Rotating electric machine

Abstract

This rotating electrical machine is provided with a housing, and a lid member (90) covering an opening of the housing. The lid member (90) comprises a disk section (91), an outer peripheral ring section (92), a middle ring section (93), a plurality of flange sections (94, 94x), and a plurality of rib sections (95, 95x). The plurality of rib sections include a general rib section (95) and a special rib section (95x). The general rib section (95) has a shape that extends in the radial direction of the disk section (91) and that links the outer peripheral ring section (92) and the middle ring section (93). The special rib section (95x) has a shape comprising: an arc section (95x1) extending in the circumferential direction along the inner peripheral surface of the outer peripheral ring section (92); and side sections (95x2) extending radially inward from both ends of the arc section (95x1) in the circumferential direction. A hole (91a) intersecting a special surface (S2) is located between a pair of side sections (95x2). A special flange section (94x) intersecting the special surface (S2) is located on the radially outward side of the arc section (95x1).

Description

Rotating electrical machine Cross-reference to related applications

[0001] This application is based on Japanese Patent Application No. 2024-165512 filed in Japan on September 24, 2024, and the contents of the base application are incorporated herein by reference in their entirety.

[0002] The disclosure in this specification relates to a rotating electrical machine provided with a motor.

[0003] The rotating electrical machine described in Patent Document 1 includes a lower bracket (housing) that houses a rotor and a stator, and an upper bracket (lid member) that is fastened to the lower bracket with screws. The lid member has a bottomed cylindrical shape. The lid member is formed with a recess into which a screw is inserted, an opening through which a connector is exposed, and ribs for reinforcement. The ribs extend radially in the radial direction from the center of the cylinder of the lid member.

[0004] Japanese Unexamined Patent Application Publication No. 2014-099971

[0005] The stress applied to the lid member tends to be large at the recessed portion. Therefore, it is desirable that the position of the rib extends radially along a straight line connecting the center of the cylinder of the lid member and the recess. However, if, for example, some kind of hole is provided on that straight line, it becomes impossible to form the rib at a desirable position, and it becomes difficult to sufficiently ensure the strength of the lid member.

[0006] One object to be disclosed is to provide a rotating electrical machine that can sufficiently ensure the strength of the lid member.

[0007] To achieve the above objective, the rotating electric machine according to this disclosure comprises a motor having a stator and a rotor, a housing having a circular opening that opens at a position through which the rotation axis of the rotor passes and housing the motor inside, and a cover member attached to the housing and covering the opening, wherein the cover member has a disc shape that extends perpendicular to the axial direction which is the direction in which the rotation axis extends, and has a disk portion having a plurality of holes at positions off the rotation axis, a cylindrical outer ring portion extending axially from the outer circumference of the disk portion, a cylindrical central ring portion extending axially from the center of the disk portion, a plurality of flange portions protruding from the outer surface of the outer ring portion and connected to the housing, and a plurality of rib portions protruding from the plate surface of the disk portion, and a virtual plane that extends to include the rotation axis, with a virtual plane that intersects both the flange portions and the holes being defined as a general plane, and a virtual plane that intersects the flange portions but not the holes being defined as a special plane. The multiple rib sections include general rib sections located at positions where they intersect with the general surface and special rib sections located where they intersect with the special surface. The general rib sections have a shape that extends radially in the disc section and connects the outer ring section and the central ring section. The special rib sections have a shape that includes an arc section extending circumferentially along the inner surface of the outer ring section and side sections extending radially inward from both circumferential ends of the arc section. A hole intersecting with the special surface is located between the pair of side sections, and a flange section intersecting with the special surface is located radially outward of the arc section.

[0008] According to the above-described rotating electric machine, the lid member has a special rib section in addition to the general rib section. The special rib section has a shape with an arc section and a side section, and is located on a virtual plane (special plane) that intersects the hole, within a virtual plane that includes the flange section and the axis of rotation. The hole that intersects with this special plane is located between a pair of side sections, and the flange section that intersects with this special plane is located radially outward from the arc section. Therefore, even if the hole is located on the virtual plane that includes the flange section and the axis of rotation, the arc section is located on that virtual plane (special plane). From both ends of the arc section, the side sections extend radially inward to avoid the hole. Thus, even at the location of the special plane on the lid member, the strength of the lid member can be sufficiently ensured by the special rib section.

[0009] The reference numbers in parentheses above are merely examples of correspondences with specific configurations in the embodiments described later, and do not limit the technical scope in any way.

[0010] This figure shows the configuration of an eVTOL to which the electric propulsion unit according to the first embodiment is applied. This is a longitudinal cross-sectional view showing the arrangement layout of the motor device and inverter device according to the first embodiment. This is a longitudinal cross-sectional view of the inverter device according to the first embodiment. This is a perspective view of the cover member shown in Figure 3 as seen from the motor side. This is a perspective view of the cover member shown in Figure 3 as seen from the opposite motor side. This is a top view of the cover member shown in Figure 3 as seen from the motor side. This is a bottom view of the cover member shown in Figure 3 as seen from the opposite motor side.

[0011] The following describes several embodiments for implementing this disclosure with reference to the drawings. Not only can the parts that are explicitly shown to be combinable in each embodiment be combined, but embodiments can also be partially combined even if not explicitly shown, as long as there are no particular problems with the combination.

[0012] (First Embodiment) The eVTOL 10 shown in Figure 1 is an electric vertical take-off and landing aircraft, and is equipped with a rotating electric motor according to this embodiment. eVTOL is an abbreviation for electric Vertical Take-Off and Landing aircraft. The eVTOL 10 is an electric flying vehicle (mobile vehicle) that flies in the atmosphere and is capable of vertical take-off and landing. The eVTOL 10 comprises a fuselage 11 with a crew compartment, a propeller 20, a battery 31, and an EPU 50, etc. The EPU 50 corresponds to the rotating electric motor.

[0013] Multiple propellers 20 are provided on the aircraft body 11. The propellers 20 rotate around their propeller axes, generating thrust and lift for the eVTOL 10. The propellers 20 have blades 21. Multiple blades 21 are arranged in the circumferential direction of the propeller axis. In the propellers 20, multiple blades 21 are connected by bosses. In the propellers 20, the propeller shaft extends from the bosses along the propeller axis. The propellers 20 are pitch-variable propellers. In the propellers 20, the angle of the blades 21 relative to the propeller axis can be changed.

[0014] The EPU 50 is a device that drives the propeller 20 to rotate, and is also called an electric propulsion unit. EPU is an abbreviation for Electric Propulsion Unit. An EPU 50 is provided individually for each of the multiple propellers 20. The EPUs 50 are arranged along the propeller axis of the propeller 20. All of the multiple EPUs 50 are fixed to the aircraft body 11. The EPUs 50 rotatably support the propeller 20. The propeller 20 is fixed to the aircraft body 11 via the EPUs 50.

[0015] Battery 31 is a DC voltage source that applies a DC voltage to EPU 50. When EPU 50 is driven by the power supplied from battery 31, the propeller 20 rotates. eVTOL 10 flies and moves due to the rotation of the propeller 20. The propeller wind Wp (see Figure 2) generated by the rotation of the propeller 20 flows in the direction along the propeller axis (hereinafter referred to as axial direction AD). EPU 50 is located downwind of the propeller wind Wp relative to the propeller 20. The propeller wind Wp is included in the flight wind generated by the flight of eVTOL 10.

[0016] The EPU 50 comprises a motor unit 60, an inverter unit 80, a cover member 90, a blower fan 111, a duct 120, a gear unit 100, and a pitch controller 150. The motor unit 60 rotates the propeller 20. The inverter unit 80 has an inverter circuit and a control circuit. The inverter circuit converts the DC power supplied from the battery 31 into AC power and supplies it to the motor unit 60. The control circuit controls the operation of the motor unit 60 by controlling the operation of the inverter circuit. Because the motor unit 60 and the inverter unit 80 are configured as an integrated unit, the EPU 50 is a mechatronic unit. The motor unit 60 and the inverter unit 80 generate heat when energized. To suppress the temperature rise due to this heat generation, an air cooling method using outside air is employed.

[0017] As shown in Figure 2, the inverter device 80 according to this embodiment includes a first inverter device 80A and a second inverter device 80B. By providing multiple inverter devices to a single motor device 60 in this way, redundancy is provided in the power supply to the motor device 60.

[0018] The motor unit 60 and the inverter unit 80 are formed as a whole in a short cylindrical shape and extend in the axial direction A and D. The motor unit 60 and the inverter unit 80 are arranged side by side in the axial direction A and D. The inverter axis Ci (see Figure 3), which is the center line of the inverter unit 80, coincides with the motor axis Cm. The motor unit 60 is installed between the inverter unit 80 and the propeller 20 in the axial direction A and D. The first inverter unit 80A and the second inverter unit 80B are arranged side by side in the axial direction A and D.

[0019] The motor device 60 includes a motor 61 and a motor housing 70. The motor housing 70 is a casing that houses the motor 61 inside. The motor 61 is a multi-phase AC motor. The motor 61 includes a stator 62, rotors 64a and 64b, and a motor shaft 130. The motor 61 is composed of mechanical parts such as the stator 62, rotors 64a and 64b, and motor shaft 130.

[0020] The stator 62 is fixed to the motor housing 70. The stator 62 has coils 63a and 63b that form the armature. The rotors 64a and 64b rotate relative to the stator 62. The motor shaft 130 is rotatably supported by bearings 66 fixed to the motor housing 70 and rotates together with the rotors 64a and 64b. The motor 61 shown in Figure 2 is an axial gap type motor. The stator 62 and rotors 64a and 64b are arranged in the axial direction AD. However, the motor 61 may be a radial gap type motor in which the starter and rotor are arranged in the radial direction RD. The motor axis Cm, which is the rotation axis of the rotors 64a and 64b, coincides with the propeller axis.

[0021] The motor housing 70 has a motor outer circumferential wall 71 and a motor opposing wall 73. The motor outer circumferential wall 71 and the motor opposing wall 73 are made of a metal or the like and have thermal conductivity. The motor outer circumferential wall 71 extends in an annular shape in the circumferential direction CD. The motor outer circumferential wall 71 forms the outer circumferential surface of the motor housing 70. The motor outer circumferential wall 71 covers the stator 62 and rotors 64a and 64b from the outer circumferential side. The motor opposing walls 73 are arranged in pairs in the axial direction AD.

[0022] The motor housing 70 has motor fins, which are not shown in the illustration. The motor fins are provided on the outer circumferential wall 71 of the motor. The motor fins release heat from the motor housing 70 to the outside of the motor device 60. The motor fins are plate-shaped, protruding radially RD from the outer circumferential wall 71 and extending axially AD. Multiple motor fins are arranged in a row in the circumferential direction CD.

[0023] The inverter device 80 includes an inverter circuit, a control circuit, and an inverter housing 83. These inverter circuit, control circuit, and inverter housing 83 are provided in the first inverter device 80A and the second inverter device 80B, respectively.

[0024] The inverter circuit converts the DC power supplied from the battery 31 into AC power and supplies it to the motor 61. As shown in Figure 3, the inverter circuit is composed of a high-voltage power system (e.g., 400V) board 813A, 813B and a plurality of electronic components. The plurality of electronic components include a plurality of switching elements 811A, 811B and capacitor elements 812A, 812B. In this specification, components whose reference numeral ends in A indicate components included in the first inverter device 80A. Components whose reference numeral ends in B indicate components included in the second inverter device 80B.

[0025] The output terminal of switching element 811A is connected to coil 63a. The output terminal of switching element 811B is connected to coil 63b. Multiple switching elements 811A and 811B form an upper and lower arm circuit. The switching elements 811A and 811B are thermally connected to the inner circumferential surface of the inverter housing 83.

[0026] Capacitor elements 812A and 812B are connected to the input terminals of switching elements 811A and 811B and the battery 31. Capacitor elements 812A and 812B function as smoothing capacitors that reduce voltage pulsation applied to switching elements 811A and 811B.

[0027] The control circuit controls the operation of the inverter circuit by outputting on / off signals to the signal terminals of the switching elements 811A and 811B. The control circuit is provided by signal system (e.g., 5V and 28V) control boards 821A and 821B and several electronic components. The several electronic components mounted on the control boards 821A and 821B include IC chips 822A and 822B. The IC chips 822A and 822B include integrated circuits that constitute a computer, such as a processor and memory.

[0028] The high-voltage boards 813A and 813B and the control boards 821A and 821B are arranged perpendicular to the inverter axis Ci. These boards have a ring-like shape extending from the inverter axis Ci. Capacitor elements 812A and 812B are mounted on the high-voltage boards 813A and 813B. Switching elements 811A and 811B are electrically connected to the high-voltage boards 813A and 813B via busbars.

[0029] The inverter housing 83 is a metal casing with a bottomed cylindrical shape. The inverter housing 83 houses the inverter circuit and control circuit. The inverter housing 8 and the motor housing 70 are arranged side by side in the axial direction A and D. The portion of the inverter housing 83 that houses the inverter circuit and control circuit related to the first inverter device 80A corresponds to the first housing 83A. The portion of the inverter housing 83 that houses the inverter circuit and control circuit related to the second inverter device 80B corresponds to the second housing 83B. The first housing 83A and the second housing 83B are arranged side by side in the axial direction A and D. The inverter axis Ci and the motor axis Cm coincide with each other and also coincide with the cylindrical centerline of the housing E.

[0030] As shown in Figure 3, a flange portion 836 is formed on each of the first housing 83A, the second housing 83B, and the motor housing 70. The flange portion 836 is shaped to protrude radially outward from the outer circumferential surface of each housing. Multiple flange portions 836 are arranged in a row in the circumferential direction CD. Each housing is assembled as a single unit by fastening adjacent flange portions 836 in the axial direction AD with screws. In other words, the first housing 83A, the second housing 83B, and the motor housing 70 form a single housing E. In the axial direction AD, the motor housing 70, the first housing 83A, and the second housing 83B are arranged in order from the propeller 20 side.

[0031] A circular opening 83Ba is formed in the housing E. The opening 83Ba is located at a position through which the motor axis Cm, which is the rotation axis of the rotor 64a, passes. The opening 83Ba is covered by a cover member 90. The cover member 90 is attached to the second housing 83B. The structure of the cover member 90 will be described in detail later.

[0032] The inverter housing 83 has an inverter inner circumferential hole 83c. The inverter inner circumferential hole 83c penetrates the inverter housing 83 in the axial direction AD. The inverter inner circumferential hole 83c extends in the axial direction AD along the motor axis Cm. The inverter inner circumferential hole 83c is located in the center of the inverter housing 83. The center line of the inverter inner circumferential hole 83c coincides with the motor axis Cm.

[0033] As shown in Figure 3, the inverter housing 83 has inverter fins 83f. The inverter fins 83f are provided on the outer circumferential surface of the inverter housing 83 and release heat generated by the inverter device 80 to the outside. The inverter fins 83f are plate-shaped, protruding radially RD from the outer circumferential surface of the inverter housing 83 and extending axially AD. Multiple inverter fins 83f are arranged in the circumferential direction CD.

[0034] The EPU 50 has a gear device 100 as shown in Figure 2. The gear device 100 mechanically connects the motor device 60 and the propeller 20. The gear device 100 transmits the drive of the motor device 60 to the propeller 20. The gear device 100 can change the rotational speed of the rotors 64a, 64b and the motor shaft 130 and output it to the propeller 20. The motor shaft 130 is connected to the gear device 100.

[0035] The EPU 50 has a pitch controller 150 shown in Figure 2. The pitch controller 150 can change the pitch of the propeller 20. For example, the pitch controller 150 changes the pitch of the propeller 20 by changing the angle of the blades 21 with respect to the propeller axis. The pitch controller 150 has an electric actuator 151 and an actuation bar 152. The electric actuator 151 is configured to include an actuator such as a motor. The actuation bar 152 connects the electric actuator 151 and the propeller 20. The electric actuator 151 changes the pitch of the propeller 20 via the actuation bar 152.

[0036] The electric actuator 151 is attached to the cover member 90. The actuation bar 152 is stretched between the electric actuator 151 and the propeller 20 via the motor shaft 130 and the gear mechanism 100. The actuation bar 152 extends axially A through the motor shaft 130. The pitch controller 150 is shaped to extend axially A through the motor 61 and is cantilevered to the cover member 90.

[0037] <Air Cooling Flow Path> The EPU 50 has a duct 120 and a blower fan 111 as shown in Figure 2. The duct 120 covers the motor housing 70 and the inverter housing 83 from the outside. The blower fan 111 is fixed to the motor shaft 130 and rotates in conjunction with the drive of the motor 61. The blower fan 111 blows air so that it passes through the duct space 125. When the blower fan 111 rotates, the air flows through the duct 120 as shown by the arrows in Figure 2. This cools the motor unit 60 and the inverter unit 80.

[0038] Specifically, outside air flowing in from the inlet 120a of the duct 120 branches into the inverter inner circumferential hole 83c and the outer circumferential flow path 120b, and flows in the axial direction AD. The outer circumferential flow path 120b is a flow path formed between the outer circumferential surface of the housing E and the inner circumferential surface of the duct 120. The outer circumferential flow path 120b is cylindrical in shape and extends in the axial direction AD. The inverter fins 83f and motor fins, which are not shown in Figure 2, are located in the outer circumferential flow path 120b. The outside air that branches into the inverter inner circumferential hole 83c and the outer circumferential flow path 120b merges and then flows out from the outlet 120c of the duct 120. Note that the direction in which the outside air flows through the inverter inner circumferential hole 83c and the outer circumferential flow path 120b is opposite to the direction of the propeller wind Wp.

[0039] <Lid Member> The lid member 90 is made of metal and may be formed by die casting or by machining. The lid member 90 prevents foreign matter from entering the housing E through the opening 83Ba. The lid member 90 reduces electromagnetic radiation or electromagnetic intrusion from the inverter device 80 to the outside of the housing E.

[0040] A cover connector C10, which is an electrical connector, is attached to the cover member 90. A board connector C20, which is an electrical connector, is attached to each of the control boards 821A and 821B. The board connector C20 and the cover connector C10 are electrically connected by a harness H. An external connector C30 is connected to the cover connector C10. This allows power to be supplied to the inverter device 80 from the battery 31. In addition, the inverter device 80 can send and receive various signals with an external control device.

[0041] The harness H is a flexible wiring. When the lid member 90 closes the opening 83Ba of the inverter housing 83, the internal space of the lid member 90 and the internal space of the inverter housing 83 form a single internal space. The lid connector C10, the board connector C20, the control board 821, and the harness H are arranged in this internal space.

[0042] Figs. 4 to 7 are views showing the lid member 90 in a state removed from the housing E, showing the lid member 90 in a state where the lid connector C10 and the pitch controller 150 are removed. The arrow X in the figure indicates the anti-motor side in the axial direction AD. The arrow Y and the arrow Z are perpendicular to each other and also indicate a direction perpendicular to the axial direction AD. Hereinafter, the detailed structure of the lid member 90 will be described while referring to Figs. 4 to 7.

[0043] The lid member 90 has a bottomed cylindrical shape that bulges on the anti-motor side in the axial direction AD. More specifically, the lid member 90 includes a disk portion 91, an outer peripheral ring portion 92, a central ring portion 93, a plurality of flange portions 94, 94x, a plurality of rib portions 95, 95x, an outer rib portion 96, and a pedestal 97.

[0044] The disk portion 91 has a disk shape that extends perpendicular to the axial direction AD. The center position of the disk of the disk portion 91 coincides with the position of the motor axis Cm (rotation axis). By covering the opening 83Ba, the disk portion 91 prevents foreign matter from entering the housing E and reduces electromagnetic radiation or electromagnetic intrusion from the inverter device 80 to the outside of the housing E.

[0045] A plurality of holes are formed in the disk portion 91. One of the holes is a central hole 91b formed at the center of the disk portion 91. The central hole 91b is formed at a position overlapping the motor axis Cm. The above-described operating bar 152 is disposed in the central hole 91b. In addition to the central hole 91b, a plurality of holes 91a are formed at positions deviated from the motor axis Cm. The plurality of holes 91a are arranged at equal intervals around the motor axis Cm. The hole 91a is smaller than the central hole 91b.

[0046] The plurality of holes 91a include mounting holes to which the lid connector C10 described above is attached. The plurality of holes 91a include working holes for an operator to work inside the lid member 90. Specific examples of the work include work for screwing a bus bar inside the lid member 90 to a predetermined position and work for visually inspecting the inside of the lid member 90. A detachable cover plate (not shown) is attached to the working hole. Note that the members attached to the mounting holes are not limited to the lid connector C10 and the cover plate.

[0047] The outer peripheral ring portion 92 has a cylindrical shape extending in the axial direction AD from the outer periphery of the disk portion 91. The outer peripheral ring portion 92 extends toward the inverter device 80 with respect to the disk portion 91. The cylindrical end portion 92a of the outer peripheral ring portion 92 is in close contact with and sealed to the cylindrical end portion of the second housing 83B.

[0048] The central ring portion 93 has a cylindrical shape extending in the axial direction AD from the periphery of the central hole 91b. The cylindrical center position of the central ring portion 93 coincides with the cylindrical center position of the outer peripheral ring portion 92. Also, these cylindrical center positions coincide with the position of the motor axis Cm. The central ring portion 93 extends toward both the side of the inverter device 80 (inverter side) and the non-inverter side with respect to the disk portion 91. The inverter housing 83 has a central cylindrical portion 831 that forms the inverter inner peripheral hole 83c described above inside. The cylindrical end portion 93a of the central ring portion 93 is in close contact with and sealed to the cylindrical end portion of the central cylindrical portion 831.

[0049] The plurality of flange portions 94, 94x project in the radial direction RD from the outer peripheral surface of the outer peripheral ring portion 92. The plurality of flange portions 94, 94x are arranged at equal intervals in the circumferential direction. The flange portions 94, 94x are fastened to the flange portion 836 of the second housing 83B by a fastening member such as a screw. Thereby, the lid member 90 is connected to the housing E.

[0050] Multiple rib portions 95, 95x are shaped to protrude axially A / D toward the inverter side from the plate surface of the disc portion 91. The rib portions 95, 95x reinforce the disc portion 91 to increase its bending rigidity. The disc portion 91 vibrates axially A / D in its central part while its peripheral portion is fixed to the outer ring portion 92. The reinforcement by the rib portions 95, 95x contributes to suppressing the vibration of the disc portion 91. The connection portion of the rib portions 95, 95x between the disc portion 91 and the outer ring portion 92 has a shape in which the plate thickness gradually increases. The surface of this connection portion may be curved or flat.

[0051] The dashed lines shown in Figures 6 and 7 indicate the positions of the following multiple virtual planes. The virtual planes are planes that extend to include the motor axis Cm and intersect with any of the multiple flange portions 94 and 94x. Of the multiple virtual planes, the virtual plane that does not intersect with the hole 91a is called the general plane S1. The virtual plane that intersects with the hole 91a is called the special plane S2. Of the multiple rib portions 95 and 95x, the rib portion that intersects with the general plane S1 is called the general rib portion 95, and the rib portion that intersects with the special plane S2 is called the special rib portion 95x. Of the multiple flange portions 94 and 94x, the flange portion that intersects with the general plane S1 is called the general flange portion 94, and the flange portion that intersects with the special plane S2 is called the special flange portion 94x.

[0052] The general rib portion 95 extends radially RD and connects the outer ring portion 92 and the central ring portion 93. Multiple general rib portions 95 extend radially from the center of the disc portion 91. The special rib portion 95x has a shape consisting of an arc portion 95x1 and a side portion 95x2. The special rib portion 95x is connected to the outer ring portion 92 and the disc portion 91, but not to the central ring portion 93.

[0053] The arc portion 95x1 has a shape that extends circumferentially along the inner surface of the outer ring portion 92. The side portions 95x2 have a shape that extends radially inward RD from both ends of the arc portion 95x1 in the circumferential direction. In short, the special rib portion 95x has a U-shape that opens on the side of the motor axis Cm. The special flange portion 94x is located radially outward of the arc portion 95x1. The special flange portion 94x is located in the circumferential center of the arc portion 95x1.

[0054] The side portions 95x2 are offset from the special surface S2 and extend parallel to the special surface S2. Between the pair of side portions 95x2 extending from both ends of the arc portion 95x1 in the circumferential direction, there is a hole 91a that intersects with the special surface S2. The special rib portions 95x are arranged opposite each other at positions symmetrical to each other with respect to the motor axis Cm. One of the opposing pair of special rib portions 95x corresponds to the first special rib portion 95x, and the other corresponds to the second special rib portion 95x. These first and second special rib portions 95x intersect with a common special surface S2. The side portions 95x2 of the first and second special rib portions 95x extend parallel to each other. In other words, as shown in Figure 6, on one special surface S2, the special flange portion 94x, the special rib portion 95x, the hole 91a, the central hole 91b, the hole 91a, the special rib portion 95x, and the special flange portion 94x are arranged in that order.

[0055] The disk portion 91 includes a general plate portion 911, a special plate portion 911x, and a connecting plate portion 912. The general plate portion 911 is the portion located between the general rib portion 95 and the special rib portion 95x. The special plate portion 911x is the portion located between a pair of side portions 95x2. The general plate portion 911 and the special plate portion 911x are located at different positions in the axial direction AD. In the example shown in Figure 4, the special plate portion 911x is located closer to the inverter than the general plate portion 911. The connecting plate portion 912 is the portion that connects the general plate portion 911 and the special plate portion 911x. The connecting plate portion 912 has a plate shape that extends parallel to the special surface S2. The general plate portion 911 is arranged on both sides of the special plate portion 911x in the circumferential direction.

[0056] In short, the portion of the disk 91 having the general plate portion 911, the special plate portion 911x, and the connecting plate portion 912 has an uneven shape that is uneven in the axial direction AD. The disk 91 according to this embodiment has two special plate portions 911x, so it can be said to have an uneven shape with two protrusions. The two protrusions are arranged opposite each other in positions that are symmetrical with respect to the motor axis Cm. The special plate portion 911x has a shape that connects the outer ring portion 92 and the central ring portion 93.

[0057] As shown in Figure 5, the outer rib portion 96 protrudes from the outer plate surface of the disc portion 91. The plate surface of the disc portion 91 on the side from which the rib portions 95 and 95x protrude is called the inner plate surface. The plate surface opposite to the inner plate surface is called the outer plate surface. The central ring portion 93 penetrates the lid member 90 in the axial direction AD and is located on both the inner and outer plate surfaces. The outer rib portion 96 has a shape that extends radially outward from the central ring portion 93. Furthermore, the outer rib portion 96 has a shape that extends parallel to the direction in which the side portions 95x2 extend radially inward from the outer ring portion 92. The side portions 95x2 and the outer rib portion 96 are arranged on the same plane.

[0058] The base 97 is provided at the end of the central ring portion 93 on the side opposite the inverter. The aforementioned electric actuator 151 is attached to the base 97. For example, the electric actuator 151 is fixed to the base 97 by fastening members such as screws. As shown in Figure 7, the base 97 is rectangular in shape. The base 97 may be square or rectangular. The base 97 may be a rectangle with the radial direction RD along the special surface S2 as the longitudinal direction, or a rectangle with the radial direction RD along the special surface S2 as the short direction.

[0059] The central hole 91b formed in the disc portion 91 is formed in the same shape and size as the central ring portion 93 and the base 97. The operating bar 152 is positioned in the central hole 91b and the inner circumference hole 83c of the inverter, and is positioned to pass through the base 97, the central ring portion 93, the disc portion 91 and the central cylindrical portion 831.

[0060] A service opening 93b is formed in the portion of the central ring 93 that protrudes from the disk portion 91 toward the inverter side. The service opening 93b is used by an operator to perform maintenance and inspection on the pitch controller 150. A cover plate (not shown) is attached to the central ring 93 to cover the service opening 93b. The weight of the pitch controller 150 is more than twice the weight of the lid member 90 and is considered a "heavy component".

[0061] <Summary of the First Embodiment> The multiple rib portions 95, 95x function as reinforcing members that increase the bending rigidity of the plate-shaped disc portion 91. The disc portion 91 vibrates in the axial direction A and D with its peripheral edge fixed to the outer ring portion 92. The reinforcement by the rib portions 95, 95x contributes to suppressing the vibration of the disc portion 91 in the axial direction A and D. Ideally, the multiple rib portions 95, 95x should extend radially from the center of the disc portion 91 and connect the central ring portion 93 and the outer ring portion 92 in order to promote the suppression of the vibration. The ideal shape can be easily realized on a general surface S1. On the other hand, on a special surface S2, it is difficult to realize the ideal shape because the holes 91a and the rib portions 95 interfere with each other when trying to form the rib portion 95 in the ideal shape.

[0062] In view of this point, the lid member 90 according to this embodiment has a special rib portion 95x in addition to the general rib portion 95. The special rib portion 95x has a shape that includes an arc portion 95x1 and a side portion 95x2. The special rib portion 95x is located on a virtual plane (special surface S2) that intersects the hole 91a while including the special flange portion 94x and the motor axis Cm. The hole 91a that intersects with the special surface S2 is located between the pair of side portions 95x2, and the special flange portion 94x is located radially outward from the arc portion 95x1.

[0063] According to this, even if the hole 91a is located on a virtual plane including the flange portion 94 and the motor axis Cm, the arc portion 95x1 is located on that virtual plane (special surface S2). From both ends of the arc portion 95x1, the side portions 95x2 extend radially inward RD, avoiding the hole 91a. Therefore, even at the location of the special surface S2 of the lid member 90, the strength of the lid member 90 can be sufficiently ensured by the special rib portion 95x, which has a different shape from the general rib portion 95. In other words, the bending rigidity of the disc portion 91 can be sufficiently improved, and vibration of the disc portion 91 in the axial direction AD can be effectively suppressed.

[0064] Furthermore, in this embodiment, the disc portion 91 has an uneven shape with a general plate portion 911, a special plate portion 911x, and a connecting plate portion 912. Specifically, the general plate portion 911 is located between the general rib portion 95 and the special rib portion 95x, and the special plate portion 911x is located between a pair of side portions 95x2. The general plate portion 911 and the special plate portion 911x are located at different positions in the axial direction AD and are connected to each other by the connecting plate portion 912. As a result, the bending rigidity of the disc portion 91 is also improved by the uneven shape formed by the general plate portion 911, the special plate portion 911x, and the connecting plate portion 912. Therefore, vibration suppression of the disc portion 91 can be promoted.

[0065] Furthermore, in this embodiment, two special rib portions 95x are provided as a pair. The first and second special rib portions 95x are positioned symmetrically with respect to each other with respect to the motor axis Cm. Therefore, the bending rigidity of the disc portion 91 can be improved compared to the case where the special rib portions 95x are arranged asymmetrically. Specifically, the bending rigidity in the direction of bending around an axis that is perpendicular to the special surface S2 and runs along the disc portion 91 is improved by making the first and second special rib portions 95x symmetrical.

[0066] Furthermore, in this embodiment, the lid member 90 has an outer rib portion 96. While multiple rib portions 95, 95x are formed on the inside of the disc portion 91, the outer rib portion 96 is formed on the outside of the disc portion 91. The outer rib portion 96 has a shape that extends radially outward from the central ring portion 93, and the side portions 95x2 extend parallel to the direction in which they extend radially inward from the outer ring portion. In short, the disc portion 91 is reinforced from both the outside and inside by the rib portions. The outer rib portion 96 extends from the central ring portion 93, and the side portions 95x2 of the special rib portion 95x extend from the outer ring portion 92. The outer rib portion 96 and the side portions 95x2 extend parallel to each other. Therefore, the bending rigidity of the disc portion 91 around the axis can be further improved.

[0067] Here, the stress that the lid member 90 receives from the housing E tends to be large in the flange portions 94 and 94x. Therefore, in this embodiment, the special flange portion 94x that intersects with the special surface S2 is located in the circumferential center of the arc portion 95x1. As a result, the stress that the lid member 90 receives from the housing E can be directly received by the special rib portion 95x. Thus, bending deformation of the lid member 90 caused by the above stress can be suppressed.

[0068] Furthermore, in this embodiment, the special rib portion has a shape in which the plate thickness gradually increases at the connection portion with the disc portion and the outer ring portion. Therefore, stress concentration occurring at the above connection portion can be alleviated, and damage to the disc portion 91 can be suppressed.

[0069] Furthermore, in this embodiment, a pitch controller 150 (weight member) extending in the axial direction AD so as to pass through the motor 61 is cantilevered to the central ring portion 93. In this case, the load of the pitch controller 150 is cantilevered onto the disk portion 91, making the disk portion 91 more susceptible to vibration. Therefore, the vibration suppression effect of the disk portion 91 by the special rib portion 95x, as described above, is effectively demonstrated.

[0070] Furthermore, the rotating electric machine (EPU 50) according to this embodiment is mounted on the eVTOL 10, which acts as a moving body. In this case, the entire rotating electric machine vibrates due to vibrations generated as the moving body moves, making the disk portion 91 more susceptible to vibration. Therefore, the aforementioned vibration suppression effect of the special rib portion 95x is effectively utilized.

[0071] (Other Embodiments) The disclosures of this specification are not limited to the exemplary embodiments. The disclosures encompass the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to the combinations of parts and elements shown in the embodiments and can be implemented in various variations. The disclosures can be implemented in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures encompass embodiments in which parts and elements have been omitted. The disclosures encompass substitutions or combinations of parts and elements between one embodiment and another. The scope of the disclosed technical field is not limited to the descriptions of the embodiments. The scope of the disclosed technical field is indicated by the descriptions of the claims and should be understood to include all modifications within the meaning and scope equivalent to the descriptions of the claims.

[0072] The disc portion 91 described above has an uneven shape with a general plate portion 911 and a special plate portion 911x located at different positions in the axial direction A and D. In contrast, the general plate portion 911 and the special plate portion 911x may be located at the same position in the axial direction A and D. In other words, the uneven shape may be a flat shape.

[0073] In the first embodiment described above, the first and second special rib portions 95x are arranged in symmetrical positions. In contrast, these special rib portions 95x may be arranged asymmetrically. Also, one of the first and second special rib portions 95x may be omitted. Furthermore, three or more special rib portions 95x may be provided.

[0074] In the first embodiment described above, the outer rib portion 96 has a shape that extends parallel to the direction in which the side portions 95x2 extend radially inward from the outer ring portion 92. In contrast, the outer rib portion 96 may be non-parallel to the side portions 95x2. Furthermore, the outer rib portion 96 may be omitted.

[0075] In the first embodiment described above, the special flange portion 94x is located at the circumferential center of the arc portion 95x1. In contrast, the special flange portion 94x may be positioned at a location offset from the circumferential center of the arc portion 95x1.

[0076] In the first embodiment described above, a pitch controller 150 is applied to the weight member connected to the central ring portion 93. However, the weight member is not limited to the pitch controller 150; for example, a cooling device that circulates liquid coolant may be connected to the central ring portion 93.

[0077] The rotating machine according to the first embodiment described above is applied to an EPU 50 mounted on an electric aircraft, but it may also be applied to a vehicle's drive motor.

[0078] The multiple holes 91a are not limited to being arranged at equal intervals around the motor axis Cm, but may be arranged at random circumferential intervals. The multiple holes 91a are not limited to being at the same radial position, but may be arranged at random radial positions. The holes 91a are not limited to being circular, but may be rectangular, for example. The holes 91a are not limited to being at a position where their centers coincide with the general surface S1 or the special surface S2, but it is sufficient if a part of the hole 91a is located on the general surface S1 or the special surface S2.

[0079] In the first embodiment described above, the special rib portion 95x is connected to the outer ring portion 92 and the disk portion 91, but not to the central ring portion 93. In other words, there is space between the extended end of the special rib portion 95x and the central ring portion 93. This space can be effectively utilized for arranging components such as wiring. Alternatively, the special rib portion 95x may be shaped to connect the outer ring portion 92 and the central ring portion 93.

[0080] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0081] (Technical Concept 1) A rotating electric machine comprising: a motor (61) having a stator (62) and rotors (64a, 64b); a housing (E) that houses the motor and has a circular opening (83Ba) that opens at a position through which the rotation axis (Cm) of the rotor passes; and a cover member (90) attached to the housing and covering the opening, wherein the cover member has: a disc portion (91) which is disc-shaped and extends perpendicularly to the axial direction in which the rotation axis extends, and has a plurality of holes (91a) at positions off from the rotation axis; a cylindrical outer ring portion (92) which extends in the axial direction from the outer circumference of the disc portion; a cylindrical central ring portion (93) which extends in the axial direction from the center of the disc portion; a plurality of flange portions (94, 94x) which protrude from the outer surface of the outer ring portion and are connected to the housing; and a plurality of rib portions (95, 95x) which protrude from the plate surface of the disc portion, A rotating electric machine comprising a virtual plane extending to include the axis of rotation, wherein a virtual plane intersecting both the flange portion and the hole is defined as a general plane (S1), and a virtual plane intersecting the flange portion but not the hole is defined as a special plane (S2), wherein a plurality of rib portions include a general rib portion (95) located at a position intersecting the general plane and a special rib portion (95x) located at a position intersecting the special plane, the general rib portion having a shape that extends radially in the disk portion and connects the outer peripheral ring portion and the central ring portion, the special rib portion having a shape that includes an arc portion (95x1) extending circumferentially along the inner circumferential surface of the outer peripheral ring portion and side portions (95x2) extending radially inward from both circumferential ends of the arc portion, the hole intersecting the special plane located between a pair of side portions, and the flange portion intersecting the special plane located radially outward of the arc portion.

[0082] (Technical Concept 2) The rotating electric machine according to Technical Concept 1, wherein the portion of the disk portion located between the general rib portion and the special rib portion is defined as a general plate portion (911), and the portion located between the pair of side portions is defined as a special plate portion (911x), the general plate portion and the special plate portion are located at different positions in the axial direction, and the disk portion has an uneven shape with connecting plate portions (912) connecting the general plate portion and the special plate portion.

[0083] (Technical Concept 3) The rotating electric machine according to Technical Concept 2, wherein the rib portion includes a first special rib portion and a second special rib portion, and the first special rib portion and the second special rib portion are arranged symmetrically with respect to each other with respect to the axis of rotation.

[0084] (Technical Idea 4) The rotating electric machine according to any one of Technical Ideas 1 to 3, wherein the plate surface on the side of the disc portion from which the rib portion protrudes is the inner plate surface, and the plate surface on the opposite side of the inner plate surface is the outer plate surface, the lid member has an outer rib portion (96) protruding from the outer plate surface of the disc portion, the central ring portion penetrates the lid member in the axial direction and is located on both sides of the inner plate surface and the outer plate surface, the outer rib portion has a shape that extends radially outward from the central ring portion, and the side portion has a shape that extends parallel to the direction in which the outer peripheral ring portion extends radially inward.

[0085] (Technical Idea 5) The flange portion intersecting the special surface is located in the center of the circumferential direction of the arc portion, as described in any one of Technical Ideas 1 to 4.

[0086] (Technical Idea 6) The rotating electric machine according to any one of Technical Ideas 1 to 5, wherein the special rib portion has a shape in which the plate thickness gradually increases at the connection portion with the disk portion and the outer peripheral ring portion.

[0087] (Technical Idea 7) A rotating electric machine according to any one of Technical Ideas 1 to 6, wherein a weight member (150) extending in the axial direction so as to penetrate the motor is cantilevered to the central ring portion.

[0088] (Technical Concept 8) A rotating electric machine described in any one of Technical Concepts 1 to 7, which is mounted on a mobile body (10).

Claims

1. A rotating electric machine comprising: a motor (61) having a stator (62) and rotors (64a, 64b); a housing (E) that houses the motor and has a circular opening (83Ba) that opens at a position through which the rotation axis (Cm) of the rotor passes; and a cover member (90) attached to the housing and covering the opening, wherein the cover member has: a disc portion (91) which is disc-shaped and extends perpendicularly to the axial direction in which the rotation axis extends, and has a plurality of holes (91a) at positions off from the rotation axis; a cylindrical outer ring portion (92) which extends in the axial direction from the outer circumference of the disc portion; a cylindrical central ring portion (93) which extends in the axial direction from the center of the disc portion; a plurality of flange portions (94, 94x) which protrude from the outer surface of the outer ring portion and are connected to the housing; and a plurality of rib portions (95, 95x) which protrude from the plate surface of the disc portion. A rotating electric machine comprising a virtual plane extending to include the axis of rotation, wherein a virtual plane intersecting both the flange portion and the hole is defined as a general plane (S1), and a virtual plane intersecting the flange portion but not the hole is defined as a special plane (S2), wherein a plurality of rib portions include a general rib portion (95) located at a position intersecting the general plane and a special rib portion (95x) located at a position intersecting the special plane, the general rib portion having a shape that extends radially in the disk portion and connects the outer peripheral ring portion and the central ring portion, the special rib portion having a shape that includes an arc portion (95x1) extending circumferentially along the inner circumferential surface of the outer peripheral ring portion and side portions (95x2) extending radially inward from both circumferential ends of the arc portion, the hole intersecting the special plane located between a pair of side portions, and the flange portion intersecting the special plane located radially outward of the arc portion.

2. The rotating electric machine according to claim 1, wherein the portion of the disk portion located between the general rib portion and the special rib portion is defined as a general plate portion (911), and the portion located between the pair of side portions is defined as a special plate portion (911x), the general plate portion and the special plate portion are located at different positions in the axial direction, and the disk portion has an uneven shape with connecting plate portions (912) connecting the general plate portion and the special plate portion.

3. The rotating electric machine according to claim 2, wherein the rib portion includes a first special rib portion and a second special rib portion, and the first special rib portion and the second special rib portion are arranged symmetrically with respect to the axis of rotation.

4. The rotating electric machine according to any one of claims 1 to 3, wherein the plate surface on the side of the disc portion from which the rib portion protrudes is the inner plate surface, and the plate surface on the opposite side of the inner plate surface is the outer plate surface, the lid member has an outer rib portion (96) protruding from the outer plate surface of the disc portion, the central ring portion penetrates the lid member in the axial direction and is located on both sides of the inner plate surface and the outer plate surface, the outer rib portion has a shape that extends radially outward from the central ring portion, and the side portion has a shape that extends parallel to the direction in which the outer peripheral ring portion extends radially inward.

5. The rotating electric machine according to any one of claims 1 to 3, wherein the flange portion intersecting the special surface is located at the center of the circumferential direction of the arc portion.

6. The rotating electric machine according to any one of claims 1 to 3, wherein the special rib portion has a shape in which the plate thickness gradually increases at the connection portion with the disk portion and the outer peripheral ring portion.

7. The rotating electric machine according to any one of claims 1 to 3, wherein a weight member (150) extending in the axial direction so as to pass through the motor is cantilevered to the central ring portion.

8. A rotating electric machine according to any one of claims 1 to 3, mounted on a mobile body (10).

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