Rotating electrical machine

Abstract

Provided is a rotating electrical machine with ensured motor strength and improved cooling performance. A rotating electrical machine 10 comprises: a stator 130; a rotor 150; a shaft 160 connected to the rotor 150; a rotor core 151 connected via a cylindrical rotor core holding section 155; and a plurality of permanent magnets 152 inserted into the rotor core 151. The shaft 160 has a first refrigerant flow path 161 and a communication hole 170 that communicates the first refrigerant flow path 161 and the rotor core holding section 155. The rotor core holding section 155 includes: a second refrigerant flow path 162 extending to the outer circumferential side of the rotor 150 through the communication hole 170; a third refrigerant flow path 163 branching in the circumferential direction of the rotor 150 from the second refrigerant flow path 162; a fourth refrigerant flow path 164 reaching the permanent magnets 152 from the third refrigerant flow path 163; and a fifth refrigerant flow path 165 extending along the permanent magnets 152 from the fourth refrigerant flow path 164.

Description

Rotating electric machines

[0001] The present invention relates to a rotating electric machine used in electric propulsion systems for general mobility such as aircraft, transportation equipment, and construction machinery.

[0002] Recent CO ２ As a result of the trend towards reduction, countries are working to achieve a zero-carbon society. ２ There is a strong demand for emission controls. ２ As an alternative to fossil fuel-based engines that emit CO ２ Electrification, which eliminates carbon emissions, is being actively promoted. In all engine-driven mobility products, there is a demand for improved power density for future power electronics equipment.

[0003] Therefore, it is essential that the aircraft can withstand any climate around the world, and in the case of aircraft, it must be environmentally resistant to sudden changes in altitude.At the same time, there is a demand for technological solutions that can improve cooling performance, increase voltage, reduce weight, and increase speed.

[0004] One cooling method for motors is the oil cooling method, which has high cooling performance. This method circulates oil inside the motor to cool heat-generating parts such as the permanent magnets, rotor core, and stator coils. This oil cooling method improves cooling performance by providing a flow path to directly cool the heat-generating parts, but on the other hand, the structure can become complicated due to the need to form the oil flow path.

[0005] In Patent Document 1, a flywheel is formed between the output side and output shaft of the motor, and a fixing pin for fixing the core member of the motor to the flywheel and a flow path for supplying oil inside the fixing pin are provided. In other words, the purpose is to provide a motor with high cooling performance with a configuration for cooling the rotor core and permanent magnets.

[0006] In addition, in Patent Document 2, a flow passage provided along the central axis of the shaft, a penetrating flow passage provided in a direction perpendicular to the shaft axis at the portion where the rotor core and the shaft are connected, and a flow passage provided penetrating the rotor core along the inner surface of the permanent magnet are connected to each other, forming a series of penetrating flow passages. An oil pump supplies cooling oil to these flow passages, thereby cooling the rotor core and permanent magnets. In other words, as with Patent Document 1, the objective is to provide a motor with high cooling performance.

[0007] JP 2009-261214 A JP 2003-324901 A

[0008] However, in the above-mentioned conventional technology, the refrigerant oil flows through a passage that penetrates the motor's fixing member, which results in a complex structure and makes it difficult to process. Furthermore, since motors for aircraft have high rotation speeds and large load torques, if the motor's fixing member has multiple through holes, the motor's strength will be reduced, which could lead to failure of the electric system.

[0009] The object of the present invention is to provide a rotating electric machine and an electric aircraft equipped with this rotating electric machine that have a cooling structure that is simple and easy to process, thereby ensuring motor strength and improving cooling performance.

[0010] In order to achieve the above object, the present invention is configured as follows.

[0011] The rotating electric machine includes a stator having a cylindrical stator core and a coil attached to the stator core, a shaft rotatably provided inside a housing, a rotor core connected to the shaft via a cylindrical rotor core holding part, and a plurality of permanent magnets inserted into the rotor core, the rotor being disposed with a gap between the stator and the shaft, the shaft having a first refrigerant flow path through which a refrigerant flows and a communication hole communicating the first refrigerant flow path with the rotor core holding part, The core holding portion has: a second refrigerant flow path that communicates with the first refrigerant flow path via the communication hole, is provided on the surface of the rotor core holding portion and extends radially outward of the rotor; a third refrigerant flow path that communicates with the second refrigerant flow path, is provided on the surface of the rotor core holding portion and branches off from the second refrigerant flow path in the circumferential direction of the rotor; a fourth refrigerant flow path that extends from the third refrigerant flow path to the radially outward side of the rotor and reaches the permanent magnet; and a fifth refrigerant flow path that extends from the fourth refrigerant flow path along the permanent magnet.

[0012] The electric aircraft is equipped with the above rotating electric machine.

[0013] According to the present invention, by providing simple and easy-to-machine grooves and flow paths in the rotor core holding portion of the motor, it is possible to provide a rotating electric machine in which motor strength is ensured and cooling performance is improved, and an electric aircraft equipped with this rotating electric machine.

[0014] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments.

[0015] 1 is a schematic plan view of an electric aircraft including a rotating electric machine according to a first embodiment, as viewed from above; FIG. 2 is a schematic view showing a part of a cooling circuit of the rotating electric machine according to the first embodiment; FIG. 3 is a schematic view showing a part of a cooling circuit of the rotating electric machine according to the first embodiment; FIG. 4 is a schematic cross-sectional view of the rotating electric machine according to the first embodiment, as viewed from directly above in the axial direction; FIG. 5 is a schematic cross-sectional view of a part of the rotor of the rotating electric machine according to the first embodiment, as viewed from directly above in the axial direction; FIG. 6 is a schematic cross-sectional view of a part of the rotor of the rotating electric machine according to the first embodiment, as viewed from directly above in the radial direction; FIG. 7 is a schematic plan view of the rotor of the rotating electric machine according to the first embodiment, with a part broken away, as viewed from directly above in the axial direction; FIG. 8 is a schematic plan view of the rotor of the rotating electric machine according to the second embodiment, as viewed from directly above in the axial direction;

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[0017] First Embodiment A rotating electrical machine (motor) according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG.

[0018] FIG. 1 is a schematic plan view of an electric aircraft 100 equipped with a motor according to a first embodiment of the present invention, as viewed from above.

[0019] In this embodiment 1, an electric aircraft 100 is assumed in which thrust is generated by propeller rotors 201-203, 301-303 using a motor 10 (see Figure 2) that rotates a propeller and an inverter 20 (see Figure 2) that supplies power to the motor 10.

[0020] FIG. 2 is a schematic diagram showing a part of a cooling circuit including a motor (rotating electric machine) 10 and an inverter 20 according to the first embodiment of the present invention.

[0021] As shown in Fig. 1, the electric aircraft 100 generates thrust by driving propellers 201-203 and 301-303 using an inverter 20 (see Fig. 2) that supplies power to a motor 10. Also as shown in Fig. 1, the electric aircraft 100 includes a fuselage (airframe) 101, propellers 201, 202, and 203 on the left side of the fuselage 101, and propellers 301, 302, and 303 on the right side of the fuselage 101.

[0022] The electric system (electrical power components) for driving the left propellers 201-203 and the right propellers 301-303 includes motors 10 (10a-10f) and inverters 20 (20a-20f). The inverters 20 (20a-20f) convert DC power from a power source into AC power and supply the drive current to the motors 10 (10a-10f).

[0023] The inverter 20 has a plurality of power semiconductor elements (not shown) and a control circuit (not shown) that controls the power semiconductor elements. The inverter 20 is connected to a power storage device (not shown) of a power supply. The inverter 20 converts DC power from the power storage device into AC power suitable for the motors 10 (10a to 10f).

[0024] The power storage device is configured by, for example, a capacitor or a secondary battery such as a lithium ion battery, a nickel-metal hydride battery, etc. Electric power is exchanged between the power storage device and the motor 10 via an inverter 20.

[0025] The rotational torque of the motor 10 is transmitted to the propellers 201, 202, 203, 301, 302, and 303 via a reducer (not shown) and a differential gear (not shown). As a result, the propellers 201, 202, 203, 301, 302, and 303 of the electric aircraft 100 shown in FIG. 1 rotate, and the aircraft (fuselage 101) cruises.

[0026] The inverter 20 (20a to 20f) shown in Figures 2A to 2C controls the motor 10 (10a to 10f) based on a torque command from an integrated control device (not shown) so that the commanded torque output or generated power is generated.

[0027] The control circuit of the inverter 20 controls the switching operation of the power semiconductor elements based on commands from an integrated control device (not shown). The motor 10 is operated as an electric motor by the switching operation of the power semiconductor elements.

[0028] When the motor 10 is operated as an electric motor, DC power from the power storage device is supplied to DC terminals of the inverter 20. A control circuit of the inverter 20 controls the switching operation of the power semiconductor elements to convert the DC power into three-phase AC power and supplies it to the motor 10. The motor 10 according to the first embodiment is a three-phase synchronous motor with embedded permanent magnets.

[0029] As shown in Figures 2A to 2C, the electric system according to the present invention is linked to the electrical system and the mechanical system, and together with the paired propellers 201, 301, 202, 302, and 203, 303, constitutes cooling systems 700a, 700b, and 700c.

[0030] The cooling system 700a having the operating mechanism of the left propeller 201 and the operating mechanism of the right propeller 303 shown in FIG. 2A has a radiator 50a for cooling the left motor 10a and inverter 20a and the right motor 10f and inverter 20f.

[0031] A cooling system 700b having an operating mechanism for the left propeller 202 and an operating mechanism for the right propeller 302 shown in FIG. 2B has a radiator 50b for cooling the left motor 10b and inverter 20b and the right motor 10e and inverter 20e.

[0032] Cooling system 700c having the operating mechanism for left propeller 203 and the operating mechanism for right propeller 301 shown in FIG. 2C has radiator 50c for cooling left motor 10c and inverter 20c and right motor 10d and inverter 20d.

[0033] With the above-described configuration, cooling systems 700a, 700b, 700c are provided with refrigerant pipes 70a to 70c through which refrigerant flows to cool multiple motors 10a to 10f and multiple inverters 20a to 20f, pumps 60a to 60f connected to the refrigerant pipes 70a to 70c and sending out the refrigerant, and radiators 50a to 50c connected to the refrigerant pipes 70a to 70c and releasing heat from the refrigerant, thereby providing a simple and lightweight cooling system.

[0034] Fig. 3 is a schematic cross-sectional view of the motor 10 according to the first embodiment as seen from the side, Fig. 4 is a schematic plan view of the rotor 150 of the motor according to the first embodiment as seen from directly above in the axial direction of the shaft 160, Fig. 5 is a schematic cross-sectional view of a portion of the rotor 150 of the motor 10 according to the first embodiment as seen from the side, and Fig. 6 is a schematic cross-sectional view of a portion of the rotor 150 of the motor 10 according to the first embodiment as seen from the side in the radial direction.

[0035] 3, the motor 10 has a cylindrical stator 130 fixed to a housing 191, a cylindrical rotor 150 rotatably arranged across a gap from the stator 130, and a shaft 160 connected to the rotor 150. The rotor 150 is arranged on the inner circumferential side of the stator 130.

[0036] In this specification, the terms "axial direction," "circumferential direction," and "radial direction" are defined as follows: "Axial direction" refers to the direction along the central axis of rotation (hereinafter also referred to as the rotation axis) O (shown in FIG. 3) of the rotor 150. "Circumferential direction" refers to the direction along the rotation direction of the rotor 150, i.e., the circumferential direction centered on the rotation axis O. "Radial direction" refers to the direction perpendicular to the rotation axis O, i.e., the radial direction of a circle centered on the rotation axis O. Furthermore, "inner peripheral side" refers to the radially inward side, and "outer peripheral side" refers to the opposite direction, i.e., the radially outward side.

[0037] The stator 130 has a cylindrical stator core 131 and a coil 132 attached to the stator core 131. The stator core 131 is formed, for example, by laminating a plurality of annular electromagnetic steel plates. The stator core 131 is fitted and fixed inside the housing 191.

[0038] A plurality of slots (72 in the first embodiment) are formed in the inner periphery of the stator core 131, parallel to the central axis of the stator core 131. Teeth are formed between the slots. The slots are parallel slots with side surfaces parallel to each other along the radial direction of the stator core 131. In other words, the slots have a constant circumferential width from the outer circumferential edge to the tip of the tooth. A plurality of phase windings of U-phase, V-phase, and W-phase that make up the coil 132 are arranged in the slots. The plurality of slots are formed at equal intervals in the circumferential direction of the stator core 131.

[0039] The multiple teeth are formed to protrude from the annular core back toward the rotation axis O. The teeth form a radial magnetic path, and the core back forms a circumferential magnetic path. The teeth guide the rotating magnetic field generated by the coil 132 to the rotor 150, causing the rotor 150 to generate rotational torque.

[0040] As shown in FIG. 3 , the rotor 150 includes a rotor core 151 , a plurality of permanent magnets 152 fixed to the rotor core 151 , and a cylindrical rotor core holder 155 .

[0041] Shaft 160 is fixed by press fitting or shrink fitting into the through hole of rotor core holding portion 155. As shown in Figure 3, shaft 160 is supported by a plurality of bearings 200 provided in housing 191, so that rotor 150 is rotatably held inside stator core 131.

[0042] 3 and 4, the rotor core 151 is formed, for example, by laminating a plurality of annular electromagnetic steel plates. The permanent magnets 152 form the field poles of the rotor 150. The permanent magnets 152 may be neodymium-based or samarium-based sintered magnets, ferrite magnets, neodymium-based bonded magnets, or the like.

[0043] The rotor core 151 has rectangular parallelepiped magnet insertion holes formed at equal intervals in the circumferential direction near the outer periphery. Permanent magnets 152 are embedded in each magnet insertion hole and fixed in place with adhesive or the like. In this embodiment, as shown in FIG. 7 , I-shaped permanent magnets 152a extending radially and straight-line permanent magnets 152b are alternately arranged in a Halbach array (66 poles in this embodiment), thereby improving the torque of the motor. For convenience of illustration, in FIGS. 3, 4, and 5, the permanent magnets 152a and 152b are simply shown as permanent magnets 152.

[0044] The rotor core holding portion 155 has an annular shape and is attached to the rotor core 151 so as to cover a portion of the magnet insertion hole. The rotor core holding portion 155 presses the rotor core 151 and the permanent magnets 152 in the axial direction, restricting their axial position. The rotor core holding portion 155 can be made of aluminum or the like.

[0045] 3 and 4 , the shaft 160 is a cylindrical member extending axially and has a flow path (hereinafter also referred to as a first refrigerant flow path) 161 therein through which oil flows as a refrigerant. That is, the shaft 160 is formed with a plurality of communication holes 170 that connect the first refrigerant flow path 161 to the outside of the shaft 160. The communication holes 170 are connected to a second refrigerant flow path 162 (hereinafter referred to as a second refrigerant flow path) that is provided on the surface of the rotor core holding portion 155 and extends radially outward of the rotor 150. The second refrigerant flow path 162 is connected to the first refrigerant flow path 161 via the communication hole 170. The dimensions, width, and shape of the first refrigerant flow path 161 are determined based on the flow rate and pressure loss of the refrigerant used.

[0046] 4 and 5 , the second refrigerant flow path 162 is connected to a groove (hereinafter referred to as a third refrigerant flow path) 163 formed by branching near the outer periphery of the magnet insertion hole and near the arc portion of the rotor core holding portion 155. The third refrigerant flow path 163 communicates with the second refrigerant flow path 162 and branches from the second refrigerant flow path 162 in the circumferential direction of the rotor 150. By branching the third refrigerant flow path 163 in the circumferential direction, the number of second refrigerant flow paths 162 extending radially can be made smaller than the number of permanent magnets 152, thereby ensuring rotor strength. The number of third refrigerant flow paths 163 is also smaller than the number of permanent magnets 152.

[0047] As shown in FIG. 6, the permanent magnets 152a and 152b are arranged alternately, with the permanent magnet 152a having a fifth refrigerant flow path 165a connected to the fourth refrigerant flow path 164a, and the permanent magnet 152b having a fifth refrigerant flow path 165b connected to the fourth refrigerant flow path 164b.

[0048] The number of second refrigerant flow paths 162 is determined in consideration of the number of poles of the permanent magnet 152 in the present invention, the groove dimensions, and the effects of pressure loss. However, the number may be changed appropriately according to the operating conditions (required specifications, required output), and the same effect can be obtained. The dimensions, width, and shape of the second refrigerant flow paths 162 are determined based on the flow rate of the refrigerant used and the pressure loss.

[0049] 4 and 5, this third refrigerant flow path 163 is connected to a through hole that extends to approximately the axial center of the multiple magnet insertion holes arranged in the circumferential direction, that is, a fourth refrigerant flow path 164. The dimensions, width, and shape of the third refrigerant flow path 163 are determined based on the flow rate and pressure loss of the refrigerant used.

[0050] The fourth refrigerant flow path 164 extends from the third refrigerant flow path 163 toward the radially outer periphery of the rotor 150 and reaches the permanent magnets 152. The fourth refrigerant flow path 164 is connected to a fifth refrigerant flow path 165 that extends along the permanent magnets 152. The fifth refrigerant flow path 165 has an upper refrigerant flow path 165U that extends from the connection with the fourth refrigerant flow path 164 to the upper surface of the permanent magnets 152, and a lower refrigerant flow path 165L that extends to the lower surface of the permanent magnets 152. The fifth refrigerant flow path 165 not only branches upward and downward, but also has an upper surface flow path 152SU formed on the upper surface of the permanent magnets 152, a lower surface flow path 152SL formed on the lower surface of the permanent magnets 152, and a flow path that extends in the axial direction of the rotor core 151 of the permanent magnets 152. The fifth refrigerant flow path 165 increases the area for cooling the permanent magnets 152, thereby improving the cooling effect. The fifth refrigerant flow path 165 has an opening that is open in the vertical direction (axial direction), and the refrigerant is discharged from this opening, discharged from the oil discharge hole 300, and circulated through the refrigerant pipe 70a. The dimensions, width, and shape of the fourth refrigerant flow path 164 and the fifth refrigerant flow path 165 are determined based on the flow rate and pressure loss of the refrigerant used.

[0051] 5 and 6, the fifth refrigerant flow paths 165a and 165b allow oil guided from the shaft 160 through each refrigerant flow path to be directly applied to the I-shaped permanent magnet 152a and the straight-line permanent magnet 152b, improving cooling performance. Furthermore, the widths of the fifth refrigerant flow paths 165a and 165b are the same at the top and bottom branches, taking into account the effect of pressure loss. However, the dimensions and widths of both paths may be changed as appropriate to suit the operating conditions (required specifications, required output), and the same effect can be achieved.

[0052] With the above-described configuration, the number of grooves and through holes in rotor core holding portion 155 is minimized, so that rotor strength can be ensured even when motor 10 is driven at high speed.

[0053] Therefore, according to the first embodiment of the present invention, it is possible to provide a rotating electric machine that has a cooling structure that is simple and easy to process, and that can ensure motor strength and improve cooling performance, and an electric aircraft equipped with this rotating electric machine.

[0054] Second Embodiment A motor 10 according to a second embodiment of the present invention will be described with reference to Fig. 8. In Fig. 8, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and only differences will be described.

[0055] FIG. 8 is a schematic plan view of the rotor 150 of the motor 10 according to the second embodiment, as viewed from directly above in the axial direction.

[0056] In the second embodiment, the surface grooves of second refrigerant flow path 162 and third refrigerant flow path 163 are covered with a resin material such as rubber packing to form piping flow path 400. This allows oil to be guided from first refrigerant flow path 161 and communication hole 170 to the outer periphery by the centrifugal effect of rotor 150, and also reduces the number of grooves machined in rotor core holding portion 155, improving sealing performance. This allows refrigerant oil to be more efficiently guided to rotor core 151 and permanent magnets 152, ensuring motor strength and improving cooling performance.

[0057] The rubber packing pipe passage 400 may not extend all the way to the third refrigerant flow path 163, but may be used in a state where it extends partway.

[0058] According to the second embodiment, it is possible to obtain the same effects as those of the first embodiment, and also to obtain the effects described above.

[0059] Third Embodiment A motor 10 according to a third embodiment of the present invention will be described with reference to Fig. 9. In Fig. 9, the same or corresponding parts as those in the first embodiment are designated by the same reference numerals, and only differences will be described.

[0060] FIG. 9 is a schematic cross-sectional view of a part of a rotor of a rotating electrical machine according to a third embodiment, as viewed from the side.

[0061] The differences between Example 3 shown in Figure 9 and Example 1 shown in Figure 3 will be described. In Example 1 shown in Figure 3, the fifth refrigerant flow path 165 branches off in both directions (up and down in Figure 9) from the fourth refrigerant flow path 164, but in Example 3 shown in Figure 9, the refrigerant flow path 165 extends in one direction (downward in Figure 9) from the fourth refrigerant flow path 164. In other words, the refrigerant flow path 165 has a lower refrigerant flow path 165L but does not have an upper refrigerant flow path 165U. The other configurations are the same as those of the example shown in Figure 3.

[0062] When the motor 10 is applied to the electric aircraft 100, the coolant is less likely to flow upward than downward. Therefore, by configuring the fourth coolant flow path 164 to extend in one direction, the coolant circulation speed increases, improving the cooling effect.

[0063] In the third embodiment, the same effects as those in the first embodiment can be obtained.

[0064] <Modification of Third Embodiment> In the third embodiment, the coolant flow path 165 extends in one direction from the fourth coolant flow path 164 .

[0065] In the modified example of Example 3, similar to Example 1, the fifth refrigerant flow path 165 has an upper refrigerant flow path 165U and a lower refrigerant flow path 165L, but the diameter of the lower refrigerant flow path 165L is larger than the diameter of the upper refrigerant flow path 165U.

[0066] When the motor 10 is applied to the electric aircraft 100, the coolant is less likely to flow upward than downward. Therefore, by adopting the above configuration, the circulation speed of the coolant is increased, and the cooling effect can be improved.

[0067] In the modification of the third embodiment, the same effects as those of the third embodiment can be obtained.

[0068] Although the embodiments of the present invention have been described above, the above embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0069] The present invention is not limited to the configuration of the above-described embodiment, and various modifications and specific examples are possible within the scope of the appended claims.

[0070] 10 (10a, 10b, 10c, 10d)...Motor (rotating electric machine), 20 (20a, 20b, 20c, 20d, 20e, 20f)...Inverter, 50 (50a, 50b, 50c)...Radiator, 60...Pump, 70...Refrigerant piping, 100...Electric aircraft, 101...Conductor, 130...Stator, 131...Stator core, 132...Coil, 150...Rotor, 151...Rotor core, 152 (152a, 152b)...Permanent magnet, 152SU...Upper surface flow path, 152SL...Lower surface flow path, 155 Rotor core holding portion, 160... shaft, 161... first refrigerant flow path, 162... second refrigerant flow path, 163... third refrigerant flow path, 164... fourth refrigerant flow path, 165... fifth refrigerant flow path, 165L... lower refrigerant flow path, 165U... upper refrigerant flow path, 170... communication hole, 191... housing, 200... bearing, 201, 202, 203, 301, 302, 303... propeller, 300... oil discharge port, 400... piping flow path of rubber packing material, 700 (700a, 700b, 700c)... cooling system

Claims

1. A rotating electrical machine comprising: a stator having a cylindrical stator core and a coil attached to the stator core; a shaft rotatably provided inside a housing; a rotor core connected via a cylindrical rotor core holding portion centered on the shaft; and a plurality of permanent magnets inserted into the rotor core, the rotor being disposed via a gap from the stator, wherein the shaft has a first refrigerant flow path through which refrigerant flows and a communication hole that communicates the first refrigerant flow path with the rotor core holding portion, and the rotor core holding portion has a second refrigerant flow path that communicates from the first refrigerant flow path through the communication hole and extends to the radially outer peripheral side of the rotor on the surface of the rotor core holding portion, a third refrigerant flow path that communicates with the second refrigerant flow path and branches from the second refrigerant flow path in the circumferential direction of the rotor on the surface of the rotor core holding portion, a fourth refrigerant flow path that extends from the third refrigerant flow path to the radially outer peripheral side of the rotor and reaches the permanent magnet, and a fifth refrigerant flow path that extends along the permanent magnet from the fourth refrigerant flow path.

2. The rotating electrical machine according to claim 1, wherein the number of the second refrigerant flow paths and the number of the third refrigerant flow paths are less than the number of the permanent magnets.

3. The rotating electrical machine according to claim 1, wherein the dimensions, width, and shape of the first refrigerant flow path, the second refrigerant flow path, the third refrigerant flow path, the fourth refrigerant flow path, and the fifth refrigerant flow path are determined based on the flow rate of the refrigerant used and the pressure loss.

4. The rotating electrical machine according to claim 1, wherein the second refrigerant flow path is covered with a resin material.

5. The rotating electrical machine according to claim 1, wherein the fifth refrigerant flow path has an upper refrigerant flow path that branches from the fourth refrigerant flow path and extends to the upper surface portion of the permanent magnet and a lower refrigerant flow path that extends to the lower surface portion of the permanent magnet.

6. The rotating electrical machine according to claim 1, wherein the fifth refrigerant flow path has a lower refrigerant flow path that extends from the fourth refrigerant flow path to the lower surface portion of the permanent magnet.

7. The rotating electrical machine according to claim 5, wherein the diameter of the lower refrigerant flow path is larger than the diameter of the upper refrigerant flow path.

8. An electric aircraft equipped with the rotating electrical machine according to any one of claims 1 to 7.

9. The electric aircraft according to claim 8, comprising: a plurality of propellers rotated by the plurality of rotating electrical machines; a power converter that supplies power to the plurality of rotating electrical machines; a plurality of refrigerant pipes through which a refrigerant that cools the plurality of rotating electrical machines and the plurality of power converters flows; a plurality of pumps connected to the plurality of refrigerant pipes and sending out the refrigerant; and a plurality of radiators connected to the plurality of refrigerant pipes and releasing the heat of the refrigerant.

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