portion 75 is provided at a position spaced from the motor through-hole 602, the stator inner circumferential wall 66, and the bearing 80 on the outer periphery, surrounding the motor through-hole 602, the stator inner circumferential wall 66, and the bearing 80 from the outer periphery. The motor 60 is a shaftless motor and does not have a shaft. In the motor 60, the external coupling portion 75 is provided on the rotor 71, thereby achieving a shaftless structure.

[0050] 2 and 3 , the motor 60 has a bearing 80. The bearing 80 supports the rotor 71 rotatably relative to the stator 61. The bearing 80 is fixed to both the stator 61 and the rotor 71. The bearing 80 is fixed to the stator support portion 63 and the rotor support portion 73. The stator support portion 63 supports the rotor 71 via the bearing 80.

[0051] The bearing 80 extends annularly in the circumferential direction CD. The bearing 80 is provided between the stator 61 and the rotor 71. The bearing 80 is provided between the stator support portion 63 and the rotor support portion 73. For example, the bearing 80 is provided between the stator inner circumferential wall 66 and the rotor-facing wall 74 in the radial direction RD. The bearing 80 is bridged between the stator inner circumferential wall 66 and the rotor-facing wall 74. The bearing 80 is provided on the outer circumferential side of the stator inner circumferential wall 66. The bearing 80 is fixed to the inner circumferential wall surface 66b. The bearing 80 is provided on the inner circumferential side of the rotor-facing wall 74. The bearing 80 is fixed to the inner circumferential end surface of the rotor-facing wall 74.

[0052] The bearing 80 is provided at a position spaced inward from the external coupling portion 75 and the rotor outer peripheral wall 76. The bearing 80 is provided between the stator inner peripheral wall 66 and the external coupling portion 75 and the rotor outer peripheral wall 76 in the radial direction RD. The bearing 80 is provided at a position between the stator inner peripheral wall 66 and the external coupling portion 75 and the rotor outer peripheral wall 76, closer to the stator inner peripheral wall 66 than the external coupling portion 75 and the rotor outer peripheral wall 76. For example, in the radial direction RD, the distance between the bearing 80 and the stator inner peripheral wall 66 is smaller than both the distance between the bearing 80 and the external coupling portion 75 and the distance between the bearing 80 and the rotor outer peripheral wall 76.

[0053] The bearing 80 is provided at a position spaced inward from the outer peripheral end of the rotor support portion 73. The outer peripheral end of the rotor support portion 73 is formed by the outer peripheral end of the rotor facing wall 74 and the outer peripheral wall outer surface 76a of the rotor outer peripheral wall 76. For example, the bearing 80 is provided at a position spaced inward from the outer peripheral wall outer surface 76a. The bearing 80 is provided between the outer peripheral end of the rotor support portion 73 and the stator inner peripheral wall 66, and is closer to the stator inner peripheral wall 66 than the outer peripheral end of the rotor support portion 73. For example, in the radial direction RD, the distance between the bearing 80 and the inner peripheral wall outer surface 66a of the stator inner peripheral wall 66 is smaller than the distance between the bearing 80 and the outer peripheral wall outer surface 76a of the rotor outer peripheral wall 76.

[0054] The rotor outer peripheral wall 76 has an outer peripheral wall outer surface 76a and an outer peripheral wall inner surface 76b. The outer peripheral wall outer surface 76a is the outer surface of the rotor outer peripheral wall 76. The outer peripheral wall outer surface 76a forms the outer peripheral surface of the rotor 71. The outer peripheral wall inner surface 76b is the inner surface of the rotor outer peripheral wall 76. The outer peripheral wall inner surface 76b is exposed to the motor space 601. At least a portion of the outer peripheral wall outer surface 76a and at least a portion of the outer peripheral wall inner surface 76b are included in the outer surface 73a of the rotor support portion 73. For example, the outer surface 73a of the rotor support portion 73 includes the entire outer peripheral wall outer surface 76a and the portion of the outer peripheral wall inner surface 76b exposed to the motor space 601.

[0055] The bearing 80 is located at a distance inward from the rotor magnet 72. The bearing 80 is provided between the stator inner peripheral wall 66 and the rotor magnet 72 in the radial direction RD. The bearing 80 is located at a distance inward from the stator coil 62. The bearing 80 is provided between the stator inner peripheral wall 66 and the stator coil 62 in the radial direction RD.

[0056] As shown in FIG. 4 , the bearing 80 has an outer ring 81, an inner ring 82, and rolling elements 83. The outer ring 81 and the inner ring 82 extend annularly in the circumferential direction CD. The outer ring 81 and the inner ring 82 are aligned in the radial direction RD. The outer ring 81 forms the outer peripheral surface of the bearing 80. The outer ring 81 is fixed to the rotor support portion 73. For example, the outer ring 81 is fixed to the inner peripheral end surface of the rotor-facing wall 74. The inner ring 82 forms the inner peripheral surface of the bearing 80. The inner ring 82 is fixed to the stator support portion 63. For example, the inner ring 82 is fixed to the inner peripheral wall inner surface 66b of the stator inner peripheral wall 66.

[0057] The rolling elements 83 are provided between the outer ring 81 and the inner ring 82. A plurality of the rolling elements 83 are arranged in the circumferential direction CD. In the bearing 80, the inner ring 82 rotates relative to the outer ring 81 due to the rolling of the rolling elements 83. In the motor 60, the rotor 71 rotates relative to the stator 61 due to the rolling of the rolling elements 83.

[0058] As shown in Fig. 2, the motor 60 has two bearings 80, a first bearing 80A and a second bearing 80B. The first bearing 80A is provided on the first rotor 71A. The first bearing 80A supports the first rotor 71A rotatably relative to the stator 61. The second bearing 80B is provided on the second rotor 71B. The second bearing 80B supports the second rotor 71B rotatably relative to the stator 61. The first bearing 80A and the second bearing 80B are aligned in the axial direction AD.

[0059] The motor 60 has a bearing cover 84. The bearing cover 84 is made of a resin material or the like and is flexible. For example, the bearing cover 84 is formed to include an elastic member that is elastically deformable. The bearing cover 84 is formed in a plate or sheet shape. The bearing cover 84 is provided to cover the bearing 80 from one side in the axial direction AD. The bearing cover 84 is provided to span between the stator support portion 63 and the rotor support portion 73 via the bearing 80. The bearing cover 84 is fixed to one of the stator support portion 63 and the rotor support portion 73 and is provided to be rotatable relative to one of the stator 61 and the rotor 71. Note that the bearing cover 84 is not shown in FIGS. 3 and 4 . The bearing 80 does not necessarily have to be provided with a bearing cover 84.

[0060] For example, the bearing cover 84 is provided so as to span between the end face of the stator inner circumferential wall 66 and the opposing wall outer surface 74a of the rotor opposing wall 74 via the bearing 80. The bearing cover 84 is fixed to the stator inner circumferential wall 66 and is provided so as to be rotatable relative to the rotor 71.

[0061] In the motor 60, the stator support portion 63, the rotor support portion 73, and the bearing 80 define a motor space 601. The stator support portion 63, the rotor support portion 73, and the bearing 80 separate the motor space 601 from the external space of the motor 60. The bearing cover 84 closes the gap between the outer ring 81 and the inner ring 82 of the bearing 80. The bearing cover 84 regulates ventilation of the motor space 601 with the external space. For example, the motor space 601 is defined by the stator inner peripheral wall 66, the rotor facing wall 74, the rotor outer peripheral wall 76, and the bearing 80. In addition to the stator coil 62 and the rotor magnet 72, the motor space 601 also houses the stator outer peripheral wall 64 and the stator interposition portion 65.

[0062] The inverter device 90 drives the motor 60. The inverter device 90 is sometimes referred to as a motor drive device or a power conversion device. The inverter device 90 has an inverter unit 91 and an inverter housing 92. The inverter housing 92 is a case and houses the inverter unit 91. The inverter unit 91 is housed in the internal space of the inverter housing 92.

[0063] The inverter unit 91 is driven to propel the eVTOL 10. The inverter unit 91 is driven by power from the battery 31. The inverter unit 91 drives the motor 60 by supplying power to the motor 60. The inverter unit 91 converts the power supplied to the motor 60. The inverter unit 91 is sometimes referred to as a motor drive unit or a power conversion unit.

[0064] The inverter device 90 has an inverter circuit and an inverter control unit. The inverter circuit is a circuit for converting power. The inverter circuit performs power conversion for each of the multiple phases. The inverter circuit converts DC power from the battery 31 into AC power and supplies the AC power to the motor 60. The inverter circuit is, for example, a DC-AC conversion circuit. For example, the inverter circuit has upper and lower arm circuits for the multiple phases.

[0065] The inverter control unit performs motor control to control the motor 60. The inverter control unit is communicably connected to the inverter circuit. The inverter control unit performs motor control by controlling the inverter circuit. The inverter control unit outputs a command signal to the inverter circuit. The inverter control unit is sometimes called a control circuit or a motor control unit.

[0066] The inverter unit 91 forms an inverter circuit, an inverter control unit, etc. The inverter unit 91 has a circuit board, switch components, etc. In the inverter unit 91, the inverter circuit and the inverter control unit are formed by mounting switch components on the circuit board, etc. The inverter unit 91 may also have capacitor components, filter components, etc.

[0067] The inverter device 90 is arranged next to the motor 60 in the axial direction AD. Like the motor 60, the inverter device 90 is formed in an annular shape overall. An inverter through hole 92a is formed in the inverter housing 92. The inverter through hole 92a penetrates the center of the inverter housing 92 in the axial direction AD. The inverter through hole 92a is open toward both one side and the other side in the axial direction AD. The inverter through hole 92a forms the inner circumferential surface of the inverter device 90. The inverter through hole 92a also forms a hollow portion of the inverter device 90. The inverter device 90 is disposed at a position where the inverter through hole 92a and the motor through hole 602 are aligned in the axial direction AD. The inner circumferential surfaces of the inverter through hole 92a and the motor through hole 602 are aligned in the axial direction AD.

[0068] The EPU 50 has a plurality of inverter devices 90. The plurality of inverter devices 90 include a first inverter device 90A and a second inverter device 90B. The first inverter device 90A and the second inverter device 90B are arranged side by side in the axial direction AD. For example, the motor 60 and the second inverter device 90B are arranged side by side in the axial direction AD with the first inverter device 90A interposed therebetween. The first inverter device 90A and the second inverter device 90B are fixed to each other with fasteners such as bolts.

[0069] In the motor 60, when the airflow FC flows in the axial direction AD so as to pass through the inverter through-hole 92a and the motor through-hole 602, the inverter device 90 and the motor 60 are likely to be cooled by the airflow FC. The airflow FC is a flow of gas such as outside air. The airflow FC is sometimes referred to as an airflow. In the motor 60, heat from the stator coil 62 and the rotor magnet 72 is likely to be released into the airflow FC in the motor through-hole 602 via the stator inner circumferential wall 66, etc. In the inverter device 90, heat from the inverter unit 91 is likely to be released into the airflow FC in the inverter through-hole 92a.

[0070] The motor 60 is connected to the inverter device 90 by a mechanical and electrical connecting portion 95. For example, the motor 60 is connected to the first inverter device 90A by the mechanical and electrical connecting portion 95. The mechanical and electrical connecting portion 95 connects the inverter housing 92 and the stator 61. For example, the mechanical and electrical connecting portion 95 is fixed to the stator inner circumferential wall 66. The mechanical and electrical connecting portion 95 is provided between the inverter housing 92 and the stator inner circumferential wall 66. The mechanical and electrical connecting portion 95 is formed by including fasteners such as bolts, spacers, and the like. The mechanical and electrical connecting portion 95 is included in the EPU 50. In the EPU 50, the mechanical and electrical integration of the inverter device 90 and the motor 60 is achieved by the mechanical and electrical connecting portion 95. Furthermore, even if a housingless structure is adopted for the motor 60, the mechanical and electrical integration is achieved by fixing the mechanical and electrical connecting portion 95 to the stator support portion 63.

[0071] In the EPU 50, the inverter unit 91 and the motor 60 are electrically connected by a motor terminal block 67, an inverter terminal block 93, and an electromechanical bus bar 94. The terminal blocks 67, 93, and the electromechanical bus bar 94 form at least a part of an output path. The output path is a path through which current flows that is output from the inverter unit 91 to the motor 60. The inverter unit 91 supplies power to the motor 60 via the output path.

[0072] The motor terminal block 67 is included in the motor 60. The motor terminal block 67 is provided on the rotor support portion 73. The motor terminal block 67 is provided on the outside of the motor 60. For example, the motor terminal block 67 is provided in the motor through-hole 602 and fixed to the inner circumferential wall outer surface 66a. The motor terminal block 67 is electrically connected to the stator coil 62. The inverter terminal block 93 is included in the inverter device 90. The inverter terminal block 93 is housed in the inverter housing 92. The inverter terminal block 93 is electrically connected to the inverter circuit of the inverter unit 91. Note that the inverter terminal block 93 may be fixed to the outer surface of the inverter housing 92.

[0073] The electromechanical bus bar 94 is connected to each of the motor terminal block 67 and the inverter terminal block 93. The electromechanical bus bar 94 is formed including a conductive bus bar member. The electromechanical bus bar 94 is capable of supplying power from the inverter unit 91 to the motor 60. The electromechanical bus bar 94 is bridged between the motor terminal block 67 and the inverter terminal block 93 so as to avoid at least one bearing 80. For example, the electromechanical bus bar 94 is bridged between the motor terminal block 67 and the inverter terminal block 93 while making a detour to pass through the inner circumferential side of the second bearing 80B. The electromechanical bus bar 94 straddles the bearing 80 in the axial direction AD on the inner circumferential side of the bearing 80. At least a portion of the electromechanical bus bar 94 is provided in the inverter through hole 92a and the motor through hole 602.

[0074] The motor 60 has a gear device 100. The gear device 100 mechanically connects the motor 60 and the propeller 20. The gear device 100 transmits the drive of the motor 60 to the propeller 20. The gear device 100 is provided between the motor 60 and the propeller 20 in the axial direction AD. The gear device 100 is sometimes referred to as a gear box. The gear device 100 has a gear 101 and a gear shaft 102. The gear 101 is formed to include a reducer. The gear shaft 102 extends from the gear 101 in the axial direction AD. For example, the gear shaft 102 connects the gear 101 and the propeller 20.

[0075] According to the present embodiment described so far, the bearing 80 is fixed to each of the stator support portion 63 and the rotor support portion 73, and supports the rotor 71 rotatably relative to the stator 61. This configuration increases the degree of freedom regarding the positional relationship between the stator coil 62 and the rotor magnet 72 and the bearing 80. Therefore, by arranging the bearing in a position in the rotor support portion 73 where the portion between the rotor magnet 72 and the bearing 80 is less likely to deform, it is possible to prevent the rotor 71 from being deformed in the axial direction AD.

[0076] Furthermore, a portion of the stator 61 is provided on the inner circumferential side of the rotor 71. In the stator 61, at least the stator inner circumferential wall 66 is provided on the inner circumferential side of the rotor 71. In this configuration, by disposing the bearing 80 on the stator 61 side in the radial direction RD, it is possible to reduce the size of the bearing 80 in the radial direction RD. This makes it possible to suppress deformation such as bending of the bearing 80. Furthermore, by realizing a reduction in the size of the bearing 80, it is possible to simplify the manufacture of the bearing 80 and reduce the friction surface of the bearing 80, thereby reducing loss and noise.

[0077] In an axial gap motor 60, the stator 61 and rotor 71 tend to be flattened in the axial direction AD. Therefore, unlike the present embodiment, if the motor 60 has a shaft, structural components such as the rotor magnet 72 in the rotor 71 that connect the magnetic circuit to the shaft tend to be heavy. This effect is even more pronounced in a double-rotor motor 60, potentially undermining the advantages of a double axial gap motor, which can easily generate high torque. Furthermore, the rotor 71 is prone to deformation due to the attractive force between the stator coil 62 and the rotor magnet 72. The attractive force between the stator coil 62 and the rotor magnet 72 is sometimes referred to as an attractive force. Examples of this attractive force include a force generated by the magnetic force of the rotor magnet 72. When an attractive force is generated, it is thought that, for example, the portion of the rotor support portion 73 between the bearing 80 and the rotor magnet 72 is prone to deformation.

[0078] In contrast, in this embodiment, it is possible to position the bearing 80 as close as possible to the rotor magnet 72 on the rotor 71. With this configuration, the area between the bearing 80 and the rotor magnet 72 on the rotor support portion 73 can be made as small as possible. For example, the distance between the bearing 80 and the rotor magnet 72 on the rotor support portion 73 can be made as short as possible. This makes it possible to prevent deformation of the area between the bearing 80 and the rotor magnet 72 on the rotor support portion 73.

[0079] In the motor 60, to prevent deformation of the rotor 71 due to the suction force, it becomes necessary to provide the rotor 71 with a robust structure and support members capable of resisting the suction force. However, providing the rotor 71 with a robust structure and support members is thought to lead to an increase in the weight of the rotor 71 and the motor 60. In contrast, in this embodiment, by fixing the bearing 80 to the rotor 71, deformation of the rotor 71 can be suppressed. Therefore, it is not necessary to provide the rotor 71 with a robust structure and support members, and the weight of the rotor 71 and the motor 60 can be reduced.

[0080] In this embodiment, since it is possible to arrange the bearing 80 as close as possible to the rotor magnet 72, it is possible to reduce misalignment of the stator 61 and the rotor 71 relative to the bearing 80, thereby reducing misalignment of the stator coil 62 relative to the rotor magnet 72. This makes it easier to manage the axial gap. Furthermore, since it is easy to manage the relative positions of the stator 61 and the rotor 71 relative to the bearing 80 and the relative position of the stator coil 62 relative to the rotor magnet 72 together, it is possible to simplify the work of assembling the rotor 71 to the stator 61.

[0081] In this embodiment, the bearing 80 is fixed to the inner periphery of the rotor support portion 73. In this configuration, the stator support portion 63 is connected to the inner periphery of the rotor 71 via the bearing 80. Therefore, the stator support portion 63 can position the two rotors 71 in the axial direction AD and counter the magnetic attraction force that attracts the rotor magnet 72 and the coil 62 to each other in the axial direction AD. Therefore, it is possible to both suppress deformation of the rotor 71 and facilitate gap management.

[0082] An air-cooled motor 60 is generally cooled by air flowing around its outer periphery. For this reason, a configuration different from that of the present embodiment is assumed in which the bearing 80 is located between the shaft and the rotor 71. In this configuration, when the inverter device 90 is connected to the motor 60, a portion of the bearing 80 is sandwiched between the inverter device 90 and the motor 60 near the shaft, which may make it difficult for the bearing 80 to be cooled. In this case, the cooling performance of the motor 60 as a whole is impaired.

[0083] In contrast, in this embodiment, the bearing 80 can be disposed close to the inner circumferential wall outer surface 66a of the stator inner circumferential wall 66, which functions as a heat dissipation surface in the motor 60, thereby improving the heat dissipation properties of the bearing 80. Furthermore, the provision of the external coupling portion 75 on the rotor 71 makes it possible to achieve a housingless structure and a shaftless structure. Furthermore, by achieving a housingless structure and a shaftless structure, it is possible to create a motor space 601, which is a hollow portion, inside the motor 60, which increases the heat dissipation surface and improves the heat dissipation properties of the entire motor 60.

[0084] In this embodiment, the bearing 80 separates the stator coil 62 and the rotor magnet 72 from the external space. This allows the motor 60 to have a housingless structure. With a housingless structure, the stator core and rotor core can be in direct contact with the external air. Therefore, the housingless structure can improve heat dissipation. For example, adopting a housingless structure for the motor 60 can reduce the weight and cost of the motor 60 and improve heat dissipation.

[0085] According to this embodiment, the bearing 80 is provided at a position away from the outer circumferential end of the rotor support portion 73 toward the inner circumferential side. With this configuration, the bearing 80 can be disposed as close to the inner circumferential side of the motor 60 as possible. This allows the bearing 80 to be made smaller in size in the radial direction RD.

[0086] According to this embodiment, the bearing 80 is provided in a position close to the stator inner circumferential wall 66 in the radial direction RD, between the outer circumferential end of the rotor support portion 73 and the stator inner circumferential wall 66. This configuration makes it possible to reduce the size of the bearing 80 in the radial direction RD. Furthermore, this configuration makes it possible to easily dissipate heat from the bearing 80 to the outside via the stator inner circumferential wall 66.

[0087] According to this embodiment, the bearing 80 is provided at a position away from the external coupling portion 75 toward the inner circumferential side. In this configuration, the bearing 80 can be disposed as close as possible to the stator inner circumferential wall 66. This makes it possible to realize a configuration in which heat from the bearing 80 can be easily released to the outside from the stator inner circumferential wall 66, etc. Therefore, even if the bearing 80 is disposed near the boundary between the motor 60 and the inverter device 90, it is possible to prevent heat from building up in the bearing 80.

[0088] According to this embodiment, the bearing 80 is provided at a position closer to the stator inner circumferential wall 66 in the radial direction RD than the external coupling portion 75. This configuration makes it possible to realize a configuration in which heat from the bearing 80 is less likely to be transmitted to the external coupling portion 75 and is more likely to be transmitted to the stator inner circumferential wall 66. This makes it possible to prevent heat from the bearing 80 and the like from being trapped in the external coupling portion 75.

[0089] According to this embodiment, the stator inner circumferential wall 66 forms a motor through-hole 602 that penetrates the stator 61 and the rotor 71 in the axial direction AD and is open in the axial direction AD. With this configuration, heat from the stator coil 62, the rotor magnet 72, and the bearing 80 is easily dissipated from the stator inner circumferential wall 66 to the motor through-hole 602 due to, for example, the airflow FC flowing through the motor through-hole 602. This prevents heat from building up in the stator inner circumferential wall 66. In this way, the motor 60 has a hollow structure realized by the stator inner circumferential wall 66, which improves heat dissipation on the inner circumferential side, including the bearing 80. As a result, the heat dissipation performance of the entire motor 60 can be improved.

[0090] In this embodiment, the inverter device 90 is formed in a circular ring shape with a hollow portion. This makes it possible to realize a configuration in which the inverter device 90 does not block the motor through-hole 602 of the motor 60. That is, it is possible to realize a configuration in which the inverter device 90 and the motor 60 are connected so that the inverter through-hole 92a and the motor through-hole 602 are aligned in the axial direction AD. This makes it possible to prevent the inverter device 90 from impairing the heat dissipation properties of the motor 60 that are improved by the motor through-hole 602.

[0091] According to this embodiment, the external coupling part 75, which is connected to the propeller 20, is provided on the rotor support part 73 so as to rotate together with the rotor support part 73. In this configuration, the rotor 71 can be connected to the propeller 20 by the external coupling part 75 without using a shaft. Therefore, the weight of the motor 60 can be reduced by the amount that there is no need to provide a shaft for the motor 60. In addition, heat from the motor 60 can be prevented from being trapped in the shaft.

[0092] In the motor 60, the external coupling part 75, which is coupled to a rotating object such as the propeller 20, is provided on the rotor support part 73, so that it is not necessary to provide a member, such as the rotor magnet 72, that couples the magnetic circuit and the shaft near the motor axis Cm. This is advantageous not only in terms of weight reduction but also in terms of heat dissipation.

[0093] According to this embodiment, the bearing 80 is provided on the inner circumferential side of the rotor magnet 72. In this configuration, even if heat from the rotor magnet 72 is transferred to the bearing 80, this heat is likely to be released from the bearing 80 to the outside via the stator inner circumferential wall 66 or the like. Therefore, even if the bearing 80 and the rotor magnet 72 are disposed near the boundary between the motor 60 and the inverter device 90, it is possible to prevent heat from being trapped in the bearing 80 and the rotor magnet 72.

[0094] According to this embodiment, the rotor outer peripheral wall 76 connecting the first rotor 71A and the second rotor 71B is provided at a position radially outwardly spaced from the bearings 80A, 80B. In this configuration, the portions of the rotors 71A, 71B radially outwardly spaced from the bearings 80A, 80B are supported by the rotor outer peripheral wall 76. Therefore, the rotor outer peripheral wall 76 can prevent deformation of the portions of the rotors 71A, 71B radially outwardly spaced from the bearings 80A, 80B.

[0095] Furthermore, in this configuration, the rotor outer peripheral wall 76 is disposed on the outer peripheral side of the stator 61, thereby forming the outer peripheral surface of the motor 60. As a result, the heat from the stator coil 62 and the rotor magnet 72 is dissipated to the outside from the rotor outer peripheral wall 76 by, for example, the airflow FC flowing along the rotor outer peripheral wall 76. Therefore, the heat dissipation effect of the motor 60 can be improved by the rotor outer peripheral wall 76. For example, because the rotor outer peripheral wall 76 is exposed to the outside air, a relative speed is generated between the outside air and the rotor 71 due to the rotation of the rotor 71, even without air blowing by an air-cooling fan, thereby achieving excellent heat dissipation performance.

[0096] In this embodiment, in rotors 71A, 71B, the inner periphery of rotor support portion 73 is supported by bearings 80A, 80B, and the outer periphery of rotor support portion 73 is supported by rotor outer periphery wall 76. This makes it possible to realize a robust double-rotor structure with excellent heat dissipation properties.

[0097] According to this embodiment, the stator support portion 63, the rotor support portion 73, and the bearing 80 define the motor space 601. This configuration can prevent gas such as outside air from flowing into the motor space 601 of the motor 60. Therefore, in the housingless motor 60, it is possible to prevent foreign matter such as water droplets from flowing into the motor space 601 and adhering to the stator coil 62 or rotor magnet 72, which could cause an abnormality in the motor 60.

[0098] Second Embodiment In the first embodiment, the motor terminal block 67 is provided on the outside of the motor 60. In contrast, in the second embodiment, the motor terminal block 67 may be provided on the inside of the motor 60. Configurations, actions, and effects that are not particularly described in the second embodiment are the same as those in the second embodiment. The second embodiment will be described mainly focusing on the differences from the second embodiment.

[0099] As shown in Fig. 5, the stator support portion 63 has a stator extension wall 68. The stator extension wall 68 extends radially outward from the stator inner peripheral wall 66. The stator extension wall 68 is provided in a position aligned with the rotor support portion 73 in the radial direction RD. A bearing 80 is provided between the stator extension wall 68 and the rotor-facing wall 74. The bearing 80 is fixed to both the stator extension wall 68 and the rotor-facing wall 74. The bearing 80 supports the rotor-facing wall 74 rotatably relative to the stator extension wall 68.

[0100] The motor terminal block 67 is accommodated in the motor space 601. For example, the motor terminal block 67 is fixed to the inner surface 66b of the stator inner wall 66. The electromechanical bus bar 94 is disposed between the motor terminal block 67 and the inverter terminal block 93, penetrating the stator extension wall 68 and the inverter housing 92. The electromechanical bus bar 94 is disposed so as to pass through the inner periphery of the bearing 80, as in the first embodiment.

[0101] <Third Embodiment> In a third embodiment, a heat dissipation promoting portion that promotes heat dissipation of the motor 60 may be provided on at least one of the stator 61 and the rotor 71. Configurations, actions, and effects that are not specifically described in the third embodiment are the same as those in the first embodiment. In the third embodiment, differences from the first embodiment will be mainly described.

[0102] In this embodiment, the stator 61 is provided with a heat dissipation promoting portion that promotes heat dissipation from the stator 61. As shown in FIG. 6 , the stator 61 has a stator promoting portion 110 as the heat dissipation promoting portion. The stator promoting portion 110 is provided on the stator support portion 63 so as to promote heat dissipation from the stator 61. The stator promoting portion 110 is provided on the stator inner peripheral wall 66, the stator outer peripheral wall 64, or the like. The stator promoting portion 110 releases heat from the stator 61 into a gas such as the outside air. In the EPU 50, the stator promoting portion 110 forms an air-cooled motor 60.

[0103] The stator promotion portion 110 has stator outer fins 111. The stator outer fins 111 are convex portions provided on the outer surface 63a of the stator support portion 63. The stator outer fins 111 are heat dissipation fins. The stator outer fins 111 are included in the stator support portion 63. The stator outer fins 111 dissipate heat from the stator support portion 63 to the outside of the stator 61. In the stator support portion 63, the multiple stator outer fins 111 form unevenness on the outer surface 63a.

[0104] The stator external fins 111 are provided on the outside of the motor 60. For example, the stator external fins 111 are provided on the inner circumferential wall outer surface 66a of the stator inner circumferential wall 66. The stator external fins 111 extend from the inner circumferential wall outer surface 66a toward the inner circumferential side. The stator external fins 111 are provided in the motor through-hole 602. The stator external fins 111 extend in a direction perpendicular to the circumferential direction CD. Multiple stator external fins 111 are arranged in the circumferential direction CD along the inner circumferential wall outer surface 66a. The stator external fins 111 dissipate heat from the stator inner circumferential wall 66 to the airflow FC of the motor through-hole 602, for example.

[0105] According to this embodiment, the stator facilitating portion 110 promotes heat dissipation from the stator 61 by the stator outer fins 111. In the stator support portion 63, the stator outer fins 111 form irregularities on the inner circumferential wall outer surface 66a, thereby increasing the surface area of ​​the stator support portion 63. Therefore, the stator outer fins 111 can enhance the heat dissipation effect of the stator support portion 63.

[0106] In the present embodiment, as a modified example 3-1, as shown in FIG. 7 , the stator promotion portion 110 may have stator internal fins 112. The stator promotion portion 110 may have at least one of stator external fins 111 and stator internal fins 112. Like the stator external fins 111, the stator internal fins 112 are convex portions provided on the outer surface 63a of the stator support portion 63. The stator internal fins 112 are heat dissipation fins. The stator internal fins 112 are included in the stator support portion 63. The stator internal fins 112 dissipate heat from the stator support portion 63 to the outside of the stator 61. In the stator support portion 63, the multiple stator internal fins 112 form unevenness on the outer surface 63a.

[0107] The stator outer peripheral wall 64 has an outer peripheral wall outer surface 64a and an outer peripheral wall inner surface 64b. The outer peripheral wall outer surface 64a is the outer surface of the stator outer peripheral wall 64. The outer peripheral wall outer surface 64a forms the outer peripheral surface of the stator 61. The outer peripheral wall inner surface 64b is the inner surface of the stator outer peripheral wall 64. The stator interposition portion 65 is in close contact with at least a portion of the outer peripheral wall inner surface 64b. At least a portion of the outer peripheral wall outer surface 64a and at least a portion of the outer peripheral wall inner surface 64b are included in the outer surface 63a of the stator support portion 63. For example, the outer surface 63a of the stator support portion 63 includes the entire outer peripheral wall outer surface 64a and a portion of the outer peripheral wall inner surface 64b that is exposed to the motor space 601.

[0108] The stator inner fins 112 are provided inside the motor 60. That is, the stator inner fins 112 are provided in the motor space 601. The stator inner fins 112 are provided on the outer peripheral wall outer surface 64a. The stator inner fins 112 extend from the outer peripheral wall outer surface 64a toward the outer periphery. The stator inner fins 112 extend in a direction perpendicular to the circumferential direction CD. Multiple stator inner fins 112 are arranged in the circumferential direction CD along the outer peripheral wall outer surface 64a. The stator inner fins 112 release heat from the stator outer peripheral wall 64 to the air in the motor space 601, etc.

[0109] In the present embodiment, as a modified example 3-2, as shown in FIG. 8 , the stator promotion portion 110 may have a stator groove 113. The stator groove 113 is a recessed portion provided on the outer surface 63a of the stator support portion 63. The stator promotion portion 110 may have at least one of a protrusion and a recessed portion provided on the outer surface 63a. The stator groove 113 is a heat dissipation groove capable of dissipating heat. The stator groove 113 is included in the stator support portion 63. The stator groove 113 dissipates heat from the stator support portion 63 to the outside of the stator 61. In the stator support portion 63, the multiple stator grooves 113 form unevenness on the outer surface 63a. In the stator support portion 63, the stator grooves 113 increase the surface area, which tends to improve the heat dissipation effect.

[0110] The stator grooves 113 may be provided on the inner circumferential wall outer surface 66a, the inner circumferential wall inner surface 66b, the outer circumferential wall outer surface 64a, or the outer circumferential wall inner surface 64b. For example, the stator grooves 113 are provided on the inner circumferential wall outer surface 66a. The stator grooves 113 extend in a groove-like shape in the circumferential direction CD along the outer circumferential wall outer surface 64a. A plurality of the stator grooves 113 are arranged in the axial direction AD along the outer circumferential wall outer surface 64a. The stator grooves 113 dissipate heat from the stator outer circumferential wall 64 to the airflow FC of the motor through-hole 602, for example.

[0111] In the present embodiment, the stator facilitating portion 110 may be provided in the stator interposition portion 65. For example, the stator facilitating portion 110 may be provided in at least one of the stator outer peripheral wall 64, the stator interposition portion 65, and the stator inner peripheral wall 66.

[0112] <Fourth Embodiment> In the third embodiment, the stator 61 is provided with a heat dissipation promotion portion that promotes heat dissipation from the stator 61. In contrast to this, in a fourth embodiment, the rotor 71 may be provided with a heat dissipation promotion portion that promotes heat dissipation from the rotor 71. Configurations, actions, and effects that are not particularly described in the fourth embodiment are the same as those in the first embodiment. The fourth embodiment will be described mainly focusing on differences from the first embodiment.

[0113] As shown in Fig. 9, the rotor 71 has a rotor acceleration portion 120 as a heat dissipation acceleration portion. The rotor acceleration portion 120 is provided on the rotor support portion 73 to accelerate heat dissipation from the rotor 71. The rotor acceleration portion 120 is provided on the rotor outer peripheral wall 76 or the like. The rotor acceleration portion 120 releases heat from the rotor 71 into a gas such as the outside air. In the EPU 50, the rotor acceleration portion 120 constitutes an air-cooled motor 60.

[0114] The rotor accelerating portion 120 has rotor external fins 121 and rotor internal fins 122. The rotor external fins 121 and rotor internal fins 122 are convex portions provided on the outer surface 73a of the rotor support portion 73. The rotor external fins 121 and rotor internal fins 122 are heat dissipation fins. The rotor external fins 121 and rotor internal fins 122 are included in the rotor support portion 73. The rotor external fins 121 and rotor internal fins 122 dissipate heat from the rotor support portion 73 to the outside of the rotor 71. In the rotor support portion 73, the multiple rotor external fins 121 and multiple rotor internal fins 122 form unevenness on the outer surface 73a.

[0115] The rotor external fins 121 are provided on the outside of the motor 60. For example, the rotor external fins 121 are provided on the outer peripheral wall outer surface 76a. The rotor external fins 121 extend from the outer peripheral wall outer surface 76a toward the outer periphery. The rotor external fins 121 extend in a direction perpendicular to the circumferential direction CD. Multiple rotor external fins 121 are arranged in the circumferential direction CD along the outer peripheral wall outer surface 76a. The rotor external fins 121 release heat from the rotor outer peripheral wall 76 to the airflow FC that flows along the rotor external fins 121, for example.

[0116] The internal-rotor fins 122 are provided inside the motor 60. That is, the internal-rotor fins 122 are provided in the motor space 601. For example, the internal-rotor fins 122 are provided on the outer peripheral wall inner surface 76b. The internal-rotor fins 122 extend from the outer peripheral wall inner surface 76b toward the inner circumferential side. The internal-rotor fins 122 extend in a direction perpendicular to the circumferential direction CD. A plurality of the internal-rotor fins 122 are arranged in the circumferential direction CD along the outer peripheral wall inner surface 76b.

[0117] The rotor accelerating portion 120 is capable of blowing air in association with the rotation of the rotor 71. The rotor accelerating portion 120 forms an air blowing mechanism. The rotor outer fins 121 are capable of generating an airflow FC in association with the rotation of the rotor 71. The rotor outer fins 121 are provided on the rotor support portion 73 so as to generate the airflow FC in association with the rotation of the rotor 71. The rotor inner fins 122 are provided on the rotor support portion 73 so as to agitate air and generate an airflow in the motor space 601.

[0118] According to this embodiment, the rotor accelerating portion 120 promotes heat dissipation from the rotor 71 by the rotor outer fins 121 and the rotor internal fins 122. In the rotor support portion 73, the rotor outer fins 121 and the rotor internal fins 122 form irregularities on the outer peripheral wall outer surface 64a and the inner peripheral wall surface 64b, respectively, thereby making it possible to maximize the surface area of ​​the rotor support portion 73. Therefore, the rotor outer fins 121 and the rotor internal fins 122 can enhance the heat dissipation effect of the rotor support portion 73.

[0119] In the present embodiment, as Modification 4-1, as shown in FIG. 10 , the rotor accelerating portion 120 may be provided on the rotor opposing wall 74. For example, the rotor external fins 121 are provided on the opposing wall outer surface 74a. The rotor external fins 121 extend from the opposing wall outer surface 74a in the axial direction AD. A plurality of the rotor external fins 121 are arranged in the circumferential direction CD along the opposing wall outer surface 74a. At least a portion of the rotor external fins 121 are provided in a position aligned with the rotor magnet 72 in the axial direction AD. The rotor external fins 121 may be provided on at least one of the outer peripheral wall outer surface 76a and the opposing wall outer surface 74a.

[0120] The intra-rotor fins 122 are provided on the opposing wall inner surface 74b. The intra-rotor fins 122 extend from the opposing wall inner surface 74b in the axial direction AD. A plurality of the intra-rotor fins 122 are arranged in the circumferential direction CD along the opposing wall inner surface 74b. The intra-rotor fins 122 are provided on at least one of the outer circumferential side and the inner circumferential side of the rotor magnet 72. For example, the intra-rotor fins 122 are provided between the rotor magnet 72 and the rotor outer circumferential wall 76. Note that the intra-rotor fins 122 may be provided on at least one of the outer circumferential wall inner surface 76b and the opposing wall inner surface 74b.

[0121] The rotor external fins 121 and the rotor internal fins 122 can function as ribs on the rotor facing wall 74. Therefore, the rotor external fins 121 and the rotor internal fins 122 suppress deformation of the rotor facing wall 74 so that the rotor facing wall 74 is bent in the axial direction AD. In this way, the rotor facing wall 74 is reinforced by the rotor external fins 121 and the rotor internal fins 122, and this makes it possible to reduce the weight of the rotor facing wall 74.

[0122] In this embodiment, as Modification 4-2, as shown in FIGS. 11 and 12 , the rotor accelerating portion 120 may have rotor grooves 123. The rotor grooves 123 are recesses provided on the outer surface 73a of the rotor support portion 73. The rotor accelerating portion 120 may have at least one of a protrusion and a recess provided on the outer surface 73a. The rotor grooves 123 are heat dissipation grooves capable of dissipating heat. The rotor grooves 123 are included in the rotor support portion 73. The rotor grooves 123 dissipate heat from the rotor support portion 73 to the outside of the rotor 71. In the rotor support portion 73, the multiple rotor grooves 123 form unevenness on the outer surface 73a. In the rotor support portion 73, the rotor grooves 123 increase the surface area, which tends to improve the heat dissipation effect.

[0123] The rotor grooves 123 may be provided in the outer peripheral wall outer surface 76a, the outer peripheral wall inner surface 76b, the opposing wall outer surface 74a, or the opposing wall inner surface 74b. For example, the rotor grooves 123 are provided in the opposing wall outer surface 74a. The rotor grooves 123 extend in a groove-like shape in the circumferential direction CD along the opposing wall outer surface 74a. A plurality of the rotor grooves 123 are arranged in the radial direction RD along the opposing wall outer surface 74a. The rotor grooves 123 dissipate heat from the rotor opposing wall 74 to the outside of the motor 60.

[0124] The rotor grooves 123 are formed to allow airflow FC to flow in the radial direction RD and the circumferential direction CD as the rotor 71 rotates. In the motor 60, air may be actively circulated in the axial direction AD or the circumferential direction CD, but airflow is generated by the rotation of the rotor 71 even without such measures. Therefore, as in this modified example, simply providing the rotor grooves 123 parallel to the rotation direction of the rotor 71 can promote heat dissipation by the air generated by the rotation of the rotor 71 itself. This is also advantageous in terms of loss due to air resistance and noise.

[0125] The motor 60 may have at least one of the stator facilitating portion 110 and the rotor facilitating portion 120. For example, as shown in Fig. 11 , the motor 60 may be provided with both the stator groove 113 included in the stator facilitating portion 110 and the rotor groove 123 included in the rotor facilitating portion 120.

[0126] In this embodiment, the motor 60 may be provided with a blower fan that blows air in conjunction with the rotation of the rotor 71. Alternatively, the motor 60 may be provided with a blower fan that can blow air regardless of the rotation of the rotor 71. For example, the drive source of the blower fan may be an actuator separate from the motor 60.

[0127] Fifth Embodiment In a fifth embodiment, an accommodation vent hole that allows ventilation of an accommodation space such as the motor space 601 may be provided in at least one of the stator 61 and the rotor 71. Configurations, actions, and effects that are not specifically described in the fifth embodiment are the same as those in the first embodiment. The fifth embodiment will be described mainly focusing on differences from the first embodiment.

[0128] In this embodiment, the rotor 71 is provided with an accommodation vent. As shown in FIG. 13 , the rotor 71 is provided with rotor vents 125 as accommodation vents. The rotor vents 125 are provided so as to penetrate the rotor support portion 73. A plurality of rotor vents 125 are provided in the rotor support portion 73. The rotor vents 125 can ventilate the motor space 601. The rotor vents 125 open the motor space 601 to the outside of the motor 60. The rotor vents 125 are sometimes referred to as outside air introduction holes.

[0129] The rotor ventilation holes 125 have rotor-facing holes 127. The rotor-facing holes 127 are included in a plurality of rotor ventilation holes 125. For example, the rotor-facing holes 127 are provided in the rotor-facing wall 74 so as to penetrate the rotor-facing wall 74 in the axial direction AD. A plurality of the rotor-facing holes 127 are arranged in the circumferential direction CD and the radial direction RD.

[0130] The rotor-facing holes 127 are provided so that the airflow FC flows through the motor space 601 in the axial direction AD. The rotor-facing holes 127 are provided in each of the first rotor 71A and the second rotor 71B. The rotor-facing holes 127 of the first rotor 71A and the rotor-facing holes 127 of the second rotor 71B are provided in positions aligned in the axial direction AD. For example, the two rotor-facing holes 127 are aligned in the axial direction AD via the intra-stator fins 112 of the third embodiment. For example, the airflow FC flows into the motor space 601 through one of the two rotor-facing holes 127, flows along the intra-stator fins 112 in the axial direction AD, and then flows out of the motor 60 from the other. In the motor space 601, the intra-stator fins 112 tend to improve the cooling effect of the airflow FC on the stator 61.

[0131] The housing vent may be provided with a filter member such as a nonwoven fabric. In this configuration, the filter member prevents foreign matter such as dust from flowing into the motor space 601 along with the airflow FC from the housing vent. For example, the filter member may be fixed to the rotor opposing wall 74 so as to cover the rotor vent 125 from the opposing wall outer surface 74a side.

[0132] According to this embodiment, the rotor air vents 125 are provided to allow ventilation of the motor space 601 and penetrate the rotor support portion 73. In this configuration, airflow FC or the like flows through the motor space 601 through the rotor air vents 125, so that heat in the motor space 601 can be directly released to the outside together with the airflow FC from the rotor air vents 125. Therefore, the rotor air vents 125 can enhance the heat dissipation effect of the motor 60.

[0133] For example, unlike the present embodiment, in a configuration in which the motor 60 is not provided with housing vents such as the rotor vent 125, heat in the motor space 601 is indirectly released to the outside via the stator support portion 63 and the rotor support portion 73. This configuration is likely to be disadvantageous in terms of motor heat dissipation because the heat in the motor space 601 is indirectly released to the outside. In contrast, in the present embodiment, the rotor vent 125 is provided near the outer circumferential end of the stator coil 62 so that air such as the airflow FC flows, thereby improving the heat dissipation effect of the stator coil 62.

[0134] The rotor air vents 125 may be provided at positions aligned in the axial direction AD on the stator outer peripheral wall 64, the stator interposed portion 65, and the stator coil 62. For example, in a configuration in which the rotor air vents 125 are aligned in the axial direction AD on the stator coil 62, the airflow FC is more likely to impinge on the stator coil 62, thereby further enhancing the heat dissipation effect of the stator coil 62 in the motor space 601. Furthermore, the housing air vents such as the rotor air vents 125 may be provided so as to form a gyroid structure in the motor 60.

[0135] In the present embodiment, as a modified example 5-1, as shown in FIG. 14 , the rotor air vents 125 may have rotor outer peripheral holes 126. The rotor outer peripheral holes 126 are included in a plurality of rotor air vents 125. For example, the rotor outer peripheral holes 126 are provided so as to penetrate the rotor outer peripheral wall 76 in the radial direction RD. A plurality of the rotor outer peripheral holes 126 are arranged in the circumferential direction CD and the axial direction AD. The rotor outer peripheral holes 126 are provided at positions aligned with the stator coil 62, the rotor magnet 72, and the axial gap in the radial direction RD.

[0136] The rotor support portion 73 may be provided with at least one of a rotor-facing hole 127 and a rotor outer peripheral hole 126. For example, both the rotor-facing hole 127 and the rotor outer peripheral hole 126 may be provided. The rotor-facing hole 127 may be provided on the inner circumferential side of the rotor magnet 72. For example, the rotor-facing hole 127 is provided between the rotor magnet 72 and the bearing 80 in the radial direction RD. In this configuration, the airflow FC tends to flow into the motor space 601 from one of the rotor-facing hole 127 and the rotor outer peripheral hole 126 and flow out from the other. For example, when the rotor 71 is rotating, centrifugal force generated by the rotor 71 may cause the airflow FC to flow from the rotor-facing hole 127 into the motor space 601 and flow out from the rotor outer peripheral wall 76 toward the outer periphery.

[0137] In this modified example, it is preferable that the rotor accelerating portion 120 of the fourth embodiment is provided. The rotor accelerating portion 120 is provided so that the airflow FC can easily flow from the rotor-facing holes 127 into the motor space 601. For example, the rotor accelerating portion 120 is provided so as to guide the airflow FC along the facing-wall outer surface 74a to the rotor-facing holes 127. This makes it easier for the airflow FC to flow into the motor space 601 from the rotor-facing holes 127 of the first rotor 71A and the second rotor 71B.

[0138] Sixth Embodiment In the fifth embodiment, the rotor 71 is provided with an accommodation vent hole that allows ventilation of the accommodation space. In contrast, in the sixth embodiment, the accommodation vent hole is provided in the stator 61. The configurations, actions, and effects of the sixth embodiment that are not specifically described are the same as those of the first embodiment. The sixth embodiment will be described mainly focusing on the differences from the first embodiment.

[0139] 15 , the stator 61 is provided with stator air holes 115 as housing air holes. The stator air holes 115 are provided so as to penetrate the stator support portion 63. A plurality of the stator air holes 115 are provided in the stator support portion 63.

[0140] The stator air holes 115 have stator interposition holes 116. The stator interposition holes 116 are included in multiple stator air holes 115. The stator interposition holes 116 are provided in the stator interposition portion 65 so as to penetrate the stator interposition portion 65 in the axial direction AD. Multiple stator interposition portions 65 are arranged in the circumferential direction CD and the radial direction RD. For example, the stator interposition holes 116 are provided in the stator interposition portion 65 between the stator coil 62 and the stator inner circumferential wall 66.

[0141] The motor 60 may have at least one of a stator air hole 115 and a rotor air hole 125. In this embodiment, the motor 60 has both the stator air hole 115 and the rotor air hole 125. For example, a rotor-facing hole 127 is provided in the rotor-facing wall 74 as the rotor air hole 125. The rotor-facing hole 127 of the first rotor 71A and the rotor-facing hole 127 of the second rotor 71B are aligned in the axial direction AD via the stator interposition hole 116. For example, the airflow FC flows into the motor space 601 from one of the two rotor-facing holes 127, passes through the stator interposition hole 116 in the axial direction AD, and then flows out of the motor 60 from the other. In this case, the stator interposition hole 116 can prevent heat from building up in the stator interposition portion 65 between the stator coil 62 and the stator inner circumferential wall 66.

[0142] In this embodiment, as a modified example 6-1, as shown in FIG. 16 , the stator ventilation hole 115 may have a stator extension hole 117. As in the second embodiment, the stator support portion 63 has a stator extension wall 68. The stator extension hole 117 is provided so as to penetrate the stator extension hole 117 in the axial direction AD. The stator extension hole 117 can ventilate the motor space 601. The stator extension hole 117 opens the motor space 601 to the outside of the motor 60. The stator extension hole 117 is sometimes referred to as an outside air introduction hole.

[0143] The stator extension holes 117 are provided on the inner circumferential side of the rotor facing wall 74 and the bearing 80. The stator extension holes 117 are provided in the rotor facing wall 74 on the first rotor 71A side and the rotor facing wall 74 on the second rotor 71B side. The stator extension holes 117 on the first rotor 71A side and the stator extension holes 117 on the second rotor 71B side are aligned in the axial direction AD via the stator interposition holes 116. The airflow FC flows into the motor space 601 from one of the two stator extension holes 117, passes through the stator interposition hole 116, and then flows out of the motor 60 from the other.

[0144] According to this embodiment, the stator intervening holes 116 serving as the stator air vents 115 are provided to allow ventilation through the motor space 601 and penetrate the stator support portion 63. In this configuration, airflow FC or the like flows through the motor space 601 via the stator intervening holes 116, so that heat in the motor space 601 can be directly released to the outside together with the airflow FC from the stator intervening holes 116. Therefore, the stator intervening holes 116 can enhance the heat dissipation effect of the motor 60.

[0145] In the present embodiment, the stator air holes 115 may be provided in the stator inner peripheral wall 66 or the stator outer peripheral wall 64. For example, in a configuration in which the stator air holes 115 are provided in the stator inner peripheral wall 66, the motor space 601 and the motor through-hole 602 are in air-permeable communication with each other through the stator air holes 115.

[0146] Seventh Embodiment In the seventh embodiment, the motor 60 is connected to the machine body 11 by a connecting member. The configurations, actions, and effects of the seventh embodiment that are not specifically described are the same as those of the first embodiment. The seventh embodiment will be described mainly focusing on the differences from the first embodiment.

[0147] As shown in FIG. 17 , the motor 60 has a body coupling part 151. The body coupling part 151 couples the motor 60 to the body 11. The body coupling part 151 includes a coupling member. The body coupling part 151 is formed by including steel materials such as angle members and fasteners such as bolts. The body coupling part 151 is fixed to the stator 61. For example, the body coupling part 151 extends from the stator inner peripheral wall 66 toward the second rotor 71B side. The body coupling part 151 is provided on the opposite side of the motor 60 from the propeller 20. The body coupling part 151 is sometimes referred to as a rear mount.

[0148] The airframe 11 is formed with airframe vents 11a. The airframe vents 11a are provided in a position aligned in the axial direction AD in the outer peripheral space of the rotor outer peripheral wall 76. The airframe vents 11a are provided between the propeller 20 and the rotor outer peripheral wall 76 in the axial direction AD. Propeller wind generated by the rotation of the propeller 20 easily flows into the airframe vents 11a as an airflow FC. The airflow FC that flows into the airframe vents 11a easily flows along the rotor outer peripheral wall 76. This makes it easier for the airflow FC, including the propeller wind, to improve the heat dissipation effect of the rotor outer peripheral wall 76.

[0149] Eighth Embodiment In the first embodiment, the bearing 80 is provided between the stator support portion 63 and the rotor support portion 73 in the radial direction RD. In contrast, in the eighth embodiment, the bearing 80 may be provided between the stator support portion 63 and the rotor support portion 73 in the axial direction AD. Configurations, actions, and effects that are not particularly described in the eighth embodiment are the same as those in the first embodiment. The eighth embodiment will be described mainly focusing on differences from the first embodiment.

[0150] 18 , similar to the second embodiment, the stator support portion 63 has a stator extension wall 68. The stator extension wall 68 is provided on the opposite side of the stator coil 62 from the rotor-facing wall 74 in the axial direction AD. The stator extension wall 68 extends radially outward from the stator outer peripheral wall 64 to align with a portion of the rotor-facing wall 74 in the axial direction AD. A bearing 80 is provided between the stator extension wall 68 and the rotor-facing wall 74 in the axial direction AD. The bearing 80 is fixed to both the stator extension wall 68 and the rotor-facing wall 74, thereby supporting the rotor-facing wall 74 rotatably relative to the stator extension wall 68.

[0151] Ninth Embodiment In the first embodiment, a housingless structure is employed for the motor 60. In contrast, in the ninth embodiment, a housingless structure does not have to be employed for the motor 60. Configurations, actions, and effects that are not specifically described in the ninth embodiment are the same as those in the first embodiment. The ninth embodiment will be described mainly focusing on the differences from the first embodiment.

[0152] As shown in FIG. 19 , the motor 60 has a motor housing 141. The motor housing 141 is made of a metal material or the like and has thermal conductivity. The motor housing 141 accommodates the stator 61 and the rotor 71. The external coupling portion 75 is exposed to the outside of the motor housing 141 through a through hole formed in the motor housing 141. The motor 60 has a housing bearing 142. The housing bearing 142 rotatably supports the external coupling portion 75 relative to the motor housing 141. The housing bearing 142 is fixed to both the motor housing 141 and the external coupling portion 75. The housing bearing 142 is provided between the motor housing 141 and the external coupling portion 75. The housing bearing 142 is provided only on the first rotor 71A side of the first rotor 71A and the second rotor 71B.

[0153] In this embodiment, the rotor 71 is rotatably supported by the bearing 80 inside the motor housing 141, eliminating the need for multiple housing bearings 142. For example, if the housing bearing 142 can be provided on one of the first rotor 71A and the second rotor 71B, it is not necessary to provide one on the other. While providing the motor housing 141 has the disadvantages of requiring an additional housing bearing 142 and reducing heat dissipation, it eliminates the need for a sealed structure for the bearing 80, thereby reducing the contact surface between the fixed and rotating parts of the bearing 80. This has the effect of reducing frictional heat and suppressing a decrease in efficiency due to friction.

[0154] Tenth Embodiment In the first embodiment, a double-rotor motor is used as the motor 60. In contrast, in the tenth embodiment, a double-rotor motor does not have to be used as the motor 60. Configurations, actions, and effects that are not specifically described in the tenth embodiment are the same as those in the first embodiment. The tenth embodiment will be described mainly focusing on the differences from the first embodiment.

[0155] As shown in Figure 20, the motor 60 is a single-rotor motor. The motor 60 has only one rotor 71. In this embodiment, the stator 61 and the rotor 71 may have any configuration as long as one rotor 71 is rotatable relative to one stator 61. For example, the rotor 71 may or may not have a rotor outer peripheral wall 76.

[0156] Eleventh Embodiment In an eleventh embodiment, a plurality of motors 60 may be connected to one another. Configurations, actions, and effects not specifically described in the eleventh embodiment are the same as those in the first embodiment. The eleventh embodiment will be described mainly focusing on differences from the first embodiment.

[0157] 21 , the EPU 50 has a plurality of motors 60. For example, the EPU 50 has a first motor 60A and a second motor 60B. The first motor 60A and the second motor 60B are aligned in the axial direction AD. The first motor 60A is provided on the propeller 20 side in the axial direction AD. The first motor 60A has an external coupling portion 75, while the second motor 60B does not have an external coupling portion 75.

[0158] The stators 61 of the first motor 60A and the second motor 60B are connected by a first connecting portion 161, and the rotors 71 of the first motor 60A and the second motor 60B are connected by a second connecting portion 162. The connecting portions 161, 162 are provided between the first motor 60A and the second motor 60B in the axial direction AD. The first connecting portion 161 connects the stator support portion 63 of the first motor 60A to the stator support portion 63 of the second motor 60B. The second connecting portion 162 connects the rotor support portion 73 of the first motor 60A to the rotor support portion 73 of the second motor 60B. The connecting portions 161, 162 may be included in the EPU 50 or may be included in at least one of the first motor 60A and the second motor 60B.

[0159] The first connecting portion 161 connects the stator inner peripheral wall 66 of the first rotor 71A and the stator inner peripheral wall 66 of the second rotor 71B. The first connecting portion 161 has a shape and size corresponding to the shape and size of the stator inner peripheral wall 66. A through hole leading to the motor through hole 602 is formed in the first connecting portion 161. The through hole of the first connecting portion 161 airtightly connects the motor through hole 602 of the first motor 60A and the motor through hole 602 of the second motor 60B. The airflow FC flows into the motor through hole 602 of one of the first motor 60A and the second motor 60B, passes through the through hole of the first connecting portion 161, and easily flows out to the outside from the other motor through hole 602.

[0160] In this embodiment, as Modification 11-1, the first motor 60A and the second motor 60B may be directly connected without the first connecting portion 161 and the second connecting portion 162. As shown in FIG. 22 , the first motor 60A and the second motor 60B may share a single rotor 71. For example, the rotor-facing wall 74 of the second rotor 71B of the first motor 60A and the rotor-facing wall 74 of the first rotor 71A of the second motor 60B may be formed by a single rotor-facing wall 74. The rotor-facing wall 74 has a rotor magnet 72 for the first motor 60A provided on one plate surface and a rotor magnet 72 for the second motor 60B provided on the other plate surface. In this modification, the motor through-hole 602 of the first motor 60A and the motor through-hole 602 of the second motor 60B are also in air-communication with each other.

[0161] <Twelfth Embodiment> In the first embodiment, the external coupling portion 75 is formed in a cylindrical shape. In contrast, in the twelfth embodiment, the external coupling portion 75 does not have to be formed in a cylindrical shape. The configurations, actions, and effects of the twelfth embodiment that are not specifically described are the same as those of the first embodiment. The twelfth embodiment will be described mainly focusing on the differences from the first embodiment.

[0162] 23 , a plurality of external coupling portions 75 may be provided. For example, a plurality of external coupling portions 75 are arranged in the circumferential direction CD along the inner circumferential edge of the rotor-facing wall 74. The external coupling portions 75 are provided at positions spaced outward from the inner circumferential edge of the rotor-facing wall 74, the stator inner circumferential wall 66, and the bearing 80.

[0163] <Other Embodiments> The disclosure of this specification is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, and can be implemented in various modifications. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and elements from the embodiments. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0164] In each of the above embodiments, the stator 61 may not have the motor through-hole 602. That is, the stator inner circumferential wall 66 may not have the motor through-hole 602. For example, the stator inner circumferential wall 66 may be formed in a columnar shape. In a configuration in which the stator 61 does not have the motor through-hole 602, the motor 60 may not have the motor through-hole 602.

[0165] In each of the above embodiments, the bearing 80 may be provided in any position as long as it is fixed to each of the stator support portion 63 and the rotor support portion 73. The bearing 80 does not have to be provided on the inner circumferential side of the rotor magnet 72. For example, the bearing 80 may be provided on at least a portion of the rotor magnet 72 in a position aligned with the axial direction AD, or may be provided on the outer circumferential side of the rotor magnet 72. The bearing 80 does not have to be provided on the inner circumferential side of the external coupling portion 75. For example, the bearing 80 may be provided on at least a portion of the external coupling portion 75 in a position aligned with the axial direction AD, or may be provided on the outer circumferential side of the external coupling portion 75.

[0166] In each of the above embodiments, the first rotor 71A and the second rotor 71B may have different configurations. For example, the first rotor 71A and the second rotor 71B may have different sizes, shapes, etc. Furthermore, the first bearing 80A and the second bearing 80B may have different sizes, shapes, installation positions, etc. For example, the positional relationship between the rotor magnet 72 and the bearing 80 may be different between the first rotor 71A and the second rotor 71B.

[0167] In each of the above embodiments, the symmetrical connection portion, such as the external connection portion 75, may be provided in any position relative to the rotor magnet 72. For example, the symmetrical connection portion may be provided in a position aligned in the axial direction AD on at least a portion of the rotor magnet 72, may be provided on the inner circumferential side of the rotor magnet 72, or may be provided on the outer circumferential side of the rotor magnet 72.

[0168] In each of the above embodiments, the symmetrical coupling portion may be provided in any manner in the motor 60 as long as it can be coupled to a rotationally symmetrical object such as the propeller 20. For example, the external coupling portion 75 may or may not be included in the rotor support portion 73. The external coupling portion 75 may be manufactured as a separate part from the rotor support portion 73 and fixed to the rotor support portion 73 by a fastener, welding, or the like. Furthermore, the symmetrical coupling portion may be formed to include a protrusion, recess, hole, notch, or the like provided in the rotor support portion 73. For example, the external coupling portion 75 may be formed to include a bolt hole formed in the rotor-facing wall 74.

[0169] In each of the above embodiments, the symmetrical coupling portion may be formed by a shaft member. That is, the motor 60 does not need to have a shaftless structure. For example, a shaft member may be attached to the rotor 71. Even in this case, it is preferable that the bearing 80 be fixed to the rotor 71 rather than to the shaft member.

[0170] In each of the above embodiments, the motor 60 does not have to be an axial gap motor. For example, the motor 60 may be a radial gap motor. In a radial gap motor, the rotor and stator are aligned in the radial direction RD. Even in a radial gap motor, it is preferable that bearings are fixed to the rotor and stator, respectively, and support the rotor rotatably relative to the stator. For example, the bearing is provided between the stator support portion and the rotor support portion in the radial direction RD.

[0171] In each of the above embodiments, one propulsion device may have multiple EPUs 50. For example, one propulsion device may have multiple EPUs 50 arranged in the radial direction RD or the circumferential direction CD. The EPUs 50 may be provided at positions offset from the propeller 20 in the radial direction RD.

[0172] In each of the above embodiments, the vertical take-off and landing aircraft equipped with motor 60 may be an electrically powered vertical take-off and landing aircraft in which at least one EPU 50 drives at least one propeller 20. For example, a configuration in which one propeller 20 is driven by multiple EPUs 50, or a configuration in which one EPU 50 drives multiple propellers 20, may also be used.

[0173] In each of the above embodiments, the air vehicle equipped with motor 60 does not have to be a vertical take-off and landing aircraft as long as it is electrically powered. For example, the air vehicle may be an electric aircraft capable of take-off and landing with a taxiing motion. Furthermore, the air vehicle may be a rotary-wing aircraft or a fixed-wing aircraft. The air vehicle may also be an unmanned air vehicle with no crew on board. The unmanned air vehicle may or may not have a crew cabin 14. A pilot may also remotely operate the air vehicle. eVTOL 10 may be referred to as a manned air vehicle as long as it is capable of carrying a person.

[0174] In each of the above embodiments, the moving body on which the motor 60 is mounted does not have to be an aircraft, as long as it can move by rotation of a rotating body. For example, the moving body may be a vehicle, a ship, construction machinery, or agricultural machinery. For example, if the moving body is a vehicle, construction machinery, or the like, the rotating body is a wheel for movement, and the output shaft is an axle, or the like. If the moving body is a ship, the rotating body is a screw propeller for propulsion, and the output shaft is a propeller shaft, or the like. The moving body may also be an automated guided vehicle or an electric wheelchair. For example, an automated guided vehicle or an electric wheelchair is equipped with a relatively small motor 60.

[0175] In each of the above embodiments, the motor 60 does not have to be mounted on a moving object. For example, the motor 60 may be mounted on stationary equipment, machinery, or devices. In this way, the motor 60 is not limited to being mounted on a moving object, and can be used in drive devices for various applications.

[0176] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0177] (Technical Idea 1) A rotating electric machine (60) driven by a supply of electric power, comprising: a stator (61) having an energized stator coil (62) and a stator support portion (63) supporting the stator coil; a rotor (71) having rotor magnets (72) arranged on the stator coil in an axial direction (AD) of a rotation axis (Cm) and a rotor support portion (73) supporting the rotor magnet, the rotor (71) rotating around the rotation axis and arranged on the stator in the axial direction; and bearings (80) fixed to the stator support portion and the rotor support portion, respectively, and supporting the rotor rotatably relative to the stator, wherein a portion of the stator is provided on the inner peripheral side of the rotor.

[0178] (Technical Concept 2) The rotating electric machine according to Technical Concept 1, wherein the bearing is provided at a position spaced apart from the outer circumferential end of the rotor support portion toward the inner circumferential side.

[0179] (Technical Idea 3) A rotating electric machine according to Technical Idea 1 or 2, wherein the stator support portion has a stator inner wall (66) that is provided on the inner side of the stator coil and supports the stator coil, and the bearing is provided in a position between the outer peripheral end of the rotor support portion and the stator inner wall in the radial direction (RD) of the rotation axis, closer to the stator inner wall than the outer peripheral end.

[0180] (Technical Idea 4) A rotating electric machine according to any one of Technical Ideas 1 to 3, comprising an object connection part (75) provided on the rotor support part so as to rotate together with the rotor support part, and connected to a rotation object (20, 100) rotated by the rotor, and the bearing is provided at a position spaced apart from the object connection part on the inner periphery side.

[0181] (Technical Idea 5) A rotating electric machine according to Technical Idea 4, wherein the stator support portion has a stator inner wall (66) that is provided on the inner side of the stator coil and supports the stator coil, and the bearing is provided in a position between the symmetrical connection portion and the stator inner wall in the radial direction (RD) of the rotation axis, closer to the stator inner wall than the symmetrical connection portion.

[0182] (Technical Idea 6) The rotating electric machine according to Technical Idea 5, wherein the stator inner peripheral wall forms an inner peripheral air hole (602) that penetrates the stator and the rotor in the axial direction and is open in the axial direction.

[0183] (Technical Idea 7) A rotating electric machine according to any one of Technical Ideas 1 to 6, wherein the rotor has an axial coupling portion (75) that is provided on the rotor support portion so as to rotate together with the rotor support portion and is coupled to a rotational object (20, 100) that is rotated by the rotor.

[0184] (Technical Concept 8) The rotating electric machine according to any one of Technical Concepts 1 to 7, wherein the bearing is provided on the inner circumferential side of the rotor magnet.

[0185] (Technical Idea 9) A rotating electric machine according to any one of Technical Ideas 1 to 8, including a stator promotion portion (110) that has at least one of a protrusion (111, 112) and a recess (113) provided on an outer surface (63a) of the stator support portion and promotes heat dissipation of the stator.

[0186] (Technical Idea 10) A rotating electric machine according to any one of Technical Ideas 1 to 9, comprising a rotor promotion portion (120) having at least one of a convex portion (121, 122) and a concave portion (123) provided on an outer surface (73a) of the rotor support portion, and promoting heat dissipation of the rotor.

[0187] (Technical Idea 11) A rotating electric machine according to any one of Technical Ideas 1 to 10, comprising: a first rotor (71A) which is the rotor; a second rotor (71B) which is the rotor and is aligned with the first rotor in the axial direction via the stator coil; a first bearing (80A) which is the bearing and rotatably supports the first rotor relative to the stator; a second bearing (80B) which is the bearing and rotatably supports the second rotor relative to the stator; and a rotor connection portion (76) which is located at a position away from the first bearing and the second bearing on the outer circumferential side and connects the first rotor and the second rotor.

[0188] (Technical Idea 12) The rotating electric machine according to any one of Technical Ideas 1 to 11, wherein the stator support portion, the rotor support portion, and the bearing define an accommodation space (601) that accommodates the stator coil and the rotor magnet.

[0189] (Technical Idea 13) The rotating electric machine according to Technical Idea 12, further comprising: a housing vent (115, 125) that is provided to allow ventilation of the housing space and penetrates at least one of the stator support portion and the rotor support portion.

Claims

1. A rotating electric machine (60) driven by a supply of electric power, comprising: a stator (61) having an energized stator coil (62) and a stator support portion (63) supporting the stator coil; a rotor (71) having rotor magnets (72) arranged on the stator coil in the axial direction (AD) of a rotation axis (Cm) and a rotor support portion (73) supporting the rotor magnets, the rotor (71) rotating around the rotation axis and arranged on the stator in the axial direction; and bearings (80) fixed to the stator support portion and the rotor support portion, respectively, and supporting the rotor rotatably relative to the stator, wherein a portion of the stator is provided on the inner peripheral side of the rotor.

2. A rotating electric machine according to claim 1, wherein the bearing is provided at a position spaced apart from the outer circumferential edge of the rotor support portion toward the inner circumferential side.

3. A rotating electric machine as described in claim 1 or 2, wherein the stator support portion has a stator inner wall (66) that is provided on the inner side of the stator coil and supports the stator coil, and the bearing is provided in a position between the outer peripheral end of the rotor support portion and the stator inner wall in the radial direction (RD) of the rotation axis, closer to the stator inner wall than the outer peripheral end.

4. A rotating electric machine as described in claim 1 or 2, further comprising an object connection portion (75) provided on the rotor support portion so as to rotate together with the rotor support portion and connected to a rotation object (20, 100) rotated by the rotor, and the bearing is provided at a position spaced apart from the object connection portion on the inner periphery side.

5. A rotating electric machine as described in claim 4, wherein the stator support portion has a stator inner wall (66) that is provided on the inner side of the stator coil and supports the stator coil, and the bearing is provided in a position between the symmetrical connecting portion and the stator inner wall in the radial direction (RD) of the rotation axis, closer to the stator inner wall than the symmetrical connecting portion.

6. A rotating electric machine according to claim 5, wherein the stator inner peripheral wall forms an inner peripheral air hole (602) that penetrates the stator and the rotor in the axial direction and is open in the axial direction.

7. A rotating electric machine as described in claim 1 or 2, wherein the rotor is provided on the rotor support part so as to rotate together with the rotor support part, and has an object connection part (75) that is connected to a rotation object (20, 100) that is rotated by the rotor.

8. A rotating electric machine according to claim 1 or 2, wherein the bearing is provided on the inner periphery of the rotor magnet.

9. A rotating electric machine as described in claim 1 or 2, which is provided with a stator promotion portion (110) having at least one of a convex portion (111, 112) and a concave portion (113) provided on the outer surface (63a) of the stator support portion, and which promotes heat dissipation of the stator.

10. A rotating electric motor as described in claim 1 or 2, which is provided with a rotor promotion portion (120) having at least one of a convex portion (121, 122) and a concave portion (123) provided on the outer surface (73a) of the rotor support portion, and which promotes heat dissipation of the rotor.

11. A rotating electric machine according to claim 1 or 2, comprising: a first rotor (71A) which is the rotor; a second rotor (71B) which is the rotor and is arranged in the axial direction to the first rotor via the stator coil; a first bearing (80A) which is the bearing and rotatably supports the first rotor relative to the stator; a second bearing (80B) which is the bearing and rotatably supports the second rotor relative to the stator; and a rotor connecting portion (76) which is provided at a position spaced from the first bearing and the second bearing on the outer periphery side and connects the first rotor and the second rotor.

12. A rotating electric machine according to claim 1 or 2, wherein the stator support portion, the rotor support portion and the bearing define an accommodation space (601) that accommodates the stator coil and the rotor magnet.

13. A rotating electric machine according to claim 12, further comprising an accommodation vent (115, 125) that is provided to allow ventilation of the accommodation space and penetrates at least one of the stator support portion and the rotor support portion.

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